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Hypertension is a common preventable cause of cardiovascular morbidity and mortality and can substantially affect the quality of life and independence of older adults. (1) Hypertension affects 1 in 5 [...], BACKGROUND: Only a few population-based studies have examined the association between glucocorticoids and hypertension, with inconsistent results. We aimed to investigate the effect of oral glucocorticoids on incidence of hypertension in adults with chronic inflammatory diseases. METHODS: We analyzed electronic health records from 389 practices in England during 1998-2017 of adults diagnosed with any of 6 chronic inflammatory diseases but with no previous diagnosis of hypertension. We used glucocorticoid prescription data to construct time-variant daily and cumulative variables of prednisolone-equivalent dose (cumulated from 1 year before the start of follow-up) and estimated incidence rates and adjusted hazard ratios (HRs) for hypertension using Cox regression analysis. RESULTS: Among 71642 patients in the cohort, 24896 (34.8%) developed hypertension during a median follow-up of 6.6 years. The incidence rate of hypertension was 46.7 (95% confidence interval [CI] 46.0-47.3) per 1000 person-years. Incidence rates increased with higher cumulative glucocorticoid prednisolone-equivalent dose, from 44.4 per 1000 person-years in periods of nonuse to 45.3 per 1000 person-years for periods with between > 0.0 and 959.9 mg (HR 1.14, 95% CI 1.09-1.19), to 49.3 per 1000 person-years for periods with 960-3054.9 mg (HR 1.20, 95% CI 1.14-1.27), and to 55.6 per 1000 person-years for periods with [greater than or equal to] 3055 mg (HR 1.30, 95% CI 1.25-1.35). Cumulative effects were seen for the 6 diseases studied, but dose-response effects were not found for daily dose. INTERPRETATION: Cumulative dose of oral glucocorticoids was associated with increased incidence of hypertension, suggesting that blood pressure should be monitored closely in patients routinely treated with these drugs. Given that glucocorticoids are widely prescribed, the associated health burden could be high. Trial registration: ClinicalTrials.gov, no. NCT03760562.

The pathophysiological effects of glucocorticoids are well described and impact upon almost all organ systems within the body. This is highlighted in patients with glucocorticoids excess, Cushing's syndrome characterized by [...], OBJECTIVE--Glucocorticoid excess is characterized by increased adiposity, skeletal myopathy, and insulin resistance, but the precise molecular mechanisms are unknown. Within skeletal muscle, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts cortisone (11-dehydrocorticosterone in rodents) to active cortisol (corticosterone in rodents). We aimed to determine the mechanisms underpinning glucocorticoid-induced insulin resistance in skeletal muscle and indentify how 11β-HSD1 inhibitors improve insulin sensitivity. RESEARCH DESIGN AND METHODS--Rodent and human cell cultures, whole-tissue explants, and animal models were used to determine the impact of glucocorticoids and selective 11β-HSD1 inhibition upon insulin signaling and action. RESULTS--Dexamethasone decreased insulin-stimulated glucose uptake, decreased IRS1 mRNA and protein expression, and increased inactivating [pSer.sup.307] insulin receptor substrate (IRS)-1. 11β-HSD1 activity and expression were observed in human and rodent myotubes and muscle explants. Activity was predominantly oxo-reductase, generating active glucocorticoid. A1 (selective 11β-HSD1 inhibitor) abolished enzyme activity and blocked the increase in [pSer.sup.307] IRS1 and reduction in total IRS1 protein after treatment with 11DHC but not corticosterone. In C57B16/J mice, the selective 11β-HSD1 inhibitor, A2, decreased fasting blood glucose levels and improved insulin sensitivity. In KK mice treated with A2, skeletal muscle [pSer.sup.307] IRS1 decreased and [pThr.sup.308] Akt/PKB increased. In addition, A2 decreased both lipogenic and lipolytic gene expression. CONCLUSIONS--Prereceptor facilitation of glucocorticoid action via 11β-HSD1 increases [pSer.sup.307] IRS1 and may be crucial in mediating insulin resistance in skeletal muscle. Selective 11β-HSD1 inhibition decreases [pSer.sup.307] IRS1, increases [pThr.sup.308] Akt/ PKB, and decreases lipogenic and lipolytic gene expression that may represent an important mechanism underpinning their insulin-sensitizing action.

OBJECTIVE--The precise molecular mechanisms contributing to the development of insulin resistance, impaired glucose tolerance (IGT), and type 2 diabetes are largely unknown. Altered endogenous glucocorticoid metabolism, including 11[beta]-hydroxysteroid dehydrogenase type [...]

The global epidemic of obesity continues to progress at an alarming rate in both adults and children (1). The health consequences of obesity are well described along with significant increases [...], OBJECTIVE--The epidemics of obesity, insulin resistance, and type 2 diabetes have heightened the need to understand mechanisms that contribute to their pathogenesis. Increased endogenous glucocorticoid production has been implicated based on parallels with Cushing's syndrome. We have assessed the impact of weight loss on glucocorticoid secretion and metabolism (notably 11β-hydroxysteroid dehydrogenase type I and 5α-reductase [5αR] activity) and insulin sensitivity. RESEARCH DESIGN AND METHODS--Twenty obese volunteers were investigated before and after weight loss. Patients underwent hyperinsulinemic-euglycemic clamps with simultaneous adipose microdialysis and oral cortisone acetate administration. Changes in glucocorticoid secretion and metabolism were assessed using 24-h urine collections. RESULTS--Before weight loss, fat mass correlated with glucocorticoid secretion rate (total fat, r = 0.46, P < 0.05; trunk fat, r = 0.52, P < 0.05); however, glucocorticoid secretion rate was inversely related to insulin sensitivity (r = -0.51, P < 0.05). Hyperinsulinemia failed to suppress adipose tissue interstitial fluid glycerol release (180 [+ or -] 50 µmol [basal] vs. 153 ± 10 µmol [steady state], NS). After oral cortisone (25 mg), cortisol concentrations within adipose interstitial fluid increased (4.3 ± 1.1 vs. 14.2 ± 2.6 nmol/l, P < 0.01), but glycerol concentrations did not change. After weight loss, insulin sensitivity increased. Consistent with insulin sensitization, adipose tissue interstitial fluid glycerol concentrations fell under hyperinsulinemic conditions (186 ± 16 vs. 117 ± 9 µmol, P < 0.05). Glucocorticoid secretion decreased (11,751 ± 1,520 vs. 7,464 ± 937 µg/24 h, P < 0.05) as did 5αR activity (5α-tetrahydrocortisol-to-tetrahydrocortisol ratio 1.41 ± 0.16 vs. 1.12 ± 0.17, P < 0.005). CONCLUSIONS--Obesity is associated with insulin resistance within adipose tissue and increased cortisol secretion rates; both are reversed with weight loss. Reduced 5αR activity after weight loss may decrease hypothalamo-pituitary-adrenal axis activation and reduce glucocorticoid metabolite production.

