Axial spondyloarthritis and inflammatory bowel disease: association between disease activity and endothelial dysfunction markers

Objective We aimed to assess patients with axial spondyloarthritis (axSpA) and inflammatory bowel disease (IBD) for disease activity and serum markers of endothelial dysfunction. Methods We studied 161 patients (123 males, 38 females) with axSpA: 153 with ankylosing spondylitis and 8 with non-radiographic axSpA, and 30 healthy controls (HC). We collected: age; sex; disease duration; extra-articular symptoms (IBD and acute anterior uveitis), comorbidities; human leukocyte antigen B27 status; and treatment. We measured serum interleukin (IL)-6, interleukin-18, IL-23, vascular endothelial growth factor (VEGF) epidermal growth factor (EGF), asymmetric dimethylarginine (ADMA), endothelin-1 (ET-1), and fetuin-A levels. Results IBD was diagnosed in 19 (11.8%) patients with axSpA. Compared to patients with axSpA without IBD, those with IBD had higher serum C-reactive protein (CRP) level (p = 0.05), erythrocyte sedimentation rate (ESR) (p = 0.005), and serum ET-1 levels (p = 0.01). In patients with axSpA and IBD, ET-1 levels correlated positively with CRP level (p = 0.006) and ESR (p = 0.02), and ADMA levels with visual analog scale scores (p = 0.01). Patients with axSpA and IBD had higher serum levels of IL-6 (p = 0.01), IL-18 (p = 0.005), and ADMA (p = 0.01) and lower serum levels of fetuin-A (p = 0.01) than did controls. Conclusions Patients with axSpA and IBD had higher levels of disease activity, as assessed by ESR and CRP and ET-1 levels, than did patients with axSpA without IBD. Compared to HC, patients with axSpA and IBD had increased IL-18, ADMA levels and decreased fetuin-A level.