326 Relationship Between Serum Ghrelin Concentration and Kind of Feeding, Age and Weight Gain During the First Year of Life

Abstract

Background: Ghrelin, a 28 amino-acid peptide mainly secreted by the stomach, displays different metabolic functions such as the regulation of food intake. Evidences about how early feeding mode could modify ghrelin concentrations are scanty. Aim: To evaluate ghrelin levels in breast-fed (BF) and formula-fed (FF) infants in the first year of life and the correlations between ghrelin and age, gender and weight gain. Methods: We studied 100 healthy infants aged 0–12 months, recruited to our Department between June 2002 and June 2004, without gastrointestinal disease. Serum ghrelin concentrations have been determined at least 3 hours after feeding by RIA test (intra-assay 5%, inter-assay 7.6%) (Ghrelin (Total) RIA-3967, DRG, Germany). Weight gain was calculated as the ratio of the difference between infant weight at the day of the inclusion in the study and the birth weight and the age (days). Ethical Committee approved the study and parents gave written consent. Statistical analysis: Student t-test and multiple regression analysis; statistical significance set at p<0.05. Ghrelin values have been normalized with natural logarithm. Results: Mean ghrelin value ± Standard Deviation in the study group was 3026.0 ± 1386.4 pg/ml. A significant difference in ghrelin concentration between BF and FF infants was observed in the first 4 months of life (p< 0.01): BF infants had lower plasma ghrelin concentration (1974.09 ± 620.17 pg/ml) than FF ones (2609.37 ± 738.48 pg/ml). Ghrelin concentration increased with the infant age and was correlated negatively with weight gain (r= -0.302) and positively with age (r= 0.412). Conclusions: Our results support the hypothesis that plasma ghrelin concentrations are influenced by the type of feeding in the first 4 months of life. Further researches are needed to better clarify how this hormone could be involved in short-term and long-term energy balance in infancy.