Plasma Cortisol Profiles Research Articles

Effect of oral melatonin treatment on insulin resistance and diurnal blood pressure variability in night shift workers. A double-blind, randomized, placebo-controlled study

BackgroundNight shift work is associated with sleep disturbances, obesity, and cardiometabolic diseases. Disruption of the circadian clock system has been suggested to be an independent cause of type 2 diabetes and cardiovascular disease in shift workers. We aimed to improve alignment of circadian timing with social and environmental factors with administration of melatonin. MethodsIn a randomized, placebo-controlled, prospective study, we analysed the effects of 2 mg of sustained-release melatonin versus placebo on glucose tolerance, insulin resistance indices, sleep quality, circadian profiles of plasma melatonin and cortisol, and diurnal blood pressure profiles in 24 rotating night shift workers during 12 weeks of treatment, followed by 12 weeks of wash-out. In a novel design, the time of melatonin administration (at night or in the morning) depended upon the shift schedule. We also compared the baseline profiles of the night shift (NS) workers with 12 healthy non-night shift (NNS)-working controls. ResultsWe found significantly impaired indices of insulin resistance at baseline in NS versus NNS (p < 0.05), but no differences in oral glucose tolerance tests nor in the diurnal profiles of melatonin, cortisol, or blood pressure. Twelve weeks of melatonin treatment did not significantly improve insulin resistance, nor did it significantly affect diurnal blood pressure or melatonin and cortisol profiles. Melatonin administration, however, caused a significant improvement in sleep quality which was significantly impaired in NS versus NNS at baseline (p < 0.001). ConclusionsRotating night shift work causes mild-to-moderate impairment of sleep quality and insulin resistance. Melatonin treatment at bedtime improves sleep quality, but does not significantly affect insulin resistance in rotating night shift workers after 12 weeks of administration.

Plasma marker ACTH, cortisol, and beta-endorphins profile on pregnant women as targeted marker of approach for antenatal depression

Background: Antenatal depression is a frequent mental disorder with much less attention, and most women remain undiagnosed. Altered hypothalamic-pituitary-adrenal (HPA)-axis function mediates maternal depressive symptoms and has been widely reported. The present research aimed to determine the plasma marker HPA-axis including Adrenocorticotropic hormone (ACTH), cortisol, and beta-endorphin, as a suitable representation of mental health in pregnancy by evaluating the psychometric properties. Methods: Therefore, we examined a case-control study of 216 Bontang pregnant women. Psychological measures were conducted during the 27th week of pregnancy, including the Patient Health Questionnaire-9 (PHQ-9) assessment and Depression Anxiety Stress Scale (DASS). Blood samples were collected for plasma ACTH, Cortisol, and beta-endorphins assay as a marker of the HPA axis profile. Data were analyzed Stata for Mac version 14 (StataCorp, USA). Results: our finding showed that DASS scores correlated with PHQ-9 (r=0.79), ACTH (r=0.22), and beta-endorphin (r=54). PHQ-9 score significantly related to ACTH (r=0.27), cortisol (r=0.36) and beta-endorphin (r=0.71). Women with the highest DASS score and PHQ-9 depression scores at 27 weeks of pregnancy had significantly lower baby birth weight (P=0.000) than those women whose stress improved to or normal state. Plasma ACTH, cortisol, and beta-endorphin concentrations were significantly higher in pregnant women with antenatal depression compared to normal pregnancy (p&lt;0.01). All effects remain without controlling unwanted pregnancy. Conclusion: Our study demonstrates a role for circulating ACTH in regulating maternal cortisol secretion and a significant correlation between the HPA-axis profile and antenatal depression at 27 weeks of pregnancy.

Differences in Regulation of Cortisol Secretion Contribute to Left Ventricular Abnormalities in Patients With Essential Hypertension.

