Glucocorticoid Excess Increases Hepatic 11β-HSD-1 Activity in Humans: Implications in Steroid-Induced Diabetes

Assessment of steroid enzymes action in children and adolescents with obesity

Rising prevalence of obesity has become an important impulse to investigate basic mechanisms involved in regulating the energy balance. It is widely accepted that steroids are potent factors affecting glucose, fat, and protein metabolism. Our study was aimed to analyze differences in the total amount of selected enzymes implicated in steroid metabolism in a group of children suffering from obesity and those with normal weight, further subdivided according to sex and pubertal stage. Data were obtained from 187 Caucasian children and adolescents, including 113 patients (63 girls, 50 boys) with obesity and 74 (34 girls, 40 boys) normal weight volunteers. Standard clinical examinations were performed in both groups. To evaluate the impact of puberty, preadolescent children and those with advanced puberty were assessed separately. Urine steroid excretion profiles were analyzed using gas chromatography/mass spectrometry method. Children with obesity revealed several changes in in the total amount of steroid enzymes as assessed by the relevant metabolite proportions, compared to their norm weight peers. Girls showed a significant increase in the activity of 11βHSD1, while boys demonstrated a relevant elevation in 20αHSD action. Regardless of sex, children with obesity showed an increase in the activity of 5β-reductase + 3αHSD complex and a decrease in the involvement of 11βOH-lase. The effect is attenuated when consider pre- and pubertal subgroups. We hypothesize that changes in the activity levels of selected enzymes may be a compensatory mechanism to limit the glucocorticoid exposure of key target tissues as well as to improve metabolic control and reduce long-term complications of obesity.

Glucose and lipid metabolism abnormalities in Cushing's syndrome

Prolonged excess of glucocorticoids (GCs) has adverse systemic effects leading to significant morbidities and an increase in mortality. Metabolic alterations associated with the high level of the GCs are key risk factors for the poor outcome. These include GCs causing excess gluconeogenesis via upregulation of key enzymes in the liver, a reduction of insulin sensitivity in skeletal muscle, liver and adipose tissue by inhibiting the insulin receptor signalling pathway, and inhibition of insulin secretion in beta cells leading to dysregulated glucose metabolism. In addition, chronic GC exposure leads to an increase in visceral adipose tissue, as well as an increase in lipolysis resulting in higher circulating free fatty acid levels and in ectopic fat deposition. Remission of hypercortisolism improves these metabolic changes, but very often does not result in full resolution of the abnormalities. Therefore, long-term monitoring of metabolic variables is needed even after the resolution of the excess GC levels.

Medications and medical costs for diabetes patients with or without chronic respiratory disease in Beijing, China: A retrospective study

AIMS

The cost of drug regimens prescribed to Chinese patients has not been evaluated. This study aims to evaluate the medical costs and hypoglycemic agents for diabetes mellitus patients with or without chronic respiratory disease in Beijing, and to investigate the changes in the costs and number of antidiabetic medications used for diabetes patients with chronic respiratory disease from 2016 to 2018.

METHODS

This observational, retrospective study included diabetes patients with outpatient medication records from Beijing Medical Insurance between 2016 and 2018. The medications, including hypoglycemic and nonhypoglycemic drugs, insulin dosage, comorbidities, diabetes-related complications, treatment strategies, and annual medical costs, were recorded.

RESULTS

This study included 2,853,036 diabetes patients from 2016 to 2018. About 18.95%-20.53% of patients with chronic respiratory disease were predominantly distributed among those aged 45-84 years (88.7%-89.1%). Diabetes patients with chronic respiratory disease used more medications (4.48 ± 2.41 vs. 3.76 ± 2.33) and had higher total annual drug costs (¥12,286 ± 10,385 vs. ¥9700 ± 9202) to treat more comorbidities (2.52 ± 1.53 vs. 2.05 ± 1.85) than those without chronic respiratory disease (p <.0001, respectively). From 2016 to 2018, diabetes patients with chronic respiratory disease had a 4.2% increase in medication, a 1.9% decrease in comorbidities, and a 5.4% decrease in total annual drug costs.

