Expression of renal 11beta-hydroxysteroid dehydrogenase type 2 is decreased in patients with impaired renal function

Hair cortisol and changes in cortisol dynamics in chronic kidney disease

Objective

We compared hair cortisol (HC) with classic tests of the hypothalamic-pituitary-adrenal (HPA) axis in chronic kidney disease (CKD) and assessed its association with kidney and cardiometabolic status.

Design and methods

A cross-sectional study of 48 patients with CKD stages I-IV, matched by age, sex, and BMI with 24 healthy controls (CTR) was performed. Metabolic comorbidities, body composition, and HPA axis function were studied.

Results

A total of 72 subjects (age 52.9 ± 12.2 years, 50% women, BMI 26.2 ± 4.1 kg/m2) were included. Metabolic syndrome features (hypertension, dyslipidaemia, glucose, HOMA-IR, triglycerides, waist circumference) and 24-h urinary proteins increased progressively with worsening kidney function (p < 0.05 for all). Reduced cortisol suppression after 1-mg dexamethasone suppression (DST) (p < 0.001), a higher noon (12:00 h pm) salivary cortisol (p = 0.042), and salivary cortisol AUC (p = 0.008) were seen in CKD. 24-h urinary-free cortisol (24-h UFC) decreased in CKD stages III-IV compared with I-II (p < 0.001); higher midnight salivary cortisol (p = 0.015) and lower suppressibility after 1-mg DST were observed with declining kidney function (p < 0.001). Cortisol-after-DST cortisol was >2 mcg/dL in 23% of CKD patients (12.5% in stage III and 56.3% in stage IV); 45% of them had cortisol >2 mcg/dL after low-dose 2-day DST, all in stage IV (p < 0.001 for all). Cortisol-after-DST was lineally inversely correlated with eGFR (p < 0.001). Cortisol-after-DST (OR 14.9, 95% CI 1.7-103, p = 0.015) and glucose (OR 1.3, 95% CI 1.1-1.5, p = 0.003) were independently associated with eGFR <30 mL/min/m2). HC was independently correlated with visceral adipose tissue (VAT) (p = 0.016). Cortisol-after-DST (p = 0.032) and VAT (p < 0.001) were independently correlated with BMI.

Conclusion

Cortisol-after-DST and salivary cortisol rhythm present progressive alterations in CKD patients. Changes in cortisol excretion and HPA dynamics in CKD are not accompanied by significant changes in long-term exposure to cortisol evaluated by HC. The clinical significance and pathophysiological mechanisms explaining the associations between HPA parameters, body composition, and kidney damage warrant further study.

Aldosterone: Essential for Life but Damaging to the Vascular Endothelium

The renin angiotensin aldosterone system is a key regulator of blood pressure. Aldosterone is the final effector of this pathway, acting predominantly via mineralocorticoid receptors. Aldosterone facilitates the conservation of sodium and, with it, water and acts as a powerful stimulus for potassium excretion. However, evidence for the pathological impact of excess mineralocorticoid receptor stimulation is increasing. Here, we discussed how in the heart, hyperaldosteronism is associated with fibrosis, cardiac dysfunction, and maladaptive hypertrophy. In the kidney, aldosterone was shown to cause proteinuria and fibrosis and may contribute to the progression of kidney disease. More recently, studies suggested that aldosterone excess damaged endothelial cells. Here, we reviewed how damage to the endothelial glycocalyx may contribute to this process. The endothelial glycocalyx is a heterogenous, negatively charged layer on the luminal surface of cells. Aldosterone exposure alters this layer. The resulting structural changes reduced endothelial reactivity in response to protective shear stress, altered permeability, and increased immune cell trafficking. Finally, we reviewed current therapeutic strategies for limiting endothelial damage and suggested that preventing glycocalyx remodelling in response to aldosterone exposure may provide a novel strategy, free from the serious adverse effect of hyperkalaemia seen in response to mineralocorticoid blockade.

Age-dependent and sex-dependent disparity in mortality in patients with adrenal incidentalomas and autonomous cortisol secretion: an international, retrospective, cohort study

BACKGROUND

The association between cortisol secretion and mortality in patients with adrenal incidentalomas is controversial. We aimed to assess all-cause mortality, prevalence of comorbidities, and occurrence of cardiovascular events in uniformly stratified patients with adrenal incidentalomas and cortisol autonomy (defined as non-suppressible serum cortisol on dexamethasone suppression testing).

METHODS

We conducted an international, retrospective, cohort study (NAPACA Outcome) at 30 centres in 16 countries. Eligible patients were aged 18 years or older with an adrenal incidentaloma (diameter ≥1 cm) detected between Jan 1, 1996, and Dec 31, 2015, and availability of a 1 mg dexamethasone suppression test result from the time of the initial diagnosis. Patients with clinically apparent hormone excess, active malignancy, or follow-up of less than 36 months were excluded. Patients were stratified according to the 0800-0900 h serum cortisol values after an overnight 1 mg dexamethasone suppression test; less than 50 nmol/L was classed as non-functioning adenoma, 50-138 nmol/L as possible autonomous cortisol secretion, and greater than 138 nmol/L as autonomous cortisol secretion. The primary endpoint was all-cause mortality. Secondary endpoints were the prevalence of cardiometabolic comorbidities, cardiovascular events, and cause-specific mortality. The primary and secondary endpoints were assessed in all study participants.

FINDINGS

Of 4374 potentially eligible patients, 3656 (2089 [57·1%] with non-functioning adenoma, 1320 [36·1%] with possible autonomous cortisol secretion, and 247 [6·8%] with autonomous cortisol secretion) were included in the study cohort for mortality analysis (2350 [64·3%] women and 1306 [35·7%] men; median age 61 years [IQR 53-68]; median follow-up 7·0 years [IQR 4·7-10·2]). During follow-up, 352 (9·6%) patients died. All-cause mortality (adjusted for age, sex, comorbidities, and previous cardiovascular events) was significantly increased in patients with possible autonomous cortisol secretion (HR 1·52, 95% CI 1·19-1·94) and autonomous cortisol secretion (1·77, 1·20-2·62) compared with patients with non-functioning adenoma. In women younger than 65 years, autonomous cortisol secretion was associated with higher all-cause mortality than non-functioning adenoma (HR 4·39, 95% CI 1·93-9·96), although this was not observed in men. Cardiometabolic comorbidities were significantly less frequent with non-functioning adenoma than with possible autonomous cortisol secretion and autonomous cortisol secretion (hypertension occurred in 1186 [58·6%] of 2024 patients with non-functioning adenoma, 944 [74·0%] of 1275 with possible autonomous cortisol secretion, and 179 [75·2%] of 238 with autonomous cortisol secretion; dyslipidaemia occurred in 724 [36·2%] of 1999 patients, 547 [43·8%] of 1250, and 123 [51·9%] of 237; and any diabetes occurred in 365 [18·2%] of 2002, 288 [23·0%] of 1250, and 62 [26·7%] of 232; all p values <0·001).

INTERPRETATION

Cortisol autonomy is associated with increased all-cause mortality, particularly in women younger than 65 years. However, until results from randomised interventional trials are available, a conservative therapeutic approach seems to be justified in most patients with adrenal incidentaloma.

FUNDING

Deutsche Forschungsgemeinschaft, Associazione Italiana per la Ricerca sul Cancro, Università di Torino.

Adrenal insufficiency is common amongst kidney transplant recipients receiving maintenance prednisolone and can be predicted using morning cortisol

BACKGROUND

Long-term glucocorticoid therapy is a key component of immunosuppression for kidney transplant recipients (KTRs), leading to significant cumulative glucocorticoid exposure. The aims of this study are to investigate the prevalence of adrenal insufficiency (AI) in KTRs taking prednisolone and to develop a screening algorithm to identify patients at the highest risk of AI.

METHODS

In this cross-sectional cohort study, 67 KTRs receiving prednisolone underwent a short synacthen test (SST) and measurement of cumulative glucocorticoid exposure.

RESULTS

A total of 72% (n = 48) of participants failed the SST. Participants with AI had a higher daily prednisolone dose (4.9 versus 4.2 mg/day; P = .002) and greater cumulative glucocorticoid exposure (289 versus 111 mg/kg; P = .03) than those with intact adrenal function. Participants with AI had lower baseline cortisol than participants with intact adrenal function (143 versus 303 nmol/L; P < .001). Morning cortisol of >288 nmol/L predicted a normal SST with 100% specificity [95% confidence interval (CI) 92-100] and 70% sensitivity (95% CI 56-78%), therefore excluding AI.

CONCLUSIONS

Our results suggest KTRs are at a higher risk for AI than previously reported. A morning serum cortisol measurement is a useful screening tool in this cohort, reducing the need for stimulatory testing by 44%. KTRs with AI need education regarding glucocorticoid sick rules, similar to patients with other forms of AI.

Cortisol excess in chronic kidney disease - A review of changes and impact on mortality

Chronic kidney disease (CKD) describes the long-term condition of impaired kidney function from any cause. CKD is common and associated with a wide array of complications including higher mortality, cardiovascular disease, hypertension, insulin resistance, dyslipidemia, sarcopenia, osteoporosis, aberrant immune function, cognitive impairment, mood disturbances and poor sleep quality. Glucocorticoids are endogenous pleiotropic steroid hormones and their excess produces a pattern of morbidity that possesses considerable overlap with CKD. Circulating levels of cortisol, the major active glucocorticoid in humans, are determined by a complex interplay between several processes. The hypothalamic-pituitary-adrenal axis (HPA) regulates cortisol synthesis and release, 11β-hydroxysteroid dehydrogenase enzymes mediate metabolic interconversion between active and inactive forms, and clearance from the circulation depends on irreversible metabolic inactivation in the liver followed by urinary excretion. Chronic stress, inflammatory states and other aspects of CKD can disturb these processes, enhancing cortisol secretion via the HPA axis and inducing tissue-resident amplification of glucocorticoid signals. Progressive renal impairment can further impact on cortisol metabolism and urinary clearance of cortisol metabolites. Consequently, significant interest exists to precisely understand the dysregulation of cortisol in CKD and its significance for adverse clinical outcomes. In this review, we summarize the latest literature on alterations in endogenous glucocorticoid regulation in adults with CKD and evaluate the available evidence on cortisol as a mechanistic driver of excess mortality and morbidity. The emerging picture is one of subclinical hypercortisolism with blunted diurnal decline of cortisol levels, impaired negative feedback regulation and reduced cortisol clearance. An association between cortisol and adjusted all-cause mortality has been reported in observational studies for patients with end-stage renal failure, but further research is required to assess links between cortisol and clinical outcomes in CKD. We propose recommendations for future research, including therapeutic strategies that aim to reduce complications of CKD by correcting or reversing dysregulation of cortisol.

Mechanisms behind context-dependent role of glucocorticoids in breast cancer progression

Glucocorticoids (GCs), mostly dexamethasone (dex), are routinely administered as adjuvant therapy to manage side effects in breast cancer. However, recently, it has been revealed that dex triggers different effects and correlates with opposite outcomes depending on the breast cancer molecular subtype. This has raised new concerns regarding the generalized use of GC and suggested that the context-dependent effects of GCs can be taken into potential consideration during treatment design. Based on this, attention has recently been drawn to the role of the glucocorticoid receptor (GR) in development and progression of breast cancer. Therefore, in this comprehensive review, we aimed to summarize the different mechanisms behind different context-dependent GC actions in breast cancer by applying a multilevel examination, starting from the association of variants of the GR-encoding gene to expression at the mRNA and protein level of the receptor, and its interactions with other factors influencing GC action in breast cancer. The role of GCs in chemosensitivity and chemoresistance observed during breast cancer therapy is discussed. In addition, experiences using GC targeting therapeutic options (already used and investigated in preclinical and clinical trials), such as classic GC dexamethasone, selective glucocorticoid receptor agonists and modulators, the GC antagonist mifepristone, and GR coregulators, are also summarized. Evidence presented can aid a better understanding of the biology of context-dependent GC action that can lead to further advances in the personalized therapy of breast cancer by the evaluation of GR along with the conventional estrogen receptor (ER) and progesterone receptor (PR) in the routine diagnostic procedure.

Detection of Urinary Exosomal HSD11B2 mRNA Expression: A Useful Novel Tool for the Diagnostic Approach of Dysfunctional 11β-HSD2-Related Hypertension

OBJECTIVE

Apparent mineralocorticoid excess (AME) is an autosomal recessive disorder caused by the 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) enzyme deficiency, traditionally assessed by measuring either the urinary cortisol metabolites ratio (tetrahydrocortisol+allotetrahydrocortisol/tetrahydrocortisone, THF+5αTHF/THE) or the urinary cortisol/cortisone (F/E) ratio. Exosomal mRNA is an emerging diagnostic tool due to its stability in body fluids and its biological regulatory function. It is unknown whether urinary exosomal HSD11B2 mRNA is related to steroid ratio or the HSD11B2 662 C>G genotype (corresponding to a 221 A>G substitution) in patients with AME and essential hypertension (EH).

AIM OF THE STUDY

To detect and quantify HSD11B2 mRNA from urinary exosomes in samples from family members affected by AME and EH, and to evaluate the relationship between exosomal HSD11B2 mRNA, steroid ratio, 662C>G genotype, and hypertension.

METHODS

In this observational case-control study, urinary steroid ratios and biochemical parameters were measured. Urinary exosomes were extracted from urine and exosomal HSD11B2 mRNA was quantified by Droplet Digital PCR (ddPCR). B2M (β-2 microglobulin) gene was selected as the reference housekeeping gene.

RESULTS

Among family members affected by AME, exosomal urinary HSD11B2 mRNA expression was strictly related to genotypes. The two homozygous mutant probands showed the highest HSD11B2 mRNA levels (median 169, range 118-220 copies/µl) that progressively decreased in 221 AG heterozygous with hypertension (108, range 92-124 copies/µl), 221 AG heterozygous normotensives (23.35, range 8-38.7 copies/µl), and wild-type 221 AA subjects (5.5, range 4.5-14 copies/µl). Heterozygous hypertensive subjects had more HSD11B2 mRNA than heterozygous normotensive subjects. The F/E urinary ratio correlated with HSD11B2 mRNA copy number (p < 0.05); HSD11B2 mRNA strongly decreased while THF+5αTHF/THE increased in the two probands after therapy. In the AME family, HSD11B2 copy number correlated with both F/E and THF+5αTHF/THE ratios, whereas in EH patients, a high F/E ratio reflected a reduced HSD11B2 mRNA expression.

CONCLUSIONS

HSD11B2 mRNA is detectable and quantifiable in urinary exosomes; its expression varies according to the 662 C>G genotype with the highest levels in homozygous mutant subjects. The HSD11B2 mRNA overexpression in AME could be due to a compensatory mechanism of the enzyme impairment. Exosomal mRNA is a useful tool to investigate HSD11B2 dysregulation in hypertension.

Inflammation and Skeletal Muscle Wasting During Cachexia

Cachexia is the involuntary loss of muscle and adipose tissue that strongly affects mortality and treatment efficacy in patients with cancer or chronic inflammatory disease. Currently, no specific treatments or interventions are available for patients developing this disorder. Given the well-documented involvement of pro-inflammatory cytokines in muscle and fat metabolism in physiological responses and in the pathophysiology of chronic inflammatory disease and cancer, considerable interest has revolved around their role in mediating cachexia. This has been supported by association studies that report increased levels of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in some, but not all, cancers and in chronic inflammatory diseases such as chronic obstructive pulmonary disease (COPD) and rheumatoid arthritis (RA). In addition, preclinical studies including animal disease models have provided a substantial body of evidence implicating a causal contribution of systemic inflammation to cachexia. The presence of inflammatory cytokines can affect skeletal muscle through several direct mechanisms, relying on activation of the corresponding receptor expressed by muscle, and resulting in inhibition of muscle protein synthesis (MPS), elevation of catabolic activity through the ubiquitin-proteasomal system (UPS) and autophagy, and impairment of myogenesis. Additionally, systemic inflammatory mediators indirectly contribute to muscle wasting through dysregulation of tissue and organ systems, including GCs via the hypothalamus-pituitary-adrenal (HPA) axis, the digestive system leading to anorexia-cachexia, and alterations in liver and adipocyte behavior, which subsequently impact on muscle. Finally, myokines secreted by skeletal muscle itself in response to inflammation have been implicated as autocrine and endocrine mediators of cachexia, as well as potential modulators of this debilitating condition. While inflammation has been shown to play a pivotal role in cachexia development, further understanding how these cytokines contribute to disease progression is required to reveal biomarkers or diagnostic tools to help identify at risk patients, or enable the design of targeted therapies to prevent or delay the progression of cachexia.

Effect of Vasopressin on the Hypothalamic-Pituitary-Adrenal Axis in ADPKD Patients during V2 Receptor Antagonism

BACKGROUND

Patients with autosomal dominant polycystic kidney disease (ADPKD) are treated with a vasopressin V2 receptor antagonist (V2RA) to slow disease progression. This drug increases vasopressin considerably in these patients with already elevated baseline levels. Vasopressin is known to stimulate the hypothalamic-pituitary-adrenal (HPA) axis through V1 and V3 receptor activation. It is unknown whether this increase in vasopressin during V2RA treatment affects glucocorticoid production.

METHODS

Twenty-seven ADPKD patients were studied on and off treatment with a V2RA and compared to age- and sex-matched healthy controls and IgA nephropathy patients, the latter also matched for kidney function. Vasopressin was measured by its surrogate copeptin. Twenty-four-hour urinary excretions of cortisol, cortisone, tetrahydrocortisone, tetrahydrocortisol, allotetrahydrocortisol, and the total glucocorticoid pool were measured.

RESULTS

At baseline, ADPKD patients demonstrated a higher copeptin concentration in comparison with healthy controls, while urinary excretion of cortisol and cortisone was lower (medians of 0.23 vs. 0.34 μmol/24 h, p = 0.007, and 0.29 vs. 0.53 μmol/24 h, p < 0.001, respectively). There were no differences in cortisol and cortisone excretion compared to IgA nephropathy patients. Cortisol, cortisone, and total glucocorticoid excretions correlated with kidney function (R = 0.37, 0.58, and 0.19, respectively; all p < 0.05). Despite that V2RA treatment resulted in a 3-fold increase in copeptin, only cortisone excretion increased (median of 0.44 vs. baseline 0.29 μmol/24 h, p < 0.001), whereas no changes in cortisol or total glucocorticoid excretion were observed.

CONCLUSIONS

Increased concentration of vasopressin in ADPKD patients at baseline and during V2RA treatment does not result in activation of the HPA axis. The impaired glucocorticoid production in these patients is related to their degree of kidney function impairment.

Impaired 11β-Hydroxysteroid Dehydrogenase Type 2 in Glucocorticoid-Resistant Patients

CONTEXT

Six patients carrying heterozygous loss-of-function mutations of glucocorticoid (GC) receptor (GR) presented with hypercortisolism, associated with low kalemia, low plasma renin, and aldosterone levels, with or without hypertension, suggesting a pseudohypermineralocorticism whose mechanisms remain unclear. We hypothesize that an impaired activity of the 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2; encoded by the HSD11B2 gene), catalyzing cortisol (F) inactivation, may account for an inappropriate activation of a renal mineralocorticoid signaling pathway in these GC-resistant patients.

OBJECTIVE

We aim at studying the GR-mediated regulation of HSD11B2.

DESIGN

The HSD11B2 promoter was subcloned and luciferase reporter assays evaluated GR-dependent HSD11B2 regulation, and 11β-HSD2 expression/activity was studied in human breast cancer MCF7 cells, endogenously expressing this enzyme.

RESULTS

Transfection assays revealed that GR transactivated the long (2.1-kbp) HSD11B2 promoter construct, whereas a defective 501H GR mutant was unable to stimulate luciferase activity. GR-mediated transactivation of the HSD11B2 gene was inhibited by the GR antagonist RU486. A threefold increase in HSD11B2 mRNA levels was observed after dexamethasone (DXM) treatment of MCF7 cells, inhibited by RU486 or by actinomycin, supporting a GR-dependent transcription. Chromatin immunoprecipitation further demonstrated a DXM-dependent GR recruitment onto the HSD11B2 promoter. 11β-HSD2 activity, evaluated by the cortisone/F ratio, quantified by liquid chromatography/tandem mass spectrometry, was 10-fold higher in the supernatant of DXM-treated cells than controls, consistent with a GR-dependent stimulation of 11β-HSD2 catalytic activity.

CONCLUSION

Collectively, we demonstrate that 11β-HSD2 expression and activity are transcriptionally regulated by GR. In the context of GR haploinsufficiency, these findings provide evidence that defective GR signaling may account for apparent mineralocorticoid excess in GC-resistant patients.

Redefining the perioperative stress response: a narrative review

The systemic stress response triggered by surgical trauma is characterised by sterile inflammation preceding metabolic and neuroendocrine dysregulation. However, the relevance of the classically described 'stress response' is now highly questionable in an era where profound physiological deconditioning is common in older, frail surgical patients. Commonly used assessment techniques do not accurately reflect hypothalamic-pituitary-adrenal axis integrity after major surgery. Clinical interpretation of plasma concentrations of cortisol, the prototypical stress hormone, is rarely accurate, because of study heterogeneity, the inherently dynamic characteristics of cortisol production, and assay variability. Before surgery, chronic psychosocial stress and common cardiorespiratory co-morbidities are clinically relevant modifiers of neuroendocrine activation to acute stress/inflammation. The frequent development of multi-morbidity after major surgery further clouds the compartmentalised, discrete model of neuroendocrine activation after initial tissue injury. Starvation, impaired mobility, and sepsis after surgery generate distinct neuroendocrine profiles that challenge the conventional model of neuroendocrine activation. Basic science studies suggest that high circulating levels of cortisol may directly cause organ injury. Conversely, randomised controlled clinical trials investigating glucocorticoid supplementation have delivered contrasting results, with some suggesting a protective effect in the perioperative period. Here, we consider many of the confounding factors that have emerged to challenge the conventional model of the surgical stress response, and suggest that a more nuanced understanding of changes in hypothalamic-pituitary-adrenal axis physiology is warranted to advance perioperative medicine. Re-examining the perioperative stress response presents opportunities for improving outcomes through enhancing the understanding of the neuroendocrine aspects of preparation for and recovery from surgery.

