title: Exercise increases interleukin-10 levels both intraarticularly and peri-synovially in patients with knee osteoarthritis: a randomized controlled trial.
abstract: BACKGROUND
  The microdialysis method was applied to the human knee joint with osteoarthritis (OA) in order to reveal changes in biochemical markers of cartilage and inflammation, intraarticularly and in the synovium, in response to a single bout of mechanical joint loading.
  
  
  METHODS
  Thirty-one female subjects with OA of the knee were randomized to non-exercise (NEx) or exercise (Ex) groups. Following acute resistance exercise (25 sets of 10 repetitions at 60% of 1 Repetition Maximum) or none (NEx), peripheral nerve blocks just below the inguinal ligament were applied and two microdialysis catheters were positioned in two different compartments, intraarticularly and peri-synovially. The microdialysis catheters were perfused at a slow rate (2 μl/minute) with a solution of Ringer-acetate and radioactively labelled glucose allowing for determination of relative recovery (RR) and calculation of interstitial concentrations of inflammatory and cartilage biomarkers over a three-hour period.
  
  
  RESULTS
  A significant increase of Interleukin (IL) -10 was discovered in both positions of the knee in the Ex group over the three hours post exercise, whereas IL-10 remained stationary over time in the NEx group. IL-6 and IL-8 displayed significant increases over time regardless of group and position of the catheter. Cartilage oligomeric matrix protein (COMP) decreased intraarticularly in the post exercise period in the Ex group compared to the NEx group.
  
  
  CONCLUSIONS
  Exercise caused an increase in both intraarticular and peri-synovial concentrations of IL-10 in a group of human females with knee OA. This suggests a positive effect of exercise on a chondroprotective anti-inflammatory cytokine response in patients with knee OA and might contribute to explaining the beneficial effect that exercise has on OA.
  
  
  BACKGROUND
  NCT01090375.
authors.affiliation: Department of Orthopaedic Surgery, University of Copenhagen, Bispebjerg Bakke 23, Copenhagen NV, Denmark. ida_caroe@dadlnet.dk
authors.forename: Ida C
authors.initials: IC
authors.lastname: Helmark
authors.forename: Ulla R
authors.initials: UR
authors.lastname: Mikkelsen
authors.forename: Jens
authors.initials: J
authors.lastname: Børglum
authors.forename: Anders
authors.initials: A
authors.lastname: Rothe
authors.forename: Marie C H
authors.initials: MC
authors.lastname: Petersen
authors.forename: Ove
authors.initials: O
authors.lastname: Andersen
authors.forename: Henning
authors.initials: H
authors.lastname: Langberg
authors.forename: Michael
authors.initials: M
authors.lastname: Kjaer
mesh_terms: D000368:Aged; D001158:Arteries; D015415:Biomarkers / Q000378:metabolism*; D002358:Cartilage, Articular / Q000276:immunology / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000276:immunology / Q000378:metabolism*; D017551:Microdialysis; D008875:Middle Aged; D008954:Models, Biological; D020370:Osteoarthritis, Knee / Q000276:immunology / Q000378:metabolism / Q000628:therapy; D055070:Resistance Training / Q000379:methods*; D013582:Synovial Fluid / Q000378:metabolism; D016474:Weight-Bearing / Q000502:physiology
chemical_list: D015415:Biomarkers; C508609:IL10 protein, human; D016753:Interleukin-10