Assessing systemic 11beta-hydroxysteroid dehydrogenase with serum cortisone/cortisol ratios in healthy subjects and patients with diabetes mellitus and chronic renal failure

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.

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.

Mineralocorticoid Receptor Pathway and Its Antagonism in a Model of Diabetic Retinopathy

Diabetic retinopathy remains a major cause of vision loss worldwide. Mineralocorticoid receptor (MR) pathway activation contributes to diabetic nephropathy, but its role in retinopathy is unknown. In this study, we show that MR is overexpressed in the retina of type 2 diabetic Goto-Kakizaki (GK) rats and humans and that cortisol is the MR ligand in human eyes. Lipocalin 2 and galectin 3, two biomarkers of diabetes complications regulated by MR, are increased in GK and human retina. The sustained intraocular delivery of spironolactone, a steroidal mineralocorticoid antagonist, decreased the early and late pathogenic features of retinopathy in GK rats, such as retinal inflammation, vascular leakage, and retinal edema, through the upregulation of genes encoding proteins known to intervene in vascular permeability such as Hey1, Vldlr, Pten, Slc7a1, Tjp1, Dlg1, and Sesn2 but did not decrease VEGF. Spironolactone also normalized the distribution of ion and water channels in macroglial cells. These results indicate that MR is activated in GK and human diabetic retina and that local MR antagonism could be a novel therapeutic option for diabetic retinopathy.

Prolactin and Other Pituitary Disorders in Kidney Disease

Prolactin levels are increased in chronic kidney disease (CKD) as a result of reduced clearance and increased secretion. Hyperprolactinemia manifests as galactorrhea and hypogonadism. Treatment of hyperprolactinemia should focus on improving bothersome galactorrhea or hypogonadism by using dopamine agonists and/or replacement of sex hormone(s). Changes in the hypothalamic-pituitary-adrenal axis in CKD are characterized by increases in adrenocorticotropic hormone (ACTH) and cortisol levels, largely preserved circadian rhythms of ACTH and cortisol, and a normal response of cortisol to ACTH, metyrapone, and insulin-induced hypoglycemia. However, the hypothalamic-pituitary-adrenal axis is less inhibited by 1 mg dexamethasone but retains normal suppression by higher-dose dexamethasone. Diagnosis of adrenal insufficiency in CKD patients, as in normal subjects, usually is made by finding a subnormal cortisol response to ACTH. The mainstay of treatment of adrenal insufficiency is to replace glucocorticoid hormone. Cushing's disease in CKD is difficult to diagnose and relies on the dexamethasone suppression test and the midnight salivary cortisol test because the 24-hour urine free cortisol test is not useful because it is increased already in CKD. Treatment of Cushing's disease involves surgery, complemented by radiation and/or medical therapy if necessary. Growth hormone levels are increased and insulin-like growth factor 1 levels are normal in patients with CKD. In a normal patient with CKD, as in one with acromegaly, there can be a paradoxic increase in growth hormone after an oral glucose load. Therefore, diagnosis of acromegaly in renal insufficiency is challenging. The treatment of choice for acromegaly is surgery, although data for medical treatment for acromegaly in CKD are rare. In patients with renal impairment, arginine vasopressin levels are increased as a result of decreased clearance, and there also is impairment of arginine vasopressin signaling in renal tubules. Diabetes insipidus can be masked in advanced kidney disease until kidney transplantation. Diagnosis of the syndrome of inappropriate antidiuretic hormone is similar in mild or moderate kidney disease as in normal subjects, but is challenging in patients with advanced kidney disease owing to the impairment in urine dilution.

Serum cortisone and glucocorticoid receptor gene (NR3C1) polymorphism in human dysglycemia

PURPOSE

We aimed to explore the associations of serum cortisone and glucocorticoid receptor (GR) polymorphism with glucose metabolism and type 2 diabetes mellitus (T2DM) among Chinese adults.

METHODS

A total of 2315 participants were included in the present study. Serum cortisone was measured by liquid chromatography-tandem mass spectrometry. Multivariable logistic regression and linear regression were employed to assess the associations between serum cortisone and different glucose metabolism status.

