EFFECT OF DIFFERENT DIETARY PROTEIN INTAKE ON POSTNATAL GROWTH AND NEURODEVELOPMENTAL OUTCOME AT 1 YEAR IN VLBW INFANTS

BACKGROUND: Protein malnutrition is a major contributing factor to postnatal growth retardation in VLBW infants. The association with the auxological and the neurodevelopmental outcome is controversial. OBJECTIVE: To examine the effect of postnatal growth on neurodevelopmental outcome at 1 year in VLBW infants, receiving different dietary protein intake in the first months of life. DESIGN/METHODS: 40 preterm formula fed infants were randomly assigned to receive, from birth to 12 wks post term, a formula with 3.2 g/100 kcal of protein (Gr F n20, males 10, SGA 9) or 2.6 g/100 Kcal of protein (Gr C n20, males = 8, SGA 10). We analyzed auxological data at birth, discharge, 40-52 wks GA and at 1 year. Neurodevelopmental outcome at age 1 was evaluated (Griffith test). RESULTS: Groups were similar at birth (GA 30±1 vs 29 ± 2 wks, BW 1176 ± 248 vs 1200 ± 206 g Gr C vs F respectively). Auxological effects of the dietary intake are shown. No difference for growth of head circumference. No interaction between dietary intake and gender (p=0,34). At age 1, no difference on auxological parameters measured as the difference between mean values of weight (p=0.08), length (p=0.08) and head circumference (p=0.52) (Test t with Snedecor test), considering both the whole population of each group and gender as a nuisance factor. The 2 groups are homogeneous except for length in females (p= 0.04). No difference for neurodevelopmental outcome at age 1, even for males and SGA (χ² for contingency table = 0.6; p 0.44 Gr C vs Gr F ). CONCLUSIONS: In VLBW infants, an higher protein intake from birth to 12 wks GA promotes a more rapid post-natal catch-up growth. This effect reduces hospital stay but it disappears at age 1. Even if the evaluation of mental and motor development should be made later, the effect of higher protein intake on neurodevelopmental outcome at 1 year in VLBW infants is not significant. Other studies are needed to identify the sub-population of VLBW infants who really might need this dietary intervention.