Cortisol Dynamics Research Articles

Diurnal Cortisol Dynamics, Perceived Stress, and Language Production in Aphasia.

Purpose The current study investigated diurnal cortisol dynamics in adults with and without aphasia, along with subjective reports of stress and measures of language production. Dysregulation of cortisol, a common biomarker of stress, is associated with cognitive dysfunction in different clinical populations. However, little is known about the consequences of stress-induced cortisol disturbances for stroke survivors, including those with aphasia. Method Nineteen participants with aphasia and 14 age-matched neurotypical adults were tested. Saliva samples were collected from participants to assess the cortisol awakening response, a marker of the integrity of the hypothalamic-pituitary-adrenal (HPA) axis. Participants also completed 2 subjective stress questionnaires. Language was evaluated using 3 short, picture description narratives, analyzed for discourse (dys)fluency and productivity markers. Results In contrast to neurotypical participants, adults with aphasia did not show the predictable cortisol awakening response. Participants with aphasia also showed an unusual heightened level of cortisol upon awakening. Additionally, neurotypical participants demonstrated an association between intact language performance and the cortisol awakening response, whereas the participants with aphasia did not, although they did perceive the language tasks as stressful. Conclusion This study indicates that the functionality of the HPA axis, as indexed by cortisol, contributes to optimal language performance in healthy adults. The absence of an awakening response among participants with aphasia suggests that stroke leads to dysregulation of the HPA axis, although the degree to which this impairment affects language deficits in this population requires further investigation.

Acute psychosocial stress increases serum BDNF levels: an antagonistic relation to cortisol but no group differences after mental training.

Brain-derived neurotrophic factor (BDNF) is an essential facilitator of neuronal plasticity. By counteracting the adverse effects of excessive stress-induced glucocorticoid signaling, BDNF has been implicated as a resilience factor to psychopathology caused by chronic stress. Insights into the effects of acute stress on peripheral BDNF levels in humans are inconclusive. The short-term interplay between BDNF and cortisol in response to acute psychosocial stress remains unexplored. Furthermore, it is unknown whether mental training that is effective at reducing cortisol reactivity can also influence BDNF during acute stress. In the current study, we investigated serum BDNF levels during an acute psychosocial stress paradigm, the Trier Social Stress Test (TSST), in 301 healthy participants (178 women, mean age = 40.65) recruited as part of the ReSource Project, a large-scale mental training study consisting of three distinct 3-month training modules. Using a cross-sectional study design, we first examined the relationship between BDNF and salivary cortisol in a control group with no mental training. Subsequent analyses focused on differences in BDNF stress levels between control and mental training groups. We show that serum BDNF is indeed stress-sensitive, characterized by a significant post-stress increase and subsequent decline to recovery. While respective increases in BDNF and cortisol were not associated, we found two indications for an antagonistic relationship. Higher BDNF peaks after stress were associated with steeper cortisol recovery. On the other hand, the magnitude of the cortisol stress response was linked to steeper BDNF recovery after stress. BDNF levels were not modulated by any of the mental training modules. Providing novel evidence for the dynamics of BDNF and cortisol during acute stress, our findings may further inform research on the physiological mechanisms involved in stress chronification and the associated health risks.

Dynamics of salivary cortisol and testosterone during competition stress in alpine skiing in adults and children

Dynamics of salivary cortisol and testosterone during competition stress in alpine skiing in adults and children

A novel measure of glucose homeostasis (or loss thereof) comprising the joint dynamics of glucose, insulin, glucagon, and cortisol.

