Identifying patterns in cortisol secretion in an older population. Findings from the Whitehall II study

Sex-related differences in the associations between diurnal cortisol pattern and social and emotional loneliness in older adults

Introduction

Loneliness is a distressful feeling that can affect mental and physical health, particularly among older adults. Cortisol, the primary hormone of the Hypothalamic-Pituitary-Adrenal axis (HPA-axis), may act as a biological transducer through which loneliness affects health. While most previous studies have evaluated the association between loneliness, as a unidimensional construct, and diurnal cortisol pattern, no research has examined this relationship discriminating between social and emotional loneliness in older adults. As sex differences in the negative mental health outcomes of loneliness have been reported, we also investigated whether diurnal cortisol indices and loneliness associations occur in a sex-specific manner.

Methods

We analyzed the diurnal cortisol- pattern in 142 community-dwelling, non-depressed, Caucasian older adults (55,6% female) aged 60-90. Social and emotional (family and romantic) loneliness scores were assessed using the Spanish version of the Social and Emotional Loneliness Scale for Adults (SELSA). Five salivary cortisol samples were used to capture key features of the diurnal cortisol pattern, including: awakening and bedtime cortisol levels, awakening response (CAR), post-awakening cortisol output (post-awakening cortisol [i.e., the area under the curve with reference to the ground: AUCG]), total diurnal cortisol release (AUCG), and diurnal cortisol slope (DCS).

Results

After controlling for sociodemographic variables, the hierarchical linear multiple regression analyses revealed that in male older adults, higher scores on social and family loneliness were associated with elevated awakening cortisol levels, total diurnal cortisol output, and a steeper diurnal cortisol slope (DCS). However, these associations were not observed in female older adults. In addition, feelings of romantic loneliness were positively associated with bedtime cortisol levels and AUCG in older males. Multilevel growth curve modeling showed that experiencing more social and emotional loneliness predicted higher diurnal cortisol output throughout the day in older male adults.

Discussion

The presence of sex differences in the relationship between cortisol indices and loneliness among older adults holds particular significance for diagnostic and screening procedures. Combining loneliness scales as screening tools with diurnal cortisol measures has the potential to be an effective and cost-efficient approach in identifying higher-risk individuals at early stages.

Separating the influences of means and daily variations of sleep on the stress-induced salivary cortisol response

BACKGROUND

Previous research regarding the effects of sleep quality and quantity on the acute stress response has yielded inconsistent findings. This may be attributed to various factors, including composite sleep components (i.e., means and daily variations) and mixed cortisol stress response (i.e., reactivity and recovery). Thus, this study aimed to separate the effects of means and daily variations of sleep on the reactivity and recovery of cortisol responses to psychological challenges.

METHODS

In study 1, we recruited 41 healthy participants (24 women; age range, 18-23 years), monitored their sleep during seven consecutive days via wrist actigraphy and sleep diaries, and adopted the Trier Social Stress Test (TSST) paradigm to induce acute stress. Study 2 consisted of a validation experiment using the ScanSTRESS paradigm, which included 77 additional healthy individuals (35 women; age range, 18-26 years). Similarly to the TSST, the ScanSTRESS induces acute stress using uncontrollability and social evaluation. In both studies, saliva samples from the participants were collected before, during, and after the acute stress task.

RESULTS

Using residual dynamic structural equation modeling, both study 1 and study 2 demonstrated that higher means of objective sleep efficiency, and longer means of objective sleep duration were related to greater cortisol recovery. In addition, fewer daily variations in objective sleep duration were associated with greater cortisol recovery. However, there was no correlation between sleep variables and cortisol reactivity, except for the daily variations in objective sleep duration in study 2. No correlation was observed between subjective sleep and cortisol response to stress.

CONCLUSIONS

The present study separated two features of multi-day sleep patterns and two components of cortisol stress response, providing a more comprehensive picture of the effect of sleep on the stress-induced salivary cortisol response, and contributing to the future development of targeted interventions for stress-related disorders.

Investigation of the role of sleep and physical activity for chronic disease prevalence and incidence in older Irish adults

Background

Chronic diseases are the leading cause of death worldwide. Many of these diseases have modifiable risk factors, including physical activity and sleep, and may be preventable. This study investigated independent associations of physical activity and sleep with eight common chronic illnesses.

Methods

Data were from waves 1, 3 and 5 of The Irish Longitudinal Study on Ageing (n = 5,680). Inverse probability weighted general estimating equations were used to examine longitudinal lifetime prevalence and cumulative incidence of self-reported conditions.

Results

Sleep problems were significantly associated with increased odds of incident and prevalent arthritis and angina. Additionally sleep problems were associated with higher odds of lifetime prevalence of hypertension and diabetes. Physical activity was negatively associated incident osteoporosis and respiratory diseases and negatively associated with lifetime prevalence of hypertension, high cholesterol and diabetes.

Conclusions

Worse sleep quality and lower physical activity were associated with higher odds of chronic diseases. Interventions to improve sleep and physical activity may improve health outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14108-6.

Physical Activity Influences Cortisol and Dehydroepiandrosterone (Sulfate) Levels in Older Adults: A Systematic Review and Meta-Analysis

Age-related changes affect the ratio between two steroid hormones of the hypothalamic-pituitary-adrenal axis, cortisol and dehydroepiandrosterone (sulfate) (DHEA[S]). Physical activity (PA) may buffer the effects of chronic stress and counteract the aging decline of DHEA(S). Therefore, a systematic review was conducted to understand how PA influences physiological markers of cortisol and/or DHEA(S) and whether there is a difference in observational associations or experimental effects in older adults aged 65 years and older. A narrative synthesis was performed on nine observational studies, and meta-analyses were performed on 22 randomized controlled trials. There was low- to moderate-quality evidence that regular PA beneficially reduces cortisol and increases DHEA(S) levels. Subgroup analyses showed no clinically important differences between men and women, different exercise modalities, or health states. The findings cautiously suggest that regular PA of older adults' own choice that they find enjoyable could be recommended to improve cortisol and/or DHEA(S) levels.

Polysomnography-estimated sleep and the negative feedback loop of the hypothalamic-pituitary-adrenal (HPA) axis

BACKGROUND

Sleep and stress are highly interrelated. To improve our understanding of the role of sleep in functioning of the negative feedback loop of the stress system, we assessed the association between sleep and functioning of the hypothalamic-pituitary-adrenal (HPA) axis in a population-based sample.

METHODS

This study included 403 participants (mean age: 62.4 ± 5.0 years, 55% women) of the population-based Rotterdam Study. Between 2012 and 2014, sleep was assessed with polysomnography. Functioning of the negative feedback loop of the HPA axis was estimated by measuring cortisol levels before and after the intake of a very low dose of dexamethasone (0.25 mg) on average 0.9 ± 37.8 days after the polysomnography. We used linear regression analyses adjusted for multiple confounders and performed sensitivity analyses in a sample excluding those with clinically relevant depressive symptoms and using psychoactive medicine, and a sample excluding non-suppressors.

RESULTS

Short N2 sleep (adjusted difference = 0.005, 95%CI = 0.002;0.009), long N3 sleep (adjusted difference = -0.007, 95%CI = -0.010;-0.003), and short sleep onset latency (adjusted difference = 0.006, 95%CI = 0.001;0.011) were associated with an enhanced response to dexamethasone, but the association of sleep onset latency did not survive multiple testing correction. Associations remained similar after excluding those with clinically relevant depressive symptoms and those using psychoactive medicine or exclusion of non-suppressors.

