The role of week(end)-day and awakening time on cortisol and alpha-amylase awakening responses

Salivary α-amylase as a marker of sleep disorders: A theoretical review

Sleep disorders are commonplace in our modern societies. Specialized hospital departments are generally overloaded, and sleep assessment is an expensive process in terms of equipment, human resources, and time. Biomarkers would usefully complement current measures in the screening and follow-up of sleep disorders and their daytime repercussions. Among salivary markers, a growing body of literature suggests that salivary α-amylase (sAA) may be a cross-species marker of sleep debt. However, there is no consensus as to the direction of variation in sAA with sleep disorders. Herein, after describing the mechanisms of sAA secretion and its relationship with stress, studies assessing the relationship between sAA and sleep parameters are reviewed. Finally, the influence of confounding factors is discussed, along with methodological considerations, to better understand the fluctuations in sAA and facilitate future studies in the field.

The diurnal course of salivary cortisol and alpha-amylase on workdays and leisure days in teachers and the role of social isolation and neuroticism

Teachers are among the occupational groups with the highest sick leave rates due to workplace stress and burnout symptoms. A substantial body of research has suggested social isolation and neuroticism to be related to physiological stress activity. However, the relationship between such characteristics and stress experiences has rarely been studied in conjunction with physiological stress indicators in the teachers' natural settings. Thus, the present study examines salivary cortisol and α-amylase as physiological stress indicators on teachers' work and leisure days and their relationship with social isolation. Furthermore, we test whether neuroticism moderates the relationship between social isolation and salivary biomarkers. Forty-two teachers completed questionnaires assessing social isolation (Trier Inventory for the Assessment of Chronic Stress) and neuroticism (Big-Five Inventory). Participants collected eight saliva samples on three days, two workdays, and one leisure day to measure the concentration of cortisol and α-amylase as biomarkers of the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS), respectively. Results showed a significantly higher Cortisol Awakening Response (CAR) and diurnal cortisol slope (DCS) on workdays than on the leisure day but no significant differences regarding measures of α-amylase. We found a significant positive relationship between social isolation and the CAR on the leisure day but no association with the α-amylase measures. Furthermore, after controlling for confounders, social isolation was unrelated to neuroticism, and the latter did not moderate between social isolation and the CAR. Our findings suggest an association between social isolation and the HPA axis, i.e., the CAR, but do not support an association with the ANS, which would be indicated by the α-amylase assessments. Finally, our findings could not support an association of neuroticism with the HPA axis and ANS.

An ecological momentary music intervention for the reduction of acute stress in daily life: A mixed methods feasibility study

Background: Despite the growing potential of mobile-based technologies, innovative interventions targeting the reduction of acute stress in daily life remain under-researched. Music listening is an easy-to-administer activity that is associated with lower levels of biological and self-reported stress. However, the application of music as an intervention in moments of acute stress in daily life remains to be examined. We developed a just-in-time intervention delivering music in moments of stressful experiences in daily life and tested its feasibility using a mixed methods approach.

Methods: In this uncontrolled pilot study, the ecological momentary music intervention (EMMI) was tested by 10 chronically stressed women aged 23.5 ± 3.3 years. Over 18 consecutive days, whenever participants reported stressful experiences, they were encouraged to listen to a self-compiled playlist. Subjective stress levels and saliva samples were assessed at three time points per stress report (T₀, upon reporting a stressful situation; T₁, directly after music listening/15 min after T₀ in case of no music listening; T₂, 15 min after T₁). We analyzed app-based log data, in-the-moment responses, questionnaire data, and semi-structured interview data.

Results: On average, participants’ compliance with the study protocol lay at 70%. Overall, 65 stressful experiences were reported, 51 of which were followed by music listening, for an average duration of 12:53 min. Complete data (i.e., self-reports and saliva samples at all three time points) were provided for 46 stressful experiences. Participants reported immediate relaxation and distraction through music listening. The interviews revealed that the intervention was easy to use and that music listening in moments of perceived stress was viewed as a new and pleasant activity. Several aspects of the protocol (e.g., number of items and prompts) were identified, which should be improved in future studies.

Conclusion: Since repeated stressful experiences in daily life can pose a threat to physical and mental integrity, interventions that are easily applicable and deliver support when needed most are necessary. Following minor adaptations, the EMMI can be considered as a feasible approach to target psychobiological stress responses in daily life, which is worthy of investigation in future larger-scale trials.

Biological markers in clinical psychological research - A systematic framework applied to HPA axis regulation in PTSD

Biological markers, particularly endocrine measurements, are increasingly being integrated into clinical psychological research. We introduce a systematic framework that classifies different functions of such biomarkers. The framework distinguishes between diagnostic biomarkers which add a biological perspective to conventional clinical assessments, prognostic biomarkers that inform about an individual’s risk to develop or maintain a mental health disorder, and intervention-related biomarkers. Regarding interventions, including prevention and treatment, it further distinguishes between prescriptive biomarkers which predict an individual’s response to an intervention, outcome biomarkers which evaluate intervention-related changes on a biological level and indicators of change mechanisms. We demonstrate how to apply the framework by exemplarily classifying and describing previously published systematic reviews and primary empirical studies on endogenous, peripheral cortisol concentrations as a biomarker for posttraumatic stress disorder (PTSD). The evidence on cortisol’s diagnostic and prognostic value is heterogeneous and still sparse regarding parameters based on multiple cortisol measurements, such as the cortisol awakening response. With regard to interventions, most research focused on trauma-focused psychotherapy and cortisol reactivity to trauma reminders. This field of research appears to be growing and very promising due to its potential to optimize PTSD-related interventions. The proposed framework can help in gaining a systematic overview of existing research. It can assist in structuring, comparing, summarizing and evaluating empirical studies, and in identifying research gaps.

•

Iagnostic biomarkers can inform about biological alterations in mental disorders.

•

Prognostic biomarkers can help to predict the development of a mental disorder.

•

Biomarkers can indicate the outcome, differential effects, or mechanisms of change of clinical psychological interventions.

Naturalistic social cognitive and emotional reactions to technology-mediated social exposures and cortisol in daily life

The emotional and social evaluative aspects of social interactions influence cortisol. The interactions that mothers have on social networking sites and via other technology involve heightened social comparison and emotion. We examined the associations between technology-mediated social engagement, social comparisons and emotion during technology-mediated social exposures (TMSEs), and cortisol during daily life. Forty-seven mothers (mean age = 34.38) completed a 4-day monitoring period involving four saliva collections and questionnaires daily at awakening, 4 h post-awakening, 9 h post-awakening, and bedtime. Higher social comparison during TMSE was associated with lower momentary cortisol, whereas higher negative emotions during TMSE and more time spent in TMSE were associated with higher momentary cortisol. Higher average social comparison during TMSE was associated with lower average daily cortisol output (area under the curve with respect to ground; AUCg), and more time spent on TMSE was associated with higher average AUCg. This study presents the first evidence that naturalistic social-cognitive and emotional reactions to TMSE are associated with cortisol in daily life.

Associations between maternal awakening salivary cortisol levels in mid-pregnancy and adverse birth outcomes

PURPOSE

Elevated levels of maternal cortisol have been hypothesized as the intermediate process between symptoms of depression and psychosocial stress during pregnancy and adverse birth outcomes. Therefore, we examined associations between cortisol levels in the second trimester of pregnancy and risks of three common birth outcomes in a nested case-control study.

METHODS

This study was embedded in the PRIDE Study (n = 3,019), from which we selected all cases with preterm birth (n = 64), low birth weight (n = 49), and small-for-gestational age (SGA; n = 65), and 260 randomly selected controls, among the participants who provided a single awakening saliva sample in approximately gestational week 19 in 2012-2016. Multivariable linear and logistic regression was performed to assess the associations between continuous and categorized cortisol levels and the selected outcomes.

