Lipid accumulation product and triglycerides/glucose index are useful predictors of insulin resistance

Objectives: To investigate the association of triglycerides/glucose index (TyG index), anthropometrically predicted visceral adipose tissue (apVAT), lipid accumulation product (LAP), visceral adiposity index (VAI) and triglycerides (TG):high density lipoprotein-cholesterol (HDL-C) ratio with insulin resistance (IR) in adult Americans. Methods: This study was based on data from three NHANES cycles (2005 to 2010). The TyG index was calculated as ln [TG × fasting glucose / 2]. VAI was calculated using gender-specific formulas: men [waist circumference (WC)/39.68 + (1.88 × body mass index (BMI)] × (TG/1.03) × (1.31/HDL-C); women: [WC/36.58 + (1.89 × BMI)] × (TG/0.81) × (1.52/HDL-C). LAP index was calculated as [WC–65] × [TG] in men, and [WC–58] × [TG] in women. Correlation and regression analyses accounted for the complex sampling of database. Results: A total of 18,318 subjects was included in this analysis [mean age 47.6 Years]; 48.7% (n = 8918) men]. The homeostatic model assessment of insulin resistance (HOMA-IR) had a significant positive correlation with the TyG index (r = 0.502), LAP (r = 0.551), apVAT (r = 0.454), TG:HDL-C ratio (r = 0.441) and VAI (r = 451) (p < 0.001 for all comparisons). Bland-Altman plots showed no systematic errors. The optimal cut-off to predict HOMA-diagnosed IR was 0.473 (sensitivity = 74.5% and specificity = 72.7%) for LAP, 0.478 (75.9%, 71.9%) for TyG, 0.391 (70.4%, 67.1%) for VAI, 0.392 (77.1% and 62.0%) for TG:HDL-C ratio and 0.381 (63.8%, 74.8%) for apVAT. Conclusions: The LAP index is a simple, cheap and accurate although not perfect, surrogate marker of HOMA-diagnosed IR among adult Americans. Moreover, it has higher predictability than other screening tools which traditionally applied. Among the markers, apVAT had the highest specificity and the TG:HDL-C ratio had the highest sensitivity.