Associations of fat, bone, and muscle indices with disease severity in patients with obstructive sleep apnea hypopnea syndrome.

Purpose: To investigate the relationship between obstructive sleep apnea hypopnea syndrome (OSAHS) severity and fat, bone, and muscle indices.

Methods: This study included 102 patients with OSAHS and retrospectively reviewed their physical examination data. All patients underwent polysomnography, body composition analysis, dual-energy X-ray absorptiometry, computed tomography (CT) and blood test. Correlation and multiple linear regression analyses were performed using SPSS 22.0.

Results: Among the fat indices, fat mass (FM) (r = 0.27-0.43), body fat percentage (BFP) (r = 0. 25-0.35), visceral fat area (VFA) (r = 0.28-0.40) and trunk fat mass (TFM) (r = 0.26-0.34) were positively correlated with hypopnea index (HI), apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and percent of time spent with oxygen saturation below 90% (T90%), respectively, and negatively correlated with mean pulse oxygen saturation (SpO₂) (r= -0.28--0.41). For bone indexes, T8, T9, T11, L1-CT value, mean vertebral CT value and 25-Hydroxyvitamin D3 were positively correlated with mean SpO₂ (r = 0.23-0.32), respectively. For muscle indexes, pectoralis muscle density (PMD) was negatively correlated with HI, AHI, and ODI (r= -0.20--0.36) and positively correlated with mean SpO₂ (r = 0.26). In separate models predicting sleep measures, AHI increased by 0.36, 0.29, 0.34 and 0.25 events/h per unit increase in FM, BFP, VFA, and triglyceride (TG), respectively. AHI decreased by 0.27 per unit increase in PMD. T90% increased with FM, BFP, VFA, WHR, TG and total cholesterol (TC), but decreased with appendicular skeletal muscle mass (ASM) and PMD respectively.

Conclusion: Higher fat levels and lower vertebral CT values, muscle mass and density correlated with a higher degree of OSAHS severity. Intermittent hypoxia may affect fat, bone, and muscle metabolism in patients with OSAHS.