Innovative Blood Test Indicates Alzheimer's Cognitive Decline Risk

Helsinki, Finland — A groundbreaking study presented at the European Academy of Neurology (EAN) Congress 2025 has revealed that insulin resistance, as indicated by the triglyceride-glucose (TyG) index, can effectively predict cognitive decline in individuals with early-stage Alzheimer's disease. This research, conducted by neurologists at the University of Brescia, focused on 315 non-diabetic patients presenting cognitive deficits, including 200 diagnosed with biologically confirmed Alzheimer's disease.

The study, led by Dr. Bianca Gumina, assessed the TyG index alongside a clinical follow-up over three years. It found that patients categorized in the highest third of TyG values exhibited a significantly accelerated cognitive decline, losing more than 2.5 points annually on the Mini Mental State Examination, with a hazard ratio of 4.08 (95% CI 1.06–15.73). Notably, no similar correlation was found in non-Alzheimer’s patients, indicating a unique metabolic vulnerability associated with Alzheimer's.

"Once mild cognitive impairment is diagnosed, families always ask how fast it will progress," Dr. Gumina explained. "Our data show 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."

Insulin resistance has previously been linked to the onset of Alzheimer's, but its influence on the disease's progression had been under-explored. This research highlights the role of metabolic dysfunction during the prodromal mild cognitive impairment (MCI) stage, suggesting that identifying high-TyG patients could refine selection for clinical trials aimed at anti-amyloid or anti-tau therapies and prompt earlier lifestyle or pharmacological interventions to improve insulin sensitivity.

The study's findings are particularly relevant given the increasing prevalence of Alzheimer’s disease globally. According to the World Health Organization (WHO), an estimated 55 million people worldwide live with dementia, a number projected to rise to 78 million by 2030. This alarming trend underscores the need for reliable predictive markers to aid in early detection and intervention.

Dr. Gumina and her team found that high TyG levels were also associated with blood-brain barrier disruption and cardiovascular risk factors. Interestingly, they noted no interaction with the APOE ε4 genotype, suggesting that metabolic and genetic risks operate through distinct pathways. This finding may inform future research into targeted therapies that address metabolic issues in Alzheimer’s patients.

The researchers are currently investigating whether TyG levels correlate with neuroimaging biomarkers, which could further aid in the early detection and stratification of Alzheimer's disease. "If targeting metabolism can delay progression, we will have a readily modifiable target that works alongside emerging disease-modifying drugs," Dr. Gumina concluded.

This study represents a significant advancement in understanding the relationship between metabolic health and cognitive decline, potentially offering new avenues for intervention and improved patient outcomes in Alzheimer’s disease management. As ongoing research unfolds, it may pave the way for innovative strategies that integrate metabolic health into Alzheimer’s care, ultimately enhancing the quality of life for those affected by this debilitating condition.