Prevalence of diabetes mellitus, coronary heart disease and hypertension in the families of insulin dependent and insulin independent diabetics.

During an epidemiological study concerning the fate of diabetics in Warsaw, 2,356 subjects (aged 35-68 years with duration of diabetes mellitus of 3-11 years) were investigated with particular relevance to the presence of diabetes mellitus, coronary heart disease, and hypertension in their parents and siblings. Diabetics were classified into the following groups: insulin dependent, insulin independent nonobese, insulin independent obese, and a group in whom the distinction between insulin dependence and insulin independence was unclear. The findings in these groups were compared with the frequencies of these diseases in a random sample of general population. There was an excess of diabetes in close relatives of all the diabetic groups. This was highest for insulin independent non-obese diabetics. There was no difference in the prevalence of coronary heart disease and hypertension in close relatives of insulin dependent diabetics when compared with the general population, but these were twice as prevalent in close relatives of the insulin independent non-obese group. Obese insulin independent diabetics reported a similar excess of coronary heart disease and hypertension in siblings, but the excess was less marked in parents. The prevalence of these diseases in families of probands with unclassified diabetes was intermediate between the other two groups. The results demonstrate an aggregation of diabetes mellitus with coronary heart disease and hypertension in families of insulin independent non-obese diabetics. This provides further evidence for heterogeneity in diabetes mellitus.