Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia.
Australian Institute for Musculoskeletal Science (AIMSS), University of Melbourne and Western Health, St. Albans, Australia.
J Bone Miner Res. 2021 Mar;36(3):523-530. doi: 10.1002/jbmr.4208. Epub 2020 Dec 3.
Evidence from animal models suggests that undercarboxylated osteocalcin (ucOC) is involved in muscle mass maintenance and strength. In humans, the ucOC to total (t)OC ratio may be related to muscle strength and perhaps physical function and falls risk, but data are limited. We tested the hypothesis that ucOC and ucOC/tOC ratio are associated with muscle function (muscle strength and physical function) in older women and 15-year falls-related hospitalizations. Serum tOC and ucOC were assessed in 1261 older women (mean age 75.2 ± 2.7 years) forming the Perth Longitudinal Study of Aging Women (1998 to 2013). Timed-up-and-go (TUG) and grip strength were assessed at baseline and at 5 years. Falls-related hospitalizations (14.5-year follow-up) were captured by the Hospital Morbidity Data Collection, via the Western Australian Data Linkage System. At baseline, women with higher ucOC/tOC ratio (quartile 4) had slower TUG performance compared with quartile 1 (~0.68 seconds, p < .01). Grip strength and 5-year change of TUG and grip were not different (p > .05) between quartiles. Fear of falling limiting house, outdoor, and combined activities was significantly different across quartiles (p < .05). Higher ucOC/tOC was significantly associated with poorer TUG performance at baseline and 5-year change in performance, increased walking aid use, and fear of falling (all p < .05). Higher ucOC was related to lower grip strength at baseline (p < .05) but not 5-year change in strength. Those with the highest ucOC/tOC had greater falls-related hospitalizations (unadjusted log rank, p = .004) remaining significant after adjusting for key variables (hazard ratio [HR] = 1.31, 95% confidence interval [CI] 1.09-1.57, p = .004). We identified a large proportion of older women with high ucOC/tOC ratio who had reduced physical function, including its long-term decline and increased risk of falls-related hospitalizations. Early identification of women at higher risk can enable prevention and intervention strategies to occur, reducing risk for injurious falls. © 2020 American Society for Bone and Mineral Research (ASBMR)..
动物模型研究表明，非羧化骨钙素（ucOC）参与了肌肉质量的维持和力量的产生。在人类中，ucOC 与总（t）OC 的比值可能与肌肉力量有关，甚至可能与身体功能和跌倒风险有关，但数据有限。我们检验了以下假设，即 ucOC 和 ucOC/tOC 比值与老年女性的肌肉功能（肌肉力量和身体功能）以及 15 年的跌倒相关住院有关。在珀斯老年女性纵向研究（1998 年至 2013 年）中，对 1261 名年龄在 75.2 ± 2.7 岁的老年女性进行了血清 tOC 和 ucOC 的评估。在基线和 5 年内进行了计时起立行走（TUG）和握力测试。通过西澳大利亚数据链接系统，通过医院发病率数据采集系统，在 14.5 年的随访期间，记录了与跌倒相关的住院情况。在基线时，与四分位 1 相比，ucOC/tOC 比值较高的四分位 4 的 TUG 表现较慢（约 0.68 秒，p<.01）。握力和 5 年内 TUG 和握力的变化在四分位之间没有差异（p>.05）。恐惧跌倒对房屋、户外和综合活动的限制在四分位之间差异显著（p<.05）。较高的 ucOC/tOC 与基线时的 TUG 表现较差和 5 年内表现的变化、步行辅助工具的使用增加以及跌倒恐惧有关（所有 p<.05）。较高的 ucOC 与基线时握力较低有关（p<.05），但与 5 年内握力的变化无关。ucOC/tOC 最高的人跌倒相关住院的可能性更大（未经调整的对数秩检验，p=0.004），在调整了关键变量后仍然显著（风险比[HR]=1.31，95%置信区间[CI]为 1.09-1.57，p=0.004）。我们发现，很大一部分 ucOC/tOC 比值较高的老年女性身体功能下降，包括其长期下降和跌倒相关住院风险增加。早期识别高风险的女性可以使预防和干预策略得以实施，降低受伤性跌倒的风险。
