(RxWiki News) There are a lot of medications to treat high blood pressure. Some of them may even help fight Alzheimer's disease.
A recent study found that certain medications used to treat high blood pressure (antihypertensive drugs) may help reduce the risk of Alzheimer's disease — a condition that can affect basic brain function and behaviors such as speaking, walking and other motor skills.
The researchers suggested that these findings can help doctors prescribe medication with both high blood pressure and cognition (basic mental function) in mind.
"Talk to a doctor if you have high blood pressure."
The lead author of this study was Sevil Yasar, MD, PhD, from The Johns Hopkins University in Baltimore, Maryland.
Dr. Yasar and colleagues used data from a previous study called the Ginkgo Evaluation Memory Study (GEMS). The researchers selected 2,248 participants between the ages of 75 and 96, all of whom were from four different US communities.
A total of 47 percent of the participants were female, the average age was 78.7 years, and the average length of education was 14.2 years. The average follow-up time for the study was 6.1 years.
The researchers gathered demographic (age, race, sex, years of education) and health characteristics through questionnaires. The participants then self-reported their medical history on 16 different conditions such as stroke, heart failure, heart attack and diabetes.
The researchers collected the participants' medication information by visually checking which medications each person was prescribed, as well as any over-the-counter medications they took. The researchers then created a database with the participants' medication names, doses, frequencies of taking them and how they took them.
The participants either reported no use, use at one examination or at two examinations. This allowed the researchers to factor in the duration of medication use in association with risk of Alzheimer's disease.
The categories of antihypertensive medications included the following:
- Diuretics, which help rid the body of water and salt to decrease amount of fluid and pressure in the blood vessels
- Angiotensin II receptor blockers (ARBs), which block the effects of a hormone called angiotensin II - a chemical that contracts blood vessels and causes water retention
- Angiotensin-converting enzyme inhibitors (ACE-Is), which relax blood vessels by preventing production of angiotensin
- Calcium channel blockers, which prevent calcium from entering cells of heart and blood vessel walls
- Beta blockers, which block the effects of adrenaline, allowing the heart to beat slower with less force from the blood
A total of 71 percent of the participants were taking antihypertensive medications, and the rest were not taking any.
Twenty percent of the participants were taking beta blockers, 15 percent were taking calcium channel blockers, 6 percent were taking ARBs, 16 percent were taking diuretics, and 14 percent were taking ACE-Is. The rest of the participants were not taking any antihypertensive medication.
At baseline (initial examination), there were 1,928 participants with normal cognition and 320 participants with mild cognitive impairment (MCI). After an average of 5.6 years, the researchers found that 180 of those with normal cognition and 110 of those with MCI had developed Alzheimer's disease.
The researchers found that compared to the participants not using antihypertensive medications, participants with normal cognition and MCI collectively had a 54 percent decreased risk of Alzheimer's disease while taking diuretics, a 65 percent decreased risk with ARBs, a 44 percent decreased risk with ACE-Is and a 36 percent decreased risk with beta blockers.
When the participants with both normal cognition and MCI reported using the medications at two examinations, there was a 60 percent reduced risk of Alzheimer's disease with diuretics and a 63 percent reduced risk with ARBs compared to those not on antihypertensive medication.
The researchers found that calcium channel blockers were not associated with decreased risk of AD dementia, as the participants taking them only had a 23 percent decreased risk.
When the researchers split up the normal cognition and the MCI groups, the findings showed that participants with normal cognition had a 49 percent decreased risk of Alzheimer's disease with diuretics, a 69 percent decreased risk with ARBs and a 50 percent decreased risk with ACE-Is compared to those not taking antihypertensive medications.
The participants with MCI only benefitted from diuretics, with a 62 percent decreased risk of Alzheimer's disease compared to the participants not taking antihypertensive medications.
The researchers suggested that these findings could help doctors choose the antihypertensive medication that has the most cognitive and blood pressure benefits for each individual patient.
The authors noted a few limitations of their study.
First, the study data was from a previous study that had a different outcome of interest, so the data interpretation may have been biased. Second, the population was very similar in terms of race and education, so these findings may not be generalizable.
Third, the researchers looked at the participants' prescriptions but could not confirm that the participants actually used the medication as directed; the researchers also did not have information on any prior use of the medications. Lastly, the costs of some of the medications were a lot higher, and the researchers did not have information on the participants' specific socioeconomic status.
This study was published in the September edition of Neurology.
The Ginkgo Evaluation of Memory Study, the National Center for Complimentary and Alternative Medicine, the Office of Dietary Supplements, the National Institute on Aging, the National Heart, Lung, and Blood Institute, the University of Pittsburgh Alzheimer’s Disease Research Center, the Roena Kulynuch Center for Memory and Cognition Research and the National Institute of Neurological Disorders and Stroke provided funding.
