Overweight people may face higher risk of vascular dementia, study finds

A University of Bristol-led study using genetic analysis found a causal link between higher body mass index and an increased risk of vascular-related dementia, with about a quarter of the excess risk associated with high blood pressure.

A new study led by the University of Bristol reports a direct association between higher body mass index (BMI) and vascular-related dementia. The research used genetic methods to separate the effect of BMI from other lifestyle factors and analysed data from more than 500,000 people in Copenhagen and the UK. Authors and experts involved said high BMI and high blood pressure emerged as direct causes of vascular dementia in their analyses. They also noted uncertainty about whether early use of weight-loss medications will reduce dementia risk and said further testing is needed. Key findings: - The study used Mendelian randomisation to examine genetic links between higher BMI and dementia risk, finding evidence of a causal relationship with vascular-related dementia. - Researchers analysed data from over 500,000 participants across Copenhagen and the UK to generate population-representative results. - Around one quarter of the increased dementia risk associated with higher BMI appeared to be driven by high blood pressure. - Study authors said it remains to be tested whether initiating weight-loss treatments before cognitive symptoms would protect against dementia and reported no proven benefit yet for early weight-loss medication in preventing cognitive decline. Summary: The study indicates that higher BMI and hypertension are linked to increased risk of vascular-related dementia and highlights those factors as potential targets for population-level prevention efforts. Further research was announced as needed to test whether early weight-loss interventions or blood pressure management can reduce dementia risk; the timeline and outcomes of such tests are undetermined at this time.