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

Background The 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. Methods Non-diabetic AA women (n = 41) with a BMI > 25 kg/m² underwent frequently sampled intravenous glucose tolerance test (FSIGTT). Insulin sensitivity (S_I) and the acute insulin response to glucose (AIRg) were measured using minimal model and β-cell function was determined by disposition index (DI = S_I∗AIRg). IR was defined as the lowest tertile of S_I (< 1.8 × 10^{- 4} min^{- 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. Results The mean (± SD) age was 38.5 ± 11.3 years, with BMI of 33.5 ± 6.7 kg/m² and fasting glucose of 86.5 ± 10.5 mg/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. Conclusion This 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.