Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25-29, 2009: Oral Presentations
Background and Objective:
The fractional concentration of exhaled nitric oxide (FENO), a simple, non-invasive and reproducible test, has been used as a surrogate marker of airways inflammation in several studies on asthma. It is still unclear, however, how useful FENO is to investigate occupational asthma (OA) or detect bronchial hyperresponsiveness (BHR).
The association between changes in FENO levels since inception of exposure among bakery, pastry-cooking and hairdressing apprentices and the incidence of BHR was studied along their two-year training programme. At months 3, 9, 15 and 18, on average, after start of the programme, a metacholine challenge and measurement of FENO were performed during a medical visit, with completion of a standardized questionnaire and skin prick tests with common and specific occupational allergens.
Among 441 apprentices initially included, 351 completed the study. FENO values are influenced by gender (males>females), atopy (atopics>non atopics), smoking (non smokers>smokers). Increase in FENO values since inception of exposure was associated with the incidence of BHR (OR = 2.00 [95%CI = 1.21-3.32] per unit increase in log ppb), both among atopic and non-atopic volunteers, and was unrelated to past or current smoking habits, gender or training track. Incidence of BHR was also associated with atopy among bakers and pastry cooks (OR = 2.37 [1.2-4.7]) and skin sensitization to alkaline persulfaltes among hairdressers ([OR = 4.3 [0.9-21.4]).
We conclude that measurement of FENO is a convenient means for early detection of BHR in occupations at risk of asthma. Studies should be undertaken to assess its usefulness as an early marker of non-occupational asthma.