Sleep-related hypoxia may worsen COVID-19 outcomes

Sleep-related hypoxia may be a risk factor for detrimental COVID-19 outcomes, according to results of a case-control study published in JAMA Network Open.

“Hypoxia has been identified as an important consequence of COVID-19,” Cinthya Pena Orbea, MD, of the Sleep Disorders Center at Cleveland Clinic in Ohio, told Healio Neurology. “On the other hand, measures of sleep-disordered breathing, such as sleep-related hypoxia, have been associated with worse cardiovascular outcomes. Therefore, we postulated that this measure would be associated with poorer COVID-19 health-related outcomes after adjusting for other confounding factors.”

Pena Orbea and colleagues sought to determine whether sleep-disordered breathing identified using polysomnogram and sleep-related hypoxia correlated with SARS-CoV-2 positivity and WHO-designated COVID-19 clinical outcomes. They examined this potential association while accounting for confounders, including obesity, underlying cardiopulmonary disease, cancer and smoking history. They included all patients with an available sleep study record who were tested for COVID-19 between March 8, 2020, and Nov. 30, 2020, at Cleveland Clinic Health System in Ohio and Florida.

Using overlap propensity score weighting, researchers assessed sleep indices and SARS-CoV-2 positivity. They used the institutional registry to assess COVID-19 clinical outcomes.

Exposures included sleep study-identified sleep-disordered breathing, defined by frequency of apneas and hypopneas via the Apnea-Hypopnea Index (AHI), and sleep-related hypoxemia, defined as percentage of total sleep time at less than 90% oxygen saturation. SARS-CoV-2 infection and WHO-designated COVID-19 clinical outcomes, including hospitalization, supplemental oxygen use, noninvasive ventilation, mechanical ventilation or extracorporeal membrane oxygenation, and death, served as main outcomes and measures.

Data were available for 350,710 individuals tested for SARS-CoV-2, of whom 5,402 (mean age, 56.4 years; 55.6% were women; 31.4% were Black; 60.3% were white; 15.2% were reported as other race or ethnicity) had a prior sleep study. Of those with a prior sleep study, 1,935 tested positive for SARS-CoV-2.

SARS-CoV-2 positivity vs. negativity correlated with higher AHI scores and increased total sleep time at less than 90% oxygen saturation. Overlap propensity score-weighted logistic regression revealed no association between sleep-disordered breathing measures and SARS-CoV-2 positivity. Median total sleep time less than 90% oxygen saturation correlated with the WHO-designated COVID-19 clinical outcome scale (adjusted OR = 1.39; 95% CI, 1.1-1.74). Researchers noted an association between hypoxia and 31% higher rate of hospitalization and mortality (aHR = 1.31; 95% CI, 1.08-1.57), according to time-to-event analyses.

“We found that patients with COVID-19 who had hypoxia during their sleep appeared to be at higher risk for poorer health outcomes, such as increased risk for hospitalization and death, suggesting that risk-stratification strategies among those with sleep-related breathing disorders may be needed,” Pena Orbea said.