Division of Cardiovascular Disease, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA; Ciccarone Center for Prevention of Heart Disease, Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Ciccarone Center for Prevention of Heart Disease, Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
J Clin Lipidol. 2019 Jul-Aug;13(4):634-644. doi: 10.1016/j.jacl.2019.06.001. Epub 2019 Jun 11.
Remnant lipoprotein cholesterol (RLP-C) is a risk factor for atherosclerotic cardiovascular disease, but there is no standard method for measurement. Some studies have used very low-density lipoprotein cholesterol estimated by the Friedewald equation to approximate RLP-C using a basic lipid panel, whereas others have attempted to measure RLP-C with ultracentrifugation.
The aim of the study was to compare RLP-C levels estimated from basic lipid parameters to those measured by ultracentrifugation.
We analyzed 1,350,908 individuals from the Very Large Database of Lipids, comparing one estimate of RLP-C using basic lipid parameters (RLP-C = non-high-density lipoprotein cholesterol - Friedewald-estimated low-density lipoprotein cholesterol for triglycerides <355 mg/dL [4 mmol/L], or non-high-density lipoprotein - directly measured low-density lipoprotein for triglycerides ≥355 mg/dL) to levels measured by vertical auto profile ultracentrifugation (RLP-C = dense subfraction of very low-density lipoprotein cholesterol + intermediate-density lipoprotein cholesterol). We calculated correlations between RLP-C and RLP-C along with median within-subject differences between RLP-C and RLP-C across quintiles of RLP-C. We also assessed correlations with RLP-C estimated from basic lipid parameters using a novel method of calculating low-density lipoprotein cholesterol with a patient-specific conversion factor (RLP-C).
Our cohort was 48% male, and median (interquartile range) age was 59 (49-69) years. Median (interquartile range) RLP-C and RLP-C were 23 (16.4-33.2) and 24 (19-32) mg/dL, respectively. The correlation between RLP-C and RLP-C was 0.76. Based on the specified definition of RLP-C, the correlation between RLP-C and triglyceride/5 for triglyceride < 355 mg/dL was exactly 1.0. RLP-C was lower than RLP-C in the first and second quintiles of RLP-C but greater in the highest quintile. The correlations with RLP-C were 0.98 and 0.81 for RLP-C and RLP-C, respectively.
A previously used estimate of RLP-C using basic lipid parameters correlates weakly with remnants measured by ultracentrifugation. Our findings emphasize the need to standardize definitions and measurements of RLP-C.
残粒脂蛋白胆固醇（RLP-C）是动脉粥样硬化性心血管疾病的危险因素，但目前尚无测量RLP-C 的标准方法。一些研究使用Friedewald 方程估算的极低密度脂蛋白胆固醇，通过基本血脂谱来近似RLP-C，而另一些研究则试图通过超速离心法来测量 RLP-C。
本研究旨在比较基本血脂参数估算的 RLP-C 水平与超速离心法测量的 RLP-C 水平。
我们分析了来自非常大的脂质数据库的 1350908 名个体，比较了使用基本血脂参数估算的一种 RLP-C（RLP-C=非高密度脂蛋白胆固醇-Friedewald 估算的低密度脂蛋白胆固醇，用于甘油三酯<355mg/dL[4mmol/L]，或非高密度脂蛋白胆固醇-直接测量的低密度脂蛋白胆固醇，用于甘油三酯≥355mg/dL）与垂直自动谱超速离心法测量的 RLP-C（RLP-C=极低密度脂蛋白胆固醇的致密亚组分+中间密度脂蛋白胆固醇）之间的关系。我们计算了 RLP-C 与 RLP-C 之间的相关性以及 RLP-C 与 RLP-C 之间的中位数个体内差异，跨越 RLP-C 的五分位数。我们还使用一种新的方法评估了使用患者特异性转换因子（RLP-C）计算的低密度脂蛋白胆固醇与 RLP-C 之间的相关性。
我们的队列中 48%为男性，中位（四分位数间距）年龄为 59（49-69）岁。中位（四分位数间距）RLP-C 和 RLP-C 分别为 23（16.4-33.2）和 24（19-32）mg/dL。RLP-C 与 RLP-C 之间的相关性为 0.76。根据 RLP-C 的特定定义，甘油三酯<355mg/dL 时，RLP-C 与甘油三酯/5 的相关性恰好为 1.0。RLP-C 在 RLP-C 的前两个五分位数中低于 RLP-C，但在最高五分位数中高于 RLP-C。RLP-C 与 RLP-C 和 RLP-C 之间的相关性分别为 0.98 和 0.81。
使用基本血脂参数估算的 RLP-C 与超速离心法测量的残粒有弱相关性。我们的研究结果强调了标准化 RLP-C 的定义和测量的必要性。
