Intraoperative Hyperglycemia and Cognitive Decline After CABG

Background: Neurocognitive dysfunction (NCD) continues to occur in a significant number of patients after cardiac procedures. The factors influencing its incidence and severity are not completely known. We hypothesized that hyperglycemia, which is known to exacerbate other forms of cerebral injury, may exacerbate NCD after cardiac operations. Methods: A total of 525 patients having on-pump coronary artery bypass graft (CABG) procedures underwent cognitive testing at baseline and 6 weeks postoperatively. Multivariable linear regression was used to determine the relationship between NCD and intraoperative hyperglycemia (glucose ≥200 mg/dL). Diabetic and nondiabetic patients were analyzed separately to eliminate a possible confounding effects between diabetes and hyperglycemia. Results: In the nondiabetic patients, even after controlling for age, years of education, and baseline cognitive function, hyperglycemia was associated with a decrease in cognitive function at 6 weeks (p = 0.0351). Hyperglycemia had no effect on cognitive function in diabetic patients, however. Conclusions: These findings suggest that in nondiabetic patients undergoing CABG operations, intraoperative hyperglycemia is associated with an increased risk of NCD.