Background: Whether perioperative glycemic control or markers of
inflammation is associated with neurocognitive decline (NCD) after
cardiac surgery was examined. Methods: Thirty patients undergoing
cardiac surgery utilizing cardiopulmonary bypass (CPB) were screened for
NCD preoperatively and on post-operative day four (POD4). Serum cytokine
levels were measured and human transcriptome analysis was performed on
blood samples. Neurocognitive data are presented as a change from
baseline to POD4 in a score standardized with respect to age and gender.
Results: A decline in neurocognitive function was identified in 73%
(22/30) of patients on POD4. Patients with postoperative leukocytosis
(WBC ≥ 10.5) had more NCD when compared to their baseline function
(p=0.03). Patients with elevated IL-8 levels at 6 hours postoperatively
had a significant decline in NCD at POD4 (p=0.04). Surprisingly, TNF-α,
IL-1β, IL-2, or IL-6 levels were not associated with NCD
(p>0.3 for all). There was no difference in neurocognitive
function between patients with elevated HbA1c levels preoperatively
(p=0.973) or elevated fasting blood glucose levels the morning of
surgery (>126mg/dL, p=0.910), or a higher maximum blood
glucose levels during CPB (>180mg/dL, p=0.252), or higher
average glucose levels during CPB (>160mg/dL, p=0.639).
Human transcriptome analysis demonstrated unique and differential
patterns of gene expression in patients depending on the presence of DM
and NCD. Conclusions: Perioperative glycemic control does not have an
effect on NCD soon after cardiac surgery. Postoperative leukocytosis and
elevated IL-8 levels are associated with neurocognitive decline. The
profile of gene expression was altered in patients with NCD with or
without diabetes.
Neurocognitive decline in cardiac surgery—Distraction rather than destruction?
