Maternal circadian cortisol mediates the link between prenatal distress and breastfeeding

Breastfeeding is associated with positive maternal and infant outcomes. It is recommended that women exclusively breastfeed for the first 6 months postpartum; however, these recommendations are not met in the majority of women. Psychological distress in pregnancy is associated with lower rates of breastfeeding initiation and duration in the postpartum period. The mechanisms linking maternal distress to breastfeeding are not understood. In this study we examined maternal circadian cortisol as a mechanism linking distress in pregnancy to breastfeeding. This study is a secondary data analysis of 197 pregnant women with singleton pregnancies who were part of a larger study of the effects of maternal mood on fetal and infant development. About 34% of women reported exclusively breastfeeding, 18% reported exclusively formula feeding, and 48% reported mixed feeding. Participants reported on perceived stress, perinatal anxiety and depression, and socioeconomic status during pregnancy. They provided salivary cortisol samples at three times a day for 3 days at 24, 30, and 36 weeks' gestation. Participants who reported lower socioeconomic status in pregnancy were less likely to breastfeed, and lower maternal cortisol awakening responses mediated this association. This area of research may identify foci in the prenatal period that could serve as targets for interventions to increase rates of breastfeeding. Lay summary Pregnant women who reported lower socioeconomic status in pregnancy were less likely to breastfeed. This association was mediated by lower cortisol awakening responses, but not evening cortisol levels, over pregnancy.

Variability of the cortisol awakening response and morning salivary oxytocin in late adolescence

Exogenously administered oxytocin interacts with the hypothalamic-pituitary-adrenal (HPA) axis to modulate endogenous cortisol levels, suggesting a synergistic role for these two hormones in the response to stress, cognitive performance and the development of psycho-behavioural disorders. The cortisol awakening response (CAR) is considered a reliable measure of HPA axis function in humans. However, the CAR appears to vary considerably from day to day and may be strongly influenced by the anticipated demands of the day ahead. The level of variation intrinsic to the CAR is unclear because few studies have examined the CAR in the absence of daily environmental variation. It is not known whether oxytocin has a similar or complementary awakening response. Therefore, over three consecutive days, we examined 12 adolescents (aged 15-17 years) in a highly-controlled sleep laboratory. Saliva was collected on days 4-6 of a 9-day laboratory visit. Cortisol and oxytocin levels were determined by an enzyme-linked immunosorbent assay from saliva sampled at 0, 15, 30 and 45 minutes, and 8 and 12 hours post-awakening. CAR magnitude varied between days and was associated with sleep duration and pre-awakening sleep stage. Conversely, oxytocin levels dropped dramatically in the first 15 minutes post-awakening and were highly consistent across participants and days. Older participants had higher awakening oxytocin concentrations. Although cortisol increases and oxytocin rapidly declines upon awakening, their diurnal variation does not appear to be related at basal, peripheral levels, consistent with a previous finding that exogenously administered oxytocin only modulates cortisol under conditions of stress.

Cortisol response to awakening in prepubertal children and adults: Magnitude and variability

Within the first 30-45 min after awakening, there is a characteristic rise in cortisol that is referred to as cortisol awakening response (CAR). Over the past decades, the CAR has become an important biomarker, mainly because of its reported association with health and disease. Previous research showed that the CAR can already be reliably assessed in infants and children. Yet, earlier findings on the influence of age have been inconsistent, and limited attention has been devoted to prepubertal children. Here, we aimed to contrast the magnitude and stability of the CAR in prepubertal children and adults. To this end, 24 healthy adults between 35 and 50 years of age and 24 healthy children between 6 and 9 years of age collected four salivary cortisol samples within 45 min after awakening on 4 separate days, 2 weekdays, and 2 weekend days. Our results showed that there was a marked CAR on weekdays and weekend days in both adults and children. In children, however, the CAR was overall significantly attenuated relative to adults. Moreover, while the cortisol increases after awakening were, both on weekdays and weekend days, highly correlated in adults, there were no such associations in children. Together, these data suggest that the CAR is less pronounced and less stable in prepubertal children compared to adults. Such age differences need to be taken into account when using the CAR as a biomarker in clinical settings.

Being an optimist or a pessimist and its relationship with morning cortisol release and past life review in healthy older people

OBJECTIVE

Investigate the relationship between optimism and pessimism and the cortisol awakening response (CAR) and past life review in healthy older people.

DESIGN

76 older volunteers summarised their lives, highlighting the most important events, impressions and experiences. Cortisol saliva samples were collected on two consecutive weekdays. High and low optimism and pessimism groups were computed by mean split.

MAIN OUTCOME MEASURES

Percentages of positive (PE) and negative events (NE) and positive (PCE) and negative cognitions and emotions (NCE) were obtained. Optimism and pessimism were measured with the Life Orientation Test Revised. The areas under the curve with respect to the ground and with respect to the increase were computed, with the latter understood as the CAR.

RESULTS

The high pessimism group reported more NE and NCE and less PE and PCE (p's < 0.041). No significant differences in CAR were found between high and low optimism and pessimism groups after removing suspected non-adherent participants (p's > 0.116). Higher CAR was related to lower PCE, but higher NCE (both p < 0.008).

CONCLUSION

Pessimism seems to increase the focus on negative aspects of the past, which may lead to a worse perception of life in ageing, whereas optimism contributes to a healthier CAR.

Diurnal Hypothalamic-Pituitary-Adrenal Axis Measures and Inflammatory Marker Correlates in Major Depressive Disorder

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and inflammatory systems is a consistent finding in patients with Major Depressive Disorder (MDD). Cortisol is often assessed by measurement of the cortisol awakening response (CAR) and/or diurnal cortisol levels. Some methods of cortisol measurement overestimate cortisol concentration due to detection of other glucocorticoids including the relatively inert cortisone, therefore this study aimed to assess the presence of both cortisol and cortisone, and the cortisol-cortisone catalyzing enzyme 11β-hydroxysteroiddehydrogenase type 1 (11β-HSD1), in depressed patients and controls. Because the HPA axis is known to regulate the body’s immune system, relationships between measures of cytokines and cortisol were also assessed. Saliva samples were collected from 57 MDD patients and 40 healthy controls at five post-wakening time points (0, +30, +60, +720 and +750 min). Glucocorticoid concentrations were measured by liquid chromatography mass spectrometry. Whole blood mRNA expression of several inflammatory markers was measured by quantitative polymerase chain reaction. This study replicated the common finding of elevated morning cortisol and reduced CAR reactivity in MDD and found no differences in cortisone or 11β-HSD1 mRNA measures. There was a negative association between interleukin 1-β (IL-1β) mRNA and morning cortisol reactivity within the depressed group, indicating that dysregulation of the HPA axis and immune system may be interconnected.

Glucocorticoid treatment earlier in childhood and adolescence show dose-response associations with diurnal cortisol levels

Heightened levels of glucocorticoids in children and adolescents have previously been linked to prolonged changes in the diurnal regulation of the stress-hormone cortisol, a glucocorticoid regulated by the hypothalamic-pituitary-adrenal-axis (HPA-axis). To address this question, we examined the salivary cortisol awakening response (CAR) and daily cortisol output in 36 children and adolescents (25 girls/11 boys) aged 7-16 years previously treated with glucocorticoids for nephrotic syndrome or rheumatic disorder and 36 healthy controls. Patients and controls did not significantly differ in the CAR or diurnal cortisol output; however, sex-dependent group differences were observed. Specifically, female patients had a higher CAR relative to female controls, while male patients had higher daily cortisol levels compared to male controls. Notably, CAR in female patients and daily cortisol levels in male patients showed a positive linear relationship with the mean daily glucocorticoid doses administered during treatment. The observed dose-response associations suggest that glucocorticoid therapy during childhood and adolescence might trigger long-term changes in HPA-axis regulation, which may differ for males and females.

Cortisol Awakening Response as a Prospective Risk Factor for Depressive Symptoms in Women After Treatment for Breast Cancer

OBJECTIVE

The aim of the study was to investigate hypothalamic-pituitary-adrenal axis (HPA axis) functioning as a neurobiological risk factor for depressive symptoms in an ongoing longitudinal, observational study of women undergoing treatment and recovery from breast cancer. Many women with breast cancer experience depressive symptoms that interfere with their treatment, recovery, and quality of life. Psychosocial risk factors for depression among patients with cancer and survivors have been identified, yet neurobiological risk factors in this population remain largely unexamined.

METHODS

Women recently diagnosed with early-stage breast cancer (N = 135) were enrolled before starting neoadjuvant/adjuvant treatment (radiation, chemotherapy, endocrine therapy). At baseline, participants collected saliva samples to measure diurnal HPA axis functioning for 3 days: at waking, 30 minutes after waking, 8 hours after waking, and bedtime. Participants also completed a standardized measure of depressive symptoms (Center for Epidemiological Studies-Depression Scale) at baseline and 6 months after completion of primary treatment. Multivariate regression was used to predict continuous depressive symptoms at 6-month posttreatment from continuous depressive symptoms at baseline, cortisol awakening response (CAR), and other measures of diurnal HPA axis functioning.

RESULTS

The magnitude of CAR predicted changes in depressive symptoms over time, such that women with a higher CAR showed a greater increase from baseline to 6-month posttreatment (b = 5.67, p = .023). Diurnal slope and total cortisol output were not associated with concurrent depressive symptoms or their change over time.

CONCLUSIONS

Elevated CAR may be a neurobiological risk factor for increases in depressive symptoms in the months after breast cancer treatment and warrants further investigation.

The Cortisol Awakening Response and Depressive Symptomatology: The Moderating Role of Sleep and Gender

The association between depression and the cortisol awakening response (CAR) has been widely examined, yet the results are mixed and factors responsible for such inconsistencies are poorly understood. The current study investigated whether the link between depressive symptomatology and CAR varied as a function of two such factors: sleep and gender. The sample included 58 young adults (30 females; M_age  = 18.7; SD_age  = 0.91). Participants completed the Beck Depression Inventory as well as the Consensus Sleep Diary to assess depressive symptomatology and daily sleep patterns, respectively. Participants also provided four salivary cortisol samples (0, 30, 45 and 60 min after awakening) during two consecutive weekdays. Results demonstrated that greater depressive symptoms were associated with a greater CAR but only when depressive symptoms were linked to a shorter sleep time. In addition, gender significantly moderated the association between depressive symptoms and CAR. While greater depressive symptoms were associated with an elevated CAR among females, they were associated with a blunted CAR among males. These findings provide some insight into potential mechanisms linking depressive symptomatology and CAR, and suggest that future studies examining CAR as a biomarker of depression should account for differences in sleep and gender. Copyright © 2016 John Wiley & Sons, Ltd.

Recovery of rescuers from a 24-h shift and its association with aerobic fitness

OBJECTIVES

Rescuers work in 24-h shifts and the demanding nature of the occupation requires adequate recovery between work shifts. The purpose of this study has been to find out what kind of changes in autonomic control may be seen during work shift and its recovery period in the case of rescuers. An additional interest has been to see if aerobic fitness is associated with recovery from work shifts.

MATERIAL AND METHODS

Fourteen male rescuers (aged 34±9 years old) volunteered to participate in the study. Heart rate variability (HRV) was recorded for 96 h to study stress and recovery, from the beginning of a 24-h work shift to the beginning of the next shift. Aerobic fitness assessment included maximal oxygen uptake (VO2max) estimation with a submaximal bicycle ergometer test. Salivary cortisol samples were collected 0 min, 15 min, and 30 min after awakening on the 3 resting days.

RESULTS

Some HRV parameters showed enhanced autonomic control after the work shift. Stress percentage decreased from the working day to the 2nd rest day (p < 0.05). However, maximal oxygen uptake was not associated with enhanced parasympathetic cardiac control (p > 0.05). Cortisol awakening response was attenuated right after the work shift.

CONCLUSIONS

The HRV findings show that recovery after a long work shift takes several days. Thus, rescuers should pay attention to sufficient recovery before the next work shift, and an integrated model of perceived and physiological measurements could be beneficial to assess cardiovascular strain among rescuers with long work shifts. Int J Occup Med Environ Health 2017;30(3):433-444.