RESULTS

Serum cortisone was positively associated with impaired fasting glucose (IFG) and T2DM ((Quartile 4 vs Quartile 1, odds ratio (OR) = 1.36, 95% confidence interval (CI) 1.01, 1.84, and OR = 2.08, 95% CI 1.50, 2.89, respectively)). A 100% increase in cortisone was associated with a 0.015 (95% CI 0.005, 0.025) mg/dl higher fasting plasma glucose (FPG), a 0.007 (95% CI 0.001, 0.013) higher glycosylated hemoglobin (HbA1c), a 0.4% (95% CI - 0.007, 0.000) lower HOMA2-IR, and a 58.1% (95% CI - 0.788, - 0.373) lower HOMA2-β. After stratification by genotype, the association between serum cortisone and T2DM was not significant in TT genotype carriers. In addition, at the higher concentrations of cortisone, TT genotype carriers had a lower FPG, HbA1c, and HOMA2-IR and a higher HOMA2-β than GG and GT carriers.

CONCLUSIONS

Elevated serum cortisone was associated with an increased risk of IFG and T2DM, and the associations may be modified by rs9324924 polymorphism.

Clinical, Biochemical, and Genetic Characteristics of "Nonclassic" Apparent Mineralocorticoid Excess Syndrome

CONTEXT

Classical apparent mineralocorticoid excess (AME) is a rare recessive disorder, caused by severe 11β-hydroxysteroid dehydrogenase type 2 enzyme (11β-HSD2) deficiency. AME manifests as low-renin pediatric hypertension, hypokalemia and high cortisol/cortisone (F/E) ratio.

OBJECTIVE

To evaluate nonclassic AME (NC-AME) due to partial 11β-HSD2 insufficiency and its association with hypertension, mineralocorticoid receptor (MR) activation, and inflammatory parameters.

DESIGN

Cross-sectional study.

SETTING

Primary care cohort.

PARTICIPANTS

We recruited 127 adolescents and adults. Subjects with secondary hypertension were excluded. We measured clinical, biochemical, renal, vascular, and inflammatory variables. Sequencing of HSD11B2 gene was performed in all subjects.

MAIN OUTCOME MEASURE

NC-AME.

RESULTS

Serum F/E ratio was positively associated with systolic blood pressure (BP), microalbuminuria, and high-sensitivity C-reactive protein (hs-CRP). Serum cortisone correlated with MR activation parameters even when adjusted for age, body mass index, and sex: lower cortisone with higher potassium excretion (partial r = -0.29, P = 0.002) and with lower plasma renin activity (PRA) (partial r = 0.29, P = 0.001). Consistently, we identified 9 in 127 subjects (7.1%) with high F/E ratios (first quartile) and low cortisone (last quartile), suggestive of NC-AME. These subjects had higher systolic BP, 141.4 ± 25.7 mm Hg vs 127.3 ± 18.1 mm Hg, P = 0.03; lower PRA, 0.36 ± 0.19 ng/L*s vs 0.64 ± 0.47 ng/L*s, P < 0.0001; and greater potassium excretion, microalbuminuria, hs-CRP, and plasminogen activator inhibitor. We only found in 2 out of 9 subjects with NC-AME heterozygous mutations in the HSD11B2 gene.

CONCLUSIONS

These findings suggest a spectrum of partial 11β-HSD2 insufficiency in a primary care cohort without the classic phenotype and genotype of AME. NC-AME may represent a phenotype of MR activation and cardiovascular risk, suggesting that these subjects could be treated with MR antagonists.

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.

Gender-Specific Independent and Combined Effects of the Cortisol-to-Cortisone Ratio and 11-Deoxycortisol on Prediabetes and Type 2 Diabetes Mellitus: From the Henan Rural Cohort Study

OBJECTIVE

The aim of the study was to investigate the independent and combined effects of the cortisol-to-cortisone ratio (F/E) and 11-deoxycortisol on prediabetes and type 2 diabetes mellitus (T2DM) among different genders.

