Evaluating the dementia risk associated with anesthesia and surgery: A comprehensive systematic review and meta-analysis

Increasing global life expectancy has expanded the surgical population, raising concerns about postoperative outcomes. Dementia, especially Alzheimer's disease (AD), poses a significant public health challenge. This meta-analysis investigates anesthesia exposure and AD risk. Following PRISMA 2020 guidelines, we systematically searched five databases (2014-2022) for observational studies evaluating dementia risk in adults ≥60 years undergoing surgery with anesthesia. Two reviewers independently screened studies, extracted data, and assessed quality using the Newcastle-Ottawa Scale. Pooled odds ratios were calculated using a random-effects model, with subgroup and publication bias analyses conducted. Significant associations with dementia included hypertension (OR 1.36, 95% CI [1.16, 1.59]), hyperlipidemia (OR 1.19 [1.16, 1.22]), coronary artery disease (OR 2.45 [1.72, 3.50]), depression (OR 1.70 [1.27, 2.27]), and head injury (OR 1.31 [1.14, 1.51]). Subgroup analyses showed mixed results for age, surgery, and medication. Kidney-ureter-bladder surgery increased risk substantially (OR 2.52 [1.10, 5.76]). Publication bias was observed. No statistically significant association was found between general anesthesia and AD risk. However, significant heterogeneity, potential publication bias, inconsistent subgroups, and challenges in isolating anesthesia effects from surgery necessitate cautious interpretation. Large prospective cohort studies with standardized methods, adequate lag time, and rigorous confounder adjustments are imperative. Perioperative care optimization for older adults at risk of cognitive decline is clinically warranted.