A prospective study on cortisol, dehydroepiandrosterone sulfate, and cognitive function in the elderly

Area of Science:

• Neuroendocrinology
• Cognitive Neuroscience
• Gerontology

Background:

• Adrenal steroid hormones like cortisol and dehydroepiandrosterone sulfate (DHEAS) play roles in brain function.
• Age-related cognitive changes are a significant public health concern.
• Understanding the relationship between hormonal fluctuations and cognitive health is crucial for developing interventions.

Purpose of the Study:

• To investigate the association between peripheral levels of cortisol and DHEAS and cognitive impairment and decline in healthy older adults.
• To explore the predictive value of these hormones for cognitive status over time.

Main Methods:

• Prospective study design involving 189 healthy participants aged 55-80 years from the Rotterdam Study.
• Measurement of fasting blood levels of DHEAS, cortisol, and corticosteroid-binding globulin.
• Assessment of cognitive function using the Mini-Mental State Examination (MMSE) at baseline and follow-up (average 1.9 years).
• Logistic regression analysis adjusted for age, sex, education, and depressive symptoms.

Main Results:

• An increase in free cortisol was associated with cognitive impairment (OR=1.5, not significant).
• Elevated cortisol levels after dexamethasone administration were linked to cognitive decline (OR=1.5).
• Dehydroepiandrosterone sulfate (DHEAS) showed a nonsignificant inverse relationship with cognitive impairment and decline (OR=0.5 and OR=0.6, respectively).
• The ratio of free cortisol to DHEAS was significantly associated with cognitive impairment (OR=1.8).

Conclusions:

• Basal free cortisol levels may be positively related to cognitive impairment in healthy elderly individuals.
• Cortisol levels post-dexamethasone treatment appear to be associated with cognitive decline.
• While DHEAS showed a trend towards a protective effect, its association with cognitive decline was not statistically significant.