title: Associations between vitamin D, disease activity, and clinical response to therapy in rheumatoid arthritis.
abstract: OBJECTIVE
  Vitamin D deficiency is a potential risk factor for autoimmunity. Prior studies of the association between vitamin D levels and rheumatoid arthritis (RA) disease activity have yielded conflicting results.
  
  
  METHODS
  Serum 25(OH)vitamin D levels were measured at baseline in 499 participants with active RA, ages 18-85 years, enrolled in a randomised clinical trial of golimumab (Go-Before Trial). Subjects were methotrexate and biologic therapy naïve. Multivariable linear regression was used to assess associations between vitamin D levels and disease activity scores (DAS28), van der Heijde-Sharp (vdHS) erosion scores, and serum inflammatory markers. Generalised estimating equations were used to evaluate the associations between vitamin D status and the response to therapy over 52 weeks, using the DAS28 and ACR response.
  
  
  RESULTS
  Forty-eight percent of participants were vitamin D deficient, defined as serum 25(OH)vitamin D <20 ng/mL. Deficiency was not associated with greater DAS28 (β-0.021 [95% CI -0.22, 0.18]), adjusted for age, race, sex, BMI, disease duration and glomerular filtration rate. Vitamin D deficiency was not associated with baseline vdHS scores or inflammatory markers in adjusted or unadjusted models. There was no association between baseline vitamin D deficiency and change in DAS28 (β = -0.024 [-0.30, 0.25]), proportion meeting ACR response (OR 0.82 [0.56, 1.20]), or radiographic progression at 52 weeks (OR 0.91 [0.59-1.40]).
  
  
  CONCLUSIONS
  Vitamin D levels were not associated with RA disease activity, inflammatory markers, or vdHS scores at baseline. Furthermore, there was no association between baseline vitamin D level and response to therapy or radiographic progression.
authors: Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA. bakerjo@uphs.upenn.edu
authors: Joshua F
authors: JF
authors: Baker
authors: Daniel G
authors: DG
authors: Baker
authors: Gary
authors: G
authors: Toedter
authors: Justine
authors: J
authors: Shults
authors: Joan Marie
authors: JM
authors: Von Feldt
authors: Mary B
authors: MB
authors: Leonard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D004185:Disability Evaluation; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use*; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D015415:Biomarkers; D018836:Inflammation Mediators; D014807:Vitamin D; C529000:golimumab; C104450:25-hydroxyvitamin D; D008727:Methotrexate