Benefits of massive weight loss on symptoms, systemic inflammation and cartilage turnover in obese patients with knee osteoarthritis.
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.
Richette
Pascal
P
Université Paris 7, UFR médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Lariboisière, Fédération de Rhumatologie, Paris Cedex, France. pascal.richette@lrb.aphp.fr
Poitou
Christine
C
Garnero
Patrick
P
Vicaut
Eric
E
Bouillot
Jean-Luc
JL
Lacorte
Jean-Marc
JM
Basdevant
Arnaud
A
Clément
Karine
K
Bardin
Thomas
T
Chevalier
Xavier
X
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*
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