著者

Yuta Nemoto Shinichiro Sato Yoshinori Kitabatake Noriko Takeda Kazushi Maruo Takashi Arao

出版者

Japan Epidemiological Association

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

pp.JE20210419, (Released:2022-05-14)

参考文献数

53

被引用文献数

4

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Background: It has not been determined whether mentally active sedentary behavior (MASB) and passive sedentary behavior (PSB) differentially affect cognitive function and whether these associations differ according to physical activity (PA) level. We examined the comparative impacts of MASB and PSB on dementia onset and aimed to understand whether the associations differed by PA level.Methods: We conducted a 5-year longitudinal study involving all community-dwelling older adults in a rural area in Japan (n = 5,323). Dementia onset was examined using long-term care insurance data. PA was evaluated using the International Physical Activity Questionnaire and categorized as low (<2.5 metabolic equivalent of task [MET]-h/week), moderate (2.5–16.0 MET-h/week), or high (≥16.0 MET-h/week). We also assessed PSB (TV-watching time; <1 h/day, 1–3 h/day, ≥3 h/day) and MASB (Book-reading time; <10 min/day, 10–30 min/day, ≥30 min/day). To examine the associations of MASB and PSB with dementia onset, we performed the Fine-Gray models accounting for competing risk of death.Results: During the follow-up period, 606 (11.4%) participants developed dementia. MASB was independently associated with a lower risk of dementia; the magnitude of the impact was significant at higher PA levels. There was no association between PSB and developing dementia across all PA levels. Furthermore, dementia risk for individuals with high PA levels and moderate or high MASB levels was approximately 60% lower than those with low PA levels and low MASB.Conclusion: Providing interventions to promote MASB, which reduces dementia risk, and PA, which increases MASB’s effect on dementia incidence, can be beneficial in delaying or preventing dementia onset.

著者

Yuya Fujii Naruki Kitano Yuko Kai Takashi Jindo Takashi Arao

出版者

Japan Epidemiological Association

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

pp.JE20230023, (Released:2023-08-12)

参考文献数

33

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Background: The COVID-19 pandemic may have reduced opportunities for engaging in physical activity (PA) and increased sedentary behavior (SB) among workers. However, most previous studies used self-reported assessments. This study aimed to examine the changes in accelerometer-measured PA and SB from before to after COVID-19 outbreak among Japanese workers.Methods: This one-year longitudinal study used data from the annual health check-ups of workers who lived in the Tokyo metropolitan area. Baseline and follow-up data were collected from June to November, 2019 and June to November, 2020, respectively. Participants were asked to wear the accelerometer on their hip during awake hours for at least 10 days in both the surveys. Before the analysis, considering the difference in wearing time, time spent in PA and SB were converted to the percentage of wearing time. To investigate the changes in PA or SB from before to during COVID-19 outbreak, paired t-tests were performed.Results: Of the 757 eligible participants, 536 were included in the analysis (70.8%). Participants’ mean age was 53.3 years; 69.6% were female; and most were full-time employees. Time spent in PA decreased, regardless of weekdays or weekends, although changes on the weekends were not significant. Conversely, time spent in SB increased on both weekdays and weekends in 2020. These changes corresponded to approximately 10 minutes per day increase/decrease in PA/SB.Conclusion: Objectively measured PA decreased and SB increased by approximately 10 minutes per day after the COVID-19 outbreak among Japanese workers.