Ghrelin, obestatin are peptides that play a vital role in maintaining energy homeostasis. Eating disorders such as anorexia nervosa and bulimia nervosa hamper the secretion of these peptides.
Neuropeptide Y (NPY) is a peptide neurotransmitter that is found in autonomic nervous system and brain and is concerned with energy regulation. Peptide YY (PYY) is a protein released by the cells of colon and ileum. In human beings it reduces the appetite. Peptide YY (PYY) is also known as peptide tyrosine tyrosine or pancreatic peptide YY3-36.
AdvertisementDana Sedlackova and colleagues conducted a study that was published in the journal BMC Nutrition and Metabolism, 2012, to compare the effect of high carbohydrate and high protein breakfast on plasma ghrelin, obestatin, NPY and PYY in women with anorexia nervosa and bulimia.
The plasma levels of gut-brain axis peptides ghrelin, obestatin, NPY and PYY were recorded after the intake of high-protein and high-carbohydrate breakfast in healthy controls and in patients with anorexia nervosa and bulimia.
The plasma hormone levels were determined by RIA kits and blood samples were taken from the cubital vein. The first blood sample was taken before breakfast and then after 30, 60, 90,120 and 150 minutes after the intake of breakfast.
The scientists observed that plasma ghrelin levels were increased in anorexia nervosa patients while fasting and post-prandial plasma obestatin levels were raised in both bulimia and anorexia nervosa patients. After breakfast, the plasma levels of ghrelin and obestatin decreased but were still above the range of normal healthy controls. In anorexia nervosa and bulimia patients, the levels of neuropeptide Y (NPY) were recorded high and it did not change postprandially.
After the intake of a high protein breakfast the peptide YY (PYY) levels increased in bulimia nervosa and anorexia nervosa patients. In all the groups the reactions to breakfast were identical for obestatin and neuropeptideY (NPY) while the reactions were different for ghrelin and peptide YY (PYY).
It was concluded that different reactions to breakfast for peptide YY (PYY) and ghrelin are indicative of the role these hormones play in energy homeostasis regulation and it can be used in managing acute eating disorders. In anorexia nervosa and bulimia nervosa patients, obestatin and neuropeptide Y (NPY) act as eating disorder markers.
Comparison of a high-carbohydrate and high-protein breakfast effect on plasma ghrelin, obestatin, NPY and PYY levels in women with anorexia and bulimia nervosa; Dana Sedlackova et al; Nutrition and Metabolism 2012