abstract
-
The purpose of this study was to determine the efficacy of resistance exercise in reversing skeletal muscle myopathy in heart transplant recipients. Myopathy, engendered by both heart failure and immunosuppression with glucocorticoids, is a post-transplant complication. The sequelae of myopathic disease includes fiber-type shifts and deficits in aerobic metabolic capability. We randomly assigned patients to either 6 months of resistance exercise (training group; n = 8) or a control (control group; n = 7) group. Exercise was initiated at 2 months after transplant. Biopsy of the right vastus lateralis was performed before and after the 6-month intervention. Myosin heavy chain (MHC) composition was assessed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Biochemical assays were performed to determine citrate synthase, 3-hydroxyacyl-CoA-dehydrogenase, and lactate dehydrogenase activity. There were no group differences (p >or=0.05) in MHC composition and enzymatic reserve at baseline. Improvements in the training group for citrate cynthase (+40%), 3-hydroxyacyl-CoA-dehydrogenase (+10%), and lactate dehydrogenase activity (+48%) were significantly greater (p