Subcutaneous pulsatile glucocorticoid replacement therapy

Dual-release hydrocortisone improves body composition and the glucometabolic profile in patients with secondary adrenal insufficiency

PURPOSE

Studies have suggested improved metabolic profiles in patients with adrenal insufficiency treated with dual-release hydrocortisone (DR-HC) compared with conventional hydrocortisone (C-HC). This study investigates the effect of DR-HC compared with C-HC treatment on five health variables: diurnal salivary cortisol/cortisone, body composition, bone health, glucose metabolism, lipids, and blood pressure.

METHODS

Prospective study of 27 participants (24 men) with secondary adrenal insufficiency with measurements during stable C-HC and 16 weeks after treatment switch to DR-HC.

OUTCOMES

Diurnal salivary-cortisol/cortisone, body composition assessed by Dual-Energy X-ray absorptiometry scan, bone status indices (serum type I N-terminal procollagen [PINP], collagen type I cross-linked C-telopeptide [CTX], osteocalcin, receptor activator kappa-B [RANK] ligand, osteoprotegerin, and sclerostin), lipids, haemoglobin A1c (HbA1c), and 24-hour blood pressure.

RESULTS

After the switch to DR-HC, the diurnal salivary-cortisol area under the curve (AUC) decreased non-significantly (mean difference: -55.9 nmol/L/day, P = 0.06). The salivary-cortisone-AUC was unchanged. Late-evening salivary-cortisol and cortisone were lower (-1.6 and -1.7 nmol/L, P = 0.002 and 0.004). Total and abdominal fat mass (-1.5 and -0.5 kg, P = 0.003 and 0.02), HbA1c (-1.2 mmol/mol, P = 0.02), and osteocalcin decreased (-7.0 µg/L, P = 0.03) whereas sclerostin increased (+41.1 pg/mL, P = 0.0001). The remaining bone status indices, lipids, and blood pressure were unchanged.

CONCLUSION

This study suggests that switching to DR-HC leads to lower late-evening cortisol/cortisone exposure and a more favourable metabolic profile and body composition. In contrast, decreased osteocalcin with increasing sclerostin might indicate a negative impact on bones.

CLINICAL TRIAL REGISTRATION

EudraCT201400203932.

Ultradian hydrocortisone replacement alters neuronal processing, emotional ambiguity, affect and fatigue in adrenal insufficiency: The PULSES trial

BACKGROUND

Primary adrenal insufficiency (PAI) mortality and morbidity remain unacceptably high, possibly arising as glucocorticoid replacement does not replicate natural physiology. A pulsatile subcutaneous pump can closely replicate cortisol's circadian and ultradian rhythm.

OBJECTIVES

To assess the effect of pump therapy on quality of life, mood, functional neuroimaging, behavioural/cognitive responses, sleep and metabolism.

METHODS

A 6-week randomised, crossover, double-blinded and placebo-controlled feasibility study of usual dose hydrocortisone in PAI administered as either pulsed subcutaneous or standard care in Bristol, United Kingdom (ISRCTN67193733). Participants were stratified by adrenal insufficiency type. All participants who received study drugs are included in the analysis. The primary outcome, the facial expression recognition task (FERT), occurred at week 6.

RESULTS

Between December 2014 and 2017, 22 participants were recruited - 20 completed both arms, and 21 were analysed. The pump was well-tolerated. No change was seen in the FERT primary outcome; however, there were subjective improvements in fatigue and mood. Additionally, functional magnetic resonance imaging revealed differential neural processing to emotional cues and visual stimulation. Region of interest analysis identified the left amygdala and insula, key glucocorticoid-sensitive regions involved in emotional ambiguity. FERT post hoc analysis confirmed this response. There were four serious adverse events (AE): three intercurrent illnesses requiring hospitalisation (1/3, 33.3% pump) and a planned procedure (1/1, 100% pump). There was a small number of expected AEs: infusion site bruising/itching (3/5, 60% pump), intercurrent illness requiring extra (3/7, 42% pump) and no extra (4/6, 66% pump) steroid.

