Does physical activity modify the association between body mass index and colorectal adenomas?
Although both physical inactivity and obesity have been associated with an increased risk of colorectal adenomas, it is unclear whether physical activity modifies the relationship between obesity and colorectal adenomas or through what mechanism this might occur. The aim of this study is to evaluate whether physical activity modifies the relationship between body mass index (BMI) and colorectal adenomas and whether apoptosis is a plausible mechanism responsible for this effect modification. Study subjects were part of a large, cross-sectional study, the Diet and Health Study III. Consecutive patients underwent colonoscopy between August 1998 and March 2000. Apoptosis was measured by morphological evaluation of hematoxylin and eosin-stained sections obtained from rectal pinch biopsy samples. There were 226 patients with adenomas and 494 adenoma-free controls. When comparing overweight subjects with the referent group (high physical activity/normal BMI), the relative odds of having an ad
