Department of Internal Medicine 3-Rheumatology and Immunology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany.
Institute of Biomechanics and Orthopaedics, German Sport University Cologne (DSHS Köln), Köln, Germany.
J Orthop Res. 2020 Nov;38(11):2373-2382. doi: 10.1002/jor.24753. Epub 2020 Jul 23.
Biomarkers of cartilage metabolism are sensitive to changes in the biological and mechanical environment and can indicate early changes in cartilage homeostasis. The purpose of this study was to determine if a daily locomotion replacement program can serve as a countermeasure for changes in cartilage biomarker serum concentration caused by immobilization. Ten healthy male subjects (mean ± 1 standard deviation; age: 29.4 ± 5.9 years; body mass: 77.7 ± 4.1 kg) participated in the crossover 5-day bed rest study with three interventions: control (CON), standing (STA), and locomotion replacement training (LRT). Serum samples were taken before, during, and after bed rest. Biomarker concentrations were measured using commercial enzyme-linked immunosorbent assays. Cartilage oligomeric matrix protein (COMP) levels after 24 hours of bed rest decreased independently of the intervention (-16.8% to -9.8%) and continued to decrease until 72 hours of bed rest (minimum, -23.2% to -20.6%). LRT and STA did not affect COMP during bed rests (P = .056) but there was a strong tendency for a slower decrease with LRT (-9.4%) and STA (-11.7%) compared with CON (-16.8%). MMP-3 levels decreased within the first 24 hours of bed rest (CON: -22.3%; STA: -14.7%; LRT: -17%) without intervention effect. Both COMP and MMP-3 levels recovered to baseline levels during the 6-day recovery period. MMP-1, MMP-9, and TNF-α levels were not affected by immobilization or intervention. COMP and MMP-3 are mechano-sensitive cartilage biomarkers affected by immobilization, and simple interventions such as standing upright or LRT during bed rest cannot prevent these changes. Clinical significance: simple locomotion interventions cannot prevent cartilage biomarker change during bed rest.
软骨代谢的生物标志物对生物和机械环境的变化敏感，并能指示软骨内稳态的早期变化。本研究的目的是确定日常的替代运动方案是否可以作为对抗因固定而导致的软骨生物标志物血清浓度变化的对策。10 名健康男性受试者（平均±1 个标准差；年龄：29.4±5.9 岁；体重：77.7±4.1kg）参与了为期 5 天的卧床休息交叉研究，有三种干预措施：对照组（CON）、站立组（STA）和替代运动训练组（LRT）。在卧床休息前、期间和之后采集血清样本。使用商业酶联免疫吸附测定法测量生物标志物浓度。软骨寡聚基质蛋白（COMP）在 24 小时卧床休息后独立于干预因素下降（-16.8%至-9.8%），并一直持续到 72 小时卧床休息（最低值，-23.2%至-20.6%）。LRT 和 STA 在卧床休息期间对 COMP 没有影响（P=0.056），但与 CON（-16.8%）相比，LRT（-9.4%）和 STA（-11.7%）下降趋势较弱。MMP-3 水平在卧床休息的前 24 小时内下降（CON：-22.3%；STA：-14.7%；LRT：-17%），且没有干预作用。在 6 天的恢复期内，COMP 和 MMP-3 水平均恢复到基线水平。MMP-1、MMP-9 和 TNF-α水平不受固定或干预的影响。COMP 和 MMP-3 是受固定影响的机械敏感软骨生物标志物，而卧床休息期间简单的干预措施，如直立或替代运动，不能预防这些变化。临床意义：简单的运动干预不能防止卧床休息期间软骨生物标志物的变化。
