There is currently no one test that proves someone has Alzheimer's disease, but researchers might have developed a new blood test that could give patients notice well in advance of developing any symptoms of the condition.
According to a study published in the Journal of the Federation of the American Societies for Experimental Biology, measuring insulin resistance in the brain through a blood test could be an indicator of the disease up to 10 years before a patient is diagnosed with Alzheimer's.
The research, presented this week at the Society for Neuroscience's conference, was sponsored by the biotech company NanoSomiX. The company said in a news release that before this study it was not possible to determine brain insulin resistance in living patients who had Alzheimer's or how much time it took for this resistance to result in more obvious symptoms of the disease.
“This study shows that insulin resistance is a major central nervous system metabolic abnormality in [Alzheimer's disease] that contributes to neural cell damage,” Dr. Ed Goetzl, the senior author on the study, said in a statement. “As insulin resistance is a known condition in type 2 diabetes mellitus and is treatable with several classes of existing drugs, these treatments may be useful as part of a multi-agent program for [Alzheimer's disease]."
Here's how the study measured insulin resistance:
The innovative approach used in this study allowed the researchers to extract and measure phosphorylated forms of [insulin receptor substrate] from isolated neural exosomes. Exosomes are tiny membrane-encased vesicles that are excreted from cells and are present in biological fluids such as blood, cerebrospinal fluid, etc. The ability to quantify the phosphorylated forms of IRS makes it possible to evaluate insulin resistance in the central nervous system using a blood-based assay with living patients.
The study found that for patients with [Alzheimer's disease] and type 2 diabetes, the mean levels of the two extracted phosphorylated forms of IRS and their ratio (known as the insulin resistance index) were significantly different than the values for the healthy control group. In addition, the researchers reported that the mean level of the brain insulin resistance index for [Alzheimer's disease] was significantly higher than for either type 2 diabetes or frontotemporal dementia (FTD).
According to the news release about the research, 100 percent of patients with Alzheimer's were correctly identified using this technique, in addition to 97.5 percent of type 2 diabetes patients.
“We will need replication and validation, but I’m very optimistic this work will hold,” neuroscientist Dimitrios Kapogiannis, lead author of the study, said at the conference, according to Bloomberg.
NanoSomiX President and CEO John Osth said in a statement that the company hopes the test could help identify early-stage Alzheimer's patients that can then enter clinical trials, which could lead to preventative treatments and more.
"We invite pharmaceutical companies and university researchers to contact us about collaborating or partnering to generate additional data," Osth said.
According to the Alzheimer's Association, more than 5 million Americans have the disease, which is the sixth leading cause of death in the U.S.
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