METHODS

A case-control study was performed including 2676 participants from the Henan Rural Cohort Study. Liquid chromatography-tandem mass spectrometry was used to assess serum cortisol, cortisone, and 11-deoxycortisol. Conditional logistic regression was performed to estimate the associations between hormones and outcomes.

RESULTS

After adjusting for multiple variables, the negative associations of F/E and 11-dexyocortisol with T2DM were observed in females (T3 vs. T1: OR = 0.56, 95% CI: 0.39-0.80 for F/E; T3 vs. T1: OR = 0.44, 95% CI: 0.27-0.73 for 11-dexyocortisol). However, only 11-dexyocortisol showed a negative association with prediabetes both in males and females. Compared with the combination of low F/E and 11-dexyocortisol, the combination of middle F/E and high 11-dexyocortisol was significantly associated with prediabetes (OR = 0.29, 95% CI: 0.12-0.71) in males. Furthermore, the combination of high F/E and 11-dexyocortisol was associated with the lowest odds of prediabetes (OR = 0.39, 95% CI: 0.21-0.73) and T2DM (OR = 0.25, 95% CI: 0.12-0.52) in females.

CONCLUSIONS

Serum F/E level was negatively associated with T2DM only in females whereas serum 11-deoxycortisol level was negatively associated with prediabetes in males and with prediabetes and T2DM in females. Additionally, their combination has a synergistic effect on T2DM.

Liquorice-induced hypokalaemia in patients treated with Yokukansan preparations: identification of the risk factors in a retrospective cohort study

OBJECTIVE

To evaluate serum potassium levels and rates of hypokalaemia in patients treated with liquorice-containing Japanese traditional Kampo-medicines Yokukansan (YK) and Yokukansan-ka-chinpihange (YKCH).

DESIGN

Retrospective cohort study.

SETTING

Patients receiving YK preparations for dementia and other psychiatric disorders in the University of Tsukuba Hospital in Japan.

PARTICIPANTS

389 patients (male/female: 174/215, 68.6±16.1 years) were treated with YK preparations for 231 days (range 6-2788 days). Patients whose potassium levels were <3.6 mEq/L before administration of YK preparations, and drug non-compliant patients, were excluded.

MAIN OUTCOME MEASURE

The occurrence rate of hypokalaemia and assessment of the risk factors for YK preparation-induced hypokalaemia.

RESULTS

Of the 389 patients treated with YK preparations, 94 (24.2%) developed hypokalaemia (potassium levels <3.6 mEq/L) 34 days (range 1-1600 days) after administration of the preparations. 36 (38.3%) patients had co-administration with lower potassium-inducing drugs (LPIDs; diuretics, glucocorticoids, mineralocorticoids and glycyrrhizin), which was more frequent in the patients without hypokalaemia (17.3%) (p<0.05). A Cox proportional hazard model identified four risk factors for hypokalaemia: YK administration (not YKCH) (HR 3.093, 95% CI 1.408 to 6.798), co-administration of LPIDs (HR 2.743, 95% CI 1.754 to 4.289), hypoalbuminaemia at baseline (HR 2.145, 95% 1.360 to 3.384), and full dosage administration (7.5 g/day) (HR 1.600, 95% CI 1.005 to 2.549).

CONCLUSIONS

Serum potassium monitoring should be done at least monthly in patients with the following risk factors: LPID co-administration, YK administration, hypoalbuminaemia, and full dosage administration.

A Liquid Chromatography/Tandem Mass Spectometry Profile of 16 Serum Steroids, Including 21-Deoxycortisol and 21-Deoxycorticosterone, for Management of Congenital Adrenal Hyperplasia

Context:

Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency (CAH21) is most often diagnosed by newborn screening. The classic parameter studied is 17-hydroxy-progesterone, but the positive predictive value for the diagnosis of CAH is low in full-term newborns and even lower in preterm newborns.

Objective:

To evaluate the diagnostic utility of simultaneously quantifying a large number of steroids by using liquid chromatography/tandem mass spectrometry (LC-MS/MS) from a small serum volume in patients with CAH, particularly during the neonatal period.