Left ventricular (LV) abnormalities were reported in patients with overt and subclinical Cushing syndrome. The aim of this study was to investigate the relationships of daily plasma cortisol profile and cortisol response to an overnight suppression test with cardiac changes in patients with hypertension. In a cross-sectional study, we included 136 nondiabetic, patients with essential hypertension who were free of cardiovascular and renal complications. Plasma cortisol was measured at 8 am, 3 pm, and 12 am and at 8 am after overnight suppression with 1 mg dexamethasone (dexamethasone suppression test [DST]). Echocardiography was performed with standard B-mode and tissue-Doppler imaging. LV hypertrophy was present in 30% and LV diastolic dysfunction in 51% of patients who were older and had significantly higher body mass index, systolic blood pressure, duration of hypertension, and 12 am and DST cortisol. LV mass index and relative wall thickness increased progressively across tertiles of DST cortisol, together with progressive worsening of diastolic function. LV mass index was directly related to age, systolic blood pressure, duration of hypertension, and 12 am and DST cortisol, and inversely to creatinine clearance. Multivariate regression analysis showed independent correlation of LV mass index with body mass index, systolic blood pressure, and 12 am and DST cortisol. Logistic regression showed that DST cortisol independently predicted LV hypertrophy. Midnight and DST plasma cortisol levels are independent determinants of LV mass and geometry in patients with essential hypertension suggesting that even minor changes in regulation of cortisol secretion could contribute to cardiac abnormalities in these patients.

Stability and test-retest reliability of different hormonal stress markers upon exposure to psychosocial stress at a 4-month interval

The Trier Social Stress Test (TSST) has been shown to reliably induce physiological stress responses in the hypothalamus-pituitary-adrenal (HPA) and in the sympathetic-adrenal-medullary (SAM) axis in cross-sectional studies. However, it was also reported that repeated exposure to the TSST might be associated with habituation, mainly of the HPA axis responsivity. Thus, in all longitudinal stress studies involving repeated TSST administration, potential habituation of the HPA axis response complicates the interpretation of results. The goal of the present study was therefore to assess stability and test-retest reliability of a number of different endocrinological stress markers as well as subjective stress responses after two exposures to the TSST four months apart. We assessed salivary and plasma cortisol profiles, plasma ACTH and noradrenaline profiles, as well as subjective stress ratings in healthy volunteers before, during, and after the TSST at six time-points both at test-day 1 (TSST_1, n = 42) and test-day 2 (TSST_2, n = 34) 4-months later. Half of the participants received the TSST in the early, the other half in the late afternoon. Discontinuous growth models were applied to model three phases of the stress response (preTSST, reactivity, recovery) for each marker. Subsequently, the stability of these phases was analyzed. Stability and test-retest reliability of standard physiological stress markers such as Area-under-the-Curve (AUCG, AUCI), Absolute Peak Change, and Relative Peak Change (RPC) were analyzed as well. We did not observe strong test-retest effects in any of the endocrinological measures. In contrast, test-retest effects in subjective stress were characterized by a faster drop directly after the second TSST, whereas the initial increase before the test period was the same for both test-days. Regarding test-retest-reliability, AUCG was the most reliable measure across all endocrinological and subjective stress markers (range: r = .606 to .858), while AUCI and RPC (range: r = − .146 to .548) were least reliable. A 4-month interval is a sufficient time interval between two repeated TSST exposures to largely reinstate the physiological stress response, which was also true for the initial psychological stress response. Thus, the TSST is well applicable in longitudinal studies.

Modelling Hydrocortisone Pharmacokinetics on a Subcutaneous Pulsatile Infusion Replacement Strategy in Patients with Adrenocortical Insufficiency.

In the context of glucocorticoid (GC) therapeutics, recent studies have utilised a subcutaneous hydrocortisone (HC) infusion pump programmed to deliver multiple HC pulses throughout the day, with the purpose of restoring normal circadian and ultradian GC rhythmicity. A key challenge for the advancement of novel HC replacement therapies is the calibration of infusion pumps against cortisol levels measured in blood. However, repeated blood sampling sessions are enormously labour-intensive for both examiners and examinees. These sessions also have a cost, are time consuming and are occasionally unfeasible. To address this, we developed a pharmacokinetic model approximating the values of plasma cortisol levels at any point of the day from a limited number of plasma cortisol measurements. The model was validated using the plasma cortisol profiles of 9 subjects with disrupted endogenous GC synthetic capacity. The model accurately predicted plasma cortisol levels (mean absolute percentage error of 14%) when only four plasma cortisol measurements were provided. Although our model did not predict GC dynamics when HC was administered in a way other than subcutaneously or in individuals whose endogenous capacity to produce GCs is intact, it was found to successfully be used to support clinical trials (or practice) involving subcutaneous HC delivery in patients with reduced endogenous capacity to synthesize GCs.

