HOMA-IR and TyG index differ for their relationship with dietary, anthropometric, inflammatory factors and capacity to predict cardiovascular risk

Background: HOMA-IR and the triglyceride-glucose index (TyG index) are surrogate indexes of insulin resistance. However, it remains to elucidate how HOMA-IR and the TyG index compare for their relationship with cardiometabolic health. Aim: This study aimed at comparing HOMA-IR and the TyG index with regard to their relationship with anthropometric, dietary and inflammatory factors as well as ability to predict cardiovascular risk. Methods: 438 subjects aged 55–80 years, underwent anthropometric, metabolic and nutritional characterisation. Spearman's correlation coefficient was used to evaluate the association between the parameters of interest. Predictors of HOMA-IR, the TyG index and the 10-year risk of cardiovascular events were investigated using stepwise multivariable regression analysis. Results: HOMA-IR and TyG index correlated positively with body mass index, waist circumference, fat mass, systolic and diastolic blood pressure, interleukin-18 and C-reactive protein. However, only HOMA-IR correlated with dietary factors. After adjusting for age and sex, waist circumference and interleukin-18 were stronger predictors of HOMA-IR compared to the TyG index. Instead, the TyG index, but not HOMA-IR, emerged as a predictor of cardiovascular risk. Conclusions: The TyG index represents a better predictor of cardiovascular risk compared to HOMA-IR which, instead, exhibits a stronger relationship with anthropometric, inflammatory and nutritional variables.