Salbutamol effect in spinal cord injured individuals undergoing functional electrical stimulation training

Abstract Objective: Preliminary study to investigate possible changes in skeletal muscle morphology and function, as well as hormonal and metabolic effects, after treatment with a selective β 2 -adrenergic receptor agonist. Design: Double-blind, placebo-controlled trial. Participants: Three individuals with spinal cord injury (SCI). Intervention: Two-week treatment with salbutamol (2mg) or placebo (ascorbic acid, 50mg) twice a day. Program of functional electronic stimulation (FES) cycling for 30 minutes twice a week. Main Outcome Measures: Body weight, three measures of leg circumference (gluteal furrow, one third of subischial height up from tibial-femoral joint space, and minimum circumference above the knee), muscle fiber area, and total work output per session. Results: There were increases in body weight (2.30 ± .70kg), leg circumferences (gluteal furrow 1.70 ± .27cm, one third subischial height 1.53 ± 1.65cm, minimum circumference above the knee .43 ± .04cm), and muscle (vastus lateralis) cross-sectional area (1,374 ± 493 to 2,446 ± 1, 177 μ m 2 ) after salbutamol treatment, whereas quadriceps muscle contractile function was not modified. Total work output during FES cycling sessions was increased more during salbutamol treatment (64%) compared with training alone (27%). Salbutamol treatment was associated with a large decrease in skeletal muscle β -adrenergic receptor density. Conclusion: Although some side effects were noted, these results suggest that a short treatment with the β 2 -adrenergic receptor agonist salbutamol during a training program with FES cycling could be beneficial in patients with SCI.