A Study of the Association of Serum Zinc and Selenium Levels with the Severity of Asthma in Iranian Children

Abstract Background: Asthma is the most common respiratory disease among children with a growing prevalence worldwide. In addition to their multiple roles in human body, zinc and selenium have anti-inflammatory properties which is due to their presence in the structure of antioxidant enzymes namely superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Lack of these elements in the body can cause airway inflammation in asthma patients.Methods: In the present case-control study, 50 asthmatic and 50 non-asthmatic children aged 5-15 years were selected at Taleghani Hospital of Gorgan using convenience sampling. The levels of zinc and selenium were determined in blood samples by an atomic absorption spectrophotometer. T-test, Man-Whitney, ANOVA, Kruskal-Wallis test, and multiple regression were used in this study. Statistical analyses were performed using SPSS statistical software version 16 at a significance level of 0.05.Results: The case and control groups were similar in terms of demographic variables. The mean±sd level of zinc was 46.78±8.93 in the case group, and 50±7.8 in the control group (p= 0.07). The mean±sd level of selenium was 62.78±11.46 in the case group, and 67.86±7.87 in the control group (p= 0.038). The comparison of individuals in the control group and those with different degrees of asthma revealed a significant difference in the mean levels of zinc (p= 0.003) and selenium (p= 0.009). According to the multiple regression analysis, individuals with severe asthma had lower levels of zinc and selenium than the control group.Conclusions: The present study indicated that the levels of zinc and selenium were lower in individuals with asthma than in healthy individuals; and the mean levels of zinc and selenium sharply decreased with increase in the severity of asthma.