Total Cortisol Output Research Articles

Everyday discrimination and diurnal cortisol during adolescence

PurposeTo examine the associations of the frequency and type of everyday discrimination with diurnal cortisol and whether those associations depend upon adolescents' ethnicity and gender. MethodsAdolescents (N=292, Mage=16. 39years, SD=0.74; 58% female) reported the frequency of perceived everyday discrimination and whether they attributed that discrimination to race, gender, age, or height and weight. Five saliva samples were collected per day across 3days and assayed for cortisol. ResultsHigher frequency of everyday discrimination was associated with greater total daily cortisol output (area under the curve; AUC), lower wake and bedtime levels of cortisol, and less of a decline in cortisol across the day. These associations generally did not depend upon ethnicity or gender and attributions for the discrimination were not as consequential as the actual frequency of any type of unfair treatment. ConclusionEveryday discrimination, regardless of its type, may contribute to heightened HPA activity among adolescents of different ethnic backgrounds and genders.

Blunted HPA Axis Activity in Suicide Attempters Compared to those at High Risk for Suicidal Behavior.

Studies looking at the relationship of the hypothalamic-pituitary-adrenal (HPA) axis to suicidal behavior and its risk factors, such as depression, childhood abuse, and impulsive aggression, report inconsistent results. These studies also do not always differentiate between subjects who go on to attempt suicide, suicidal subjects who never attempted suicide, and non-suicidal subjects with psychiatric disorders. In this study, we examined cortisol responses to an experimental stressor, the Trier Social Stress Test (TSST), in 208 offspring of parents with mood disorder. Offspring suicide attempters showed lower total cortisol output (β=-0.47, 95% CI (-0.83, -0.11), p=0.01) compared with offspring with suicide-related behavior (SRB) but never attempted, non-suicidal offspring, and a healthy control group. The result remained significant even after controlling for sex, age, race, ethnicity, site, socio-economic status, and hour of the day when the TSST was conducted. Suicide attempters also showed lower baseline cortisol before the TSST (β=-0.45, 95% CI (-0.74, -0.17), p=0.002). However, there were no significant differences between the groups on cortisol reactivity to stress (β=4.5, 95% CI (-12.9, 22), p=0.61). Although subjects with suicide attempt and SRB have similar clinical and psychosocial characteristics, this is the first study to differentiate them biologically on HPA axis indices. Blunted HPA axis activity may increase risk for suicide attempt among individuals with psychopathology by reducing their ability to respond adaptively to ongoing stressors. These results may help better identify subjects at high risk for suicidal behavior for targeted prevention and intervention efforts.

Infant Emotion Regulation Strategy Moderates Relations between Self‐Reported Maternal Depressive Symptoms and Infant HPA Activity

Children of mothers with depressive symptoms often have high cortisol levels. Research shows that various child characteristics (e.g., attachment pattern, internalizing behaviours, and temperament) moderate this association. We suggest that these characteristics share common variance with emotion regulation strategy. Therefore, we examine infant emotion regulation strategy as a moderator of the association between maternal depressive symptoms and infant hypothalamic–pituitary–adrenal (HPA) function. We hypothesize that infants who utilize more independent emotion regulation strategies and have mothers who report higher depressive symptoms will exhibit elevated cortisol levels. Participants were 193 mothers and infants (15 months old) recruited from the community. Self‐reported maternal depressive symptoms were assessed. Infant independent regulatory behaviours (withdrawal, wandering away, distraction, scanning, orienting to another object) were coded in the context of a Toy Frustration Task. Infant cortisol was collected via saliva samples at baseline, +20, and +40 minutes. Results indicate that infant emotion regulation strategy moderates the relation between mothers' self‐reported depressive symptoms and infant total cortisol output (AUCG) and cortisol reactivity (AUCI). Infants who employed more independent regulatory behaviours and have mothers with higher depressive symptoms experience greater cortisol secretion. We discuss the findings in relation to parent‐infant interactions and the adaptive nature of emotion regulation strategies, as they relate to HPA regulatory capacities. Copyright © 2015 John Wiley & Sons, Ltd.

Sweat-inducing physiological challenges do not result in acute changes in hair cortisol concentrations

Hair cortisol concentrations (HCC) are assumed to provide a stable, integrative marker of long-term systemic cortisol secretion. However, contrary to this assumption, some recent observations have raised the possibility that HCC may be subject to acute influences, potentially related to cortisol incorporation from sweat. Here, we provide a first detailed in vivo investigation of this possibility comprising two independent experimental studies: study I (N=42) used a treadmill challenge to induce sweating together with systemic cortisol reactivity while in study II (N=52) a sauna bathing challenge induced sweating without systemic cortisol changes. In both studies, repeated assessments of HCC, salivary cortisol, cortisol in sweat and individuals' sweating rate (single assessment) were conducted on the experimental day and at a next-day follow-up. Results across the two studies consistently revealed that HCC were not altered by the acute interventions. Further, HCC were found to be unrelated to acute salivary cortisol reactivity, sweat cortisol levels, sweating rate or the time of examination. In line with previous data, cortisol levels in sweat were strongly related to total salivary cortisol output across the examined periods. The present results oppose recent case report data by showing that single sweat-inducing interventions do not result in acute changes in HCC. Our data also tentatively speak against the notion that cortisol in sweat may be a dominant source of HCC. Further, our findings also indicate that HCC are not subject to diurnal variation. This research provides further support for hair cortisol analysis as a marker of integrated long-term systemic cortisol secretion.

The impact of PTSD treatment on the cortisol awakening response.

Posttraumatic stress disorder (PTSD) is associated with abnormal functioning of the hypothalamic-pituitary-adrenal (HPA) axis; however, limited research has examined whether cortisol levels change following successful PTSD treatment. The current study examined the impact of successful PTSD treatment on the cortisol awakening response (CAR). Twenty-nine adults participating in a treatment trial for chronic PTSD provided saliva samples (upon waking, and 30-, 45-, and 60 min postwaking) before and after receiving either prolonged exposure therapy or sertraline. PTSD responder status (i.e., loss or retention of a PTSD diagnosis) served as the predictor variable. Outcome measures included area under the curve with respect to ground and increase, reflecting total cortisol output and HPA axis reactivity, respectively. A series of hierarchical regressions revealed no significant main effects of PTSD responder status for either CAR outcome. However, a significant gender by treatment response interaction for cortisol reactivity revealed that female treatment nonresponders displayed higher cortisol reactivity following treatment than female responders, whereas cortisol reactivity did not change pre- to posttreatment for male responders. Findings remained after controlling for age, trauma history, baseline medication status, baseline PTSD, and baseline depressive symptoms. Loss of a PTSD diagnosis may contribute to decreased cortisol reactivity in females. Neuroendocrine changes following treatment may emerge only for specific subgroups, highlighting the importance of exploring treatment moderators.

A sustained hypothalamic-pituitary-adrenal axis response to acute psychosocial stress in irritable bowel syndrome.

Despite stress being considered a key factor in the pathophysiology of the functional gastrointestinal (GI) disorder irritable bowel syndrome (IBS), there is a paucity of information regarding the ability of IBS patients to respond to acute experimental stress. Insights into the stress response in IBS could open the way to novel therapeutic interventions. To this end, we assessed the response of a range of physiological and psychological parameters to the Trier Social Stress Test (TSST) in IBS. Thirteen female patients with IBS and 15 healthy female age-matched control participants underwent a single exposure to the TSST. Salivary cortisol, salivary C-reactive protein (CRP), skin conductance level (SCL), GI symptoms, mood and self-reported stress were measured pre- and post-exposure to the TSST. The hypothalamic-pituitary-adrenal (HPA) axis response to the TSST was sustained in IBS, as shown by a greater total cortisol output throughout (p = 0.035) and higher cortisol levels measured by an area under the curve with respect to ground (AUCG) analysis (p = 0.044). In IBS patients, GI symptoms increased significantly during the recovery period following exposure to the TSST (p = 0.045). Salivary CRP and SCL activity showed significant changes in relation to stress but with no differential effect between experimental groups. Patients with IBS exhibit sustained HPA axis activity, and an increase in problematic GI symptoms in response to acute experimental psychosocial stress. These data pave the way for future interventional studies aimed at identifying novel therapeutic approaches to modulate the HPA axis and GI symptom response to acute psychosocial stress in IBS.

