Body mass index and physical activity as risk factors for pancreatic cancer:: the Multiethnic Cohort Study

To examine body mass index (BMI) and physical activity as risk factors for pancreatic cancer. Eight-year prospective data from 77,255 men and 90,175 women including 237 and 235 pancreatic cancer cases, respectively, in the Hawaii-Los Angeles Multiethnic Cohort Study were analyzed. Participants completed a questionnaire that included questions on body weight, height, and physical activity. Cox proportional hazards models were calculated to estimate relative risks (RR) of pancreatic cancer by levels of BMI and total physical activity (as metabolic equivalents (METs)) adjusted for several potential confounders. Obesity (BMI >= 30 kg/m(2) stop) was associated with an increased pancreatic cancer risk in men (RR = 1.51 (95% CI: 1.02-2.26)), but a reduced risk in women (RR = 0.65 (95% CI: 0.43-0.99)). In men the risk was higher in never smokers than in current or former smokers, though differences were not statistically significant. Physical activity was not associated with pancreatic cancer risk in either men or women. The findings suggest, that a BMI of >= 30 kg/m(2) stop may be a risk factor for pancreatic cancer in men. No evidence of an effect of physical activity on risk was found.