All ETDs from UAB

Advisory Committee Chair

Ariel Salas

Advisory Committee Members

Brenda Bertrand

Paula Chandler-Laney

Peng Li

Colm Travers

Document Type


Date of Award


Degree Name by School

Doctor of Philosophy (PhD) School of Health Professions


Adequate nutrition and optimal growth are critical goals of clinical care for premature infants in the NICU due to rapid brain growth and development that occur during this time. Emerging evidence suggests that body composition in preterm infants is predictive of neurodevelopmental and metabolic outcomes later in childhood. The objective of this dissertation is to investigate factors affecting premature infant growth and body composition, including high enteral protein supplementation, nutrition during the first two weeks of life, and race of infants born at 22-32 weeks gestational age admitted to the UAB NICU. In a pilot study, 56 preterm infants were randomized to receive either fortified milk enriched with a fixed amount of extensively hydrolyzed protein (high protein group) or fortified milk without additional protein (standard protein group). Infants fed high enteral protein had higher fat free mass (FFM) accretion, weight, and length. In an observational study of 94 infants in the NICU, we investigated the relationship between protein intake, including source of protein, during the first two weeks of life and FFM accretion. We found that total protein intake and protein source during the first two weeks of life was associated with growth and body composition in the first two weeks and enteral protein was associated with more FFM at discharge. Given that there are race differences iii in risk for prematurity, birthweight, and early life growth of term infants, we investigated race differences in body composition and weight gain velocity in a group of 143 preterm infants. Black infants had higher weight gain from birth to discharge, but comparable body composition measurements at discharge. Together, the results of this dissertation suggest that protein intake is a modifiable aspect of clinical care in the NICU that can be used to increase FFM and growth in preterm infants. Additionally, weight gain velocity differs by race in the NICU, and future research should investigate reasons underlying race differences in growth of premature infants. Given the importance of growth during early infancy on long-term cardiometabolic and neurodevelopmental health, research should continue to identify strategies to optimize growth and body composition during NICU admission.



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