Diurnal Cortisol Rhythm Research Articles

Hypothalamic-Pituitary-Adrenal Axis Recovery Following the 1-mg Overnight Dexamethasone Suppression Test in Healthy Volunteers.

BackgroundThe recovery of hypothalamic-pituitary-adrenal (HPA) axis suppression following pharmacological doses of various steroids has been studied previously. However, no study has been conducted using the more commonly used 1-mg dexamethasone in the overnight dexamethasone suppression test (ODST). Hence, we aimed at evaluating HPA axis recovery after the 1-mg ODST.ObjectivesThis study aimed at investigating the pattern and time of recovery of the HPA axis following the 1-mg ODST in healthy subjects.MethodsTen healthy volunteers aged 18 - 40 years, BMI < 30 kg/m2, with neither exposure to steroids nor interfering drugs were included. The 1-mg ODST was performed, and the adrenocorticotropic hormone (ACTH) and cortisol samples were withdrawn at regular intervals. The serum cortisol of < 1.8 µg/dL was considered as HPA axis suppression, whereas the cortisol value equal to or more than baseline was deemed as recovery.ResultsCortisol and ACTH levels were suppressed in all subjects 9 hours following the 1-mg ODST. Although ACTH showed an early increase after 8 hours, the upsurge was noticed following 24 hours (mean ± SD, 34.42 ± 18 pg/mL). Later, cortisol accompanied ACTH, and both reached their baseline after 72 hours (mean ± SD, ACTH, 37.48 ± 12.44 pg/mL; cortisol, 8.45 ± 3.32 μg/dL). A small dip in ACTH and cortisol (mean ACTH, 23.84 pg/mL; mean cortisol, 2.3 μg/dL) was observed after 24 - 36 hours indicating the return of the diurnal rhythm before complete recovery.ConclusionsThe complete recovery of the HPA axis occurs only 72 hours following the 1-mg ODST. ACTH begins to recover as early as 8 hours after the maximal suppression and diurnal rhythm of ACTH and cortisol resume 24 to 36 hours later.

Diurnal variation of salivary cortisol in captive African elephants (Loxodonta africana) under routine management conditions and in relation to a translocation event.

The present study assessed the diurnal variation in salivary cortisol in captive African elephants during routine management (baseline) and in relation to a potential stressor (translocation) to evaluate to what extent acute stress may affect diurnal cortisol patterns. Under baseline conditions, we collected morning and afternoon saliva samples of 10 animals (three zoos) on different days in two study periods (n = 3-10 per animal, daytime and period). Under stress conditions, we sampled the transported cow (newcomer) and the two cows of the destination zoo before and after the transport in the morning and afternoon (n = 3-9 per animal, daytime and transport phase), as well as after the first introduction of the newcomer to the bull (n = 1 per animal). Cortisol was measured in unextracted samples by enzyme immunoassay. Under baseline conditions, we observed the expected diurnal variation with higher cortisol levels in the morning than in the afternoon. Under stress conditions, neither a significant difference between pre- and posttransport, nor between morning and afternoon levels was found. The percentage difference between morning and afternoon cortisol after the transport, however, was remarkably lower than before the transport in the newcomer potentially indicating a stress response to familiarization. Saliva samples taken immediately after the introduction of the newcomer to the bull revealed a marked cortisol increase. Our findings indicate that stressors may disturb the diurnal cortisol rhythm. Furthermore, provided that samples can be collected promptly, salivary cortisol is a useful minimally invasive measure of physiological stress in the African elephant.

Dysregulation of Hypothalamic-Pituitary-Adrenal Axis Explain the Dynamic Association Between Glucose Fluctuation and Cognitive