Setting and participants:

LC-MS/MS was applied to sera from patients with CAH who had a classic form (n = 48) and rare forms (n = 2) of 21-hydroxylase deficiency, normal preterm (n = 10) and normal full-term (n = 20) neonates, and young patients without CAH (non-CAH; n = 149) but with various other diseases (delayed or advanced puberty, hirsutism, pubarche, adrenarche, simple growth retardation).

Methods:

Sixteen steroids (glucocorticoids, mineralocorticoids, androgens, Δ5-steroids) were analyzed in 150 µL of serum by LC-MS/MS.

Results:

An LC-MS/MS serum steroid profile was developed and validated to provide a reliable etiologic diagnosis of CAH. The serum levels of 17OH-progesterone and 21 deoxycortisol in non-CAH are reported, along with the rarely assayed 21-deoxycorticorticosterone and 11β hydroxy Δ4-androstenedione, which will aid in the diagnosis of CAH21. In addition, serum levels of mineralocorticoids, androgens, and Δ5-steroids allowed investigation of other forms of CAH.

Conclusion:

This steroid LC-MS/MS approach on a small serum volume is well suited for pediatrics, particularly neonatal medical practice, to aid in the diagnosis and monitoring of various forms of CAH.

Piper sarmentosum Effects on 11β-Hydroxysteroid Dehydrogenase Type 1 Enzyme in Serum and Bone in Rat Model of Glucocorticoid-Induced Osteoporosis

Glucocorticoid-induced osteoporosis is one of the common causes of secondary osteoporosis. Piper sarmentosum (Ps) extract possesses antioxidant and anti-inflammatory activities. In this study, we determined the correlation between the effects of Ps leaf water extract with the regulation of 11β-hydroxysteroid dehydrogenase (HSD) type 1 enzyme activity in serum and bone of glucocorticoid-induced osteoporotic rats. Twenty-four Sprague-Dawley rats were grouped into following: G1: sham-operated group administered with intramuscular vehicle olive oil and vehicle normal saline orally; G2: adrenalectomized (adrx) control group given intramuscular dexamethasone (120 μg/kg/day) and vehicle normal saline orally; G3: adrx group given intramuscular dexamethasone (120 μg/kg/day) and water extract of Piper sarmentosum (125 mg/kg/day) orally. After two months, the femur and serum were taken for ELISA analysis. Results showed that Ps leaf water extract significantly reduced the femur corticosterone concentration (p < 0.05). This suggests that Ps leaf water extract was able to prevent bone loss due to long-term glucocorticoid therapy by acting locally on the bone cells by increasing the dehydrogenase action of 11β-HSD type 1. Thus, Ps may have the potential to be used as an alternative medicine against osteoporosis and osteoporotic fracture in patients on long-term glucocorticoid treatment.

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.

Tandem mass spectrometry determined maternal cortisone to cortisol ratio and psychiatric morbidity during pregnancy-interaction with birth weight

Maternal serum cortisol has been suggested to be influenced by psychiatric morbidity, and may also influence fetal growth. However, several studies found equal cortisol levels in depressed and healthy pregnant women. Placental 11-β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) shields the fetus from maternal cortisol by conversion to cortisone, a function that may be compromised by maternal stress. We aimed to compare the serum ratio of cortisone to cortisol, in women with and without psychiatric morbidity during pregnancy. A secondary aim was to investigate whether fetal growth, approximated by infant birth weight, was associated with the cortisone to cortisol ratio. We performed tandem mass spectrometry analysis of serum cortisol and cortisone in late pregnancy in 94 women with antenatal psychiatric morbidity and 122 controls (cohort 1). We also compared the placental gene expression of HSD11B1 and 2 in another group of 69 women with psychiatric morbidity and 47 controls (cohort 2). There were no group differences in cortisol to cortisone ratio, absolute levels of cortisone and cortisol (cohort 1), or expression of HSD11B1 or 2 (cohort 2). However, cortisone to cortisol ratio was positively associated with birth weight in women with psychiatric morbidity, also after adjustment for gestational length, fetal sex, maternal height, smoking, SSRI use, and time of blood sampling (standardized β=0.35, p<0.001), with no association in the healthy controls Thus, the maternal serum cortisone to cortisol ratio does not seem to be affected by psychiatric morbidity, but psychiatric morbidity may increase fetal exposure to cortisol or other metabolic factors influencing fetal growth.

