Association between obstructive sleep apnea severity and clinical outcomes in COVID-19 patients: a retrospective study

Obstructive sleep apnea (OSA) may influence the clinical course of coronavirus disease 2019 (COVID-19). This study aimed first to determine the prevalence of COVID-19 among patients with polysomnography-confirmed OSA and subsequently to evaluate the association between OSA severity and clinical outcomes in patients with COVID-19. Patients diagnosed with OSA or simple snoring by polysomnography were screened through the hospital database for COVID-19. Demographic and clinical characteristics, hospitalization, mortality, and laboratory parameters were analyzed. Among 431 patients with OSA, 183 (42%) were diagnosed with COVID-19, and complete clinical data were available for 79 patients. The study included 181 patients: 79 with OSA and 102 age-matched controls. Admission peripheral oxygen saturation (SpO₂) and length of hospital stay differed significantly across OSA severity groups ( p < 0.05). Among patients with OSA, those with severe OSA had higher rates of dyspnea and nasal oxygen requirement at admission. In unadjusted analyses, the apnea–hypopnea index (AHI) was positively correlated with length of hospital stay, lactate dehydrogenase, fibrinogen, and C-reactive protein levels and negatively correlated with admission SpO₂. In the multivariable linear regression model, fibrinogen was significantly associated with ln(AHI) (B = 0.00187, p = 0.011), whereas hypertension was not significantly associated ( p = 0.169). In the ordinal logistic regression model, smoking, platelet count, and mean platelet volume were significantly associated with higher ordered study-group categories. These findings indicate that although greater OSA severity was associated with several markers of a more complicated COVID-19 course in unadjusted analyses, many of these associations were attenuated after multivariable adjustment. Further studies with larger cohorts and more complete assessment of potential confounders are needed to clarify the independent contribution of OSA severity to COVID-19 outcomes. Clinical trial number: Not applicable.