High Risk Of Colorectal Polyps In Men With Nonalcoholic Fatty Liver Disease

Background and AimThis meta-analysis aims to explore the risk of colorectal polyps among non-alcoholic fatty liver disease(NAFLD)patients.MethodsWe searched Pub Med,EMBASE,and Cochrane library databases using predefined search term to identify eligible studies(published up to 7 November 2019).Data from selected studies were extracted by using a standardized information collection form,and meta-analyses were performed using random-effects model.The statistical heterogeneity among studies(I~2),subgroup analyses,meta-regression analyses,and the possibility of publication bias were assessed.ResultsTwenty observational(12 cross-sectional,2 case–control,and 6 cohort)studies met the eligibility criteria,involving 142,387 asymptomatic adults.In cross-sectional/case–control studies,NAFLD was found to be associated with an increased risk of colorectal polyps(odds ratio[OR]=1.34;95%confidence interval[CI]=1.23–1.47)(including unclassified colorectal polyps,hyperplastic polyps,adenomas,and cancers)with statistically significant heterogeneity(I~2=67.8%;P<0.001).NAFLD was also associated with a higher risk of incident colorectal polyps(hazard ratio=1.60;95%CI=1.36–1.87)with low heterogeneity(I~2=21.8%;P=0.263)in longitudinal studies.The severity of NAFLD was associated with a higher risk of colorectal adenomas(OR=1.57;95%CI=1.30–1.88),but not colorectal cancer(OR=1.37;95%CI=0.92–2.03).The subgroup analysis according to gender showed that NAFLD was significantly associated with a higher risk of colorectal polyps in the male population without significant heterogeneity(OR=1.47;95%CI=1.29–1.67,I~2=0%),but not in the female population(OR=0.88;95%CI=0.60–1.29,I~2=34.2%).ConclusionsNAFLD was associated with an increased risk of colorectal polyps.There was a significant difference of the relationship between genders,which suggested more precise screening colonoscopy recommendation in NAFLD patients according to gender.