Hypothalamic-pituitary-adrenal axis activity is associated with the prevalence of chronic kidney disease in diabetic patients

Progression of chronic kidney disease (CKD) in diabetic patients can occur through enhanced hypothalamic-pituitary-adrenal (HPA) axis activity. The purpose of our study was to determine whether HPA axis activity influences the prevalence of CKD in patients with type 2 diabetes mellitus. Seventy-seven diabetic patients (mean age, 60 years) were enrolled. CKD was defined by K/DOQI criteria, and serum cortisol level was measured after the 1 mg overnight dexamethasone suppression test (F-DST). F-DST values were significantly negatively correlated with estimated glomerular filtration rate (eGFR), and significantly positively correlated with cystatin C level and spot urine albumin to creatinine ratio in simple and multiple regression analyses. The subjects were divided into 3 groups (low, middle, and high) according to the F-DST, and the odds for CKD were 8.7-fold (95% confidence interval 2.56 to 29.6, P=0.01) and 12.5-fold (95% confidence interval 3.3 to 47.9, P<0.001) higher in subjects in the middle and high groups than those in the low group, respectively. In multivariate regression analysis, subjects in the middle group and high group (compared to those in the low group) had 13.0-fold (95% confidence interval, 2.9 to 58.8 and P=0.001) and 14.7-fold (95% confidence interval, 2.8 to 78.5 and P=0.002), respectively, higher risk for CKD. In conclusion, F-DST values have a relationship with decreased eGFR and increased cystatin C or albumin excretion involved in CKD, and enhanced HPA axis activity may be an independent risk factor for CKD in patients with type 2 diabetes mellitus.

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.

Simultaneous determination of cortisol and cortisone from human serum by liquid chromatography-tandem mass spectrometry

A fast, sensitive, and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated and then the levels of cortisol and cortisone from sera of healthy adults were determined by the LC-MS/MS method. One hundred μ L of serum sample was directly extracted by adding 2 mL ethyl acetate, followed by chromatographic separation on a C18 column with a mobile phase consisting of 5 mM ammonium acetate and methanol (25 : 75, v/v). The precision, accuracy, and average recovery of the method were 1.5-5.3%, 95.4-102.5%, and 96.4% for cortisol, and 1.9-6.0%, 89.2-98.8%, and 79.9% for cortisone, respectively. The method was linear from 1.0 to 500.0 ng/mL (r(2) = 0.999) for cortisol and 2.5 to 100.0 ng/mL (r(2) = 0.998) for cortisone. The limits of detection (LOD) and quantification (LOQ) were 0.2 and 1.0 ng/mL for cortisol, and 1.0 and 2.5 ng/mL for cortisone, respectively. The average cortisol concentration (133.9 ± 63.7 ng/mL) of samples collected between 9:00 and 11:00 a.m. was higher approximately 4.4 times than that of cortisone (30.5 ± 10.7 ng/mL) (P < 0.0001). The average cortisone/cortisol ratio was 0.225. Therefore, the LC-MS/MS method may be useful for the diagnosis of some adrenal diseases and the assessment of 11 β -hydroxysteroid dehydrogenase (11 β -HSD) activity in clinical laboratories.

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.

