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 for assessing gastrointestinal function in these patients. Research has shown patients with enteral feeding intolerance demonstrated altered ghrelin levels (1), however another study found no correlation between ghrelin and enteral feeding intolerance measured by gastric residual volume (2). Several moieties of ghrelin are present in the human body. Acyl ghrelin was previously thought to be the active hormone; however recent evidence suggests that des-acyl ghrelin also possesses activity, and the enzyme ghrelin-Oacyl transferase regulates their interconversion (3).
References:
- Crona D, MacLaren R. Gastrointestinal hormone concentrations associated with gastric feeding in critically ill patients. JPEN – J Parenter Enter Nutr 2012;36(2):189e96.
- Santacruz CA, Quintairos A, Righy C, Crippa IA, Couto L, Imbault V, et al. Is there a role for enterohormones in the gastroparesis of critically ill patients? Crit Care Med 2017;45(10):1696e701.
- Pinkney J. The role of ghrelin in metabolic regulation. Curr Opin Clin Nutr Metab Care 2014;17(6):497e502.