Resistance-Based Muscle Therapy, Frailty, and Muscle Biopsy Findings in Kidney Transplant Candidates: A Clinical Trial.

Rationale & Objective: Frailty is associated with increased morbidity and mortality in kidney transplant recipients. We hypothesized that frailty may be attributable to diminished muscle function associated with muscle morphologic changes. This trial in kidney transplant candidates tested the reversibility of frailty by specifically targeting the affected major muscle groups. Study Design: Randomized clinical trial. Setting & Participants: Kidney transplant candidates. Exposure: Supervised, resistance-based muscle therapy program delivered for 1 hour, 2 times per week for 1 year. Outcomes: Baseline, 6-month, and 12-month Short Physical Performance Battery, gait speed, grip strength, sit-to-stand in 30 s, 36-item Short Form Survey, Patient-Reported Outcomes Measurement Information System-29, and muscle biopsy light and electron microscopy and immunohistochemistry. Analytic Approach: Paired 2-tailed Results: Twenty-nine participants (mean age, 55 years; female, 55%; African American, 65%) were analyzed: 23 intervention and 6 control. Exercise intervention participants had significant improvements in Short Physical Performance Battery, baseline 5.2 (95% CI, 3.6-6.7) versus 6 months, 6.9 (95% CI, 5.2-8.5; Limitations: Significant under-enrollment in the control group required a paired Conclusions: One year of muscle rehabilitation therapy resulted in significant improvements in physical performance metrics accompanied by significant improvements in muscle morphology.