GHRELIN LEVELS AND WEIGHT GAIN IN THE FIRST YEAR OF LIFE

Abstract

Aim: Ghrelin is a 28-amino acid peptide mainly secreted by the stomach and involved in the regulation of food intake. It has been described as a regulator of energy balance and in infancy higher ghrelin levels have been detected in small for gestational age (SGA) neonates. Information about the role of ghrelin in the regulation of energy homeostasis and body weight in healthy infants in the first year of life is scanty. The aim of our study was to evaluate the correlation between ghrelin levels and weight gain in the first year of life. Methods: We studied 93 AGA healthy infants (52 males, 41 females) aged 1-12 months seen in our Department, without chronic or acute gastrointestinal disease. Serum ghrelin concentrations have been determined at least 3 hours after feeding by RIA test (R-90, Mediagnost, Reutlingen, Germany). Mean weight gain was calculated as the difference between the weight at the day of blood sampling and birth weight, divided by the age in days. The study was approved by the hospital's Ethical Committee and parents gave their written consent. Statistical analysis was performed by Pearson's correlation (p < 0.05). Ghrelin values have been normalized with natural logarithm (nl). Results: Our study sample had a mean age of 197.52 ± 116.19 days, with mean ghrelin level of 3026.01 ± 1386.37 pg/ml and mean ln of ghrelin of 7.92 ± 0.44; the weight gain had a mean value of 23.09 ± 8 g/day. In the study group we have observed a significant negative correlation between ghrelin levels and weight gain (r = -0.302; p = 0.003) (Fig. 1).Figure 1: Correlation between ghrelin levels and weight gain.Summary: In our cross-sectional study we have enrolled 93 healthy infants aged 1-12 months. We have observed a negative correlation between ghrelin levels and weight gain. Conclusions: Our findings show that infants who have gained more gram for day have lower ghrelin levels than those who have gained less. Considering that ghrelin levels are reported to be increased in anorexia nervosa and after fasting, whereas in obese patients and after feeding they are decreased, we could hypothise that also in healthy infants in the first year of life ghrelin may change as part of an adaptive response to a condition of positive energy balance.