Prevalence and Risk Factors of Gallbladder Polyps Among Jeju Natives and Migrants: Retrospective Cross-Sectional Study

Background/Aim: Routine ultrasonography now detects gallbladder polyps (GBPs) more often, but reported prevalence varies across populations. Jeju Island has South Korea’s highest obesity prevalence and red meat consumption, suggesting a rapid nutritional transition similar to that reported in Native Hawaiians. This study aimed to first analyze risk factors influencing GBP prevalence, including birthplace, and second compare clinical variables between JNs and JMs. Methods: Between May 2018 and October 2023, 28,751 individuals underwent medical checkups at Jeju National University Hospital. GBPs were diagnosed via ultrasonography, and risk factors including age, sex, birthplace, metabolic syndrome, hepatitis B virus antigen (HBsAg) positivity, lipid profiles, and alcohol consumption were assessed using univariate and multivariate logistic regression. Results: After exclusions, 15,219 participants were analyzed. The overall prevalence of GBPs was 10.3%. Male participants had a higher prevalence than females (11.4% vs. 9.1%, p < 0.001). The younger age group (20–49 years) showed the highest prevalence, while those aged ≥70 years had the lowest (11.6% vs. 8.6%, p = 0.001). Jeju Natives (JNs) exhibited a significantly higher prevalence than Jeju migrants (JMs) (10.6% vs. 9.0%, p = 0.004). Multivariate analysis identified female sex [odds ratio (OR) = 0.644, p < 0.001], age ≥ 70 years (OR = 0.601, p < 0.001), JN birthplace (OR = 1.260, p = 0.015), HBsAg positivity (OR = 1.347, p = 0.040), and high-risk alcohol drinking (OR = 0.758, p = 0.001) as independent predictors. Notably, the 60–69 age group did not reach statistical significance in the optimized model (p = 0.158). Compared to JMs, JNs were older and had a higher prevalence of fatty liver disease, a higher BMI, and higher levels of AST and GGT, but lower levels of HDL-cholesterol and triglycerides. Conclusions: GBPs are more prevalent among JNs compared to JMs, with birthplace emerging as a novel independent risk factor. Fatty liver disease, BMI, and reduced HDL-cholesterol were associated with GBP risk. These findings hypothesize that dietary and metabolic health factors may be potential pathways for the higher GBP prevalence among JNs, though direct dietary assessment is required for confirmation.