ASSOCIATION OF MILD COGNITIVE IMPAIRMENT WITH EXPOSURE TO GENERAL ANESTHESIA FOR SURGICAL AND NON-SURGICAL PROCEDURES IN OLMSTED COUNTY, MINNESOTA

Abstract

Cognitive impairment is often attributed to exposure to general anesthesia and surgery even when the temporal relationship is remote. We had the opportunity to examine the relationship of prior anesthesia and surgery to earliest manifestations of cognitive impairment using a prospective population-based cohort combined with medical record documentation of prior surgical events. The Mayo Clinic Study of Aging (MCSA) is a population-based study of individuals in Olmsted County MN who were age 70-89 years at enrollment beginning in 2004. They have been followed for a median of 4.8 years and standard criteria were used to diagnose incident MCI in the subset of individuals who were cognitively normal at baseline. Exposure to surgery and anesthesia after age 40 years of age was documented by medical record review using the facilities of the Rochester Epidemiology Project's records linkage system for Olmsted County. Thirty one percent (n=536) of 1731 initially cognitively normal individuals developed incident MCI over the period of observation. Exposure to anesthesia was not associated with incident MCI when analyzed as a dichotomous variable (HR=1.07, 95% CI 0.83-1.37) or when multiple exposures were considered. Exposure to anesthesia after age 60 years of age was weakly associated with incident MCI (HR=1.25, 95%CI 1.02-1.55, p=0.04). Overall there was no significant associations between exposure to general anesthesia beginning at age 40 years. Our results do not exclude the possibility of an association with incident MCI of exposure to general anesthesia after age 60, but the latter is confounded by the presence of underlying comorbidities that could be directly linked to dementia risk. Supported by: R01-AG034676, P50-AG16574, U01-AG006786.