Insulin-like growth factor I (somatomedin C) in premature infants on total parenteral nutrition. Relations with nutritional status and protein-energy intakes]

Insulin-like growth factor I (IGF I) is like prealbumin and transferrin a marker of nutritional status. Its level increases with gestational age. The levels of IGF I (96 times), transferrin (86 times) and prealbumin (69 times) were measured in blood samples from 26 premature infants aged 8 to 78 days (gestational age: 28 to 34 weeks, birth weight: 840 to 1,800 g). At the time of sampling, all the infants were on total parenteral nutrition (360 +/- 42 kJ/kg/day and 2.5 +/- 0.3 g of proteins/kg/day). The results were analysed with reference to anthropometric parameters (weight, height, head circumference, skinfolds and arm circumference). There was no correlation between plasma IGF I and anthropometric measurements. There were significant correlations between IGF I and transferrin (p less than 0.01), prealbumin (p less than 0.05), protein intake (p less than 0.01) an energy intake (p less than 0.05). Plasma IGF I increased at the end of the first week of parenteral nutrition in all the 5 infants having initial low values. The plasma IGF I was not correlated with the duration of parenteral nutrition in the 26 infants after the second week of nutrition. IGF I measurement is useful for evaluating the protein nutritional status of premature infants on total parenteral nutrition.