title: Prevalence of ankylosing spondylitis and other spondyloarthropathies among patients with inflammatory bowel disease: a population study (the IBSEN study).
abstract: OBJECTIVE
  To study the occurrence of spondyloarthropathies (SpA) in patients with inflammatory bowel disease (IBD) seen 6 years after IBD diagnosis.
  
  
  METHODS
  In a population based cohort of 654 patients with IBD, 521 patients (80%) were investigated, which included a complete rheumatological examination. Radiographs of the sacroiliac joints and lumbar spine were performed in 406 of these patients (78%). The development of SpA was analyzed with regard to the presence of HLA-B27, duration of IBD symptoms, and the extent of intestinal inflammation.
  
  
  RESULTS
  The occurrence of ankylosing spondylitis (AS) was 2.6% in ulcerative colitis and 6% in Crohn's disease (p = 0.08), yielding an overall prevalence of 3.7% in IBD. No correlation between localization or extent of the intestinal inflammation and presence of AS was found. HLA-B27 was present in 73% of cases with AS. The overall prevalence of SpA was 22%. Inflammatory back pain without AS (IBP) was found in 18% of the patients. Typical features of SpA were rare, while fibromyalgia was common in IBP, indicating that IBP is not a precursor or manifestation of SpA in patients with IBD. The prevalence of radiological sacroiliitis without clinical features of SpA was 2.0%.
  
  
  CONCLUSIONS
  AS occurred frequently in patients with newly diagnosed IBD. IBP did not seem to predispose to AS or other forms of SpA. The overall prevalence of SpA was 22%, whereas the prevalence of asymptomatic radiological sacroiliitis was low.
authors.affiliation: Department of Rheumatology, Ostfold Central Hospital, Sarpsborg, Norway.
authors.forename: Oyvind
authors.initials: O
authors.lastname: Palm
authors.forename: Bjørn
authors.initials: B
authors.lastname: Moum
authors.forename: Aksel
authors.initials: A
authors.lastname: Ongre
authors.forename: Jan Tore
authors.initials: JT
authors.lastname: Gran
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015535:Arthritis, Psoriatic / Q000453:epidemiology; D016918:Arthritis, Reactive / Q000453:epidemiology; D002648:Child; D003093:Colitis, Ulcerative / Q000453:epidemiology*; D003424:Crohn Disease / Q000453:epidemiology*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011859:Radiography; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging; D013167:Spondylitis, Ankylosing / Q000000981:diagnostic imaging / Q000453:epidemiology*