Cotinine Levels in Asthmatic Children

Abstract

Introduction: Asthmatic children are more at risk to environmental tobacco smoke exposure (ETS) due to impaired lower airway function. Objective: To investigate the association of low socio-economic status and ETS exposure in asthmatic children. Design: A cross-sectional study on 425 primary school children (aged 5-11years) in Merseyside, using a parent completed questionnaire and childrens’ saliva samples. Results: 25.9 % of children had doctor diagnosed asthma and 12 % had a history of hospital admission for respiratory illnesses. The symptom triad of cough, wheeze and breathlessness were reported for 8.5% of children. Mean cotinine level was 2.1 ng/ml (±0.6 SD). 45.6% of children were ETS exposed (cotinine levels >1.0 ng/ml). Asthmatic children and those from disadvantaged households were more likely to be ETS exposed, compared to non-asthmatic and those from advantaged households [OR=1.7 (95%CI=1.1-2.4)] and [OR=2.1(1.8-3.2) respectively]. A synergic effect of parental asthma, deprivation and high cotinine levels on childhood asthma was observed in multivariate analysis. Conclusions: A high cotinine level was significantly associated with an increased risk of asthma in children particularly amongst disadvantaged households. Interventions aimed at limiting ETS exposure particularly among disadvantaged groups with asthmatic children are needed.