Obstructive sleep apnea is an independent risk factor for severe COVID-19: A population-based study

Abstract

Study Objectives: Obstructive sleep apnea (OSA) has been proposed as a risk factor for severe COVID-19. Confounding is an important consideration as OSA is associated with several known risk factors for severe COVID-19. Our aim was to assess the association of OSA with hospitalization due to COVID-19 using a population-based cohort with detailed information on OSA and comorbidities. Methods: Included were all community-dwelling Icelandic citizens 18 years of age and older diagnosed with SARS-CoV-2 infection in 2020. Data on demographics, comorbidities, and outcomes of COVID-19 was obtained from centralized national registries. Diagnosis of OSA was retrieved from the centralized Sleep Department Registry at Landspitali - The National University Hospital. Severe COVID-19 was defined as the composite outcome of hospitalization and death. The associations between OSA and the outcome were expressed as odds ratios (OR) with 95% confidence intervals (95% CI), calculated using logistic regression models and inverse probability weighting. Results: A total of 4,756 individuals diagnosed with SARS-CoV-2 infection in Iceland were included in the study (1.3% of the Icelandic population), of whom 185 had a diagnosis of OSA. In total, 238 were hospitalized or died, 38 of whom had OSA. Adjusted for age, sex, and BMI, OSA was associated with poor outcome (OR 2.2, 95% CI 1.4-3.5). This association was slightly attenuated (OR 2.0, 95% CI 2.0, 1.2-3.2) when adjusted for demographic characteristics and various comorbidities. Conclusions: OSA was associated with twofold increase in risk of severe COVID-19, and the association was not explained by obesity or other comorbidities. Statement of Significance Obstructive sleep apnea (OSA) has been proposed as a risk factor for severe COVID-19. However, previous studies have lacked comprehensive information on comorbidities, have not been population-based and do not sufficiently address possible confounding. In this nationwide study, diagnoses recorded in primary care services, private specialty practice and from hospitals were combined and supplemented with information from telehealth enrollment interviews to obtain an accurate estimate of comorbidities. OSA was associated with a twofold increase in risk of severe COVID-19, a finding that was not explained by obesity or other comorbidities.