Fatigue in Patients with Newly Diagnosed Inflammatory Bowel Disease: Results from a Prospective Inception Cohort, the IBSEN III Study

BACKGROUND AND AIMS: Although fatigue is common in inflammatory bowel disease IBD, its pathogenesis remains unclear. This study aimed to determine the prevalence of fatigue and its associated factors in a cohort of patients newly diagnosed with IBD. METHODS: Patients ≥18 years old were recruited from the Inflammatory Bowel Disease South-Eastern Norway IBSEN III study, a population-based, observational inception cohort. Fatigue was assessed using the Fatigue Questionnaire and compared with data from a Norwegian general population. Univariate and multivariate linear and logistic regression analyses were performed to evaluate the associations of total fatigue TF; continuous score and substantial fatigue SF; dichotomized score ≥4 with sociodemographic, clinical, endoscopic, laboratory, and other relevant patient data. RESULTS: In total, 983/1509 65.1% patients with complete fatigue data were included (ulcerative colitis UC, 68.2%; Crohn's disease CD, 31.8%). The prevalence of SF was higher in CD 69.6% compared with UC 60.2% p < 0.01, and in both diagnoses when compared to the general population p < 0.001. In multivariate analyses, depressive symptoms, pain intensity, and sleep disturbances were associated with increased TF for both diagnoses. In addition, increased clinical disease activity and Mayo endoscopic score were significantly associated with TF in UC, whereas all disease-related variables were insignificant in CD. Similar findings were observed for SF, except regarding the Mayo endoscopic score. CONCLUSIONS: SF affects approximately two-thirds of patients newly diagnosed with IBD. Fatigue was associated with depressive symptoms, sleep disturbances, and increased pain intensity in both diagnoses, while clinical and endoscopic activity were associated factors only in UC.