Atherosclerosis, diabetes and obesity.

Many post-mortem studies have reported a higher level of atherosclerosis in diabetics. The two most convincing are the International Atherosclerosis Project (Robertson & Strong, 1968) and the Five Towns Study (Zdanov & Vihert, 1976). In the first of these, the influence of many factors, including diabetes, was assessed on the nature and degree of atherosclerosis in more than 34000 autopsies from thirteen national centres, using standardized techniques of preparation and measurement. Diabetics had significantly more fatty streaks in the coronary arteries, though not in the aorta. However, raised lesions were more frequent both in the coronary arteries and the aorta of diabetics. This was true even when cases with other associated conditions, like hypertension, were excluded from the analysis. Diabetics also had more fibrous plaques, more complicated lesions, more calcification and more coronary stenoses than non-diabetics. There was, nevertheless, considerable geographical variation in the prevalence of atherosclerotic lesions in the diabetics, broadly reflecting the prevalence in the populations from which the diabetics were derived. The Five Towns Study was similarly standardized. The extent and severity of atherosclerosis was greater in diabetics than matched non-diabetics, especially in the coronary arteries. Diabetes was also particularly associated with calcified lesions, both in the aorta and in coronary arteries. The combination of diabetes and hypertension was associated with the greatest degree and severity of atherosclerotic lesions. There are many reports in the literature concerning increased mortality and morbidity from arterial disease in diabetics (see Jarrett & Keen, 1975). In the Framingham prospective community study (Garcia et al. 1974) there was increased mortality amongst diabetics from sudden death, cardiac infarction and cerebral vascular disease, There was also an increase in non-fatal events due to coronary, cerebral and peripheral vascular disease amongst the diabetics. Particularly striking was the increased incidence of coronary deaths among female