Management of patients on chronic glucocorticoid therapy: an endocrine perspective

A systematic review of steroid use in peripheral nerve pathologies and treatment

Background

The use of corticosteroids has become a part of the standard of care in various pathologies but their use in peripheral nerve injury treatment is limited. Given corticosteroids' anti-inflammatory properties and their regulatory role in neuronal protein production and myelination, corticosteroids could serve as an adjunct therapy for peripheral nerve injuries. This review aims to systematically investigate the current use of corticosteroid treatment in peripheral nerve pathologies.

Methods

The systematic search was performed on PubMed, MEDLINE, EMBASE, Scopus, Cochrane, and Web of Science using keywords such as "corticosteroid treatment," "peripheral nerve damage," "peripheral neuropathy," and "complications." The PRISMA guidelines were used to conduct the systematic review and all articles were reviewed by the corresponding author. After the initial search, individual study titles and abstracts were further screened and categorized using an inclusion and exclusion criteria followed by a final full-text review.

Results

Out of the total 27,922 identified records, 203 studies were included based on the selection criteria. These studies focused on the use and efficacy of steroids across a spectrum of compression and non-compression peripheral neuropathies such as cubital tunnel syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. Various studies noted the promising role of steroids in offering pain relief, nerve block, and nerve regeneration effects. Additionally, safety considerations and potential complications regarding steroid use in peripheral nerve injuries were analyzed.

Conclusion

While there is currently limited clinical utilization of corticosteroids in peripheral nerve pathologies, the anti-inflammatory and regenerative effects that steroids provide may be a beneficial tool in managing various peripheral neuropathies and their associated pain. Additional clinical trials and investigation into the mechanism of action could improve the reputation of steroid use as peripheral nerve injury treatment.

Treating the Side Effects of Exogenous Glucocorticoids; Can We Separate the Good From the Bad?

It is estimated that 2% to 3% of the population are currently prescribed systemic or topical glucocorticoid treatment. The potent anti-inflammatory action of glucocorticoids to deliver therapeutic benefit is not in doubt. However, the side effects associated with their use, including central weight gain, hypertension, insulin resistance, type 2 diabetes (T2D), and osteoporosis, often collectively termed iatrogenic Cushing's syndrome, are associated with a significant health and economic burden. The precise cellular mechanisms underpinning the differential action of glucocorticoids to drive the desirable and undesirable effects are still not completely understood. Faced with the unmet clinical need to limit glucocorticoid-induced adverse effects alongside ensuring the preservation of anti-inflammatory actions, several strategies have been pursued. The coprescription of existing licensed drugs to treat incident adverse effects can be effective, but data examining the prevention of adverse effects are limited. Novel selective glucocorticoid receptor agonists and selective glucocorticoid receptor modulators have been designed that aim to specifically and selectively activate anti-inflammatory responses based upon their interaction with the glucocorticoid receptor. Several of these compounds are currently in clinical trials to evaluate their efficacy. More recently, strategies exploiting tissue-specific glucocorticoid metabolism through the isoforms of 11β-hydroxysteroid dehydrogenase has shown early potential, although data from clinical trials are limited. The aim of any treatment is to maximize benefit while minimizing risk, and within this review we define the adverse effect profile associated with glucocorticoid use and evaluate current and developing strategies that aim to limit side effects but preserve desirable therapeutic efficacy.

Basal-bolus insulin therapy for the treatment of non-critically ill patients with type 2 diabetes in Vietnam: effectiveness and factors associated with inpatient glycemic control

Purpose

This study assessed the effectiveness of basal-bolus insulin therapy (BBIT) in non-critically ill patients with type 2 diabetes mellitus (DM) and the factors associated with optimal inpatient glycemic control (IGC) with BBIT.

Methods

This prospective study included 103 patients who were admitted to the University Medical Center and were treated with BBIT. Clinical characteristics, glucose, and glycated hemoglobin (HbA1c) levels at admission, renal function tests, basal-bolus insulin dosing, and other treatments were recorded. The optimal IGC was defined and classified for the analysis.

Results

The mean age of the patients was 67.2 ± 12.0 years. The blood glucose and HbA1c levels at admission were 319.2 ± 184.8 mg/dL and 10.7 ± 2.6%, respectively. Optimal IGC was defined as patients with ≥60% of in-hospital blood glucose values within the target range (3.9–10 mmol/L). Of the 103 patients, 66 patients (64%) achieved optimal IGC and only 5 patients (4.9%) had at least one hypoglycemic episode. The number of patients consuming snacks was higher in the poor than in the optimal IGC group whereas an estimated glomerular filtration rate (eGFR) <45-mL/min/1.73 m2 was predominant in the optimal IGC group. Multivariate analysis revealed that snack consumption and glucocorticoid (GC) use were factors associated with poor IGC, while eGFR <45 mL/min/1.73 m2 was a favorable factor for optimal IGC.

Conclusion

BBIT is safe and effective for the treatment of IGC in non-critically ill patients. Moreover, eGFR <45 mL/min/1.73 m2 at admission, snack consumption, and GC therapy were independent factors associated with IGC outcomes.

Steroid-Induced Diabetic Ketoacidosis: A Case Report and Review of the Literature

It has been well documented that corticosteroid treatment can precipitate hyperglycemia and may lead to new diagnoses of type 2 diabetes mellitus. However, steroid-induced diabetic ketoacidosis (DKA) has rarely been reported in the literature. We report the case of an obese 73-year-old man with no known history of diabetes mellitus who presented with DKA after two months of treatment with high-dose steroids. Our patient’s presentation and clinical course were consistent with ketosis-prone type 2 diabetes (KPDM-2). A literature review revealed three other reports of patients with steroid-induced DKA, two of whom also had clinical and biochemical features that were consistent with KPDM-2. We postulate that high-dose steroid treatment can trigger DKA in a subgroup of obese, middle-aged patients with risk factors for KPDM-2. Physicians should suspect steroid-induced KPDM-2 in obese patients who present with new-onset DKA after initiation of steroid treatment.

A Practical Guide for the Management of Steroid Induced Hyperglycaemia in the Hospital

Glucocorticoids represent frequently recommended and often indispensable immunosuppressant and anti-inflammatory agents prescribed in various medical conditions. Despite their proven efficacy, glucocorticoids bear a wide variety of side effects among which steroid induced hyperglycaemia (SIHG) is among the most important ones. SIHG, potentially causes new-onset hyperglycaemia or exacerbation of glucose control in patients with previously known diabetes. Retrospective data showed that similar to general hyperglycaemia in diabetes, SIHG in the hospital and in outpatient settings detrimentally impacts patient outcomes, including mortality. However, recommendations for treatment targets and guidelines for in-hospital as well as outpatient therapeutic management are lacking, partially due to missing evidence from clinical studies. Still, SIHG caused by various types of glucocorticoids is a common challenge in daily routine and clinical guidance is needed. In this review, we aimed to summarize clinical evidence of SIHG in inpatient care impacting clinical outcome, establishment of diagnosis, diagnostic procedures and therapeutic recommendations.

Diabetes and Cancer: Metabolic Association, Therapeutic Challenges, and the Role of Natural Products

Cancer is considered the second leading cause of death worldwide and in 2018 it was responsible for approximately 9.6 million deaths. Globally, about one in six deaths are caused by cancer. A strong correlation was found between diabetes mellitus and carcinogenesis with the most evident correlation was with type 2 diabetes mellitus (T2DM). Research has proven that elevated blood glucose levels take part in cell proliferation and cancer cell progression. However, limited studies were conducted to evaluate the efficiency of conventional therapies in diabetic cancer patients. In this review, the correlation between cancer and diabetes will be discussed and the mechanisms by which the two diseases interact with each other, as well as the therapeutics challenges in treating patients with diabetes and cancer with possible solutions to overcome these challenges. Natural products targeting both diseases were discussed with detailed mechanisms of action. This review will provide a solid base for researchers and physicians to test natural products as adjuvant alternative therapies to treat cancer in diabetic patients.