A Lower Maternal Cortisol-to-Cortisone Ratio Precedes Clinical Diagnosis of Preterm and Term Preeclampsia by Many Weeks

CONTEXT

Previous studies have shown reduced placental levels of 11-β-hydroxysteroid dehydrogenase type 2 (11βHSD2) in preeclampsia (PE). However, it is unknown if the maternal cortisol-to-cortisone ratio is predictive of placental complications of pregnancy.

OBJECTIVE

To determine the relationship between the maternal serum cortisol-to-cortisone ratio at different stages of pregnancy and the risk of PE or fetal growth restriction (FGR).

DESIGN

Women from the Pregnancy Outcome Prediction Study experiencing PE (n = 194) or FGR (n = 185), plus a random sample of healthy controls (n = 279), were studied. Steroids were measured at ∼12, ∼20, ∼28, and ∼36 weeks of gestational age (wkGA). Separate analyses were performed for outcomes with term or preterm delivery. Associations were modeled using logistic regression.

RESULTS

At 28 wkGA, the cortisol-to-cortisone ratio was negatively associated (OR per 1 SD increase, 95% CI)] with preterm PE (OR 0.33, 95% CI 0.19 to 0.57), term PE (OR 0.61, 95% CI 0.49 to 0.76), and preterm FGR (OR 0.50, 95% CI 0.29 to 0.85). At 36 wkGA, the cortisol-to-cortisone ratio was negatively associated with term PE (OR 0.42, 95% CI 0.32 to 0.55) but not term FGR (OR 1.07, 95% CI 0.87 to 1.31). Associations were not materially affected by adjustment for maternal characteristics.

CONCLUSIONS

A lower maternal serum cortisol-to-cortisone ratio precedes clinical manifestation of PE and preterm FGR by many weeks, despite previous reports of reduced levels of placental 11βHSD2 in these conditions. Our observations implicate enhanced maternal 11βHSD2 activity or reduced 11βHSD type 1 activity in the pathophysiology of PE.

Glucocorticoid activation by 11β-hydroxysteroid dehydrogenase enzymes in relation to inflammation and glycaemic control in chronic kidney disease: A cross-sectional study

OBJECTIVE

Patients with chronic kidney disease (CKD) have dysregulated cortisol metabolism secondary to changes in 11β-hydroxysteroid dehydrogenase (11β-HSD) enzymes. The determinants of this and its clinical implications are poorly defined.

METHODS

We performed a cross-sectional study to characterize shifts in cortisol metabolism in relation to renal function, inflammation and glycaemic control. Systemic activation of cortisol by 11β-HSD was measured as the metabolite ratio (tetrahydrocortisol [THF]+5α-tetrahydrocortisol [5αTHF])/tetrahydrocortisone (THE) in urine.

RESULTS

The cohort included 342 participants with a median age of 63 years, median estimated glomerular filtration rate (eGFR) of 28 mL/min/1.73 m2 and median urine albumin-creatinine ratio of 35.5 mg/mmol. (THF+5αTHF)/THE correlated negatively with eGFR (Spearman's ρ = -0.116, P = 0.032) and positively with C-reactive protein (ρ = 0.208, P < 0.001). In multivariable analysis, C-reactive protein remained a significant independent predictor of (THF+5αTHF)/THE, but eGFR did not. Elevated (THF+5αTHF)/THE was associated with HbA1c (ρ = 0.144, P = 0.008) and diabetes mellitus (odds ratio for high vs low tertile of (THF+5αTHF)/THE 2.57, 95% confidence interval 1.47-4.47). Associations with diabetes mellitus and with HbA1c among the diabetic subgroup were independent of eGFR, C-reactive protein, age, sex and ethnicity.

CONCLUSIONS

In summary, glucocorticoid activation by 11β-HSD in our cohort comprising a spectrum of renal function was associated with inflammation and impaired glucose control.

Lower Renal Function Is Associated With Derangement of 11-β Hydroxysteroid Dehydrogenase in Type 2 Diabetes

Context

Derangement of 11-β hydroxysteroid dehydrogenase type 1 and type 2 (11β-HSD1 and 11β-HSD2), which regulate intracellular cortisol production, has been suggested in both type 2 diabetes (T2D) and chronic kidney disease (CKD). However, activity of 11β-HSD enzymes in patients with T2D and CKD has never been assessed.

Objectives

To compare 11β-HSD activities between patients with T2D and healthy controls, and assess whether in T2D, renal function is associated with 11β-HSD activities.

Design

Cross-sectional analysis in the Diabetes and Lifestyle Cohort Twente (DIALECT-1).

Setting

Referral center for T2D.

Patients

Patient with T2D [n = 373, age 64 ± 9 years, 58% men, 26% of patients estimated glomerular filtration rate (eGFR) <60 mL/min·1.73 m²] and healthy controls (n = 275, age 53 ± 11 years, 48% men).

Mean Outcome Measure

We measured cortisol, cortisone, and metabolites [tetrahydrocortisol (THF), allo-THF (aTHF), and tetrahydrocortisone (THE)] in 24-hour urine samples. Whole body 11β-HSD and 11β-HSD2 activities were calculated as the urinary (THF + aTHF)/THE and cortisol/cortisone ratios, respectively.

Results

Patients with T2D had a higher (THF + aTHF)/THE ratio [1.02 (0.84 to 1.27) vs 0.94 (0.79 to 1.0), P < 0.001] and cortisol/cortisone ratio [0.70 (0.58 to 0.83) vs 0.63 (0.54 to 0.74), P < 0.001] than healthy controls. In T2D, lower eGFR was associated with a higher (THF + aTHF)/THE ratio (β = −0.35, P < 0.001), and a higher cortisol/cortisone ratio (β = −0.16, P = 0.001).

Conclusions

In this real-life secondary care setting of patients with T2D, 11β-HSD enzymes activities were shifted to higher intracellular cortisol production in T2D, which was further aggravated in patients with CKD. Prospective analyses are warranted to investigate causality of these associations.

Dynamics of salivary cortisol in chronic kidney disease patients at stages 1 through 4

CONTEXT

End-stage renal disease has been associated with derangement of the HPA function. The dynamics of this axis in early stages of renal disease (CKD) has not been assessed.

OBJECTIVES

To evaluate in patients with CKD at stages 1-4 (KDOQI): the diurnal variation of salivary cortisol; the suppressibility of cortisol in saliva and serum after an overnight oral 1 mg dexamethasone suppression test (1 mg DST) with simultaneous measurement of circulating dexamethasone.

DESIGN AND METHODS

80 CKD outpatients and 40 healthy subjects were included. All CKD collected whole saliva at 08·00 and 23·00 h (SAF23 ) on two nonconsecutive days. Thereafter at 08·00 h, following 1 mg DST, saliva and blood were obtained. Salivary and serum cortisol as well as CBG were assessed by RIA, dexamethasone by ELISA and serum free cortisol was calculated.