Objective—Type 2 diabetes mellitus is a risk factor for cognitive dysfunction. However, the underlying mechanism of cognitive decline in patients with type 2 diabetes mellitus is still elusive. Dysregulation of HPA axis is related to cognitive impairment. The present study aims to calculate explanation of the association between glucose fluctuation and cognitive function by HPA axis in type 2 diabetes mellitus patients. Methods—The mean amplitude of glycemic excursion (MAGE) was analyzed by a continuous glucose monitoring system (CGMS) for 3 days in 330 elderly type 2 diabetes mellitus patients. All the subjects received a set of neuropsychological test battery for cognitive assessment. The diurnal rhythm of cortisol was also analyzed. Linear multivariate regression analysis was performed to explore the relationship between glucose fluctuation, cortisol parameters and cognitive parameters. Results—MAGE was observed to be associated with diurnal cortisol fall but with neither cortisol awakening response (CAR) nor overall mean cortisol levels (t = –2.195, P = 0.030). Linear multivariate regression analysis displayed that MAGE and average diurnal cortisol fall were uniquely associated with some cognitive parameters, such as AVLT trial, FAS, and TMT (P &lt; 0.05). Conclusion—Glucose fluctuation was strongly associated with cognitive impairment in elderly type 2 diabetes mellitus patients. Especially in executive function, attention and processing speed. Dysregulation of HPA axis was probably the cause of cognitive dysfunction in these patients.

Sleep Quality in Young Adult Informal Caregivers: Understanding Psychological and Biological Processes.

Providing informal care for a relative or friend with medical or mental needs can extol a physical burden on the caregiver, including impaired aspects of sleep quality such as suboptimal sleep duration, lengthened sleep latency, frequent awakenings, daytime sleepiness, and poor self-rated sleep quality. Diminished sleep quality can worsen the health in the caregiver, including dysregulation of hypothalamic-pituitary-adrenal axis (HPA) activity. Few studies have attempted to describe sleep in young adults who provide regular informal care. This study examines subjective and objective indicators of sleep quality and diurnal cortisol rhythms among young adult caregivers relative to non-caregiving peers. We expect that caregivers will exhibit poorer objective and subjective sleep quality and greater dysregulation in diurnal cortisol indices, than demographically similar non-caregivers, and that caregivers with poorer sleep will exhibit pronounced cortisol dysregulation. Participant self-reported sleep quality over the prior month via the Pittsburgh Sleep Quality Index and objective sleep quality was observed via wrist actigraph for three consecutive days. Diurnal salivary cortisol was also measured across the three days of actigraph monitoring. Informal caregivers exhibited more self-reported sleep disturbance and greater sleep latency than non-caregivers, as well as more objectively measured sleep fragmentation. Caregivers with a shorter sleep duration were observed to have flatter diurnal cortisol slopes than caregivers with a relatively longer sleep duration. Young adult caregivers appear to be at risk for impairment in sleep quality, which in turn might impact health through HPA axis dysregulation. Longitudinal research is needed to identify these relationships across time.

The effect of saliva stimulation on the secretion of cortisol during stress and physiological conditions.

Many studies use stimulated saliva for the assessment of cortisol. However, it is not yet clear how stimulation affects the flow of specific markers. The aim was to assess whether stimulation of salivation affects the physiological flow of cortisol during a stressing day as compared to an ordinary day. The second aim was to show how the normalising factor affects the outcome of the study. Stimulated saliva was taken from 42 children at 8:00 a.m. and 12:00 a.m. on two separate days one month apart. During the first day, the children were exposed to stress situation, while the second day was considered acontrol day. The concentration of cortisol was analysed using ELISA. The highest level of cortisol was observed in the morning of the stress day (p 0.99). Based on our results, the examination of the cortisol diurnal rhythm is not reliable in stimulated saliva. Moreover, the effect of saliva stimulation has to be taken into account for every marker individually (Fig. 2, Ref. 22).

The association between abuse history in childhood and salivary rhythms of cortisol and DHEA in postmenopausal women

A history of child abuse (CA) is associated with morbidity and mortality in adulthood, and one proposed mechanism is dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Therefore, we evaluated whether a history of physical and sexual CA was associated with daily rhythms of HPA hormones (cortisol and dehydroepiandrosterone (DHEA)) among postmenopausal women (mean age: 60.6 years). In 2013, 233 participants from the Nurses’ Health Study II provided up to 5-timed saliva samples over the course of a day: immediately upon awakening, 45 min, 4 h, and 10 h after waking, and prior to going to sleep. Among these 233 participants, 217 provided ≥4 timed saliva samples. Assessment of physical and sexual CA history occurred in 2001 using the Revised Conflict Tactics Scale. Cumulative CA history was derived by combining reports of physical and sexual abuse prior to age 18. Piecewise linear mixed models compared diurnal rhythms of cortisol and DHEA between participants with none-to-moderate CA (n = 104, reference group) versus high-to-severe CA (n = 113). Models adjusted for characteristics at each saliva collection, health status, sleep quality, medications, and hormone use. Compared to those with none-to-moderate CA, women with high-to-severe CA had different diurnal rhythms in the early and evening hours, including blunted (less steep) early declines in DHEA (% difference (%D) = 10.7, 95 % Confidence Interval (CI) 4.3, 17.5), and steeper late declines in both cortisol and DHEA (cortisol %D = -2.5, 95 % CI -4.8, -0.1, and DHEA %D= -3.9, 95 % CI -6.0, -1.8). In conclusion, high-to-severe abuse history prior to age 18 was more strongly associated with differences in DHEA rather than cortisol, suggesting that early life abuse may be related to dysregulation of stress-response mechanisms later in life.

