Sex- and BMI-related differences in risk factors for coronary artery disease in patients with type 2 diabetes mellitus

There are contrasting data about the relationship between obesity and macrovascular complications in type 2 diabetes mellitus, and it is not known if risk factors for coronary artery disease are different in normal weight and overweight or obese patients. All 2113 patients with type 2 diabetes mellitus referring to the Diabetic Clinic of Asti were studied. Patients were divided into tertiles of body mass index, according to their sex (BMI < 26.9; ≥ 26.9 and < 31.4; ≥ 31.4 kg/m² for females and BMI < 25.7; ≥ 25.7 and < 28.8; ≥ 28.8 kg/m² for males). Age, BMI, duration of diabetes, blood pressure, HbA_1c total cholesterol, HDL-cholesterol, LDL-cholesterol, and prevalence of insulin treatment and hypertension were higher in females, whereas exercise, alcohol intake, smoking habits and prevalence of dyslipidemia were higher in males. An increase in BMI was associated with an increase in HbA_1c, number of cigarettes/day, blood pressure, triglycerides, C-peptide, prevalence of hypertension and dyslipidemia, and with a decrease in age, duration of diabetes and HDL-cholesterol values. In spite of an apparently worse cardiovascular risk profile, females showed a 50% lower prevalence of CAD than males and the prevalence of CAD was not significantly different in obese compared to other BMI categories. Multiple logistic regression showed that risk factors for CAD were different in males and females and similar in the lower tertiles of BMI, while different in the highest. In obese females, risk factors for CAD were age, reduced HDL-cholesterol and increased HbA_1c levels; in males they were years of smoking and duration of diabetes. These data suggest that in type 2 diabetes, risk factors for CAD are different in the two sexes and in patients with the highest BMI compared to the normal and overweight subjects; blood glucose control and duration of diabetes seem more important than conventional cardiovascular risk factors in obese patients. Received: 11 May 1998 / Accepted in revised form: 30 July 1999