Associations between cognitive function and naturally occurring daily cortisol during middle adulthood: timing is...

Area of Science:

• Psychoneuroendocrinology
• Cognitive Neuroscience
• Gerontology

Background:

• Cortisol, a key stress hormone, exhibits a diurnal rhythm that influences cognitive function.
• Understanding the interplay between daily cortisol profiles and cognitive performance is crucial for midlife health.
• Previous research has primarily focused on average cortisol levels, not daily patterns.

Purpose of the Study:

• To investigate the association between cognitive function (CF) and naturally occurring daily cortisol levels.
• To explore how different aspects of cognitive function relate to specific diurnal cortisol patterns.
• To emphasize the significance of cortisol sampling timing in research.

Main Methods:

• Utilized data from the Midlife in the United States survey and the National Study of Daily Experiences.
• Analyzed a national sample of 1,500 adults (mean age 57 years).
• Collected saliva samples over 4 days to measure cortisol at multiple time points (waking, 30 min post-waking, lunch, bedtime).

Main Results:

• Higher cognitive function, especially executive function, correlated with healthier daily cortisol profiles.
• Healthier profiles included a steeper diurnal cortisol slope (faster decline).
• Higher morning cortisol levels and lower afternoon/evening levels were associated with better CF.

Conclusions:

• Enhanced cognitive function is associated with more optimal diurnal cortisol patterns.
• The findings underscore the importance of considering the timing of cortisol measurements in research.
• This research contributes to understanding the bidirectional relationship between stress physiology and cognition.