EFFECTS OF AN ART GALLERY INTERVENTION IN PEOPLE LIVING WITH DEMENTIA: A PILOT STUDY

Art gallery programs tailored to the needs of people living with dementia are becoming more popular worldwide. This study aimed to observe the effects of six consecutive weekly discussion-based small group visits to the National Gallery of Australia Art and Dementia program on the salivary cortisol (SC) diurnal rhythm, salivary interleukin-6, quality of life (QoL), depressive symptoms, and cognitive function. Twenty-five participants (17 female; mean age 84.6 ± 7.27 years) completed the study with data collection at baseline, post-intervention, and at a six-week follow-up. Statistical methods were selected based on data distribution. The waking to evening (WE) SC ratio was altered (p = 0.016) (Baseline: 1.35 (1.19, 1.64), Post-intervention: 1.72 (1.54, 1.96), Follow-up: 1.44 (1.22, 1.79)) in the 22 participants who provided viable saliva samples. The WE SC ratio was higher post-intervention compared with baseline (p = 0.011), indicating a more dynamic SC rhythm, but returned to baseline levels at follow-up (p = 0.020). Interleukin-6 levels were unchanged (p = 0.664). In the total sample, no improvements in QoL (Proxy) (p = 0.165) were observed. However, self-reported depressive symptoms differed (p = 0.006), decreasing post-intervention (2.00 (1.00, 2.00)) compared with baseline (3.00 (2.00, 4.50)) (p = 0.015), and verbal fluency was affected (p = 0.027), improving from baseline (2.00 (0.00, 3.00)) to post-intervention (2.00 (0.50, 4.00)) (p = 0.027). Art and Dementia programs appear to have quantifiable benefits, including improved hypothalamic-pituitary-adrenal axis function, justifying a longer controlled trial inclusive of physiological outcomes.

Diurnal rhythms of cortisol and melatonin in night eating and non-night eating male police officers

Abstract Background Working during the night has in previous studies been associated with behavioural changes and diseases. Disturbance between behavioural and biological circadian rhythms have been suggested as a possible mechanism linking night work with cardiovascular diseases and pre-diabetic changes. The aim of this study was to investigate if night eating during two, four and seven consecutive night shifts is associated with differences in the diurnal rhythms of cortisol and melatonin in male police officers in Denmark. Methods We conducted an experimental study among 37 male police officers in Denmark who all collected data on the last night shift in three different work schedules with two, four and seven consecutive night shifts, respectively. Night eating was self-reported and defined as eating at least one main meal between midnight and early morning. Differences in the diurnal rhythms of concentrations of cortisol and melatonin in saliva were tested by phase changes and amplitude differences. Results Sixteen (43.2%) police officers ate a main meal during the last night shift in all three work schedules. The timing of the lowest cortisol concentration was on average delayed with 2:10 hours (95% CI 0:24-3:56 hours) and the level of the lowest cortisol concentration was on average supressed with 66% (95% CI 47-94%) for night eaters compared to non-night eaters. There was no association with number of consecutive night shifts. The phase and amplitude of melatonin were not statistically significantly different between night eaters and non-night eaters. Conclusions Night eating behaviour is associated with differences in the diurnal rhythm of cortisol in Danish male police officers working during the night. The difference in cortisol rhythm between night eaters and non-night eaters on night shifts is not affected by the number of consecutive night shifts. Key messages Night eating behaviour is associated with differences in the diurnal rhythm of cortisol. Future studies should focus on potential health outcomes of night eating behaviour among night workers.

