绝经后妇女雌激素受体基因Px单倍型对骨密度的影响

The effect of estrogen receptor gene Px haplotype on bone mineral density in Chinese postmenopausal women

目的 探讨绝经后妇女雌激素受体基因 (ER)多态性与骨密度 (BMD)和骨生化指标之间的关系。方法 用双能X线骨密度仪 (DEXA)检测 186名绝经后妇女的腰椎和股骨颈的BMD(Z值 ) ,以PCR RFLP的方法检测ER基因PvuII和XbaI多态性 ,同时测定血清碱性磷酸酶 (AKP)、骨钙素(BGP)和尿吡啶酚 (Pyd)。结果 pp型 (14 5 % )股骨颈BMD高于Pp型 (5 0 0 % ) ;XX型 (7 0 % )的腰椎BMD高于Xx型 (2 7 4% )和xx型 (6 5 6 % ) ,无Px单倍型的妇女腰椎和股骨颈BMD明显高于有Px单倍型的妇女 ,其血清AKP更低。结论 ER基因pp和XX基因型分别对股骨颈和腰椎骨量的维持有一定意义 ,无Px单倍型的ER基因型可能对BMD有益 。

Objective To investigate the relationship among the PvuII and XbaI polymorphism of estrogen receptor (ER) gene and bone mineral density (BMD,z score) and bone biochemical markers in Chinese postmenopausal women. Methods The BMD of lumbar vertebrae (L2～4) and femoral neck (FN) of 186 postmenopausal women (aged 65.0±0.6 yr) were measured by DEXA. The polymorphism of ER gene (PvuII and XbaI) was detected by PCR RFLP method. Serum AKP, BGP and urinary Pyd were measured by ELISA. Results The polymorphism of ER receptor can be divided into two sets: PP (14.5%), Pp ( 50.0%), and pp (35 5%); and 3 PvuII RFLPs and XX ( 7.0% ), Xx ( 27.4% ), and xx ( 65.6% ) 3 XbaI RFLPs. The bone markers were not significantly different among the 3 groups in each of the two sets of polymorphism. The FN BMD of women of pp genotype was higher than that of Pp genotype ( P =0.02). The BMD of L2～4 was higher in women of XX genotype than those in women of Xx and xx genotypes ( P =0.000 3 and 0.000 2 respectively). Women without Px haplotype (PPXX, PpXX, ppxx, n =79) had higher L2～4 BMD ( P =0.02) and FN BMD ( P =0.03) and lower serum AKP ( P =0.04) than those with Px genotype (PPxx and PPXx, Ppxx, PpXx, n =107). Conclusion pp and XX genotype of ER gene may play a certain role in maintaining FN and L2～4 BMD. The genotpyes without Px haplotype might exert some favorable effect on BMD, while those with Px haplotype may be harmful to bone mass.