The influence of disease activity on fatigue in patients with ulcerative colitis – a longitudinal study

The relationship between the disease activity of ulcerative colitis and fatigue is unclear. We investigated how reaching deep remission versus remaining in active disease influenced the severity of fatigue.We included 149 consecutive patients in a longitudinal study. Patients were re-examined after 3 months of conventional treatment and dichotomized into A: Active disease or B: Deep remission. The Partial Mayo Score (PMS) was recorded in all patients. Fatigue was rated using the fatigue visual analog scale (fVAS), Fatigue Severity Scale (FSS), and Short Form-36 Vitality Subscale (SF-36vs). A control group of 22 age and sex-matched healthy subjects were included as controls for patients reaching deep remission.After 3 months there were no significant differences in fVAS, FSS and SF-36vs scores in patients with active disease compared to patients reaching deep remission, when adjusting for baseline fatigue scores. Patients in remission based on MES-UC scores had no significant reduction in fatigue scores, whereas patients in remission based on PMS had all three fatigue scores reduced. However, patients reaching deep remission still had higher fVAS and lower SF-36vs scores compared to healthy control subjects.After 3 months of conventional treatment there were no differences in fatigue severity in patients reaching deep remission compared with patients still having active disease. Fatigue was more pronounced in patients in deep remission than in healthy subjects, and was associated with subjective and not objective measures of disease activity. This indicates that other potent factors than inflammation influence fatigue in UC.