RESULTS

We did not observe any associations between maternal cortisol levels and preterm birth and low birth weight. However, high cortisol levels (≥ 90th percentile) seemed to be associated with SGA (adjusted odds ratio 2.1, 95% confidence interval 0.9-4.8), in particular among girls (adjusted odds ratio 3.7, 95% confidence interval 1.1-11.9, based on eight exposed cases) in an exploratory analysis.

CONCLUSION

The results of this study showed no suggestions of associations between maternal awakening cortisol levels in mid-pregnancy and adverse birth outcomes, except for an increased risk of SGA.

Salivary Cortisol and Alpha-Amylase in Posttraumatic Stress Disorder and Their Potential Role in the Evaluation of Cognitive Behavioral Treatment Outcomes

Alterations in HPA-axis and autonomic nervous system activity have been associated with posttraumatic stress disorder (PTSD) development and maintenance and are potentially associated with trauma-focused cognitive behavioral therapy (TF-CBT) outcomes. We examined the role of salivary cortisol (sCort) and alpha-amylase (sAA) in PTSD and TF-CBT outcomes in German Armed Forces service members (N = 100). Participants categorized as PTSD patients (n = 39), previously deployed healthy controls (n = 33), and nondeployed healthy controls (n = 28) provided diurnal profiles of sCort and sAA; PTSD patients provided samples before, immediately after, and 3 months after an internet-based TF-CBT intervention. No group differences emerged regarding total daily sCort and sAA output or daily slopes, ps = .224-.897, fs = 0.05-0.24. Participants with PTSD demonstrated a significantly attenuated sCort awakening response compared to deployed, p = .021, d = 0.59, but not nondeployed controls, p = .918, d = 0.08. Moreover, a significantly steeper sAA awakening response emerged in PTSD patients, p = .034, d = 0.67, and deployed controls, p = .014, d = 0.80, compared to nondeployed controls. From pretreatment to posttreatment (n = 21) and posttreatment to follow-up (n = 14), stable sCort, ps = .282-.628, fs = 0.34-0.49, and sAA concentrations, ps = .068-.758, fs = 0.24-1.13 paralleled a nonsignificant treatment effect. Both PTSD and trauma exposure were associated with alterations in awakening responses, but further investigation is needed to determine whether the observed correspondence remains when PTSD symptoms significantly decline.

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.

Application of Salivary Biomarkers in the Diagnosis of Fibromyalgia

Fibromyalgia (FM) is a highly prevalent syndrome that impairs the quality of life of the patients; however, its diagnosis is complex and mainly centered on pain symptoms. The study of salivary biomarkers has proven highly useful for the diagnosis and prognosis of numerous diseases. The objective of this review was to gather published data on the utilization of salivary biomarkers to facilitate and complement the diagnosis of FM. Salivary biomarkers used in FM diagnosis include cortisol; calgranulin; and the enzymes α-amylase, transaldolase, and phosphoglycerate mutase. Increased serum levels of C-reactive protein, cytokines interleukin 1-β, interleukin 6, interleukin 8, interleukin 10, interleukin 17, tumor necrosis factor α, and various chemokines may serve as salivary biomarkers, given observations of their increased serum levels in patients with FM. Further research is warranted to study in depth the role and performance of biomarkers currently used in FM diagnosis/prognosis and to identify novel salivary biomarkers for this disease.

Increased adrenocorticotropic hormone (ACTH) levels predict severity of depression after six months of follow-up in outpatients with major depressive disorder

Previous studies have reported dysfunction in the hypothalamic-pituitary-adrenal (HPA) axis in patients with major depressive disorder (MDD). Outpatients diagnosed with MDD (n = 199) underwent psychological evaluation, and were followed up with a phone interview after 6 months, using the Patient Health Questionnaire (PHQ-9). At 6-month follow-up, 59 out of 199 patients with MDD were still depressed (29.5%), as shown by scores ≥ 10 on the PHQ-9. The depressed group at follow-up showed significantly higher anxiety and suicidality levels at baseline than the non-depressed group at follow-up. Among the complete blood counts, lipid profiles, and hormone levels, adrenocorticotropic hormone (ACTH) was the only parameter that was significantly increased in the still depressed group. Levels higher than 40 pg/mL of ACTH at baseline were associated with higher depression scores at follow-up. Multiple linear regression analyses revealed that ACTH and cortisol predicted depression scores at follow-up, after controlling for baseline depression scores. Increased ACTH level at baseline may predict ongoing symptoms and severity of depression at follow-up, suggesting the role of dysfunctional HPA axis in MDD prognosis.

Salivary cortisol in post-traumatic stress disorder: a systematic review and meta-analysis

BACKGROUND

Studies investigating salivary cortisol level as susceptibility marker for post-traumatic stress disorder (PTSD) produced inconsistent results. The aim of this study was to compare salivary cortisol concentration levels in PTSD patients with those in controls by synthesizing published data.

METHODS

We did a systematic review, meta-analysis and meta-regression of studies comparing concentrations of salivary cortisol between patients with PTSD and controls. The electronic databases of PubMed, Embase, Web of Science and Psyc-ARTICLES were searched for relevant articles. A random-effects model with restricted maximum-likelihood estimator is used to synthesize the effect size (assessed by standardized mean difference).

RESULTS

A total of 784 articles were identified of which 22 were included in the final analysis. A trend of lower salivary cortisol levels was found in PTSD patients when compared with the controls (SMD = - 0.28, 95% CI-0.53;-0.04, p = 0.022). Subgroup analysis showed that the salivary cortisol levels were lower in patients with PTSD than in controls in studies conducted after 2007 or in studies using saliva samples collected in the morning.

CONCLUSIONS

The evidence from this meta-analysis supports that salivary samples collected in the morning consistently showed a lower salivary cortisol level in patients with PTSD than in controls, although whether salivary cortisol could be used as a diagnostic tool requires further research.

Combining ecological momentary assessment with objective, ambulatory measures of behavior and physiology in substance-use research

Whereas substance-use researchers have long combined self-report with objective measures of behavior and physiology inside the laboratory, developments in mobile/wearable electronic technology are increasingly allowing for the collection of both subjective and objective information in participants' daily lives. For self-report, ecological momentary assessment (EMA), as implemented on contemporary smartphones or personal digital assistants, can provide researchers with near-real-time information on participants' behavior and mood in their natural environments. Data from portable/wearable electronic sensors measuring participants' internal and external environments can be combined with EMA (e.g., by timestamps recorded on questionnaires) to provide objective information useful in determining the momentary context of behavior and mood and/or validating participants' self-reports. Here, we review three objective ambulatory monitoring techniques that have been combined with EMA, with a focus on detecting drug use and/or measuring the behavioral or physiological correlates of mental events (i.e., emotions, cognitions): (1) collection and processing of biological samples in the field to measure drug use or participants' physiological activity (e.g., hypothalamic-pituitary-adrenal axis activity); (2) global positioning system (GPS) location information to link environmental characteristics (disorder/disadvantage, retail drug outlets) to drug use and affect; (3) ambulatory electronic physiological monitoring (e.g., electrocardiography) to detect drug use and mental events, as advances in machine learning algorithms make it possible to distinguish target changes from confounds (e.g., physical activity). Finally, we consider several other mobile/wearable technologies that hold promise to be combined with EMA, as well as potential challenges faced by researchers working with multiple mobile/wearable technologies simultaneously in the field.

Psychobiological stress in vital exhaustion. Findings from the Men Stress 40+ study

OBJECTIVE

Despite the increased risk for cardiovascular morbidity associated with vital exhaustion (VE), the underlying pathophysiological mechanisms remain unclear. Allostatic load may constitute the missing link between VE and cardiovascular diseases. The aim of the present study was to investigate whether men with different degrees of VE would differ in terms of allostatic load, chronic stress, and social support.

