The impact of passive smoking on asthma control in children

Abstract

Objectives: To determine whether passive smoking affects spirometry parameters and allergy blood test results in children; to verify if there is a difference in spirometry parameters and allergy blood test results in children whose household members smoke within the household and children whose household members smoke outside the household; to verify if there is a difference in spirometry parameters and allergy blood test results in children in regard to the number of smokers in the household; to determine if there is a connection between tobacco smoke and the number of allergens in children; to determine if the number of daily smoked cigarettes inside the household correlates with the spirometry parameters and allergy blood test results in children. Design: A retrospective cohort study was conducted. Settings: The study was conducted in the allergy clinic of the Children's ward of the Clinical Medical Centre Split. Patients and methods: The study included 60 children, aged between 5 and 18 with a diagnosis of asthma, who were brought in the allergy clinic by their parents. Children were divided into two groups: a group of 36 children whose household members smoke and a group of 24 children whose household members do not smoke. We analyzed: spirometric parameters (PEF, FVC, FEV1, FEF25, FEF50, FEF75) before and after (VENT_FEF50, VENT_FEF75) we performed a bronchodilatator test with two salbutamol 100 micrograms/dose inhalations; allergy blood tests (Dunger test, relative eosinophile count, concentration of eosinophil cationic protein (ECP), total serum IgE concentration) and eosinophile count in the nasal swab. All the necessary data was gathered from the questionnaire filled out by the parents and by accessing the patients' medical history on the computer. Results: There is no statistically significant difference in spirometry parameters (PEF, FVC, FEV1, FEF25, FEF50, FEF75, VENT_FEF50, VENT_FEF75), eosinophile count in the nasal swab and allergy blood tests (Dunger test, relative eosinophile count, concentration of eosinophil cationic protein (ECP), total serum IgE concentration) between the group of children whose household members smoke and whose household members do not smoke. ECP concentration has shown a statistically significant difference between the group of children whose household members smoke within the household and the group of children whose household members smoke outside the household (P = 0,009). The number of daily smoked cigarettes inside the household statistically significantly correlates with relative eosinophile count in children (P = 0,048). There is no statistically significant difference in spirometry parameters (PEF, FVC, FEV1, FEF25, FEF50, FEF75, VENT_FEF50, VENT_FEF75), eosinophile count in the nasal swab and allergy blood tests (Dunger test, relative eosinophile count, concentration of eosinophil cationic protein (ECP), total serum IgE concentration) between the groups of children in regard to the number of smokers in the household. There is no statistically significant connection between the smoking of the household members and the number of allergens in children. Conclusion: Even though most of the published papers have proven that passive smoking has an effect on development of childhood asthma, this research did not find statistically significant difference in spirometry parameters (PEF, FVC, FEV1, FEF25, FEF50, FEF75, VENT_FEF50, VENT_FEF75), eosinophile count in the nasal swab and allergy blood tests (Dunger test, relative eosinophile count, concentration of eosinophil cationic protein (ECP), total serum IgE concentration) between the groups of children whose household members smoke and children whose household members do not smoke. The number of smokers in the household also did not show significant effect on the aforementioned values. We did not find a connection between passive smoking and the number of allergens in children. A statistically significant difference was found in the ECP value between the group of children whose household members smoke within the household and the group whose household members smoke outside the household. Also, a positive correlation was found between the number of daily smoked cigarettes and relative eosinophile count. These results suggest that passive smoking might have an effect on childhood asthma. There is an obvious difference in the sensitivity of the observed parameters, but despite the small number of patients in this research, it was still possible to find a significant difference in some of the parameters. This way we can explain why the values of ECP and relative eosinophile count showed a statistically significant difference while other observed parameters did not. It is possible that in a larger number group of patients, other parameters would also show statistically significant difference.