Unstimulated cortisol secretory activity in everyday life and its relationship with fatigue and chronic fatigue syndrome: A systematic review and subset meta-analysis

The hypothalamic-pituitary-adrenal (HPA) axis is a psychoneuroendocrine regulator of the stress response and immune system, and dysfunctions have been associated with outcomes in several physical health conditions. Its end product, cortisol, is relevant to fatigue due to its role in energy metabolism. The systematic review examined the relationship between different markers of unstimulated salivary cortisol activity in everyday life in chronic fatigue syndrome (CFS) and fatigue assessed in other clinical and general populations. Search terms for the review related to salivary cortisol assessments, everyday life contexts, and fatigue. All eligible studies (n=19) were reviewed narratively in terms of associations between fatigue and assessed cortisol markers, including the cortisol awakening response (CAR), circadian profile (CP) output, and diurnal cortisol slope (DCS). Subset meta-analyses were conducted of case-control CFS studies examining group differences in three cortisol outcomes: CAR output; CAR increase; and CP output. Meta-analyses revealed an attenuation of the CAR increase within CFS compared to controls (d=-.34) but no statistically significant differences between groups for other markers. In the narrative review, total cortisol output (CAR or CP) was rarely associated with fatigue in any population; CAR increase and DCS were most relevant. Outcomes reflecting within-day change in cortisol levels (CAR increase; DCS) may be the most relevant to fatigue experience, and future research in this area should report at least one such marker. Results should be considered with caution due to heterogeneity in one meta-analysis and the small number of studies.

Blunted cortisol response to stress is associated with higher body mass index in low-income preschool-aged children.

No known studies have tested the hypothesis that a blunted pattern of cortisol reactivity to stress, which is often found following exposure to chronic life stressors, is associated with a higher body mass index (BMI) in very young children. Low-income children (n=218, mean age 56.6 (range: 38.1-78.5; SD 7.0) months, 49.1% male, 56.4% white, 16.1% black, 11.5% Hispanic/Latino) participated in a series of behavioral tasks designed to elicit stress. Cortisol was sampled in saliva 5 times during the protocol, and area under the curve (AUC), representing total cortisol output during stress elicitation, was calculated. Children were weighed and height measured and body mass index (BMI) z-score was calculated. Linear regression was used to evaluate the association between cortisol AUC and BMI z-score, controlling for child age, sex, and race/ethnicity (non-Hispanic white vs. not); primary caregiver weight status (overweight, defined as BMI ≥ 25 vs. not); and family income-to-needs ratio. Mean child BMI z-score was 0.88 (SD=1.03). Mean cortisol AUC was 6.11 μg/dL/min (SD=10.44). In the fully adjusted model, for each 1-standard deviation unit decrease in cortisol AUC, the child's BMI z-score increased by 0.17 (SE 0.07) standard deviation units (p<0.02). A blunted cortisol response to stress, as is often seen following chronic stress exposure, is associated with increased BMI z-score in very young children. Further work is needed to understand how associations between stress, cortisol, and elevated body mass index may develop very early in the lifespan.

Adult cognitive ability and socioeconomic status as mediators of the effects of childhood disadvantage on salivary cortisol in aging adults

In this longitudinal study we investigate the influence of childhood disadvantage on midlife hypothalamic-pituitary-adrenal (HPA) axis regulation. Two mechanisms by which early life stress may affect later pathophysiology are through its influence on cognitive functioning or later socioeconomic (SES) disadvantage. We predicted that individual differences in young adult cognitive ability and midlife SES would mediate the influence of childhood disadvantage on midlife cortisol. On each of three nonconsecutive days, participants provided five salivary cortisol samples corresponding to their diurnal rhythm (N=727 men; mean age 55, SD=2.6). We calculated three measures of cortisol regulation (area-under-the curve cortisol reflecting total daytime cortisol output; cortisol-awakening-response; and wake-to-bed slope), averaging scores for each measure across multiple days. Childhood disadvantage combined four dichotomous indicators used previously by Rutter (1985): father low SES; mother education less than 12th grade; major family disruption/separation before age 18; and large family size (more than 5 siblings). The two mediators were a measure of general cognitive ability assessed at age 20 and highest achieved midlife SES. Men from more disadvantaged childhoods were significantly more likely to have dysregulated cortisol at midlife, with higher daytime cortisol levels decades after their childhood experience. Effects of childhood disadvantage were both direct and indirect. Cognitive ability and adult SES, however, only partially mediated the associations between early life stress and midlife cortisol. Specific indirect effects accounted for 33.8% of the total effect of childhood disadvantage [β=0.12 (0.05; 0.18)] on total daytime cortisol. Associations remained significant after accounting for ethnicity, smoking status, and self-reported depressive symptoms.

