THURSDAY, March 19, 2026 (HealthDay News) -- Individuals with chronic obstructive pulmonary disease (COPD) with coexisting obstructive sleep apnea (OSAS) have greater impairments in muscle quality and physical performance than those with COPD alone, according to a study recently published in Scientific Reports.
Patrícia Faria Camargo, from Federal University of Sao Carlos in Sao Paulo, Brazil, and colleagues examined the association between nocturnal oxygen desaturation, muscle quality, and functional performance in individuals with COPD with and without coexisting OSAS. A standardized three-day evaluation protocol was performed among 44 participants (22 with COPD; 22 with COPD-OSAS), including clinical assessment, body composition analysis, and pulmonary function testing; cardiac function evaluation and home sleep monitoring; and handgrip strength (HGS) and the six-minute walk test (6MWT).
The researchers found that compared with patients with isolated COPD, those with COPD-OSAS showed significantly reduced 6MWT distance and HGS values. Significant inverse associations with functional performance and muscle quality were exhibited by indices of sleep-disordered breathing. Sex, apnea-hypopnea index, and oxygen desaturation index (ODI) were identified as independent predictors of muscle quality in multivariable regression; after adjustment, ODI represented the strongest contributor.
"The study results indicate that the magnitude of nocturnal oxygen desaturation during sleep is more strongly associated with muscle quality and functional performance than the frequency of respiratory events itself," Camargo said in a statement. "This suggests that intermittent nocturnal hypoxia, by compromising tissue oxygenation, may be a central pathophysiological mechanism in the loss of muscle mass and function in patients with COPD and OSAS, possibly through oxidative stress, systemic inflammation, and muscle metabolic dysfunction."