In this cohort study, we found high glucocorticoid dose-dependent increased risks of adrenal dysfunction and death but low absolute risks, indicating potential underdiagnosis in clinical practice.

An exciting era is upon us in terms of new therapies for patients with diabetes, obesity, and metabolic syndrome. One such advance is the ability to selectively manipulate tissue levels [...]

In the post-genome era, clinical research couldn't be simpler. Exposure to human disease stimulates an enquiring mind to investigate underlying pathogenesis or new therapeutic targets. New functions are ascribed to […]

'Oh let me lead an academicke life' B Hall, Virgidem 1599;IV:83 A recent report for the council of heads of medical schools for the United Kingdom has concluded that 1000 [...]

Glucocorticoids (GCs) are potent regulators of energy metabolism. Chronic GC exposure suppresses brown adipose tissue (BAT) thermogenic capacity in mice, with evidence for a similar effect in humans. Intracellular GC levels are regulated by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity, which can amplify circulating GC concentrations. Therefore, 11β-HSD1 could modulate the impact of GCs on BAT function. This study investigated how 11β-HSD1 regulates the molecular architecture of BAT in the context of GC excess and aging. Circulating GC excess was induced in 11β-HSD1 knockout (KO) and wild-type mice by supplementing drinking water with 100 μg/mL corticosterone, and the effects on molecular markers of BAT function and mitochondrial activity were assessed. Brown adipocyte primary cultures were used to examine cell autonomous consequences of 11β-HSD1 deficiency. Molecular markers of BAT function were also examined in aged 11β-HSD1 KO mice to model lifetime GC exposure. BAT 11β-HSD1 expression and activity were elevated in response to GC excess and with aging. 11β-HSD1 KO BAT resisted the suppression of uncoupling protein 1 (UCP1) and mitochondrial respiratory chain subunit proteins normally imposed by GC excess. Furthermore, brown adipocytes from 11β-HSD1 KO mice had elevated basal mitochondrial function and were able to resist GC-mediated repression of activity. BAT from aged 11β-HSD1 KO mice showed elevated UCP1 protein and mitochondrial content, and a favorable profile of BAT function. These data reveal a novel mechanism in which increased 11β-HSD1 expression, in the context of GC excess and aging, impairs the molecular and metabolic function of BAT.

Context:Patients with adrenal insufficiency (AI) (primary AI [PAI], secondary AI due to a pituitary disorder [PIT] and congenital adrenal hyperplasia [CAH]) have reduced life expectancy; however, the underlying explanation remains unknown.Objective:To evaluate characteristics, comorbidities, and hospitalizations in AI patients.Design:Retrospective observational.Setting and Population:Using a United States-based national payer database comprising of more than 108 million members, strict inclusion criteria including diagnostic codes and steroid prescription records were used to identify 10 383 adults with AI; 1014 with PAI, 8818 with PIT, and 551 with CAH. Patients were matched 1:1 to controls, based on age (±5 y), gender, insurance, and region and followed for more than 12 months.Intervention:None.Main Outcome Measures:Demographic variables, comorbidities (diabetes mellitus [DM] types 1 and 2, depression, anxiety, hyperlipidemia, hypertension) and hospitalization incidence.Results:Compared with controls, patients with AI had higher odds of DM, hypertension, hyperlipidaemia, depression, and anxiety, ranging from an odds ratio (OR) of 1.51 for hyperlipidaemia in PAI to 3.85 for DM in CAH. Odds of having DM (OR, 3.85; 95% confidence interval, 2.52–5.90) or anxiety (OR, 2.99; 95% confidence interval, 2.02–4.42) compared with controls were highest in CAH, whereas depression was highest in PAI and PIT (OR, 2.40 and 2.55). ORs of hyperlipidaemia and hypertension (OR, 1.98 and 2.24) were highest in the PIT cohort. Inpatient admissions were more frequent in PAI (4.64:1; P< .0001) and PIT (4.00:1; P< .0001) than controls; infection was the most common cause for admission.Conclusion:Patients with AI carry a significant metabolic and psychiatric burden, with higher risk of comorbidities and hospital admissions than matched controls.

Nonalcoholic fatty liver disease (NAFLD) defines a spectrum of conditions from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis and is regarded as the hepatic manifestation of the metabolic syndrome. Glucocorticoids can promote steatosis by stimulating lipolysis within adipose tissue, free fatty acid delivery to liver and hepatic de novolipogenesis. Glucocorticoids can be reactivated in liver through 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme activity. Inhibition of 11β-HSD1 has been suggested as a potential treatment for NAFLD. To test this, male mice with global (11β-HSD1 knockout [KO]) and liver-specific (LKO) 11β-HSD1 loss of function were fed the American Lifestyle Induced Obesity Syndrome (ALIOS) diet, known to recapitulate the spectrum of NAFLD, and metabolic and liver phenotypes assessed. Body weight, muscle and adipose tissue masses, and parameters of glucose homeostasis showed that 11β-HSD1KO and LKO mice were not protected from systemic metabolic disease. Evaluation of hepatic histology, triglyceride content, and blinded NAFLD activity score assessment indicated that levels of steatosis were similar between 11β-HSD1KO, LKO, and control mice. Unexpectedly, histological analysis revealed significantly increased levels of immune foci present in livers of 11β-HSD1KO but not LKO or control mice, suggestive of a transition to NASH. This was endorsed by elevated hepatic expression of key immune cell and inflammatory markers. These data indicate that 11β-HSD1-deficient mice are not protected from metabolic disease or hepatosteatosis in the face of a NAFLD-inducing diet. However, global deficiency of 11β-HSD1 did increase markers of hepatic inflammation and suggests a critical role for 11β-HSD1 in restraining the transition to NASH.

