The Association Between Nonalcoholic Fatty Liver Disease And Risk Of Colorectal Adenoma And Cancer Incident:a Meta-analysis

Objective:To systematically evaluate the relationship between the existence and severity of nonalcoholic fatty liver disease and the risk of colorectal adenoma and colorectal cancer,in order to provide evidence for the early clinical prevention and treatment of colorectal tumors.Methods:PubMed,Embase,Web of Science,The Cochrane Library,CNKI,Wanfang,and Weipu databases were searched for Chinese and English literature published before December 2019 on the relationship between NAFLD and risk of CRA and CRC.Two researchers screened the literature independently on the basis of inclusion and exclusion criteria.If the inclusion results are inconsistent,they will jointly view the full text of the divergent literature and discuss it.If necessary,a third party can be asked for evaluation.Evaluating the quality of literature,and extract the essential information,employ Rev Man 5.3 software to analyse data,the forest map of the corresponding research was drawn,then assess the sensitivity analysis and publication bias.Results:1.Literature retrieval results: initial literatures were gradually selected after weighting,reading titles,abstracts and full text.Contains 3 longitudinal cohort studies and 18 crosssectional studies.A total of 130 271 study subjects were included,including 43 707 NAFLD patients.Among them,16 studies explored the relationship between NAFLD and the risk of all CRA,13 studies explored the relationship between NAFLD and the risk of advanced CRA/CRC,and 7 studies explored the severity of NAFLD and the risk of CRA/CRC.2.Statistical analysis results:(1)NAFLD patients have an increased risk of CRA[aOR=1.27,95% CI(1.18,1.36),P<0.00001] and advanced CRA/CRC[aOR=1.45,95% CI(1.27,1.65),P<0.00001].(2)Patients with NASH and/or advanced liver fibrosis have a significantly increased risk of CRA/CRC [aOR=1.93,95% CI(1.61,2.31),P<0.00001].3.Sensitivity analysis and publication bias results: The sensitivity analysis indicated that the results in this meta-analysis were stable.The funnel chart is used to evaluate the publication bias of the included literature,and there is no obvious publication bias.Conclusion:The presence of NAFLD is associated with an increased risk of CRA and CRC.The higher the severity of NAFLD,the higher the risk of CRA and CRC.