Blood Pressure Drug Might Work Against Alzheimer's
By Ed Edelson
HealthDay ReporterThu Oct 25, 6:59 PM ET
THURSDAY, Oct. 25 (HealthDay News) -- The blood pressure drug valsartan shows the ability to reduce Alzheimer's disease-like symptoms in mice, researchers report.
The potential value of valsartan, marketed as Diovan, emerged from a screening program that started with 55 high blood pressure drugs, said study author Dr. Giulio Maria Pasinetti, a professor of psychiatry and neurosciences at Mount Sinai School of Medicine in New York City.
"With screening in vivo [animal studies], we came up with seven candidates," Pasinetti said, adding that valsartan was the most promising of the lot.
Specifically, valsartan interfered with the formation of clumps of the protein beta-amyloid in the brains of mice genetically engineered to be susceptible to an Alzheimer's-like disease, Pasinetti said. Beta-amyloid deposits are a leading feature of Alzheimer's disease in humans.
"We also found that in this animal model, there was some kind of effect of valsartan even at doses that were threefold lower than the common equivalent doses given to patients with hypertension [high blood pressure]," he said.
The findings are published in the Oct. 26 issue of the Journal of Clinical Investigation.
Valsartan is a member of the family of angiotensin II blockers that are widely used to control high blood pressure. Other studies already have linked a related class of blood pressure drugs, called ACE inhibitors, to a reduced risk of Alzheimer's disease. Pasinetti said his group's research with mice has identified three other blood pressure drugs that have the same effect as valsartan. He did not identify the drugs, saying, "That will be the subject of another paper."
The next step with valsartan, Pasinetti said, will be "to develop a series of clinical studies to see if the same effect seen in mice can be replicated in humans."
Dr. Sam Gandy, chairman of the Alzheimer's Association's medical and scientific advisory council, said recent experiences with other medications have shown that such tests are essential, because the experimental therapies often don't pan out.
"This is another example of laboratory work on Alzheimer's disease testing existing drugs to see if they have activity," said Gandy, who's also director of Emory University's Center for Neurodegenerative Diseases. "We have been down this road with Epogen, with non-steroidal anti-inflammatory drugs; now we're going down the road with statins."
What's needed, he said, is "a real controlled clinical trial to see if it [valsartan] works. Just because it makes sense, and the evidence looks good, doesn't mean that it is going to work. The acid test is a clinical trial."
Gandy said he has become wary of reports such as the one from Pasinetti "because of our experience with estrogen." Early reports said the female sex hormone was highly promising as an Alzheimer's preventive treatment, but it failed in a controlled trial.
Panisetti said his group now is trying to determine the potential mechanism by which valsartan and the other drugs might work against Alzheimer's disease. "We are working primarily on the brain rather than on blood pressure," he said.
More information:
To learn more about Alzheimer's, visit the Alzheimer's Association.
Showing posts with label Alzheimer's disease. Show all posts
Showing posts with label Alzheimer's disease. Show all posts
Monday, October 29, 2007
Monday, August 27, 2007
Statins and Alzheimer's disease
Heart Drug May Hold Off Alzheimer's
By Alice Park
The long goodbye of Alzheimer's disease may become increasingly common as our population ages in coming years, but scientists in Seattle provide reassuring evidence that at least some of the disease's gradual mental decline can be held off with, of all things, cholesterol-lowering drugs.
In a study of 110 elderly volunteers, aged 65 to 79, who donated their brains for research and whose cognitive functions were monitored over several years prior to their death, scientists led by Dr. Eric Larson of the Group Health Center for Health Studies found that those who had taken statin drugs to lower their cholesterol had fewer nerve-damaging plaques and tangles — protein deposits that form in and around neurons — in their brains than those not taking the medications. Buildup of these protein plaques and tangles are the hallmark of Alzheimer's disease; they inexorably disrupt the critical connections between neurons that govern thought processes and sabotage everything from the storage and retrieval of memories to learning and language skills.
The new findings are the latest and most definitive results linking the popular statin drugs to Alzheimer's. Earlier studies had produced conflicting results: some found that statins reduced the risk of the brain disorder, while others found no effect. Larson's study is the first to directly compare the brains, on autopsy, of statin users and non-users (Alzheimer's can be conclusively diagnosed only after death, when pathologists confirm the presence of the plaques and tangles in the brain). "This data does give us some additional hope that statins may turn out to have a useful relationship in slowing Alzheimer's disease," says William Thies, vice president of medical and scientific relations of the Alzheimer's Association.
How do cholesterol-lowering drugs work on the brain? As experts learn more about Alzheimer's, they believe that it's less a disease of the brain than of the vasculature, or blood vessel system. It turns out that many of the risk factors for Alzheimer's are the same ones for heart disease, and that the build up of protein in the brain is not unlike the gradual accumulation of plaque in the heart vessels. "We are learning that Alzheimer's disease isn't just plaques and tangles appearing through a series of biochemical processes, but that vascular stress may play a role in their development," says Larson. "Anything we can do to lower the vascular risk profile could lower the risk of Alzheimer's." Statins, then, could be inhibiting the development of Alzheimer's by keeping the brain's neural highways free of potentially bottlenecking protein plaques. In addition, says Larson, statins may be working on a more molecular level, by actually blocking the formation of the sticky, fibrous tangles that can jam nerve connections.
To learn more about exactly how statins could be thwarting the Alzheimer's disease process, Larson acknowledges that the first step involves having another, independent group replicate his team's findings. In the meantime, he plans to continue his study by adding more volunteers. Within the next year, Thies expects two more trials to produce results and hopefully solidify the effect statins have on the brain.
By Alice Park
The long goodbye of Alzheimer's disease may become increasingly common as our population ages in coming years, but scientists in Seattle provide reassuring evidence that at least some of the disease's gradual mental decline can be held off with, of all things, cholesterol-lowering drugs.
In a study of 110 elderly volunteers, aged 65 to 79, who donated their brains for research and whose cognitive functions were monitored over several years prior to their death, scientists led by Dr. Eric Larson of the Group Health Center for Health Studies found that those who had taken statin drugs to lower their cholesterol had fewer nerve-damaging plaques and tangles — protein deposits that form in and around neurons — in their brains than those not taking the medications. Buildup of these protein plaques and tangles are the hallmark of Alzheimer's disease; they inexorably disrupt the critical connections between neurons that govern thought processes and sabotage everything from the storage and retrieval of memories to learning and language skills.
The new findings are the latest and most definitive results linking the popular statin drugs to Alzheimer's. Earlier studies had produced conflicting results: some found that statins reduced the risk of the brain disorder, while others found no effect. Larson's study is the first to directly compare the brains, on autopsy, of statin users and non-users (Alzheimer's can be conclusively diagnosed only after death, when pathologists confirm the presence of the plaques and tangles in the brain). "This data does give us some additional hope that statins may turn out to have a useful relationship in slowing Alzheimer's disease," says William Thies, vice president of medical and scientific relations of the Alzheimer's Association.
How do cholesterol-lowering drugs work on the brain? As experts learn more about Alzheimer's, they believe that it's less a disease of the brain than of the vasculature, or blood vessel system. It turns out that many of the risk factors for Alzheimer's are the same ones for heart disease, and that the build up of protein in the brain is not unlike the gradual accumulation of plaque in the heart vessels. "We are learning that Alzheimer's disease isn't just plaques and tangles appearing through a series of biochemical processes, but that vascular stress may play a role in their development," says Larson. "Anything we can do to lower the vascular risk profile could lower the risk of Alzheimer's." Statins, then, could be inhibiting the development of Alzheimer's by keeping the brain's neural highways free of potentially bottlenecking protein plaques. In addition, says Larson, statins may be working on a more molecular level, by actually blocking the formation of the sticky, fibrous tangles that can jam nerve connections.
To learn more about exactly how statins could be thwarting the Alzheimer's disease process, Larson acknowledges that the first step involves having another, independent group replicate his team's findings. In the meantime, he plans to continue his study by adding more volunteers. Within the next year, Thies expects two more trials to produce results and hopefully solidify the effect statins have on the brain.
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