Diagnostic and prognostic value of triglyceride-glucose index in obesity phenotypes transition: a nested case-control...

While triglyceride-glucose (TyG) index has been proposed as an indicator of various cardiovascular outcomes, the diagnostic and prognostic value of TyG in obesity phenotypes transition remain unclear. We aimed to investigate the longitudinal association between TyG and transitions between metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO).

Data were derived from a 2-year follow-up prospective cohort study included 15,391 children aged 6-16 years in China. A nested case-control design was employed, identifying 331 pairs of incident MUO cases and matched MHO controls, as well as 420 pairs of incident MHO cases and matched MUO controls. Conditional logistic regression was used to analyze the associations between TyG and obesity phenotype transitions. An approximately linear association between TyG and the odds of obesity phenotype transition was observed in sex-stratified restrict cubic spine regression. Per 1-unit increase in TyG index was significantly associated with a 2.39-fold (OR 3.39; 95 %CI 2.20-5.21; P < 0.001) increase in the risk of progression from MHO to MUO, after controlling for sociodemographic factors and baseline cardiovascular parameters. Accordingly, higher TyG levels were linked to decreased odds of transitioning from MUO to MHO (OR 0.17; 95 % CI 0.11-0.26; P < 0.001). The TyG index demonstrated greater variable importance and standardized regression coefficient than other cardiovascular metabolic parameters in the prediction of obesity phenotypes transition.

Our findings suggest that TyG index is a valuable predictor of pediatric obesity phenotype transitions, highlighting its potential as a valuable tool for obesity management.