Mothers' parenting stress is associated with salivary cortisol profiles in children with attention deficit hyperactivity disorder

The aim of this study was to explore the relation between mothers' parenting stress and the functioning of the hypothalamic-pituitary-adrenal axis (HPAA), as expressed by daily salivary cortisol concentrations, in their children diagnosed with attention deficit hyperactivity disorder (ADHD). Seventy-five children aged 6-11 years diagnosed with ADHD predominant hyperactive-impulsive/combined (ADHD-HI/C, N = 49) and inattentive symptoms (ADHD-I, N = 26) and 45 healthy peers and their mothers participated in the study. Μothers completed measures assessing their children's ADHD status, perceived parenting stress (Parenting Stress Index - Short Form, PSI-SF), mothers' symptoms of psychopathology, social support and socioeconomic status. Children's salivary cortisol samples were collected at six different time points on a single day. Mothers of children with ADHD-HI/C reported higher levels of parenting stress than mothers of children with ADHD-I and controls. All PSI-SF subscales showed significant associations with children's cortisol awakening response (CAR) in both ADHD groups, with the exception of the parental distress subscale in the ADHD-I group. In both ADHD groups, the parent-child dysfunctional interaction subscale, the difficult child subscale and the PSI total score were significantly associated with children's CAR. An interrelation is revealed between mothers' high levels of parenting stress and HPAA functioning in children with ADHD. In this population, CAR has been identified as a sensitive peripheral measure of HPAA functioning in children. Lay summaryThis study showed that in families of children diagnosed with ADHD, there is a complex relation between the mothers' high levels of parenting stress and children's atypical hypothalamic-pituitary-adrenal axis functioning.

Balancing scientific accuracy and participant burden: testing the impact of sampling intensity on diurnal cortisol indices

Despite the increasing popularity of incorporating salivary cortisol measurement into health and social science research, relatively little empirical work has been conducted on the number of saliva samples across the day required to capture key features of the diurnal cortisol rhythm, such as the diurnal cortisol slope, the area under the curve (AUC), and the cortisol awakening response (CAR). The primary purpose of this study is to compare slope, AUC, and CAR measures obtained from an intensive sampling protocol with estimates from less intensive protocols, to identify sampling protocols with minimal participant burden that still provide reasonably accurate assessment of each of these measures. Twenty-four healthy adults provided samples four times in the first hour awake, and then every hour throughout the rest of the day until bedtime (M = 17.8 samples/day; SD = 2.0), over two consecutive days (N = 862 total samples). We compared measures calculated from this maximum intensity protocol to measures calculated from two to six sampling points per day. Overall, results show that salivary cortisol protocols with two fixed samples (waking and bedtime) and three additional daily samples, closely approximates the full cortisol decline (slope). Abbreviated sampling protocols of total cortisol exposure across the day (AUC), however, were not well approximated by reduced sampling protocols. CAR measures based on only two samples, including waking cortisol and a second sample measured at a fixed time point between 30 and 60 min after waking, provided a measure of the CAR that closely approximated CAR measures obtained from 3 or 4 sampling points.

Blunted Cortisol Awakening Response and Poor Self-Perceived Health in Informal Caregivers of People with Eating Disorders

Caring for offspring diagnosed with eating disorders (EDs) entails being under high chronic stress, with negative consequences for health. However, most previous research has only evaluated self-report measures of health, biological markers being poorly studied. In this regard, the evaluation of the cortisol awakening response (CAR) could add significant information about the biological basis of health disturbances in this population. The main aim of the present study was to compare CAR and self-reported health between informal caregivers (ICs) of people with EDs and non-caregivers. Furthermore, we explored the effect of the nature of the diagnosis, comparing ICs of people with anorexia and bulimia nervosa. ICs had a blunted CAR, and more anxiety and insomnia, and social dysfunction, together with poorer perceived general health than non-caregivers. ICs of people with anorexia nervosa had higher levels of morning cortisol and burden, and more social dysfunction and severe depression than those of people with bulimia nervosa. Our results demonstrate marked health problems in ICs of people with EDs, especially when the care recipient has anorexia nervosa. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

High Anger Expression is Associated with Reduced Cortisol Awakening Response and Health Complaints in Healthy Young Adults

The extant evidence suggests a robust positive association between expression (anger expression-out) and suppression (anger expression-in) of anger and compromised health. Nevertheless, the underlying psychobiological mechanisms which explain these relationships are not well understood. This study examined whether anger expression would predict general health, cortisol awakening response (CAR) and evening cortisol levels in a community sample of 156 healthy young adults of both genders. Participants were distributed into two groups according to their anger expression scores: high and low anger expression (HAE and LAE, respectively). Findings indicated that those with HAE had worse self-reported health (p = .02) and higher CAR than the LAE group (p = .04). Moreover, high levels of anger expression-out (p < .01) and -in (p < .01, for all) predicted a worse self-reported health in both groups. On the other hand, high anger expression-out was associated with flattened CAR but only in the HAE group (p < .01). This study reinforces the need to develop effective strategies to provide mechanisms to regulate anger expression by promoting personal growth and positive skills that enhance individuals' well-being and quality of life and, in turn, their own health.

