The Correlations between Extremity Circumferences with Total and Regional Amounts of Skeletal Muscle and Muscle Strength in Obese Women with Type 2 Diabetes

BACKGROUND Insulin resistance is related to central obesity and the amount of skeletal muscle. A simple and practical anthropometric marker for muscle mass is not known, although waist circumference (WC) is used as an indicator of abdominal obesity. The aims of this study were to investigate whether arm (AC) and thigh circumferences (TC) can be used as an indicator of muscle mass and if they are related to muscle strength. METHODS A total of 110 obese (body mass index [BMI]≥25 kg/m(2)) women with type 2 diabetes were enrolled, and WC, AC, and TC were measured. Abdominal visceral fat (AVF), subcutaneous fat (ASF), and total fat (ATF) were assessed by computed tomography, regional muscle (MM), and fat mass by dual-energy X-ray absorptiometry, muscle strength by one repetition maximum (1RM) of both extremities (chest and leg press) and insulin resistance by K(ITT). RESULTS The mean age was 56.2±7.3 years, duration of diabetes was 4.2±4.4 years, and BMI was 27.2±2.8 kg/m(2). WC was correlated with ATF, AVF, and ASF (r=0.728, P<0.001; r=0.515, P<0.001; r=0.608, P<0.001, respectively). Arm MM was correlated with AC (r=0.500, P<0.001), and leg MM with TC (r=0.291, P=0.002). Upper 1RM was related to AC/WC ratio (r=0.359, P<0.001), and lower 1RM was to TC/WC ratio (r=0.286, P=0.003). Insulin resistance had significant relations with AVF, WC, and total MM (r=-0.262, P=0.008; r=-0.217, P=0.029; r=0.160, P=0.031, respectively). CONCLUSION The muscle mass was related to extremity circumferences, and muscle strength was to extremity/waist circumference ratio in obese women with type 2 diabetes.