Association between the triglyceride-glucose index and kidney stone disease: a systematic review and dose-response meta-analysis

Background The triglyceride-glucose (TyG) index is an accessible marker of insulin resistance and may reflect metabolic susceptibility to kidney stone disease (KSD). This review synthesizes observational evidence on TyG and KSD and examines whether the association varies with increasing TyG. Methods PubMed, Embase, Web of Science, Scopus, the Cochrane Library, and ProQuest were searched up to May 22, 2026 according to PRISMA 2020 and a PROSPERO-registered protocol. Eligible studies enrolled adults, assessed TyG as either a continuous or categorical exposure, reported KSD as the outcome, and provided extractable effect estimates. Study quality was evaluated using the Joanna Briggs Institute (JBI) tools. Maximally adjusted odds ratios (ORs) were synthesized using the restricted maximum likelihood (REML) random-effects model. One-stage dose-response meta-analyses using linear and restricted cubic spline models were also conducted, and the certainty of evidence was judged using GRADE. Results Fourteen studies (total n = 1,066,215; KSD cases = 50,286) met the inclusion criteria. In the continuous analysis, each 1-unit increment in TyG corresponded to higher KSD odds (pooled adjusted OR: 1.33; 95% confidence interval [CI]: 1.15–1.54). Compared with the lowest TyG category, the highest had 52% higher odds of KSD (OR: 1.52; 95% CI: 1.26–1.84). In a one-stage random-effects dose-response meta-analysis, restricted cubic spline models provided the best fit but showed no statistical evidence of non-linearity, supporting a linear association with a 26% increase in odds per 1-unit increase in TyG (OR: 1.26; 95% CI: 1.12–1.42; 95% PI: 0.91–1.75). Conclusion A higher TyG index was associated with greater odds of KSD in a broadly linear manner; however, the marked heterogeneity across studies suggests that TyG should be viewed as a potential metabolic risk marker rather than a routine screening tool. These findings may support broader cardiometabolic risk assessment and standard preventive counseling in patients at risk of KSD.