Hydrocortisone Suppression Research Articles

Abstract # 3136 Diurnal variation in immune markers among caregivers of children newly diagnosed with cancer

Many human PNI studies examine associations between psychosocial factors and immune markers assessed at a single time point, without consideration of time of day (TOD). However, immune parameters show circadian variation, and stress exposure may affect these biological rhythms. We examined diurnal variation in immune markers among 120 mothers sampled at 1,6, and 12 months following their child’s cancer diagnosis. Using linear mixed models, we assessed the impact of time of blood draw on monocyte and white blood cell(WBC) concentration, peripheral levels of interleukin(IL)-6, LPS-stimulated levels of IL-6 (whole blood), and glucocorticoid receptor(GR) sensitivity (LPS, hydrocortisone suppression). Controlling for age, education, race, BMI, child’s cancer treatment intensity, and repeated measures, we found significant increases in WBC concentration (B = 1669.3cells/mL/h, p = .003), and LPS-stimulated levels of IL-6 (B = 1074.0 pg/mL/h, p = .018) over the course of the day. These findings replicate prior work showing inverse associations between daily cortisol levels and immune parameters. In contrast, we found no association between TOD and monocyte concentration, peripheral levels of IL-6, or GR sensitivity (p’s > .05). These latter results conflict with findings in healthy individuals, suggesting that in the context of stress, some immune parameters may show disruption in circadian rhythm. Possible mechanisms include disruption of environmental cues that entrain circadian rhythms, such as sleep or eating patterns. Future studies should consider the impact of TOD on blood sampling, particularly for individuals under high stress conditions.

Pharmacokinetics of intra-articular betamethasone sodium phosphate and betamethasone acetate and endogenous hydrocortisone suppression in exercising horses.

To the date, no reports exist of the pharmacokinetics (PK) of betamethasone (BTM) sodium phosphate and betamethasone acetate administered intra-articular (IA) into multiple joints in exercising horses. The purpose of the study was to determine the PK of BTM and HYD concentrations in plasma and urine after IA administration of a total of 30 mg BTM. Eight 4 years old Thoroughbred mares were exercised on a treadmill and BTM was administered IA. Plasma and urine BTM and HYD were determined via high performance liquid chromatography spectrometry for 6 weeks. Concentration-time profiles of BTM and HYD in plasma and urine were used to generate PK estimates for non-compartmental analyses and comparisons among times and HYD concentrations. BTM in plasma had greater Tmax (Tmax 0.8 h) vs. urine (Tmax 7.1 h). Urine BTM concentration (ng/mL) and amount (AUClast ; h × ng/mL) were greater than plasma. HYD was suppressed for at least 3 days (<1 ng/mL) for all horses. The time of last quantifiable concentration of BTM (Tlast ; hour) was not significantly different in plasma than urine. Use of highly sensitive HPLC-MS/MS assays enabled early detection and prolonged and consistent determination of BTM in plasma and urine.

Plasma concentration-dependent suppression of endogenous hydrocortisone in the horse after intramuscular administration of dexamethasone-21-isonicotinate.

Detection times and screening limits (SL) are methods used to ensure that the performance of horses in equestrian sports is not altered by drugs. Drug concentration-response relationship and knowledge of concentration-time profiles in both plasma and urine are required. In this study, dexamethasone plasma and urine concentration-time profiles were investigated. Endogenous hydrocortisone plasma concentrations and their relationship to dexamethasone plasma concentrations were also explored. A single dose of dexamethasone-21-isonicotinate suspension (0.03 mg/kg) was administered intramuscularly to six horses. Plasma was analysed for dexamethasone and hydrocortisone and urine for dexamethasone, using UPLC-MS/MS. Dexamethasone was quantifiable in plasma for 8.3 ± 2.9 days (LLOQ: 0.025 μg/L) and in urine for 9.8 ± 3.1 days (LLOQ: 0.15 μg/L). Maximum observed dexamethasone concentration in plasma was 0.61 ± 0.12 μg/L and in urine 4.2 ± 0.9 μg/L. Terminal plasma half-life was 38.7 ± 19 h. Hydrocortisone was significantly suppressed for 140 h. The plasma half-life of hydrocortisone was 2.7 ± 1.3 h. Dexamethasone potency, efficacy and sigmoidicity factor for hydrocortisone suppression were 0.06 ± 0.04 μg/L, 0.95 ± 0.04 and 6.2 ± 4.6, respectively. Hydrocortisone suppression relates to the plasma concentration of dexamethasone. Thus, determination of irrelevant plasma concentrations and SL is possible. Future research will determine whether hydrocortisone suppression can be used as a biomarker of the clinical effect of dexamethasone.

