Amund Riiser

The significance of early recurrent wheeze for asthma outcomes in late childhood

Recurrent early life wheeze is not always asthma, and up to 50% of children are reported to remit. With reports of adult asthma symptom relapse, we assessed the prognosis of recurrent bronchial obstruction (rBO) through adolescence in the Environment and Childhood Asthma (ECA) prospective birth cohort study. The present study is based on data from investigations at ages 2, 10 and 16 years of 550 young people (52% males) attending at 16 years of age. Based on the presence of rBO from 0–2 years, defined as recurrent (at least two episodes) doctor-diagnosed wheeze, and asthma from 2–10 years and 10–16 years, defined as at least two episodes of doctor-diagnosed asthma, symptoms and medication use, prognosis of rBO was assessed. Bronchial hyperresponsiveness (BHR) was diagnosed by a metacholine provocation dose ≤8 &mgr;mol that caused 20% reduction in the forced expiratory volume in 1 s. At 10–16 years, 34% of the 143 rBO children had asthma. All children with rBO had reduced lung function compared with the never asthmatics. Of the rBO children in remission, 48.4% had asthma symptoms, medication use and/or BHR compared with 26.7% with never asthma (p<0.001). Only 34.3% of rBO children were without asthma symptoms, medication use or BHR by 16 years, possibly indicating future asthma risk.

Asthma severity in childhood, untangling clinical phenotypes*

Lang A, Mowinckel P, Sachs‐Olsen C, Riiser A, Lunde J, Carlsen K‐H, Lødrup Carlsen KC. Asthma severity in childhood, untangling clinical phenotypes.
Pediatr Allergy Immunol 2010: 21: 945–953.
© 2010 John Wiley & Sons A/S

Does Bronchial Hyperresponsiveness in Childhood Predict Active Asthma in Adolescence

RATIONALE Bronchial hyperresponsiveness (BHR) is an important, but not specific, asthma characteristic. OBJECTIVES We aimed to assess the predictive value of BHR tested by methacholine and exercise challenge at age 10 years for active asthma 6 years later. METHODS From a Norwegian birth cohort, 530 children underwent methacholine challenge and exercise-induced bronchoconstriction (EIB) test (n = 478) at 10 years and structured interview and clinical examination at age 16 years. The methacholine dose causing 20% reduction in FEV(1) (PD(20)) and the reduction in FEV(1) (%) after a standardized treadmill test were used for BHR assessment. Active asthma was defined with at least two criteria positive: doctors diagnosis of asthma, symptoms of asthma, and/or treatment for asthma in the last year. MEASUREMENTS AND MAIN RESULTS PD(20) and EIB at 10 years of age increased the risk of asthma (β = 0.94 [95% confidence interval (CI), 0.92-0.96] per μmol methacholine and β = 1.10 [95% CI, 1.06-1.15] per %, respectively). Separately the tests explained 10 and 7%, respectively, and together 14% of the variation in active asthma 6 years later. The predicted probability for active asthma at the age of 16 years increased with decreasing PD(20) and increasing EIB. The area under the curve (receiver operating characteristic curves) was larger for PD(20) (0.69; 95% CI, 0.62-0.75) than for EIB (0.60; 95% CI, 0.53-0.67). CONCLUSIONS BHR at 10 years was a significant but modest predictor of active asthma 6 years later, with methacholine challenge being superior to exercise test.

Asthma with allergic comorbidities in adolescence is associated with bronchial responsiveness and airways inflammation

Childhood asthma frequently has allergic comorbidities. However, there is limited knowledge of the longitudinal development of asthma comorbidites and their association to bronchial hyper‐responsiveness (BHR) and airway inflammation markers. We therefore aimed to assess the association between childhood asthma with allergic comorbidities and BHR and fractional exhaled nitric oxide (FENO) and the impact of gender on these associations.

Bronchial hyperresponsiveness decreases through childhood

Limited knowledge exists about development of bronchial hyperresponsiveness (BHR) through adolescence. We aimed to assess changes in and risk factors for BHR in adolescence. From a Norwegian birth cohort 517 subjects underwent clinical examinations, structured interviews and methacholine challenges at age 10 and 16. BHR was divided into four categories: no BHR (cumulative methacholine dose required to reduce FEV(1) by 20% (PD(20)) >16 μmol), borderline BHR (PD(20) ≤16 and >8 μmol), mild to moderate BHR (PD(20) ≤8 and >1 μmol), and severe BHR (PD(20) ≤ 1 μmol). Logistic regression analysis was used to assess risk factors and possible confounders. The number of children with PD(20) ≤ 8 decreased from 172 (33%) to 79 (15%) from age 10-16 (p < 0.001). Most children (n = 295, 57%) remained in the same BHR (category) from age 10-16 (50% with no BHR), whereas the majority 182 (82%) of the 222 children who changed BHR category, had decreased severity at age 16. PD(20) ≤ 8 at age 10 was the major risk factor for PD(20) ≤ 8 6 years later (odds ratio 6.3), without significant confounding effect (>25% change) of gender, active rhinitis, active asthma, height, FEV(1)/FVC, or allergic sensitization. BHR decreased overall in severity through adolescence, was stable for the majority of children and only a minority (8%) had increased BHR from age 10 to 16. Mild to moderate and severe BHR at age 10 were major risk factors for PD(20) ≤ 8 at 16 years and not modified by asthma or body size.

Early risk factors for pubertal asthma

Early life risk factors are previously described for childhood asthma, but less is known related to asthma in adolescence. We aimed to investigate early risk factors (before 2 years) for pubertal asthma and secondarily for pubertal asthma phenotypes based upon allergic comorbidities.

Early-life wheeze: “the Child is father of the Man”

From the authors: We wish to thank R.J. Kurukulaaratchy and co-workers for their positive response to our article [1]. We were happy to see that our paper encouraged the Isle of Wight Birth Cohort (IOWBC) to assess the prognosis of …