title: Leisure-time, occupational, and commuting physical activity and risk of type 2 diabetes in Japanese workers: a cohort study.
abstract: BACKGROUND
  Physical activity has been suggested to reduce the risk of type 2 diabetes. However, evidence is limited regarding whether vigorous-intensity activity yields the same benefits in preventing type 2 diabetes compared with an equivalent dose of moderate-intensity activity as well as other type of physical activity. We examined the risk of type 2 diabetes associated with exercise intensity during leisure and occupational and commuting physical activity among Japanese individuals.
  
  
  METHODS
  Participants included 26,628 workers (23,207 men and 3,421 women) aged 30 to 64 years without diabetes at baseline. There was 6 years of follow-up maximum. Leisure-time exercise, occupational physical activity, and duration of walking to and from work were self-reported. Diabetes was diagnosed by using HbA1c, fasting or random blood glucose, and self-report. We used Cox regression analysis to estimate the hazard ratio (HR) and the 95% confidence interval (CI) of incident diabetes.
  
  
  RESULTS
  During a mean follow-up of 5.2 years, 1,770 participants developed type 2 diabetes. Compared with individuals who engaged in no exercise, the HRs (95% CIs) for <7.5, 7.5 to <15.0, and ≥15.0 MET-hours per week of exercise were 0.94 (0.81, 1.08), 1.07 (0.88, 1.30), and 0.90 (0.67, 1.21), respectively, among individuals who engaged in moderate-intensity exercise alone; 0.68 (0.44, 1.06), 0.86 (0.54, 1.34), and 0.89 (0.56, 1.41), respectively, among individuals who engaged in vigorous-intensity exercise alone; and 0.70 (0.44, 1.11), 0.57 (0.37, 0.90), and 0.76 (0.52, 1.11), respectively, among individuals who engaged in the two intensities, with adjustments for potential confounders and the total volume of exercise. Occupational physical activity and walking to and from work were not associated with diabetes.
  
  
  CONCLUSIONS
  The results suggest that vigorous-intensity exercise can reduce the risk of type 2 diabetes among Japanese workers.
authors.affiliation: Hitachi Health Care Center, Hitachi, Ltd., 4-3-16 Ose-cho, Hitachi, Ibaraki, Japan. toru.honda.kv@hitachi.com.
authors.forename: Toru
authors.initials: T
authors.lastname: Honda
authors.affiliation: Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan. kkuwahara@med.teikyo-u.ac.jp.|Teikyo University Graduate School of Public Health, 2-11-1 Kaga, Itabashi-ku, Tokyo, Japan. kkuwahara@med.teikyo-u.ac.jp.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kuwahara
authors.affiliation: Hitachi Health Care Center, Hitachi, Ltd., 4-3-16 Ose-cho, Hitachi, Ibaraki, Japan. tohru.nakagawa.rh@hitachi.com.
authors.forename: Tohru
authors.initials: T
authors.lastname: Nakagawa
authors.affiliation: Hitachi Health Care Center, Hitachi, Ltd., 4-3-16 Ose-cho, Hitachi, Ibaraki, Japan. shuichiro.yamamoto.sr@hitachi.com.
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Yamamoto
authors.affiliation: Hitachi Health Care Center, Hitachi, Ltd., 4-3-16 Ose-cho, Hitachi, Ibaraki, Japan. takeshi.hayashi.nq@hitachi.com.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, Japan. mizoue@ri.ncgm.go.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mizoue
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000517:prevention & control; D015444:Exercise; D005260:Female; D015438:Health Behavior; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009784:Occupational Diseases / Q000453:epidemiology* / Q000517:prevention & control; D009790:Occupations / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires