Fatigue trajectory during the first year of an inflammatory bowel disease diagnosis, results from the IBSEN III study

Background Fatigue is common in Crohn's disease (CD) and ulcerative colitis (UC), but the pathogenesis remains poorly understood. Aims This study aimed to assess changes in fatigue prevalence during the first year after diagnosis and examine the association between disease course and substantial fatigue (SF) at the 1-year follow-up. Methods Adults with newly diagnosed CD or UC were recruited from the population-based IBSEN III cohort. Fatigue was assessed at diagnosis and the 1-year follow-up using the Fatigue Questionnaire. Associations between SF at the 1-year follow-up and disease-related factors were quantified using multivariate logistic regression adjusted for sex, age and comorbidities. Results In total, 596 patients were included (CD: 196, UC: 400). SF was present at both baseline and after one year of disease for 46.9% (n=92/196) and 40.5% (n=162/400) of patients with CD and UC, respectively. In CD, development of endoscopically non-passable stricture and/or surgically treated stricture within first year of disease (OR=4.52, 95%CI [1.61;12.68]), self-reported flares since diagnosis (OR=2.55, 95%CI [1.26;5.16]), female sex (OR=3.12, 95%CI [1.53;6.37]) and comorbidities (OR=4.05, 95%CI [1.89;8.69]) were independently associated with SF at the 1-year follow-up. In UC, SF was associated with current biological treatment (OR=5.14, 95%CI [1.56;16.96]), increasing Mayo endoscopic score at the 1-year follow-up (OR=1.54, 95%CI [1.01;2.35]), self-reported flares since diagnosis (OR=2.66, 95%CI [1.24;5.72]) and female sex (OR=2.20, 95%CI [1.06;4.57]). Conclusions Fatigue frequently persists through the first year after IBD diagnosis. Clinical factors reflecting a more severe disease course were associated with SF one year after diagnosis in both CD and UC.