Effects of acarbose on proinsulin and insulin secretion and their potential significance for the intermediary metabolism and cardiovascular system.

The alpha-glucosidase inhibitor acarbose is administered to control blood glucose levels in type 2 diabetic patients and, in several countries, in those with impaired glucose tolerance. The efficacy and safety of the drug has been well established in these patient populations. Acarbose shows no weakening of efficacy in long-term diabetes treatment, reduces the development of type 2 diabetes in those with impaired glucose tolerance, and also appears to reduce the risk of cardiovascular disease. The underlying mechanisms of its effect on the risk of developing macrovascular complications have still to be elucidated. The mode of action of acarbose, which precedes all other metabolic processes involved in blood glucose regulation, inhibits high increases in postprandial blood glucose. Due to this early mode of action, acarbose also modifies insulin and proinsulin secretion which are both involved in ss-cell dysfunction and insulin resistance and may be independent risk factors for cardiovascular mortality. Based on the literature available the present state of knowledge on insulin and proinsulin as risk factors for cardiovascular mortality is reviewed as well as the effect of acarbose on the regulation of the ss-cells as monotherapy and in combination regimens. Possible associated interactions with the cardiovascular system are identified.