Holmes Daniel T, Frohlich Jiri, Buhr Kevin A
St. Paul's Hospital Healthy Heart Lipid Clinic and the University of British Columbia Department of Pathology and Laboratory Medicine, Vancouver, BC, Canada.
Clin Biochem. 2008 May;41(7-8):631-5. doi: 10.1016/j.clinbiochem.2008.01.023. Epub 2008 Feb 7.
The atherogenic index of plasma (AIP), defined as the base 10 logarithm of the ratio of plasma triglyceride (TG) to high density lipoprotein cholesterol (HDL-C), has been employed as a predictor of cardiovascular risk. We seek to quantify the analytical precision of the AIP using the coefficients of variation (CVs) of the TG and HDL-C assays.
Error propagation methods are employed to develop a simple formula for the standard deviation of the random analytical error in the AIP assuming that the errors in the TG and HDL-C assays are normally distributed. An alternative derivation assuming log-normal distribution of errors gives nearly identical results while avoiding subtle technical problems.
The SD of the AIP is given by sigma(AIP) approximately = 1/ln(10) square root(CV(TG)(2) + CV(HDL-C)(2)) and this formula will provide SD results that are accurate within 0.4% for CVs of TG and HDL-C less than 5%, as compared with results of Monte Carlo simulation. We also explain that the concept of CV cannot be applied to the AIP since it is a logarithm.
The formula provides a simple means to quantify the precision of the AIP from precision data available for the TG or HDL-C assays.
血浆致动脉粥样硬化指数（AIP）定义为血浆甘油三酯（TG）与高密度脂蛋白胆固醇（HDL-C）比值的常用对数，已被用作心血管风险的预测指标。我们试图通过TG和HDL-C检测的变异系数（CV）来量化AIP的分析精密度。
采用误差传播方法，在假设TG和HDL-C检测误差呈正态分布的情况下，推导出一个计算AIP随机分析误差标准差的简单公式。另一种基于误差对数正态分布的推导方法可得出几乎相同的结果，同时避免了一些细微的技术问题。
AIP的标准差由σ(AIP) ≈ 1/ln(10)√(CV(TG)² + CV(HDL-C)²)给出，与蒙特卡洛模拟结果相比，对于TG和HDL-C的CV小于5%的情况，该公式给出的标准差结果精确在0.4%以内。我们还解释了由于AIP是一个对数，CV的概念不能应用于AIP。
该公式提供了一种简单的方法，可根据TG或HDL-C检测可用的精密度数据来量化AIP的精密度。