RESULTS

SAF23 correlated negatively with glomerular filtration rate (GFR). The fraction of free cortisol in serum and saliva after 1 mg DST, correlated positively and significantly in both patients with CKD and healthy subjects (r: 0·86 and r: 0·85, respectively; P < 0·0001 for both). Ten percent of CKD with GFR < 90 ml/min/1·73 m(2) had false positive results unrelated to dexamethasone and CBG concentrations.

CONCLUSIONS

False positive responses to 1 mg DST were associated with GFR < 90 ml/min/1·73 m(2) . This could not be ascribed to either defects in dexamethasone absorption or CBG concentrations. Higher dexamethasone doses were necessary to achieve adequate HPA suppression. Salivary cortisol was useful to assess circadian cortisol levels and feed-back regulation in CKD.

Moderately impaired renal function increases morning cortisol and cortisol levels at dexamethasone suppression test in patients with incidentally detected adrenal adenomas

OBJECTIVE

Patients with incidentally detected adrenal adenomas may have subclinical hypercortisolism. We hypothesized that impaired renal function could lead to increased cortisol levels in these patients.

DESIGN

Descriptive retrospective study of consecutive patients.

PATIENTS

A total of 166 patients with incidentally detected unilateral adrenal adenomas were examined during 2008-2013.

MEASUREMENTS

Levels of cortisol, ACTH and cortisol at 1 mg overnight dexamethasone suppression test (DST) were measured. The estimated glomerular filtration rate (eGFR) was calculated using the MDRD equation.

RESULTS

Renal function was normal, mildly impaired, moderately impaired or severely impaired (eGFR >90, 60-90, 30-60 and 15-30 ml/min/1·73 m(2)) in 34, 54, 10 and 1% of the patients, respectively. Patients with normal and mildly impaired renal function had similar cortisol levels. Patients with moderately impaired renal function, compared to all the patients with eGFR >60 ml/min/1·73 m(2), exhibited increased cortisol (541 vs 456 nmol/l, P = 0·02), increased cortisol at DST (62 vs 37 nmol/l, P = 0·001), but similar ACTH levels (4·1 vs 2·9 pmol/l, P = 0·21). Patients with moderately impaired renal function thus exhibited cortisol at DST ≥ 50 nmol/l, more often than patients with eGFR >60 ml/min/1·73 m(2) (76% vs 30%, P = 0·000), while the prevalence of ACTH below 2 pmol/l was similar (24% vs 31%, P = 0·51).

CONCLUSIONS

Moderately impaired renal function increases cortisol and cortisol at DST in patients with adrenal adenomas, while mildly impaired renal function has no such effect. Cortisol level at DST ≥ 50 nmol/l therefore seems to have low specificity in diagnosing subclinical adrenal hypercortisolism, and an additional criterion, for example low ACTH, is required.

Effect of Luteolin on 11Beta-Hydroxysteroid Dehydrogenase in Rat Liver and Kidney

11Beta-hydroxysteroid dehydrogenase (11β-HSD) enzymes control the glucocorticoid (GC) signaling, which is essential in regulating homeostasis. Our previous study revealed that Eclipta prostrata (EP) affected the activity and expression of 11β-HSD enzymes which might improve the efficacy and reduce the adverse drug effects of glucocorticoid in patients undergoing combinational therapy. However, it is still unclear which composition of EP plays a major role and how it works. In this paper, we chose Luteolin which is one of the main ingredients of EP and evaluated its effect and metabolism in combination with prednisone. The effects of different concentrations of Luteolin extract on prednisone/prednisolone metabolism indicated the enzyme activity of 11β-HSD, so the production rate (pmol/min per mg protein) of metabolites was used to indicate enzyme activity. Furthermore, we explored the influence of Luteolin on gene and protein expressions of 11β-HSD I/II in rat liver and kidney tissue. Our results showed that oral administration of Luteolin significantly increased the gene and protein expressions of hepatic 11β-HSD I and renal 11β-HSD II, which may improve the efficacy and reduce the adverse drug effect of glucocorticoid in clinical application. A potential clinical value of Luteolin would also be indicated in combination therapy with prednisone for the treatment of nephrotic syndrome.

The acute autonomic stress response and amniotic fluid glucocorticoids in second-trimester pregnant women

OBJECTIVE

The maternal autonomic nervous system (ANS) has received little attention in the investigation of biological mechanisms linking prenatal stress to fetal cortisol (F) excess. In vitro, norepinephrine and epinephrine inhibit placental 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which protects the fetus from F overexposure by inactivating it to cortisone (E). Here, we investigated the acute ANS stress response to an amniocentesis and its association with amniotic fluid F, E, and E/(E + F) as a marker of fetoplacental 11β-HSD2 activity.

METHODS

An aliquot of amniotic fluid was obtained from 34 healthy, second-trimester pregnant women undergoing amniocentesis. Repeated assessment of mood states served to examine the psychological stress response to amniocentesis. Saliva samples were collected to measure stress-induced changes in salivary α-amylase concentrations in response to amniocentesis. Cardiac parameters were measured continuously.

RESULTS

Undergoing amniocentesis induced significant psychological and autonomic alterations. Low-frequency (LF)/high-frequency (HF) baseline, suggested to reflect sympathovagal balance, was negatively correlated with amniotic E/(E + F) (r=-0.53, p = .002) and positively with F (r = 0.62, p < .001). In contrast, a stronger acute LF/HF response was positively associated with E/(E + F) (r = 0.44, p = .012) and negatively with F (r=-0.40, p = .025).

CONCLUSIONS

These findings suggest that the maternal ANS is involved in the regulation of the fetoplacental barrier to stress. Allostatic processes may have been initiated to counterbalance acute stress effects. In contrast, higher LF/HF baseline values, possibly indicative of chronic stress exposure, may have inhibited 11β-HSD2 activity in the fetoplacental unit. These results parallel animal findings of up-regulated placental 11β-HSD2 in response to acute stress but impairment under chronic stress.

Role of 11βHSD type 2 enzyme activity in essential hypertension and children with chronic kidney disease (CKD)

BACKGROUND

The mineralocorticoid receptor is protected from excess of glucocorticoids by conversion of active cortisol to inactive cortisone by enzyme 11β-hydroxysteroid dehydrogenase type 2 present in the kidney. The metabolites of cortisol and cortisone are excreted in the urine as tetrahydrocortisol (5αTHF+5βTHF) and tetrahydrocortisone (THE), respectively.

HYPOTHESIS

Patients with chronic kidney disease (CKD) and essential hypertension have a functional defect in their ability to convert cortisol to cortisone, thus leading to the activation of mineralocorticoid receptor.

OBJECTIVE

The objective of the investigation was to study the ratio of urinary steroids (5αTHF+5βTHF) to THE in patients with CKD, postrenal transplant, and essential hypertension and to compare the ratio with controls.

DESIGN/METHODS

We enrolled 44 patients (17 with CKD, eight postrenal transplant, 19 with essential hypertension) and 12 controls. We measured spot urinary 5α-THF, 5β-THF, THE, free active cortisol and inactive cortisone by gas chromatography/mass spectrometry. We collected data on age, sex, cause of kidney disease, height, weight, body mass index, blood pressure, serum electrolytes, aldosterone, and plasma renin activity. Blood pressure percentiles and z-scores were calculated. The glomerular filtration rate was calculated using the modified Schwartz formula.

