People with obstructive sleep apnea (OSA) have almost three times a greater risk of dying from COVID-19 if they are admitted to a hospital. That’s the result of an analysis of 18 studies on the relationship between sleep apnea and the coronavirus by researchers from the University of Warwick in England.

The scientists found that people who suffer from the condition, which is characterized by snoring and choking when the muscles of the throat temporarily relax, believe that the inflammation triggered by COVID-19 increases complications for sufferers.

According to the Daily Mail, OSA is already associated with other known risk factors for the novel coronavirus such as obesity and diabetes. However, the scientists believe that patients with these conditions should be aware that sleep apnea increases their risk even further, adding that more research is needed to determine how much of an impact it actually has on COVID-19 outcomes.

One of the studies the researchers examined showed that in 1,300 people with diabetes and sleep apnea, the risk of death was 2.8 times higher after seven days in the hospital, according to the Daily Mail. In Finland, a separate study revealed that a “disproportionate number of patients admitted to hospital with COVID-19 had pre-existing OSA.”

Approximately 22 million people in the U.S. suffer from OSA, according to the Daily Mail, and the British researchers warned that “this group of patients should be more aware that obstructive sleep apnea could be an additional risk for COVID-19.”

Dr. Michelle Miller, one of the lead authors of the study, said:

“Make sure you are compliant with your treatment and take as many precautions as you can to reduce your risk, such as wearing a mask, social distancing, and getting tested if you notice any symptoms.”