Ehab S Eshak1,2, Hiroyuki Noda3, Akiko Tamakoshi4, Hiroyasu Iso3,5. 1. Department of Public Health and Community Medicine, Faculty of Medicine, Minia University, Main Road, Shalaby land, Minia, 61519, Egypt. ehab@pbhel.med.osaka-u.ac.jp. 2. Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. ehab@pbhel.med.osaka-u.ac.jp. 3. Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. 4. Department of Public Health, Hokkaido University Graduate School of Medicine, 7-15 Kita-Ku, Sapporo, 060-8638, Japan. 5. Department of Public Health Medicine, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.
Abstract
PURPOSE: An inverse association between physical activity and colorectal cancer (CRC) has been suggested. We aimed to assess the specific and combined effects of leisure-time and occupational physical activities on CRC risk among Japanese adults. METHODS: Using Cox proportional hazard models, we tested whether walking time, sports activity, body posture during work, and job type-or the combination of these variables-were associated with CRC incidence in a prospective cohort of 26,897 Japanese adults aged 40-79 years. RESULTS: During a median 17-year follow-up (1990-2009) period, we ascertained 423 incident cases of CRC (267 colon and 156 rectum cancer). Time spent walking suggested a dose-response inverse relationship with CRC risk (p-trend = 0.051). Manual labor was associated with lower CRC risk when compared to office work with HRs (95% CIs) of 0.74 (0.56-0.97) for CRC and 0.68 (0.48-0.96) for colon cancer. Compared to sitting, moving during work tended to be inversely associated with rectal cancer risk, especially after censoring early incident cases within 3 years after baseline; HR (95% CI) = 0.63 (0.40-0.99). Combining walking and job type suggested mutual and synergistic benefits on the risk of colon cancer (p-interaction = 0.03). Compared to office workers walking < 1 h/day, the HR (95% CI) of colon cancer was 0.48 (0.23-0.98), 0.61 (0.42-0.89), and 0.59 (0.41-0.87) in office workers walking ≥ 1 h/day, non-office workers walking < 1 h/day, and non-office workers walking ≥ 1 h/day, respectively. CONCLUSION: The time spent walking, job type, and posture during work were independently associated with the reduced incident CRC risk among Japanese men and women.
PURPOSE: An inverse association between physical activity and colorectal cancer (CRC) has been suggested. We aimed to assess the specific and combined effects of leisure-time and occupational physical activities on CRC risk among Japanese adults. METHODS: Using Cox proportional hazard models, we tested whether walking time, sports activity, body posture during work, and job type-or the combination of these variables-were associated with CRC incidence in a prospective cohort of 26,897 Japanese adults aged 40-79 years. RESULTS: During a median 17-year follow-up (1990-2009) period, we ascertained 423 incident cases of CRC (267 colon and 156 rectum cancer). Time spent walking suggested a dose-response inverse relationship with CRC risk (p-trend = 0.051). Manual labor was associated with lower CRC risk when compared to office work with HRs (95% CIs) of 0.74 (0.56-0.97) for CRC and 0.68 (0.48-0.96) for colon cancer. Compared to sitting, moving during work tended to be inversely associated with rectal cancer risk, especially after censoring early incident cases within 3 years after baseline; HR (95% CI) = 0.63 (0.40-0.99). Combining walking and job type suggested mutual and synergistic benefits on the risk of colon cancer (p-interaction = 0.03). Compared to office workers walking < 1 h/day, the HR (95% CI) of colon cancer was 0.48 (0.23-0.98), 0.61 (0.42-0.89), and 0.59 (0.41-0.87) in office workers walking ≥ 1 h/day, non-office workers walking < 1 h/day, and non-office workers walking ≥ 1 h/day, respectively. CONCLUSION: The time spent walking, job type, and posture during work were independently associated with the reduced incident CRC risk among Japanese men and women.
Authors: D J Harriss; G Atkinson; A Batterham; K George; N Tim Cable; T Reilly; N Haboubi; A G Renehan Journal: Colorectal Dis Date: 2009-01-17 Impact factor: 3.788