Quantification of disturbances in glucose-insulin homeostasis has been the cornerstone of appraising insulin resistance and detecting early-stage diabetes. Metabolic homeostasis arises from feedback and feed-forward interactions among (at least) all four of glucose, insulin, glucagon, and cortisol. Quantifying such tetrapartite interactions in the fasting (endogenously regulated) state overnight could elucidate very early regulatory disruption. In the present study, healthy subjects without diabetes (ND; n = 20) and patients with Type 2 diabetes (T2D; n = 21) were investigated by repeated overnight blood sampling of all four of glucose, insulin, glucagon, and cortisol concentrations. To obviate confounding by hormone-specific disappearance rates, analyses were performed at the level of production (glucose) or secretion (insulin, glucagon, and cortisol) rates estimated by regularized deconvolution analysis. Then, a novel method for quantifying the loss of homeostasis among glucose, insulin, and glucagon (and, when available, cortisol) secretion patterns was developed. Potential early stage prediabetic candidates were identified. The new methodology avoids many of the difficulties encountered in the conventional estimation of insulin-glucose sensitivity or resistance, while incorporating the dynamics of the key coregulators under fasting conditions.

BDNF Val66Met genotype moderates the impact of rumination on cortisol awakening response and subjective well-being

The cortisol awakening response (CAR) is a well-established biomarker for the integrity of the hypothalamic-pituitary-adrenal (HPA) axis in healthy as well as clinical samples. Cortisol rise during the first 60 min after awakening is often used as a proxy of HPA axis regulation in health and disease. Ultradian pulsatility of cortisol is known to superimpose its circadian rhythmicity with the CAR being the first rise after awakening. However, the exact length of the complete first pulse (rise and fall) after awakening, as well as the association between the CAR, the complete first pulse, and successive ultradian pulses, has not yet been studied systematically.Aim of this study was to investigate cortisol dynamics after awakening beyond the standard assessment duration of 60 min in order to assess the cortisol awakening pulse, in relation to ultradian rhythmicity of cortisol after awakening. In a sample of 51 healthy participants, salivary cortisol was collected for the first 270 min after awakening in intervals of 30 min, on two separate days. Different parameters describing individual cortisol pulses over time with respect to inter- and intraindividual variations such as duration, amplitude and area under the curve (AUC) were calculated. Special emphasis was put on the first rise and fall after awakening, called the cortisol awakening pulse (CAP).Mean duration of the CAP was 108 min with high interindividual differences. Duration of first and second pulse were associated with subject’s sex and menstrual cycle status, with a longer first pulse and an attenuated second pulse in male and female subjects in the luteal phase, compared to female subjects in the follicular phase, or women taking oral contraceptives.These results point to the potential usefulness of a longer sampling period for assessing ultradian pulsatility of cortisol in the morning, especially the CAP. To assess the complete pulse rather than the rise alone, measurement of cortisol levels after awakening for 120 min is recommended.

АНЕСТЕЗИОЛОГИЧЕСКОЕ ОБЕСПЕЧЕНИЕ РАДИКАЛЬНОЙ МАСТЭКТОМИИ И ДИНАМИКА СОДЕРЖАНИЯ КОРТИЗОЛА, ТИРЕОТРОПНОГО ГОРМОНА, ТИРОКСИНА В ПЛАЗМЕ КРОВИ

Background. The dynamics of cortisol, thyroid-stimulating hormone (TSH), thyroxine (T4) in radical mastectomy (RM) has not been sufficiently studied. Objective. Determine the dynamics of the content of cortisol, TSH and T4 in patients with RME using two methods of anesthesia. Metherial and Methods. 52 patients underwent RM. Anesthesia in group 1 (n=14) - general anesthesia (GA), in group 2 (n=38) - GA and paravertebral blockade (PVB). The study was conducted in 4 stages: 1 - admission to the operating room; 2 - 30 min after the start of the operation; 3 - 2 h after the operation; 4 - 20-24 h after surgery. Results. In groups 1 and 2, cortisol levels increased in step 3 (p 0,05). Conclusion. In the conditions of GA with PVB, an increase in TSH is 1.55 times. When RM in the conditions of GA and GA with PVB, the content of cortisol does not increase.

