Active exercise after polypectomy reduces the risk of metachronous advanced colorectal neoplasm

Background and study aims Exercise is associated with a lower risk of colorectal neoplasm but its association with metachronous advanced colorectal neoplasm development after polypectomy remains unclear. We aimed to investigate associations between subjects' exercise habits and the risk of metachronous advanced colorectal neoplasm. Patients and methods This study analyzed subjects older than 40 years who received screening colonoscopy with polypectomy and surveillance colonoscopy between January 2009 and December 2016. All participants completed a standard questionnaire containing exercise habits before surveillance colonoscopy. Subjects' exercise habits were quantified as weekly exercise amounts (metabolic equivalents of task-day/week) and dichotomized (active/sedentary exercise habit) using averages as the cut-off point. The associations between incidence of metachronous advanced colorectal neoplasm and exercise habits were evaluated using Kaplan-Meier analysis and Cox regression models. Results A total of 1820 subjects comprised the study cohort and 86 (4.73%) of them developed metachronous advanced colorectal neoplasm during the surveillance period. An active exercise habit after polypectomy was associated with a lower risk of metachronous advanced colorectal neoplasm (adjusted hazard ratio [aHR] 0.57, 95% confidence interval [CI] 0.35-0.91). Furthermore, this protective effect from exercise was specific for subjects having advanced neoplasm at screening colonoscopy (aHR 0.32, 95% CI 0.11-0.94). Conclusions An active exercise habit after polypectomy, a surrogate for a more active lifestyle, is associated with a lower risk for developing metachronous advanced colorectal neoplasm. A positive lifestyle modification, such as maintaining/establishing an active exercise habit, should be advised after polypectomy, especially for those with advanced colorectal neoplasm during screening.