RESULTS

The ratios of 5αTHF+5βTHF to THE were significantly higher in patients with CKD [mean±sd score (SDS)=1.31±1.07] as compared with essential hypertension (mean±SDS=0.59±0.23; P=0.02) and controls (mean±SDS=0.52±0.25; P=0.01). In the postrenal transplant group, the ratio was not significantly different (mean±SDS=0.71±0.55). The urinary free cortisol to free cortisone ratios were significantly higher in the hypertension and CKD groups as compared with the controls. The 5αTHF+5βTHF to THE ratio negatively correlated with the glomerular filtration rate and positively correlated with systolic and diastolic blood pressure z-scores. The correlation of the blood pressure z-scores with ratios was stronger in the CKD group than the essential hypertension and posttransplant groups.

CONCLUSIONS

We have elucidated a functional deficiency of 11β-hydroxysteroid dehydrogenase type 2 in children with CKD and a subset of essential hypertension. Urinary 5α-THF, 5β-THF, and THE analysis by gas chromatography/mass spectrometry should be a part of routine work-up of CKD and hypertensive patients.

Selection and optimization of MCF-7 cell line for screening selective inhibitors of 11beta-hydroxysteroid dehydrogenase 2

An 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) produces glucocorticoid (GC) from 11-keto metabolite, and its modulation has been suggested as a novel approach to treat metabolic diseases. In contrast, type 2 isozyme 11beta-HSD2 is involved in the inactivation of glucocorticoids (GCs), protecting the non-selective mineralocorticoid receptor (MR) from GCs in kidney. Therefore, when 11beta-HSD1 inhibitors are pursued to treat the metabolic syndrome, preferential selectivity of inhibitors for type 1 over type 2 isozyme is rather important than inhibitory potency. Primarily, to search for cell lines with 11beta-HSD2 activity, we investigated the expression profiles of enzymes or receptors relevant to GC metabolism in breast, colon, and bone-derived cell lines. We demonstrated that MCF-7 cells had high expression for 11beta-HSD2, but not for 11beta-HSD1 with its cognate receptor. Next, for the determination of enzyme activity indirectly, we adopted homogeneous time resolved fluorescence (HTRF) cortisol assay. Obviously, the feasibility of HTRF to cellular 11beta-HSD2 was corroborated by constructing inhibitory response to an 11b-HSD2 inhibitor glycyrrhetinic acid (GA). Taken together, MCF-7 that overexpresses type 2 but not type 1 enzyme is chosen for cellular 11beta-HSD2 assay, and our results show that a nonradioactive HTRF assay is applicable for type 2 as well as type 1 isozyme.

The effect of spironolactone upon corticosteroid hormone metabolism in patients with early stage chronic kidney disease

CONTEXT

Aldosterone has emerged as an important mediator of disease progression and mortality in patients with chronic heart and kidney disease (CKD). Despite the increasing use of mineralocorticoid receptor antagonists in these patients, little is known about the effects on corticosteroid hormone secretion and metabolism.

OBJECTIVE

To assess corticosteroid hormone secretion and metabolism in patients with early stage CKD before and after spironolactone (Spiro).

DESIGN

Randomized, double-blind, placebo-controlled interventional study.

SETTING

Single tertiary referral centre.

PATIENTS

A total of 112 patients with stable stage 2/3 CKD.

INTERVENTIONS

Patients were randomized to receive either Spiro 25 mg once daily or placebo for 36 weeks.

MAIN OUTCOME MEASURES

Plasma renin activity (PRA), angiotensin II (AngII) and steroid hormones were analysed by standard assays; urinary corticosteroid hormone metabolites (5α+5β-tetrahydro-cortisol (5α+5β-THF), TH-cortisone (THE), 3α5β-TH-aldosterone (TH-Aldo), 5α+5β-TH-deoxycorticosterone (5α+5β-TH-DOC), TH-11-desoxycortisol (THS)) were analysed by gas chromatography/mass spectrometry.

RESULTS

Plasma aldosterone concentration (PAC) was inversely correlated with eGFR (r = -0·331, P < 0·001). Urinary 24-h excretion of TH-Aldo was correlated with PAC (r = 0·214, P < 0·05) and diastolic blood pressure (BP) (r = 0·212, P = <0·05), whereas total 24-h urinary cortisol metabolite excretion was correlated with systolic BP (r = 0·316, P < 0·01). In addition, 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 activity (urinary 5α+5β-THF)/THE) ratio) was correlated with PRA (r = 0·277, P < 0·01). Spiro treatment significantly reduced BP (123 ± 11/76 ± 7 vs 119 ± 11/73 ± 8 mmHg, P < 0·01) despite renin-angiotensin-aldosterone system induction, reflected by increased urinary 24-h TH-Aldo excretion (17·6 (12, 86) vs 26 (18, 80) μg/24 h, P < 0·05). By contrast, Spiro had no effect on total urinary cortisol metabolite excretion, 11β-hydroxylase, 11β-HSD type 1 and 2 activity.

CONCLUSIONS

Aldo and cortisol are positively associated with BP suggesting that adrenal hyperactivity may in part explain the increased cardiovascular risk in patients with early end-stage CKD. Addition of Spiro had no effect on glucocorticoid metabolism or total 24-h corticosteroid production.

11β-Hydroxysteroid dehydrogenase type-2 and type-1 (11β-HSD2 and 11β-HSD1) and 5β-reductase activities in the pathogenia of essential hypertension

Cortisol availability is modulated by several enzymes: 11β-HSD2, which transforms cortisol (F) to cortisone (E) and 11β-HSD1 which predominantly converts inactive E to active F. Additionally, the A-ring reductases (5α- and 5β-reductase) inactivate cortisol (together with 3α-HSD) to tetrahydrometabolites: 5αTHF, 5βTHF, and THE. The aim was to assess 11β-HSD2, 11β-HSD1, and 5β-reductase activity in hypertensive patients. Free urinary F, E, THF, and THE were measured by HPLC-MS/MS in 102 essential hypertensive patients and 18 normotensive controls. 11β-HSD2 enzyme activity was estimated by the F/E ratio, the activity of 11β-HSD1 in compare to 11β-HSD2 was inferred by the (5αTHF + 5βTHF)/THE ratio and 5β-reductase activity assessed using the E/THE ratio. Activity was considered altered when respective ratios exceeded the maximum value observed in the normotensive controls. A 15.7% of patients presented high F/E ratio suggesting a deficit of 11β-HSD2 activity. Of the remaining 86 hypertensive patients, two possessed high (5αTHF + 5βTHF)/THE ratios and 12.8% had high E/THE ratios. We observed a high percentage of alterations in cortisol metabolism at pre-receptor level in hypertensive patients, previously misclassified as essential. 11β-HSD2 and 5β-reductase decreased activity and imbalance of 11β-HSDs should be considered in the future management of hypertensive patients.

