Diurnal salivary cortisol is associated with body mass index and waist circumference: the Multiethnic Study of Atherosclerosis

OBJECTIVE

Neuroendocrine abnormalities, such as activation of the hypothalamic-pituitary-adrenal (HPA) axis, are associated with obesity; however, few large-scale population-based studies have examined HPA axis and markers of obesity. We examined the cross-sectional association of the cortisol awakening response (CAR) and diurnal salivary cortisol curve with obesity.

DESIGN AND METHODS

The Multiethnic Study of Atherosclerosis Stress Study includes 1,002 White, Hispanic, and Black men and women (mean age 65 ± 9.8 years) who collected up to 18 salivary cortisol samples over 3 days. Cortisol profiles were modeled using regression spline models that incorporated random parameters for subject-specific effects. Cortisol curve measures included awakening cortisol, CAR (awakening to 30-min postawakening), early decline (30 min to 2-h postawakening), late decline (2-h postawakening to bedtime), and the corresponding areas under the curve (AUC). Body mass index (BMI) and waist circumference (WC) were used to estimate adiposity.

RESULTS

For the entire cohort, both BMI and WC were negatively correlated with awakening cortisol (P < 0.05), AUC during awakening rise, and early decline and positively correlated to the early decline slope (P < 0.05) after adjustments for age, race/ethnicity, gender, diabetes status, socioeconomic status, β-blockers, steroids, hormone replacement therapy, and smoking status. No heterogeneities of effects were observed by gender, age, and race/ethnicity.

CONCLUSIONS

Higher BMI and WC are associated with neuroendocrine dysregulation, which is present in a large population sample, and only partially explained by other covariates.

Parenting stressors and morning cortisol in a sample of working mothers

The cortisol awakening response (CAR) is a normative rise in cortisol levels across the 30 minutes post awakening. Both the levels and the degree of change in cortisol across this time period are sensitive to the perceived challenges of the day and are thought to prepare the individual to meet these tasks. However, working parents of young children may be under unique strains at this time as they attempt to simultaneously care for their children while also preparing themselves for the workday ahead. In these analyses we examined the contributions of both work and parenting stress on maternal cortisol levels and awakening responses, and how these relationships differed on workdays compared with nonworkdays. To do this, saliva samples were collected from 56 working mothers (25% single) with a child between the ages of 2 and 4 years old (mode = 2 children), at awakening and 30 min postawakening. Samples were collected on 4 consecutive days-2 nonworkdays followed by 2 workdays. Analyses revealed mothers reporting higher levels of parenting stress had higher average a.m. cortisol on workdays compared with nonworkdays. Further, mothers reporting a combination of high job strain and high parenting stress had significantly higher cortisol levels and steeper CAR increases on workdays compared with nonworkdays. Findings are discussed by integrating knowledge from the fields of parenting stress, work-family, and stress physiology.

Childhood sexual abuse is associated with cortisol awakening response over pregnancy: preliminary findings

INTRODUCTION

Childhood sexual abuse (CSA) has been associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in non-pregnant samples. However, it is not yet known whether CSA is associated with HPA dysregulation over pregnancy. In the present study we assessed whether maternal cortisol levels across pregnancy differed in women with CSA histories compared to women with histories of non-sexual child abuse (CA) and no abuse (NA).

METHODS

135 pregnant mothers (CSA=30, CA=58, NA=47) provided salivary cortisol samples at wakeup, wake +30 min, and bedtime for 3 consecutive days at 1-3 time points over second and third trimester. Cortisol awakening responses and slopes were computed.

RESULTS

Women with CSA histories displayed increasing cortisol awakening response over pregnancy compared to women with CA and NA histories. Group differences were not observed for slope.

CONCLUSIONS

This is the first study to show that cortisol awakening responses increase over pregnancy in women with CSA histories compared to women with CA and NA histories.

Cortisol awakening response and nighttime salivary cortisol levels in healthy working Korean subjects

PURPOSE

Cortisol awakening response (CAR) and nighttime cortisol levels have been used as indices of adrenocortical activity. However, population-based statistical information regarding these indices has not been provided in healthy subjects. This study was carried out to provide basic statistical information regarding these indices.

