Serum ghrelin concentration and weight gain in healthy term infants in the first year of life

Objectives: Ghrelin, a recently discovered hormone mainly secreted by the stomach, has several metabolic functions including regulation of food intake, energy homeostasis and body weight. There are few studies on this hormone in healthy infants during the first year of life. The aim of this study was to examine the correlations between ghrelin and weight gain in healthy term infants in the first year of life. Methods: 104 healthy term infants aged 0 to 12 months were included in a cross-sectional study. Anthropometric measurements were assessed and mean weight gain was calculated. Serum ghrelin concentrations have been determined at least 3 hours after feeding by radioimmunoassay test. Results: Ghrelin concentrations were correlated negatively to weight gain (r = -0.302; P = 0.003) and positively to age (r = 0.412; P < 0.001), weight (r= 0.374; P < 0.001) and length (r = 0.387; P < 0.001). In breastfed infants a statistically significant negative correlation between ghrelin concentration and infant weight gain (r = -0.407; P = 0.001) was observed, whereas in formula-fed infants this correlation was not statistically significant (r = -0.067; P = 0.719). Conclusions: The negative correlation observed between ghrelin concentration and infant weight gain suggests that ghrelin might also play a role in the regulation of body weight in healthy infants with a physiologic energy balance. Further studies are needed to clarify how ghrelin might be involved in both short-term and long-term energy balance.