CONCLUSIONS

These findings support the administration of hormone therapy that mimics physiology.

Recent Advances in Multiplexed Wearable Sensor Platforms for Real-Time Monitoring Lifetime Stress: A Review

Researchers are interested in measuring mental stress because it is linked to a variety of diseases. Real-time stress monitoring via wearable sensor systems can aid in the prevention of stress-related diseases by allowing stressors to be controlled immediately. Physical tests, such as heart rate or skin conductance, have recently been used to assess stress; however, these methods are easily influenced by daily life activities. As a result, for more accurate stress monitoring, validations requiring two or more stress-related biomarkers are demanded. In this review, the combinations of various types of sensors (hereafter referred to as multiplexed sensor systems) that can be applied to monitor stress are discussed, referring to physical and chemical biomarkers. Multiplexed sensor systems are classified as multiplexed physical sensors, multiplexed physical-chemical sensors, and multiplexed chemical sensors, with the effect of measuring multiple biomarkers and the ability to measure stress being the most important. The working principles of multiplexed sensor systems are subdivided, with advantages in measuring multiple biomarkers. Furthermore, stress-related chemical biomarkers are still limited to cortisol; however, we believe that by developing multiplexed sensor systems, it will be possible to explore new stress-related chemical biomarkers by confirming their correlations to cortisol. As a result, the potential for further development of multiplexed sensor systems, such as the development of wearable electronics for mental health management, is highlighted in this review.

Cell Networks in Endocrine/Neuroendocrine Gland Function

Reproduction, growth, stress, and metabolism are determined by endocrine/neuroendocrine systems that regulate circulating hormone concentrations. All these systems generate rhythms and changes in hormone pulsatility observed in a variety of pathophysiological states. Thus, the output of endocrine/neuroendocrine systems must be regulated within a narrow window of effective hormone concentrations but must also maintain a capacity for plasticity to respond to changing physiological demands. Remarkably most endocrinologists still have a "textbook" view of endocrine gland organization which has emanated from 20^th century histological studies on thin 2D tissue sections. However, 21^st -century technological advances, including in-depth 3D imaging of specific cell types have vastly changed our knowledge. We now know that various levels of multicellular organization can be found across different glands, that organizational motifs can vary between species and can be modified to enhance or decrease hormonal release. This article focuses on how the organization of cells regulates hormone output using three endocrine/neuroendocrine glands that present different levels of organization and complexity: the adrenal medulla, with a single neuroendocrine cell type; the anterior pituitary, with multiple intermingled cell types; and the pancreas with multiple intermingled cell types organized into distinct functional units. We give an overview of recent methodologies that allow the study of the different components within endocrine systems, particularly their temporal and spatial relationships. We believe the emerging findings about network organization, and its impact on hormone secretion, are crucial to understanding how homeostatic regulation of endocrine axes is carried out within endocrine organs themselves. © 2022 American Physiological Society. Compr Physiol 12:3371-3415, 2022.

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.

Applications of cosinor rhythmometry in pharmacology

Study design and data analysis are two important aspects relevant to chronopharmacometrics. Blunders can be avoided by recognizing that most physiological variables are circadian periodic. Both ill health and treatment can affect the amplitude, phase, and/or period of circadian (and other) rhythms, in addition to their mean. The involvement of clock genes in molecular pathways related to important physiological systems underlies the bidirectional relationship often seen between circadian rhythm disruption and disease risk. Circadian rhythm characteristics of marker rhythms interpreted in the light of chronobiologic reference values represent important diagnostic tools. A set of cosinor-related programs is presented. They include the least squares fit of multiple-frequency cosine functions to model the time structure of individual records; a cosinor-based spectral analysis to detect periodic signals; the population-mean cosinor to generalize inferences; the chronobiologic serial section to follow the time course of changing rhythm parameters over time; and parameter tests to assess differences among populations. Relative merits of other available cosinor and non-parametric algorithms are reviewed. Parameter tests to compare individual records and a self-starting cumulative sum (CUSUM) make personalized chronotherapy possible, where the treatment of each patient relies on an N-of-1 design. Methods are illustrated in a few examples relevant to endocrinology, cancer and cardiology. New sensing technology yielding large personal data sets is likely to change the healthcare system. Chronobiologic concepts and methods should become an integral part of these evolving systems.

