Association of serum zinc levels and symptom control of asthma in children and adolescents— a prospective observational study

Dysregulation of zinc (Zn) homeostasis causes a shift in the Th1/Th2 balance towards a Th2 response, which may lead to a heightened inflammatory response. Asthma is associated with an exaggerated Th2 response to antigens. This study attempts to find the association of serum Zn with the status of symptom control of asthma in children and adolescents with bronchial asthma. A total of 67 asthmatic children, diagnosed as per Global Initiative for Asthma (GINA) 2019 guidelines, were included in the study. Symptom control of asthma was assessed by Asthma Control Test (ACT) and Childhood Asthma Control Test (C-ACT) scores. Spirometry was performed on those participants who were able to perform satisfactorily. Serum Zn was analyzed using the photometric method. Participants were divided into two groups: controlled and uncontrolled groups according to ACT/C-ACT score. Mean age of the participants was 10.78 ± 3.67 years. The mean S. Zn (µg/dL) was 136.97 ± 48.37. This study found a higher mean S. Zn value in the controlled asthma group as compared to the uncontrolled group (158.06 vs 129.23, p = 0.006). At a cutoff of S. Zn (µg/dL) ≥ 126.84, it predicted controlled asthma with a sensitivity of 89% and a specificity of 55%. No significant difference was found between the mean serum Zn levels in terms of age, sex, severity, and CRP levels. Conclusion: A significant difference was observed between the mean value of Zn and symptom control of asthma (p = 0.006) with a weak positive correlation between the two which was statistically significant (rho = 0.26, p = 0.031). However, low levels of zinc were not significantly associated with symptom control of asthma. Thus, we conclude that maintaining an adequate zinc level could help in achieving better control of asthma in pediatric populations.