title: Sedentary time assessed by actigraphy and mortality: The Rotterdam Study.
abstract: Research suggests that sedentary behavior is a risk factor for mortality. However, most studies rely on questionnaires, which are prone to reporting error. We examined the association between sedentary time assessed by actigraphy and mortality among 1839 participants, aged 45-98years, from the prospective population-based Rotterdam Study, enrolled between 2004 and 2007. Participants wore an actigraph around the wrist for seven days. Sedentary time was evaluated continuously, per 1h/day increase, and categorically in three groups (<8, 8-11, ≥11h/day). The lowest category was used as reference. Mortality risks were examined using Cox proportional hazard models, adjusted for confounders and biological risk factors. We examined the association between sedentary behavior and mortality over and beyond other activity measures (including physical activity (PA) and activities of daily living (ADL)) in a final model. During 11years of follow-up (median: 7.5years, interquartile range: 6.6-8.3years), 212 participants (11.5%) died. In the multivariable model, the hazard ratio (HR) and 95% confidence interval (95% CI) per 1 more hour/day sedentary time was 1.09 (1.00, 1.18). The HR (95% CI) after adjustment for PA and ADL was 1.04 (0.96, 1.13). Participants sedentary for ≥11h/day had a higher mortality risk (HR: 1.80, 95% CI: 1.14, 2.84) than those sedentary <8h/day, in the multivariable model. After adjusting for PA and ADL, this association was clearly attenuated (HR: 1.50, 95% CI: 0.93, 2.41). In conclusion, our study suggests that sedentary behavior is a risk factor for mortality. Further investigation is needed to examine whether this association is distinct from the effect of other measures of activity.
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
authors.forename: Chantal M
authors.initials: CM
authors.lastname: Koolhaas
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands; Department of Nutrition, Harvard School of Public Health, 677 Huntington Ave, Boston, MA 02115, United States.
authors.forename: Klodian
authors.initials: K
authors.lastname: Dhana
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
authors.forename: Frank J A
authors.initials: FJ
authors.lastname: van Rooij
authors.affiliation: Department of Child and Adolescent Psychiatry, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
authors.forename: Desana
authors.initials: D
authors.lastname: Kocevska
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands; Department of Epidemiology, Harvard School of Public Health, 677 Huntington Ave, Boston, MA 02115, United States.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
authors.forename: Oscar H
authors.initials: OH
authors.lastname: Franco
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands; Department of Child and Adolescent Psychiatry, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands. Electronic address: h.tiemeier@erasmusmc.nl.
authors.forename: Henning
authors.initials: H
authors.lastname: Tiemeier
mesh_terms: D056044:Actigraphy / Q000379:methods*; D000368:Aged; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D009426:Netherlands; D011446:Prospective Studies; D012307:Risk Factors; D057185:Sedentary Behavior; D013997:Time Factors
keywords: Elderly; Mortality; Rotterdam Study; Sedentary time