Diurnal variation of cortisol in people with dementia: relationship to cognition and illness burden

Psychobiological Monitoring of a Home-Based Dyadic Intervention for People Living with Dementia and Their Caregivers: Added Value to Evaluate Treatment Success and Understand Underlying Mechanisms

BACKGROUND

Research concerning people living with dementia (PwD) and their informal caregivers (ICs) has recently begun to focus on dyadic aspects of psychosocial interventions.

OBJECTIVE

We adapted a dyadic psychosocial intervention and examined its effects on psychobiological stress in daily life.

METHODS

Twenty-four PwD-caregiver dyads were visited seven times at home by specialized nursing staff. Momentary subjective stress, salivary cortisol (sCort), and salivary alpha-amylase (sAA) were measured in PwD and ICs before and after each home visit as well as six times per day at two days each at the beginning and end of the intervention as part of an ambulatory assessment. Hair cortisol concentrations (HCC) were measured twice.

RESULTS

After each home visit session, ICs reported lower subjective stress. sCort was lower in both ICs and PwD, whereas sAA did not change. In daily life, area under the curve (AUCg) concerning sCort secretion indicated that PwD had lower sCort daily output at the end of the intervention, and AUCg concerning subjective stress indicated that both PwD and ICs reported lower subjective stress than at the beginning of the intervention. AUCg concerning sAA did not change over time in either group. HCC did not vary over time but increased with disease severity.

CONCLUSION

The psychosocial intervention reduced psychobiological stress but affected psychobiological stress measures differently in PwD and ICs. In particular, the discrepancy between subjective and physiological markers of stress in PwD emphasizes the added value to evaluate treatment success and understand underlying mechanisms as a complement to self-reports.

Feasibility of Hair Cortisol as a Biomarker of Chronic Stress in People With Dementia

Hair cortisol concentrations (HCC) are an innovative way to measure chronic stress relying on a small sample of hair. To date, there are no studies that have studied HCC as a biomarker of chronic stress in individuals with dementia. Given the vulnerability to chronic stress in people with dementia, using HCC as an objective measure of physiological stress in those with dementia has potential to enhance our understanding of this population. The goal of this exploratory, multidisciplinary, pilot study was to establish feasibility of HCC testing in people with dementia as a biomarker of chronic stress. HCC was examined over a 6-month period to assess physiological stress response during a transition to memory care. Newly admitted memory care residents ( n = 13, mean age = 82) were followed over 6 months. Residents’ hair samples and health information were collected at 3-month intervals. HCC levels significantly changed during the transition to memory care, which may reflect chronic physiological stress. Participants with frequent behavioral and psychological symptoms of dementia (BPSD) had significantly lower HCC at baseline and exhibited a blunted cortisol reactivity at follow-up. Based on detected changes in HCC, participants likely experienced stress reactions during the transition to memory care, providing preliminary evidence that HCC may be a useful, non-invasive measure of physiological stress in this population. This approach may also be applied to understanding the significance of person-centered care environments on minimizing chronic stress for people with dementia.

Psychophysiological Responses in People Living with Dementia after an Art Gallery Intervention: An Exploratory Study

The use of existing public spaces by people living with dementia, such as museums and art galleries, are becoming popular due to their ability to facilitate programs which promote social engagement and inclusion. However, few studies have investigated physiological outcomes of art gallery-based programs. Using a quasi-experimental design, the present study aimed to investigate the levels of salivary biomarkers of cortisol and interleukin-6, quality of life (QoL), depressive symptoms, cognition, and wellbeing, after attending the National Gallery of Australia (NGA) Art and Dementia program. Twenty-eight people living with dementia, each supported by a carer or family member, were recruited for a six-week program and were followed up at twelve weeks. In total, 25 participants (17 female; mean age 84.6±7.27 years) completed the study, and 22 provided viable saliva samples. The waking to evening salivary cortisol ratio was higher post-intervention (p = 0.033), and returned to baseline levels at follow-up (p = 1.00), indicating a more dynamic salivary cortisol rhythm in response to the six-week program. Interleukin-6 levels remained unchanged (p = 0.664). No improvements in QoL (DEMQOL-Carer) were observed between baseline and post-intervention (p = 0.076). However, self-reported depressive symptoms decreased post-intervention compared with baseline (p = 0.015), and memory (immediate recall) (p = 0.009) and verbal fluency (p = 0.027) improved between the same timepoints. The NGA Art and Dementia program appears to have quantifiable benefits, including improved hypothalamic-pituitary-adrenal axis function, justifying a need for longer controlled trial inclusive of physiological outcomes.

Psychophysiological Effects of Dance Movement Therapy and Physical Exercise on Older Adults With Mild Dementia: A Randomized Controlled Trial

OBJECTIVES

Dementia interferes with older adults' functioning in cognitive, daily, psychosocial, and neuroendocrine domains. The present study examined the psychophysiological effects of dance movement therapy (DMT) and physical exercise for older adults with dementia.

METHODS

This randomized controlled trial recruited 204 older adults diagnosed with mild dementia into the DMT, exercise, or waitlist control group. Both DMT and exercise interventions had similar intensity and comprised 24 hr of intervention that spanned over 12 weeks. All participants completed self-report questionnaires on psychosocial well-being, daily functioning, neurocognitive assessments, and salivary cortisol measures at baseline and 3 follow-up measurements more than 1 year.

RESULTS

The DMT group showed significant decreases in depression, loneliness, and negative mood (d = 0.33-0.42, p < .05) and improved daily functioning (d = 0.40, p < .01) and diurnal cortisol slope (d = 0.30, p < .01). The effects on daily functioning and cortisol slope remained at 1-year follow-up. The exercise group of matched intensity showed no significant effects on the outcomes.

DISCUSSION

The study findings support the potential utility of DMT as a multifaceted intervention for improving various aspects of functioning in older adults with declining cognitive abilities. The lack of beneficial effects for our exercise intervention and long-term DMT effects highlights the need to maintain persistent levels of exercise with adequate intensity and duration.

Current State of Saliva Biomarkers for Aging and Alzheimer's Disease

INTRODUCTION

Aging is the primary risk factor for major human pathologies, including cancer, diabetes, cardiovascular diseases, and neurodegenerative diseases such as Alzheimer's Disease (AD). AD is a progressive degenerative disorder of the brain and is the most common form of dementia.

METHODS

To-date no simple, inexpensive and minimally invasive procedure is available to confirm with certainty the early diagnosis of AD prior to the manifestations of symptoms characteristic of the disease. Therefore, if population screening of individuals is to be performed, easily accessible tissues would need to be used for a diagnostic test that would identify those who exhibit altered or aberrant aging profiles that may be indicative of AD risk, so that they can be prioritized for primary prevention. This need for minimally invasive tests could be achieved by targeting saliva, since it is now well recognized that many aging diseases including AD are associated with peripheral biomarkers that are not only restricted to pathology and biomarkers within the brain.

RESULTS

Therefore, the aim of this review is to summarize some of the main findings of salivary biomarkers of aging and AD; including various proteins, metabolites, and alterations to DNA and miRNA. The future of healthy aging resides in innovative platforms, biosensors and point-of-care devices that can extract real time information on the health status of an individual. Those platforms may be achieved through the development and validation of novel biomarkers of health using saliva which, although being the least explored for biomedical purposes, has the distinct advantage that it can be self-collected in a non-invasive manner.

The effects of stress on cardiovascular disease and Alzheimer's disease: Physical exercise as a counteract measure

AD is a complicated multi-systemic neurological disorder that involves different biological pathways. Several risk factors have been identified, including chronic stress. Chronic stress produces an alteration in the activity of the hypothalamic pituitary adrenal (HPA) system, and the autonomic nervous system (ANS), which over time increase the risk of AD and also the incidence of cardiovascular disease (CVD) and risk factors, such as hypertension, obesity and type 2 diabetes, associated with cognitive impairment and AD. Considering the multi-factorial etiology of AD, understanding the complex interrelationships between different risk factors is of potential interest for designing adequate strategies for preventing, delaying the onset or slowing down the progression of this devastating disease. Thus, in this review we will explore the general mechanisms and evidence linking stress, cardiovascular disease and AD, and discuss the potential benefits of physical activity for AD by counteracting the negative effects of chronic stress, CVD and risk factors.

Exercise, the diurnal cycle of cortisol and cognitive impairment in older adults

Exercise has been shown to reduce the risk of developing Mild Cognitive Impairment and Alzheimer's disease as well as to improve cognition in healthy and cognitively impaired individuals. However, the mechanisms of these benefits are not well understood. The stress hypothesis suggests that the cognitive benefits attributed to exercise may partially be mediated by changes in the cortisol secretion pattern. Chronic stress may increase the risk of AD and exacerbate the cognitive deficits and brain pathology characteristic of the condition while physical activity has been shown to attenuate most of stress consequences and risk factors for AD. Initially, research on the effects of cortisol on cognition and physical activity focused on cortisol levels at one time point but the circadian pattern of cortisol secretion is complex and it is still unclear which aspects are most closely associated with cognitive function. Thus, the aim of this review was to analyze the exercise/stress/cognition hypothesis focusing on the effects of the diurnal cycle of cortisol on cognitive function and physical activity in older adults with and without cognitive impairment.

Circadian Rhythm Sleep-Wake Disorders

PURPOSE OF REVIEW

The endogenous circadian rhythms are one of the cardinal processes that control sleep. They are self-sustaining biological rhythms with a periodicity of approximately 24 hours that may be entrained by external zeitgebers (German for time givers), such as light, exercise, and meal times. This article discusses the physiology of the circadian rhythms, their relationship to neurologic disease, and the presentation and treatment of circadian rhythm sleep-wake disorders.

RECENT FINDINGS

Classic examples of circadian rhythms include cortisol and melatonin secretion, body temperature, and urine volume. More recently, the impact of circadian rhythm on several neurologic disorders has been investigated, such as the timing of occurrence of epileptic seizures as well as neurobehavioral functioning in dementia. Further updates include a more in-depth understanding of the symptoms, consequences, and treatment of circadian sleep-wake disorders, which may occur because of extrinsic misalignment with clock time or because of intrinsic dysfunction of the brain. An example of extrinsic misalignment occurs with jet lag during transmeridian travel or with intrinsic circadian rhythm sleep-wake disorders such as advanced or delayed sleep-wake phase disorders. In advanced sleep-wake phase disorder, which is most common in elderly individuals, sleep onset and morning arousal are undesirably early, leading to impaired evening function with excessive sleepiness and sleep-maintenance insomnia with early morning awakening. By contrast, delayed sleep-wake phase disorder is characterized by an inability to initiate sleep before the early morning hours, with subsequent delayed rise time, leading to clinical symptoms of severe sleep-onset insomnia coupled with excessive daytime sleepiness in the morning hours, as patients are unable to "sleep in" to attain sufficient sleep quantity. Irregular sleep-wake rhythm disorder is misentrainment with patches of brief sleep and wakefulness spread throughout the day, leading to unstable sleep and waking behavioral patterns and an entirely idiosyncratic sleep-wake schedule.

SUMMARY

Familiarity with these major circadian rhythm sleep-wake disorder phenotypes and their overlap with other neurologic disorders is essential for the neurologist so that clinicians may intervene and improve patient functioning and quality of life.

A Randomized Controlled Trial Examining the Effect of Acupressure on Agitation and Salivary Cortisol in Nursing Home Residents with Dementia

BACKGROUND

Acupressure has been used to manage agitation in people with dementia because it is safe and inexpensive. However, its effect on agitation and at the biochemical level is uncertain.

METHODS

This randomized controlled trial examined the effect of acupressure on agitation, as measured by the Cohen-Mansfield Agitation Inventory (CMAI); and on salivary cortisol, as measured at baseline (T0) and in the 3rd (T1), 5th (T2), and 8th (T3) weeks. There were 119 agitated residents with dementia randomized into 3 groups: acupressure (n = 39), sham (n = 41), and usual-care group (n = 39).

RESULTS

A downward trend in agitation over time was noted in the acupressure group, which almost reached a level of significance in interaction effects between groups and time points (p = 0.052). Post hoc pairwise tests in the acupressure group showed that acupressure significantly reduced agitation at T2 (mean difference -6.84, 95% CI -10.60, -3.08) compared to baseline. Significant interaction effects between groups and time points were observed on the level of salivary cortisol (p = 0.022).

CONCLUSION

Acupressure is a multicomponent intervention that can reduce agitation. Acupoint activation may not be a significant component in reducing agitation, although this result may have been limited by the inadequate sample size. Acupressure is effective in reducing salivary cortisol in people with dementia.

Effect of cortisol diurnal rhythm on emotional memory in healthy young adults

Few studies have investigated the relationship between cortisol diurnal rhythm and cognitive function in healthy young adults, especially for emotional memory. To address this deficiency, this study examined the effect of diurnal cortisol slope (DCS) and heart rate variability (HRV) on emotional memory. Participants included healthy volunteers (44 men and 23 women; mean age 20.60 yrs). Participants were shown emotionally arousing slides and were asked to return to the laboratory one week later where they were given a "surprise" memory test to examine their emotional memory retention. Participants were asked to collect saliva samples at four time points (08:00, 11:00, 15:00, and 20:00) on the experimental days; these samples were used to calculate the DCS. Moreover, HRV was measured during the experiment. The multiple linear regression analysis revealed that declarative memory ability, sleep duration, and the DCS were the final significant determinants for emotional memory enhancement (B = -20.41, 0.05, -48.20, ps < 0.05), with participants having flatter cortisol slopes showing reduced or absent emotional memory enhancement. These findings are discussed in reference to the possible effects of diurnal rhythm mechanisms of the hypothalamus-pituitary-adrenal axis and the autonomic nervous system on emotional memory.

A 3-arm randomized controlled trial on the effects of dance movement intervention and exercises on elderly with early dementia

Background

Dementia is characterized by a progressive decline and deterioration of brain regions such as memory, spatial navigation and language, along with disturbances in daily functioning. Non-pharmacological interventions that offer a holistic approach by targeting cognitive functioning, prognosis and the psychological and social effects of dementia require rigorous investigation. The well-established benefits of physical activity for cognitive functioning and psychological support in dementia have been observed with dance-movement intervention. There is substantial evidence that dance-movement interventions provide emotional and social advantages. Thus, a randomized controlled trial (RCT) is planned to investigate the positive effects of a dance movement intervention, compared with mild physical exercise, on the physical and psychological well-being of elderly Chinese individuals with early dementia.

Methods/Design

A 3-arm RCT with waitlist control design will be used in this study. Two hundred and one elderly participants with very mild to mild dementia will be screened and randomized into the following groups: (i) dance movement based intervention, (ii) stretching and exercise intervention and (iii) no intervention waitlist-control group. The two intervention groups will receive a 1-h intervention, twice a week, for 12 weeks. The participants will be assessed four times over the course of 12 months: baseline before randomization, post-intervention (3 months), 6 months from baseline and 12 months from baseline. The primary outcomes will be compared between assessment points and between groups on neuropsychiatric symptoms, psychosocial well-being and cognitive and daily functioning. Secondary outcomes will assess the changes in salivary cortisol levels and their relationships with the primary outcome measures.

Discussion

This study will provide substantial evidence of the efficacy of a dance-movement-based intervention in slowing down dementia progression, due to its ability to act as a buffer against decline and improve areas affected by dementia. We also anticipate an association between cortisol levels and the outcome measures. The further development of this intervention into a structural program may be warranted for early psychosocial support among elderly populations.

Trial registration

The trial has been registered in the Chinese Clinical Trial Registry (ChiCTR-IOR-15006541).

Lower morning to evening cortisol ratio is associated with cognitive impairment in men but not women: An analysis of 733 older subjects of the cross-sectional KORA-Age study

BACKGROUND

A dysregulated hypothalamic-pituitary-adrenocortical axis (HPA) is thought to play a role in the pathophysiology of cognitive impairment. Surprisingly, little agreement exists on the association of cortisol and cognitive impairment. Thus, we sought to examine the association between cognitive function and salivary cortisol levels in a representative sample of older men and women.

METHODS

A cross-sectional analysis was conducted among 733 study participants (65-90 years old, mean age=74.9) of the population-based KORA (Cooperative Health Research in the Region of Augsburg)-Age study. Associations were examined between cognitive function (determined by telephone interview for cognitive status-modified, TICS-m) and salivary cortisol measured upon waking (M1), 30min after awakening (M2), and in the late evening (E).

RESULTS

In a dose response manner, lower morning (M1 and M2), and increased evening levels were observed in participants with probable dementia (4.5%, N=33) and slightly increased in those with mild cognitive impairment (MCI) (13.8%, N=101) compared to healthy individuals. Higher morning to evening ratios were associated with reduced odds of cognitive impairment, even after adjustments for important confounders (M1/E ratio: OR=1.50, 95% CI=1.08-2.07, M2/E ratio: 1.41, 1.01-1.95, per 1 standard deviation (SD) increase). However, the significant association of an increased risk for cognitive impairment was observed among men (M1/E: OR=1.94, 95% CI=1.24-3.02; M2/E=1.74, 1.12-2.71) but not women (M1/E: OR=1.11, 0.69-1.78; M2/E=1.09, 0.67-1.77).

CONCLUSION

Our findings suggest that dysregulated HPA axis reactivity, evidenced by blunted diurnal cortisol responses, are associated with impaired cognitive function in an aged population.