Steroid-Induced Diabetes Ketoacidosis in an Immune Thrombocytopenia Patient: A Case Report and Literature Review

Patient: Female, 53-year-old

Final Diagnosis: Diabetic KetoAcidosis (DKA)

Symptoms: Gum bleeding

Medication: Steroids

Clinical Procedure: —

Specialty: Metabolic Disorders and Diabetics

Patterns of Glucose Fluctuation are Challenging in Patients Treated for Non-Hodgkin's Lymphoma

Purpose

This cohort study aimed to determine patterns of glycemic fluctuation and changes in metabolic parameters during and after corticosteroid administration in newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients treated with R-CHOP chemotherapy.

Patients and Methods

The study was performed in 20 patients of whom 11 had diabetes and 9 were nondiabetics. Anthropometric parameters were collected, and blood samples were taken four times during the study to analyze metabolic parameters. Capillary glucose was measured seven times a day (fasting, before mean meals, postprandial, and before bedtime) to evaluate the glycemic profile.

Results

In all 20 patients, acute glucocorticoid administration resulted in the elevation of average glucose levels, dominantly postprandial in the afternoon which correlates with corticosteroid peak action. In 7 out of 11 diabetics, prandial insulin was started during corticosteroid administration and discontinued afterward. Although none of our nondiabetic patients met diabetes criteria, evident is the elevation in average glycemia levels six weeks after corticosteroid administration. Potentially, even transient corticosteroid administration reduces insulin sensitivity and contributes to later glycemic disturbances. HbA1c levels were higher at the end of the study while fructosamine levels were higher during the study.

Conclusion

Patients and health-care professionals need to be aware of corticosteroid-induced hyperglycemia. We recommend identifying risk factors, measuring glycemia before, during, and after corticosteroid administration, and starting the adequate therapy as soon as possible.

Pentoxifylline versus Steroid Therapy for Idiopathic Sudden Sensorineural Hearing Loss with Diabetes

OBJECTIVES

To compare the efficacy of pentoxifylline with that of conventional steroid therapy in diabetic patients with idiopathic sudden sensorineural hearing loss (ISSNHL) and to compare blood sugar levels during hospitalization.

MATERIALS AND METHODS

Medical charts were retrospectively reviewed for all diabetic patients admitted to one institution for ISSNHL between 2000 and 2015. We analyzed 298 cases; 50 patients received pulse steroid treatment (steroid group) and 248 received intravenous administration of pentoxifylline only (pentoxifylline group). Hearing change was evaluated by comparing the initial hearing tests with follow-up hearing tests for up to 3 months. Blood sugar levels were also compared between the 2 groups.

RESULTS

At 3 months post-treatment, the degree of hearing recovery was similar between the 2 groups. The pure-tone average was improved from baseline by 17.9±21.2 dB in the steroid group and 18.9±20.7 dB in the pentoxifylline group (p=0.776); hearing recovery rates were also similar (40% vs 39.1%; p=0.826). During hospitalization, average fasting blood sugar levels were higher (203.9±92.0 vs 174.4±54.8 mg/dL; p=0.033) and acute hyperglycemia was more common (48.0% vs 33.1%; p=0.044) with steroid versus pentoxifylline treatment.

CONCLUSION

Hearing recovery rates did not significantly differ between steroid and pentoxifylline treatment in diabetic patients with ISSNHL, but pentoxifylline appeared to be associated with better blood sugar control.

Long-term dexamethasone treatment diminishes store-operated Ca2+ entry in salivary acinar cells

Corticosteroids are used in the treatment of many diseases; however, they also induce various side effects. Dexamethasone is one of the most potent corticosteroids, and it has been reported to induce the side effect of impaired salivary gland function. This study aimed to evaluate the effects of dexamethasone on mouse submandibular gland function to gain insight into the mechanism of dexamethasone-induced salivary hypofunction. The muscarinic agonist carbachol (CCh) induced salivary secretion and was not affected by short-term dexamethasone treatment but was decreased following long-term dexamethasone administration. The expression levels of the membrane proteins Na⁺-K⁺-2Cl^- cotransporter, transmembrane member 16A, and aquaporin 5 were comparable between the control and long-term dexamethasone treatment groups. The CCh-induced increase in calcium concentration was significantly lower in the presence of extracellular Ca²⁺ in the long-term dexamethasone treatment group compared to that in the control group. Furthermore, CCh-induced salivation in the absence of extracellular Ca²⁺ and Ca²⁺ ionophore A23187-induced salivation was comparable between the control and long-term dexamethasone treatment groups. Moreover, salivation induced by the Ca²⁺-ATPase inhibitor thapsigargin was diminished in the long-term dexamethasone treatment group. In summary, these results demonstrate that short-term dexamethasone treatment did not impair salivary gland function, whereas long-term dexamethasone treatment diminished store-operated Ca²⁺ entry, resulting in hyposalivation in mouse submandibular glands.