Gender Specific Effect of Psychological Stress and Cortisol Reactivity on Adolescent Risk Taking

The purpose of this study was to evaluate how psychological stress, gender and cortisol response to stress relate to risk behavior among 132 14-18year old adolescents. Participants completed a laboratory based risk task prior to and immediately after a computerized psychological stress task, and salivary cortisol was collected from pre-stress to 60min following initial stress exposure. Results indicate that adolescent boys (n = 59) and girls (n = 73) demonstrate different patterns of risk taking (RT) in response to stress, such that boys evidenced an increase in RT following stress exposure, whereas girls evidenced a decrease in RT. In addition, a gender by cortisol interaction demonstrated that for boys, both a smaller total cortisol output (AUCg) and peak cortisol response to stress (PC) was associated with greater stress-induced RT. Both cortisol measures were unrelated to stress-induced RT among girls. Taken together, data suggest that among boys, a blunted cortisol response to stress underlies an increase in risk taking in the context of psychological stress. Further research with an additional behavioral stress task is needed prior to drawing conclusions regarding the relation between female gender, cortisol response to stress, and risk taking in the context of psychological stress.

Epigenetic and Genetic Factors Predict Women's Salivary Cortisol following a Threat to the Social Self

Evidence suggests that the reactivity of the Hypothalamus-Pituitary-Adrenal axis (HPAA) is modulated by both genetic and environmental variables. Of special interest are the underlying molecular mechanisms driving gender differences to psychosocial stressors. Epigenetic mechanisms that sculpt the genome are ideal candidates for mediating the effects of signals on the HPAA. In the current study, we analyzed by pyrosequencing, bisulfite-treated buccal DNA from male and female university students who participated in the Trier Social Stress Test (TSST). A linear regression model was used to ascertain the effects of sex, CpG methylation and genes on stress response. Total cortisol output (area under the curve, AUC) was significantly predicted by glucocorticoid receptor (NR3C1) exon 1F methylation (averaged across 39 CpG sites) solely in female subjects. A single CpG site located in the exon 1F noncanonical nerve growth factor-inducible protein A (NGFI-A) transcription factor was a highly significant predictor of AUC in female subjects. Additionally, variations in the estrogen receptor alpha (ESR1) and the serotonin transporter promoter (5-HTTLPR) genes were independent additive predictors of AUC. The full model accounted for half of the variance (50.06%) in total cortisol output. Notably, this is the first demonstration that epigenetic changes at the GR exon 1F correlate with HPAA reactivity. These findings have important implications for understanding the molecular mechanisms underlying gender differences in stress-related disorders and underscore the unique value of modeling both epigenetic and genetic information in conferring vulnerability to stress.

Restraint Stress Restrains Cholesterol in the Intestine

Epidemiological studies have observed that psychosocial stress, for example, by unemployment, low socioeconomic status, or work stress, increases the risk of cardiovascular events.1 The pathophysiological basis of this association is poorly understood. Restraint stress, which is an experimental model for psychosocial stress, is characterized by the activation of the sympathetic nervous system involving the fast release of epinephrine and norepinephrine and the hypothalamic-pituitary-adrenal axis, resulting in a slow but sustained increase in circulating glucocorticoids.2 Both neuroendocrine axes elicit multiple and complex responses, aiming to protect the threatened organism. As yet, there is little and mixed epidemiological evidence about which of these pathways is relevant for the pathogenesis of cardiovascular diseases.3–6 Diurnal and other intraindividual variation of cortisol and catecholamine plasma concentrations make the design of meaningful observational studies difficult. More recently, measurements of cortisol in saliva or urine found positive associations between cortisol and risk of incident coronary events.5,6 Elevated cortisol levels in plasma or saliva have also been associated with increased blood pressure, diabetes mellitus, hyperglycemia, hypertriglyceridemia, and central adiposity. However, these associations have been questioned by 2 recent population studies that did not find any significant association of cortisol awakening response, evening cortisol, cortisol decline across the waking day, total cortisol output, and cortisol after dexamethasone suppression with metabolic syndrome or its individual components.7,8 Article, see p 1459 In addition to their importance of mobilizing stored energy and maintaining vascular tone during stress, glucocorticoids limit their own production by negative feedback inhibition, primarily via inhibiting the hypothalamic release of cortisol-releasing factor and the release of adrenocorticotropic hormone in the pituitary gland.2 Because cholesterol is a precursor of steroidogenesis, regulation of cholesterol metabolism is another potential target of glucocorticoid release in psychosocial stress. In this issue of …