Would Cortisol Measurements Be a Better Gauge of Hydrocortisone Replacement Therapy? Congenital Adrenal Hyperplasia as an Exemplar.

There is an increase in mortality and morbidity as well as poor quality of life in patients with congenital adrenal hyperplasia (CAH) and other causes of adrenal insufficiency. Glucocorticoid replacement therapy should aim to replace the missing cortisol as close as possible to the normal circadian rhythm using hydrocortisone. Dosing should be based on the individual's absorption and clearance of the drug. Adequacy of dosing should be checked using 24-hour profiles of plasma cortisol with samples drawn preferably every hour or at least every 2 hours. Measurement of cortisol should be the preferred method of assessing replacement therapy as it is over- and undertreatment with hydrocortisone, both of which can occur over a 24-hour period, which leads to the problems observed in patients with CAH and adrenal insufficiency.

Plasma B-endorphin and cortisol profiles around periparturient period in Friesian Cattle suffering from reproductive disorders in Egypt

The present study aimed to determine plasma β-endorphin and cortisol concentrations in cattle with reproductive disorders (dystocia and retained placenta) and weakness body condition score during periparturient period. Stress may cause an overproduction of beta-endorphins and free radicals. Twenty multiparous Friesian cows weighing 400–650 kg aged 6-10 years and between (3-8) parities at late pregnancy period was used for two months before parturition. From ten days before the expected birth date the birth canal of each animal was monitored by rectal and vaginal palpations, and the body temperature was checked daily to predict the probable time of parturition. Animals were divided into four groups according to parturition disorders’ five animals in each one. First group delivered spontaneously at term with no obstetrical assistance(A), second group delivery was at term but was accompanied by dystocia(B), third group delivery was at term but was accompanied by retained placenta(C), and fourth group delivery was at term but animals showed weakness body condition score (D). Results illustrated that Plasma β-endorphin level in Friesian cattle during pregnancy state increased gradually through gestation period. It reaches its highest level during the third trimester due to stressful state. Also, it reaches its peak at zero time of parturition by appearing its analgesic action. Meanwhile, it decreases gradually towards re-establishment of ovarian cycle. Generally, cows suffering reproductive disorders had a clear impact on blood plasma β-endorphin concentration around parturition process.

Plasma Β-Endorphin and Cortisol Profiles around Periparturient Period at Stressful Conditions in Egyptian Buffalo

&lt;p&gt;The study determined the level of plasma β-endorphin and cortisol concentrations in peripheral blood circulation of buffalo cows suffering from reproductive disorders (dystocia and retained placenta) and weakness body condition score during periparturient period. Twenty multi-parous Egyptian buffalo cows at late pregnancy period were used for two months before parturition. β-endorphin concentrations were higher in buffalo suffering from reproductive disorders groups. Whereas, β-endorphin concentrations were 134.9±4.8 for retained placenta, 121.3±4.9 for dystocia, 114.2±8.4 for weakness and 113.5±6.5 pg/ml for control. In the closer period around parturition both of plasma β-endorphin and cortisol followed the same trend toward a gradually increased values during -2,-1days and zero time in all groups. A concomitant trend was noticed in β-endorphin and cortisol concentrations in postpartum period with reduce values were observed in all groups after parturition continued for month or more. Buffalo suffering from reproductive disorders were showed a high relative values in β-endorphin and cortisol concentrations. A significant differences (P&amp;lt;0.01) were observed between the experimental groups. Generally, buffaloes suffering reproductive disorders had a clear impact on blood plasma β-endorphin concentration around parturition process.&lt;/p&gt;&lt;p&gt;The aim of this study was to determine the relationship between various reproductive disorders as a stress factors with plasma β–endorphin and cortisol in buffalo cows around parturition and changes in these parameters could be used as an objective measure of the stress associated labour. Stress has been hypothesized to be a cause of impaired reproductive efficiency. Stress may cause an overproduction of beta-endorphins and free radicals&lt;/p&gt;