Steroid-induced hyperglycemia: An underdiagnosed problem or clinical inertia? A narrative review

Corticosteroids are widely diffused drugs. An important side effect is the impairment of glycemic control both in patients with known diabetes and in normoglycemic ones potentially leading to steroid-induced diabetes mellitus (SIDM). In this review based on papers released on PubMed, MEDLINE, and EMBASE from January 2015 to October 2017, we summarized and discussed main updates about the definition, the diagnosis, and the pathophysiology of steroid-induced hyperglycemia (SIH), with a look to new therapies. Main alterations responsible for the diabetogenic effect of corticosteroids are a negative impact on insulin sensitivity along with a derangement on insulin secretion, explaining the typical post-prandial hyperglycemia linked to the promotion of gluconeogenesis. An early and precise diagnosis of SIH and/or SIDM is necessary, but current criteria do not seem sensible enough. As an afterthought, the treatment should be reasoned and tailored according to proposed glycemic thresholds and patient comorbidities, choosing between antidiabetic oral drugs and insulin, the latter being preferable among hospitalized patients. SIDM and SIH are frequent problems, but often underdiagnosed due to old diagnostic criteria. Dedicated guidelines universally shared are mandatory in order to harmonize the treatment of these conditions, thus overtaking single therapeutic strategies mostly arising from literature.

Use of parenteral glucocorticoids and the risk of new onset type 2 diabetes mellitus: A case-control study

BACKGROUND

Use of oral glucocorticoids (GCs) has been associated with hyperglycaemia and type 2 diabetes mellitus (T2DM). However, unlike oral GCs, there is minimal or no data on the effect of parenteral GC use on T2DM.

OBJECTIVE

To assess the association between use of parenteral GCs and the risk of receiving a first prescription of a non-insulin antidiabetic drug (NIAD) as a proxy for new onset of T2DM.

METHODS

A population based case-control study was performed using the Clinical Practice Research Datalink (CPRD). Cases (n = 177,154) were defined as patients >18 years of age who had their first ever NIAD prescription between January 1987 and October 2013. Controls were matched by age, gender and general practitioner practice. Conditional logistic regression analyses were used to estimate the risk of NIAD prescription and use of parenteral GCs. Our analyses were statistically adjusted for lifestyle factors, comorbidities and concomitant drug use.

RESULTS

Although this study confirmed that oral GCs increases the risk of receiving a first prescription of a NIAD (OR 2.63 [95% CI 2.53-2.73]), there was no association between the use of parenterally administered GCs and the risk of receiving a first prescription of a NIAD (OR 0.88 [95% CI 0.76-1.02]). The number of GC prescriptions was not associated with risk of new onset T2DM compared to no parenteral GCs use; neither the type of GC.

CONCLUSION

Our study does not demonstrate an association between the use of parenteral GCs and the risk of new onset of T2DM.

Steroid hyperglycemia: Prevalence, early detection and therapeutic recommendations: A narrative review

Steroids are drugs that have been used extensively in a variety of conditions. Although widely prescribed for their anti-inflammatory and immunosuppressive properties, glucocorticoids have several side effects, being hyperglycemia one of the most common and representative. In the present review, we discuss the main epidemiologic characteristics associated with steroid use, with emphasis on the identification of high risk populations. Additionally we present the pathophysiology of corticosteroid induced hyperglycemia as well as the pharmacokinetics and pharmacodynamics associated with steroid use. We propose a treatment strategy based on previous reports and the understanding of the mechanism of action of both, the different types of glucocorticoids and the treatment options, in both the ambulatory and the hospital setting. Finally, we present some of the recent scientific advances as well as some options for future use of glucocorticoids.

