Controlling Blood Pressure can Help in the Prevention of Dementia
High blood pressure, or hypertension, is the most common primary diagnosis in the United States, and it is one of the most common worldwide diseases afflicting humans and is a major risk factor for stroke, myocardial infarction, vascular disease, and chronic kidney disease.
According to the American Heart Association (AHA), approximately 86 million adults (34%) in the United States are affected by hypertension, which is defined as a systolic blood pressure (SBP) of 140 mm Hg or more or a diastolic blood pressure (DBP) of 90 mm Hg or more, taking antihypertensive medication, or having been told by clinicians on at least 2 occasions as having hypertension.
Dementia is fast becoming a global epidemic, currently affecting an estimated 50 million people worldwide. This is projected to triple by 2050, mainly driven by aging populations. And one of the causes related to some types of dementia is Hypertension problems.
A global study of over 28,000 people has provided the strongest evidence to date that lowering blood pressure in later life can cut the risk of dementia.
Dr Ruth Peters, Associate Professor at UNSW Sydney and Program Lead for Dementia in The George Institute’s Global Brain Health Initiative, said that in the absence of significant dementia treatment breakthroughs, reducing the risk of developing the disease would be a welcome step forward.
Dr Peters explained that while many trials have looked at the health benefits of lowering blood pressure, not many included dementia outcomes and even fewer were placebo-controlled, considered to provide the best level of evidence.
To examine the relationship between blood pressure and dementia more closely, researchers analyzed five double-blind placebo-controlled randomized trials that used different blood pressure lowering treatments and followed patients until the development of dementia. A total of 28,008 individuals with an average age of 69 and a history of high blood pressure from 20 countries were included. Across these studies, the mid-range of follow up was just over four years.
They found there was a significant effect of treatment in lowering the odds of dementia associated with a sustained reduction in blood pressure in this older population..
This results imply a broadly linear relationship between blood pressure reduction and lower risk of dementia, regardless of which type of treatment was used
Researchers hope the results will help in designing public health measures to slow the advance of dementia as well as informing treatment, where there may be hesitations around how far to lower blood pressure in older age.
This study provides the highest grade of available evidence to show that blood pressure lowering treatment over several years reduces the risk of dementia, and they did not see any evidence of harm.
This work is an important foundation for clinical trials to provide reliable estimates of the benefits and risks of preventative treatments, and how best to apply them across different populations.
Ruth Peters, Ying Xu, Oisin Fitzgerald, Htein Linn Aung, Nigel Beckett, Christopher Bulpitt, John Chalmers, Francoise Forette, Jessica Gong, Katie Harris, Peter Humburg, Fiona E Matthews, Jan A Staessen, Lutgarde Thijs, Christophe Tzourio, Jane Warwick, Mark Woodward, Craig S Anderson, (October 25 2022). Blood pressure lowering and prevention of dementia: an individual patient data meta-analysis. European Heart Journal. Retrieved from: https://academic.oup.com/eurheartj/advance-article-abstract/doi/10.1093/eurheartj/ehac584/6770632?redirectedFrom=fulltext