Lower skeletal muscle mass is associated with diabetes and insulin resistance: A cross-sectional study

Aims: The association between skeletal muscle mass and diabetes incidence/insulin resistance/glycated hemoglobin (HbA1C) is unknown. The aim of this study was to investigate such association in clinically apparently healthy males and females. Methods: A cross-sectional study of 372,399 Korean males and females who completed bioelectrical impedance analysis (BIA) in a health-screening programme was performed. Skeletal muscle index was used as an indicator of skeletal muscle mass. Skeletal muscle index (%) [appendicular skeletal muscle mass (kg)/body weight (kg)X100] was estimated using BIA. The study outcomes were diabetes incidence, homoeostasis model assessment of insulin resistance (HOMA-IR), and HbA1C. Results: The mean age of study participants was 38.92 ± 8.54 years. Multiple logistic regression analysis revealed a significant negative association between Skeletal muscle index and diabetes incidence/HOMA-IR/HbA1C after adjusting for various confounding factors. Odds ratios (95% confidence interval (CI)) of diabetes incidence in Q2, Q3, and Q4 compared to the lowest quantile (Q1) were 0.95 (0.85–1.05), 0.88 (0.78–0.99), and 0.79 (0.69–0.9), respectively. Beta coefficients (95% CI) of HOMA-IR in Q2, Q3, and Q3 with Q1 were 0.05 (0.03–0.07), −0.06 (−0.09∼−0.04), and −0.19 (−0.22∼−0.16), respectively. Beta coefficients (95% CI) of HbA1C in Q2, Q3, and Q4 with Q1 were 0.02 (0.01–0.03), −0.001 (−0.01∼0.01), and −0.02 (−0.03∼−0.01), respectively. Conclusions: This study demonstrated negative associations of skeletal muscle mass with diabetes incidence, insulin resistance, and HbA1C levels in healthy adults.