title: Walking and mortality in Japan: the Miyagi Cohort Study.
abstract: BACKGROUND
  Although many studies in western populations demonstrated that time spent walking was associated with a reduced risk of all-cause mortality, data on Japanese has been sparse.
  
  
  METHODS
  In 1990, 20,004 men and 21,159 women in Miyagi Prefecture in rural northern Japan (40-64 year of age) completed a self-administered questionnaire including a question on time spent walking. Cox regression was used to estimate relative risk (RR) of mortality according to three levels of walking (30 minutes or less, between 30 minutes and one hour, and one hour or more), with adjustment for age, education, marital status, past history of diseases, smoking, drinking, body mass index, and dietary variables. During 11 years of follow-up, 1,879 subjects had died.
  
  
  RESULTS
  Time spent walking was inversely associated with risk of all-cause mortality: compared with men and women who walked one hour or more per day, multivariate RR (95% confidence intervals) was 1.06 (0.95-1.19) for subjects who walked between 30 minutes and one hour per day, and 1.16 (1.04-1.29) for subjects who walked 30 minutes or less per day (P for trend=0.007). Shorter duration of walking was associated with increased mortality among men who were never smokers (P for trend=0.081) and past smokers (P for trend=0.026), but not among currently smoking men (P for trend=0.751). We observed similar effect modification for women.
  
  
  CONCLUSIONS
  Time spent walking was associated with a reduced risk for all-cause mortality, especially among nonsmoking men and women.
authors.affiliation: Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8575, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Fujita
authors.forename: Hideko
authors.initials: H
authors.lastname: Takahashi
authors.forename: Chihaya
authors.initials: C
authors.lastname: Miura
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ohkubo
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sato
authors.forename: Takashi
authors.initials: T
authors.lastname: Ugajin
authors.forename: Kayoko
authors.initials: K
authors.lastname: Kurashima
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tsubono
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tsuji
authors.forename: Akira
authors.initials: A
authors.lastname: Fukao
authors.forename: Shigeru
authors.initials: S
authors.lastname: Hisamichi
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D016016:Proportional Hazards Models; D012307:Risk Factors; D013997:Time Factors; D016138:Walking