The duration of the cortisol awakening pulse exceeds sixty minutes in a meaningful pattern

The cortisol awakening response (CAR) is a well-established biomarker for the integrity of the hypothalamic-pituitary-adrenal (HPA) axis in healthy as well as clinical samples. Cortisol rise during the first 60 min after awakening is often used as a proxy of HPA axis regulation in health and disease. Ultradian pulsatility of cortisol is known to superimpose its circadian rhythmicity with the CAR being the first rise after awakening. However, the exact length of the complete first pulse (rise and fall) after awakening, as well as the association between the CAR, the complete first pulse, and successive ultradian pulses, has not yet been studied systematically.Aim of this study was to investigate cortisol dynamics after awakening beyond the standard assessment duration of 60 min in order to assess the cortisol awakening pulse, in relation to ultradian rhythmicity of cortisol after awakening. In a sample of 51 healthy participants, salivary cortisol was collected for the first 270 min after awakening in intervals of 30 min, on two separate days. Different parameters describing individual cortisol pulses over time with respect to inter- and intraindividual variations such as duration, amplitude and area under the curve (AUC) were calculated. Special emphasis was put on the first rise and fall after awakening, called the cortisol awakening pulse (CAP).Mean duration of the CAP was 108 min with high interindividual differences. Duration of first and second pulse were associated with subject’s sex and menstrual cycle status, with a longer first pulse and an attenuated second pulse in male and female subjects in the luteal phase, compared to female subjects in the follicular phase, or women taking oral contraceptives.These results point to the potential usefulness of a longer sampling period for assessing ultradian pulsatility of cortisol in the morning, especially the CAP. To assess the complete pulse rather than the rise alone, measurement of cortisol levels after awakening for 120 min is recommended.

Associations of ambivalent leadership with distress and cortisol secretion.

Ambivalent social ties, i.e., whereby a relationship is evaluated simultaneously in positive and negative terms, are a potential source of distress and can perturb health-relevant biological functions. Social interactions at the workplace, in particular with supervisors, are often described in ambivalent terms, but the psychological and psychobiological impact of such interactions has received little scientific attention. The current study examined associations between ambivalent attitudes towards one's supervisor, perceived distress (general and work-related), and diurnal dynamics of the stress hormone cortisol. 613 employees evaluated their supervisor in terms of positive and negative behaviors, which was combined into an ambivalent index. Higher ambivalence was associated with higher perceived distress and work-related stress (p < .001), and with a larger cortisol awakening response and higher day-time secretion post-awakening (p < .01). The present study is the first to identify ambivalence towards supervisors as a predictor of employee distress and stress-related endocrine dysregulation. In consequence, focusing solely on positive or negative leader behavior may insufficiently capture the true complexity of workplace interactions and attempts to compensate negative behaviors with positive are unlikely to reduce distress-but quite the opposite-by increasing ambivalence.

Maternal stress and fish reproduction: The role of cortisol revisited

AbstractStressor‐induced elevation of circulating cortisol levels is generally considered to have an inhibitory effect on reproduction in teleosts. However, mature female fish have higher levels of circulating cortisol levels, and this is particularly telling in salmonids during their spawning migration. This raises the possibility that a cortisol buffering capacity is active at the level of the gonad. This is particularly important given the recent findings in zebrafish (Danio rerio, Cyprinidae) that zygotic cortisol content, either high or low, can alter developmental programming. Therefore, a tight regulation of corticosteroid during oogenesis may be essential for proper ovarian development. Here, we focus on the temporal dynamics of cortisol in the ovary and its role in regulating the different processes related to oogenesis. Maternally deposited cortisol along with the local production of this steroid by the ovary may be involved in the regulation of oogenesis. We propose two critical stages when cortisol may exert a modulatory effect on oogenesis. The first stage occurs during vitellogenesis when maternal cortisol is incorporated into the yolk, and the second is during maturation and ovulation when cortisol may have a regulatory role on the action of maturation‐inducing hormones. A key protective mechanism to prevent excess cortisol deposition appears to be the upregulation of 11β‐hydroxysteroid dehydrogenase 2 in the theca and/or granulosa cells of the developing oocyte in response to excess maternal cortisol stimulation. Taken together, cortisol dynamics during oogenesis is complex, but maintaining a “Goldilocks” concentration of this steroid may be a critical process governing successful spawning and progeny development.

