AIMS OF THE STUDY: The aim of this study is to assess the level and the effects of perioperative insulin resistance on clinical outcome in cardiac surgery patients. Based on previous studies suggesting glucose homeostasis and insulin resistance are associated with severity of illness and outcome in critically ill patients,it is proposed that patients with marked insulin resistance suffer from worse clinical outcome. This study protocol evaluates the ability of homeostasis model assessment (HOMA), quantitative insulin sensitivity check index (QUICKI), HbA1c, the adipokines Angiopoietin-like protein 2 (ANGPTL2), C-X-C motif chemokine 5 (CXCL5), and visfatin, and the myokine irisin to indicate perioperative insulin resistance and explores for correlation with adverse clinical outcomes after 30 days.