Experiences of adversity in childhood and adolescence and cortisol in late adolescence

Early life adversity influences the diurnal cortisol rhythm, yet the relative influence of different characteristics of adversity remains unknown. In this study, we examine how developmental timing (childhood vs. adolescence), severity (major vs. minor), and domain of early life adversity relate to diurnal cortisol rhythms in late adolescence. We assessed adversity retrospectively in early adulthood in a subsample of 236 participants from a longitudinal study of a diverse community sample of suburban adolescents oversampled for high neuroticism. We used multilevel modeling to assess associations between our adversity measures and the diurnal cortisol rhythm (waking and bedtime cortisol, awakening response, slope, and average cortisol). Major childhood adversities were associated with flatter daily slope, and minor adolescent adversities were associated with greater average daily cortisol. Examining domains of childhood adversities, major neglect and sexual abuse were associated with flatter slope and lower waking cortisol, with sexual abuse also associated with higher cortisol awakening response. Major physical abuse was associated with higher waking cortisol. Among adolescent adversities domains, minor neglect, emotional abuse, and witnessing violence were associated with greater average cortisol. These results suggest severity, developmental timing, and domain of adversity influence the association of early life adversity with stress response system functioning.

Ethnic differences in diurnal cortisol profiles in healthy adults: A meta-analysis.

Cortisol is a well-known biomarker of the physiological stress system; atypical cortisol patterns have been linked to many psychological and physiological illnesses. Previous studies have found vast health disparities among ethnic groups; however, studies examining the relationship between cortisol and ethnicity have found mixed results. This meta-analysis investigated whether there are differences in diurnal cortisol outcomes among ethnic groups, while considering the moderating roles of various individual factors and methodological approaches. Search phrases were entered into MEDLINE, PsycINFO, EMBASE, Cochrane Library, CINAHL, Scopus, and Web of Science. Effect sizes were extracted for ten diurnal cortisol outcomes, including waking, 30min after waking, cortisol awakening response, slope, area under the curve, urinary twenty-four-hour secretion, total cortisol output, and midday, evening, and bedtime concentrations, for eight ethnic group comparisons, including Asians, Blacks, Hispanics, Indigenous people, Whites, Minority and Majority groups, and Multiethnic groups. Moderator analyses, including variables such as gender, age, and number of cortisol collection time points, were conducted. There were significant ethnic differences in diurnal cortisol profiles, including cortisol awakening responses, with more robust differences in ethnic comparisons that included White participants. Differences in diurnal cortisol profiles were also moderated by gender, mean age, and sample size. This meta-analysis supports the notion that ethnic groups exhibit distinct diurnal cortisol profiles, which, according to the biopsychosocial model of health, may be a result of unique sociocultural experiences. The limitations of this meta-analysis and future directions for stress research with various ethnic groups are discussed. Statement of contribution What is already known on this subject? Studies have found vast health disparities among ethnic groups. Psychological and physiological illnesses and atypical diurnal cortisol profiles are strongly correlated. Studies have examined the relationship between diurnal cortisol rhythms and ethnicity, but findings are mixed. What does this study add? This study is a systematic examination of the relationship between diurnal cortisol rhythm and ethnicity. Psychosocial and methodological factors moderate the relationship between diurnal cortisol output and ethnicity. This study provides insight on factors that contribute to health disparities among ethnic groups.

Obesogenic Alterations in Adrenal Function and Neurotransmitter Balance Improved with Dietary Supplementation (P21-008-19)

ObjectivesDysfunction of the HPA axis, as evidenced by alterations in the diurnal salivary cortisol rhythm, has been shown to contribute to the pathophysiology of obesity both directly by skewing body composition and indirectly by altering appetite and microbiome. The aim of this study was to assess the impact of a laboratory and clinical-guided dietary supplemental protocol on HPA axis dysfunction. MethodsThis study examines a cohort of 703 patients utilizing a clinical analysis of 1. Hypothalamic-pituitary-adrenal axis tests which were 4 point salivary cotisol, 2 point salivary DHEA, and 6 urinary neurotransmitters. 2. Self-reported Quality of Life questionnaire 3. Personalized dietary supplementation with neurotransmitter amino acid precursors and/or adrenal support monitored for 8 months. ResultsPre and post test demonstrated improved sleep quality (47%, P < 0.05); increased serotonin by 172% (P < 0.05); increased norepinephrine (P < 0.05); improved adrenal tone with increased morning cortisol (P < 0.05) and decreased evening cortisol (P < 0.08). ConclusionsA personalized medicine approach consisting of symptom analysis, noninvasive laboratory testing and dietary supplementation improved parameters of HPA axis dysfunction. Lab-guided personalized medicine may be able to diagnose early and treatable HPA axis dysfunction and in this way curtail a known pathway to obesity. Funding SourcesNo grant funding was received. The research is an IRB-exempted analysis of data collected by Sanesco International, Inc. Supporting Tables, Images and/or Graphs▪

