BACKGROUND Hip fracture is both a cause and a consequence of sarcopenia. Older persons with sarcopenia have an increased risk of falling, and the prevalence of sarcopenia may be increased in those who suffer a hip fracture. The aim of this study was to explore potential biomarkers (neuromuscular and peripheral pro-inflammatory and oxidative stress markers) that may be associated with sarcopenia in very old persons with hip fracture. METHODS We recruited 150 consecutive patients ≥80 years old admitted to an orthogeriatric unit for an osteoporotic hip fracture. Muscle mass was assessed pre-operatively using bioelectrical impedance analysis; Janssen's (J) and Masanés' (M) reference cut-off points were used to define low muscle mass. Muscle strength was assessed with handgrip strength (Jamar's dynamometer). Sarcopenia was defined by having both low muscle mass and strength and using the European Working Group on Sarcopenia in Older People 2 definition of probable sarcopenia (low grip strength). Peripheral markers-pro-inflammatory and oxidative stress parameters-were determined either in the plasma or in the erythrocyte fraction obtained from peripheral whole blood of every patient pre-operatively. RESULTS Mean age was 87.6 ± 4.9 years, and 78.7% were women. The prevalence of sarcopenia was 11.5% with Janssen's, 34.9% with Masanés' cut-offs, and 93.3% with the European Working Group on Sarcopenia in Older People 2 definition of probable sarcopenia. Among the four pro-inflammatory cytokines tested in plasma, only tumour necrosis factor-α was different (lower) in sarcopenic than in non-sarcopenic participants using both muscle mass cut-offs (J 7.9 ± 6.2 vs. 8.3 ± 5.8, M 6.8 ± 4.7 vs. 9.1 ± 6.2). Erythrocyte glutathione system showed a non-significant tendency to lower glutathione levels and glutathione/oxidized glutathione ratios in sarcopenic participants compared with non-sarcopenic subjects. Catalase activity was also lower in sarcopenic participants (J 2904 ± 1429 vs. 3329 ± 1483, M 3037 ± 1430 vs. 3431 ± 1498). No significant differences were found between groups in chymotrypsin-like activity of the 20S proteasome, superoxide dismutase, glutathione peroxidase and butyrylcholinesterase activity, C-terminal agrin fragment, interferon-γ, or interleukin-1β. CONCLUSIONS The prevalence of sarcopenia in patients with hip fracture varies according to the definition and the muscle mass reference cut-off points used. We did not find differences in most neuromuscular, pro-inflammatory, or oxidative stress markers, except for lower peripheral tumour necrosis factor-α levels and catalase activity in sarcopenic participants, which may be markers of an early inflammatory reaction that is hampered in sarcopenic patients.

中文翻译：

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老年髋关节骨折患者肌肉减少症的生物标志物。

背景技术髋部骨折是肌肉减少症的原因和结果。患有少肌症的老年人跌倒的风险增加，患有髋部骨折的人少肌症的患病率可能会增加。这项研究的目的是探讨潜在的生物标志物（神经肌肉和周围的促炎性和氧化应激标志物），这些标志物可能与非常年老的髋部骨折的肌肉减少症有关。方法我们招募了150名年龄≥80岁的连续患者，他们因骨质疏松性髋部骨折而接受了老年医学科的治疗。术前使用生物电阻抗分析法评估肌肉质量。使用Janssen（J）和Masanés（M）的参考分界点来定义低肌肉质量。用握力（Jamar测功机）评估肌肉强度。肌肉减少症是指肌肉质量和强度均低，并使用欧洲老年人肌肉减少症工作组2对可能的肌肉减少症（低握力）的定义。术前在血浆或从每名患者外周全血中获得的红细胞分数中测定外周标志物的促炎和氧化应激参数。结果平均年龄为87.6±4.9岁，女性为78.7％。詹森氏症的肌肉减少症患病率为11.5％，Masanés临界值的患病率为34.9％，欧洲老年人骨骼肌减少症工作组2对可能的肌肉减少症的定义为93.3％。在血浆中测试的四种促炎细胞因子中，使用两个肌肉质量临界值，肌肉减少症患者的肌肉减少症患者与非肌肉减少症患者只有肿瘤坏死因子-α不同（较低）（J 7.9±6.2 vs. 8.3±5.8，M 6.8±4.7 vs. 9.1±6.2）。与非肌肉少的受试者相比，肌肉少的参与者的谷胱甘肽系统显示出降低谷胱甘肽水平和谷胱甘肽/氧化型谷胱甘肽比率的非显着趋势。肌肉减少症参与者的过氧化氢酶活性也较低（J 2904±1429对3329±1483，M 3037±1430对3431±1498）。两组之间在20S蛋白酶体的胰凝乳蛋白酶样活性，超氧化物歧化酶，谷胱甘肽过氧化物酶和丁酰胆碱酯酶活性，C端凝集素片段，干扰素-γ或白介素-1β的活性之间没有发现显着差异。结论髋骨骨折患者的肌肉减少症患病率根据定义和所用的肌肉质量参考临界点而异。除了在肌肉减少症患者中较低的外周肿瘤坏死因子-α水平和过氧化氢酶活性外，我们在大多数神经肌肉，促炎性或氧化应激指标中均未发现差异，这可能是肌肉减少症患者早期炎症反应的指标。