No agreement has been reached on the long-term survival prospects for patients with Cushing's disease. We studied life expectancy in patients who had received curative treatment and whose hypercortisolism remained in remission for more than 10 years, and identified factors determining their survival.

Context:Cushing's syndrome is characterized by marked changes in body composition (sarcopenia, obesity, and osteoporosis) that have similarities with those seen in aging. 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts glucocorticoids to their active form (cortisone to cortisol in humans), resulting in local tissue amplification of effect.Objective:To evaluate 11β-HSD1 expression and activity with age, specifically in muscle. To determine putative causes for increased activity with age and its consequences upon phenotypic markers of adverse aging.Design:Cross-sectional observational study.Setting:National Institute for Health Research-Wellcome Trust Clinical Research Facility, Birmingham, United Kingdom.Patients or Other Participants:Healthy human volunteers age 20 to 81 years (n = 134; 77 women, 57 men).Interventions:Day attendance at research facility for baseline observations, body composition analysis by dual-energy x-ray absorptiometry, jump-plate mechanography, grip strength analysis, baseline biochemical profiling, urine collection, and vastus lateralis muscle biopsy.Main Outcome Measure(s):Skeletal muscle gene expression, urine steroid profile, bivariate correlations between expression/activity and phenotypic/biochemical variables.Results:Skeletal muscle 11β-HSD1 expression was increased 2.72-fold in women over 60 years of age compared to those aged 20–40 years; no differences were observed in men. There was a significant positive correlation between skeletal muscle 11β-HSD1 expression and age in women across the group (rho = 0.40; P= .009). No differences in expression of 11β-HSD type 2, glucocorticoid receptor, or hexose-6-phosphate dehydrogenase between age groups were observed in either sex. Urinary steroid markers of 11β-HSD1, 11β-HSD type 2, or 5α-reductase were similar between age groups. Skeletal muscle 11β-HSD1 expression was associated with reduced grip strength in both sexes and correlated positively with percentage of body fat, homeostasis model of assessment for insulin resistance, total cholesterol, LH, and FSH and negatively with bone mineral content and IGF-1 in women.Conclusions:Skeletal muscle 11β-HSD1 is up-regulated with age in women and is associated with reduced grip strength, insulin resistance, and an adverse body composition profile. Selective inhibition of 11β-HSD1 may offer a novel strategy to prevent and/or reverse age-related sarcopenia.

The prevalence of non-alcoholic fatty liver disease is increasing worldwide and an effective and safe pharmacological treatment is needed. We investigated whether inhibition of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1, also known as HSD11B1) by RO5093151 could safely and effectively decrease liver-fat content in patients with this disorder.

Although the inhibitory effects of therapeutic glucocorticoids (GCs) on dendritic cells (DCs) are well established, the roles of endogenous GCs in DC homeostasis are less clear. A critical element regulating endogenous GC concentrations involves local conversion of inactive substrates to active 11-hydroxyglucocorticoids, a reduction reaction catalyzed within the endoplasmic reticulum by an enzyme complex containing 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) and hexose-6-phosphate dehydrogenase (H6PDH). In this study, we found that this GC amplification pathway operates both constitutively and maximally in steady state murine DC populations and is unaffected by additional inflammatory stimuli. Under physiologic conditions, 11βHSD1-H6PDH increases the sensitivity of plasmacytoid DCs (pDCs) to GC-induced apoptosis and restricts the survival of this population through a cell-intrinsic mechanism. Upon CpG activation, the effects of enzyme activity are overridden, with pDCs becoming resistant to GCs and fully competent to release type I interferon. CD8α+ DCs are also highly proficient in amplifying GC levels, leading to impaired maturation following toll-like receptor–mediated signaling. Indeed, pharmacologic inhibition of 11βHSD1 synergized with CpG to enhance specific T-cell responses following vaccination targeted to CD8α+ DCs. In conclusion, amplification of endogenous GCs is a critical cell-autonomous mechanism for regulating the survival and functions of DCs in vivo.

The aim of this study was to conduct a pilot study for the feasibility of planning a definitive clinical trial comparing traditional acupuncture (TA) with sham acupuncture (SA) and waiting control (WC) on menopause-related vasomotor symptoms (VMS), quality of life, and the hypothalamic-pituitary-adrenal axis in perimenopausal and postmenopausal women.

AbstractBackground:Toll-like receptor-4 (TLR4) has been implicated in the pathogenesis of different renal diseases in rodent models. However, in human kidney disease, TLR4 expression and regulation is not well understood. We hypothesized that renal TLR4 expression plays a role in chronic kidney disease (CKD) and is associated with proteinuria, kidney function, histological diagnosis, and inflammatory mediators. Methods:We quantified TLR4 mRNA as well as expression of macrophage chemoattractant protein-1 (MCP-1), transforming growth factor-β1(TGF-β1) and interleukin-6 (IL-6) in human kidney biopsies from 70 patients with CKD. We measured kidney function, urinary MCP-1 protein excretion, and the amount of chronic damage. Macrophage load was quantified by CD68 and vascularization by CD34 immunostaining. Results:TLR4 expression correlated significantly with MCP-1 and TGF-β1expression. High TLR4 expression was associated with high IL-6 expression. TLR4 expression was significantly upregulated in patients with severe proteinuria, and in patients with chronic ischemic renal damage and IgA nephropathy, when compared to patients with thin glomerular basement membrane disease. TLR4 expression did not correlate with creatinine clearance, renal outcome, macrophage load or chronic damage. Conclusions:We show for the first time that renal TLR4 expression was significantly associated with the pro-inflammatory marker MCP-1 and the profibrotic molecule TGF-β1in kidney biopsies from patients with CKD, suggesting that increased expression of TLR4 is an important feature of CKD.Copyright © 2011 S. Karger AG, Basel

Polymorphisms in 11- hydroxysteroid dehydrogenase type 1 (11-HSD1, encoded by HSD11B1) have been reported to be associated with obesity-related cardiovascular risk factors, such as type II diabetes and hypertension. Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular death associated with these factors but has significant additional heritability, the cause of which is undetermined. The 11-HSD1 is believed to maintain tonic inhibition of the mineralocorticoid receptor in cardiomyocytes, and mineralocorticoid receptor activation is involved in the pathophysiology of LVH. We assessed the association between polymorphisms in the HSD11B1gene and left ventricular mass (LVM) in 248 families ascertained through a proband with hypertension.

