TUESDAY, March 20, 2007 (HealthDay News) -- Confirming the long-standing prediction that Alzheimer's disease will approach epidemic proportions as the U.S. population ages, a new report finds that more than five million Americans are now living with the mind-robbing condition.
That represents a 10 percent increase from five years ago and more than double the number in 1980, according to the study released Tuesday by the Alzheimer's Association.
One in every eight people over the age of 65 now has Alzheimer's disease, including half of those over 85. Between 2000-04, Alzheimer's-related deaths rose 33 percent.
Scientists now project that 7.7 million older Americans will have the illness by 2030, the association said. By 2050, unless new ways are found to prevent or treat the disease, the total could climb to 16 million.
Younger people are also affected: According to the report, between 200,000 and 500,000 Americans under the age of 65 now suffer from early onset Alzheimer's or some other form of dementia.
But, the biggest risk factor for Alzheimer's is increasing age, and with the first round of the 78 million baby boomers turning 60 last year, it's estimated that Alzheimer's now strikes someone in America every 72 seconds. By mid-century, someone will develop Alzheimer's every 33 seconds, the association said.
"Alzheimer's Disease Facts and Figures clearly shows the tremendous impact this disease is having on the nation. And with the projected growth of the disease, the collective impact on individuals, families, Medicare, Medicaid, and businesses will be even greater," Harry Johns, president of the Alzheimer's Association, said in a prepared statement.
"However, there is hope," he added. "There are currently nine drugs in phase III clinical trials for Alzheimer's, several of which show great promise to slow or stop the progression of the disease. This, combined with advancements in diagnostic tools, has the potential to change the landscape of Alzheimer's."
Scientists are even now reporting one of those advances. An international team of researchers has used PET scans to distinguish living, healthy brains from the brains of patients with Alzheimer's disease.
Right now, Alzheimer's can only be definitely identified upon autopsy.
The new brain scans relied on a compound called AV-1, which binds to the beta-amyloid proteins that build up in the brain and are the hallmark of the disease.
"People with Alzheimer's had a significant 'signal' in the brain in areas known from autopsy where amyloid tends to deposit," said Alan Carpenter, vice president of business development at Avid Radiopharmaceuticals in Philadelphia, which licensed the compound.
The results, presented Sunday at the 8th International Conference on Alzheimer's Disease in Salzburg, Austria, hold out the hope that doctors will one day be able to better diagnose the disease. Researchers might also use the technology to judge the effectiveness of drugs that target the amyloid beta protein.
But there is still a long way to go, one expert said.
"This is another brick in the yellow brick road, but it's not the end," said Dr. Gary Kennedy, director of geriatric psychiatry at Montefiore Medical Center in New York City. "We should be excited that this is moving technology along, but it's not ready for clinical application. Still, the more studies like this we have, the closer we get to it being useful to patients."
According to Kennedy, compounds currently being tested, including this one, need to be much more specific and more sensitive before they can be considered reliable.
In addition, doctors need ways to predict who will develop the disease, not just distinguishing who currently has it compared with who doesn't, he added.
Diagnosis of Alzheimer's is a notoriously tricky affair and is never 100 percent definite until an autopsy is performed. "It's done with great difficulty," Carpenter said. "Autopsy is the only definitive means."
Many experts believe that Alzheimer's is caused by a build-up of amyloid plaque proteins in the brain. But, again, the protein can only be detected through an autopsy.
Last week, scientists confirmed that an imaging agent known as Pittsburgh Compound B binds to beta-amyloid accumulations in the brain.
AV-1 was developed by a researcher at the University of Pennsylvania and is licensed exclusively by Avid. The new study was a joint effort between Austin Health, the University of Melbourne (Australia), Neuroscience Victoria (Australia), Avid, the University of Pennsylvania and Bayer Schering Pharma.
The study involved five individuals with mild Alzheimer's disease and six healthy controls, all of whom underwent PET imaging over three hours after injection with AV-1. The PET imaging clearly distinguished patients with Alzheimer's from healthy individuals.
"This is basically the proof-of-concept stage," Carpenter said. "We will now need to go into phase 2 and phase 3 trials before submission of data to the FDA (U.S. Food and Drug Administration)."
AV-1 is one of three compounds that Avid has in clinical trials, he added. "Our goal is to select the compound with the best imaging properties within the next few months for multi-center clinical development studies and FDA approval," Carpenter said.
More information
Visit the Alzheimer's Association for more on this disease.
