Zinc Intake From Oral and Enteral Nutrition and Clinical Outcomes in Critically Ill Elderly Patients With COVID‐19
Zahra Gholi, Masoud Rezaei, Reza Amiri Khosroshahi, Seyede Zahra Sadat, Mehdi Fallah Bagher Shaidaei, Mohammad Reza Afifi, Mohammad Reza RajabiBackground and Aim
The coronavirus disease 2019 (COVID‐19) pandemic has disproportionately affected elderly patients, particularly those with comorbidities, leading to severe outcomes such as respiratory failure, delirium, and high mortality rates. Zinc, an essential micronutrient, has been hypothesized to play a role in immune modulation and inflammation reduction, potentially influencing COVID‐19 outcomes. However, most previous studies have examined serum zinc status, while little is known about the impact of estimated zinc intake from nutrition support and supplements in critically ill elderly patients.
Methods
This prospective cohort study aimed to evaluate the impact of zinc intake on clinical outcomes in critically ill elderly COVID‐19 patients admitted to the intensive care unit (ICU). A total of 310 patients aged ≥ 65 years were categorized into tertiles on the basis of daily zinc intake (lowest: < 26.79 mg, middle: 26.79–33.99 mg, highest: > 33.99 mg). Zinc exposure was defined exclusively by estimated daily intake from enteral and oral supplements; serum zinc levels were not measured due to logistical constraints during the pandemic. The outcomes assessed included delirium incidence, invasive mechanical ventilation (IMV) requirements, 45‐day mortality, ICU mortality, hospital and ICU stay duration, and rehospitalization rates.
Results
Mean daily intake was 30.8 ± 14.0 mg/day; after multivariable adjustment, no significant associations were observed between zinc intake tertiles and delirium, IMV requirement, ICU mortality, or 45‐day mortality (all p ‐trend > 0.05). Delirium occurred in 70% of patients, 45‐day mortality was 61.3%, and 10.6% required IMV. Zinc intake did not influence these outcomes or affect hospital or ICU stay duration or rehospitalization rates.
Conclusion
These findings suggest that zinc intake alone may not significantly alter the course of COVID‐19 in critically ill elderly patients, likely due to the complex interplay of systemic inflammation, altered zinc homeostasis, and multifactorial disease progression in this population. The absence of serum zinc measurements limits direct conclusions on zinc status. Nevertheless, our data emphasize the importance of ensuring adequate trace element provision as recommended by ESPEN guidelines, while highlighting the need for randomized controlled trials combining zinc intake assessment with biochemical monitoring.