Genetic Testing: Why Bother?

Thursday, May 31, 2012


Genes and Disease Risk

If either of your parents had Huntington's disease (a severe degenerative disease of the nervous system, which typically manifests after age 35), there is a 50% chance that you are going to have it too. If you are under 35 and worried about developing the disease because of family hsitory, there is a genetic test you can take which will let you know where you stand, one way or the other. The result is quite straightforward -- either it lets you stop worrying about the possibility, because you're in the clear, or it forces you to abandon all hope that you will escape the disease, because you are definitely going to have it.

What a lot of people don't realize is that most genetic testing for diseases is not like that. Huntington's disease is very unusual in having so unambiguous a genetic signature.

Much more typically, a disease is associated with various genetic variants. Each of those genetic variants heightens the risk -- at least to some degree -- of developing the disease, but none of them makes the risk 100%, and the absence of all of them would not make the risk 0%. Therefore, genetic testing cannot tell you that you are doomed or in the clear; it can only tell you whether your risk is above average or below average.

This raises the question of whether taking a genetic test to assess your susceptibility to a given disease is a useful thing to do. If you're going to take the test, what exactly are you going to take it for?

Even in the case of the unambiguous test for Huntington's disease, it would have to be hard to decide whether to take the test or not. Suppose you're 21 -- mightn't it be better to try to enjoy your young adulthood, without having to live with the certain knowledge that you're going to develop a terrible, disabling condition by the time you're middle-aged? On the other hand, you might be able to enjoy that young adulthood a lot more if the test comes back negative, and you can forget about the issue. You have to decide which scares you more: knowing, or not knowing? Probably a lot of the people who take this test are trying to make decisions about whether or when to have children, and don't want to make decisions that important without having the facts.

For genetic tests which don't yield a definite, yes-or-no answer, it is not always clear that taking the test adds anything of value to what you already know. The counter-argument, from the genetic-testing industry, would certainly be that you need to know which diseases you are most at risk for, so that you and your doctor know what to look out for. That sounds good in principle, but it's only useful in practice if the genetic test reveals information about your disease risk which is not otherwise available, and enables you to do something about the problem which, if not for the test, you would never do.

It is well known that there are many genetic variants which increase one's risk of developing Type 2 diabetes -- but does testing for these gene variants actually allow doctors to predict who will develop Type 2, any more accurately than they could predict it from more ordinary clinical information about the patient's state of health?

In a word, no. This study found that genetic risk scores for Type 2, based on 24 different SNPs (single-nucleotide polymorphisms -- variants of a gene) which are associated with the disease do not improve the accuracy of forecasting a patient's diabetes risk. Doctors can do that just as well on the basis of the patient's physical condition, medical history, and family history. Genetic test results don't add anything.

I used to worry about the medical insurance industry performing genetic tests (without the patient's knowledge or permission) on lab blood samples, in order to blacklist patients whose genetic profile put them at risk for diabetes. Probably they would love to do that, but now it appears that they don't need to bother. Everything else in your medical files, which the insurance industry surely can access without difficulty, is already telling them what your diabetes risk is, without any secret genetic testing having to take place.

The thing is, diabetes is not some rare disorder that only a few unlucky people need to worry about. It's a common problem. Doctors don't need genetic tests to tell them to look out for the possibility of their patients becoming diabetic. More than 11% of their patients (if they practice in the U.S., anyway) have already become diabetic. Trust me, they know to look for it. They also know to look for the unhealthy trends which suggest a patient is probably headed for diabetes in the long run, and they do their best to warn patients that things are not moving in a good direction. The problem is that patients don't take such warnings seriously, or at least don't make a serious effort to act on them. (I didn't, so I know what I'm talking about.)

Perhaps that is where genetic testing could play a role: in overcoming patients' reluctance to acknowledge that the doctor's warnings might very well be valid. The test might be useless in a strict scientific sense, but if it enables patients to get past a psychological barrier, and start taking the issue seriously, perhaps testing can actually do some good. 


Big Green Smoothie

Wednesday, May 30, 2012


Nutrition: It's What You Can Get Away With

According to a recent survey by the International Food Information Council Foundation (by the way: is it a council or a foundation? don't call it both, please!), slightly over half of Americans think that figuring out how to eat a healthy diet is a more difficult assignment than filing their income-tax return.

Readers outside the U.S. may not realize what that implies, as they have never been exposed to any bureaucratic system as absurdly over-complicated as the U.S. tax code; they'll have to take my word for it that nutrition would have to be a very confusing subject indeed to be competitive in this regard.

Baffled as I am by our tax code, I have to admit that I agree with those who say nutrition is more baffling still. I struggle with my tax return, and I often doubt that I'm doing it quite right, but I get the thing done somehow, and the government has not challenged me on it so far. So, I must conclude that getting your taxes done is at least possible, even if it is not easy. Figuring out what a healthy diet is, however -- I'm not at all sure that can be done.

The practical constraints on testing nutritional theories (we don't raise humans in cages) have made it impossible to turn nutrition into a hard science. For what it's worth, there is a consensus among most nutritionists about what constitutes a healthy diet, but there are passionate dissenters against that consensus, and it's pretty clear that the diet recommended by the majority of nutritionists (in short: low fat, high carb) is terribly impractical for patients with Type 2 diabetes. Maybe that kind of diet works for non-diabetic people, and maybe it doesn't (some say it helps turn non-diabetic people into diabetic people), but there can't be many diabetic people who can do well on a diet which emphasizes grains as heavily as the nutritionists recommend.

I can probably get away with more, in terms of high-carb meals, than most Type 2 patients -- because I exercise more than most Type 2 patients (which tends to boost sensitivity to insulin), and because I have a long period of good glycemic control behind me (which apparently tends to boost production of insulin, if you give it enough time, despite what most people assume about impairment of beta cells being permanent). Even so, I am nervous about challenging myself with high-carb meals, and I try to do it only when I feel that the deck is somehow stacked in my favor.

The deck seemed to be stacked in my favor today: I started the day with an unusually low fasting test (74) and I did an unusually hard workout (a 5.7-mile run on super-steep hills). Why not try something high-carb for lunch and see if I could get away with it?

The espresso bar at work makes a big green "smoothie" with kale and other vegetables in it -- but it also has fruit in it, and although I don't know its carb count, I figure it has to be pretty high. One of my running buddies has one of those, as his lunch, after we run. I've been tempted to try it, but have been worried that it would spike me. Today I decided to chance it. Surely I could get away with it this time, after such a hard workout and such a low fasting level at the start of the day?

I was nervous about doing the post-prandial test after that. It wouldn't have amazed me if it had been well above 150 (my doctor's recommended upper limit for an hour after a meal), and if that happened, I would know that the green smoothie was definitely not for me.

The result ended up being 135. That's within my doctor's guidance -- but it's also about 10 points higher than the average non-diabetic person goes after a meal. In other words, it's not quite low enough to reassure me.

I think it's safest to aim for results that are truly normal -- results that would not seem unusual in a non-diabetic person. So, if the green smoothie pushes me above that range, even when I consume it under ideal conditions, I don't think it's a good choice for me under more typical conditions.

For dinner I had a meal that was much lower in carbs, and the post-prandial result was 98. I'm a lot more comfortable with 98 than I am with 135.

The thing is, I don't want to eat low-carb meals all the time. I was craving that green smoothie, for whatever reason, and I thought that under the circumstances it was an acceptable risk.

I don't want to be an absolutist, following a set of rules fanatically. I figure that, if I'm usually eating low-carb meals, and only indulging in high-carb ones under circumstances which seem to give me a good shot at getting away with it, that's probably good enough.

If this philosophy stops working for me, though, I'll have to change it. That's why glucose testing is so important -- how else are you going to know when your philosophy has stopped working for you?   


Yet More A1c Questions!

Tuesday, May 29, 2012


Search-Engine Inquiries

People want to know what they want to know. As usual, a lot of them want to know about the A1c test.

 

"6.2 a1c risk of heart attack"

There isn't a direct mapping between A1c and heart-attack risk. An A1c result of 6.2 is usually interpreted as a sign "pre-diabetes", meaning diabetes that hasn't quite reached the diagnostic threshold. Unfortunately, "pre-diabetes", and the insulin resistance and hyperinsulinemia which typically come with it, are significant risk factors for heart attack.

"a1c result misleading"

Last month I talked about some of the difficulties involved in interpreting the A1c test. In brief: the assumption that average blood sugar can be estimated accurately by plugging the A1c result into a formula rests on two assumptions: that the glycation rate for a given blood sugar level is the same in everybody, and that the recycling rate of hemoglobin is the same in everybody. But in fact people vary, at least to some degree, in both respects. Some ethnic populations have a higher glycation rate than others for the same blood sugar level. And replacement rate can altered by medical treatment, such as hemodialysis.

Assuming you're not on hemodialysis, the A1c result is a good relative indicator of how you're doing with glycemic control (if your A1c went up, so did your average blood sugar, it's pretty safe to say). It is more approximate as an indicator of absolute blood sugar levels, because two people with identical average blood sugar but differing replacement rates will not get the same result on an A1c test.

What the A1c test does measure accurately is what percentage of your hemoglobin is sugar-coated -- and that is a fact worth knowing, even if we have to be cautious in interpreting it.

"a1c spike but glucose test normal"

I am skeptical that anyone is going to see an A1c "spike", if by that we mean a brief interval during which the value is much higher than usual.

But if by "spike" you mean "result that's higher than I wanted it to be", that is perfectly compatible with a glucose level which appears normal during the moment when you happen to check it. It is quite possible to go into the lab to have blood drawn one fine morning, and get a normal glucose result but an elevated A1c result. The reason is that glucose is a moving target (it might be high or low at any given moment), but if it tends to be high during too much of the 24-hour cycle, this will cause an elevated A1c result, regardless of what was going on during the moment in time when you take the glucose test. The A1c test reflects conditions during a period of a few months, not conditions during one moment in time. The glucose test can be "fooled" a lot easier than the A1c test can.

"can your a1c testing result be off the first time"

What does "off" mean? Inaccurate? Or accurate but unwelcome?

There's no reason why your first A1c test should be less accurate on one occasion than another, unless something which can distort the results (such as hemodialysis treatment) played a role.

"what can scrub red blood cells before an a1c test"

Nothing that I've heard of.

Clearly you're looking for ways to cheat on the test. A bit of hemodialysis treatment would be one way for you to do that. Hemodialysis doesn't "scrub" glucose off the red blood cells, it just forces the body to replace red blood cells faster. This causes the test to yield a lower result than it should. However, I don't know how you'd get hemodialysis done without your doctor knowing about it.

However, you could probably donate a pint of blood without your doctor finding out about it, and that would have a similar (but perhaps smaller) effect.

This leaves unanswered the question of what you will gain by fooling your doctor into thinking your glycemic control is a little better than it actually is.

"estimated average glucose 126 is good or bad"

Depending on whom you believe, that's either the upper end of normal, or a little above normal (but not in the diabetic range).

If you have been diagnosed with diabetes, and you can work your average glucose down to 126, I'd say that's pretty good. If you haven't been diagnosed with diabetes, and your average glucose has drifted up to 126, that's worrisome, because you don't want it to go any higher than that.

