Abstract P188: The Triglyceride-Glucose Index in Africans is an Important Marker of Both an Atherogenic Lipid Profile and Insulin Resistance

Abstract

Background: Type 2 diabetes (T2D) and cardiovascular disease (CVD) are rapidly increasing in Africa. Both are linked to insulin resistance (IR). Measuring insulin levels and entering the values into formulas such as the Matsuda Sensitivity Index are classic ways to measure IR. But due to cost and technological issues, the insulin assay is unavailable in most clinics in African countries. However, the Triglyceride-Glucose Index (TyG) may be an inexpensive, readily available alternative and could have the added benefit of indicating dyslipidemia. As the value of TyG in Africans is uncertain, we assessed in African-born Blacks living in America, the ability of the TyG index to (a) predict IR, (b) the optimal cut-off for TyG to predict IR, and (c) differences in the strength of the correlations between five lipid parameters which are closely linked to IR, specifically HDL-C, HDL-size, LDL-C, LDL-size and LDL-particle number, and both the TyG and Matsuda Index. Methods: OGTTs and fasting lipid profiles were performed in 589 African-born Blacks living in America (Male: 64%, Age: 39±11y, (mean±SD) (range 20 -69y); BMI 27.9±4.5 kg/m 2 (range 19.5-41.9 kg/m 2 )). The formula for TyG was: ln(fasting glucose * fasting TG)/2. IR was defined by the threshold of the lowest quartile of the population distribution of the Matsuda Index (≤2.89). Area under the receiver operating characteristic (AUC-ROC) curve was used to determine the ability of TyG to predict IR. Youden Index was used to identify the optimal cut-off. Results: T2D, preT2D and normal glucose tolerance occurred in 7% (40/589), 32% (188/589) and 62% (361/589), respectively. AUC-ROC curve for TyG to predict IR was 0.76 (95% CI: 0.71, 0.80). The optimal cut-off was: 4.3. Lipid correlations are provided in the table and were significantly stronger between each lipid parameter and TyG than with the Matstuda Index. Conclusions: TyG is an effective marker of IR in Africans and due to stronger correlations with atherogenic lipids may be a better predictor of CVD than the Matsuda Index.