Association of estrogen receptor-alpha and vitamin D receptor genotypes with therapeutic response to calcium in postmenopausal Chinese women.
OBJECTIVE
To investigate the correlation between calcium treatment in postmenopausal women and estrogen receptor-alpha (ER-alpha) Xba I and Pvu II genotype and vitamin D receptor (VDR) Apa I genotype.


METHODS
One hundred fifteen postmenopausal Chinese women of Han population were enrolled and treated with calcichew-D3 (1000 mg calcium and 400 U vitamin D3) daily for 1 year. At entry and after 1 year treatment, the bone mineral density (BMD), serum and urinary bone turnover biochemical markers were evaluated. ER-alpha and VDR genotype were analyzed using PCR-restriction fragment length polymorphism.


RESULTS
After 1 year of calcium supplementation, a significant increase of BMD and a marked reduction in serum ALP and PTH levels, and a significant increase of serum 25-(OH) vitamin D level were observed (P<0.01 or P<0.05). At entry and after 1 year of treatment, no significant association was found between Xba I, Pvu II, and Apa I genotypes and BMD in L1-4, Neck, and Troch, and all bone turnover marker levels. However, the percentage of change (median, QR) in Neck BMD was significantly different in homozygous XX [-4.14 (from -6.54 to -1.34)] in comparison with Xx [1.72 (from -1.12 to 3.20)] (P<0.001) or xx [1.22 (from -1.74 to 3.06)] Xba I ER-alpha genotype (P=0.001).


CONCLUSIONS
Women with ER-alpha Xba I genotype XX may have a higher risk of relatively fast bone mass loss in femoral neck after menopause and that they may have a poor responsiveness to calcium supplementation. The changes in BMD are not associated with ER-alpha Pvu II genotype and VDR Apa I genotype after 1 year of calcium supplementation.
Zhang
Zhen-lin
ZL
Center for Preventing and Treating Osteoporosis, Osteoporosis Research Unit, The Sixth People Hospital, Shanghai Jiaotong University, Shanghai 200233, China. ZZL2002@medmail.com.cn
Qin
Yue-juan
YJ
Huang
Qi-ren
QR
He
Jin-wei
JW
Li
Miao
M
Zhou
Qi
Q
Hu
Yun-qin
YQ
Li
Yu-juan
YJ
D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D044466:Asian People; D015519:Bone Density; D002118:Calcium / Q000627:therapeutic use*; D002762:Cholecalciferol / Q000627:therapeutic use; D047628:Estrogen Receptor alpha / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D017698:Postmenopause / Q000235:genetics*; D018167:Receptors, Calcitriol / Q000235:genetics*
D047628:Estrogen Receptor alpha; D010281:Parathyroid Hormone; D018167:Receptors, Calcitriol; D002762:Cholecalciferol; D000469:Alkaline Phosphatase; D002118:Calcium