Sex differences in cortisol and memory following acute social stress in amnestic mild cognitive impairment

Older adults with amnesic mild cognitive impairment (aMCI) develop Alzheimers-type Dementia approximately ten times faster annually than the normal population. Higher levels of adrenal hormones are associated with both aging and cognitive decline. In this study, salivary cortisol was sampled diurnally and during memory testing to explore differences in the relationship between cortisol and memory function in males and females with normal cognition and those with aMCI. Participants with aMCI (n=14, mean age=75) were compared to age-matched controls (n=14, mean age=75) on tests of episodic, associative, and working memory across two sessions with a psychosocial stressor in the second session. The aMCI group performed worse on the memory tests than controls and males with aMCI had consistently elevated cortisol levels on both test days. Immediate episodic memory performance was enhanced by stress in controls but not in the aMCI group, indicating that aMCI is associated with increased vulnerability to stress-induced alterations in cortisol that can negatively impact memory function.