Of Sugar & Homicide

Wednesday, July 31, 2013

 


Why Doctors Shouldn't Murder

If murder mysteries and true-crime stories have made one thing clear to me, it's that murder is not the sort of hobby which should be taken up by busy people who don't have time to give their full attention to the details involved.

Impulsive people, who kill without having thought about how to avoid prosecution for the crime, tend not to be good at murder. And it's beginning to look as if doctors in general should not get involved in murder, if the two doctors now facing prosecution for the crime are any indication.

If you are known to have a long-standing grudge against a set of people, you need to be awfully careful about murdering them. For example, if you were once fired from a residency program in Nebraska because of "unprofessional behavior", and the people who fired you start getting murdered, that can look to the police like a suspicious chain of events.

Another suspicious chain of events: if you're a neuroscientist working at the University of Pittsburgh, and you ordered a large supply of cyanide (charging it to your university credit card, and also paying extra for overnight delivery), and your wife dies of cyanide poisoning shortly after the stuff arrives, police might start to wonder if those events are possibly related.

Doctors need to take the trouble to imagine themselves in someone else's place, and figure out how their actions would look to others. If they don't have the time, or the patience, for mental exercises such as this, then murder is not for them.

 


Internet Question

Somebody out there wants to know, "by omitting sugar from your diet will that bring down your a1c result?".

I guess it depend on what you mean by sugar. The culinary world is full of foods (cereals, breads, pasta, potatoes) which are not called sugar, but are, in a sense, constructed of sugar. People say that these foods are not sugar -- they're starch, they're complex carbohydrates Okay, fine, but how long do they remain "complex"? Starches consist of sugar molecules chained together, but digestion breaks those chains apart into their constituent sugars in a hurry.

In other words, the distinction between sugars and complex carbohydrates -- which many people assume is a very significant distinction -- only lasts until you swallow the stuff. Once digestion begins (and it begins soon, because even the saliva in your mouth is enough to start breaking down complex carbs into simple ones), the distinction goes away. Not understanding this can mislead you badly. A lot of people assume that they can pour themselves a big bowl of cornflakes, and it won't count as a high-carb breakfast so long as they refrain from sprinkling a spoonful of sugar on top. The reality is that there's a great deal more "sugar" (although not yet in liberated form) in the cornflakes themselves. "Sugar-free" means nothing unless it also says "carbohydrate-free" (which it probably doesn't).

To return to the original question: if you severely restrict your intake of all carbohydrates, your A1c test result will probably go down. If you eliminate only what you thik of as "sugar", while continuing to consume the sugars that have been cleverly disguised as mounds of rice and French fries, your A1c result is likelier to go up.

 


Bad News, Good News!

Tuesday, July 30, 2013

Just when I thought I had it all but eliminated, the adhesive capsulitis in my right shoulder flared up painfully yesterday, and is worse today. It's worse when I'm trying to sleep than at any other time. I can function, but getting my arm in or out of a sleeve is tough, and I haven't dared trying to play the fiddle yet. Here's an indication of what it's like: every time I move my right hand from the computer keyboard to the mouse, I grab my right wrist with my left hand and lift it over to the mouse; whatever muscle or tendon gets engaged, when I lift my right arm and move it to the left or right, puts pressure on my inflamed shoulder joint and hurts me. I've had it worse than this, certainly, but it's not fun. I'm doing the Ice & Ibuprofen thing, and doing the shoulder rotations that the physical therapist taught me. But I know it will take time to make this better, and it breaks my heart a little to realize that a problem which I had been working to overcome (seemingly successfully) over the past several months has probably come back and settled in for another long visit.

Who invited it?

 


Something Diabetes Isn't Linked To!

A comedian whose name I can't recall (but it may have been Will Durst) once defined a liberal newspaper as one which would report a nuclear holocaust with the headline, "Civilization Destroyed; Women, Minorities Hardest Hit". Something roughly similar goes on in regard to diabetes. Many a health headline could be paraphrased as "Gruesome Health Problem Is Worse and/or More Common In People With Diabetes".

Heart disease, kidney disease, retinopathy, stroke, depression, shoulder-joint problems, foolish investment choices, hallucinations involving ostriches, inability to make up your mind what you want on your plate and move your ass through the damned buffet line, already! -- anything that might go wrong with you is more likely to happen to you if you have diabetes, and probably more likely to be severe, too.

I have read studies suggesting that dementia is on the list of problems caused or made worse by diabetes. So imagine my pleasurable surprise when I saw a health headline today which read, "Diabetes Not Linked to Dementia". Huh? Did I read that right? Since when was diabetes ever found not to be linked to some health problem everyone hopes not to have?

It seems a little amazing, but a study reported in JAMA says that "no significant correlation" was found between diabetes (or its lesser cousins, glucose intolerance and insulin resistance) and Alzheimer's Disease (or the amyloid-beta deposits in the brain which are thought to cause it).

Of course, like all studies, this study concludes with a call for further studies, to confirm what it found. Whether you want to call that good science or unemployment insurance is your own decision to make. But anyway, it appears that we may have found a serious, much-feared disorder which diabetes doesn't make you any likelier to suffer from. And that's so rare that it seems like cause for celebration.

Probably someone will find a basis for challenging this finding before long, but for now, diabetes seems unlikely to give me Alzheimers! (It's not much, perhaps, but I'll take whatever comfort I can get.)

 


Monday Thoughts

Monday, July 29, 2013

Sorry, but I really ran dry late last week, and absolutely could not face writing any blog posts for Thursday and Friday. Sometimes you need to step back from a thing like this.

 


Trying Something Different

I was reading an article by a guy who claims that lengthy aerobic workouts (such as my long trail-runs on the weekends) are not necessary for health, and actually cause problems -- he thinks walking does just as much good for you, without all that wear and tear on the body.

I'm not sure if that's true (or, if it's true for some people, whether it's true for someone in my situation), and I'm not offering an opinion on that today. But yesterday, when I went to the state park to do a trail run, I decided on impulse to make it a hike instead. I walked the same route that I would have run. (It's a 7-miler, and very hilly, so it's not exactly trivial even if you walk it instead of running.)

And the aftermath? Well, blood sugar was okay today, so there's that. (I had been thinking I needed a hard run, to make up for the food I'd had at a party on Saturday, but maybe the hike was enough.) And blood pressure/heart rate are quite low for me. But here's the weird part: I had some very sore muscles today, in places where I'm usually not sore from a run of exactly the same length! I am continually surprised by the way any unaccustomed activity, even if it's remarkably similar to (and seemingly easier than) an accustomed activity, always makes you sore afterward, in places where you're not used to being sore.

I told my yoga teacher tonight where I was sore (mainly the hips) and she adapted the program to that. We did plenty of hip stretching, all right. My hips feel better now; I hope they still do tomorrow!

 


Why Does it Work?

A form of weight-loss surgery known as Roux-en-Y Gastric Bypass has been described as a "cure" for Type 2 diabetes, but it hasn't been entirely clear why it works as well as it does. How exactly does the surgery "cure" diabetes?

In this type of surgery, the stomach is bypassed except for a small, egg-sized pouch which is allowed to continue participating in the digestive process. Also bypassed: the upper portion of the small intestine (known as the duodenum). The small stomach pouch is connected directly to the middle portion of the small intestine, known as the jejunum. The surgery is intended to reduce body weight by (1) placing a severe (and painful) limitation on how much one can eat, and (2) placing an additional limitation on how well the body can absorb nutrients from whatever food gets through.

However, the surgery has also been found to bring about something other than weight loss: it often produces a remarkable improvement in glycemic control for Type 2 diabetes patients. The question is: why, exactly? How does this surgery combat diabetes?

One might be tempted to take it for granted that the surgery "cures" Type 2 diabetes simply by forcing people to lose body weight, thus decreasing insulin resistance. However, the improvement in glycemic control typically begins very early, before significant weight loss has occurred. The surgery does something else, apparently, which improves glycemic control.