"how much weight can you expect to loose on dapagliflozin"

This is the drug I wrote about in January, which sheds glucose from the blood by causing it to leak through your kidneys into your urine. As calories are clearly lost in that way, it stands to reason that people who take dapagliflozin can expect to lose at least some weight. But how much?

Well, this study found that, over the course of 38 days, people taking the highest dosage of dapgliflozin reduced their body weight by 4% (and more, if they were restrained from overeating to compensate).

So there's the bright side. The dark side is that dapagliflozin appears to multiply your risk of certain cancers by five. The matter is being looked into, but that's where it stands at the moment. The drug maker says their drug didn't give those people cancer; they had cancer anyway but it wasn't discovered until after they started taking dapagliflozin. It's not clear how the drug maker knows that, though, and so far the FDA isn't buying the story.

"how much does a1c decline with weight loss"

There is no direct one-for-one relationship between A1c and weight. Sometimes A1c declines dramatically with weight loss and/or increased physical activity.

"who know I would get type 2 diabetes"

It sounds as if you didn't know it, and perhaps your doctor didn't know it either. Sometimes people who don't seem to be candidates for Type 2 (no obesity, no family history) develop it anyway.

However, as I mentioned last Friday,  a lot of people in that situation have been misdiagnosed, and actually have Type 1, not Type 2. Check into that if you have any doubts.

"is there any way to escape the insulin route with type 2 diabetes"

Well, if there isn't, I've certainly been wasting the last 11 years of my life, haven't I? But I'm still getting normal glucose and A1c results without any help from insulin (or any other medication), so I'm inclined to think that it's a lot more possible than we have been led to believe.

"meal planning for unmedicated diabetics"

It all comes down to total carbohydrate content, and specifically how much carbohydrate you can handle without getting an unacceptably high post-prandial glucose result. Experiment until you find out what kind of meal your system can handle. But be aware that the kind of meal your system can handle is probably not going to include a generous portion of rice, noodles, potatoes, bread, cereal, or sugar.

"should diabetes produce by drugs be medicated"

Sure, why not? Just to make the symmetry perfect, if your cholesterol drug is what's raising your blood sugar, see if you can find a diabetes drug that also raises your cholesterol.

"write an essay in which you discuss how you can control diabetes"

Sorry, I'm not doing your homework assignment for you!


Weather this Week

It's been a fairly cool and windy May, but it looks as if it's time for the skimpier running clothes...
   


Memorial Day

Monday, May 28, 2012


A Brief Holiday Blog

I had the day off, and the weather was sunny and mild, so I went to the state park nearby for a longish trail run. Exercising in the great outdoors always makes me feel better than exercising in a gym or on a busy street.

Afterwards, I wanted to have lunch at a restaurant, but the first one I went to was overcrowded (I was too hungry to wait) and the second place I went to was closed for the holiday, so I settled for what I could find: a Chinese restaurant.

I figured the 8.3-mile run would counteract any excessive carbs in the meal. But I tried to keep things within bounds, ordering a vegetables in the place of the usual mound of rice or noodles. What I forgot to think about was what might be in the gooey sauces on the other items. They both tasted pretty sweet, looking back on it; there was probably a big load of sugar in them. Also, I ate the damned fortune cookie. So, my result of 142 mg/dl after lunch shouldn't have surprised me as much as it did.

142 is within my doctor's guidance for a post-prandial result, but let's face it: 142 is a not-bad-for-someone-with-diabetes result, not a normal result. A normal result would be 125 or less, and that's what I try to aim for. Often, if I eat lunch right after a hard run, I can get that kind of result, even if the lunch is comparatively high-carb. Today that plan didn't work for me, either because the lunch was more rich in carbs than I had assumed, or for some other reason. It's possible that I went slightly hypoglyemic after the run, while I was impatiently scouting for a place to eat, and my system overcorrected for this. But I didn't feel that low, so I imagine the explanation is simply that I had underestimated the carb content of the lunch.

You can never really be sure why a glucose result is higher than you wanted or expected it to be, but even so, I think it is always a good idea to think about what the possible explanations could be, and consider what lessons can be learned from the experience. I guess the lesson in this case is that skipping the rice is not necessarily a complete solution to the Chinese Restaurant Problem.

I decided to test again after dinner, to make sure I can still get a normal number when the meal is low in carbohydrate. I had a salmon burger (without a bun) and green vegetables. Result: 100 mg/dl. So there you go. 


Another Failed Doomsday Prediction!

Perhaps you weren't even aware that the world was supposed to end yesterday, but it was -- at least according to followers of Ronald Weinland. This makes his third end-of-the-world prediction within the past six years which failed to come true. Some other things he predicted would happen before yesterday also failed to take place, including World War III and the death of everyone who had cast doubt on his abilities as a prophet. In other words, I should be dead by now, according to him.

Of course, everyone who cast doubt on Weinland's abilities as a prophet will die eventually, including me -- but we're disinclined to do it on his schedule, and we don't think he'll be in entitled to take much credit for it when the time comes.

People who claim to know what they couldn't possibly know can always find an audience of gullible people ready to take them at their word. That situation isn't likely to change; intelligent people are so much better at birth control!


Missing the Point by a Mile

Friday, May 25, 2012


The Art (and Science, and Industry) of Medicine

Is medicine a science, or an art, or an industry? You could make a case for any of these three choices, and as a practical matter it tries to be all of these things at once.

Clearly medicine is science-driven at this point (however shaky the science itself sometimes turns out to be, when you take a close look at it).

But because medicine involves human individuals, and because the science behind it is so tentative, medicine must sometimes function on an intuitive basis -- as an art form.

Still, everyone involved in medicine has to function within an existing system of financial incentives -- a system which cares very litttle about science, and not at all about people. So, whether we like it or not, medicine functions as an industry. Whatever else it is, it is also big business.

Unfortunately, it is impossible for medicine to do all of these things equally well. And when a conflict arises, business considerations win -- especially when the conflict is between medicine-as-art and medicine-as-industry.

That, at least, is how I interpret the trend towards sweeping, one-size-fits all pronouncements about how patients with various conditions should be treated. Everyone diagnosed with Type 2 diabetes should be put on metformin immediately, whether they can tolerate it or not! Everyone with high cholesterol -- or without it, for that matter -- should be put on lipitor immediately, whether they can tolerate it or not! 

This kind of thinking is justified on a business basis: the drugs are comparatively cheap, and prescribing them without thinking about it is cheaper than spending a bunch of time with the patient exploring alternatives. And this approach supposedly helps more people than it harms, so why not go ahead with it?

Of course, the Hippocratic oath says "do no harm", not "do less harm than good, on average, over the course of this fiscal year". It is the oath of an artist, not a businessman. The oath does not seem to be doing much to restrain the trend towards one-size-fits-all thinking, but I thought it would be worth a reminder that the oath exists.

The Art of Misdiagnosis

A particularly troubling aspect of one-size-fits-all thinking, as it applies to medicine, is the tendency to identify a pattern in diagnosis ("statistics show that most people who get this disease are over 50") and then exaggerate it into a rule ("he can't have that disease, because he's only 40"). This sort of thinking is suprisingly common, and it creates a lot of problems.

For example, coronary heart disease is often regarded as a man's problem simply because (up to a certain age) it is more common in men. But so what if it's more common in men? That doesn't mean middle-aged women don't get it. It does mean, however, that when women do get it, their doctors often ignore the possibility, and dismiss warning signs of the condition as "stress". Because women don't get the same kind of cardiac care, women with coronary heart disease are less likely than men to survive a heart attack if they do have one. Often, when a woman has a heart attack, there is a dangerous delay before doctors even realize what's wrong with her. (It's harder to recognize a heart attack in a woman, if you're used to thinking of a heart attack as something women don't have.)

When diseases are seen through a kind of filter, based on what is typical of that disease, people who don't fit the typical profile tend to get hurt. From a business point of view, that's fine, as long as the people who get hurt are in the minority. But perhaps it would be better, in such cases, to take the artist's point of view, and be more perfectionist -- or at least aim for something loftier than being right more than half the time.

Misdiagnosing Type 1 as Type 2

In the case of diabetes, there is a dangerous tendency to jump to conclusions about which "type" of diabetes is involved. From a business point of view, it's all right to jump to a conclusion if it's likelier right than wrong, but like I said, people tend to get hurt when that happens.

Type 1 diabetes, which is an auto-immune disease (in which the body becomes allergic to one of its own tissues -- in this case the beta cells in the pancreas), is no longer called juvenile diabetes, but doctors still think of it as a disease which starts quite early in life. Well, it usually does, sure. But not always.

Type 2 diabetes, which is not an auto-immune disease (the cause seems to be a complex interaction of genes and lifestyle), is usually not called geriatric diabetes or adult-onset diabetes anymore, but doctors still think of it as a disease which starts after 40. Well, it usually does, sure. But not always.

The result of these assumptions is that people who develop Type 1 as adults are often mistakenly assumed to have Type 2. And people who develop Type 2 early in life are often mistakenly assumed to have Type 1 (although this must be happening less often now, given the recent publicity about the epidemic of childhood obesity and diabetes).

The interesting thing about Type 1 which develops in adulthood is that, although it is an autoimmune reaction (the immune system attacks and knocks out the pancreatic beta cells that make insulin), it proceeds more gradually than the same autoimmune reaction does when it happens to children. So, Type 1 looks a little different when it happens to adults. It looks less severe, at least at first. Naturally it is mistaken for Type 2.

The term LADA (Latent Autoimmune Diabetes of Adults) has been coined for Type 1 diabetes when it appears in this form. Some have called it "Type 1.5", because it is a form of Type 1 that looks like Type 2 if you don't examine it closely enough. But in terms of what causes it and how it needs to be treated, it is just Type 1, misdiagnosed as Type 2.

LADA may get off to a slow start -- the pancreas isn't knocked out overnight -- but before too long it gets a lot worse. Soon the patient's pancreas is creating little or no insulin, do the patient needs insulin, not oral drugs intended for Type 2. Unfortunately, if the patient was misdiagnosed originally, the patient won't get appropriate treatment, and will do very poorly. Type 1 can be diagnosed by means of an antibody test, but the patient might never get that test, if the doctor has already decided that the patient has Type 2. Therefore, the patient will be regarded as a Type 2 patient who is going downhill fast, not as a Type 1 patient who isn't getting proper treatment.

According to a study presented at the American Association of Clinical Endocrinologists 21st Annual Meeting and Clinical Congress, 48% of non-obese adults with poorly controlled diabetes actually have Type 1 (LADA) that has been misdiagnosed as Type 2. The researchers recommend more widespread testing for antibodies in Type 2 patients, especially if they are non-obese, lack a family history of Type 2, and are having great difficulty with glycemic control. The probability is high that they are being treated for the wrong disease.

Kind of sobering, ain't it?


In other news, researchers are training dogs to hold still in MRI tubes, long enough for their brains to be scanned.

The goal is to try to work out what dogs are thinking.

I can save the research team a lot of trouble: what they're thinking is, "A STRANGER! HATE HATE! KILL KILL!".

Maybe that's not true in all cases, but I see no reason why I need to have a higher batting average than the health care industry. It's as true as I need it to be.


Of Mice and Men

Thursday, May 24, 2012


Interesting Post-Prandials

Lunch, which I ate after I had my lunchtime run, was a sandwich. Glucose an hour later: 116.