Plasma Cortisol and Thyroid Hormone Profile in Theileria equi Affected Horses

Equine theileriosis caused by Theileria equi is an endemic disease in most of the countries. The latently infected animals may exhibit low performance following physical, immunological or mental stress due to the flare-up of underlying parasitemia leading to clinical form of the disease. In the present study, 72 horses were screened for T. equi by using polymerase chainm reaction based on equine merozoite antigen-5 and 6, which revealed 25 to be positive for theileriosis. Further study was conducted to assess the cortisol and thyroid hormone (T3 and T4) levels in healthy (n=47) and in T. equi infected (n=25) horses. In horses positive for T. equi, there was significant increase (p less than 0.05) in cortisol (42.80±0.69 vs. 24.44± 0.12 ng/ml) and T4 level (47.56±4.06 vs. 38.14±2.40 ng/ml) with significant reduction (p less than 0.01) in T3 level (0.44±0.13 vs. 1.20±0.19 ng/ml) when compared to the healthy group. This may be the first report revealing that theileriosis infected horses are under stress due to the involvement of endocrine system as well as metabolic pathways.

FGF21 decreases food intake and body weight in obese Göttingen minipigs.

The aim of this study was to assess the effect of FGF21 on food intake, body weight, body composition, glucose homeostasis, bone mineral density (BMD), cortisol and growth hormone (GH) in obese minipigs. The pig is a unique model for studying FGF21 pharmacology as it does not express UCP1, unlike mice and humans. Twelve obese Göttingen minipigs with a mean body weight of 91.6 ± 6.7 kg (mean ± SD) received subcutaneously either vehicle (n = 6) or recombinant human FGF21 (n = 6) once daily for 14 weeks (0.1 mg/kg for 9.5 weeks and 0.3 mg/kg for 4.5 weeks). Treatment of obese minipigs with FGF21 led to a 50% reduction in food intake and a body weight loss of, on average, 18 kg compared to the vehicle group after 14 weeks of dosing. Glucose tolerance and insulin sensitivity, evaluated by intravenous glucose tolerance test, were significantly improved in the FGF21 group compared to the vehicle group at the end of the study. The plasma cortisol profile was unaffected by FGF21, whereas a small decrease in peak GH values was observed in the FGF21-treated animals after 7 to 9.5 weeks of treatment compared to the vehicle group. Whole-body BMD was not affected by 13 weeks of FGF21 dosing. Despite a lack of UCP-1 in obese minipigs, FGF21 treatment induced a significant weight loss, primarily a result of reduction in food intake, with no adverse effect on BMD or plasma cortisol.

A5980 Plasma cortisol secretion and left ventricular changes in essential hypertension

Objectives: Cushing syndrome and subclinical hypercortisolism are associated with changes in left ventricular (LV) structure. No data are available on the relationship between cortisol production and LV mass and geometry in essential hypertension (EH). Methods: In 103 EH patients, we evaluated clinical characteristics, general biochemistries, the circadian level of plasma cortisol (8 AM, 5 PM, and 11 PM) together with the area under the curve (C-AUC), 24-h urinary cortisol excretion, and the response of plasma cortisol to an overnight suppression test with 1 mg of dexamethasone (DMT). Echocardiography was performed with a standard technique. Results: LV hypertrophy (LVH) was detected in 34 of 103 EH patients. Patients with LVH were significantly older, had longer duration of hypertension, and greater BMI, systolic BP, plasma triglycerides, and post-DMT plasma cortisol (P = 0.004) than patients without LVH. No differences were detected in circadian plasma cortisol profile nor urinary cortisol excretion between patients with or without LVH. Eccentric LVH was present in 13 EH patients who showed greater post-DMT plasma cortisol levels than patients with other types of LV geometry. In a logistic regression, LVH was associated independently with BMI and post-DMT plasma cortisol (P = 0.045). LV mass index (LVMI) was significantly and directly related to age, duration of hypertension, BMI, systolic blood pressure, plasma glucose and triglycerides, HOMA-index, and post-DMT plasma cortisol (r = 0.349, P = 0.002), whereas a borderline relationship was found with C-AUC (r = 0.201, P = 0.053). In multivariate models, LVMI was independently associated with post-DMT cortisol and C-AUC. Conclusion: Subtle changes in the regulation of plasma cortisol secretion contribute to LV changes in patients with EH.

