Physical activity and all-cause mortality in Japan: the Jichi Medical School (JMS) Cohort Study.
BACKGROUND
In April 2008, a new health check-up and health guidance system was introduced by the Japanese Government to promote increased physical activity. However, few studies have documented the health benefits of physical activity in Asian populations. We examined the association between all-cause mortality and level of physical activity in a Japanese multicommunity population-based study.


METHODS
The Jichi Medical School Cohort Study is a multicommunity, population-based study based in 12 districts in Japan. Baseline data from 4222 men and 6609 women (mean age, 54.8 and 55.0 years, respectively) were collected between April 1992 and July 1995. The participants were followed for a mean duration of 11.9 years. To determine the association between all-cause mortality and level of physical activity, crude mortality rates per 1000 person-years and hazard ratios (HRs) with 95% confidence intervals (CI) were determined using the Cox proportional hazards model. Physical activity was categorized by using physical activity index (PAI) quartiles. The lowest (first) PAI quartile was defined as the HR reference.


RESULTS
In men, the lowest mortality rate was observed in the third quartile, with 95 deaths and a crude mortality rate of 7.6; the age- and area-adjusted HR was 0.59 (95% CI, 0.45-0.76), and the mortality curve had a reverse J shape. In women, the lowest mortality rate was observed in the highest PAI quartile, with 69 deaths and a crude mortality rate of 3.5; the HR was 0.81 (95% CI, 0.58-1.12).


CONCLUSIONS
Our results suggest that increased physical activity lowers the risk for all-cause death in Japanese.
Hayasaka
Shinya
S
Department of Community Health and Preventive Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan. hayasaka@hama-med.ac.jp
Shibata
Yosuke
Y
Ishikawa
Shizukiyo
S
Kayaba
Kazunori
K
Gotoh
Tadao
T
Noda
Tatsuya
T
Murata
Chiyoe
C
Yamada
Tomoyo
T
Goto
Yasuaki
Y
Nakamura
Yosikazu
Y
Ojima
Toshiyuki
T
D017677:Age Distribution; D000368:Aged; D002423:Cause of Death; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009026:Mortality; D009043:Motor Activity; D016017:Odds Ratio; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires