Comparison of two methods using plasma triglyceride concentration as a surrogate estimate of insulin action in nondiabetic subjects: triglycerides × glucose versus triglyceride/high-density lipoprotein cholesterol.

The objective was to compare relationships between insulin-mediated glucose uptake and surrogate estimates of insulin action, particularly those using fasting triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) concentrations. Insulin-mediated glucose uptake was quantified by determining the steady-state plasma glucose (SSPG) concentration during the insulin suppression test in 455 nondiabetic subjects. Fasting TG, HDL-C, glucose, and insulin concentrations were measured; and calculations were made of the following: (1) plasma concentration ratio of TG/HDL-C, (2) TG × fasting glucose (TyG index), (3) homeostasis model assessment of insulin resistance, and (4) insulin area under the curve (insulin-AUC) during a glucose tolerance test. Insulin-AUC correlated most closely with SSPG (r ∼ 0.75, P < .001), with lesser but comparable correlations between SSPG and TG/HDL-C ratio, TyG index, homeostasis model assessment of insulin resistance, and fasting TG and insulin (r ∼ 0.60, P < .001). Calculations of TG/HDL-C ratio and TyG index correlated with SSPG concentration to a similar degree, and the relationships were comparable to estimates using fasting insulin. The strongest relationship was between SSPG and insulin-AUC.