Triglyceride-glucose index, Alzheimer's disease plasma biomarkers, and dementia in older adults: The MIND-China study

IntroductionPopulation-based studies have rarely explored the associations of the triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, with dementia and plasma biomarkers for amyloid beta (A beta) and neurodegeneration. MethodsThis population-based study included 5199 participants (age >= 65 years); of these, plasma A beta, total tau, and neurofilament light chain (NfL) were measured in 1287 persons. Dementia and subtypes were diagnosed following the international criteria. TyG index was calculated as ln(fasting triglyceride(mg/dL) x fasting glucose[mg/dL]/2). Data were analyzed using logistic and general linear regression models. ResultsDementia, Alzheimer's disease (AD), and vascular dementia (VaD) were diagnosed in 301, 195, and 95 individuals, respectively. A high TyG index was significantly associated with increased likelihoods of dementia and AD; the significant association with dementia remained among participants without cardiovascular disease or diabetes. In the biomarker subsample, a high TyG index was correlated with elevated plasma A beta, but not with total tau or NfL. DiscussionHigh TyG index is associated with dementia, possibly via A beta pathology.