Is a family history of diabetes associated with an increased level of cardiovascular risk factors? Studies in healthy people and in subjects with different degree of glucose intolerance.

In order to evaluate whether the presence of a positive family history of diabetes (PFH) may have a negative impact on both glucose metabolism and cardiovascular risk factors, we studied parameters of carbohydrate metabolism (fasting and 2h-plasma glucose, HbA1c) and beta-cell function (fasting insulin and C-peptide), as well as the levels of some established cardiovascular risk factors (total cholesterol and triglycerides, HDL-cholesterol, blood pressure) in 729 subjects who were seen within the frame of a Regional Health Program in Taranto, South Italy. According to the NDDG criteria, 147 men and 235 women had normal glucose tolerance, 54 men and 66 women non-diagnostic OGTT, 65 men and 79 women impaired glucose tolerance, and 45 men and 58 women newly-diagnosed Type 2 diabetes. There was a continuous increase of PFH across the categories of glucose intolerance (p < 0.001). Subjects with PFH were younger (4 years on the average) than subjects without PFH. After adjustment for age, there was no difference in the clinical and metabolic parameters considered across the categories of glucose tolerance between subjects with or without PFH. Only in OGTT-diagnosed diabetics, was the presence of PFH associated with significantly greater levels of total cholesterol and 2h-plasma glucose, as well as a trend for triglycerides and HbA1c to be higher. There was a continuous increase in fasting glucose, HbA1c, insulin and C-peptide across the categories; however, the C-peptide/insulin molar ratio was lowest in OGTT-diagnosed diabetics. There was a graded and significant increase in the levels of cardiovascular risk factors across the categories.(ABSTRACT TRUNCATED AT 250 WORDS)