Cortisol Response to Social Stress in Parentally Bereaved Youth

Parental bereavement is associated with increased risk for psychiatric illness and functional impairment in youth. Dysregulated hypothalamic-pituitary-adrenal (HPA) axis functioning may be one pathway through which bereaved children experience increased risk for poor outcomes. However, few studies have prospectively examined the association between parental bereavement and cortisol response while accounting for psychiatric disorders in both youth and their caregivers. One-hundred and eighty-one bereaved and nonbereaved offspring and their caregivers were assessed at multiple time points over a 5-year period after parental death. Offspring participated in an adaptation of the Trier Social Stress Task (TSST), and salivary cortisol samples were collected before and after exposure to social stressors. Mixed models for repeated measures were used to analyze the effects of bereavement status, psychiatric disorder in both offspring and caregiver, and demographic indices on trajectories of cortisol response. After controlling for demographic variables and offspring depression, bereaved offspring demonstrated significantly different trajectories of cortisol response compared with nonbereaved offspring, characterized by higher total cortisol output and an absence of cortisol reactivity to acute social stress. Within the bereaved group, offspring of parents who died by sudden natural death demonstrated significant cortisol reactivity to social stress compared with offspring whose parents died by suicide, who demonstrated more blunted trajectory of cortisol response. Parentally bereaved youth demonstrate higher cortisol output than nonbereaved youth but are less able to mount an acute response in the face of social stressors.

Influences of early shift work on the diurnal cortisol rhythm, mood and sleep: Within-subject variation in male airline pilots

SummaryWe aimed to investigate how early and late work shifts influenced the diurnal cortisol rhythm using a within-subjects study design. Participants were 30 healthy male non-smoking pilots, mean age 39.4, employed by a short-haul airline. The standard rotating shift pattern consisted of 5 early shifts (starting before 0600 h), followed by 3 rest days, 5 late shifts (starting after 1200 h) and 4 rest days. Pilots sampled saliva and completed subjective mood ratings in a logbook 6 times over the day on two consecutive early shift days, two late days and two rest days. Sampling was scheduled at waking, waking + 30 m, waking + 2.5 h, waking + 8 h, waking + 12 h and bedtime. Waking time, sleep duration, sleep quality and working hours were also recorded. Cortisol responses were analysed with repeated measures analysis of variance with shift condition (early, late, rest) and sample time (1–6) as within-subject factors. Early shifts were associated with a higher cortisol increase in response to awakening (CARi), a greater total cortisol output over the day (AUCG) and a slower rate of decline over the day than late shifts or rest days. Early shifts were also associated with shorter sleep duration but co-varying for sleep duration did not alter the effects of shift on the cortisol rhythm. Both types of work shift were associated with more stress, tiredness and lower happiness than rest days, but statistical adjustment for mood ratings did not alter the findings. Early shift days were associated with significantly higher levels of circulating cortisol during waking hours than late shifts or rest days.

Intimate partner violence exposure, salivary cortisol, and childhood asthma

ObjectivesNeuroendocrine alterations may help explain health differences between intimate partner violence (IPV) exposed children and non-exposed children. We sought to determine the feasibility of having families, recruited at a child asthma visit, collect at home and return via mail child salivary samples, and whether socio-demographic variables were associated with sample return. For those returning samples, we examined whether past-year IPV exposure was associated with total cortisol output (AUC) and the magnitude of the cortisol awakening response (CAR), and whether these cortisol values were associated with asthma control. MethodsFifty-five families with an asthmatic child of any age were recruited from 2 pediatric asthma clinics. At the time of the visit, parents completed a survey packet which included a modified version of the Conflict Tactics Scale to assess IPV. Parents were given supplies to collect 3 child salivary cortisol samples (awakening, 30-min after awakening, bedtime) at home on a typical day, and return them via mail. Medical records also were abstracted. ResultsFifty-three percent (n=29) returned child salivary samples. Families who returned samples typically returned them within 2 weeks, most commonly before we made a reminder call. Parental male sex was associated (p=.06) with increased rate of return at the trend level. In multivariable models, a 1-unit increase in IPV was significantly associated with a .93 SD increase in root-transformed total cortisol output (AUC) (un-standardized beta=2.5; SE .59; p=.001). The odds of uncontrolled asthma were marginally higher for every nmol/l increase in CAR (OR 1.04; 95% CI 1.0, 1.1; p=.06). ConclusionsThis study provides support for the feasibility of obtaining a moderate return of salivary specimens from a convenience sample. Findings that IPV was associated with elevated total cortisol output and uncontrolled asthma was marginally associated with cortisol awakening response suggest that future studies should investigate whether cortisol mediates the IPV-child asthma relationship.

