ABSTRACT
Background: People with post-COVID syndrome (PCS) suffer from persisting symptoms, e.g. self-reported sleep disorders (31%). However, sleep has not yet been objectively measured by polysomnography (PSG) in PCS. Objective(s): To examine differences in sleep characteristics between PCS and healthy controls (HC). Method(s): People with PCS and HC were included in this prospective trial. All subjects performed baseline characteristics, 1-minute sit-to-stand test (STST), subjective impairments of sleep and a single night sleep assessment in a sleep lab via PSG and Whoop strap (digital health coach). Post-COVID functional scale (PCFS) and Ordinal Scale for Clinical Improvement (OSCI) were assessed only in PCS. Result(s): To date, 20 PCS patients (49+/-11y, FVC 87+/-12%pred., DLCO: 81+/-19%pred., PCFS: 2.8+/-0.9, OSCI: 2.7+/-1.3pts) and 3 HC (44+/-9y, FVC 92+/-3%pred., DLCO 105+/-25%pred.) completed the trial. Only PCS patients reported an impaired sleep ("Is your sleep impaired since COVID?" [yes: 89%]) mainly due to insomnia in the middle of the night (61%). Total sleep time and the distribution of sleep stages (light, deep, REM) were comparable between PCS and HC. The REM latency trended to be longer in PCS vs. HC (114+/-51 vs. 52+/-17 min.). Apnea-hypopnea index (AHI) trended to be higher in PCS (8.9+/-8.5 vs. 0.9+/-1.2 events/h), 55.6% of PCS reported an AHI>5/h. The individual quality of recovery after the study night was classified to be "adequate" (PCS: 56+/-21%, HC: 52+/-15%). Conclusion(s): In PCS, sleep seems to be subjectively and objectively impaired compared to HC. A significant number of PCS patients (44%) was diagnosed with obstructive sleep apnea. Hence, measuring sleep might be an important diagnostic tool in the management of PCS.