Riancho J A, Valero C, Zarrabeitia M T
Department of Internal Medicine, Hospital U. M. Valdecilla, University of Cantabria, Av. Valdecilla s/n, Santander, 39008, Spain.
Calcif Tissue Int. 2006 Nov;79(5):289-93. doi: 10.1007/s00223-006-0143-y. Epub 2006 Nov 14.
The C677T (rs1801133) polymorphism of methylenetetrahydrofolate reductase (MTHFR) has been associated with bone status in some studies, but the results have been mixed. In order to have a better understanding of this issue, we performed a meta-analysis of studies about the association of the C677T polymorphism and bone mineral density (BMD). Eight studies analyzed the relationship with spine BMD. When their results were combined, individuals with TT genotype showed a small but significantly reduced BMD compared to those with TC and CC genotypes. The weighted mean difference (WMD) was 18.0 mg/cm2 (P = 0.001, 95% confidence interval [CI] 7.1-28.9), without statistical evidence for between-study heterogeneity (P = 0.28, I2 = 17%). Six studies analyzed femoral neck BMD. A test for heterogeneity was significant (P = 0.03, I2 = 56%). Individuals with TT alleles tended to have somewhat lower BMD, but the difference was not statistically significant. In random effects model, the WMD between the TT and TC/CC genotypes was 6.4 mg/cm2 (95% CI -7.8 to 21.2, P = 0.36). Total hip BMD was measured in four studies. They showed a significantly lower BMD in subjects with TT alleles: WMD 19.7 (95% CI 5.3-34.1) mg/cm2, P = 0.007, in comparison with TC/CC subjects. When we considered only studies on women, the WMD in BMD between TT and TC/CC genotypes was significant at the spine (22.1 mg/cm2, 95% CI 8.6-35.6; P = 0.001) and the femoral neck (15.5 mg/cm2, 95% CI 4.3-26.7; P = 0.007). There was no evidence for heterogeneity. The small number of studies did not allow a meaningful sex-stratified analysis of total hip BMD or a separate analysis of male data. In conclusion, the C677T polymorphism of the MTHFR gene is associated with small differences in BMD, at least in women.
在一些研究中，亚甲基四氢叶酸还原酶（MTHFR）的C677T（rs1801133）多态性与骨状态相关，但结果不一。为了更好地理解这个问题，我们对有关C677T多态性与骨密度（BMD）关联的研究进行了荟萃分析。八项研究分析了与脊柱骨密度的关系。当合并其结果时，与TC和CC基因型个体相比，TT基因型个体的骨密度虽有小幅下降，但差异显著。加权平均差（WMD）为18.0mg/cm²（P = 0.001，95%置信区间[CI]7.1 - 28.9），研究间异质性无统计学证据（P = 0.28，I² = 17%）。六项研究分析了股骨颈骨密度。异质性检验显著（P = 0.03，I² = 56%）。TT等位基因个体的骨密度往往略低，但差异无统计学意义。在随机效应模型中，TT与TC/CC基因型之间的WMD为6.4mg/cm²（95%CI -7.8至21.2，P = 0.36）。四项研究测量了全髋骨密度。与TC/CC受试者相比，TT等位基因受试者的骨密度显著降低：WMD为19.7（95%CI 5.3 - 34.1）mg/cm²，P = 0.007。当我们仅考虑女性研究时，TT与TC/CC基因型之间的骨密度WMD在脊柱（22.1mg/cm²，95%CI 8.6 - 35.6；P = 0.001）和股骨颈（15.5mg/cm²，95%CI 4.3 - 26.7；P = 0.007）处显著。无异质性证据。由于研究数量较少，无法对全髋骨密度进行有意义的性别分层分析或对男性数据进行单独分析。总之，MTHFR基因的C677T多态性与骨密度的微小差异相关，至少在女性中如此。