Cortisol levels and history of depression in acute coronary syndrome patients

Depressed mood following an acute coronary syndrome (ACS) is a risk factor for future cardiac morbidity. Hypothalamic-pituitary-adrenal (HPA) axis dysregulation is associated with depression, and may be a process through which depressive symptoms influence later cardiac health. Additionally, a history of depression predicts depressive symptoms in the weeks following ACS. The purpose of this study was to determine whether a history of depression and/or current depression are associated with the HPA axis dysregulation following ACS. A total of 152 cardiac patients completed a structured diagnostic interview, a standardized depression questionnaire and a cortisol profile over the day, 3 weeks after an ACS. Cortisol was analysed using: the cortisol awakening response (CAR), total cortisol output estimated using the area under the curve method, and the slope of cortisol decline over the day. Total cortisol output was positively associated with history of depression, after adjustment for age, gender, marital status, ethnicity, smoking status, body mass index (BMI), Global Registry of Acute Cardiac Events (GRACE) risk score, days in hospital, medication with statins and antiplatelet compounds, and current depression score. Men with clinically diagnosed depression after ACS showed a blunted CAR, but the CAR was not related to a history of depression. Patients with a history of depression showed increased total cortisol output, but this is unlikely to be responsible for associations between depression after ACS and later cardiac morbidity. However, the blunted CAR in patients with severe depression following ACS indicates that HPA dysregulation is present.

The cortisol awakening response in amyotrophic lateral sclerosis is blunted and correlates with clinical status and depressive mood

Considerable evidence indicates that amyotrophic lateral sclerosis (ALS), a progressive neurodegenerative disease of the motor system, has an enormous impact on the patient's emotional and physical well-being. As previous findings indicated that particularly the rise in cortisol levels immediately after awakening, i.e., the cortisol awakening response (CAR), is associated with indices of physical and emotional well-being, we compared the CAR of 29 admitted ALS patients with that of 12 age-matched caregiver controls. Saliva samples for cortisol measurement were collected immediately, 15, 30 and 45 min after awakening. The severity of ALS progression was quantified using the ALS functional rating scale (ALSFRS) and manual muscle test (MMT). Depressive mood status in ALS patients was determined with the Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HDRS). Salivary cortisol levels of ALS patients did not differ from those of caregiver controls at awakening, 15 min or 45 min after awakening, but were significantly lower at 30 min after awakening. Area under the curve analysis confirmed that the CAR was significantly smaller in ALS patients than in caregiver controls. A smaller CAR in ALS patients was significantly correlated to poorer clinical status, as assessed with both the ALSFRS and MMT rating instruments. Further, a smaller CAR significantly correlated with a more severe depressive mood status. No correlations were observed between total cortisol output during the first 45 min post-awakening and clinical or depressive status. In conclusion, our findings indicate that ALS patients show a blunted CAR, correlated with disease and depression severity.

Shiftwork Duration and the Awakening Cortisol Response Among Police Officers

Police officers are required to work irregular hours, which induces stress, fatigue, and sleep disruption, and they have higher rates of chronic disease and mortality. Cortisol is a well-known “stress hormone” produced via activation of the hypothalamic-pituitary-adrenal axis. An abnormal secretion pattern has been associated with immune system dysregulation and may serve as an early indicator of disease risk. This study examined the effects of long- and short-term shiftwork on the cortisol awakening response among officers (n = 68) in the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) pilot study (2001–2003). The time each officer spent on day (start time: 04:00–11:59 h), afternoon (12:00–19:59 h), or night (20:00–03:59 h) shifts was summarized from 1994 to examination date to characterize long-term (mean: 14 ± 9 yrs) and short-term (3, 5, 7, or 14 days prior to participation) shiftwork exposures. The cortisol awakening response was characterized by summarizing the area under the curve (AUC) for samples collected on first awakening, and at 15-, 30-, and 45-min intervals after waking. Data were collected on a scheduled training or off day. The cortisol AUC with respect to ground (AUCG) summarized total cortisol output after waking, and the cortisol AUC with respect to increase (AUCI) characterized the waking cortisol response. Officers also completed the Center for Epidemiologic Studies Depression scale. Waking cortisol AUC values were lower among officers working short-term night or afternoon shifts than day shifts, with maximal differences occurring after 5 days of shiftwork. The duration of long-term shiftwork was not associated with the cortisol awakening response, although values were attenuated among officers with more career shift changes. (Author correspondence: burch@mailbox.sc.edu)

