305 - A longitudinal study of whole blood zinc content in very preterm infants over the neonatal hospitalization

Poster Number: 305
Publication Number: 305.128

Christopher M. Elitt, Boston Children's Hospital, Newton, MA, United States; Sara Cherkerzian, Brigham and Women's Hospital, Boston, MA, United States; Katherine A. Bell, Brigham and Women's Hospital, Boston, MA, United States; Jordan M. O'Brien, Brigham and Women’s Hospital, Brookline, MA, United States; Meghana S. Iragavarapu, Brigham and Women's Hospital, Boston, MA, United States; Silvi Minga, Brigham and Women's Hospital, Boston, MA, United States; Rachel Suttin, Brigham and Women's Hospital, Newton, MA, United States; Jianlin Wang, Boston Children's Hospital, Boston, MA, United States; Madeline Ross, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Samantha G. Remis, Boston Children's Hospital, Saint Louis, MO, United States; Jane E. Shanahan, Boston Children's Hospital, Saint Louis, MO, United States; helen christou, Brigham and Women's Hospital, Boston, MA, United States; Mandy Belfort, Brigham and Women's Hospital, Boston, MA, United States; Paul A. Rosenberg, Boston Children's Hospital, Boston, MA, United States

Background: Zinc is an essential micronutrient.  In very preterm infants, zinc is important for linear growth, fat-free mass accretion and brain development.  Very preterm infants are at risk for nutritional deficiencies.  Currently, little is known about their zinc status at birth and how it evolves over time in the neonatal intensive care unit (NICU) given contemporary nutritional support practices.

Objective: To determine longitudinal changes in whole blood zinc content among hospitalized very preterm infants and to compare levels with healthy full-term infants at birth.

Design/Methods: We studied 43 very preterm infants (gestational age range, 24-30 completed weeks) and 15 full-term infants (gestational age range, 37-39 completed weeks).  We used inductively coupled plasma-mass spectrometry (ICP-MS) to measure zinc content based on Zn⁶⁴ in peripheral whole blood samples collected from very preterm infants at 4 time points (24 hours, 2 weeks, 1 month, hospital discharge) and in cord blood from full-term infants at birth.  We plotted whole blood zinc content over time in the NICU and compared values at each time point with zinc content in cord blood from full-term infants.

Results: Distributions of zinc content for each sample group are shown in Figure 1. Among very preterm infants, median zinc content decreased from birth through 1 month of chronological age, then increased by hospital discharge (Figure 2). Cord blood zinc levels (median, interquartile range) from full-term infants are shown in Figure 2 as a reference. Correlations of zinc content between time points were low to moderate (Table 1). Very preterm infants at NICU discharge had higher zinc content than full-term infants at birth.

Conclusion(s): This cohort of very preterm infants showed a decline in whole blood zinc content over the first month of NICU hospitalization. Subsequently, whole blood zinc content increased such that by discharge, very preterm infants’ whole blood zinc content was higher than that of full-term infants at birth. These findings may have implications for micronutrient supplementation strategies in the NICU.