A comparison of inpatient glucose management guidelines: implications for patient safety and quality

Inpatient glucose management guidelines and consensus statements play an important role in helping to keep hospitalized patients with diabetes and hyperglycemia safe and in optimizing the quality of their glycemic control. In this review article, we compare and contrast seven prominent US guidelines on recommended glycemic outcome measures and processes of care, with the goal of highlighting how variation among them might influence patient safety and quality. The outcome measures of interest include definitions of glucose abnormalities and glycemic targets. The relevant process measures include detection and documentation of diabetes/hyperglycemia, methods of and indications for insulin therapy, management of non-insulin agents, blood glucose monitoring, management of special situations (e.g., parenteral/enteral nutrition, glucocorticoids, surgery, insulin pumps), and appropriate transitions of care. In addition, we address elements of quality improvement, such as glycemic control program infrastructure, glucometrics, insulin safety, and professional education. While most of these guidelines align with respect to outcome measures such as glycemic targets, there is significant heterogeneity among process measures, which we propose might introduce variation or even confusion in clinical practice and possibly affect quality of care. Guideline-related factors, such as rigor of development, clarity, and presentation, may also affect provider trust in and adherence to guidelines. There is a need for high-quality research to address knowledge gaps in optimal glucose management practice approaches in the hospital setting.

Glucocorticoid-induced hyperglycemia is prevalent and unpredictable for patients undergoing cancer therapy: an observational cohort study

BACKGROUND

Patients with cancer are often treated with glucocorticoids (gcs) as part of therapy, which may cause hyperglycemia. We sought to define the prevalence of, and risk factors for, hyperglycemia in this setting.

METHODS

Adult patients taking gc as part of therapy protocols for primary brain tumour or metastasis, for lymphoma, or for bone marrow transplant (bmt) were screened with random glucometer measurements taken at least 3 hours after the last dose gcs.

RESULTS

We screened 90 patients [44.4% women, 55.6% men; mean age: 59.6 years (range: 25-82 years); mean body mass index (bmi): 26.4 kg/m(2) (range: 15.8-45.3 kg/m(2))] receiving gc as part of cancer treatment. Mean total daily gc dose in the group was 238.5 mg (range: 30-1067 mg) hydrocortisone equivalents. Hyperglycemia (glucose ≥ 8.0 mmol/L) was found in 58.9% (53 of 90), and diabetes mellitus (dm)-range hyperglycemia (glucose ≥ 11.1 mmol/L) in 18.9% (17 of 90). The mean time from gc ingestion to glucometer testing was 5.5 hours (range: 3-20 hours). Presence of hyperglycemia did not correlate with traditional dm risk factors such as age, sex, bmi, and personal or family history of dm. A longer interval from gc dose to testing (p < 0.05), a higher gc dose (p = 0.04), and a shorter interval between the preceding meal and testing (p = 0.02) were risk factors for hyperglycemia in some patient groups.

CONCLUSIONS

Glucocorticoid-induced hyperglycemia is common in patients undergoing cancer treatment and cannot be predicted by traditional risk factors for dm. We recommend that all cancer patients receiving gc be screened for hyperglycemia at least 4-6 hours after gc administration.

Glucocorticoid-induced hyperglycemia

OBJECTIVES

Provide treatment guidelines for glucocorticoid-induced hyperglycemia and to understand the clinical implications of glucocorticoid-induced hyperglycemia.

METHODS

The authors analyzed an electronic search (Medline) and a literature review of the pertinent articles published from 1980 to September 2012.

RESULTS

In patients treated with glucocorticoids, the odds ratio for development of new-onset diabetes mellitus has been reported to be 1.36 to 2.31. The prevalence of abnormal glucose metabolism in post renal transplant patients taking glucocorticoids has been reported to be 17% to 32%. Sustained glucocorticoid treatment increases the potential for future cardiovascular disease through multiple pathways, resulting in a trade-off between benefit and harm. Complications related to glucocorticoid treatments are associated with the total glucocorticoid dose and duration of therapy. Other risk factors include age and body mass index. Understanding the pharmacodynamics and clinical implications of glucocorticoid-induced hyperglycemia can promote recognition and improvement of its treatment.

