Chest
Volume 131, Issue 4, April 2007, Pages 1181-1187
Journal home page for Chest

Original Research
Cystic Fibrosis
Effect of Albuterol on Maximal Exercise Capacity in Cystic Fibrosis

https://doi.org/10.1378/chest.06-1697Get rights and content

Background

Inhaled, short-acting β-adrenergic agonists (SAβAs) are widely prescribed in cystic fibrosis (CF) subjects, despite a lack of convincing data for efficacy and the potential for these agents to result in airway instability. We tested the hypothesis that inhaled albuterol would improve maximal exercise performance in CF subjects with airflow obstruction, as a result of acute bronchodilation.

Methods

Randomized, double-blind, placebo-controlled crossover study of the effect of inhaled albuterol on maximal exercise performance in 20 stable adult CF patients (mean ± SD age, 23.3 ± 6.1 years; FEV1, 57.65 ± 17.13% of predicted).

Results

Ventilatory limitation to exercise was demonstrated in 16 subjects (80%). Significant bronchodilation occurred with exercise alone (end-exercise FEV1, 2.24 ± 0.8 L; vs preexercise FEV1, 2.09 ± 0.77 L; p < 0.0001), but albuterol resulted in significantly greater exercise-induced bronchodilation than placebo (change in FEV1, 0.3 ± 0.15 L vs 0.15 ± 0.11 L; 95% confidence interval [CI], + 0.07 to + 0.23; p < 0.001). However, there was no difference in maximal workload achieved (albuterol, 158 ± 46 W; vs placebo, 158 ± 45 W; 95% CI, − 4.41 to + 4.71; p = 0.95), nor any other measure of exercise performance including maximal oxygen uptake.

Conclusions

Despite causing significant acute bronchodilation, inhaled albuterol did not improve maximal exercise performance in ventilatory-limited CF adults, adding to the body of literature that fails to show any clinical benefit of SAβAs in CF subjects. The current results provide further evidence to question the widespread use of these agents, although the potential for adrenergic β-agonists to instead improve submaximal exercise performance merits further investigation.

Section snippets

Subjects

Adults with CF previously diagnosed on standard clinical and laboratory criteria were recruited from the adult CF clinic at the Mater Adult Hospital, a regional specialist CF clinic in Australia. All subjects were ≥ 16 years of age and provided written informed consent. The protocol was approved by the Local Regional Ethics Committee.

Subjects with CF were included in the study if they had been clinically stable for at least 21 days and had received no supplemental antibiotic therapy over that

Results

Twenty-two adult CF subjects were enrolled and randomized, and 20 subjects completed the study. One subject declined to participate following enrollment, and a second subject did not complete the second exercise test for personal reasons. Data from both of these were excluded. Three subjects did not perform bronchoprovocation testing, and only seven subjects completed full Borg scores during the tests. Ten subjects received albuterol first, and 10 received placebo first. Baseline

Discussion

The current study demonstrates that inhaled albuterol does not improve indexes of maximal exercise performance in CF subjects with moderate severity airways obstruction, despite causing significant acute bronchodilation. This lack of benefit persisted when only subgroups with positive bronchoprovocation test results, significant acute bronchodilator reversibility, or ventilatory limitation to exercise were considered. Furthermore, these findings are consistent with those reported by Dodd et al22

ACKNOWLEDGMENT

We are sincerely grateful to the CF patients who so willingly donated their time and effort to be involved in this study.

References (38)

  • Balfour-LynnIM et al.

    “CF asthma”: what is it and what can we do about it?

    Thorax

    (2002)
  • TobinMJ et al.

    Atopy and bronchial reactivity in older patients with cystic fibrosis

    Thorax

    (1980)
  • BrandPL

    Bronchodilators in cystic fibrosis

    J R Soc Med

    (2000)
  • HordvikNL et al.

    A longitudinal study of bronchodilator responsiveness in cystic fibrosis

    Am Rev Respir Dis

    (1985)
  • ZachMS et al.

    Bronchodilators increase airway instability in cystic fibrosis

    Am Rev Respir Dis

    (1985)
  • ZinmanR et al.

    Nonhomogeneous lung emptying in cystic fibrosis patients

    Am Rev Respir Dis

    (1991)
  • NixonPA et al.

    The prognostic value of exercise testing in patients with cystic fibrosis

    N Engl J Med

    (1992)
  • ShahAR et al.

    Determinants of aerobic and anaerobic exercise performance in cystic fibrosis

    Am J Respir Crit Care Med

    (1998)
  • De MeerK et al.

    Peripheral muscle weakness and exercise capacity in children with cystic fibrosis

    Am J Respir Crit Care Med

    (1999)
  • Cited by (0)

    This work was performed at Mater Adult Hospital, South Brisbane, Australia.

    The authors have no conflicts of interest to disclose.

    View full text