393 Evaluation of Fat and Nitrogen Faecal Losses in Aga and Sga Preterm Newborns

Abstract

Background and aims: In preterm newborns an adequate nutrition is important to obtain a growth pattern similar to the intrauterine one, without overloading the immature metabolic and excretive functions. The ESPGHAN guidelines for preterm enteral nutrition recommend to aim at 3.5-4.5 g/kg/ day protein and 4.8-6.6 g/kg/day fat enteral intake, with no distinction between AGA and SGA infants. Our aim was to evaluate faecal fat and nitrogen losses in preterm infants, highlighting differences between AGA and SGA infants in order to optimize their fat and protein enteral intake. Materials and Methods: Faecal fat and nitrogen content was measured at 15 days of life by NIRA (Near-Infrared-Reflectance-Analysis) in 49 preterm infants (GA< 32 wks; 33 AGA and 16 SGA) hospitalized in our NICU. Differences between AGA and SGA newborns in faecal fat and nitrogen content were evaluated by independent samples t test. Results: Faecal fat content (g/100g of stools) was significantly higher (p=0.043) in SGA infants (mean 15.65 [SD 2.36]) than in AGA (mean 13.76 [3.24]); furthermore, SGA had a higher faecal nitrogen excretion (g/100g of stools) than AGA (1.09 [0.24] vs 0.95 [0.18], p=0.036). Conclusions: Given these data, we believe to be useful to optimize fat and protein enteral intake for preterm SGA infants according to their ability to retain ingested macronutrients, which is different from AGA. For this reason, this study will be further developed in order to evaluate the relationship between protein and fat intake and either urinary and faecal losses in these two populations of preterm infants.