Influence of the light spectrum on the daily rhythms of stress and humoral innate immune markers in pikeperch Sander lucioperca

This study investigated the daily variations of stress markers namely plasma cortisol and glucose and some humoral innate immune markers, including peroxidase, lysozyme and complement activities, of pikeperch (Sander lucioperca) and the effect of light spectrum on these variations. Fish were reared under a white or red light spectrum at a constant photoperiod (12D:12 L). Samples were collected at 22:00, 04:00, 10:00 and 16:00 at days 1 and 42 of the experiment. After 42 days, the use of a red light spectrum led to a significant increase in final bodyweight. Specific growth rate reached 2.1 ± 0.18 and 1.8 ± 0.17% d−1 under red and white spectra respectively. The profiles of plasma cortisol followed a cyclic activity with a surge during photophase at 10:00 without any effect of the light spectrum at day 42. Both lysozyme and peroxidase activities in blood followed a day-night variation with a peak at 4:00 corresponding to low cortisol values. No rhythmicity was detected for the complement activity but higher values were observed at 16:00 when cortisol values were lowest. Light spectra also influenced humoral immune markers with an increase in lysozyme activity and a decrease in peroxidase activity in a red light environment. The present results indicate a strong effect of the light environment, including the light-dark cycle and the light spectrum, on pikeperch physiology. Especially, some innate immune status seemed stimulated during the dark phase in relation to a decrease in the stress level markers. Such parallelism in the relationship between the immune status and stress markers may be affected positively or negatively by the light characteristics. Humoral immune markers were also modulated according to the light spectrum without no clear trend (stimulation or inhibition) for the immunocompetence status.

Pharmacokinetics of Glucocorticoid Replacement Before and After Bariatric Surgery in Patients With Adrenal Insufficiency.

Adequate glucocorticoid replacement in patients with primary or secondary adrenal insufficiency is essential to maintain general well-being. Little is known about the effects of bariatric surgery on glucocorticoid absorption. This study evaluates glucocorticoid absorption before and after bariatric surgery, with assessment of plasma cortisol profiles in five patients receiving glucocorticoid replacement therapy for primary (n = 1) or secondary (n = 4) adrenal insufficiency. One patient underwent sleeve gastrectomy (SG), one a one-anastomosis gastric bypass (mini-GB), and three a Roux-en-Y gastric bypass (RYGB). Pharmacokinetic calculations were based on plasma cortisol measurements performed during the first 6 hours after ingestion of the morning dose. Plasma cortisol profiles were very similar before and after surgery; only minor differences were observed. After SG, plasma peak cortisol concentration and cortisol area under the curve (AUC) were higher by 23% and 24%, respectively, and time to peak cortisol was 10 minutes shorter. The mini-GB had no marked effect on pharmacokinetic parameters. In the three patients who underwent RYGB, AUC changes ranged from −12% to 20%. In conclusion, in this small number of patients with adrenal insufficiency, plasma cortisol profiles were similar before and after bariatric surgery. However, in view of individual differences in response to different types of surgery, we recommend postoperative cortisol profiling to guide appropriate glucocorticoid dose adjustment.