Hydrocortisone suppression of the fear-potentiated startle response and posttraumatic stress disorder

This study examined the effects of oral administration of 20mg hydrocortisone on baseline and fear-potentiated startle in 63 male veterans with or without PTSD. The procedure was based on a two-session, within-subject design in which acoustic startle eyeblink responses were recorded during intervals of threat or no threat of electric shock. Results showed that the magnitude of the difference between startle responses recorded during anticipation of imminent shock compared to "safe" periods was reduced after hydrocortisone administration relative to placebo. This effect did not vary as a function of PTSD group nor were there were any significant group differences in other indices startle amplitude. Findings suggest that the acute elevations in systemic cortisol produced by hydrocortisone administration may have fear-inhibiting effects. This finding may have implications for understanding the role of hypothalamic-pituitary-adrenal (HPA)-axis function in vulnerability and resilience to traumatic stress.

Hydrocortisone Suppression of the Expression of VEGF May Relate to Toll-Like Receptor (TLR) 2 and 4

Purpose: The purpose of this study was to investigate hydrocortisone's potential in inhibiting the expression of VEGF in cultured human cornea fibroblasts (HCF) and to determine whether the role of hydrocortisone in the expression of VEGF may relate to toll-like receptors 2 and 4 (TLR2 and TLR4). Methods: Three different concentrations of hydrocortisone were used to stimulate the cultured HCF. The cellular abundance of the mRNAs for VEGF and TLR2, 4 were determined by real-time polymerase chain reaction analysis. The release of IL-6, IL-8, and VEGF from cultured HCF was measured using enzyme-linked immunosorbent assays (ELISA) in the presence and absence of specific blocking antibodies to TLR2, 4. The proteins of TLR2, 4 were also compared by Western blot. Results: Following incubation of HCF with hydrocortisone, we found the mRNA expression of TLR2, 4 and VEGF were markedly inhibited. ELISA and Western blot analysis confirmed that protein expression of TLR2, 4 and VEGF was down-regulated in response to hydrocortisone. The result of ELISA also showed the release of IL-6 and IL-8 can be inhibited by hydrocortisone. But all these inhibitions were partly counteracted after pretreatment with anti-TLR2 and/or anti-TLR4 monoclonal antibody. Conclusions: Hydrocortisone may decrease the expression of VEGF through inhibiting TLR2, 4 activity in cultured human corneal fibroblasts.

Troglitazone induces CYP3A4 activity leading to falsely abnormal dexamethasone suppression test.

