Serum cartilage biomarker concentrations in response to 5 days of immobilization in healthy female adults – first data from the Vivaldi study

Immobilization and unloading leads to changes in cartilage metabolism, which may initiate catabolic processes. First studies reported changes in cartilage biomarker concentrations in male study participants exposed to bed
rest1. However, the effect of immobilization on women through dry immersion (DI), which simulates a support free environment, remains to be studied. Thereto, the purpose of the study was to investigate the effect of 5 days
of immobilization by dry immersion on serum concentrations of cartilage biomarkers.

The "Vivaldi" study is part of a research program of the European space agency (ESA) and was conducted at the Institute de Médecine et de Physiologie Spatiales (MEDES) in Toulouse (France). Eighteen healthy female volunteers (29±5 years, 165±6 cm, 59±6 kg) underwent 4 days of baseline data collection (BDC), 5 days of DI and 3 days of recovery (R). During DI volunteers were immersed in a water tank for 24 hrs per day, limiting all movements and ground support. Fasting, venous blood samples were taken on 5 days: BDC-2, BDC-1, DI3, R+0 and R+2. We analyzed serum concentrations of COMP, TIMP-1 and TIMP-2 with commercially available ELISAs (one-way repeated measures ANOVA, LSD post-hoc test).

The serum COMP concentration was significantly reduced (p
All analyzed biomarkers responded to the immobilization through DI and were in the same range as previously reported for bed rest studies in male adults1. The results suggest that even a short period of immobilization has significant effects on cartilage metabolism in female adults.

[1] Liphardt AM et al., J Orthop Res. 38:2373-2382, 2020