Cortisol awakening response in drug-naïve panic disorder

BACKGROUND

It is unclear whether hypothalamic-pituitary-adrenal axis is involved in the pathophysiology of panic disorder (PD). The findings remain inconsistent. Cortisol awakening response (CAR) is a noninvasive biomarker of stress system activity. We designed the study to assess CAR in drug-naïve PD patients.

MATERIALS AND METHODS

We assessed CAR in 14 psychotropic drug-naïve outpatients with PD and 14 healthy controls. The severity of PD was assessed with Panic and Agoraphobia Scale. The severity of anxiety and depression was screened with Hospital Anxiety and Depression Scale.

RESULTS

No significant difference in CAR between PD patients and control group was found. No correlations were observed between CAR and anxiety severity measures in PD patients and controls.

LIMITATIONS

The number of participating subjects was relatively small, and the study results apply to nonsuicidal drug-naïve PD patients without agoraphobia and with short-illness duration. There was a lack of control on subjects' compliance with the sampling instructions.

CONCLUSION

The study provides no support for elevated CAR levels in drug-naïve PD patients without agoraphobia.

Ambulatory assessed implicit affect is associated with salivary cortisol

One of the presumed pathways linking negative emotions to adverse somatic health is an overactive HPA-axis, usually indicated by elevated cortisol levels. Traditionally, research has focused on consciously reported negative emotions. Yet, given that the majority of information processing occurs without conscious awareness, stress physiology might also be influenced by affective processes that people are not aware of. In a 24-h ambulatory study we examined whether cortisol levels were associated with two implicit measures. Implicit affect was assessed using the Implicit Positive and Negative Affect Test, and implicit negative memory bias was assessed with the word fragment completion tasks. In 55 healthy participants, we measured subjective stress levels, worries, implicit, and explicit affect each hour during waking hours. Also, saliva samples were collected at three fixed times during the day, as well as upon waking and 30 min thereafter (cortisol awakening response). Multilevel analyses of the daytime cortisol levels revealed that the presence of an implicit negative memory bias was associated with increased cortisol levels. Additionally, implicit PA and, unexpectedly, implicit NA were negatively associated with cortisol levels. Finally, participants demonstrating higher levels of implicit sadness during the first measurement day, had a stronger cortisol rise upon awakening at the next day. Contrary to previous research, no associations between explicit affect and cortisol were apparent. The current study was the first to examine the concurrent relation between implicit measures and stress physiology in daily life. The results suggest that the traditional focus on consciously reported feelings and emotions is limited, and that implicit measures can add to our understanding of how stress and emotions contribute to daily physiological activity and, in the long term, health problems.

The effects of an anticipated challenge on diurnal cortisol secretion

In healthy, non-challenged individuals, the secretion of cortisol typically follows a diurnal profile characterized by a peak in the period following waking (cortisol awakening response) and a gradual decline throughout the day. In addition, cortisol secretion is increased in response to acutely stressful stimuli, particularly stressors involving social evaluation. The current study is the first to assess the impact of an anticipated acute laboratory stressor upon the typical diurnal pattern of HPA activation and relationship to acute cortisol secretion. A sample of 23 healthy young adults provided salivary cortisol samples at four time points (immediately upon awakening, 30-min post-awakening, 1200 h and before bed) on 2 consecutive days. On the second day, participants attended the laboratory and undertook an anticipated acute socially evaluative stressor immediately following provision of their 1200 h saliva sample. Heart rate, blood pressure and mood were recorded immediately before and after the stressor and at 10 and 20 min post-stressor along with additional salivary cortisol samples. Typical patterns of cortisol secretion were observed on both days and exposure to the laboratory stressor was associated with the expected increases in cortisol, heart rate, blood pressure and negative mood. However, significant differences in diurnal cortisol secretion were observed between the two days with greater secretion, in particular, during the period following awakening, evident on the day of the anticipated laboratory stressor. Furthermore, secretion of cortisol during the period following awakening was positively related to secretion during the acute reactivity periods. This is the first study to integrate a laboratory stressor into a typical day and assess its impact on indices of diurnal cortisol secretion in an ambulatory setting. The current findings support the notion that the cortisol awakening response is associated with anticipation of the upcoming day and the subsequent demands required of the individual.

