Decreased muscle percentage and increased fat percentage associated with obstructive sleep apnea syndrome severity in males: Insight from body composition and polysomnogram

Objectives: To determine the association between obstructive sleep apnea syndrome (OSAS) severity with the percentages of muscle and fat in males. Methods: A cross-sectional study was performed on 195 eligible males (25–72 years, average age 50). Muscle mass and fat mass were obtained by bioelectrical impedance analysis (BIA), and objective indicators associated with OSAS were recorded by polysomnography. The differences in various indicators (such as body composition) between groups with different severities of OSAS were analyzed, and the correlations between variables are also discussed. Results: The correlation analysis demonstrated that the muscle percentage was negatively associated with the waist-to-hip ratio (r = −0.378, P < 0.01), body mass index (BMI) (r = −0.656, P < 0.01), uric acid level (r = 0.152, P < 0.05), hemoglobin level (r = 0.168, P < 0.05), carbon dioxide (CO2) level (r = 0.152, P < 0.05), and apnea-hypopnea index (AHI) (r = −0.230, P < 0.01). In contrast, the fat percentage was positively correlated with the AHI (r = 0.242, P < 0.01) and was negatively correlated with the extracellular water/total body water (ECW/TBW) ratio (r = −0.187, P < 0.01). Even after adjusting for the ECW/TBW, uric acid, hemoglobin, CO2, and other factors, the AHI showed significant independent linear relationships with the muscle percentage [standardized beta coefficient (β) = -0.029, P = 0.047] and fat percentage (β = 0.036, P = 0.005). Conclusions: The severity of OSAS in males was associated with a decreased muscle percentage and an increased fat percentage.