Effects of Lifestyle Changes to Reduce Risks of Diabetes and Associated Cardiovascular Risks: Results from Large Scale Efficacy Trials

The increasing prevalence of type 2 diabetes throughout the world is now recognized as a major health problem. A growing segment of the population has impaired glucose tolerance (IGT), which is a strong predictor of progression to type 2 diabetes. Further, 24% of Americans now meet the criteria for the metabolic syndrome, a risk factor for both type 2 diabetes and cardiovascular disease (CVD). The diabetes epidemic is associated with changes in lifestyle-most notably increased energy intake, changes in diet composition and decreased levels of physical activity-and the development of overweight and obesity. This review examines the effects of several intensive lifestyle intervention trials on the risk of diabetes and CVD among high-risk populations. Common features of these lifestyle interventions are dietary modification, weight loss and increased physical activity. These trials indicate that lifestyle modification is effective in decreasing the progression from IGT to type 2 diabetes and reducing CVD risk factors. However, the effectiveness of lifestyle interventions for reductions in CVD events has yet to be determined.