CONCLUSIONS

Glucocorticoid-induced hyperglycemia has significant clinical implications in patients with diabetes mellitus and without diabetes mellitus. Early recognition and proper proactive management of glucocorticoid-induced hyperglycemia should enhance care for patients receiving glucocorticoid treatment. Furthermore, treatment has been effective for both the inpatient and the outpatient settings.

Steroid-induced diabetes: is it just unmasking of type 2 diabetes?

Aims. We compared the demographic profile and clinical characteristics of individuals with new onset steroid-induced diabetes (NOSID) to Type 2 diabetes (T2DM) patients with and without steroid treatment. Methods. The demographic profile and clinical characteristics of 60 individuals who developed NOSID were examined and matched to 60 type 2 diabetes patients receiving steroid therapy (T2DM+S) and 360 diabetic patients not on steroids (T2DM) for age, duration of diabetes, HbA1c, gender, and ethnicity. Results. Patients who developed NOSID had less family history of diabetes (P ≤ 0.05) and were less overweight (P ≤ 0.02). NOSID was more commonly treated with insulin. Despite a matching duration of diabetes and glycaemic control, significantly less retinopathy was found in the group of patients with NOSID (P < 0.03). Conclusions. It appears that steroid treatment primarily precipitated diabetes in a group of individuals otherwise less affected by risk factors of diabetes at that point in time, rather than just opportunistically unmasking preexisting diabetes. Furthermore, the absence of retinopathy suggests that patients with NOSID had not been exposed to long periods of hyperglycaemia. However, the impact of the underlying conditions necessitating steroid treatment and concomitant medications such as immunosuppressants on diabetes development remain to be defined.

Risk of corticosteroid-induced hyperglycemia requiring medical therapy among patients with inflammatory eye diseases

OBJECTIVE

To identify the incidence and risk factors for corticosteroid-induced hyperglycemia requiring medical therapy among patients with inflammatory eye diseases.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients with ocular inflammation followed at 5 United States tertiary centers that initially were neither diabetic nor taking hypoglycemic medications.

METHODS

Eligible patients who used oral corticosteroids during follow-up were identified and followed longitudinally for initiation of hypoglycemic medication over 1 year after beginning corticosteroids. The remaining eligible patients were followed for 1 year after their initial visit. Survival analysis was used to calculate the risk of hyperglycemia requiring medical therapy and to identify potential risk factors.

MAIN OUTCOME MEASURES

Initiation of hypoglycemic medications.

RESULTS

Among 2073 non-diabetic patients treated with oral corticosteroids, 25 (1.21%) initiated hypoglycemic therapy compared with 5 of 2666 patients (0.19%) not treated with oral corticosteroids (relative risk [RR], 4.39; 95% confidence interval [CI], 1.68-11.5). The RR tended to be higher in association with higher initial doses (for initial doses <40 mg of prednisone per day: RR, 3.23; 95% CI, 1.08-9.64; for initial prednisone dose ≥40 mg/d: RR, 5.51; 95% CI, 2.01-15.1). Other risk factors for the initiation of hypoglycemic therapy included older age (RR [per each additional 10 years], 1.46; 95% CI, 1.15-1.85; P = 0.002) and African-American race (RR, 2.94; 95% CI, 1.34-6.43; P = 0.007).

CONCLUSIONS

These results suggest that the absolute risk of corticosteroid-induced hyperglycemia that is detected and treated with hypoglycemic therapy in the tertiary ocular inflammation setting is low (an excess cumulative risk on the order of 1% within 1 year), although on a relative scale it is approximately 4.4-fold higher than in patients not treated with oral corticosteroids. Older age and African-American race also were risk factors. Physicians who use systemic corticosteroids for ocular inflammatory diseases should be aware of this risk, and should consider surveillance for hyperglycemia among high-risk patients. However, given the low absolute risk, routine laboratory monitoring or referral for monitoring may not be necessary for low-risk patients.

