Association of Triglyceride-Glucose Index With Cognitive Function and Brain Atrophy: A Population-Based Study

Am J Geriatr Psychiatry. 2024 Feb;32(2):151-162. doi: 10.1016/j.jagp.2023.09.007. Epub 2023 Sep 16.

Abstract

Objective: To investigate the associations of triglyceride-glucose (TyG) index, a reliable surrogate marker for insulin resistance, with the function of various cognitive domains and brain structures among older adults.

Design: A population-based cross-sectional study.

Setting: Older adults living in the rural communities in China.

Participants: About 4,541 rural-dwelling dementia-free participants (age ≥65 years; 56.37% women) undertook examinations in March-September 2018 for MIND-China.

Measurements: TyG index was calculated as ln[fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. A neuropsychological test battery was used to assess memory, attention, verbal fluency, and executive function. Volumetric brain measures were assessed on magnetic resonance imaging (MRI) in a subsample (n = 1,019). Data were analyzed with restricted cubic spline and multivariable general linear models.

Results: An inverted J-shaped association was observed between TyG index and z-scores of multiple cognitive domains, such that among individuals with TyG index ≥8.57 (median), a higher TyG index was significantly associated with lower z-scores of memory, attention, verbal fluency, executive function, and global cognition (all p < 0.05); among people with TyG index <8.57, a higher TyG index was significantly associated with a higher executive function z-score (p < 0.05), but not with any of the other examined cognitive domains. In the MRI subsample, a higher TyG index was significantly associated with lower volumes of total brain tissue, gray matter, and white matter as well as greater cerebrospinal fluid volume (p < 0.05), but not with white matter hyperintensity volume.

Conclusions: Insulin resistance, as indicated by a high TyG index, was associated with poor function in multiple cognitive domains and global brain atrophy.

Keywords: Cognitive function; TyG index; insulin resistance; population-based study; structural brain aging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Atrophy
  • Biomarkers
  • Blood Glucose
  • Brain / diagnostic imaging
  • Cognition
  • Cross-Sectional Studies
  • Female
  • Glucose*
  • Humans
  • Insulin Resistance*
  • Male
  • Risk Factors
  • Triglycerides

Substances

  • Glucose
  • Blood Glucose
  • Triglycerides
  • Biomarkers