Joint impact of muscle mass and waist circumference on type 2 diabetes in Japanese middle-aged adults: The Circulatory Risk in Communities Study (CIRCS).

Abstract

Although evidence about skeletal muscle mass loss and type 2 diabetes risk has accumulated, little information is available on the combined effect of skeletal muscle mass and abdominal obesity on type 2 diabetes. We examined whether skeletal muscle mass and abdominal obesity were synergistically associated with the prevalence of type 2 diabetes. Skeletal muscle mass and waist circumference (WC) were measured in 1515 Japanese aged 40 to 69 years. Relative muscle mass was calculated as percentage of total skeletal muscle mass in body weight (SMM%). Type 2 diabetes was identified as fasting serum glucose ≥7.0 mmol/L (126 mg/dL), nonfasting serum glucose ≥11.1 mmol/L (200 mg/dL), glycosylated hemoglobin ≥ 6.5%, and/or diabetes medication use. The multivariable-adjusted odds ratio (OR) of prevalent diabetes from the lowest to the third quartile of SMM% compared to the highest quartile gradually increased in both sexes. The association between a high WC and prevalent diabetes was similar. The multivariable-adjusted OR (95% confidence intervals) for the prevalence of type 2 diabetes in the low skeletal muscle mass/high WC group was 3.19 (1.78-5.71) for men and 4.46 (2.09-9.51) for women compared with the high skeletal muscle mass/low WC group. The relative excess risk due to interaction was 2.2 (0.5-3.9) in men and 2.8 (0.2-5.3) in women for an excess burden of type 2 diabetes for low skeletal muscle mass and high WC. Low skeletal muscle mass and abdominal obesity were synergistically associated with presence of type 2 diabetes.