Effect of aerobic exercise on plasma adiponectin levels and insulin resistance in type 2 diabetes.

A erobic exercise is a generally accepted therapeutic strategy for type 2 diabetes because it has beneficial effects not only on glycemic profile, but also on reducing metabolic risk factors for cardiovascular diseases including insulin resistance. Previous studies (1,2) have showed the effects of moderate-intensity exercise on the improvement of insulin sensitivity. Adiponectin, a protein secreted by adipose tissue, presents lower plasma levels in subjects with obesity or type 2 diabetes and is closely correlated with the degree of insulin resistance assessed by the glucose clamp technique (3). Adiponectin also plays a protective role against the development of atherosclerosis by suppressing inflammatory processes on the vascular endothelium (4,5). Therefore, adiponectin is a candidate link between insulin resistance and the high risk of cardiovascular diseases in type 2 diabetes. To date, however, little is known about whether the improvement in insulin resistance induced by short-term aerobic exercise is associated with changes in plasma adiponectin in type 2 diabetes. Only a few reports (6,7) have examined the acute or chronic effect of highintensity exercise on plasma adiponectin, mainly in healthy subjects using surrogate insulin resistance indexes. The aim of this study was to assess the effect of aerobic exercise on plasma adiponectin in relation to the improvement of insulin sensitivity in the euglycemic-hyperinsulinemic clamp in type 2 diabetes.