Return to school accompanied by changing associations between family ecology and cortisol

This study examines everyday family life as a social regulator of child adrenocortical activity during the normative challenge of return to school. If positive family function facilitates child adaptation, we expected that mother-child relationships following school entry would predict individual differences in evening cortisol, a context-sensitive marker for the response to concurrent demands. Among 28 children followed longitudinally, late in pre-kindergarten those living with single and/or employed mothers had higher evening cortisol. Yet early during the following school year, children with poorer mother-child relationships had higher evening cortisol. Cortisol awakening response, a comparatively stable marker of anticipated demands, was higher with maternal employment, single parents, and busier child schedules before school re-entry, and with maternal employment afterwards. We argue for a layered ecological approach to social regulation, recognizing that family structure, family functioning, and proximal features of everyday life within the family moderate child adrenocortical activity differently across contexts.     

The cortisol awakening response (CAR) in 2- to 4-year-old children: effects of acute nighttime sleep restriction, wake time, and daytime napping

The cortisol awakening response (CAR) is presumed critically important for healthy adaptation. The current literature, however, is hampered by systematic measurement difficulties relative to awakening, especially with young children. While reports suggest the CAR is smaller in children than adults, well‐controlled research in early childhood is scarce. We examined whether robust CARs exist in 2‐ to 4‐year‐old children and if sleep restriction, wake timing, and napping influence the CAR (n = 7). During a 25‐day in‐home protocol, researchers collected four salivary cortisol samples (0, 15, 30, 45 min post‐wake) following five polysomnographic sleep recordings on nonconsecutive days after 4 hr (morning nap), 7 hr (afternoon nap), 10 hr (evening nap), 13 hr (baseline night), and 16 hr (sleep restriction night) of wakefulness (20 samples/child). The CAR was robust after nighttime sleep, diminished after sleep restriction, and smaller but distinct after morning and afternoon (not evening) naps. Cortisol remained elevated 45 min after morning and afternoon naps. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 54:412–422, 2012.     

Morningness and eveningness: the free cortisol rise after awakening in "early birds" and "night owls"

We investigated salivary cortisol profiles in the first hour after awakening in morning versus evening chronotypes. Chronotypes were defined by Horne and Ostberg's Owl-and-Lark-Questionnaire. In a sample of 112 healthy, day-active young men, we identified 9 morning and 29 evening chronotypes. Saliva samples were collected 0, 30, 45, and 60min after awakening on 2 consecutive days. Log-transformed cortisol levels were analyzed with General Linear Model procedures (GLMs) and awakening time and sleep duration were entered as covariates. On both days, a significant main effect of chronotype emerged (both p=0.02), and this effect could not be explained by differences in awakening time or sleep duration. The present data support the idea that morning relative to evening chronotypes might show higher cortisol levels in the first hour after awakening. In sum, individual chronotype should be acknowledged as one further possible source of interindividual variability in the cortisol rise after awakening.     

Heritability of Daytime Cortisol Levels in Children

Individual differences in the level of the stress hormone cortisol play a prominent role as an explanatory variable in studies on psychopathology. Relatively few studies have paid attention to individual differences in cortisol levels and the etiology of these differences, in particular their possible genetic basis. All these studies have been in adults. The aim of this study was to estimate genetic and environmental influences on basal cortisol levels in 12-year-old children. To this end, four samples of salivary cortisol were collected on two consecutive days in a sample of 180 twin pairs. Low correlations were found between cortisol levels at different points in time during the day. A significant genetic contribution was found to the variation of basal cortisol levels in the morning and afternoon samples, but not in the evening sample. Heritability did not differ for boys and girls and was highest (60%) for cortisol levels during the sample taken about 45 minutes after awakening. This cortisol awakening response provides a useful endophenotype in the search for genes that may affect hypothalamic-pituitary adrenocortical functioning in children.     

The relationship between long-term job strain and morning and evening saliva cortisol secretion among white-collar workers

The objective of this study was to assess long-term job strain impact on morning and evening salivary cortisol secretion. In all 77 white-collar workers (31% women; sample mean age, 42 years at baseline) volunteered to sample morning (immediately after waking up) and evening (10 p.m.) salivary cortisol for 7 consecutive days. By median split on aggregated self-reported isostrain from three consecutive questionnaires distributed in a period of approximately 3.5 years the participants were classified into a high or low long-term isostrain condition. Regardless of strain condition, there was a significant reduction in morning salivary cortisol secretion from the working week to the weekend, whereas evening salivary cortisol secretion showed no significant variation during the week. Although chronic isostrain did not affect the morning saliva cortisol measures, evening cortisol secretion was significantly elevated in the chronic high isostrain group throughout the whole week. The elevated evening cortisol measures associated with chronic high strain are concordant with the findings in other studies on long-term strain.     

