The Very Low-Dose Dexamethasone Suppression Test in the General Population: A Cross-Sectional Study

Glucocorticoids and HPA axis regulation in the stress-obesity connection: A comprehensive overview of biological, physiological and behavioural dimensions

Chronic stress, characterized by increased long-term exposure to the glucocorticoid hormone cortisol, is increasingly linked to obesity development. Still, various knowledge gaps persist, including on underlying pathophysiological mechanisms. The aim of the current review is to provide the latest insights on the connection between stress and obesity. We discuss three biological stress systems-the autonomic nervous system, the hypothalamus-pituitary-adrenal (HPA) axis and the immune system-and their link with obesity, with a particular focus on the HPA axis. The role of cortisol and its regulatory variations (including glucocorticoid rhythmicity and altered sensitivity) in adipose tissue biology and obesity development is discussed. Moreover, we highlight the physiological, affective, cognitive and behavioural dimensions of the stress response offering a deeper understanding of how stress contributes to obesity development and vice versa. Finally, stress as a treatment target for obesity is discussed. We conclude that the link between stress and obesity is complex and multifaceted, influenced by physiological, affective, cognitive and behavioural stress response mechanisms, which especially when chronically present, play a key role in the development of obesity and associated cardiometabolic diseases. This necessitates integrated approaches tailored to individual needs, including lifestyle modifications, behavioural interventions, psychosocial support and possible additional pharmacological interventions.

Impaired accuracy of the dexamethasone suppression test after bariatric surgery: implications for post-surgical cortisol interpretation

IMPORTANCE

The impact of bariatric surgery (BS) on the performance of the 1 mg dexamethasone suppression test (DST) is not well established.

OBJECTIVE

(1) To evaluate the intraindividual results of the DST in a group of patients before and 2 years after BS, and (2) to assess plasma dexamethasone levels and other factors influencing the reliability of the DST.

METHODS

We conducted a prospective longitudinal study, including 38 subjects evaluating DST before and 2 years after BS. We also compared DST results, plasma dexamethasone levels, and related factors across 3 groups: individuals of the previous cohort 2 years post-BS (n = 21), patients with severe obesity without BS (pwO; n = 10), and healthy controls (n = 7).

RESULTS

Post-BS patients had higher cortisol levels after DST compared with prior (0.9 vs 0.7 µg/dL; P < .01). Four individuals post-BS had cortisol levels >1.8 µg/dL in the absence of autonomous cortisol secretion. Plasma dexamethasone levels were significantly lower in post-BS patients (1.9 ng/dL) compared with non-operated pwO (3.7 ng/dL) and healthy controls (4.0 ng/mL), P < .01. Multivariate analysis identified BS (β = -1.258, P = .01) and sex hormone-binding globulin levels (β = -.013, P = .04) as significant independent predictors of plasma dexamethasone concentrations.

CONCLUSION

Post-BS subjects showed higher post-DST cortisol levels and reached lower plasma dexamethasone concentration compared with non-operated individuals, which may lead to false-positive results. These findings highlight the need to consider dexamethasone measurements to enhance DST interpretation in post-BS patients. Further studies are necessary to validate these findings in broader populations. The underlying mechanisms need to be explored.

Do Cortisol Levels Play a Role in Suicidal Behaviors and Non-Suicidal Self-Injuries in Children and Adolescents?-A Narrative Review

Background/Objectives: Suicidal behaviors (SBs) and non-suicidal self-injury (NSSI) are significant mental health concerns in children and adolescents. The hypothalamic-pituitary-adrenal (HPA) axis, of which cortisol is a key hormone, has been implicated in these behaviors. This narrative review aims to explore whether cortisol levels play a role in SBs and NSSI in youth and to synthesize current evidence on this topic. Methods: A comprehensive literature search was conducted on studies published through November 2024, using PubMed, Web of Science, and Google Scholar databases. Studies were screened for eligibility, including only human studies published in English, with no animal models or studies excluding cortisol levels. A narrative synthesis approach was used due to the methodological diversity across studies. Due to limited adolescent-focused research, studies involving adults were also considered. Results: Findings indicate inconsistent cortisol patterns in relation to SBs and NSSI. Elevated cortisol levels are linked to SBs, with some studies suggesting they may predict future suicide attempts, though no definitive cause-and-effect relationship is established. Conversely, cortisol levels in relation to NSSI show mixed results, with some studies reporting no differences. Cortisol responses to stress, measured by saliva, blood, and hair, reveal complex interactions with psychological factors such as depression and impulsivity, influencing cortisol secretion. Discussion: Despite some evidence pointing to a role of cortisol dysregulation in SBs and NSSI, the relationship remains unclear due to study heterogeneity, including small sample sizes and methodological variations. Gender and the type of stressor used in studies also complicate the findings. Future research should prioritize longitudinal studies, better control for confounding factors, and utilize more diverse cortisol assessment methods to clarify these links. Conclusions: While cortisol may play a role in the pathophysiology of SBs and NSSI, further research is needed to establish clearer, more reliable patterns. Identifying alterations in cortisol levels may aid in early detection and targeted interventions for at-risk adolescents.

