The relationship between serum ghrelin levels and hair zinc concentrations in children

Abstract

Zinc (Zn) plays a central role in the activation of numerous enzyme systems that synthesize and degrade bioactive peptides. Some of these bioactive peptides, also called neuropeptides, are involved in the regulation of food intake. In this study we aimed to demonstrate the relationship between serum ghrelin and hair Zn concentrations in children. Prepubertal children brought to our outpatient clinics by their parents because of signs and symptoms of pica, poor appetite, poor growth, and other complaints were included in the study. The children were divided into two groups according to Zn hair concentrations. Group 1 consisted of children with low (< 70 μg/g) hair Zn levels, and group 2 of children with normal ( ≥ 70 μg/g) hair Zn levels. Hair Zn concentrations, serum ghrelin, insulin-like growth factor I (IGF-I) and IGF-binding protein-3 (IGFBP-3) levels were measured in all children. There were 10 children with low hair Zn levels (group 1) and 15 with normal levels (group 2). Serum IGF-I, IGFBP-3 and ghrelin concentrations of group 1 (103.1 ± 71.8 ng/mL, 1412.8 ± 615.7 ng/mL and 0.96 ± 0.22 ng/mL, respectively) were lower than in group 2(164.9 ± 40.5 ng/mL, 2398.5 ± 295.5 ng/mL and 1.21 ± 0.23 ng/mL, respectively). In univariate analysis, Zn hair concentration was positively associated with serum IGF-I (r=0.424, p=0.035) and IGFBP-3 (r=0.671, p < 0.001) concentrations. The correlation between ghrelin and hair Zn concentrations was not significant (r=0.202, p=0.333). Serum ghrelin concentrations might be affected by low hair Zn concentrations in children.