Airway hyperreactivity in asymptomatic military personnel.
OBJECTIVE
Asthma is frequently diagnosed in military personnel despite strict guidelines that disqualify persons with active disease or a recent history of asthma. It is generally considered incompatible with military service, because of the regular physical training, outdoor training exercises, and deployments to remote locations. The objective of this study was to determine the prevalence of airway hyperreactivity in asymptomatic military personnel, as an estimate of subclinical reactive airway disease.


METHODS
A prospective study of healthy, asymptomatic, military personnel with no previous history of asthma and <1 year on active duty status was conducted. After completion of a screening questionnaire, personnel underwent baseline spirometry with a portable spirometer. Personnel with obstructive indices (based on published guidelines) and matched control subjects participated in an exercise test (1.5-mile run), with pre- and postexercise spirometry.


RESULTS
A total of 222 asymptomatic military personnel completed baseline spirometry, and 31 (14%) were found have airway obstruction. A normal matched control group of 31 military personnel and 26 personnel with obstruction performed exercise spirometry. Twenty-three percent of the participants with obstruction demonstrated increased airway hyper-reactivity after exercise, based on a reduction in forced expiratory volume at 1 second, compared with 19% of control subjects.


CONCLUSIONS
Asymptomatic airway obstruction has a prevalence of 14% in young military personnel. A significant percentage of individuals also have evidence of worsening obstruction during exercise. These data suggest that screening spirometry may identify early reactive airway disease in asymptomatic individuals and should be considered as a method to identify persons predisposed to developing symptomatic asthma.
Pulmonary Disease/Critical Care Medicine Service, Department of Medicine, Brooke Army Medical Center, Fort Sam Houston, TX 78234, USA.
Michael J
MJ
Morris
Darin S
DS
Schwartz
Jana L
JL
Nohrenberg
Sean N
SN
Dooley
D000328:Adult; D000402:Airway Obstruction / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008403:Mass Screening; D008887:Military Medicine; D008889:Military Personnel; D015995:Prevalence; D011446:Prospective Studies; D012129:Respiratory Function Tests; D012307:Risk Factors; D013147:Spirometry; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology