Background: Heredity, obesity and fat distribution may interact with each other in their association with diabetes risk. Therefore we tried to elucidate the role of familial diabetes as effect modifier in the association of obesity, glucose metabolism and lipoproteins with non-insulin-dependent diabetes mellitus.
Methods: A cross-sectional study was carried out among 468 elderly men. Within strata of family history, men with diabetes and normal glucose tolerance were compared with respect to anthropometry, characteristics of glucose metabolism and serum lipids.
Results: Of the participants, 14.5 percent were diabetic. In diabetic men a family history of diabetes occurred more often (22.1 percent) than in men with normal (6.8 percent, P < 0.001) or impaired glucose tolerance (8.5 percent). In diabetic men with a family history, the ratio of fasting insulin to glucose and the ratio of areas under the insulin and glucose curves during oral glucose tolerance testing were lower compared to men with normal glucose tolerance. In men without a family history, these differences were smaller (interaction P = 0.06). In diabetic men without a family history, fasting insulin levels were markedly elevated (P < 0.001), whereas in men with a family history there was only a slight elevation. The presence of a family history resulted in more severe deteriorations in lipids, especially in fasting triglycerides (interaction P = 0.075). No interaction between indices of obesity and a family history was observed.
Conclusions: Our findings suggest that elderly diabetic men with a family history of diabetes represent a different subgroup than elderly men without such a history, characterized by larger deteriorations in indices for beta-cell function and higher triglyceride levels.