Researchers think they have found another explanation for the improved glycemic control following surgery. (Actually, I've thought of an explanation too: when your stomach has been replaced by a pouch the size of an egg, there's probably a limit to how many doughnuts you can consume -- but science has not yet weighed in on that, so pretend I didn't mention it.) Anyway, some researchers in Boston think that the surgery effectively reprograms the small intestine (or what's left of it after the surgery) to process nutrients differently.

The abstract: "The resolution of type 2 diabetes after Roux-en-Y gastric bypass (RYGB) attests to the important role of the gastrointestinal tract in glucose homeostasis. Previous studies in RYGB-treated rats have shown that the Roux limb displays hyperplasia and hypertrophy. Here, we report that the Roux limb of RYGB-treated rats exhibits reprogramming of intestinal glucose metabolism to meet its increased bioenergetic demands; glucose transporter-1 is up-regulated, basolateral glucose uptake is enhanced, aerobic glycolysis is augmented, and glucose is directed toward metabolic pathways that support tissue growth. We show that reprogramming of intestinal glucose metabolism is triggered by the exposure of the Roux limb to undigested nutrients. We demonstrate by positron emission tomography–computed tomography scanning and biodistribution analysis using 2-deoxy-2-[18F]fluoro-D-glucose that reprogramming of intestinal glucose metabolism renders the intestine a major tissue for glucose disposal, contributing to the improvement in glycemic control after RYGB."

Got that? Good.

Anyway, it appears that the small intestine plays a bigger role than previously suspected in glucose regulation, and this type of bypass surgery somehow triggers it to change the way it does business.

Well, that's good. I'm glad to know that a surgery created as a weight-loss treatment (and is not necessarily as effective at that as people tend to assume) also has another benefit. If you're going to let a surgeon hack you up to that degree, there had better be a payoff for it.

But if I can get the benefit without being hacked up, I'd still prefer to avoid the surgery.

 



Disability and Breakfast and Stuff

Wednesday, July 24, 2013

 


Diabetes and Disability

The Lancet has published a meta-analysis study that looks at the risk of physical disability in adults, and at the effect that diabetes has on that risk. You'll never guess what they found.

It turns out that diabetes increases the disability risk! Wow. That turns everything we thought we knew upside down.

How much does diabetes increase the risk of developing a disability somewhere down the road? Well, it adds about 70% to the normal risk, more or less, depending on what kind of disability, or definition of disability, you're looking at. The added risk is 82% if you look at disabilities impacting routine behaviors such as getting out of bed, dressing, and using the bathroom (which would be my definition of a disability, but there are other definitions).

Anyway, the bottom line is: the risk of disability is significantly increased if you have diabetes.

Okay, so what non-depressing lesson can we take away from this? Well, the only thing that suggests itself to me at the moment is my standard position on scary diabetes statistics: the statistics reflect what happens to The Average Patient -- and diabetes management consists almost entirely of not being like The Average Patient.

The Average Patient assumes that diabetes management consists of taking whatever pills the doctor prescribes, and hoping that's good enough. If that was good enough, The Average Patient would do a lot better than The Average Patient does. In particular, The Average Patient would not be mucking up the disability statistics. If you want to avoid disability, don't be The Average Patient!

 


A Day Without Breakfast

We've always heard that skipping breakfast is an unhealthy habit, but I for one have never been all that clear on what is supposed to be bad about it. Not that I skip breakfast myself (I can't face the day without something to eat), but it's never been clear to me what harm skipping breakfast was supposed to do to people who can manage it.

Well, one study says that men who skip breakfast have their heart-attack risk increased by 27%, compared to men who do eat breakfast.

The trouble is, nobody knows why this should be so. The best science can do, so far, is to hypothesize that a very prolonged fast, or becoming active in the morning with no food consumed first, creates some kind of harmful stress within the body, and eventually this stress takes its toll.

Anyway: don't skip breakfast.

I suspect that many people with diabetes are nevertheless going to be tempted to skip breakfast, simply because most breakfast foods are so heavy on the carbohydrates. Cereal, toast, and orange juice? Might as well swig corn-syrup straight from the bottle!

But there are low-carb breakfast possibilities; the problem is that they're more trouble. Pouring cornflakes in a bowl is quicker than scrambling eggs, and a lot of people don't have time in the morning to do more than they must. So breakfast is not an easy meal for people with diabetes, and those who feel capable of skipping it are going to want to skip it. So it's too bad that skipping it increases your heart-attack risk!

 


The Mystery Deepens

Tuesday, July 23, 2013

I didn't think I'd done anything yesterday to bring about a fasting result as high as 98 this morning but you never know. I'll hope to see something a little lower tomorrow.

 


The Diabetes Mystery Revisited

Yesterday I toyed with the concept of a murder mystery in which giving someone Type 2 diabetes was the murder method, and I speculated about what the ideal title for such a book might be.

A reader, apparently located in the UK, proposed a fresh take on an old hard-boiled detective tale by Dashiell Hammett: 'The Malteser Falcon'.

That's pretty good one -- but it might be lost on American readers. The only reason I know there is a candy called Maltesers is that they are mentioned in Graham Greene's novel 'The Human Factor'. I don't think they've ever been sold in the USA. According to Google Images, they look like this:

Actually, those could probably work on a mystery cover: they look a little menacing. Like grapeshot.

Well, plenty of books have been sold with two different titles, on either side of the Atlantic. To stick with the Dashiell Hammett theme while also retaining the diabetes theme, we could call the American edition 'The Not-So-Thin Man'.

 


Damned If You Do, Damned If You Don't

Sometimes I read two health research papers appearing side by side in the same place, papers which seem to convey opposite messages. And I wonder why the publisher doesn't try to clear up the contradiction.

Today, Medscape gives us a pairing of that type. One ('Unhealthy Behaviors Linked to Disability Later in Life') tells us that, surprise surprise, physical inactivity (along with tobacco and low intake of fruit and vegetables) throughout life is associated with disability late in life. The other ('Low Heart Rate During Exercise Linked to Future Risk of AF') tells us that men who get in shape, so that their heart rate is comparatively low during a workout, have a heightened risk of a heart-rhythm irregularity known as Atrial Fibrillation or AF -- an irregularity which can cause disabling health problems, including strokes.

I guess there is just no such thing as a clear message from health researchers, and we should stop expecting it.

I assume we will eventually be given some kind of clarification about this. My guess, while we are waiting for that clarification, is that the increased risk of AF if you do get in shape is probably a lot smaller than the increased risk of everything else if you don't get in shape.

From time to time we learn some bizarre fact about lifestyle and risk (for example: that smoking slightly reduces your risk of Alzheimer's disease) which is easy to overinterpret. If smoking reduces your risk of one disease while greatly increasing the risk of several other diseases, that one risk reduction is not a reason to smoke. That AF risk is apparently higher (for unknown reasons) in regular exercisers is not a reason to ignore all the other risks that are lower in regular exercisers -- tempting as it might be to do that, if you hate exercise and wish you didn't need to do it.

 


The Diabetes Mystery

Monday, July 22, 2013

Saturday was all about relaxation. In the late morning, a musician friend organized a special jam session in which we would only play waltzes. That's actually my favorite kind of tune to play, but I rarely get an opportunity to play a bunch of them. We played waltzes from various musical traditions (Ireland, Venezuela, Quebec, you name it). And from there I drove down to the Oakland hills, for a family picnic after which we attended an amphitheater performance of "Annie Get Your Gun".

I ate and drank too much a the picnic, of course, so Sunday was all about penance. I did a 9.3-mile trail run to make up for the sins of the day before.

 


Diabetes as a Weapon

I have noticed a disturbing trend in the kind of Google search-strings that result in referrals to my site: some of the people typing in these questions appear to be up to no good. Recently I fielded a question from someone wanting to know how to fool a hemoglobin A1c test.

Today I got this: "is there a substance one can be given by accident or design that makes a person type 2 diabetic?".

