Department of Orthopaedic Surgery, School of Medicine, University of California, San Diego, La Jolla, CA, USA.
Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA, USA.
J Bone Miner Res. 2022 Aug;37(8):1537-1544. doi: 10.1002/jbmr.4634. Epub 2022 Jul 11.
Low vertebral bone mass is a major risk factor for vertebral compression fractures. Although sarcopenia has been shown to be associated with low bone mineral density (BMD), it is not known whether trunk musculature is directly associated with lumbar BMD, and whether exercise modifies this association. Using data from the Multi-Ethnic Study of Atherosclerosis (MESA), we sought to determine the association of muscle density and fat fraction of the psoas, paraspinal, and oblique muscle groups with L lumbar volumetric BMD, and whether these associations were modified by exercise. We obtained L vBMD measurements, and fat and muscle measurements (in Hounsfield units [HU]) from abdominal computed tomography (CT) scans spanning the L -L intervertebral disc spaces. Muscle density was defined as the mean HU value for a muscle group area. Fat fraction was calculated as the mean HU value for the muscle group fat area/total muscle group area (cm ). Exercise data were self-reported (MET-minute/week). We utilized multivariable linear regression to evaluate these associations, stratified by gender, and adjusting for demographics, body mass index (BMI), smoking status, impaired fasting glucose, and corticosteroid and anti-resorptive medication use. Among 1923 MESA participants, mean ± standard deviation (SD) age was 62 ± 10 years, 49% were female, 40% white, 21% black, 26% Hispanic/Latino, and 13% Chinese. In fully adjusted analysis, for every 1-SD higher psoas fat fraction, there was a 3.19-SD lower L vBMD in men and 4.3-SD lower L vBMD in women (p < 0.001). For every 1-SD higher psoas density, there was a 0.2-SD higher L vBMD (p < 0.001) in men and 0.19-SD higher L vBMD (p < 0.001) in women. Findings were similar for paraspinal and oblique muscles. Intentional exercise did not modify these associations. In men and women, trunk muscle density was positively associated with higher lumbar BMD, suggesting a local association. Future studies are warranted to determine the temporality of this association. © 2022 American Society for Bone and Mineral Research (ASBMR).
低椎体骨量是椎体压缩性骨折的主要危险因素。虽然已经表明肌肉减少症与低骨矿物质密度（BMD）有关，但尚不清楚躯干肌肉是否与腰椎 BMD 直接相关，以及运动是否会改变这种关联。本研究使用动脉粥样硬化多民族研究（MESA）的数据，旨在确定腰大肌、椎旁和斜肌群的肌肉密度和脂肪分数与腰椎容积 BMD 的关系，以及这些关系是否受运动的影响。我们从腹部 CT（CT）扫描中获得了 L 腰椎 vBMD 测量值，以及脂肪和肌肉测量值（以亨氏单位[HU]表示），这些扫描横跨 L -L 椎间盘间隙。肌肉密度定义为肌肉区域的平均 HU 值。脂肪分数是肌肉区域的平均 HU 值/肌肉区域的总脂肪面积（cm ）。运动数据是自我报告的（MET 分钟/周）。我们利用多变量线性回归来评估这些关联，按性别分层，并调整了人口统计学、体重指数（BMI）、吸烟状况、空腹血糖受损以及皮质类固醇和抗吸收药物的使用情况。在 1923 名 MESA 参与者中，平均年龄±标准差（SD）为 62±10 岁，49%为女性，40%为白人，21%为黑人，26%为西班牙裔/拉丁裔，13%为中国人。在完全调整分析中，对于男性，每增加 1 个 SD 的腰大肌脂肪分数，腰椎 vBMD 就会降低 3.19 SD；对于女性，腰椎 vBMD 会降低 4.3 SD（p<0.001）。对于男性，每增加 1 个 SD 的腰大肌密度，腰椎 vBMD 就会升高 0.2 SD（p<0.001）；对于女性，腰椎 vBMD 会升高 0.19 SD（p<0.001）。椎旁和斜肌的结果相似。有意运动并没有改变这些关联。在男性和女性中，躯干肌肉密度与腰椎 BMD 呈正相关，表明存在局部关联。未来的研究需要确定这种关联的时间顺序。© 2022 美国骨骼矿物质研究协会（ASBMR）。
