Surgery Is Not Associated With Early Presentation of Alzheimer's Disease and Mild Cognitive Impairment or Increased Risk for Both.

backgroundAlzheimer's disease (AD) is the most common form of dementia in elderly patients. Mild cognitive impairment (MCI) may be a prodromal status of AD. Previous studies show inconsistent findings on whether surgery increases MCI and AD incidence. Moreover, it remains unknown whether surgery expedites the development of MCI or AD.

methodsThis was a retrospective propensity score-matched cohort study using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database between September 2005 (ADNI initiation time) and May 2025 (time of data downloaded). Two outcomes were assessed: age at first diagnosis of MCI or AD, and incidence of MCI or AD. Nearest-neighbor matching was used to balance demographic and comorbidity covariates.

resultsThe study was composed of 1114 subjects with MCI, 760 subjects with AD, and 397 subjects with normal cognition. Surgery was not associated with a decrease in the age of patients when MCI was diagnosed but was associated with a delayed presentation of AD by 1.7 years. Surgery performed on patients younger than 60 years was associated with a decrease in age when the first diagnosis of MCI or AD was made. Surgery at an age older than 60 years was associated with an increase in the age at MCI or AD diagnosis (mean difference: 5.1 and 5.6 years, respectively). Surgery was not associated with a change in the incidence of MCI or AD.

conclusionSurgery may be associated with delayed presentation of AD or MCI, except for the surgery performed in patients younger than 60 years. Surgery may not affect the incidence of MCI or AD. These findings do not support deferring clinically indicated surgery for the concern of development of MCI or AD.