Impact of two light programs and two levels of dietary tryptophan for weanling piglets

Photoperiod and supplementary tryptophan can attenuate the effects of stressful weaning. However, few studies have evaluated tryptophan metabolism in the presence of light. This study aimed to evaluate the effects of tryptophan levels (TL) on the diet of weanling piglets submitted to different light programs (LP). Seventy-two piglets weaned at 21 days of age (starting weight 6.6 ± 2.33 kg) were used. The experimental design consisted of randomized blocks with 24 days of duration in a 2 × 2 factorial arrangement. Two LP were used: 12-h or 23-h light/day. Two digestible TL were used: 2.6 g or 5.2 g of Trp/kg feed on pre-starter I diet (from 0 to 14 trial days) and 2.4 g or 4.8 g of Trp/kg feed on pre-starter II diet (from 15 to 24 trial days). Six replicates of three animals per treatment were performed. Growth performance, blood glucose, plasma cortisol profiles and animal behavior were assessed. Blood glucose was measured on experimental days 0 and 24, and cortisol was measured on days 0 and 8. Behavior was observed on days 2, 9, 16 and 23. Neither growth performance nor blood glucose were affected by the interaction between LP and TL. The treatments did not influence daily weight gain, daily feed intake and blood glucose during the periods of 0–14, and 0–24 days. Feed:gain ratio improved during the 0–14 days period for piglets receiving 12-h light/day. The treatments did not influence the frequency of “moving” behaviors. However, the interaction between LP and TL affected the plasma cortisol and frequency of “feeding” and “lying” behaviors. Piglets that received the highest TL had lower plasma cortisol levels, reduced “feeding” behaviors and increased “lying” behaviors, compared to animals that received normal TL, when subjected to LP of 23-h light/day. The results suggest that use of LP of 23 h light/day is not indicated for piglets.

RELATIVELY IMPAIRED CORTISOL SUPPRESSION BY DEXAMETHASONE IS ASSOCIATED WITH LEFT VENTRICULAR MASS AND GEOMETRIC CHANGES IN PATIENTS WITH ESSENTIAL HYPERTENSION

Objective: Both subclinical hypercortisolism and overt Cushing syndrome are associated with cardiovascular events and changes in left ventricular (LV) geometry. However, few data are available on the relationship between cortisol production and LV mass and geometry in essential hypertensive (EH) patients. Design and method: In 103 EH subjects (age 50 ± 14 y, 58 males, 33 never treated with antihypertensive drugs), we evaluated clinical characteristics, renal function, plasma levels of glucose, insulin, and lipids, the circadian levels of plasma cortisol (8 AM, 5 PM, and 11 PM) with the area under the curve (C-AUC), 24-h urinary cortisol excretion, and the response of plasma cortisol to an overnight suppression test with 1 mg of dexamethasone (DMT). Echocardiography was performed in all patients with a standard technique. Results: LV hypertrophy (LVH) according to current criteria was detected in 34 of 103 EH patients. Patients with LVH were significantly older, had longer duration of hypertension, and greater BMI, systolic blood pressure, plasma triglycerides, and post-DMT plasma cortisol level (P = 0.004) than patients without LVH. No differences were detected in circadian plasma cortisol profile nor urinary cortisol excretion between with and without LVH. Eccentric LVH was present in 13 EH patients who showed greater post-DMT plasma cortisol levels than patients with other types of LV geometry. In a logistic regression model, LVH was associated independently with BMI (OR 1.20, P = 0.022) and post-DMT plasma cortisol (OR = 1.06, P = 0.045). LV mass index (LVMI) was significantly and directly related to age (r = 0.329, P = 0.001), duration of hypertension (r = 0.243, P = 0.015), BMI (r = 0.317, P = 0.001), systolic blood pressure (r = 0.397, P < 0.001), plasma glucose (r = 0.215, P = 0.031) and triglycerides (r = 0.323, P = 0.001), HOMA-index (r = 0.226, P = 0.029), and post-DST plasma cortisol (r = 0.349, P = 0.002), whereas a borderline significant relationship was found with C-AUC (r = 0.201, P = 0.053). In multivariate regression models, LVMI was independently associated post-DMT cortisol (B = 0.245, P = 0.026) and C-AUC (B = 0.233, P = 0.018). Conclusions: Subtle changes in the regulation of plasma cortisol secretion contribute to cardiac hypertrophy and LV geometric changes in patients with EH.

The impact of exertional-heat stress on gastrointestinal integrity, gastrointestinal symptoms, systemic endotoxin and cytokine profile.

