Association between the triglyceride glucose-body mass index and the risk of incident type 2 diabetes: a systematic review and meta-analysis

Objective The rising prevalence of type 2 diabetes (T2D) has created a huge global public health burden. Although triglyceride glucose-body mass index (TyG-BMI) has been associated with incident T2D risk in observational studies, the overall evidence remains to be systematically evaluated. Methods This study systematically searched Chinese databases (China National Knowledge Infrastructure, Wanfang Data, and China Science and Technology Journal Database) and English databases (PubMed, Web of Science, Cochrane Library, Embase), with the search period covering from the establishment of each database to May 1, 2026. Literature screening, data extraction, and quality assessment were independently performed by two reviewers using the Newcastle-Ottawa Scale (NOS) for study quality evaluation. Meta-analysis was conducted using Stata 16.0 and Review Manager 5.4.1 software: Effect sizes were pooled using a random-effects model, with results reported as hazard ratios (HR) and 95% confidence intervals (CI). Subgroup analyses by the proportion of male participants, follow-up duration, and sample size explored sources of heterogeneity. Sensitivity analyses using exclusion of individual studies validated result robustness. Finally, risk of publication bias was assessed via funnel plot symmetry testing and Egger’s regression. Results A total of six cohort studies involving 176,127 participants were included in this meta-analysis. For continuous-variable analysis, four studies reporting hazard ratios (HRs) per 1-standard deviation (SD) increase in TyG-BMI were included. The pooled analysis demonstrated that each 1-SD increase in TyG-BMI was significantly associated with an increased risk of incident type 2 diabetes (HR = 1.68, 95% CI: 1.50–1.88, I 2 = 87%). Subgroup analyses according to sex distribution, follow-up duration, and sample size revealed no significant differences in effect estimates, except that sample size may partially contribute to between-study heterogeneity. For categorical-variable analysis, six studies showed that higher TyG-BMI categories were associated with an increased risk of incident type 2 diabetes (HR = 3.35, 95% CI: 2.24–5.03, I 2 = 89%). Subgroup analyses indicated that follow-up duration significantly modified the association, with stronger effects observed in studies with follow-up duration < 7 years (HR = 6.22, 95% CI: 3.49–11.10) compared with those with follow-up duration ≥ 7 years (HR = 2.50, 95% CI: 1.77–3.53). Sensitivity analyses demonstrated that the pooled estimates remained stable after sequential exclusion of individual studies. Funnel plots and Egger’s tests showed no statistically significant evidence of publication bias. Conclusion This meta-analysis reveals a possible association between elevated TyG-BMI and higher risk of incident T2D in the general population. With the advantages of convenience and low cost, TyG-BMI may represent a potential marker associated with T2D risk stratification, although further studies are required to determine its clinical applicability. Due to the limited number of eligible studies, the assessment of publication bias was insufficient. Therefore, our findings should be regarded as preliminary and require validation in future large-scale investigations. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420251232373 , identifier CRD420251232373.