I guess the most hopeful spin we can put on this is that the questioner is an author specializing in murder mysteries, who is looking for a murder method that hasn't already been featured in other whodunits. This particular mystery would have to feature a killer gifted with more patience than murderers are usually credited with, but I know that mystery writers are always looking for a really new twist, and this would provide one.

I don't know of a substance one can be given, "by accident or design", which will immediately give anyone Type 2 diabetes. Substances habitually consumed over long periods are another story. The closest thing to a smoking gun we've come up with as a cause of diabetes is high-fructose corn syrup. But refined grains in general are probably as much to blame as HFCS is. The most reasonable guess we can draw from the data we have is that the historically recent introduction into the human diet of refined carbohydrates -- in greater amounts than human physiology is naturally capable of handling -- is probably the reason for the historically recent emergence of Type 2 diabetes as a commonplace chronic condition.

I doubt that one could make a decent thriller out of the role that the processed-food industry has been playing in human life of late, but that's what my hypothetical mystery writer has to work with.

So what would be this mystery be called? I've been working on a list of potential titles:

Well, perhaps the ideal title for a murder mystery with refined carbs as the murder weapon has yet to be found. I'll work on it.

But if the questioner is not an author of murder mysteries, but an actual murderer (or would-be murderer), I hope they will get hold of themselves, realize how crazy they are allowing themselves to become, and resolve to find a quicker method.

 


Type 2 is Worse?

Friday, July 19, 2013

 


Competing Diseases

Type 1 diabetes is very often described as the more severe variety of diabetes. Not that Type 2 is a headcold, you understand, but everyone seems to agree that Type 1 is a more extreme, more dangerous, more hard-to-manage variety of diabetes. This has led some who have Type 1 to become rather resentful of the amount of attention (and research funding) which Type 2 receives. Sure, Type 2 is far more common than Type 1, but shouldn't Type 1 be given a disproportionate priority because it is more severe? Type 1 patients may be less numerous, but their need is greater. After all, medical research spending prioritizes cancer over many other medical conditions which are more common but less life-threatening.

I have always taken it for granted that Type 2 really is less severe than Type 1 -- that anyone who has Type 1 has a much more serious medical problem than I have. At first glance, this seems very obviously true.

First of all, before there were treatments available for either form of diabetes, Type 1 (or "juvenile" diabetes as it was then known, because it usually develops early in life) progressed more rapidly, had more severe symptoms, and often killed young patients who had only had the disease for a short time. And even after insulin treatments for Type 1 became available, patients with Type 1 tended to die younger on average than Type 2 patients.

However, once insulin became available, Type 1 patients were far less likely to die soon after diagnosis; perhaps the two diseases are now competing on a more level playing field. And as for dying young, most Type 1 patients develop the disease in their youth, and most Type 2 patients develop the disease after they are forty years old. Comparing age at death for Type 1 and Type 2 patients may be misleading, if the Type 1 patients have been diabetic a lot longer than the Type 2 patients. Maybe, instead of asking how old diabetes patients are when they die, we should be asking how long after diagnosis they die.

Could it be time to revisit the issue of comparative severity of the two basic forms of diabetes? Certainly that has become easier to do, now that a lot of people are developing Type 2 early in life. Isn't it time we compared people who have had Type 1 and Type 2 for the same number of years, to see how they are doing in terms of complications and death rates?

Well, researchers have started looking into that -- comparing Type 1 patients with Type 2 patients who were diagnosed at an early age, to see how their health fared over a couple of decades. Surprisingly, the Type 2 patients did worse, and not by just a little. The Type 2 patients had a death rate twice as high, and they died younger. They also did worse in terms of diabetes complications, and in terms of various other measures of health (such as lipids and blood pressure). And Type 2 patients experienced these disadvantages "despite equivalent glycemic control and shorter disease duration".

The study authors conclude,"Young-onset T2DM is the more lethal phenotype of diabetes and associated with a greater mortality, more diabetes complications and unfavorable cardiovascular disease risk factors than T1DM."

Okay, so what the hell is going on here?

Why is the "less severe" form of diabetes twice as deadly, at least to those who develop it early in life?

Well, for starters, we should remember that "Type 2" diabetes may be nothing more than a category, encompassing multiple distinct diseases. It could be that people who develop Type 2 early in life have a different (and more severe) disease than those who develop Type 2 after forty.

Another issue to consider is that the Type 2 patients in the study also had other health problems (problems commonly associated with Type 2, but not necessarily with Type 1), including obesity, dyslipidemia, and hypertension. Perhaps those issues are the real cause of the higher death rates in Type 2 patients. (But is Type 2 causing those problems in some way?)

I'm sure that a lot more epidemiological research is going to have to be done before we figure out why the "less severe" form of diabetes is apparently worse. But, for right now, any complacency I might have been feeling because I "only" have Type 2 has vanished.

 


That Other Diabetes

Thursday, July 18, 2013

 


Unflavored Diabetes

Here's a simple question asked by a Google searcher: "does a1c go up in diabetes insipidus?".

I could just say "no" and move on, but maybe it's time I wrote something about that other diabetes which we sometimes hear about (mainly from people who are hoping that that's the kind they've got).

Diabetes insipidus is a term bound to cause confusion, because most people think "diabetes" means "chronic high blood sugar". Well, "diabetes mellitus" means that. But diabetes comes in flavored and unflavored varieties. Diabetes mellitus is the sweet kind, and diabetes insipidus is the unflavored kind. The flavor referred to, I regret to say, is the flavor of your urine.

Diagnostic technology has come a long way in the last few centuries, so much so that you might be surprised (and not pleasantly so) to learn that tasting a patient's urine used to be a routine element of a medical exam. The reason this was needed was to determine whether or not a patient had "diabetes mellitus" (sugary urine). Strictly speaking, the term "diabetes" by itself refers to any disease which can cause overproduction of urine; the qualifiers "mellitus" and "insipidus" were invented to make a distinction between a common disease which caused overproduction of sweetened urine and an uncommon disease which caused overproduction of unflavored urine.

The distinction between these two basic varieties of diabetes is not trivial; it isn't just a matter of flavor. The causal mechanisms behind the diseases are utterly different. People with diabetes mellitus (or at least people with poorly-controlled diabetes mellitus) produce an excess of urine because their blood is so sugary that the sugar is leaking through their kidneys into their urine -- and when that happens, osmotic pressure causes a heightened flow of water into their urine as well. People with diabetes insipidus, on the other hand, don't have a problem with their blood sugar; they produce an excess of urine simply because of problems with the hormones which regulate the production of urine.

One thing that needs to be said about diabetes insipidus is that it is far less common than diabetes mellitus. The incidence of diabetes insipidus is 3 per 100,000. The incidence of diabetes mellitus is 8,300 per 100,000. That's a pretty big difference; diabetes mellitus is 2,767 times more common than diabetes insipidus. It's almost surprising that diabetes insipidus ever gets mentioned at all.

Diabetes insipidus can have various causes:

It might sound as if diabetes mellitus would be annoying but harmless; actually, a chronically high rate of water flowing through the body can be harmful -- especially if it results in hyponatremia -- low blood sodium, a painful and dangerous condition. People with diabetes insipidus need to be treated for it (fortunately, treatments are available for most forms of the condition).

Diabetes insipidus has absolutely nothing to do with "diabetes" as we normally think of it. It does not elevate your blood sugar, and thus cannot give you an elevated hemoglobin A1c result. But it's worth knowing a little about the condition, if only to avoid confusion on the subject.

 


How Smart Is Your Sponge?

Wednesday, July 17, 2013

 


Spongebob Transplants!

Want to have a bunch of little sponges injected into you?

If so, your dream may soon come true!

But these are no ordinary sponges. These are smart sponges. They don't just sit around doing nothing; they react. But what to they react to, and how do they react? I will do my best to explain.

