Regional abdominal fat distribution in lean and obese Thai type 2 diabetic women: relationships with insulin sensitivity and cardiovascular risk factors

To determine the relationships of body fat distribution and insulin sensitivity and cardiovascular risk factors in lean and obese Thai type 2 diabetic women, 9 lean and 11 obese subjects, with respective mean age 41.7 +/- 6.3 (SD) and 48.0 +/- 8.5 years, and mean body mass index (BMI) 23.5 +/- 1.8 and 30.3 +/- 3.7 kg/m2, were studied. The amount of total body fat (TBF) and total abdominal fat (AF) were measured by dual-energy x-ray absorptiometer, whereas subcutaneous (SAF) and visceral abdominal fat areas (VAF) were measured by computerized tomography (CT) of the abdomen at the L4-L5 level. Insulin sensitivity was determined by euglycemic hyperinsulinemic clamp. Cardiovascular risk factors, which included fasting and post-glucose challenged plasma glucose and insulin, systolic (SBP) and diastolic blood pressure (DBP), lipid profile, fibrinogen, and uric acid, were also determined. VAF was inversely correlated with insulin sensitivity as determined by glucose infusion rate (GIR) during the clamp, in both lean (r=-0.8821; P=.009) and obese subjects (r=-0.582; P=.078) independent of percent TBF. SAF and TBF were not correlated with GIR. With regards to cardiovascular risk factors, VAF was correlated with SBP (r=0.5279; P=.024) and DBP (r=0.6492; P=.004), fasting insulin (r=0.7256; P=.001) and uric acid (r=0.4963; P=.036) after adjustment for percent TBF. In contrast, TBF was correlated with fasting insulin (r=0.517; P=.023), area under the curve (AUC) of insulin (r=0.625; P=.004), triglyceride (TG) (r=0.668; P=.002), and uric acid (r=0.49; P=.033). GIR was not correlated with any of cardiovascular risk factors independent of VAF. In conclusion, VAF was a strong determinant of insulin sensitivity and several cardiovascular risk factors in both lean and obese Thai type 2 diabetic women.