Department of Orthopaedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China.
Calcif Tissue Int. 2020 Nov;107(5):440-445. doi: 10.1007/s00223-020-00736-w. Epub 2020 Sep 28.
Body mass index (BMI) is closely associated with bone mineral density (BMD) in both men and women. However, the relationship between BMI and BMD varies according to different studies. Using SNPs strongly associated with BMI in 336,107 individuals, we conducted a two-sample Mendelian randomization study to identify whether and to what extent BMD at different skeletal sites was affected by BMI. A power calculation was also performed. We found that BMI may causally increase lumbar BMD (β 0.087; 95% CI 0.025 to 0.149; P = 0.006) and heel calcaneus BMD (β 0.120; 95% CI 0.082 to 0.157; P = 1 × 10). The associations of BMI with forearm and femoral neck BMD were not statistically significant. Our study suggested that higher BMI plays a causal role in increasing BMD and the effects are similar across the skeleton. BMI was causally and positively associated with lumbar and heel calcaneus BMD. However, no statistically significant effects were observed for BMI on femoral neck or forearm BMD.
体重指数 (BMI) 与男性和女性的骨密度 (BMD) 密切相关。然而，BMI 与 BMD 的关系因不同的研究而有所不同。我们使用与 336107 个人的 BMI 密切相关的 SNP，进行了一项两样本 Mendelian 随机化研究，以确定不同骨骼部位的 BMD 是否受到 BMI 的影响以及影响程度如何。还进行了功效计算。我们发现 BMI 可能会导致腰椎 BMD（β 0.087；95%CI 0.025 至 0.149；P=0.006）和跟骨 BMD（β 0.120；95%CI 0.082 至 0.157；P=1×10）增加。BMI 与前臂和股骨颈 BMD 的关联没有统计学意义。我们的研究表明，较高的 BMI 对增加 BMD 起着因果作用，并且这种影响在整个骨骼中是相似的。BMI 与腰椎和跟骨 BMD 呈正相关。然而，BMI 对股骨颈或前臂 BMD 没有观察到统计学上显著的影响。
