Prostate cancer risk in relation to anthropometry and physical activity: the National Health and Nutrition Examination Survey I Epidemiological Follow-Up Study.

We studied the relationship of prostate cancer to anthropometry and self-reported physical activity among 5377 African-American and Caucasian participants in the National Health and Nutrition Examination Survey I cohort. The cohort was first examined between 1971 and 1975 and then followed prospectively through the Epidemiologic Follow-up Study in 1982-1984, 1986, 1987, and 1992. Men who reported low levels of nonrecreational physical activity had increased risk of prostate cancer compared with very active men. These findings were unchanged after adjustment for potential confounders and were stronger for African-Americans (relative risk, 3.7; 95% confidence interval, 1.7-8.4) than for Caucasians (relative risk, 1.7; confidence interval, 0.8-2.3). Lower levels of recreational activity were weakly associated with increased prostate cancer risk among African-Americans but not among Caucasians. Prostate cancer risk was unrelated to a variety of anthropometric variables. These results suggest that inactive men are at increased risk of prostate cancer.