The dexamethasone suppression test as a biomarker for suicidal behavior: A systematic review and meta-analysis

BACKGROUND

The dexamethasone suppression test (DST), which measures HPA-axis functioning, is a potential biomarker for suicidal behavior. The current study aimed (a) to synthesize available knowledge on the association between DST non-suppression and suicidal behavior, and (b) to study potential moderators.

METHODS

A total of 4236 studies were screened, 43 were included. Suicide attempts and suicide completion were studied separately. The meta-analysis included 37 effect sizes for suicide attempts (n = 3733) and 11 effect sizes for suicide completion (n = 1626).

RESULTS

DST non-suppression was associated with completed suicide (odds ratio (OR) = 2.10, (95 % CI [1.37, 3.23]). For suicide attempts, we found no evidence that DST status was associated in the overall meta-analysis including all patient samples. However, moderator analysis indicated that the DST status was associated with suicide attempts in patient samples that included psychopathology other than just mood disorders, such as psychotic, substance use and personality disorders (OR = 2.34, 95 % CI [1.39-3.93], k = 11).

LIMITATIONS

The potential influence of publication bias and exclusion of some relevant published studies (since effect sizes could not be calculated, authors could not supply data or authors could not be reached) are limitations. Furthermore, missing moderator data decreased our ability to explain heterogeneity between studies.

CONCLUSIONS

The results of this meta-analysis support the hypothesis that DST non-suppression is predictive of suicidal behavior. More research is needed to investigate optimal cut-off values, confounding factors and the potential usefulness of the DST in clinical practice in terms of personalized medicine.

Psychosocial health modifies associations between HPA-axis function and brain structure in older age

BACKGROUND

Dysregulation of the negative feedback loop of the hypothalamic-pituitary-adrenal (HPA) axis may have damaging effects on the brain, potentially under influence of psychosocial health factors. We studied associations between functioning of the negative feedback loop of HPA-axis, measured with a very low-dose dexamethasone suppression test (DST), and brain structure in middle-aged and older adults, and whether these associations were modified by psychosocial health.

METHODS

From 2006 to 2008, 1259 participants (mean age 57.6 ± 6.4, 59.6 % female) of the population-based Rotterdam Study completed a very low-dose DST (0.25 mg) and underwent magnetic resonance imaging (MRI) of the brain. Self-reported psychosocial health (depressive symptoms, loneliness, marital status, perceived social support) were assessed in the same time period. Multivariable linear and logistic regression were used to study cross-sectional associations between cortisol response and brain volumetrics, cerebral small vessel disease markers and white matter structural integrity. To assess the effect of psychosocial health on these associations, analyses were further stratified for psychosocial health markers.

RESULTS

Cortisol response was not associated with markers of global brain structure in the overall study sample. However, in participants with clinically relevant depressive symptoms, a diminished cortisol response was associated with smaller white matter volume (mean difference: - 1.00 mL, 95 %CI = - 1.89;- 0.10) and smaller white matter hyperintensity volume (mean difference: - 0.03 mL (log), 95 %CI = - 0.05;0.00). In participants with low/moderate perceived social support compared to those with high social support, a diminished cortisol response was associated with larger gray matter volume (mean difference: 0.70 mL, 95 %CI = 0.01;1.39) and higher fractional anisotropy (standardized mean difference 0.03, 95 %CI = 0.00;0.06).

CONCLUSION

Diminished function of the HPA-axis is differently associated with brain structure in community-dwelling middle-aged and older adults with clinically relevant depressive symptoms or suboptimal social support, but not in adults without depressive symptoms or with optimal social support.

Polysomnography-estimated sleep and the negative feedback loop of the hypothalamic-pituitary-adrenal (HPA) axis

BACKGROUND

Sleep and stress are highly interrelated. To improve our understanding of the role of sleep in functioning of the negative feedback loop of the stress system, we assessed the association between sleep and functioning of the hypothalamic-pituitary-adrenal (HPA) axis in a population-based sample.

