Circulating ghrelin levels in the newborn are positively associated with gestational age
1Division of Pediatrics, Department of Medical Sciences, University of Piemonte Orientale, Novara, Italy.
Insights
Newborns have higher ghrelin levels than mothers, which increase with gestational age. This study found no link between cord ghrelin and fetal growth factors in healthy newborns.
Area of Science:
- Endocrinology
- Neonatal Physiology
- Reproductive Biology
Background:
- Ghrelin, a hormone, stimulates growth hormone (GH) release and appetite.
- Elevated ghrelin is observed in conditions like anorexia and cachexia, while it's reduced in obesity.
- Newborns typically exhibit high GH secretion, potentially linked to peripheral GH resistance indicated by low Insulin-like Growth Factor-I (IGF-I).
Purpose of the Study:
- To investigate ghrelin levels in umbilical cord blood of newborns.
- To explore the relationship between cord ghrelin and gestational age.
- To assess the correlation between newborn ghrelin and other biochemical markers relevant to fetal growth.
Main Methods:
- Measurement of ghrelin concentrations in cord blood from 117 newborns.
- Comparison of ghrelin levels between newborns and their mothers at delivery.
- Analysis of ghrelin levels in relation to gestational age, gender, and other hormones (GH, IGF-I, insulin, glucose, leptin).
Main Results:
- Cord blood ghrelin levels were significantly higher than maternal levels, with no gender disparity.
- A positive correlation was found between maternal and newborn ghrelin concentrations.
- Newborns born at term displayed substantially higher ghrelin levels compared to preterm infants, indicating a positive association with gestational age.
Conclusions:
- Cord ghrelin levels demonstrate a clear dependence on gestational age.
- The absence of a direct correlation between ghrelin and anthropometric or biochemical parameters in newborns suggests ghrelin may not play a significant role in fetal GH secretion or growth.
Objective:
Ghrelin exerts potent GH-releasing activity and stimulates food intake. Circulating ghrelin levels are increased in anorexia and cachexia, reduced in obesity and restored by weight recovery. Newborns are characterized by GH hypersecretion associated with low IGF-I levels reflecting peripheral GH resistance.
Study Design:
The aim of our study was to measure cord ghrelin levels in 117 newborns appropriate for gestational age, born either at term or preterm.
Results:
Ghrelin levels in cord blood (median; 25th-75th centile: 327.6; 206.0-413.0 pg/ml) were higher (P < 0.0001) than those in maternal blood at delivery (133.0; 89.0-173.7 pg/ml), without gender differences. A positive correlation between ghrelin levels in mothers and newborns (r = 0.26, P < 0.01) was observed. Ghrelin levels in newborns born at term (399.0; 229.0-438.0 pg/ml) were remarkably higher (P < 0.0001) than those in born preterm (208.0; 144.5-278.9 pg/ml). A clear positive association was present between ghrelin levels and gestational age. No association between ghrelin and GH, IGF-I, insulin, glucose and leptin levels were found.
Conclusions:
Cord ghrelin levels show clear gestational age-related dependency. The lack of any direct relationship between ghrelin and anthropometric or biochemical parameters in adequate for gestational age newborns does not support the hypothesis that ghrelin has major role in foetal GH secretion and growth.
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