Mild cognitive impairment is prevalent in persons with severe obesity.

Objective: This study examines the prevalence of mild cognitive impairment (MCI) in a sample of adults with severe obesity and whether undergoing bariatric surgery reduces the frequency of MCI.

Methods: A total of 171 participants with severe obesity (mean age = 43.07 ± 11.21) completed computerized cognitive testing. A subset of participants underwent bariatric surgery as part of the Longitudinal Assessment of Bariatric Surgery project. MCI was operationalized using commonly used criteria to establish prevalence in the overall sample and to examine possible changes after bariatric surgery.

Results: More than half of the overall sample met criteria for MCI at baseline (53.8%), and MCI was prevalent even in young and middle-aged adults with severe obesity. Within the subset of participants who underwent bariatric surgery, the prevalence of MCI was reduced by 48.9% at 12-month follow-up (from 53.4% to 27.3%).

Conclusions: Findings suggest that many individuals with severe obesity meet criteria for MCI and that prevalence rates decline after bariatric surgery. A better understanding of the mechanisms linking severe obesity to adverse neurological outcomes is much needed.