Role of 11beta-hydroxysteroid dehydrogenase 2 renal activity in potassium homeostasis in rats with chronic renal failure

Aldosterone concentrations vary in advanced chronic renal failure (CRF). The isozyme 11beta-hydroxysteroid dehydrogenase 2 (11beta-HSD2), which confers aldosterone specificity for mineralocorticoid receptors in distal tubules and collecting ducts, has been reported to be decreased or normal in patients with renal diseases. Our objective was to determine the role of aldosterone and 11beta-HSD2 renal microsome activity, normalized for glomerular filtration rate (GFR), in maintaining K+ homeostasis in 5/6 nephrectomized rats. Male Wistar rats weighing 180-220 g at the beginning of the study were used. Rats with experimental CRF obtained by 5/6 nephrectomy (N = 9) and sham rats (N = 10) were maintained for 4 months. Systolic blood pressure and plasma creatinine (Pcr) concentration were measured at the end of the experiment. Sodium and potassium excretion and GFR were evaluated before and after spironolactone administration (10 mg.kg-1.day-1 for 7 days) and 11beta-HSD2 activity on renal microsomes was determined. Systolic blood pressure (means +/- SEM; Sham = 105 +/- 8 and CRF = 149 +/- 10 mmHg) and Pcr (Sham = 0.42 +/- 0.03 and CRF = 2.53 +/- 0.26 mg/dL) were higher (P < 0.05) while GFR (Sham = 1.46 +/- 0.26 and CRF = 0.61 +/- 0.06 mL/min) was lower (P < 0.05) in CRF, and plasma aldosterone (Pald) was the same in the two groups. Urinary sodium and potassium excretion was similar in the two groups under basal conditions but, after spironolactone treatment, only potassium excretion was decreased in CRF rats (sham = 0.95 +/- 0.090 (before) vs 0.89 +/- 0.09 microEq/min (after) and CRF = 1.05 +/- 0.05 (before) vs 0.37 +/- 0.07 microEq/min (after); P < 0.05). 11beta-HSD2 activity on renal microsomes was lower in CRF rats (sham = 0.807 +/- 0.09 and CRF = 0.217 +/- 0.07 nmol.min-1.mg protein-1; P < 0.05), although when normalized for mL GFR it was similar in both groups. We conclude that K+ homeostasis is maintained during CRF development despite normal Pald levels. This adaptation may be mediated by renal 11beta-HSD2 activity, which, when normalized for GFR, became similar to that of control rats, suggesting that mineralocorticoid receptors maintain their aldosterone selectivity.

Urinary cortisol/cortisone ratios in hypertensive and normotensive cats

Hypertension is a common problem in older cats, particularly associated with chronic kidney disease (CKD). Reduced activity of 11β-hydroxysteroid dehydrogenase type 2 predisposes to hypertension in human patients by allowing excessive stimulation of the mineralocorticoid receptor by cortisol. This study was designed to test the hypothesis that reduced conversion of cortisol to cortisone contributes to the development of systemic hypertension in some cats with CKD and idiopathic hypertension (iHT). The study included 60 client-owned cats: 21 clinically normal, 16 normotensive cats with CKD (NTCKD), 14 hypertensive cats with CKD (HTCKD) and nine iHTs. Urine cortisol and cortisone were extracted into dichloromethane and chloroform, respectively, prior to analysis by radioimmunoassay. Data are reported as median and range. The Kruskall–Wallis test was used to compare cortisol:cortisone ratios between groups with post-hoc testing using the Mann–Whitney U test. Wilcoxon signed-ranks test was used to compare results before and after treatment of hypertensive cats with amlodipine. The urinary cortisol:cortisone ratio was significantly higher in clinically normal cats (0.87; 0.46–1.39) when compared to NTCKD (0.60; 0.35–1.20; P<0.001), HTCKD (0.62; 0.34–1.00; P=0.002) and cats with iHT (0.65; 0.46–0.85; P=0.015). No statistical difference was detected between NTCKD, HTCKD and iHT groups. No effect of anti-hypertensive treatment on the urinary cortisol–cortisone ratio was detected ( P=0.327). Reduced urinary cortisol to cortisone conversion does not appear to be associated with systemic hypertension in cats. In fact, the cortisol to cortisone shuttle appears to be more effective in cats with CKD (hypertensive and normotensive) and iHT than clinically normal cats. The mechanism for this potentially adaptive response to kidney disease is not clear.

Age-dependent decrease in 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) activity in hypertensive patients

BACKGROUND

The prevalence of arterial hypertension lacking a defined underlying cause increases with age. Age-related arterial hypertension is insufficiently understood, yet known characteristics suggest an aldosterone-independent activation of the mineralocorticoid receptor. Therefore, we hypothesized that 11beta-HSD2 activity is age-dependently impaired, resulting in a compromised intracellular inactivation of cortisol (F) with F-mediated mineralocorticoid hypertension.

METHODS

Steroid hormone metabolites in 24-h urine samples of 165 consecutive hypertensive patients were analyzed for F and cortisone (E), and their TH-metabolites tetrahydro-F (THF), 5alphaTHF, TH-deoxycortisol (THS), and THE by gas chromatography-mass spectroscopy. Apparent 11beta-HSD2 and 11beta-hydroxylase activity and excretion of F metabolites were assessed.

RESULTS

In 72 female and 93 male patients aged 18-84 years, age correlated positively with the ratios of (THF + 5alphaTHF)/THE (P = 0.065) and F/E (P < 0.002) suggesting an age-dependent reduction in the apparent 11beta-HSD2 activity, which persisted (F/E; P = 0.020) after excluding impaired renal function. Excretion of F metabolites remained age-independent most likely as a consequence of an age-dependent diminished apparent 11beta-hydroxylase activity (P = 0.038).

CONCLUSION

Reduced 11beta-HSD2 activity emerges as a previously unrecognized risk factor contributing to the rising prevalence of arterial hypertension in elderly. This opens new perspectives for targeted treatment of age-related hypertension.

Epigenetic control of 11 beta-hydroxysteroid dehydrogenase 2 gene promoter is related to human hypertension

BACKGROUND

Lower activity of 11 beta-hydroxysteroid dehydrogenase 2 (11beta-HSD2) classically induces hypertension by leading to an altered tetrahydrocortisol- versus tetrahydrocortisone-metabolites (THFs/THE) shuttle. Recent cell culture and animal studies suggest a role for promoter methylation, a major epigenetic feature of DNA, in regulation of HSD11B2 expression. Little is known, however, of human HSD11B2 epigenetic control and its relationship with the onset of hypertension.

OBJECTIVE

To explore the possible relevance of HSD11B2 promoter methylation, by examining human peripheral blood mononuclear cell (PBMC) DNA and urinary THFs/THE ratio as a biochemical indicator of 11beta-HSD2 activity, in blood pressure control.

METHODS

Twenty-five essential hypertensives and 32 subjects on prednisone therapy were analyzed, the latter to investigate 11beta-HSD2 function in the development of hypertension.

RESULTS

Elevated HSD11B2 promoter methylation was associated with hypertension developing in glucocorticoid-treated patients in parallel with a higher urinary THFs/THE ratio. Essential hypertensives with elevated urinary THFs/THE ratio also showed higher HSD11B2 promoter methylation.

CONCLUSIONS

These results show a clear link between the epigenetic regulation through repression of HSD11B2 in PBMC DNA and hypertension.

