Assessment of fatigue and its impact in chronic liver disease

Patient reported outcomes (PROs) such as health related quality of life (HRQL) are important outcome measures for patients with chronic liver diseases (CLDs). Presence of cirrhosis and advanced liver disease have been associated with worsened HRQL and fatigue. On the other hand, some patients with earlier stages of CLD such as primary biliary cholangitis (PBC), chronic hepatitis C viral infection (HCV) and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), also experience fatigue causing PRO impairment. Treatment for some CLDs may improve HRQL and, sometimes, levels of fatigue. We aimed to provide an in-depth expert review of concepts related to fatigue and HRQL in patients with PBC, HCV and MASLD. As such, a panel of experts in fatigue and CLD reviewed and discussed the literature and collaborated to provide this expert review of fatigue in CLD. Herein, we review and report on the complexity of fatigue highlighting that fatigue is comprised of peripheral (neuromuscular failure, often in conjunction with sub-maximal cardiorespiratory function) and central (central nervous system dysfunction) causes. Fatigue and HRQL are measured using validated self-report instruments. Additionally, fatigue can be measured through objective tests (e.g. grip strength). Fatigue has deleterious effects on HRQL and one's ability to be physically active and socially engaged but does not always correlate with CLD severity. Treatments for HCV and MASLD can improve levels of fatigue and HRQL, but current treatments for PBC do not seem to affect levels of fatigue. We conclude that obtaining PRO data to include HRQL and fatigue are essential for determining the comprehensive burden of CLD and its potential treatments. IMPACT AND IMPLICATIONS: Fatigue is a complex phenomenon associated with both a peripheral cause (neuromuscular failure and sub-maximal cardiorespiratory function) and a central cause (central nervous system dysfunction). Although fatigue is common among patients with CLD, it does not always correlate with the severity of the liver disease, but fatigue is related with significant decreases in patients' health related quality of life (HRQL). Appreciating the impact of fatigue using validated self-report measurements is important to better understand the burden of CLD and the effectiveness of treatment.