Background Beta-quantification (BQ) is the reference method for LDL-C but is not widely available. It is difficult, therefore, for clinical laboratories to independently assess the accuracy of their methods for either calculating or directly measuring LDL-C. Our goal was to investigate if an interrelationship between the tests in the standard lipid panel could be used to compare the performance of different LDL-C methods against BQ, specifically in samples with hypertriglyceridemia, a major cause of bias for LDL-C testing. Methods BQ results from Mayo Medical Labs (n=39,667) and the NIH (n=18,338) were used to identify a linear relationship by least-squares regression analysis between lipid panel test results and LDL-C to facilitate a statistical comparison between different LDL-C methods. Results It is well established that the number of VLDL particles increases as TG increases, because VLDL is the main carrier of TG. As a consequence, the ratio of LDL-C to non-HDL-C is inversely related to TG, which can be made linear by taking the square root of TG (Figure). Nearly identical regression equations were found for this relationship, using two different BQ datasets. When LDL-C was calculated by either Sampson equation, the LDL-C/non-HDL-C regression lines nearly overlapped with the one for BQ. In contrast, the Martin equation showed a positive bias with increasing TG, whereas the Friedewald equation showed a negative bias, consistent with past reports on their LDL-C biases with hypertriglyceridemia. In the UKBiobank, the Beckman direct LDL-C showed a positive bias for TG, which was confirmed in CAP proficiency test surveys. By simulation analysis, approximately 80 samples with high (>200 mg/dL) and low (<100 mg/dL) TG is statistically sufficient to assess if the LDL-C/non-HDL-C regressions lines of LDL-C methods differ from BQ. Conclusions The LDL-C/non-HDL-C ratio method is a simple way to examine LDL-C methods for bias on hypertriglyceridemic samples.

中文翻译：

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A-210 Ldl-c 与非 hdl-c 比率法：确定高甘油三酯样品中 LDL-C 方法偏差的简单方法


背景 Beta 定量 (BQ) 是 LDL-C 的参考方法，但尚未广泛应用。因此，临床实验室很难独立评估其计算或直接测量 LDL-C 方法的准确性。我们的目标是调查标准脂质组中测试之间的相互关系是否可用于比较不同 LDL-C 方法与 BQ 的性能，特别是在高甘油三酯血症样本中，高甘油三酯血症是 LDL-C 测试偏差的主要原因。方法 使用 Mayo Medical Labs (n=39,667) 和 NIH (n=18,338) 的 BQ 结果通过最小二乘回归分析确定血脂面板测试结果与 LDL-C 之间的线性关系，以便于不同 LDL 之间的统计比较-C 方法。结果 众所周知，VLDL 颗粒的数量随着 TG 的增加而增加，因为 VLDL 是 TG 的主要载体。因此，LDL-C 与非 HDL-C 的比率与 TG 成反比，可以通过取 TG 的平方根使其呈线性关系（图）。使用两个不同的 BQ 数据集发现了这种关系几乎相同的回归方程。当通过任一 Sampson 方程计算 LDL-C 时，LDL-C/非 HDL-C 回归线几乎与 BQ 的回归线重叠。相比之下，Martin 方程随着 TG 的增加而显示出正偏差，而 Friedewald 方程则显示出负偏差，这与过去有关 LDL-C 与高甘油三酯血症的偏差的报道一致。在 UKBiobank 中，贝克曼直接 LDL-C 对 TG 显示出正偏差，这在 CAP 能力测试调查中得到了证实。 通过模拟分析，大约 80 个具有高 (>200 mg/dL) 和低 (<100 mg/dL) TG 的样品在统计上足以评估 LDL-C 方法的 LDL-C/非 HDL-C 回归线是否不同来自BQ。结论 LDL-C/非 HDL-C 比率方法是检查 LDL-C 方法对高甘油三酯样本的偏差的简单方法。