Impaired exercise performance after successful liver transplantation.
BACKGROUND
Recipients of heart, lung, and kidney transplants have impaired peak exercise performance (peak Vo2 40% to 60% predicted, reduced anaerobic threshold [AT]) without evidence of ventilatory or cardiac limitations. The aim of this study was to determine whether similar exercise impairment occurs in liver transplant recipients.


METHODS
We studied eight healthy liver transplant recipients (age 42+/-9 [SD] years, 6 male, 31+/-13 months posttransplant). Immunosuppression included FK506 or cyclosporine, azathioprine or mycophenolate mofetil, and prednisone. Subjects underwent lung function testing and cardiopulmonary exercise testing on a cycle ergometer.


RESULTS
Peak exercise oxygen consumption (Vo2) was 22+/-8 ml/min/kg (66+/-20% predicted maximum). No subject demonstrated exercise desaturation or ventilatory limitation (peak minute ventilation 55+/-8% predicted maximum voluntary ventilation). Peak heart rate was 87+/-8% of predicted maximum. Early AT was evident (1.2+/-0.34 L/min, 48+/-11% predicted Vo2max).


CONCLUSIONS
Liver transplant recipients exhibit impaired peak exercise performance similar to that observed after other solid organ transplants, possibly as a result of chronic deconditioning or myopathy related to immunosuppressive medications.
Stephenson
A L
AL
Respiratory Division, Vancouver General Hospital, 2775 Heather Street, Vancouver, BC, Canada, V5Z 3J5.
Yoshida
E M
EM
Abboud
R T
RT
Fradet
G
G
Levy
R D
RD
D000328:Adult; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010807:Physical Endurance; D011184:Postoperative Period; D012129:Respiratory Function Tests