Strength training and albuterol in facioscapulohumeral muscular dystrophy

Background: In animals and healthy volunteers beta2-adrenergic agonists increase muscle strength and mass, in particular when combined with strength training. In patients with facioscapulohumeral muscular dystrophy (FSHD) albuterol may exert anabolic effects. The authors evaluated the effect of strength training and albuterol on muscle strength and volume in FSHD. Methods: Sixty-five patients were randomized to strength training of elbow flexors and ankle dorsiflexors or non-training. After 26 weeks albuterol (sustained-release, 8 mg BID) was added in a randomized, double-blind, placebo-controlled design. Primary outcome was maximum voluntary isometric strength (MVIC) at 52 weeks. Secondary outcomes comprised dynamic strength and muscle volume. Results: Training and albuterol were well tolerated. Training of elbow flexors did not result in a significant effect on MVIC, but dynamic strength improved significantly. Elbow flexor MVIC strength increased significantly in albuterol vs placebo treated patients. Ankle dorsiflexor strength decreased in all groups. Eleven out of twelve non-trained muscles in the albuterol group showed a positive effect on MVIC compared to the placebo group (p<0.05 in seven muscle groups). Muscle volume decreased in the placebo-treated, and increased in the albuterol-treated patients. No synergistic or antagonistic effects were observed between training and albuterol. Conclusions: In FSHD strength training and albuterol appear safe interventions with limited positive effect on muscle strength and volume. Consequences of prolonged use are presently unclear, which precludes routine prescription.