Association of the Triglyceride-Glucose Index With Risk of Alzheimer's Disease: A Prospective Cohort Study

Triglyceride-glucose index (TyG) is a reliable surrogate marker of insulin resistance, and insulin resistance has been implicated in Alzheimer's disease pathophysiology. However, the relationship between the TyG index and Alzheimer's disease remains unclear. This study aimed to evaluate the association of the TyG index with the risk of Alzheimer's disease.This prospective study included 2,170 participants free of Alzheimer's disease from the Framingham Heart Study Offspring Cohort Exam 7 (1998-2001), whose follow-up data were collected until 2018. The TyG index was calculated as Ln(fasting triglyceride [mg/dL] × fasting glucose [mg/dL]/2). The association of the TyG index with Alzheimer's disease was evaluated by competing risk regression model. Statistical analyses were performed in 2023.During a median follow-up of 13.8 years, 163 (7.5%) participants developed Alzheimer's disease. When compared with the reference (TyG index ≤8.28), a significantly elevated risk of Alzheimer's disease was seen in the group with a triglyceride-glucose index of 8.68-9.09 (adjusted hazard ratio=1.69, 95% CI=1.02, 2.81). When the TyG index was considered as a continuous variable, each unit increment in the TyG index was not significantly associated with the risk of Alzheimer's disease (adjusted hazard ratio=1.32, 95% CI=0.98, 1.77).This study showed that moderately elevated TyG index was independently associated with a higher incidence of Alzheimer's disease. TheTyG index might be used to define a high-risk population of Alzheimer's disease.