Albuterol increases lean body mass in ambulatory boys with Duchenne or Becker muscular dystrophy.
BACKGROUND
Albuterol is a beta-2 agonist that has been demonstrated to increase muscle strength in studies in animals and humans. Based on a pilot study of extended-release albuterol Repetabs in children with dystrophinopathies, the authors conducted a randomized, double-blind, placebo-controlled study with a crossover design.


METHODS
Fourteen boys with Duchenne or Becker muscular dystrophy, 6 to 11 years old, completed two treatment periods (albuterol and placebo), 12 weeks each, separated by a 12-week washout period. As the albuterol Repetab formulation was no longer available, an alternate extended release albuterol was used (Volmax, 12 mg per day). Outcome measurements included 1) lean body mass, 2) fat mass, 3) isometric knee extensor and flexor moments, 4) manual muscle testing, and 5) timed functional tests.


RESULTS
Lean body mass was significantly higher for subjects following albuterol treatment compared to placebo treatment, while fat mass was significantly lower. No differences were found in isometric knee moments or manual muscle tests. Time to run/walk 30 feet was improved following albuterol.


CONCLUSIONS
Short-term treatment with extended release albuterol may increase lean body mass, decrease fat mass, and improve functional measures in patients with dystrophinopathies. However, the significant change in strength of specific muscle groups found in the pilot study was not observed in the present study. These findings may be attributed to differences in the drug release and kinetics between Repetab and Volmax formulations as they affect the concentration of available beta-2 receptors on the muscle cell surface differently.
Skura
C L
CL
David Geffen School of Medicine at UCLA, 635 Charles Young Drive South, NRB1 Room 401, Los Angeles, CA 90095-7334, USA.
Fowler
E G
EG
Wetzel
G T
GT
Graves
M
M
Spencer
M J
MJ
D000318:Adrenergic beta-Agonists / Q000627:therapeutic use*; D000420:Albuterol / Q000627:therapeutic use*; D015992:Body Mass Index; D002648:Child; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000188:drug therapy*
D000318:Adrenergic beta-Agonists; D000420:Albuterol