CONCLUSIONS

In summary, diabetes patients with chronic respiratory disease had more comorbidities, required more hypoglycemic drugs, and had higher medical costs. During 2016-2018, diabetes patients with chronic respiratory disease used more medications and spent less money on medical care.

Long-term adjustment of hepatic lipid metabolism after chronic stress and the role of FGF21

Chronic stress leads to post-traumatic stress disorder (PTSD) and metabolic disorders including fatty liver. We hypothesized that stress-induced molecular mechanisms alter energy metabolism, thereby promoting hepatic lipid accumulation even after a stress-free recovery period. In this context, we investigated fibroblast growth factor-21 (FGF21) as protective for energy and glucose homeostasis. FGF21 knockout mice (B6.129S6(SJL)-Fgf21tm1.2Djm; FGF21KO) and control mice (C57BL6; WT) were subjected to chronic variable stress. Mice were examined directly after acute intervention (Cvs) and long-term after 3 months of recovery (3mCvs). In WT, Cvs reduced insulin sensitivity and hepatic lipid accumulation, whilst fatty acid uptake increased. FGF21KO mice responded to Cvs with improved glucose tolerance, insulin resistance but liver triglycerides and plasma lipids were unaltered. Hepatic gene expression was specifically altered by genotype and stress e.g. by PPARa and SREBP-1 regulated genes. The stress-induced alteration of hepatic metabolism persisted after stress recovery. In hepatocytes at 3mCvs, differential gene regulation and secreted proteins indicated a genotype specific progression of liver dysfunction. Overall, at 3mCvs FGF21 was involved in maintaining mitochondrial activity, attenuating de novo lipogenesis, increased fatty acid uptake and histone acetyltransferase activity. Glucocorticoid release and binding to the FGF21 promoter may contribute to prolonged FGF21 release and protection against hepatic lipid accumulation. In conclusion, we showed that stress favors fatty liver disease and FGF21 protected against hepatic lipid accumulation after previous chronic stress loading by i) restored physiological function, ii) modulated gene expression via DNA-modifying enzymes, and iii) maintained energy metabolism.

The Role of Very Low Calorie Ketogenic Diet in Sympathetic Activation through Cortisol Secretion in Male Obese Population

Adipose tissue is considered an endocrine organ, and its excess compromises the immune response and metabolism of hormones and nutrients. Furthermore, the accumulation of visceral fat helps to increase the synthesis of cortisol. The hypothalamus-pituitary-adrenal (HPA) axis is a neuroendocrine system involved in maintaining homeostasis in humans under physiological conditions and stress, and cortisol is the main hormone of the HPA axis. It is known that a stress-induced diet and cortisol reactivity to acute stress factors may be related to dietary behavior. In obesity, to reduce visceral adipose tissue, caloric restriction is a valid strategy. In light of this fact, the aim of this study was to assess the effects of a commercial dietary ketosis program for weight loss on the sympathetic nervous system and HPA axis, through evaluation of salivary cortisol and GSR levels. Thirty obese subjects were recruited and assessed before and after 8 weeks of Very Low Calorie Ketogenic Diet (VLCKD) intervention to evaluate body composition and biochemical parameters. Salivary cortisol levels and GSR significantly decreased after dietary treatment; in addition, body composition and biochemical features were ameliorated. The VLCKD had a short-term positive effect on the SNS and HPA axes regulating salivary cortisol levels. Finally, the effects of the VLCKD on the SNS and HPA axis may lead to more individualized treatment strategies that integrate obesity and stress and support the usefulness of such therapeutic interventions in promoting the reduction of the individual disease burden.

Drugs Affecting Body Weight, Body Fat Distribution, and Metabolic Function-Mechanisms and Possible Therapeutic or Preventive Measures: an Update

PURPOSE OF REVIEW

Weight gain and body fat redistribution are common side effects of many widely used drugs. We summarize recent literature on prevalence data and mechanisms associated with drug-induced body fat changes and mechanisms to prevent or treat metabolic side effects.