METHODS

This study included 403 participants (mean age: 62.4 ± 5.0 years, 55% women) of the population-based Rotterdam Study. Between 2012 and 2014, sleep was assessed with polysomnography. Functioning of the negative feedback loop of the HPA axis was estimated by measuring cortisol levels before and after the intake of a very low dose of dexamethasone (0.25 mg) on average 0.9 ± 37.8 days after the polysomnography. We used linear regression analyses adjusted for multiple confounders and performed sensitivity analyses in a sample excluding those with clinically relevant depressive symptoms and using psychoactive medicine, and a sample excluding non-suppressors.

RESULTS

Short N2 sleep (adjusted difference = 0.005, 95%CI = 0.002;0.009), long N3 sleep (adjusted difference = -0.007, 95%CI = -0.010;-0.003), and short sleep onset latency (adjusted difference = 0.006, 95%CI = 0.001;0.011) were associated with an enhanced response to dexamethasone, but the association of sleep onset latency did not survive multiple testing correction. Associations remained similar after excluding those with clinically relevant depressive symptoms and those using psychoactive medicine or exclusion of non-suppressors.

CONCLUSIONS

This study suggests that more slow wave sleep is particularly associated with a stronger suppression of cortisol within the negative feedback loop of the HPA axis. These findings provide further support that slow wave sleep is important for health.

Glucocorticoid Receptor Signaling in Diabetes

Stress and depression increase the risk of Type 2 Diabetes (T2D) development. Evidence demonstrates that the Glucocorticoid (GC) negative feedback is impaired (GC resistance) in T2D patients resulting in Hypothalamic-Pituitary-Adrenal (HPA) axis hyperactivity and hypercortisolism. High GCs, in turn, activate multiple aspects of glucose homeostasis in peripheral tissues leading to hyperglycemia. Elucidation of the underlying molecular mechanisms revealed that Glucocorticoid Receptor (GR) mediates the GC-induced dysregulation of glucose production, uptake and insulin signaling in GC-sensitive peripheral tissues, such as liver, skeletal muscle, adipose tissue, and pancreas. In contrast to increased GR peripheral sensitivity, an impaired GR signaling in Peripheral Blood Mononuclear Cells (PBMCs) of T2D patients, associated with hyperglycemia, hyperlipidemia, and increased inflammation, has been shown. Given that GR changes in immune cells parallel those in brain, the above data implicate that a reduced brain GR function may be the biological link among stress, HPA hyperactivity, hypercortisolism and hyperglycemia. GR polymorphisms have also been associated with metabolic disturbances in T2D while dysregulation of micro-RNAs—known to target GR mRNA—has been described. Collectively, GR has a crucial role in T2D, acting in a cell-type and context-specific manner, leading to either GC sensitivity or GC resistance. Selective modulation of GR signaling in T2D therapy warrants further investigation.

HPA axis regulation and epigenetic programming of immune-related genes in chronically stressed and non-stressed mid-life women

Hypothalamic-pituitary-adrenal (HPA) axis dysregulation has been associated with altered immune function, but the underlying molecular mechanisms are unclear. Epigenetic processes, including DNA methylation, respond to the glucocorticoid end-products of the HPA axis (cortisol in humans) and could be involved in this neuroendocrine-immune crosstalk. Here we examined the extent to which variations in HPA axis regulation are associated with peripheral blood DNA (CpG) methylation changes in 57 chronically stressed caregivers and 67 control women. DNA methylation was determined with the Illumina 450k array for a panel of genes involved in HPA axis and immune function. HPA axis feedback was assessed with the low-dose dexamethasone suppression test (DST), measuring the extent to which cortisol secretion is suppressed by the synthetic glucocorticoid dexamethasone. After multiple testing correction in the entire cohort, higher post-DST cortisol, reflecting blunted HPA axis negative feedback, but not baseline waking cortisol, was associated with lower DNA methylation at eight TNF and two FKBP5 CpG sites. Caregiver group status was associated with lower methylation at two IL6 CpG sites. Since associations were most robust with TNF methylation (32% of the 450k-covered sites), we further examined functionality of this epigenetic signature in cultured peripheral blood mononuclear cells in 33 participants; intriguingly, lower TNF methylation resulted in higher ex vivo TNF mRNA following immune stimulation. Taken together, our findings link chronic stress and HPA axis regulation with epigenetic signatures at immune-related genes, thereby providing novel insights into how aberrant HPA axis function may contribute to heightened inflammation and disease risk.

