Obstructive sleep apnea is associated with altered skeletal muscle composition using computed tomography-derived indices.

PURPOSE: To examine the association between obstructive sleep apnea (OSA) and skeletal muscle characteristics using computed tomography (CT) imaging.

METHODS

This cross-sectional study included 209 participants who underwent polysomnography and either a chest or abdominal CT. OSA was defined as AHI ≥ 10 events/hour (n = 134) versus the comparison group (AHI < 10, n = 75). Skeletal muscle density (SMD, HU) and skeletal muscle index (SMI, cm²/m²) were assessed at T12-L1. Associations with PSG measures were assessed using correlation and multivariate regression.

RESULTS

OSA was associated with lower SMD (p = 0.012) and higher SMI (p < 0.001). AHI, oxygen desaturation index, and BMI kg/m² correlated negatively with SMD (r = -0.118, -0.255, -0.279; p < 0.03) and positively with SMI (r = 0.346, 0.186, 0.456; p < 0.002). In multivariate analysis, SMD was lower in males (β = -2.58, p = 0.034), age > 60 years (β = -7.73, p < 0.001), and BMI > 30 (β = -5.72, p < 0.001), but not with AHI > 10. SMI was associated with AHI > 10 (β = 1.83, p = 0.029) and BMI > 30 (β = 7.21, p < 0.001), and negatively associated in males (β = -7.74, p < 0.001) and age > 60 (β = -1.78, p = 0.02).

CONCLUSIONS

OSA was associated with lower muscle density and higher muscle mass index in univariate analyses; however, after multivariate adjustment, the association between AHI and muscle density was no longer significant, with age and body weight identified as the primary factors. Further studies are needed to clarify the relationship between metabolic dysfunction, physical activity, and muscle composition in OSA.