Impaired glucose tolerance and insulin resistance are associated with increased adipose 11beta-hydroxysteroid dehydrogenase type 1 expression and elevated hepatic 5alpha-reductase activity

Exploration of the shared pathways and common biomarker in adamantinomatous craniopharyngioma and type 2 diabetes using integrated bioinformatics analysis

Craniopharyngiomas are rare tumors of the central nervous system that typically present with symptoms such as headache and visual impairment, and those reflecting endocrine abnormalities, which seriously affect the quality of life of patients. Patients with craniopharyngiomas are at higher cardiometabolic risk, defined as conditions favoring the development of type 2 diabetes and cardiovascular disease. However, the underlying common pathogenic mechanisms of craniopharyngiomas and type 2 diabetes are not clear. Especially due to the difficulty of conducting in vitro or in vivo experiments on craniopharyngioma, we thought the common pathway analysis between craniopharyngioma and type 2 diabetes based on bioinformatics is a powerful and feasible method. In the present study, using public datasets (GSE94349, GSE68015, GSE38642 and GSE41762) obtained from the GEO database, the gene expression associated with adamantinomatous craniopharyngioma, a subtype of craniopharyngioma, and type 2 diabetes were analyzed using a bioinformatic approach. We found 11 hub genes using a protein-protein interaction network analysis. Of these, seven (DKK1, MMP12, KRT14, PLAU, WNT5B, IKBKB, and FGF19) were also identified by least absolute shrinkage and selection operator analysis. Finally, single-gene validation and receptor operating characteristic analysis revealed that four of these genes (MMP12, PLAU, KRT14, and DKK1) may be involved in the common pathogenetic mechanism of adamantinomatous craniopharyngioma and type 2 diabetes. In addition, we have characterized the differences in immune cell infiltration that characterize these two diseases, providing a reference for further research.

Cortisol secretion and abnormalities of glucose metabolism in nondiabetic patients with hypertension

OBJECTIVE

Glycometabolic changes are associated with hypercortisolism in Cushing's syndrome. Because impaired glucose tolerance (IGT) and insulin resistance are frequently detected in patients with essential hypertension, we hypothesized that in these patients, early glycometabolic abnormalities might be related to differences in regulation of cortisol secretion.

METHODS

In a cross-sectional study, we included 155 nondiabetic, essential hypertensive patients who were free of organ complications. The homeostasis model assessment (HOMA) index and the area under the curve of plasma glucose (AUC-glucose) and insulin (AUC-insulin) concentration following an oral glucose tolerance test were measured, together with daily plasma cortisol (8 a.m., 3 p.m. and 12 a.m.; AUC-cortisol) and 8 a.m. cortisol after 1 mg overnight dexamethasone suppression test (DST).

RESULTS

IGT was present in 27% of patients who were older and had higher BMI, plasma triglycerides and uric acid, AUC-cortisol and DST-cortisol, and lower HDL-cholesterol. Frequency of IGT increased progressively across tertiles of DST-cortisol, together with levels of glycated hemoglobin, fasting insulin and C-peptide, HOMA-index, AUC-glucose, and AUC-insulin. AUC-cortisol and DST-cortisol were directly correlated with insulin, C-peptide, HOMA-index, AUC-glucose, and AUC-insulin. Multivariate regression analysis showed that DST-cortisol was directly and independently correlated with HOMA index, AUC-glucose, and AUC-insulin. In a logistic regression model, both AUC-cortisol and DST-cortisol independently predicted IGT.

CONCLUSION

Daily cortisol and cortisol response to DST are independent determinants of IGT and insulin resistance in nondiabetic patients with hypertension, suggesting that even subtle differences in regulation of cortisol secretion might increase the risk of these patients to develop diabetes.

The effect of GLP-1RA exenatide on idiopathic intracranial hypertension: a randomized clinical trial

Therapeutics to reduce intracranial pressure are an unmet need. Preclinical data have demonstrated a novel strategy to lower intracranial pressure using glucagon-like peptide-1 (GLP-1) receptor signalling. Here, we translate these findings into patients by conducting a randomized, placebo-controlled, double-blind trial to assess the effect of exenatide, a GLP-1 receptor agonist, on intracranial pressure in idiopathic intracranial hypertension. Telemetric intracranial pressure catheters enabled long-term intracranial pressure monitoring. The trial enrolled adult women with active idiopathic intracranial hypertension (intracranial pressure >25 cmCSF and papilloedema) who receive subcutaneous exenatide or placebo. The three primary outcome measures were intracranial pressure at 2.5 h, 24 h and 12 weeks and alpha set a priori at less than 0.1. Among the 16 women recruited, 15 completed the study (mean age 28 ± 9, body mass index 38.1 ± 6.2 kg/m2, intracranial pressure 30.6 ± 5.1 cmCSF). Exenatide significantly and meaningfully lowered intracranial pressure at 2.5 h -5.7 ± 2.9 cmCSF (P = 0.048); 24 h -6.4 ± 2.9 cmCSF (P = 0.030); and 12 weeks -5.6 ± 3.0 cmCSF (P = 0.058). No serious safety signals were noted. These data provide confidence to proceed to a phase 3 trial in idiopathic intracranial hypertension and highlight the potential to utilize GLP-1 receptor agonist in other conditions characterized by raised intracranial pressure.

Idiopathic Hirsutism and Metabolic Status: A Population-based Prospective Cohort Study

BACKGROUND

A limited number of studies have investigated the impact of idiopathic hirsutism (IH) on cardiometabolic parameters with contradictory and inconclusive results. This study aimed to explore the effect of IH on metabolic outcomes.

METHOD

In this population-based prospective study, 334 women with IH and 1226 women as healthy controls were selected from Tehran Lipid and Glucose Study. The generalized estimation equations method was applied to investigate the secular longitudinal trends of metabolic indices, including fasting blood sugar (FBS), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL), non-HDL, triglyceride (TG), systolic blood pressure (SBP), diastolic blood pressure (DBP), and waist circumference (WC) in both groups. Unadjusted and adjusted Cox regression models were applied to assess the hazard ratios (HR) and 95% CIs for the association between IH and metabolic disorders. Potential confounding factors such as age, body mass index, smoking, physical activity, history of hypertension (HTN), and family history of diabetes were included in the adjusted model.

RESULTS

This study showed that compared with healthy controls, women with IH had lower SHBG and higher total testosterone (median [interquartile ratio; IQR]: 0.37 [0.16-0.70] vs 0.33 [0.14-0.58]; P = 0.01), free androgen index (median [IQR]: 0.85 [0.38-1.54] vs 0.54 [0.26-0.97]; P = 0.001), androstenedione (median [IQR]: 1.60 [1.00-2.25] vs 1.10 [0.90-1.70]; P = 0.001), and dehydroepiandrosterone sulfate (median [IQR]: 168.5 [91.1-227.8] vs 125.2 [66.3-181]; P = 0.001). Over time, mean changes of FBS, HDL-C, LDL-C, non-HDL-C, TG, SBP, DBP, and WC were not significantly different in women with IH, compared with healthy controls. According to the unadjusted Cox regression model, except for type 2 diabetes mellitus (T2DM) (HR [95% CI]: 1.45 [1.00-2.11]) P = 0.05; there was no statistically significant difference in hazard of metabolic disorders (ie, HTN, pre-HTN, pre-T2DM, and metabolic syndrome) in IH, compared with healthy controls. Besides, the adjusted Cox regression model showed no significant differences in the hazard of these outcomes.

CONCLUSION

This study showed no significant difference in overtime mean changes of metabolic risk factors and cardiometabolic outcomes in women with IH, compared with the healthy control group, except marginally significant difference on T2DM, which disappeared after further adjustment for potential confounders. Accordingly, routine screening of women for these metabolic outcomes should not recommend.

Approach to the Patient: Diagnosis of Cushing Syndrome

Cushing syndrome results from supraphysiological exposure to glucocorticoids and is associated with significant morbidity and mortality. The pathogenesis includes administration of corticosteroids (exogenous Cushing syndrome) or autonomous cortisol overproduction, whether or not ACTH-dependent (endogenous Cushing syndrome). An early diagnosis of Cushing syndrome is warranted; however, in clinical practice, it is very challenging partly because of resemblance with other common conditions (ie, pseudo-Cushing syndrome). Initial workup should start with excluding local and systemic corticosteroid use. First-line screening tests including the 1-mg dexamethasone suppression test, 24-hour urinary free cortisol excretion, and late-night salivary cortisol measurement should be performed to screen for endogenous Cushing syndrome. Scalp-hair cortisol/cortisone analysis helps in the assessment of long-term glucocorticoid exposure as well as in detection of transient periods of hypercortisolism as observed in cyclical Cushing syndrome. Interpretation of results can be difficult because of individual patient characteristics and hence requires awareness of test limitations. Once endogenous Cushing syndrome is established, measurement of plasma ACTH concentrations differentiates between ACTH-dependent (80%-85%) or ACTH-independent (15%-20%) causes. Further assessment with different imaging modalities and dynamic biochemical testing including bilateral inferior petrosal sinus sampling helps further pinpoint the cause of Cushing's syndrome. In this issue of "Approach to the patient," the diagnostic workup of Cushing syndrome is discussed with answering the questions when to screen, how to screen, and how to differentiate the different causes. In this respect, the latest developments in biochemical and imaging techniques are discussed as well.

