The triglyceride-glucose index is superior to homeostasis model assessment of insulin resistance in predicting metabolic syndrome in an adult population in the United States.

BACKGROUND: Metabolic syndrome (MetS) is a cluster of cardio-metabolic features portending an increased risk for both type 2 diabetes mellitus (T2DM) and premature atherosclerotic cardiovascular disease (ASCVD). Homeostasis model assessment of insulin resistance (HOMA-IR) is a widely used surrogate measure of insulin resistance. The triglyceride-glucose (TyG) index is another validated measure of insulin resistance that predicts both diabetes and cardiovascular disease in low and medium-income countries, but only diabetes in high income countries.

OBJECTIVE: Due to the paucity of data on the TyG index in the US population, we compared the validity of the TyG index and HOMA-IR in predicting MetS.

METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018 on Non-Hispanic White (NHW), Hispanic American (HA), and African American (AA) individuals (n = 5380) aged 20-80 years were used for analysis. Individuals were classified as having MetS based on three or more of its components. HOMA-IR and the TyG index were determined from fasting samples.

RESULTS: Both the TyG index and HOMA-IR were significantly increased in MetS and increased significantly with increasing severity of the syndrome. Also both indices correlated significantly with all 5 features of MetS, hsCRP and non-HDL-C. ROC-AUC analysis for TyG index was significantly greater than that of HOMA-IR in predicting MetS: 0.87 (95 % CI 0.85-0.88) versus 0.82 (95 % CI 0.81-0.83) respectively, p < 0.0001. This was not evident for the small AA subgroup.

CONCLUSION: The TyG index outperformed HOMA-IR in predicting MetS, a proxy for both T2DM and ASCVD, in a general US population and is a valuable biomarker.