METHODS

The Men Stress 40+ study sample consisted of N=121 apparently healthy men aged 40 to 75years. The following allostatic load markers were aggregated to create a cumulative index of biological stress: salivary cortisol, salivary dehydroepiandrosterone sulfate (DHEA-S), waist-to-hip-ratio, systolic and diastolic blood pressure. Long-term cortisol and DHEA were additionally measured in hair. Chronic stress and social support were assessed via validated questionnaires. Groups of mildly, substantially, and severely exhausted men were compared using one-way ANOVAs with appropriate post-hoc tests.

RESULTS

Men who reported mild or severe levels of vital exhaustion had the highest scores on the cumulative index of biological stress. Hair cortisol was unrelated to vital exhaustion; hair DHEA was highest in men with substantial levels of exhaustion. Men with mild exhaustion reported the lowest levels of chronic stress, while men with severe exhaustion reported the lowest levels of social support.

CONCLUSIONS

Signs of allostatic load are detectable in vitally exhausted men at a stage where no major cardiovascular consequences have yet ensued.

Psychobiological impact of ethnic discrimination in Turkish immigrants living in Germany

Perceived ethnic discrimination has a negative impact on health. One of the key mechanisms may be a dysregulation of stress-responsive systems. Our aims were to investigate whether (1) acute face-to-face ethnic discrimination induces a stress response, and (2) to compare long-term endocrine functioning between immigrants and nonimmigrants. 30 male Turkish immigrants living in Germany underwent an ethnic discrimination condition and a control condition in the laboratory. Perceived ethnic discrimination, stress, salivary alpha-amylase and cortisol were measured four times. Heart rate and electrodermal activity were measured continuously. In addition, hair samples were collected from immigrants and 25 male nonimmigrants to determine long-term cortisol concentrations. Immigrants showed increases in perceived ethnic discrimination, stress, heart rate, alpha-amylase and cortisol during the ethnic discrimination condition. Immigrants had significantly lower hair cortisol concentrations than nonimmigrants. These findings suggest that acute ethnic discrimination elicits a psychobiological stress response. Abnormalities in long-term endocrine functioning in ethnic minorities may set the stage for the development of stress-related illnesses. Lay summary The present study found that racial discrimination of Turkish immigrants induced both psychological and physiological stress responses in the laboratory. Immigrants showed lower hair cortisol concentrations than nonimmigrants, indicating a dysregulated biological stress system.

Single awakening salivary measurements provide reliable estimates of morning cortisol levels in pregnant women

Mood disorders during pregnancy have been associated with adverse effects on maternal as well as fetal health. Since mood, anxiety, and stress disorders are related with elevated cortisol levels, salivary cortisol may be a useful biomarker. Although multiple samples are generally recommended, a single measurement of awakening salivary cortisol could be a simpler and more cost-effective method to determine whether women have elevated morning cortisol levels during a specific period of pregnancy. Therefore, the aim of this validation study among 177 women in the PRIDE Study was to examine whether one awakening salivary cortisol measurement will suffice to classify pregnant women as having normal or elevated cortisol levels compared to awakening salivary cortisol measurements on three consecutive working days. We calculated intraclass correlation coefficients (ICC) and Cohen's kappa statistics (κ) overall as well as in sub-analyses within strata based on maternal age, level of education, net household income, pre-pregnancy BMI, parity, complications during pregnancy, caffeine consumption, gestational week of sampling, and awakening time. The mean cortisol concentrations were 8.98ng/ml (SD 5.32) for day one, 8.62ng/ml (SD 4.55) for day two, and 8.39ng/ml (SD 4.58) for day three. The overall ICC was 0.86 (95% CI 0.82-0.89) while the κ was 0.75 (95% CI 0.64-0.86). For the ICCs calculated within sub-analyses, a maximum difference of 0.11 was observed between the strata. For the κ statistics, most strata did not differ more than 0.12, except for pre-pregnancy BMI, severe nausea, and extreme fatigue with differences up to 0.22. In conclusion, one awakening salivary cortisol measurement is as reliable for the classification of pregnant women into normal and elevated morning cortisol levels as salivary cortisol measurements on three consecutive working days.