Nearly a decade worth of studies, with another one just published (online first), June 3, 2010, have explored the effectiveness of using one or a combination of two blood-glucose (BG) lowering medications (approved for type 2 diabetes) to prevent and/or delay the onset of type 2 diabetes in people with prediabetes or at high risk of type 2. These studies have used Actos (pioglitazone), Avandia (rosiglitazone), metformin, and others. The latest study, CAnadian Normoglycemia Outcomes Evaluation, abbreviated as CANOE, used a combination of Avandia and metformin.
Yes, most of these studies demonstrate an ability to slow the progression to type 2 diabetes. That’s great and I’m all for zeroing in on any and all effective treatments for the nearly 80 million people with prediabetes in the U.S. alone (a mere 35% of the adults over 20 yrs according to CDC). But are these drugs being studied fair and square? I don't believe so for two reasons I detail below. These studies, in their design, give the usual Lip Service to Lifestyle Change promoting the commonly held notion that lifestyle intervention is just so costly and labor-intensive. Yes, that’s in part true but in part a cop out as well. But look closer at how these drugs are, or more accurately, not studied, fair and square.
Reason #1: The effectiveness of the BG lowering medication(s) are not compared in studies with a group of people using intensive lifestyle intervention, such as the successful model used in the NIH-Diabetes Prevention Program (DPP) study and other prevention studies. The drug(s) are just compared with a group of people (placebo) being given standard lip service lifestyle advice (which we know very well doesn’t work well!).
When it comes to lifestyle change, what we do know works well from the DPP study is intensive lifestyle intervention/ This consists of frequent visits with behavior change experts and regular follow up to help people change behavior regarding healthy eating and regular physical activity to achieve 5 to 7% weight loss. Intensive lifestyle intervention was more successful at reducing the progression to type 2 diabetes during the three initial years of the study (reducing incidence by 58%) vs. metformin (paired with limited lifestyle intervention) which only decreased the incidence by 31% (about half as successful as intensive lifestyle intervention). There’s now follow up data from the DPPOS showing that people who were in the intensive lifestyle group continued to have the greatest reduction in progressing to type 2 diabetes over 10 years.
Could the reason intensive lifestyle change efforts are given lip service in these studies (and unfortunately by so many healthcare providers in general) is that the researchers (and pharmaceutical companies) don’t really want to know the results of a study which stacks their drug against intensive lifestyle? My bet is yes!
Reason #2: Effectiveness of these medications have never (to the best of my knowledge) been studied paired with intensive lifestyle intervention. Why? Isn’t it fairly obvious that pairing a successful lifestyle intervention with a successful BG lowering medication(s) would produce positive outcomes (albeit more challenging data to sort out)? Aren’t researchers curious about the outcome of this type of study? Or are we just so resigned to eventually treating prediabetes with medications vs. assisting and supporting people to make the all important lifestyle changes? When I ask this question of researchers a response I often get is “Oh, you’re correct, this should be done (or should have been done) but this type of study would be very expensive.”
Yes, let’s continue to find cost-effective and clinically-effective ways to help the millions of people at high risk of type 2 diabetes. But let’s study pharmaceutical agents aimed at slowing the progression of type 2 diabetes fair and square…against or paired with intensive lifestyle intervention. Let’s keep in mind that intensive lifestyle interventions are effective for far more than simply preventing or delaying the progression to type 2 diabetes – blood lipid and blood pressure management for starters, as well as many other weight-related problems. And add into the mix that using intensive lifestyle iinterventions typically causes no negative side effects, as many medications do.
So, let’s just not give lip service to intensive lifestyle interventions for prediabetes in both clinical studies and in clinical practice. I know I’ll keep raising this question when the opportunity arises. Please join with me.