著者

Shiho Amagasa Noritoshi Fukushima Hiroyuki Kikuchi Koichiro Oka Sebastien Chastin Catrine Tudor-Locke Neville Owen Shigeru Inoue

出版者

Japan Epidemiological Association

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

pp.JE20200080, (Released:2020-06-13)

参考文献数

39

被引用文献数

18

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Background: Daily step count is the most simple measure of physical activity. However, little is known about how daily step count related to time spent in different intensities of physical activity (PA) and sedentary behavior (SB).Methods: These cross-sectional data were derived from 450 older Japanese adults (56.7% men, mean age 74.3 years) who were randomly selected from three communities and responded a survey. Daily step count and time spent in moderate-to-vigorous PA (MVPA), light-intensity PA (LPA), and SB were measured using a validated wearable technology (HJA-350IT). Associations of daily step count with time spent in measured behaviors were examined by linear regression models using isometric log-ratio transformations of time-use composition, adjusting for gender, age and residential area.Results: Participants averaged 5,412 (SD: 2,878) steps/d and accumulated MVPA, LPA, and SB corresponding to 4.0, 34.8, and 61.2% of daily waking time, respectively. Daily step count significantly increased with increase in time spent in MVPA relative to other behaviors (i.e. LPA and SB) and in the ratio of LPA to SB after allowing for MVPA. After stratification, daily step count was significantly related to the ratio of LPA to SB in those taking <5,000 steps/d, but not in those taking 5,000-7,499 and ≥7,500 steps/d.Conclusions: Higher daily step count can be an indicator of not only larger relative contribution of time spent in MVPA, but also higher ratio between LPA and SB, particularly among those who are the least physically active.

著者

Shiho Amagasa Shigeru Inoue Hiroshi Murayama Takeo Fujiwara Hiroyuki Kikuchi Noritoshi Fukushima Masaki Machida Sebastien Chastin Neville Owen Yugo Shobugawa

出版者

Japan Epidemiological Association

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

pp.JE20190141, (Released:2019-10-26)

参考文献数

45

被引用文献数

22

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Background: Physical activity can help to protect against cognitive decline in older adults. However, little is known about the potential combined relationships of time spent in sedentary behavior (SB), light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) with indices of cognitive health. We examined the cross-sectional associations of objectively-determined sedentary and physically-active behaviors with an indicator of cognitive function decline (CFD) in older adults.Methods: A randomly-recruited sample of 511 Japanese older adults (47% male; aged 65-84 years) wore a tri-axial accelerometer (HJA-750C, Omron) for seven consecutive days in 2017. Cognitive function was assessed by interviewers using the Japanese version of Mini-Mental State Examination, with a score of ≤23 indicating CFD. Associations of sedentary and physically-active behaviors with CFD were examined using a compositional logistic regression analysis based on isometric log-ratio transformations of time use, adjusting for potential confounders.Results: Forty one (9.4%) of the participants had an indication of CFD. Activity compositions differed significantly between CFD and normal cognitive function (NCF); the proportion of time spent in MVPA was 39.1% lower, relatively to the overall mean composition in those with CFD, and was 5.3% higher in those with NCF. There was a significant beneficial association of having a higher proportion of MVPA relative to other activities with CFD. LPA and SB were not associated with CFD when models were corrected for time spent in all activity behaviors.Conclusions: Larger relative contribution of MVPA was favorably associated with an indicator of CFD in older adults.