CONCLUSIONS

This study suggests that more slow wave sleep is particularly associated with a stronger suppression of cortisol within the negative feedback loop of the HPA axis. These findings provide further support that slow wave sleep is important for health.

Vitamin D in Osteosarcopenic Obesity

Osteosarcopenic obesity is a unique clinical condition where low bone and muscle mass coexist in individuals with obesity. Alterations in adipose tissue, skeletal muscle and bone are strictly interconnected, and vitamin D plays key roles in several metabolic pathways that are involved in maintaining musculoskeletal health and glucose homeostasis. We reviewed the available literature on mechanisms underlying osteosarcopenic obesity, with a focus on the role of vitamin D in the pathogenesis and treatment of the condition. We found that, although evidence from large observational studies and pre-clinical experiments strongly supports a role of vitamin D deficiency in the pathogenesis of osteosarcopenic obesity, the common belief that vitamin D improves musculoskeletal health lacks solid clinical evidence, as trials specifically aimed at assessing the effects of vitamin D supplementation in patients with osteosarcopenic obesity are not available, and trials that investigated the role of vitamin D on muscle and bone health in other patient populations either showed no or even detrimental effects. We conclude that large observational and interventional studies including individuals with osteosarcopenic obesity representative of different sex, age and race are needed to better define the role of vitamin D in the pathogenesis and treatment of this condition.

How to assess and interpret everyday life salivary cortisol measures: A tutorial on practical and statistical considerations

Salivary cortisol has been the central marker in psychoneuroendocrinological stress research for three decades. Given the technological possibilities to assess data in ecologically valid circumstances, many studies have implemented longitudinal assessments of salivary cortisol in study participants' everyday life. Such studies bear the potential to understand real-life associations of cortisol with psychological traits, states, and health variables. Furthermore, changes in the neuroendocrine regulation and in cortisol reactivity can be used to evaluate the effects of behavioral interventions in real-life circumstances. While standardized paradigms have been developed to measure cortisol in laboratory settings, there is high heterogeneity in the assessment, statistical processing, and interpretation of everyday life cortisol measures. This methodological tutorial aims at summarizing important knowledge which had been accumulated during the past two decades and which could be used to set up an ambulatory assessment study focusing on salivary cortisol in everyday life. Practical advice for possible strategies at all stages of the research process is outlined in detail. Additionally, an example on how to statistically process cortisol data in a multilevel framework (including syntax) is provided. In these analyses, we investigate within- and between-person research questions regarding the association between stress and cortisol in daily life. Thus, the present work (a) can be used as tutorial for setting up everyday life studies focusing on the assessment of salivary cortisol, and (b) can be useful to avoid inconsistencies in study planning, data assessment and data processing in future studies.

Cortisol and Dehydroepiandrosterone Response to Adrenocorticotropic Hormone and Frailty in Older Women

BACKGROUND

The response to adrenocorticotropic hormone (ACTH) is poorly characterized in old-old adults and may provide insight into the physiologic response to stress.

METHOD

We performed a standard 250 µg ACTH stimulation test in a home-based substudy of 51 women aged 85-96 years enrolled in the Women's Health and Aging Study II who were not taking corticosteroids. We examined the cortisol and dehydroepiandrosterone (DHEA) responses at 0, 30, 60, and 120 minutes, overall and by frailty status.

RESULTS

The peak cortisol response to ACTH could not be determined, with the highest levels at the 120-minute time point. Pre- and post-ACTH stimulated cortisol levels did not differ by frailty status over this time frame, with no difference in the characteristics of the dose-response curves. Pre- and post-ACTH stimulated DHEA levels also did not differ by frailty status, though the dose-response curves suggested divergence after stimulation, with a more rapid DHEA response with increasing frailty.

CONCLUSIONS

Our data demonstrate a robust cortisol response to ACTH challenge testing, but inadequate negative feedback in old-old women, resulting in prolonged exposure to cortisol. Future studies should examine dynamic cortisol and DHEA responses in this age group, using a less potent ACTH stimulus and longer collection period.

Therapeutic implications of hypothalamic-pituitaryadrenal-axis modulation in Alzheimer's disease: A narrative review of pharmacological and lifestyle interventions

With disease-modifying treatments for Alzheimer's disease (AD) still elusive, the search for alternative intervention strategies has intensified. Growing evidence suggests that dysfunction in hypothalamic-pituitaryadrenal-axis (HPAA) activity may contribute to the development of AD pathology. The HPAA, may therefore offer a novel target for therapeutic action. This review summarises and critically evaluates animal and human studies investigating the effects of pharmacological and non-pharmacological intervention on HPAA modulation alongside cognitive performance. The interventions discussed include glucocorticoid receptor antagonists and 11β-hydroxysteroid dehydrogenase inhibitors as well as lifestyle treatments such as physical activity, diet, sleep and contemplative practices. Pharmacological HPAA modulators improve pathology and cognitive deficit in animal AD models, but human pharmacological trials are yet to provide definitive support for such benefits. Lifestyle interventions may offer promising strategies for HPAA modification and cognitive health, but several methodological caveats across these studies were identified. Directions for future research in AD studies are proposed.

Plasma levels of corticosterone, tumor necrosis factor receptor 1 and interleukin 6 are influenced by age, sex and chronic inflammation in mice treated with acute temperature stress

Resiliency is the ability to respond to, adapt to and recover from stressors. Deterioration of resiliency in older adults has been hypothesized to be regulated by age-related changes in stress response systems, including the Hypothalamic Pituitary Adrenal (HPA) axis and the innate immune system response. Although age-related chronic inflammation is strongly related to lack of resiliency, the impact of chronic inflammation on acute stress response is unclear. Here we describe the impact of a five-hour exposure to cold temperature acute stressor, on immune and corticosterone response using older and younger IL-10^tm/tm mice, a mouse model with chronic inflammatory pathway activation, and age and gender matched C57/Bl6 background control (WT) mice. Overall, mice exposed to 4 °C for 5 h had significantly higher plasma corticosterone levels compared to those that remained at room temperature (25 °C), with the exception of the WT females. Cold stressed mice had lower plasma tumor necrosis factor receptor 1 (TNFR1) levels with varying significance, in all ages and phenotypes, with the exception of the old female WT mice. In contrast, the effects of cold stress on pro-inflammatory cytokine interleukin 6 (IL-6) levels were inconsistent and not significant, with the exception of the female IL-10^tm/tm mice. In conclusion, these findings demonstrate that sex, age and chronic inflammatory pathway activation all influence corticosterone secretion and inflammatory processes in the face of acute cold stress.

The wrinkling of time: Aging, inflammation, oxidative stress, and the circadian clock in neurodegeneration

A substantial body of research now implicates the circadian clock in the regulation of an array of diverse biological processes including glial function, metabolism, peripheral immune responses, and redox homeostasis. Sleep abnormalities and other forms of circadian disruption are common symptoms of aging and neurodegeneration. Circadian clock disruption may also influence the aging processes and the pathogenesis of neurodegenerative diseases. The specific mechanisms governing the interaction between circadian systems, aging, and the immune system are still being uncovered. Here, we review the evidence supporting a bidirectional relationship between aging and the circadian system. Further, we explore the hypothesis that age-related circadian deterioration may exacerbate multiple pathogenic processes, priming the brain for neurodegeneration.

Physiological stress markers, mental health and objective physical function

OBJECTIVE

The observed poorer physical function in persons with mental disorders could partly be due to dysregulation in physiological stress systems. However, an integrated picture of the role of physiological stress systems on objective physical function is lacking. This study examined the association of multiple physiological stress systems with objective physical function, and explored whether these stress systems contribute to the relationship between depression/anxiety and poorer physical function.

METHODS

Data of 2860 persons of the Netherlands Study of Depression and Anxiety was used. Physical function was indicated by hand grip strength assessed using a hand-held dynamometer and lung function assessed using a peak flow meter. Inflammatory markers (CRP, IL-6, TNF-α), salivary cortisol (cortisol awakening response (AUCg, AUCi), evening cortisol) and ANS markers (heartrate, PEP, RSA) were determined. Depression/anxiety disorders were determined using psychiatric interviews. Linear regression analyses were adjusted for sociodemographics, health and lifestyle factors.

RESULTS

Higher inflammation levels were associated with lower hand grip strength (B_CRP = -0.21(SE = 0.06), p < .001) and lower lung function (B_CRP = -2.07(SE = 0.66), p = .002), B_TNF-α = -3.35(SE = 1.42), p = .022). Higher salivary cortisol levels were associated with lower lung function (B_{evening cortisol} = -2.22(SE = 0.59), p < .001). The association, in women, between depression/anxiety disorders and poorer physical function did not significantly diminish after adjustment for physiological stress markers.

CONCLUSION

This large cohort study showed that stress system dysfunction (especially the immune-inflammatory system and HPA-axis) contributes to poorer objective physical function. Stress system dysfunction did not explain the poorer physical function observed in persons with depression/anxiety disorders, suggesting that other pathways are involved to explain that association.

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.

Investigating associations between momentary stress and cortisol in daily life: What have we learned so far?

Since cortisol measurement in saliva has been established, it has been used as an indicator of stress-related hypothalamic-pituitary-adrenocortical axis activity. Concurrent development of methodological frameworks such as ambulatory assessment, ecological momentary assessment, and experience sampling have provided opportunities to combine both approaches in daily life research. The current review provides a summary of basic methodological principles and recommendations, as well as abstracts of findings of studies investigating momentary associations between stress and cortisol in daily life with an emphasis on within-subject associations (i.e. average covariance in repeated momentary assessments of stress and cortisol, and individual-specific deviations from the average covariance). Methodological challenges related to stress measurement, sampling principles, and appropriate statistical modeling are discussed, followed by a description of the historical development of studies on within-subject associations between momentary daily life stress and cortisol. The review concludes with a discussion of controversial methodological characteristics of these studies regarding operationalizations of stress, compliance, timing and frequency of stress and cortisol sampling, and reporting of effect sizes. Future research in this area would benefit from automated cortisol assessment, broadening of the scope of stress response measures, use of advanced statistical models that better account for dynamics in the stress process in daily life, and attempts to replicate findings. While previous studies of momentary stress and concurrent cortisol assessments have reliably confirmed some fundamental predictions from stress theory in daily life, future studies should aim at providing progress by testing innovative research questions and utilizing new technological developments.

Retirement and Socioeconomic Differences in Diurnal Cortisol: Longitudinal Evidence From a Cohort of British Civil Servants

Objectives

Early old age and the period around retirement are associated with a widening in socioeconomic inequalities in health. There are few studies that address the stress-biological factors related to this widening. This study examined whether retirement is associated with more advantageous (steeper) diurnal cortisol profiles, and differences in this association by occupational grade.

Method

Data from the 7th (2002–2004), 8th (2006), and 9th (2007–09) phases of the London-based Whitehall II civil servants study were analysed. Thousand hundred and forty three respondents who were employed at phase 8 (mean age 59.9 years) and who had salivary cortisol measured from five samples collected across the day at phases 7 and 9 were analysed.

Results

Retirement was associated with steeper diurnal slopes compared to those who remained in work. Employees in the lowest grades had flatter diurnal cortisol slopes compared to those in the highest grades. Low-grade retirees in particular had flatter diurnal slopes compared to high-grade retirees.

Discussion

Socioeconomic differences in a biomarker associated with stress increase, rather than decrease, around the retirement period. These biological differences associated with transitions into retirement for different occupational groups may partly explain the pattern of widening social inequalities in health in early old age.

Dysregulation of the hypothalamic pituitary adrenal (HPA) axis and cognitive capability at older ages: individual participant meta-analysis of five cohorts

Evidence on the association between functioning of the hypothalamic pituitary adrenal (HPA) axis and cognitive capability at older ages is mixed. We undertook a systematic review (until October 2016) and individual participant data (IPD) meta-analysis to test if dysregulation of the HPA axis is associated with worse cognitive capability. Five cohort studies were included in the IPD meta-analysis of diurnal cortisol patterns with crystallised and fluid cognitive ability. Higher night time cortisol was associated with worse fluid ability (standardised coefficient per SD increase −0.063, 95% CI −0.124, −0.002, P = 0.04; I² = 79.9%; age and gender adjusted). A larger diurnal drop was associated with better fluid ability (standardised coefficient per SD increase 0.037, 95% CI 0.008, 0.065, P = 0.01; I² = 49.2%; age and gender adjusted). A bigger cortisol awakening response (CAR) was weakly associated with better fluid (P = 0.09; I² = 0.0%; age and gender adjusted) and crystallised (P = 0.10; I² = 0.0%; age and gender adjusted) ability. There is weak evidence that a greater diurnal decline of the HPA axis and a larger CAR are associated with improvements in cognition at older ages. As associations are cross-sectional, we cannot rule out reverse causation.

Frailty and the endocrine system

Frailty is a condition characterised by loss of biological reserves, failure of homoeostatic mechanisms, and vulnerability to adverse outcomes. The endocrine system is considered particularly important in frailty, because of its complex inter-relationships with the brain, immune system, and skeletal muscle. This Review summarises evidence indicating a key role for the hypothalamic-pituitary axis in the pathogenesis of frailty through aberrant regulation of glucocorticoid secretion, insulin-like growth factor signalling, and androgen production. Evidence also indicates a potential role for vitamin D and insulin resistance in the pathogenesis of frailty. The role of thyroid hormones in the pathogenesis of frailty remains uncertain. Key convergent pathological effects of frailty include loss of muscle mass and strength, with consequent impact on mobility and activities of daily living. Future translational research should focus on the understanding of endocrine mechanisms, to identify potential biomarkers of the condition, modifiable targets for treatment, and novel pharmacological drugs targeted at the endocrine components of frailty.

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.

Diurnal cortisol profiles, inflammation, and functional limitations in aging: Findings from the MIDUS study

OBJECTIVE

The current study examined the association between diurnal cortisol profiles, inflammation, and functional limitations, among adults ranging in age from 34-84 years.

METHOD

Participants (N = 799) completed Waves 2 (between 2004 and 2006) and 3 (between 2014 and 2016) of the Midlife Development in the United States Survey. At Wave 2, participants provided saliva samples across 4 consecutive days, from which cortisol was assayed. Previously validated diurnal cortisol profiles (i.e., normative, flattened, or elevated) were examined in relation to concurrent inflammation risk burden and to predict long-term changes in functional limitations.

RESULTS

Compared with participants with normative profiles across all interview days, participants with dysregulated profiles across all interview days (i.e., all days elevated, flattened, or a combination of elevated and flattened) showed greater concurrent inflammation risk burden and more functional limitations at follow-up. Regions of significance testing indicated that the association was significant beginning at age 60 for inflammation risk burden and beginning at age 66 for functional limitations. Variable profiles (i.e., a mix of normative and flattened and/or elevated across the four days of assessment) were not significantly associated with these health indices.

CONCLUSIONS

Findings, consistent with the theoretical model of Strength and Vulnerability Integration, illustrate the importance of considering age when examining cortisol and its association with other health indices. (PsycINFO Database Record

Stress evokes stronger medial posterior cingulate deactivations during emotional distraction in slower paced aging

INTRODUCTION

Middle-aged offspring from long-lived families are thought to have a slower pace of aging, possibly related to HPA-axis function. Here, we investigated the neural and behavioral effects of social stress in offspring compared to their regular aging partners on emotional distraction during working memory (WM).

METHODS

104 middle-aged participants (53 males) consisting of offspring and their partners underwent the Trier Social Stress Test or a control procedure. Hereafter, a WM task with emotional distracters was performed using fMRI. Saliva cortisol levels were obtained during the procedure.

RESULTS

Partners had higher overall cortisol levels than offspring. In addition, partners had decreased deactivations compared to offspring in the medial posterior cingulate cortex (mPCC) during emotional distraction, which were significantly correlated with lower accuracy during emotional distraction.

DISCUSSION

mPCC-deactivations are known to be modulated by chronological aging, with more deactivations in the young than in the old. Here we show the same pattern in familial longevity versus regular aging after mild stress, with more deactivations related to better accuracy during emotional distraction. Functional mPCC deactivations might thus be related to pace of aging, and can be revealed by inducing mild stress.

Diurnal cortisol and mental well-being in middle and older age: evidence from four cohort studies

OBJECTIVES

We conducted an individual participant meta-analysis to test the hypothesis that cortisol patterns indicative of dysregulated hypothalamic-pituitary-adrenal axis functioning would be prospectively associated with poorer well-being at follow-up.

SETTING

Four large UK-based cohort studies.

PARTICIPANTS

Those providing valid salivary or serum cortisol samples (n=7515 for morning cortisol; n=1612 for cortisol awakening response) at baseline (age 44-82) and well-being data on the Warwick Edinburgh Mental Wellbeing Scale at follow-up (0-8 years) were included.

RESULTS

Well-being was not associated with morning cortisol, diurnal slope or awakening response though a borderline association with evening cortisol was found. Adjusting for sex and follow-up time, each 1 SD increase in evening cortisol was associated with a -0.47 (95% CI -1.00 to 0.05) point lower well-being. This was attenuated by adjustment for body mass index, smoking and socioeconomic position. Between-study heterogeneity was low.

CONCLUSIONS

This study does not support the hypothesis that diurnal cortisol is prospectively associated with well-being up to 8 years later. However, replication in prospective studies with cortisol samples over multiple days is required.

Differences in mood and cortisol by menstrual phase during acute smoking abstinence: A within-subject comparison

There is evidence that smoking-cessation success differs by menstrual phase and sex hormone levels; however, the biological mechanisms underlying these differences are not clear. One possibility is that variation in cortisol throughout the menstrual cycle and early smoking abstinence may be partly responsible. The goal of this secondary-data analysis was to conduct a within-subject examination of the effects of menstrual phase and smoking abstinence on salivary cortisol and mood. Data are from a controlled crossover trial, in which participants completed 2 testing weeks during their follicular and luteal phases. During each testing week, they smoked ad libitum during the first 2 days and then abstained from smoking during the next 4 days. Salivary cortisol and self-reported mood were collected 5 times on the day before abstinence (D0) and the first (D1) and third (D3) days of abstinence. Participants (n = 125) were, on average (mean ± SE), 29.4 ± 0.6 years old and smoked 12.6 ± 0.5 cigarettes/day. Whereas salivary cortisol varied significantly by time of day (p < .0001) and smoking abstinence (D0 to D1: β = -0.06 ± 0.02 log[ng/ml], p = .0074 and D3: β = -0.05 ± 0.02 log[ng/ml], p = .0117). no significant differences by menstrual phase were observed. Craving increased from D0 to D1 during the follicular phase but decreased in the luteal phase (+0.31 vs. -0.15, β = 0.46 ± 0.19, p = .0162). This work builds on prior observations in demonstrating a decrease in cortisol in acute smoking abstinence and menstrual phase differences in craving. The results provide further evidence that cortisol levels do not vary by menstrual phase in the first few days of abstinence. (PsycINFO Database Record

Does the diurnal cycle of cortisol explain the relationship between physical performance and cognitive function in older adults?

Background

Regular physical activity is a promising strategy to treat and prevent cognitive decline. The mechanisms that mediate these benefits are not fully clear but physical activity is thought to attenuate the harmful effects of chronic psychological stress and hypercortisolism on cognition. However, the circadian pattern of cortisol secretion is complex and it is not known which aspects are most closely associated with increased cognitive function and better physical performance. This is the first study to simultaneously measure cognitive function, the diurnal cycle of salivary cortisol and physical performance in older adults, without cognitive impairment (n = 30) and with amnestic Mild Cognitive Impairment (aMCI) (n = 30).

Results

Regression analysis showed that better cognitive function was associated with better physical performance. A greater variance in cortisol levels across the day from morning to evening was associated with better cognitive function and physical performance.

Conclusions

The results support the idea that a more dynamic cortisol secretion pattern is associated with better cognitive function and physical performance even in the presence of cognitive impairment, but our results could not confirm a mediating role in this relationship.

Lead exposure is related to hypercortisolemic profiles and allostatic load in Brazilian older adults

Lead levels (Pb) have been linked to both hyper- and hypo-reactivity of hypothalamic-pituitary-adrenal axis (HPA) axis to acute stress in animals and humans. Similarly, allostatic load (AL), the 'wear and tear' of chronic stress, is associated with inadequate HPA axis activity. We examined whether Pb levels would be associated with altered diurnal cortisol profile, as a primary mediator of AL, during aging. Pb levels were measured from blood samples (BPb) of 126 Brazilian individuals (105 women), between 50 and 82 years old. Six neuroendocrine, metabolic, and anthropometric biomarkers were analyzed and values were transformed into an AL index using clinical reference cut-offs. Salivary samples were collected at home over 2 days at awakening, 30-min after waking, afternoon, and evening periods to determine cortisol levels. A multiple linear regression model showed a positive association between BPb as the independent continuous variable and cortisol awakening response (R²=0.128; B=0.791; p=0.005) and overall cortisol concentration (R²=0.266; B=0.889; p<0.001) as the outcomes. Repeated measures ANOVA showed that individuals with high BPb levels showed higher cortisol at 30min after awakening (p=0.003), and in the afternoon (p=0.002) than those with low BPb values. Regarding AL, regression model showed that BPb was positively associated with AL index (R²=0.100; B=0.204; p=0.032). Correlation analyzes with individual biomarkers showed that BPb was positively correlated with HDL cholesterol (p=0.02) and negatively correlated with DHEA-S (p=0.049). These findings suggest that Pb exposure, even at levels below the reference blood lead level for adults recommended by the National Institute for Occupational Safety and Health and by the Center for Disease Control and Prevention, may contribute to AL and dysregulated cortisol functioning in older adults. Considering these findings were based on cross-sectional data future research is needed to confirm our exploratory results.

The Functional and Clinical Significance of the 24-Hour Rhythm of Circulating Glucocorticoids

Adrenal glucocorticoids are major modulators of multiple functions, including energy metabolism, stress responses, immunity, and cognition. The endogenous secretion of glucocorticoids is normally characterized by a prominent and robust circadian (around 24 hours) oscillation, with a daily peak around the time of the habitual sleep-wake transition and minimal levels in the evening and early part of the night. It has long been recognized that this 24-hour rhythm partly reflects the activity of a master circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus. In the past decade, secondary circadian clocks based on the same molecular machinery as the central master pacemaker were found in other brain areas as well as in most peripheral tissues, including the adrenal glands. Evidence is rapidly accumulating to indicate that misalignment between central and peripheral clocks has a host of adverse effects. The robust rhythm in circulating glucocorticoid levels has been recognized as a major internal synchronizer of the circadian system. The present review examines the scientific foundation of these novel advances and their implications for health and disease prevention and treatment.

Use of Salivary Diurnal Cortisol as an Outcome Measure in Randomised Controlled Trials: a Systematic Review

Background

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is associated with diverse adverse health outcomes, making it an important therapeutic target. Measurement of the diurnal rhythm of cortisol secretion provides a window into this system. At present, no guidelines exist for the optimal use of this biomarker within randomised controlled trials (RCTs).

Purpose

The aim of this study is to describe the ways in which salivary diurnal cortisol has been measured within RCTs of health or behavioural interventions in adults.

Methods

Six electronic databases (up to May 21, 2015) were systematically searched for RCTs which used salivary diurnal cortisol as an outcome measure to evaluate health or behavioural interventions in adults. A narrative synthesis was undertaken of the findings in relation to salivary cortisol methodology and outcomes.

Results

From 78 studies that fulfilled the inclusion criteria, 30 included healthy participants (38.5 %), 27 included patients with physical disease (34.6 %) and 21 included patients with psychiatric disease (26.9 %). Psychological therapies were most commonly evaluated (n = 33, 42.3 %). There was substantial heterogeneity across studies in relation to saliva collection protocols and reported cortisol parameters. Only 39 studies (50 %) calculated a rhythm parameter such as the diurnal slope or the cortisol awakening response (CAR). Patterns of change in cortisol parameters were inconsistent both within and across studies and there was low agreement with clinical findings.

Conclusions

Salivary diurnal cortisol is measured inconsistently across RCTs, which is limiting the interpretation of findings within and across studies. This indicates a need for more validation work, along with consensus guidelines.

Electronic supplementary material

The online version of this article (doi:10.1007/s12160-015-9753-9) contains supplementary material, which is available to authorized users.

Aging and the HPA axis: Stress and resilience in older adults

Hypothalamic-pituitary-adrenal (HPA) axis function may change over the course of aging, and altered diurnal or stress-induced secretion of the hormone cortisol could predispose older adults to negative health outcomes. We propose that psychological resilience may interact with diurnal cortisol to affect health outcomes later in life. Emotion regulation and social support are two constructs that contribute to resilience and exhibit age-specific patterns in older adults. Determining how the use of resilience resources interacts with age-related diurnal cortisol will improve our understanding of the pathways between stress, resilience, and well-being. In this review, we assess published studies evaluating diurnal cortisol in older adults to better understand differences in their HPA axis functioning. Evidence thus far suggests that diurnal cortisol may increase with age, although cross-sectional studies limit the conclusions that can be drawn. We also review extant evidence connecting age-specific signatures of emotion regulation and social support with diurnal cortisol. Conclusions are used to propose a preliminary model demonstrating how resilience resources may modulate the effects of cortisol on health in aging.

Trait positive and negative emotionality differentially associate with diurnal cortisol activity

Inter-individual variability in metrics of hypothalamic-pituitary-adrenocortical (HPA) activity, such as the slope of the diurnal decline in cortisol, cortisol awakening response (CAR), and total cortisol output, have been found to associate inversely with trait ratings of extraversion and positive affect (E/PA) and positively with neuroticism and negative affect (N/NA) in some, but not all, investigations. These inconsistencies may partly reflect varied intensity of cortisol sampling among studies and reliance on self-rated traits, which are subject to reporting biases and limitations of introspection. Here, we further examined dispositional correlates of HPA activity in 490 healthy, employed midlife volunteers (M age=43 years; 54% Female; 86% white). Trait ratings were requested from participants and 2 participant-elected informants using the Positive and Negative Affect Schedule (PANAS) and Extraversion and Neuroticism dimensions of NEO personality inventories. CAR was assessed as percent increase in cortisol levels from awakening to 30min after awakening; and the diurnal slope and total output of cortisol [Area Under the Curve (AUC)] were determined from cortisol measurements taken at awakening, +4 and +9h later, and bedtime, across 3 workdays. Structural equation modeling was used to estimate multi-informant E/PA and N/NA factors. We used 3days of measurement as indicators to model each of the three latent cortisol factors (slope, CAR, and AUC). With the two latent emotionality and three latent cortisol indices included there was good fit to the data (χ(2)(200)=278.38, p=0.0002; RMSEA=0.028, 90% CI=0.02-0.04; CFI/TLI=0.97/0.96; SRMR=0.04). After controlling for covariates (age, sex, race), results showed higher latent E/PA associated with a steeper diurnal slope (Standardized β=-0.19, p=0.02) and smaller CAR (Standardized β=-0.26, p=0.004), whereas N/NA did not associate with any cortisol metric (Standardized β's=-0.12 to 0.13, p's=0.10 to 0.53). These findings suggest that positive emotionality may be more closely associated with indices of diurnal cortisol release than negative emotionality.

Cortisol Awakening Response and Walking Speed in Older People

In older people, less diurnal variability in cortisol levels has been consistently related to worse physical performance, especially to slower walking speed (WS). The cortisol awakening response (CAR) is a discrete component of the hypothalamic-pituitary-adrenal axis that has been related to several health problems, such as cardiovascular disease and/or worse performance on executive function and memory. The relationship between the CAR and physical performance in older people is poorly understood. In this study, in 86 older people (mean age = 64.42, SD = 3.93), we investigated the relationship between the CAR and WS, a commonly used measure of physical performance in the older population that has also been related to health problems, such as cardiovascular disease and executive function performance in older people. Additionally, we studied whether the relationship between the CAR and WS was independent from cortisol levels on awakening and several possible confounders. Results showed that a CAR of reduced magnitude (measured with 3 samples each day, for two consecutive days, and calculated as the area under the curve with respect to the increase), but not cortisol levels on awakening, was related to slower WS. In addition, this relationship was independent from cortisol levels on awakening. It is possible that a CAR of reduced magnitude would contribute to less diurnal cortisol variability, affecting physical performance. Additionally, it is possible that a CAR of reduced magnitude affects WS through a possible negative effect on executive function, or that the association between the CAR and WS is due to the fact that both are related to similar health problems and to changes in cognitive performance in older people.

