Is sleep apnea a risk factor for Covid-19? findings from a retrospective cohort study

Background: In the early phase of the coronavirus disease-19 (Covid-19) pandemic, Southwest Finland remained relatively spared. By the 3 rd of May 2020, a total of 28 patients have been admitted to the Turku University Hospital. We explore baseline characteristics in order to identify risk for severe disease and critical care admission. Methods: For this retrospective cohort study, data were derived from hospital records. Basic descriptive statistics were used to characterise patients, including medians, percentiles and frequencies. Differences were tested with Mann Whitney U-test and Pearson’s chi-square test. Results: Pre-existent obstructive sleep apnea (OSA) was present in 29% of patients admitted in the hospital for Covid-19. Overall, other findings on admission were comparable with those reported elsewhere. C-reactive protein and procalcitonin were higher in patients who were eventually transferred to critical care in comparison to in those who were not (median CRP 187 mg/L versus 52 mg/L, p<0.005 and median PCT 0.46 versus 0.12, p=0.047). Conclusion: OSA was pre-existent in a disproportional large group of patients, which suggests that it is an important risk factor for severe Covid-19. Furthermore, we identified high CRP, PCT and possibly native oxygen saturation as useful clinical measures to identify patients at risk for critical care.