Relationship between the distribution of plasma HDL subclasses and the polymorphisms of APOA5 in hypertriglyceridemia

This study aims to examine the possible associations between high density lipoprotein (HDL) subclass distribution and APOA5-1131T>C polymorphism in hypertriglyceridemia.

The distribution of HDL subclasses was quantified by 2-dimensional electrophoresis in conjunction with immunodetection method. The APOA5-1131T>C polymorphism was identified in 95 hypertriglyceridemic (HTG) patients and 102 healthy subjects by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP).

The APOA5-1131C (C) allele frequency was higher in the HTG group than in the control group. Plasma triglycerides (TG) were significantly higher and apoA5 was significantly lower in patients with the C allele when compared to patients with the APOA5-1131T (T) allele, even more dramatically so in the APOA5-1131CC homozygote. In both the HTG group and the control group, the frequency of the C allele was positively correlated with levels of TG, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and apolipoprotein B100 (apoB100), and negatively correlated with levels of high density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (apoA1) and apolipoprotein A5 (apoA5) (P<0.001). In all subjects, the frequency of the C allele was positively correlated with the level of small-sized HDL (preβ(1)-HDL and HDL(3a)), and negatively correlated with levels of HDL(2a) and HDL(2b).

Changes in HDL subclass distributions in HTG may be related to the APOA5-1131T>C polymorphism. This polymorphism leads to a general shift towards smaller-sized HDL.