PT  - JOURNAL ARTICLE
AU  - K Boutet
AU  - J-L Malo
AU  - H Ghezzo
AU  - D Gautrin
TI  - Airway hyperresponsiveness and risk of chest symptoms in an occupational model
AID  - 10.1136/thx.2005.056333
DP  - 2007 Mar 01
TA  - Thorax
PG  - 260--264
VI  - 62
IP  - 3
4099  - http://thorax.bmj.com/content/62/3/260.short
4100  - http://thorax.bmj.com/content/62/3/260.full
SO  - Thorax2007 Mar 01; 62
AB  - Background: The clinical outcome of asymptomatic airway hyperresponsiveness (AHR) remains unclear. A study was undertaken to evaluate the incidence of respiratory symptoms in a cohort of asymptomatic subjects with AHR at baseline.Methods: A 3 year prospective study involving methacholine challenge tests and serially administered questionnaires was undertaken in 769 apprentices exposed to high molecular weight allergens. Analyses were performed on 428 initially asymptomatic subjects.Results: Thirty eight subjects (8.9%) were airway hyperresponsive (PC20 ⩽8 mg/ml) and asymptomatic at the start of the study. Forty four apprentices (10.3%) developed two or more respiratory symptoms unrelated to work, 13 (34.2%) in the AHR group and 31 (7.9%) in the non-AHR group (risk ratio (RR) 7.88 (95% CI 2.53 to 24.55) among subjects with AHR). The RR of developing two or more respiratory symptoms increased as the degree of PC20 decreased with a significant trend (p<0.001). In a multivariate analysis, AHR (RR 8.33, 95% CI 2.65 to 26.16) and self-reported rhinitis on exposure to pollen through an interaction with a family history of asthma (RR 6.3, 95% CI 1.29 to 31.89) were associated with the incidence of two or more respiratory symptoms; atopy was not a significant covariate.Conclusion: AHR in asymptomatic subjects is an important determinant for the development of respiratory symptoms outside the workplace among apprentices exposed to high molecular weight allergens in their training environment.