Abstract Body (Do not enter title and authors here): Background: The Triglyceride-glucose (TyG) index , a novel indicator of insulin resistance, has been associated with mortality from non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD). However, the association between the TyG index and the derived index of TyG (TyG-WHtR) and CVD in NAFLD patients remains unclear.
Methods: This study enrolled 6627 adults aged 18 and above diagnosed NAFLD from the National Health and Nutrition Examination Survey (NHANES, 1999-2018). Binary weighted logistic regression analyses, cox proportional hazards model, restricted cubic spline (RCS), and receiver operating characteristic (ROC) were used to analyze the relationship between TyG and TyG-WHtR and all-cause mortality, CVD mortality and CVD related diseases. Mediation analysis explored the mediating role of glycohemoglobin (HbA1c), insulin and hypertension in the above relationships.
Results: Except for no significant association between TyG and all-cause mortality and chronic heart failure (CHF), both TyG and TyG-WHtR exhibited significant positive correlations or trends of positive correlation with all-cause mortality, CVD mortality, total-CVD, CHF, coronary heart disease (CHD) and angina pectoris. For all-cause mortality, CVD mortality and CHF, TyG-WHtR was a better predictor than TyG (HR 1.31, 95%CI 1.03-1.66; HR 2.22, 95%CI 1.42-3.47; OR 3.99, 95%CI 1.79-8.93). However, TyG index demonstrated a stronger association with total-CVD, CHD and angina pectoris (OR 2.00, 95%CI 1.26-3.18; OR 1.85, 95%CI 1.19-2.91; OR 2.93, 95%CI 1.23-7.00). Otherwise, the ROC curve illustrated that, for all-cause mortality, CVD mortality, CHD and angina pectoris, TyG had a higher diagnostic efficacy. For CHF, the diagnostic efficacy of TyG-WHtR is higher. For total-CVD, TyG and TyG-WHtR had approximately equal diagnostic efficacy. RCS analysis showed that after adjusting for covariates, most of the above relationships were linearly correlated (P-overall < 0.0001, P-nonlinear> 0.05), while TyG and TyG-WHtR were non-linearly associated with all-cause mortality and CHF (P-overall < 0.0001, P-nonlinear< 0.05) in NAFLD patients.
Conclusions: The predictive value of TyG or TyG-WHtR for mortality and cardiovascular risk in NAFLD patients was significant. The TyG index and TyG-WHtR might be a valid predictor of cardiovascular outcomes of patients with NAFLD.