Association Between Serum Zinc Levels and Clinical Outcomes in Diabetic Patients Hospitalized With COVID-19: A Retrospective Study

Background: Coronavirus disease 2019 (COVID-19) is associated with significant morbidity and mortality, particularly in patients with underlying conditions such as diabetes mellitus. Zinc is an essential trace element with important immunomodulatory and antiviral properties, and zinc deficiency has been suggested to worsen outcomes in viral respiratory infections. However, the relationship between serum zinc levels and clinical outcomes in diabetic patients with COVID-19 remains insufficiently explored. Methods: This retrospective descriptive–analytical study was conducted on 158 diabetic patients hospitalized with confirmed COVID-19 at Shahid Sadoughi Hospital, Yazd, Iran. COVID-19 diagnosis was confirmed using RT-PCR and/or chest CT scan. Serum zinc levels were obtained from medical records, and patients were categorized into low zinc (<50 µg/dL) and normal zinc (50–70 µg/dL) groups. Clinical outcomes including ICU admission, intubation, length of hospital stay, and mortality were compared. Statistical analysis was performed using SPSS version 26. Results: Patients with low serum zinc levels were significantly older than those with normal zinc levels (p = 0.001). ICU admission (26.3% vs. 12.8%, p = 0.034) and mortality (27.5% vs. 7.7%, p = 0.001) were significantly higher in the low zinc group. Low serum zinc was associated with increased odds of ICU admission (OR = 2.42) and death (OR = 4.55). No significant differences were observed in intubation rates or length of hospital stay. Conclusion: Low serum zinc levels were associated with worse clinical outcomes, including higher ICU admission and mortality rates, in diabetic patients hospitalized with COVID-19. Assessment and correction of zinc deficiency may be beneficial in this high-risk population.