Therapy options for adrenal insufficiency and recommendations for the management of adrenal crisis

Adrenal insufficiency (AI) is a life-threatening condition requiring life-long glucocorticoid (GC) substitution therapy, as well as stress adaptation to prevent adrenal crises. The number of individuals with primary and secondary adrenal insufficiency in Europe is estimated to be 20-50/100.000. A growing number of AI cases are due to side effects of GC treatment used in different treatment strategies for cancer and to immunotherapy in cancer treatment. The benefit of hormone replacement therapy is evident but long-term adverse effects may arise due to the non-physiological GC doses and treatment regimens used. Given multiple GC replacement formulations available comprising short-acting, intermediate, long-acting and novel modified-release hydrocortisone as well as subcutaneous formulations, this review offers a concise summary on the latest therapeutic improvements for treatment of AI and prevention of adrenal crises. As availability of various glucocorticoid formulations and access to expert centers across Europe varies widely, European Reference Networks on rare endocrine conditions aim at harmonizing treatment and ensure access to specialized patient care for individual case-by-case treatment decisions. To improve the availability across Europe to cost effective oral and parenteral formulations of hydrocortisone will save lives.

Dynamics of ACTH and Cortisol Secretion and Implications for Disease

The past decade has seen several critical advances in our understanding of hypothalamic-pituitary-adrenal (HPA) axis regulation. Homeostatic physiological circuits need to integrate multiple internal and external stimuli and provide a dynamic output appropriate for the response parameters of their target tissues. The HPA axis is an example of such a homeostatic system. Recent studies have shown that circadian rhythmicity of the major output of this system-the adrenal glucocorticoid hormones corticosterone in rodent and predominately cortisol in man-comprises varying amplitude pulses that exist due to a subhypothalamic pulse generator. Oscillating endogenous glucocorticoid signals interact with regulatory systems within individual parts of the axis including the adrenal gland itself, where a regulatory network can further modify the pulsatile release of hormone. The HPA axis output is in the form of a dynamic oscillating glucocorticoid signal that needs to be decoded at the cellular level. If the pulsatile signal is abolished by the administration of a long-acting synthetic glucocorticoid, the resulting disruption in physiological regulation has the potential to negatively impact many glucocorticoid-dependent bodily systems. Even subtle alterations to the dynamics of the system, during chronic stress or certain disease states, can potentially result in changes in functional output of multiple cells and tissues throughout the body, altering metabolic processes, behavior, affective state, and cognitive function in susceptible individuals. The recent development of a novel chronotherapy, which can deliver both circadian and ultradian patterns, provides great promise for patients on glucocorticoid treatment.

Dynamic Pituitary-Adrenal Interactions in the Critically Ill after Cardiac Surgery

CONTEXT

Patients with critical illness are thought to be at risk of adrenal insufficiency. There are no models of dynamic hypothalamic-pituitary-adrenal (HPA) axis function in this group of patients and thus current methods of diagnosis are based on aggregated, static models.

OBJECTIVE

To characterize the secretory dynamics of the HPA axis in the critically ill (CI) after cardiac surgery.

DESIGN

Mathematical modeling of cohorts.

SETTING

Cardiac critical care unit.

PATIENTS

20 male patients CI at least 48 hours after cardiac surgery and 19 healthy (H) male volunteers.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Measures of hormone secretory dynamics were generated from serum adrenocorticotrophic hormone (ACTH) sampled every hour and total cortisol every 10 min for 24 h.

RESULTS

All CI patients had pulsatile ACTH and cortisol profiles. CI patients had similar ACTH secretion (1036.4 [737.6] pg/mL/24 h) compared to the H volunteers (1502.3 [1152.2] pg/mL/24 h; P = .20), but increased cortisol secretion (CI: 14 447.0 [5709.3] vs H: 5915.5 [1686.7)] nmol/L/24 h; P < .0001). This increase in cortisol was due to nonpulsatile (CI: 9253.4 [3348.8] vs H: 960 [589.0] nmol/L/24 h, P < .0001), rather than pulsatile cortisol secretion (CI: 5193.1 [3018.5] vs H: 4955.1 [1753.6] nmol/L/24 h; P = .43). Seven (35%) of the 20 CI patients had cortisol pulse nadirs below the current international guideline threshold for critical illness-related corticosteroid insufficiency, but an overall secretion that would not be considered deficient.

CONCLUSIONS

This study supports the premise that current tests of HPA axis function are unhelpful in the diagnosis of adrenal insufficiency in the CI. The reduced ACTH and increase in nonpulsatile cortisol secretion imply that the secretion of cortisol is driven by factors outside the HPA axis in critical illness.

Improving glucocorticoid replacement profiles in adrenal insufficiency

There is an increased mortality associated with adrenal insufficiency despite glucocorticoid replacement therapy with a standardized mortality ratio greater than two. The cause of the increased mortality is yet to be definitively elucidated, but may be due to excess steroid exposure, or replacement regimens that are uncoupled from the normal physiological cortisol profile. Cortisol secretion follows an ultradian pattern which is not possible to reproduce using oral replacement. With the advent of new pumps, it is now possible to mimic the pulsatility of the adrenal glands. While the cognitive and emotional benefits of reproducing the ultradian rhythm are known, the presence of long-term benefits is not yet clear. There is a dearth of evidence and high-quality studies to underline our current understanding of the pathophysiology of adrenal insufficiency and replacement therapy. There is a particular lack of research comparing objective outcomes between patients receiving hydrocortisone replacement (either standard therapy or new sustained release preparations), prednisolone replacement and ultradian pumps. Direct comparative studies are now warranted to understand the optimal approach.

Mathematical Modelling of Endocrine Systems

Hormone rhythms are ubiquitous and essential to sustain normal physiological functions. Combined mathematical modelling and experimental approaches have shown that these rhythms result from regulatory processes occurring at multiple levels of organisation and require continuous dynamic equilibration, particularly in response to stimuli. We review how such an interdisciplinary approach has been successfully applied to unravel complex regulatory mechanisms in the metabolic, stress, and reproductive axes. We discuss how this strategy is likely to be instrumental for making progress in emerging areas such as chronobiology and network physiology. Ultimately, we envisage that the insight provided by mathematical models could lead to novel experimental tools able to continuously adapt parameters to gradual physiological changes and the design of clinical interventions to restore normal endocrine function.

MANAGEMENT OF ENDOCRINE DISEASE: Congenital adrenal hyperplasia due to 21-hydroxylase deficiency: update on the management of adult patients and prenatal treatment

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is characterized by cortisol and in some cases aldosterone deficiency associated with androgen excess. Goals of treatment are to replace deficient hormones and control androgen excess, while avoiding the adverse effects of exogenous glucocorticoid. Over the last 5 years, cohorts of adults with CAH due to 21-hydroxylase deficiency from Europe and the United States have been described, allowing us to have a better knowledge of long-term complications of the disease and its treatment. Patients with CAH have increased mortality, morbidity and risk for infertility and metabolic disorders. These comorbidities are due in part to the drawbacks of the currently available glucocorticoid therapy. Consequently, novel therapies are being developed and studied in an attempt to improve patient outcomes. New management strategies in the care of pregnancies at risk for congenital adrenal hyperplasia using fetal sex determination and dexamethasone have also been described, but remain a subject of debate. We focused the present overview on the data published in the last 5 years, concentrating on studies dealing with cardiovascular risk, fertility, treatment and prenatal management in adults with classic CAH to provide the reader with an updated review on this rapidly evolving field of knowledge.

