Aerobic capacity in patients with chronic liver disease: Very modest effect of liver transplantation

Abstract

Aerobic capacity is commonly impaired in patients with liver cirrhosis, as demonstrated by their low oxygen consumption at peak exercise (peak VO(2)). This impairment is correlated with the severity of the liver disease. We investigated the effect of orthotopic liver transplantation (OLT) alone on exercise capacity in this prospective study of patients with liver cirrhosis. Twenty liver transplant candidates, aged 27 to 61years, underwent resting pulmonary function tests, echocardiography, and incremental cardiopulmonary exercise testing (CPET) before OLT and 16.3 + or - 1.6months after OLT. Following OLT, peak VO(2) increased by a mean of only 7.7% (from 63.4 to 71.1% of predicted value), and decreased in one-quarter of the patients. Cardiac function was normal before OLT and no changes in respiratory indicators followed OLT. Change in peak VO(2) after OLT (Delta peak VO(2)) was related to changes in hemoglobin level (r(2)=0.45, p=0.04), the stopping of beta-blocker therapy, and muscle impairment, as suggested by the correlation between Delta peak VO(2) and peak lactate concentration before OLT (r(2)=0.64, p<0.01). Our study provides evidence of a very modest and inconsistent increase in aerobic capacity in liver transplant candidates after liver transplantation alone. This persistent impairment of exercise tolerance was principally of peripheral origin but anemia and beta-blocker treatment should be considered as major aggravating factors. Rehabilitation programs before and after transplantation may increase its benefits to these deconditioned liver transplant recipients in their daily lives.