The role of central fat distribution in coronary artery disease in obesity: comparison of nondiabetic obese, diabetic obese, and normal weight subjects

OBJECTIVE: To investigate the degree of coronary artery disease (CAD) in relation to obesity and fat distribution in obese patients with normal glucose tolerance, in comparison with CAD of diabetic obese patients and of normal weight subjects with CAD. DESIGN: Patients listed for coronary angiography with different body mass index (BMI) with or without diabetes: study of the correlation between severity of coronary damage and fat distribution. SUBJECTS: 92 patients subdivided into: 30 normal glucose tolerant obese (BMI 31.7 +/- 0.5, aged 53 +/- 1.7 y), 28 type 2 diabetic: obese (BMI 30.7 +/- 0.3, aged 57 +/- 1.2 y), and 34 normal weight patients (BMI 23.1 +/- 0.3, aged 54 +/- 1.7 y). MEASUREMENTS: CAD assessed by angiography and evaluated according to the method of Gensini. Fat mass and fat distribution assessed by bioelectrical impedance and anthropometry. Clinical, biochemical and hormonal variables, as well as smoking habits and alcohol intake. RESULTS: The angiographic coronary scores were similar in nondiabetic obese and in diabetic obese patients, and were significantly higher than those of normal weight subjects. In the entire population coronary score correlated with indices of abdominal fat distribution. In the stepwise analysis of each group separately, waist hip ratio (WHR) correlated with coronary score only in normal weight nondiabetic patients. CAD was inversely associated with BMI only in nondiabetic obese patients. CONCLUSION: CAD of obese patients: 1) is similar to that of diabetic obese patients; 2) is more severe than that of normal weight individuals; and 3) is inversely correlated with BMI. CAD appears to be associated with WHR, not with BMI, only in nondiabetic patients with normal body weight. On the contrary, CAD of diabetic obese patients is unrelated to BMI and parameters of fat distribution, but is associated with smoking habits.