Postoperative cognitive dysfunction after noncardiac surgery: effects of metabolic syndrome

Abstract

Purpose: Vascular risk factors, including metabolic syndrome, are known to contribute to the development of cognitive dysfunction. We tested the hypothesis that patients with metabolic syndrome are more likely to develop cognitive dysfunction after noncardiac surgery.

Methods: Age- and education-balanced patients (n = 60) undergoing elective noncardiac surgery with and without metabolic syndrome and 30 nonsurgical controls were enrolled. Recent verbal and nonverbal memory and executive functions were assessed using a psychometric test battery before and 1 month after noncardiac surgery or at a 1-month interval in nonsurgical controls.

Results: Neurocognitive scores under baseline conditions were similar in surgical patients with versus without metabolic syndrome in all examined cognitive modalities (recent nonverbal and verbal memory, executive functions). Pronounced reductions in tests of verbal memory (delayed story recall, immediate and delayed word list recall) and executive function (backward digit span) were observed in patients with versus without metabolic syndrome after surgery. Overall cognitive performance after surgery was also significantly (P = 0.03) more impaired in patients with versus without metabolic syndrome. The prevalence rate of POCD wasdifferent in the studied groups (17/30 [corrected] and 8/30 in patientswith versus without metabolic syndrome; P < 0.02).

Conclusions: The results indicate that cognitive functions were more profoundly impaired in patients with metabolic syndrome undergoing noncardiac surgery compared with their healthier counterparts.