Glucocorticoid ultradian rhythmicity differentially regulates mood and resting state networks in the human brain: A randomised controlled clinical trial

Circadian and ultradian rhythms: Clinical implications

The hypothalamic-pituitary-adrenal axis is an extremely dynamic system with a combination of both circadian and ultradian oscillations. This state of 'continuous dynamic equilibration' provides a platform that is able to anticipate events, is sensitive in its response to stressors, remains robust during perturbations of both the internal and external environments and shows plasticity to adapt to a changed environment. In this review, we describe these oscillations of glucocorticoid (GC) hormones and why they are so important for GC-dependent gene activation in the brain and liver, and their consequent effects on the regulation of synaptic and memory function as well as appetite control and metabolic regulation. Abnormalities of mood, appetite and metabolic regulation are well-known consequences of GC therapy, and we suggest that the pattern of GC treatment and hormone replacement should be a much higher priority for endocrinologists and the pharmaceutical industry. One of the major impediments to our research on the importance of these cortisol rhythms in our patients has been our inability to measure repeated levels of hormones across the day in patients in their home or work surroundings. We describe how new wearable methodologies now allow the measurement of 24-h cortisol profiles - including during sleep - and will enable us to define physiological normality and allow us both to develop better diagnostic tests and inform, at an individual patient level, how to improve replacement therapy.

Cell Signaling in the Circadian Pacemaker: New Insights from in vivo Imaging

BACKGROUND

"One for all, and all for one," the famous rallying cry of the Three Musketeers, in Alexandre Dumas's popular novel, certainly applies to the 20,000 cells composing the suprachiasmatic nuclei (SCN). These cells work together to form the central clock that coordinates body rhythms in tune with the day-night cycle. Like virtually every body cell, individual SCN cells exhibit autonomous circadian oscillations, but this rhythmicity only reaches a high level of precision and robustness when the cells are coupled with their neighbors. Therefore, understanding the functional network organization of SCN cells beyond their core rhythmicity is an important issue in circadian biology.

SUMMARY

The present review summarizes the main results from our recent study demonstrating the feasibility of recording SCN cells in freely moving mice and the significance of variations in intracellular calcium over several timescales.

KEY MESSAGE

We discuss how in vivo imaging at the cell level will be pivotal to interrogate the mammalian master clock, in an integrated context that preserves the SCN network organization, with intact inputs and outputs.

Comparison of adrenalectomy with conservative treatment on mild autonomous cortisol secretion: a systematic review and meta-analysis

Objective

This systematic review and meta-analysis was conducted to compare the benefits of adrenalectomy and conservative treatment for comorbidities associated with mild autonomous cortisol secretion (MACS) in patients diagnosed with MACS.

Background

MACS is the most common benign hormone-secreting functional adrenal incidentaloma. Overproduction of cortisol is observed in MACS patients, resulting in a variety of long-term health issues, including arterial hypertension (HTN), diabetes mellitus (DM), dyslipidemia, obesity, and osteoporosis; however, the classic clinical manifestations of Cushing's syndrome (CS) are not present.

Methods

A systematic search was conducted using MEDLINE, Embase, Web of Sciences, and Scopus databases on December, 2023. Two reviewers independently extracted data and assessed the quality of the included articles. A meta-analysis was performed to compare the beneficial effects of adrenalectomy versus conservative management for MACS-related comorbidities.

Results

Fifteen articles were included in this study, which evaluated 933 MACS patients (384 Adrenalectomy and 501 Conservative treatment, and 48 excluded due to incomplete follow-up duration). MACS diagnosis criteria were different among the included articles. All studies, however, stated that there must be no overt CS symptoms. Meta-analysis demonstrates the overall advantage of adrenalectomy over conservative treatment for MACS-related comorbidities (Cohen's d = -0.49, 95% CI [-0.64, -0.34], p = 0.00). Subgroup analysis indicated that the systolic blood pressure (pooled effect size = -0.81, 95% CI [-1.19, -0.42], p = 0.03), diastolic blood pressure (pooled effect size = -0.63, 95% CI [-1.05, -0.21], p = 0.01), and BMD (pooled effect size = -0.40, 95% CI [-0.73, -0.07], p = 0.02) were significantly in favor of adrenalectomy group rather than conservative treatment but no significant differences between the two treatment groups in other MACS-related comorbidities were reported.