Physiological responding to stress in middle-aged males enriched for longevity: a social stress study

Individuals enriched for familial longevity display a lower prevalence of age-related diseases, such as cardiovascular- and metabolic diseases. Since these diseases are associated with stress and increased cortisol levels, one of the underlying mechanisms that may contribute to healthy longevity might be a more adaptive response to stress. To investigate this, male middle-aged offspring from long-lived families (n = 31) and male non-offspring (with no familial history of longevity) (n = 26) were randomly allocated to the Trier Social Stress Test or a control condition in an experimental design. Physiological (cortisol, blood pressure, heart rate) and subjective responses were measured during the entire procedure. The results showed that Offspring had lower overall cortisol levels compared to Non-offspring regardless of condition, and lower absolute cortisol output (AUCg) during stress compared to Non-Offspring, while the increase (AUCi) did not differ between groups. In addition, systolic blood pressure in Offspring was lower compared to Non-offspring during the entire procedure. At baseline, Offspring had significantly lower systolic blood pressure and reported less subjective stress than Non-offspring and showed a trend towards lower heart rate. Offspring from long-lived families might thus be less stressed prior to potentially stressful events and consequently show overall lower levels in physiological responses. Although attenuated physiological responding cannot be ruled out, lower starting points and a lower peak level in physiological responding when confronted with an actual stressor, might already limit damage due to stress over a lifetime. Lower physiological responding may also contribute to the lower prevalence of cardiovascular diseases and other stress-related diseases in healthy longevity.

High Cardiorespiratory Fitness Is Negatively Associated with Daily Cortisol Output in Healthy Aging Men

Physical fitness has salutary psychological and physical effects in older adults by promoting neuroplasticity and adaptation to stress. In aging, however, the effects of fitness on the hypothalamic-pituitary-adrenal (HPA) axis are mixed. We investigated the association between cardiorespiratory fitness and HPA activity in healthy elderly men (n = 22, mean age 68 y; smokers, obese subjects, those taking drugs or reporting recent stressful events were excluded), by measuring in saliva: i) daily pattern of cortisol secretion (6 samples: 30' post-awakening, and at 12.00, 15.00, 18.00, 21.00, 24.00 h); and ii) the cortisol response to a mental challenge. Cardiorespiratory fitness (VO2max) was estimated using the Rockport Walking Test and the participants were assigned to high-fit (HF, ≥60°, n = 10) and low-fit (LF, ≤35°, n = 12) groups according to age-specific percentiles of VO2max distribution in the general population. At all daytimes, basal cortisol levels were lower in the HF than the LF group, most notably in the evening and midnight samples, with a significant main effect of physical fitness for cortisol levels overall; the area-under-the-curve for total daily cortisol output was significantly smaller in the HF group. Among the subjects who responded to mental stress (baseline-to-peak increment >1.5 nmol/L; n = 13, 5 LF, 8 HF), the amplitude of cortisol response and the steepness of recovery decline displayed an increasing trend in the HF subjects, although between-group differences failed to reach the threshold for significance. In conclusion, cardiorespiratory fitness in healthy aging men is negatively correlated with daily cortisol output and contributes to buffering the HPA dysregulation that occurs with advancing age, thus possibly playing a beneficial role in contrasting age-related cognitive and physical decline.

Hypothalamic-pituitary-adrenal (HPA) axis and aging

Human aging is associated with increasing frailty and morbidity which can result in significant disability. Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis may contribute to aging-related diseases like depression, cognitive deficits, and Alzheimer's disease in some older individuals. In addition to neuro-cognitive dysfunction, it has also been associated with declining physical performance possibly due to sarcopenia. This article reviews the pathophysiology of HPA dysfunction with respect to increased basal adrenocorticotropic hormone (ACTH) and cortisol secretion, decreased glucocorticoid (GC) negative feedback at the level of the paraventricular nucleus (PVN) of the hypothalamus, hippocampus (HC), and prefrontal cortex (PFC), and flattening of diurnal pattern of cortisol release. It is possible that the increased cortisol secretion is secondary to peripheral conversion from cortisone. There is a decline in pregnolone secretion and C-19 steroids (DHEA) with aging. There is a small decrease in aldosterone with aging, but a subset of the older population have a genetic predisposition to develop hyperaldosteronism due to the increased ACTH stimulation. The understanding of the HPA axis and aging remains a complex area with conflicting studies leading to controversial interpretations.

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.

A functional polymorphism in the HTR2C gene associated with stress responses: a validation study

Previously we have shown that a functional nonsynonymous single nucleotide polymorphism (SNP), rs6318 on the HTR2C gene located on the X-chromosome, is associated with hypothalamic-pituitary-adrenal axis response to a laboratory stress recall task. The present paper reports a validation of the cortisol response to stress in a second, independent sample. The study population consisted of 60 adult participants (73.3% males). Consistent with our prior findings, compared to Cys23 G allele carriers, persons homozygous for the Ser23C allele had a significantly greater average cortisol response (p=0.007) and area under the curve (p=0.021) over the course of an emotional stress recall protocol. Also parallel to our prior report, the change in cortisol from baseline to the average during the stress protocol was roughly twice as large among Ser23C homozygotes than among persons with Cys23 G. These findings validate our initial observation of association between rs6318 and cortisol response to an acute stressor, and extend the results to include females.

Clinical study of electro-acupuncture treatment with different intensities for functional constipation patients

Functional constipation (FC) is a common functional bowel disorder disease that affects life quality of a large number of people. This study aimed to explore the impact of different intensities of electro-acupuncture (EA) treatment for FC patients. Totally, 111 patients with FC meeting the Rome III criteria were randomly assigned to different intensities of EA groups (low and high intensity of EA groups) and medicine-controlled (MC) group. In EA groups, patients were treated with EA at quchi (LI11) and shangjuxu (ST37) bilaterally for 4 weeks, 5 times/week in the first 2 weeks, and 3 times/week in the last 2 weeks. In MC group, 5 mg mosapride citrate was administered orally 3 times/day for 4 weeks. Spontaneous bowel movement frequency each day was recorded using a constipation diary. Self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were used to assess the patients' psychological state. Cortisol (CORT), substance P (SP), and vasoactive intestinal polypeptide (VIP) were evaluated at baseline and at the end of 4 weeks after treatment. As compared with the baseline, there was statistically significant increase in stool frequency every week (P<0.01), but there was no statistically significant difference among the three groups. As compared with the baseline, after 4 weeks of EA therapy, the scores of SDS and serum levels of CORT were decreased significantly in low intensity of EA group (P<0.01), and the serum levels of SP and VIP were increased significantly (P<0.05); the scores of SAS and SDS and serum levels of CORT were decreased significantly in high intensity of EA group (P<0.05), and the serum levels of SP and VIP were increased significantly (P<0.05); the serum levels of CORT and VIP were increased significantly in MC group (P<0.05). As compared with MC group, after 4 weeks of treatment, the serum levels of SP were signifcicantly increased in low intensity of EA group (P<0.01). Low and high intensities of EA could increase the stool frequency, improve the FC patient's anxiety and depression, reduce the serum levels of CORT, and increase the serum levels of SP and VIP effectively. It is concluded that both low and high intensities of EA are effective for FC patients, but there is no significant difference between the low and high intensities of EA.

