Purpose: To evaluate the accuracy of lipoprotein lipids and apoproteins in predicting coronary heart disease (CHD) in diabetic American Indians.
Methods: This study included 2099 diabetic participants of the Strong Heart Study, which is a longitudinal study of cardiovascular disease (CVD) and its risk factors in American Indians in Arizona, Oklahoma, and South and North Dakota. Diabetic participants with incident CHD (N = 126) were selected as the case group, and those without CHD or any cardiovascular events were the control group (N = 1732). Previous vascular events such as stroke were the sole exclusion criterion (N = 241). Baseline measurements of lipoprotein lipids and apoproteins were used to predict CHD diagnosed at the 4-year follow-up examination by using Receiver-Operating Characteristic (ROC) curve analysis.
Results: The ratio of high-density lipoprotein (HDL) to total cholesterol had the highest area under the ROC curve (0.69 +/- 0.02). The areas for the ratios of HDL to low-density lipoprotein (LDL) cholesterol (0.68 +/- 0.02), apo AI/B (0.66 +/- 0.02), and the single component of total cholesterol (0.64 +/- 0.03) and LDL cholesterol (0.63 +/- 0.05) were not significantly different from the area for HDL/total cholesterol. However, the areas for apo B (0.64 +/- 0.02), HDL cholesterol (0.62 +/- 0.03), triglycerides (0.58 +/- 0.03), and apo AI (0.57 +/- 0.05) were significantly lower than the area for HDL/total cholesterol. Logistic regression analysis indicates that only HDL and LDL cholesterol were significant independent lipoprotein lipid and apoprotein predictors for CHD. The other significant predictors in the model were study center, age, gender, and albuminuria. The ROC area for this model is 0.75.
Conclusions: HDL and LDL cholesterol were the most important independent predictors for incident CHD in diabetic American Indians. The ratios of HDL/total cholesterol, HDL/LDL cholesterol, and apo AI/B had higher accuracy for predicting CHD. Although the values for all lipoprotein lipids and apoproteins and their ratios were not large enough to definitely predict CHD, they can be used as screening tools for CHD in diabetic American Indians.