Cardiovascular benefits of acarbose in impaired glucose tolerance and type 2 diabetes

Impaired glucose metabolism is associated with an increased risk of cardiovascular events and cardiovascular-associated mortality. Postprandial hyperglycaemia is one of the earliest identifiable indicators of impaired glucose control. It contributes to the progression from impaired glucose tolerance to overt type 2 diabetes and exacerbates chronic hyperglycaemia in established diabetes. It is also an independent risk factor for cardiovascular disease in patients with impaired glucose tolerance and type 2 diabetes. Thus, an important strategy to reduce cardiovascular risk in patients with impaired glucose metabolism is to reduce postprandial glucose excursions. Acarbose, an alpha (α)-glucosidase inhibitor, reduces postprandial hyperglycaemia by delaying carbohydrate absorption from the small intestine. This mechanism of action provides glycaemic control without increasing insulin levels and exacerbating coexisting cardiovascular risk factors. The Study to Prevent Non-Insulin Dependent Diabetes Mellitus (STOP-NIDDM) assessed the ability of acarbose to reduce cardiovascular risk. In this study of 1429 individuals with impaired glucose tolerance, acarbose therapy reduced the risk of any cardiovascular event by 49% (P = 0.03), of an acute myocardial infarction by 91% (P = 0.02) and of developing hypertension by 34% (P = 0.006). Furthermore, a retrospective meta-analysis of randomised studies of acarbose in type 2 diabetes patients showed that acarbose therapy reduced the risk of any cardiovascular event by 35% (P = 0.006) and the risk of a myocardial infarction by 64% (P = 0.012). These results suggest that acarbose is useful in reducing the risk of cardiovascular events in patients with impaired glucose metabolism.