Association of serum low-density lipoprotein metabolism with oestrogen receptor gene polymorphisms in healthy children

The aim of this study was to reveal the association of serum lipid and apolipoprotein levels with oestrogen receptor (ER) Xba I and Pvu II polymorphisms in 102 healthy Japanese school children (56M, 46F) aged 10-15 y. Each genotype of the genomic DNA extracted from peripheral leukocytes was determined using polymerase chain reaction and digestion with Xba I or Pvu II. The genotypes were coded as either X1 or X2 (Xba I) and P1 or P2 (Pvu II), when XI, P1 signified the absence of and X2, P2 the presence of restriction sites. The fasting serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein (LDL) cholesterol, triglyceride and apolipoproteins A1, B and E were measured. In the Xba I polymorphism, LDL cholesterol, apolipoprotein B levels of the XI/XI genotype were significantly higher than those of the others. The other lipid and apolipoprotein levels were not significantly different among the three genotypes. In the Pvu II polymorphism, there were no significant differences in serum lipids and lipoproteins among the three genotypes. This study reveals that Xba I polymorphisms are related to LDL metabolism. These findings support previous reports that the LDL-lowering effects of oestrogen occur through the ER (alpha) pathway. The Xba I polymorphism may be one of the genetic factors in the control of LDL metabolism.