Low Serum Zinc in Critically Ill Patients Fed Oral and Enteral Nutrition in a Brazilian Terciary Hospital: A Cross-Sectional Study

Abstract

Purpose: Since zinc is required for immunity and inflammation regulations, this paper aimed to investigate serum zinc levels in critically ill patients receiving Enteral (EN) and Oral Nutrition (ON) and correlate these values with demographic, clinical and laboratory parameters. Material and Methods: This is a cross-sectional study. Researchers collected data from electronic medical records in Intensive Care Units (ICUs) of a Brazilian tertiary hospital. Flame Atomic Absorption Spectrophotometry measured serum zinc (normal range: 70-120 mcg/dl). Evaluated variables: age, sex, diagnoses, ICU type, iron, hemoglobin, leukocytes, C-reactive protein, severity score, and mortality. Results: Researches assessed 203 medical records. Mean zinc score was low (EN: 59.13 ±16.26 mcg/dl; ON: 64.75 ±16.80 mcg/dl; p= 0.010). Mean age was high (EN: 77.48 ± 16.26 years; ON: 75.01 ± 13.03 years; p= 0.012). Iron was positively correlated with zinc in EN (p= 0.012). Age was correlated negatively with zinc in ON (p=0.001). Hemoglobin was correlated positively with zinc in EN (p= 0.007) and ON (p= 0.018). Conclusions: Most of the ICU patients had low zinc. EN had lower zinc levels than ON. L