Effect of intensive insulin therapy on inflammatory response after cardiac surgery using bedside artificial pancreas: a propensity score‐matched analysis

Background Perioperative hyperglycemia leads to poor postoperative clinical outcomes, including compromised immune function, cardiovascular events, and mortality. The optimal perioperative blood glucose levels during cardiac surgery remain unclear. A closed-loop glycemic control system (artificial pancreas, target blood glucose range:120-150 mg/dl) prevents postoperative inflammatory response more effectively than conventional insulin therapy (<200 mg/dl). However, the clinical effects of intensive insulin therapy with strict glycemic control (80-110 mg/dl) are controversial. This study aimed to determine whether intensive insulin therapy would further suppress postoperative inflammatory reactions. Methods This study analyzed 262 patients who underwent cardiovascular surgery with cardiopulmonary bypass. The patients were divided into two groups according to their target blood glucose range: 80-110 mg/dl and 120-150 mg/dl. The primary outcome was the difference in the C-reactive protein levels between the two groups. Results Propensity score matching resulted in 95 patients in each group based on their covariates. There was no difference in the postoperative maximum C-reactive protein levels between the two groups (14.81 +/- 5.93 mg/dl vs. 14.34 +/- 5.52 mg/dl; p = 0.571) following propensity score matching. Hypoglycemia did not occur during intensive insulin therapy. Conclusions Intensive insulin therapy following cardiac surgery with cardiopulmonary bypass did not demonstrate significant advantages in the suppression of postoperative inflammatory reactions compared to that with mild glycemic control. However, intensive insulin therapy using an artificial pancreas was found to be safe, with no hypoglycemic events.