One of the big problems with injected insulin, as a diabetes treatment, is that it's an "open-loop" system rather than a "closed-loop" system. That is, there is no feedback mechanism to adjust how much insulin goes in. You just put insulin in, hoping it was the right amount. Maybe it was too much, or maybe it wasn't enough; who knows? (Engineers often use the term "open-loop" to mean "out of control", even when they're talking about a dysfunctional business plan; if you want things to be regulated properly, you want a loop that's closed.)

An example of a closed-loop system is the automatic-gain-control system in a car radio. When you drive toward a city while listening to a radio station located in that city, does the music get louder and louder the closer you get? No, it doesn't -- which is remarkable when you consider how much stronger the radio signal is getting. The automatic-gain-control system enables a radio receiver to increase its amplification when the received radio signal is weak, and decrease its amplification when the received signal is strong, so that a more or less constant volume level is maintained despite fluctuations in the strength of the received signal. This is a "closed-loop-system", because there is a feedback loop which sends a control signal back from the output of the amplifier to the circuit which adjusts the amplification level. When the loop is working, we don't notice its effects. A car radio doesn't become quieter as you drive farther from the station you're listening to, because the radio amplifies the signal more to make it sound just as loud. The only thing you notice is that, as you get farther from the station and the radio has to amplify the weak signal more and more, random radio-frequency noise is also amplified more, with the result that you get more static and distortion and funny noises. If the radio were an open-loop system, the amplification would not be adjusted, and the radio would often be amplifying a nearby station too much, or a distant station too little.

Insulin injections are like a radio with open-loop amplification. With no feedback mechanism to adjust insulin input, you just give yourself a shot, hoping it was the right amount -- but a lot of the time it will be more than you need, or not as much as you need.

The body's endocrine system doesn't operate in an open-loop fashion. A pancreas doesn't simply release insulin at the same level regardless of circumstances. The endocrine system is a closed-loop system: it monitors fluctuations in blood-sugar levels, and feeds back this information to the beta cells in the pancreas, causing them to adjust the amount of insulin they are producing. If you have Type 1 diabetes, your insulin supply isn't coming from your beta cells any more -- it comes from a syringe. And there is no feedback mechanism controlling how much insulin is entering your bloodstream. You're operating on an open-loop basis, and therefore extremely likely to get the dosage wrong, and overcorrect or undercorrect your blood sugar level.

Researchers have been looking for better ways to administer insulin, so that there is a feedback mechanism to fine-tune dosages. Often their solutions involve some sort of "artificial pancreas" -- a device which monitors blood sugar continuously, and releases insulin at variable rates to keep thing in balance. Inevitably such devices are highly complex and expensive. Is there anything simpler that might get the job done?

Researchers at North Carolina State University think there is. They have developed injectable microscopic sponges which surround a core of glucose, and which release the stuff gradually -- at a rate which fluctuates according to the current blood sugar level.

The sponges are made of a matrix of chitosan (a material found in the shells of shrimp and crabs). Also present in the matrix are nanocapsules containing enzymes which react to sugar in the blood. An increase in blood sugar causes the enzymes to release hydrogen ions, which bind to the chitosan matrix and give its strands a positive charge. Because like charges repel, the strands of the matrix are forced apart from one another, the sponge expands, and the insulin at its core is released at a faster rate. And voila! The sponges act as a closed-loop system, releasing more insulin when blood sugar is high, and less insulin when blood sugar is low.

In test on laboratory mice, the injectable sponges controlled blood sugar for 48 hours, but it is believed that the system can be made to work for several days. (After they run out of insulin and enzymes, what's left of the chitosan sponge matrix is broken down by the body.)

This is an alternative version of a nanoparticle-based system developed at the same university, which I wrote about in May. I guess we'll see which of them (if either) becomes a viable therapy. A lot might hinge on how expensive it is to make the sponges or nanoparticles.

These systems are being designed for use by patients with Type 1 diabetes. Of course, a lot of people with Type 2 diabetes take insulin as well. Would this approach work as well for them? A complication here is that most people with Type 2 are insulin-resistant (but not all to the same degree), and this might make it difficult to get the feedback mechanism fine-tuned well enough to meet their needs. But it does seem as if, for anyone injecting insulin, injecting it in a form which adjusts its own dosage has got to be an improvement on the open-loop approach.

 


Sleep, Fat, and Island Chains

Tuesday, July 16, 2013

Sorry, just couldn't blog yesterday. I'm only human...

Last night, someone in my yoga class brought fresh peaches from her trees and handed them out. And today, my neighbor brought me cucumbers from her vegetable garden (with a promise of tomatoes soon, once we get another heat wave). The world is conspiring to get me to eat more fresh produce.

 


Sugar and Sleep

One of the peculiar things that happens, from time to time, when you try to follow what's going on in health research, is that a new study is declared, rather grandly, to have finally come up with proof... of something which you thought had been proved years ago.

A study reported in Diabetes Care claims to have shown for the first time that inadequate sleep is an independent risk factor for Type 2 diabetes (and not simply a marker for other problems, such as depression, which are associated with diabetes). Well, okay, if they say so. But I thought the sleep-deprivation studies at the University of Chicago had been showing for years that sleep deprivation is not only "a risk factor for Type 2 diabetes" but is a direct cause of the condition (some of those studies had to be discontinued because of abnormally elevated blood sugar levels in the healthy young volunteers who participated!). I'm sure there is still plenty of room for speculation about why and how sleep deprivation triggers increases in blood sugar, but I didn't think there was any doubt that it does have that effect. Well, okay, now I guess there really isn't any doubt.

But, having settled that issue, could researchers please concentrate on trying to figure out why it is so?

 


The Get-Fat Gene

There is a gene known as FTO, and if you inherited a certain version of it from both parents (and about 16% of the population did inherit that version), you have a heightened risk of obesity and Type 2 diabetes. This gene variation apparently gives people strong cravings for high-calorie foods. Its association with diabetes is thought to be nothing more than an indirect consequence of its tendency to stimulate weight gain.

I think I have this gene. Unfortunately, nobody has figured out (so far) what people who have this gene can do about it.

 


The Archipelago

Biologists love "natural experiments" -- that is, odd situations which arise naturally but which, by their vary nature, reveal information in the way that a well-designed experiment would. Island archipelagos are especially good examples of this, because the organisms living on each island are all of common stock, but are bound to diverge evolutionarily because they are separated from one another and live under slightly different conditions on each island. (It was studying the variations among finches living on each of the Galapagos Islands that first gave Charles Darwin ideas about the origins of biological diversity.)

But it isn't always about finches! It can be interesting to study variations among human beings living on different islands within an archipelago.

Which brings us to the Vanuatu islands in the South Pacific.

The people living on these islands are a pretty uniform ethnic population, but the people living on different islands have different lifestyles. The islands are very unequal in terms of wealth, and habits, and diet... and obesity. Studying this population of people who share a common genetic stock but are divergent in terms of how they live seems like an ideal way to study the effect of lifestyle on obesity (and other things).

Well, the researchers are finding that, at least in the Vanuatu islands, obesity risk increases with wealth -- and that, although various behaviors correlate with increased obesity risk, the strongest correlation is with a movement away from the traditional diet of the islands (fresh fish and vegetables) and towards calorie-dense convenience foods (canned fish packed in oil, served with instant noodles).

Affluence is often associated in people's minds with leisure, but if you're not at the level of the super-rich, it is actually associated with a diminishment of free time -- and a resulting tendency to rely heavily on convenience products -- including convenience foods. Apparently, adopting a way of life that involves a lot of convenience foods can be a problem.

 


Deadly Lows?

Friday, July 12, 2013

 


How Serious Is Hypoglycemia?

Some of my readers have been wondering if hypoglycemia can actually kill you.

Obviously hypoglycemia makes us feel as if we're about to die. But lots of non-fatal experiences make us feel as if we're about to die. I have experienced visits to the Department of Motor Vehicles during which I not only felt as if I was about to die, but was more or less looking forward to it. The ridiculously extended campaigns for the presidency in the USA, which supposedly occur every four years but are actually pretty much continuous, can have a similar effect. But visits to the DMV, or news broadcasts speculating about a presidential election that's still three years in the future, don't actually kills us, even if we sometimes wonder whether it would be more merciful if they did.

