Leptin: A new predictor of outcome in the patients undergoing traditional on-pump CABG surgery?

Abstract

Leptin, a 16 kDa peptide product of the obese gene, is an adipocyte-derived cytokine-like molecule which is structurally related to the IL-6 cytokine family. Through its interaction with its receptor Ob-R, a member of the class I cytokine receptor family which is ubiquitously expressed including endothelium, vascular smooth muscle and myocardium, leptin plays a role in a wide range of biological responses such as control of body weight and energy expenditure, neuroendocrine function, angiogenesis, bone formation, modulating immune responses. More and more studies indicated that leptin may be involved in the acute stress response to severe illness and surgery by way of its interaction with hypothalamic–pituitary–adrenal axis and the inflammatory cytokine system. Systemic inflammatory response (SIR) is one of the common complications after on-pump coronary artery bypass grafting in which the severity of SIR directly correlates with the outcome and prognosis. We based our hypothesis on that leptin may participate in the acute stress-SIR induced by on-pump coronary artery bypass grafting and its levels and secretion patterns might be related to the extent of activation of SIR and might serve as marker of the severity and predict the outcome.