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Locomotion replacement exercise cannot counteract cartilage biomarker response to 5 days of immobilization in healthy adults
Author(s) -
Liphardt AnnaMaria,
Mündermann Annegret,
Heer Martina,
Achtzehn Silvia,
Niehoff Anja,
Mester Joachim
Publication year - 2020
Publication title -
journal of orthopaedic research®
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.24753
Subject(s) - cartilage oligomeric matrix protein , cartilage , biomarker , bed rest , medicine , chemistry , osteoarthritis , endocrinology , anatomy , pathology , biochemistry , alternative medicine
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.