Scientists at Northern Arizona University are developing a non-invasive blood test that could help detect Alzheimer’s disease before symptoms appear by examining how the brain uses glucose through tiny blood-borne microvesicles. Led by assistant professor Travis Gibbons and supported in part by the Arizona Alzheimer’s Association, the project aims to enable earlier diagnosis and intervention, similar to how doctors manage cardiovascular disease.
Researchers at Northern Arizona University (NAU) are advancing a new method to identify Alzheimer’s disease at very early stages by studying how the brain metabolizes glucose, according to NAU communications and a summary on ScienceDaily.
The project is led by Travis Gibbons, an assistant professor in NAU’s Department of Biological Sciences, and is supported in part by a grant from the Arizona Alzheimer’s Association. The research centers on the brain’s metabolism of glucose, the main fuel for thinking, movement and emotion.
“The brain is like a muscle,” Gibbons said in an NAU news release. “It needs fuel to do work, and its gasoline is blood glucose. A healthy brain is greedy; it burns through glucose fast. But brain metabolism is slower when you have Alzheimer’s. It can be viewed as a canary in the coal mine in the development of the disease.”
Because the brain is difficult to access directly, measuring its glucose use has historically required invasive procedures. In earlier studies, scientists sometimes threaded catheters into veins in a patient’s neck to sample blood as it exited the brain — a technique that is not practical for routine screening.
To address this challenge, Gibbons and his team are using commercially available kits to isolate and analyze microvesicles — tiny particles circulating in the bloodstream. Some of these microvesicles originate in neurons and carry molecular cargo that reflects brain metabolism. “Some of these microvesicles originate in a neuron in your brain, and they’re like messengers carrying cargo,” Gibbons explained. “With these test kits, we can find what kind of cargo is in a microvesicle and run tests on it. It’s been described as a biopsy for the brain, but much less invasive. That’s the appeal of it.”
The technique is still in development but is being positioned as a potential way to detect and monitor Alzheimer’s disease through a simple blood draw rather than more invasive procedures. NAU reports that the approach is technically complex and requires careful laboratory work, but the potential clinical impact is significant.
Gibbons’s current work builds on an earlier study in which his team administered insulin intranasally — a route that allows more of the hormone to reach the brain than traditional injections. After treatment, the researchers sampled blood exiting participants’ brains and identified biomarkers associated with improved neuroplasticity. The new project is focused on detecting those same brain-related markers in circulating microvesicles, which could remove the need to sample blood directly from veins near the brain.
According to NAU, the research is unfolding in stages. First, the team is validating the method in healthy volunteers. Next, they plan to compare results among people with mild cognitive impairment and those diagnosed with Alzheimer’s disease, with the goal of tracking disease progression through changes in brain glucose metabolism reflected in the microvesicles.
The study team includes Gibbons, a member of the Arizona Alzheimer’s Consortium; Emily Cope, an NAU associate professor of biological sciences and fellow consortium member; NAU biological sciences Ph.D. student K. Riley Connor; and Philip Ainslie, a professor at the University of British Columbia’s Centre for Heart, Lung & Vascular Health.
“Brain function is notoriously hard to measure, but we’re getting better and better at interrogating brain function through biomarkers,” Gibbons said. He added that, if the approach proves successful, clinicians might one day be able to help people protect brain health and reduce Alzheimer’s risk in ways comparable to cardiovascular prevention — for example, through moderate exercise and healthy diet recommendations — potentially easing the burden of the disease on aging individuals and society.