Pituitary disease is associated with increased mortality predominantly due to vascular disease. Control of cortisol secretion and GH hypersecretion (and cardiovascular risk factor reduction) is key in the reduction of mortality in patients with Cushing's disease and acromegaly, retrospectively. For patients with acromegaly, the role of IGF-I is less clear-cut. Confounding pituitary hormone deficiencies such as gonadotropins and particularly ACTH deficiency (with higher doses of hydrocortisone replacement) may have a detrimental effect on outcome in patients with pituitary disease. Pituitary radiotherapy is a further factor that has been associated with increased mortality (particularly cerebrovascular). Although standardized mortality ratios in pituitary disease are falling due to improved treatment, mortality for many conditions are still elevated above that of the general population, and therefore further measures are needed. Craniopharyngioma patients have a particularly increased risk of mortality as a result of the tumor itself and treatment to control tumor growth; this is a key area for future research in order to optimize the outcome for these patients.

CONTEXT: Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, anovulation, and susceptibility to the metabolic syndrome. Altered peripheral cortisol metabolism has been reported in PCOS, but also in simple obesity. OBJECTIVE: The aim of the study was to describe cortisol metabolism and metabolic characteristics of a large PCOS cohort and to delineate the effect of obesity by comparison to body mass index (BMI)-matched controls. DESIGN AND SETTING: We conducted an observational, cross-sectional study at outpatient clinics of two secondary/tertiary care centers. Patients or Other Participants: A total of 178 PCOS patients fulfilling Rotterdam criteria and 100 BMI-matched controls participated in the study. INTERVENTION: The study included 24-h urine collection for steroid metabolite excretion and fasting blood samples, followed by an oral glucose tolerance test. MAIN OUTCOME MEASURES: We measured urinary steroid metabolites including glucocorticoids and androgens and the ratios reflecting enzymatic activities involved in peripheral cortisol and androgen metabolism, 5-reductase, and 11β-hydroxysteroid dehydrogenase types 1 and 2. We also measured circulating levels of glucose, insulin, dehydroepiandrosterone, dehydroepiandrosterone sulfate, and testosterone and calculated homeostasis model assessment. RESULTS: Total androgen metabolites were higher in PCOS patients compared to BMI-matched controls (4,105 ± 2,047 vs. 2,532 ± 1,610 µg/24 h for the nonobese; 5,547 ± 2,911 vs. 2,468 ± 1,794 µg/24 h for the obese; both P < 0.001). Total glucocorticoid metabolites were higher in obese PCOS vs. controls (10,786 ± 3,852 vs. 8,834 ± 4,487 µg/24 h; P = 0.001). 5-Reductase activity correlated with BMI, insulin levels, and homeostasis model assessment. Both obese and nonobese PCOS patients had higher 5-reductase activity than controls (all P < 0.05). 11β-Hydroxysteroid dehydrogenase activities did not differ between PCOS and controls. CONCLUSIONS: PCOS is associated with enhanced androgen and cortisol metabolite excretion and increased 5-reductase activity that cannot be explained by obesity alone. Increased adrenal corticosteroid production represents an important pathogenic pathway in PCOS.

Nearly half of the over 400 North American crayfish species are imperiled and need some level of protection to ensure sustainable populations, but the detailed life histories of only about 12% of these crayfishes have been published. We provide needed baseline information on the reproductive biology of the Sly Crayfish, Procambarus versutus(Hagen, 1870), through sampling a small stream monthly (N= 23 samples) in the Choctawhatchee River watershed, southeastern Alabama, USA for two years. We collected data on 2,026 individuals (mean 88 sample–1) over the duration of the study and found minimum size at sexual maturity to be 18.3 mm for both males and females. Life cycles were consistent across both years with a major peak in reproductively active males in June and reproductively active females in July. Reproductively-active males and females were nevertheless collected nearly year-round, suggesting continuous low levels of reproduction throughout a given year, with three peaks in reproduction that vary in magnitude. Only three ovigerous females were collected over the study period, possibly because ovigerous females become reclusive and inactive, therefore difficult to collect. The maximum brood size sampled was 242 eggs female–1. There was no evidence for distinct age classes, likely due to year-round reproduction. Similar regional species with detailed information on reproductive biology available have reproduction patterns similar to those in our data. The information herein contributes to the largely lacking information on the life history of North American crayfishes and emphasizes the need to further evaluate the reproductive biology of species lacking sufficient data to aid conservation efforts.

Glucocorticoids, through activation of the glucocorticoid receptor (GR), regulate hepatic gluconeogenesis. Elevated hepatic expression and activity of 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) play a key role in ligand-induced activation of the GR through the production of cortisol. Evidence from genetically modified mice suggests that inhibition of 11βHSD1 might be a therapeutic approach to treat the metabolic syndrome. We have identified a potent 11βHSD1 inhibitor, 4′-cyano-biphenyl-4-sulfonic acid (6-amino-pyridin-2-yl)-amide (PF-915275), that is selective for the primate and human enzymes. The objective of this study was to demonstrate target inhibition with PF-915275 and to quantify the relationship between target inhibition and drug exposure in monkeys. We characterized the ability of PF-915275 to inhibit the conversion of prednisone, a synthetic cortisone analog that can be distinguished from the endogenous substrate cortisone, enabling a direct measure of substrate to product conversion without the complication of feedback. Adult cynomolgus monkeys were administered either vehicle or various doses of PF-915275 followed by a 10-mg/kg dose of prednisone. Prednisone conversion to prednisolone and the concentrations of PF-915275 were measured by liquid chromatography/tandem mass spectrometry. PF-915275 dose-dependently inhibited 11βHSD1-mediated conversion of prednisone to prednisolone, with a maximum of 87% inhibition at a 3-mg/kg dose. An exposure-response relationship was demonstrated, with an estimated EC50of 391 nM (total) and 17 nM (free). Insulin levels were also reduced in a dose-related manner. These results should enable the development of a biomarker for evaluating target modulation in humans that will aid in identifying 11βHSD1 inhibitors to treat diabetes and other related metabolic diseases.

