A Randomized Clinical Trial of Elemental Zinc Add-on Therapy on Clinical Outcomes of Patients with Chronic Rhinosinusitis with Nasal Polyposis (CRSwNP)

Recent studies suggest a relationship between zinc deficiency and inflammation. In the present study, we studied the effect of oral zinc supplementation on clinical improvement of chronic rhinosinusitis with nasal polyposis. In this single-blind randomized controlled trial, 44 patients with chronic rhinosinusitis with polyposis referring to ENT clinic of the Loghman Hakim hospital during 2013-2014 were randomly allocated in two groups. The treatment group (n = 28) was treated with a four-drug fixed-dose regimen (FD_FDR) consisting of oral dexamethasone (0.02 mg/kg), fluticasone nasal spray, fexophenadine 60 mg daily, montelukast 10 mg daily plus 220mg zinc sulfate capsules containing 55 mg elemental zinc, b.d., and the control group (n = 16) received the FD_FDR without supplemental zinc, for six weeks. After sixth week, two groups were compared regarding clinical outcomes based on the SNOT20 (Sinonasal outcome test) questionnaire, the general health questionnaire (SF12), the Lund-Mackay, and the Lund-Kennedy scoring systems. In the treatment group, serum zinc levels were significantly increased compared to those at the baseline (1.33 fold-increase; p = 0.0002). Within groups analysis revealed a significant reduction (p < 0.01) in LM and LK in both treatment (55% LM; 50% LK) and control groups (45% LM; 53% LK). Incontrast, between groups analysis revealed no significant differences in the LM and LK. The treatment group showed a mild superiority in general health improvement compared to that of the control group. Add-on therapy with supplemental zinc sulfate was not associated with significant improvement in patients with chronic rhinosinusitis with nasal polyposis (CRSwNP). The advantage of zinc supplementation on the general health improvement of the patients with CRSwNP requires further assessments.