A new genetic study indicates that obesity and high blood pressure directly contribute to dementia, beyond merely raising its risk. Researchers from Denmark and the U.K. used advanced methods to establish this causal link, emphasizing prevention through weight and blood pressure management. The findings suggest early interventions could avert vascular-related dementia.
Dementia, a group of brain disorders including Alzheimer's and vascular dementia, leads to progressive declines in memory, thinking, and daily functioning, with no current cure. A study published online ahead of print in The Journal of Clinical Endocrinology & Metabolism reveals that high body mass index (BMI) and hypertension play direct causal roles in its development, particularly through vascular damage affecting brain blood flow and cognition. The research analyzed data from large populations in Copenhagen, Denmark, and the U.K., employing a Mendelian randomization design to mimic randomized trials by leveraging genetic variants associated with BMI and blood pressure. This approach isolates their effects from confounding factors, confirming causality rather than mere correlation. Lead author Ruth Frikke-Schmidt, M.D., Ph.D., Professor and Chief Physician at Copenhagen University Hospital -- Rigshospitalet and the University of Copenhagen, stated, 'In this study, we found high body mass index (BMI) and high blood pressure are direct causes of dementia. The treatment and prevention of elevated BMI and high blood pressure represent an unexploited opportunity for dementia prevention.' The analysis showed that much of the dementia risk from obesity stems from resulting high blood pressure, making both conditions key targets for intervention. Frikke-Schmidt added, 'This study shows that high body weight and high blood pressure are not just warning signs, but direct causes of dementia. That makes them highly actionable targets for prevention.' While weight-loss medications failed to halt cognitive decline in early Alzheimer's patients, the researchers propose testing them before symptoms emerge to potentially prevent dementia, especially the vascular type. The study, funded by Danish research bodies including the Independent Research Fund Denmark, involved collaborators from the University of Bristol and other institutions. Its DOI is 10.1210/clinem/dgaf662.
