RESUMEN
OBJECTIVE: Whilst the prevalence and severity of asthma influenced by environmental factors, the effect of parental smoking on asthma status of their children was examined. PATIENTS AND METHODS: Ninety asthmatic children, 32 with smoker and 58 with non-smoker parents (baseline age, 8.5 ± 3.5 and 8.2 ± 3.3 respectively) were studies in two sessions 3 years apart by evaluating respiratory symptoms (RS) prevalence and severity, various drugs used, and pulmonary function tests (PFT) including forced vital capacity; forced volume in the first second, peak expiratory flow; and maximum expiratory low at 75, 50 and 25% of vital capacity (FVC, FEV1, PEF, MEF75, MEF50 and MEF25, respectively). RESULTS: The prevalence and severity of all RS were significantly increased in asthmatic children with smoking parents after 3 years except prevalence and severity of night wheeze and the prevalence of chest wheeze (p < 0.05 to p < 0.001), but the PFT values were non-significantly reduced. In asthmatic children with non-smoking parents, the prevalence and severity of RS were decreased after 3 years, which was significant for night and chest wheeze for prevalence and night cough and chest wheeze for severity (all, p < 0.05), and the PFT values were increased, which were statistically significant for FVC, FEV1, MEF50 and MEF25 (p < 0.05 to p < 0.01). Drugs used by the group with smoking parents were increased and were significantly higher than their reduction in the groups with non-smoking parents at the end of the study (p < 0.05 for fluticasone propionate 125/salmeterol and budesonide160/formoterol). CONCLUSION: Long-term parental smoking increased prevalence and severity of RS and drug used but decreased PFT values of their asthmatic children.