Conclusion

Despite the limited and diverse data, this study demonstrates the advantage of adrenalectomy over conservative treatment for MACS-related comorbidities.

Neuroscience meets behavior: A systematic literature review on magnetic resonance imaging of the brain combined with real-world digital phenotyping

A primary goal of neuroscience is to understand the relationship between the brain and behavior. While magnetic resonance imaging (MRI) examines brain structure and function under controlled conditions, digital phenotyping via portable automatic devices (PAD) quantifies behavior in real-world settings. Combining these two technologies may bridge the gap between brain imaging, physiology, and real-time behavior, enhancing the generalizability of laboratory and clinical findings. However, the use of MRI and data from PADs outside the MRI scanner remains underexplored. Herein, we present a Preferred Reporting Items for Systematic Reviews and Meta-Analysis systematic literature review that identifies and analyzes the current state of research on the integration of brain MRI and PADs. PubMed and Scopus were automatically searched using keywords covering various MRI techniques and PADs. Abstracts were screened to only include articles that collected MRI brain data and PAD data outside the laboratory environment. Full-text screening was then conducted to ensure included articles combined quantitative data from MRI with data from PADs, yielding 94 selected papers for a total of N = 14,778 subjects. Results were reported as cross-frequency tables between brain imaging and behavior sampling methods and patterns were identified through network analysis. Furthermore, brain maps reported in the studies were synthesized according to the measurement modalities that were used. Results demonstrate the feasibility of integrating MRI and PADs across various study designs, patient and control populations, and age groups. The majority of published literature combines functional, T1-weighted, and diffusion weighted MRI with physical activity sensors, ecological momentary assessment via PADs, and sleep. The literature further highlights specific brain regions frequently correlated with distinct MRI-PAD combinations. These combinations enable in-depth studies on how physiology, brain function and behavior influence each other. Our review highlights the potential for constructing brain-behavior models that extend beyond the scanner and into real-world contexts.

Effects of Cortisol Administration on Resting-State Functional Connectivity in Women with Depression

Previous resting-state functional connectivity (rsFC) research has identified several brain networks impacted by depression and cortisol, including default mode (DMN), frontoparietal (FPN), and salience networks (SN). In the present study, we examined the effects of cortisol administration on rsFC of these networks in individuals varying in depression history and severity. We collected resting-state fMRI scans and self-reported depression symptom severity for 74 women with and without a history of depression after cortisol and placebo administration using a double-blind, crossover design. We conducted seed-based rsFC analyses for DMN, FPN, and SN seeds to examine rsFC changes after cortisol vs. placebo administration in relation to depression history group and severity. Results revealed a main effect of depression group, with lower left amygdala (SN)-middle temporal gyrus connectivity in women with a history of depression. Cortisol administration increased insula (SN)-inferior frontal gyrus and superior temporal gyrus connectivity. We also found that greater depression severity was associated with increased PCC (DMN)-cerebellum connectivity after cortisol. These results did not survive Bonferroni correction for seed ROIs and should be interpreted with caution. Our findings indicate that acute cortisol elevation may normalize aberrant connectivity of DMN and SN regions, which could help inform clinical treatments for depression.

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.

