Characterisation of asthma that develops during adolescence; findings from the Isle of Wight Birth Cohort

Abstract

Understanding of adolescent-onset asthma remains limited. We sought to characterise this state and identify associated factors within a longitudinal birth cohort study. The Isle of Wight Whole Population Birth Cohort was recruited in 1989 (N=1456) and characterised at 1, 2, 4, 10 and 18-years. "Adolescent-onset asthma" was defined as asthma at age 18 without prior history of asthma, "persistent-adolescent asthma" as asthma at both 10 and 18 and "never-asthma" as those without asthma at any assessment. Adolescent-onset asthma accounted for 28.3% of asthma at 18-years and was of similar severity to persistent-adolescent asthma. Adolescent-onset asthmatics showed elevated bronchial hyper-responsiveness (BHR) and atopy at 10 and 18 years. BHR in this group at 10 was intermediate to that of never-asthmatics and persistent-adolescent asthma. By 18 their BHR, bronchodilator reversibility and sputum eosinophilia was greater than never-asthmatics and comparable to persistent-adolescent asthma. At 10, males who later developed adolescent-onset asthma had reduced FEV(1) and FEF(25-75), while females had normal lung function but then developed impaired FEV(1) and FEF(25-75) in parallel with adolescent asthma. Factors independently associated with adolescent-onset asthma included atopy at 10 (OR=2.35; 95% CI=1.08-5.09), BHR at 10 (3.42; 1.55-7.59), rhinitis at 10 (2.35; 1.11-5.01) and paracetamol use at 18-years (1.10; 1.01-1.19). Adolescent-onset asthma is associated with significant morbidity. Predisposing factors are atopy, rhinitis and BHR at age 10 while adolescent paracetamol use is also associated with this state. Awareness of potentially modifiable influences may offer avenues for mitigating this disease state.