Women with Cushing's syndrome are often misdiagnosed as having polycystic ovarian syndrome. The authors highlight the importance of correctly diagnosing the two disorders and describe the clinical features and investigations that can help to distinguish them.

CONTEXT: The pathophysiological importance of glucocorticoids (GCs) is exemplified by patients with Cushing’s syndrome who develop hypertension, obesity, and insulin resistance. At a cellular level, availability of GCs to the glucocorticoid and mineralocorticoid receptors is controlled by the isoforms of 11{szligbeta}-hydroxysteroid dehydrogenase (11{szligbeta}-HSD). In liver and adipose tissue, 11{szligbeta}-HSD1 converts endogenous, inactive cortisone to active cortisol but also catalyzes the bioactivation of the synthetic prednisone to prednisolone. OBJECTIVE: The objective of the study was to compare markers of 11{szligbeta}-HSD1 activity and demonstrate that inhibition of 11{szligbeta}-HSD1 activity limits glucocorticoid availability to adipose tissue. DESIGN AND SETTING: This was a clinical study. PATIENTS: Seven healthy male volunteers participated in the study. INTERVENTION: Intervention included carbenoxolone (CBX) single dose (100 mg) and 72 hr of continuous treatment (300 mg/d). MAIN OUTCOME MEASURES: Inhibition of 11{szligbeta}-HSD1 was monitored using five different mechanistic biomarkers (serum cortisol and prednisolone generation, urinary corticosteroid metabolite analysis by gas chromatography/mass spectrometry, and adipose tissue microdialysis examining cortisol generation and glucocorticoid-mediated glycerol release). RESULTS: Each biomarker demonstrated reduced 11{szligbeta}-HSD1 activity after CBX administration. After both a single dose and 72 hr of treatment with CBX, cortisol and prednisolone generation decreased as did the urinary tetrahydrocortisol+5-tetrahydrocortisol to tetrahydrocortisone ratio. Using adipose tissue microdialysis, we observed decreased interstitial fluid cortisol availability with CBX treatment. Furthermore, a functional consequence of 11{szligbeta}-HSD1 inhibition was observed, namely decreased prednisone-induced glycerol release into adipose tissue interstitial fluid indicative of inhibition of GC-mediated lipolysis. CONCLUSION: CBX is able to inhibit rapidly the generation of active GC in human adipose tissue. Importantly, limiting GC availability in vivo has functional consequences including decreased glycerol release.

Most of the essays in this volume have adopted a reductionist approach and have focused on the biochemistry either in skeletal muscle or in the vascular wall. There is however a complex interaction between the biochemistry in the endothelium of the microvascular wall, the vascular smooth muscle and the skeletal muscle fibres involving signalling pathways in the three tissues and an intense exchange of signal molecules between them. In the present essay an integrative overview is given of this complex metabolic interaction and the impairments in it that lead to type 2 diabetes and cardiovascular disease.A reduced nitric oxide production by the (micro)vascular endothelium is identified as the key event and is reversible by regular exercise and a reduced calorie intake. The chapter also contains a description of the complex metabolic network controlled by the inducible transcription factor nuclear factor-?B, that is activated in more advanced stages of the chronic diseases, and either leads to repair of the microvascular wall or to irreversible damage and the severe complications of end stage cardiovascular disease and type 2 diabetes.

Glucocorticoids (GCs) have a profound effect on adipose biology increasing tissue mass causing central obesity. The pre-receptor regulation of GCs by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) that activates cortisol from cortisone has been postulated as a fundamental mechanism underlying the metabolic syndrome mediating adipocyte hyperplasia and hypertrophy in the omental (OM) depot. Orbital adipose tissue (OF) is the site of intense inflammation and tissue remodelling in several orbital inflammatory disease states. In this study, we describe features of the GC metabolic pathways in normal human OF depot and compare it with subcutaneous (SC) and OM depots. Using an automated histological characterisation technique, OF adipocytes were found to be significantly smaller (parameters: area, maximum diameter and perimeter) than OM and SC adipocytes (P<0.001). Although immunohistochemical analyses demonstrated resident CD68+cells in all three whole tissue adipose depots, OF CD68 mRNA and protein expression exceeded that of OM and SC (mRNA, P<0.05; protein, P<0.001). In addition, there was higher expression of glucocorticoid receptor (GR)α mRNA in the OF whole tissue depot (P<0.05). Conversely, 11β-HSD1 mRNA together with the markers of late adipocyte differentiation (FABP4 and G3PDH) were significantly lower in OF. Primary cultures of OF preadipocytes demonstrated predominant 11β-HSD1 oxo-reductase activity with minimal dehydrogenase activity. Orbital adipocytes are smaller, less differentiated, and express low levels of 11β-HSD1 but abundant GRα compared with SC and OM. OF harbours a large CD68+population. These characteristics define an orbital microenvironment that has the potential to respond to sight-threatening orbital inflammatory disease.

