Association of nonalcoholic fatty liver disease with colorectal adenomatous polyps and non-adenomatous polyps: a cross-sectional study.

Aim: This study aimed to investigate the association between non-alcoholic fatty liver disease (NAFLD) and both colorectal adenomatous polyps and non-adenomatous polyps, in order to provide evidence for the prevention of colorectal cancer (CRC) in patients with NAFLD.

Methods: A retrospective, cross-sectional study was conducted at the First People's Hospital of Kunshan, Jiangsu, China. The study included 3028 adults who underwent abdominal ultrasonography and colonoscopy over a 5 year period. We compared characteristics among patients with adenomatous polyps, non-adenomatous polyps, and without colorectal polyps using descriptive statistics. Logistic regression analyses were used to detect associations between NAFLD with the prevalence of adenomatous polyps and non-adenomatous polyps. NAFLD was determined by abdominal ultrasound. Colorectal polyps were assessed by data in the colonoscopy report and pathology report.

Results: A total of 65% of patients with NAFLD had colorectal polys (52% adenomatous polyps and 13% non-adenomatous polyps), and 40% of patients without NAFLD had polyps (29% adenomatous polyps and 11% non-adenomatous polyps). After adjusting for confounding variables, NAFLD was significantly associated with the prevalence of adenomatous in males and females [odds ratio (OR) = 1.8, 95% confidence interval (CI): 1.6-2.2, P  < 0.01], but was not associated with non-adenomatous polyps (OR = 1.2, 95% CI:0.9-1.5, P  > 0.05).

Conclusion: NAFLD is associated with an increased risk of colorectal adenomatous polyps compared to the absence of polyps, but not associated with an increased risk of non-adenomatous polyps. These results provide important evidence for the prevention of CRC in patients with NAFLD.