Dinner, which I ate after I got home from lifting at the gym, was low carb (pan-fried fish and a salad). Glucose an hour later: 80.

Usually, a post-prandial result as low as 80 would make me concerned that I was heading for a hypoglycemic episode and should eat something else to head that off. But I didn't feel bad at all, so I decided to leave things alone. I seem to have made the right choice. I don't feel low. Instead of feeling like something creepy is going on here, I'm feeling glad that I'm able to get a post-prandial result as low as that. The circumstances favor it, obviously: I worked out hard today (twice!) and had a low-carb dinner. But it's still significant that I can make that happen if I try hard enough; this is not true for a lot of people who are 11 years past diagnosis, no matter what meds they're taking.


Lab Rats

Whenever I read about health research which draws its conclusions about human health from studies of laboratory rodents, I worry that what's good for a mouse and what's good for me could turn out to be two different things. It would build my confidence in the applicability of such studies to my own life, if the test subjects in these studies did not have tails.

Of course, if the test subjects were human beings instead of rodents, they wouldn't have tails but they would have lawyers, and that consideration would tend to impose limits on what scientists could do to them. If we restricted health research to studies on humans, there would be a lot fewer studies, and certain kinds of studies could not be done at all. The choice, it seems, is between (1) a lot of health research which might turn out not to apply to us, and (2) a little bit of health research which does apply to us, but dares not ask the most important questions.

Anyway, for whatever it is worth, here's what researchers think they have learned from two recent experiments in which the test subjects were furry, very small, and not in a position to complain...

What You Eat -- or When You Eat it?

One possible reason why obesity has been increasing in recent history is that technology and social changes have made eating a round-the-clock activity.

For most animals, eating takes place only within a limited span of time within the 24-hour cycle, and until recently this was true of humans as well. Eating was a daytime activity, and it took the form of isolated events known as breakfast, lunch, and dinner -- all of which occurred within a period of not much more than 8 hours. Once dinner was over, eating was over for the day, until breakast the next morning.

Now that all that has changed -- and many people are snacking during all of their waking hours, and perhaps even getting up in the middle of the night to have something more -- obesity is skyrocketing. Is that a coincidence, or has the former played some role in causing the latter?

Dr. Satchin Panda of the Salk Institute and his colleagues did a study which tried to find that out, by feeding mice around the clock, to see what happened to them. Well, what happened to them was that they got fat. They gained a lot of weight, and they developed obesity-related health problems (including diabetes and fatty liver disease). That's not terribly surprising, of course.

What is surprising was that the mice gained weight and developed obesity-related health problems even if their calorie intake was no higher than that of mice which ate only during an 8-hour interval each day. Apparently the open-ended eating schedule itself caused problems, regardless of the calorie count. When the mice ate was as important as how much they ate.

To clarify: the mice that were fed only within an 8-hour span of the day, and did not gain weight, still ate frequently. This experiment is not seen as an indictment of the idea that frequent but small meals can be better than less-frequent, larger ones. What the study seemed to find is that the body (the body of a mouse, anyway) needs to have a long stretch of the 24-hour cycle during which it is not taking in food. Shorten that meal-free span of the day, and serious trouble starts. 

In short: the problem is not so much eating between meals, but continuing to eat after the day's meals are supposed to be over.

This Is Your Brain on Fructose

Another study found that fructose (a type of sugar that comes mainly from fruit, but is also abundant in the HFCS that is used to sweeten soft drinks and junk foods) is not good for your brain -- at least if you're a rat, and possibly if you're not.

Researchers at UCLA found that rats given a diet high in fructose suffered impaired cognitive function as a result (their maze-running skills declined significantly, and various problems within the brain were observed). But the researchers also found out something else: that a diet short of omega-3 fatty acids also degraded cognitive function, especially if combined with fructose. Rats on the high-fructose diet who were given omega-3 fatty acids were largely protected from degradation of cognitive function.

The researchers speculate that a diet high in fructose and low in omega-3 fatty acids -- which apparently is typical for military personnel -- could be causing or aggravating mental problems such as post-traumatic stress disorder. That's a pretty bold conclusion to leap to, from a study of rats running mazes, but I mention it for whatever it may turn out to be worth.

The study authors also think that a diet rich in fructose and short of omega-3 fatty acids is not good for children -- which means that water is probably a better bet than soft-drinks or fruit juice.

As for the question of how likely it is it that the conclusions drawn from a rat study are applicable to your children, I guess you're in a better position to judge that than I am.


Branding is Different in Germany


It Ain't the Protein

Wednesday, May 23, 2012


Impact of Protein Digestion on Blood Glucose

When I was first diagnosed with Type 2 diabetes, in 2001, I was sent to a class on the subject. One of the things I learned in class which stuck most firmly in my memory was that the body can create glucose out of any of the three macronutrients it can digest (carbohydrate, protein, or fat) -- but it gets a lot more glucose from the first of those than it can from the other two. Digesting fat yields only a small amount of glucose (perhaps 15% of the original mass), but digesting carbohydrate is almost ruthlessly efficient: it all turns into glucose. In between, I was told, was protein.

Supposedly about half of the mass of any protein you ate was converted into glucose. (However, because of the slowness of protein digestion, this glucose did not hit the bloodstream all at once, in a pronounced peak, as in the case of carbohydrate.)

The bottom line was that protein in a meal did have an impact on blood glucose after a meal -- but the impact was overshadowed by the much greater impact of carbohydrate in the meal (because 100% of carbohydrate was converted to glucose, and the conversion was rapid instead of slow).

In the years since, I have become increasingly aware that most other diabetes patients were not being told this about protein. They seemed to think that blood glucose was always the result of digesting carbohydrate, and never the result of digesting protein. So who had been mis-educated about this issue: them or me?

It now looks to me as if none of us quite got the true story, which (as so often happens with diabetes) turns out to be a bit complicated and mysterious.

The Protein "Spike": Hardly Worth Mentioning

I guess the shortest way to summarize the situation is that, theoretically, digesting 10 grams of protein should yield 5 grams or more of glucose -- but, in practice, the yield always seems to be far lower than expected. As a practical matter, eating protein causes blood glucose to rise only a small amount, and only briefly. Much as we might expect protein digestion to produce a post-prandial glucose spike that is at least half as large as the one caused by digesting a comparable amount of carbohydrate, the actual result is much smaller than that.

Strange as it seems, this very muted impact of protein on blood glucose is not just true for non-diabetic people. One study found that it is also true for patients with Type 2 diabetes:

The graph above shows the change (up or down) in blood glucose of diabetes patients given either a serving of lean beef (solid line) or water (dotted line) at 8 AM, and nothing else for the next eight hours. After a very modest initial increase (only 5 mg/dl on average!), the glucose level drops back to its starting point in about 2 hours, and keeps dropping. Note that, for much of the rest of the day, glucose was slightly lower in patients who had protein than in patients who had water only. And these are diabetes patients; if anybody was going to get their blood glucose spiked by protein, it would seemingly be them.

The reasons for this are not absolutely clear, but it's pretty clear what actually happens, as distinct from what we would expect to happen on purely theoretical grounds: digestion of protein has only a trivial impact on blood glucose levels.

In assessing the likely impact of a meal on your blood sugar, you can just focus on the carbs, and forget about everything else. Protein and fat are more like to moderate the impact of carbohydrate in the same meal (by slowing down digestion of starch and sugar) than to add to it.

I hasten to add that a food product which is promoted for its "super-protein" content (a protein bar, a protein smoothie, etc) is not necessarily a food product which won't impact your blood sugar. The protein itself will have little glycemic impact, but if the protein is mixed with a bucketload of sugar, it's going to spike you, protein or no protein. So, if you want to minimize your post-prandial glucose, don't think "How can I get more protein into this meal?" -- think "How can take more carbohydrate out of it?".

Now, there are reasons (unrelated to glycemic control) why you might want to avoid getting too carried away with protein. Eating more protein than your body needs is not necessarily a great idea. Protein, unlike carbohydrate and fat, is a nitrogen compound, and when your body digests a large amount of protein, it gets stuck with toxic nitrogen compounds (ammonia and urea) as byproducts; having too much of that sort of stuff circulating in your system is suspected of having a negative impact on the kidneys and also on the bones. For that reason, I'm not advocating that you go absolutely crazy with protein.

However, if you're diabetic and you're going to eat too much of anything, protein would be a better thing to overdo than carbs!


Implied Diabetes Questions

Tuesday, May 22, 2012


Google Sent Them

People are searching for information, and sometimes they end up at my door. Yes, it's time once again for...

Here are my comments on recent search requests that resulted in a reference to my site.

"a1c and hyperinsulinemia"

There is no direct connection between hyperinsulinemia (abnormally elevated insulin levels) and the result you get on a hemoglobin A1c test. In fact, there isn't even an indirect connection worth mentioning.

Hyperinsulinemia is the body's attempt to correct for a loss of sensitivity to insulin. If your cells aren't responding properly to a normal amount of insulin, your pancreas tries to pump out enough extra insulin to get the desired result. (It's like talking louder to someone with hearing loss.) For as long as this strategy works, and the extra insulin is able to normalize your blood sugar, your A1c results stay normal, too. This situation is not called diabetes, because it doesn't manifest as elevated blood sugar. But it tends to get worse over time, and then a point is reached where your pancreas cannot make up enough extra insulin to compensate for (and hide) the problem. Then your blood sugar, and A1c results, start going up. But the increase in the A1c result is not caused by hyperinsulinemia -- it's caused by the failure of hyperinsulinemia to make up for the problem.

To the extent that there is any relationship between A1c results and hyperinsulinemia, the relationship is this: hyperinsulinemia means that your A1c is probably going to start going up later on, because hyperinsulinemia usually doesn't keep working forever.

"can non-diabetics have normal fructosamine/ gsp level"

That's who would have a normal level; it's people who are diabetic whose results would probably be above normal.

The fructosamine and GSP (glycosylated serum protein) tests are similar to the hemoglobin A1c tests, except that they reflect glycation rates over a shorter time period than the A1c test does; hence these tests are used when doctors are trying to assess the effect of recent changes (such as a new medication).

"how accurate is a1c for non-diabetics"

The hemoglobin A1c test is as accurate for non-diabetics as it is for anyone else.

If, by "accurate", you mean "accurately reflects the percentage of hemoglobin that is currently glycated", the test is pretty accurate, regardless of who is taking it.

If, by "accurate", you mean "can be used to compute an accurate estimate of average blood sugar", there are some problems, as I discussed in detail last month. Because of individual differences in hemoglobin glycation rates (for the same blood sugar level) and in hemoglobin recycling rates, the relationship between A1c results and average blood sugar is variable. It can be thrown off dramatically by certain kinds of medical treatment (especially hemodialysis).

However, being diabetic or non-diabetic would not be among the reasons why the the results of the A1c test might be misleading.

"how bad is hemoglobin a1c 6.2"  "is 6.2 mean you have diabetes"

A hemoglobin A1c result of 6.5% is usually regarded as the diagnostic threshold for diabetes. However, according to my lab's version of the test, the normal range only goes up to 5.6%.

So what does it mean if your result is between 5.6 and 6.5%? It means that you're on your way to becoming diabetic -- and should do something about it now, instead of waiting to get to 6.5%. The longer you wait to do something about the problem, the harder it will be.