Biomedical evaluation of cortisol, cortisone, and corticosterone along with testosterone and epitestosterone applying micellar electrokinetic chromatography

The validated micellar electrokinetic chromatography (MEKC) was proposed for the determination of five steroid hormones in human urine samples. That technique allowed for the separation and quantification of cortisol, cortisone, corticosterone, testosterone, and epitestosterone and was sensitive enough to detect low concentrations of these searched steroids in urine samples at the range of 2–300 ng/mL. The proposed MEKC technique with solid-phase extraction (SPE) procedure was simple, rapid, and has been successfully applied as a routine procedure to analyze steroids in human urine samples. The MEKC method offered a potential in clinical routine practice because of the short analysis time (8 min), low costs, and simultaneous analysis of five endogenous hormones. Due to its simplicity, speed, accuracy, and high recovery, the proposed method could offer a tool to determine steroid hormones as potential biomarkers in biomedical investigations, what was additionally revealed with healthy volunteers.

Hypertension in small animal kidney disease

Kidney disease is commonly associated with hypertension in dogs, cats and other species. There are multiple mechanisms underlying the development of renal hypertension including sodium retention, activation of the renin-angiotensin system and sympathetic nerve stimulation. The relative importance of these and other mechanisms may vary both between species and according to the type of kidney disease that is present. Consideration of underlying disease mechanisms may aid in the rational choice of therapy in hypertensive patients.

Continuous positive airway pressure therapy decreases evening cortisol concentrations in patients with severe obstructive sleep apnea

Patients with obstructive sleep apnea syndrome (OSAS) show recurrent episodes of nightly hypoxic stress. The purpose of this study is the detection of alterations of the hypothalamic-pituitary-adrenal stress axis in OSAS patients before and after continuous positive airway pressure (CPAP) therapy. An activation of the hypothalamic-pituitary-adrenal axis was proposed because of the nightly hypoxic stress in these patients, but previous studies were not conclusive. Here we hypothesize that CPAP therapy decreases salivary cortisol concentrations in patients with severe OSAS. We performed a clinical within-subject study including 50 patients with newly diagnosed OSAS and an apnea-hypopnea index greater than or equal to 40 h(-1). Diurnal profiles of salivary cortisol concentrations were compiled before and after 3 months of treatment with CPAP. Therefore, 6 cortisol samples were collected: before and after lunch, in the evening, the next morning after awakening, and before and after breakfast. Thirty-eight patients returned after 3 months of CPAP therapy for follow-up. According to the reference range for healthy subjects, cortisol values were not pathologically increased. Analysis of variance revealed a significant effect of CPAP therapy on diurnal cortisol profiles (P = .048). Subjects with severe OSAS showed a decrease (3.04 +/- 0.55 nmol L(-1) pre-CPAP vs 2.48 +/- 0.78 nmol L(-1) post-CPAP, P = .038) of evening cortisol levels after CPAP treatment, whereas prelunch levels were increased after CPAP therapy (7.18 +/- 0.83 nmol L(-1) pre-CPAP vs 10.22 +/- 1.10 nmol L(-1) post-CPAP, P = .044). Our results show that CPAP therapy decreases evening cortisol concentrations in patients with severe OSAS. These data suggest that OSAS may increase the cortisol nadir that is reversed after CPAP therapy.

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 11beta-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.

[Pharmacological bases of coffee nutrients for diabetes prevention]

With an increasing number of studies describing the negative correlation of coffee consumption and the risk for type 2 diabetes mellitus, we were compelled to elucidate the nutrients which bring pharmacological effects on risk reduction for diabetes. In this review, the author's interest is focused on chlorogenic and caffeic acids derived from lightly roasted coffee beans, as well as nicotinic acid, volatile Maillard reaction products (vMRPs), and another structurally unknown compound contained in heavily roasted beans. Caffeine is a common compound in both lightly and heavily roasted beans and its anti-inflammatory effects on degenerative diseases such as diabetes mellitus has been reevaluated recently. The prophylactic effects of coffee on diabetes involve pleiotropy of plural components in accordance to the degree of the roasting. A new concept of nutritional blended coffee may be important to optimize the prophylactic effects of coffee on lowering the risk factors of diabetes and delaying the progress of diabetes complications as well.

Asymmetric dimethylarginine, cortisol/cortisone ratio, and C-peptide: markers for diabetes and cardiovascular risk?

