Higher glucose levels associated with lower memory and reduced hippocampal microstructure.
Level 4 - case-series / case-control
Cross-sectional observational study without longitudinal follow-up or intervention
PubMed 24153444 · doi:10.1212/01.wnl.0000435561.00234.ee
What was done
In a cross-sectional study of 141 healthy, nondiabetic, dementia-free older adults (72 women, mean age 63.1 ± 6.9 years), researchers assessed memory using the Rey Auditory Verbal Learning Test. Fasting peripheral HbA1c, glucose, and insulin were measured alongside 3-Tesla MRI scans to evaluate hippocampal volume and microstructure (gray matter barrier density). Linear regression and simple mediation models evaluated relationships among glycemic markers, memory, and hippocampal metrics.
What was found
Lower HbA1c and glucose levels were significantly associated with better scores in delayed recall, learning ability, and memory consolidation. HbA1c remained strongly associated with memory performance in multiple regression models. Mediation analyses indicated that the association between lower HbA1c and memory was partially mediated by hippocampal volume and microstructure. The abstract did not report exact numerical effect sizes, regression coefficients, or p-values.
Why it matters
This study indicates that higher blood glucose levels, even within normal ranges, are linked to worse memory and reduced hippocampal integrity in older adults. It highlights the potential value of testing glycemic interventions for cognitive preservation in non-diabetic populations.
Limits
The cross-sectional design prevents drawing causal or temporal conclusions. The sample size is modest (n = 141) and limited to healthy older individuals, and the abstract omits specific numerical estimates and confidence intervals.
Cited by
- supports Elevated fasting blood glucose levels and elevated cortisol levels are associated with hippocampal volume reduction.