The study aimed to determine the effects of exertional-heat stress on gastrointestinal integrity, symptoms, systemic endotoxin and inflammatory responses; and assess the relationship between changes in body temperature and gastrointestinal perturbations. Ten endurance runners completed 2h running at 60% [Formula: see text]O2max in hot (HOT: 35°C) and temperate (TEMP: 22°C)-ambient conditions. Rectal temperature (T re) and gastrointestinal symptoms were recorded every 10min during exercise. Blood samples were collected pre- and post-exercise, and during recovery to determine plasma intestinal fatty acid binding protein (I-FABP), cortisol, bacterial endotoxin and cytokine profile. Calprotectin was determined from pre- and post-exercise faecal samples. Urinary lactulose:L-rhamnose ratio was used to measure intestinal permeability. Compared with TEMP, HOT significantly increased T re (1.4 ± 0.5 vs 2.4 ± 0.8°C, p < 0.001), cortisol (26 vs 82%, p < 0.001), I-FABP (127 vs 432%, p < 0.001), incidence (70 vs 90%) and severity (58 counts vs 720 counts, p = 0.008) of total gastrointestinal symptoms. Faecal calprotectin and circulating endotoxin increased post-exercise in both trials (mean increase 1.5 ± 2.5µg/g, p = 0.032, and 6.9 ± 10.3pg/ml, p = 0.047, respectively), while anti-endotoxin antibodies increased 28% post-exercise in TEMP and decreased 21% in HOT (p = 0.027). However, intestinal permeability did not differ between trials (p = 0.185). Inflammatory cytokines were greater on HOT compared to TEMP (p < 0.05). Increases in T re were positively associated with I-FABP, IL-10, cortisol, nausea and urge to regurgitate (p < 0.05). Exertional-heat stress induces a thermoregulatory strain that subsequently injures the intestinal epithelium, reduces endotoxin clearance capacity, promotes greater cytokinaemia, and development of gastrointestinal symptoms.

Effect of peripartum nutritional supplementation on postpartum fertility and blood biochemical and steroid hormone profile in crossbred cows

Advanced pregnant healthy HF crossbred cows (n=20) of 2-4 parity were equally divided in to control (routine farm feeding-RFF) and treatment/nutrients supplementation (RFF + bypass fat @ 100-200 g/h/d and ASMM @ 50 g/h/d) groups and were studied from 2 wks prepartum to 8 wks postpartum for plasma profile of steroid hormones and metabolites on days -14, -3, 0, +3, +14, +28 and +42 as well as for puerperal events and postpartum fertility. The mean plasma progesterone values were maximum (&gt;6 ng/ml) on day 14 prepartum, which declined significantly (p&gt;0.01) on day 3 prepartum reached to the basal levels (&gt;1 ng/ml) on the day of calving, remained basal till day 14, and thereafter showed a rising trend on days 28 and 42 postpartum. The oestradiol-17b values were at its peak on the day of calving (p&gt;0.01), showed a rapid fall by day 3 postpartum and remained low till recrudesce of follicular activity around day 35 postpartum. However, there were no statistical differences between the two groups in either of the hormones, except on day 42 postpartum. The levels of cortisol and PGF2 a Metabolites (PGFM) were 3-8 times higher on the day of parturition as compared to values at day 14 pre- and postpartum, and declined further till day 42 postpartum reaching to prepartum levels. The plasma cholesterol gradually decreased as parturition approached and increased in postpartum days to reach the highest value (p&gt;0.01) at day 42. The nutrients supplemented cows had significantly (p&gt;0.01) higher plasma cortisol, PGFM and cholesterol values than the control cows around parturition. However, no such variation was noted in plasma protein profile. The period of uterine involution in control and supplemented groups was identical (31.97±1.82 and 30.27±1.41 days), yet the cows in treatment group resumed estrous cycle earlier (38.00±1.95 vs 42.32±4.14 days, p&gt;0.05) and had shorter service period (85.22±7.17 vs 100.67±5.60 days) with improved pregnancy rate (80 vs 60 %) as compared to those in control group. Thus, the peripartum nutrient supplementation in crossbred cows was beneficial and had positive effect on the postpartum fertility and plasma cortisol, PGFM and cholesterol profile.