Diurnal variation of the startle reflex in relation to HPA-axis activity in humans

Diurnal variation of baseline startle amplitude was examined in 14 normal inpatients on a research unit where behavioral activity and environmental stimuli were highly controlled. We tested a hypothesized association between diurnal variations of salivary cortisol and reflex amplitude by recording acoustic startle eyeblinks shortly before bedtime, when cortisol was near its lowest daily level, and just after awakening, when cortisol was at its peak. Results showed that startle eyeblinks were greater during evening than morning sessions, whereas the opposite was true for cortisol levels. Skin conductance levels and reaction time performance also increased from morning to evening. These findings are consistent with accumulating evidence suggesting a possible link between startle reactivity and hypothalamic-pituitary-adrenal axis activity, and an association between diurnal variations in endogenous arousal and startle amplitude.     

Sickle Cell Disease Pain in Children and Adolescents: Change in Pain Frequency and Coping Strategies Over Time

Examined 9-month follow-up data obtained from children and adolescentswith sickle cell disease (SCD) and their parents participatingin a longitudinal study of pain coping strategies. Of 87 subjectscompleting the baseline assessment of pain coping strategies,70 (80%) of their parents completed a structured pain interviewassessing their child's health care use and activity reductionduring painful episodes over the follow-up period. Regressionanalyses controlling for age and pain frequency revealed thatbaseline Coping Attempts were associated with higher levelsof school, household, and social activity during painful episodes.Baseline Passive Adherence was associated with more frequenthealth care contacts during the subsequent 9 months. Increasesin Negative Thinking over time were associated with furtherincreases in health care contacts during the follow-up period.Comparing pain coping strategies assessed at baseline to paincoping strategies measured at follow-up revealed that pain copingstrategies were relatively stable over time for younger childrenbut changed more for adolescents.     

Declines in peer conflict from preschool through first grade: Influences from early attachment and social information processing

The transition from preschool to early school years is critical for the growth of social skills. Using data from the NICHD Study of Early Child Care and Youth Development (for this study N = 942), the purpose of this study was to evaluate the longitudinal influence of attachment security and social information processing skills (social problem-solving and hostile attribution biases) on normative changes in peer conflict over the transition from preschool to first grade. Using latent growth curve modeling (LGM), this study found that children exhibited progressive declines in peer conflict over this period. Security of attachment (assessed via the Attachment Q-Set at 24 months) was related to lower rates of peer conflict in first grade, and steeper declines in peer conflict from 54 to 84 months. Differences in children's social information processing (assessed at 54 months) were marginally related to steeper declines in peer conflict. These findings suggest that the social skills and social expectations associated with early attachment security, together with subsequent advances in social information processing, are related to changes in peer conflict during the transition to school.     

Day-to-day variation in saliva cortisol—Relation with sleep, stress and self-rated health

The objective was to examine the day-to-day variation in cortisol among healthy individuals and its relation to the time of saliva sampling, work, stress and fatigue. During 4 consecutive weeks, 14 office workers provided saliva samples (at awakening, 15 min after awakening and at bedtime) and made diary ratings for each day. Results showed a variation in cortisol values between participants but also within individuals. After controlling for the individual differences, results showed that low cortisol levels in the morning were associated with sleepiness at awakening and anxiety, exhaustion, and poor health the day before. High evening levels of cortisol were associated with symptoms of stress and poor self-rated health. Further analysis of the cortisol awakening response (CAR) showed that all participants had a mixture of both a positive and negative responses. During mornings with a negative response participants stayed in bed for a longer time after the initial awakening, which might be a sign of snoozing, thus missing the awakening response.     

Sleep quality,cortisol levels,and behavioral regulation in toddlers

This study examines the association between nighttime sleep characteristics and cortisol levels and how these variables relate to aspects of children's temperament and behavior. Twenty‐seven healthy children, aged 12–36 months, attending group childcare settings, participated in the study. Each child's sleep was measured at home with actigraphy over three nights. Saliva samples were collected by the mothers at bedtime and within 30 min of awakening. In addition, both the mother and the daycare teacher rated the child's behavioral difficulties and negative emotionality. It was found that children with more fragmented sleep displayed higher awakening cortisol levels compared to children with more efficient sleep. Moreover, elevated awakening cortisol levels were correlated with teachers' ratings of internalizing behavior and negative emotionality. These preliminary findings suggest that awakening cortisol may serve as a useful index of adrenocortical reactivity in young children, signaling a disturbance in physiological regulation, and underscore the need for more research pertaining to the dynamic associations between sleep and HPA‐axis across the 24‐hr period. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 52: 44–53, 2010     

Sleep disturbance during the menopausal transition in a multi-ethnic community sample of women

STUDY OBJECTIVES: Examine age-adjusted odds and racial/ethnic differences in self-reported difficulties falling and staying asleep and early morning awakening in midlife women to determine whether difficulty sleeping increased with progression through the menopausal transition. DESIGN: Longitudinal analysis. SETTING: Community-based. PARTICIPANTS: 3,045 Caucasian, African American, Chinese, Japanese, and Hispanic women, aged 42-52 years and pre- or early peri-menopausal at baseline, participating in the Study of Women's Health Across the Nation (SWAN). Interventions: None. MEASUREMENTS AND RESULTS: Self-reported number of nights of difficulty falling asleep, staying asleep, and early morning awakening during the previous 2 weeks were obtained at baseline and 7 annual assessments. Random effects logistic regression was used to model associations between each of the 3 sleep measures and the menopausal transition, defined by bleeding patterns, vasomotor symptoms (VMS), and estradiol (E2) and follicle stimulating hormone (FSH) serum levels. Adjusted odds ratios (ORs) for difficulty falling asleep and staying asleep increased through the menopausal transition, but decreased for early morning awakening from late perimenopause to postmenopause. Naturally and surgically postmenopausal women using hormones, compared with those who were not, generally had lower ORs for disturbed sleep. More frequent VMS were associated with higher ORs of each sleep difficulty. Decreasing E2 levels were associated with higher ORs of trouble falling and staying asleep, and increasing FSH levels were associated with higher ORs of trouble staying asleep. Racial/ethnic differences were found for staying asleep and early morning awakening. CONCLUSIONS: Progression through the menopausal transition as indicated by 3 menopausal characteristics--symptoms, bleeding-defined stages, and endogenous hormone levels--is associated with self-reported sleep disturbances.     

Work family balance, stress, and salivary cortisol in men and women academic physicians

Background: The stress of medical practice has been recurrently studied, but work- and family-related determinants of health by gender remain under researched. Purpose: To test the hypothesis that cortisol excretion would be affected by the perceived severity of total workload imbalance. Method: By hierarchical regression analysis, the associations between work-family balance and diurnal salivary cortisol levels by sex in academic physicians (n = 40) were investigated. Results: Men physicians reported more paid work hours per week than women physicians and women more time in childcare, but their total working hours were similar. Controlling for sex and age, the mean of the diurnal cortisol release was associated with a combined effect of sex and responsibility at home. When morning cortisol, sex, and children at home were held constant, cortisol levels in the evening were associated with responsibility at home without significant gender interaction. Conclusion: With increasing responsibility at home, women and men reacted differently with regard to cortisol responses over the day. However, in the evening, controlling for the morning cortisol, these gender differences were not as obvious. These findings highlight traditional gender patterns among both women and men physicians in the challenge of finding a balance between work and family.     

Behavioral and neuroendocrine responses in shy children

Previous research has shown that infants who display a high frequency of motor activity and negative affect at 4 months of age are likely to be behaviorally inhibited toddlers. We examined social behaviors, maternal report of temperament, salivary cortisol, and baseline startle responses at age 4 in a sample of children, some of whom displayed a high frequency of motor activity and negative affect at 4 months of age. Infants who displayed this temperamental profile were reported by their mothers as more shy at age 4 compared with other children. We also found that 4-year-olds who displayed a high frequency of wary behavior during peer play exhibited relatively high morning salivary cortisol, were reported as contemporaneously shy by their mothers, and were behaviorally inhibited at 14 months of age. There were no significant relations found between baseline startle and morning salivary cortisol and measures of shyness at age 4. We speculate that high levels of cortisol in shy children may induce changes in the amygdala, exacerbating their fearfulness. © 1997 John Wiley & Sons, Inc. Dev Psychobiol 30: 127–140, 1997     

Job strain and anger expression predict early morning elevations in salivary cortisol

