Al Saedi Ahmed, Phu Steven, Vogrin Sara, Gunawardene Piumali, Duque Gustavo
Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, Victoria, Australia.
Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, Victoria, Australia.
Gerontology. 2022;68(9):1038-1043. doi: 10.1159/000520488. Epub 2021 Dec 2.
Circulating osteoprogenitor (COP) cells are a surrogate of the bone marrow mesenchymal stem cells with high levels observed in osteoporosis and the initial stages of fracture healing. Conversely, a low percentage of COP cells (%COP) is strongly associated with frailty and disability. However, it is unknown whether %COP is associated with sarcopenia, a musculoskeletal disease closely related to frailty.
This study sought to determine the associations between %COP and sarcopenia defined using the Sarcopenia Definitions and Outcomes Consortium (SDOC) criteria.
Data from a random sample of 73 community-dwelling older persons enrolled in the Nepean Osteoporosis and Frailty study (median age 74 years; 60% female) were analyzed. %COP was quantified by flow cytometry using selective gating of CD45/osteocalcin (OCN) + cells. Sarcopenia was defined using handgrip strength and gait speed with cut points as per the SDOC criteria. Linear regression was used for analysis.
Sarcopenia was identified in 19% of participants, all of whom were frail. After adjusting for age, sex, and interleukin 6, sarcopenic participants had 36% lower %COP (95% confidence interval [CI] -56%, -6%, p = 0.024). Both grip strength and gait speed showed associations with %COP (p = 0.065 and 0.002, respectively); however, after adjusting for age and frailty, only gait speed remained associated with %COP (0.1 m/s increase in gait velocity was associated with a 5% increase in %COP cells (95% CI 0%, 10%, p = 0.052).
High levels of %COP are associated with better muscle function. Future longitudinal studies are required to elucidate the clinical utility of %COP as a potential biomarker or disease stratifier for sarcopenia.
循环骨祖细胞（COP）是骨髓间充质干细胞的替代物，在骨质疏松症和骨折愈合初期水平较高。相反，COP细胞百分比（%COP）较低与虚弱和残疾密切相关。然而，尚不清楚%COP是否与肌肉减少症相关，肌肉减少症是一种与虚弱密切相关的肌肉骨骼疾病。
本研究旨在确定%COP与使用肌肉减少症定义和结果联盟（SDOC）标准定义的肌肉减少症之间的关联。
分析了从参加内皮恩骨质疏松症和虚弱研究的73名社区居住老年人随机样本中获得的数据（中位年龄74岁；60%为女性）。通过流式细胞术对CD45/骨钙素（OCN）+细胞进行选择性门控来定量%COP。根据SDOC标准，使用握力和步速以及切点来定义肌肉减少症。采用线性回归进行分析。
19%的参与者被确定患有肌肉减少症，他们均为虚弱者。在调整年龄、性别和白细胞介素6后，患有肌肉减少症的参与者的%COP降低了36%（95%置信区间[CI]为-56%，-6%，p = 0.024）。握力和步速均与%COP相关（分别为p = 0.065和0.002）；然而，在调整年龄和虚弱程度后，只有步速仍与%COP相关（步速每增加0.1 m/s，%COP细胞增加5%（95% CI为0%，10%，p = 0.052）。
高水平的%COP与更好的肌肉功能相关。未来需要进行纵向研究，以阐明%COP作为肌肉减少症潜在生物标志物或疾病分层指标的临床效用。