Fresh insights into glucocorticoid-induced diabetes mellitus and new therapeutic directions

Glucocorticoid hormones were discovered to have use as potent anti-inflammatory and immunosuppressive therapeutics in the 1940s and their continued use and development have successfully revolutionized the management of acute and chronic inflammatory diseases. However, long-term use of glucocorticoids is severely hampered by undesirable metabolic complications, including the development of type 2 diabetes mellitus. These effects occur due to glucocorticoid receptor activation within multiple tissues, which results in inter-organ crosstalk that increases hepatic glucose production and inhibits peripheral glucose uptake. Despite the high prevalence of glucocorticoid-induced hyperglycaemia associated with their routine clinical use, treatment protocols for optimal management of the metabolic adverse effects are lacking or underutilized. The type, dose and potency of the glucocorticoid administered dictates the choice of hypoglycaemic intervention (non-insulin or insulin therapy) that should be provided to patients. The longstanding quest to identify dissociated glucocorticoid receptor agonists to separate the hyperglycaemic complications of glucocorticoids from their therapeutically beneficial anti-inflammatory effects is ongoing, with selective glucocorticoid receptor modulators in clinical testing. Promising areas of preclinical research include new mechanisms to disrupt glucocorticoid signalling in a tissue-selective manner and the identification of novel targets that can selectively dissociate the effects of glucocorticoids. These research arms share the ultimate goal of achieving the anti-inflammatory actions of glucocorticoids without the metabolic consequences.

Associations of Obesity with Linear Growth and Puberty

BACKGROUND

The prevalence of obesity in childhood has increased dramatically in recent decades with increased risk of developing cardiometabolic and other comorbidities. Childhood adiposity may also influence processes of growth and puberty.

SUMMARY

Growth patterns of obesity during childhood have been shown to be associated with increased linear growth in early childhood, leading to accelerated epiphyseal growth plate (EGP) maturation. Several hormones secreted by the adipose tissue may affect linear growth in the context of obesity, both via the growth hormone IGF-1 axis and via a direct effect on the EGP. The observation that children with obesity tend to mature earlier than lean children has led to the assumption that the degree of body fatness may trigger the neuroendocrine events that lead to pubertal onset. The most probable link between obesity and puberty is leptin and its interaction with the kisspeptin system, which is an important regulator of puberty. However, peripheral action of adipose tissue could also be involved in changes in the onset of puberty. In addition, nutritional factors, epigenetics, and endocrine-disrupting chemicals are potential mediators linking pubertal onset to obesity. In this review, we focused on interactions of obesity with linear growth and pubertal processes, based on basic research and clinical data in humans.

KEY MESSAGE

Children with obesity are subject to accelerated linear growth with risk of impaired adult height and early puberty, with its psychological consequences. The data highlight another important objective in combatting childhood obesity, for the prevention of abnormal growth and pubertal patterns.

Carbonyl reductase 1 amplifies glucocorticoid action in adipose tissue and impairs glucose tolerance in lean mice

OBJECTIVE

Carbonyl reductase 1 (Cbr1), a recently discovered contributor to tissue glucocorticoid metabolism converting corticosterone to 20β-dihydrocorticosterone (20β-DHB), is upregulated in adipose tissue of obese humans and mice and may contribute to cardiometabolic complications of obesity. This study tested the hypothesis that Cbr1-mediated glucocorticoid metabolism influences glucocorticoid and mineralocorticoid receptor activation in adipose tissue and impacts glucose homeostasis in lean and obese states.

METHODS

The actions of 20β-DHB on corticosteroid receptors in adipose tissue were investigated first using a combination of in silico, in vitro, and transcriptomic techniques and then in vivo administration in combination with receptor antagonists. Mice lacking one Cbr1 allele and mice overexpressing Cbr1 in their adipose tissue underwent metabolic phenotyping before and after induction of obesity with high-fat feeding.

RESULTS

20β-DHB activated both the glucocorticoid and mineralocorticoid receptor in adipose tissue and systemic administration to wild-type mice induced glucose intolerance, an effect that was ameliorated by both glucocorticoid and mineralocorticoid receptor antagonism. Cbr1 haploinsufficient lean male mice had lower fasting glucose and improved glucose tolerance compared with littermate controls, a difference that was abolished by administration of 20β-DHB and absent in female mice with higher baseline adipose 20β-DHB concentrations than male mice. Conversely, overexpression of Cbr1 in adipose tissue resulted in worsened glucose tolerance and higher fasting glucose in lean male and female mice. However, neither Cbr1 haploinsfficiency nor adipose overexpression affected glucose dyshomeostasis induced by high-fat feeding.

CONCLUSIONS

Carbonyl reductase 1 is a novel regulator of glucocorticoid and mineralocorticoid receptor activation in adipose tissue that influences glucose homeostasis in lean mice.

Systemic and adipocyte transcriptional and metabolic dysregulation in idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a condition predominantly affecting obese women of reproductive age. Recent evidence suggests that IIH is a disease of metabolic dysregulation, androgen excess, and an increased risk of cardiovascular morbidity. Here we evaluate systemic and adipose specific metabolic determinants of the IIH phenotype.

METHODS

In fasted, matched IIH (n = 97) and control (n = 43) patients, we assessed glucose and insulin homeostasis and leptin levels. Body composition was assessed along with an interrogation of adipose tissue function via nuclear magnetic resonance metabolomics and RNA sequencing in paired omental and subcutaneous biopsies in a case-control study.

RESULTS

We demonstrate an insulin- and leptin-resistant phenotype in IIH in excess of that driven by obesity. Adiposity in IIH is preferentially centripetal and is associated with increased disease activity and insulin resistance. IIH adipocytes appear transcriptionally and metabolically primed toward depot-specific lipogenesis.

CONCLUSION

These data show that IIH is a metabolic disorder in which adipose tissue dysfunction is a feature of the disease. Managing IIH as a metabolic disease could reduce disease morbidity and improve cardiovascular outcomes.

FUNDING

This study was supported by the UK NIHR (NIHR-CS-011-028), the UK Medical Research Council (MR/K015184/1), Diabetes UK, Wellcome Trust (104612/Z/14/Z), the Sir Jules Thorn Award, and the Midlands Neuroscience Teaching and Research Fund.

Dynamic behavior of metabolic syndrome progression: a comprehensive systematic review on recent discoveries

BACKGROUND

The assessment of the natural history of metabolic syndrome (MetS) has an important role in clarifying the pathways of this disorder.

OBJECTIVE

This study purposed to provide a rational statistical view of MetS progression pathway.

METHODS

We performed a systematic review in accordance with the PRISMA Statement until September 2019 in the Medline/PubMed, Scopus, Embase, Web of Science and Google Scholar databases. From the 68 found studies, 12 studies were eligible for review finally.

RESULTS

The selected studies were divided in 2 groups with Markovian and non-Markovian approach. With the Markov approach, the most important trigger for the MetS chain was dyslipidemia with overweight/obesity in the under-50 and with hypertension in the over-50 age group, where overweight/obesity was more important in women and hypertension in men. In non-Markov approach, the most common trigger was hypertension. Transition probability (TP) from no component to MetS were higher in all Markovian studies in men than in women. In the Markovians the combination of dyslipidemia with overweight/obesity and in non-Markovians, hyperglycemia with overweight/obesity were the most common combinations. Finally, the most important components, which predict the MetS, were 2-component states and hyperglycemia in Markovian approach and overweight/obesity in non-Markovians.

CONCLUSIONS

Among the components of the MetS, dyslipidemia and hypertension seems to be the main developer components in natural history of the MetS. Also, in this chain, the most likely combination over time that determines the future status of people seems to be the combination of dyslipidemia with obesity or hyperglycemia. However, more research is needed.

The role of 5-reduction in physiology and metabolic disease: evidence from cellular, pre-clinical and human studies

The 5-reductases (5α-reductase types 1, 2 and 3 [5αR1-3], 5β-reductase [5βR]) are steroid hormone metabolising enzymes that hold fundamental roles in human physiology and pathology. They possess broad substrate specificity converting many steroid hormones to their 5α- and 5β-reduced metabolites, as well as catalysing crucial steps in bile acid synthesis. 5αRs are fundamentally important in urogenital development by converting testosterone to the more potent androgen 5α-dihydrotestosterone (5αDHT); inactivating mutations in 5αR2 lead to disorders of sexual development. Due to the ability of the 5αRs to generate 5αDHT, they are an established drug target, and 5αR inhibitors are widely used for the treatment of androgen-dependent benign or malignant prostatic diseases. There is an emerging body of evidence to suggest that the 5-reductases can impact upon aspects of health and disease (other than urogenital development); alterations in their expression and activity have been associated with metabolic disease, polycystic ovarian syndrome, inflammation and bone metabolism. This review will outline the evidence base for the extra-urogenital role of 5-reductases from in vitro cell systems, pre-clinical models and human studies, and highlight the potential adverse effects of 5αR inhibition in human health and disease.

