Epidemiological evidence for the association of hyperglycaemia and atherosclerotic vascular disease in non-insulin-dependent diabetes mellitus.

Non-insulin-dependent diabetes mellitus (NIDDM) increases the risk for all manifestations of atherosclerotic vascular disease, coronary heart disease (CHD), cerebrovascular disease and peripheral vascular disease. Only a small proportion of this excess risk can be explained by the effects of conventional cardiovascular risk factors, which implies that the diabetic state or factors related to it have to play a significant role in the pathogenesis of macrovascular disease in NIDDM. Six recent prospective population-based studies including a large number of NIDDM patients have indicated that poor glycaemic control evaluated by fasting hyperglycaemia or glycosylated haemoglobin levels increases the risk for CHD, stroke and amputation independently of other risk factors. A dose-response relationship between markers of glycaemic control and the incidence of cardiovascular mortality and morbidity has been demonstrated in all these studies. However, there is so far no direct proof that strict glycaemic control would delay or prevent atherosclerotic complications.