Cardiovascular Risk Indices Differentially Linked to Hippocampal Subfield Volumes: A Comparison Between Younger and Older Adults.

Hypertension predicted smaller subiculum volume in younger adults.

• Sample of younger adults was n=37, ages 18-29 years.
• The association was specific to the subiculum subfield, not other hippocampal regions.
• This finding suggests hypertension may have early detrimental effects on hippocampal structure even in young adulthood.
• Age moderated the relation between hypertension and subiculum volume.

Higher BMI was correlated with larger CA1-2 volumes in younger adults.

• This association was observed in the younger adult group (n=37, ages 18-29 years).
• The direction of the effect (larger volume) contrasts with the expected negative association seen with other cardiovascular risk indices.
• The association was specific to CA1-2 subfields rather than the subiculum or other regions.
• BMI did not show the same pattern in older adults, suggesting age-dependent effects.

Higher blood pressure variation (BPV) predicted smaller subiculum volume in older adults, independent of hypertension.

• Sample of older adults was n=22, ages 60-79 years.
• BPV's effect on subiculum volume was independent of hypertension status.
• This finding highlights BPV as a distinct cardiovascular risk index from hypertension for hippocampal aging in older adults.
• Age moderated the relation between BPV and subiculum volume.

Hypertension correlated with larger regional hippocampal volume in older adults, contrasting with the pattern seen in younger adults.

• In older adults (n=22, ages 60-79 years), hypertension was associated with larger rather than smaller regional volume.
• This is the opposite direction from the hypertension-subiculum association observed in younger adults.
• Age moderated the relation between hypertension and subiculum volume across the two groups.
• This differential association by age group suggests the effect of hypertension on hippocampal structure changes across the lifespan.

The subiculum showed greater sensitivity to cardiovascular risk indices compared to other hippocampal subfields.

• Hippocampal subfields examined included the dentate gyrus (DG), Cornu Ammonis (CA1-3), and subiculum.
• Multiple cardiovascular risk indices—hypertension, BPV, and BMI—showed subfield-specific rather than global hippocampal associations.
• The subiculum was implicated across multiple risk factors and both age groups, suggesting particular regional vulnerability.
• The specificity of findings to the subiculum underscores the importance of subfield-level analysis in hippocampal aging research.

Age moderated the relationship between cardiovascular risk indices and subiculum volume for all indices except waist-to-hip ratio.

• Cardiovascular risk indices examined were hypertension, blood pressure variation (BPV), BMI, and waist-to-hip ratio.
• Age moderation was observed for hypertension, BPV, and BMI in relation to subiculum volume.
• Waist-to-hip ratio was the only index for which age did not moderate the subiculum volume association.
• The study compared younger adults (n=37, ages 18-29) and older adults (n=22, ages 60-79).

The study examined cardiovascular risk indices and hippocampal subfield volumes in distinct younger and older adult cohorts using neuroimaging.

• Younger adult group: n=37, ages 18-29 years; older adult group: n=22, ages 60-79 years.
• Cardiovascular risk indices assessed included hypertension, blood pressure variation (BPV), BMI, and waist-to-hip ratio.
• Hippocampal subfields segmented included the dentate gyrus (DG), Cornu Ammonis (CA1-3), and subiculum.
• The study design allowed for comparison of age-dependent associations between cardiovascular risk and hippocampal subfield volumes.