How an appreciation of dynamics has altered our understanding of the HPA axis

Rhythmicity is a intrinsic feature of biological systems, including the hypothalamic-pituitary-adrenal axis, a mammalian neurohormonal system crucial both in daily life and as a network that responds to stressful stimuli. Circadian and ultradian rhythmicity underlie HPA activity in rodents and in humans, regulating gene expression, metabolism and behavior, and adverse consequences occur when rhythms are disturbed. In the assessment of human disease, the complexity of HPA rhythmicity is rarely acknowledged or understood, and is currently a limitation to better diagnosis and treatment. However, the recent emergence of ambulatory, high frequency and blood-free hormone sampling techniques has the promise to substantially change our understanding of the function of HPA axis in healthy normal life, and provide new opportunities for the diagnosis and treatment of disease.

The role of the hypothalamic-pituitary-adrenal axis in depression across the female reproductive lifecycle: current knowledge and future directions

The aim of this narrative review is to consolidate knowledge on the role of the hypothalamic-pituitary-adrenal (HPA) axis in depression pathophysiology at different reproductive stages across the female lifespan. Despite growing evidence about the impact of gonadal hormones on mood disorders, no previous review has examined the interaction between such hormonal changes and the HPA axis within the context of depressive disorders in women. We will focus on HPA axis function in depressive disorders at different reproductive stages including the menstrual cycle (e.g., premenstrual dysphoric disorder [PMDD]), perinatally (e.g., postpartum depression), and in perimenopausal depression. Each of these reproductive stages is characterized by vast physiological changes and presents major neuroendocrine reorganization. The HPA axis is one of the main targets of such functional alterations, and with its key role in stress response, it is an etiological factor in vulnerable windows for depression across the female lifespan. We begin with an overview of the HPA axis and a brief summary of techniques for measuring HPA axis parameters. We then describe the hormonal milieu of each of these key reproductive stages, and integrate information about HPA axis function in depression across these reproductive stages, describing similarities and differences. The role of a history of stress and trauma exposure as a contributor to female depression in the context of HPA axis involvement across the reproductive stages is also presented. This review advances the pursuit of understanding common biological mechanisms across depressive disorders among women. Our overarching goal is to identify unmet needs in characterizing stress-related markers of depression in women in the context of hormonal changes across the lifespan, and to support future research in women's mental health as it pertains to pathophysiology, early diagnosis, and treatment targets.

Glucocorticoid feedback paradox: a homage to Mary Dallman

As the end product of the hypothalamus-pituitary-adrenal (HPA) axis, the glucocorticoid hormones cortisol and corticosterone coordinate circadian activities, stress-coping, and adaptation to change. For this purpose, the hormone promotes energy metabolism and controls defense reactions in the body and brain. This life-sustaining action exerted by glucocorticoids occurs in concert with the autonomic nervous and immune systems, transmitters, growth factors/cytokines, and neuropeptides. The current contribution will focus on the glucocorticoid feedback paradox in the HPA-axis: the phenomenon that stress responsivity remains resilient if preceded by stress-induced secretion of glucocorticoid hormone, but not if this hormone is previously administered. Furthermore, in animal studies, the mixed progesterone/glucocorticoid antagonist RU486 or mifepristone switches to an apparent partial agonist upon repeated administration. To address these enigmas several interesting phenomena are highlighted. These include the conditional nature of the excitation/inhibition balance in feedback regulation, the role of glucose as a determinant of stress responsivity, and the potential of glucocorticoids in resetting the stress response system. The analysis of the feedback paradox provides also a golden opportunity to review the progress in understanding the role of glucocorticoid hormone in resilience and vulnerability during stress, the science that was burned deeply in Mary Dallman's emotions.

Depressive and anxiety disorders and antidepressant prescriptions among insured children and young adults with congenital adrenal hyperplasia in the United States

Background

Dysfunction in the hypothalamic-pituitary-adrenal axis has been associated with depressive and anxiety disorders. Little is known about the risk for these disorders among individuals with congenital adrenal hyperplasia (CAH), a form of primary adrenal insufficiency.

Objective

We investigated the prevalence of depressive and anxiety disorders and antidepressant prescriptions in two large healthcare databases of insured children, adolescents, and young adults with CAH in the United States.

