Blood Test Can Identify Dementia Risk 10 Years Before Diagnosis: Study

A machine learning model created by researchers had a 90 percent accuracy rate in predicting the potential of dementia.

Memory lapses, forgetting things, degenerative disease. in a 3D rendering Shutterstock

Screening for a few proteins in the blood could lead to earlier detection of dementia, sometimes even a decade before diagnosis, according to a recent study.

The peer-reviewed study, published in the Nature Journal on Feb. 12, examined data from more than 52,000 adults with dementia and found over 1,400 cases of the illness. Researchers identified that four types of proteins found in the blood were “consistently associated most with incident all-cause dementia (ACD), Alzheimer’s disease (AD) and vascular dementia (VaD).” These four proteins are GFAP, NEFL, GDF15, and LTBP2.

“Individuals with higher GFAP levels were 2.32 times more likely to develop dementia,” the study said. Both GFAP and LTBP2 were found to be “highly specific for dementia prediction.” High GFAP levels were also associated with almost three times the likelihood of developing Alzheimer’s.

“GFAP and NEFL began to change at least 10 years before dementia diagnosis. Our findings strongly highlight GFAP as an optimal biomarker for dementia prediction, even more than 10 years before the diagnosis.”

Researchers designed predictive algorithms using machine learning, training the model on two-thirds of the more than 52,000 study participants. They then tested the performance of the algorithms on data from the remaining dataset.

The model had a 90 percent accuracy rate in predicting the incidence of three dementia subtypes, including Alzheimer’s. The prediction was made using data from more than ten years prior to when these individuals were diagnosed with the illnesses.

The study findings have “implications for screening people at high risk for dementia and for early intervention,” with researchers screening 1,463 proteins before finally zeroing in on the four critical ones.

Currently, people are only usually diagnosed with dementia when memory problems or other related symptoms start to crop up. However, by this time, the disease may have progressed.

“Once we diagnose it, it’s almost too late … And it’s impossible to reverse it,” said study co-author Jian-Feng Feng, a computational biologist at Fudan University in Shanghai, China, according to a Feb. 12 Nature post.

Authors claim that their findings can lead to the development of blood tests to identify people at risk of dementia.

Data from the study came from the UK Biobank, a large-scale biomedical database containing genetic, lifestyle, health information, and biological samples of over half a million people from the United Kingdom.

The study was funded by multiple institutions and universities in China, and the authors declared no competing interests.

Detecting Dementia

Commenting on the study, Dr. Sheona Scales, director of research at Alzheimer’s Research UK, said that “further studies, including in more diverse populations, are needed to verify these tests and predictive models,” according to Science Media Center.

“Blood tests could unlock early diagnosis and are showing great promise, but so far, none have been validated for use in the UK.”

In the Feb. 12 Science Media Center post, Dr. Amanda Heslegrave, a senior research fellow at the UK Dementia Research Institute, University College London, pointed to a limitation of the study, specifically that the UK BioBank is highly curated and thus “may not capture all populations that we need to know the risk for.”

Prof Tara Spires-Jones, president of the British Neuroscience Association, called the research “a well-conducted study that adds to what we know about changes in blood that occur very early in diseases that cause dementia, which will be important for early diagnosis in the future.

The Feb. 12 study comes weeks after another research published in the JAMA Network on Jan. 22 found that a new blood test had a “high accuracy” in determining the risk of Alzheimer’s.

Currently, individuals have to undergo a spinal tap or brain scan to identify protein buildup like amyloid beta and tau in the brain, which would suggest the risk of Alzheimer’s.

However, these can be expensive and oftentimes inaccessible. The study focused on a form of tau protein called p-tau217—a key biomarker of Alzheimer’s.

The new blood test had an accuracy rate of up to 97 percent in identifying tau and up to 96 percent accuracy in identifying amyloid beta.

Cheaper and simpler tests are critical given the large number of people with Alzheimer’s and other types of dementia living in the United States. According to the Alzheimer’s Association, over six million Americans are living with the illness, with the number expected to grow to nearly 13 million by 2050.

One in three seniors dies with Alzheimer’s or another dementia. The total cost of such illnesses to the nation was $345 billion last year, which is expected to rise to almost $1 trillion by mid-century.

Recently, researchers from the University of Queensland’s Brain Institute identified the mechanism by which memories get formed and consolidated in the brain, which could pave the way to potential treatments for dementia and Alzheimer’s.