The Clinical Center's blood glucose management service: a story in quality integrated care

PURPOSE

Blood glucose management in the inpatient setting has been shown to be crucial to patient outcomes. As the evidence develops to determine best clinical practices for achieving inpatient glycemic goals, the Clinical Center at the National Institutes of Health has implemented a streamlined multidisciplinary approach to managing blood glucose levels for hospitalized patients. The purpose of this article is to describe the blood glucose management service at the Clinical Center.

CONCLUSION

The blood glucose management service has established a consistent plan of care for diabetes management that has gained acceptance among staff and patients and improved safety and patient outcomes. This plan of care has been applied across various nursing units that serve patient populations on clinical research trials investigating common and rare diseases and treating patients from the United States and around the world.

Glucocorticoids differentially regulate the expression of CRFR1 and CRFR2α in MIN6 insulinoma cells and rodent islets

Urocortin 3 (Ucn 3), member of the corticotropin-releasing factor (CRF) family of peptide hormones, is released from β-cells to potentiate insulin secretion. Ucn 3 activates the CRF type-2 receptor (CRFR2) but does not activate the type-1 receptor (CRFR1), which was recently demonstrated on β-cells. While the direct actions of Ucn 3 on insulin secretion suggest the presence of cognate receptors within the islet microenvironment, this has not been established. Here we demonstrate that CRFR2α is expressed by MIN6 insulinoma cells and by primary mouse and human islets, with no detectable expression of CRFR2β. Furthermore, stimulation of MIN6 cells or primary mouse islets in vitro or in vivo with glucocorticoids (GCs) robustly and dose-dependently increases the expression of CRFR2α, while simultaneously inhibiting the expression of CRFR1 and incretin receptors. Luciferase reporters driven by the mouse CRFR1 or CRFR2α promoter in MIN6 cells confirm these differential effects of GCs. In contrast, GCs inhibit CRFR2α promoter activity in HEK293 cells and inhibit the expression of CRFR2β in A7r5 rat aortic smooth muscle cells and differentiated C2C12 myotubes. These findings suggest that the GC-mediated increase of CRFR2α depends on the cellular context of the islet and deviates from the GC-mediated suppression of CRFR1 and incretin receptors. Furthermore, GC-induced increases in CRFR2α expression coincide with increased Ucn 3-dependent activation of cAMP and MAPK pathways. We postulate that differential effect of GCs on the expression of CRFR1 and CRFR2α in the endocrine pancreas represent a mechanism to shift sensitivity from CRFR1 to CRFR2 ligands.

Glucocorticoid-induced hyperglycemia

OBJECTIVE

To review the current literature on glucocorticoid-induced hyperglycemia and provide a strategy for its treatment.

METHODS

We undertook an electronic (MEDLINE) and a library review of the existing pertinent literature published from 1950 to March 2009.

RESULTS

Glucocorticoid-induced hyperglycemia is common in patients with and without diabetes. The odds ratio for new-onset diabetes mellitus in patients treated with glucocorticoids ranges from approximately 1.5 to 2.5. Total glucocorticoid dose and duration of therapy are strong predictors of diabetes induction. Other risk factors include age and body mass index. Failure to treat glucocorticoid-induced hyperglycemia is related to the presumed short duration of administration of glucocorticoid treatment and the emphasis on fasting plasma glucose only. Understanding the pharmacodynamics of glucocorticoids can lead to increased recognition and improved treatment of the condition. Recent demonstrations that even shortterm elevations in blood glucose level may be associated with adverse sequelae argue for greater attention to the condition.

CONCLUSION

Glucocorticoid-induced hyperglycemia is an important clinical finding that, if recognized, can be effectively treated. We propose a relatively simple schema for the proactive management of corticosteroid-induced hyperglycemia that has been effective and easily adaptable to both the inpatient and the outpatient setting.

