Background The concentration of peptides from gut or from fat in plasma could vary due to different types of feeding, but little is known about how parenteral feeding affects secretion of these peptides, especially in infants. Therefore the aim of the study was to determine plasma concentration of GLP-1, CCK, orexin as well as leptin and adiponectin in infants maintained on parenteral nutrition.

Studied groups and Methods The parenteral fed group consisted of children on total parenteral nutrition (TPN) lasting at least 18 hours. A control group comprised 15 healthy infants on continuous glucose venous infusion lasting minimum 8 hours. All children were at similar age (4.5±2.5 months) and their weight was between 75% and 125% of ideal weight for age. Plasma levels of peptides were measured by EIA.

Results There were no statistical differences in the mean concentrations of ghrelin, CCK, GLP-1 and orexin between studied groups. In children with TPN the mean values of PYY (1.13±0.37 pg/ml) and adiponectin (5.81±2.42 μg/ml) were higher than in the controls (0.72±0.15 pg/ml; 3.33±2.29 μg/ml, respectively; p<0.01 in both cases). Mean leptin concentration observed in children with TPN (1.08±0.43 ng/ml) were higher than in the control group (1.48±0.45 ng/ml; p<0.02).

Conclusion Total parenteral nutrition surprisingly affects plasma levels of long-term signals of hunger from fatty tissue than short-term signals from the gut.