Corticosteroids in septic shock: a systematic review and network meta-analysis

Background

Multiple corticosteroids and treatment regimens have been used as adjuncts in the treatment of septic shock. Qualitative and quantitative differences exist at cellular and tissular levels between the different drugs and their patterns of delivery. The objective of this study was to elucidate any differences between the drugs and their treatment regimens regarding outcomes for corticosteroid use in adult patients with septic shock.

Methods

Network meta-analysis of the data used for the recently conducted Cochrane review was performed. Studies that included children and were designed to assess respiratory function in pneumonia and acute respiratory distress syndrome, as well as cross-over studies, were excluded. Network plots were created for each outcome, and all analyses were conducted using a frequentist approach assuming a random-effects model.

Results

Complete data from 22 studies and partial data from 1 study were included. Network meta-analysis provided no clear evidence that any intervention or treatment regimen is better than any other across the spectrum of outcomes. There was strong evidence of differential efficacy in only one area: shock reversal. Hydrocortisone boluses and infusions were more likely than methylprednisolone boluses and placebo to result in shock reversal.

Conclusions

There was no clear evidence that any one corticosteroid drug or treatment regimen is more likely to be effective in reducing mortality or reducing the incidence of gastrointestinal bleeding or superinfection in septic shock. Hydrocortisone delivered as a bolus or as an infusion was more likely than placebo and methylprednisolone to result in shock reversal.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1659-4) contains supplementary material, which is available to authorized users.

The Functional and Clinical Significance of the 24-Hour Rhythm of Circulating Glucocorticoids

Adrenal glucocorticoids are major modulators of multiple functions, including energy metabolism, stress responses, immunity, and cognition. The endogenous secretion of glucocorticoids is normally characterized by a prominent and robust circadian (around 24 hours) oscillation, with a daily peak around the time of the habitual sleep-wake transition and minimal levels in the evening and early part of the night. It has long been recognized that this 24-hour rhythm partly reflects the activity of a master circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus. In the past decade, secondary circadian clocks based on the same molecular machinery as the central master pacemaker were found in other brain areas as well as in most peripheral tissues, including the adrenal glands. Evidence is rapidly accumulating to indicate that misalignment between central and peripheral clocks has a host of adverse effects. The robust rhythm in circulating glucocorticoid levels has been recognized as a major internal synchronizer of the circadian system. The present review examines the scientific foundation of these novel advances and their implications for health and disease prevention and treatment.

Novel treatment strategies in congenital adrenal hyperplasia

PURPOSE OF REVIEW

In recent years, important steps have been taken to improve the treatment of congenital adrenal hyperplasia (CAH), a relatively stagnant area for decades. In this review, we summarize these advances and propose future lines of investigation.

RECENT FINDINGS

The two main goals of CAH treatment are to replace the deficient hormones when necessary and to dampen the adrenocorticotropin activation and the ensuing adrenal androgen excess. Glucocorticoids have been the mainstay of CAH treatment, but available preparations only partially meet the clinical needs. Recent efforts have focused on improving the delivery of glucocorticoid replacement agents, to closer mimic the physiologic secretion pattern. Examples include modified release oral glucocorticoids and continuous subcutaneous hydrocortisone pumps. Furthermore, nonglucocorticoid approaches to address the androgen excess have emerged, such as inhibition of key androgenic enzymes and adrenocorticotropin secretion blockade by corticotropin-releasing hormone receptor antagonists.

SUMMARY

The promising recent progress made in CAH treatment brings new perspectives for individualized care in this complex disease.

Dynamic transitions in a model of the hypothalamic-pituitary-adrenal axis

Dynamic properties of a nonlinear five-dimensional stoichiometric model of the hypothalamic-pituitary-adrenal (HPA) axis were systematically investigated. Conditions under which qualitative transitions between dynamic states occur are determined by independently varying the rate constants of all reactions that constitute the model. Bifurcation types were further characterized using continuation algorithms and scale factor methods. Regions of bistability and transitions through supercritical Andronov-Hopf and saddle loop bifurcations were identified. Dynamic state analysis predicts that the HPA axis operates under basal (healthy) physiological conditions close to an Andronov-Hopf bifurcation. Dynamic properties of the stress-control axis have not been characterized experimentally, but modelling suggests that the proximity to a supercritical Andronov-Hopf bifurcation can give the HPA axis both, flexibility to respond to external stimuli and adjust to new conditions and stability, i.e., the capacity to return to the original dynamic state afterwards, which is essential for maintaining homeostasis. The analysis presented here reflects the properties of a low-dimensional model that succinctly describes neurochemical transformations underlying the HPA axis. However, the model accounts correctly for a number of experimentally observed properties of the stress-response axis. We therefore regard that the presented analysis is meaningful, showing how in silico investigations can be used to guide the experimentalists in understanding how the HPA axis activity changes under chronic disease and/or specific pharmacological manipulations.

Diagnosis and Treatment of Primary Adrenal Insufficiency: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

This clinical practice guideline addresses the diagnosis and treatment of primary adrenal insufficiency.

PARTICIPANTS

The Task Force included a chair, selected by The Clinical Guidelines Subcommittee of the Endocrine Society, eight additional clinicians experienced with the disease, a methodologist, and a medical writer. The co-sponsoring associations (European Society of Endocrinology and the American Association for Clinical Chemistry) had participating members. The Task Force received no corporate funding or remuneration in connection with this review.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to determine the strength of recommendations and the quality of evidence.

CONSENSUS PROCESS

The evidence used to formulate recommendations was derived from two commissioned systematic reviews as well as other published systematic reviews and studies identified by the Task Force. The guideline was reviewed and approved sequentially by the Endocrine Society's Clinical Guidelines Subcommittee and Clinical Affairs Core Committee, members responding to a web posting, and the Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments.

CONCLUSIONS

We recommend diagnostic tests for the exclusion of primary adrenal insufficiency in all patients with indicative clinical symptoms or signs. In particular, we suggest a low diagnostic (and therapeutic) threshold in acutely ill patients, as well as in patients with predisposing factors. This is also recommended for pregnant women with unexplained persistent nausea, fatigue, and hypotension. We recommend a short corticotropin test (250 μg) as the "gold standard" diagnostic tool to establish the diagnosis. If a short corticotropin test is not possible in the first instance, we recommend an initial screening procedure comprising the measurement of morning plasma ACTH and cortisol levels. Diagnosis of the underlying cause should include a validated assay of autoantibodies against 21-hydroxylase. In autoantibody-negative individuals, other causes should be sought. We recommend once-daily fludrocortisone (median, 0.1 mg) and hydrocortisone (15-25 mg/d) or cortisone acetate replacement (20-35 mg/d) applied in two to three daily doses in adults. In children, hydrocortisone (∼8 mg/m(2)/d) is recommended. Patients should be educated about stress dosing and equipped with a steroid card and glucocorticoid preparation for parenteral emergency administration. Follow-up should aim at monitoring appropriate dosing of corticosteroids and associated autoimmune diseases, particularly autoimmune thyroid disease.

Effects of the pattern of glucocorticoid replacement on neural processing, emotional reactivity and well-being in healthy male individuals: study protocol for a randomised controlled trial

Background

Deviation from the physiological glucocorticoid dynamics (circadian and underlying ultradian rhythmicity) is a common characteristic of various neuropsychiatric and endocrine disorders as well as glucocorticoid-based therapeutics. These states may be accompanied by neuropsychiatric symptomatology, suggesting continuous dynamic glucocorticoid equilibrium is essential for brain homeostasis.

Methods/design

The study consists of two parts. The preliminary stage of the study aims to validate (technically and pharmacologically) and optimise three different patterns of systemic cortisol administration in man. These patterns are based on the combinatory administration of metyrapone, to suppress endogenous cortisol production, and concurrent hydrocortisone replacement. The second, subsequent, core part of the study is a randomised, double-blinded, placebo-controlled, crossover study, where participants (healthy male individuals aged 18–60 years) will undergo all three hydrocortisone replacement schemes. During these infusion regimes, we plan a number of neurobehavioural tests and imaging of the brain to assess neural processing, emotional reactivity and perception, mood and self-perceived well-being. The psychological tests include: ecological momentary assessment, P1vital Oxford Emotional Test Battery and Emotional Potentiated Startle Test, Leeds Sleep Evaluation Questionnaire and the visual working memory task (n-back). The neuroimaging protocol combines magnetic resonance sequences that capture data related to the functional and perfusion status of the brain.