The cortisol awakening response predicts same morning executive function: results from a 50-day case study

A relationship between individual differences in trait estimates of the cortisol-awakening response (CAR) and indices of executive function (EF) has been reported. However, it is difficult to determine causality from such studies. The aim of the present study was to capitalise upon state variation in both variables to seek stronger support for causality by examining daily co-variation. A 50 days researcher-participant case study was employed, ensuring careful adherence to the sampling protocol. A 24-year-old healthy male collected saliva samples and completed an attention-switching index of EF on the morning of each study day. Subsidiary control measures included wake time, sleep duration, morning fatigue, and amount of prior day exercise and alcohol consumption. As the CAR preceded daily measurement of EF, we hypothesised that, over time, a greater than average CAR would predict better than average EF. This was confirmed by mixed regression modelling of variation in cortisol concentrations, which indicated that the greater the increase in cortisol concentrations from 0 to 30 min post-awakening (CAR) the better was subsequent EF performance at 45 min post-awakening (t = 2.29, p = 0.024). This effect was independent of all potential confounding measures. Results are discussed in terms of implications for the understanding of the relationship between the CAR and the cognitive function, and the previously suggested role of the CAR in "boosting" an individual's performance for the day ahead.

Day-to-day dynamics of associations between sleep, napping, fatigue, and the cortisol diurnal rhythm in women diagnosed as having breast cancer

OBJECTIVES

To examine whether day-to-day variations in sleep behaviors, ongoing sleep disturbance, and fatigue predict the cortisol diurnal rhythm in women recently diagnosed as having early-stage breast cancer.

METHODS

Women (N = 130, mean [standard deviation] age = 55.6 [9.4] years) collected saliva 5×/day/2 days for cortisol. Diaries were used to assess prior-day nap duration, nocturnal awakenings, sleep latency, and morning restfulness. Ongoing fatigue and sleep disturbance were measured using the Multidimensional Fatigue Symptom Inventory and the Pittsburg Sleep Quality Inventory. Data were analyzed using a multilevel growth curve modeling.

RESULTS

Greater ongoing fatigue (b = 0.035, p = .032), or sleep disturbance (b = 0.026, p = .006) predicted a slower cortisol decline. Greater ongoing fatigue also predicted higher awakening cortisol (b = 0.154, p = .030) and lower cortisol awakening response (CAR; b = -0.146, p = .005). Longer prior-day naps predicted higher CAR (b = 0.042, p = .050) and a steeper cortisol decline (b = -0.035, p = .003). Longer sleep latency predicted both a greater cortisol linear decline (b = -0.013, p < .001) and a greater quadratic slope curvature (b = 0.0007, p < .001). Feeling less rested in the morning predicted lower awakening cortisol (b = -0.187, p = .004), higher CAR (b = 0.124, p = .016), and a slower cortisol decline (b = 0.023, p = .042).

CONCLUSIONS

Both daily variations in sleep behaviors and ongoing sleep disturbance and fatigue are associated with a disrupted cortisol rhythm. In contrast, prior-day napping is associated with a more robust cortisol rhythm. These findings are particularly relevant to women with breast cancer who often experience sleep disturbance and fatigue. Additional research is needed to determine causal pathways between sleep disturbance and dysregulation of the hypothalamic-pituitary-adrenal axis in patients with breast cancer.

Cortisol awakening response and spatial working memory in man: a U-shaped relationship

OBJECTIVE

The association between hypothalamic-pituitary-adrenal (HPA)-axis function and cognition has long been investigated. An inverted U-shaped relationship has been described between various measures of HPA-axis function and neuropsychological performance in animals and man. Work with glucocorticoid receptor manipulation has corroborated these findings, with particular effects observed in relation to spatial working memory (SWM). As HPA-axis dysfunction is frequently found in patients with psychiatric illness, research in this area has potential implications for the treatment of the commonly observed cognitive impairment in such disorders. Here, we present the results of a pilot study examining the relationship between cortisol awakening response (CAR) and cognitive functions known to be susceptible to HPA-axis manipulation.