Regulation of divergent cortisol responsiveness in European sea bass, Dicentrarchus labrax L.

Mechanisms regulating differences in cortisol responsiveness between low (LR) and high response (HR) individuals have been poorly studied. In this context, we aimed to study key regulatory processes in cortisol dynamics at the head kidneys of LR and HR European sea bass. To do so, resting plasma cortisol and ACTH concentrations were quantified in these fish. Additionally, the head kidneys of these individuals were superfused through an in vitro superfusion system and stimulated with the same amount of ACTH to assess their cortisol biosynthetic capacity. Moreover, the expression of important genes in cortisol regulation was assessed. Results showed that LR fish had lower resting cortisol concentrations than HR, although no differences existed in the circulating levels of ACTH. Additionally, the biosynthetic capacity of HR was higher than that of LR fish when in vitro stimulated with ACTH. At the molecular level, a statistically significant 3.4-fold higher expression of the ACTH receptor, mc2r, and a 2.3-fold, though not significant, higher expression of 11β-hydroxylase (cyp11b1), an enzyme involved in cortisol biosynthesis, was observed in the HR fish. Finally, a statistically significant 1.3-fold lower expression of 11β-hydroxysteroid dehydrogenase 2 (hsd11b2), an enzyme involved in cortisol inactivation, was observed in HR when compared to LR fish. Therefore, it was for the first time indicated that cortisol dynamics can also be regulated at the post-production level in the head kidney. Collectively, our results highlight the crucial role of the interrenal tissue in the regulation of differences in cortisol response between LR and HR sea bass individuals.

Effect of laughter yoga on salivary cortisol and dehydroepiandrosterone among healthy university students: A randomized controlled trial

ObjectiveTo examine whether laughter yoga (LY), i.e., simulated laughter, alters cortisol and dehydroepiandrosterone (DHEA) levels and cortisol/DHEA (C/D) ratios. MethodsIn a randomized controlled trial, 120 healthy university students were allocated to experiencing LY, watching a comedy movie (spontaneous laughter), or reading a book. Salivary cortisol and DHEA levels were measured immediately before, immediately after, and 30 min after the intervention. ResultsCortisol levels and C/D ratios significantly decreased by time in the LY and comedy movie groups. Significant group*time interactions were found between these two groups for cortisol levels and C/D ratios. DHEA levels did not change by time in the LY group. ConclusionsLY decreased cortisol levels and C/D ratios but did not affect DHEA levels. Simulated and spontaneous laughter differently affected the dynamics of cortisol levels and C/D ratios. Effect of spontaneous laughter on the cortisol dynamics lasted longer than that of simulated laughter. (UMIN000019409).

Application of lithium ascorbate for regulation of lipid-cholesterol metabolism and glutathione redox system in pregnant sows

