Asthma phenotypes and lung function up to 16 years of age-the BAMSE cohort.

BACKGROUND: Asthma is a disease affecting many locations throughout the airway. Most studies have used spirometry as the primary assessment of airway obstruction, a method that may be less sensitive in regard to peripheral airway obstruction. The aim of this study was to elucidate the associations between asthma phenotypes based on age of onset and duration of symptoms, and (i) spirometry and (ii) small airway involvement measured by impulse oscillometry (IOS) in adolescence. METHODS: Children and adolescents taking part in BAMSE, a prospective birth cohort study, performed spirometry at 8 and 16 years and IOS at 16 years of age. Based on data collected in questionnaires, children were categorized into the following groups: 'never asthma', 'early transient asthma', 'early persistent asthma', and 'late onset asthma'. RESULTS: Compared with the never asthma group, all asthma groups were associated with lower FEV1 at 16 years of age (early transient-119 ml, 95% confidence interval -204 to -34; early persistent-410 ml, 95%CI -533; -287; and late onset-148 ml, 95%CI -237; -58). Between 8 and 16 years, significantly less increase in FEV1 was observed in the early persistent and late onset groups. The small airway index 'R5-20 ' was significantly associated with active asthma at 16 years, but not transient asthma. CONCLUSIONS: All asthma phenotypes studied were negatively associated with FEV1 in adolescence. IOS measurements indicated that active asthma could be associated with small airway impairments. These results provide new insights into the physiology underlying wheezing phenotypes based on age of onset and duration of disease.

Asthma in children exposed to nitrogen dioxide in ice arenas.

Very high concentrations of nitrogen dioxide (NO2) have been measured in arenas using combustion engine-powered resurfacing machines. This study was performed to compare the occurrence of asthma in children playing ice hockey in arenas using propane-powered machines and in children attending arenas using electric machines. Children regularly playing hockey in the arenas (nine propane, six electric) were sent a questionnaire, including questions on allergic disease and risk factors. Measurements of NO2 were performed with passive diffusion samplers during 3 consecutive days. The mean NO2 concentration in the propane arenas was 276 microg x m(-3) (range 28-1015 microg x m(-3)) and 11 microg x m(-3) (2-30) in the electric arenas. Questionnaires were answered by 1,536 children (78%), with an overall prevalence of asthma of 16%. The odds ratio (OR) for asthma was 0.9 (95% confidence interval (CI) 0.7-1.2) comparing propane arenas to electric. However, children in propane arenas with higher than median concentration of NO2 reported more wheezing (OR 1.4, 95% CI 1.0-1.9) and nasal symptoms (OR 1.7, 95% CI 1.3-2.3) than children in propane arenas with lower concentrations. In conclusion, children playing ice hockey in indoor arenas have a high prevalence of asthma, but it appears unlikely that increased exposure to combustion products, including nitrogen dioxide, is a major contributor to this excess risk.

Prophylactic intermittent treatment with inhaled corticosteroids of asthma exacerbations due to airway infections in toddlers.

The aim of this study was to investigate whether budesonide, for 10 d, administered at the first sign of an upper respiratory tract infection, could reduce asthma symptoms in 1-3-y-old children with asthma during infections. The primary efficacy variable was symptom scores. The study had a multicentre, randomized, double-blind, placebo-controlled design with parallel groups. Fifty-five children with a mean age of 26 months received either budesonide or placebo via a spacer with a facemask. Each child was monitored for 1 y. Budesonide was given 400 microg q.i.d. for the first 3 d and b.i.d. for 7 d. Symptoms (cough, wheeze, noisy breathing and breathlessness) were scored (0-3) daily by the parents. Asthma symptom scores were lower in children treated with budesonide than in those given placebo. The effect was most pronounced for cough and noisy breathing, but it did not affect the need for hospital care. In conclusion, treatment with budesonide, started at the first sign of a respiratory infection, reduced asthma symptoms in toddlers with episodic asthma.