Association between regional adipose tissue distribution and both type 2 diabetes and impaired glucose tolerance in elderly men and women.

OBJECTIVE We examined whether regional adipose tissue distribution, specifically that of skeletal muscle fat and visceral abdominal fat aggregation, is characteristic of elderly individuals with hyperinsulinemia, type 2 diabetes, and impaired glucose tolerance (IGT). RESEARCH DESIGN AND METHODS A total of 2,964 elderly men and women (mean age 73.6 years) were recruited for cross-sectional comparisons of diabetes or glucose tolerance, generalized obesity with dual-energy X-ray absorptiometry, and regional body fat distribution with computed tomography. RESULTS-Approximately one-third of men with type 2 diabetes and less than half of women with type 2 diabetes were obese (BMI > or =30 kg/m(2)). Despite similar amounts of subcutaneous thigh fat, intermuscular fat was higher in subjects with type 2 diabetes and IGT than in subjects with normal glucose tolerance (NGT) (11.2 +/- 9.4, 10.3 +/- 5.8, and 9.2 +/- 5.9 cm(2) for men; 12.1 +/- 6.1, 10.9 +/- 6.5, and 9.4 +/- 5.3 cm(2) for women; both P < 0.0001). Visceral abdominal fat was also higher in men and women with type 2 diabetes and IGT than in subjects with NGT (172 +/- 79, 163 +/- 72, and 145 +/- 66 cm(2) for men; 162 +/- 66, 141 +/- 60, and 116 +/- 54 cm(2) for women; both P < 0.0001 across groups). Higher rates of intermuscular fat and visceral abdominal fat were associated with higher fasting insulin in normal-weight (BMI <25 kg/m(2)) men (r = 0.24 for intermuscular fat, r = 0.37 for visceral abdominal fat, both P < 0.0001) and women (r = 0.20 for intermuscular fat, r = 0.40 for visceral abdominal fat, both P < 0.0001). These associations were not found in obese subjects. CONCLUSIONS Elderly men and women with normal body weight may be at risk for metabolic abnormalities, including type 2 diabetes, if they possess an inordinate amount of muscle fat or visceral abdominal fat.