title: Physical activity and cardiovascular disease in Japan: the Jichi Medical School Cohort Study.
abstract: BACKGROUND
  Many studies have reported an association between physical activity and cardiovascular disease (CVD); however, the effect of physical activity remains controversial. Few such studies have been conducted in Japan. Therefore, we examined the relationship between physical activity and death from CVD using prospective data from a Japanese population.
  
  
  METHODS
  From a prospective cohort study that comprised 12 490 participants, data from 9810 were analyzed. From April 1992 through July 1995, a baseline survey was conducted in 12 communities in Japan. The participants were followed up until December 2005. Physical activity was assessed using the physical activity index (PAI). PAI scores were grouped in quartiles: Q1 was the lowest PAI quartile and Q4 was the highest. Hazard ratios (HRs) for death from CVD, stroke, and myocardial infarction (MI) were calculated for all PAI quartiles.
  
  
  RESULTS
  The mean follow-up period was 11.9 years, during which time 194 participants died of CVD. With Q1 as the reference, the HRs for death from CVD in Q2, Q3, and Q4, were 0.62 (95% confidence interval, 0.40-0.98), 0.53 (0.31-0.88), and 0.40 (0.22-0.73), respectively, in men, and 0.71 (0.38-1.32), 0.52 (0.26-1.04), and 0.48 (0.22-1.05), respectively, in women. The HRs for death from CVD subtypes were similar but not statistically significant.
  
  
  CONCLUSIONS
  Among a Japanese population, physical activity was associated with a decreased risk of death from CVD. However, more evidence is needed to elucidate the relationships between physical activity and CVD subtypes.
authors.affiliation: Department of Community Health and Preventive Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan. shibata-yosuke@umin.ac.jp
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Shibata
authors.forename: Shinya
authors.initials: S
authors.lastname: Hayasaka
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Yamada
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Goto
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ojima
authors.forename: Shizukiyo
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kayaba
authors.forename: Tadao
authors.initials: T
authors.lastname: Gotoh
authors.forename: Yosikazu
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D002318:Cardiovascular Diseases / Q000401:mortality*; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012423:Rural Health; D020521:Stroke / Q000401:mortality*