The response to bronchodilators in adults is not predictive of bronchial-hyperreactivity.

Abstract

BACKGROUND:

In some subjects with suspected asthma who have normal spirometry, administration of bronchodilators (BD) improves expiratory flow rates. The predictive value of this phenomenon in adults is not known.

OBJECTIVES:

To evaluate the predictive value of the response to BD for bronchial hyper-responsiveness (BHR) using the metacholine challenge test (MCT). Patients and methods. The study population included 62 non-smoking adult patients (41.9% women) 29.5 +/- 15.5 years of age (range 18-64 years) with suspected asthma with normal spirometry that underwent MCT within 1 week. The response to BD (200 mu g inhaled salbutamol) was compared between subjects with positive and negative MCT using cutoff levels of provocative concentrations of metacholine causing a 20% decrease in forced expiratory volume in 1 second (FEV(1)) (PC(20)) of 4 and 8 mg/mL.

RESULTS:

Mean (+/- SD) baseline FEV(1) was 87.8 +/- 12% of predicted. After BD administration the mean FEV(1) increased by 4.3 +/- 3.9%. The prevalence of BHR was 17.7% and 25.8% for PC(20) for PC(20) of 4 mg/mL and 8 mg/mL, respectively. The post-BD FEV(1) increment for subjects with positive and negative MCT tests was 3.9% +/- 3.3% versus 4.4% +/- 4.1%, respectively; p = 0.89, using cutoff of 4 mg/mL. The corresponding figures for cutoff of 8 mg/ml were 4.3% +/- 3.1% vs. 4.3% +/- 4.2%, respectively; p = 0.8465. There was no correlation between post-BD FEV(1) increment and PC(20) values in patients with positive MCT test for the above-mentioned cutoff levels (correlation coefficient r = 0.1645, p = 0.6289; and r = 0.2417, p = 0.4051, respectively).

CONCLUSIONS:

In adults with suspected asthma who have normal spirometry, the response to BD cannot be used to predict BHR.

• Authors: Oren Fruchter, Emilia Hardak, Mordechai Yigla
• Journal: The Journal of asthma : official journal of the Association for the Care of Asthma (J Asthma) Vol. 46 Issue 5 Pg. 455-9 (Jun 2009) ISSN: 1532-4303 [Electronic] England
• PMID: 19544164 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Bronchodilator Agents
• Methacholine Chloride
• Albuterol

Topics

• Administration, Inhalation
• Adolescent
• Adult
• Albuterol (therapeutic use)
• Bronchial Hyperreactivity (diagnosis, drug therapy)
• Bronchodilator Agents (therapeutic use)
• Female
• Humans
• Male
• Methacholine Chloride
• Middle Aged
• Predictive Value of Tests
• Respiratory Function Tests
• Young Adult