High risk of colorectal polyps in men with non‐alcoholic fatty liver disease: A systematic review and meta‐analysis
Wenxia Chen, Muqing Wang, Xubin Jing, Chaofen Wu, Yicheng Zeng, Jianwei Peng, Xianbin Cai
Abstract
Abstract Background and Aim This meta‐analysis aims to explore the risk of colorectal polyps among non‐alcoholic fatty liver disease (NAFLD) patients. Methods We searched PubMed, 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. Results Twenty observational (12 cross‐sectional, two case–control, and six 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%). Conclusions NAFLD 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.