Hypoglycemia, though: surely that can kill us?

Well, yes... in principle. And yet deaths from hypoglycemia alone are, according to the Joslin Diabetes Center, "very, very rare". Still, hypoglycemia is a threat, and a serious one. There are two reasons for this.

First, hypoglycemia can result in loss of consciousness, or at least severe impairment of mental faculties. This might not be so big a problem if you are sleeping, or sitting on the couch, when it happens. It's not so good if you're driving a car at the time you lose it. Hypoglycemic episodes which don't kill you directly can certainly kill you indirectly, if they lead you into driving at 80 miles per hour on the wrong side of the road.

And accidents are not the only potentially dangerous consequences of severe hypoglycemia. If you survive a series of non-fatal hypoglycemic episodes, you still don't have the comfort of being sure that these episodes have not had a cumulative, destructive effect on brain cells and nerve cells generally. Any blood-glucose excursion that takes you below 50 mg/dl is pretty sure to have killed off some brain cells. Admittedly, brain cells are numerous, and you can lose a fair number of them without suffering noticeable consequences. But a series of severe lows, with each one killing off a sizeable cohort of neurons? That's the sort of thing that might catch up to you after a while, ultimately manifesting itself as neuropathy or some other neurological disorder.

Hypoglycemia serious enough to cause lasting harm is usually the result of excessive medication (or the result of medication dosages chosen without adequate consideration of the amount of alcohol one has been consuming lately). That is one of the reasons I've been glad to avoid being medicated for diabetes (so far, at least): hypoglycemia is an issue that affects me no more than once or twice in an average year, and is not much more than a discomfort and an inconvenience when it happens. Hypoglycemia feels awful to me, and it makes me panicky, but I know in my heart that it isn't at all likely to kill me.

And, if you ask me, not having to worry about death from a cause which other people do have to worry about (or at least do worry about) is a pleasant relief.

 


Cheating For Dummies

Thursday, July 11, 2013

 


Can The A1c Test Be Fooled?

Among the recent search-engine referrals to my site was one in response to someone who entered the search phrase "how to fool the a1c test".

My goodness. I think this person is on the wrong track.

I see plenty of searches from people who are obviously trying to fool themselves about the hemoglobin A1c test (in other words, they are seeking excuses for assuming that the test result is probably wrong). But it's pretty unusual to see a search from someone who is consciously looking for a way to cheat on the test, and deceive their doctor or their insurance company.

Leaving aside, at least for the moment, the question of why one would want to cheat on an A1c test, let me first discuss whether it is even possible to do so.

Certainly it would not be easy to fool the A1c test. The methods that come to mind seem likely to be difficult, expensive, and unpleasant.

First of all, you could go on hemodialysis. I have never heard hemodialysis described as an experience which anyone would want to undergo by choice. Hemodialysis is a blood-filtering technology which is intended to clean out the bloodstream, for those whose diseased kidneys are not getting the job done. But "kidney machines", unfortunately, are not nearly as sophisticated in their operation as an actual kidney would be; they filter bad things out of the blood, and they also filter some good things out of the blood, and they do some harm to red blood cells. In people who undergo hemodialysis, the red blood cells don't have as long a lifespan as they should; they're replaced more often. This means that, in a dialysis patient, the red blood cells are abnormally young on average, and this means they have had abnormally brief exposure, on average, to glucose levels in the blood. This causes dialysis patients to get A1c rest results which are significantly lower than they would otherwise be, given their average glucose levels. One study found that hemodialysis can cause people who ought to be getting an A1c result of 7.5% to get a result of 6.5% instead, and that's a huge difference in the world of A1c results.

However, even if you wanted to undergo needless hemodialysis just to fool the A1c test, you would still have to persuade a doctor to sign you up for the treatment. Hemodialysis facilities are not like tanning salons; you don't just show up and ask them for the works. Those places are there for the benefit of kidney patients, not thrill-seekers. So let's forget hemodialysis as a method of cheating.

The other methods of cheating I can think of are going to require you to get hold of some OPB. I imagine there's an existing black market for this stuff, and the customer base that this market serves would probably consist of athletes who are trying to conceal their use of banned performance-enhancing drugs. So, if you have any connections in the sports world, ask around and see if you can find anyone who can score some OPB for you. Oh, and if you haven't guessed, OPB stands for Other People's Blood.

What I can't help you with is how you go about substituting the OPB for your own blood sample at the lab. You might want to consult with a magician, but it doesn't sound like an easy trick to pull off. Not only do you have to substitute a vial of OPB for the one containing the blood the lab technician extracted from you, you also have to slap an authentic lab label on the thing. (Or perhaps you can get hold of the real vial, pour your blood out of it, pour in the OPB, and slip it back where it was. How you can do this without being caught is hard to say.)

Of course, there's always the possibility of placing a whole lot of OPB inside you before you to go the lab. One has heard of wealthy celebrities (rock stars and such) going to special clinics overseas where they have their blood supply essentially replaced by means of a series of transfusions. It sounds as if it would be expensive, but if you really want to fool the A1c test and get away with it, that might be your best bet.

But, let's get back to planet Earth: do you really want to cheat on an A1c test, and if so, why?

Actually, I can imagine circumstances in which fooling the test might seem like a non-insane thing to do. To someone who fears that an A1c result above a certain value is going to have personally painful consequences (health-insurance consequences, for example, or job consequences, or being-forced-to-take-insulin consequences), sheer panic might drive a person to want to avoid a bad lab report at any cost. So long as people fear that they will somehow be punished, blamed, and criticized for their state of health, people are going to feel an impulse to cheat on lab tests.

But lab tests are just data, and you need data. Decision-making in the absence of data is nearly always bad decision-making. To manage your health effectively, you need to find out what's really going on inside you -- even if the news is unwelcome. And, depending on what sort of treatment you're getting, it might be harmful, even hazardous, to create a situation where you, or your doctor, or both, are making decisions based on false data.

So, even if fooling the A1c test was a lot easier to accomplish than I have explained it to be, you don't really want to fool the A1c test.

 


The Great Risk/Benefit Tradeoff

Wednesday, July 10, 2013

 


What's A Poor PPAR Agonist To Do?

These are not good times for the thiazolidinediones (or TZDs), also known as glitazones. This is a class of diabetes drugs with a troubled history. They sometimes produce alarming side effects, leading to them being either taken off the market or subjected to restrictions on their use.

One of these TZDs (troglitazone) was taken off the market (in 1997 in the UK, later on in the USA and Japan as well) because of concerns about liver toxicity. (I should mention that TZDs tend to have the lovely syllable "glit" in their names; unfortunately, drug companies have been finding that all that glitters is not gold.)

Another TZD known as rosiglitazone (and sold under the trade name Avandia) was very widely used until a 2007 study found that it significantly increased the risk of heart attack (the drug is thought to have caused tens of thousands of heart attacks in the USA alone). After much controversy about the validity of the research results, the drug was not taken off the market, but now there are restrictions on its use, and it comes with such scary warning labels that use of it has dropped dramatically.

Today the pharmaceutical company Roche announced that it is halting a clinical trial of a new TZD called aleglitazar, because of safety concerns about three side effects that are showing up (heart failure, gastrointestinal bleeding, and bone fractures). Other TZDs that failed to make it through clinical trials, because of safety concerns, included muraglitazar and tesaglitazar, both of which were dropped in 2006.

Okay, so what are these TZDs exactly, and why do they have so many unpleasant side effects?

Well, the TZDs function as PPAR agonists, if that helps. And since it doesn't, let me explain what PPAR agonists are.

First of all, PPAR stands for "peroxisome proliferator-activated receptor" -- it's a type of receptor on a cell membrane which, when stimulated, acts as a DNA transcription factor to regulate gene expression. An "agonist" is a drug which acts to stimulate a cell receptor, as a substitute for whatever compound is supposed to be doing that and, for whatever reason, isn't. So, the TZDs stimulate PPAR receptors on cell walls, and trigger changes in gene expression within the cell.

