Written by Staff Writer
Regular screenings with an inexpensive blood test could detect Alzheimer’s disease — before the symptoms appear, according to new research.
The test detected the progression of Alzheimer’s disease in memory-impaired patients much earlier than the current method which relies on relatively infrequent assessments of behavioral changes, a study published in the journal Aging found.
The researchers at Oregon Health and Science University (OHSU) found that they could predict progression of Alzheimer’s in multiple aspects of the disease during a fraction of a second, an important development, the scientists said.
Researchers monitor patients’ dementia and changes in blood sugar levels, oxidative stress, inflammation and fatty acid oxidation — a key indicator of Alzheimer’s — with the help of a test they have used to detect disease in more than 1,000 subjects.
They developed a patient-friendly, oral glucose tolerance test for Alzheimer’s disease that could be easily administered in clinic visits. The test contains three sugar molecules — glucose, sodium and fructose — embedded in protein molecules. When the glucose, sodium and fructose molecules are ingested, they are converted to glucose by the liver.
The test was confirmed with the results of a separate study at Case Western Reserve University School of Medicine that included 218 subjects with mild cognitive impairment and 154 healthy elderly people, who took part in a demographic analysis.
“The degree of depression is lower, and there is a lower rate of slow cognitive decline among subjects who received the low dose of the test compared to those who received the high dose,” Ted Kaptchuk, assistant professor of neurology at OHSU and lead author of the study, said in a news release.
Kaptchuk said that the test has been shown to work on healthy elderly people, and on cognitively impaired subjects with an IQ of at least 60 who have a family history of Alzheimer’s.
Study participants were divided into three groups based on their blood sugar level.
The low-dose group had the blood sugar testing completed within 15 minutes after a meal, the medium-dose group between 10 minutes and 15 minutes and the high-dose group between 15 minutes and 60 minutes.
Within 15 minutes of glucose ingestion, the test identified 80% of subjects with evidence of Alzheimer’s disease, an 84% degree of accuracy, compared to the current method, which relies on assessments of changes in verbal and fine motor memory and verbal and motor decline of individuals with mild cognitive impairment, according to the study.
The glucose intolerance test may also work on Alzheimer’s patients even if there is no dementia but an estimated 15% of Alzheimer’s patients may be functioning below normal and have no dementia, the study found.
The research team, which is continuing to study glucose tolerance tests, said they are encouraged by the tests’ ability to detect Alzheimer’s disease at earlier stages, when much more can be done to prevent its development.
“Because of what we know about metabolic pathology, we may be able to reduce the amount of time before symptoms develop by changing blood sugar, cholesterol and blood pressure,” Kaptchuk said.