SUN-LB061 Midnight Salivary Cortisol (MiSC): Diagnostic Concordance in a Normal Sample Population Using Different Immunoassays

Salivary cortisol (SC) is a measure of free cortisol and follows diurnal rhythm of serum or plasma cortisol, so it is convenient for collection noninvasively on an outpatient basis. The Endocrine Society recommends measuring MiSC concentrations as a first-line test in screening for Cushing's syndrome. To define its utility as a diagnostic test, it is important to know whether assay techniques or thresholds affect the rate of false-positive results. Revision of literature showed that there are marked differences in sensitivity and specificity, and cutoff values of SC assays. The aim of this study was to compare MiSC results obtained by available immunoassays with different analytical sensitivity (AS) in an Argentinian population, and compare by pairs of methods their Diagnostic Concordance (DC) using individual reported cutoffs (RCO). Material and methods: Salivary samples obtained at 11 PM, from 133 adults subjects (18-74 years), with no corticoid therapy (last 6 months), psychiatric medication, depression, thyroid diseases, statins administration, or smoking. MiSC (nmol/L) were measured by ECLIA Cobas Roche (RCO: 4.9; AS: 1.5); RIA Beckman Coulter (RCO: 0.8; AS: 0.8), CLIA Liaison DiaSorin (RCO: 8.0; AS: 4.4), CLIA Access Beckman Coulter (RCO: 8.3; AS: 0.3) and CLIA Immulite 1000 Siemens (modified methodic) (RCO: 5.0 own data not reported; AS: 1.0). Bland & Altman biases were calculated between methods. Results: Calculated median, range and p95 (nmoL/L) for each method were: ECLIA Cobas (n=131): 1.6 (1.5-14.5) 6.4; RIA (n=90): 1.33 (0.8-7.7) 3.6, CLIA Liaison (n=126): 4.4 (8.4-22.1) 8.2, CLIA Access (n= 125): 4.1 (0.3-28) 15.6, and CLIA Immulite1000 (n: 99): 2.5 (1.4-20) 7.6. Calculated p95 was higher than RCO in all methods, being RIA the highest. ANOVA analysis for paired samples measured by all methods showed significant (p<0.005) differences except for Access and Liaison (p=1,000). Biases (nmol/L) obtained were: Cobas vs Immulite = -1; Access vs Cobas = 3.2; Cobas vs Liaison = -2.8; Cobas vs RIA = 0.9; Access vs Immulite = 2.4; Immulite vs Liaison = -1.8; Access vs Liaison = 0.3; Access vs RIA = 4.1; Liaison vs RIA = 3.6; Immulite vs RIA = 1.9. Lowest bias found was between Access and Liaison, result coincident with ANOVA. %DC between pairs of methods using RCOs was: Cobas vs Immulite = 87%; Access vs Cobas= 84%; Cobas vs Liaison = 95%; Cobas vs RIA = 64%; Access vs Immulite = 85%; Immulite vs Liaison = 90%; Access vs Liaison = 84%; Access vs RIA= 72%; Liaison vs RIA = 63%; Immulite vs RIA = 70%. Lowest %DC was found when RIA was involved in the comparison, which could be due to its low AS and RCO that are the same. Conclusions: Differences in %DC observed could be due to not only differences between methods but differences in composition of the population studied. Validating MiSC cutoff values in individual laboratories is important for good clinical use of results in the diagnosis and follow-up of Cushing’s syndrome. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

SUN-058 Concurrent Hypercortisolism in Primary Aldosteronism Patients at a Tertiary Care Center: 2007-2017

