A routine blood test may help identify which patients with early signs of Alzheimer’s are likely to deteriorate more rapidly, new research suggests.
The test uses the triglyceride-glucose (TyG) index – a measure based on levels of fat and sugar in the blood – to detect insulin resistance, a condition where the body responds less effectively to insulin, the hormone that regulates blood sugar.
In a study of 315 non-diabetic people with cognitive problems, including 200 with Alzheimer’s disease, those with the highest TyG scores experienced cognitive decline four times faster over three years than those with lower scores.
Researchers from the University of Brescia in Italy focused on people with mild cognitive impairment due to Alzheimer’s – a condition involving early memory and thinking difficulties.
The findings suggest insulin resistance may accelerate Alzheimer’s progression by reducing the brain’s ability to use glucose for energy, promoting inflammation, and disrupting the blood-brain barrier – the protective layer that controls what substances can pass into brain tissue.
It may also contribute to the build-up of amyloid, a toxic protein found in the brains of people with Alzheimer’s.
The researchers found that high TyG scores were associated with disruption of the blood-brain barrier and cardiovascular risk factors. However, they found no link between elevated TyG levels and other neurodegenerative diseases.
Dr Bianca Gumina, lead researcher, said: “Once mild cognitive impairment is diagnosed, families always ask how fast it will progress.
“Our data shows that a simple metabolic marker available in every hospital laboratory can help identify more vulnerable subjects who may be suitable candidates for targeted therapy or specific intervention strategies.”
The findings will be presented at the European Academy of Neurology Congress in Helsinki.