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Zinc and Coronavirus Disease 2019

Year: 2023

Type: article

Abstract: To the Editor—A recent article by Abdallah et al reported results of a prospective, randomized, placebo-controlled, multicenter trial evaluating the role of zinc as a potential treatment for coronavirus disease 2019 (COVID-19) [1]. The authors conclude that oral zinc can decrease 30-day death and intensive care unit (ICU) admission rate and can shorten symptom duration, findings that are in contrast to other published studies [2, 3]. The study included adults who were ambulatory (n = 190) and hospitalized (n = 280), without stratification at randomization, and the primary combined outcome was ICU or death due to COVID-19. Some clarification is needed to interpret the study findings. In Figure 2, in the outpatient subgroup [1], 21 of 85 (24.7%) recipients of zinc were reported to have experienced a primary outcome event versus 28 of 100 (28.0%) placebo recipients. In contrast, the corresponding event rates in the zinc versus placebo inpatient subgroup were 3 of 146 (2.1%) and 12 of 134 (9.0%), respectively. The possible reasons why outpatients had rates of ICU admission or death that were several-fold greater than inpatients are not discussed or explained. In the text of the Results section, the hospitalization rates for outpatients assigned zinc versus placebo are reported as 1.2% versus 3.8%, respectively. As the outpatient placebo cohort size was 100 participants, it is unclear how a rate of 3.8% is possible. In addition, 28% of outpatient placebo recipients are reported to have experienced an endpoint of ICU admission or death whereas only 3.8% were noted to have been hospitalized, a finding that is difficult to reconcile. Using another approach, Table 2 states that 27 participants in the combined (inpatient and outpatient) placebo group required ICU admission [1]. If 3.8% of outpatient placebo recipients were hospitalized, then 23 inpatients would have had to require ICU admission to reconcile these numbers; however, there were only 12 events in the inpatient placebo group. There also appear to be other discrepancies in Figure 2. For example, it is noted that there were 239 placebo recipients, but these are not all accounted for when considering those defined as inpatients and outpatients, having symptoms for ≤3 versus >3 days, or being age ≤65 or >65 years at baseline. Of the 231 reported to have been assigned zinc, all are once again not accounted for based upon having symptoms for ≤3 versus >3 days or being age ≤65 versus >65 years at baseline. In addition, it is noted that participants with unknown status at 30 days are excluded. Although this represents only 2 participants per arm, inclusion of all participants in the analyses would be preferred.

Source: Clinical Infectious Diseases

DOI: 10.1093/cid/ciad229

Authors: Susan Swindells, Gregory A Eschenauer, Martha Nason, Eric S Daar