Does intra-abdominal adipose tissue in black men determine whether NIDDM is insulin-resistant or insulin-sensitive?
Insulin resistance in black Americans with non-insulin-dependent diabetes mellitus (NIDDM) is found in only 60% of those with a body mass index (BMI) of < 30 kg/m2, suggesting that NIDDM can occur independent of peripheral insulin resistance. When insulin resistance is present, it is not necessarily correlated with obesity. Numerous studies have shown that increased amounts of intra-abdominal adipose tissue are associated with various metabolic abnormalities. We therefore investigated whether the occurrence of insulin resistance in black NIDDM men could be explained by the pattern of body adipose tissue distribution rather than total adiposity. Twenty-two near-normoglycemic black men (fasting plasma glucose [mean +/- SD] = 104 +/- 10 mg/dl, HbA1c = 4.6 +/- 0.78%, age 48.9 +/- 9.2 years, and BMI 26.5 +/- 2.4 kg/m2) were studied. The euglycemic insulin clamp with 1 mU.kg-1.min-1 insulin infusion and D-[3-3H]glucose was used to measure insulin action. Whole-body computed tomography with 2
