[Fasting glycosylated hemoglobin A1c and behavior of blood sugar and blood insulin after oral glucose tolerance test in subjects with a family history of diabetes].

In a group of subjects with a known family history of diabetes (subjects with high risk of diabetes) and in two control groups, one of normal subjects and the other of poorly controlled insulin-dependent diabetic patients, all with normal blood levels of cholesterol and triglyceride, the fasting HbA1c concentration and the glycemic and insulin response to OGTT (1 g/kg of body weight) were studied. A prompt increase in serum insulin was observed both in normals and in subjects with a known family history of diabetes (poor in diabetics, of course), but insulin peak was significantly higher in the second ones. As in diabetes patients as in subjects with a known family history of diabetes, the HbA1c levels were significantly higher than in normal subjects, but significantly less high in subjects with a known family history of diabetes than in diabetics. These data might suggest that the prediabetic states generally joint with hyperinsulinemia and the HbA1c determination could contribute to the selection of those prediabetic states.