Fatigue in primary biliary cirrhosis: a possible role of comorbidities

Fatigue is considered to be a specific manifestation of primary biliary cirrhosis (PBC). Recent reports have, however, questioned these findings. Considering the high rate of comorbidities in PBC patients and the fact that fatigue is a multifactorial symptom, we hypothesized that it might also be due to nonhepatic causes. Our aim was to evaluate fatigue in PBC patients and its relationship with comorbidities and depression.

We enroled 49 Italian PBC patients (44 women; mean age: 58.9 years, range: 21-73 years) and 30 matched healthy controls, who completed the Fatigue Impact Scale (FIS), Modified FIS (MFIS), Fatigue Severity Score (FSS) and Rand Medical Outcomes Study Depression Screener. Comorbidities and several clinical and biochemical data were investigated. Linear regression, analysis of variance and post-hoc analysis were applied.

Fatigue was higher in patients than in controls (FIS: 33 vs. 24; MFIS: 24 vs. 14; FSS: 3.3 vs. 1.9). Physical domain was significantly different in all the three questionnaires (FIS: P=0.05; MFIS: P=0.002; FSS: P=0.0002). Comorbidities (38% of patients) were independently associated with higher fatigue scores (FIS: 45; MFIS: 32; FSS: 3.3). Depressed patients (30%) were more fatigued, even if not always significantly (FIS: 43; MFIS: 29; FSS: 3.5), than controls and patients with no depression. Patients without comorbidities or depression (51%) did not have higher fatigue than controls (FIS: 20; MFIS: 17; FSS: 2.4).

Fatigue in patients with PBC was higher, but not always significantly, than in healthy controls. Comorbidities and depression might have played a role in its pathogenesis. Our data arouse doubts about the specificity of fatigue in PBC and the pathogenetic role of liver impairment.