Impact of non-alcoholic fatty liver disease and smoking on colorectal polyps

// Qin-Fen Chen 1, * , Xiao-Dong Zhou 2, * , Dan-Hong Fang 3 , Yang-Jie Sun 1 , Qian Zhao 1 , Jun-Hua Huang 1 , Yin Jin 1 and Jian-Sheng Wu 3 1 Department of Gastroenterology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China 2 Department of Cardiovascular Medicine, First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China 3 Medical and Health Care Center, First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China * Co-first author Correspondence to: Jian-Sheng Wu, email: wenzhouwujs@163.com , wzwujs@wzhospital.cn Keywords: colorectal polyps, smoking, non-alcoholic fatty liver disease, health check Received: February 27, 2017      Accepted: July 25, 2017      Published: August 24, 2017 ABSTRACT Objectives: Non-alcoholic fatty liver disease (NAFLD) and smoking have similar mechanisms of promoting colorectal polyps. The potential link between NAFLD and smoking in men and colorectal polyps has not been adequately evaluated. The aim is to investigate this association. Methods: A retrospective cross-sectional study was conducted on 2409 individuals undergoing a health check. Univariate and multivariate logistic regression were performed for analyzing the association between risk factors and colorectal polyps. Individuals were divided into four groups: Q1: NAFLD (-)/smoking (-); Q2: NAFLD (+)/smoking (-); Q3: NAFLD (-)/smoking (+); Q4: NAFLD (+)/smoking (+). Logistic analyses were used to explore associations for the whole study population and stratified groups. Results: The prevalence of colorectal polyps was 38.8% in males, and that of colorectal polyps in smokers and individuals with NAFLD were 47.0% (428/911) and 42.9% (267/622), respectively. With Q1 as reference, subjects with NAFLD (+) and smoking habits (+) had the highest ORs for colorectal polyps (OR = 2.64, 95% CI: 1.91 - 3.64, P < 0.001), adenomatous polyps (OR = 2.06, 95% CI: 1.38 - 3.05, P < 0.05), non-adenomatous polyps (OR = 1.97, 95% CI: 1.39 - 2.80, P < 0.05), ≥ 3 polyps (OR = 2.05, 95% CI: 1.31 - 3.22, P < 0.05) and proximal polyps (OR = 1.58, 95% CI: 1.02 - 2.45, P < 0.05) after adjusting for confounding variables. Conclusions: Men with NAFLD and smoking habits have an increasing risk of colorectal polyps.