Discussion

Results of this clinical trial are designed to evaluate the impact (with possible mechanistic insights) of different patterns of daily glucocorticoid dynamics on neural processing and reactivity related to emotional perception and mood. This evidence should contribute to the optimisation of the clinical application of glucocorticoid-based therapeutics.

Trial registration

UK Clinical Research Network, IRAS Ref: 106181, UKCRN-ID-15236 (23 October 2013)

Using Cox cluster processes to model latent pulse location patterns in hormone concentration data

Many hormones, including stress hormones, are intermittently secreted as pulses. The pulsatile location process, describing times when pulses occur, is a regulator of the entire stress system. Characterizing the pulse location process is particularly difficult because the pulse locations are latent; only hormone concentration at sampled times is observed. In addition, for stress hormones the process may change both over the day and relative to common external stimuli. This potentially results in clustering in pulse locations across subjects. Current approaches to characterizing the pulse location process do not capture subject-to-subject clustering in locations. Here we show how a Bayesian Cox cluster process may be adapted as a model of the pulse location process. We show that this novel model of pulse locations is capable of detecting circadian rhythms in pulse locations, clustering of pulse locations between subjects, and identifying exogenous controllers of pulse events. We integrate our pulse location process into a model of hormone concentration, the observed data. A spatial birth-and-death Markov chain Monte Carlo algorithm is used for estimation. We exhibit the strengths of this model on simulated data and adrenocorticotropic and cortisol data collected to study the stress axis in depressed and non-depressed women.

Subcutaneous fluid and drug delivery: safe, efficient and inexpensive

Patients with difficult venous access or oral intolerance and clinical situations with inadequate response to oral therapy have generated the need for alternative routes of delivery for drugs and fluids.

The purpose of this study was to conduct a systematic review examining the evidence for subcutaneous (SC) administration of drugs and/or fluids.

We used a broad search strategy using electronic databases CINAHL, EMBASE, PubMed and Cochrane library, key terms and ‘Medical Subject Headings’ (MeSH) such as ‘subcutaneous route’, ‘hypodermoclysis’ and the name/group of the most used drugs via this route (e.g. ‘ketorolac, morphine, ceftriaxone’, ‘analgesics, opioids, antibiotics’).

We conclude that the SC route is an effective alternative for rehydration in patients with mild–moderate dehydration and offers a number of potential advantages in appropriately selected scenarios. Experience of administering drugs by this route suggests that it is well tolerated and is associated with minimal side-effects.

A phase 2 study of Chronocort, a modified-release formulation of hydrocortisone, in the treatment of adults with classic congenital adrenal hyperplasia

CONTEXT

Treatment of congenital adrenal hyperplasia (CAH) is suboptimal. Inadequate suppression of androgens and glucocorticoid excess are common and current glucocorticoid formulations cannot replace the cortisol circadian rhythm.

OBJECTIVES

The primary objective was to characterize the pharmacokinetic profile of Chronocort, a modified-release hydrocortisone formulation, in adults with CAH. Secondary objectives included examining disease control following 6 months of Chronocort with dose titration.

DESIGN, SETTING, AND PATIENTS

Sixteen adults (eight females) with classic CAH participated in an open-label, nonrandomized, Phase 2 study at the National Institutes of Health Clinical Center. Twenty-four-hour blood sampling was performed on conventional glucocorticoids and following 6 months of Chronocort. Chronocort was initiated at 10 mg (0700 h) and 20 mg (2300 h). Dose titration was performed based on androstenedione and 17-hydroxyprogresterone (17-OHP) levels and clinical symptomatology.

