Association of triglyceride-glucose index and diabesity: evidence from a national longitudinal study.

Abstract

Background: Diabesity, a co-occurrence of diabetes and obesity, is a growing public health concern globally. The triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, has been associated with various metabolic disorders. This study aimed to investigate the association between TyG index and new-onset diabesity in a national longitudinal study.

Methods: We utilized data from the China Health and Retirement Longitudinal Study (CHARLS). Baseline data from the first wave (2011) and follow-up data from the third wave (2015) were analyzed. A Competing risks model based on Fine and Gray's subdistribution hazard approach was employed to examine the association between the TyG index and developing of three mutually exclusive outcomes: remaining free of diabetes and obesity, diabetes alone, and new-onset diabesity (co-occurrence of diabetes and obesity).

Results: A total of 6,976 participants were included in the analysis. During a mean follow-up period of 4.0 years, a total of 557 diabetes and 155 diabesity were recorded, respectively. After adjusting for socio-demographic information, lifestyle and comorbidities, compared with participants in the lowest quartile of TyG, the corresponding adjusted subdistribution hazard ratios (HRs) with 95% confidence intervals (95% CIs) for participants in the second, third, and fourth quartiles were 2.112 (95% CI: 1.047-4.259; P-value = 0.037), 2.911 (95% CI: 1.481-5.722, P-value = 0.002), and 4.305 (95% CI: 2.220-8.346, P-value < 0.001). The association between TyG and diabetes alone was equally significant when diabesity treated as the competing risk. Sensitivity analyses proved the robustness of results.

Conclusion: This national longitudinal study in China provides evidence that a higher TyG index is associated with an increased risk of developing diabesity.