Abstract
The current understanding of the correlation between insulin resistance (IR) and
cognitive dysfunction is limited. Therefore, the objective of this systematic
review and meta-analysis was to assess the association between the triglyceride
glucose (TyG) index, a recently suggested indicator of IR, and cognitive
impairment and dementia in the adult population. Observational studies pertinent
to our research were identified through comprehensive searches of the PubMed,
Embase, and Web of Science databases. To account for potential heterogeneity,
the random-effects models were employed to aggregate the findings. This
meta-analysis included ten observational studies involving 5602409 participants.
Compared to those with the low TyG index, subjects with the high TyG index were
significantly associated with the risk of cognitive impairment [risk ratio (RR):
1.39, 95% confidence interval (CI): 1.22 to 1.59, p<0.001; I2=45%) and
dementia (RR: 1.30, 95% CI: 1.06 to 1.60, p=0.01; I2=50%). The association was
consistent for Alzheimer’s disease (RR: 1.35, 95% CI: 1.04 to 1.76, p=0.03;
I2=54%) and vascular dementia (RR: 1.18, 95% CI: 1.13 to 1.24, p<0.001;
I2=0%). Subgroup analyses showed that the association between TyG index with
cognitive impairment and dementia were stronger in cross-sectional studies than
that in cohort studies (p for subgroup difference=0.02), but not significantly
modified by age, sex, or diabetic status of the participants. In conclusion, a
high TyG index may be associated with higher risk of cognitive impartment and
dementia in adult population.
Keywords
triglyceride glucose index - cognitive impairment - dementia - meta-analysis - insulin
