绝经妇女补充大豆异黄酮和钙后骨密度的改变及与ER基因Px单倍型的关系

目的 探讨绝经妇女补充大豆异黄酮和钙1年后骨密度(BMD)的改变及与雌激素受体(ER)基因Px单倍型的关系.方法 应用多聚酶链反应.限制性片段长度多态性(PCR-RFLP)检测691名汉族45～65岁绝经妇女的ER-α的PvuⅡ和Xba Ⅰ酶切位点多态性,从497名Pvu Ⅱ-Xba Ⅰ单倍体确定者中抽取93名进行为期1年的随机对照干预实验.根据基线时BMD测定结果,将T＜-1.5者纳入干预组(共52名),其余的作为观察组(共29名).将干预组对象随机分为2组:补钙+维生素D(VD)组和补钙+VD+大豆异黄酮组.给予的剂量分别为:钙440 mg/d;VD 100 IU/d;大豆异黄酮100 mg/d,正常观察组不给予任何特殊处理,干预期为12个月.采用双能X线吸收仪(DXEA)测量测定基线和终期腰椎及髋部的BMD.结果 试验结束后,观察组的绝经后妇女,全身、腰椎及股骨颈的BMD较基线时降低,变化率分别为-1.88%,-3.31%,-3.09%.ER-α的Px基因型全身BMD较基线时性降低2.44%,而non-Px基因型则无显著性改变.补钙组和补钙+大豆异黄酮组,全身及股骨颈的BMD都较基线时降低,但组间的变化率差异并无统计学意义;而腰椎、大转子的BMD较基线未有显著性的改变,甚至有略微升高.补钙和补大豆异黄酮对BMD的影响与ER-α的基因型无关.结论 妇女绝经后骨量开始丢失,丢失速率似乎与ER基因Px单倍型有相关性.已出现骨量减少的绝经后妇女补钙1年能降低骨量的丢失速率,但补充大豆异黄酮1年尚未观察到对BMD保护的作用.补钙及大豆异黄酮对BMD的干预效果与ER-α基因多态性无关.

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. CONCLUSION: 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.