There are different classes of PPAR, and different kinds of PPAR agonists to stimulate them; the class known as PPAR-alpha mainly relates to cholesterol, and TZDs which act as PPAR-alpha agonists are used to treat cholesterol problems. The class known as PPAR-gamma mainly relates to insulin sensitivity, and TZDs which act as PPAR-gamma agonists are used to improve insulin sensitivity in people with Type 2 diabetes. As many people with Type 2 diabetes also have cholesterol problems, the new TZD known as aleglitizar functions both as a PPAR-alpha agonist and a PPAR-gamma agonist. But the result of this two-for-one approach seems to be an increase in the number of undesirable side effects.

Okay, so what's going on with all these side effects? Heart attack, heart failure, bone fractures, hepatitis, gastrointestinal bleeding... why do TZDs produce so many undesirable effects, along with the desirable effect of reducing blood sugar or blood fats?

Well, we need to keep in mind that PPARs serve a lot of different purposes in a lot of different kinds of cells. The researchers developing PPAR agonists for diabetes treatment are mainly focused on finding a way to trigger fat cells to absorb more glucose than they have been doing lately. But that doesn't mean the drugs are having that effect and no other. Stimulating a class of receptors on cellular walls (and causing them to alter gene expression within the cells) could have all sorts of unforeseen consequences. If you ask me, what's surprising about PPAR agonists is not that they cause so many unwanted side effects, but that they don't cause more of them.

Obviously the researchers think they are taking a very sharply focused approach, and are making one simple change to body chemistry which will have a single, specific, limited effect. And it's not that way.

Many doctors are unhappy that the TZDs are being discontinued or restricted, because they think the risk of serious side effects isn't high enough to be worse than the consequences of abandoning a diabetes drug, at least for a patient who has had success with that drug and not with others. Instead of reacting to potential side effects in a vacuum (that is, comparing them to no side effects), we should compare the side-effect risk with all the risks involved in not having the drug available.

These are very tricky problems. Even though I don't want to take diabetes drugs at this time, if I need them later I will want to have as many choices available to me as possible, so that I can decide which kinds of risk are acceptable to me.

But, for now, I'm sticking with exercise. So long as it continues to work for me, I will continue to take comfort in the knowledge that its known side effects are beneficial ones.

 


USA Loses Obesity Competition!

Tuesday, July 9, 2013

I got a little too busy at the office to do my lunchtime run, so I went to the state park after work to take advantage of the late sunset and do a long trail run. It was pretty warm today (about 90 degrees when the run started), so I had to take it easy (I took a couple of rest breaks). But the run was mostly shady, and it didn't seem that uncomfortable.

I did see something ugly, though. There are always a lot of mountain-bikers in the park, and although they look like they're having fun, my few attempts at it have convinced me that mountain-biking is not something I can do without great risk of hurting myself. Today, on the trail, I passed a group of mountain-bikers surrounding one of their own who had evidently had a bad accident. He was siting up, rigidly and silently, on a boulder, and there was enough blood on him (including a all over his head) to make it clear that this wasn't a minor injury. They were using a cell phone to call in an emergency rescue for the guy -- perhaps a helicopter evacuation. If that's what he got, he'll probably spend the rest of his life paying for it. (As if the pain he was obviously in was not bad enough!)

If you're going to exercise regularly, you have to figure out how to make the tradeoff between keeping it interesting and keeping it safe. I err on the side of safety, myself. I have to keep up this exercise program on a permanent basis; I can't take up a sport because I think it's fun (even though it carries a high risk of injury), and then abandon it afer a few years because I'm hurting myself too much to keep going. I have to keep going a long time, so I look for the safer options.

 


America No Longer Has The Fattest Americans!

The USA is no longer the fattest nation in the Americas; our obesity rate of 31.8% has been edged out by Mexico, with a rate of 32.8%. The rapid growth of Mexico's obesity rate has been blamed on a shift from traditional foods to snacks and sugary drinks.

But even Mexico still isn't the fattest nation on earth. The champions in that field tend to be small Pacific-island nations, where sugar and other processed carbohydrates have been introduced to the diet of a population long isolated from such things, and poorly adapted to handling them. The leading example is tiny Nauru, with a population slightly under 10,000.

Nauru has an obesity rate of 71.1%, and most of those who don't qualify as obese are at least overweight, so the "normal-weight" contingent on Nauru makes up only about 5% of the population. A group photo of their police force gives some idea of what comparatively fit citizens look like there.

But a lot of people say we can be healthy at any weight; what are the public health statistics like on Nauru? Not so good. Nauru has the world's highest diabetes rate (over 40%), and a lot of problems typically associated with diabetes, such as heart disease and kidney disease.

It may be that tiny island nations such as Nauru provide us with a heightened (and easier-to-analyze) example of what has been going wrong with other countries to cause the recent, rapid increases in rates of obesity and obesity-related illnesses. Genetic and cultural differences might make it hard to interpret what we find, if we take a close look at Nauru. But I think we should take that look.

 


Jargon Gone Wild

Monday, July 8, 2013

 


Expert Miscommunicators

Few things in life are more frustrating than having to listen to people vigorously discussing a subject which you understand and they don't. Usually those people are journalists, but not always.

Once, when I was a very young amateur astronomer, I attended an outdoor event on a summer evening, and on that evening the moon and Venus happened to be very closely adjacent to one another in the sky. Both had been appearing in the evening sky lately without most people noticing them, but they happened to line up on this night so that one looked very close to the other (Venus was actually millions of miles farther away than the moon was, but both lay in the same direction). Suddenly people were noticing them, and reacting to them as if something dramatic was going on. At that time, there was an Apollo mission on the way to the moon, and every person there was making the same dopey comment: "Look! You can see the astronauts!". I kept trying to explain to people that, no, the Apollo spacecraft wasn't big enough to visible to the naked eye from so far away; the very bright thing next to the moon was Venus, and nothing weird was going on with it, it just happened to be in the same direction as the moon tonight. I made no headway whatsoever. "Look, Gladys! You can see the astronauts!". The frustration of it was maddening. This happened more than forty years ago, and you might argue that I really ought to be over it by now, but it made a vivid impression. And yesterday I was reminded of it once more, because I experienced the same kind of frustration when confused reporters were trying to explain to the public why Asiana Flight 214 had crashed into the runway (or slightly short of the runway) at San Francisco International Airport the day before.

I used to have a private pilot's license. It's been a mighty long time since I flew a plane, but I still tend to feel as if I have a personal stake in any kind of news about aviation. Of course, "news about aviation" tends to mean a plane crash. (Flight Completed Without Incident is not a headline one often sees.) It drives me crazy when journalists who are unfamiliar with aviation, and only write about it when disaster strikes, try to explain to the public some aviation safety issue which they don't remotely understand themselves.

Saturday's accident involved a Boeing 777 (from Korea) which slammed into runway 28 Left, which extends out into San Francisco Bay (much to the alarm of tourists arriving there for the first time, who are landing in the water as far as they can see).

The plane's tail section and wheels broke off; the plane skidded off the runway and caught fire. There were many serious injuries, but only two deaths, which is amazing when you consider what sort of condition the plane was in after the emergency was over.

On Saturday, information about the crash was hard to come by, but it sounded as if the plane had come down tail-first, which made me wonder what kind of angle the pilot was holding during the descent. Did the plane have its nose in the air for some reason? I could only guess.

On Sunday I went off to the State Park for a long trail run (9.3 miles; it left me a little sore in the hips but otherwise fine). I came home, and while I was luxuriating in a hot shower, I listened to a radio broadcast of a live press conference being held by Deborah Hersman of the NTSB (the agency that investigates air crashes). She was giving a very preliminary report on what the investigators were finding so far. She said there was evidence from the flight data recorder that the airspeed of the plane was too low as it approached the runway -- considerably below the normal, safe landing speed. Also, she said that the plane's stall-warning indicators went off shortly before the crash.

