Surgery is associated with ventricular enlargement as well as cognitive and functional decline

Introduction: In preclinical studies, surgery/anesthesia contribute to cognitive decline and enhance neuropathologic changes underlying Alzheimer's disease (AD). Nevertheless, the link between surgery, anesthesia, apolipoprotein E epsilon 4 (APOE epsilon 4), and AD remains unclear. Methods: We performed a retrospective cohort analysis of two prospective longitudinal aging studies. Mixed-effects statistical models were used to assess the relationship between surgical/anesthetic exposure, the APOE genotype, and rate of change in measures of cognition, function, and brain volumes. Results: The surgical group (n = 182) experienced a more rapid rate of deterioration compared with the nonsurgical group (n = 345) in several cognitive, functional, and brain magnetic resonance imaging measures. Furthermore, there was a significant synergistic effect of anesthesia/surgery exposure and presence of the APOE epsilon 4 allele in the decline of multiple cognitive and functional measures. Discussion: These data provide insight into the role of surgical exposure as a risk factor for cognitive and functional decline in older adults. (C) 2015 Alzheimer's Association. Published by Elsevier Inc. All rights reserved.