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

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.

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).

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.

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