Researchers have identified a simple blood test that can predict which early Alzheimer’s patients are most at risk for rapid cognitive decline. The TyG index, which measures insulin resistance, identified patients who were four times more likely to experience faster disease progression, offering a powerful new tool for early intervention and treatment planning.

The TyG Index Discovery

The triglyceride-glucose (TyG) index is calculated using routine blood tests for triglycerides and fasting glucose levels. In a study of early Alzheimer’s patients, researchers found that those with high insulin resistance as measured by the TyG index showed significantly faster cognitive decline over time. This finding builds on growing evidence that metabolic dysfunction, particularly insulin resistance, plays a crucial role in Alzheimer’s disease development and progression (Clinical Research, June 22, 2025).

Insulin Resistance and Brain Function

Insulin resistance impairs the brain’s ability to use glucose effectively, leading to cellular energy deficits and increased inflammation. The brain consumes approximately 20% of the body’s glucose, making it particularly vulnerable to insulin-related metabolic dysfunction. When brain cells cannot efficiently use glucose for energy, they become more susceptible to the toxic effects of amyloid plaques and tau tangles that characterize Alzheimer’s disease. This metabolic vulnerability explains why diabetes is associated with doubled Alzheimer’s risk (Clinical Research, June 22, 2025).

Clinical Applications and Early Intervention

The TyG index test could revolutionize Alzheimer’s care by identifying patients who need more aggressive early intervention. Those with high insulin resistance scores could benefit from intensified lifestyle modifications, including specific dietary changes, exercise programs, and potentially medications that improve insulin sensitivity. Early identification of rapid progressors allows families to make informed decisions about care planning and treatment options while patients still have decision-making capacity. The test’s simplicity and low cost make it accessible for widespread clinical use (Clinical Research, June 22, 2025).

My Recommendations

If you have early signs of cognitive decline or a family history of Alzheimer’s disease, ask your doctor about testing your TyG index using routine triglyceride and fasting glucose measurements. Regardless of your TyG score, focus on improving insulin sensitivity through regular exercise, particularly resistance training and aerobic activity. Follow a diet that emphasizes whole foods, limits refined carbohydrates, and includes anti-inflammatory foods like fatty fish, leafy greens, and berries. Maintain a healthy weight and manage other cardiovascular risk factors, as what’s good for your heart is good for your brain. If your TyG index is elevated, work with your healthcare provider to address insulin resistance aggressively through lifestyle modifications and appropriate medical management.