Bariatric Surgery Is Associated With Reduced Incidence of Mild Cognitive Impairment and Alzheimer Disease and Related Dementias: A Retrospective Cohort Study.

Objective: To evaluate the association of bariatric surgery with reduced incidence and delayed development of mild cognitive impairment (MCI) and Alzheimer disease and related dementias (ADRD) in patients with obesity. Background: This retrospective longitudinal study utilized Electronic Health Records from Vanderbilt University Medical Center, covering 5303 patients who underwent bariatric surgery and 10,606 propensity score-matched obese patients who did not, from 2000 to 2023. Patients with prior MCI, ADRD, schizophrenia, alcoholism, gastric cancer, gastric ulcers, inflammatory bowel disease, coagulopathy, stroke, Parkinson disease, or brain cancer were excluded from both groups. Methods: Differences in time to MCI/ADRD between surgical and control groups were analyzed using linear regression, and adjusted for confounders: demographics, medical history, and socioeconomic status. Survival probability differences for MCI and ADRD between the 2 groups over time were assessed using Kaplan-Meier curves and log-rank tests. Incidence differences of MCI and ADRD between the groups were evaluated using Fine-Gray subdistribution hazard models, accounting for the competing risk of death and confounders. Results: Bariatric surgery was associated with a significantly reduced incidence of ADRD, evidenced by a subdistribution hazard ratio (SHR) of 0.37 (95% confidence interval [CI]: 0.15-0.89; Conclusions: These findings suggest that bariatric surgery may serve as an effective strategy to delay the onset of MCI and reduce the risk of both MCI and ADRD in patients with obesity.