Stress system dysregulation in pediatric generalized anxiety disorder associated with comorbid depression.

Because chronic stress is an important risk factor for anxiety states and depressive disorders, we studied hypothalamus-pituitary-adrenal (HPA) axis and sympathetic system activity via changes in cortisol and alpha amylase activity levels in pediatric generalized anxiety disorder (GAD) patients (n=26) with comorbid depression and a healthy comparison group (n=26). Morning plasma cortisol and diurnal profiles of salivary cortisol and salivary alpha amylase (sAA) activity were assessed, also reactivity of HPA-axis, sAA activity, and heart rate following a psychosocial stressor (Trier Social Stress Test for children). GAD patients with comorbid depression showed increased morning plasma and salivary cortisol levels, ameliorating throughout in-patient treatment, and higher sAA activity in their diurnal profile. Both HPA and sympathetic activity positively correlated with the severity of anxiety and depression. We also demonstrated a blunted HPA and sympathetic response to acute stress in patients. This pattern of neuroendocrine and sympathetic changes seems to be distinct from the one previously reported in pediatric patients with only social anxiety or depressive disorders. We propose morning plasma and saliva cortisol levels as potential physiological indicators for supporting the evaluation of symptoms' severity and treatment progress in children with GAD and comorbid depressive disorder.

임상간호사의 직무 스트레스와 건강증진행위 및 건강상태의 관련성

Purpose: This study examined association of job stress with health-promoting behaviors and objective health status in 129 clinical nurses working at a university hospital. Methods: A cross- sectional and descriptive design was used. Job stress and health behaviors were measured with Korean Occupational Stress Scale and Heath Promoting Lifestyle Profile-II, respectively. Health status measured with afternoon plasma cortisol, C-peptide, and lipid profiles. Results: The level of job stress among clinical nurses was moderate with 51.41 on average. The mean for health-promoting behavior in the low stress group was significantly higher than that in the high or moderate stress groups (p<.001). The proportions of nurses with high C-peptide and cortisol levels, or low high-density lipoprotein levels, ranged from 14.0% to 35.7%. In particular, the percentage of nurses with high C-peptide levels was significantly higher in moderate and high stress groups than in the low stress group (24.1% versus 11.6%, p<.05). Conclusion: The study findings affirmed the associations of job stress with health-promoting behaviors as well as selected health status indicators such as C-peptide in clinical nurses. Job stress management intervention can help clinical nurses to improve their health-promoting behaviors and health status.

Feeding rates affect stress and non-specific immune responses of juvenile blunt snout bream Megalobrama amblycephala subjected to hypoxia.

This study aimed to investigate the effects of feeding rates on stress response, innate immunity and hypoxia resistance of juvenile blunt snout bream Megalobrama amblycephala. Fish were randomly assigned to one of six feeding rates (2, 3, 4, 5, 6 and 7% of body weight/day) for 60 days. Then, fish were subjected to hypoxic conditions and haemato-immunological parameters were analyzed pre- and post-challenge. Low feed ration resulted in decreased liver superoxide dismutase and catalase activities and reduced glutathione contents. Inadequate feeding also adversely affected the immune functions of fish, as was characterized by the relatively low haemato-immunological parameters (including alternative complement (ACH50), myeloperoxidase (MPO), plasma protein profiles and transferring) and high hypoxia-induced mortality. High feed ration did not lead to the improvement in antioxidant capability, immune responses and survival. In addition, plasma cortisol, glucose and transferrin levels as well as lysozyme activities all increased significantly after hypoxia challenge, whereas the opposite was true for plasma ACH50 and MPO activities as well as protein profiles in terms of hypoxia challenge. An interaction between feeding rate and hypoxia was also observed in plasma cortisol, glucose and protein profiles. In conclusion, a feeding rate of 4-5% of body weight/day is optimal to boost the innate immunity of juvenile blunt snout bream. Low ration resulted in decreased antioxidant capability, compromised immune functions and reduced hypoxia resistance, while over feeding did not benefit the health status.