The bone mass density in postmenopausal women using hormonal replacement therapy in relation to polymorphism in vitamin D receptor and estrogen receptor genes

Abstract

The aims of the study were as follows: (1) To identify the differences in spinal body mass density (BMD) in relation to polymorphism in vitamin D receptor (VDR) and estrogen receptor-α (ERα) genes in untreated women with postmenopausal osteoporosis. (2) To assess the efficacy of treatment in women with postmenopausal osteoporosis in relation to polymorphism in VDR and ERα genes. (3) To find the estradiol concentration necessary to protect bone tissue in patients with a given polymorphism in VDR and ERα genes.

Methods. The study included 44 postmenopausal women with primary osteoporosis who used cyclic hormonal replacement therapy (HRT) for a year. The polymorphism of ERα and VDR genes were evaluated. We also determined the age, body mass index and spinal BMD before and after 12 months of administration the HRT.

Results. We found a significant spinal BMD increase, what is connected with ERα genotype and both VDR and ERα genes. There is no such a correlation observed in polymorphism of VDR gene.

Conclusions. (1) There is no relationship between VDR and ERα genes polymorphism and the stage of osteoporosis related to the spinal BMD value before treatment. (2) The XX, PP or Bb markers or only X, P, B alleles are connected with a significant decrease of treatment efficacy. (3) Estradiol serum concentration before and during HRT is not dependent on the polymorphism of VDR and ERα genes.

Keywords:

• Bone mass density
• vitamin D receptor gene
• estrogen receptor genes
• hormonal replacement therapy