Resistance Exercise Prevents Glucocorticoid-Induced Myopathy in Heart Transplant Recipients.

Braith RW, Welsch MA, Mills RM Jr, et al (Center for Exercise Science and College of Medicine, University of Florida, Gainesville, Fla; Division of Cardiovascular Medicine, University of Kentucky, Lexington, Ky), Med Sci Sports Exerc. 1998;30:483-489.

Muscle atrophy and weakness due to high-dose steroid use following heart transplantation is a well-documented phenomenon. The authors attempted to determine if a program of resistance exercise begun during the acute posttransplant phase could prevent or reduce these effects in recipients of heart transplants.

Fourteen consecutive male patients who received heart transplants were randomly and prospectively assigned to either a training group (mean age = 54 [+ or -] 3 years, 18 [+ or -] 9 weeks of waiting time) or control group (mean age=51 [+ or -] 8 years, 20 [+ or -] 10 weeks of waiting time). All subjects were measured for body composition, using dual x-ray absorptiometry, and strength, using a maximal isometric lumbar extension test, a dynamic one-repetition maximum knee extension test, and a chestpress test. All tests were performed at the pretransplant baseline and at 3 and 6 months of the exercise program.

The resistance training program began at 2 months posttransplant and consisted of lumbar extension training once per week and upper-body and lower-body training using weight machines twice per week. The initial training resistance was set at 50% of the 1-repetition maximum. This weight was increased when the subjects could complete more than 15 repetitions. The resistance training was preceded and followed by a 5-minute treadmill walk.

The data that were collected were analyzed using an ANOVA for descriptive characteristics and an ANCOVA with repeated measures for body composition and muscle strength measurements. Post hoc analysis was performed for any significant group x time interactions. Significance was set at an alpha level of P [is less than or equal to] .05.

The results of body composition testing revealed that both groups gained fat mass following transplantation, but the control group continued to gain fat at the 6-month follow-up (up to 22%), whereas the exercise group lost fat following training (-4%). Both groups lost fat-free mass immediately following transplantation, but the exercise group gained fat-free mass over pretransplant baselines after 6 months of training (+3.9%), whereas the control group continued to lose fat-free mass (-6.9%). Both groups improved their strength 8 months following transplantation; however, the exercise group had a 4-fold greater gain in upper-body strength and knee strength and a 4- to 6-fold greater gain in lumbar extension strength.

According to the authors, this study demonstrated clear glucocorticoid-induced changes in body composition during the acute posttransplant period. These authors also demonstrated that a 6-month program of resistance exercise could reverse the muscle atrophy and attenuate the catabolic effect on skeletal muscle. They found this program of resistance exercise to be safe and effective and recommended its use in the early posttransplant period.

Anne K Swisher, PT West Virginia University Morgantown, WVa