People with obesity who underwent bariatric surgery had stable cognition two years later, researchers at the University of Michigan (UoM) have found.
The findings suggest that bariatric surgery may mitigate the natural history of cognitive decline expected in people with obesity, the researchers said.
The study is published in the Journal of Nutrition, Health & Aging.
First author Evan Reynolds, Ph.D. is lead statistician for the NeuroNetwork for Emerging Therapies at Michigan Medicine.
The researcher said: “Since individuals with obesity experience more rapid cognitive decline than those without, stable cognition two years after bariatric surgery may be considered a success against historical trends, yet future controlled trials are needed to test this.”
Using a collection of memory and language tests developed by the National Institutes of Health (NIH), as well as the Rey Auditory Verbal Learning Test, the researchers assessed over 85 bariatric surgery patients at two-year follow up.
The researchers found that NIH Cognitive Battery test scores remained stable, with secondary executive function tests showing improvement.
However, one of the memory assessments declined following surgery.
While the current study is the largest to assess changes two years after bariatric surgery, researchers said, the results conflict with previous studies which found improved memory and executive functioning among similar patients.
Reynolds said: “That study was primarily made up of patients who received gastric bypass, while our study was made up primarily of individuals that completed a sleeve gastrectomy.
“To provide the best evidence on the effectiveness of bariatric surgery on cognition and potential differences between surgery types, we must conduct larger observational studies or randomised, controlled trials.”
Following bariatric surgery, improvements in diabetes complications, such as peripheral neuropathy, chronic kidney disease and retinopathy, were not associated with improved cognition.
Senior author Brian Callaghan, M.D is a neurologist at University of Michigan Health and the Eva L. Feldman., M.D, Ph.D., professor of neurology at U-M Medical School.
He said: “Metabolic factors, including diabetes and obesity, are associated with cognitive decline, but we still need to better understand how best to treat these factors to improve patients’ cognitive outcomes.”