METHODS

Nineteen healthy male volunteers were recruited, and their CAR and performance in a task of SWM were assessed.

RESULTS

A highly significant quadratic relationship was observed between the CAR and SWM error rate (R(2)=0.63, p=0.001).

CONCLUSION

We provide novel evidence supporting the existence of an inverted U-shaped relationship between corticosteroid levels and cognitive function in humans.

Individual differences in the cortisol and salivary α-amylase awakening responses in early childhood: relations to age, sex, and sleep

Recent studies have examined post-waking changes in cortisol as a marker of HPA functioning, but questions remain about the stability of this response, as well as its relation to sleep and other ANS markers. The purposes of this study were to a) examine the presence and developmental changes in the cortisol awakening response (CAR) and salivary α-amylase awakening (sAA-AR) in a toddler sample and b) determine whether and how sleep relates to these responses in this age group. We measured cortisol and sAA upon awakening (and 30 min post-waking) and sleep characteristics using actigraphy (e.g., total sleep time, sleep efficiency, number of awakenings) in toddlers (N = 47; 36% female, ages 12-24 months). Forty-six percent of toddlers demonstrated a CAR and 52% demonstrated a sAA-AR. Strength of either response did not change linearly with age. Additionally, likelihood of demonstrating the CAR and sAA-AR was unrelated to age, sex, awakening time, time between samples, and time since feeding. Higher waking cortisol levels were associated with a shorter total sleep time and an earlier awakening. No associations were observed between sleep characteristics and the sAA-AR, ps > .05. Our findings suggest that these awakening responses function independently of sleep in toddlers. Additionally, the lack of change in percentage of children showing a CAR or sAA-AR across these ages suggests that these responses are stable and not emerging reliably across the second year of life.

Children's heart rate variability as stress indicator: association with reported stress and cortisol

Stress is a complex phenomenon coordinated by two main neural systems: the hypothalamic-pituitary-adrenal system with cortisol as classical stress biomarker and the autonomic nervous system with heart rate variability (HRV) as recently suggested stress marker. To test low HRV (5 minute measurements) as stress indicator in young children (5-10 y), associations with self-reported chronic stress aspects (events, emotions and problems) (N=334) and salivary cortisol (N=293) were performed. Peer problems, anger, anxiety and sadness were associated with lower root mean square of successive differences (RMSSD) and high frequency power (i.e. lower parasympathetic activity). Anxiety and anger were also related to a higher low frequency to high frequency ratio. Using multilevel modelling, higher cortisol levels, a larger cortisol awakening response and steeper diurnal decline were also associated with these HRV patterns of lower parasympathetic activity.

CONCLUSION

Low HRV (lower parasympathetic activity) might serve as stress indicator in children.

Examining the association between salivary cortisol levels and subclinical measures of atherosclerosis: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

To investigate the association between salivary cortisol and two markers of subclinical cardiovascular disease (CVD), coronary calcification (CAC), and ankle-brachial index (ABI).

METHODS

Data from an ancillary study to the Multi-Ethnic Study of Atherosclerosis (MESA), the MESA Stress Study, were used to analyze associations of salivary cortisol data collected six times per day over three days with CAC and ABI. The authors used mixed models with repeat cortisol measures nested within persons to determine if specific features of the cortisol profile were associated with CAC and ABI.

RESULTS

A total of 464 participants were included in the CAC analysis and 610 in the ABI analysis. The mean age of participants was 65.6 years. A 1-unit increase in log coronary calcium was associated with a 1.77% flatter early decline in cortisol (95% CI: 0.23, 3.34) among men and women combined. Among women low ABI was associated with a steeper early decline (-13.95% CI: -25.58, -3.39) and a marginally statistically significant flatter late decline (1.39% CI: -0.009, 2.81). The cortisol area under the curve and wake to bedtime slope were not associated with subclinical CVD.

