The Association Between Energy Expenditure And Colon Cancer Risk Reduction

Abstract

PURPOSE The objective of this study was to analyze existing data examining colon cancer risk reduction associated with an increased amount of leisure-time physical activity, in order to summarize the amount of activity associated with risk-reduction. METHODS A meta-analysis using Stata 7.0 was performed, and only studies using the Compendium of Physical Activities to assign MET-scores to leisure-time physical activites were included in the analysis (4 studies: 2 including both males and females; 1 including males; 1 including females). Subjects from the studies were combined and categorized as either having a “low” (< 2 MET hours-per-week), “moderate” (> 2 MET hours-per-week, <∼18 MET hours-per-week), or “high” (> ∼18 MET hours-per-week) amount of total weekly energy expenditure. RESULTS Males and females with a “high” amount of weekly energy expenditure had a significantly reduced colon cancer risk versus those exercising a “low” amount (OR = 0.52, p = 0.02, Males; OR = 0.63, p = 0.11, Females). No significant difference in colon cancer risk was reported for males or females with a “moderate” amount of energy expenditure compared with those exercising a “low” amount (OR = 0.88, p = .70, Males; OR = 0.83, p = .23, Females). CONCLUSION While additional studies (reporting caloric expenditure and using the Compendium) are necessary to further examine the relationship between energy expenditure and colon cancer risk, increased energy expenditure greater than approximately 18 MET hours-per-week may be associated with a reduction in colon cancer risk.