Department of Orthopedics, Fuzhou Second Hospital, Fuzhou, China.
Fujian Provincial Clinical Medical Research Center for First Aid and Rehabilitation in Orthopaedic Trauma (2020Y2014), Fuzhou, China.
Front Endocrinol (Lausanne). 2022 Jun 20;13:900109. doi: 10.3389/fendo.2022.900109. eCollection 2022.
Cow milk contains more calcium, magnesium, potassium, zinc, and phosphorus minerals. For a long time, people have believed that increasing milk intake is beneficial to increasing bone density. Many confounding factors can affect milk consumption, and thus the association described to date may not be causal. We explored the causal relationship between genetically predicted milk consumption and Bone Mineral Density (BMD) of the femoral neck and lumbar spine based on 53,236 individuals from 27 studies of European ancestry using the Mendelian randomization (MR) study. 32,961 individuals of European and East Asian ancestry were used for sensitivity analysis.
A genetic instrument used for evaluating milk consumption is rs4988235, a locus located at 13,910 base pairs upstream of the gene. A Mendelian randomization (MR) analysis was conducted to study the effect of selected single nucleotide polymorphisms (SNPs) and BMD. The summary-level data for BMD of the femoral neck and lumbar spine were obtained from two GWAS meta-analyses ['Data Release 2012' and 'Data Release 2015' in the GEnetic Factors for OSteoporosis Consortium (GEFOS)].
we found that genetically predicted milk consumption was not associated with FN-BMD(OR 1.007; 95% CI 0.991-1.023; P = 0.385), LS-BMD(OR 1.003; 95% CI 0.983-1.024; P = 0.743) by performing a meta-analysis of several different cohort studies. High levels of genetically predicted milk intake were positively associated with increased FN-BMD in Women. The OR for each additional milk intake increasing allele was 1.032 (95%CI 1.005-1.059; P = 0.014). However, no causal relationship was found between milk consumption and FN-BMD in men (OR 0.996; 95% CI 0.964-1.029; P = 0.839). Genetically predicted milk consumption was not significantly associated with LS-BMD in women (OR 1.017; 95% CI 0.991-1.043; P = 0.198) and men (OR 1.011; 95% CI 0.978-1.045; P = 0.523).
Our study found that women who consume more milk have a higher FN-BMD. When studying the effect of milk consumption on bone density in further studies, we need to pay more attention to women.
牛奶含有更多的钙、镁、钾、锌和磷矿物质。长期以来，人们一直认为增加牛奶的摄入量有益于增加骨密度。许多混杂因素会影响牛奶的摄入量，因此迄今为止描述的关联可能不是因果关系。我们基于欧洲血统的 27 项研究中的 53236 人，使用孟德尔随机化（MR）研究，探讨了基于 32961 名欧洲和东亚血统个体的基因预测牛奶摄入量与股骨颈和腰椎骨密度（BMD）之间的因果关系。
用于评估牛奶摄入量的遗传工具是 rs4988235，它位于基因上游 13910 个碱基对处的一个基因座。进行孟德尔随机化（MR）分析以研究选定的单核苷酸多态性（SNP）和 BMD 的影响。股骨颈和腰椎骨密度的汇总水平数据来自两个 GWAS 荟萃分析[GEnetic Factors for OSteoporosis Consortium (GEFOS) 的“Data Release 2012”和“Data Release 2015”]。
通过对多个不同队列研究进行荟萃分析，我们发现基因预测的牛奶摄入量与 FN-BMD（OR 1.007；95%CI 0.991-1.023；P=0.385）和 LS-BMD（OR 1.003；95%CI 0.983-1.024；P=0.743）无显著相关性。高水平的基因预测牛奶摄入与女性 FN-BMD 的增加呈正相关。每增加一个牛奶摄入等位基因的 OR 为 1.032（95%CI 1.005-1.059；P=0.014）。然而，在男性中，牛奶摄入与 FN-BMD 之间没有发现因果关系（OR 0.996；95%CI 0.964-1.029；P=0.839）。基因预测的牛奶摄入量与女性（OR 1.017；95%CI 0.991-1.043；P=0.198）和男性（OR 1.011；95%CI 0.978-1.045；P=0.523）的 LS-BMD 无显著相关性。
我们的研究发现，摄入牛奶较多的女性 FN-BMD 较高。在进一步的研究中，当研究牛奶摄入对骨密度的影响时，我们需要更加关注女性。
