Ghrelin

Ghrelin is a 3.5-kDa protein of 28-amino-acid peptide that is the natural ligand for the growth hormone secretagogue receptor. Based on its structure, it is a member of the motilin family of peptides. When administered peripherally or into the CNS, ghrelin stimulates secretion of growth hormone, increases food intake, and produces weight gain. Ghrelin, which is produced by the stomach, increases during periods of fasting or under conditions associated with negative energy balance such as starvation or anorexia. In contrast, ghrelin levels are low after eating or with hyperglycemia and in obesity. Accumulating evidence indicates that ghrelin plays a central role in the neurohormonal regulation of food intake and energy homeostasis.

Normal range (fasting plasma levels): approximately 550 " “650 pg/mL.

Interpretation

Increased In

Fasting

Cachexia and anorexia

Decreased In

After eating

Limitations

This test is not available routinely in many commercial clinical laboratories.