New research into the biomarkers that predict the onset of Alzheimer’s suggests that more than twice as many people are in some stage of the disease than the official numbers indicate. Roughly 5.4 million people in the US are estimated to have Alzheimer’s, but that number is likely closer to 11 million when including those who aren’t yet symptomatic.
The study analyzed 10 years of data from the Alzheimer’s Disease Neuroimaging Initiative, an effort focused on understanding the biomarkers that arise before symptomatic Alzheimer’s begins. The most critical biomarker is an elevated level of amyloid beta, the toxic protein that accumulates as a plaque in the brains of Alzheimer’s patients. Most people with elevated amyloid levels who aren’t yet symptomatic will develop full-blown Alzheimer’s within 10 years.
“This study is trying to support the concept that the disease starts before symptoms, which lays the groundwork for conducting early interventions,” said Michael Donohue, lead author of the study and an associate professor of neurology at USC, in a press statement.
The researchers compare measuring amyloid levels before Alzheimer’s symptoms begin to the approach taken to prevent heart disease by monitoring cholesterol levels. Identifying those with above-normal levels of the protein opens the door for earlier treatment, just as we intervene to treat those with elevated cholesterol levels. And as with cholesterol monitoring, tracking levels of amyloid should begin years in advance.
The findings should spark more research into earlier stages of the disease where medical intervention has a better chance of making a difference. About 80 clinical trials for a range of treatments are in progress nationwide, all of which focus on ways of preventing or decreasing the accumulation of amyloid plaques.
“We need more studies looking at people before they have Alzheimer’s symptoms,” said Paul Aisen, senior study author and director of the USC Alzheimer’s Therapeutic Research Institute (ATRI) at the Keck School of Medicine. “The reason many promising drug treatments have failed to date is because they intervened at the end-stage of the disease when it’s too late. The time to intervene is when the brain is still functioning well–when people are asymptomatic.”
This research is especially timely because new stats from the CDC show that Alzheimer’s deaths in the US have increased by more than 50% in the past 15 years. It’s estimated that nearly one in 10 Americans 65 or older have Alzheimer’s, but it’s possible that estimate is low. As we develop a better understanding of the biomarkers that presage full-blown Alzheimer’s, it’s likely that a higher percentage of the population will be diagnosed with earlier stages of the disease.
The study was published in The Journal of the American Medical Association.
Source : Forbes