Physical activity, water intake and risk of colorectal cancer in Taiwan: a hospital-based case-control study.
The age-adjusted mortality rates of colorectal cancer have been rising in Taiwan over the past 2 decades, and colorectal cancer is now the third leading cause of cancer mortality in the country. We conducted a hospital-based case-control study to clarify the nature of the association between physical activity, water intake and colorectal-cancer risk in Taiwan. A total of 163 subjects (aged 33-80 years) with histologically confirmed primary colorectal cancer and 163 hospital controls were enrolled during 1992. Dietary intake, physical activity and other lifestyle activities were assessed using a comprehensive food-frequency and lifestyle-activity questionnaire. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic-regression analysis. A strong inverse dose-response relation between increased water intake and rectal cancer was found among men after adjustment for other risk factors (p for trend = 0.0005). The OR for rectal cancer among men in the highest tertile of water intake was 0.08 (95% CI, 0.02-0.35) compared with that among men in the lowest tertile (OR = 1). Similar but not significant trends were seen among women (p = 0.29). The OR for colon cancer among men with active leisure-time physical activity was 0.19 (95% CI, 0.05-0.77) times that among sedentary men (p for trend = 0.03). However, physical activity was not associated with colon-cancer risk among women (p = 0.48). No differences in the amount of water intake were found related to level of physical activity. These findings add to the evidence that leisure-time activity may reduce colon-cancer risk, not only in high-risk but also in low-risk populations, and support the potential beneficial effect of increased water intake in reducing colorectal-cancer risk.
Colorectal Section, Department of Surgery, Chang Gung Medical Center, Tao-Yuan, Taiwan.
R
R
Tang
J Y
JY
Wang
S K
SK
Lo
L L
LL
Hsieh
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000453:epidemiology*; D016001:Confidence Intervals; D004326:Drinking; D002149:Energy Intake; D015444:Exercise; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012004:Rectal Neoplasms / Q000453:epidemiology*; D018570:Risk Assessment; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D013177:Sports; D013624:Taiwan / Q000453:epidemiology