The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio as a predictor of β-cell function in African American women

Abstract

BackgroundThe TG/HDL-C ratio is used as a marker of insulin resistance (IR) in Caucasians. However, there are conflicting data on TG/HDL-C ratio as a predictor of IR in African Americans. Compared to Caucasians, African Americans have lower TG levels and increased insulin levels despite a greater risk for diabetes. We hypothesized that the TG/HDL-C ratio is predictive of IR and/or β-cell function in African American (AA) women. MethodsNon-diabetic AA women (n=41) with a BMI>25kg/m2 underwent frequently sampled intravenous glucose tolerance test (FSIGTT). Insulin sensitivity (SI) and the acute insulin response to glucose (AIRg) were measured using minimal model and β-cell function was determined by disposition index (DI=SI*AIRg). IR was defined as the lowest tertile of SI (<1.8×10−4min−1/μU/ml) and inadequate β cell compensation was defined as the lowest tertile of DI (<900). Data were analyzed using logistic regression models and area under the receiver operating characteristic curve (AUC-ROC). An AUC-ROC>0.70 was defined as significant discrimination. ResultsThe mean (± SD) age was 38.5±11.3years, with BMI of 33.5±6.7kg/m2 and fasting glucose of 86.5±10.5mg/dL. The AUC-ROC for the prediction of DI<900 was 0.74 indicating that a higher TG/HDL-C ratio was associated with decreased DI. However, the AUC-ROC for prediction of IR or low AIRg (<335 μU/ml) was not significant. ConclusionThis study confirmed that the TG/HDL-C ratio is a poor predictor of IR in AA women. However, we did show an inverse association between the TG/HDL-C ratio and β-cell function, suggesting that this simple tool may effectively identify AA women at risk for DM2.