MATERIALS AND METHODS

Cortisol levels were measured in saliva samples collected immediately upon awakening (0 min), 30 min after awakening and in the nighttime on two consecutive days in 133 healthy subjects.

RESULTS

We determined the mean [standard deviation (SD)], median (interquartile range) and 5th-95th percentile range for each measure and auxiliary indices for CAR, i.e., the secreted cortisol concentration within 30 min of awakening (CARscc) and absolute and relative increases in cortisol level within 30 min of awakening (CARi and CARi%, respectively). We also determined these values for auxiliary indices derived from nighttime cortisol level, i.e., the ratio of cortisol level 30 min after awakening (CA(₃₀ min)) to nighttime level (CA(₃₀ min)/NC), as well as absolute and relative decreases in cortisol levels from CA(₃₀ min) to nighttime (DCd and DCd%, respectively). We found no significant differences in cortisol level for any time point or in auxiliary indices between collection days, genders and ages.

CONCLUSION

The provided descriptive information and statistics on the CAR and nighttime cortisol level will be helpful to medical specialists and researchers involved in hypothalamus- pituitary-adrenal axis assessment.

PCLO rs2522833 impacts HPA system activity in healthy young adults

Recent genetic studies showed evidence for a role of the single-nucleotide polymorphism rs2522833 within the PCLO gene in the etiology of major depression, and rs2522833 has been shown to modulate hypothalamic pituitary adrenal (HPA) axis activity during antidepressant treatment. Monoaminergic modulation of the HPA system may be one possible pathomechanism by which PCLO exerts its effect on depression. In the present study, we investigated the effect of rs2522833 on the cortisol awakening response (CAR) in healthy young adults. A total of 66 healthy volunteers from the community (36 men and 30 women) aged 18-25 years without individual or family history of affective disorders and schizophrenia collected saliva cortisol samples at 0, 30, 45 and 60 min after awakening on two consecutive working days. We identified a blunted CAR (AUCinc) in rs2522833 risk-allele (C) carriers, possibly indicating exhausted regulatory mechanisms underlying the HPA system. We also identified higher neuroticism scores in rs2522833 risk-allele carriers but no phenotypic correlation between the CAR (AUCinc) and neuroticism. These findings suggest that the rs2522833 risk variant might increase vulnerability to depression both by physiological and behavioral pathways, which appear, however, not to be substantially overlapped. Replication with larger samples is warranted.

Prospective prediction of major depressive disorder from cortisol awakening responses in adolescence

Levels of the stress-sensitive hormone cortisol increase dramatically in the first 30-40min after waking, an effect known as the cortisol awakening response (CAR). There is considerable cross-sectional evidence that psychosocial stress is associated with an increased CAR, and the CAR has been found to be altered in the presence of stress-related diseases, including major depressive disorder (MDD). To date, no prospective longitudinal studies have examined whether individual differences in the CAR serve as a premorbid risk factor for MDD. In a sample of 230 late adolescents, clinical diagnoses of MDD were predicted from the CAR as well as other indicators of basal cortisol functioning gathered 1 year earlier, including: waking cortisol levels, bedtime cortisol levels, the size of the CAR, average cortisol, and the slope of the diurnal cortisol rhythm across the waking day. Age and gender, health and health behaviors, baseline neuroticism, exposure to stressful life events and past episodes of mood and anxiety disorders were included as covariates, to help ensure effects are attributable to the CAR rather than related variables. A higher baseline CAR was associated with a significantly increased risk of developing MDD by follow-up, even when excluding individuals with baseline MDD. No other baseline cortisol measures were significant prospective predictors of MDD. In summary, the CAR is a significant prospective risk factor for the development of MDD in young adults, providing some support for the possibility that a heightened CAR may play a role in the etiology of major depressive disorder.