Adverse effects of two nights of sleep restriction on the hypothalamic-pituitary-adrenal axis in healthy men

CONTEXT

Insufficient sleep is associated with increased cardiometabolic risk. Alterations in hypothalamic-pituitary-adrenal axis may underlie this link.

OBJECTIVE

Our objective was to examine the impact of restricted sleep on daytime profiles of ACTH and cortisol concentrations.

METHODS

Thirteen subjects participated in 2 laboratory sessions (2 nights of 10 hours in bed versus 2 nights of 4 hours in bed) in a randomized crossover design. Sleep was polygraphically recorded. After the second night of each session, blood was sampled at 20-minute intervals from 9:00 am to midnight to measure ACTH and total cortisol. Saliva was collected every 20 minutes from 2:00 pm to midnight to measure free cortisol. Perceived stress, hunger, and appetite were assessed at hourly intervals by validated scales.

RESULTS

Sleep restriction was associated with a 19% increase in overall ACTH levels (P < .03) that was correlated with the individual amount of sleep loss (rSp = 0.63, P < .02). Overall total cortisol levels were also elevated (+21%; P = .10). Pulse frequency was unchanged for both ACTH and cortisol. Morning levels of ACTH were higher after sleep restriction (P < .04) without concomitant elevation of cortisol. In contrast, evening ACTH levels were unchanged while total and free cortisol increased by, respectively, 30% (P < .03) and 200% (P < .04). Thus, the amplitude of the circadian cortisol decline was dampened by sleep restriction (-21%; P < .05). Sleep restriction was not associated with higher perceived stress but resulted in an increase in appetite that was correlated with the increase in total cortisol.

CONCLUSION

The impact of sleep loss on hypothalamic-pituitary-adrenal activity is dependent on time of day. Insufficient sleep dampens the circadian rhythm of cortisol, a major internal synchronizer of central and peripheral clocks.

Blunted diurnal cortisol pattern is associated with frailty: a cross-sectional study of 745 participants aged 65 to 90 years

BACKGROUND

The role of neuroendocrine alterations in the etiology of frailty syndrome is still poorly understood. Hypothalamic-pituitary-adrenal axis dysregulation is a plausible candidate pathway contributing to frailty. Thus, we sought to examine the associations of diurnal cortisol secretion with frailty in older adults.

METHODS

A cross-sectional analysis was conducted among 745 study participants (age 65-90 years, mean age 75.1 years) of the population-based KORA Age study. Associations between salivary cortisol measures at awakening (morning 1 [M1]), 30 minutes after awakening (M2), and evening (E) and frailty criteria were determined.

RESULTS

Lower cortisol levels in the first morning sample (M1) (P = .18) and M2 (P = .14) and increased E levels (P = .004) were observed in prefrail (35.17%, n = 262) and frail (3.36%, n = 25) individuals, in a dose-response manner. Frailty was strongly associated with smaller ratios of morning to evening levels; M1 to E ratio (P = .02) and M2 to E ratio (P = .003). Higher evening cortisol levels were associated with a 24% increased risk of a prefrail state (odds ratio, 1.22; 95% confidence interval, 1.03-1.44). A smaller morning to evening ratio was associated with an increased risk of low grip strength (1.42, 1.09-1.86) and gait speed (1.31, 1.02-1.68).

CONCLUSION

Frailty status is associated with blunted cortisol reactivity as demonstrated by lower morning and higher evening salivary cortisol levels.

Predictors of hair cortisol concentrations in older adults

People at older ages are at increased risk for developing stress-related diseases associated with chronically elevated cortisol secretion. However, the main factors contributing to such endocrine alterations in this age group are still largely unknown. This cross-sectional study examined patterns of long-term integrated cortisol secretion, as assessed in hair, in a sample of 654 participants in middle and old adulthood (mean age: 65.8 years; range: 47-82 years) from the German cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC) study in Potsdam. Hair cortisol concentrations (HCC) were determined from the first scalp-near 3 cm hair segment and several sociodemographic, lifestyle, anthropometric, disease-related, and psychological parameters were assessed. In simple linear regressions, HCC were found to increase with participants' age and to be higher in men compared to women. HCC also showed positive associations with waist-to-hip ratio, waist circumference, smoking, prevalent type 2 diabetes mellitus, mental health, daytime sleeping, and being unemployed or retired--as well as a negative association with diastolic blood pressure. After full mutual adjustment, only age and smoking remained independent predictors of HCC. The association between prevalent type 2 diabetes mellitus and HCC was attenuated but still persisted independently in women. Similar, a positive relationship between HCC and alcohol consumption was found in women. The current results confirm previous evidence of positive associations of HCC with age, sex, alcohol consumption, and type 2 diabetes mellitus and add new knowledge on factors--such as smoking--that may contribute to elevated cortisol levels in people at older ages.

A functional polymorphism in the 5HTR2C gene associated with stress responses also predicts incident cardiovascular events

Previously we have shown that a functional nonsynonymous single nucleotide polymorphism (rs6318) of the 5HTR2C gene located on the X-chromosome is associated with hypothalamic-pituitary-adrenal axis response to a stress recall task, and with endophenotypes associated with cardiovascular disease (CVD). These findings suggest that individuals carrying the rs6318 Ser23 C allele will be at higher risk for CVD compared to Cys23 G allele carriers. The present study examined allelic variation in rs6318 as a predictor of coronary artery disease (CAD) severity and a composite endpoint of all-cause mortality or myocardial infarction (MI) among Caucasian participants consecutively recruited through the cardiac catheterization laboratory at Duke University Hospital (Durham, NC) as part of the CATHGEN biorepository. Study population consisted of 6,126 Caucasian participants (4,036 [65.9%] males and 2,090 [34.1%] females). A total of 1,769 events occurred (1,544 deaths and 225 MIs; median follow-up time =  5.3 years, interquartile range  = 3.3–8.2). Unadjusted Cox time-to-event regression models showed, compared to Cys23 G carriers, males hemizygous for Ser23 C and females homozygous for Ser23C were at increased risk for the composite endpoint of all-cause death or MI: Hazard Ratio (HR)  = 1.47, 95% confidence interval (CI)  = 1.17, 1.84, p  = .0008. Adjusting for age, rs6318 genotype was not related to body mass index, diabetes, hypertension, dyslipidemia, smoking history, number of diseased coronary arteries, or left ventricular ejection fraction in either males or females. After adjustment for these covariates the estimate for the two Ser23 C groups was modestly attenuated, but remained statistically significant: HR  = 1.38, 95% CI = 1.10, 1.73, p = .005. These findings suggest that this functional polymorphism of the 5HTR2C gene is associated with increased risk for CVD mortality and morbidity, but this association is apparently not explained by the association of rs6318 with traditional risk factors or conventional markers of atherosclerotic disease.

Social isolation and diurnal cortisol patterns in an ageing cohort

BACKGROUND

Social isolation may operate as a psychosocial stressor which disrupts functioning of the hypothalamic-pituitary-adrenocortical axis.

