title: Exhaled nitric oxide levels in military recruits with new onset asthma.
abstract: Approximately 800 United States Air Force basic military trainees (BMTs) are diagnosed with asthma, annually, resulting in separation from the military. With training costs of approximately 10,000 dollars/person, around 8 million dollarsis lost per year. Improved methods in diagnosing asthma would be beneficial. The aim of this study was to determine the fraction of exhaled nitric oxide (FENO), a marker of airway inflammation, in a military recruit population referred for an asthma evaluation. In BMTs referred for respiratory complaints during basic training, FENO levels were determined before an asthma evaluation consisting of a history, physical, baseline spirometry, and histamine bronchoprovocation. Of 172 BMTs who had symptoms suggestive of asthma and underwent histamine bronchoprovocation, 80% were diagnosed with asthma. FENO levels were significantly higher in asthmatic patients than nonasthmatic patients (mean, 30 parts per billion [ppb] versus 19 ppb, p < 0.001; median, 21 ppb versus 17 ppb, p < 0.02). Various FENO cutoff points provided a range of sensitivity and specificity for the diagnosis of asthma. However, an optimal FENO cutoff level for asthma was not obtained. An FENO value of 10.5 ppb provided a sensitivity of 86% for the diagnosis of asthma, but specificity was only 21%. In contrast, an FENO value of 46 ppb provided 100% specificity but only 17% sensitivity. FENO levels were significantly elevated in BMTs diagnosed with asthma but the lack of an optimal cutoff level limits the test as a diagnostic tool for asthma. Additional studies are necessary to determine the value of FENO for asthma screening in a military population.
authors.affiliation: Department of Allergy/Immunology, Wilford Hall Medical Center, San Atitonio, Texas 78236-5033, USA. rajiv.arora@us.army.mil
authors.forename: Rajiv
authors.initials: R
authors.lastname: Arora
authors.forename: Carl E
authors.initials: CE
authors.lastname: Thornblade
authors.forename: Pierre-Alain L
authors.initials: PA
authors.lastname: Dauby
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Flanagan
authors.forename: Anneke C
authors.initials: AC
authors.lastname: Bush
authors.forename: Larry L
authors.initials: LL
authors.lastname: Hagan
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000378:metabolism* / Q000503:physiopathology; D015415:Biomarkers; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D008889:Military Personnel; D009569:Nitric Oxide / Q000378:metabolism*; D011446:Prospective Studies; D014481:United States
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide