Increased saliva cortisol awakening response in patients with mild cognitive impairment
ABSTRACT It is unknown whether HPA-axis dysfunction is present in patients with mild cognitive impairment (MCI). The aim of the present study was to investigate whether cortisol levels are elevated among patients with MCI and/or whether the individuals have adequate feedback control of their HPA axis.
27 patients with MCI and 15 healthy controls were included in the study. Saliva samplings were performed 5 times a day before intake of 0.5 mg dexamethasone, and 5 times a day after intake of dexamethasone, respectively.
Significantly higher cortisol levels were found 15 min after awakening among patients with MCI in comparison with the controls, both before and after dexamethasone administration (p<0.05). Also, the ratio between cortisol at awakening time and 15 min after awakening was lower in the patient group after dexamethasone administration (p<0.05). There were no significant differences in basal cortisol levels before or after dexamethasone between groups.
The results indicate that there is an HPA-axis disturbance, with normal basal cortisol levels and increased awakening response among patients with MCI. The dissociation between basal values and the awakening response may be of pathophysiological importance for the cognitive impairment.
- SourceAvailable from: Stuart Watson
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- "The CAR has been examined in relation to cognitive function in a number of studies in both healthy subjects and patients with a variety of psychiatric illnesses (e.g. Lind et al., 2007; Aas et al., 2011; van der Werf-Eldering et al., 2012). Studies examining the relationship between CAR and memory performance have been largely equivocal , although a study by Almela et al. (2012) did suggest a quadratic relationship between CAR and measures of declarative memory processes in 55-to 77-year-olds. "
ABSTRACT: Objective The association between hypothalamic–pituitary–adrenal (HPA)-axis function and cognition has long been investigated. An inverted U-shaped relationship has been described between various measures of HPA-axis function and neuropsychological performance in animals and man. Work with glucocorticoid receptor manipulation has corroborated these findings, with particular effects observed in relation to spatial working memory (SWM). As HPA-axis dysfunction is frequently found in patients with psychiatric illness, research in this area has potential implications for the treatment of the commonly observed cognitive impairment in such disorders. Here, we present the results of a pilot study examining the relationship between cortisol awakening response (CAR) and cognitive functions known to be susceptible to HPA-axis manipulation.Methods Nineteen healthy male volunteers were recruited, and their CAR and performance in a task of SWM were assessed.ResultsA highly significant quadratic relationship was observed between the CAR and SWM error rate (R2 = 0.63, p = 0.001).Conclusion We provide novel evidence supporting the existence of an inverted U-shaped relationship between corticosteroid levels and cognitive function in humans. Copyright © 2014 John Wiley & Sons, Ltd.Human Psychopharmacology Clinical and Experimental 05/2014; 29(3). DOI:10.1002/hup.2399 · 1.85 Impact Factor
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- "As there are no longitudinal studies revealing to what degree early stress induces reduced hippocampal volume , changes in serotonin receptor levels, dysfunction in the HPA-axis response results in depression, it is not yet possible to determine whether these features comprise purely risk factors or are also causal effectors of the disease. In any case, what is interesting is that both reduced hippocampal volume  , hyperresponsive HPA-axis , and changes in serotonin receptor levels  are by themselves associated with increased risk for developing AD. "
ABSTRACT: The existence of a high co-morbidity between Alzheimer's disease (AD) and depression has been known for a long time. More interesting though are recent studies indicating that depression and number of depressive episodes earlier in life is associated with increased risk of AD development. This suggests the existence of common neuropathological mechanisms behind depression and AD. Here we propose that the brain changes associated with depressive episodes that compromise the brain's ability to cope with stress may constitute risk factors for development of AD. Furthermore, in individuals with a genetic linkage to depression, there may be an increased vulnerability towards the initiation of a detrimental neurodegenerative cascade. The following review will deal with the various observations reported within the different neurobiological systems known to be involved and affected in depression, like serotonergic and cholinergic system, hypothalamic-pituitary-adrenal axis and brain derived neurotrophic factor, and discussed in relation to AD.Journal of Alzheimer's disease: JAD 01/2011; 23(2):177-93. DOI:10.3233/JAD-2010-100390 · 4.15 Impact Factor
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- "Although the current literature recommends five readings of cortisol levels taken throughout the day to assess the diurnal rhythm secretion of glucocorticoids , some authors have demonstrated that morning cortisol levels also represent a reliable measure of basal hypothalamic-pituitary-adrenal (HPA) axis activity  . Moreover, results from diurnal rhythm of cortisol assessment in both MCI and AD subjects have revealed that when high cortisol levels were detected in these individuals, this tended to occur during the morning after awakening  . "
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.Journal of Alzheimer's disease: JAD 01/2010; 19(3):839-48. DOI:10.3233/JAD-2010-1282 · 4.15 Impact Factor