Altered hormonal and autonomic nerve responses to hypo- and hyperglycaemia are found in overweight and insulin-resistant individuals and may contribute to the development of type 2 diabetes

AIMS/HYPOTHESIS

Results from animal models and some clinical work suggest a role for the central nervous system (CNS) in glucose regulation and type 2 diabetes pathogenesis by modulation of glucoregulatory hormones and the autonomic nervous system (ANS). The aim of this study was to characterise the neuroendocrine response to various glucose concentrations in overweight and insulin-resistant individuals compared with lean individuals.

METHODS

Overweight/obese (HI, n = 15, BMI ≥27.0 kg/m²) and lean (LO, n = 15, BMI <27.0 kg/m²) individuals without diabetes underwent hyperinsulinaemic euglycaemic-hypoglycaemic clamps and hyperglycaemic clamps on two separate occasions with measurements of hormones, Edinburgh Hypoglycaemic Symptom Scale (ESS) score and heart rate variability (HRV). Statistical methods included groupwise comparisons with Mann-Whitney U tests, multilinear regressions and linear mixed models between neuroendocrine responses and continuous metabolic variables.

RESULTS

During hypoglycaemic clamps, there was an elevated cortisol response in HI vs LO (median ΔAUC 12,383 vs 4793 nmol/l × min; p = 0.050) and a significantly elevated adrenocorticotropic hormone (ACTH) response in HI vs LO (median ΔAUC 437.3 vs 162.0 nmol/l × min; p = 0.021). When adjusting for clamp glucose levels, obesity (p = 0.033) and insulin resistance (p = 0.009) were associated with elevated glucagon levels. By contrast, parasympathetic activity was less suppressed in overweight individuals at the last stage of hypoglycaemia compared with euglycaemia (high-frequency power of HRV, p = 0.024). M value was the strongest predictor for the ACTH and P_HF responses, independent of BMI and other variables. There was a BMI-independent association between the cortisol response and ESS score response (p = 0.024). During hyperglycaemic clamps, overweight individuals displayed less suppression of glucagon levels (median ΔAUC -63.4% vs -73.0%; p = 0.010) and more suppression of sympathetic relative to parasympathetic activity (low-frequency/high-frequency power, p = 0.011).

CONCLUSIONS/INTERPRETATION

This study supports the hypothesis that altered responses of insulin-antagonistic hormones and the ANS to glucose fluctuations occur in overweight and insulin-resistant individuals, and that these responses are probably partly mediated by the CNS. Their potential role in development of type 2 diabetes needs to be addressed in future research. Graphical abstract.

Differential activity and expression of human 5β-reductase (AKR1D1) splice variants

Steroid hormones, including glucocorticoids and androgens, exert a wide variety of effects in the body across almost all tissues. The steroid A-ring 5β-reductase (AKR1D1) is expressed in human liver and testes, and three splice variants have been identified (AKR1D1-001, AKR1D1-002, AKR1D1-006). Amongst these, AKR1D1-002 is the best described; it modulates steroid hormone availability and catalyses an important step in bile acid biosynthesis. However, specific activity and expression of AKR1D1-001 and AKR1D1-006 are unknown. Expression of AKR1D1 variants were measured in human liver biopsies and hepatoma cell lines by qPCR. Their three-dimensional (3D) structures were predicted using in silico approaches. AKR1D1 variants were overexpressed in HEK293 cells, and successful overexpression confirmed by qPCR and Western blotting. Cells were treated with either cortisol, dexamethasone, prednisolone, testosterone or androstenedione, and steroid hormone clearance was measured by mass spectrometry. Glucocorticoid and androgen receptor activation were determined by luciferase reporter assays. AKR1D1-002 and AKR1D1-001 are expressed in human liver, and only AKR1D1-006 is expressed in human testes. Following overexpression, AKR1D1-001 and AKR1D1-006 protein levels were lower than AKR1D1-002, but significantly increased following treatment with the proteasomal inhibitor, MG-132. AKR1D1-002 efficiently metabolised glucocorticoids and androgens and decreased receptor activation. AKR1D1-001 and AKR1D1-006 poorly metabolised dexamethasone, but neither protein metabolised cortisol, prednisolone, testosterone or androstenedione. We have demonstrated the differential expression and role of AKR1D1 variants in steroid hormone clearance and receptor activation in vitro. AKR1D1-002 is the predominant functional protein in steroidogenic and metabolic tissues. In addition, AKR1D1-001 and AKR1D1-006 may have a limited, steroid-specific role in the regulation of dexamethasone action.

Type 2 diabetes risk gene Dusp8 regulates hypothalamic Jnk signaling and insulin sensitivity

Recent genome-wide association studies (GWAS) identified DUSP8, encoding a dual-specificity phosphatase targeting mitogen-activated protein kinases, as a type 2 diabetes (T2D) risk gene. Here, we reveal that Dusp8 is a gatekeeper in the hypothalamic control of glucose homeostasis in mice and humans. Male, but not female, Dusp8 loss-of-function mice, either with global or corticotropin-releasing hormone neuron-specific deletion, had impaired systemic glucose tolerance and insulin sensitivity when exposed to high-fat diet (HFD). Mechanistically, we found impaired hypothalamic-pituitary-adrenal axis feedback, blunted sympathetic responsiveness, and chronically elevated corticosterone levels driven by hypothalamic hyperactivation of Jnk signaling. Accordingly, global Jnk1 ablation, AAV-mediated Dusp8 overexpression in the mediobasal hypothalamus, or metyrapone-induced chemical adrenalectomy rescued the impaired glucose homeostasis of obese male Dusp8-KO mice, respectively. The sex-specific role of murine Dusp8 in governing hypothalamic Jnk signaling, insulin sensitivity, and systemic glucose tolerance was consistent with functional MRI data in human volunteers that revealed an association of the DUSP8 rs2334499 risk variant with hypothalamic insulin resistance in men. Further, expression of DUSP8 was increased in the infundibular nucleus of T2D humans. In summary, our findings suggest the GWAS-identified gene Dusp8 as a novel hypothalamic factor that plays a functional role in the etiology of T2D.

Altered Cortisol Metabolism Increases Nocturnal Cortisol Bioavailability in Prepubertal Children With Type 1 Diabetes Mellitus

OBJECTIVE

Disturbances in the activity of the hypothalamus-pituitary-adrenal axis could lead to functional alterations in the brain of diabetes patients. In a later perspective of investigating the link between the activity of the hypothalamus-pituitary-adrenal axis and the developing brain in children with diabetes, we assessed here nocturnal cortisol metabolism in prepubertal children with type 1 diabetes mellitus (T1DM).

METHODS

Prepubertal patients (aged 6-12 years) diagnosed with T1DM at least 1 year previously were recruited, along with matched controls. Nocturnal urine samples were collected, with saliva samples taken at awakening and 30 minutes after awakening. All samples were collected at home over 5 consecutive days with no detectable nocturnal hypoglycaemia. The State-Trait Anxiety Inventory (trait scale only) and Child Depression Inventory were also completed. Glucocorticoid metabolites in the urine, salivary cortisol (sF) and cortisone (sE) were measured by liquid chromatography-tandem mass spectrometry. Metabolic data were analysed by logistic regression, adjusting for sex, age, BMI and trait anxiety score.

RESULTS

Urine glucocorticoid metabolites were significantly lower in T1DM patients compared to controls. 11β-hydroxysteroid dehydrogenase type 1 activity was significantly higher, while 11β-hydroxysteroid dehydrogenase type 2, 5(α+β)-reductase and 5α-reductase levels were all lower, in T1DM patients compared to controls. There was a significant group difference in delta sE level but not in delta sF level between the time of awakening and 30 minutes thereafter.

CONCLUSIONS

Our findings suggest that altered nocturnal cortisol metabolism and morning HPA axis hyperactivity in children with T1DM leads to greater cortisol bioavailability and lower cortisol production as a compensatory effect. This altered nocturnal glucocorticoid metabolism when cortisol production is physiologically reduced and this HPA axis hyperactivity question their impact on brain functioning.

Steroid Metabolism in Children and Adolescents With Obesity and Insulin Resistance: Altered SRD5A and 20α/20βHSD Activity

Alterations in glucocorticoid metabolism may contribute to the development of obesity and insulin resistance (IR). Obesity in turn affects the androgen balance. The peripheral metabolism of steroids is equally an important determinant of their bioavailability and activity. The aim of this study was to evaluate steroid metabolism in obese children and to define which enzyme alterations are associated with IR. Clinical characteristics and anthropometric measurements were determined in 122 obese children and adolescents (72 girls, 50 boys) aged 8 - 18 years. 26 of them (21.3%) were diagnosed with IR (13 boys, 13 girls). Routine laboratory tests were performed and 24h urinary steroid excretion profiles were analyzed by gas chromatography/mass spectrometry. Positive relationship between 5α-reductase (SRD5A) activity and IR was found. According to the androsterone to etiocholanolone (An/Et) ratio the activity of SRD5A was significantly increased in obese children with IR, but the difference remained insignificant once the 5α-dihydrotestosterone to testosterone (5αDHT/T) ratio was considered. Furthermore, this relationship persisted in boys but was not observed in girls. The activity of 20α-hydroxysteroid dehydrogenase (20αHSD) and 20β-hydroxysteroid dehydrogenase (20βHSD) was reduced only in obese girls with IR. Conclude, in the context of obese children and adolescents with IR, we surmise that increased SRD5A represents a compensatory mechanism to reduce local glucocorticoid availability. This phenomenon is probably different in the liver (restriction) and in the adipose tissue (expected increase in activity). We show significant changes in 20αHSD and 20βHSD activity in obese girls with IR, but it is difficult to clearly determine whether the activity of these enzymes is an indicator of the function in their ovaries or adrenal glands.

The contribution of serum cortisone and glucocorticoid metabolites to detrimental bone health in patients receiving hydrocortisone therapy

BACKGROUND

Glucocorticoid therapy is the most common cause of iatrogenic osteoporosis. Less is known regarding the effect of glucocorticoids when used as replacement therapy on bone remodelling in patients with adrenal insufficiency. Enhanced intracellular conversion of inactive cortisone to active cortisol, by 11 beta-hydroxysteroid dehydrogenase type 1(11β-HSD1) and other enzymes leading to alterations in glucocorticoid metabolism, may contribute to a deleterious effect on bone health in this patient group.

METHODS

Study design: An open crossover prospective study randomizing ten hypopituitary men, with severe ACTH deficiency, to three commonly used hydrocortisone dose regimens.

MEASUREMENTS

Following 6 weeks of each regimen, patients underwent 24-h serum cortisol/cortisone sampling, measurement of bone turnover markers, and a 24-h urine collection for measurement of urinary steroid metabolites by gas chromatography-mass spectrometry (GC-MS). Serum cortisone and cortisol were analysed by liquid chromatography-mass spectrometry (LC-MS).

RESULTS

Dose-related and circadian variations in serum cortisone were seen to parallel those for cortisol, indicating conversion of ingested hydrocortisone to cortisone. The median area under the curve (AUC) of serum cortisone was significantly higher in patients on dose A (20 mg/10 mg) [670.5 (IQR 621-809.2)] compared to those on dose C (10 mg/5 mg) [562.8 (IQR 520.1-619.6), p = 0.01]. A negative correlation was observed between serum cortisone and bone formation markers, OC [1-49] (r = - 0.42, p = 0.03), and PINP (r = - 0.49, p = 0.01). There was a negative correlation between the AUC of night-time serum cortisone levels with the bone formation marker, OC [1-49] (r = - 0.41, p = 0.03) but there were no significant correlations between day-time serum cortisone or cortisol with bone turnover markers. There was a negative correlation between total urinary cortisol metabolites and the bone formation markers, PINP (r = - 0.39, p = 0.04), and OC [1-49] (r = - 0.35, p = 0.06).

CONCLUSION

Serum cortisol and cortisone and total urinary corticosteroid metabolites are negatively associated with bone turnover markers in patients receiving replacement doses of hydrocortisone, with nocturnal glucocorticoid exposure having a potentially greater influence on bone turnover.

TRIAL REGISTRATION

Irish Medicines Board Clinical Trial Number - CT900/459/1 and EudraCT Number - 2007-005018-37 . Registration date: 07-09-2007.

Maternal high-fructose intake during pregnancy and lactation induces metabolic syndrome in adult offspring

BACKGROUND/OBJECTIVES

Nutritional status and food intake during pregnancy and lactation can affect fetal programming. In the current metabolic syndrome epidemic, high-fructose diets have been strongly implicated. This study investigated the effect of maternal high-fructose intake during pregnancy and lactation on the development of metabolic syndrome in adult offspring.

SUBJECTS/METHODS

Drinking water with or without 20% fructose was administered to female C57BL/6J mice over the course of their pregnancy and lactation periods. After weaning, pups ate regular chow. Accu-Chek Performa was used to measure glucose levels, and a tail-cuff method was used to examine systolic blood pressure. Animals were sacrificed at 7 months, their livers were excised, and sections were stained with Oil Red O and hematoxylin and eosin (H&E) staining. Kidneys were collected for gene expression analysis using quantitative real-time Polymerase chain reaction.

RESULTS

Adult offspring exposed to maternal high-fructose intake during pregnancy and lactation presented with heavier body weights, fattier livers, and broader areas under the curve in glucose tolerance test values than control offspring. Serum levels of alanine aminotransferase, aspartate aminotransferase, glucose, triglycerides, and total cholesterol and systolic blood pressure in the maternal high-fructose group were higher than that in controls. However, there were no significant differences in mRNA expressions of renin-angiotensin-aldosterone system genes and sodium transporter genes.

CONCLUSIONS

These results suggest that maternal high-fructose intake during pregnancy and lactation induces metabolic syndrome with hyperglycemia, hypertension, and dyslipidemia in adult offspring.

Altered cortisol metabolism in individuals with HNF1A-MODY

OBJECTIVE AND CONTEXT

Maturity onset diabetes of the young due to variants in HNF1A (HNF1A-MODY) is the most common form of monogenic diabetes. Individuals with HNF1A-MODY usually have a lean phenotype which contrasts with type 2 diabetes (T2DM). Data from hepatocytes derived from Hnf1a knock-out mice demonstrated dysregulation of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which regulates glucocorticoid availability and action in target tissues, together with 11β-HSD2 and steroid A-ring reductases, 5α- and 5β-reductase. We proposed that altered glucocorticoid metabolism might underpin some of the phenotypic differences between patients with HNF1A-MODY and those with T2DM.

DESIGN

A retrospective matched cohort study.

PATIENTS AND MEASUREMENTS

24-hours urine steroid metabolome profiling was carried out by gas chromatography-mass spectrometry in 35 subjects with HNF1A-MODY, 35 individuals with T2DM and 35 healthy controls matched for age, sex and BMI. The steroid metabolites were expressed as μg/L in all groups and measured in mid-morning urine in diabetic subjects and 24-hour urine collection in healthy controls. Hence, only ratios were compared not the individual steroids. Established ratios of glucocorticoid metabolites were used to estimate 11β-HSD1/2 and 5α- and 5β-reductase activities.

RESULTS

While 11β-HSD1 activity was similar in all groups, 11β-HSD2 activity was significantly lower in subjects with HNF1A-MODY and T2DM than in healthy controls. The ratio of 5β- to 5α-metabolites of cortisol was higher in subjects with HNF1A-MODY than in T2DM and healthy controls, probably due to increased activity of the 5β-reductase (AKR1D1) in HNF1A-MODY.

CONCLUSIONS

This is the first report of steroid metabolites in HNF1A-MODY. We have identified distinct differences in steroid metabolism pathways in subjects with HNF1A-MODY that have the potential to alter steroid hormone availability. Further studies are required to explore whether these changes link to phenotype.

Co-administration of 5α-reductase Inhibitors Worsens the Adverse Metabolic Effects of Prescribed Glucocorticoids

CONTEXT

Glucocorticoids (GCs) are commonly prescribed, but their use is associated with adverse metabolic effects. 5α-reductase inhibitors (5α-RI) are also frequently prescribed, mainly to inhibit testosterone conversion to dihydrotestosterone. However, they also prevent the inactivation of GCs.

OBJECTIVE

We hypothesized that 5α-RI may worsen the adverse effects of GCs.

DESIGN

Prospective, randomized study.

PATIENTS

A total of 19 healthy male volunteers (age 45 ± 2 years; body mass index 27.1 ± 0.7kg/m2).

INTERVENTIONS

Participants underwent metabolic assessments; 2-step hyperinsulinemic, euglycemic clamp incorporating stable isotopes, adipose tissue microdialysis, and biopsy. Participants were then randomized to either prednisolone (10 mg daily) or prednisolone (10 mg daily) plus a 5α-RI (finasteride 5 mg daily or dutasteride 0.5 mg daily) for 7 days; metabolic assessments were then repeated.

MAIN OUTCOME MEASURES

Ra glucose, glucose utilization (M-value), glucose oxidation, and nonesterified fatty acids (NEFA) levels.

RESULTS

Co-administration of prednisolone with a 5α-RI increased circulating prednisolone levels (482 ± 96 vs 761 ± 57 nmol/L, P = 0.029). Prednisolone alone did not alter Ra glucose (2.55 ± 0.34 vs 2.62 ± 0.19 mg/kg/minute, P = 0.86), M-value (3.2 ± 0.5 vs 2.7 ± 0.7 mg/kg/minute, P = 0.37), or glucose oxidation (0.042 ± 0.007 vs 0.040 ± 0.004 mmol/hr/kg/minute, P = 0.79). However, co-administration with a 5α-RI increased Ra glucose (2.67 ± 0.16 vs 3.05 ± 0.18 mg/kg/minute, P < 0.05) and decreased M-value (4.0 ± 0.5 vs 2.6 ± 0.4 mg/kg/minute, P < 0.05), and oxidation (0.043 ± 0.003 vs 0.036 ± 0.002 mmol/hr/kg, P < 0.01). Similarly, prednisolone did not impair insulin-mediated suppression of circulating NEFA (43.1 ± 28.9 vs 36.8 ± 14.3 μmol/L, P = 0.81), unless co-administered with a 5α-RI (49.8 ± 8.6 vs 88.5 ± 13.5 μmol/L, P < 0.01).

CONCLUSIONS

We have demonstrated that 5α-RIs exacerbate the adverse effects of prednisolone. This study has significant translational implications, including the need to consider GC dose adjustments, but also the necessity for increased vigilance for the development of adverse effects.

Associations of SRD5A1 gene variants and testosterone with dysglycemia: Henan Rural Cohort study

BACKGROUND AND AIM

Multiple studies support a complex relationship between testosterone and type 2 diabetes mellitus (T2DM) and the transformation of testosterone is affected by several reductases. Thus, we aimed to explore the associations of steroid-5α-reductase type 1 (SRD5A1) gene polymorphism with impaired fasting glucose (IFG) and T2DM and the interactive effects of testosterone and genotypes on glycometabolism.

METHODS AND RESULTS

A case-control study including 2365 participants was performed. Genomic DNA was extracted from the whole blood and genotyped for the SRD5A1 single nucleotide polymorphisms (SNP) rs1691053. Multivariable logistic regression and linear regression were performed to estimate the associations of SRD5A1 rs1691053 alleles and genotypes with glycometabolism. Generalized linear models were used to investigate the modulatory effects of serum testosterone on glycometabolism indexes in males. After multivariable adjustment, the odds ratio (OR) of homozygous CC genotypes in male carriers was 2.62 (95%CI: 1.11-6.18) for IFG. Furthermore, significant associations of SRD5A1 rs1691053 polymorphisms with adverse indices of glycometabolism were observed in males. Interestingly, the opposite associations in females were observed. The interactive associations of SNP and testosterone were found and mutations were more likely to lead unfavorable metabolic phenotypes.

CONCLUSION

These results showed that SRD5A1 rs1691053 gene polymorphism was independently associated with glycometabolism. The interaction between a genetic polymorphism from SRD5A1 and testosterone involved glycometabolism was identified in males. Although this preliminary data should be replicated with other rigorous researches, it highlighted the importance of the SNP-testosterone interaction over the present of glycometabolism.

Diet-induced weight loss alters hepatic glucocorticoid metabolism in type 2 diabetes mellitus

CONTEXT

Altered tissue-specific glucocorticoid metabolism has been described in uncomplicated obesity and type 2 diabetes. We hypothesized that weight loss induced by diet and exercise, which has previously been shown to reverse abnormal cortisol metabolism in uncomplicated obesity, also normalizes cortisol metabolism in patients with type 2 diabetes.

OBJECTIVE

Test the effects of a diet intervention with added exercise on glucocorticoid metabolism.

DESIGN

Two groups followed a Paleolithic diet (PD) for 12 weeks with added 180 min of structured aerobic and resistance exercise per week in one randomized group (PDEX).

SETTING

Umeå University Hospital.

PARTICIPANTS

Men and women with type 2 diabetes treated with lifestyle modification ± metformin were included. Twenty-eight participants (PD, n = 15; PDEX, n = 13) completed measurements of glucocorticoid metabolism.

MAIN OUTCOME MEASURES

Changes in glucocorticoid metabolite levels in 24-h urine samples, expression of HSD11B1 mRNA in s.c. adipose tissue and conversion of orally administered cortisone to cortisol measured in plasma. Body composition and insulin sensitivity were measured using a hyperinsulinemic-euglycemic clamp, and liver fat was measured by magnetic resonance spectroscopy.

RESULTS

Both groups lost weight and improved insulin sensitivity. Conversion of orally taken cortisone to plasma cortisol and the ratio of 5α-THF + 5β-THF/THE in urine increased in both groups.

CONCLUSIONS

These interventions caused weight loss and improved insulin sensitivity with concomitant increases in the conversion of cortisone to cortisol, which is an estimate of hepatic HSD11B1 activity. This suggests that dysregulation of liver glucocorticoid metabolism in these patients is a consequence rather than a cause of metabolic dysfunction.

Maternal Glucocorticoid Metabolism Across Pregnancy: A Potential Mechanism Underlying Fetal Glucocorticoid Exposure

CONTEXT

Across pregnancy, maternal serum cortisol levels increase up to 3-fold. It is not known whether maternal peripheral cortisol metabolism and clearance change across pregnancy or influence fetal cortisol exposure and development.

OBJECTIVES

The primary study objective was to compare maternal urinary glucocorticoid metabolites, as markers of cortisol metabolism and clearance, between the second and third trimester of pregnancy. Secondary objectives were to test associations of total maternal urinary glucocorticoid excretion, with maternal serum cortisol levels and offspring birth weight z score.

DESIGN, PARTICIPANTS, AND SETTING

A total of 151 women with singleton pregnancies, recruited from prenatal clinic at the Pittsburgh site of the Measurement of Maternal Stress (MOMS) study, had 24-hour urine collections during both the second and third trimesters.

RESULTS

Between the second and third trimester, total urinary glucocorticoid excretion increased (ratio of geometric means [RGM] 1.37, 95% CI 1.22-1.52, P < .001), and there was an increase in calculated 5β-reductase compared to 5α-reductase activity (RGM 3.41, 95% CI 3.04-3.83, P < .001). During the third trimester total urinary glucocorticoid excretion and serum cortisol were negatively correlated (r = -0.179, P = .029). Mean total urinary glucocorticoid excretion across both trimesters and offspring birth weight z score were positively associated (β = 0.314, P = .001).

CONCLUSIONS

The estimated activity of maternal enzymes responsible for cortisol metabolism change between the second and third trimester of pregnancy. Additionally, maternal peripheral metabolism and clearance of cortisol may serve as a novel mechanism affecting fetal cortisol exposure and growth.

The Association Between Polycystic Ovary Syndrome and Its Dermatological Manifestations

Polycystic ovary syndrome (PCOS) commonly occurs in reproductive-age females. It elevates the hormonal levels, creates an imbalance in the metabolic system, and affects their reproductive system too. A number of studies have been conducted on PCOS, and it has been diagnosed together with several dermatological conditions. In this paper, we attempt a traditional review to study the relationship between PCOS and its cutaneous manifestations the patients are predisposed to. To uncover this association, we gathered information from English-language articles on the Pubmed database using six keywords. Materials were also collected from studies done on animal models, which helped in putting down all the data together and interlinking them with other studies. From this data collection, it is ultimately concluded that the association between PCOS and dermatological conditions is a very intricate interconnecting network comprising many factors, such as inflammation, genetics, and hormonal. This study raises some questions that are still unanswered. We believe further research is needed to uncover the various facts about this disease and its associations, in order to make its management more effective. As there is a strong association between PCOS and certain dermatological disorders, it is recommended to develop a questionnaire that should be distributed to every woman who presents to dermatology departments with symptoms that are linked to PCOS, as it will help in diagnosing the condition at an early stage.

Steroid Metabolomic Signature of Insulin Resistance in Childhood Obesity

OBJECTIVE

On the basis of urinary steroidal gas chromatography-mass spectrometry (GC-MS), we previously defined a novel concept of a disease-specific "steroid metabolomic signature" and reclassified childhood obesity into five groups with distinctive signatures. The objective of the current study was to delineate the steroidal signature of insulin resistance (IR) in obese children.

RESEARCH DESIGN AND METHODS

Urinary samples of 87 children (44 girls) aged 8.5-17.9 years with obesity (BMI >97th percentile) were quantified for 31 steroid metabolites by GC-MS. Defined as HOMA-IR >95th percentile and fasting glucose-to-insulin ratio >0.3, IR was diagnosed in 20 (of 87 [23%]) of the examined patients. The steroidal fingerprints of subjects with IR were compared with those of obese children without IR (non-IR). The steroidal signature of IR was created from the product of IR - non-IR for each of the 31 steroids.

RESULTS

IR and non-IR groups of children had comparable mean age (13.7 ± 1.9 and 14.6 ± 2.4 years, respectively) and z score BMI (2.7 ± 0.5 and 2.7 ± 0.5, respectively). The steroidal signature of IR was characterized by high adrenal androgens, glucocorticoids, and mineralocorticoid metabolites; higher 5α-reductase (An/Et) (P = 0.007) and 21-hydroxylase [(THE + THF + αTHF)/PT] activity (P = 0.006); and lower 11βHSD1 [(THF + αTHF)/THE] activity (P = 0.012).

CONCLUSIONS

The steroidal metabolomic signature of IR in obese children is characterized by enhanced secretion of steroids from all three adrenal pathways. As only the fasciculata and reticularis are stimulated by ACTH, these findings suggest that IR directly affects the adrenals. We suggest a vicious cycle model, whereby glucocorticoids induce IR, which could further stimulate steroidogenesis, even directly. We do not know whether obese children with IR and the new signature may benefit from amelioration of their hyperadrenalism.

S100A16-induced adipogenesis is associated with up-regulation of 11 β-hydroxysteroid dehydrogenase type 1 (11β-HSD1)

The steadily increasing epidemic of obesity continues at alarming rates, is an important public health problem, and expression changes of S100A16 and 11 β-hydroxysteroid dehydrogenase type 1(11β-HSD1) is attributable to the adipocyte differentiation. In our previous study, we found that 11β-HSD1 protein expression increased in S100A16-overexpressed 3T3-L1 cell model. In order to further investigate the relationship between S100A16 and 11β-HSD1, and the molecular mechanisms of S100A16-induced adipogenesis, we constructed S100A16 transgenic and knockout mouse, and S100A16-overexpressed 3T3-L1 preadipocyte cell. Using S100A16 transgenic (S100A16^Tg/+) mice fed with normal fat diet (NFD) and high fat diet (HFD) diet model, we evaluated the effect of S100A16 on adipogenesis, expression of 11β-HSD1, and RNA sequencing and quantification of gene expression. Using the 3T3-L1 cell model, we examined the effect of S100A16 and 11β-HSD1 on pre-adipocyte differentiation, and cell signaling events of 11β-HSD1 overexpression induced by S100A16. We found that when compared with C57BL/6 mice, overexpression of S100A16 under the condition of HFD increased lipid content in WAT and fat infiltration in hepatocytes, 11β-HSD1 protein expression increased along with S100A16. Elevated S100A16 and 11β-HSD1 expression promoted adipogenesis in 3T3-L1 cells. Overexpression of S100A16 inhibited the degradation of 11β-HSD1. We conclude that S100A16-induced adipogenesis is associated with up-regulation of 11β-HSD1.

AKR1D1 regulates glucocorticoid availability and glucocorticoid receptor activation in human hepatoma cells

Steroid hormones, including glucocorticoids and androgens, have potent actions to regulate many cellular processes within the liver. The steroid A-ring reductase, 5β-reductase (AKR1D1), is predominantly expressed in the liver, where it inactivates steroid hormones and, in addition, plays a crucial role in bile acid synthesis. However, the precise functional role of AKR1D1 to regulate steroid hormone action in vitro has not been demonstrated. We have therefore hypothesised that genetic manipulation of AKR1D1 has the potential to regulate glucocorticoid availability and action in human hepatocytes. In both liver (HepG2) and non-liver cell (HEK293) lines, AKR1D1 over-expression increased glucocorticoid clearance with a concomitant decrease in the activation of the glucocorticoid receptor and the down-stream expression of glucocorticoid target genes. Conversely, knockdown of AKR1D1 using siRNA decreased glucocorticoid clearance and reduced the generation of 5β-reduced metabolites. In addition, the two 5α-reductase inhibitors finasteride and dutasteride failed to effectively inhibit AKR1D1 activity in either cell-free or hepatocellular systems. Through manipulation of AKR1D1 expression and activity, we have demonstrated its potent ability to regulate glucocorticoid availability and receptor activation within human hepatoma cells. These data suggest that AKR1D1 may have an important role in regulating endogenous (and potentially exogenous) glucocorticoid action that may be of particular relevance to physiological and pathophysiological processes affecting the liver.

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.

Ginseng-plus-Bai-Hu-Tang ameliorates diet-induced obesity, hepatic steatosis, and insulin resistance in mice

Background

Dietary fat has been suggested to be the cause of various health issues. Obesity, hypertension, cardiovascular disease, diabetes, dyslipidemia, and kidney disease are known to be associated with a high-fat diet (HFD). Obesity and associated conditions, such as type 2 diabetes mellitus and nonalcoholic fatty liver disease (NAFLD), are currently a worldwide health problem. Few prospective pharmaceutical therapies that directly target NAFLD are available at present. A Traditional Chinese Medicine, ginseng-plus-Bai-Hu-Tang (GBHT), is widely used by diabetic patients to control glucose level or thirst. However, whether it has therapeutic effects on fat-induced hepatic steatosis and metabolic syndrome remains unclear.

Methods

This study was conducted to examine the therapeutic effect of GBHT on fat-induced obesity, hepatic steatosis, and insulin resistance in mice.

Results

GBHT protected mice against HFD-induced body weight gain, hyperlipidemia, and hyperglycemia compared with mice that were not treated. GBHT inhibited the expansion of adipose tissue and adipocyte hypertrophy. No ectopic fat deposition was found in the livers of HFD mice treated with GBHT. In addition, glucose intolerance and insulin sensitivity in HFD mice was also improved by GBHT.

Conclusion

GBHT prevents changes in lipid and carbohydrate metabolism in a HFD mouse model. Our findings provide evidence for the traditional use of GBHT as therapy for the management of metabolic syndrome.

Development and validation of a scoring system for prediction of insulin requirement for optimal control of blood glucose during glucocorticoid treatments

AIMS

We have developed and validated a novel scoring system to predict insulin requirement for optimal control of blood glucose during glucocorticoid (GC) treatments, by retrospective analyses of clinical parameters before GC treatment.

METHODS

Three hundred-three adults (the Developing set) undergoing their first treatment of prednisolone (PSL) were divided into two groups, depending on treatment with or without insulin. Independent risk factors for insulin requirement were identified by a stepwise logistic regression analysis after univariate analyses between the two groups. We constructed a point-addition scoring system consisting of several categories and their coefficients in each risk factor derived from another logistic regression analysis. We validated it to two validation sets, A and B.

RESULTS

Male, higher levels of fasting plasma glucose (FPG), HbA1c, and serum creatinine (CRE) and a higher initial dose of PSL were identified as the risk factors. The sensitivity, specificity, and accuracy were 90.0%, 88.1%, and 88.4%; 87.5%, 66.7%, and 70.5%; 83.3%, 76.1%, and 76.6% in the Developing set, Validation set A, and Validation set B, respectively, when the scoring system was applied.

CONCLUSIONS

The scoring system is a valid and reliable tool to predict insulin requirements in advance during GC treatment.

Exercise activates the PI3K-AKT signal pathway by decreasing the expression of 5α-reductase type 1 in PCOS rats

Hyperandrogenism and hyperinsulinemia are main clinical endocrine features of PCOS. Exercise can adjust the androgen level, as well as increase the sensitivity of insulin by activating PI3K-Akt insulin signaling pathways. 5αR1 has certain effects on insulin resistance and can synthesize dihydrotestosterone by metabolizing testosterone. So 5αR1 may be the target of androgen and insulin for exercise-induced regulation. To investigate the role of 5αR1 in the PI3K-Akt signaling pathway in skeletal muscle of PCOS rats activated by exercise, fifty-four female rats were randomly divided into the PCOS group (n = 42) and the control group(n = 12). After injection of testosterone propionate for 28 days, the remaining 36 rats in the PCOS group were randomly assigned to six groups: the sedentary group (PS, n = 6), sedentary and 5αRI (5α-reductase inhibitor) group (PS + RI, n = 6), sedentary and 5αR2I (5α-reductase type 2 selective inhibitor) group (PS + R2I, n = 6), exercise group (PE, n = 6), exercise and 5αRI group (PE + RI, n = 6), and exercise and 5αR2I group (PE + R2I, n = 6). The rats undergoing exercise were trained to swim for 14 days. Finasteride (5α-reductase type 2 selective inhibitor) and dutasteride (5α-reductase inhibitor) were administered once daily and were dosed based on weight. At the end, the expression of 5αR1 proteins, the phosphorylation level of PI3K and AKT, were determined by Western blot. The PCOS non-exercise group and the PE + RI group displayed significantly lower phosphorylation of Akt, PI3K p85 and GLUT4 expression, while in the PE + R2I group, the level of Akt phosphorylation and PI3K p85 expression was significantly higher than that of the PCOS non-exercise group and the PE + RI group. In summary, our study demonstrated that exercise can activate the PI3K/AKT signal pathway of PCOS rats by decreasing the expression of 5αR1.

Evaluating the Fat Distribution in Idiopathic Intracranial Hypertension Using Dual-Energy X-ray Absorptiometry Scanning

Idiopathic intracranial hypertension (IIH) is strongly associated with obesity. We aimed to utilise dual-energy X-ray absorptiometry (DEXA) to characterise fat distribution, and to evaluate change in fat mass and distribution following weight loss. IIH patients (n = 24) had a similar fat distribution to body mass index (BMI)- and gender-matched obese controls (n = 47). In the IIH cohort, truncal fat mass correlated with lumbar puncture pressure. Weight loss in IIH patients resulted in a significant reduction in disease activity and fat mass, predominantly from the truncal region (-4.40 ± 1.6%; p = 0.008) compared with the limbs (+0.79 ± 6.5%; p = 0.71). These results indicate that, contrary to previous studies using waist-hip ratios, IIH adiposity is centripetal, similar to simple obesity. Future studies should establish the risk of the metabolic syndrome and the role of adipose tissue depot-specific function in IIH.

Intrauterine growth restriction combined with a maternal high-fat diet increased adiposity and serum corticosterone levels in adult rat offspring

Intrauterine growth restriction (IUGR) and fetal exposure to a maternal high-fat diet (HFD) independently increase the risk of developing obesity in adulthood. Excess glucocorticoids increase obesity. We hypothesized that surgically induced IUGR combined with an HFD would increase adiposity and glucocorticoids more than in non-IUGR offspring combined with the same HFD, findings that would persist despite weaning to a regular diet. Non-IUGR (N) and IUGR (I) rat offspring from dams fed either regular rat chow (R) or an HFD (H) were weaned to either a regular rat chow or an HFD. For non-IUGR and IUGR rats, this study design resulted in three diet groups: offspring from dams fed a regular diet and weaned to a regular diet (NRR and IRR), offspring rats from dams fed an HFD and weaned to a regular diet (NHR and IHR) and offspring from dams fed an HFD and weaned to an HFD (NHH and IHH). Magnetic resonance imaging or fasting visceral and subcutaneous adipose tissue collection occurred at postnatal day 60. IHH male rats had greater adiposity than NHH males, findings that were only partly normalized by weaning to a regular chow. IHH male rats had a 10-fold increase in serum corticosterone levels. IHH female rats had increased adiposity and serum triglycerides. We conclude that IUGR combined with an HFD throughout life increased adiposity, glucocorticoids and triglycerides in a sex-specific manner. Our data suggest that one mechanism through which the perinatal environment programs increased adiposity in IHH male rats may be via increased systemic glucocorticoids.

