Association Between Triglycerides-Glucose Index and Left Ventricular Mass. Uric Acid Right for Heart Health Project

Objective: The triglyceride-glucose (TyG) index is a novel surrogate marker of insulin resistance. Epidemiological studies show positive relationships between TyG and cardiovascular risk; previous studies showed significant associations between TyG index, arterial stiffness and renal damage, while few data explored the association with left ventricular mass (LVM) and function. We aimed to assess the association between TyG index and LVM in a large Italian cohort of the Working Group on Uric Acid and Cardiovascular Risk of the Italian Society of Hypertension, the URic acid Right for heArt Health (URRAH) study. Design and method: The TyG index was calculated using this formula: Ln (TG [mg/dL] * fasting glucose [mg/dL])/2). We used the TyG threshold of 4.54 Units to identify subjects at higher risk of cardiovascular mortality. LVH was defined as LVM indexed to height 2.7 > 47 g/m2.7 in women and 50 g/m2.7 in men. Results: N=6392 patients (51% men, mean age 53 + 13 years) with echocardiography and without previous CV events were included. Univariable analyses showed a significant correlation between TyG index and age, body mass index (BMI), Pulse pressure (PP), heart rate (HR), uric acid (UA), HDL cholesterol, LVMi, estimated glomerular filtration rate (eGFR), and UA/ creatinine ratio (UA/C). Multivariable linear regression with TyG index as continuous dependent variable revealed significant associations with HDL-C (Beta=-0,26, p=0.001), eGFR (Beta=-0,060, p=0.001), PP (Beta=0.062, p<0.001), LVMi (Beta=-0,033, p=0.04), UA (Beta=0.159, p<0.001), HR (Beta=0.082, p<0.001); age and sex did not enter the equation. Logistic regression demonstrated a significant association of high TyG index with the presence of LVH (OR=1.164; 95% CI 1.004-1.350, p=0.045) independently of HDL-cholesterol (OR=0.97; 95% CI 0.96-0.97, p=0.001), BMI (OR=1.094; 95% CI 1.073-1.008, p=0.001), PP (OR=1.004 95%; CI 1.00-1.008, p=0.001), eGFR (OR=0.987; 95% CI 0.984-0.991, p=0.001), and HR (OR=1.001; 95% CI 1.005-1.017, p=0.001). Conclusions: In this analysis of the URRAH study, the TyG index was significantly associated to an increase in LVM index, independently of several possible confounders, including UA. These findings can explain at least in part the association between TyG index and the risk of CV events.