Background: Primary aldosteronism patients often have co-morbidities, such as diabetes mellitus and osteopenia/osteoporosis, that are consistent with states of cortisol dysregulation. Recent studies have alluded to co-secretory adrenal states. Methods: Subjects were evaluated under an IRB-approved protocol. Patients seen between 2007 and 2017 identified as having primary aldosteronism with meeting one of the following criteria: saline suppression test with 4-hr aldosterone value >10 ng/dl, 24-hr urinary aldosterone >14mcg/24 hrs on unrestricted salt diet, or prior diagnosis of primary aldosteronism. Abnormal cortisol status was defined as evening diurnal cortisol >1.8 mcg/dl, urinary free cortisol >50mcg/24 hrs, dexamethasone suppression test with post-test cortisol >1.8 mcg/dl, 8mg dexamethasone suppression test with failure to suppress cortisol >68%, or 6-day Liddle’s test (if done) with failure to suppress urinary free cortisol >90% over 6 days or 17-hydroxysteroid >69%. Data are reported as frequencies and percentages, or mean ±standard deviation. Results: The cohort seen between 2007 and 2017 consisted of 130 patients (mean age=49.7±11.5 yrs; 46% female; mean BMI=31.4±6.5). Self-reported race was 46% black, 35% white, 6% Asian, 5% multi-racial, and 8% unknown. At study visit, mean Hemoglobin A1c was 5.9%±1.2. Aldosterone value at 4-hour time point of saline suppression test was 28.8 ± 37.7ng/dl, and 24-hour urinary aldosterone mean was 63.5±54.9mcg/24 hrs. Loss of diurnal cortisol rhythm was seen in 90% (98/109) of patients. 24-hour urinary free cortisol values were elevated in 18% (19/103) patients. 1mg or 2mg dexamethasone suppression test was performed in 63 patients, with 9 (14%) patients with failure to suppress cortisol. 8mg dexamethasone suppression test was performed in 61 patients, with 5 (8%) patients failing to suppress cortisol by >68%. 53 patients underwent the 6-day Liddle’s test, with 52% (13/25) failing to suppress urinary free cortisol by >90%, and 87% (20/23) failing to suppress 17-hydroxysteroids by >69%. Conclusions: The majority of primary aldosteronism patients seen between 2007-2017 demonstrate loss of diurnal cortisol rhythm. Some met criteria for hypercortisolemia, with elevated 24-hour urinary free cortisol or failure to suppress on dexamethasone suppression test, or failure to suppress 17-hydroxysteroids on 6-day Liddle’s test. This is suggestive of autonomous adrenal cortisol secretion, which may explain the detrimental co-morbidities seen in these patients and has implications for the need for earlier diagnosis and treatment and may be an area of further study.

Early-life adversity and dysregulation of adult diurnal cortisol rhythm

Pubertal immune challenge can permanently alter hippocampus-dependent memory processes in a sex-specific manner. Although gonadal hormones can influence various cognitive processes, their role in regulating the cognitive sequelae to pubertal immune challenge has not been thoroughly assessed. We examined whether a pubertal immune challenge could affect hippocampus-dependent memory functions in adulthood and whether these effects are regulated by gonadal steroid hormones. We hypothesized that exposure to an immune challenge during puberty would induce sex-specific deficits in the behavioral and cellular correlates of hippocampus-dependent memory during adulthood. At six weeks of age, during the stress-vulnerable pubertal period, male and female CD-1 mice were injected with either saline or the bacterial endotoxin lipopolysaccharide (LPS). Three weeks later, mice underwent either gonadectomy or sham-surgery. At ten weeks of age (i.e., in adulthood), mice began behavioral testing in an open field, Barnes maze, and Morris water maze. Brain tissue was collected at 17 weeks of age and stained for doublecortin and Ki67 to examine migrating neuronal progenitor cells and cellular proliferation in the neurogenic subgranular zone (SGZ) and the cornus ammonis (CA)1 and CA3 regions of the hippocampus. Pubertal LPS treatment impaired learning during adulthood in both sexes and increased cellular proliferation in the CA1 region in castrated males only. Although adult sex hormones did not reliably modulate these changes, gonadectomy impaired learning during the Morris water maze in both sexes. Learning deficits were more prominent during the Barnes maze, which suggests a stress-dependent expression of LPS-induced cognitive deficits. Neurogenesis in the SGZ and cellular proliferation in the CA3 were not affected by pubertal LPS treatment or gonadectomy. These novel findings emphasize the sensitivity of developing cognitive processes during puberty to immune challenges and suggest a possible mechanism for learning-based difficulties in adulthood.