After evaluating a patient who appeared to have a falsely abnormal response to the dexamethasone suppression test while taking troglitazone, we examined the effects of troglitazone on the activity of hepatic CYP3A4 and the screening tests for Cushing's syndrome. We studied five healthy women and three healthy men, aged 25 +/- 2 yr, before and after treatment with troglitazone (600 mg daily) for 28 d. Baseline 0800 h cortisol and corticosterone were similar before and after troglitazone treatment. Before troglitazone treatment, all subjects suppressed 0800 h cortisol below 1.8 micro g/dl (mean, 0.66 +/- 0.08 micro g/dl) during the 1-mg overnight dexamethasone suppression test (DST), whereas during troglitazone treatment none of the subjects suppressed 0800 h cortisol below 1.8 micro g/dl (mean, 9.0 +/- 1.8 micro g/dl). Serum dexamethasone levels decreased by 66 +/- 4%, and the erythromycin breath test measurements increased by 27 +/- 8%, indicating increased CYP3A4 activity during troglitazone treatment. The hydrocortisone suppression test (HST) was performed by administering 50 mg hydrocortisone at 2300 h. Using the criterion of suppression of 0800 h plasma corticosterone by more than 50%, the specificity of the HST was 100% both before and after troglitazone treatment. In conclusion, troglitazone induced the activity of CYP3A4 leading to falsely abnormal DST. HST is a useful alternative to the DST in patients taking medications that increase the activity of CYP3A4.

Paper Chromatography prior to Cortisol RIA Allows for Accurate Use of the Dexamethasone Suppression Test in Chronic Renal Failure

The assessment of the hypothalamic-pituitary-adrenal axis in patients with chronic renal failure (CRF) on hemodialysis is often hampered by abnormal responses to the standard 1-mg dexamethasone suppression test. Various mechanisms have been proposed to explain this lack of suppressibility. The present study was designed to look into the mechanisms possible for these findings in patients with CRF. We studied 6 patients with CRF on hemodialysis and 5 healthy subjects utilizing the 1-mg dexamethasone suppression test as well as the 50-mg hydrocortisone suppression test. Samples were assayed for dexamethasone, adrenocorticotropic hormone, corticosterone, and cortisol by both direct radioimmunoassay (RIA) and RIA after paper chromatography. Utilizing the direct cortisol RIA, 4 of 6 patients with CRF exhibited blunted dexamethasone suppression, while all 6 patients showed normal suppressibility after dexamethasone when cortisol was measured after paper chromatography. In contrast, all controls showed normal suppressibility regardless of the cortisol assay procedure used. The hydrocortisone suppression test was unreliable in the setting of CRF. Mean dexamethasone levels were similar in both groups. Plasma adrenocorticotropic hormone levels were significantly higher in the CRF patients, possibly indicative of an underlying hypothalamic-pituitary-adrenal axis abnormality. Abnormalities in dexamethasone suppression testing in patients with CRF may be explained by the overestimation of cortisol levels by direct RIA rather than by alteration of dexamethasone absorption or metabolism. Measurement of cortisol after paper chromatography is superior to direct RIA of cortisol in patients with CRF.

Differential effects of hydrocortisone and dexamethasone on cortisol suppression in a child psychiatric population.

The suppressive effect of hydrocortisone and dexamethasone on salivary cortisol was investigated in a 2-year study of pituitary-adrenal function in a variety of child psychiatric patients and healthy controls. Symptomatology was assessed using the Child Behavioral Checklist (CBCL). Cortisol day profiles were assessed at 2-h intervals from 0800 to 2000 h on three occasions. Dexamethasone and hydrocortisone were administered orally twice at 2000 h, the doses being adjusted for bodyweight according to the standard dexamethasone suppression test. Fifty-one patients, including patients with dysthymia, oppositional defiant disorder, pervasive developmental disorder, and attention deficit hyperactivity disorder, and ten age and sex matched controls participated. Basal cortisol levels in patients were generally lower than in controls. Both dexamethasone and hydrocortisone were effective in suppressing salivary cortisol, although dexamethasone was somewhat more potent and its effect lasted longer. Hyporesponsiveness to hydrocortisone, but not to dexamethasone, distinguished patients with dysthymia and oppositional defiant disorder from controls. Responsiveness to hydrocortisone was correlated with the symptom clusters social problems and anxious/depressed. The data support the idea that there exist syndrome aspecific disturbances in feedback activity beyond the level of the pituitary, i.e. at the hypothalamic level, at an early age. From this perspective, hydrocortisone suppression is a useful tool for studying pituitary-adrenal function in children. Behavioral correlates of these disturbances of pituitary-adrenal function should be determined.