"good blood glucose control good last 4 weeks who will it impact"

You, I imagine. But perhaps you meant to write "how" instead of "who", and perhaps you were thinking of an upcoming hemoglobin A1c test.

Red blood cells last about three months, so blood sugar control over the last three months can't help but affect the A1c result. However, because some of the red blood cells that were around two to three months ago have been recycled already, conditions from two or three months ago have a lessened impact on the outcome. The result is "weighted" toward whatever was going on in the last month -- that is, glucose control during the last month has a disproportionately large influence on the results, compared to glucose control during earlier months.

"no sugar in urine but could it be juvenile diabetes still"

Juvenile (Type 1) diabetes tends to elevate blood sugar more severely than adult-onset (Type 2) diabetes does, so I imagine most people with juvenile diabetes have sugary urine, at least before the problem is diagnosed and they start taking insulin. But I supposed there could be exceptions.

Anyway, the relationship between sugar in the blood and sugar in the urine is indirect; the latter is not the most reliable guide to the former.

When doctors are trying to determine what type of diabetes you have, they don't look for the answer in your urine.

"diabetes sweat ants"

Finally, I get an insect question that isn't about urine! Apparently it is true that elevated blood glucose can result in sugary sweat. From time to time one hears about attempts to produce a pain-free blood glucose monitor which measures the glucose in your sweat, so that there is no need to take a blood sample. I'm not sure, but I think that no device of that type has yet won regulatory approval. If not, the reason is probably that a measurement of glucose in the sweat isn't a terribly accurate reflection of glucose in the blood.

But if your blood sugar is very high, it might be true that ants and bees would take a special interest in your sweat, not just in your urine.

"is a 122/70 blood pressure and resting pulse 60 good"

Yes, it's good, although some purists would advise you to get that 122 below 120 if you can.

"when a diabetic is incoherent what does it mean"

Probably that he's blogging when he should be sleeping. That's what does it to me, anyway.

However, it might also indicate a severe hypoglycemic episode. You need to do something about that. Test if possible, to make sure that's what the issue is. If testing isn't possible, you may have no choice but to try to get a little sugar into him, as the safest bet in an uncertain (and dangerous) situation.


Science, Music, Blood Pressure, Eclipses, & Ignorance

Monday, May 21, 2012


Blood Pressure & Music

An Italian study, presented recently at a gathering of the American Society for Hypertension, looked at the effect of music on the blood pressure of hypertension patients waiting to be seen in a doctor's office. The researchers used a device to monitor people's blood pressure continuously while they sat in the waiting room, and they compared the measured results of patients who waited in silence to patients who waited while listening to a Mozart adagio (an adagio is the flowing, slow-tempo section that occurs in the middle of a concerto or symphony) and to patients who waited while listening to a frenetic song by the rock band Queen.

The result: the Mozart adagio tended to bring blood pressure down. The Queen song tended to bring it up.

In the old days, this result wouldn't matter very much in any practical sense, because people could not be listening to music all day and night. Now that the iPod has changed all that, hypertension patients know what to do.

My blood-pressure reading was good tonight. At the time I took the reading, I was listening to some flute music by the Swiss composer Arthur Honegger. So that works, too.


Eclipse Uncovers Widespread Stupidity!

There was a partial solar eclipse of the sun in California later yesterday afternoon -- that is, the moon passed in front of the sun, but didn't block it completely.

If you hadn't heard that there was an eclipse going on, you might not have noticed it -- it was still light outside, and although the sunshine was somewhat dim (as if there was smoke in the air from a wildfire), the difference wasn't all that striking. Shadows looked a bit odd, if you thought to examine them. Those blobs of light on the ground under a tree, where the sunlight peeks through, were crescent-shaped rather than round.

I did manage to take a photo of the sun that came out pretty clearly, though, even though my camera definitely does not like zooming in on that particular target.

I was outside running, at a local park, during the later stages of the eclipse, and I had the chance to overhear some conversations about the eclipse, from other people who were out walking around the lake -- conversations which made me despair for the society I live in.

One man was trying (and seemingly failing) to persuade his wife that, no matter what problem she was having with her cell phone, the eclipse could not be the cause of it. He was right, of course: unless someone is trying to call you from the sun, it isn't relevant that the moon is blocking your view of it. Cell-phone networks are very local affairs (your phone is reaching the network through a base station perched up on a pole somewhere in your immediate neighborhood). Because the base station is within a few miles of you (and the moon and sun are like way far from here), there is not the slightest risk that either the sun or the moon will get in the way and block your reception. Worrying about that is like worrying that movement of a glacier in Greenland is going to affect the alignment of your teeth.

Paradoxically, as America relies more and more on science and technology, Americans become more and more ignorant of both. It wouldn't surprise me if an actual majority of Americans could not give even a rough explanation of what an eclipse is. Nor would it surprise me to learn that those who think an eclipse can block cell phone reception could be wholly unable to say how they think such a thing could happen. It might not even occur to them to consider that they ought to have a reason for thinking whatever it is they think.

Amazing numbers of people simply assume it is beyond their powers to learn anything about science -- or reality -- and must either make stuff up or believe any story they hear. Perhaps that is why so many people think the world is coming to an end this year. Some are waiting for December, but the prophet Ronald Weinland (who also predicted the world would end in 2008, then in 2011) is now predicting it will end on the 27th of this month. A lot has to happen in the next six days to make his prophecies come true, including the death, by cancer, of everyone who has mocked his prophecies, and also including a little matter known as World War III. It's going to be a busy week. Fasten your seatbelts, ladies and gentlemen!

I don't think I will ever understand this phenomenon of people choosing to remain ignorant of the universe they inhabit -- thus making themselves vulnerable to anybody who might notice that their ignorance makes them ripe for exploiting.
 


Something for Nothing!

Friday, May 18, 2012


Don't Work Out -- Just Buy Our Shoes

Oh, gosh -- it turns out that shoe manufacturers are not allowed to claim that their shoes promote strength, fitness, and weight loss, if they have no evidence to show that this is true! The Skechers company has agreed to pay $50 million to settle Federal and State complaints that the company has been deceiving consumers about the health benefits supposedly provided by its line of "toning shoes".

On the one hand, I can see how government regulators might be skeptical of the claim that Skechers toning shoes enable consumers to "get in shape without setting foot in a gym", especially as the "scientific evidence" backing this claim was gathered by a chiropractor who happened to be married to a marketing executive for Skechers.

On the other hand, I can hardly blame the Skechers executives for being surprised that anyone would try to stop them. I mean, who knew that consumer-protection laws were still being enforced? I thought those had gone the way of the dodo, and the people at Skechers clearly thought so as well. But, strange as it seems, there are still a few government regulators keeping an eye on such things.

The theory behind the toning shoes is that their convex soles make them slightly unstable, and that walking on them will therefore engage stabilizer muscles which might otherwise remain idle. Yeah, you can see how that would make you drop the pounds like nobody's business.

Anyway, if you bought Skechers toning shoes, and wearing them did not cause you to get in shape without setting foot in the gym, you may be able to get your money back -- contact the Federal Trade Commission!

It seems amazing that any consumers actually fell for this, but I suppose we should never underestimate the popular appeal of the something-for-nothing concept. Whenever there is a benefit which you have to work to obtain, most people start daydreaming about finding a way to collect the benefit without doing the work. Marketing people realize this, and they try their best to exploit that common daydream.

Remember sleep-teaching?


You Decide...

I heard from a reader today who thinks I look a lot like the British actor Hugh Laurie, from the TV series House.   

It's hard to judge these things when you're personally involved, but I was surprised by the comparison, and I didn't think at first that I especially resembled him. But perhaps, even though the resemblance is slight to begin with, it gets amplified by the power of suggestion -- because he plays a sarcastic American doctor, and I'm an American who is sarcastic about doctors.

Of course, it may be that the reason I have trouble seeing a strong resemblance is that I don't associate Hugh Laurie mainly with his role in House -- I associate him with his role as the dim-witted Bertie Wooster in the British TV adaptations of P.G. Wodehouse's Jeeves stories.

Of course, I can't say for sure that I never stand around with my mouth hanging open in the way that Bertie so often does, but I do try to keep it to an absolute minimum. 


Lipids: Beyond Good & Evil

Thursday, May 17, 2012


Are You a Good Lipoprotein, or a Bad Lipoprotein?

Once upon at time, when we were gathered around the family TV set watching The Wizard of Oz, my brother raised the question of what the Witch of the South is like. We are told that the Wicked Witch of the West is worse than her late sister, the Witch of the East. We are told that the Witch of the North is good. But we are told absolutely nothing about the Witch of the South. My brother said, "So what's she like? Just kind of trampy or something?". As there seemed to be degrees of goodness and badness among the witches in Oz, he wanted to know where the fourth witch fell on that spectrum.

And yet, the first question that Dorothy is confronted with, upon arriving in Oz, is starkly simplistic: "Are You a Good Witch, or a Bad Witch?". As if those were the only possibilities. Some other answer ought to be possible, surely?

Maybe some other answer ought to be possible in the case of "good cholesterol" and "bad cholesterol", too. I don't think we know enough about what is going on with those two, to be characterizing them in such a black-and-white fashion. 

LDL & HDL

The so-called bad cholesterol is LDL (low-density lipoprotein) and the so-called good cholesterol is HDL (high-density lipoprotein). LDL is considered "bad" in the sense that it is thought to promote plaque buildup on arterial walls, and HDL is considered "good" in the sense that it is thought to remove plaque buildup from arterial walls. Apparently it is pretty well established that the two substances do play those roles... but it might be wrong to say that the amount of plaque on arterial walls is determined simply by how much "good" and "bad" cholesterol is in the blood. Does the rate of plaque deposition always go up when LDL goes up? Does the rate of plaque removal always go up when HDL goes up? 

Even if HDL really does remove plaque from arterial walls, this action might be triggered or facilitated by processes we don't yet understand -- and if that is the case, an increase in HDL won't necessarily result in cleaner arteries. Perhaps it takes more than just a good supply of HDL to make that plaque-removal happen. 

Similarly, even if LDL really does deposit plaque on arterial walls, this action might be triggered or facilitated by processes we don't yet understand -- and if that is the case, a reduction in LDL won't necessarily result in cleaner arteries. Perhaps it takes more than just a reduction in the supply of LDL to achieve a reduction in the rate of plaque deposition.

Here's an example of a separate factor which might play a role in all this: inflammation of the arteries (as a result of high blood pressure, or high levels of stress hormones, or some other disturbing factor) is thought to encourage plaque buildup. Seemingly, two people with the same amount of LDL but different degrees of inflammation could have different levels of plaque buildup. I doubt it helps to have an excess of LDL in your blood, but maybe the amount of it is not as important as other factors in determining how much plaque builds up. 

Also: if your HDL level goes up, is that necessarily a good sign? Could it signify that the body is trying to respond to a problem, rather than that all is going well?

In short, we don't really understand the full story on LDL and HDL and their interaction with other factors that effect plaque deposition and removal. Therefore, we should not be entirely surprised if evidence turns up which seems to show that changes in the levels of LDL and HDL in the blood do not alter cardiac risk in the way we expect.

