Department of Biostatistics, Erciyes University School of Medicine, Kayseri, Turkey.
Drug Application and Research Center (ERFARMA), Erciyes University, Kayseri, Turkey.
PLoS One. 2022 May 13;17(5):e0263860. doi: 10.1371/journal.pone.0263860. eCollection 2022.
Low-density lipoprotein cholesterol (LDL-C) is an important biomarker for determining cardiovascular risk and regulating lipid lowering therapy. Therefore, the accurate estimation of LDL-C concentration is essential in cardiovascular disease diagnosis and prognosis. Sampson recently proposed a new formula for the estimation of LDL-C. However, little is known regarding the validation of this formula.
This study aimed to validate this new formula with other well-known formulas in Turkish population, composed of adults.
A total of 88,943 participants above 18 years old at Sivas Cumhuriyet University Hospital (Sivas, Turkey) were included to this study. LDL-C was directly measured by homogeneous assays, i.e., Roche, Beckman and Siemens and estimated by Friedewald's, Martin-Hopkins', extended Martin-Hopkins' and Sampson's formulas. The concordances between the estimations obtained by the formulas and the direct measurements were evaluated both in general and separately for the LDL-C, TG and non-HDL-C sublevels. Linear regression analysis was applied and residual error plots were generated between each estimation and direct measurement method. Coefficient of determination (R2) and mean absolute deviations were also calculated.
The results showed that the extended Martin-Hopkins approach provided the most concordant results with the direct assays for LDL-C estimation. The results also showed that the highest concordances were obtained between the direct assays with the extended Martin-Hopkins formula calculated with the median statistics obtained from our own population. On the other hand, it was observed that the results of the methods may differ in different assays. The extended Martin-Hopkins approach, calculated from the median statistics of our population, gave the most concordant results in patients with "low LDL-C level (LDL-C levels < 70 mg/dL) or hypertriglyceridemia (TG levels ≥ 400 mg/dL)".
Although the results of the formulas in different assays may vary, the extended Martin-Hopkins approach was the best one with the highest overall concordances. The validity of the Martin Hopkins' and Sampson's formulas has to be further investigated in different populations.
低密度脂蛋白胆固醇（LDL-C）是确定心血管风险和调节降脂治疗的重要生物标志物。因此，准确估计 LDL-C 浓度对于心血管疾病的诊断和预后至关重要。Sampson 最近提出了一种新的 LDL-C 估计公式。然而，对于该公式的验证知之甚少。
本研究旨在用其他著名公式验证该公式在土耳其成年人中的有效性。
共纳入 88943 名年龄在 18 岁以上的 SivasCumhuriyet 大学医院（土耳其 Sivas）患者。采用均相测定法（罗氏、贝克曼和西门子）直接测定 LDL-C，采用 Friedewald 公式、Martin-Hopkins 公式、扩展 Martin-Hopkins 公式和 Sampson 公式估计 LDL-C。评估公式估计值与直接测量值之间的一致性，分别评估 LDL-C、TG 和非 HDL-C 亚水平的一致性。应用线性回归分析并生成每个估计值与直接测量方法之间的残差图。还计算了决定系数（R2）和平均绝对偏差。
结果表明，对于 LDL-C 的估计，扩展 Martin-Hopkins 方法与直接检测法最为一致。结果还表明，从我们自己的人群中获得的中位数统计数据计算出的扩展 Martin-Hopkins 公式与直接检测法之间的一致性最高。另一方面，观察到不同检测方法的结果可能不同。对于“低 LDL-C 水平（LDL-C 水平<70mg/dL）或高甘油三酯血症（TG 水平≥400mg/dL）”患者，从我们人群的中位数统计数据计算出的扩展 Martin-Hopkins 方法给出了最一致的结果。
虽然不同检测方法的公式结果可能有所不同，但扩展 Martin-Hopkins 方法是总体一致性最高的最佳方法。需要在不同人群中进一步研究 MartinHopkins 公式和 Sampson 公式的有效性。
