title: Serum vitamin D level and disease activity in patients with recent onset rheumatoid arthritis.
abstract: BACKGROUND
  Rheumatoid Arthritis (RA) is one of the most prevalent autoimmune diseases. Due to the significance of the relationship between serum vitamin D levels and autoimmune diseases, this study aimed to determine the relationship between serum vitamin D level and the severity of disease activity in patients with newly diagnosed RA.
  
  
  METHODS
  This cross-sectional study was conducted on 66 patients meeting the American College of Rheumatology - European League Against Rheumatism classification criteria for RA. It was performed in 2012 using simple sampling. The disease activity was measured based on Disease Activity Score of 28 joints - erythrocyte sedimentation rate (DAS28-ESR) and serum 25-OH vitamin D (25(OH)D) levels using the chemiluminescent immunoassay method. In addition, the levels of ESR and C-reactive protein (CRP), the duration of morning stiffness, and the number of joints with tenderness and swollen were calculated as well. The data were analyzed using the Pearson correlation coefficient.
  
  
  RESULTS
  In this study, 10 patients were male (15.2%) and 56 were female (84.8%). The average age of the participants was 45.2 ± 15.3 years. The average level of 25(OH)D in the patients' serum was 30.5 ± 28.9 ng/mL and the mean DAS28-ESR was 5.6 ± 1.1. The correlation coefficient showed that there was an inverse relationship between 25(OH)D and DAS28-ESR, the number of tender and swollen joints, global patient assessment and duration of morning stiffness (P < 0.01). However, the average 25(OH)D level was not related to ESR (P = 0.779) and CRP (P = 0.269).
  
  
  CONCLUSIONS
  The results of this analysis indicated that patients with more active RA have a lower serum vitamin D level.
authors.affiliation: Department of Internal Medicine, Ali-Ebne-Abitaleb Hospital, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Zakeri
authors.affiliation: Department of Internal Medicine, Ali-Ebne-Abitaleb Hospital, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Mahnaz
authors.initials: M
authors.lastname: Sandoughi
authors.affiliation: Department of Internal Medicine, Ali-Ebne-Abitaleb Hospital, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Mashhadi
authors.affiliation: Department of Internal Medicine, Ali-Ebne-Abitaleb Hospital, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Vajihollah
authors.initials: V
authors.lastname: Raeesi
authors.affiliation: Tehran University of Medical Sciences (TUMS), Tehran, Iran.
authors.forename: Sogol
authors.initials: S
authors.lastname: Shahbakhsh
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D003430:Cross-Sectional Studies; D015536:Down-Regulation; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: disease activity; rheumatoid arthritis; vitamin D