Having high blood pressure or hypertension is a recognised risk factor for Alzheimer’s and other forms of dementia, particularly vascular dementia.
The simple act of getting your blood pressure checked by your doctor regularly is paramount.
You can’t tell when your blood pressure is up. But your doctor can. Keeping your blood pressure within the normal range is very important for both heart and brain health.
There are some simple lifestyle choices, which can help keep your blood pressure normal:
• Keep your weight in the healthy range
• Exercise daily – gotta “find that thirty”
• Eat healthily with lots of green leafy vegetables and fruit
• Manage stress levels through exercise, meditation or mindfulness
• Stop smoking
• Cut the salt
If you are doing all of the above and your blood pressure is still too high, then it may be time to consider using an antihypertensive. This is where the choice of which antihypertensive used can possibly make a difference for preventing Alzheimer’s or slowing down the progression of the disease if already present.
At least that what research from a large observational study in the UK has found.
The findings from this study have been published in the Journal of Alzheimer’s Disease and indicate that for older patients (age 60+) being prescribed what is called an angiotensin 11 receptor blocker (ARB) was associated with a 53% lower risk of developing Alzheimer’s disease compared to a 24% reduction for those prescribed an angiotensin converting enzyme (ACE) agent.
These findings come from an observational study of over 9000 patients aged 60+ who were diagnosed at some time between 1997 and 2008 with either probable or possible Alzheimer’s disease or other dementia. The data suggested that being prescribed an ARB or ACE was associated with a lowered risk of developing Alzheimer’s disease, vascular or other dementia. Controlling for control and age, and other illnesses made no difference to the risk reduction and there was also noted to be an apparent dose- response relationship between ARBs and Alzheimer’s.
This research supports the move to now undertake actual clinical trials to verify these findings.
These results support findings from previous studies conducted elswhere. In 2010 a study from Boston University School of Medicine compared the incidence of Alzheimer’s disease and dementia in men taking ARBs compared to either the ACE drugs or other antihypertensives.
Reducing Alzheimer’s incidence and nursing home admission.
In this study a significant reduction in the actual incidence of Alzheimer’s and other dementia was reported as well as a reduction in the rate of disease progression measured in terms of lengthening time to admission to a nursing home or death.
Dr Wolozin reported that those people who did the best were prescribed a combination of an ARB and ACE with 55% reduction in the incidence of Alzheimer’s and other dementias and a 70% reduction in nursing home admissions. Being prescribed an ARD on its own was associated with a 50% reduction of risk of incidence of Alzheimer’s.
This in itself is of major implications as keeping a person with Alzheimer’s or other dementia at home for longer is highly desirable as well as a major cost saving.
In this study, data was collected from the US Veterans Affairs administrative database (this contains information on over 5 million people!) looking at the rate of incidence of Alzheimer’s or dementia being diagnose over a four years period in men over the age of 65 with a history of cardiovascular disease. The subjects were divided into three groups taking either a) an ARB b) taking an ACE (Lisinopril) or c) taking other cardiovascular drugs.
Adjustments were made for age, diabetes, stroke, cardiovascular disease and the findings were that those taking the ARB drugs had a lower incidence of Alzheimer’s and significantly lower risk of being admitted to a nursing home, again with a dose response for the ARB.
So why the difference?
Both ARBs and ACEs work by reducing angiotensin 11 signalling at the level of two receptors AT1 and AT2.
ARBs appear to make the difference by selectively inhibiting the angiotensin 1 receptor.
If the AT1 receptor is stimulated, this leads to vasoconstriction.
If the AT2 receptor is stimulated, this leads to vasodilation, neuronal differentiation and neuronal repair.
ARBs selectively inhibit the AT1 receptor, so vasoconstriction doesn’t occur and it is thought that this allows for increased blood flow to the brain and accounts for the neuroprotective effect.
Using a combination of an ARB and ACE was found to be of particular benefit perhaps because of the reduced risk of stroke and the ARB preventing vascular damage induced by beta amyloid that accumulates in the brain in Alzheimer’s disease.
The bottom line.
The most important factor here is to ensure that you keep your blood pressure in the normal range.
If you haven’t had your blood pressure checked in a while, NOW is a good time to make an appointment to see your doctor.
If you do have high blood pressure then ensure you make all the necessary lifestyle adjustments to see if you can bring it down to normal on your own.
If despite all this, your blood pressure remains elevated, talk to your doctor about which medication would be the most appropriate for you. Remember these observational studies are only suggestive that certain medications i.e. the ARBs may be of benefit in preventing the risk of Alzheimer’s and other dementias. Your doctor is in the best position to know which medication may be most suitable for your own particular needs. The main thing is to keep your blood pressure in the normal range.
Meanwhile further research will help to ascertain whether in fact the ARBs do have an advantage in helping to reduce the incidence of Alzheimer’s. Time will tell.
Do you know if your blood pressure is normal?
Refs:
Davies,N.M., Kehoe, P.G., Ben-Shlomo, Y., Martin, R.M.
Associations of Anti-Hypertensive Treatments with Azlheimer’s Disease, Vascular Dementia and other Dementias . Journal Of Alzheimer’s Disease October 2011 pg 699-708
Boston University Medical Center (2010, January 12). Angiotensin receptor blockers associated with lower risk of Alzheimer’s disease. ScienceDaily. Retrieved October 31, 2011, from http://www.sciencedaily.com¬ /releases/2010/01/100112201345.htm
