Change in daily ambulatory activity and cardiovascular events in people with impaired glucose tolerance.

Patients with pre-diabetes have a tenfold higher risk of developing Type 2 DM and a twofold higher risk of developing coronary heart disease compared to non-diabetics. Interventions targeted at those in an early stage of impaired glucose metabolism can delay or prevent diabetes. Effects of these interventions on cardiovascular outcome are unknown. This article aims to review current and available data on lifestyle intervention, specifically physical activity, on cardiovascular outcomes in populations at risk for diabetes. We searched PubMed database from 1990 to present with focus on more recent literature published over the last 2 years. Various permutations of keywords used included glucose intolerance, pre-diabetes, diabetes, lifestyle modifications, physical activity, and cardiovascular disease. Intensive glycemic control, specific medications, and lifestyle intervention including increase in physical activity have been evaluated in diabetes and pre-diabetes. Most studies we reviewed showed that these interventions prevented progression of pre-diabetes to diabetes and improved cardiovascular risk surrogate measures. Direct decrease in cardiovascular mortality, non-fatal stroke, and non-fatal myocardial infarctions was shown in one recent trial. Increase in physical activity has a positive effect on decreasing cardiovascular risk by modifying several important risk factors and may decrease risk of events in pre-diabetics. More randomized high power trials are needed to verify and characterize these effects.