Association between triglyceride-glucose and fibrosis-4 indices and nephrolithiasis: a cross-sectional case-control study.

OBJECTIVE

Fibrosis-4 (a liver fibrosis index) and triglyceride-glucose (an insulin resistance surrogate) indices may be markers associated with kidney stone risk. The aim of this study was to evaluate the association between triglyceride-glucose and fibrosis-4 indices and the presence of nephrolithiasis in adults.

METHODS

This retrospective cross-sectional case-control study included 918 adults (785 with nephrolithiasis, 133 controls) evaluated between January 2016 and December 2023. Controls were consecutive patients from the same urology outpatient population who underwent abdominal imaging for non-stone-related urological indications, with no radiological evidence of nephrolithiasis. Triglyceride-glucose and fibrosis-4 indices were calculated using standard formulas. The triglyceride-glucose index was standardized (per 1 SD=0.23 units) prior to multivariable logistic regression including age, sex, and fibrosis-4.

RESULTS

Triglyceride-glucose was significantly higher in stone formers (4.87±0.21 vs. 4.64±0.20; p<0.001). In multivariable analysis, triglyceride-glucose independently predicted nephrolithiasis (adjusted OR per 1 SD=3.52; 95%CI 2.48-5.00; p<0.001); male sex was also independently associated. Fibrosis-4 was not independently associated (p=0.809). Triglyceride-glucose area under the curve was 0.779 (95%CI 0.729-0.827), consistent across both sexes (interaction p=0.135).

CONCLUSION

Each 1 SD increase in triglyceride-glucose was associated with a 3.5-fold increase in odds of nephrolithiasis, independent of age, sex, and fibrosis-4. Fibrosis-4 showed no independent utility. Prospective studies are needed to confirm these findings.