title: Plasma adiponectin in patients with active, early, and chronic rheumatoid arthritis who are steroid- and disease-modifying antirheumatic drug-naive compared with patients with osteoarthritis and controls.
abstract: OBJECTIVE
  Rheumatoid arthritis (RA) is a systemic chronic inflammatory joint disease, whereas osteoarthritis (OA) is a local joint disease with low-level inflammatory activity. The pathogenic role of the adipocytokine adiponectin is largely unknown in these diseases. We hypothesized (1) that plasma adiponectin concentrations differ in healthy controls and patients with early disease-modifying antirheumatic drug (DMARD)-naive RA, chronic RA, and OA; (2) that changes in adiponectin are observed during methotrexate (MTX) treatment of chronic RA; and (3) that adiponectin correlates to disease activity measures in RA.
  
  
  METHODS
  Plasma adiponectin was analyzed with a validated in-house immunoassay. We measured adiponectin in healthy controls (n = 45) and patients with early DMARD-naive RA (n = 40), chronic RA (n = 74), and OA (n = 35). In a subgroup of patients with chronic RA (n = 31), the longitudinal effect of MTX treatment on adiponectin (Week 0 vs Week 28) was investigated.
  
  
  RESULTS
  Adiponectin differed significantly between healthy controls (mean 4.8 +/- SD 2.7 mg/l) and the 3 groups, with 8.9 +/- 4.8 mg/l in early RA, 11.6 +/- 5.6 mg/l in chronic RA, and 14.1 +/- 6.4 mg/l in OA. Longitudinally, MTX treatment increased adiponectin significantly from 9.7 +/- 4.5 mg/l at Week 0 to 11.0 +/- 4.5 mg/l at Week 28 in chronic RA. No correlations to disease activity measures were found.
  
  
  CONCLUSIONS
  Both early DMARD-naive and chronic RA were associated with higher plasma adiponectin compared to healthy controls, but lower plasma adiponectin than OA. Adiponectin increased 13% during MTX treatment. In patients with RA and OA body mass index, age, sex, and disease activity measures failed to explain the findings.
authors.affiliation: Department of Rheumatology, Aarhus University Hospital, Noerrebrogade 44, Aarhus C, Denmark. trine_bay@dadlnet.dk
authors.forename: Trine Bay
authors.initials: TB
authors.lastname: Laurberg
authors.forename: Jan
authors.initials: J
authors.lastname: Frystyk
authors.forename: Torkell
authors.initials: T
authors.lastname: Ellingsen
authors.forename: Ib T
authors.initials: IT
authors.lastname: Hansen
authors.forename: Anette
authors.initials: A
authors.lastname: Jørgensen
authors.forename: Ulrik
authors.initials: U
authors.lastname: Tarp
authors.forename: Merete Lund
authors.initials: ML
authors.lastname: Hetland
authors.forename: Kim
authors.initials: K
authors.lastname: Hørslev-Petersen
authors.forename: Nete
authors.initials: N
authors.lastname: Hornung
authors.forename: Jørgen Hjelm
authors.initials: JH
authors.lastname: Poulsen
authors.forename: Allan
authors.initials: A
authors.lastname: Flyvbjerg
authors.forename: Kristian
authors.initials: K
authors.lastname: Stengaard-Pedersen
mesh_terms: D052242:Adiponectin / Q000097:blood*; D000328:Adult; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000188:drug therapy*; D016022:Case-Control Studies; D003718:Denmark; D004305:Dose-Response Relationship, Drug; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D010003:Osteoarthritis / Q000097:blood* / Q000188:drug therapy*; D012720:Severity of Illness Index; D013256:Steroids / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D052242:Adiponectin; D018501:Antirheumatic Agents; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D013256:Steroids; D008727:Methotrexate