title: Prospective associations between sedentary behaviour and incident depressive symptoms in older people: a 15-month longitudinal cohort study.
abstract: This study aimed to investigate whether sitting time, as a form of sedentary behaviour, is related to incident depressive symptoms in older people.
  
  
  
  This study included 3503 participants (mean age 71.7 years, 50.1% female) from the 'Obu Study of Health Promotion for the Elderly' cohort study. At baseline and then 15 months later, the participants reported their status of depressive symptoms using the 15-item Geriatric Depression Scale. During the baseline assessment, the participants were also asked about their sedentary behaviour on weekdays over the past 7 days and, from there, categorized into three groups (<240, 240-480, ≥480 min/day). Demographic data and the other health behaviours were also assessed at the baseline.
  
  
  
  Cross-sectional analysis revealed that 437 participants (12.0%) had depressive symptoms. In a prospective analysis, the logistic regression model revealed that the odds ratio for depressive symptom incidence was higher in participants who, at baseline, spent 480 min or more per day sitting (1.636; 95% confidence interval [CI] 1.015 to 2.636, p = 0.043), and in those who spent 240-480 min (1.605; 95% CI 1.085 to 2.375, p = 0.018) in comparison with those who spent less than 240 min.
  
  
  
  Sedentary behaviour significantly affects the risk of incident depressive symptoms. Further research is needed to develop an intervention strategy to manage depressive symptoms, as the second most common cause of burden of disease among older adults. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Preventive Gerontology, Center for Gerontology and Social Science, Obu, Aichi, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Tsutsumimoto
authors.affiliation: Department of Preventive Gerontology, Center for Gerontology and Social Science, Obu, Aichi, Japan.
authors.forename: Hyuma
authors.initials: H
authors.lastname: Makizako
authors.affiliation: Department of Preventive Gerontology, Center for Gerontology and Social Science, Obu, Aichi, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Doi
authors.affiliation: Department of Preventive Gerontology, Center for Gerontology and Social Science, Obu, Aichi, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Hotta
authors.affiliation: Department of Preventive Gerontology, Center for Gerontology and Social Science, Obu, Aichi, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Nakakubo
authors.affiliation: Department of Preventive Gerontology, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimada
authors.affiliation: National Center for Geriatrics and Gerontology, Obu, Aichi, Japan.|Department of Gerontology, J. F. Oberlin University Graduate School, Tokyo, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D016017:Odds Ratio; D011446:Prospective Studies; D012044:Regression Analysis; D057185:Sedentary Behavior
keywords: depressive symptoms; incident depression; older people; sedentary behaviour