The study is aimed at developing a method for using a new, organic drug – lithium ascorbate. The aim of the work is to develop a new, more effective and more physiological way to combat all forms of stress in farm animals to increase productivity. Lithium ascorbate is an adaptogen preparation capable of becoming one of the new effective and physiological elements of pork production biotechnology rationalization. The experiment was carried out on 5 groups of pregnant sows of Landrace breed (4 experimental and 1 control sows) with 5 heads each. After 30 days of fruitful insemination of sows 1, 2, 3 and 4 groups received daily with food lithium ascorbate in powder form in the dose of 10; 5; 2; 0.5 mg/kg of live weight, respectively. Weighing was carried out before the introduction of the drug. Repeated weighing was carried out in 2 and 3 months after fertilization and just before farrowing. In the blood plasma was determined dialdehyde, restored glutathione, oxidized glutathione, triacylglycerol, total cholesterol, total protein, lipoprotein fraction is HDL, LDL, VLDL, thiol-disulfide ratio (SH/SS); activity of superoxide dismutase and glutathione peroxidase. It is established that the introduction of feed sows at a dosage of 10, 5 and 2 mg/kg of body weight, ascorbate, lithium exhibits a pronounced adaptogen and stress-protection properties, supported on a physiological level, the dynamics of cortisol and progesterone during pregnancy. Lithium ascorbate contributes to increase of nonspecific resistance, growth of gestating sows, the tread in relation to technological and spontaneous stressors. The obtained data indicate that lithium ascorbate in sows in all studied parameters was effective, affecting lipid-cholesterol metabolism, glutathione reduction system and as a result, increasing the safety, live weight and reproductive function of sows. The experimental verification of the developed dose, scheme and method of administration, lithium ascorbate based on a set of biochemical and physiological parameters confirmed the validity of the proposed concept on the possibility of creating with its help new methods of effective and physiological management of behavioral reactions, non-specific resistance and productivity of animals.

Circadian cortisol dynamics across reproductive stages and in relation to breastfeeding in the Philippines

An increase in cortisol during human pregnancy helps coordinate the onset of parturition, and can have long-term effects on offspring biology. Maternal cortisol can also be transferred to offspring via breast milk during lactation. However, little is known about how diurnal cortisol profiles vary by trimester of pregnancy or during the postpartum period. Here, we describe diurnal cortisol profiles among a large cross-sectional sample of healthy Filipino young adult women varying in reproductive status and, during the postpartum period, in whether or not they are breastfeeding. Salivary cortisol, anthropometric, and questionnaire data were obtained from participants in a birth cohort in metropolitan Cebu, Philippines (N = 741; age 20.8-22.4 years). Cortisol was assessed at waking, thirty minutes after waking (cortisol awakening response, CAR), and before bed. Compared with nulliparous women, morning cortisol was roughly 50% higher among women in late gestation, while evening cortisol was roughly 4-fold higher and the CAR was lower. Postpartum waking and evening cortisol were lower among currently breastfeeding women compared to nulliparous women, but were comparable in the absence of breastfeeding. The CAR was significantly lower among postpartum women compared to nulliparous women irrespective of breastfeeding status. These findings are consistent with known alterations in hypothalamic-pituitary-adrenal axis function during reproduction, and in particular point to marked and progressive elevation in maternal cortisol during the course of gestation. Cortisol appears to return to nulliparous levels after parturition, with levels suppressed below nulliparous levels during lactation.

Epidural block in local kidney cancer as a way to preserve the adrenal function influencing urine formation processes.

592 Background: Our purpose was to study the dynamics of cortisol (C) and aldosterone (A) in the blood plasma in patients receiving surgery with the epidural block (EB) for local kidney cancer. Methods: 58 patients aged 56.5±8.7 years underwent partial nephrectomy with warm ischemia for 15-20 minutes (EB – 35 patients, standard anesthesia (SA) - 23 patients). EB involved catheterization of the epidural space at Th10-L1 with the following infusion of a mixture of ropivacaine 2 mg/ml and epinephrine 2 μg/ml at 6-10 ml/hr using a syringe doser, intraoperatively and within the first three postoperative days. The levels of C and A were studied by radioimmunoassay in the blood plasma of patients before the surgery (b/s), 40 min after the start of the surgery (40' s/s) and on days 1 and 3 after the surgery (a/s). Results were compared to the levels in the blood plasma of 32 healthy donors (N). Results: C and A exceeded N in all patients b/s (p &lt; 0.01). C increased by an order of magnitude 40' s/s only in SA (p &lt; 0.001), while A increased in all patients, compared to the levels b/s. C decreased by 1.5 times in EB on day 1 a/s; C in SA was similar to the levels b/s; A decreased to similar levels in all patients but was still higher than N by 1.4 times on average (p &lt; 0.01). The C levels remained stable in all patients on day 3; A levels became normal in EB only, while in SA they were 2.1 times lower which caused the loss of salts and fluid. Conclusions: SA affected the regulation of the adrenal function by the central nervous system and urine formation processes in the kidney. In SA, abnormal C and A levels preserve for a longer period of time enhancing the water and salt imbalance in the body. Significant decrease of C and the normalization of A in EB indicate the preservation of the adrenal function influencing urine formation processes in the kidney. In local kidney cancer, it is advisable to use epidural block instead of standard anesthesia as the latter blocks regulatory functions of the central nervous system.