She seemed very professional and sensible, and I wanted to think well of her, so I waited for her to explain, for the benefit of the reporters and the general public, what the word "stall" means in aviation. To my disgust, she didn't, and I washed my hands of her.

After the press conference was over, and the news commentators started interpreting what had been said, I waited for the inevitable horrors to come, and I didn't have to wait long. An NPR reporter stated (without being challenged by anybody) that the stall-warning system on the plane had indicated that the engines were about to fail.

I wanted to hurl my radio at the wall. No, no, no! A "stall" in aviation has nothing to do with engine performance!

A stall relates to what the wings are doing, not what the engines are doing. Even with the engines off, you can glide a plane to a landing without experiencing a stall. (Of course, you only get one shot at it, so you do need to get it right.) A stall is a dramatic loss of lift. If the plane is angled up too much for the speed at which it is moving, airflow over the wing surface is disrupted, and the wings stop generating lift and the plane loses altitude rapidly. A plane that's flying too slow, with its nose too high, is in danger of stalling.

The evidence gathered so far indicates that this plane was landing with its speed too low and its nose too high; the most reasonable guess is that the plane stalled as it approached the runway -- that is, the wings stopped generating lift and the plane simply fell to the runway instead of gliding onto it.

A stall is usually caused by pilot error, but occasionally a problem with the plane's control surfaces can cause a stall. Maybe the flaps or the spoilers did something they shouldn't have. There have been cases where a pilot was blamed for a stall which actually turned out to be caused by mechanical problems. So, we need to be cautious about saying that the pilot stalled the plane, when it's possible that the plane stalled itself. Also, a stall is suspected in this case on the basis of a hasty first look at partial evidence -- further investigation may uncover other issues that contributed to the accident.

But what drives me crazy about all this is that, in talking about a "stall", the NTSB spokesperson knew perfectly well that most people unfamiliar with aviation jargon would misinterpret the term. Under the circumstances, she had a clear duty to explain what "stall" means, and she didn't do it. If she didn't want to explain the term, at least she could have given a hint, by calling it a "wing stall" or something, so that people would at least have some clue that she wasn't talking about stalled engines.

I guess she would say that she's just used to speaking the language of aviation, but I don't think that's good enough. Every specialized area of knowledge involves jargon which is sure to be misunderstood whenever non-experts encounter it. Sometimes these misunderstandings are amusing and harmless -- for example, the expressive use of musical terms, by the sort of authors who think "crescendo" means "climax"). But the confusion is not always so benign. For example, scientists use the word "theory" to mean a well-confirmed understanding of how something works -- even though they know everyone else uses the word "theory" to mean a speculative idea that hasn't been confirmed at all. Scientists can't be bothered to care that their use of the word "theory" is misunderstood by practically everybody -- and then they act surprised when creationists exploit that popular misunderstanding!

Experts need to realize that they have a responsibility, when addressing non-experts, to explain their jargon, especially when it suggests a false meaning. If they fail to do this, I don't have a lot of sympathy for them when the confusion they are sowing causes trouble for them later. If hackers don't like what the general public assumes about the meaning of the word "hacker", they should either stop calling themselves hackers or do a much better job of explaining to the general public that "hacker" doesn't mean "criminal with computer skills". Experts in every field should, I think, be cautious about using professional jargon whenever they communicate with non-experts.

Doctors should, at least in my opinion, be extremely cautious about using misleading terms such as "prediabetes". I don't see how any doctor can doubt that the implications of this term are misunderstood by the majority of patients who hear it. If you called it "nondiabetes" you couldn't more strongly imply that it's not a problem to be taken seriously. Having the condition which doctors are calling "prediabetes" means that your health is in serious danger and you must start making changes right now. But the word makes most patients think that their health might develop some problems in the distant future and they might have to start making changes then. Surely it's obvious to doctors from the way most patients react to the word that the significance of it is not sinking in. Surely they ought to know better than to assume they don't need to clear this up.

I'm not alone in feeling this way; Riva Greenberg calls prediabetes "the lie that's killing us".

No doubt doctors bristle at hearing a commonplace diagnosis called a "lie", but it seems to me that the difference between lying to people and telling them something which you know they will misinterpret is not large. In fact, like a moonlander seen from earth, the difference is probably too small to be seen with the unaided eye.

 


After The Fourth

Friday, July 5, 2013

My glucose numbers weren't great today, but they certainly could have been worse! Yesterday was Independence Day in the U.S., which basically means an all-day barbecue with lots to eat and drink. That's how I spent the day, anyway, so I'm not kidding when I say it could have been worse.

In other news: today the earth reached aphelion, which means that we are as far away from the sun as earth's mildly elliptical orbit ever takes us. The reason it's hotter rather than cooler at this time of year (north of the equator, anyway) is that the north pole is pointed toward the sun rather than away from it now, so the days are longer, the sun goes higher in the sky, and its rays beat down on us directly, instead of making a long diagonal through a bunch of extra atmosphere on their way down.

The same thing happens in Australia in January, but when it does, the earth is closer to the sun, so Australian weather in January is even more fiercely hot than California weather in July. Most people in the northern hemisphere assume we're unusually close to the sun in July, not unusually far from it, but that's just because most people don't know anything about the world they live in. This tends to complicate the principle of popular rule. It's generally best not to leave the decision-making to kings and princes, but if you're going to hand the responsibility over to the peasants, it would be better for the peasants not to be a bunch of dopes. I don't know how to solve that problem; I'm merely admitting that the problem exists.

 


How Low Was My SES

Poverty (or low "Socio-Economic Status", as the sociologists call it) is strongly associated with Type 2 diabetes. But why is that? What does "SES" have to do with an endocrine disorder? How exactly would "low SES" cause anybody to become diabetic?

Lifetimes could probably spent figuring that one out, but a recent study says that inflammation accounts for about a third of the difference in diabetes risk between rich and poor potential diabetes patients.

But of course this finding only replaces one question with another: why, exactly, do poor people have more inflammation than rich people? Is the inflammation simply the result of stress? (I'm just taking it for granted here that not knowing where the rent money is going to come from is stressful -- I could be wrong about that.)

Even if we figure out for sure what is causing poor people to have higher rates of inflammation, this still leaves two-thirds of the diabetes risk faced by poor people unaccounted for. Researchers still have some work to do!

 


If You're Hungry, Your Workout Was Too Easy

Another study finds that caloric intake is lower after a high-intensity workout than it is after a workout that was less demanding.

I'm a little skeptical about this; my experience has been that the appetite-killing effect of a hard workout is extremely temporary. I may not feel hungry right after a hard, hilly run, but I tend to get there within an hour or so -- and I also tend to feel as if, because I just did a really tough workout, I should be able to get away with something high-carb, such as rice or potatoes. "Do you want fries with that?", they ask you. Well, why not, if you just did a hard workout?

Of course, my own experience may be atypical. Maybe, for the average person, a hard workout does not lead to overindulgence later.

When it comes to diabetes management, you have to realize that what's true for other people is only a possibility which you may want to try, to see if it is true for you, too. If it isn't, move on!

 


Flipping Genetic Switches

Wednesday, July 3, 2013

I couldn't go running at lunchtime, because I had to confer with an engineer who had some information I desperately needed, and that was the only time he was free. It was too bad, because one of my running buddies (who has been out with an injury) wanted to try running again today, and wanted me to join him for it. Well, we'll try again later.

I managed to make time to do the run after all, at 3:30. Somehow it feels strange to have a workout then, because most people at work exercise at lunchtime. But if you're going to get regular exercise into your life, you'll have to be flexible. Whatever works!

Along my running route, a guy coming out of his house said, "It's a little hot for that, hoss!". I said "Not as hot as it was yesterday!". Exercising in public view is one of the things that makes strangers think they should offer some commentary. Why, I wonder? It's tempting to think that the internet has taught us to assume everything exists only so that we can comment on it. But I suspect that sort of thing was happening before the internet existed.

