Impact of nonalcoholic fatty liver disease on the risk of gallbladder polyps in lean and non-obese individuals: A cohort study.

ABSTRACT

BACKGROUND: The association between non-obese or lean nonalcoholic fatty liver disease (NAFLD) and gallbladder polyps (GBPs) has not yet been evaluated. We aimed to determine whether NAFLD is an independent risk factor for the development of GBPs, even in non-obese and lean individuals. METHODS: We analyzed a cohort of 331 208 asymptomatic adults who underwent abdominal ultrasonography (US). The risk of GBP development was evaluated according to the obesity and NAFLD status. RESULTS: The overall prevalence of NAFLD and GBPs ≥ 5 mm was 28.5% and 2.9%, respectively. The prevalence of NAFLD among 160 276 lean, 77 676 overweight and 93 256 obese participants was 8.2%, 31.2%, and 61.1%, respectively. Individuals with NAFLD had a significantly higher incidence of GBPs with a size of ≥ 5 mm [adjusted odds ratio (OR) = 1.18; 95% confidence interval (CI) 1.11-1.25]. A higher body mass index and its categories were also significantly associated with an increased risk of GBPs ≥ 5 mm. Moreover, risk of GBPs ≥ 5 mm was significantly increased even in NAFLD individuals who are not obese (lean adjusted OR = 1.36, 95% CI 1.19-1.54; overweight adjusted OR = 1.14, 95% CI 1.03-1.26, respectively). CONCLUSIONS: Non-obese/lean NAFLD is an independent risk factor for GBP development, suggesting that NAFLD may play an important role in the pathogenesis of GBPs regardless of the obesity status. Therefore, a more thorough evaluation for GBPs may be necessary when hepatic steatosis is detected on abdominal US, even in non-obese or lean individuals.