PYY (peptide YY) is a hormone produced by the gastrointestinal tract that regulates appetite and food intake. PYY is released from the enteroendocrine cells of the small intestine in response to the presence of nutrients. PYY levels in the blood […]


Ghrelin is a hormone produced by the stomach that stimulates appetite and regulates energy balance. In critically ill patients, ghrelin levels may be reduced, which can contribute to delayed gastric emptying and feeding intolerance. Monitoring ghrelin levels may be useful […]


GDF15 is a stress response cytokine that is induced by injury and inflammation (Tsai et al 2018, Luan et al 2019). Increased levels of GDF15 have been observed in critically ill patients, anorexia nervosa, cancer cachexia and obesity (Clark et […]