Study of Zinc Serum Concentration and Effect of Zinc Supplementation on Lung Function in Asthmatic patients

Asthma, as the most prevalent disorder of the airways is accompanied with excessive inflammatory, oxidative and apoptotic activity. In asthmatic patients, serum and hair levels of zinc are decreased. Zinc, as an essential micronutrient for human is reported to have anti inflammatory, anti oxidant and anti apoptosis roles. This study was conducted to investigate the effect of zinc supplementation on lung function in asthmatic patients in Hazrat Rasool Akram Hospital.Patients and Materials: A cross sectional clinical trial was conducted on 29 patients with asthma who received 50 mg zinc supplementation every other day for a period of 8 weeks. 10 ml blood sample was drawn prior to initiation of supplementation period. Serum Zinc concentration was measured by Atomic Absorption spectrophotometry and compared with that of 29 non-asthmatic individuals. Respiratory factors such as Forced Expiratory Volume in 1 second (FEV1), Forced Vital Capacity (FVC), Vital Capacity (VC) and FEV1: FVC ratio were measured by Spirometer in asthmatic patients before and after Zinc supplementation. Dietary intake in asthmatic patients was assessed by Dietary recall questionnaire. Data were analysed by Paired t-test and Independent t-test. SPSS V. 10 was used. The serum zinc concentration of treated patients was 0.68±0.16 mg/l, which shows significant difference (P<0.05) when compared to that of normal group. The differences of FEV1, FVC, VC, FEV1:FVC were not statistically significant before and after zinc supplementation (P>0.05) and the daily food intake of zinc in patients, was 60% of the Recommended Dietary Allowance (RDA). Zinc status of serum in asthmatic patients was significantly lower than non-asthmatic subjects and supplementation with 50 mg zinc taken every other day for 8 weeks did not lead to significant effect on respiratory factors. More interventional trials are recommended.