title: Prospective study of body mass index, height, physical activity and incidence of bladder cancer in US men and women.
abstract: We evaluated prospectively the association between body mass index (BMI), height, recreational physical activity and the risk of bladder cancer among US adults. Data were used from 2 ongoing cohorts, the Health Professionals Follow-up Study and the Nurses' Health Study, with 3,542,012 years of follow-up and 866 incident bladder cancer cases (men = 507; women = 359) for the anthropometric analysis and 1,890,476 years of follow-up and 706 incident bladder cancer cases (men = 502; women = 204) for the physical activity analysis. Cox proportional hazard models were used to estimate incidence rate ratios (RR) and 95% confidence intervals (CI) between BMI, height, physical activity and bladder cancer risk adjusting for age, pack-years of cigarette smoking and current smoking. Estimates from each cohort were pooled using a random-effects model. We observed no association between baseline BMI and bladder cancer risk, even when we compared a BMI of > or =30 kg/m(2) to a BMI of 18-22.9 kg/m(2) [pooled multivariate (MV) RR, 1.16; 95% CI: 0.89-1.52]. A weak, but statistically significant, association was observed for the same comparison after excluding bladder cancer cases diagnosed within the first 4 years of follow-up (pooled MV RR, 1.33; 95% CI: 1.01-1.76). Height was not related to bladder cancer risk (pooled MV RR, 0.82; 95% CI: 0.65-1.03, top vs. bottom quintile). Total recreational physical activity also was not associated with the risk of bladder cancer (pooled MV RR, 0.97; 95% CI: 0.77-1.24, top vs. bottom quintile). Our findings do not support a role for BMI, height or physical activity in bladder carcinogenesis.
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, MA 02115, USA. cholick@hsph.harvard.edu
authors.forename: Crystal N
authors.initials: CN
authors.lastname: Holick
authors.forename: Edward L
authors.initials: EL
authors.lastname: Giovannucci
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.forename: Dominique S
authors.initials: DS
authors.lastname: Michaud
mesh_terms: D000328:Adult; D000368:Aged; D001827:Body Height; D015992:Body Mass Index; D015331:Cohort Studies; D015444:Exercise; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014481:United States / Q000453:epidemiology; D001749:Urinary Bladder Neoplasms / Q000453:epidemiology*