Associations of tibial lead levels with BsmI polymorphisms in the vitamin D receptor in former organolead manufacturing workers
Associations of tibial lead levels with BsmI polymorphisms in the vitamin D receptor in former organolead manufacturing workers
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DOI：
10.2307/3454434
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发表时间：
2000-03-01
影响因子：
10.4
通讯作者：
Todd, AC
中科院分区：
文献类型：
--
作者：
Schwartz, BS;Stewart, WF;Todd, AC
我们评估了胫骨铅水平与维生素D受体（VDR）多态性的关联，在504名有铅暴露史的前有机铅制造工人中。在这项横断面研究中，我们用Cd-109 K壳层X射线荧光测量胫骨电极导线。在使用BsmI限制性内切酶定义的不同VDR基因型受试者中评价胫骨电极导线，调整混杂变量。研究参与者的平均年龄+/- SD为57.4 +/- 7.6岁。共有169例（33.5%）受试者为BsmI限制性位点纯合子（指定为bb），251例（49.8%）为杂合子（Bb），84例（16.7%）为无限制性位点纯合子（BB）。在所有研究对象中，胫骨铅浓度较低，平均+/- SD为14.4 +/- 9.3 μ g Pb/g骨矿物质。不同VDR基因型的胫骨铅浓度只有很小的差异，平均+/- SD胫骨铅浓度分别为13.9 +/- 7.9，14.3 +/- 9.5，bb、Bb和BB受试者分别为15.5 ± 11.1。在胫骨铅浓度的多元线性回归模型中，VDR基因型改变了年龄和胫骨铅浓度之间的关系;具有B等位基因的受试者胫骨铅浓度随年龄增加而增加（bb、Bb和BB受试者分别为0.37、0.48和0.67 μ g/g/岁;斜率趋势的校正p值= 0.04）。VDR基因型也改变了自上次铅暴露以来的年数与胫骨铅浓度之间的关系。bb受试者的胫骨铅浓度自上次暴露于铅后平均每年下降0.10 μ g/g，而Bb和BB受试者的胫骨铅浓度分别平均每年增加0.03和0.11 μ g/g（斜率趋势的校正p值= 0.01）。维生素D受体的多态性改变了年龄和最后一次接触铅的时间与胫骨铅浓度的关系。尽管VDR基因型对骨密度的影响仍存在争议，但数据表明，VDR等位基因变体通过影响铅含量或钙含量或两者来改变骨中的铅浓度。
We evaluated associations of tibial lead levels with polymorphisms in the vitamin D receptor (VDR) in 504 former organolead manufacturing workers with past exposure to lead. In this cross-sectional study, we measured tibial lead by Cd-109 K-shell X-ray fluorescence. Tibial lead was evaluated in subjects with different VDR genotypes defined using the BsmI restriction enzyme, adjusting for confounding variables. Study participants had a mean age +/- SD of 57.4 +/- 7.6 years. A total of 169 (33.5%) subjects were homozygous for the BsmI restriction site (designated bb), 251 (49.8%) were heterozygous (Bb), and 84 (16.7%) were homozygous for the absence of the restriction site (BB). Among all of the study subjects, tibial lead concentrations were low, with a mean +/- SD of 14.4 +/- 9.3 mu g Pb/g bone mineral. There were only small differences in tibial lead concentrations by VDR genotype, with mean +/- SD tibial lead concentrations of 13.9 +/- 7.9, 14.3 +/- 9.5, and 15.5 +/- 11.1 in subjects with bb, Bb, and BB, respectively. In a multiple linear regression model of tibial lead concentrations, the VDR genotype modified the relation between age and tibial lead concentrations; subjects with the B allele had larger increases in tibia lead concentrations with increasing age (0.37, 0.48, and 0.67 mu g/g per year of age in subjects with bb, Bb, and BB, respectively; the adjusted p-value for trend in slopes = 0.04). The VDR genotype also modified the relation between years since last exposure to lead and tibial lead concentrations. Subjects with bb evidenced an average decline in tibial lead concentrations of 0.10 mu g/g per year since their last exposure to lead, whereas subjects with Bb and BB evidenced average increases of 0.03 and 0.11 mu g/g per year, respectively (the adjusted p-value for trend in slopes = 0.01). Polymorphisms in the vitamin D receptor modified the relations of age and years since the last exposure to lead with tibial lead concentrations. Although controversy remains on the influence of the VDR genotype on bone mineral density, the data suggest that variant VDR alleles modify lead concentrations in bone, either by influencing lead content or calcium content or both.