 


Exercise & Epigenetics

Genetics (which is concerned with which genes we have) is starting to be eclipsed by epigenetics (which is concerned with which of our genes are being expressed). Although genes supposedly regulate what goes on inside our cells, there is a process known as DNA methylation which regulates which of our genes are turned "on" or "off". Compounds known as methyl groups, attached to the genes on a DNA strand, are used as chemical switches to activate or inactivate individual genes.

So the naive picture of genetics which most of us have (you are born with a set of inherited genes, and they control your fate forever) needs a bit of revision. It's not that simple. Whatever genes you have inherited might be expressed -- or not -- depending on what whether the methylation process turns those genes on or doesn't.

So what drives methylation? What flips the methyl-group switches attached to our genes, and causes genes to be expressed or not expressed? That turns out to be a complicated question; in a lot of cases it's not clear what is flipping the switches. But lifestyle changes can have an impact; one recent study (conducted at Lund University in Sweden) looked at genes which control fat storage in cells; some of these genes are associated with Type 2 diabetes. The study found that, in formerly sedentary men, starting a program of regular exercise changed expression of those genes. "We found changes in those genes too, which suggests that altered DNA methylation as a result of physical activity could be one of the mechanisms of how these genes affect the risk of disease".

Genetics taught us to think of ourselves as slaves of our DNA; epigenetics is starting to teach us to think of ourselves as having at least some capacity to control the way our DNA expresses itself (or doesn't).

But there are no doubt many factors which influence epigenetics, so trying to discipline your DNA, so to speak, is a tricky proposition. JAMA reports that the therapeutic effect of exercise on glycemic control is influenced by how far out of control you are at the point when you start exercising. For patients with hemoglobin A1c levels above 6.2 at the beginning of an exercise program, exercise was less effective in bringing blood glucose levels down.

This is why I think doctors need to do more to persuade "prediabetes" patients to take the problem very seriously, and get things under control while it's still comparatively easy to do it. Waiting too long to get started makes it a lot harder to succeed!

 


Unfair! Unfair!

Tuesday, July 2, 2013

Another hot day, but I carried water with me on the run this time, which seemed wise and actually seemed to help.

 


Comparing Doctors Based On Patient A1c Results

Health-insurance companies and other institutions have been increasingly interested in finding "metrics" for doctors -- numerical measures of how well doctors are doing their jobs, so that these statistics can be fed into pay-for-performance schemes, and can be otherwise also be used in assessing different approaches to clinical care.

In other words, doctors are being increasingly scrutinized in the way that public schoolteachers are scrutinized these days. And, like schoolteachers, doctors are increasingly worried that the metrics applied to them are not fair. Are apples being compared to oranges?

Endocrinologists are especially concerned about a metric which evaluates a doctor's success in caring for diabetes patients, simply by looking at the hemoglobin A1c test results of their patients. The statistics seem to show that endocrinologists do worse than other doctors, in that their diabetes patients tend to have higher A1c values.

Not so fast, say the endocrinologists! Some diabetes patients end up seeing an endocrinologist, and some don't (I still haven't been referred to an endocrinologist, after 12 years with diabetes), and the patients who do end up seeing an endocrinologist tend to be the patients whose diabetes is farther out of control. How can it be fair to compare the endocrinologists with general practitioners, if the endocrinologists get the tougher cases? (Essentially it's the same as the complaint we hear from teachers at schools in poor neighborhoods: the students we get aren't like the ones that the schools for rich kids get, so you can't expect them to do as well.)

Data presented recently at the American Diabetes Association's scientific sessions in Chicago indicates that the diabetes patients who are sent to endocrinologists have more difficult cases and need more time to get under control. For example, a large share of diabetes patients who are sent to endocrinologists are insulin-dependent, and it's a lot harder for such patients to hit A1c targets. A1c results above 7% were seen in 66% of patients who were using mealtime insulin, but in only in 21% of patients who weren't. If endocrinologists get more insulin-dependent patients than other doctors do, isn't it pretty much unavoidable that their patients will have higher A1c scores?

I'm inclined to be skeptical of this compulsion to reduce complex situations to simple metrics, in medicine and in most other areas of life. I don't think it's a particularly healthy impulse. It is more likely than not to be a reaction to fatigue: if you're tired of thinking about a complex problem, why not boil it all down to comparing a couple of simple numbers, so that no further observation or analysis is needed? A metric is often the graveyard of thought. We love a metric because it means we don't have to think anymore, and programs based on the desire to stop thinking generally don't lead to great things.

Given the peculiar challenges involved in medical practice, and especially medical practice involving patients whose health care depends heavily on the patient's willingness to adopt a new way of living, I'm not sure there is any fair way to compare doctors based on how well their patients do on a standardized test.

To put it metaphorically, we may need to judge doctors more on their ability to lead a horse to water than on their ability to make the creature drink.

 


Heat Wave

Monday, July 1, 2013

 


The Sun Is Getting Mean

There's a whole lot of nuclear fusion going on, just 93 million miles from here, and all the heat it releases has to go somewhere. A lot of it has been going to the western U.S. in recent days.

Saturday was almost nightmarishly hot (I was at my Dad's place, and when I went outside to light the gas grill, I came right back inside and asked him if actually lighting the thing was strictly necessary, as it seemed to be hot enough to cook ribs on already).

A serious heat wave can be tough to cope with, if you exercise regularly and you do most of your exercise outdoors. Saturday, fortunately, was my rest day from exercise, but Sunday I had a long trail-run planned (it ended up being 8.3 miles). It wasn't as hot as Saturday, and the trail I was running on had a lot of shade on it, so I figured I'd be fine so long as I carried enough water. Still, it was tough, and on the steepest climb felt that I had to walk it for a spell, which I normally don't do. And when I was getting back to my car at the end of the run, I suddenly ran out of gas 0.2 miles from the end and walked back. I didn't feel terrible at either point, but when it's hot I've learned not to ignore a message from my body saying that I'm pushing it too hard and need to give it a break. Trying to force your way through a rough patch when you're exercising in the heat is a good way to end up passing out.

Today it was in the mid 90s; I ran at lunchtime, but I made it a comparatively short route, and I did okay. Earlier today, the forecast for tomorrow was 111 degrees. When I heard that, I thought "there's no way I'm running in that kind of heat!", but the forecast has been downgraded to a repeat of today, so maybe I'll run after all.

Maybe it seems crazy to you that I'd even consider running outside on a hot day, when an air-conditioned gym is available to me. It's hard to describe my feeling about gym workouts, or at least gym aerobic workouts, but somehow they seem to me much harder and more boring, and I never get half as thorough a workout on a treadmill or a stair-climber as I get on the road. So, for me, the gym is a very inferior choice and I always try to avoid it if I can.

I'll play it by ear tomorrow. I'll consider running, but if it feels like it's building up to 100 degrees or more I'll declare an emergency and go to the gym instead.

In terms of diabetic control, heat can be an issue, simply because dehydration tends to reduce insulin sensitivity. Also an issue for diabetes patients: dehydration can produce symptoms which feel like hypoglycemia; you can easily be tricked into taking in sugar when your blood sugar is already high, simply because you feel bad in a way which suggests your blood sugar is low. Under other circumstances, you can probably assume that feeling low means you are low; in a heat wave, don't make that assumption: test! If you feel low and you don't test low, what you're low on may be water.

I'm speaking from experience here. I used to do a lot of long-distance cycling evens, some of them 100 miles or more. Participating in those events and thinking (incorrectly, as it turned out) that I was keeping up well enough on hydration, I ended feeling hypoglycemic and trying to correct it by taking in sugar. Which didn't help, because my problem (as the muscle cramps and weight loss revealed later in the day) was dehydration. It's good to recognize symptoms which typically indicate hypoglycemia, but don't forget that (at least during a heat wave) they might indicate something else entirely.

 


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