Exercise capacity and muscle strength in patients with cirrhosis.

Exercise capacity and muscle strength are predictors of outcome in a number of clinical populations. Advanced liver disease is a catabolic state, and patients often have muscle wasting. However, the relationships between exercise capacity, strength, and outcomes for patients undergoing liver transplantation are poorly understood. Thirteen studies have examined the association between these parameters in patients with cirrhosis, and they have found a significant reduction in the exercise capacity and muscle strength of patients with cirrhosis versus healthy controls. These impairments appear to be independent of the etiology of cirrhosis, but the data are equivocal with respect to their association with disease severity. Two studies reported a significant and independent association between pretransplant exercise capacity and posttransplant survival. Another 2 studies found that exercise training was well tolerated in patients with cirrhosis and resulted in improvements in exercise capacity (both studies) and muscle mass (1 study). These data are provocative and suggest that measuring and improving the exercise capacity and muscle strength of patients with cirrhosis who are awaiting liver transplantation could potentially improve outcomes.