Association of triglyceride-glucose-related indices with all-cause and cause-specific mortality in individuals with prediabetesss.

Background: The triglyceride-glucose (TyG) index has been linked to the occurrence of prediabetes, but there is limited evidence regarding its association with mortality in individuals with prediabetes. Thus, this study aimed to explore the association between TyG-related indices and all-cause and cause-specific mortality in individuals with prediabetes.

Method: Based on NHANES data from 1999 to 2018, the TyG index, TyG-waist circumference (TyG-WC), and TyG-waist-to-height ratio (TyG-WHtR) were calculated. Mortality data including all-cause mortality, cardiovascular disease (CVD) mortality, and cancer mortality were determined as of December 31, 2019. Kaplan-Meier curves, Cox regression analysis, and restricted cubic splines (RCS) were used to assess associations of TyG-related indices with all-cause and cause-specific mortality (CVD and cancer) in individuals with prediabetes. Subgroup and sensitivity analyses were used to confirm the robustness of the results.

Results: In total, 9,574 participants with prediabetes were included. Kaplan-Meier curves indicated that overall survival and cancer-specific survival were associated with different quartiles of the TyG index, with quartile 1 having the lowest all-cause mortality (P = 0.042 and P = 0.008). TyG-WHtR was negatively correlated with overall survival and CVD-specific survival (P < 0.001 and P = 0.012). Multivariate Cox regression analysis showed a significant positive correlation between the TyG index and cancer mortality (Q4: HR = 1.957, 95% CI: 1.126-3.402, P = 0.017). High quartiles of TyG-WC were significantly associated with cancer mortality in participants with prediabetes (HR = 2.397, 95% CI, 1.062-5.409, P = 0.035). Similarly, higher quartiles of TyG-WHtR were positively associated with all-cause, CVD, and cancer mortality. RCS analysis showed that TyG-WC and TyG-WHtR were nonlinearly correlated with cancer mortality (P for nonlinear = 0.028 and 0.006).

Conclusion: Elevated TyG and TyG-WC levels were significantly associated with increased cancer mortality risk, while TyG-WHtR showed stronger associations with all-cause and cause-specific mortality in individuals with prediabetes. These indices could serve as surrogate biomarkers for follow-up and clinical management of individuals with prediabetes.