Worrisome Indicators

A class of drugs called CETP inhibitors have been developed which artificially raise the level of "good" cholesterol, HDL. (The names of the drugs in this family tend to end in "cetrapib".) The pharmaceutical companies have been having a hard time getting these drugs approved. One of them (torcetrapib) was abandoned altogether because it seemed to increase rather than decrease the rate of heart attack and death. Another (dalcetrapib) ran into trouble recently when clinical trials failed to demonstrate efficacy. And the drugs that have been able to demonstrate efficacy, in the sense that they measurably increase HDL, are having a hard time demonstrating efficacy in the sense of reducing the risk of a heart attack.

So what's going wrong here? If HDL is "good", doesn't it seem a bit unfair that boosting the amount of it in the bloodstream doesn't prevent heart attacks? Well, like I said, the relationship between HDL and coronary heart disease is not so simple and straightforward as to justify an assumption that having more of one means you will have less of the other. Even if HDL is indeed a good witch, there might be limits to her powers. Also, it might matter what you did to raise your HDL level! Perhaps taking a CETP inhibitor raises your HDL in a way which doesn't benefit you in the cardiac-risk department, even if other ways of raising it would help.

What About Genes that Raise HDL?

To at least some degree, people have the LDL and HDL levels they do because of the influence of certain genes which they have inherited. Some people have a genetic variant which gives them an unusually high level of HDL, without having to take any pills to achieve that. Recently some researchers in Philadelphia and London decided to study people with that genetic variant, to see if having a high HDL for genetic reasons is protective against heart attacks (even if having a high HDL because you're taking a CETP inhibitor isn't protective).

Well, the answer disappointed them. Having a higher HDL level, even if you owe it to your genes and not to the pharmacy, does not seem to make you any less likely to suffer a heart attack (or an "MI", as they call it -- a myocardial infarction).

However, they did find that people who have a gene variant which gives them a higher LDL level do consistently show a higher rate of heart attack. In other words, "bad" cholesterol is pretty good at being bad, but "good" cholesterol is pretty bad at being good.

The authors conclude that, based on the data they collected, "interventions (lifestyle or pharmacological) that raise plasma HDL cholesterol cannot be assumed ipso facto to lead to a corresponding benefit with respect to risk of myocardial infarction".

I have to register a small complaint here: if the researchers wanted to take a swipe at lifestyle interventions, they probably should have studied people who increased their HDL through lifestyle changes, to see if those people received more of a benefit than those whose high HDL was inherited from their parents or purchased from the pharmacy. Admittedly, the researchers only said that such people shouldn't be assumed to be receiving a benefit. But if there are three known ways to achieve a high HDL level, a scientist who truly wants to understand the issue would probably study all three, instead of studying two of them and shrugging off the third.

What about Exercise Raising HDL?

I can hardly pretend not to have a personal stake in this issue. Like most people with Type 2 diabetes, I have a natural tendency towards low HDL, and during the first six months after diagnosis (when I was making so much progress on reducing LDL and triglycerides), my progress on raising HDL was almost non-existent (I went up from 32 to 33). At the time, my doctor told me that the genetic predisposition to low HDL in Type 2 patients is very hard to fight, and he doubted I would ever be able to raise it any higher than 37. (He said not to worry about it, and concentrate on keeping LDL low, because that was achievable and was probably more important.)

Over the next few years, my exercise program gradually brought my HDL level up above this supposed ceiling of 37 (my doctor later said he had set the ceiling that low because he never expected me to exercise as much as I ended up doing). The last time I had lab work done, my HDL was 55 -- well within the normal range.

I had been getting a lot of ego points out of this accomplishment, so obviously I'm reluctant to let go of the idea that it's helping me, just because the results of the new study seem to throw cold water on the idea. Here's what I'm clinging to:

 


Miscellaneous

Wednesday, May 16, 2012


My Dental Visit

I went to the dentist's office as promised, and had my gag-reflex tested (X-ray film carriers to bite down on, and then a cleaning session with the hygienist that seemed to involve more hardware, or bigger hardware, than usual). Finally the dentist himself came in to join us, and he made a long, slow, silent examination of my X-rays through a magnifier, hoping to find something with real money-potential. The suspense was terrible. At length he had to give up, and say that it all looked fine. Whatever boat he's buying this summer, it will have to be with someone else's money, ha ha!


Wildlife on the Run

While running at lunchtime today, I found myself stepping around a big snake that had slithered out of the grass and onto the footpath beside me. Didn't seem to be a rattler, and didn't seem to have any aggressive intent toward me. It was content to let me go about my business. Still, encountering a snake always adds just that little touch of drama to your day.

It's actually an aspect of outdoor exercise that I rather like: the little reminders that we still live in the natural world, no matter how walled-off we are from it most of the time. You see deer, you see crows and turkeys; once I saw a bobcat. Once, I'm pretty sure, I saw a mountain lion. It was stretched out in a field, and I tried to talk myself into thinking it was a log, but its absence the next day reminded me that logs are not migratory. I could have done without that one, actually, since mountain lions do occasionally kill and eat people, and when it happens it's nearly always a jogger. But the other creatures are interesting.


Some Health News Items

Some recent Medscape articles report that:


Infections & A1c Results

Tuesday, May 15, 2012


High A1c Result? Look for an Excuse!

Search strings have been turning up in my site statistics, from people wanting to know if having an infection can raise your A1c test results.

Like many questions that people ask about A1c results, this one sounds like wishful thinking to me. It's always tempting to dream up reasons why an elevated A1c result doesn't really mean what it appears to mean. Isn't there something besides high blood sugar that this high A1c result can be blamed on?

Unfortunately, the things that can make your A1c test result misleading (dialysis treatment, for example) tend to make it read artificially low, not artificially high. If your A1c result went up, it's hard to construct a scenario under which this could have happened without your blood sugar also going up. This is not to say that infection couldn't have an indirect impact on your A1c result... but even so, your A1c result would only be rising if your blood sugar was rising, too.

An infection produces an inflammatory response in the body, and the inflammatory response tends to impair your sensitivity to insulin. Unless your body can produce enough extra insulin to compensate for this loss of sensitivity, the result is that your blood sugar goes up. This, presumably, is why Type 2 diabetes is more common in people with periodontal disease or other chronic infections. At any rate, chronic infections can exert an upward pressure on blood sugar.

When your blood sugar goes up, it increases the rate of glycation (unwanted bonding of sugar to proteins). One of the proteins affected by this increased glycation is the hemoglobin in your red blood cells, and glycated hemoglobin is what the A1c test measures. Therefore, when your blood sugar goes up, your A1c result goes up, because your hemoglobin starts to be glycated faster than the body can replace it.

So, the point to keep in mind here is not that a chronic infection can "throw off" or "invalidate" your A1c results -- it's that a chronic infection can cause your blood sugar to go up, and give you an A1c result which is unwelcome but accurate.

I guess another point to keep in mind is that periodontal disease is something which diabetes patients need to take seriously. I've struggled with it myself over the years, but there's been an improving trend during my last few dental appointments. I hope that trend continues, because I have a dental appointment first thing in the morning.


One Size Fits All, Dammit!

Monday, May 14, 2012


The Cult of Metformin

An opinion piece recently published in Medscape by Gregory A. Nichols, PhD, asks the question, "Are Patients With Newly Diagnosed Diabetes Mellitus Being Prescribed Metformin?". It soon become clear that Dr. Nichols thinks all of them should be, and is disturbed to find that not all of them are. (I am disturbed at finding him so disturbed, as we shall see.)

Nichols is described as Senior Investigator for Kaiser Permanente Center for Health Research. He has disclosed financial relationships with five pharmaceutical companies. He is discussing a study of prescription claims in the cases of a quarter-million diabetes patients who were newly initiated on oral hypoglycemic monotherapy during the years 2006 to 2008.

During that time, the proportion of patients initially treated with metformin rose from 51% to 65%. Seemingly a heartening development from the point of view of a metformin partisan, but Dr. Nichols is by no means satisfied. Let me quote at some length:

"The American Diabetes Association and the European Association for the Study of Diabetes currently recommend initiating metformin when diabetes is first diagnosed, a recommendation that was already in place over the course of this study. It is rather disturbing, then, that about 35% of newly initiated therapy in this study was for something other than metformin, especially considering the substantial cost differences between metformin and other agents (except sulfonylureas).

The latest clinical guideline from the American College of Physicians does not call for metformin initiation at diagnosis, but it does recommend metformin as the initial therapy after lifestyle modifications have failed. However, observational studies have suggested that patients are more likely to attain glycemic goals with metformin, and to maintain them for longer periods, when initiated at diagnosis and before glycemic levels have been allowed to rise. In any case, whether initiated immediately or after attempting lifestyle changes, metformin should be the first medication attempted.

Another disturbing finding was that patients receiving pharmacy coverage from Medicare or sources other than employer or carve-out plans were less likely to receive metformin. This suggests that patients with coverage sources that do not include cost containment-based formularies were more likely to start newer and more expensive medications."

Oh, how my heart sinks, when I have to read the gloomy poetry of medical officialdom! The purported concern about some patients being prescribed expensive drugs instead of cheap ones does little to disguise the basic inhumanity of an insistence on one-size-fits-all solutions for a whole patient population. And no attempt at all is made to disguise the presumption that lifestyle modification is a waste of time: metformin should start before lifestyle modifications have been "attempted", or at least after they have "failed". For heaven's sake, if the situation is as hopeless as all that, why not throw in the towel at once, and bury the patient without further ado? For a physician to traffic in this sort of self-fulfilling prophecy is cruelly irresponsible.

Nichols finds it "disturbing" that meformin is taken less often by those patients who are able to afford something else. I find it disturbing that he can't imagine a legitimate reason for that. It looks to me like the same situation we see with statin drugs (which many patients refuse to take, to the outrage of their physicians): most patients don't like to take medications that make them feel awful. Yes, amazing but true -- they really don't!

Metformin very commonly causes gastrointestinal distress (about half the people who take it develop diarrhea, and about a quarter of the people who take it develop nausea). For people who can tolerate the stuff, fine. But if the people who respond badly to it are reluctant to sign on to the diarrhea-for-life plan, I really have to question the moral intelligence of any doctor who would condemn them for their bad attitude (or would condemn their physicians for letting them try something else).

If Dr. Nichols is so disturbed at finding that doctors aren't rigidly following the recommendations of the A.D.A. and the guidelines of the A.C.P., perhaps his disturbance arises from confusion about what the words "recommendation" and "guideline" mean. If those organizations had wanted to use the word "commandment" instead, presumably they could have.

If the practice of medicine can be reduced to a simple formula which applies to every patient with a given condition, why do doctors need to play any role at all in the treatment of patients? Surely the metformin-for-everybody algorithm could be administered just as reliably (more reliably, from Dr. Nichols' perspective) by a computer application.

I think we may be witnessing the death of the medical profession. Medicine will still exist, of course, but not as a profession. It's an industry now; a mechanism.

The human element will have to be provided by the patients themselves. Like this guy, I guess.


Venom as Medicine

Friday, May 11, 2012


Can a Killer Snail Help Diabetes Patients?

Drug research works in myterious ways. A poisonous tropical sea-snail called Conus striatus, which preys on small fish by stinging them with a harpoon-tipped proboscis and injecting a lethal venom, is being investigated as the source of a new medication for Type 2 diabetes.