Insufficient glucocorticoid receptor signaling and flattened salivary cortisol profile are associated with metabolic and inflammatory indices in type 2 diabetes

PURPOSE

Impaired negative feedback and hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis characterizes type 2 diabetes mellitus (T2DM). The glucocorticoid receptor (GR) is a key mediator of HPA axis negative feedback; however, its role in linking hypercortisolemia and T2DM-associated hyperglycemia, hyperlipidemia and inflammation is not yet known.

METHODS

In peripheral mononuclear cells (PBMC) from 31 T2DM patients and 24 healthy controls, we measured various GR-signaling parameters such as phosphorylated GR (pGR-S211), GRα/GRβ gene expression and GC-sensitivity [using the basal and dexamethasone (DEX)-induced leucine zipper (GILZ) and FK506 binding-protein (FKBP5) mRNA levels as well as the basal interleukin (IL)-1β protein levels]. Diurnal salivary cortisol curve parameters such as the cortisol awaking response (CAR) and area under the curve (AUC_total and AUCi) as well as inflammatory and metabolic indices were also determined.

RESULTS

T2DM patients exhibited diminished pGR-S211 protein content, increased GRβ, decreased basal GILZ and FKBP5 mRNA levels and increased IL-1β levels. Flattened DEX-induced GILZ and FKBP5 response curves and a flattened salivary cortisol profile characterized T2DM patients. Significant associations of GR measures and saliva cortisol curve parameters with biochemical and clinical characteristics were found.

CONCLUSION

Our novel data implicate an insufficient GR signaling in PBMCs in T2DM patients and HPA axis dysfunction. The significant associations of GR-signaling parameters with inflammatory and metabolic indices implicate that GR may be the critical link between HPA axis dysfunction, hypercortisolemia and diabetes-associated metabolic disturbances. Our findings provide significant insights into the contribution of GR-mediated mechanisms in T2DM aetiopathology and therapy.

Risk factors for corticosteroid insufficiency during the sub-acute phase of acute traumatic brain injury

Hypothalamic-pituitary-adrenal axis dysfunction may lead to the occurrence of critical illness-related corticosteroid insufficiency. Critical illness-related corticosteroid insufficiency can easily occur after traumatic brain injury, but few studies have examined this occurrence. A multicenter, prospective, cohort study was performed to evaluate the function of the hypothalamic-pituitary-adrenal axis and the incidence of critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury. One hundred and forty patients with acute traumatic brain injury were enrolled from the neurosurgical departments of three tertiary-level hospitals in China, and the critical illness-related corticosteroid insufficiency incidence, critical-illness-related corticosteroid insufficiency-related risk factors, complications, and 28-day mortality among these patients was recorded. Critical illness-related corticosteroid insufficiency was diagnosed in patients with plasma total cortisol levels less than 10 μg/dL (275.9 nM) on post-injury day 4 or when serum cortisol was insufficiently suppressed (less than 50%) during a dexamethasone suppression test on post-injury day 5. The results demonstrated that critical illness-related corticosteroid insufficiency occurred during the sub-acute phase of traumatic brain injury in 5.6% of patients with mild injury, 22.5% of patients with moderate injury, and 52.2% of patients with severe injury. Traumatic brain injury-induced critical illness-related corticosteroid insufficiency was strongly correlated to injury severity during the sub-acute stage of traumatic brain injury. Traumatic brain injury patients with critical illness-related corticosteroid insufficiency frequently presented with hemorrhagic cerebral contusions, diffuse axonal injury, brain herniation, and hypotension. Differences in the incidence of hospital-acquired pneumonia, gastrointestinal bleeding, and 28-day mortality were observed between patients with and without critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury. Hypotension, brain-injury severity, and the types of traumatic brain injury were independent risk factors for traumatic brain injury-induced critical illness-related corticosteroid insufficiency. These findings indicate that critical illness-related corticosteroid insufficiency is common during the sub-acute phase of traumatic brain injury and is strongly associated with poor prognosis. The dexamethasone suppression test is a practical assay for the evaluation of hypothalamic-pituitary-adrenal axis function and for the diagnosis of critical illness-related corticosteroid insufficiency in patients with traumatic brain injury, especially those with hypotension, hemorrhagic cerebral contusions, diffuse axonal injury, and brain herniation. Sub-acute infection of acute traumatic brain injury may be an important factor associated with the occurrence and development of critical illness-related corticosteroid insufficiency. This study protocol was approved by the Ethics Committee of General Hospital of Tianjin Medical University, China in December 2011 (approval No. 201189).

