Triglyceride-glucose index, a silent predictor for osteosarcopenic adiposity occurrence and risk of cardiovascular and all-cause mortality.

BACKGROUND: The evidence linking the triglyceride-glucose (TyG) index to osteosarcopenic adiposity (OSA) in young and middle-aged populations is limited. This study aimed to investigate the association between the TyG index and OSA, and to determine the predictive value of the TyG index for all-cause and cardiovascular disease (CVD) mortality in OSA patients. METHODS: This cross-sectional and cohort study enrolled 8,098 participants aged 20-59 in the National Health and Nutrition Examination Survey (1999-2006 and 2011-2018). Mortality was determined by linkage to the National Death Index through December 31, 2019. Multivariable logistic regression models and restricted cubic splines (RCS) were constructed to determine the association between the TyG index and the prevalence of OSA. Multivariable Cox proportional hazards regression and competing risk analyses were employed to evaluate the association between the TyG index and mortality among OSA patients. RESULTS: There were 4,153 participants in the 1999-2006 cycle (weighted proportion male, 50.8%; mean [SD] age, 39.53 [10.98] years), and 3,945 in the 2011-2018 cycle (weighted proportion male, 50.7%; mean [SD] age, 39.00 [11.72] years). A higher TyG index was significantly associated with a greater prevalence of OSA, with an odds ratio (OR) of 4.52 (95% confidence interval [CI]: 3.78, 5.42) for the highest quartile. A J-shaped association was identified between the TyG index and the prevalence of OSA. Additionally, during a mean follow-up period of 131.1 months, OSA patients with the TyG index ≥ 8.5 exhibited a significantly elevated risk of all-cause mortality (hazard ratio [HR] = 1.93, 95% CI: 1.37, 2.71) and CVD mortality (HR = 2.10, 95% CI: 1.13, 3.88). Furthermore, sex disparity markedly affected the association between the TyG index and the prevalence of OSA and all-cause mortality in OSA patients. CONCLUSIONS: This study revealed that a higher TyG index was associated with an increased risk of OSA and predicted a higher all-cause and CVD mortality in OSA patients. The implementation of public health interventions to reduce the TyG index may prove an effective method to decrease the incidence of OSA and related mortalities.