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Metabolic differences between AGA- and SGA-infants of very low birthweight. II. Relationship to protein intake

G Boehm1, H Senger, D Müller

  • 1Department of Paediatrics, Karl-Marx University, Leipzig, GDR.

Acta Paediatrica Scandinavica
|September 1, 1988
PubMed

Insights

Small for gestational age (SGA) infants show increased sensitivity to high protein intake, indicated by altered nitrogen metabolism and bile acid levels. This highlights the need for tailored nutritional management in very low birthweight (VLBW) infants.

Area of Science:

  • Neonatology
  • Nutritional Biochemistry
  • Pediatric Gastroenterology

Background:

  • Infant nutrition, particularly protein intake, is critical for very low birthweight (VLBW) infants.
  • Assessing metabolic responses in appropriate for gestational age (AGA) and small for gestational age (SGA) VLBW infants is crucial for optimizing growth and development.
  • Understanding the impact of varying protein levels on nitrogen and bile acid metabolism is essential for clinical practice.

Purpose of the Study:

  • To investigate the metabolic response to different human milk protein intakes in VLBW AGA and SGA infants.
  • To compare nitrogen metabolism and serum bile acid concentrations between AGA and SGA infants at different protein intake levels.
  • To identify potential markers for detecting metabolic sensitivity in SGA infants.

Main Methods:

  • Study involved 23 AGA and 19 SGA VLBW infants from birth.
  • Infants received either fresh preterm human milk or fortified human milk, establishing protein intakes from 1.94 to 3.34 g/kg/d.
  • Serum alpha-amino-nitrogen, bile acids, and urinary excretion of nitrogen metabolites were measured on the eighth day of life.

Main Results:

  • At protein intakes <2.5 g/kg/d, no significant differences in nitrogen metabolism were observed, but SGA infants had higher serum bile acids.
  • At protein intakes >2.5 g/kg/d, SGA infants exhibited higher serum alpha-amino-nitrogen and bile acids, and increased urinary nitrogen excretion compared to AGA infants.
  • These differences intensified with increasing protein intake, suggesting greater sensitivity in SGA infants.

Conclusions:

  • SGA infants are more sensitive to excessive protein intake than AGA infants by the eighth day of life.
  • Intrauterine growth retardation may contribute to hepatocellular dysfunction, impacting protein metabolism in SGA infants.
  • Serum bile acid concentration can serve as a marker for metabolic sensitivity in VLBW SGA infants, informing nutritional management strategies.

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