Unfolding Novel Mechanisms of Polyphenol Flavonoids for Better Glycaemic Control: Targeting Pancreatic Islet Amyloid Polypeptide (IAPP)

Type 2 diabetes (T2D) is characterised by hyperglycaemia resulting from defective insulin secretion, insulin resistance, or both. The impact of over-nutrition and reduced physical activity, evidenced by the exponential rise in obesity and the prevalence of T2D, strongly supports the implementation of lifestyle modification programs. Accordingly, an increased consumption of fruits and plant-derived foods has been advocated, as their intake is inversely correlated with T2D prevalence; this has been attributed, in part, to their contained polyphenolic compounds. Over the last decade, a body of work has focussed on establishing the mechanisms by which polyphenolic compounds exert beneficial effects to limit carbohydrate digestion, enhance insulin-mediated glucose uptake, down-regulate hepatic gluconeogenesis and decrease oxidative stress; the latter anti-oxidative property being the most documented. Novel effects on the inhibition of glucocorticoid action and the suppression of amylin misfolding and aggregation have been identified more recently. Amyloid fibrils form from spontaneously misfolded amylin, depositing in islet cells to elicit apoptosis, beta cell degeneration and decrease insulin secretion, with amyloidosis affecting up to 80% of pancreatic islet cells in T2D. Therefore, intervening with polyphenolic compounds offers a novel approach to suppressing risk or progression to T2D. This review gives an update on the emerging mechanisms related to dietary polyphenol intake for the maintenance of glycaemic control and the prevention of T2D.

Androsterone glucuronide to dehydroepiandrosterone sulphate ratio is discriminatory for obese Caucasian women with polycystic ovary syndrome

BACKGROUND

Androsterone glucuronide (ADTG) concentrations have been suggested as a marker of the effects of androgens at the target tissue level. As the mechanism for hyperandrogenemia in obese and nonobese polycystic ovary syndrome (PCOS) may differ, this study compared the different androgen parameters in non-obese compared to obese women with PCOS, and in normal subjects.

METHODS

Eleven non-obese and 14 obese women with PCOS were recruited and compared to 11 control women without PCOS. Total testosterone, dehydroepiandrosterone sulphate (DHEAS), ADTG, and androstenedione were analysed using gold standard tandem mass spectrometry, and the free androgen index (FAI) was calculated.

RESULTS

Total testosterone, ADTG and androstendione levels did not differ between non-obese (body mass index (BMI) ≤25 kg/m²) and obese PCOS (BMI >25 kg/m²) but all were significantly higher than for controls (p < 0.01). The ADTG to DHEAS ratio was significantly elevated 39 ± 6 (p < 0.01) in obese PCOS in comparison to non-obese PCOS and controls (28 ± 5 and 29 ± 4, respectively). The free androgen index (FAI) and insulin resistance (HOMA-IR) were significantly higher in obese PCOS compared to non-obese PCOS and controls (p < 0.01). DHEAS was significantly higher in the non-obese versus obese PCOS (p < 0.01). All androgen parameters were significantly lower and sex hormone binding globulin (SHBG) significantly higher in normal subjects compared to those with obese and non-obese PCOS.

CONCLUSIONS

The ADTG:DHEAS ratio was significantly elevated in obese PCOS compared to non-obese PCOS and controls suggesting that this may be a novel biomarker discriminatory for obese PCOS subjects, perhaps being driven by higher hepatic 5α reductase activity increasing ADTG formation in these women.

Fructose, Glucocorticoids and Adipose Tissue: Implications for the Metabolic Syndrome

The modern Western society lifestyle is characterized by a hyperenergetic, high sugar containing food intake. Sugar intake increased dramatically during the last few decades, due to the excessive consumption of high-sugar drinks and high-fructose corn syrup. Current evidence suggests that high fructose intake when combined with overeating and adiposity promotes adverse metabolic health effects including dyslipidemia, insulin resistance, type II diabetes, and inflammation. Similarly, elevated glucocorticoid levels, especially the enhanced generation of active glucocorticoids in the adipose tissue due to increased 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) activity, have been associated with metabolic diseases. Moreover, recent evidence suggests that fructose stimulates the 11β-HSD1-mediated glucocorticoid activation by enhancing the availability of its cofactor NADPH. In adipocytes, fructose was found to stimulate 11β-HSD1 expression and activity, thereby promoting the adipogenic effects of glucocorticoids. This article aims to highlight the interconnections between overwhelmed fructose metabolism, intracellular glucocorticoid activation in adipose tissue, and their metabolic effects on the progression of the metabolic syndrome.

Fructose increases corticosterone production in association with NADPH metabolism alterations in rat epididymal white adipose tissue

Metabolic syndrome is an array of closely metabolic disorders that includes glucose intolerance/insulin resistance, central obesity, dyslipidemia, and hypertension. Fructose, a highly lipogenic sugar, has profound metabolic effects in adipose tissue, and has been associated with the etiopathology of many components of the metabolic syndrome. In adipocytes, the enzyme 11 β-HSD1 amplifies local glucocorticoid production, being a key player in the pathogenesis of central obesity and metabolic syndrome. 11 β-HSD1 reductase activity is dependent on NADPH, a cofactor generated by H6PD inside the endoplasmic reticulum. Our focus was to explore the effect of fructose overload on epididymal white adipose tissue (EWAT) machinery involved in glucocorticoid production and NADPH and oxidants metabolism. Male Sprague-Dawley rats fed with a fructose solution (10% (w/v) in tap water) during 9 weeks developed some characteristic features of metabolic syndrome, such as hypertriglyceridemia, and hypertension. In addition, high levels of plasma and EWAT corticosterone were detected. Activities and expressions of H6PD and 11 β-HSD1, NAPDH content, superoxide anion production, expression of NADPH oxidase 2 subunits, and indicators of oxidative metabolism were measured. Fructose overloaded rats showed an increased potential in oxidant production respect to control rats. In parallel, in EWAT from fructose overloaded rats we found higher expression/activity of H6PD and 11 β-HSD1, and NADPH/NADP⁺ ratio. Our in vivo results support that fructose overload installs in EWAT conditions favoring glucocorticoid production through higher H6PD expression/activity supplying NADPH for enhanced 11 β-HSD1 expression/activity, becoming this tissue a potential extra-adrenal source of corticosterone under these experimental conditions.

5α-reductase activity in women with polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

5α-reductase activity might be important during the development of polycystic ovary syndrome (PCOS). However, the changes of 5α-reductase activity in PCOS subjects and the relationship between 5α-reductase activity and body mass index (BMI), insulin resistance (IR) remain largely unknown.

METHODS

We performed a meta-analysis to examine 5α-reductase activity in women with PCOS; exploratory subgroup analyses were also performed.

RESULTS

Five articles (with 356 cases and 236 controls) reporting 5α-reductase activity in patients with PCOS were selected for the meta-analysis. We observed significantly higher ratios of 5αTHF/THF (5α-reduced tetrahydrocortisol to 5β-reduced tetrahydrocortisol) and An/Et (androsteroneto/etiocholanolone) levels, which were used to assess 5α-reductase activity, among the patients with PCOS, [standardized mean differences (SMD) =0.43, 95%confidence intervals (95%CI) =0.25-0.61, P < 0.00001; SMD = 0.86, 95% CI = 0.29-1.44, P = 0.003]. We observed significant heterogeneity between studies for An/Et (I² = 89% and P < 0.00001). According to the group analysis, women with PCOS exhibited increased 5α-reductase activity which was significantly associated with homeostasis model assessment of insulin resistance (HOMA-IR) regardless of obesity.

CONCLUSIONS

5α-reductase activity was enhanced in women with PCOS. Increased 5α-reductase activity in patients with PCOS was related to IR.

Cortisol metabolism, postnatal depression and weight changes in the first 12 months postpartum

BACKGROUND & OBJECTIVES

Postnatal depression correlates with postpartum weight retention, and dysregulated cortisol metabolism is evident in depressed individuals. Cortisol metabolism, BMI and metabolic phenotype are robustly associated, but the role of cortisol metabolism in postnatal mental health and weight loss has never been examined.

DESIGN

A longitudinal observation.

PATIENTS

Forty nine healthy women with uncomplicated pregnancy.

MEASUREMENTS

BMI and urinary steroid metabolites at 1 week and 1, 3, 6 and 12 months postpartum. Validated urinary steroid metabolite ratios were measured to determine the activities of 11β-hydroxysteroid dehydrogenases (11β-HSD) that interconvert inactive cortisone and active cortisol and the 5α-reductases that clear cortisol to its inactive metabolites. Postnatal depression symptoms were measured at 1, 6 and 12 months.

