“As the COVID-19 pandemic continues, and the disease remains highly variable from patient to patient, it is critical to improve our ability to predict who will have more severe illness so that we can appropriately allocate resources,” says Dr. Reena Mehra.
Dr. Mehra is the senior investigator of the new Cleveland Clinic study, which has identified certain sleep disorders as factors that may result in more severe COVID-19 outcomes.
The study finds that people with COVID-19 who experience sleep disordered breathing have a 31% higher likelihood of hospitalization and death.
The study authors write, “Chronic exposure to sleep-related hypoxia may serve as a priming mechanism to the untoward consequences of COVID-19 illness.”
The study’s lead author, Dr. Cinthya Peña Orbea, explained to Medical News Today:
“It is possible that increased hypoxia caused by disordered breathing during sleep leads to increased inflammation in different organs in our body, including the brain, lungs, and heart, resulting in more severe COVID-19.”
The research found no evidence that any of the breathing disorders makes a person more likely to acquire SARS-CoV-2, the virus that causes COVID-19.
Sleep medicine specialist Dr. Atul Malhotra, who was not involved in the study, told MNT that there is likely a much simpler reason that many people contract the infection:
“I think the risk of who gets [the infection] is probably related to wearing a mask and getting vaccinated and also social distancing, those kinds of things.”
The Cleveland Clinic is a nonprofit academic medical center in Cleveland, OH. The new study has been published in JAMA Network Open.
Sleep disordered breathing is a common syndrome, characterized by an abnormal respiratory pattern during sleep. It includes snoring, upper airway resistance syndrome, and obstructive sleep apnea. Recent data suggests that it affects 1 billion people globally.
The syndrome is known to cause hypoxia, an insufficient supply of oxygen. “Hypoxia” is also used as shorthand for “hypoxemia,” which refers to an inadequate amount of oxygen in the blood.
“Between a third and half of people snore,” said Dr. Malhotra. “Not everyone who snores has sleep apnea.”
“So,” he continued, “when we worry about snoring is if it’s habitual, like they snore all night every night, or if it’s very loud, where the spouse is in a different room. The other time you worry about it is if somebody has daytime sleepiness. Then we take it more seriously.”
“But what I usually say is just, ‘If you’re concerned about it, talk to your doctor.’ There are different questionnaires that have been validated, but basically, the history and physical exam can be quite helpful.”
For the study, the researchers used data from the Cleveland Clinic’s nearly 360,000-patient research registry. In this registry, the records for 5,402 individuals included sleep study data, and these individuals comprised the study’s cohort.
“Our findings suggest,” the authors write, “that baseline sleep-related hypoxia is associated with progression of hypoxic insult and hypoxia-related injury in COVID-19 pathophysiology, hence serving as an amplifier” of the disease. “Insult” refers to the effect of a potentially destructive stressor, and “injury” connotes that damage has been done.
The study also hypothesizes that disordered breathing during sleep may promote the occurrence of other COVID-19 risk factors, such as “microinfarcts, pulmonary parenchymal inflammation, hypoxic pulmonary vasoconstriction, and lung injury.”
Dr. Peña Orbea notes that “Risk stratification strategies among those with sleep-related breathing disorders may be needed. Further investigation is needed to understand the influence of sleep-related hypoxia in vaccine effectiveness.”
The authors of the study hope that their research will prompt further investigation into whether to institute early interventions in COVID-19 patients with disordered breathing during sleep.
Providing supplemental oxygen or using positive airway pressure machines, for example, may help people with “high nocturnal hypoxic physiological stress” avoid severe COVID-19 outcomes.
In addition, if chronic sleep disordered breathing is a marker of severe COVID-19, physicians can intervene more aggressively in early stages of the disease to prevent dire consequences.
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