Abnormalities of cholesterol metabolism in diabetes.

The basic lesion leading to the high morbidity and mortality in diabetes is atherosclerosis. The histological picture of atherosclerosis in the diabetic is similar to that found in the non-diabetic, yet atherosclerosis is more frequent and more severe in diabetes (West, 1978; Krolewski et al. 1987a,h). Gangrene of the foot is five times more common and myocardial infarction and strokes are also more frequent than in non-diabetic subjects (Fuller et al. 1983; Brand et al. 1989). The relationship between cholesterol and atherosclerosis is well known in the non-diabetic population. For example, Castelli et al. (1986) reporting on the famous Framingham study, in which about 5000 men and women between 30 and 60 years of age on entry to the study were followed and reviewed at regular intervals, found that there was a direct and independent relationship between elevated serum cholesterol levels and symptoms suggestive of atherosclerosis. In the diabetic population Brand et al. (1989) examined the incidence of diabetes in intermittent claudication in 1813 men and 2004 women during a 34-year follow-up. For both sexes diabetes was associated with a two-threefold excess risk of intermittent claudication compared with its absence. Reckless ef al. (1978) have shown that the connection between lipoprotein-cholesterol and the prevalence of vascular disease in the diabetic patient is the same as the non-diabetic, but it is not known why the diabetic with similar lipid profile to his non-diabetic counterpart is much more at risk of developing atherosclerosis. For this reason, there has been a proliferation of research work on more complex alterations in lipoprotein-cholesterol in the diabetic in an effort to understand the way in which diabetes speeds up the atherogenic process.