Socioeconomic and race/ethnic differences in daily salivary cortisol profiles: the multi-ethnic study of atherosclerosis

It has often been hypothesized that stress and its biological consequences mediate the relationship between low socioeconomic status (SES) or minority status and poor cardiovascular disease outcomes. The objective of this study was to determine if daily cortisol patterns, a biomarker of the stress response, differ by race/ethnicity and socioeconomic status. Data were collected from 935 Black, White and Hispanic adults age 48-90 years old. Salivary cortisol samples were collected six times per day over 3 days: at awakening, 30min later, at 1000h, noon, 1800h and at bedtime. Blacks and Hispanics had lower levels of wake-up cortisol and less steep early declines, while Blacks had flatter and Hispanics steeper late day declines relative to Whites. Similarly the low socioeconomic status group also had lower levels of wake-up cortisol and less steep decline during the early part of the day. These patterns remained after adjustment for health behaviors and psychosocial factors. This study finds an association between salivary cortisol and race/ethnicity and SES in a multi-ethnic study population. Further work is needed to determine the health consequences of these differences.

What constitutes too long of a delay? Determining the cortisol awakening response (CAR) using self-report and PSG-assessed wake time

The cortisol awakening response (CAR) is a burst of cortisol in response to awakening from sleep that is superimposed on the circadian rhythm of cortisol. Determination of the CAR is contingent on the timing of sample collection: a delay between waking and collection of the first sample may affect the rise of the CAR, and could explain equivocal findings reported in the literature. We evaluated the impact of a delay between wake time and collection of waking cortisol samples on the CAR. Two methods were used to identify wake time: polysomnography (PSG) and self-report (S-R). Participants (total n=207, mean age 74.0+/-7.2 years) included bereaved older adults (n=35), caregivers (n=50), patients with insomnia and co-morbid medical disorders (n=68), and the healthy older adults (n=54). We used ANOVA to test if a delay >15 min affected the CAR. We also fitted cubic spline models to assess expected cortisol levels, the expected CAR, and the expected decrease in CAR. Wake times measured by PSG and S-R did not differ significantly. Large delays were observed (for both PSG and S-R) between wake time and collection of the waking cortisol sample (24.8+/-32.2 min for PSG and 28.3+/-49.2 min for S-R). Both statistical methods indicated that a delay >15 min between wake time and first cortisol sample collection significantly affected the CAR (p's<.005); later collection times were associated with smaller CAR values. Later collection times and reduced CAR values may affect the interpretation of clinical associations. Our data also show that S-R assessments of wake time perform equally well to PSG for evaluating adherence with CAR sampling procedures.

Association of salivary cortisol circadian pattern with cynical hostility: multi-ethnic study of atherosclerosis

OBJECTIVE

To determine if cynical hostility is associated with alterations in diurnal profiles of cortisol. Hostility has been linked to cardiovascular disease but the biological mechanisms mediating this association remain unknown.

METHODS

Up to 18 measures of salivary cortisol taken over 3 days were obtained from each of 936 participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Cynical hostility was measured using an eight-item subscale of the Cook-Medley Hostility Scale. Cortisol profiles were modeled using regression spline models that incorporated random parameters for subject-specific effects. Models were adjusted for race, sex, age, socioeconomic position, and lifestyle factors. The association of cynical hostility with key features of the cortisol diurnal profile, both in the full sample and important subsamples, was examined.

RESULTS

Waking cortisol levels as well as the extent of the morning surge in cortisol levels did not differ significantly across tertiles of cynical hostility. Respondents in the lowest tertile of cynical hostility experienced a 22% sharper decline in salivary cortisol (age- and sex-adjusted slope of -0.49 microg/dL per hour) than respondents in the highest tertile (-0.40 microg/dL per hour, p for difference = .0004). Intertertile differences in these parameters remained unaltered after further adjustment for potential confounders. This pattern of differences in cortisol diurnal profile tended to be related in a dose-response way to level of cynical hostility, and persisted in stratified analyses.

CONCLUSIONS

Cynical hostility is associated with the declining phase of the awakening cortisol response. The implications of this for cardiovascular and other health outcomes remain to be determined.