Sex differences in cortisol response to corticotropin releasing hormone challenge over puberty: Pittsburgh Pediatric Neurobehavioral Studies

Consistent sex differences in regulation of the hypothalamic pituitary adrenocortical (HPA) axis have been shown in animal models and emerge over puberty. However, parallel work in humans is lacking despite implications for elucidating the emergence of sex differences in depression over puberty. We investigated sex differences in HPA response to corticotropin releasing hormone (CRH) challenge over puberty in a carefully screened normative sample. Participants were 68 healthy children (41% girls), ages 6-16, with no personal or family history of psychiatric disorder. Pubertal maturation was determined by Tanner staging. Following 24h of adaptation, 9-10 plasma cortisol samples were collected over 30-40 min pre-infusion baseline, 1 μg/kg CRH infusion, and 90-180 min post-infusion recovery. Thirty-seven participants completed 2+ CRH challenges allowing inclusion of cross-sectional and longitudinal data in all analyses. The influence of gender and pubertal maturation on parameters of cortisol response to CRH challenge was investigated using nonlinear mixed model methodology. Girls showed increasing total cortisol output following CRH challenge over puberty, while boys showed little change in total cortisol output over puberty. Increased cortisol output in girls was explained by slower reactivity and recovery rates leading to prolonged time to reach peak cortisol and delayed return to baseline over puberty. Girls also showed increasing baseline cortisol over puberty, while boys showed declining baseline over puberty. Results reveal subtle normative sex differences in the influence of pubertal maturation on HPA regulation at the pituitary level. This normative shift may tip the balance towards stress response dysregulation in girls at high risk for depression, and may represent one potential mechanism underlying elevated rates of depression among pubescent girls.

P.1.031 Expression of glucose metabolism genes in a psychosis model: a molecular link between NMDA receptor hypofunction and metabolism disorders?

of bisulfite-treated DNA (EpigenDx, Worcester MA). Altogether, we examined the methylation level across 39 CpG sites in the GR exon 1F promoter region for each subject. Two genes were genotyped; the 5HTTLPR and the ESR1. All statistical tests were carried out using SPSS version 15. A linear regression model was used to ascertain the effects of sex, GR methylation level and genes on stress response. Statistical normality of the data was checked using the Kolmogorov-Smirnov test. Results: Marked individual differences were observed in methylation levels of GR exon 1F at individual CpG sites for females and males. Overall, women showed significantly greater methylation levels than did men (t = 2.538, p = 0.013). There was a correlation between total cortisol output (area under the curve, AUC) and average methylation level at GR exon 1F in female subjects (R2D= 0.214, F(1,44) = 11.997, p = 0.001) accounting for 21.4% of the variance. Additionally, variations in the ESR1 and the 5-HTTLPR genes were significant predictors of AUC. A significant main effect of 5-HTTLPR (R2D= 0.172, F1,42 = 12.032, p = 0.001) and ESR1 (R2D= 0.132, F2,40 = 5.634, p = 0.007) was observed on AUC but there was no interaction between methylation and either gene. The full model accounted for nearly half of the variance (48%) in total cortisol output. Conclusions: We provide the first evidence that accumulated epigenetic changes at the peripheral GR exon 1F correlate with HPAA reactivity. Importantly, women show significantly greater methylation across the GR promoter exon 1F compared to men. The averaged methylation levels and each of the two polymorphisms are highly significant independent predictors of total cortisol response (AUC) in the TSST. These findings have important implications for understanding the molecular mechanisms underlying gender differences in stressrelated mental health disorders, and underscore the unique value of modeling both epigenetic and genetic information in conferring vulnerability to stress.