Social jetlag and its influence on health: a nationwide, cross-sectional survey

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K07545
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied anthropology
• Research Institution: Meiji Pharmaceutical University (2017-2019); Tokyo Medical University (2016)
• Principal Investigator: Komada Yoko 明治薬科大学, 薬学部, 准教授 (40451380)
• Co-Investigator(Kenkyū-buntansha): 岡島 義 東京家政大学, 人文学部, 期限付准教授 (50509867) ; 高江洲 義和 杏林大学, 医学部, 講師 (90421015)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 社会的ジェットラグ / 概日リズム / 睡眠負債 / クロノタイプ / 健康

Outline of Final Research Achievements

Misalignment between an individual’s circadian phase and his/her environment due to social imposition is called social jetlag (SJL). This study aimed to elucidate the percentage of SJL in a large Japanese population using the Japanese version of the Munich ChronoType Questionnaire (MCTQ). A total of 10,000 participants responded to a web-based cross-sectional survey, and the final sample comprised 3,708 participants. SJL was measured by subtracting each participant’s midpoint of sleep on workdays from their midpoint of sleep on free days. The average [SD] absolute SJL (SJLabs) value was 0.91 [0.89] hours, and the percentage of participants with SLJabs of more than 1 hour was 40.1%. Our data also showed that SJLabs becomes progressively smaller with advancing age. A considerable number of participants of our Japanese population showed differences in sleep behavior between workdays and free days.

Free Research Field

睡眠科学

Academic Significance and Societal Importance of the Research Achievements

睡眠負債や睡眠の問題がもたらす経済損失は、日本ではGDP比で2.92%にのぼると試算されている。睡眠負債を補うための週末のいわゆる寝だめは日常的にみられる対処法であるが、social jetlagという新たな問題を引き起こす。Social jetlagは2006年に提唱された概念で、個人のもつ体内時計と勤務スケジュールなど社会要因によって規定される社会的時計の不一致によって生ずる睡眠時間帯のずれを指す。概日リズム変調による心身健康被害の発現が懸念されるが、日本ではこれまで系統的研究は行われていなかった。本研究では、social jetlagの現状と日中機能への悪影響を明らかにした。