RECENT FINDINGS

The highest prevalence of metabolic complications is seen with antipsychotics and antiretroviral drugs used in the treatment of HIV and may, at least partly, be responsible for the increased risk for co-morbid diseases such as diabetes, steatosis of the liver, and cardiovascular disease. The pathogenetic mechanisms leading to weight gain from antipsychotics are increasingly known and help to unravel the complex interaction that exists between psychopathology and metabolic complications. Although the classic lipodystrophy mainly occurred with older HIV drugs, also with the newer HIV treatment, weight gain seems to be a major side effect. Early detection of the metabolic consequences of drugs can lead to an early diagnosis of the complications and their treatment. Different medications, including the newer antidiabetics, are being studied in the therapy of drug-induced obesity. Future research should focus on identifying individuals at risk for metabolic side effects and on early markers to identify individuals with side effects so that timely treatment of metabolic complications can be initiated.

Glucose metabolism in Cushing's syndrome

PURPOSE OF REVIEW

Impairment of glucose metabolism is commonly encountered in Cushing's syndrome. It is the source of significant morbidity and mortality even after successful treatment of Cushing's. This review is to understand the recent advances in understanding the pathophysiology of diabetes mellitus from excess cortisol.

RECENT FINDINGS

In-vitro studies have led to significant advancement in understanding the molecular effects of cortisol on glucose metabolism. Some of these findings have been translated with human data. There is marked reduction in insulin action and glucose disposal with a concomitant, insufficient increase in insulin secretion. Cortisol has a varied effect on adipose tissue, with increased lipolysis in subcutaneous adipose tissue in the extremities, and increased lipogenesis in visceral and subcutaneous truncal adipose tissue.

SUMMARY

Cushing's syndrome results in marked impairment in insulin action and glucose disposal resulting in hyperglycemia. Further studies are required to understand the effect on incretin secretion and action, gastric emptying, and its varied effect on adipose tissue.

Glucocorticoids regulate AKR1D1 activity in human liver in vitro and in vivo

Steroid 5β-reductase (AKR1D1) is highly expressed in human liver where it inactivates endogenous glucocorticoids and catalyses an important step in bile acid synthesis. Endogenous and synthetic glucocorticoids are potent regulators of metabolic phenotype and play a crucial role in hepatic glucose metabolism. However, the potential of synthetic glucocorticoids to be metabolised by AKR1D1 as well as to regulate its expression and activity has not been investigated. The impact of glucocorticoids on AKR1D1 activity was assessed in human liver HepG2 and Huh7 cells; AKR1D1 expression was assessed by qPCR and Western blotting. Genetic manipulation of AKR1D1 expression was conducted in HepG2 and Huh7 cells and metabolic assessments were made using qPCR. Urinary steroid metabolite profiling in healthy volunteers was performed pre- and post-dexamethasone treatment, using gas chromatography-mass spectrometry. AKR1D1 metabolised endogenous cortisol, but cleared prednisolone and dexamethasone less efficiently. In vitro and in vivo, dexamethasone decreased AKR1D1 expression and activity, further limiting glucocorticoid clearance and augmenting action. Dexamethasone enhanced gluconeogenic and glycogen synthesis gene expression in liver cell models and these changes were mirrored by genetic knockdown of AKR1D1 expression. The effects of AKR1D1 knockdown were mediated through multiple nuclear hormone receptors, including the glucocorticoid, pregnane X and farnesoid X receptors. Glucocorticoids down-regulate AKR1D1 expression and activity and thereby reduce glucocorticoid clearance. In addition, AKR1D1 down-regulation alters the activation of multiple nuclear hormone receptors to drive changes in gluconeogenic and glycogen synthesis gene expression profiles, which may exacerbate the adverse impact of exogenous glucocorticoids.