Dynamics of postoperative serum cortisol after transsphenoidal surgery for Cushing's disease: implications for immediate reoperation and remission.

OBJECTIVESuccessful transsphenoidal surgery for adrenocorticotropin hormone (ACTH)-producing pituitary tumors is associated with subnormal postoperative serum cortisol levels, which may guide decisions regarding immediate reoperation. However, little is known about the detailed temporal course of changes in serum cortisol in the immediate postoperative period, and the relationship of postoperative cortisol dynamics to remission and late recurrence.METHODSA single-center retrospective cohort analysis was performed for all patients undergoing pituitary surgery from 2007 through 2015. Standardized diagnostic and treatment algorithms were applied to all patients with potential Cushing's disease (CD), including microsurgical transsphenoidal adenomectomy (TSA) by a single surgeon. All patients had serum cortisol levels drawn at 6-hour intervals for 72 hours after surgery, and were offered reoperation within 3 days for normal or supranormal postoperative cortisol levels. Primary outcomes were 6-month remission and late recurrence; secondary outcomes were persistent postoperative hypocortisolism and surgical morbidity. Discriminatory levels of postoperative serum cortisol for predicting remission were calculated at various intervals after surgery using receiver operating characteristic (ROC) curves.RESULTSAmong 89 patients diagnosed with CD, 81 underwent initial TSA for a potentially curable lesion; 23 patients (25.8%) underwent an immediate second TSA. For the entire cohort, 6-month remission was achieved in 77.8% and late recurrences occurred in 9.5%, at a mean of 43.5 months. Compared with patients with a single surgery, those with an immediate second TSA had similar rates of remission (78.3% vs 77.6%) and late recurrence (5.6% vs 11.1%). The rate of hypocortisolism for patients with 2 surgeries (12/23, 52.2%) was significantly greater than that for patients with single surgeries (13/58, 22.4%; p < 0.001). There was no difference in the incidence of CSF leaks between the first and second operations. Remission was achieved in 58 (92.1%) of 64 patients who completed the 2-surgery protocol. The temporal course of postoperative serum cortisol levels among patients varied considerably, with subnormal nadir levels < 2 μg/dl occurring between 12 hours and 66 hours. Patients achieving remission had significantly lower mean serum cortisol levels at every time point after surgery (p < 0.01). By ROC curve analysis, nadir cortisol levels < 2.1 μg/dl were predictive of 6-month remission for the entire cohort over 3 days (positive predictive value [PPV] = 94%); discriminating cortisol levels for predicting remission on postoperative day (POD) 2 were < 5.4 μg/dl (PPV = 97%), although patients with remission after postoperative cortisol levels of 2-5 μg/dl had a significantly higher rate of late recurrence.CONCLUSIONSThere is substantial variation in the temporal course of serum cortisol levels over the first 72 hours after TSA for CD, with nadir levels predictive for remission occurring as late as POD 3. Although a cortisol level of 2.1 μg/dl at any point was an accurate predictor of 6-month remission, levels less than 5.4 μg/dl on POD 2 were reasonably accurate. These data may enable decisions regarding the efficacy of an immediate second surgical procedure performed during the same hospitalization; immediate reoperation is associated with excellent remission rates and low recurrence rates in patients otherwise unlikely to achieve remission, but carries a higher risk of permanent hypocortisolism.

