To comprehensively characterize diurnal salivary cortisol in a large, racially diverse cohort of older adults and examine its associations with cognitive decline and incident Alzheimer’s Disease (AD).
Approach:
Study Design: Cohort study conducted as part of the Chicago Health and Aging Project (CHAP) involving nearly 4000 older adults.
Data Collection: Saliva samples were collected at three times daily (morning, afternoon, evening) to assess diurnal cortisol patterns.
Cohort Characteristics: Participants included a stratified random sample of Black and White older adults from the South Side of Chicago.
Cortisol Measurement: Five indices of diurnal HPA axis activities were derived to evaluate their associations with cognition and incident AD.
Key Findings:
Salivary cortisol is a noninvasive and specific marker of biologically active cortisol exposure.
Higher peripheral cortisol levels have been linked to hippocampal atrophy and increased AD risk.
Existing studies show mixed results on the relationship between cortisol levels and cognitive outcomes.
Interpretation:
Limitations:
Previous studies often utilized cross-sectional designs and small, homogeneous samples.
Limited examination of nonlinear associations and longitudinal cognitive change.
Conclusion:
The study aims to fill gaps in understanding the relationship between diurnal cortisol patterns and cognitive decline in a diverse older adult population.
A regional UK audit found wide variation in imaging intervals among patients referred for mechanical thrombectomy and identified potentially modifiable barriers to timely vascular imaging.