BACKGROUND

Diabetes and prediabetic conditions are growing cardiovascular risk factors. Better understanding and earlier recognition and treatment of dysglycemia-related risk are health priorities. We assessed the predictive value of 3 proposed new markers for diabetes and cardiovascular risk. We tested whether the plasma levels of (1) asymmetric dimethylarginine (ADMA), (2) cortisol/cortisone (Cl/Cn) ratio, and (3) C-peptide predicted glycemic status, coronary artery disease, and death or myocardial infarction (MI) in a nested case-control cohort (N = 850) with normal fasting glucose (< 110 mg/dL), impaired fasting glucose (110-125), or diabetic (> or = 126) status.

METHODS

High-sensitivity C-reactive protein (hsCRP) served as a control risk marker. Follow-up averaged 2.6 +/- 1.4 years. High-pressure liquid chromatography with pre-column derivitization and fluorescence was used to assay ADMA, liquid chromatography/tandem mass spectrometry for Cl and Cn, and chemiluminescent immunoassay for C-peptide.

RESULTS

Asymmetric dimethylarginine levels were positively associated with glycemic category (P < .001). Quartiles 2 to 4 ADMA also conferred increased risk of death/MI independent of hsCRP and other risk factors (adjusted hazard ratio, 2.1; P = .002). Cortisol/Cortisone ratios (P = .013) and C-peptide (P = .047) were associated with glycemic categories but less strongly than ADMA. Quartiles 2 to 4 Cl/Cn were protective against incident death/MI (adjusted hazard ratio, 0.48; P < .001), whereas C-peptide did not predict outcomes.

CONCLUSIONS

Among a high coronary risk case-control cohort, ADMA (strongly), Cl/Cn (moderately), and C-peptide (weakly) predicted glycemic categories. Asymmetric dimethylarginine and Cl/Cn also predicted clinical outcome independent of and more strongly than hsCRP. Asymmetric dimethylarginine and Cl/Cn represent promising new candidate markers of dysglycemia and associated cardiovascular risk.

Insulin resistance in diabetic nephropathy--cause or consequence?

Insulin resistance (IR) is associated with multiple risk factors for cardiovascular disease. Many studies have shown that IR is present in chronic renal failure (CRF), and recent evidence suggests that IR can also occur in the early stages of renal disease. Patients with diabetic nephropathy (DN) have an increase in cardiovascular mortality, and since IR may be a contributing factor, this emphasizes the importance of a detailed understanding of the mechanisms linking IR and renal dysfunction at different stages of DN. IR can be detected early on in DN, e.g. at the stage of microalbuminuria (MA) and this could indicate a common genetic trait for IR and DN. As DN progresses further, IR is aggravated and it may, in addition to other factors, possibly accelerate the decline in renal function toward end-stage renal disease (ESRD). Several potentially modifiable mechanisms including circulating hormones, neuroendocrine pathways and chronic inflammation, are said to contribute to the worsening of IR. In ESRD, uremic toxins are of major importance. In this review article, we address the association between different stages of DN and IR and attempt to summarize major findings on potential mechanisms linking DN and IR. We conclude that IR is a consequence, and potentially also a cause of DN. In addition, there are probably genetic and environmental background factors that predispose to both IR and DN.

Activity of 11β-hydroxysteroid dehydrogenase in tissues of hypertensive NISAG rats

11beta-Hydroxysteroid dehydrogenase activity in the kidneys of NISAG rats (rat strain with hereditary stress-induced arterial hypertension) was 1.5-fold higher than in WAG rats. An inverse relationship was observed in the liver of these animals. After stress exposure 11beta-hydroxysteroid dehydrogenase activity remained unchanged in the kidneys of NISAG and WAG rats, but significantly increased in the liver of NISAG rats. Functional activity of 11beta-hydroxysteroid dehydrogenase probably reflects the hypertensive state of NISAG rats.

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

OBJECTIVE

Renal 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) enables selective access of aldosterone to the mineralocorticoid receptor (MR). Impaired 11beta-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 11beta-HSD2 activity.

