Physical Activity is Associated with a Decreased Risk of Developing Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Background and Aims Modifiable risk factors in inflammatory bowel disease [IBD], such as physical activity, may be used as prevention strategies. However, the findings of previous studies on the association between physical activity and IBD risk have been inconsistent. We aimed to perform a systematic review and meta-analysis to estimate the effect of physical activity on IBD risk.Methods A search was conducted for relevant studies published before April 2023 that assessed the effect of pre-IBD diagnosis levels of physical activity on IBD incidence. Individual summary statistics [relative risks; RR], and confidence intervals [CI] were extracted with forest plots generated. We used the Grading of Recommendations Assessment, Development and Evaluation [GRADE] approach to assess the quality of evidence.Results Ten observational studies were included. For cohort studies, there were 1182 Crohn's disease [CD] and 2361 ulcerative colitis [UC] patients, with 860 992 participants without IBD. For case-control studies, there were 781 CD to 2636 controls, and 1127 UC to 3752 controls. Compared with individuals with low physical activity levels, the RRs of CD in individuals with high physical activity levels for cohort and case-control studies were 0.78 [95% CI 0.68-0.88, p = 0.0001] and 0.87 [95% CI 0.79-0.95, p = 0.003], respectively. For UC, the RRs were 0.62 [95% CI 0.43-0.88, p = 0.008] and 0.74 [95% CI 0.51-1.07, p = 0.11].Conclusion This meta-analysis suggests that physical activity is inversely associated with the risk of developing IBD, more so in CD than in UC.