The Role of Insulin Resistance in the Development of Complications after Coronary Artery Bypass Grafting in Patients with Coronary Artery Disease

The aim of the study was to investigate the effect of carbohydrate metabolism disorders and insulin resistance indices on the immediate results of coronary artery bypass grafting (CABG). Method. Patients with coronary artery disease who underwent CABG (n = 383) were examined to determine glycemic status, free fatty acid and fasting insulin levels, and insulin resistance indices (Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), McAuley index, Quantitative Insulin Sensitivity Check Index (QUICKI), Revised-QUICKI). Patients were assessed for the development of perioperative complications and their length of stay in the hospital. Two groups were formed: group 1, patients with a combined endpoint (CEP, any complication and/or duration of hospital stay >10 days), n = 291; and group 2 (n = 92) without a CEP. Perioperative characteristics were analyzed, and predictors of hospital complications and prolonged hospital stay were evaluated. Results. Patients in the CEP group were older, and there were more women among them (p = 0.003). Additionally, in this group, there were more patients with diabetes mellitus (37.5% vs 17.4%, p < 0.001), obesity (p < 0.001), and a higher percentage of combined operations (p = 0.007). In the group with a CEP, the levels of glucose (p = 0.031), glycated hemoglobin (p = 0.009), and free fatty acids (p = 0.007) and the Revised-QUICKI (p = 0.020) were higher than in the group without complications. In a regression analysis, the independent predictors of complications were combined operations (p = 0.016) and the predictors of a long hospital stay (>14 days) were female gender, the left atrium size, and diabetes mellitus (p < 0.001). The predictors of a composite endpoint included female gender, age, the left atrium size, and free fatty acid levels (p < 0.001). Conclusions: In the group with in-hospital complications after CABG, not only was the presence of diabetes mellitus more often detected, but there were also higher levels of free fatty acids and a higher Revised-QUICKI. Therefore, additional assessments of insulin resistance and free fatty acid levels are advisable in patients before CABG.