[Relationship between estrogen receptor gene Px haplotype and the effect of calcium and soy isoflavone supplementation on bone mineral density of Chinese postmenopausal women].
OBJECTIVE
To investigate the relationship between estrogen receptor gene Px haplotype and the effect of calcium and soy isoflavone supplementation on bone mineral density (BMD) of Chinese postmenopausal women.


METHODS
It was a randomly controlling test for 12 months. The Pvu II and Xba I polymorphisms of ER-alpha gene were detected by using restriction fragment length polymorphisms (RFLP) in 691 Chinese postmenopausal women, aged 45-65 years. In 497 carriers of definitive Pvu II-Xba I haplotype, 93 subjects were chosen randomly. BMD was measured by dual energy X-ray absorptiometry (DXEA). According to BMD T score in any skeleton site of 81 subjects at baseline, 29 subjects with T > or = -1.5 were grouped into observation group, and 52 subjects with T < -1.5 were randomly assigned into two intervention groups and received either a 100 mg soy isoflavone and 440 mg Ca and 100 IU VD supplement/d (n = 26) or 440 mg Ca and 100 IU VD supplement/d (n = 26). BMD of the whole body, lumber (L2-L4), and hip were measured at baseline and after 12 months.


RESULTS
After one year fellow-up, the BMD at L2-L4, femur neck site and whole body were significantly decreased as compared with those of baseline (P < 0.05, change percent of BMD as follows: -3.31%, -3.09%, -1.88%) in observation group, and the whole body BMD was significantly lower at 12 month than that at baseline in subjects with Px haplotype (percent change was -2.44%, P < 0.05), but no difference was found in subjects without Px haplotype. Whole body and femur neck BMD were significantly decreased in both Ca group and Ca + soy isoflavone group, but no significant difference of change percent between two groups. There were no significant changes in L2-L4 and trochanter BMD irrespective of treatment. ER-alpha Px haplotype had no effect on the changes in BMD in both Ca group and Ca + soy isoflavone group.


CONCLUSIONS
The rate of bone loss in Chinese postmenopausal women seems to haverelation to ER Px haplotype. Calcium supplementation for 1 year might lower the bone loss rate, but soy isoflavone supplementation for 1 year had notshowu no effects. The effect of supplementation had no relationship with ER Px haplotype.
Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, China.
Jie
J
Dong
Zhen-wu
ZW
Huang
Jian-hua
JH
Piao
Fang
F
Li
Jing
J
Zeng
Jie
J
Gong
Xiao-guang
XG
Yang
D000368:Aged; D044466:Asian People / Q000235:genetics; D015519:Bone Density / Q000187:drug effects* / Q000235:genetics*; D017610:Calcium Compounds / Q000494:pharmacology*; D019587:Dietary Supplements; D047628:Estrogen Receptor alpha / Q000235:genetics; D005260:Female; D006801:Humans; D007529:Isoflavones / Q000494:pharmacology*; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D017698:Postmenopause; D011960:Receptors, Estrogen / Q000235:genetics*; D030262:Soybean Proteins / Q000494:pharmacology*
D017610:Calcium Compounds; D047628:Estrogen Receptor alpha; D007529:Isoflavones; D011960:Receptors, Estrogen; D030262:Soybean Proteins