Prevalence of colonic adenomas in patients with nonalcoholic fatty liver disease

Background: Epidemiologic data suggest that colonic adenomas have an increased tendency to occur in patients who are obese, African American, or have a positive family history of colon cancer, or diabetes mellitus. Recent data suggest that impaired glucose tolerance, dyslipidemia, and metabolic syndrome are associated with a higher risk for colonic adenomas. Patients with nonalcoholic fatty liver disease (NAFLD) often share several of the aforementioned risk factors for colonic adenomas. However, data are lacking about the relationship between NAFLD and colonic adenomas. The aim of this study was to systematically evaluate whether NAFLD is an independent risk factor for colonic adenomas.

Methods: We performed a retrospective cohort observational study on 233 patients who underwent screening colonoscopies at Brooke Army Medical Center from November 2007 to March 2010 to assess for the association between NAFLD and colonic adenomas. Patients who had previously been found to have biopsy-proven simple steatosis (n = 65) or nonalcoholic steatohepatitis (NASH) (n = 29) were compared with a control group without fatty liver disease on sonographic imaging (n = 139). Patients were stratified based on gender, race, body mass index (BMI), and family history and adjusted for variables previously known to be associated with increased adenoma risk.

Results: The mean age was 54.7 ± 6.0 years (48.5% women). Racial demographics were: 62.7% White, 18.5% Hispanic, 13.7%, African American, and 5.2% other. The mean BMI was 29.7 ± 5.8. The prevalence of colonic adenomas was 25.1% in the control group and 24.4% in the NAFLD group to include simple steatosis and NASH (p = 1.00). Furthermore, when adjusting for known confounders to include race, BMI, and family history no significant differences were found (p = 0.33). However, the ultrasound-negative patients ranked lower in the number of adenomas per person (p = 0.016).

Conclusions: There was no difference in the prevalence of colonic adenomas when comparing the NAFLD group who had undergone colonoscopy with a group of control patients without NAFLD who had undergone colonoscopy. However, patients with negative ultrasounds appeared to have a lower polyp burden.