Abstract
Musculoskeletal (MSK) disease is the most common extra-intestinal manifestation of inflammatory bowel disease (IBD). The emphasis in the published literature has been on the inflammatory arthritis associated with IBD, spondyloarthritis (SpA). There is a lack of data regarding common, non-inflammatory MSK diseases such as osteoarthritis and fibromyalgia. This distinction is important, as these two conditions have different prognoses, require different clinical approaches and management.
To evaluate the prevalence of non-inflammatory MSK disease in a cohort of Crohn’s disease (CD) patients.
This was a cross-sectional study of a validated CD cohort from a single center registry in New York City conducted from 9/2019 - 1/2021. Recruitment was limited due to the COVID-19 Pandemic. Patients were sent a four question MSK survey (Figure 1) addressing peripheral joint and back symptoms. Those who answered positively to any question were considered to have MSK symptoms. All patients underwent one study visit with a rheumatologist that included: 66/68 tender/swollen joint count (TJC/SJC), Spondyloarthritis Research Consortium of Canada Enthesitis Index (SPARCC), Bath Ankylosing Spondylitis Metrology Index (BASMI), American College of Rheumatology fibromyalgia criteria, ESR and CRP. Disease activity was measured via a modified Ankylosing Spondylitis Disease Activity Score (ASDAS), Harvey Bradshaw Index (HBI), and Inflammatory Bowel Disease Questionnaire (IBD-Q).
26 CD patients participated. Median age was 45.6±17.7 years, 35% were male, median disease duration was 17.7±14.2 years and 73% were on immunomodulatory agents for CD. Median values (range) for the following physical exam and disease features were: TJC 10.8±13.2 (0-68), SJC 0.9±2.2 (0-66), SPARCC 2.8±3.1 (0-16), BASMI 1.5±1.0 (0-10, higher values: more motion limitation) ASDAS 1.5±0.9 (<1.3: inactive disease, >2.1: high disease activity), HBI 6.8±3.5 and IBD-Q 159±36. Median ESR and CRP were 18.9±22.2 mm/hr (normal 0-22) and 0.6±0.5 mg/dL (normal<0.7), respectively. 16/26 (62%) reported MSK symptoms. 7/16 (43.8%) had features of SpA, while 9/16 (56.3%) did not have evidence by history or exam of SpA and were therefore determined to have non-inflammatory MSK disease. 13/26 (50%) met fibromyalgia diagnostic criteria.
MSK conditions were very common in this pilot cohort. Though features of SpA were present in almost half of patients, non-inflammatory MSK disease was present in the majority of those with MSK symptoms. While both rheumatologists and gastroenterologists need to recognize the importance of SpA, it is additionally essential to understand that the most common MSK disease in IBD may be non-inflammatory, which has distinct implications for management. Future studies should examine the prevalence of these conditions in larger cohorts of IBD patients.
