Changes in fatigue over 2 years are associated with activity of inflammatory bowel disease and psychological factors

Cross-sectional studies have identified high levels of fatigue in patients with active or quiescent inflammatory bowel disease (IBD), but there has been little attention to the long-term effects of fatigue in these patients. We performed a longitudinal study of fatigue in patients with IBD to determine its course and contributing factors.

Data were obtained from participants in the Manitoba IBD Cohort Study (N = 312; 51% with Crohn's disease), a longitudinal population-based study. Symptomatic disease activity was measured every 6 months for 2 years to characterize long-term disease patterns as active, fluctuating, or inactive, based on the validated Manitoba IBD Index. We collected data concurrently on fatigue (Multidimensional Fatigue Inventory), psychological function, and laboratory biomarkers at the point of study entry and 1 and 2 years later.

Of the study participants, 26% had consistently inactive, 29% had fluctuating, and 45% had consistently active disease over the 2-year time period. Mean levels of fatigue were strongly associated with disease activity; participants with consistently inactive disease had the lowest level of fatigue at each time point. Multivariate analyses indicated fatigue levels increased over time regardless of disease pattern (P < .001). Adjusting for disease activity, disease type and age, sex (female; P < .001), and psychological variables of distress (P < .001), reduced psychological well-being (P = .002) and poor sleep quality (P < .001) were associated independently with increases in fatigue over time.

Fatigue can increase over time in patients with IBD, even when their disease is in remission. Psychological factors are useful targets for intervention to reduce fatigue.