{Our study examined if dietary long-chain polyunsaturated fatty acids (LCPUFA) have an impact on oxidative stress in preterm infants. Serum malonyldialdehyde (MDA), total peroxide concentrations, and total antioxidant capacity were determined at mean (standard deviation [SD]) 34.7 (10.9) days of life in 104 healthy preterm infants (gestational age, 32.6 [2.9] weeks; birthweight; 1605 [285] g) who were randomly assigned to be fed since birth either a formula containing LCPUFA (arachidonic and docosahexaenoic) (group A

{OBJECTIVE: To determine circulating levels of adiponectin in preterm infants and examine possible associations with anthropometric measurements, weight gain, and leptin and insulin levels. DESIGN: Prospective study. SETTING: A university hospital neonatal care unit. Study population: 62 preterm (mean (SD) gestational age 32.0 (2.1) weeks) and 15 full-term infants (reference group). INTERVENTIONS: Blood samples taken at discharge (40.9 (14.8) days of life) from the preterm infants and at a comparable postnatal age in full-term infants. All infants were fed the same commercial formula, but in nine preterms the formula contained long-chain polyunsaturated fatty acids (LCPUFAs). MAIN OUTCOME MEASURES: Serum levels of adiponectin, leptin and insulin. Associations of adiponectin levels were tested only in the preterm group. RESULTS: Serum levels of adiponectin were lower in preterm (40.9 (14.8) microg/ml) than full-term infants (53.1 (16.0) microg/ml, p<0.01). However, after adjustment for body weight, the influence of prematurity on adiponectin levels was no longer significant. In preterm infants, adiponectin levels independently correlated with being born small for gestational age (SGA) (beta=-0.35

The gut hormone peptide YY 3-36 [PYY (3-36)] has been suggested to posses anorexigenic actions in animals and human adults. However, its circulating concentrations and function have not been studied in neonates. Serum concentrations of PYY (3-36) were determined by RIA (RIA) in 62 healthy preterm infants [mean(SD) gestational age, 32.0(2.1) weeks; postnatal age, 40.9(14.8 d)] and 15 healthy fullterm infants of comparable postnatal age and gender. The correlations between PYY (3-36) levels and anthropometric characteristics, food intake, growth rates and circulating concentrations of total PYY, ghrelin, leptin, insulin and adiponectin were examined. Mean (SD) PYY (3-36) concentrations were higher in preterm [543.7(157.6) ng/L) than full term infants [350.9(114.1) ng/L; p < 0.001) and accounted for 48% and 42% of total PYY basal plasma immunoreactivity in preterm and full term infants, respectively. In multiple regression analysis, PYY (3-36) concentrations correlated negatively with the infants’ BMI and positively with serum ghrelin concentrations, but not with caloric intake, weight gain or concentrations of any other hormone studied. In conclusion, PYY (3-36) represents almost half of total PYY immunoreactivity in neonates. It’s correlations with ghrelin and BMI suggest a role of this peptide in the regulation of energy homeostasis; however, its specific functions and physiologic significance in neonates remain to be elucidated.