Sexual dimorphism in cortisol secretion starts after age 10 in healthy children: urinary cortisol metabolite excretion rates during growth

Detailed data on the physiological pattern of adrenocortical activity during normal growth are lacking. An established method to determine adrenocortical glucocorticoid secretion is the measurement of 24-h excretion rates of major urinary cortisol metabolites (C21). To test the hypothesis that the frequently reported higher cortisol secretion in men than in women develops during puberty, we examined C21 together with excretions of combined urinary free and conjugated cortisol (F(comb)) in 400 healthy boys and girls aged 3-18 yr using GC-MS. Daily excretion rates of C21, F(comb), and body surface area (BSA)-corrected F(comb) significantly increased with age in both sexes. In contrast, C21/BSA (microgxm(-2).day(-1)) declined from the age of 3-4 yr to 7-8 yr in boys and girls (P < 0.01; e.g., in boys: from 3,991 +/- 1,167 to 3,193 +/- 804), then increased in both sexes, and finally became discordant after the age of 11-12 yr with a further rise in males only (17- to 18-yr-olds: boys, 5,275 +/- 1,414; girls 3,939 +/- 1,586, P < 0.01). This pattern was associated with the occurrence of a lower index for 5alpha-reductase activity (allotetrahydrocortisol/tetrahydrocortisol) in females compared with males. Our results demonstrate dynamic changes in adrenocortical activity in healthy children resulting in an emerging sexual dimorphism in cortisol secretion after age 11. The latter can be explained, at least partly, by diverging 5alpha-reductase activities in boys and girls. F(comb), a frequently analyzed GC-MS parameter, proved not to reflect dynamic changes in cortisol secretion. In conclusion, the varying metabolic need for cortisol during normal growth may have implications for future improvements in glucocorticoid replacement therapy.

11β-hydroxystéroïde déshydrogénases. Avancées récentes

11beta-hydroxysteroide dehydrogenase (11beta-OHSD) enzymes exhibit a regulating action upon cortisol metabolism before access to its receptors. Two types of isoenzymes have been described, type 2 being the most anciently known. Type 2 11beta-OHSD, which changes cortisol into cortisone, is a unidirectional dehydrogenase mainly located in kidney, that protects mineralocorticoid receptors from illicit activation by glucocorticoids. Mutations of the gene coding for this enzyme has been demonstrated in apparent mineralocorticoid excess, which induces hypertension and hypokalemia with low renin and aldosterone levels. Polymorphisms of this gene could modulate essential hypertension and also be responsible for certain forms of acquired apparent mineralocorticoid excess especially after liquorice intoxication, in hypothyroidism, Cushing syndrome, and chronic renal insufficiency. Type 1 11beta-OHSD, which changes cortisone into cortisol, is a reductase, mainly located in liver and adipose tissue. Functional defects of this enzyme have been shown in polycystic ovaries and cortisone reductase deficiency. By contrast, metabolic syndrome, corticoid-induced osteoporosis, and glaucoma are linked to a local over-activity of this enzyme. The understanding of action mechanisms of these two enzymes currently leads to 11beta-OHSD inhibitors development, therefore opening new therapeutic strategies, especially in metabolic syndrome.

Role of Aldosterone in Oxidative Stress and Renal Injury

Recent clinical studies have indicated the utility of mineralocorticoid receptor (MR) antagonists in cardiovascular and renal injuries. Chronic treatment with aldosterone/salt resulted in severe cardiac and renal injuries in rats. Further studies showed that the aldosterone-induced organ injuries were associated with increases in expression of NADPH oxidase components and reactive oxygen species (ROS) levels. Treatment with a selective MR antagonist, eplerenone, prevented the elevation of ROS levels and ameliorated organ injuries. In vitro studies also showed that MR is highly expressed in cultured vascular smooth muscle cells, glomerular mesangial cells and renal fibroblasts. In these cells, aldosterone-induced cell injuries were associated with increases in NADPH oxidase activity and superoxide generation. Further, the aldosterone-dependent cell injuries were markedly attenuated by treatment with eplerenone. These accumulating data support the notion that the aldosterone/MR is involved in the pathogenesis of cardiovascular and renal injuries through NADPH oxidase-dependent ROS production.

Evidence of altered cortisol metabolism in critically ill patients: a prospective study

CONTEXT

Changes in cortisol metabolism due to altered activity of the enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD) have been implicated in the pathogenesis of hypertension, obesity and the metabolic syndrome. No published data exist on the activity of this enzyme in critical illness.

OBJECTIVE

To investigate cortisol metabolism in critically ill patients utilising plasma cortisol: cortisone ratio as an index of 11beta-HSD activity.

SETTING

Tertiary level intensive care unit.

PATIENTS

Three cohorts of critically ill patients: sepsis (n = 13); multitrauma (n = 20); and burns (n = 19).

MAIN OUTCOME MEASURES

Serial plasma cortisol: cortisone ratios.

MEASUREMENTS AND MAIN RESULTS

Plasma total cortisol cortisone ratios were determined serially after admission to the intensive care unit. As compared with controls, the plasma cortisol:cortisone ratio was significantly elevated in the sepsis and trauma cohorts on day 1 (22 +/- 9, p = 0.01, and 23 +/- 19, p = 0.0003, respectively) and remained elevated over the study period. Such a relationship was not demonstrable in burns. The ratio was significantly correlated with APACHE II (r = 0.77, p = 0.0008) and Simplified Acute Physiology Score (r = 0.7, p = 0.003) only on day 7 and only in the burns cohort. There were no significant correlations observed between total plasma cortisol or cortisone and sickness severity in the sepsis and trauma cohorts.

CONCLUSIONS

In critically ill patients, there is evidence of altered cortisol metabolism due to an increase in 11beta-HSD activity as demonstrated by an elevation of plasma cortisol: cortisone ratios. Further studies with larger sample sizes specifically designed to examine altered tissue 11beta-HSD activity and its clinical significance and correlation with outcome are warranted.

Exaggerated adrenarche and altered cortisol metabolism in Type 1 diabetic children

Reported literature data strongly suggest that steroid metabolism is dysregulated in Type 1 diabetes mellitus. The aim of this study was to non-invasively examine the cortisol metabolism in children with Type 1 diabetes mellitus (T1DM) in detail and to test the hypothesis that adrenarche is affected under conventional intensive insulin therapy. In 24-h urine samples of 109 patients aged 4-18 years with T1DM of more than 1 year, steroids were profiled using gas chromatography-mass spectrometry. Additionally, urinary free cortisol (UFF) and cortisone (UFE) were quantified by RIA after extraction and chromatographic purification. Data on urinary steroids from 400 healthy controls served as reference values. Enzyme activities were assessed by established steroid metabolite ratios, e.g. 5alpha-reductase and 11beta-hydroxysteroid dehydrogenase Type 2 (11beta-HSD2) by 5alpha-tetrahydrocortisol/tetrahydrocortisol and UFE/UFF, respectively. Urinary markers of adrenarche, especially dehydroepiandrosterone and its direct metabolites were elevated in patients, as were urinary 6beta-hydroxycortisol, UFE, and 11beta-HSD2 activity. However, overall cortisol secretion, as reflected by the sum of major urinary cortisol metabolites, was mostly normal and activity of 5alpha-reductase clearly reduced. Our study provides evidence for an exaggerated adrenarche in T1DM children, which may help to understand reported sequelae in female patients like hyperandrogenic symptoms. The findings also suggest a reduced cortisol inactivation via 5alpha-reductase that is not compensated by a fall in cortisol secretion. Whether the elevated urinary 6beta-hydroxycortisol and cortisone excretion, observed in the patients, are also present in other forms of hypercortisolism and may thus serve as non-invasive clinical stress markers deserves further study.