Cone-snail venom is powerful stuff (sometimes fatal to humans), and it is chemically very complex: it's really a cocktail of hundreds of different compounds, each one targeting a particular nerve channel or cell receptor. These compounds are of great interest to the pharmaceutical companies, because each one is so narrowly focused and so swift-acting -- and might become the basis for a powerful medication. (Perhaps I need to make it clear that some of these compounds, taken in isolation, are not poisonous, and have potentially useful effects. The ones which target nerve receptors could become powerful pain-killers, for example.)

The latest compound in cone-snail venom to be studied for possible medical benefits is a peptide (a small protein molecule) known as Conkunitzin-S1. It binds to a potassium channel in the pancreas, and this stimulates a temporarily increase in insulin production. How this is of any use to the snail is not clear, but it's fairly clear how this could be of use to the pharmaceutical industry.

A particularly useful aspect of Conkunitzin-S1 is that the stimulated insulin production does not occur if blood sugar is already low -- which means that a drug developed from the stuff would seemingly not carry a risk of causing hypoglycemia in patients who took it at the wrong time. That is always one of the problems with taking insulin, or drugs which boost insulin production: it's too easy to overdo it, and create a dangerous low. A drug based on this peptide seemingly would not have this problem.

The main problem with using this peptide as a medicine is that it's a peptide. In other words, it is highly vulnerable to being broken down by digestion, which means that developing an oral form of the medication might not be possible. Like insulin (and for the same reason), you might have to inject it. Researchers are hoping to find a way to encapsulate the stuff so that it survives digestion and gets into the bloodstream intact, but it's best if we don't hold our breaths waiting for that to happen.

Is More Insulin Necessarily Better?

One of the issues that tends to go undiscussed, in connection with therapies which treat Type 2 diabetes by injecting insulin or stimulating production of insulin, is whether the goal is to give the patient a normal insulin supply or an insulin supply well in excess of normal.

If the patient isn't able to produce normal insulin levels (always true for Type 1 patients, and often true for Type 2 patients as well, especially if they have had the condition a long time), then I don't see any reason not to do whatever can be done to bring them up to a normal level.

But many Type 2 patients produce more than the normal amount of insulin, because they have become insensitive to the stuff, and their bodies manufacture it in excessive amounts in an attempt to overcome this "insulin resistance", as it's called. The condition of producing abnormally high insulin levels is called hyperinsulinemia, and it's a serious medical problem in its own right. Hyperinsulinemia has an inflammatory effect on the arteries, encourages the buildup of cholesterol plaques on arterial walls, and may be the reason why Type 2 diabetes tends to promote coronary heart disease.

My view is that, if you have become insensitive to insulin, the best solution is not necessarily to overdose on insulin to make up for it. How about doing whatever you can to boost your insulin sensitivity, so that extra insulin is not needed? That's what I'm doing all this exercise for, and for as long as it keeps working for me I'm going to continue to do it.

If exercise stops working for me, or I become disabled from doing it, and my sensitivity to insulin declines again, maybe the next step will be to take some medication (perhaps derived from the venom of a poisonous sea snail) which causes me to produce more insulin. But I don't think I'm going to reach for a solution like that until I have to.

Others can decide for themselves, of course! 


White Grains of Death!

Thursday, May 10, 2012


White Rice and Diabetes

You will no doubt be astonished to hear that eating white rice frequently correlates with a high risk of develping diabetes!

This comes form some research by scientists at the Harvard School of Public Health, and published in "BMJ". I assumed at first that "BMJ" was an abbreviation for "British Medical Journal". Well, it used to be. The thing used to be called the "British Medical Journal", but in 1988 they decided to rename it "BMJ" officially, so it's really just an arbitrary series of letters now. I guess that 1988 was when the folks at the British Medical Journal became so "FOT" (Full Of Themselves) that the use of actual words began to seem a bit beneath them.

Anyway, the study they published looked at rates of white rice consumption in the U.S., Australia, Japan, and China, and found that, the more servings of white rice you consume per day (a serving is defined as a cup of cooked rice), the higher your risk of developing Type 2 diabetes. An added serving increases your diabetes risk by 10% (though the summary of the study I read was unclear about whether that was an added serving per day, or per week, or per lifetime).

Of course, rates of white rice consumption vary a lot from country to country. In China, four cups of rice a day is considered typical. In the U.S., it's closer to four cups a week. Anyway, whatever the rate of consumption is in your country, the people who eat rice at an above-average rate also have an above-average probability of being diagnosed with diabetes.

Why would this be? Well, take a look at the nutrition stats on white rice:
 

White rice consists of starch and very little else. A very modest amount of protein, a tiny amount of fiber, and only traces of fat. In other words, white rice is a carbohydrate bomb. With practically nothing else in it to slow digestion and moderate the impact of all that starch, rice is converted rapidly into a wave of glucose that hits the bloodstream hard and fast. The "glycemic load" of a cup of white rice is about a quarter of what a non-diabetic person's endocrine system should be asked to cope with over the course of a full day (and, of course, a diabetic person's endocrine system should be given less challenging assignments).

For all intents and purposes, you might as well look at a rice bowl and pretend that you're looking at a sugar bowl. In terms of glycemic impact, it might as well be.

However, looking at the nutritional facts only answers the question "Why is white rice such a problem food for diabetes patients?". It doesn't answer the more interesting question: "How does eating white rice increase the risk of becoming diabetic?".

I don't think the latter question is answerable at this point -- no doubt people have opinions about it, but I don't think we really know what's going on. Does overwhelming your endocrine system with starch consumption "wear out" the pancreas? Do people who eat more rice simply tend to gain more weight -- with diabetes resulting from the obesity, rather than from the rice?

I'm curious about how white rice consumption might cause someone to develop diabetes, but I guess it's not an especially relevant point to anyone who already has developed diabetes. Once your endocrine system's capacity for glycemic control is already compromised, you know that white rice is not your friend.

I'm not so happy with the advice, commonly given, to replace white rice with various brown varieties of it. The nutritional stats on brown rice really aren't that much better. 5 grams of protein instead of 4? Nothing to write home about. 4 grams of fiber instead of 1? Well, a step in the right direction, but not an extremely large step. The fact that white rice is a slightly worse carbohydrate bomb than brown rice is does not mean that brown rice isn't also a problem food for diabetes patients.

If you're avoiding white rice, don't convince yourself that rice is okay for you so long as it's brown. At most, I would suggest that you experiment carefully with post-prandial testing to see how much brown rice you can get away with. You'll probably find that the amount of brown rice you can get away with is not significantly higher than the amount of white rice you can get away with. Proceed with caution!

The problem with white rice is that it is so central to various culinary traditions, you can hardly be a strict avoider of the stuff and still eat popular ethnic foods. When you are out with friends and considering restaurant choices, you don't want to be the wet blanket who keeps voting against every ethnic place suggested ("No, Chinese is out. Forget Mexican. And Indian is impossible for me..."). You can go ahead and eat in these places, but try to arrange it so that the rice is, at least to some degree, separable from the rest of what you're eating. This isn't easily arranged when you're eating a burrito, I admit, but for most ethnic foods you can avoid or at least limit rice consumption.

I find that, in the right circumstances (such as having recently finished a hard workout) I can get away with having a small amount of rice. Not the whole mountain of rice that is typically served to me, and probably not half of it either -- but some. Enough to keep me from feeling freakish in the resturant, for leaving an entire hillock of rice untouched on my plate. But I try to avoid getting myself in front of a hillock of rice when I haven't charged up my system to be ready to handle the challenge. 


The Bike Commute

Yeah, I fulfilled my pledge to participate in Bike to Work Day. That part was easy -- biking to work is the downhill direction. I found it much, much harder to participate in Bike Home from Work Day. That is one steep hill! I had to climb about 450 feet in little more than a mile. It certainly hasn't gotten any easier in the months since I last did it. Such a short ride, yet such a sweaty ordeal! After I got home I felt like going to sleep immediately, and I certainly didn't feel like going to the gym after dinner for my weight-lifting workout, but I dragged myself there somehow. It was very hard to do the workout at first, but then I started feeling stronger, and started upping the weights I was using a little bit.

Well, I guess the bike ride home from work will be a little easier next time I do it. But the next time I do it won't be tomorrow, as I have some errands to run that require a car.


Biking to Work

Wednesday, May 9, 2012


Oh, no -- Not Another Special Occasion!

Perhaps the following important document from American history has hitherto escaped your notice:

Proclamation 5834 -- National Dairy Goat Awareness Week, 1988

June 17, 1988
By the President of the United States of America

A Proclamation
 
For many centuries, dating perhaps to prehistoric times, dairy goats have provided mankind with a reliable and abundant source of milk and milk products, meat, and clothing. Here in the United States, goats have been valued throughout our history primarily as dairy animals. Because of their ability to thrive in either lush or arid country, efficiently converting a wide variety of vegetation into nutritious milk and meat, these animals often accompanied American pioneer families in the days of westward expansion. Goats have long been a part of the typical mix of animals on farms in every region of the United States.
 
Today, among the contributions of dairy goat farming to our Nation's economy is an impressive array of dairy products. The interest of both domestic and foreign consumers in U.S. domestic goat cheeses, or Chevre, continues to increase, as does awareness of all dairy goat products. These trends deserve every encouragement.
 
The Congress, by House Joint Resolution 423, has designated the period beginning the second Saturday and ending the third Saturday of June 1988 as "National Dairy Goat Awareness Week" and has authorized and requested the President to issue a proclamation in its observance.
 
Now, Therefore, I, Ronald Reagan, President of the United States of America, do hereby proclaim the period beginning the second Saturday and ending the third Saturday of June 1988 as National Dairy Goat Awareness Week. I call upon the people of the United States to observe this week with appropriate programs, ceremonies, and activities.
 
In Witness Whereof, I have hereunto set my hand this seventeenth day of June, in the year of our Lord nineteen hundred and eighty-eight, and of the Independence of the United States of America the two hundred and twelfth.
 
Ronald Reagan

[Filed with the Office of the Federal Register, 10:16 a.m., June 20, 1988]

Apparently most of the legislation that actually makes it through congress and lands on the President's desk for signature is of precisely this sort: the never-ending effort to fill the calendar with special occasions designed to remind us of the importance (or at least the existence) of some subject or other.

Because there are so many of these special occasions, it's hard for people to take them terribly seriously, and most people ignore most of them altogether. I'm certainly no exception. I'll admit to eating a bit of chevre now and again, but I'm not exactly going to devote a week in June to celebrating the stuff.

Every once in a while, though, one of these awareness events snags my attention, and actually motivates me to do something.

Bike to Work Day

More often than not, Bike to Work Day (which is tomorrow, folks -- so get those tires pumped up!) actually does get me to ride a bike to work. With luck, that will happen tomorrow. I say "with luck" because I'll have to get up early to make sure it can happen. There's an 8 AM meeting I have to attend, and can't attend late, so I need to make sure I've got enough time for the slightly slower method of getting to the office. Last year, I missed out on Bike to Work Day because of a time problem of that sort.

It's been a rainy spring around here, but lately the weather has been sunny and warm, so it's clearly high time I started getting back into the habit of biking to work.