METHODS

Using data from the MRC National Survey of Health and Development, we tested whether living alone, not being married and social network size were associated with diurnal cortisol patterns at 60-64 years. We hypothesised that recent onset compared with long-term isolation would be more strongly associated with cortisol awakening response, cortisol decline over the day and evening cortisol. Models were adjusted for sex, smoking, body mass index, alcohol intake, psychological distress and financial difficulties.

RESULTS

Those widowed within the last three years had a 36% (95%CI 6%, 73%) higher night time cortisol than those who were currently married. Those newly living alone also had a higher night time cortisol and flatter diurnal slope than those living with others.

CONCLUSION

Independently of multiple behavioural and psychosocial correlates, recent onset of social isolation is related to diurnal cortisol patterns that increase the risk of morbidity and mortality.

Cortisol profile and depressive symptoms in older adults residing in Brazil and in Canada

BACKGROUND AND AIM

How cortisol, a stress biological marker, differs according to depressive symptoms has mostly been examined in high-income countries. Including low- and middle-income countries in research on this matter would allow examining a wider range of exposure to adversity and improving the estimates of the associations between diurnal cortisol and depression. The aim of this study is to compare the profile of diurnal cortisol and depressive symptoms in 65- to 74-year-old residents of Santa Cruz (in an underdeveloped region, northeast Brazil, n = 64) and Saint-Bruno (a suburban area, QC, Canada, n = 60).

METHODS

Home interviews included assessments of socioeconomic variables, health behaviors, depressive symptoms (Center for Epidemiologic Studies Depression Scale, CES-D) and Cortisol Awakening Response (CAR: awakening, 30, 60 min afterward), and at 1500 hours and bedtime from saliva collected over 2 days. Mixed linear models were used to estimate the associations between diurnal cortisol and depressive symptoms.

RESULTS

Santa Cruz residents had lower cortisol levels upon awakening (β = -1.24, p = 0.04) and elevated bedtime levels (β = 20.29, p < 0.001) indicating chronic stress compared to Saint-Bruno residents. Elevated depressive symptoms were associated with a blunted CAR (flatter slope, indicative of chronic stress) in Santa Cruz residents (β = -0.19, p = 0.04), while greater diurnal cortisol levels (larger area under the curve), indicative of moderate stress, were observed in Saint-Bruno residents (β = 1.96, p = 0.047).

CONCLUSION

Adverse living conditions in this remote area of Brazil may lead to a state of chronic stress and a different relationship with elevated depressive symptoms from persons aging in a Canadian suburban area.

A day-centered approach to modeling cortisol: diurnal cortisol profiles and their associations among U.S. adults

Diurnal cortisol is a marker of HPA-axis activity that may be one of the biological mechanisms linking stressors to age-related health declines. The current study identified day-centered profiles of diurnal cortisol among 1101 adults living in the United States. Participants took part in up to four consecutive days of salivary cortisol collection, assessed at waking, 30min post-waking, before lunch, and before bedtime. Growth mixture modeling with latent time basis was used to estimate common within-day trajectories of diurnal cortisol among 2894 cortisol days. The 3-class solution provided the best model fit, showing that the majority of study days (73%) were characterized by a Normative cortisol pattern, with a robust cortisol awakening response (CAR), a steep negative diurnal slope, coupled with low awakening and bedtime levels. Relative to this profile, diurnal cortisol on the remainder of days appeared either elevated throughout the day (20% of days) or flattened (7% of days). Relative to the normative trajectory, the elevated trajectory was distinguished by a higher morning cortisol level, whereas the flattened trajectory was characterized by a high bedtime level, with weaker CAR and diurnal slope parameters. Relative to the normative profile, elevated profile membership was associated with older age and cigarette smoking. Greater likelihood of the flattened cortisol pattern was observed among participants who were older, male, smoked cigarettes, used medications that are known to affect cortisol output, and reported poorer health. The current study demonstrates the value of a day-centered growth mixture modeling approach to the study of diurnal cortisol, showing that deviations from the classic robust rhythm of diurnal cortisol are associated with older age, male sex, use of medications previously shown to affect cortisol levels, poorer health behaviors, and poorer self-reported health.

Green space and stress: evidence from cortisol measures in deprived urban communities

Contact with green space in the environment has been associated with mental health benefits, but the mechanism underpinning this association is not clear. This study extends an earlier exploratory study showing that more green space in deprived urban neighbourhoods in Scotland is linked to lower levels of perceived stress and improved physiological stress as measured by diurnal patterns of cortisol secretion. Salivary cortisol concentrations were measured at 3, 6 and 9 h post awakening over two consecutive weekdays, together with measures of perceived stress. Participants (n = 106) were men and women not in work aged between 35–55 years, resident in socially disadvantaged districts from the same Scottish, UK, urban context as the earlier study. Results from linear regression analyses showed a significant and negative relationship between higher green space levels and stress levels, indicating living in areas with a higher percentage of green space is associated with lower stress, confirming the earlier study findings. This study further extends the findings by showing significant gender differences in stress patterns by levels of green space, with women in lower green space areas showing higher levels of stress. A significant interaction effect between gender and percentage green space on mean cortisol concentrations showed a positive effect of higher green space in relation to cortisol measures in women, but not in men. Higher levels of neighbourhood green space were associated with healthier mean cortisol levels in women whilst also attenuating higher cortisol levels in men. We conclude that higher levels of green space in residential neighbourhoods, for this deprived urban population of middle-aged men and women not in work, are linked with lower perceived stress and a steeper (healthier) diurnal cortisol decline. However, overall patterns and levels of cortisol secretion in men and women were differentially related to neighbourhood green space and warrant further investigation.

Adult attachment style and cortisol responses across the day in older adults

The association between cortisol and adult attachment style, an important indicator of social relationships, has been relatively unexplored. Previous research has examined adult attachment and acute cortisol responses to stress in the laboratory, but less is known about cortisol levels in everyday life. The present study examined adult romantic attachment style and cortisol responses across the day. Salivary cortisol was collected at six time points during the course of the day in 1,807 healthy men and women from a subsample of the Whitehall II cohort. Significant associations were found between attachment on cortisol across the day and slope of cortisol decline. The lowest cortisol output was associated with fearful attachment, with preoccupied attachment having the highest levels and a flatter cortisol profile. The results tentatively support the proposition that attachment style may contribute to HPA dysregulation.

Application of the model of allostasis to older women's relocation to senior housing

OBJECTIVES

Adjustment to senior housing entails significant lifestyle changes and is a stressful process. The adaptation process is dynamic and has yet to be studied using the conceptual model of allostasis. This article presents exemplars of women whose profiles represent three allostatic states: successful adaptation (homeostasis), ongoing adaptation (allostasis), and maladaptation (allostatic load).

METHOD

Older women who had relocated to senior housing participated in three interviews and monthly saliva sample collection over a 6-month period. Saliva was assayed for diurnal cortisol secretion. Triangulation of mixed methods was used to analyze data, and psychosocial data were mapped onto the cortisol graphs to illustrate changes in stress reactivity and well-being.

RESULTS

Coping abilities, perceptions of stressors, and cortisol measures provide a detailed picture of the interplay among events and perceptions and the effects of both on well-being.

DISCUSSION

The case exemplars provide detailed information on the complexity of psychosocial and physiological components of the model of allostasis. This study also fills a gap in knowledge on negative relocation outcomes using the allostatic model.