Rapid turnover transport proteins, plasma albumin, and growth in low birth weight infants.

The purpose of this investigation was to establish normative data and to determine the value of measuring rapid plasma turnover proteins in low birth weight infants during the neonatal period. Forty-three premature, adequate for gestational age infants were divided in three groups according to their birth weight: group A less than 1000 g, group B 1001 to 1500 g, group C 1501 to 2000 g. Weekly anthropometric measurements and biochemical determinations were obtained. Anthropometric measurements included weight, crown heel length, midtricipital skinfold thickness, and midarm circumference. Biochemical studies in plasma included total proteins, albumin, prealbumin, and retinol-binding protein. A significant increase in prealbumin concentration preceded weight gain. The elevation in prealbumin concentration was statistically significant (p less than 0.02) for the combined data from all groups and for infants included in group B and C (p less than 0.05). No concomitant changes were demonstrated in plasma retinol-binding protein, or total proteins. The transient rise in prealbumin plasma concentrations remains unexplained, but may be related to the infant's nutritional status.