MAIN OUTCOME MEASURES

The primary outcome was cortisol pharmacokinetics of Chronocort and secondary outcomes included biomarkers of CAH control (androstenedione and 17-OHP).

RESULTS

In patients with CAH, Chronocort cortisol profiles were similar to physiologic cortisol secretion. Compared with conventional therapy, 6 months of Chronocort resulted in a decrease in hydrocortisone dose equivalent (28 ± 11.8 vs 25.9 ± 7.1 mg/d), with lower 24-hour (P = .004), morning (0700-1500 h; P = .002), and afternoon (1500-2300 h; P = .011) androstenedione area under the curve (AUC) and lower 24-hour (P = .023) and morning (0700-1500 h; P = .02) 17-OHP AUC.

CONCLUSIONS

Twice-daily Chronocort approximates physiologic cortisol secretion, and was well tolerated and effective in controlling androgen excess in adults with CAH. This novel hydrocortisone formulation represents a new treatment approach for patients with CAH.

Plasma, salivary and urinary cortisol levels following physiological and stress doses of hydrocortisone in normal volunteers

BACKGROUND

Glucocorticoid replacement is essential in patients with primary and secondary adrenal insufficiency, but many patients remain on higher than recommended dose regimens. There is no uniformly accepted method to monitor the dose in individual patients. We have compared cortisol concentrations in plasma, saliva and urine achieved following "physiological" and "stress" doses of hydrocortisone as potential methods for monitoring glucocorticoid replacement.

METHODS

Cortisol profiles were measured in plasma, saliva and urine following "physiological" (20 mg oral) or "stress" (50 mg intravenous) doses of hydrocortisone in dexamethasone-suppressed healthy subjects (8 in each group), compared to endogenous cortisol levels (12 subjects). Total plasma cortisol was measured half-hourly, and salivary cortisol and urinary cortisol:creatinine ratio were measured hourly from time 0 (between 0830 and 0900) to 5 h. Endogenous plasma corticosteroid-binding globulin (CBG) levels were measured at time 0 and 5 h, and hourly from time 0 to 5 h following administration of oral or intravenous hydrocortisone. Plasma free cortisol was calculated using Coolens' equation.

RESULTS

Plasma, salivary and urine cortisol at 2 h after oral hydrocortisone gave a good indication of peak cortisol concentrations, which were uniformly supraphysiological. Intravenous hydrocortisone administration achieved very high 30 minute cortisol concentrations. Total plasma cortisol correlated significantly with both saliva and urine cortisol after oral and intravenous hydrocortisone (P <0.0001, correlation coefficient between 0.61 and 0.94). There was no difference in CBG levels across the sampling period.

CONCLUSIONS

An oral dose of hydrocortisone 20 mg is supraphysiological for routine maintenance, while stress doses above 50 mg 6-hourly would rarely be necessary in managing acute illness. Salivary cortisol and urinary cortisol:creatinine ratio may provide useful alternatives to plasma cortisol measurements to monitor replacement doses in hypoadrenal patients.

Adrenal Clocks and the Role of Adrenal Hormones in the Regulation of Circadian Physiology

The mammalian circadian timing system consists of a master pacemaker in the suprachiasmatic nucleus (SCN) and subordinate clocks that disseminate time information to various central and peripheral tissues. While the function of the SCN in circadian rhythm regulation has been extensively studied, we still have limited understanding of how peripheral tissue clock function contributes to the regulation of physiological processes. The adrenal gland plays a special role in this context as adrenal hormones show strong circadian secretion rhythms affecting downstream physiological processes. At the same time, they have been shown to affect clock gene expression in various other tissues, thus mediating systemic entrainment to external zeitgebers and promoting internal circadian alignment. In this review, we discuss the function of circadian clocks in the adrenal gland, how they are reset by the SCN and may further relay time-of-day information to other tissues. Focusing on glucocorticoids, we conclude by outlining the impact of adrenal rhythm disruption on neuropsychiatric, metabolic, immune, and malignant disorders.