Also, peer pressure plays a role in this: a lot of the people I work with are bike commuters, and there's always a large participation in Bike to Work Day at my company. Managers included, by the way: two of the people I work for (that is, people positioned at a noticeable altitude above me in the hierarchy) are very serious cyclists indeed. Ours is not a corporate culture which admires couch potatoes. (Which is a good thing for me, because it means ours is not a corporate culture which begrudges employees the time they spend working out.)

What makes bike-commuting problematic for me is not that I live too far from the office, but that I live too close to it. It's not a long enough ride to count as my exercise for the day. And yet, the ride home involves a ferocious hill climb; it is frustrating to come home with your clothes drenched in sweat, and yet not have been pedaling up that hill long enough to say you've had a workout. Well, it's a bonus workout, and who's to say I don't need it?

Anyway, I hope I manage to get up early enough in the morning to have time to participate in Bike to Work Day tomorrow, and I will do my best to make it a routine way of getting to work for as long as the good weather lasts. (This being northern California, it ought to last till autumn.) 


Blood Sugar vs. Brain Cells

Tuesday, May 8, 2012


Diabetes Shrinks Your Brain!

A two-year study in Australia found that the brains of elderly people (as assessed by means of MRI scans) shrink if they develop impaired fasting glucose -- and shrink more if they progress to a diabetes diagnosis.

This squares with previous data showing that diabetes correlates with an increased risk of dementia. And this new study, apparently, was able to show that elevated glucose is a risk factor independent of other known risk factors for dementia, including high blood pressure and high cholesterol.

The study results suggest that glycemic management is important even for elderly patients (many doctors would otherwise be inclined to assume that blood sugar doesn't matter all that much, if the patient is old eough to be likely to die from something else before diabetes has a chance to do serious harm).

Of course, all of this discussion leaves unanswered the most interesting question (most interesting to me, anyway): exactly how does diabetes shrink your brain? Nobody knows. More research is needed. (That is the real conclusion that every scientific study comes to -- we need to study this more!)

I'd like to know something about the mechanism of diabetic brain shrinkage. Is it simply a question of brain cells dying off, and not being replaced? Or do the cells themselves shrink? Or does something in between the brain cells contract?

If I had to bet, I would bet on the idea that episodes of hyperglycemia kill brain cells, and most of them don't get replaced. (I don't think it's correct to say that brain cells are never replaced -- apparently there is a replacement process for brain cells, but it proceeds slowly, and if you're killing them off faster than the replacement rate, there's a net loss over time.)

Unfortunately, it doesn't take an extremely high level of blood glucose to start killing cells. The damage point is reached somewhere areound 140 or 150 mg/dl, and most people with diabetes (or even "impaired fasting glucose") are getting that high after meals. Some of these people probably lose some more brain cells every time they eat a sandwich.

I don't know if I'm right in thinking that any post-prandial excursions above the truly normal range (which has an upper limit somewhere around 125 mg/dl) should be avoided if at all possible, but that's what I think. I aim to keep my post-prandial results that low, at least most of the time.

I don't know if my brain is shrinking or not; this is probably not the sort of thing that I can be relied upon to assess objectively. The other night I had a long series of dreams relating to my struggle with my Jewish identity -- only to wake up and remember that I don't have a struggle of that sort, because I'm not Jewish. Signs of a shrinking brain? Perhaps. But maybe it means that my brain is growing instead, and slopping over into territories where it has no business going!


Call it "Personal Growth"!

Monday, May 7, 2012


The Fattening-up of America

In 1995, there was not a single U.S. state that had an obesity rate as high as 20%. Today, 49 of the 50 states have an obesity rate higher than 20%. And even the lone exception (Colorado) is nearly there, at 19.8%.

There are now 12 states that have an obesity rates above 30%. Mississippi, at 34%, is still holding on to its position as the fattest state (after 7 years of leadership in this area).

These and other interesting facts come to us from the Centers for Disease Control. The number-crunchers there expect that 42% of the U.S. population will be obese by 2030. They have been trying to sound the alarm about this for years, and have been trying out various ways to illustrate the point. On one of their web pages, you can watch a series of pictures showing the obesity map of the nation as it evolves year by year. I have isolated some pictures from the series at 5-year intervals below:

It's creepy to watch the obesity epidemic spreading over the country like blood from a wound, but it's also fascinating, in a rather alarming way. We want to know what the explanation for this ever-growing problem is. And, as usual when it comes to explaining major problems, we want the explanation to support our prejudices. If problem X in our society is getting unmistakably worse, it must be owing to the growing influence of people and ideas we don't like.

Fortunately for us, the trend towards higher obesity rates in the U.S. coincides with all sorts of societal trends and technological developments. This means we can blame the obesity epidemic on just about anything we feel like blaming it on.  Cell phone use? The internet? Increasing use of high-fructose corn syrup in processed foods? Increasing use of trans fats in processed foods? McDonald's? Paula Deen?

Many advocates of low-carb diets argue that the obesity epidemic is the result of bad public-health guidelines which mislead people into adopting low-fat diets as a means of losing weight. Regardless of who is right or wrong about the low-carb approach generally, this line of argument appears highly questionable to me. It seems to include a couple of unstated (and unlikely) assumptions: that most people have actually been following the low-fat diet that was recommended to them, and that obesity didn't become a problem until people started hearing that they should eat a low-fat diet. (One wonders why anyone bothered to hand out such advice in the first place, if there was no obesity problem up to that point.)

I suspect that a great many factors are contributing to the obesity epidemic, ranging from increasing physical inactivity to a cultural change which has replaced "meals" (formal eating rituals, taking place at fixed hours of the day) with "grazing" (a way of eating that is so informal as to be almost unconscious, and can occur at absolutely any time of the day or night).  Maybe the most important issue is not what we're eating -- it's that we never stop eating it, whatever it is, for very long.

But all sorts of other factors are clearly at work. The dramatic expansion of "serving sizes", for example: once upon a time, bagels were smaller than sofa cushions, and even smaller than baseball gloves!

I doubt if we can actually round up all of the issues that play a role in driving the obesity epidemic. We'll be lucky if we can figure out what the top 5 issues are. Of course, each of us will have his own pet theory about which issue is the most important one of the bunch. But let's try not get too nutty about blaming it all on one thing.


Is Your Genome Your Fate?

Friday, May 4, 2012


 Compensating for Genetic Risk

It seems that Otzi the Iceman chose the wrong parents. I'm referring, of course, to that 5300-year-old man whose body was found in a melting glacier in 1991, in the Otztal Alps (on the Austro-Italian border).  

Otzi has probably been the most closely-studied forensic case on record.

Just recently, it was announced that Otzi's entire genome had been sequenced, and one of the discoveries this brought to light was that he suffered from a genetic predisposition to arterial disease. This is seen as an explanation for his having hardening of the arteries at a relatively young age (he is thought to have been no more than 45 when he died), despite leading what appears to have been an unusually active lifestyle even for the times.

When a man dies with an arrow in his back and a wounded skull, it could be argued that his biggest problem in life was not arterial health. But suppose he had not been hanging around with the wrong crowd, and had managed to avoid all violence. Would there have been anything he could have done, to overcome the genetic predisposition he was born with? Or would heart disease have killed him soon enough, even if his fellow humans didn't?

Genetic Risk & Lifestyle

People like to take a fatalistic view of any health problem for which there is a known genetic component. If you have "the gene for" this or that disease, there's nothing you can do about it. Why bother trying?

I think this is the wrong way to look at it. Genetics seldom boils down to anything as simple as inheriting or not inheriting "the gene for" a specific health problem. Usually the genes that are associated with a health problem don't guarantee you will develop that health problem. They only increase your risk of developing that problem, and they might not increase it all that much.

And even if gentic factors increase your risk of a given health problem, there might be something else you can do to compensate for that, so that the impact of those genetic factors is reduced.

Last month the American Journal of Cardiology published a study, based on data collected under the Physician's Health Study on 20,000 adult males over two decades. The purpose of the study was to see how much difference it would make if men with a family history of premature heart disease adopted healthy habits, or didn't adopt them.

A man was considered to have a bad family history if either of his parents had a heart attack before age 55.

A man was considered to have a good lifestyle if he met at least three of four criteria: not smoking, exercise, normal weight, and moderation in alcohol.

The question was, how much impact did family history have on the rate of heart attack, followed by heart failure, among these men over the period studied? And how much impact did a good or bad lifestyle have?

Here's how the numbers broke down:

Heart Risk, Family History, & Lifestyle
Rate of Heart Attack + Heart Failure (per 10,000)
Good History,
Good Lifestyle
3
Good History,
Bad Lifestyle
5 - 6
Bad History,
Good Lifestyle
7
Bad History,
Bad Lifestyle
14

Speaking very roughly, patients have about twice the normal risk if they have a bad family history or a bad lifestyle, but not both.

However, patients have more than four times the normal risk if they have a bad family history and a bad lifestyle.

Yes, it's unfortunate to get stuck with double the normal risk, just because you didn't inherit the best possible set of genes from your parents. Apparently Otzi wasn't winning that particular gamble, despite his active lifestyle. But even that doubled risk is doubled again, and then some, if you don't adopt healthy habits. So you might as well do what you can! 


Thoughts on Two Meals; Causes of Frequent Urination

Thursday, May 3, 2012


A Tale of Two Post-Prandial Results

I didn't run at lunchtime because it was raining. Having skipped my usual exercise beforehand, I wondered how well my system would cope with a sandwich for lunch. It turned out that the post-prandial result was 126. That is within my doctor's guidance, and it's just barely over the normal range for a non-diabetic person. But I often do better than that, if I exercise first, and especially if the meal is low-carb.

To see how much of a difference it would make if my next meal was low-carb (and came right a workout), I had a dinner of chicken and green vegetables when I got home from the gym. The post-prandial result after that was 99.  So, yeah, it makes a difference.

Some people would think that 126 after lunch is more than good enough. Well, it's good enough if it never gets any higher than that. But, for anyone with a predisposition to become diabetic, there is a natural tendency for blood glucose, and especially post-prandial blood glucose, to get higher over time, if you don't fight that tendency. So, I try to give myself a safety margin, and aim for middle of the normal range, not the upper edge of it.

I'm not superhuman, so sometimes I am content to settle for "good enough" rather than "excellent", but I hope I never get to the point of settling for "not bad, really, for a guy with diabetes".


More About Those Over-Productive Kidneys

I web search on this phrase yielded a referral to my site yesterday: "other than diabetes what can cause sugar in urine".

I wonder if this was someone indulging in wishful thinking -- that is, someone who knows he has sugar in his urine, and is hoping to find a more comforting explanation for it than diabetes.

Unfortunately, non-diabetic explanations for sugary urine (a condition known as "glycosuria", sometimes spelled "glucosuria") are not numerous or common. If you have glycosuria, it is unlikey that the explanation for it is anything other than diabetes.

Some drugs that are used to treat a urinary tract infection can cause temporary glycosuria. And a special class of diabetes drugs known as SGLT2 inhibitors (such as Dapagliflozin), which block the kidney's ability to return glucose to the bloodstream, can cause glycosuria at comparatively low blood glucose levels. But you wouldn't be taking an SGLT2 inhibitor in the first place, if you hadn't already been diagnosed with diabetes. And if you're being treated for a urinary tract infection with a drug which can cause glycosuria, I assume your doctor is aware of that.

