Relationship between Triglyceride Concentrations and LDL Size Evaluated by Malondialdehyde-modified LDL

Abstract

Background: 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. Methods: 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. Results: 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 ≤ φ (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 ≤ φ < 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. Conclusion: 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.

Association of oxidative stress and PON1 with LDL and HDL particle size in middle‐aged subjects

“….− in LDL (Table 1). These findings are in agreement with the results of Kondo et al [38], who recently showed that subjects with sdLDL particles and a high TG concentration have an elevated concentration of MDA-modified LDL particles. Furthermore, Miyazaki et al [39] reported higher MDA-LDL levels in CVD patients compared to control subjects and a significant association between smaller LDL particle size and higher MDA-LDL levels in both examined groups.…”

Low‐density lipoprotein (LDL) particle size in healthy prepubertal children: The STRIP study

“…In addition, the mean serum triglyceride concentrations were clearly lower in our study children than in Japanese children [20, 21]. Actually, the maximum serum triglyceride value in our study children was as low as 1.6 mmol/l, which is below the cut‐off value (1.7 mmol/l) marking susceptibility of LDL to oxidation and shifting towards sdLDL [22]. It appears that the strong inverse correlation between LDL particle size and serum triglyceride values in adults is probably jointly caused by age‐related changes in triglyceride values and body composition.…”

Antihyperglycemic and hypolipidemic effects of Costus speciosus in alloxan induced diabetic rats

“…On the other hand, increased LDL-cholesterol may arise from glycosylation of the lysyl residues of apoprotein B (Ravi et al, 2005). The ability of LDL-cholesterol to form lipid peroxides was found to be specifically responsible for the atherogenesis in diabetic patients (Kondo et al, 2001). It is reported that a deficiency in lipoprotein lipase activity in diabetics may contribute to significant elevation of triglycerides in blood (Braun and Severson, 1992) and with insulin administration, elevated lipoprotein lipase activity and also lowered plasma triglyceride concentrations were noted (Lopes-Virella et al, 1983).…”