Peri-operative dysglycaemia and plasma glucose control on the risk of developing post-operative neurocognitive disorders: A systematic review

Title : Peri-operative dysglycaemia and plasma glucose control on the risk of developing post-operative neurocognitive disorders: A systematic review

Abstract:

Background: The neurocognitive disorders of post-operative delirium (POD) and post-operative cognitive dysfunction (POCD) increase morbidity and mortality in patients. This article aims to perform a comprehensive systematic review of current literature to assess whether peri-operative dysglycaemia increases the risk of such neurocognitive disorders, analyse the trends of glucose levels that increase the risk to a higher degree, and appraise glucose management protocols for reducing the risk of cognitive deficits.
Methods: Registered with PROSPERO (ID: CRD420251153796). Following PRISMA guidelines, searches were conducted in MEDLINE, Embase, Web of Science, and Cochrane Library October 2025. Primary studies of adult surgical patients with sufficient peri-operative glycaemic measurements and cognitive assessments were included. Critical appraisal was conducted using ROBINS-E and Rob 2 risk of bias tools. A narrative synthesis of the results was conducted.
Results: Five cohort studies and one randomised controlled trial were included, aggregating data from 3358 patients. Peri-operative dysglycaemia was associated with an increased risk of both POD and POCD. Patients without diabetes developed cognitive deficits at lower levels of hyperglycaemia than patients with diabetes. Patients on a tight intra-operative glucose control protocol compared to liberal had a decreased incidence of long-term POCD. High glycaemic variability intra-operatively, and 24 hours post-operatively, was implicated with a higher incidence of POD.
Conclusion: Reducing peri-operative glucose variability could protect against POD and POCD development. Due to considerable heterogeneity of outcome measurements across the studies, further research is warranted to draw firm conclusions, with the aim of optimising peri-operative blood glucose control in the future.

Keywords: Glucose control, peri-operative hyperglycaemia, peri-operative hypoglycaemia, post-operative cognitive dysfunction, post-operative delirium

Biography:

Gurleen Athwal completed her BMSc at University of Western Ontario in 2022 and is a current 3rd year medical student at Warwick Medical School. She has always had an interest in neurology and in studying CNS injury and decline, topics that were explored in her undergraduate thesis and most recent systematic review.