Division of Physical and Rehabilitation Medicine, Osteoporosis Research Center, Presidio Sanitario San Camillo, Fondazione Opera San Camillo, Strada Santa Margherita 136, 10131, Turin, Italy.
Division of Physical and Rehabilitation Medicine, Department of Surgical Sciences, University of Turin, Corso Bramante 88, 10128, Turin, Italy.
Aging Clin Exp Res. 2018 Dec;30(12):1429-1435. doi: 10.1007/s40520-018-1058-y. Epub 2018 Nov 7.
Subjects with osteosarcopenia, the concurrent presence of sarcopenia and osteoporosis, have prognostic disadvantages and can benefit from treatments targeted at both the conditions. Our aim was to elucidate whether the available definitions of low appendicular lean mass (aLM) capture or not the men with associated low bone mineral density (BMD) following a hip fracture.
80 men admitted to our rehabilitation hospital underwent a dual-energy X-ray absorptiometry scan 19.1 ± 4.1 (mean ± SD) days after hip fracture occurrence. Low aLM was identified according to either Baumgartner's definition (aLM/height < 7.26 kg/m) or the criteria from the Foundation for the National Institutes of Health (FNIH): aLM < 19.75 kg, or aLM adjusted for body mass index (BMI) < 0.789. Low BMD was diagnosed with a T-score < - 2.5 at the unfractured femur.
We found a significant positive correlation between aLM and BMD assessed at either femoral neck (r = 0.44; p < 0.001) or total hip (r = 0.50; p < 0.001). After categorization according to the FNIH threshold for aLM, we found a significant association between low aLM and low BMD: χ(1, n = 80) = 5.4 (p = 0.020), which persisted after adjustment for age and fat mass. Conversely, categorization according to neither Baumgartner's threshold for aLM/height nor to the FNIH threshold for aLM/BMI was associated with low BMD.
The association between low aLM and low BMD in men with hip fracture dramatically depends on the adopted definition of low aLM. FNIH threshold for aLM (< 19.75 kg) emerges as a useful tool to capture men with damage to both the components of the muscle-bone unit.
同时患有肌少症和骨质疏松症的骨骼肌肉减少症患者预后较差，可以从针对两种疾病的治疗中获益。我们的目的是阐明现有的四肢骨骼肌量（aLM）降低定义是否能够捕捉到髋部骨折后相关的低骨密度（BMD）男性。
80 名入住我院康复科的男性患者在髋部骨折发生后 19.1±4.1（均值±标准差）天接受双能 X 射线吸收法扫描。根据 Baumgartner 定义（aLM/身高＜7.26 kg/m）或美国国立卫生研究院基金会（FNIH）标准：aLM＜19.75 kg，或校正 BMI 的 aLM＜0.789，确定低 aLM。未骨折股骨的 T 评分＜-2.5 诊断为低 BMD。
我们发现 aLM 与股骨颈（r=0.44；p＜0.001）或全髋关节（r=0.50；p＜0.001）的 BMD 之间存在显著正相关。根据 FNIH 对 aLM 的阈值进行分类后，我们发现低 aLM 与低 BMD 之间存在显著相关性：χ(1，n=80)＝5.4（p=0.020），调整年龄和脂肪量后仍然存在。相反，根据 Baumgartner 对 aLM/身高的阈值或 FNIH 对 aLM/BMI 的阈值对 aLM 进行分类与低 BMD 无关。
髋部骨折男性中低 aLM 与低 BMD 之间的相关性强烈取决于采用的低 aLM 定义。FNIH 对 aLM（＜19.75 kg）的阈值可作为捕捉同时存在肌肉骨骼单位两个成分受损的男性的有用工具。