The Hepato-Hypothalamic-Pituitary-Adrenal-Renal Axis: Mathematical Modeling of Cortisol's Production, Metabolism, and Seasonal Variation.

Cortisol dynamics are governed by the integration of influences from the suprachiasmatic nucleus (SCN), the hypothalamic-pituitary-adrenal (HPA) axis, and metabolic enzymes, such as the 11β-hydroxysteroid dehydrogenase (HSD) family, which are highly expressed in hepatic and renal tissue. The coordinated regulation of cortisol dynamics is essential for the maintenance of a healthy state, and aberrant cortisol circadian rhythms are associated with various pathophysiological conditions. The duration of the light-dark cycle, or photoperiod, which regulates SCN activity, varies seasonally, and the shorter photoperiod winter season is associated with elevated cortisol levels, peak inflammatory disease incidence, and symptom exacerbation. Elevated expression and activity of 11β-HSD1 protein, assumed to also occur during the winter, have been allied with numerous inflammatory conditions. A comprehensive understanding of the communication between the underlying regulatory mechanisms of cortisol as well as how changes in their activity could lead to the development of disease is yet to be elucidated. In this work, we propose the use of a semimechanistic mathematical model to explore the impact of the hepato-hypothalamic-pituitary-adrenal-renal axis in modulating neuroendocrine-immune system dynamics. Our model predicts the predominance of a winter proinflammatory state and that genetic variations could alter 11β-HSD enzyme functionality, rendering certain subpopulations more susceptible to disease as a consequence of HPA axis dysregulation.

Impact of age, sex and body mass index on cortisol secretion in 143 healthy adults.

ContextStudies on 24-h cortisol secretion are rare. The impact of sex, age and adiposity on cortisol levels, often restricted to one or a few samples, are well recognized, but conflicting.ObjectiveTo investigate cortisol dynamics in 143 healthy men and women, spanning 7 decades and with a 2-fold body mass index (BMI) range with different analytic tools.SettingClinical Research Unit.DesignCortisol concentrations in 10-min samples collected for 24 h. Outcomes were mean levels, deconvolution parameters, approximate entropy (ApEn, regularity statistic) and 24-h rhythms.ResultsTotal 24-h cortisol secretion rates estimated by deconvolution analysis were sex, age and BMI independent. Mean 24-h cortisol concentrations were lower in premenopausal women than those in men of comparable age (176 ± 8.2 vs 217 ± 9.4 nmol/L, P = 0.02), but not in subjects older than 50 years. This was due to lower daytime levels in women, albeit similar in the quiescent overnight period. Aging increased mean cortisol by 10 nmol/L per decade during the quiescent secretory phase and advanced the acrophase of the diurnal rhythm by 24 min/decade. However, total 24-h cortisol secretion rates estimated by deconvolution analysis were sex, age and BMI independent. ApEn of 24-h profiles was higher (more random) in premenopausal women than those in men (1.048 ± 0.025 vs 0.933 ± 0.023, P = 0.001), but not in subjects older than 50 years. ApEn peaked during the daytime.ConclusionSex and age jointly determine the 24-h cortisol secretory profile. Sex effects are largely restricted to age <50 years, whereas age effects elevate concentrations in the late evening and early night and advance the timing of the peak diurnal rhythm.

Capturing effort and recovery: reactive and recuperative cortisol responses to competition in well-trained rowers

Background/aimIt is well known that physical strain is associated with increased cortisol production. And although mental stress elevates cortisol concentrations as well, little is known of the independent and/or combined...

Sleep duration partially accounts for race differences in diurnal cortisol dynamics.

