NEW DELHI: People with obesity and high blood pressure may face a higher risk of dementia, according to a new study.
Published in The Journal of Clinical Endocrinology and Metabolism, the study said, dementia is a devastating neurodegenerative disease currently affecting 50 million individuals worldwide, with a steep increase in prevalence.
Highlighting that treatment and prevention options for dementia are scarce, the study flagged the importance of reducing risk factors, like high BP and obesity, which is a growing health problem affecting more than 600 million individuals globally.
People with dementia experience a severe decline in mental abilities, like memory, thinking and reasoning.
The most common forms of dementia are Alzheimer's disease, vascular dementia and mixed dementia. Dementia is a progressive brain disease that causes nerve cell damage that worsens over time, affecting memory, language, problem-solving and behaviour.
“In this study, we found high body mass index (BMI) and high blood pressure are direct causes of dementia,” said study author Ruth Frikke-Schmidt, Professor and Chief Physician at Copenhagen University Hospital - Rigshospitalet and the University of Copenhagen in Copenhagen, Denmark.
“The treatment and prevention of elevated BMI and high blood pressure represent an unexploited opportunity for dementia prevention.”
The researchers analysed data from participants in Copenhagen and the UK and identified a causal link between higher body weight and dementia.
The researchers were able to establish a direct causal link between high BMI and dementia because they used a so-called Mendelian randomisation design that mimics a randomised controlled trial.
In the Mendelian randomisation study design, common genetic variants causing high BMI are used as proxies for BMI-altering medications.
As active drug versus placebo is randomly assigned due to the randomisation process in drug trials, and as BMI-increasing genetic variants versus neutral variants are randomly assigned from parents to offspring, the effects on the disease endpoint will be clear and not affected by confounding factors.
Therefore, this strategy enabled the researchers to establish a direct causal link between high BMI and risk of dementia.
Much of this increased dementia risk appeared to be driven by high blood pressure, suggesting that preventing or treating obesity and high blood pressure could help reduce dementia risk.
“This study shows that high body weight and high blood pressure are not just warning signs, but direct causes of dementia,” Frikke-Schmidt said. “That makes them highly actionable targets for prevention.”
“Weight-loss medication has recently been tested for halting cognitive decline in early phases of Alzheimer’s disease, but with no beneficial effect. An open question that remains to be tested is if weight-loss medication initiated before the appearance of cognitive symptoms may be protective against dementia. Our present data would suggest that early weight-loss interventions would prevent dementia, and especially vascular-related dementia,” she added.
Obesity is a growing public health concern, increasing the risk of a number of diseases, including diabetes, atherosclerotic cardiovascular disease, certain types of cancer, and premature death.