Kinetics of Physiological and Behavioural Responses in Endotoxemic Pigs with or without Dexamethasone Treatment

Although dexamethasone (DEX) is a widely used immunoregulatory agent, knowledge about its pharmacological properties in farm animals, especially pigs, is insufficient. Previous studies suggest that compared to other species, pigs are less sensitive to the immunosuppression conferred by DEX and more sensitive to the threat of bacterial endotoxins. However, there is a paucity of studies examining DEX immunomodulation in endotoxemia in this species. In this study, a porcine endotoxemia model was established by lipopolysaccharide (LPS) and the effect of DEX-pretreatment on the magnitude and kinetics of neuroendocrine, metabolic, hematologic, inflammatory, and behavioural responses were examined. DEX decreased cortisol, adrenocorticotropic hormone (ACTH), red blood cell, hemoglobin, hematocrit, and lymphocyte whereas glucose concentration was increased under both normal and endotoxemic conditions. By contrast, DEX decreased triglyceride, lactate, and IL-6 concentrations and increased platelet count only under an endotoxemic condition. DEX also reduced the frequency of sickness behaviour following LPS challenge. PCA showed that glucose and triglyceride metabolism together with red blood cell count mainly contributed to the separation of clusters during DEX treatment. Our study demonstrates that DEX protects pigs from inflammation and morbidity in endotoxemia, in spite of their less sensitivity to DEX. Moreover, its considerable role in the regulation of the metabolic and hematologic responses in endotoxemic pigs is revealed for the first time.

Hypothalamic-pituitary-adrenal axis activity in the comorbidity between obsessive-compulsive disorder and major depression

Major depressive disorder (MDD) is the most common psychiatric comorbidity in patients with obsessive-compulsive disorder (OCD). Hypothalamic-pituitary-adrenal (HPA) axis abnormalities have been described in both disorders and might play a role in the association between them. We aimed to study the role of HPA axis activity in the comorbidity between OCD and MDD, while controlling for psychopathological dimensions such as anxiety and depressive symptoms. We studied 324 participants belonging to four diagnostic groups: 1) MDD (n = 101), 2) OCD with comorbid MDD (n = 33), 3) OCD without MDD (n = 52), and 4) healthy subjects (n = 138). State anxiety, trait anxiety and depressive symptoms were assessed. Three HPA axis measures were analyzed in saliva: cortisol awakening response (CAR), diurnal cortisol slope (calculated using two formulas: [1] awakening to 11 p.m. [AWE diurnal slope]; [2] considering fixed time points [FTP diurnal slope] from 10 a.m. to 11 p.m.), and dexamethasone suppression test ratio after 0.25 mg of dexamethasone (DSTR). Multiple linear regression analyses were conducted to explore the contribution of clinical diagnosis and symptom dimensions to each HPA axis measure. A more flattened FTP diurnal cortisol slope was observed for OCD patients with comorbid MDD. Regarding the CAR and DSTR, a significant interaction was found between trait anxiety and OCD, as OCD patients with greater trait anxiety showed an increased CAR and reduced cortisol suppression after dexamethasone administration. Our results suggest that trait anxiety plays an important role in the relationship between HPA axis measures and OCD/MDD comorbidity.

The Rotterdam Study: 2018 update on objectives, design and main results

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1500 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

The functioning of the hypothalamic-pituitary-adrenal (HPA) axis in postpartum depressive states: a systematic review

A large body of literature suggests the role of the hypothalamic-pituitary-adrenal (HPA) axis in postpartum depression (PPD). Nonetheless, these studies present discrepant methodology and results; thus, this hypothesis deserves further exploration. Areas covered: This review included studies investigating the HPA axis in PPD or postpartum blues published until November 2016. In total, 48 studies met the inclusion criteria. The HPA axis was mostly investigated in the immediate postpartum period (62.5%), and the majority of studies collected samples in the morning (43.8%), with one measure in a single day (43.8%), and blood was the fluid more often collected (58.4%). Seven out of 21 studies evaluating postpartum blues, and 15 out of 28 studies evaluating PPD detected abnormalities in the HPA axis functioning. Expert commentary: We found a significant heterogeneity in the methodology adopted by studies and consequently, in the results. Despite that, the majority of studies reported HPA changes in women with PPD during the remote period. Notably, reactivity tests pointed to attenuated HPA axis response. Ideally, future investigations should use validated reactivity tests, include larger sample sizes, consider many measures of cortisol throughout the day, and more than one day of collection. We also recommend that studies continue to use validated scales for mood assessment.