Incidence of Spondyloarthropathy in Patients with Ulcerative Colitis: A Population-based Study

Objective. Spondyloarthritis (SpA) is an important extraintestinal manifestation of inflammatory bowel disease (IBD). We assessed the cumulative incidence and clinical spectrum of SpA in a population-based cohort of patients with ulcerative colitis (UC). Methods. The medical records of a population-based cohort of residents of Olmsted County, Minnesota, USA, diagnosed with UC from 1970 through 2004 were reviewed. Patients were followed longitudinally until moving from Olmsted County, death, or June 30, 2011. We used the European Spondylarthropathy Study Group, Assessment of Spondyloarthritis International Society (ASAS) criteria, and modified New York criteria to identify patients with SpA. Results. The cohort included 365 patients with UC, of whom 41.9% were women. The median age at diagnosis of UC was 38.6 years (range 1.2-91.4). Forty patients developed SpA based on the ASAS criteria. The cumulative incidence of a diagnosis of SpA after an established diagnosis of UC was 4.8% at 10 years (95% CI 95% CI 2.2%-7.3%), 13.7% at 20 years (95% CI 9.0%-18.1%), and 22.1% at 30 years (95% CI 4.3%-29.1%). Conclusion. The cumulative incidence of all forms of SpA increased to about 22% by 30 years from UC diagnosis. This value is slightly greater than what we previously described in a population-based cohort of Crohn disease diagnosed in Olmsted County over the same time period. SpA and its features are associated with UC, and heightened awareness on the part of clinicians is needed for diagnosing and managing them.