Relationship Between Cortisol Levels and Memory Performance may be Modulated by the Presence or Absence of Cognitive Impairment: Evidence from Healthy Elderly, Mild Cognitive Impairment and Alzheimer's Disease Subjects

Abstract

An inverted U-shape function between cortisol levels and memory performance has been reported in studies on both young animals and humans. Yet little is known about this relationship in normal aging or in older subjects with cognitive impairment. This issue is particularly significant since increased levels of cortisol have been reported in Alzheimer's disease (AD). The present study examined the association between cortisol levels and visual memory performance in healthy subjects as well as in individuals presenting mild cognitive impairment (MCI) or AD. Salivary cortisol was measured in 40 healthy elderly subjects, 31 individuals with amnestic MCI, and 40 subjects with mild probable AD. Memory performance was evaluated using the Brief Cognitive Screening Battery. Higher cortisol levels were associated with better memory performance in healthy elderly (p=0.005), while higher cortisol levels were correlated with poorer memory performance in MCI subjects (p=0.011). No correlation between cortisol and memory was found in the AD group (p > 0.05). These results suggest that the relationship between cortisol levels and memory performance in the aging process could vary according to the presence or absence of cognitive impairment.

Daily stress magnifies the association between cognitive decline and everyday memory problems: An integration of longitudinal and diary methods.

“…Future work is needed to explore this and other possible interpretations. As Souza-Talarico and colleagues noted (2010), the moderating effects of cortisol on memory may be further complicated by changes in neuropathology and glucocorticoid receptors in the brain associated with cognitive decline. Future research could incorporate neuroimaging information and longitudinal data regarding cortisol profiles to examine the nature of the relationship between cognitive decline, memory problems, and cortisol profiles.…”

“…However, work has yet to examine whether physiological markers of stress are related to naturally-occurring reports of everyday memory problems, and whether physiological stress may exacerbate memory problems for individuals with fluid cognitive decline. Evidence from Souza-Talarico and colleagues found that individuals with mild cognitive impairment who had higher morning cortisol levels were more likely to have worse memory performance when compared to individuals with mild cognitive impairment who had lower morning cortisol levels (Souza-Talarico, Chaves, Lupien, Nitrini, & Caramelli, 2010). However, this work examined cortisol once in the morning rather than diurnal profiles over the course of a day, they examined cognitive functioning cross-sectionally rather than longitudinally, and they examined memory performance in the lab rather than naturally-occurring performance in everyday life.…”

Queixa subjetiva de comprometimento da memória em idosos saudáveis: influência de sintomas depressivos, percepção de estresse e autoestima

“…Additionally, the study also verified that the higher the stress level, the higher the SMC. These findings are quite important, as several studies indicate higher concentrations of cortisol and lower memory performance in healthy elderly individuals and individuals with pathologic cognitive deficit (8,(19)(20) .…”

Mild Cognitive Impairment with Associated Inflammatory and Cortisol Alterations as Independent Risk Factor for Postoperative Delirium

“…Venero et al [52] reported that, compared to cognitively normal controls, in subjects with naMCI or multidomain MCI profiles, increased waking salivary cortisol levels have been found. Higher cortisol measures have also been revealed in AD and are associated with poorer memory performance in subjects with cognitive decline [26,53]. Moreover, cortisol has been implicated as a potential biomarker for AD in the Australian Imaging Biomarker and Lifestyle Study [54].…”

“…Higher cortisol measures have been reported in AD and are associated with poorer memory performance in subjects with cognitive decline [26,27]. Moreover, significant increases in the levels of IL-6, IL-8 and IL-10 produced by peripheral blood mononuclear cells stimulated for 24 h with phytohemagglutinin have been demonstrated in MCI subjects compared to healthy elderly controls [25].…”