title: Benefits of massive weight loss on symptoms, systemic inflammation and cartilage turnover in obese patients with knee osteoarthritis.
abstract: OBJECTIVE
  To investigate the effect of massive weight loss on (1) knee pain and disability, (2) low-grade inflammation and metabolic status and (3) joint biomarkers in obese patients with knee osteoarthritis (OA).
  
  
  METHODS
  140 patients involved in a gastric surgery programme were screened for painful knee OA, and 44 were included (age 44 ± 10.3 years, body mass index (BMI) 50.7 ± 7.2 kg/m(2)). Clinical data and biological samples were collected before and 6 months after surgery.
  
  
  RESULTS
  Before surgery, interleukin 6 (IL-6) levels were correlated with levels of high-sensitivity C reactive protein (hsCRP) (p=0.006) and Helix-II (p=0.01), a biomarker of cartilage turnover, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function score (p=0.03). Surgery resulted in substantial decrease in BMI (-20%). Levels of insulin and insulin resistance were decreased at 6 months. Knee pain decreased after surgery (24.5 ± 21 mm vs 50 ± 26.6 mm; p<0.001), and scores on all WOMAC subscales were improved. Levels of IL-6 (p<0.0001), hsCRP (p<0.0001), orosomucoid (p<0.0001) and fibrinogen (p=0.04) were decreased after surgery. Weight loss resulted in a significant increase in N-terminal propeptide of type IIA collagen levels (+32%; p=0.002), a biomarker of cartilage synthesis, and a significant decrease in cartilage oligomeric matrix protein (COMP) (-36%; p<0.001), a biomarker of cartilage degradation. Changes in COMP concentration were correlated with changes in insulin levels (p=0.02) and insulin resistance (p=0.05).
  
  
  CONCLUSIONS
  Massive weight loss improves pain and function and decreases low-grade inflammation. Change in levels of joint biomarkers with weight loss suggests a structural effect on cartilage.
authors.affiliation: Université Paris 7, UFR médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Lariboisière, Fédération de Rhumatologie, Paris Cedex, France. pascal.richette@lrb.aphp.fr
authors.forename: Pascal
authors.initials: P
authors.lastname: Richette
authors.forename: Christine
authors.initials: C
authors.lastname: Poitou
authors.forename: Patrick
authors.initials: P
authors.lastname: Garnero
authors.forename: Eric
authors.initials: E
authors.lastname: Vicaut
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Bouillot
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Lacorte
authors.forename: Arnaud
authors.initials: A
authors.lastname: Basdevant
authors.forename: Karine
authors.initials: K
authors.lastname: Clément
authors.forename: Thomas
authors.initials: T
authors.lastname: Bardin
authors.forename: Xavier
authors.initials: X
authors.lastname: Chevalier
mesh_terms: D054392:Adipokines / Q000097:blood; D000328:Adult; D050110:Bariatric Surgery; D015415:Biomarkers / Q000097:blood; D064236:Cartilage Oligomeric Matrix Protein; D002358:Cartilage, Articular / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000097:blood; D005260:Female; D006023:Glycoproteins / Q000097:blood; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000209:etiology / Q000628:therapy*; D018836:Inflammation Mediators / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D008055:Lipids / Q000097:blood; D008297:Male; D064235:Matrilin Proteins; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000601:surgery; D020370:Osteoarthritis, Knee / Q000209:etiology / Q000378:metabolism / Q000628:therapy*; D010146:Pain / Q000209:etiology; D010147:Pain Measurement / Q000379:methods; D011184:Postoperative Period; D011446:Prospective Studies; D015431:Weight Loss / Q000502:physiology*
chemical_list: D054392:Adipokines; D015415:Biomarkers; D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D018836:Inflammation Mediators; D008055:Lipids; D064235:Matrilin Proteins; C577553:TSP5 protein, human