The prereceptor regulation of glucocorticoids (GCs) by 11β-hydroxysteroid dehydrogenase type-1 (11β-HSD1), a bidirectional isozyme that interconverts active (cortisol) and inactive (cortisone) GCs, is an established determinant of GC function in tissues such as liver, adipose and bone. Although the therapeutic use of GCs is abundant in ophthalmic practice, where GC interactions with nuclear receptors modulate gene transcription, the prereceptor regulation of endogenous cortisol is not well described in ocular tissues. Recent descriptive studies have localised 11β-HSD1 to the human corneal epithelium and non-pigmented epithelium (NPE) of the ciliary body, indicating a link to corneal epithelial physiology and aqueous humour production. In this study, we characterise the functional aspects of the autocrine regulation of GCs in the anterior segment of the rabbit eye. Using our in-house generated primary antibody to human 11β-HSD1, immunohistochemical analyses were performed on paraffin-embedded sections of whole New Zealand white albino rabbits, (NZWAR) eyes. As in human studies, 11β-HSD1 was localised to the corneal epithelium and the NPE. No staining was seen in the albino ‘pigmented’ ciliary epithelium. Specific enzyme assays for oxo-reductase (cortisone→cortisol) and dehydrogenase (cortisol→cortisone) activity indicated predominant 11β-HSD1 oxo-reductase activity from both the intact ciliary body tissue (n=12, median 2.1 pmol/mg per h and range 1.25–2.8 pmol/mg per h; P=0.006) and primary cultures of corneal epithelial cells (n=12, median 3.0 pmol/mg per h and range 1.0–7.4 pmol/mg per h, P=0.008) compared with dehydrogenase activity (median 1.0 pmol/mg per h and range 0.5–2.0 pmol/mg per h; median 0.5 pmol/mg per h and range 0.25–1.9 pmol/mg per h respectively). These findings were supported by expression of 11β-HSD1 protein as visualised by Western blotting of ciliary body tissue and immunocytochemistry of corneal epithelial cells. Reduction of corneal epithelial cell proliferation was seen after primary cultures were co-incubated with cortisol and cortisone. 11β-HSD1 activity was not demonstrated in naïve conjunctival fibroblasts or corneal stromal keratocytes. Our results indicate that the distribution of 11β-HSD1 in the rabbit resembles that of the human eye and activates cortisone to cortisol in both corneal and uveal tissues. The NZWAR provides a suitable in vivomodel for the further evaluation of 11β-HSD1 activity in the eye, especially its role in corneal epithelial and ciliary body physiology.

Isoenzymes of 11[beta]-hydroxysteroid dehydrogenase affect the tissue-specific interconversion of cortisone and cortisol. In rodents, selective inhibitors of these enzymes improve insulin sensitivity, and we await clinical trials to test whether such drugs can be “magic bullets” to treat type 2 diabetes and the metabolic syndrome.

OBJECTIVE: Renal 11{szligbeta}-hydroxysteroid dehydrogenase type 2 (11{szligbeta}-HSD2) enables selective access of aldosterone to the mineralocorticoid receptor (MR). Impaired 11{szligbeta}-HSD2 activity has been suggested in patients with hypertension as well as in patients with renal disease, where it may contribute to sodium retention, oedema and hypertension. To date, these studies have relied upon urinary cortisol (F) metabolite levels as surrogate markers of renal 11{szligbeta}-HSD2 activity. METHODS: We have directly analysed renal 11{szligbeta}-HSD2 mRNA expression in 95 patients undergoing kidney biopsy using TaqMan real-time PCR. Serum and 24-h urine samples were used to document underlying renal function and endocrine parameters. Urinary F and cortisone (E) metabolites were analysed using gas chromatography/mass spectrometry. RESULTS: Expression of 11{szligbeta}-HSD2 did not correlate with blood pressure or urinary Na/K ratio, but a significant positive correlation with creatinine clearance was observed (r = 0.284; P < 0.01). Immunofluorescence and confocal laser microscopy confirmed decreased 11{szligbeta}-HSD2 expression in patients with impaired renal function. For the first time, we showed that 11{szligbeta}-HSD2 mRNA expression correlated negatively with the urinary free (UF) F/E (UFF/UFE) ratio (r = 0.276; P < 0.05) as well as with the urinary tetrahydrocortisol + 5α-tetrahydrocortisol/tetrahydrocortisone ((THF + αTHF)/THE) ratio (r = 0.256; P < 0.05). No difference in 11{szligbeta}-HSD2 mRNA expression or in the UFF/UFE ratio was found between groups with no proteinuria, microalbuminuria, moderate or severe proteinuria. In contrast, the urinary (THF + αTHF)/THE ratio increased significantly (P < 0.05) in patients with severe albuminuria, suggesting increased hepatic 11{szligbeta}-HSD1 in those patients. CONCLUSIONS: These data suggest that renal 11{szligbeta}-HSD2 expression may be represented only marginally better, if at all, by the UFF/UFE than by the (THF + αTHF)/THE ratio. Reduced renal 11{szligbeta}-HSD2 expression may lead to occupancy of the MR by glucocorticoids such as cortisol and may contribute to the increased sodium retention seen in patients with impaired renal function.

Two isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD1 and 11β-HSD2) catalyse the interconversion of hormonally active cortisol and inactive cortisone. The enzyme evolved from a metabolic pathway to a novel mechanism underpinning human disease with the elucidation of the role of the type 2 or ‘kidney’ isozyme and an inherited form of hypertension, ‘apparent mineralocorti-coid excess’. ‘Cushing’s disease of the kidney’ arises because of a failure of 11β-HSD2 to inactivate cortisol to cortisone resulting in cortisol-induced mineralocorticoid excess.Conversely, 11β-HSD1 has been linked to human obesity and insulin resistance, but also to other diseases in which glucocorticoids have historically been implicated (osteoporosis, glaucoma). Here, the activation of cortisol from cortisone facilitates glucocorticoid hormone action at an autocrine level. The molecular basis for the putative human 11β-HSD1 ‘knockout’ – ‘cortisone reductase deficiency’ - has recently been described, an observation that also answers a long standing conundrum relating to the set-point of 11β-HSD1 activity. In each case, these clinical studies have been underpinned by studies in vitroand the manipulation of enzyme expression in vivousing recombinant mouse models.

