MATSUI Kentaro    Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine    Position
Article types	Original article
Language	English
Peer review	Non peer reviewed
Presence of invitation	Invited paper
Title	Social Jetlag Changes During the COVID-19 Pandemic as a Predictor of Insomnia - A Multi-National Survey Study.
Journal	Formal name：Nature and science of sleep Abbreviation：Nat Sci Sleep ISSN code：11791608/11791608
Domestic / Foregin	Foregin
Volume, Issue, Page	13,pp.1711-1722
Author and coauthor	Brandão Luiz Eduardo Mateus, Martikainen Teemu, Merikanto Ilona, Holzinger Brigitte, Morin Charles M, Espie Colin A, Bolstad Courtney J, Leger Damien, Chung Frances, Plazzi Giuseppe, Dauvilliers Yves, Matsui Kentaro, De Gennaro Luigi, Sieminski Mariusz, Nadorff Michael R, Chan Ngan Yin, Wing Yun Kwok, Mota-Rolim Sérgio Arthuro, Inoue Yuichi, Partinen Markku, Benedict Christian, Bjorvatn Bjorn, Cedernaes Jonathan
Publication date	2021/10/06
Summary	Purpose:Lifestyle and work habits have been drastically altered by restrictions due to the COVID-19 pandemic. Whether the associated changes in sleep timing modulate the risk of suffering from symptoms of insomnia, the most prevalent sleep disorder, is however incompletely understood. Here, we evaluate the association between the early pandemic-associated change in 1) the magnitude of social jetlag (SJL) - ie, the difference between sleep timing on working vs free days - and 2) symptoms of insomnia.Patients and Methods:A total of 14,968 anonymous participants (mean age: 40 years; 64% females) responded to a standardized internet-based survey distributed across 14 countries. Using logistic multivariate regression, we examined the association between the degree of social jetlag and symptoms of insomnia, controlling for important confounders like social restriction extension, country specific COVID-19 severity and psychological distress, for example.Results:In response to the pandemic, participants reported later sleep timing, especially during workdays. Most participants (46%) exhibited a reduction in their SJL, whereas 20% increased it; and 34% reported no change in SJL. Notably, we found that both increased and decreased SJL, as a result of the COVID-19 pandemic, were associated with later sleep midpoint (indicating a later chronotype) as well as more recurrent and moderate-to-severe symptoms of insomnia (about 23-54% higher odds ratio than subjects with unchanged SJL). Primarily those with reduced SJL shifted their bedtimes to a later timepoint, compared with those without changes in SJL.Conclusion:Our findings offer important insights into how self-reported changes to the stability of sleep/wake timing, as reflected by changes in SJL, can be a critical marker of the risk of experiencing insomnia-related symptoms - even when individuals manage to reduce their social jetlag. These findings emphasize the clinical importance of analyzing sleep-wake regularity.
DOI	10.2147/NSS.S327365
PMID	34675720