Prevention of type 2 diabetes mellitus: is it feasible?

The increasing global prevalence of type 2 diabetes mellitus (T2DM) requires the implementation of preventive strategies to halt this trend, tailored to the specific needs of individual regions. Risk factors for T2DM are among the main targets for improving health outcomes and curbing the development of diabetes; excessive weight and obesity are two of the most important risk factors that need to be addressed. A growing body of evidence suggests that subjects with pre-diabetes who lose body weight and increase physical activity can delay or prevent the onset of T2DM, and in some cases, blood glucose levels may return to normal. Several studies have shown that moderate to intensive levels of exercise are effective in reducing both intra-abdominal and total adiposity among obese subjects, both improving cardiovascular risk profile and reducing the risk of T2DM development. These consistent observations have given rise to large-scale randomized controlled trials that use lifestyle intervention (including behavioural strategies for the reinforcement of prescribed changes in nutritional intake, physical activity or both), with or without pharmacological treatment, in populations at high risk of developing T2DM. In this review, large-scale national trials that have focused on the prevention of T2DM are critically evaluated.