Two isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD) interconvert active cortisol and inactive cortisone. 11β-HSD2 (renal) acts only as a dehydrogenase, converting cortisol to cortisone. 11β-HSD1 (liver) is a bi-directional enzyme in cell homogenates, whereas in intact cells it typically displays oxo-reductase activity, generating cortisol from cortisone. We recently established that cortisone reductase deficiency is a digenic disease requiring mutations in both the gene encoding 11β-HSD1 and in the gene for a novel enzyme located within the lumen of the endoplasmic reticulum (ER), hexose-6-phosphate dehydrogenase (H6PDH). This latter enzyme generates NADPH, the co-factor required for oxo-reductase activity. Therefore, we hypothesized that H6PDH expression may be an important determinant of 11β-HSD1 oxo-reductase activity. Transient transfection of chinese hamster ovary (CHO) cells with 11β-HSD1 resulted in the appearance of both oxo-reductase and dehydrogenase activities in intact cells. Co-transfection of 11β-HSD1 with H6PDH increased oxo-reductase activity whilst virtually eliminating dehydrogenase activity. In contrast, H6PDH had no effect on reaction direction of 11β-HSD2, nor did the cytosolic enzyme, glucose-6-phosphate dehydrogenase (G6PD) affect 11β-HSD1 oxo-reductase activity. Conversely in HEK 293 cells stably transfected with 11β-HSD1 cDNA, transfection of an H6PDH siRNA reduced 11β-HSD1 oxo-reductase activity whilst simultaneously increasing 11β-HSD1 dehydrogenase activity. In human omental preadipocytes obtained from 15 females of variable body mass index (BMI), H6PDH mRNA levels positively correlated with 11β-HSD1 oxo-reductase activity, independent of 11β-HSD1 mRNA levels. H6PDH expression increased 5.3-fold across adipocyte differentiation (P<0.05) and was associated with a switch from 11β-HSD1 dehydrogenase to oxo-reductase activity. In conclusion, H6PDH is a crucial determinant of 11β-HSD1 oxo-reductase activity in intact cells. Through its interaction with 11β-HSD1, H6PDH may represent a novel target in the pathogenesis and treatment of obesity.

Women with polycystic ovary syndrome (PCOS) have high circulating androgens, thought to originate from ovaries and adrenals, and frequently suffer from the metabolic syndrome including obesity. However, serum androgens are positively associated with body mass index (BMI) not only in PCOS, but also in simple obesity, suggesting androgen synthesis within adipose tissue. Thus we investigated androgen generation in human adipose tissue, including expression of 17β-hydroxysteroid dehydrogenase (17β-HSD) isozymes, important regulators of sex steroid metabolism. Paired omental and subcutaneous fat biopsies were obtained from 27 healthy women undergoing elective abdominal surgery (age range 30–50 years; BMI 19.7–39.2 kg/m2). Enzymatic activity assays in preadipocyte proliferation cultures revealed effcient conversion of androstenedione to testosterone in both subcutaneous and omental fat. RT-PCR of whole fat and preadipocytes of subcutaneous and omental origin showed expression of 17β-HSD types 4 and 5, but no relevant expression of 17β-HSD types 1, 2, or 3. Microarray analysis confirmed this expression pattern (17β-HSD5>17β-HSD4) and suggested a higher expression of 17β-HSD5 in subcutaneous fat. Accordingly, quantitative real-time RT-PCR showed significantly higher expression of 17β-HSD5 in subcutaneous compared with omental fat (P<0.05). 17β-HSD5 expression in subcutaneous, but not omental, whole fat correlated significantly with BMI (r=0.51, P<0.05). In keeping with these findings, 17β-HSD5 expression in subcutaneous fat biopsies from six women taking part in a weight loss study decreased significantly with weight loss (P<0.05). A role for 17β-HSD5 in adipocyte differentiation was further supported by the observed increase in 17β-HSD5 expression upon differentiation of stromal preadipocytes to mature adipocytes (n=5; P<0.005), which again was higher in cells of subcutaneous origin. Functional activity of 17β-HSD5 also significantly increased with differentiation, revealing a net gain in androgen activation (androstenedione to testosterone) in subcutaneous cultures, contrasting with a net gain in androgen inactivation (testosterone to androstenedione) in omental cultures. Thus, human adipose tissue is capable of active androgen synthesis catalysed by 17β-HSD5, and increased expression in obesity may contribute to circulating androgen excess.

Two isoforms of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) interconvert the active glucocorticoid, cortisol, and inactive cortisone. 11beta-HSD1 acts predominantly as an oxo-reductase in vivo using NADP(H) as a cofactor to generate cortisol. In contrast, 11beta-HSD2 is a NAD-dependent dehydrogenase inactivating cortisol to cortisone, thereby protecting the mineralocorticoid receptor from occupation by cortisol. In peripheral tIssues, both enzymes serve to control the availability of cortisol to bind to corticosteroid receptors. 11beta-HSD2 protects the mineralocorticoid receptor from cortisol excess; mutations in the HSD11B2 gene explain an inherited form of hypertension, the syndrome of 'apparent mineralocorticoid excess', in which 'Cushing's disease of the kidney' results in cortisol-mediated mineralocorticoid excess. Inhibition of 11beta-HSD2 explains the mineralocorticoid excess state seen following liquorice ingestion and more subtle defects in enzyme expression might be involved in the pathogenesis of 'essential' hypertension. 11beta-HSD1 by generating cortisol in an autocrine fashion facilitates glucocorticoid receptor-mediated action in key peripheral tIssues including liver, adipose tissue, bone and the eye. 'Cushing's disease of the omentum' has been proposed as an underlying mechanism in the pathogenesis of central obesity and raises the exciting possibility of selective 11beta-HSD1 inhibition as a novel therapy for patients with the metabolic syndrome. 'Pre-receptor' metabolism of cortisol via 11beta-HSD isozymes is an important facet of corticosteroid hormone action. Aberrant expression of these isozymes is involved in the pathogenesis of diverse human diseases including hypertension, insulin resistance and obesity. Modulation of enzyme activity may offer a future therapeutic approach to treating these diseases whilst circumventing the endocrine consequences of glucocorticoid excess or deficiency.

Acromegaly is a chronic disorder invariably caused by a growth hormone (GH)-secreting pituitary tumour and is characterised by disabling symptoms (sweating, arthralgia, headache, paraesthesiae, fatigue), significant comorbidities (diabetes mellitus, hypertension, sleep apnoea), and premature mortality. Symptomatic control can be achieved by lowering insulin-like growth factor-I (IGF-I) concentrations to within the age-adjusted normal range, and survival can be improved to match that of the general population. However, even with optimal surgery and current medical therapies (dopamine agonists, somatostatin analogues), 30% to 50% of patients do not achieve target concentrations of IGF-I and GH.Pegvisomant is a new GH-receptor antagonist that blocks GH activity by inhibiting functional dimerisation of GH-receptors. Given as subcutaneous injections at dosages of 10 mg, 15 mg, or 20 mg/day for 3 Months, pegvisomant normalised serum IGF-I concentrations in, respectively, 54%, 81%, and 89% of acromegalic patients. Moreover, long-term pegvisomant therapy normalised IGF-I concentrations in 97% of patients treated for 12 Months or longer, with no evidence of tachyphylaxis. Pegvisomant is the most effective medical therapy, reported to date, in terms of normalisation of circulating IGF-I concentrations. In addition, pegvisomant appears to be safe and well tolerated. Although additional long-term studies are required to further assess safety, the introduction of this innovative treatment should allow for optimal disease control in patients with acromegaly.

