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.
“Given population ageing and the substantial costs of caring for people with dementia, even a small reduction could have considerable global impact,” she said.
“Our study suggests that using readily available treatments to lower blood pressure is currently one of our ‘best bets’ to tackle this insidious disease.”
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.
It is currently estimated to cost US$20-$40,000 per person with the condition each year.
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.
“Most trials were stopped early because of the significant impact of blood pressure lowering on cardiovascular events, which tend to occur earlier than signs of dementia,” she said.
To examine the relationship between blood pressure and dementia more closely, researchers analysed five double-blind placebo-controlled randomised 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.
“We 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,” said Dr Peters.
“Our 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.
“Our study provides the highest grade of available evidence to show that blood pressure lowering treatment over several years reduces the risk of dementia, and we did not see any evidence of harm,” said Dr Peters.
“But what we still don’t know is whether additional blood pressure lowering in people who already have it well-controlled or starting treatment earlier in life would reduce the long-term risk of dementia,” she added.
Professor Craig Anderson, Director of the Global Brain Health program at The George Institute said, “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.”
European Heart Journal
Method of Research
Subject of Research
Blood pressure lowering and prevention of dementia: an individual patient data meta-analysis
Article Publication Date
The authors report no targeted funding. R.P. is funded by the Australian National Health and Medical Research Centre Australian Dementia Centre for Research Collaboration, and Neuroscience Research Australia; Y.X. is funded by NHMRC Project Grant (APP1160373); M.W. and C.S.A. are supported by Investigator Grants (APP1174120 and GNT1175861 respectively) from the National Health and Medical Research Council (NHMRC) of Australia, and together with J.C. receive funding from an NHMRC Program Grant (APP1149987); M.W. is a consultant to Amgen, Kyowa Kirin, and Freeline; J.C. has received research grants from Servier, and from the NHMRC for both PROGRESS and ADVANCE, and honoraria from Servier for speaking about them at Scientific meetings; C.S.A. has received research grants from Penumbra, Takeda, Credit, and Genesis paid to his institution.