Aging, health behaviors, and the diurnal rhythm and awakening response of salivary cortisol

Spatially and temporally resolved metabolome of the human oral cavity

Saliva is a complex bodily fluid composed of secretions by major and minor salivary glands. Salivary glands and their secretions are known to be unevenly distributed in the human oral cavity. Moreover, saliva flow rate and composition vary across locations and time of the day. This remarkable heterogeneity of salivary secretions suggests that different subtypes of saliva fulfill different functions. By coupling a non-invasive and facile collection method with comprehensive metabolomic profiling, we investigated the spatial and temporal distributions of salivary components. We identified location-specific metabolite profiles, novel oscillating metabolites, and location-specific diurnal patterns. In summary, our study paves the way for a deeper and more comprehensive understanding of the complex dynamics and functionalities of the salivary metabolome and its integration in multi-omics studies related to oral and systemic (patho-)physiology.

Circadian Rhythm Changes in Healthy Aging and Mild Cognitive Impairment

Disruptions in circadian rhythms can occur in healthy aging; however, these changes are more severe and pervasive in individuals with age-related and neurodegenerative diseases, such as dementia. Circadian rhythm alterations are also present in preclinical stages of dementia, for example, in patients with mild cognitive impairments (MCI); thus, providing a unique window of opportunity for early intervention in neurodegenerative disorders. Nonetheless, there is a lack of studies examining the association between relevant changes in circadian rhythms and their relationship with cognitive dysfunctions in MCI individuals. In this review, circadian system alterations occurring in MCI patients are examined compared to healthy aging individuals while also considering their association with MCI neurocognitive alterations. The main findings are that abnormal circadian changes in rest-activity, core body temperature, melatonin, and cortisol rhythms appear in the MCI stage and that these circadian rhythm disruptions are associated with some of the neurocognitive deficits observed in MCI patients. In addition, preliminary evidence indicates that interventions aimed at restoring regular circadian rhythms may prevent or halt the progress of neurodegenerative diseases and mitigate their related cognitive impairments. Future longitudinal studies with repeated follow-up assessments are needed to establish the translational potential of these findings in clinical practice.

Subjective memory complaints in young people: the role of resilience

OBJECTIVE

Little is known about the origin and associated factors of subjective memory complaints (SMCs) in the young population, although they might be closely related to the psychophysiological states produced by stress exposure, such as anxiety and depression. In this regard, resilience has been related to a reduction in these negative states, as well as to more adaptive hypothalamic-pituitary-adrenal (HPA) axis functioning. We aimed to investigate the importance of depression, anxiety, and HPA axis activity in SMCs in the young population. We also analysed the relationship between resilience and SMCs through the mediation of depression, anxiety, and the cortisol awakening response (CAR).

DESIGN

To do so, we measured SMCs, depression and anxiety states, resilience, and the CAR in 77 healthy young people.

RESULTS

Both depression and anxiety were associated with SMCs. In addition, greater resilience was related to fewer SMCs through depression and anxiety. However, the CAR was not related to SMCs, and it did not mediate the relationship between resilience and SMCs.

CONCLUSION

These results suggest that negative affective states have greater importance in SMCs than HPA functioning in this age group, and they also highlight the importance of resilience in the psychological adjustment to stressful situations.

The effects of physical activity on cortisol and sleep: A systematic review and meta-analysis

BACKGROUND

Managing stress and having good quality sleep are inter-related factors that are essential for health, and both factors seem to be affected by physical activity. Although there is an established bidirectional relationship between stress and sleep, remarkably few studies have been designed to examine the effects of physical activity on cortisol, a key biomarker for stress, and sleep. Research is particularly scarce in older people despite both sleep and cortisol changing with age. This systematic literature review addresses this gap.

METHODS

A systematic review was conducted following the PRISMA guidelines. Original, peer-reviewed records of intervention studies such as randomized controlled trials (RCTs) and non-RCTs with relevant control groups were eligible for inclusion. The Participant, Intervention, Comparison, Outcome (PICO) characteristics were (1) adults or older adults (2) physical activity programmes of any duration, (3) controls receiving no intervention or controls included in a different programme, (4) cortisol measurement, and subjective or objective measures of sleep.

RESULTS

Ten original studies with low-to-moderate risk of bias were included. Findings from this review indicated with moderate- and low-certainty evidence, respectively, that physical activity was an effective strategy for lowering cortisol levels (SMD [95% CI] = -0.37 [-0.52, -0.21] p < .001) and improving sleep quality (SMD [95% CI] = -0.30 [-0.56, -0.04], p = .02). Caution is needed to generalize these findings to the general population, as included trials were predominantly participants with breast cancer, included few males and no older adults.

CONCLUSION

Cortisol regulation and sleep quality are intertwined, and physical activity programmes could improve both in several ways. Further, physical activity may benefit adults with long term conditions or current poor (mental) health states the most, although more research is needed to support this claim fully. Few intervention studies have examined the inter-relationship between cortisol and sleep outcomes in males or older adults, indicating fruitful enquiry for future research.

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.

The Association between Diet and Sleep Quality among Spanish University Students

While it has long been recognized that diet is a leading behavioral risk factor for human health, recent scientific findings have also suggested that diet and sleep quality may be connected. The purpose of the present study is to evaluate the association between diet and sleep quality among a group of Spanish university students. To do so, a cross-sectional study of 868 students was carried out. Sleep quality was assessed using the Spanish version of the Pittsburgh Sleep Quality Index (PSQI), while diet was assessed using the Spanish Healthy Eating Index (SHEI). The study revealed a noteworthy rate of bad sleepers (51.6%) and students whose diet needed modifications (82.2%). Unhealthy eaters were more likely to have poor sleep quality (aOR = 4.20; CI 95%: 2.07-8.52). The unbalanced intake of vegetables (aOR = 1.63; CI 95%: 1.14-2.34), fruits (aOR = 4.08; CI 95%: 2.90-5.74), dairy products (aOR = 1.96; CI 95%: 1.41-2.72), lean meats (aOR = 1.82; CI 95%: 1.19-2.78), legumes (aOR = 1.43; CI 95%: 1.00-2.02), sweets (aOR = 1.60; CI 95%: 1.13-2.25) and sugary soft drinks (aOR = 1.46; CI 95%: 1.07-1.99) was associated with lower sleep quality.

Teachers on the margins: How low-income public schools burden our teachers

BACKGROUND: Teachers experience high work-related stress, which can lead to missed workdays and lower quality of life. OBJECTIVE: The objective of this exploratory pilot study was to assess occupational and environmental stressors in public school districts by income level to examine the influence these stressors have on teachers perceived stress and biological stress response. METHODS: Fifty-nine teachers were recruited from four school districts in Michigan (three low-income and one high-income). Participants completed a self-administered survey on teaching stressors, health, and demographics. Stress response was measured through blood pressure, heart rate, and salivary cortisol. Six salivary cortisol measurements were collected for each participant; three in the afternoon and three in the evening. Each teacher’s classroom and school underwent an environmental assessment on quality and proximity to environmental hazards. RESULTS: Teachers at low-income school districts had significantly higher afternoon cortisol levels, lower self-reported health, higher body mass index, higher perceived teaching stressors, and worked at schools within one km of a greater number of environmentally-contaminated sites, in comparison to their high-income school district counterparts. CONCLUSIONS: This research aims to inform future interventions that could lessen occupational and environmental stressors for teachers, improve teacher health outcomes and retention, and impact student success rates.

Gene Expression Changes of Murine Cortex Homeostasis in Response to Sleep Deprivation Hint Dysregulated Aging-like Transcriptional Responses

Sleep deprivation leads to the deterioration in the physiological functioning of the brain, cognitive decline, and many neurodegenerative diseases, all of which progress with advancing age. Sleep insufficiency and impairments in cognitive function are characterized by progressive neuronal losses in the cerebral cortex. In this study, we analyze gene expression profiles following sleep-deprived murine models and circadian matched controls to identify genes that might underlie cortical homeostasis in response to sleep deprivation. Screening of the literature resulted in three murine (Mus musculus) gene expression datasets (GSE6514, GSE78215, and GSE33491) that included cortical tissue biopsies from mice that are sleep deprived for 6 h (n = 15) and from circadian controls that are left undisturbed (n = 15). Cortical differentially expressed genes are used to construct a network of encoded proteins that are ranked based on their interactome according to 11 topological algorithms. The analysis revealed three genes-NFKBIA, EZR, and SGK1-which exhibited the highest multi-algorithmic topological significance. These genes are strong markers of increased brain inflammation, cytoskeletal aberrations, and glucocorticoid resistance, changes that imply aging-like transcriptional responses during sleep deprivation in the murine cortex. Their potential role as candidate markers of local homeostatic response to sleep loss in the murine cortex warrants further experimental validation.

Stress Responses to One-Day Athletic Tournament in Sport Coaches: A Pilot Study

Simple Summary

Judo coaches respond to stress during one-day tournaments, as evidenced by significant changes in hormonal status. The cumulative effect of stressful stimuli was noticeable especially at the end of the day. The results of the present study indicate the usefulness of using tools and a way to study stress among coaches. A similar research protocol can be used to assess stress responses to single-day stimuli associated with other social and occupational roles in healthy middle-aged men.

Abstract

Background: Watching athletic tournaments induces emotional and physiological responses in sports fans and coaches. The aim of the study was to investigate hormonal and cardiovascular responses in judo coaches observing the fights of their athletes during one-day, high-level tournaments. Material and methods: We studied the biological responses of a group of seventeen judo club coaches between the ages of 39 and 57 years to a one-day judo tournament attended by the adult male and/or female athletes that they coached. At the time of the tournaments and also in neutral conditions, the coaches’ capillary blood and saliva samples were collected concurrently two times a day, both at 7:30 a.m. and after completion of the tournament (at about 8:00 p.m.). Cardiovascular parameters were also determined at the same times of day. Sleep quality (SQ) was assessed on a 6-point scale both on the night preceding the tournament and in neutral conditions. Cortisol (C) and testosterone (T) levels were determined from serum and saliva samples. The results for both days at different times of day were compared. Results: Statistical calculations showed higher concentrations of cortisol and a greater reduction of testosterone levels in serum and saliva at the end of the day during the tournament compared with those on a neutral day. Morning and evening cardiovascular indices were higher during the tournament. Conclusion: The study showed that during one-day tournaments, judo coaches were exposed to stress that induced intermittent hormonal changes in blood and saliva and activated the autonomic nervous system.

Advancing health equity through integrated biology and population health research: A community-based sample cortisol feasibility and exploratory study

Background

Community-based research inclusive of self-assessment and objective environmental metrics can be enhanced by the collection of biomarker data in unity toward assessing the health impacts of the totality of environmental stress driven by structural racism. Cortisol dynamic range (CDR), a measure of chronic stress burden, may underpin place-based connections to health, but a gap remains in elucidating community-based CDR methodology.

Purpose

To 1) assess the feasibility of cortisol collection and CDR measurement in a community-based study with home-based, participant-directed specimen collection, and 2) explore the association between CDR and other individual and environmental measures in a sample of predominantly Black participants. Methods: In this cross-sectional, observational study in predominantly Black urban neighborhoods, participants (n = 73) completed health assessments and in-home, self-collected salivary cortisol. For feasibility, CDR (peak-nadir) was compared to cortisol awakening response (CAR) slope over time. Comparisons of CDR quartile by person and place variables were explored (ANOVA).

Results

The cohort (77% Black, 39.7% <$15 k/year income, high perceived stress) completed 98.6% of cortisol collection timepoints. CDR was calculated in all participants without interruptions to sleep-wake cycle as seen with CAR collection. Participants in the lowest quartile of CDR were the oldest (p = 0.03) with lowest reported mental health (p = 0.048) with no associations seen for CAR.

Conclusion

Participant-collected 10.13039/501100011622CDR is more feasible than cortisol measures dependent on slopes over time in a community-based, predominately Black cohort with exploratory findings supporting relevance to outcomes of interest to future work. Future community-based studies should integrate CDR with environment and psychosocial measures.

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Biological and social metrics can enhance community studies of structural racism.

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Cortisol dynamic range (CDR) may reflect the burden of chronic stress in a community.

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In-home, participant-collected salivary cortisol is feasible with in-field guidance.

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CDR may be more feasible in community-based study than measures dependent on time.

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Greatest CDR is seen with youngest age and best self-reported mental health.

Sleep Problems in Chronic Inflammatory Diseases: Prevalence, Treatment, and New Perspectives: A Narrative Review

Epidemiological studies have shown that individuals with sleep problems are at a greater risk of developing immune and chronic inflammatory diseases. As sleep disorders and low sleep quality in the general population are frequent ailments, it seems important to recognize them as serious public health problems. The exact relation between immunity and sleep remains elusive; however, it might be suspected that it is shaped by others stress and alterations of the circadian rhythm (commonly caused by for example shift work). As studies show, drugs used in the therapy of chronic inflammatory diseases, such as steroids or monoclonal antibodies, also influence sleep in more complex ways than those resulting from attenuation of the disease symptoms. Interestingly, the relation between sleep and immunity appears to be bidirectional; that is, sleep may influence the course of immune diseases, such as inflammatory bowel disease. Thus, proper diagnosis and treatment of sleep disorders are vital to the patient's immune status and, in effect, health. This review examines the epidemiology of sleep disorders and immune diseases, the associations between them, and their current treatment and novel perspectives in therapy.

Joint associations of regular exercise and healthy diet with psychobiological stress reactivity in a healthy male sample

Objectives: Engaging in physical activity and exercise have long been shown to have beneficial effects on (psychosocial) stress reactivity. Initial studies could reveal that these positive effects on stress reactivity also exist for a healthy diet. Aim of this study was to examine whether combining a healthy diet and regular exercise can provide additional benefits on psychobiological stress levels. Methods: Forty-two men self-identifying as non-exercisers or regular exercisers between 18 and 30 years were exposed to the Trier Social Stress Test for Groups. Salivary cortisol (sCort) and alpha-amylase (sAA) as biological stress markers, and self-reported momentary stress were repeatedly examined. Questionnaires on regular exercise and dietary intake were completed once. Results: Two-stage hierarchical multiple regressions predicting participants' stress reactivity, i.e. response and recovery, from diet quality, exercise as well as their interaction appeared inconsistent. sCort response was significantly predicted by regular exercise whereas greater sCort recovery was predicted by higher diet quality. In contrast, higher sAA reactivity was predicted by higher diet quality while participants eating less healthy and exercising more showed the most pronounced sAA recovery. None of the other outcome variables was predicted by the interaction. Subjective stress was unrelated to either health behavior. Conclusions: The present examination among an all-male sample emphasized the stress-buffering capabilities of regular exercise and provided initial evidence for a distinct link to healthy diet. Assumed synergistic benefits could, however, not be confirmed. Advances are needed to better understand how individuals profit the most from which behaviors as well as their interactive effects.

Exploring the effects of daily hassles and uplifts on eating behaviour in young adults: The role of daily cortisol levels

Existing stress-eating research has shown that daily hassles are associated with increases in food intake and that cortisol reactivity to stress has been found to influence the stress-eating relationship. However, the moderating effects of daily cortisol levels (e.g., the cortisol awakening response, CAR) remain unknown. Moreover, recent evidence has shown that daily uplifts, as well as daily hassles, are important in understanding daily influences on eating behaviour. Therefore, in the same study, the current investigation explored the effects of daily hassles and uplifts on eating behaviour and whether these relationships were moderated by mean daily cortisol levels in young female adults. Forty-nine female participants (M age: 19.13 years) recorded the daily hassles and uplifts that they experienced over a 4-day period, together with the between-meal snacks they consumed each day, using an online daily diary. Cortisol samples were provided daily immediately upon waking, at +30 min and +12 h. Mean CAR and mean cortisol levels were calculated across the 4 days. Using multi-level modeling, daily hassles and uplifts were both significantly associated with greater unhealthy snacking. Daily uplifts, but not daily hassles, were also associated with lower healthy snack intake. Higher levels of mean CAR were associated with lower daily healthy snack intake. Moreover, the effects of daily uplifts on healthy snacking were found to be moderated by mean daily cortisol levels, such that participants with the highest levels of mean cortisol consumed less healthy snacks on days when they experienced uplifts. The current study provides novel evidence that mean daily cortisol levels, as well as daily hassles and uplifts, are implicated in daily snack consumption in young female adults. The role of hypothalamic-pituitary adrenal axis activity should be explored further in the context of the daily hassles/uplifts and eating behaviours relationship, in men and in individuals from lower socio-economic status and minority groups.

Salivary Testosterone and Cortisol as Biomarkers for the Diagnosis of Sarcopenia and Sarcopenic Obesity in Community-Dwelling Older Adults

Simple Summary

Sarcopenia (S) and sarcopenic obesity (SO) are diseases that increasingly affect society and constitute an important part of the pathologies that affect elderly due to the high life expectancies of the current population. The search for accessible, inexpensive, and noninvasive biomarkers that can help diagnose these diseases quickly and easily is a new field that deserves an in-depth study. The aim of this study was to find relationships between salivary cortisol (C) and testosterone (T) levels and these pathologies’ appearance in 190 community-dwelling men and women over 65 years old. The results reflect a relationship between salivary T and the age of the participants with differences by sex, and a relationship was found between lower levels of T and a greater presence of S and SO. Despite the significant results obtained, more studies are necessary to determine a potential panel of salivary biomarkers for the study of S and SO.

Abstract

Nowadays, the appearance of sarcopenia (S) or sarcopenic obesity (SO) is related to aging. According to the criteria of the European Working Group on Sarcopenia in Older People (EWGSOP), the feasibility of using salivary cortisol and testosterone levels was analyzed as diagnostic biomarkers of S or SO. One hundred and ninety non-institutionalized people aged ≥65 years were studied, independent of the activities of daily living (ADLs) (Barthel > 60), and sociodemographic variables were determined together with criteria for the diagnosis of S and SO including grip force, lower body strength, appendicular skeletal muscle mass, physical performance, total body fat percentage, body mass index (BMI), waist circumference, and triceps skinfold, together with the levels of salivary cortisol and testosterone. Our results reflected that women presented a higher prevalence of S and SO (21.2% and 30.2%, respectively). A significant difference was observed between salivary testosterone levels and the age of the participants with differences by sex. Testosterone values in men with S and SO were significantly lower (p = 0.043 and p = 0.048, respectively), which suggests a potential use of the biomarker for diagnostic purposes. No significant differences were shown with cortisol values.

Effects of Health Behavior Interventions on Psychosocial Outcomes and Cortisol Regulation Among Chronically Stressed Midlife and Older Adults

BACKGROUND

Altered cortisol dynamics have been associated with increased risk for chronic health problems among midlife and older adults (≥ 45 years of age). Yet, studies investigating the impact of health behavior interventions on cortisol activity in this age group are limited.

OBJECTIVE AND METHODS

The current study examined whether 48 midlife and older adults (50% family caregivers, 69% women) randomized to one of four telephone-based health behavior interventions (stress management (SM), exercise (EX), nutrition (NUT), or exercise plus nutrition (EX+NUT)) showed improvements in their perceived stress, mood, and cortisol dynamics at 4 months post-intervention. Participants collected four salivary cortisol samples (waking, 30 min after waking, 4 p.m., and bedtime) across two collection days at baseline and at 4 months post-intervention to assess for total cortisol, cortisol awakening response (CAR), and diurnal cortisol slope.

RESULTS

Participants in SM showed lower levels of total cortisol and a smaller CAR compared with those in EX, NUT, or EX+NUT from baseline to 4 months post-intervention. Participants in EX showed lower levels of perceived stress, depression, and anxiety compared with those in NUT or SM. Finally, participants in NUT showed a greater diurnal decline in cortisol and lower levels of anxiety compared with those in SM.

CONCLUSIONS

These findings provide support for the efficacy of telephone-based, health behavior interventions in improving different stress outcomes among chronically stressed midlife and older adults and suggest the need to test the longer-term effects of these interventions for improving health outcomes in this population.

Biomarking Trait Resilience With Salivary Cortisol in Chinese Undergraduates

This study aimed to examine the relationship between trait resilience and salivary cortisol in a group of Chinese undergraduates. The Chinese versions of the Brief Resilience Scale and a measure of optimism, the revised Life Orientation Test were administered to 49 Chinese undergraduates who provided self-collected saliva samples six times per day (immediately after waking; 0.5, 3, 6, and 12 h thereafter; and at bedtime) over 3 consecutive weekdays. The cortisol data were aggregated across the 3 days to examine the association between resilience and components of the diurnal rhythm of cortisol using multiple regression. The results showed that higher resilience was associated with a stronger cortisol response to awakening and a steeper diurnal decline in cortisol from waking to bedtime. Resilience was positively associated with cortisol output over the course of the day but this relationship was not significant (p = 0.065). This pattern of diurnal rhythm is consistent with that typically observed in better adjusted individuals. Generated by an intensive protocol with compliance objectively monitored, these findings clearly indicate the important role of the hypothalamic-pituitary-adrenocortical axis in health and adjustment and contribute to the growing literature on resilience and cortisol in humans.

Stress-Related Trajectories of Diurnal Cortisol in Older Adulthood Over 12 Years

OBJECTIVE

Although evidence shows that stress experiences can predict both hyper- and hypo-cortisol regulation, there is a lack of research examining these associations longitudinally. Our study assessed whether levels and increases in psychological stress experiences predicted 12-year changes in circadian cortisol levels (area under the curve; AUC) and cortisol slopes in a sample of community-dwelling older adults.

METHODS

In 2004, 190 community dwelling older adults (57 to 94 years) started providing three days of diurnal cortisol and stress experience data every two years for a total of seven waves of data. All analyses controlled for relevant covariates including: SES, BMI, age, sex, cortisol-related medication, chronic illness, and smoking status.

RESULTS

Growth-curve modeling documented that compared to participants who reported generally lower stress experiences (T-ratio = -5.57, p < .01), their counterparts with higher stress experiences showed significantly steeper declines in cortisol AUC over time (T-ratio = -9.23, p < .01). Higher stress experience was associated with generally flatter cortisol slopes. In addition, among participants with high and increasing stress experience over 12 years, cortisol slopes became increasingly flatter over time (T-ratio = 2.78, p < .01).

CONCLUSIONS

Among individuals with high, as compared to low, levels of chronic stress experience, cortisol levels displayed steeper declines across the study period. Moreover, cortisol slopes became increasingly flatter as a function of high and increasing stress experience. Implications for theory and research on the associations between stress experience and cortisol in the context of longitudinal observations are discussed.

Associations between Health Behaviors and Factors on Markers of Healthy Psychological and Physiological Functioning: a Daily Diary Study

Background

Cross-sectional and experimental knowledge highlight the contribution of various health-promoting behaviors, such as physical activity, regular sleep, and healthy nutrition to mental and physical health. Beyond these well-studied lifestyle behaviors, music listening and perceived respect in social interactions are just recently proposed everyday life experiences, which may act as health-promoting factors.

Purpose

This study tested the simultaneous contribution of several health-promoting behaviors and factors and examined listening to music and positive social interaction by means of perceived respect as new potentially preventive and health-promoting behaviors and factors using an ambulatory assessment design.

Methods

Seventy-seven young healthy adults (38 women, 23.9 ± 4.5 years) completed surveys on their psychological state (i.e., mood, stress, and fatigue) five times a day for four consecutive days. A saliva sample was collected with each data entry to explore the physiological stress markers salivary cortisol, alpha-amylase, and flow rate as further outcome variables. As predictors, perceived respect, self-reported physical activity, the sleep’s restfulness, daily coffee, alcohol, vegetable/fruit consumption, and music listening behavior were recorded.

Results

Overall, restful sleep, mean daily perceived respect, and listening to music were most clearly associated with more positive psychological states, that is, better mood and lower fatigue and perceived stress. Associations with daily alcohol, coffee, and vegetable/fruit consumption appeared rather minor. While perceived respect scores were associated with lower daily cortisol output, coffee consumption was positively related to daily cortisol and alpha-amylase. Self-reported physical activity was unrelated to either outcome measure.

Conclusions

These findings provide important insights regarding potential resources of health (i.e., music and respect), their covariation, and which psycho-physiological mechanisms may underlie the links between health factors and well-being. Findings also have implications for the development of interventions aiming to increase resilience and foster health. Here, strategies for improving sleep quality, the use of music, and approaches that emphasize mutual respect and appreciation appear useful additions.

Adrenal Aging and Its Implications on Stress Responsiveness in Humans

Normal aging results in subtle changes both in ACTH and cortisol secretion. Most notable is the general increase in mean daily serum cortisol levels in the elderly, without a noteworthy alteration in the normal circadian rhythm pattern. Glucocorticoid excess seen in the elderly population can have serious consequences in both the structural and functional integrity of various key areas in the brain, including the hippocampus, amygdala, prefrontal cortex, with consequent impairment in normal memory, cognitive function, and sleep cycles. The chronically elevated glucocorticoid levels also impinge on the normal stress response in the elderly, leading to an impaired ability to recover from stressful stimuli. In addition to the effects on the brain, glucocorticoid excess is associated with other age-related changes, including loss of muscle mass, hypertension, osteopenia, visceral obesity, and diabetes, among others. In contrast to the increase in glucocorticoid levels, other adrenocortical hormones, particularly serum aldosterone and DHEA (the precursor to androgens and estrogens) show significant decreases in the elderly. The underlying mechanisms for their decrease remain unclear. While the adrenomedullary hormone, norephinephrine, shows an increase in plasma levels, associated with a decrease in clearance, no notable changes observed in plasma epinephrine levels in the elderly. The multiplicity and complexity of the adrenal hormone changes observed throughout the normal aging process, suggests that age-related alterations in cellular growth, differentiation, and senescence specific to the adrenal gland must also be considered.

Effects of single moor baths on physiological stress response and psychological state: a pilot study

Moor mud applications in the form of packs and baths are widely used therapeutically as part of balneotherapy. They are commonly given as therapy for musculoskeletal disorders, with their thermo-physical effects being furthest studied. Moor baths are one of the key therapeutic elements in our recently developed and evaluated 3-week prevention program for subjects with high stress level and increased risk of developing a burnout syndrome. An embedded pilot study add-on to this core project was carried out to assess the relaxing effect of a single moor bath. During the prevention program, 78 participants received a total of seven moor applications, each consisting of a moor bath (42 °C, 20 min, given between 02:30 and 05:20 p.m.) followed by resting period (20 min). Before and after the first moor application in week 1, and the penultimate moor application in week 3, salivary cortisol was collected, blood pressure and heart rate were measured, and mood state (Multidimensional Mood State Questionnaire) was assessed. A Friedman test of differences among repeated measures was conducted. Post hoc analyses were performed using the Wilcoxon signed-rank test. A significant decrease in salivary cortisol concentration was seen between pre- and post-moor bath in week 1 (Z = -3.355, p = 0.0008). A non-significant decrease was seen between pre- and post-moor bath in week 3. Mood state improved significantly after both moor baths. This pilot study has provided initial evidence on the stress-relieving effects of single moor baths, which can be a sensible and recommendable therapeutic element of multimodal stress-reducing prevention programs. The full potential of moor baths still needs to be validated. A randomized controlled trial should be conducted comparing this balneo-therapeutic approach against other types of stress reduction interventions.

Exercise and the Cortisol Awakening Response: A Systematic Review

BACKGROUND

The cortisol awakening response (CAR) has been used as a biomarker of stress response in a multitude of psychological investigations. While a myriad of biochemical responses have been proposed to monitor responses to exercise training, the use of CAR within the exercise and sports sciences is currently limited and is a potentially underutilized variable. Therefore, the purpose of this review was to collate studies that incorporate both exercise and CAR, in an effort to better understand (a) whether CAR is a useful marker for monitoring exercise stress and (b) how CAR may be most appropriately used in future research.

METHODS

A systematic review of the literature was conducted, following PRISMA guidelines. Searches were conducted using PubMed, SportDISCUS, Scopus, and PsychInfo databases, using search terms related toCAR and exercise and physical activity.

RESULTS

10,292 articles were identified in the initial search, with 32 studies included in the final analysis. No studies investigated the effects of laboratory-controlled exercise on CAR. Variable effects were observed, possibly due to inconsistencies in study design, methodology, population, and CAR analysis. The available literature suggests a threshold of exercise may be required to alter the HPA axis and affect CAR. Moreover, CAR may represent a combination of previous exercise load and upcoming stress, making current interpretation of field-based observational research challenging.

CONCLUSIONS

More research is needed to fully elucidate the influence of exercise on CAR and address a number of gaps in the literature, including controlling exercise load, consistent sample collection, and CAR calculation and analysis.

HPA-axis and inflammatory reactivity to acute stress is related with basal HPA-axis activity

INTRODUCTION

Inflammation is drawing attention as pathway between psychosocial stress and health, and basal HPA axis activity has been suggested to exert a consistent regulatory influence on peripheral inflammation. Here we studied the relationship between basal HPA axis activity and inflammatory and HPA axis acute stress reactivity.

METHODS

We recruited 48 healthy individuals and collected saliva for diurnal cortisol sampling at 6 points. Participants were previously exposed to the Trier Social Stress Test (TSST) on two consecutive days. Plasma interleukin-6 (IL-6) and salivary cortisol reactivity to acute stress were measured, and their relationships with basal HPA axis activity were analyzed.

RESULTS

Steeper cortisol awakening response (CAR) linear increase was related with stronger cortisol stress reactivity (γ=0.015; p=0.042) and marginally significantly with greater habituation (γ=0.01; p=0.066). Greater curvilinearity of CAR was related with stronger cortisol reactivity (γ=-0.014; p=0.021) and greater cortisol habituation (γ=-0.011; p=0.006). Steeper daily linear decline was related with significant or marginally significantly stronger cortisol and IL-6 reactivity (cortisol: γ=-0.0004; p=0.06; IL-6: γ=-0.028; p=0.031) and greater habituation (cortisol: γ=-0.002; p=0.009, IL-6: γ=-0.015; p=0.033). Greater curvilinearity of daily decline was related with stronger IL-6 reactivity (γ=0.002; p=0.024) and also greater cortisol and IL-6 habituation (cortisol: γ=0.00009; p=0.03, IL-6: γ=0.001; p=0.024).

CONCLUSIONS

Patterns of basal HPA axis activity that are related with healthier outcomes were found to be related with stronger initial cortisol and IL-6 reactivity and greater habituation. This is an important step in understanding the long-term health implications of acute stress responsiveness, and future studies should employ longitudinal designs to identify the direction of these relationships.

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.

Associations between Sleep, Cortisol Regulation, and Diet: Possible Implications for the Risk of Alzheimer Disease

Accumulation of proteinaceous amyloid β plaques and tau oligomers may occur several years before the onset of Alzheimer disease (AD). Under normal circumstances, misfolded proteins get cleared by proteasome degradation, autophagy, and the recently discovered brain glymphatic system, an astroglial-mediated interstitial fluid bulk flow. It has been shown that the activity of the glymphatic system is higher during sleep and disengaged or low during wakefulness. As a consequence, poor sleep quality, which is associated with dementia, might negatively affect glymphatic system activity, thus contributing to amyloid accumulation. The diet is another important factor to consider in the regulation of this complex network. Diets characterized by high intakes of refined sugars, salt, animal-derived proteins and fats and by low intakes of fruit and vegetables are associated with a higher risk of AD and can perturb the circadian modulation of cortisol secretion, which is associated with poor sleep quality. For this reason, diets and nutritional interventions aimed at restoring cortisol concentrations may ease sleep disorders and may facilitate brain clearance, consequentially reducing the risk of cognitive impairment and dementia. Here, we describe the associations that exist between sleep, cortisol regulation, and diet and their possible implications for the risk of cognitive impairment and AD.

Characterization and novel analyses of acute stress response patterns in a population-based cohort of young adults: influence of gender, smoking, and BMI

Dysregulation of the biological stress response system has been implicated in the development of psychological, metabolic, and cardiovascular disease. Whilst changes in stress response are often quantified as an increase or decrease in cortisol levels, three different patterns of stress response have been reported in the literature for the Trier Social Stress Test (TSST) (reactive-responders (RR), anticipatory-responders (AR) and non-responders (NR)). However, these have never been systematically analyzed in a large population-based cohort. The aims of this study were to examine factors that contribute to TSST variation (gender, oral contraceptive use, menstrual cycle phase, smoking, and BMI) using traditional methods and novel analyses of stress response patterns. We analyzed the acute stress response of 798, 18-year-old participants from a community-based cohort using the TSST. Plasma adrenocorticotrophic hormone, plasma cortisol, and salivary cortisol levels were quantified. RR, AR, and NR patterns comprised 56.6%, 26.2%, and 17.2% of the cohort, respectively. Smokers were more likely to be NR than (RR or AR; adjusted, p < 0.05). Overweight and obese subjects were less likely to be NR than the other patterns (adjusted, p < 0.05). Males were more likely to be RR than NR (adjusted, p = 0.05). In addition, we present a novel AUC measure (AUCR), for use when the TSST baseline concentration is higher than later time points. These results show that in a young adult cohort, stress-response patterns, in addition to other parameters vary with gender, smoking, and BMI. The distribution of these patterns has the potential to vary with adult health and disease and may represent a biomarker for future investigation.

Examining the cross-sectional and longitudinal association between diurnal cortisol and neighborhood characteristics: Evidence from the multi-ethnic study of atherosclerosis

We examined cross-sectional and longitudinal associations between neighborhood socioeconomic status, social cohesion and safety and features of the diurnal cortisol curve including: area under the curve (AUC), wake-to-bed slope, wake-up, cortisol awakening response (CAR, wake-up to 30 min post-awakening), early decline (30 min to 2 h post-awakening) and late decline (2 h post-awakening to bed time). In cross-sectional analyses, higher neighborhood poverty was associated with a flatter early decline and a flatter wake-to-bed slope. Higher social cohesion and safety were associated with higher wake-up cortisol, steeper early decline and steeper wake-to-bed slope. Over 5 years, wake-up cortisol increased, CAR, early decline, late decline and wake-to-bed slope became flatter and AUC became larger. Higher poverty was associated with less pronounced increases in wake-up and AUC, while higher social cohesion was associated with greater increases in wake-up and AUC. Adverse neighborhood environments were cross-sectionally associated with flatter cortisol profiles, but associations with changes in cortisol were weak and not in the expected direction.

