The effects of bariatric surgery on dementia in patients with diabetes and obesity

Why clinicians should know about it

• Picked for Bariatric and Metabolic Surgery (paper of the day, 25 August 2026): Propensity‑matched cohort, bariatric surgery reduces dementia risk

Abstract

INTRODUCTION: Type 2 diabetes (T2D) and obesity are among the most important risk factors for dementia. Although weight loss is an important preventive strategy, the impact of metabolic and bariatric surgery (MBS) on dementia risk remains contradictory. METHODS: We conducted a propensity score matched study using nationwide, high-quality clinical registries to compare the outcomes in patients with obesity and T2D who underwent MBS with matched controls who did not undergo surgery. RESULTS: Over a mean follow-up of 9 years, MBS was associated with a reduced risk of dementia (15-year cumulative incidence 1.8% vs. 2.7%, subdistribution hazard ratio [SHR] 0.60, 95% CI 0.47-0.76). The incidence was lower for Alzheimer's disease (1.2% vs. 1.9%, SHR 0.56, 95% CI 0.41-0.76) and vascular dementia (0.4% vs. 0.7%, SHR 0.49, 95% CI 0.29-0.85), but increased for alcohol-related dementia (0.2% vs. 0.04%, SHR 3.67, 95%CI 1.33-10.14). DISCUSSION: These findings suggest that the collected long-term effects of MBS may reduce the risk of developing dementia in individuals with obesity and T2D.

Abstract as published, via PubMed.