Last year, we discussed an early article proposing that sleep apnea significantly increased risks of COVID hospitalization. However, we believed this study had several problems. First, it had too small a population size. Second, it was in early review and hadn’t yet been through peer review (the process when other scientists look critically at a study and its data).

Now a newly published study in the Journal of the American Medical Association’s JAMA Network Open imprint confirms that sleep apnea might be linked to worse COVID outcomes (hospitalization and death). This highly prestigious journal has very selective criteria for publication, showing that this article’s conclusions are quite reliable. 

woman laying on couch, suffering headache and cold

Looking at a starting population of more than 350,000, the study focused on 5402 patients who had available sleep studies–the definitive diagnostic tool for sleep apnea. The study showed that people with sleep apnea were not significantly more likely to contract COVID. However, people with sleep apnea were significantly more likely to be hospitalized for and/or die of COVID.

Statistical analysis showed this increased risk was linked to sleep apnea and not to secondary conditions like heart disease. 

Sleep Apnea Doesn’t Increase Risk of Catching COVID

Researchers first wanted to answer whether sleep apnea made it more likely for people to catch COVID. Out of the 350,710 individuals tested for COVID in the Cleveland Clinic’s health system, 5402 had prior sleep tests, and 1935 of these tested positive for COVID. Those who tested positive had a higher apnea-hypopnea index (AHI), 16.2 compared to 13.6 for those who tested negative.

However, statistical analysis showed this was not significant once other risk factors were taken into account. 

Sleep Apnea Increases Risk of Worse COVID Outcomes

Researchers next wanted to determine whether sleep apnea increased the risk of worse outcomes from COVID-19. They tested this in two different ways.

First, they compared the amount of time a person spent with blood oxygen saturation below 90% to the numerical classification scale for COVID outcomes designed by the World Health Organization (WHO). They found that higher time spent with low oxygen was associated with a 39% higher risk of poor COVID outcomes.

To strengthen their results, researchers then compared the amount of time spent with low oxygen to the risk of hospitalization and/or death from COVID. They found that people who spent more than 1.8% of their sleep time with less than 90% oxygen saturation (about 8½ minutes out of 8 hours’ sleep) were 31% more likely to be hospitalized or die from COVID. More time spent with low oxygen increased the risk further.

These risks remained even after accounting for potential confounding factors like obesity, cardiopulmonary disease, cancer, and smoking. This makes researchers conclude that low oxygen saturation associated with sleep apnea is an independent predictor of worse COVID outcomes.

After looking at potential reasons why sleep apnea might lead to worse COVID outcomes, researchers concluded that systemic inflammation, including elevated levels of C-reactive protein (CRP) levels, was most consistent with their results. 

What This Study Doesn’t Tell Us

Researchers noted that although their study was fairly rigorous, it did have limitations. Because of the way they selected the study population via health records and used mostly health records to analyze their risks, there might have been other confounding factors not listed in the medical records. They also noted that not all sleep tests are equal, and this might have affected their analysis.

Perhaps the biggest limitation of the study, though, is that it can’t tell us whether sleep apnea treatment improves outcomes. Although medical records did include information about CPAP usage for people in this study, researchers didn’t have enough data to make conclusions about this aspect of the disease. They suggest that this would be an important direction for future researchers to focus their attention on. 

Sleep Apnea Sufferers Should Be Considered High Risk

Researchers suggested that their data shows that people with sleep apnea should consider themselves at higher risk for worse outcomes for COVID. Of course, this means that sleep apnea sufferers should follow preventive measures recommended to avoid contracting COVID. People with sleep apnea seeking care at a hospital for COVID should make sure the care providers know about their condition. Hopefully, this should get them appropriately higher levels of care. 

While we don’t know if sleep apnea treatment does help with COVID complications, we do know that it helps with other sleep apnea complications. If you have sleep apnea and are looking for treatment, please contact the Advanced Dental Sleep Treatment Center in Omaha, for help finding the best sleep treatment option for you.