A SIMPLE blood test measuring insulin resistance can predict rapid cognitive decline in early Alzheimer’s disease, according to study results presented recently at the 11th European Academy of Neurology (EAN) Congress in Helsinki, Finland.
Metabolic dysfunction, particularly insulin resistance, is increasingly recognised as a key factor in the development of Alzheimer’s disease, but its influence on the rate of cognitive decline has been less clear. Identifying reliable, accessible markers to forecast disease progression could help clinicians tailor interventions and support families in planning for the future.
In a retrospective single-centre study conducted at the University of Brescia, researchers analysed data from 315 non-diabetic patients with neurodegenerative conditions, including 210 with cerebrospinal fluid-confirmed Alzheimer’s disease and 115 with other neurodegenerative disorders. All participants underwent baseline clinical and biochemical assessments, including calculation of the triglyceride-glucose (TyG) index (a routine marker of insulin resistance) followed by at least six months of clinical follow-up. Patients were grouped into tertiles based on their TyG index. In the subgroup of 161 patients with mild cognitive impairment due to Alzheimer’s disease, those in the highest TyG tertile were over four times more likely to experience rapid cognitive decline, defined as a loss of more than 2.5 points per year on the Mini Mental State Examination (hazard ratio: 4.08; 95% CI: 1.06–15.73). This association was not observed in patients with other neurodegenerative diseases. High TyG in Alzheimer’s patients was also linked to greater cardiovascular risk and markers of blood–brain barrier disruption, but did not interact with the APOE ε4 genotype. No significant effect of TyG was seen on progression in the non-Alzheimer’s group.
These findings suggest that insulin resistance, measured using the TyG index, is a disease-specific predictor of cognitive decline in early Alzheimer’s, but not in other neurodegenerative conditions. For clinical practice, this means that a widely available, low-cost blood test could help identify Alzheimer’s patients at higher risk of rapid deterioration, enabling more targeted use of lifestyle interventions, metabolic therapies, or inclusion in clinical trials for disease-modifying treatments.
Reference
Gumina B et al. The Triglyceride-Glucose Index as predictor of cognitive decline in alzheimer’s spectrum disorders. Abstract OPR-066. EAN Congress, 21-24 June, 2025.