METHODS

We have directly analysed renal 11beta-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 11beta-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 11beta-HSD2 expression in patients with impaired renal function. For the first time, we showed that 11beta-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 + 5alpha-tetrahydrocortisol/tetrahydrocortisone ((THF + alphaTHF)/THE) ratio (r = 0.256; P < 0.05). No difference in 11beta-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 + alphaTHF)/THE ratio increased significantly (P < 0.05) in patients with severe albuminuria, suggesting increased hepatic 11beta-HSD1 in those patients.

CONCLUSIONS

These data suggest that renal 11beta-HSD2 expression may be represented only marginally better, if at all, by the UFF/UFE than by the (THF + alphaTHF)/THE ratio. Reduced renal 11beta-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.

Tissue-specific dysregulation of 11beta-hydroxysteroid dehydrogenase type 1 and pathogenesis of the metabolic syndrome

Glucocorticoids are important regulators of glucose, lipid and protein metabolism, acting mainly in the liver, adipose tissue and muscle. Chronic glucocorticoid excess is associated with clinical features, such as insulin resistance, visceral obesity, hypertension, and dyslipidemia, which also represent the classical hallmarks of the metabolic syndrome. Elevenbeta-hydroxysteroid dehydrogenase type 1 (11beta-HSD-1), a key intracellular enzyme which catalyses the conversion of inactive cortisone to active cortisol, has been implicated in the development of the metabolic syndrome. The shift of this reaction towards cortisol generation may lead to tissutal overexposure to glucocorticoids even with normal circulating cortisol levels. The most robust evidence in support of a pathogenetic role of this enzyme in the development of the metabolic syndrome has been reported in experimental animals, whereas results of human studies are less convincing with several case control and cross-sectional studies showing an association between with 11beta-HSD-1 setpoint and individual features of the metabolic syndrome. However, recent data suggest a tissue-specific rather than systemic alteration of this shuttle, with down-regulation in liver but up-regulation in adipose tissue and skeletal muscle of obese subjects. New techniques based on direct tissutal estimates of cortisol/cortisone ratios are clearly needed to precisely assess the role of enzyme in all target tissues. If confirmed, these results would prompt the development of selective and tissue-specific 11beta-HSD-1 inhibitors to decrease insulin resistance and treat the metabolic syndrome, thus contrasting the harmful effects of glucocorticoid excess in peripheral tissues.

Plasma cortisol and cortisone concentrations in normal subjects and patients with adrenocortical disorders

Two isozymes of the 11beta-hydroxysteroid dehydrogenase (11-HSD) are responsible for the interconversion of cortisol (F) and cortisone (E). The type 1 isozyme, 11-HSD1, acts mainly as a reductase in vivo, activating E to F, whereas the type 2, 11-HSD2, acts as a dehydrogenase, inactivating F to E. 11-HSD1 is the most abundant in the liver and 11-HSD2 in the kidney. In this study, we attempted to determine which isozyme and organs primarily contribute to equilibrium of plasma F and E concentrations in the peripheral circulation and to clarify differences in 11-HSD activities among adrenocortical disorders. Upon selective catheterizations for adrenocortical and renovascular disorders, plasma F and E concentrations in the femoral vein were closer to those in the renal vein than those in the hepatic vein. Values for mean plasma F/E ratios in the peripheral vein were in-between those of the adrenal and renal veins. A double reciprocal plot between peripheral plasma F and E concentrations in patients with various adrenocortical tumors was almost identical to that in normal subjects. Mean plasma F/E ratio in peripheral blood was higher in patients with Cushing's syndrome and was lower in patients with primary aldosteronism and nonfunctioning adrenocortical adenoma than that in normal subjects. These results suggest that renal 11-HSD2 is a main factor controlling the equilibrium of plasma F and E concentrations in the periphery and that cortisol and aldosterone excess do not change the equilibrium of plasma F and E concentrations in the peripheral circulation, but may alter expression of 11-HSD2. Alternation of 11-HSD2 activities as well as corticosteroid levels may be important in the pathophysiology of adrenocortical disorders.