Higher relative fat mass was associated with a higher prevalence of gallstones in US adults

Our study aimed to investigate the association between the relative fat mass (RFM) and gallstones in adults.

Information obtained from the National Health and Nutrition Examination Survey (NHANES) 2017-2023 was utilized to examine the correlation between RFM and gallstones based on weighted multivariable regression analysis, smoothing curve fitting, and threshold effect analyses. Using subgroup analysis and interaction tests, we investigated whether this association remained consistent across different populations. We evaluated the effectiveness of RFM and Body Mass Index (BMI) in detecting gallstones through receiver operating characteristic (ROC) analysis and by calculating the area under the curve (AUC).

The study involved 7618 participants in total. RFM mean was 30.74 ± 5.68. Based on the fully adjusted model, gallstone prevalence was positively associated with RFM (OR = 1.09; 95% CI: 1.07-1.11; p < 0.001), with a 9% increase for each unit increase in RFM. This correlation was particularly evident among individuals under the age of 40 and among females. Smoothing curve fitting revealed a nonlinear association between RFM and the occurrence of gallstones, with an inflection point identified at 19.8. Additionally, ROC analysis showed that RFM (AUC = 0.674) outperformed BMI (AUC = 0.634) as a predictor of gallstone formation.

Higher RFM was associated with higher gallstone prevalence. RFM may be a more useful tool for gallstone prediction than BMI in the general population. Gallstones may be alleviated or improved by RFM management at an early age.

Not applicable.