Researchers have found that a drug, called nilvadipine that is consumed as a pill to control hypertension, could also help patients combat Alzheimer’s disease without affecting other parts of the brain. Nilvadipine is a calcium channel blocker used to treat high blood pressure (HBP).
According to the study published in Hypertension: Journal of the American Heart Association, these findings indicate that the known decrease in cerebral blood flow in patients with Alzheimer’s can be reversed in some regions.
“This high blood pressure treatment holds promise as it doesn’t appear to decrease blood flow to the brain, which could cause more harm than benefit,” said the study lead author Jurgen Claassen, Associate Professor at the Radboud University in the Netherlands.
“Even though no medical treatment is without risk, getting treatment for high blood pressure could be important to maintain brain health in patients with Alzheimer’s disease,” Claassen said.
For the study, researchers sought to discover whether nilvadipine could help treat Alzheimer’s disease by comparing the use of nilvadipine and a placebo among people with mild to moderate Alzheimer’s disease.
Researchers randomly assigned 44 participants to receive either nilvadipine or a placebo for six months. They measured blood flow to specific regions of the brain using a unique magnetic resonance imaging (MRI) technique.
Results showed that blood flow to the hippocampus, the brain’s memory and learning centre, increased by 20 per cent among the nilvadipine group compared to the placebo group. Blood flow to other regions of the brain was unchanged in both groups.
However, the sample sizes were too small and follow-up time too short to reliably study the effects of this cerebral blood flow increase on structural brain measures and cognitive measures, the researchers noted. (IANS)
New research gives some biological clues to why women may be more likely than men to develop Alzheimer’s disease and how this most common form of dementia varies by sex.
At the Alzheimer’s Association International Conference in Los Angeles on Tuesday, scientists offered evidence that the disease may spread differently in the brains of women than in men. Other researchers showed that several newly identified genes seem related to the disease risk by sex.
Two-thirds of Alzheimer’s cases in the U.S. are in women and “it’s not just because we live longer,” said Maria Carrillo, the association’s chief science officer. There’s also “a biological underpinning” for sex differences in the disease, she said.
Some previous studies suggest that women at any age are more likely than men to develop Alzheimer’s. Scientists also know that a gene called APOE-4 seems to raise risk more for women than for men in certain age groups.
At the same time, women with the disease in its early stages may go undiagnosed because they tend to do better on verbal tests than men, which masks Alzheimer’s damage. The new studies add more evidence and potential explanations for suspected variations between how men and women develop the disease.
Vanderbilt University researchers found differences in how tau, a protein that forms tangles that destroy nerve cells, spreads in the brains of women compared to men. Using scans on 301 people with normal thinking skills and 161 others with mild impairment, they mapped where tau was deposited and correlated it with nerve networks — highways that brain signals follow.
They found that tau networks in women with mild impairment were more diffuse and spread out than in men, suggesting that more areas of the brain were affected.
It’s long been known that women do better on tests of verbal memory — skills like recalling words and lists. University of California, San Diego, researchers found that women did better on these skills despite similar signs of early to moderate Alzheimer’s than men.
Using scans on more than 1,000 older adults, they found sex differences in how the brain uses sugar, its main energy source. Women metabolized sugar better, which may give them more ability to compensate for the damage from dementia and make them less likely to be diagnosed with it by tests that involve verbal skills.
“The female advantage might mask early signs of Alzheimer’s and delay diagnosis,” said study leader Erin Sundermann. “Women are able to sustain normal verbal performance longer,” partly because of better brain metabolism.
At the University of Miami, scientists analyzed genes in 30,000 people — half with Alzheimer’s, half without it — and found four that seem related to disease risk by sex. “One confers risk in females and not males and three confer risk in males but not females,” said one study leader, Eden Martin.
Researchers don’t know yet exactly how these genes affect risk — or by how much. “Some of these look like they’re tied to the immune system and we know there are differences between males and females” in how that works, said another study leader, Brian Kunkle.
Seven other genes seem to have different effect on risks in men versus women. The researchers have a National Institute on Aging grant to do an international study on nearly 100,000 people to try to validate and extend the results. (VOA)