Beta-blockers may lower dementia risk
8th January 2013 - A study by US researchers has found that men prescribed beta-blockers for high blood pressure are less likely to have changes in their brains that can be signs of Alzheimer’s disease or other types of dementia.
Earlier research has shown that high blood pressure in midlife is a strong risk factor for dementia, and it's already known that certain types of blood pressure medications may help lower the risk. This study looked at patients taking various blood-pressure lowering medications, and found that beta-blockers, a specific type of widely prescribed blood pressure drug, seemed to have a particularly beneficial effect on dementia.
Researchers at the Pacific Health Research and Education Institute in Honolulu studied data from 774 elderly Japanese-American men who had taken part in the Honolulu-Asia Aging Study. The team looked at the participants’ blood pressure in mid-life, as well as their history of taking blood pressure medication, and checked post mortem results for signs of Alzheimer’s and vascular dementia.
Of the 774 men, 610 had high blood pressure or were being treated with medication for high blood pressure. Among about 350 who had been treated, 15% received only a beta-blocker medication, 18% received a beta-blocker plus one or more other medications and the rest of the participants received other blood pressure drugs.
The study found that all types of blood pressure medications seemed to have a positive effect on the risk of dementia. However, men who had received beta-blockers as their only blood pressure medication had fewer abnormalities in their brains compared to those who had not been treated for their hypertension, or who had received other blood pressure medications.
The brains of participants who had received beta-blockers plus other medications showed an intermediate reduction in numbers of brain abnormalities.
The abnormalities included two distinct types of brain lesion: those indicating Alzheimer’s disease, and lesions called microinfarcts, usually attributed to tiny, multiple, unrecognised strokes.
Study participants who had taken beta blockers alone or in combination with another blood pressure medication had significantly less shrinkage in their brains.
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, says in a press statement: "Hypertension is a known risk factor for Alzheimer’s and other causes of dementia, and keeping high blood pressure in check could be important for preventing these diseases. This study suggests a link between the use of beta-blockers and fewer signs of dementia, but as the results of this study have yet to be published in full, it’s not clear what caused this link."
He says it's also worth noting that the study only looked at Japanese-American men and the results may not be applicable to a wider population.
"While we can’t conclude from this study that beta-blockers can prevent dementia, a better understanding of the links between high blood pressure and dementia could be crucial for developing new treatments or approaches to prevention. With 820,000 people affected by dementia in the UK, and that number increasing, we urgently need to find ways to prevent the diseases that cause it - that requires a massive investment in research."
The study findings will be presented at the American Academy of Neurology’s 65th Annual Meeting in San Diego, in March 2013. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinise the data prior to publication in a medical journal.