Sex differences in the association between the change in triglyceride‑glucose index and cognitive decline: A population-based cohort study

Previous studies indicated that insulin resistance (IR) was related to cognitive decline. This study aimed to investigate whether triglyceride-glucose (TyG) as a surrogate marker of IR can detect the association between IR and cognitive decline, and explore sex-specific association between the longitudinal change in TyG index and cognitive decline in the middle-aged and elderly population in China. Data from the China Health and Retirement Longitudinal Study, which include 2358 females and 2062 males, were used. The TyG index was calculated as ln (fasting triglyceride [mg/dL] × fasting blood glucose [mg/dL] / 2). Cognitive score was measured by word recall test and mental status test. Logistic regression was used to assess the association between change in TyG index and cognitive decline in men and women from 2011 to 2015, respectively. Subgroup analysis by age was also performed. The fourth quartile of change in TyG index was significantly associated with the increased risk of decline in global cognition compared with the first quartile in men [odds ratio (OR) 1.32, 95 % CI 1.03 to 1.71]. Stratified by age groups, the significant association between TyG index and cognitive decline was only found in men aged under 60 years old (OR 1.51, 95 % CI 1.07 to 2.13). We only observed the association between TyG index and cognitive decline, but not the severity of the decline. The increased TyG index is related to the risk of cognitive decline in men. This study provided new evidence for formulating sex-specific prevention and treatment strategies for cognitive decline.