Methods

We conducted a retrospective cohort study using administrative data from October 2015 through December 2019 for individuals aged 4-25 years enrolled in employer-sponsored or Medicaid health plans.

Results

Adjusting for age, the prevalence of depressive disorders [adjusted prevalence ratio (aPR) = 1.7, 95% confidence interval (CI): 1.4-2.0, p<0.001], anxiety disorders [aPR = 1.7, 95% CI: 1.4-1.9, p<0.001], and filled antidepressant prescriptions [aPR = 1.7, 95% CI: 1.4-2.0, p<0.001] was higher among privately insured youth with CAH as compared to their non-CAH peers. Prevalence estimates were also higher among publicly insured youth with CAH for depressive disorders [aPR = 2.3, 95% CI: 1.9-2.9, p<0.001], anxiety disorders [aPR = 2.0, 95% CI: 1.6-2.5, p<0.001], and filled antidepressant prescriptions [aPR = 2.5, 95% CI: 1.9-3.1, p<0.001] as compared to their non-CAH peers.

Conclusions

The elevated prevalence of depressive and anxiety disorders and antidepressant prescriptions among youth with CAH suggests that screening for symptoms of depression and anxiety among this population might be warranted.

Cardio-metabolic pathophysiology in mild glucocorticoid excess: Potential implications for management of adrenal incidentaloma

Adrenal adenomas are incidentally identified in up to 5% of computer tomography scans performed for unrelated indications. A proportion of these adrenal incidentalomas are found to autonomously secrete cortisol based on definitions in current guidelines. Epidemiological studies suggest that chronic exposure to mild glucocorticoid excess from adrenal incidentalomas is associated with significantly increased cardiometabolic risk. However, current management guidelines adopt a conservative approach as no large prospective randomized studies have demonstrated that these patients benefit from surgery. This narrative review examines the epidemiological and mechanistic studies related to three common clinical settings of mild glucocorticoid excess to gain further insight into the potential benefits of treating patients with adrenal incidentaloma and possible autonomous cortisol secretion.

Transcriptional and cell type profiles of cortical brain regions showing ultradian cortisol rhythm dependent responses to emotional face stimulation

The characteristic endogenous circadian rhythm of plasma glucocorticoid concentrations is made up from an underlying ultradian pulsatile secretory pattern. Recent evidence has indicated that this ultradian cortisol pulsatility is crucial for normal emotional response in man. In this study, we investigate the anatomical transcriptional and cell type signature of brain regions sensitive to a loss of ultradian rhythmicity in the context of emotional processing. We combine human cell type and transcriptomic atlas data of high spatial resolution with functional magnetic resonance imaging (fMRI) data. We show that the loss of cortisol ultradian rhythm alters emotional processing response in cortical brain areas that are characterized by transcriptional and cellular profiles of GABAergic function. We find that two previously identified key components of rapid non-genomic GC signaling - the ANXA1 gene and retrograde endocannabinoid signaling - show most significant differential expression (q = 3.99e^-10) and enrichment (fold enrichment = 5.56, q = 9.09e^-4). Our results further indicate that specific cell types, including a specific NPY-expressing GABAergic neuronal cell type, and specific G protein signaling cascades underly the cerebral effects of a loss of ultradian cortisol rhythm. Our results provide a biological mechanistic underpinning of our fMRI findings, indicating specific cell types and cascades as a target for manipulation in future experimental studies.

Brain structure in autoimmune Addison's disease

Long-term disturbances in cortisol levels might affect brain structure in individuals with autoimmune Addison's disease (AAD). This study investigated gray and white matter brain structure in a cohort of young adults with AAD. T1- and diffusion-weighted images were acquired for 52 individuals with AAD and 70 healthy controls, aged 19-43 years, using magnetic resonance imaging. Groups were compared on cortical thickness, surface area, cortical gray matter volume, subcortical volume (FreeSurfer), and white matter microstructure (FSL tract-based spatial statistics). Individuals with AAD had 4.3% smaller total brain volume. Correcting for head size, we did not find any regional structural differences, apart from reduced volume of the right superior parietal cortex in males with AAD. Within the patient group, a higher glucocorticoid (GC) replacement dose was associated with smaller total brain volume and smaller volume of the left lingual gyrus, left rostral anterior cingulate cortex, and right supramarginal gyrus. With the exception of smaller total brain volume and potential sensitivity of the parietal cortex to GC disturbances in men, brain structure seems relatively unaffected in young adults with AAD. However, the association between GC replacement dose and reduced brain volume may be reason for concern and requires follow-up study.