A blunted cortisol awakening response and hippocampal atrophy in type 2 diabetes mellitus

There is emerging evidence from healthy individuals, as well as direct and indirect evidence from psychiatric and neurological patients with disease-related hippocampal atrophy, linking the cortisol awakening response (CAR) to hippocampal volume. Type 2 diabetes mellitus (T2DM) is a metabolic disease that is also accompanied by hippocampal atrophy, and therefore can serve as a model for ascertaining the relationship between CAR and hippocampal volume. We contrasted a group of 18 individuals with T2DM with 12 matched controls on MRI-based hippocampal volume and salivary diurnal cortisol profile including CAR. Individuals with T2DM had smaller hippocampal volumes and exhibited a blunting of the CAR relative to controls, while diurnal cortisol was not affected. Across all subjects, fasting insulin and hippocampal volume were associated with the CAR, independent of diagnosis. Our findings support the hypothesis that hippocampal integrity is an important predictor of the CAR.

Salivary cortisol among American Indians with and without posttraumatic stress disorder (PTSD): gender and alcohol influences

Disruptions in hypothalamic-pituitary-adrenal regulation and immunity have been associated with posttraumatic stress disorder (PTSD). We examined the association of PTSD with diurnal rhythms in salivary cortisol in a convenience sample from a population-based study of male and female American Indians. Subjects with and without PTSD were identified from American Indians living on/near a Northern Plains reservation as part of a larger study. Over two days diurnal saliva samples were collected by staff at the University of Colorado Denver Clinical Research Center at waking, 30min after waking, before lunch, and before dinner. Generalized estimating equations linear regression models investigated the influence of PTSD on cortisol over time. The association of a lifetime diagnosis of PTSD with salivary cortisol level was assessed in subjects with complete data (PTSD: n=27; no PTSD n=32) for age, gender, and alcohol consumption in the past month. Subject mean age was 44 years, and 71% were women. When stratified by gender, women with a lifetime diagnosis of PTSD had significantly higher mean cortisol levels throughout the day than women without PTSD (p=0.01); but there was no significant association between PTSD and cortisol levels in men (p=0.36). The cortisol awakening response - the difference in cortisol levels from waking to 30min after waking - was not associated with PTSD in men or women. A lifetime diagnosis of PTSD may influence diurnal cortisol among American Indian women. These effects were independent of influences of current alcohol use/abuse. The unexpected elevation in cortisol in American Indian women with a lifetime diagnosis of PTSD may reflect acute anxiety associated with experiencing a number of novel tests in a strange location (e.g., cardiac imaging, medical, dental exams, etc.), or concurrent depression.

Cortisol diurnal rhythm and stress reactivity in male adolescents with early-onset or adolescence-onset conduct disorder

BACKGROUND

Previous studies have reported lower basal cortisol levels and reduced cortisol responses to stress in children and adolescents with conduct disorder (CD). It is not known whether these findings are specific to early-onset CD. This study investigated basal and stress-induced cortisol secretion in male participants with early-onset and adolescence-onset forms of CD.

METHODS

Forty-two participants with early-onset CD, 28 with adolescence-onset CD, and 95 control subjects participated in the study. They collected saliva across the day to assess their cortisol awakening response and diurnal rhythm. Subsequently, salivary cortisol was measured before, during, and after a psychosocial stress procedure designed to elicit frustration. Cardiovascular activity and subjective mood states were also assessed during stress exposure.

RESULTS

There were no group differences in morning cortisol levels or the size of the cortisol awakening response. Basal cortisol levels in the evening and at 11 am during the laboratory visit were higher in both CD subgroups relative to control subjects. In contrast, cortisol and cardiovascular responses to psychosocial stress were reduced in both CD subgroups compared with control subjects. All groups reported similar increases in negative mood states during stress.

CONCLUSIONS

Our findings suggest that group differences in cortisol secretion are most pronounced during stress exposure, when participants with CD show cortisol hyporeactivity compared with control subjects. There was no evidence for reduced basal cortisol secretion in participants with CD, but rather increased secretion at specific time points. The results do not support developmentally sensitive differences in cortisol secretion between CD subtypes.