OBJECTIVE: The objectives of this study were to test the hypothesis that high job demands and low job control (job strain) are associated with elevated free cortisol levels early in the working day and with reduced variability across the day and to evaluate the contribution of anger expression to this pattern. METHODS: One hundred five school teachers (41 men and 64 women) classified 12 months earlier as high (N = 48) or low (N = 57) in job strain according to the demand/control model sampled saliva at 2-hour intervals from 8:00 to 8:30 hours to 22:00 to 22:30 hours on a working day. Anger expression was assessed with the Speilberger State-Trait Anger Expression Inventory, and negative affect was also measured. RESULTS: Free cortisol was significantly elevated at 8:00 to 8:30 hours in the high job strain group but not at later times of the day or evening. After adjustment for age and negative affect, cortisol was an average of 21.7% higher early in the working day in the high job strain group. This effect was significantly greater in high job strain teachers, who also reported high anger-out. The cortisol decline from morning to evening was greater in the high than low job strain individuals. Independently of job strain, women had a higher cortisol concentration at 8:00 to 8:30 hours than men, whereas cortisol concentration was greater in men than women in the middle of the working day between 12:00 and 16:30 hours. CONCLUSIONS: Job strain is associated with elevated free cortisol concentrations early in the working day but not with reduced cortisol variability. The interaction with outward anger expression suggests that individual characteristics modulate the impact of chronic work stress on the hypothalamic-pituitary-adrenocortical system.     

Burnout, perceived stress, and cortisol responses to awakening

OBJECTIVE: The effects of burnout and perceived stress on early morning free cortisol levels after awakening were investigated in a group of teachers. Previous studies revealed that cortisol levels show a significant increase after awakening, with high intraindividual stability. METHODS: Sixty-six teachers from local public schools (42 women and 24 men, mean age 42+/-5 years) were asked to sample saliva for cortisol analysis on 3 consecutive days. On each day, cortisol levels were measured at the time of awakening and 15, 30, and 60 minutes thereafter. On the night before the third day, subjects took 0.5 mg dexamethasone orally for testing glucocorticoid feedback inhibition. Burnout and perceived stress were measured by three different questionnaires. RESULTS: Perceived stress correlated with increases of cortisol levels during the first hour after awakening after dexamethasone pretreatment. In addition, teachers scoring high on burnout showed lower overall cortisol secretion on all sampling days, and a higher suppression of cortisol secretion after dexamethasone administration. In the subgroup of teachers with both high levels of perceived stress and high levels of burnout, a lower overall cortisol secretion was observed on the first 2 days, with stronger increases during the first hour after awakening after dexamethasone suppression. This subgroup also showed the lowest self-esteem, the highest external locus of control, and the highest number of somatic complaints. CONCLUSIONS: These results demonstrate differential effects of burnout and perceived stress on hypothalamic-pituitary-adrenal axis regulation.     

Short-term stability of physiological measures in kindergarten children: respiratory sinus arrhythmia, heart period, and cortisol

The short-term stability of measures of respiratory sinus arrhythmia (RSA), heart period, and salivary cortisol and the relation of these variables to one another and to measures of social competence in kindergartners were examined. Physiological measures were collected during multiple individual sessions with 30 kindergarten children, ages 5 to 6 years. Three sessions were scheduled at 2-week intervals and included a negative affect task as a challenge. Cardiovascular and cortisol responses to the challenge were assessed. Results indicated that baseline measures of RSA and heart period were stable across time. Baseline cortisol levels were not stable. The change in RSA in response to a task that elicited emotional responses was not stable over time. Consistent with findings observed in adults and older children, changes in RSA were related to the cortisol response. Children who increased cortisol over the course of Session 1 exhibited larger decreases in RSA than children who did not show increased cortisol levels. In addition, the children who had larger decreases in RSA had higher ratings of sociability on the Colorado Childhood Temperament Inventory. Greater decreases in heart period during the task were associated with lower ratings of shyness. The relation of RSA measures to ratings of social competence supports the Polyvagal Theory (Porges, 1995, 2001), which suggests that the ability to engage and disengage with objects and people in one's environment, necessary for social competence, is related to the regulation of vagal control of the heart.     

Morningness-eveningness, habitual sleep-wake variables and cortisol level

The free cortisol rise immediately after awakening is a distinctive part of the cortisol circadian rhythm. Few studies have focused on the relationship between morningness and cortisol awakening response (CAR). As the suprachiasmatic nucleus may be of major importance for both, one may hypothesise that the CAR should also be associated with morningness. We used saliva samplings and applied questionnaires in adolescents and young adults. Saliva samplings were made at awakening (t1) and 30 min later (t2). Chronotype was measured using the Composite Scale of Morningness (CSM), and habitual time in bed was calculated from habitual rise times and bed times. In both, the adolescent sample and the young adults, positive correlations existed between cortisol measures at t1 immediately after awakening and CSM scores. Using a multivariate model controlling for age group, smoking status and time of t1, we identified CSM scores and bed times as the most relevant variables for CAR. When comparing extreme chronotypes, morning types had higher cortisol levels immediately after awakening than evening types. These results strongly suggest an association between morningness-eveningness and CAR.     

