维生素D受体和降钙素受体基因多态性与新疆地区汉族女性人群骨密度的相关性

Associations between bone mineral density and genetic polymorphisms of vitamin D receptor gene and calcitonin receptor gene in female Han population in Xinjiang region

目的研究维生素D受体(VDR)和降钙素受体(CTR)基因多态性与新疆地区汉族女性人群骨密度(BMD)的关系,探讨原发性骨质疏松症发病的遗传易感因素。方法采用聚合酶链反应(PCR-RFLP)限制性片段长度多态性技术,对336例新疆地区汉族女性人群的VDR和CTR基因进行多态性分析,双能X线吸收法测定受试者L_(2~4)、Ward's三角、大粗隆、股骨干4个部位的BMD值,比较不同基因型各部位BMD值的差异。结果(1)336例受试者VDR、CTR受体基因型频率分布均符合Hardy-Weinberg定律,90例骨质疏松组与246例非骨质疏松组VDR与CTR基因型分布频率差异无统计学意义(P>0.05)。(2)年龄与不同部位BMD值之间呈负相关(P<0.05),体质指数与BMD值之间呈正相关(P<0.05),在将年龄和体质指数进行校正后发现非骨质疏松组中CTR CT基因型在Ward's三角的BMD值高于CC基因型(P<0.05);VDR Bb基因型在L_(2~4)、Ward's三角部位BMD均低于bb型(P<0.05),Bb基因型的BMD值在大粗隆、股骨干部位较bb型有降低趋势(P>0.05);VDRCTR复合基因CCBb型的BMD值最低。结论年龄与BMD值变化密切相关;体质指数是新疆汉族女性非骨质疏松的保护性因素,适当增加体重对防治骨质疏松有积极的意义;VDR Bb基因型与BMD降低密切相关;VDR-CTR复合基因CCBb型可作为预测新疆地区女性发生骨质疏松危险性的遗传学标志。

Objective To investigate the associations of bone mineral density （BMD） with vitamin D receptor （VDR） gene and calcitonin receptor （CTR） gene polymorphisms in Han women from Xinjiang; and to discuss the genetic susceptibility factors of osteoporosis （OP）. Methods VDR and CTR genotypes were identified with polymerase chain reaction -restriction fragment length polymorphism （PCR -RFLP） , so as to analyze distribution of VDR and CTR poly- morphisms of 336 Hart women from Xinjiang. BMD was measured by dual energy X- ray absorptiometry （DEXA） at the lumbar spine （L2-4） , Ward＇s triangle, great trochanter, and femoral shaft. Comparing the differences of BMD values of different locations among different genotypes. Results A total of 336 women were included in the study. The distributions of VDR and CTR genotypes met Hardy - Weinberg equilibrium （ all P 〉 0.05 ） ; and there was no significant difference in VDR or CTR genotype frequency between osteoporosis group （ n = 90 ） and non - osteoporosis group （ n = 246 ） （ P 〉 0. 05 ）. We also found that BMD values of different locations were significantly negatively correlated with age （ P 〈 0. 05 ） and positively correlated with body mass index （BMI） （ P 〈 0. 05 ）. When BMD were adjusted by age and BMI, the women with CT genotype of CTR gene had a higher adjusted BMD than CC genotype at Ward＇s triangle （ P 〈 0. 05 ） in non - osteoporosis group. The adjusted BMDs at L2-4 and Ward＇s triangle were significant lower in the women with Bb geno- type of VDR gene compared to the bb genotype （ P 〈 O. 05 ）. Compared to the bb genotype at great troehanter and femoral neck in non - osteoporosis group, the adjusted BMDs showed a decreasing tendency in women with Bb genotype. The ad- justed BMD of CCBb genotype was the lowest. Conclusion Age is closely correlated to the change of BMD. BMI is a protective factor for OP in Hart women in Xinjiang, and increasing weight may have a positive effect on preventing and treating osteoporosis. Bb genotype of VDR is associated with lower BMD. Compound CCBb genotype may be regarded as a genetic marker to predict the risk of osteoporosis in Han women in Xinjiang.