RESULTS

Low 5α-reductase activity was associated with greater weight loss across the first year, independent of demographics, breastfeeding and depression. Postpartum BMI change was unrelated to postnatal depression at any time. Symptoms of postnatal depression were related to higher cortisol metabolite production at 12 months, independent of demographics and breastfeeding.

CONCLUSIONS

Greatest weight loss in the postpartum year was associated with lower conversion of cortisone to cortisol and lower conversion of cortisol to its metabolites, supporting previous work that demonstrates the facilitative role of lower 5α-reductase and 11β-HSD-1 in weight loss. Greater depression symptoms were associated with higher cortisol metabolite production rates. Whilst weight and mental health are both associated with dysregulation of the HPA axis, there may be different pathways towards depressed and obese phenotypes in healthy postpartum samples.

Influence of sub-chronic selective 11β-hydroxysteroid dehydrogenase 1 inhibition on the hypothalamic-pituitary-adrenal axis in female cynomolgus monkeys

Inhibition of local cortisol regeneration from circulating cortisone by blocking 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) has been shown to ameliorate the risk factors associated with the metabolic syndrome. Chronic modulation of glucocorticoid homeostasis may result in hypothalamic-pituitary-adrenal (HPA) axis stimulation. HPA axis over-activation leading androgen excess would be undesirable in a therapeutic intervention designed to treat a chronic condition such as the metabolic syndrome. To address whether 11β-HSD1 inhibition would lead to excess androgens, we treated female cynomolgus monkeys with a selective inhibitor, BI 135558, for 4 weeks. Continual action of the compound over the dosing period was confirmed by constant plasma exposure, and a maintained change in urinary glucocorticoid metabolites consistent with 11β-HSD1 inhibition. No significant changes in adrenal function, as evidenced by an adrenocorticotropic hormone (ATCH) challenge, were observed. An examination of androgenic hormones revealed a slight increase in dehydroepiandrosterone sulfate (DHEA-S), while other hormones such as testosterone remained within reference values. Overall, treatment with BI 135558 in monkeys did not result in obvious over-activation of the HPA axis.

Equine metabolic syndrome

Laminitis is one of the most common and frustrating clinical presentations in equine practice. While the principles of treatment for laminitis have not changed for several decades, there have been some important paradigm shifts in our understanding of laminitis. Most importantly, it is essential to consider laminitis as a clinical sign of disease and not as a disease in its own right. Once this shift in thinking has occurred, it is logical to then question what disease caused the laminitis. More than 90 per cent of horses presented with laminitis as their primary clinical sign will have developed it as a consequence of endocrine disease; most commonly equine metabolic syndrome (EMS). Given the fact that many horses will have painful protracted and/or chronic recurrent disease, a good understanding of the predisposing factors and how to diagnose and manage them is crucial. Current evidence suggests that early diagnosis and effective management of EMS should be a key aim for practising veterinary surgeons to prevent the devastating consequences of laminitis. This review will focus on EMS, its diagnosis and management.

Dual-5α-Reductase Inhibition Promotes Hepatic Lipid Accumulation in Man

CONTEXT

5α-Reductase 1 and 2 (SRD5A1, SRD5A2) inactivate cortisol to 5α-dihydrocortisol in addition to their role in the generation of DHT. Dutasteride (dual SRD5A1 and SRD5A2 inhibitor) and finasteride (selective SRD5A2 inhibitor) are commonly prescribed, but their potential metabolic effects have only recently been identified.

OBJECTIVE

Our objective was to provide a detailed assessment of the metabolic effects of SRD5A inhibition and in particular the impact on hepatic lipid metabolism.

DESIGN

We conducted a randomized study in 12 healthy male volunteers with detailed metabolic phenotyping performed before and after a 3-week treatment with finasteride (5 mg od) or dutasteride (0.5 mg od). Hepatic magnetic resonance spectroscopy (MRS) and two-step hyperinsulinemic euglycemic clamps incorporating stable isotopes with concomitant adipose tissue microdialysis were used to evaluate carbohydrate and lipid flux. Analysis of the serum metabolome was performed using ultra-HPLC-mass spectrometry.

SETTING

The study was performed in the Wellcome Trust Clinical Research Facility, Queen Elizabeth Hospital, Birmingham, United Kingdom.

MAIN OUTCOME MEASURE

Incorporation of hepatic lipid was measured with MRS.

RESULTS

Dutasteride, not finasteride, increased hepatic insulin resistance. Intrahepatic lipid increased on MRS after dutasteride treatment and was associated with increased rates of de novo lipogenesis. Adipose tissue lipid mobilization was decreased by dutasteride. Analysis of the serum metabolome demonstrated that in the fasted state, dutasteride had a significant effect on lipid metabolism.

CONCLUSIONS

Dual-SRD5A inhibition with dutasteride is associated with increased intrahepatic lipid accumulation.

Glucocorticoids and non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the global obesity and metabolic disease epidemic and is rapidly becoming the leading cause of liver cirrhosis and indication for liver transplantation worldwide. The hallmark pathological finding in NAFLD is excess lipid accumulation within hepatocytes, but it is a spectrum of disease ranging from benign hepatic steatosis to steatohepatitis through to fibrosis, cirrhosis and risk of hepatocellular carcinoma. The exact pathophysiology remains unclear with a multi-hit hypothesis generally accepted as being required for inflammation and fibrosis to develop after initial steatosis. Glucocorticoids have been implicated in the pathogenesis of NAFLD across all stages. They have a diverse array of metabolic functions that have the potential to drive NAFLD acting on both liver and adipose tissue. In the fasting state, they are able to mobilize lipid, increasing fatty acid delivery and in the fed state can promote lipid accumulation. Their action is controlled at multiple levels and in this review will outline the evidence base for the role of GCs in the pathogenesis of NAFLD from cell systems, rodent models and clinical studies and describe interventional strategies that have been employed to modulate glucocorticoid action as a potential therapeutic strategy.

Adverse effects of 5α-reductase inhibitors: What do we know, don't know, and need to know?

Steroids are important physiological orchestrators of endocrine as well as peripheral and central nervous system functions. One of the key processes for regulation of these molecules lies in their enzymatic processing by a family of 5α-reductase (5α-Rs) isozymes. By catalyzing a key rate-limiting step in steroidogenesis, this family of enzymes exerts a crucial role not only in the physiological control but also in pathological events. Indeed, both 5α-R inhibition and supplementation of 5α-reduced metabolites are currently used or have been proposed as therapeutic strategies for a wide array of pathological conditions. In particular, the potent 5α-R inhibitors finasteride and dutasteride are used in the treatments of benign prostatic hyperplasia (BPH), as well as in male pattern hair loss (MPHL) known as androgenetic alopecia (AGA). Recent preclinical and clinical findings indicate that 5α-R inhibitors evoke not only beneficial, but also adverse effects. Future studies should investigate the biochemical and physiological mechanisms that underlie the persistence of the adverse sexual side effects to determine why a subset of patients is afflicted with such persistence or irreversible adverse effects. Also a better focus of clinical research is urgently needed to better define those subjects who are likely to be adversely affected by such agents. Furthermore, research on the non-sexual adverse effects such as diabetes, psychosis, depression, and cognitive function are needed to better understand the broad spectrum of the effects these drugs may elicit during their use in treatment of AGA or BPH. In this review, we will summarize the state of art on this topic, overview the key unresolved questions that have emerged on the pharmacological targeting of these enzymes and their products, and highlight the need for further studies to ascertain the severity and duration of the adverse effects of 5α-R inhibitors, as well as their biological underpinnings.

5α-Reductase Type 2 Regulates Glucocorticoid Action and Metabolic Phenotype in Human Hepatocytes

Glucocorticoids and androgens have both been implicated in the pathogenesis of nonalcoholic fatty liver disease (NAFLD); androgen deficiency in males, androgen excess in females, and glucocorticoid excess in both sexes are associated with NAFLD. Glucocorticoid and androgen action are regulated at a prereceptor level by the enzyme 5α-reductase type 2 (SRD5A2), which inactivates glucocorticoids to their dihydrometabolites and converts T to DHT. We have therefore explored the role of androgens and glucocorticoids and their metabolism by SRD5A2 upon lipid homeostasis in human hepatocytes. In both primary human hepatocytes and human hepatoma cell lines, glucocorticoids decreased de novo lipogenesis in a dose-dependent manner. Whereas androgen treatment (T and DHT) increased lipogenesis in cell lines and in primary cultures of human hepatocytes from female donors, it was without effect in primary hepatocyte cultures from men. SRD5A2 overexpression reduced the effects of cortisol to suppress lipogenesis and this effect was lost following transfection with an inactive mutant construct. Conversely, pharmacological inhibition using the 5α-reductase inhibitors finasteride and dutasteride augmented cortisol action. We have demonstrated that manipulation of SRD5A2 activity can regulate lipogenesis in human hepatocytes in vitro. This may have significant clinical implications for those patients prescribed 5α-reductase inhibitors, in particular augmenting the actions of glucocorticoids to modulate hepatic lipid flux.