Evaluation of LDL subfractions in vascular complications of familial hypercholesterolemia

The authors attempted to investigate the possibility of estimating modified LDL (acetylated LDL, oxidative LDL and glucosylated LDL) with peroxidized lipid in the native LDL from patients with familial hypercholesterolemia (FH). A group of 7 patients with FH were studied, with age ranging from 18 to 60 years. 10 ml of fasting blood were collected into siliconized syringes with 0.5 ml of 0.05 M ethylene diamine tetraacetic acid 2Na. LDL, LDL1 and LDL2 were separated by sequential ultracentrifugation. Total cholesterol (TC), triglycerides (TG) and phospholipids (PL) were estimated by enzymatic methods. Analyses of lipids in each LDL were done by thin layer chromatography (TCL). The modified LDL in native LDL of the FH patients was estimated by the authors' own method. The cholesterol concentration of LDL was 0.49 +/- 0.28 mmol/L in FH patients and 0.07 +/- 0.04 mmol/L in the healthy persons (P < 0.001). The LDL1 cholesterol concentrations in the patients with FH and the normal controls were similar while that of the LDL2 was of significant difference (P < 0.05). On the TLC plate, the detection of the spot X1 was considered an indicator of the existence of modified LDL. The percentages of spot X1 in LDL of FH patients were higher in all 3 fractions (LDL, LDL1, and LDL2), as compared to the corresponding percentages of spot X1 in the healthy controls. (P < 0.001). Using the authors' own method, the molecular size were found in the order of LDL > LDL1 > LDL2.