Diabetes mellitus is associated with an increased risk of postoperative neurocognitive disorders: a systematic review

Background: Diabetes mellitus (DM) is increasingly recognized as an independent risk factor for perioperative neurocognitive disorders (PND). The rising global incidence of DM, projected to affect over 783 million people by 2045, necessitates a deeper understanding of its implications for surgical outcomes. Methods: This review conducted a bibliometric analysis of 182 studies indexed in the Web of Science, focusing on the relationship between DM and PND. A systematic search was performed across multiple electronic databases, including PubMed and The Cochrane Library, to identify relevant articles published up to November 2024. Results: The analysis revealed that DM significantly increases the risk of PND, particularly POD, with studies indicating a 1.84-fold increased risk of POCD in diabetic patients. Key mechanisms identified include vascular brain injury, impaired glucose metabolism, inflammation, and oxidative stress. Notably, countries such as China, the USA, and Germany are leading research efforts in this area, highlighting a global interest in understanding these associations. Conclusion: Further research is needed to elucidate causal mechanisms between DM and PND. Enhanced understanding of these mechanisms may inform targeted interventions to mitigate the risk of cognitive decline in diabetic patients undergoing surgery, ultimately improving patient outcomes and reducing healthcare burdens.