IL1B and irritable bowel syndrome: In multiple regression, IL-1β (rpartial = 0.71, p = 0.0001) and VEGF-A (rpartial = 0.45, p = 0.026) were found independently associated with L-Nampt in IBD patients with active disease, with R2 = 0.59 (F = 15.96, p = 0.0001).