Exploring Diurnal Cortisol Rhythms of Kindergarten Teachers in Kosovo and Ukraine.

Teachers' stress is a dynamic combination of the individual teacher's characteristics and characteristics of the classroom and school environment. To date, there are limited studies on teachers' stress in the context of lower-middle-income countries (LMICs), where working conditions as well as general political and economic circumstances might pose a considerable threat for teachers' well-being. This study explores whether certain combinations of individual and environmental experiences of teachers in LMICs may result in stress, assessed as patterns of diurnal cortisol rhythm. Participants were kindergarten teachers in Kosovo and Ukraine, two LMICs in Europe. Latent Profile Analysis identified three subgroups of teachers that significantly differed on teachers' education and experience. Preliminary results of Latent Growth Modeling suggested differences between profiles in baseline waking cortisol and patterns of diurnal decline. Teachers in the profile that was characterized by the longest experience working in the field but the lowest level of education showed blunted cortisol in the morning and a flatter slope; a pattern that could indicate a maladaptive cortisol response. Future directions for studying stress processes among teachers in LMICs and implications for policy and practice on how to support teacher well-being in low-resource contexts are discussed.

A Clinical Study on the Circadian Rhythm of Salivary Cortisol on Aggressive Periodontitis and Its Correlation with Clinical Parameters using Electrochemiluminescence Immunoassay Method

Periodontal pathologies are gaining importance as there is a clear indication of bi-way control on general homeostasis of an individual. The study of HPA axis in various diseases has proved that there is evident vulnerability existing for any organism when the Cortisol diurnal rhythm is altered. The aim was to compare the diurnal rhythm of salivary cortisol in aggressive periodontitis with control patients. This study also compared various parameters like body mass index (BMI), waist circumference, Hamilton anxiety scale, OHI-S, clinical attachment loss in aggressive periodontitis. 30 control patients were compared against 30 aggressive periodontitis patients in Salivary cortisol diurnal rhythm. It was estimated using the electrochemiluminescence (ECL) method on a 3 point analysis-Soon after waking up, 30 minutes after waking up, 1 hour before sleep to see the diurnal variation in aggressive periodontitis patients. The samples were transferred to CABRI labs to be frozen to -20°C. The analysis was done using Cobas e-411 autoanalyzer by Roche, USA. The average cortisol in aggressive patients was found to be higher compared to control patients and was found to be statistically significant with a p value of 0.012. Control group is moderately skewed left (negative skewness graph) while the aggressive p periodontitis patients showed moderately skewed right (+ve skewness graph). The cortisol awakening response seen in control patients is not observed in aggressive periodontitis. Instead of giving a surge, the cortisol showed a dip in the first 30 minutes followed by a gradual increase in aggressive periodontitis instead of decline as observed in normal patients. The study will focus on the importance of cortisol circadian rhythm on periodontal health allowing the microorganism to create an environment of dysbiosis.

The Effects of Naturalistic Light on Diurnal Plasma Melatonin and Serum Cortisol Levels in Stroke Patients during Admission for Rehabilitation: A Randomized Controlled Trial.

Background: Stroke patients admitted for rehabilitation often lack sufficient daytime blue light exposure due to the absence of natural light and are often exposed to light at unnatural time points.We hypothesized that artificial light imitating daylight, termed naturalistic light, would stabilize the circadian rhythm of plasma melatonin and serum cortisol levels among long-term hospitalized stroke patients.Methods: A quasi-randomized controlled trial. Stroke patients in need of rehabilitation were randomized between May 1, 2014, and June 1, 2015 to either a rehabilitation unit equipped entirely with always on naturalistic lighting (IU), or to a rehabilitation unit with standard indoor lighting (CU). At both inclusion and discharge after a hospital stay of at least 2 weeks, plasma melatonin and serum cortisol levels were measured every 4 hours over a 24-hour period. Circadian rhythm was estimated using cosinor analysis, and variance between time-points.Results: A total of 43 were able to participate in the blood collection. Normal diurnal rhythm of melatonin was disrupted at both inclusion and discharge. In the IU group, melatonin plasma levels were increased at discharge compared to inclusion (n = 23; median diff, 2.9; IQR: -1.0 to 9.9, p = 0.030) and rhythmicity evolved (n = 23; p = 0.007). In the CU group, melatonin plasma levels were similar between discharge and inclusion and no rhythmicity evolved. Overall, both patient groups showed normal cortisol diurnal rhythms at both inclusion and discharge.Conclusions: This study is the first to demonstrate elevated melatonin plasma levels and evolved rhythmicity due to stimulation with naturalistic light.

Hypothalamic-pituitary-adrenal axis differentially responses to morning and evening psychological stress in healthy subjects.

AimThe hypothalamic‐pituitary‐adrenal (HPA) axis responds to changing environmental demands including psychological stressors. The aim of the present study was to assess whether the time of day effects on the acute response of HPA axis activity to acute psychological stress.MethodWe studied 27 healthy young subjects. The subjects were participated two experiments as follows. In the first experiment, subjects were instructed to keep their regular sleep schedule for 2 weeks which were measured by using a wrist‐worn activity monitor. Afterward, to evaluate a diurnal rhythm of salivary cortisol, eight saliva samples were collected during waking period every 2 hours from when the subjects woke up. In the second experiment, the subjects were randomly assigned to two groups. The Trier Social Stress Test (TSST) was performed either in the morning (n = 14) or in the evening (n = 13). We measured diurnal rhythm of salivary cortisol and stress response of salivary cortisol and heart rate by the TSST. Morning and evening tests were started at 2 hours and 10 hours after woke up, respectively.ResultsAll subjects showed a normal diurnal rhythm of salivary cortisol concentration, with a peak in the morning immediately after awaking and a minimum in the evening. The salivary cortisol response after the TSST was significantly increased from the prestress level in the morning but not in the evening.ConclusionThe HPA response to acute psychological stress was more pronounced in the morning than in the evening, correlating with the circadian regulation of cortisol synthesis.

Effects of feeding frequency during lactation in primiparous sows on reproduction performance and diurnal rhythm of endocrine profiles at the weaning-to-ovulation interval

ABSTRACTWhether the diurnal rhythm of endocrine hormones in sows are affected by feeding frequency remains to be studied. The present study was conducted to investigate the effects of feeding frequency during lactation in primiparous sows on the diurnal rhythm of glucose, insulin, cortisol and luteinizing hormone (LH) levels during the weaning-to-ovulation interval, as well as their reproductive efficiency. Sixty primiparous Landrace × Yorkshire sows were randomly assigned into two groups during lactation: one treatment received feed twice daily and another treatment three times daily. The results showed that feeding the sows three times daily during lactation decreased weaning-to-estrus interval and lowered the return to estrus rates when compared with feeding the sows twice daily. We observed the diurnal rhythms in glucose, insulin and cortisol level in sows at the weaning-to-ovulation interval, and the daily variations were affected by the feeding frequency during lactation and the LH surge. Our results indicated that the alternation of reproductive performance of sows by feeding frequency may mediate by its effects on the diurnal rhythm of glucose, insulin and cortisol.

Reduced Slow-Wave Sleep and Altered Diurnal Cortisol Rhythms in Patients with Addison's Disease.

Cortisol plays a key role in initiating and maintaining different sleep stages. Patients with Addison's disease (AD) frequently report disrupted sleep, and their hydrocortisone medication regimes do not restore the natural diurnal rhythm of cortisol. However, few studies have investigated relations between sleep quality, especially as measured by polysomnographic equipment, and night-time cortisol concentrations in patients with AD. We used sleep-adapted EEG to monitor a full night of sleep in 7 patients with AD and 7 healthy controls. We sampled salivary cortisol before bedtime, at midnight, upon awakening, and at 30-minutes post-waking. Controls had lower cortisol concentrations than patients before bedtime and at midnight. During the second half of the night, patient cortisol concentrations declined steeply, while control concentrations increased steadily. Whereas most controls experienced a positive cortisol awakening response, all patients experienced a decrease in cortisol concentrations from waking to 30-minutes post-waking (P = .003). Patients experienced significantly lower proportions of slow-wave sleep (SWS; P = .001), which was associated with elevated night-time cortisol concentrations. Overall, these results suggest that patients with AD demonstrate different patterns of night-time cortisol concentrations to healthy controls, and that relatively elevated concentrations are associated with a reduction of SWS. These hormonal and sleep architectural aberrations may disrupt the routine sleep-dependent processes of memory consolidation, and hence may explain, at least partially, the memory impairments often experienced by patients with AD.