Effects of an exercise and hypocaloric healthy eating intervention on indices of psychological health status, hypothalamic-pituitary-adrenal axis regulation and immune function after early-stage breast cancer: a randomised controlled trial

Introduction

Many women experience emotional distress, depression and anxiety after a diagnosis of breast cancer. Psychological stress and depression have been associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation that may adversely affect immune system functioning and impact upon survival. This study investigated the effects of a lifestyle intervention on indices of psychological health status, HPA axis regulation and immune function in overweight women recovering from early-stage breast cancer treatment.

Methods

A total of 85 women treated for breast cancer 3 to 18 months previously were randomly allocated to a 6-month exercise and hypocaloric healthy eating program plus usual care or usual care alone (control group). Women in the intervention group received three supervised exercise sessions per week and individualized dietary advice, supplemented by weekly nutrition seminars. Depressive symptoms (Beck Depression Inventory version II: BDI-II), perceived stress (Perceived Stress Scale: PSS), salivary diurnal cortisol rhythms; inflammatory cytokines (IL-6 and Tumor necrosis factor-α), leukocyte phenotype counts, natural killer (NK) cell cytotoxicity and lymphocyte proliferation following mitogenic stimulation were assessed at baseline and 6-month follow up.

Results

Compared with the control group, the intervention group exhibited a reduction in depressive symptoms (adjusted mean difference, 95% confidence intervals (95% CI): −3.12, −1.03 to −5.26; P = 0.004) at the 6-month follow-up but no significant decrease in PSS scores (−2.07, −4.96 to 0.82; P = 0.16). The lifestyle intervention also had a significant impact on diurnal salivary cortisol rhythm compared with usual care alone, as evidenced by an increase in morning salivary cortisol at the 6-month follow-up (P <0.04), indicating a change in HPA axis regulation. Women in the control group had higher total leukocyte, neutrophil and lymphocyte counts in comparison to the intervention group at the 6-month follow-up (P ≤0.05), whereas there was no difference in NK cell counts (P = 0.46), NK cell cytotoxicity (P = 0.85) or lymphocyte proliferation responses (P = 0.11) between the two groups.

Conclusion

Our results show that the lifestyle intervention resulted in a reduction in depressive symptoms and a normalisation of HPA axis regulation. Such changes could have important implications for long-term survival in women recovering from early-breast cancer treatment.

Trial registration

Current Controlled Trials: ISRCTN08045231

The effects of multivitamin supplementation on diurnal cortisol secretion and perceived stress

Recent evidence suggests that dietary intake of vitamins, in particular the B-vitamins including B6, B9 and B12 may have a number of positive effects on mood and stress. Given the effects of stress on a range of biological mechanisms including the endocrine system, it could be reasonably expected that multivitamin supplementation may also affect markers of these mechanisms such as diurnal cortisol secretion. In the current double-blind placebo-controlled study 138 adults (aged 20 to 50 years) were administered a multivitamin containing B-vitamins versus placebo over a 16-week period. Salivary cortisol measurements were taken at waking, 15-min, 30-min and at bedtime, at baseline, 8-weeks and 16-weeks. Perceived Stress (PSS) was measured at baseline, 8-weeks and 16-weeks, while blood serum measures of B6, B12 and homocysteine (HCy) as well as red cell folate (B9) were also collected at these time points. A significant interaction was found between treatment group and study visit for the Cortisol Awakening Response (CAR). Compared to placebo, at 16-weeks multivitamin supplementation was found to be associated with a near-significant trend towards an increased CAR. No significant differences in PSS were found between groups, with PSS increasing in both groups across the course of the study. Red cell folate was found to be significantly correlated with the CAR response at 16-weeks while HCy levels were not found to be associated with the CAR response, although HCy significantly correlated with waking cortisol levels at 8-weeks. A possible interpretation of the elevation in CAR associated with multivitamin supplementation is that this represents an adaptive response to everyday demands in healthy participants.

Age-dependent and gender-dependent regulation of hypothalamic-adrenocorticotropic-adrenal axis

Tightly regulated output of glucocorticoids is critical to maintaining immune competence, the structure of neurons, muscle, and bone, blood pressure, glucose homeostasis, work capacity, and vitality in the human and experimental animal. Age, sex steroids, gender, stress, body composition, and disease govern glucocorticoid availability through incompletely understood mechanisms. According to an ensemble concept of neuroendocrine regulation, successful stress adaptations require repeated incremental signaling adjustments among hypothalamic corticotropin-releasing hormone and arginine vasopressin, pituitary adrenocorticotropic hormone, and adrenal corticosteroids. Signals are transduced via (positive) feedforward and (negative) feedback effects. Age and gonadal steroids strongly modulate stress-adaptive glucocorticoid secretion by such interlinked pathways.