Department of Internal Medicine, American University of Beirut, Beirut, Lebanon.
Eur J Clin Nutr. 2010 Apr;64(4):383-91. doi: 10.1038/ejcn.2010.5. Epub 2010 Feb 10.
BACKGROUND/OBJECTIVES: Hypovitaminosis D is a major public health problem worldwide and unexpectedly more so in sunny countries. Vitamin D receptor (VDR) gene is associated with inter-individual variance in bone mineral density (BMD). Studies assessing the effect of VDR gene polymorphisms on BMD yielded conflicting results. The aim of this study was to assess the relationship between VDR polymorphisms and BMD in the Lebanese, across age groups and genders and to assess the effect of PTH and lean mass and vitamin D levels on such relationship.
SUBJECTS/METHODS: In total, 203 subjects aged 65-85 years and 336 children aged 10-17 years. Polymorphisms in the VDR gene were assessed with the restriction enzymes BsmI, TaqI and ApaI. Bone mineral content, BMD and lean mass were measured using Dual-Energy X-ray Absorptiometry (DXA). The dominant hand strength was measured in children.
Heterozygote genotype was the most frequent in both age groups. There was no difference in the frequency distribution of genotypes between the young and the elderly. No relationship between VDR genotypes and lean mass was found in either age group. Heterozygote boys had the lowest parathormone (PTH) and heterozygote elderly women had the highest BMD at the spine and forearm.
In the Lebanese, the relationship between VDR polymorphisms and BMD differs by age. Survival does not seem to differ by VDR genotype. However, further studies are needed to assess the effect of VDR gene polymorphisms on mortality per se and time to mortality, not evaluated in this study.
背景/目的：维生素 D 缺乏症是一个全球性的重大公共卫生问题，在阳光充足的国家尤其如此。维生素 D 受体（VDR）基因与个体间骨密度（BMD）的差异有关。评估 VDR 基因多态性对 BMD 影响的研究结果存在差异。本研究旨在评估 VDR 基因多态性与黎巴嫩人群 BMD 的关系，包括不同年龄组和性别，并评估甲状旁腺激素（PTH）、瘦体重和维生素 D 水平对这种关系的影响。
受试者/方法：共有 203 名年龄在 65-85 岁的受试者和 336 名年龄在 10-17 岁的儿童。使用限制性内切酶 BsmI、TaqI 和 ApaI 评估 VDR 基因多态性。使用双能 X 射线吸收法（DXA）测量骨矿物质含量、BMD 和瘦体重。在儿童中测量优势手的力量。
两种年龄组中杂合基因型最常见。年轻组和老年组的基因型频率分布无差异。两种年龄组均未发现 VDR 基因型与瘦体重之间存在关系。杂合子男孩的甲状旁腺激素（PTH）最低，杂合子老年女性的脊柱和前臂 BMD 最高。
在黎巴嫩，VDR 基因多态性与 BMD 的关系因年龄而异。生存似乎与 VDR 基因型无关。然而，需要进一步研究来评估 VDR 基因多态性对死亡率本身和死亡率时间的影响，本研究未对此进行评估。
