Clinical and predictor significance of alternative markers of carbohydrate metabolism in patients with disorders of carbohydrate metabolism under elective coronary bypass surgery

Introduction: All patients with diabetes are recommended to determine glycated hemoglobin no earlier than 3 months before any surgical interventions, including before coronary bypass surgery. Patients with multivessel coronary disease often have a severe comorbid background. Factors such as anemia, bleeding, severe chronic kidney disease in patients with can affect the result of measuring HbA1c, due to these limitations, alternative markers may be useful: fructosamine, 1,5-anhydroglucitol, which reflect the glucose level for 1-3 weeks previous research.Target. The study of alternative markers of carbohydrate metabolism (fructosamine and 1,5-anhydroglucitol (1,5-AG)), and their relationship with the clinical characteristics of patients and the incidence of hospital complications after coronary bypass grafting (CABG).Materials and methods. 383 consecutive patients with ischemic heart disease who underwent elective CABG at one center were examined. Before surgery, all patients were examined for glycemic status and additionally determined glycated hemoglobin (HbA1c), fructosamine and 1,5-anhydroglucitol before CABG and on days 7-8 after surgery. Patients were divided into 3 groups depending on their glycemic status: Group 1 - patients with type 2 diabetes mellitus (DM 2, n=125), Group 2 - patients with prediabetes (n=67), Group 3 - patients without disorders carbohydrate metabolism (n=191). We assessed the perioperative dynamics of carbohydrate metabolism parameters, their relationship with the clinical characteristics of patients and postoperative complications.Results. In groups without DM, the values of glucose, fructosamine, and 1,5-anhydroglucitol had a small interquartile range when assessed before surgery, which significantly increased on days 7-8 after CABG. In all 3 groups, there was a significant decrease in the level of fructosamine on the 7th day after CABG compared with the baseline (p 1-2nd point 0.030, 0.001, 0.038 in groups 1, 2 and 3, respectively), while level 1 ,5-anhydroglucitol and HbA1c did not change significantly after surgery. The preoperative level of fructosamine had a direct correlation with the risk of surgery according to the EuroSCORE II scale (p=0.002), the number of shunts (p=0.012), body mass index and overweight (p<0.001 in both cases), triglycerides (p<0.001), fibrinogen (p=0.002), preoperative and postoperative glucose and HbA1c levels (p<0.001 in all cases), left atrial size (p=0.028), number of cardioplegia, duration of cardiopulmonary bypass, and time of aortic clamping (p<0.001 in all cases) . Preoperative 1,5-anhydroglucitol levels were inversely correlated with preoperative fasting glucose and fructosamine levels (p<0.001 in all cases), intima-media thickness (p=0.016) and positively correlated with LV end-diastolic volume (p=0.020) . Any significant postoperative complication and/or hospital stay after CABG >10 days was selected as the composite endpoint (CCT). In binary logistic regression analysis, fructosamine levels were independently associated with the development of this composite endpoint. Also, independent predictors of CCT were: female gender, age, body mass index, duration of cardiopulmonary bypass, size of the left atrium, end diastolic size of the left ventricle, DM 2, average glycemia on the 1st day after CABG, failure to achieve the target range of perioperative glycemia. At the same time, other markers of carbohydrate metabolism showed no connection with CCP.Conclusions. The preoperative level of fructosamine, the average glycemia on the 1st postoperative day are independent predictors of postoperative complications of CABG.