Association between physical activity and inflammatory bowel disease risk: A meta-analysis.
BACKGROUND
Previous studies of an association between physical activity and inflammatory bowel disease have yielded conflicting results.


OBJECTIVE
This meta-analysis was conducted to clarify whether there is an association between physical activity and inflammatory bowel disease.


METHODS
The PubMed and Web of Science databases were searched for relevant studies published up to October 2015. Data were extracted and the summary relative risks (RRs) were calculated using a random effects or a fixed-effects model, according to heterogeneity.


RESULTS
Seven studies were included in the analysis. Relative to individuals with low physical activity, those who participated in high physical activity had an RR of 0.63 (95% CI, 0.50-0.79) for developing Crohn's disease. In stratified analyses, a significantly lower risk for Crohn's disease was associated with high physical activity in Europeans only (RR, 0.62; 95% CI, 0.43-0.91); population-based control studies (RR, 0.56; 95% CI, 0.41-0.76); and case-control studies (RR, 0.56; 95% CI, 0.41-0.75). The data of 6 studies were pooled to analyze the effect of physical activity on the risk of ulcerative colitis, and no significant association was found (RR, 0.82; 95% CI, 0.68-1.00).


CONCLUSIONS
The pooled results of observational studies support that physical activity has a protective effect against Crohn's disease.
Department of Gastroenterology, Changzhou No. 2 Hospital, Affiliated with Nanjing Medical University, Changzhou City, Jiangsu Province, China.
Qiang
Q
Wang
Department of Gastroenterology, Changzhou No. 2 Hospital, Affiliated with Nanjing Medical University, Changzhou City, Jiangsu Province, China.
Ke-Qun
KQ
Xu
Department of Gastroenterology, Changzhou No. 2 Hospital, Affiliated with Nanjing Medical University, Changzhou City, Jiangsu Province, China.
Xiang-Rong
XR
Qin
Department of Gastroenterology, Changzhou No. 2 Hospital, Affiliated with Nanjing Medical University, Changzhou City, Jiangsu Province, China.
Wen-Lu
Department of Gastroenterology, Changzhou No. 2 Hospital, Affiliated with Nanjing Medical University, Changzhou City, Jiangsu Province, China.
Yan-Liu
Department of Gastroenterology, Changzhou No. 2 Hospital, Affiliated with Nanjing Medical University, Changzhou City, Jiangsu Province, China. Electronic address: wxy20009@126.com.
Xiao-Yong
XY
Wang
D003424:Crohn Disease / Q000453:epidemiology* / Q000517:prevention & control*; D015444:Exercise; D006801:Humans; D064887:Observational Studies as Topic; D018570:Risk Assessment
Crohn's disease; Inflammatory bowel disease; Meta-analysis; Physical activity; Ulcerative colitis