Alpha-Melanocyte-stimulating hormone and agouti-related protein: Do they play a role in appetite regulation in childhood obesity?

Objective: the hypothalamus plays a crucial role in the regulation of feeding behavior. the anorexigenic neuropeptide alpha-melanocyte-stimulating hormone (α-msh) and the orexigenic neuropeptide agouti-related protein (agrp) are among the major peptides produced in the hypothalamus. this study investigated the plasma concentrations of α-msh and agrp in underweight and obese children and their healthy peers. the associations between α-msh and agrp levels and anthropometric and nutritional markers of malnutrition and obesity were also assessed. methods: healthy sex-matched subjects aged 2 to 12 years were divided into 3 groups,as underweight (n=57),obese (n=61),and of normal weight (n=57). plasma fasting concentrations of α-msh and agrp were measured by enzyme-linked immunosorbent assay. the differences between the three groups as to the relationships between plasma concentrations of α-msh and agrp and anthropometric data,serum biochemical parameters and homeostatic model assessment of insulin resistance were evaluated. results: obese children had significantly lower α-msh levels than underweight (1194±865 vs. 1904±1312 ng/ml,p=0.006) and normal weight (1194±865 vs. 1762±1463 ng/ml,p=0.036) children; there were no significant differences in the α-msh levels between the underweight and normal weight children (p=0.811). also,no significant differences were observed between the underweight and obese children regarding the agrp levels (742±352 vs. 828±417 ng/ml,p=0.125). we found a significant positive correlation between plasma α-msh and agrp levels across the entire sample. conclusion: this study is the first to demonstrate body weight-related differences in α-msh and agrp levels in children. circulating plasma α-msh levels in obese children were markedly lower than those of underweight and normal-weight children. this suggests that α-msh could play a role in appetite regulation. © 2016,journal of clinical research in pediatric endocrinology,published by galenos publishing.