Young adult Swedish patients with autoimmune Addison's disease report difficulties with executive functions in daily life despite overall good cognitive performance

OBJECTIVES

Sub-optimal replacement of glucocorticoids (GC) in autoimmune Addison's disease (AAD) may affect cognitive functioning. The present study therefore sought to investigate cognitive performance and self-reported problems with executive functions in a cohort of young adult patients with AAD.

DESIGN AND METHODS

67 patients with AAD (39 females), mean age 32 yrs. (range 19-41), and 80 control participants (43 females), mean age 29 yrs. (range 19-43), completed neuropsychological tests estimating verbal and non-verbal intellectual ability, learning, memory and executive functioning, in addition to self-report scales assessing problems with executive functions, fatigue and symptoms of anxiety and depression.

RESULTS

Patients performed within the average range on all cognitive tests compared to population norms. However, female AAD patients reported more problems than controls with both hot (emotion regulation) and cold (cognitive regulation) executive functions in daily life. Moreover, experienced problems with executive functions in both male and female patients were associated with increased mental fatigue and lower GC replacement doses.

CONCLUSIONS

Despite average performance in neuropsychological tests by both sexes, young adult female patients with AAD experience problems with executive functions in daily life. Coping with mental fatigue and optimization of pharmacotherapy may be important factors to be addressed in order to provide timely support for patients. Future research is needed to further determine other risk factors for experiencing executive function impairments in AAD.

Efficacy of Treatments Targeting Hypothalamic-Pituitary-Adrenal Systems for Major Depressive Disorder: A Meta-Analysis

Abnormal hypothalamic-pituitary-adrenal (HPA) axis has been implicated in major depressive disorder (MDD). A number of studies have attempted to use HPA-modulating medications to treat depression. However, their results are inconsistent. The efficacy of these drugs for MDD remains uncertain. The aims of this meta-analysis were to determine the effect and safety profile of HPA-targeting medications for MDD. World of Science and PubMed databases were comprehensively searched up to March 2021. All randomized controlled trials (RCTs) and open-label trials exploring antiglucocorticoid and related medications in patients with depression were included. Standardized mean differences (SMDs) and risk ratios (RRs) with 95% confidence intervals (CIs) were calculated for continuous or dichotomous outcomes, respectively. In the meta-analysis, we identified 16 RCTs and seven open-label studies that included 2972 subjects. Pooling the change data that assessed the efficacy across all included HPA-targeting medications for depression showed a significant difference between interventions and controls with very small heterogeneity after influence analysis (SMD = 0.138, 95%CI = 0.052, 0.224, p = 0.002; I² = 20.7%, p = 0.212). No obvious publication bias was observed (p = 0.127). Effectiveness remained significant in patients with MDD (SMD = 0.136, 95%CI = 0.049, 0.223, p = 0.002). Subgroup analysis showed a significant difference favoring mifepristone and vasopressin 1B (V_1B) receptor antagonist treatment. Adverse events were reported by 14 studies and our analysis of high-quality studies showed a significant difference in favor of controls (RR = 1.283, 95%CI = 1.134, 1.452, p = 0). Our study suggested that patients with MDD may benefit from mifepristone and V_1B receptor antagonist treatments that have tolerable side effects. HPA-based medications are promising for depression treatment. However, additional high-quality RCTs, including head-to-head trials, are needed.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier registration number: CRD42021247279

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.