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Methacholine challenge testing in Reserve Officer Training Corps cadets
B J Roth1, L M Hammers, T A Dillard
1From the Pulmonary/Critical Care Service , Department of Medicine, Soldier Care Service, Madigan Army Medical Center, Tacoma, WA 98431, USA. Bernard.J.Roth@NW.amedd.army.mil
Chest
|March 13, 2001
Summary
Asymptomatic Reserve Officer Training Corps (ROTC) cadets may experience false-positive methacholine challenge tests. This study found that positive results in healthy cadets occurred at higher concentrations, suggesting potential overdiagnosis of asthma.
Area of Science:
- Pulmonary Medicine
- Clinical Trials
- Respiratory Health
Background:
- The methacholine challenge test is used to diagnose asthma by assessing bronchial hyperresponsiveness.
- Asymptomatic individuals, particularly those in demanding physical training programs like ROTC, require careful evaluation to avoid misdiagnosis.
Purpose of the Study:
- To investigate the prevalence of positive methacholine challenge test results in asymptomatic Reserve Officer Training Corps (ROTC) cadets without a history of asthma.
- To evaluate the significance of positive test results in this specific population.
Main Methods:
- A prospective, blinded cohort comparison study was conducted at a US Army tertiary-care medical center.
- 103 college students were divided into two groups: 63 asymptomatic cadets with no asthma history (Group 1) and 40 cadets with a history or symptoms suggestive of asthma (Group 2).
- Methacholine challenge testing was performed using increasing concentrations, with a positive result defined as a 20% decline in FEV(1).
Main Results:
- Group 2 (with asthma history/symptoms) showed a significantly higher rate of positive methacholine challenge tests (57.5%) compared to Group 1 (12.7%, p < 0.05).
- In Group 1, positive responses occurred at higher methacholine concentrations (2.5 mg/mL and above).
- Using current American Thoracic Society criteria, a small percentage of asymptomatic cadets (4.8%) exhibited mild bronchial hyperresponsiveness.
Conclusions:
- Asymptomatic US Army ROTC cadets without a history of asthma may exhibit false-positive methacholine challenge test results at concentrations greater than 0.25 mg/mL.
- These findings highlight the need for careful interpretation of methacholine challenge tests in asymptomatic, physically active populations to prevent potential overdiagnosis of asthma.