Abstract

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 ≥30 kg/m2). 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 cm2 for men; 12.1 ± 6.1, 10.9 ± 6.5, and 9.4 ± 5.3 cm2 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 cm2 for men; 162 ± 66, 141 ± 60, and 116 ± 54 cm2 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/m2) 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.