Sleep symptoms are essential features of long-COVID - Comparing healthy controls with COVID-19 cases of different severity in the international COVID sleep study (ICOSS-II).
Merikanto I., Dauvilliers Y., Chung F., Wing YK., de Gennaro L., Holzinger B., Bjorvatn B., Morin CM., Penzel T., Benedict C., Koscec Bjelajac A., Chan NY., Espie CA., Hrubos-Strøm H., Inoue Y., Korman M., Landtblom A-M., Léger D., Matsui K., Mota-Rolim S., Nadorff MR., Plazzi G., Reis C., Yordanova J., Partinen M.
Many people report suffering from post-acute sequelae of COVID-19 or "long-COVID", but there are still open questions on what actually constitutes long-COVID and how prevalent it is. The current definition of post-acute sequelae of COVID-19 is based on voting using the Delphi-method by the WHO post-COVID-19 working group. It emphasizes long-lasting fatigue, shortness of breath and cognitive dysfunction as the core symptoms of post-acute sequelae of COVID-19. In this international survey study consisting of 13,628 subjects aged 18-99 years from 16 countries of Asia, Europe, North America and South America (May-Dec 2021), we show that post-acute sequelae of COVID-19 symptoms were more prevalent amongst the more severe COVID-19 cases, i.e. those requiring hospitalisation for COVID-19. We also found that long-lasting sleep symptoms are at the core of post-acute sequelae of COVID-19 and associate with the COVID-19 severity when COVID-19 cases are compared with COVID-negative cases. Specifically, fatigue (61.3%), insomnia symptoms (49.6%) and excessive daytime sleepiness (35.8%) were highly prevalent amongst respondents reporting long-lasting symptoms after hospitalisation for COVID-19. Understanding the importance of sleep-related symptoms in post-acute sequelae of COVID-19 has a clinical relevance when diagnosing and treating long-COVID.