Dose threshold for radiation induced fetal programming in a mouse model at 4 months of age: Hepatic expression of genes and proteins involved in glucose metabolism and glucose uptake in brown adipose tissue

Exposure to ionizing radiation contributing to negative health outcomes is a widespread concern. However, the impact of low dose and sub-lethal dose radiation (SLDR) exposures remain contentious, particularly in pregnant women who represent a vulnerable group. The fetal programming hypothesis states that an adverse in utero environment or stress during development of an embryo or fetus can result in permanent physiologic changes often resulting in progressive metabolic dysfunction with age. To assess changes in gene expression profiles of glucose/insulin signaling and lipid metabolism caused by radiation exposure in utero, pregnant C57Bl/6J mice were irradiated using a dose response ranging from low dose to SLDR and compared to a Sham-irradiated group. mRNA expression analysis in 16 week old offspring (n = 84) revealed that genes involved in metabolic function including glucose metabolism, insulin signaling and lipid metabolism were unaffected by prenatal radiation exposures up to 300 mGy. However, female offspring of dams exposed to 1000 mGy had upregulated expression of genes contributing to insulin resistance and gluconeogenesis. In a second cohort of mice, the effects of SLDR on fetal programming of hepatic SOCS3 and PEPCK protein expression were assessed. 4 month old female offspring of dams irradiated at 1000 mGy had: 1) increased liver weights, 2) increased hepatic expression of proteins involved in glucose metabolism and 3) increased ¹⁸F-fluorodeoxyglucose (FDG) uptake in interscapular brown adipose tissue (IBAT) measured by positron emission tomography (PET) (n = 25). The results of this study indicate that prenatal radiation exposure does not affect metabolic function up to 300 mGy and 1000 mGy may be a threshold dose for sex-specific alterations in glucose uptake and hepatic gene and protein expression of SOCS3, PEPCK, PPARGC1A and PPARGC1B. These findings suggest that SLDR doses alter glucose uptake in IBAT and hepatic gene and protein expression of offspring and these changes may progress with age.

Alterations of Cortisol Metabolism in Human Disorders

The interconversion of active and inactive corticosteroids - cortisol and cortisone, respectively, in humans - is modulated by isozymes of 11β-hydroxysteroid dehydrogenase (11-HSD). Studies of this process have provided crucial insights into glucocorticoid effects in a wide variety of tissues. The 11-HSD1 isozyme functions mainly as an oxoreductase (cortisone to cortisol) and is expressed at high levels in the liver and other glucocorticoid target tissues. Because it is required for full physiological effects of cortisol, it has emerged as a drug target for metabolic syndrome and type 2 diabetes. Mutations in the corresponding HSD11B1 gene, or in the H6PD gene encoding hexose-6-phosphate dehydrogenase (which supplies the NADPH required for the oxoreductase activity of 11-HSD1), cause apparent cortisone reductase deficiency, a rare syndrome of adrenocortical hyperactivity and hyperandrogenism. In contrast, the 11-HSD2 isozyme functions as a dehydrogenase (cortisol to cortisone) and is expressed mainly in mineralocorticoid target tissues, where it bars access of cortisol to the mineralocorticoid receptor. Mutations in the HSD11B2 gene encoding 11-HSD2 cause the syndrome of apparent mineralocorticoid excess, a severe form of familial hypertension. The role of this enzyme in the pathogenesis of common forms of low-renin hypertension remains uncertain.

Local Cortisol Elevation Contributes to Endometrial Insulin Resistance in Polycystic Ovary Syndrome

CONTEXT

Endometrial insulin resistance (IR) may account for the endometrial dysfunction in polycystic ovary syndrome (PCOS). The underlying mechanism remains to be elucidated.

OBJECTIVE

To investigate whether the abundance of 11β-hydroxysteroid dehydrogenases (11β-HSDs) 1 and 2 and cortisol as well as the insulin signaling pathway are altered in PCOS endometrium and to clarify the relationship between endometrial IR and local cortisol.