Sensitivity to hydrocortisone is a relevant factor in the immunoendocrine relationship: I. The cell-mediated immune response in relation to blood levels and in vitro immunosuppressive effects of hydrocortisone in patients with asthma and healthy control subjects

The role of endogenous hydrocortisone in the regulation of lymphocyte activity was assayed in patients with asthma (patients with chronic nonspecific lung disease, characterized by attacks of dypsnea, alternating with symptom-free periods) and healthy control subjects. After priming, delayed-type hypersensitivity skin reactions were induced with Helix pomatia hemocyanin (HPH). Hydrocortisone blood levels were measured. The effect of hydrocortisone on HPH-induced lymphocyte proliferation was determined in vitro. The results demonstrate that hydrocortisone in low concentrations (100 ng/ml) inhibited in vitro lymphocyte proliferation equally in patients and control subjects. However, both groups demonstrated a large interindividual variation in hydrocortisone sensitivity. Therefore, in order to determine the immunologic effect of hydrocortisone blood levels in vivo, a hydrocortisone suppression index (HSI) was calculated by use of the information on hydrocortisone concentrations in vivo and the biologic effect of hydrocortisone in vitro. This HSI appeared to be inversely related with the in vivo cell-mediated immune response to HPH. This was reflected in an inverse correlation between HSI and delayed-type hypersensitivity skin reactions to HPH, both in patients (R = −0.64), in control subjects (R = −0.69), and in the total group (R = −0.68; p < 0.001). No differences were observed between patients and control subjects. It is concluded that endogenous hydrocortisone is likely to play an important role in the regulation of lymphocyte activity in patients with asthma and healthy control subjects. This may have important consequences for the clinical expression of asthmatic symptoms, since the role of lymphocyte activity in the pathogenesis of asthma is increasingly recognized.

Pharmacokinetics and pharmacodynamics of glucocorticoid suspensions after intra-articular administration.

Triamcinolone acetonide, triamcinolone hexacetonide, and a combination of betamethasone phosphate and acetate were given intra-articularly in different doses. Plasma levels of the steroids were measured and pharmacokinetic parameters were calculated. As a pharmacodynamic parameter for systemic steroid activity, plasma hydrocortisone levels were monitored for 3 weeks. Results indicate complete absorption from the site of injection over a period of 2 to 3 weeks. Because of its lower solubility, triamcinolone hexacetonide is absorbed slower than triamcinolone acetonide, thus maintaining synovial levels for a longer time and creating lower systemic corticoid levels. Endogenous hydrocortisone suppression correlated with exogenous steroid levels. Threshold concentrations for maximum suppression were determined.

Effect of dose size on the pharmacokinetics of intravenous hydrocortisone during endogenous hydrocortisone suppression.

The pharmacokinetics of hydrocortisone were examined following single intravenous doses of 5, 10, 20, and 40 mg hydrocortisone, as the sodium succinate salt, to healthy male volunteers. Endogenous hydrocortisone was suppressed by administration of 2 mg dexamethasone the night before hydrocortisone injection. Plasma samples obtained serially during 8 h after hydrocortisone injection were assayed by reverse-phase HPLC using a fixed wavelength (254 nm) ultraviolet detector. Initial concentrations of hydrocortisone in plasma were proportional to dose size. The subsequent decline in hydrocortisone concentrations was biphasic, and individual data sets were adequately described in terms of the pharmacokinetic two-compartment open model. Values of pharmacokinetic parameters were similar from the 5, 10, and 20 mg doses. Following the 40 mg dose, the overall elimination rate constant decreased, while the distribution volume, Vdss, and plasma clearance increased, in comparison with the values obtained from lower doses. Changes in the pharmacokinetics of hydrocortisone at high doses may be related to drug concentration-dependent changes in the binding of hydrocortisone to plasma proteins. Previously reported dose-dependent changes in some pharmacokinetic parameters following oral hydrocortisone are attributed to absorption rather than distribution or elimination effects.

