Tuesday, March 16, 2010

What? No request for more grant money??

Here's a rare science/medicine story that doesn't end with a plea for more money for further study. Indeed, the answer is clear -- but it has been for decades.

"No quick drug fix for diabetes risk", the BBC story is entitled. (There's a different take on this story in the NYTimes, in which Gina Kolata concentrates on potential harm from the drugs under investigation.) A study published in two parts the New England Journal of Medicine (here and here) of 9300 people defined as 'pre-diabetic' (meaning they are beginning to stop responding to insulin) comparing two medications with a placebo showed no difference in the proportion of either group who went on to develop diabetes and subsequent heart disease. "Researchers said the results showed the only way to ensure future health in people at high risk of diabetes was exercise and a healthy diet." And, rather than asking for more money for an even larger study, they call for an increase in money for preventive care.

Why are they sure that prevention is the best cure? We were interested to note that part of the treatment for people in this study in either the group receiving drugs or the group receiving placebo was 'lifestyle intervention'. That is, they asked all subjects to add a 5% reduction in weight and 150 minutes of exercise per week to their drug regimen. Rigorously done, from what is known from other studies about the significant effects of lifestyle changes on risk of obesity and diabetes, this could have made interpretation of the results of drug intervention difficult. But in fact in this study, subjects were followed up only once a year, and, as the accompanying NEJM editorial suggests, lifestyle changes must have been minimal, since, contrary to expectation, risk of diabetes was not significantly lowered in this study.

Ironically, that inference itself assumes what's being tested -- a real no-no in science!, namely, that lifestyle is the cause. That may be right, but it's not right to assume!

And, indeed, the researchers' conclusion that lifestyle modification was more effective at reducing risk of diabetes and cardiovascular disease than the two tested compounds was based on these other studies, not their own -- something they couldn't have shown, given their study design.

So, in fact what we learn from this large and expensive study are things we already knew. Once or twice, such confirmation is a powerful tool for science. But enough repetition is enough!

It is pretty clear, based on what previous studies have shown, that diabetes and its complications are best prevented by diet and exercise.  But, lifestyle changes are easy to explain but hard to implement. We repeat what a colleague once told us; it might well be cheaper to give everyone at risk of diabetes a personal trainer than to continue doing studies that show, in effect, that everyone should have a personal trainer.

But maybe there's progress -- at least the researchers aren't asking for more money to confirm their results.

**Update:  As we've said before (e.g., here), it's looking as though inflammation may be the underlying process behind more and more chronic diseases.  Today's NYTimes reports that this may be true for type 2 diabetes, as well.  Study subjects taking a cheap generic anti inflammatory related to aspirin were able to lower their blood glucose levels far more than those on placebo.  The idea is that obesity may induce inflammation, which then induces insulin resistance. In this case, however, the researchers conclude that "more research is needed."

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