Physical Activity and All-cause Mortality in Japan: The Jichi Medical School (JMS) Cohort Study

Shinya Hayasaka,Shizukiyo Ishikawa,Tadao Gotoh,Yasuaki Goto,Kazunori Kayaba,Tomoyo Yamada,Toshiyuki Ojima,Tatsuya Noda,Yosikazu Nakamura,Yosuke Shibata,Chiyoe Murata

doi:10.2188/jea.je20080043

Abstract

BackgroundIn 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.MethodsThe 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.ResultsIn 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).ConclusionOur results suggest that increased physical activity lowers the risk for all-cause death in Japanese.

Highlights

In April 2008, a new health check-up and health guidance system entitled, “Health Checkups and Healthcare Advice with Particular Focus on Metabolic Syndrome,” was introduced by the Japanese Government
Participants were followed for an average of 11.9 years from the time of baseline measurement until either death due to any cause, incident cardiovascular disease, relocation to another area, or the end of the study; follow-up was completed for 99% of the cohort
Population-based study found that, among both men and women, groups with a higher physical activity index (PAI) had a lower risk of all-cause death than groups with a lower PAI

Summary

Introduction

In April 2008, a new health check-up and health guidance system entitled, “Health Checkups and Healthcare Advice with Particular Focus on Metabolic Syndrome,” was introduced by the Japanese Government. Many epidemiological studies have confirmed the health benefits of physical activity,[2,3,4,5,6] noting an association between a high level of physical activity and lower mortality. Most of these studies have been conducted in Western countries; only a few have been conducted within Asian populations. We examined the association between all-cause mortality and level of physical activity in a Japanese multicommunity population-based study. Conclusion: Our results suggest that increased physical activity lowers the risk for all-cause death in Japanese

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