By Jasminee Sahoye
High blood pressure or hypertension is associated with stroke and heart disease but a new study reveals that people with a genetic predisposition to high blood pressure could have a lower risk for Alzheimer’s disease.
But the researchers state the connection may have more to do with anti-hypertension medication than high blood pressure itself.
“It’s likely that this protective effect is coming from antihypertensive drugs,” said co-author John Kauwe, associate professor of biology at Brigham Young University (BYU).
“These drugs are already FDA approved. We need to take a serious look at them for Alzheimer’s prevention.”
The study analyzed genetic data from 17,008 individuals with Alzheimer’s and 37,154 people without the disease.
BYU researchers worked with scholars from the University of Cambridge, Aarhus University in Denmark and the University of Washington on the massive study.
The research team looked for links between Alzheimer’s disease and a number of health conditions – including diabetes, obesity and high cholesterol – but only found a significant association between higher systolic blood pressure and reduced Alzheimer’s risk.
“Our results are the opposite of what people might think,” said co-author Paul Crane, a University of Washington associate professor of internal medicine.
“It may be that high blood pressure is protective or it may be that something that people with high blood pressure are exposed to more often, such as antihypertensive medication, is protecting them from Alzheimer’s disease.”
University of Cambridge senior investigator scientist Robert Scott led the study to find if the risk factors (BMI, insulin resistance, blood pressure, cholesterol, diabetes) for Alzheimer’s had a causal impact.
“This is to date the most authoritative paper looking at causal relationships between Alzheimer’s disease and these potentially modifiable factors,” Kauwe said.
“In terms of the number of samples, it can’t get bigger at this point.”
Meanwhile, medical researchers Franz Weber and Manfred Anlauf who contribute to Deutsches Ärzteblatt International say one in five people with hypertension does not respond to therapy. This, they say is often due to inadequate diagnosis.
They say if a patient’s blood pressure is not controlled by treatment, this can be due to a number of reasons. “Often it is the medication the patient is on. Some patients may be taking other medicines – in addition to their antihypertensive therapy – which increase blood pressure as a side effect.
“In these cases, the treatment of the high blood pressure appears to be ineffective but all that would be needed is some adjustment to the medication regimen.
Then there is diet. Licorice, for example, does increase blood pressure; so eating too much of it may reduce the effect of the antihypertensive therapy. Likewise, salt-sensitive patients may increase their blood pressure by eating salt; thus they have to keep this in mind when seasoning their dishes.”
The two professors also said that certain symptoms may interfere with antihypertensive therapy.
“Once the underlying condition has been successfully treated, blood pressure control does often improve. An example for this is the sleep apnea syndrome: Apart from sleep problems and fatigue, it makes high blood pressure worse.
“Here, most patients find their blood pressure improved with targeted treatment of the apnea and quite often the antihypertensive medication can be reduced.”