Association between fibrosis-4 index (FIB-4) and gallstones: an analysis of the NHANES 2017-2020 cross-sectional study.

Background: Gallstones are a common digestive disorder, yet the association between the fibrosis-4 index (FIB-4) and gallstone formation remains poorly understood. This study explores the link between FIB-4 levels and gallstone prevalence among US adults.

Methods: This study was based on data from the 2017-2020 National Health and Nutrition Examination Survey (NHANES), which included 7,771 participants. The association between FIB-4 and gallstone risk was analyzed using multivariate logistic regression with restricted cubic spline (RCS) analysis to assess nonlinear correlations, and threshold effects analysis to identify inflection points. Robustness checks included subgroup analysis.

Results: The weighted prevalence of gallstones in this study was 11%. Multiple logistic regression analysis showed that FIB-4 levels were significantly and positively associated with the risk of gallstones. In the fully adjusted model, each unit increase in FIB-4 as a continuous variable increased the risk of gallstones by 19% (OR = 1.19, 95% CI: 1.10, 1.29). When FIB-4 was grouped by quartiles, the risk of gallstones was increased by 60% (OR = 1.60, 95% CI: 1.25, 2.03) in the Q4 group compared to the Q1 group. RCS analysis further revealed a nonlinear positive correlation between FIB-4 and gallstones (P for nonlinear = 0.015) with an inflection point at 2.43, (P for log likelihood ratio test = 0.001). Bonferroni-corrected subgroup analyses showed that the association of FIB-4 with gallstones was statistically significant among non-Hispanic whites, those without heart failure, those without coronary heart disease, alcohol drinkers, and smokers (P < 0.00217).

Conclusion: In this study, we found that elevated levels of FIB-4 were significantly and positively association with the risk of gallstones, and showed a non-linear trend. FIB-4 may have a potential application in the risk assessment of gallstones.