Kondo A, Muranaka Y, Ohta I, Notsu K, Manabe M, Kotani K, Saito K, Maekawa M, Kanno T
Department of Laboratory Medicine and Central Laboratory for Ultrastructure Research, Hamamatsu University School of Medicine, 3600 Handa-cho, Hamamatsu City 431-3192, Japan.
Clin Chem. 2001 May;47(5):893-900.
Hypertriglyceridemia is associated with decreased HDL-cholesterol (HDL-C) and increased small dense LDL. In addition, small dense LDL is known to be susceptible to oxidation.
We measured LDL particle size, using gradient gel electrophoresis, and malondialdehyde-modified LDL (MDA-LDL), using an ELISA, and investigated the association between triglyceride (TG) concentrations, LDL size, and MDA-LDL.
TG concentrations correlated negatively with the predominant LDL size (r = -0.650) and HDL-C concentration (r = -0.556). The relationship between TG concentration and LDL size, evaluated by measuring MDA-LDL, distinguished subgroups derived from four subfractions of TG concentrations and four distribution ranges of LDL size. These experiments indicated that there is a threshold for oxidation susceptibility at an LDL size of 25.5 nm and a TG concentration of 1500 mg/L. To investigate the relationship between LDL size, MDA-LDL concentration, and other lipids (TGs, HDL-C, apolipoprotein B, and total cholesterol), we evaluated them in control subjects and patients with diabetes mellitus or hypertriglyceridemia. When the size range for normal LDL was postulated to be 25.5 < or = phi (LDL diameter) < 26.5 nm, the MDA-LDL concentration was significantly higher in the subgroups of patients with LDL in the size range 24.5 < or = phi < 25.5 nm compared with patients with normal LDL. This result also suggests that the threshold is at a LDL size of 25.5 nm.
The threshold for oxidation susceptibility coincided with the point of LDL size separation between the LDL subclass patterns A and B as an atherosclerotic risk.
高甘油三酯血症与高密度脂蛋白胆固醇（HDL-C）降低及小而密低密度脂蛋白（LDL）增加有关。此外，已知小而密LDL易被氧化。
我们使用梯度凝胶电泳测量LDL颗粒大小，使用酶联免疫吸附测定法（ELISA）测量丙二醛修饰的LDL（MDA-LDL），并研究甘油三酯（TG）浓度、LDL大小与MDA-LDL之间的关联。
TG浓度与主要LDL大小呈负相关（r = -0.650），与HDL-C浓度呈负相关（r = -0.556）。通过测量MDA-LDL评估的TG浓度与LDL大小之间的关系，区分了源自TG浓度四个亚组和LDL大小四个分布范围的亚组。这些实验表明，在LDL大小为25.5 nm且TG浓度为1500 mg/L时存在氧化易感性阈值。为了研究LDL大小、MDA-LDL浓度与其他脂质（TG、HDL-C、载脂蛋白B和总胆固醇）之间的关系，我们在对照组以及糖尿病或高甘油三酯血症患者中对它们进行了评估。当正常LDL的大小范围假定为25.5≤φ（LDL直径）＜26.5 nm时，与正常LDL患者相比，LDL大小在24.5≤φ＜25.5 nm范围内的患者亚组中MDA-LDL浓度显著更高。该结果也表明阈值在LDL大小为25.5 nm处。
氧化易感性阈值与作为动脉粥样硬化风险的LDL亚类模式A和B之间的LDL大小分离点一致。
