July 9th, 2013
Look AHEAD: More Questions Than Answers
Lifestyle approaches have long been the cornerstone of diabetes care. The diabetes epidemic has been driven largely by increasing obesity and changes in lifestyle; it follows logically that changing lifestyle should prevent and treat diabetes. Indeed, we know that lifestyle interventions reduce weight, improve well-being, decrease risk of diabetes, and can sometimes lead to remission of type 2 diabetes. However, it has been unclear whether lifestyle interventions for weight loss actually reduce cardiovascular events, the leading cause of morbidity and mortality in type 2 diabetes. The Look AHEAD study examined this very question and found that an intensive lifestyle intervention led to greater weight loss compared with a conventional diabetes support and education strategy among overweight or obese patients with type 2 diabetes, but did not result in a reduced rate of cardiovascular events. What do these findings mean for patients and health care systems?
First, should we hold lifestyle interventions to the same high standards of scrutiny as pharmacological interventions? It’s true that the primary outcome was negative, but there were many secondary outcomes that improved with the lifestyle intervention. This type of evidence should not be sufficient to approve a new drug, but isn’t it enough to promote changes in lifestyle? The safety of lifestyle interventions seems relatively well established. In fact, there seems to be little downside to encouraging diabetes patients to embark on an intensive lifestyle plan aimed at weight reduction. But, despite the fact that lifestyle interventions are overwhelmingly safer and less likely to result in adverse effects than are medications, there are potential downsides. We have to be fairly confident that lifestyle interventions are worth the cost, effort, and burden they impose – and this requires that we hold them to a relatively high standard when we evaluate their impact.
Second, don’t we already have enough evidence about the impact of lifestyle interventions to implement them in care? I admit that I am still enthusiastic about promoting lifestyle changes for my diabetes patients despite the fact that the primary outcome of the large, well-designed, long-term randomized controlled trial was negative. To me, this suggests that the trial may not have a huge impact on clinical practice – we already know that losing weight and exercising is good for health. Alternatively, I may be experiencing cognitive dissonance and unwilling to admit it!
The third question I will leave up for debate. I may be convinced about the benefits of lifestyle interventions, but will health care systems be willing to pay for them given the results of Look AHEAD?