The effect of different treatment regimens on hormonal profiles in congenital adrenal hyperplasia.

Optimal steroid therapy for patients with congenital adrenal hyperplasia (CAH) is still controversial. While hydrocortisone suppression therapy (20–25 mg/m2·day) has received acceptance, the use of nocturnal synthetic glucocorticoids and the control of renin secretion by mineralocorticoids have recently been recommended. To determine the relative merits of these treatments, hormonal profiles have been obtained in six patients (aged 10–16 yr; three with salt wasting and three with simple virilizing 21-hydroxylase CAH) who were stabilized for at least 3 months on 1) nocturnal dexamethasone (0.25–0.75 mg/ day) and 2) twice daily hydrocortisone (25 mg/m2·day) therapy. The effect of changes in mineralocorticoid therapy was also studied. Profiles for cortisol, 17-hydroxyprogesterone (17OHP), and ACTH were determined by hourly venous sampling for 24 h. Nocturnal secretion of ACTH and renin (PRA) was assessed by half-hourly sampling from 0200–0800 h. GH secretion was assessed by sampling during slow wave sleep. P...

HYDROCORTISONE SUPPRESSION TEST AND DISCRIMINANT ANALYSIS IN DIFFERENTIAL DIAGNOSIS OF HYPERCALCÆMIA

Experience is reported of the hydrocortisone suppression test in 140 hypercalcæmic patients, comprising 98 new cases of hyperparathyroidism and 42 cases of non-parathyroid malignant disease. The diagnostic accuracy of the test was compared in 168 patients with that of discriminant analysis, the discriminant functions being derived from plasma inorganic phosphate, alkaline phosphatase, chloride, bicarbonate, and urea, and the erythrocyte sedimentation rate. The hydrocortisone test and discriminant analysis each achieved a diagnostic accuracy of about 93% in 148 patients with either non-parathyroid malignant disease or hyperparathyroidism without osteitis fibrosa. When both tests pointed to the same diagnosis, they were wrong in less than 1% of cases. The hydrocortisone test was not helpful in patients with osteitis fibrosa. Both tests can be performed in any hospital with reliable standard laboratory services. Used in combination they have a high predictive value in distinguishing hypercalcæmia of parathyroid origin from that due to non-parathyroid malignant disease and have not led to errors of clinical importance. They should continue to play a major role in the differential diagnosis of hypercalcæmia until a prompt and reliable service finally establishes parathyroid hormone assay as the definitive laboratory procedure.

Hydrocortisone Suppression Test for Cushing Syndrome

To develop a reliable suppression test for corticotropin (adrenocorticotrophic hormone, ACTH) for use in patients receiving anticonvulsant drugs, we selected hydrocortisone suppression of plasma corticosterone (B), whose secretion is regulated by corticotropin, thus eliminating the drug interference observed with the dexamethasone suppression test. By estimating an 8 AM base line plasma B concentration and administering 50 mg of hydrocortisone orally at midnight, we could evaluate its effect on plasma B suppression the following morning at 8 AM. The overnight suppression tests with 1 mg of dexamethasone and 50 mg of hydrocortisone reduced the plasma B concentration to less than 50% of the base line value and to less than 120 ng/deciliter in control subjects, but they failed to result in suppression in patients with Cushing syndrome. The 1-mg dose of dexamethasone caused no suppression in patients treated with anticonvulsants, whereas following hydrocortisone, base line plasma concentrations were reduced by more than 50%. The test appears to be as reliable a screening test for Cushing syndrome in drug-treated patients as the overnight dexamethasone suppression test is in patients not receiving drugs.