DESIGN

We measured cortisol and cortisone concentrations, 11β-HSD1 and 11β-HSD2, and core insulin signaling molecules in endometrial biopsies collected from non-PCOS and PCOS with or without IR patients on the seventh day after human chorionic gonadotropin injection. We also studied the effects of cortisol on glucose uptake and the insulin signaling pathway in primary cultured endometrial epithelial cells (EECs).

RESULTS

The cortisol concentration was elevated, whereas 11β-HSD2 expression was diminished in endometrial biopsies obtained from PCOS with IR patients compared with those from non-PCOS and PCOS without IR patients. The implantation rate was relatively impaired and the endometrial insulin signaling pathway was defective in PCOS with IR patients. In addition, cortisol attenuated insulin-stimulated glucose uptake in EECs, which was mediated by inhibition of Akt phosphorylation and glucose transporter type 4 translocation via induction of phosphatase and tensin homolog deleted on chromosome ten (PTEN).

CONCLUSIONS

Decreased oxidation of cortisol and defects of insulin signaling in endometrium were observed in PCOS with IR patients. The excessive cortisol level, derived from the reduction of 11β-HSD2, might contribute to the development of endometrial IR by inhibiting the insulin signaling pathway via induction of PTEN expression in EECs.

Stress and Obesity: Are There More Susceptible Individuals?

PURPOSE OF REVIEW

Stress has long been suspected to be interrelated to (abdominal) obesity. However, interindividual differences in this complex relationship exist. We suggest that the extent of glucocorticoid action partly explains these interindividual differences. We provide latest insights with respect to multiple types of stressors.

RECENT FINDINGS

Increased long-term cortisol levels, as measured in scalp hair, are strongly related to abdominal obesity and to specific mental disorders. However, not all obese patients have elevated cortisol levels. Possibly, the interindividual variation in glucocorticoid sensitivity, which is partly genetically determined, may lead to higher vulnerability to mental or physical stressors. Other evidence for the important role for increased glucocorticoid action is provided by recent studies investigating associations between body composition and local and systemic corticosteroids. Stress may play a major role in the development and maintenance of obesity in individuals who have an increased glucocorticoid exposure or sensitivity. These insights may lead to more effective and individualized obesity treatment strategies.

Drug-induced obesity and its metabolic consequences: a review with a focus on mechanisms and possible therapeutic options

Weight gain is a common side effect of many widely used drugs. Weight gain of a few kilograms to an increase of 10% or more of initial body weight has been described. Not only the weight gain as such puts a burden on the health risks of the involved patients, the accompanying increase in the incidence of the metabolic syndrome, type 2 diabetes mellitus, and cardiovascular risk factors urges the caregiver to identify and to closely monitor the patients at risk. In this review, the different classes of drugs with significant weight gaining properties and the metabolic consequences are described. Specific attention is given to pathogenetic mechanisms underlying the metabolic effects and to potential therapeutic measures to prevent them.

Glucose Metabolism Abnormalities in Cushing Syndrome: From Molecular Basis to Clinical Management

An impaired glucose metabolism, which often leads to the onset of diabetes mellitus (DM), is a common complication of chronic exposure to exogenous and endogenous glucocorticoid (GC) excess and plays an important part in contributing to morbidity and mortality in patients with Cushing syndrome (CS). This article reviews the pathogenesis, epidemiology, diagnosis, and management of changes in glucose metabolism associated with hypercortisolism, addressing both the pathophysiological aspects and the clinical and therapeutic implications. Chronic hypercortisolism may have pleiotropic effects on all major peripheral tissues governing glucose homeostasis. Adding further complexity, both genomic and nongenomic mechanisms are directly induced by GCs in a context-specific and cell-/organ-dependent manner. In this paper, the discussion focuses on established and potential pathologic molecular mechanisms that are induced by chronically excessive circulating levels of GCs and affect glucose homeostasis in various tissues. The management of patients with CS and DM includes treating their hyperglycemia and correcting their GC excess. The effects on glycemic control of various medical therapies for CS are reviewed in this paper. The association between DM and subclinical CS and the role of screening for CS in diabetic patients are also discussed.