CONCLUSIONS

This study provides weak support for the link between cortisol and measures of subclinical atherosclerosis. We found an association between some features of the diurnal cortisol profile and coronary calcification and ABI but associations were not consistent across subclinical measures. There are methodological challenges in detecting associations of cortisol measures at a point in time with health outcomes that develop over a lifetime. Studies of short-term mechanisms linking stress to physiological processes related to the development of early atherosclerosis may be more informative.

Self- or parent report of (co-occurring) internalizing and externalizing problems, and basal or reactivity measures of HPA-axis functioning: a systematic evaluation of the internalizing-hyperresponsivity versus externalizing-hyporesponsivity HPA-axis hypothesis

BACKGROUND

Previous research findings on the link between adolescents' psychopathology and hypothalamic-pituitary-adrenal (HPA) axis activity have been heterogeneous.

METHOD

Adolescents (n=211) with a preadolescent DSM-IV diagnosis participated in a lab-based social stress task. Saliva cortisol was assessed at awakening and during social stress. It was investigated if continuous measures of internalizing and externalizing problems and their interaction, using both self- and parent report, were associated with basal or reactivity measures of HPA-axis functioning.

RESULTS

During social stress, an enhanced total release of cortisol was associated with self-reported internalizing problems and a blunted total release of cortisol with self-reported externalizing problems. Post hoc analyses revealed that the association between enhanced cortisol output and internalizing problems held for boys but not for girls. Associations with morning cortisol measures were overall weak.

CONCLUSIONS

Only in the context of stress, and particularly when based on self-report, blunted cortisol output was associated with externalizing and enhanced cortisol output with internalizing problems. Our broad approach demonstrates the importance of who reports on psychopathology, the use of dimensional measures of psychopathology, simultaneous analysis of internalizing and externalizing problems, and the use of awakening and social stress related measures of cortisol.

Salivary cortisol lower in posttraumatic stress disorder

Altered cortisol has been demonstrated to be lower in those with posttraumatic stress disorder (PTSD) in most studies. This cross-sectional study evaluated salivary cortisol at waking and 30 minutes after, and at bedtime in 51 combat veterans with PTSD compared to 20 veterans without PTSD. It also examined the relationship of cortisol to PTSD symptoms using 2 classifications: the Diagnostic and Statistical Manual of Mental Disorders (4th ed., DSM-IV; American Psychiatric Association, 1994) and the more recent 4-factor classification proposed for DSM-5. The PTSD group had lower cortisol values than the control group, F(6, 69) = 3.35, p = .006. This significance did not change when adding age, body mass index, smoking, medications affecting cortisol, awakening time, sleep duration, season, depression, perceived stress, service era, combat exposure, and lifetime trauma to the model. Post hoc analyses revealed that the PTSD group had lower area-under-the-curve ground and waking, 30 min, and bedtime values; the cortisol awakening response and area-under-the-curve increase were not different between groups. The 4-factor avoidance PTSD symptom cluster was associated with cortisol, but not the other symptom clusters. This study supports the finding that cortisol is lower in people with PTSD.

The cortisol awakening response predicts major depression: predictive stability over a 4-year follow-up and effect of depression history

BACKGROUND

The cortisol awakening response (CAR) has been shown to predict major depressive episodes (MDEs) over a 1-year period. It is unknown whether this effect: (a) is stable over longer periods of time; (b) is independent of prospective stressful life events; and (c) differentially predicts first onsets or recurrences of MDEs.

METHOD

A total of 270 older adolescents (mean age 17.06 years at cortisol measurement) from the larger prospective Northwestern-UCLA Youth Emotion Project completed baseline diagnostic and life stress interviews, questionnaires, and a 3-day cortisol sampling protocol measuring the CAR and diurnal rhythm, as well as up to four annual follow-up interviews of diagnoses and life stress.

RESULTS

Non-proportional person-month survival analyses revealed that higher levels of the baseline CAR significantly predict MDEs for 2.5 years following cortisol measurement. However, the strength of prediction of depressive episodes significantly decays over time, with the CAR no longer significantly predicting MDEs after 2.5 years. Elevations in the CAR did not significantly increase vulnerability to prospective major stressful life events. They did, however, predict MDE recurrences more strongly than first onsets.

CONCLUSIONS

These results suggest that a high CAR represents a time-limited risk factor for onsets of MDEs, which increases risk for depression independently of future major stressful life events. Possible explanations for the stronger effect of the CAR for predicting MDE recurrences than first onsets are discussed.