The novel coronavirus (SARS-CoV-2) attacks the human body primarily through the airways and the lungs. Classic symptoms of COVID-19, the disease caused by the coronavirus, are fever, cough, and shortness of breath. But for many — perhaps as many as half of those infected — there are few if any symptoms. People who suspect they have been infected are asked to shelter in place and to check their temperatures every day. But for those who do not develop a fever or obvious shortness of breath or cannot get a COVID-19 test due to shortages, they may ignore their problems for many days while the disease silently ravages their lungs. A better diagnostic tool than a thermometer could be an oximeter that is widely available and not much more expensive than a thermometer and much more accessible than a COVID-19 test. Oxygen saturation levels below 88% were found to be the most useful marker of critical illness in NY hospital admissions.
We now know that COVID-19 mortality is strongly associated with age, gender, and comorbidities such as obesity. Obesity (BMI>40) and heart failure were the next most important indicators after age. What is it about obesity that makes COVID-19 so much more deadly while other more suspicious conditions such as asthma do not seem to? We suggest that another medical condition that is associated with obesity but sometimes ignored may be more predictive of hospitalization and mortality: obstructive sleep apnea (OSA). OSA is known to be associated with age, gender, and obesity. Older men who are obese are more likely to have sleep apnea than any other combination of demographic factors. While OSA has been clinically diagnosed in only 4% of American males and 2% of American females, it is suspected to afflict nearly 10% of the US population in milder/ undiagnosed forms. One additional demographics factor that has emerged recently is race: African Americans (AA) are more likely to die from COVID-19 than Whites. Many socioeconomic factors such as poorer access to health care in general and testing, in particular, have been suggested, but one factor that has not is OSA. It turns out that OSA prevalence among AA may be as high as 24% — much higher than the 5% formerly diagnosed.
Sleep apnea is a breathing disorder that may be greatly exacerbated by COVID-19 leading to respiratory distress and possibly failure. Moreover, we think that persons with sleep apnea may have learned to adapt to mild oxygen deprivation and so that they may not notice a change in their breathing pattern until the coronavirus has caused severe damage to the lungs — leading to hospitalization and eventual death. Sleep apnea patients on CPAP (Continuous Positive Airway Pressure) and BiPAP (Bilevel Positive Airway Pressure) machines may actually feel no change because small initial damage can be easily compensated by the machines at night, and more rapid breathing during the day. However, the use of these machines can cause the disease to spread more rapidly because CPAPs, unlike true ventilators, blow contaminated air into the room that may circulate into the building causing widespread infections in apartment buildings, nursing homes, veteran homes, prisons, etc.
It is important to test this hypothesis immediately, but equally important to have the CDC recommend the use of oximeters to detect and monitor potential victims of COVID-19. As soon as they are identified, they should be tested, isolated, and treated to reduce the risk of infection to others.