title: Vitamin D, disease activity and comorbidities in early spondyloarthritis.
abstract: OBJECTIVE
  To assess the vitamin D status in patients presenting inflammatory back pain suggestive of axial spondyloarthritis and to assess the relationship between vitamin D status and disease activity/severity; comorbidities at baseline and during the first two years of follow-up.
  
  
  METHODS
  DESIR is a prospective, multicentre, observational study. Vitamin D deficiency was defined as <50 nmol/L and severe deficiency less than 25 nmol/L. Clinical variables were collected at each six month interval visits during the two-year follow-up.
  
  
  RESULTS
  A total of 700 patients were analysed. The mean vitamin D was 54.2±28.7 nmol/L. Severe deficiency were observed in 11.7% versus 5% in the DESIR cohort versus the French population respectively. In the DESIR cohort, after adjusting for season and ethnicity, vitamin D deficiency remained significantly associated with presence of radiological sacroiliitis, higher ASDAS score and elevated BASDAI. Such association was also found between vitamin D deficiency and the mean value of disease activity/severity parameters during the two-year follow-up. Otherwise, vitamin D deficiency was significantly associated with the presence of baseline abdominal obesity (OR=1.65 [1.05-2.61], p=0.03), low HDL (OR=1.71 [1.14-2.55], p=0.01) and presence of metabolic syndrome (OR=2.20 [1.04-4.64], p=0.03) at baseline.
  
  
  CONCLUSIONS
  We found a higher percentage of patients with severe vitamin D deficiency in early axial spondyloarthritis. Vitamin D deficiency was associated with higher disease activity and severity and presence of metabolic syndrome. Further longitudinal studies are required to evaluate the interest of vitamin D supplementation on the long-term outcome of the disease.
authors.affiliation: Rheumatology Dept., Paris Descartes Univ., APHP Cochin Hosp., INSERM (U1153), Paris, France; and Faculty of Medicine, Laboratory of Biostatistics Clinical Research and Epidemiology, Rheumatology Dept., Mohammed V Univ., El Ayachi Hosp., Rabat, Morocco.
authors.forename: Ihsane
authors.initials: I
authors.lastname: Hmamouchi
authors.affiliation: Rheumatology Department, Paris Descartes University, APHP Cochin Hospital, INSERM (U1153), Paris, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Paternotte
authors.affiliation: Rheumatology Department, Paris Descartes University, APHP Cochin Hospital, INSERM (U1153), Paris, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Molto
authors.affiliation: Rheumatology Department, Paris Descartes University, APHP Cochin Hospital, INSERM (U1153), Paris, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Etcheto
authors.affiliation: Biology Department, Paris Descartes University, APHP Cochin Hospital, Paris, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Borderie
authors.affiliation: Department of Rheumatology, Montpellier I University, Lapeyronie Hospital, UMR 5535, EA2415, Montpellier, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Combe
authors.affiliation: Rheumatology Department, Paris Descartes University, APHP Cochin Hospital, INSERM (U1153), Paris, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Dougados
mesh_terms: D000328:Adult; D017668:Age of Onset; D015897:Comorbidity; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging*; D012621:Seasons; D012720:Severity of Illness Index; D025241:Spondylarthritis / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D014808:Vitamin D Deficiency / Q000175:diagnosis / Q000453:epidemiology