Sleep apnea is a risk factor for COVID-19, according to researchers at Turku University Hospital and the University of Turku in Finland who studied patients during the first wave of the pandemic.
Southwest Finland, with a population of 480,000, managed the first wave of the pandemic with a relatively small number of infected people, the researchers said. Of the 278 who tested positive, 28 were admitted to Turku University Hospital by May 3, 2020.
“The idea behind the study was the need for real-time information about COVID-19,” said Thijs Feuth, MD, a fellow in pulmonary diseases and first author of the study.
“The research permission was extensive, because little was known about the novel coronavirus. We quickly observed that there was quite a few cases of sleep apnea among the patients,” said Feuth.
A comparison of the register information revealed that 29% of the patients admitted to hospital care already had been diagnosed with sleep apnea, though only 3.1% of the Southwest Finland population is getting treatment for sleep apnea.
Even though the total number of patients in the study was low, the share of sleep apnea patients was high, the researchers said. The extent of sleep apnea among the patients cannot only be explained by the obesity that sleep apnea patients often have, as obesity already is known as one of the risk factors for severe COVID-19.
“The finding was strong enough to justify the question of sleep apnea as a risk factor for COVID-19. In principle, a patient may need hospital care when they have a COVID-19 infection if they also have sleep apnea,” Feuth said. “Sleep apnea anticipates a severe form of COVID-19.”
The connection between sleep apnea and COVID-19 has been confirmed by other studies now under review and available as pre-publications, the researchers said, adding that their findings were comparable with these other studies.
Other findings included higher levels of C-reactive protein (CRP) in those patients who were eventually admitted to intensive care. Most viral diseases do not elevate CRP levels that much, the researchers said.