Fatigue in IBD Is Related to Poor Quality of Life And Sleep, Not Inflammation

Abstract

Fatigue is common in patients with Inflammatory Bowel Disease (IBD), and the etiology is likely multifactorial. The aim of our study was to identify factors associated with fatigue. We conducted a retrospective chart review of consecutive adult patients enrolled in the IBD registry between 7/2010 and 5/2011 in a tertiary care clinic. Crohn's disease (CD) and ulcerative colitis (UC) disease severity was measured with either Harvey-Bradshaw Index (HBI) or the UC Activity Index (UCAI), respectively. Labs were obtained to measure anemia, vitamin deficiencies, and inflammatory markers. Fatigue was defined by Item-1 of the Short IBD Questionnaire (SIBDQ), a quality of life (QOL) measure, which is scored on a 7-point Likert scale. Threshold for fatigue was defined as ‘some of the time’. The selection of fatigue threshold on SIBDQ was validated using the Patient Reported Outcomes Measurement Information System (PROMIS) fatigue scale on a subset of patients (n = 40; r = 0.67; P < 0.001). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Patients with and without fatigue were assessed for differences in baseline characteristics using t-tests (continuous variables) and chisquare tests (categorical variables). Use of psychotropic medications and narcotics were assessed between patients as proxy measures of psychopathology and pain. There were 781 patients enrolled in the registry; 37.4% UC and 62.6% CD. Of these, 695 (258 UC, 437 CD) completed the SIBDQ at the office visit. Many (58%) patients had fatigue at time of evaluation: 401 reported fatigue ‘all the time’, ‘most of the time’, ‘good bit of the time’, or ‘some of the time’, whereas 294 recorded fatigue ‘a little of the time’, ‘hardly any of the time’, or ‘none of the time’ on Item-1. Fatigue correlated significantly with sleep disturbance (PSQI), QOL (total SIBDQ), and HBI/UCAI scores for the entire population and also when stratified into UC and CD cohorts. These findings were also clinically significant; sleep and QOL scores were clinically impaired in patients with fatigue. More females than males reported fatigue and a higher percentage had CD. There was no difference in C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), hemoglobin, vitamin B12, and albumin levels between patients with fatigue and those without, however this may be due to our smaller sample size assessing those variables. Patients with fatigue had decreased QOL (lower total SIBDQ score) and also had greater sleep disturbance (higher PSQI scores). While disease severity did have an association with fatigue, it appeared more related to symptom burden rather than elevated inflammatory markers. Patients with fatigue were more likely to be taking psychotropic medications and/or narcotics, suggesting that psychopathology and pain may play a role in etiology of fatigue. Interestingly, the impact of inflammation or anemia on fatigue was less than the impact of sleep disturbance. These findings suggest that better understanding of pathways to fatigue can inform comprehensive treatment of IBD patients. Future studies will need to assess the predictive relationships between sleep, psychopathology and disease activity and also the impact of IBD-related medications.