Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States.
Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States.
Clin Biochem. 2022 Oct;108:1-4. doi: 10.1016/j.clinbiochem.2022.07.005. Epub 2022 Jul 26.
Low density lipoprotein cholesterol (LDL-C) is traditionally calculated using the Friedewald (LDL-F) equation. New equations by Martin (LDL-M) and Sampson (LDL-S) have improved accuracy relative to LDL-F for samples with high triglycerides (TG) or low LDL-C. However, most labs still rely on LDL-F and few studies have examined the accuracy and impact of contemporary LDL-C equations applied to a retrospective dataset. 934 lipid panels with a concurrent direct enzymatic LDL-C (dLDL-C) result were extracted from the laboratory information system. LDL-F, LDL-M, and LDL-S were calculated and the accuracy of each equation determined in a predominantly hypertriglyceridemic population. The impact of implementing each equation was compared by analyzing the LDL-C treatment group miscategorization rate relative to dLDL-C. The slope for the LDL-F, LDL-M and LDL-S were 0.59, 0.78, and 0.94, relative to dLDL-C. The three equations performed comparably for samples with TG <4.52 mmol/L (<400 mg/dL). The LDL-C treatment group miscategorization rate was 48.6 % for LDL-F, 28.8 % for LDL-M and 37.2 % for LDL-S in specimens with TG ≥4.52 mmol/L (≥400 mg/dL) (n = 817). LDL-S underestimated treatment group category (31.3 %, 95 % CI 17.2-22.4) relative to LDL-M (9.0 %, 4.39-7.41, P < 0.001). 5.9 % of samples were overestimated for treatment group category by LDL-S vs 19.8 % for LDL-M (P = 0.1883). LDL-M and LDL-S demonstrate reduced bias with a dLDL-C method compared to LDL-F in samples with TG ≥4.52 mmol/L (≥400 mg/dL). LDL-M reduces LDL-C treatment group miscategorization rate leading to fewer underestimations of risk overall compared to LDL-S; however, neither may be sufficiently accurate to report LDL-C in patients with TG ≥4.52 mmol/L (≥400 mg/dL).
低密度脂蛋白胆固醇（LDL-C）传统上是通过 Friedewald（LDL-F）方程计算得出的。Martin（LDL-M）和 Sampson（LDL-S）的新方程对于甘油三酯（TG）较高或 LDL-C 较低的样本，在准确性方面相对于 LDL-F 有所提高。然而，大多数实验室仍然依赖 LDL-F，很少有研究检查应用于回顾性数据集的当代 LDL-C 方程的准确性和影响。从实验室信息系统中提取了 934 个具有同时进行的直接酶法 LDL-C（dLDL-C）结果的脂质组。在以高甘油三酯血症为主的人群中计算了 LDL-F、LDL-M 和 LDL-S，并确定了每个方程的准确性。通过分析相对于 dLDL-C 的 LDL-C 治疗组分类错误率来比较每个方程的影响。LDL-F、LDL-M 和 LDL-S 的斜率相对于 dLDL-C 分别为 0.59、0.78 和 0.94。对于 TG <4.52 mmol/L（<400 mg/dL）的样本，三个方程的性能相当。在 TG ≥4.52 mmol/L（≥400 mg/dL）的标本中，LDL-F 的 LDL-C 治疗组分类错误率为 48.6%，LDL-M 为 28.8%，LDL-S 为 37.2%（n=817）。与 LDL-M（9.0%，4.39-7.41）相比，LDL-S 相对低估了治疗组类别（31.3%，95%CI 17.2-22.4%）（P<0.001）。与 LDL-M（P=0.1883）相比，LDL-S 高估了治疗组类别的 5.9%的样本，而 LDL-M 高估了 19.8%。与 LDL-F 相比，LDL-M 和 LDL-S 在 TG ≥4.52 mmol/L（≥400 mg/dL）的样本中，使用 dLDL-C 方法时，偏差较小。与 LDL-S 相比，LDL-M 降低了 LDL-C 治疗组分类错误率，从而总体上降低了风险低估的总体比例；然而，由于 TG ≥4.52 mmol/L（≥400 mg/dL）的患者，两种方法可能都不够准确，无法报告 LDL-C。
