Triglyceride–glucose index, Alzheimer's disease plasma biomarkers, and dementia in older adults: The MIND‐China study
Na Tian, Wenxin Fa, Yi Dong, Rui Liu, Cuicui Liu, Keke Liu, Ming Mao, Min Zhu, Xiaoyan Liang, Nan Wang, Yixun Ma, Tiia Ngandu, Lenore J. Launer, Yongxiang Wang, Tingting Hou, Yifeng Du, Chengxuan Qiu
Abstract
Introduction: Population-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 (Aβ) and neurodegeneration. Methods: This population-based study included 5199 participants (age ≥ 65 years); of these, plasma Aβ, 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) × fasting glucose[mg/dL]/2). Data were analyzed using logistic and general linear regression models. Results: Dementia, 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 Aβ, but not with total tau or NfL. Discussion: High TyG index is associated with dementia, possibly via Aβ pathology.