First degree family history of diabetes and risk factors for cardiovascular disease in non-diabetic subjects in the National Telephone Company: a metabolic survey.

The effect of first degree family history of diabetes on known risk factors for cardiovascular disease was evaluated in 4989 non-diabetic employees of the Italian Telephone Company. Family history of diabetes was present in 759 subjects (476 males and 283 females); in these subjects body mass index, diastolic blood pressure, blood glucose levels (fasting and one and two-hour post-load), triglyceride and cholesterol levels were significantly higher than in age and sex-matched controls. In different age groups (less than 30, 31-40, 41-50, greater than 50 years) the effect of first degree family history of diabetes was evaluated after stratification by sex. In males with first degree family history of diabetes, this effect was strongest in the under 30 age group: body mass indices, systolic and diastolic blood pressures, fasting and two-hour post-load blood glucose levels, triglyceride and cholesterol levels were all significantly higher than in subjects with negative family history of diabetes. These differences between subjects with negative and positive family histories declined with age and disappeared in subjects over 50. In females the effect of familial diabetes was weaker and delayed for body mass index and one hour blood glucose, appearing only in subjects over 30. Multiple logistic analysis indicated that only body mass index and one-hour blood glucose levels were independently associated with positive family history of diabetes. The differences observed between males and females in the youngest age group were also confirmed by this analysis. These data may indicate a multifactorial genetic link leading to increased cardiovascular morbidity in subjects with diabetes.