Finally, there is a kidney disease which can block the ability of the kidneys to return glucose to the blood stream -- the effect is the same as you'd get by taking an SGLT2 inhibitor, but it occurs spontaneously. That is called renal glycosuria, meaning that the kidneys are causing the problem all by themselves, without any help from drugs or diabetes. However, renal glycosuria is rare. It is far more common for glycosuria to be caused by diabetes than for it to be caused by anything else.

Excess Urination Without Glycosuria

Because there are so few non-diabetic explanation for glycosuria, you might expect that there would also be few non-diabetic explanations for polyuria (excessive production of urine) -- but that turns out not to be the case. The list of things that can cause polyuria is as long as your arm.

Polyuria goes by a lot of names (two of the more common alternatives are hydruria and diuresis). I don't know why doctors couldn't settle on a single term for this, at the conference where these names were proposed. Maybe they were impatient to get to the bathroom and they just agreed to disagree. Anyway, the over-rich nomenclature makes it a little harder to read up on the subject, but I did my best.

A common non-diabetic cause of polyuria is "diabetes insipidus", which is a very different problem than the more familiar diabetes mellitus. If you have diabetes insipidus, you have polyuria, but your urine isn't sugary (it is "insipid" -- meaning that it lacks flavor). Diabetes inspidus is not caused by elevated blood sugar. It occurs because your pituitary gland isn't producing enough of a hormone called vasopressin, or because your kidneys aren't sensitive enough to the vasporessin that your pituitary gland is producing. That hormone is supposed to regulate urine production, and when it isn't present, or the kidneys aren't responding to it, urine is produced too freely.

But there are plenty of causes for polyuria besides diabetes insipidus or diabetes. All sorts of diseases, rare and common, minor and life-threatening, include polyuria as a symptom. Pregnancy can cause polyuria. So can migraine. So can oxygen-deprivation. Many foods and beverages have "diuretic" properties, meaning that they cause polyuria (examples include coffee, beer, orange juice, hot peppers... and, at least in my case, artichokes). 

So, if you are urinating excessively, there could be a lot of possible reasons for it besides diabetes mellitus. But if the urine you're producing is sweet enough that the bees never complain of its insipidity... well, that points pretty strongly toward one likely explanation. 


Exercise: Necessary & Humiliating

Tuesday, May 2, 2012


Dementia Prevention: More than Just Crosswords

In recent years we've been hearing that dementia associated with aging can be prevented, or at least delayed, through mental activities (such as solving puzzles). It appears that physical activities can do this for us, too. A couple of studies at the University of British Columbia and at the Mayo Clinic have found that physical exercise (resistance training and aerobic workouts) can have a preventive effect in this area.

I don't know how much of a difference exercise alone will make, in terms of preventing dementia, but it's one more fact to throw on the existing pile of evidence that says exercise is necessary to human health (and that doing without it costs us, in a lot of ways).

I mean, look at me: I just turned 55 but I can often complete a sentence! Maybe it's because of all that running.


Exercise is Embarrassing!

A diabetes diagnosis typically requires (among many other things which most people don't want to deal with) converting oneself from a sedentary person to an active person.

There are many reasons why people find that transition hard to make. One reason which we usually don't discuss, because it is embarrassing, is that... well, exercise is embarrassing.

At least, exercise seems to have a lot of potential to be embarrassing, even for those who are talented athletes. 
 

And if the active life often proves embarrassing even for real athletes, how much worse is it likely to be for us impostors? The typical newly-diagnosed diabetes patient is over 40, overweight, and over with sporting activity. Asking such a person to head for the gym or the jogging path -- and feel at ease there -- is asking a lot.

Of course, a lot of diabetes patients were never athletic, even as kids. I certainly wasn't. Unless my experience was wildly atypical, and I doubt that it was, most "physical education" programs in the schools do more to discourage than encourage exercise among young people. It's a system which involves a lot of bullying and humiliation (all of it ignored or condoned by the adults involved -- for whom hell is too good), and its main effect on kids is convince many of them that the world of athletics is enemy territory. They have no place in it. They aren't meant to exercise. And they're certainly not going to, once they leave school. Why we spend money on programs that do so much more harm than good, I cannot fathom. But we do, so a lot of young people enter adulthood determined not to get involved in sporting activities -- which they have learned to associate with personal degradation.

So, you might say a lot of adults do not have a positive attitude toward exercise, by the time they are diagnosed with diabetes and told that they really had better start getting more active (assuming someone does tell them that, and certainly their doctors are supposed to). If they get up the nerve to go to the gym, or to the local high school to run around the track, they foresee nothing but opportunities to make fools of themselves.

What tends to worry people most in this situation is the feeling that they aren't the right sort of person to be exercising, and that anyone who seems them attempting it is going to recognize that fact instantly, and snicker. Why is this person (who is clearly too old, too fat, and too awkward to be engaged in exercise) hanging around in this health club or on this jogging trail? Does he think he's fooling anybody?

Actually, nobody is going to be thinking that about you -- if you imagine them evaluating you in that kind of detail, you greatly overestimate the degree of interest which most health club members are going to have in the person who is using the machine next to them.

The easiest way to get over the feeling of being an impostor in the gym is... to go to the gym. Notice what kind of people you see there. Are they all young athletes with perfect bodies? Not likely (and if they are, you just chose the wrong gym). Most of the time you will see plenty of people who are in exactly your situation. If you participate in outdoor exercise, you will probably encounter a higher proportion of young, fit people -- because the less fit people tend to gravitate toward indoor spaces for exercise, in the hope of cutting down the number of potential witnesses. But even on the jogging trail, not everyone you see is going to be a triathlete. You probably won't be the oldest and least-fit person out there.

I had a lot of anxiety about looking pathetic exercising, back when I started my exercise program in 2001. I got over it, or most of it anyway. My main problem with embarrassment while exercising, these days, is that I'm a slower runner than my running buddies are, and it bothers me that I tend to fall behind them, especially going uphill. But it doesn't bother me so much that it discourages me from exercising. So, to that extent, I've overcome the problem.

Maybe, once you reach the point where you realize you are going to keep exercising whether it's embarrassing or not, it starts to become less embarrassing.

 

Seek and Ye Might Find, But What Are the Odds?

Tuesday, May 1, 2012


I like to ponder the questions implicit in the phrases people have typed into search engines, resulting in a reference to this site. It gives me a lot of opportunity to guess at what people are thinking, and react to my own guess.

Of course, by the time I get around to answering these implicit question, the person who originally asked them has long ago given up in frustration. An internet search so often yields thousands of hits that are mostly a waste of time, and I know my own site doesn't show up very high in the results (although I'm working on some subtle tricks which may improve that situation).

Anyway, here are some of the issues that people have been trying to learn more about.

Hypoglycemia without Meds   

"can i get hypoglycemic if i had type 2 diabetes and am not medicated"

Anybody can get hypoglycemic. You don't have to be on diabetes medications; neither do you have to have diabetes.

You are most at risk for hypoglycemia during endurance sports; if you're training for a marathon and you're doing long runs without taking in any snacks or sports drink, you face a high probability of becoming hypoglycemic somewhere in the 10 to 15 mile range.

However, you can also become hypoglycemic while sitting down doing nothing, especially if it's been a long time since your last meal.

Insulin and oral diabetes drugs certainly do increase the probability of hypoglycemia. But the probability is never zero, for anybody. 

Incurable Diabetes

"doctors saying that diabetes cant be cured"

Strictly speaking, a cure is any sort of treatment, and diabetes can be treated. However, in this case doctors are using "cured" in the popular sense of "eradicated forever". Most people think a cure for diabetes would mean that you never have to worry about your diabetes ever again, and you never have to do anything about it again, either.

That kind of cure isn't available. Even for people who have normalized their blood sugar by means of heavy-duty bariatric surgery, diabetes and other health issues will always be a concern, and will always have to be kept track of.

Doctors are afraid of patients being hoodwinked by some quack selling a fake cure, and in reaction they tend to get a little carried away with the diabetes-is-incurable message. The impression they give patients is that diabetes cannot even be ameliorated -- that it gets worse and worse over time, and nothing can change that. This is untrue. You can't make diabetes a non-issue in your life, to the point that you never need think about it again, but if you play your cards right, you can keep it from ruining your health.

Depressing Diabetes

"diabetes is depressing me"

Yeah, well, diabetes does tend to be depressing, especially since most of what you hear about it suggests that it will inevitably destroy you (see above discussion of incurability). Whether it has any direct effect on the brain that can alter one's mood, I don't know, but having any kind of serious health problem to deal with could certainly be one stressor too many for a lot of people who were on the verge of depression anyway.

My own view is that a lot of the depression that occurs among diabetes patients arises from feelings of helplessness. Most diabetes patients experience management of their condition as a passive thing -- they are supposed to do what they're told, and take all the pills they're given, and hope for the best. They don't feel in control of the situation, and what could be more depressing than loss of control over the situation, when the situation in question is your life?

That is one of the reasons I think my approach to diabetes management is less depressing than other approaches. At least I'm in control of it!

Hemoglobin A1c Confusion 

"does a1c 6.2 mean non diabetic"

It means that you haven't yet reached the diagnostic threshold at which doctors are allowed to tell you you're diabetic. However, it also means you're on the way there. The underlying problem is the same anyway, so you might as well deal with it now, when it's easier to do so.

"what does it mean if my glucose is ok but my a1c is high"

It probably means that you have a naive view of how much glucose is OK. Or, it means that your glucose is higher at the times when you don't test it than it is at the times when you do.

"does infection cause higher a1c"

Not directly. But infection (or anything else causing an inflammatory response) tends to diminish your sensitivity to insulin, and that tends to lead to higher glucose levels, and higher glucose levels do tend to raise your A1c test results.

A short-term infection is unlikely to have a measurable impact on an A1c test (which reflects average conditions over a period of about three months), but a long-term infection that's constantly going on "in the background" (gum disease, for example) might do it. That's one of the reasons why periodontal care is important for people with diabetes (and lack of periodontal care tends to increase the risk of diabetes).

Diabetes Without Meds

"what if you don't do any treatment for type 2 diabetes"

If, by "don't do any treatment", you mean "don't do anything at all, not even lifestyle adjustments", then in that case diabetes tends to get out of control and undermine your health in various painful and disabling ways. Then you die.

If, by "don't do any treatment", you mean "change your lifestyle instead of taking diabetes drugs", you have a pretty good shot at becoming healthy again. As least, it seems to be working for me.

"is it really possible to have diabetes without taking medicine"

Easily, but I suppose what you meant was "is it really possible to control diabetes without taking medicine?", and in that case the answer is "easily" -- or at least "pretty easily".

Diabetic Diet

"should a person over 80 years old be on a diabetic diet"

Wait a minute: what is a diabetic diet?

There is a serous lack of agreement on what a diabetic diet should consist of. Even the principle that carbohydrate intake should be at least a little lower (and maybe a lot lower) for diabetes patients than for other people is not universally accepted.

Believe whomever you want to about what a diabetic diet should be like, but I don't think age is a factor in this matter. Being diabetic or non-diabetic seemingly matters more than being under or over 80.

Panic

"should i panic if i have type 2 diabetes"

No, panic isn't useful. But complacency isn't useful, either. You should be concerned and engaged and doing what you can about the problem. 

Probably under-reaction does more harm to diabetes patients than over-reaction does, but neither should be aimed for. 


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