In addition to its classical calciotropic effects, the active form of vitamin D, 1,25-dihydroxyvitamin D3(1,25(OH)2D3) is a potent anti-proliferative/immunomodulatory secosteroid. The enzyme that catalyzes the synthesis of 1,25(OH)2D3, 1α-hydroxylase (1α-OHase), is expressed in many human tissues, highlighting its possible role as an autocrine/paracrine activator of vitamin D. Immunohistochemical and RNA analyses were used to characterize the ontogeny of 1α-OHase expression in human placenta and decidua. Protein for 1α-OHase was detectable in trophoblast and decidua; the latter being stronger in decidualized stromal cells than macrophages, with no staining of lymphocytes. Quantitative reverse transcriptase-polymerase chain reaction was used to assess changes in mRNA expression for 1α-OHase at different gestations: first (mean, 9.1 ± 1.5 weeks); second (mean, 14 ± 1.8 weeks), and third trimester (mean, 39.3 ± 2.5 weeks). 1α-OHase expression in decidua was ∼1000-fold higher in first (95% confidence limits, 611 to 1376) and second (95% confidence limits, 633 to 1623) trimester biopsies when compared with the third trimester (95% confidence limits, 0.36 to 2.81) (both P< 0.001). In placenta, 1α-OHase expression was 80-fold higher in the first (range, 42 to 137) and second (range, 30 to 199) trimester when compared with third trimester biopsies (0.6 to 1.6) (both P< 0.001). Similar results were obtained by semiquantitative IHC. Parallel analysis of the receptor for 1,25(OH)2D3(vitamin D receptor) indicated that, as with 1α-OHase, highest levels of expression occurred in first trimester decidua. However, changes in vitamin D receptor mRNA expression across gestation were less pronounced than 1α-OHase. These spatiotemporal data emphasize the potential importance of 1α-OHase during early fetoplacental life and, in particular, suggest an autocrine/paracrine immunomodulatory function for the enzyme.

The risk of glucocorticoid‐induced osteoporosis increases substantially with age but there is considerable individual variation. In recent studies we have shown that the effects of glucocorticoids on bone are dependent on autocrine actions of the enzyme 11β‐hydroxysteroid dehydrogenase type 1 (11β‐HSD1); expression of 11β‐HSD1 in osteoblasts (OBs) facilitates local synthesis of active glucocorticoids with consequent effects on osteoblastic proliferation and differentiation. Using primary cultures of human OBs, we have now characterized the age‐specific variation in osteoblastic 11β‐HSD1 and defined enzyme kinetics and regulation using natural and therapeutic glucocorticoids. 11β‐HSD1 reductase activity (cortisone to cortisol conversion) was recognized in all OB cultures and correlated positively with age (r= 0.58 with all cultures, p< 0.01, and n= 18; r= 0.87 with calcaneal‐derived cultures, p< 0.001, and n= 14). Glucocorticoid treatment caused a time‐ and dose‐dependent increase in 11β‐HSD1 activity over control (e.g., dexamethasone [DEX; 1 μM], 2.6‐fold ± 0.5 (mean ± SE), p< 0.001, and n= 16; cortisol (100 nM), 1.7‐fold ± 0.1, p< 0.05, and n= 14). Similar increases in 11β‐HSD1 mRNA expression were indicated using real‐time quantitative reverse‐transcription polymerase chain reaction (RT‐PCR) analyses (3.5‐fold with DEX, p< 0.01; 2.5‐fold with cortisol, p< 0.05). The capacity of 11β‐HSD1 to metabolize the synthetic glucocorticoids prednisone and prednisolone was investigated in human OBs (hOBs) and fetal kidney‐293 cells stably transfected with human 11β‐HSD1 cDNA. Transfected cells and hOBs were able to interconvert prednisone and prednisolone with reaction kinetics indistinguishable from those for cortisone and cortisol. To assess the in vivo availability of substrates for osteoblastic 11β‐HSD1, plasma cortisone and prednisone levels were measured in normal males before and after oral prednisolone (5 mg). The 9:00 a.m. serum cortisone levels were 110 ± 5 nmol/liter and prednisone levels peaked at 78 ± 23 nmol/liter 120 minutes after administration of prednisolone. Thus, therapeutic use of steroids increases substrate availability for 11β‐HSD1 in bone. These studies indicate that activation of glucocorticoids at an autocrine level within bone is likely to play an important role in the age‐related decrease in bone formation and increased risk of glucocorticoid‐induced osteoporosis.

Physical habitat was quantified in 105 randomly selected streams across the Northern Lakes and Forests Ecoregion during 1998 and 1999 to develop a stream habitat index for the region. Physical habitat measures (106) were classified into four groups: substrate, instream cover, riparian zone–land use, and geomorphology–hydrology. Variable reduction procedures yielded seven variables: sinuosity, percent of substrate gravel or larger, percent substrate as detritus or muck, percent of bank with forested cover, amount of bank erosion, number of large logs per 100 m, and mean length of pools. Streams were separated by a gradient value of 3 m/km (low N= 70; high N= 35) and assigned to model and test data sets. For low-gradient streams in the model data set, the seven habitat variables explained 47% of the variation in index of biotic integrity (IBI) scores. To produce the habitat index, the coefficients in the regression were used to weight each of the seven variables. For low-gradient streams in the test data set, the habitat index explained 20% of the variation in IBI scores. A habitat index could not be developed for high-gradient sites, probably due to the low number of sites. Comparison of habitat to IBI scores provides resource managers with a method to evaluate the contribution of habitat quality to the IBI score.