Circadian cortisol profiles and psychological self-reports in shift workers with and without recent change in the shift rotation system

Cortisol profiles including the cortisol rise in the first hour after awakening (CAR) were assessed during shift work and days off (eight saliva samples per shift). Participants were 102 healthy permanent day and night shift workers (comparison groups) and former permanent day and night shift workers after implementation of a new fast-forward rota including morning, evening, and night shifts. Results show that the CAR is detectable in day as well as night shifts. In permanent night workers cortisol profiles appear to be blunted during night work and days off. However, circadian cortisol profiles are not disturbed in former night workers who recently switched to the fast rotating shift schedule. In contrast, implementation of night work in former day workers seems to lead to initially blunted cortisol profiles that normalize after a short adjustment period. Results of a psychological assessment including exhaustion, chronic stress, effort-reward imbalance, and ratings of sleep quality and sleep length are also presented.     

Diurnal rhythms in plasma cortisol, insulin, glucose, lactate and urea in pigs fed identical meals at 12-hourly intervals

Diurnal rhythms in plasma cortisol, insulin, glucose, lactate and urea concentrations were investigated in eight catheterized pigs of approximately 35 kg BW. Pigs were fed isoenergetic/isoproteinic diets at a restricted level (2.5 x maintenance requirement for energy) in two daily rations (06:00 and 18:00 hours) in order to obtain equal intervals between feed intake. Preprandial plasma cortisol concentration was 22+/-3 ng/mL in the morning and 14+/-2 ng/mL in the evening (p<0.025), whereas the concentrations of insulin, glucose, lactate, and urea were similar. In the postprandial period in the morning (06:00-09:00 hours) plasma cortisol, insulin and lactate concentrations (expressed as the total area under the curve) were greater (p<0.001) compared to the evening (18:00-21:00 hours) by 100%, 42%, and 24%, respectively, while postprandial plasma glucose and urea concentrations were not affected by time of the meal. When postprandial plasma concentrations were expressed as a response over preprandial concentrations (decremental or incremental area under the curve), the diurnal rhythm was not observed for cortisol and glucose, persisted for insulin and lactate, and appeared for urea with a smaller postprandial urea response (p<0.05) in the morning compared to the evening. We conclude that the diurnal rhythm in plasma cortisol is independent of feeding whereas the diurnal rhythms in plasma insulin, lactate and urea are unveiled by the morning/evening meals in pigs. At equal 12-h intervals between meals, the postprandial responses of lactate and urea show diurnal variations, each in a specific manner, which suggest decreased postprandial efficiency of carbohydrate metabolism and increased postprandial efficiency of protein metabolism in the morning compared to the evening.     

One-year efficacy and safety of inhaled formoterol dry powder in children with persistent asthma.

BACKGROUND: The long-term efficacy and safety of formoterol dry powder capsules for inhalation in pediatric asthma have not previously been evaluated. OBJECTIVE: We examined the effectiveness of inhaled formoterol over a period of 12 months in asthmatic children who were still symptomatic despite anti-inflammatory treatment. METHODS: After a run-in period, 518 patients (5 to 12 years old) were randomized in a double-blind manner to receive 12 or 24 microg formoterol dry powder (Foradil, Novartis Pharma AG, Basel, Switzerland) or placebo twice daily for 12 months. The drug was administered by inhaler (Aerolizer, Novartis Pharma AG) and was given in addition to their anti-inflammatory treatment. The primary variable was the area under the curve for forced expiratory volume in 1 second measured over 12 hours after the morning dose of study medication. RESULTS: The area under the curve for forced expiratory volume in 1 second after the first dose of treatment and after 3 and 12 months of treatment was significantly greater for patients receiving formoterol 12 microg and 24 microg than for patients receiving placebo (all P < or = 0.0062). Compared with placebo, both doses of formoterol significantly improved morning and evening premedication peak expiratory flow rate (all P < 0.001). In the group treated with formoterol 24 microg, median symptom score and median dose of rescue medication at night were lower than during the run-in period, whereas the opposite occurred in the placebo group. The incidence of hospitalizations for asthma was higher in the formoterol groups than in the placebo group. CONCLUSION: Our results indicate that, in asthmatic children who are still symptomatic despite anti-inflammatory therapy, the addition of formoterol consistently improves airflow obstruction and nocturnal symptoms and reduces the use of rescue medication. However, this treatment requires close disease monitoring to detect early signs of acute exacerbation.