甲状旁腺激素基因多态性与女性骨量及骨相关生化指标的关系

目的探讨正常女性人群甲状旁腺素(PTH)基因多态性与骨量、血清骨相关生化指标的关系。方法用ELISA法测定314名20～80岁(平均年龄43±16岁)血清PTH、骨特异性碱性磷酸酶(BAP)、Ⅰ型胶原羧基末端肽、Ⅰ型胶原氨基末端肽和护骨素及瘦素的浓度;对女性志愿者基因组的DNA样品作限制性内切酶BstBI的聚合酶链反应限制性片段长度多态性检测以确定其基因型(存在BstBI限制性酶切位点用“B”表示,不存在则用“b”表示);DXA测定腰椎正位总体(AP)、仰卧侧位腰椎和股骨颈的骨密度(BMD)。结果(1)健康女性PTH基因BB型(绝经前120例,绝经后118例),Bb型(绝经前37例,绝经后36例)和bb型分布频率分别为75.8%,23.3%和0.9%;等位基因频率为87.5%,12.5%。绝经前妇女PTH基因多态性频率较绝经后妇女无差异。(2)协方差分析显示女性BB和Bb基因型在正侧位腰椎、股骨颈的BMD和血清骨生化指标(PTH、BAP、CTX、NTX、OPC及瘦素)差异无统计学意义;(3)多元逐步回归显示PTH基因多态性对BMD的变异无影响。结论PTH基因多态性与女性骨量及血清骨生化指标不相关。

Relationship between polymorphism of parathyroid hormone and bone mineral density and relevant biochemical indicators in women

OBJECTIVE: To investigate the distribution of parathyroid hormone (PTH) gene polymorphisms and the relationships of PTH gene polymorphisms with bone mass and serum bone relative biochemical markers. METHODS: Blood samples of 314 normal female volunteers, aged 20 - 80, were collected. Serum PTH, bone alkaline phosphatase (sBAP), cross-linked N-telopeptide of collagen type I (sNTX), cross-linked C-telopeptide of collagen type I (sCTX), osteoprotegerin (OPG) and leptin were determined by ELISA. Polymorphisms of PTH gene were detected by polymerase chain reaction fragment length polymorphisms (PCR-RFLP) of restriction enzyme BstBI. BMD (QDR4500A) of the anteroposterior spine (AP), supine lateral spine (Lat), and femoral neck (FN) were measured. RESULTS: (1) The genotype frequency of BB, Bb, and bb were 75.8%, 23.3% and 0.9% respectively in normal females volunteers. The frequencies of RFLP alleles B and b were 87.5% and 12.5% respectively. There was no difference in the polymorphism frequency of PTH gene between the post- and pre menopausal women. (2) There were no significant differences in the BMD of the AP, Lat, and FN and the serum biochemical markers between the BB and Bb genotypes. (3) Multiple stepwise regression analysis showed that PTH did not influence the BMD values. CONCLUSION: PTH gene polymorphism has no relationship with bone mass and serum bone biochemical markers in normal females.