- Asymptomatic middle-aged adults with higher cortisol levels had worse cognitive function and smaller brain volumes, as well as evidence of altered brain microstructure.
Why this matters
- Previous studies have focused mainly on older adults and a limited number of brain areas.
- Participants with top-tertile vs middle-tertile cortisol levels had:
- Worse global cognition (β, –0.18; P=.001);
- Worse visual perception, Hooper Visual Organization Test (−0.08; P=.002);
- Smaller total cerebral brain volume (−0.38; P=.008);
- Smaller occipital gray volume (−0.05; P=.052); and
- Smaller frontal lobe gray volume (−0.12; P=.006).
- Sex difference for association of higher cortisol with smaller cerebral brain volume:
- Significant in women (β, −0.73; P=.001);
- Not significant in men (β, −0.07; P=.717).
- APOE4 genotype did not significantly modify association of cortisol with cognitive or imaging measures.
- Cross-sectional cohort study of 2231 dementia-free Framingham Heart Study (generation 3) participants with mean age of 48.5 years.
- Main outcomes: cognitive measures, brain MRI measures.
- Funding: Framingham Heart Study’s National Heart, Lung, and Blood Institute Study; others.
- Causal and temporal relationships unknown.
- Cortisol measured only once.
- Unclear generalizability.