Emerging research demonstrates race differences in diurnal cortisol slope, an indicator of hypothalamic-pituitary-adrenocortical (HPA)-axis functioning associated with morbidity and mortality, with African Americans showing flatter diurnal slopes than their White counterparts. Sleep characteristics are associated with both race and with HPA-axis functioning. The present report examines whether sleep duration may account for race differences in cortisol dynamics. Participants were 424 employed African American and White adults (mean age = 42.8 years, 84.2% White, 53.6% female) with no cardiovascular disease (Adult Health and Behavior Project-Phase 2 [AHAB-II] cohort, University of Pittsburgh). Cortisol slope was calculated using 4 salivary cortisol readings, averaged over each of 4 days. Demographic (age, sex), psychosocial (socioeconomic status [SES], affect, discrimination), and health behaviors (smoking, alcohol use, physical activity) variables were used as covariates, and sleep (self-report and accelerometry) was also assessed. African Americans had flatter slopes than Whites (F(1, 411) = 10.45, B = .02, p = .001) in models adjusting for demographic, psychosocial, and health behavior covariates. Shorter actigraphy-assessed total sleep time was a second significant predictor of flatter cortisol slopes (F(1, 411) = 25.27, B = -.0002, p < .0001). Total sleep time partially accounted for the relationship between race and diurnal slope [confidence interval = .05 (lower = .014, upper .04)]. African Americans have flatter diurnal cortisol slopes than their White counterparts, an effect that may be partially attributable to race differences in nightly sleep duration. Sleep parameters should be considered in further research on race and cortisol. (PsycINFO Database Record

Effects of chronic exposure to dietary selenomethionine on the physiological stress response in juvenile white sturgeon (Acipenser transmontanus)

Selenium (Se) is an essential micronutrient, but at low concentrations can be toxic to aquatic organisms. Selenomethionine (SeMeth) is the primary dietary form of Se aquatic organisms are exposed to and is an environmental concern because it persists and bioaccumulates. White sturgeon (WS) might be particularly susceptible to bioaccumulative toxicants, such as SeMeth, due to their longevity and benthic lifestyle. Se exposure is known to have adverse effects on the physiological stress response in teleosts, but these effects are unknown in WS. Therefore, the goal of this study was to determine effects of dietary SeMeth on the ability of WS to mount a stress response. Juvenile WS were administered food spiked with 1.4, 5.6, 22.4 and 104.4μg Se/g dry mass (dm) for 72days. Lower doses were chosen to represent environmentally relevant concentrations, while the high dose represented a worst case scenario exposure. On day 72, fish were subjected to a 2min handling stressor, and they were sampled at 0, 2 and 24h post-stressor. Cortisol, glucose and lactate concentrations were quantified in blood plasma and glycogen concentrations were quantified in muscle and liver. Transcript abundance of genes involved in corticosteroidogenesis and energy metabolism were determined using qPCR. Under basal conditions, WS fed 104.4μg Se/g dm had significantly greater concentrations of plasma cortisol and lactate, and significantly lower concentrations of plasma glucose and liver glycogen, compared to controls. Corticosteroid 11-beta dehydrogenase 2 (hsd11b2) abundance was lower in WS fed 22.4 and 104.4μg Se/g dm, indicating less conversion of cortisol to cortisone. Abundance of the glucocorticoid receptor (gcr) was significantly lower in high dose WS, suggesting lower tissue sensitivity to glucocorticoids. The increasing trend in phosphoenolpyruvate carboxykinase (pepck) abundance, with increasing SeMeth exposure, was consistent with greater cortisol and glucose concentrations in high dose WS. Exposure to an acute handling stressor elicited a typical cortisol response, but the magnitude of the response appeared to be significantly lower than those typically observed in teleosts. SeMeth also did not appear to modulate the cortisol response to a secondary stressor. However, WS exposed to 22.4μg Se/g dm and sampled 2h post-stressor, had significantly higher concentrations of muscle glycogen compared to controls, indicating effects on their ability to utilize muscle glycogen for energy. Overall, the results indicate that chronic exposure to dietary SeMeth concentrations >22.4μg/g can affect cortisol dynamics and mobilization of energy substrates in juvenile WS.