Risk of Severe COVID-19 Heightened in Patients With Obstructive Sleep Apnea

In Icelandic patients, obstructive sleep apnea were associated with a 2-fold increased risk of severe COVID-19 that required hospitalization or led to death after accounting for obesity and other comorbidities.

Incidence of obstructive sleep apnea (OSA) regardless of obesity or other comorbidities may double the risk of adverse events related to COVID-19, including hospitalization and death. Results were published recently in Sleep.

Associated with several comorbidities known to exacerbate risk of severe COVID-19, OSA has also been proposed as an independent risk factor for adverse outcomes, but researchers note that clinical data reflecting the general population has been scarce.

“Most studies have suggested an association but have been limited by highly selective study populations and/or inability to adequately adjust for important confounding factors,” they wrote. “Confounding is especially important as OSA is known to be strongly associated with male gender, obesity, diabetes mellitus, and heart failure; all of which are well established risk factors for severe COVID-19.”

Seeking to further assess OSA as a potential independent risk factor for severe COVID-19, defined as the composite outcome of hospitalization and death, the study authors examined a population-based cohort of community-dwelling Icelandic citizens 18 years of age and older diagnosed with the virus in 2020 (N = 4756).

Data on demographics, comorbidities, and outcomes of COVID-19 was obtained from centralized national registries, with diagnosis of OSA retrieved from the centralized Sleep Department Registry at Landspitali–The National University Hospital (LUH).

As all Icelandic individuals positive for COVID-19 were treated at the COVID-19 Outpatient Clinic of LUH at the time of diagnosis–the only referral center for OSA diagnosis in Iceland and sole provider of positive airway pressure (PAP) treatment–researchers additionally sought to examine if risk of severe COVID-19 was mitigated in the subgroup of patients with OSA treated with a PAP device.

From those diagnosed with COVID-19, 185 (3.9%) had a diagnosis of OSA. Compared with patients without OSA, those with the condition were older (median age, 59 vs 39 years; P < .001), had higher body mass index (BMI; median, 32 vs 26; P < .001), more likely to be male (72% vs 51%; P < .001), and more likely to have hypertension (44% vs 11%; P < .001), diabetes mellitus (18% vs. 3%; P < .001), chronic kidney disease (9% vs 2%; P < .001), chronic obstructive pulmonary disease (6% vs 1%; P < .001), and heart failure (5% vs. 1%; P < .001).

In total, 238 were hospitalized or died, of which 38 had OSA. After adjusting for age, sex, and BMI, OSA was associated with a more than 2-fold increased risk of severe COVID-19 (OR, 2.2; 95% CI, 1.4-3.5). Researchers then further adjusted for demographic characteristics and various comorbidities, with risk of severe COVID-19 shown to be slightly attenuated but still doubled in patients with OSA (OR, 2.0; 95% CI, 1.2-3.2), compared with those without OSA.

PAP treatment was not found to modify risk of severe COVID-19 in patients with OSA.

Speaking on the study findings, researchers said results are likely to be representative of the general population due to the nationwide study design and the unselected cohort of persons with SARS-CoV-2 infection. “Larger studies are needed to further evaluate different phenotypes of OSA, examine possible pathophysiological mechanisms, and investigate the effect of PAP treatment on outcomes of COVID-19,” they concluded.


Rögnvaldsson KG, Eyþórsson ES, Emilsson OI, et al. Obstructive sleep apnea is an independent risk factor for severe COVID-19: a population-based study. Sleep. Published online November 17, 2021. doi:10.1093/sleep/zsab272