Exocrine pancreas trans-differentiation to hepatocytes--a physiological response to elevated glucocorticoid in vivo

Damage or ectopic expression of some growth factors can lead to the appearance of hepatocyte-like cells within the pancreas. Since glucocorticoids promote liver hepatocyte phenotype in vitro, the effect of glucocorticoid on pancreatic differentiation in vivo was examined. Treatment of rats with glucocorticoid for 25 days at levels that significantly inhibited weight gain resulted in the appearance of acinar cells expressing cytokeratin 7 and hepatocyte markers glutamine synthetase, carbamoyl phosphate synthetase and cytochrome P450 2E (the nomenclature employed is that given at http://drnelson.utmem.edu/CytochromeP450.html). Using a plastic pancreatic acinar cell line, this response was shown to be associated with changes in the regulation of WNT signalling-related gene expression and a repression of WNT signalling activity. These data suggest that a pathological response of the pancreas in vivo to elevated glucocorticoid is a differentiation of exocrine pancreatic cells or pancreatic progenitor cells to an hepatocyte-like phenotype.

Diabetes management in the hospital

Hyperglycemia is an increasingly common and often complex condition to manage in the inpatient setting. Numerous clinical trials have demonstrated associations between uncontrolled diabetes and poor clinical outcomes in a number of inpatient settings. Insulin remains the treatment of choice for the majority of hyperglycemic hospitalized patients and should be prescribed in a physiologic manner, employing basal and bolus insulin. Intravenous insulin should be used liberally in the ICU setting where randomized studies have demonstrated improved outcomes. Recommendations for insulin use in the inpatient setting are provided.

Immunosuppressive agents: effects on glucose and lipid metabolism

Immunosuppressive therapies are critical elements in successful organ transplantation. Although immunosuppressant drugs are essential in preventing graft rejection and graft maintenance after transplantation, their use is complicated by adverse effects, many being detrimental to graft and even patient long-term survival. Commonly used agents are associated with dysregulated glucose metabolism and dyslipidemia. This article focuses on the effects of immunosuppressive agents on glucose and lipid metabolism. Adrenal effects of these drugs, where known, also are discussed.

The Etiology of Steroid Cataract

Steroid-induced posterior subcapsular cataracts (PSCs) exhibit three main distinctive characteristics: (i) association only with steroids possessing glucocorticoid activity, (ii) involvement of aberrant migrating lens epithelial cells, and (iii) a central posterior location. The first characteristic suggests a key role for glucocorticoid receptor activation and subsequent changes to the transcription of specific genes. Glucocorticoid receptor activation is associated in many cell types with proliferation, suppressed differentiation, a reduced susceptibility to apoptosis, altered transmembrane transport, and enhancement of reactive oxygen species activity. Glucocorticoids may be capable of inducing changes to the transcription of genes in lens epithelial cells that are related to many of these cellular processes. This review examines the various mechanisms that have been proposed to account for the development of PSC in the context of recent DNA array studies. Additionally, given that the glucocorticoid receptor can also engender wide-ranging indirect activities, glucocorticoids could also indirectly affect the lens through the responses of other cells within the ocular compartment and/or through effects on cells at more remote locations. These indirect mechanisms, which, for example, could be mediated through alterations to the intraocular levels of growth factors that normally orchestrate lens development and maintain lens homeostasis, are also discussed. Although the mechanism of steroid cataract induction remains unknown, glucocorticoid-induced gene transcription events in lens epithelial cells, and also other intraocular or systemic cells, likely interact to generate steroid cataracts. Finally, although evidence for glucocorticoid-protein adduct formation in the lens is inconclusive, the generation of such adducts cannot yet be discounted as a contributing factor and must necessarily be retained in discussions of the etiology of steroid cataract.

Drug-Induced Endocrine and Metabolic Disorders

Complex interactions exist amongst the various components of the neuroendocrine system in order to maintain homeostasis, energy balance and reproductive function. These components include the hypothalamus-pituitary- adrenal and -gonadal axes, the renin-angiotensin-aldosterone system, the sympathetic nervous system and the pancreatic islets. These hormones, peptides and neurotransmitters act in concert to regulate the functions of many organs, notably the liver, muscles, kidneys, thyroid, bone, adrenal glands, adipocytes, vasculature, intestinal tract and gonads, through many intermediary pathways. Endocrine and metabolic disorders can arise from imbalance amongst numerous hormonal factors. These disturbances may be due to endogenous processes, such as increased secretion of hormones from a tumour, as well as exogenous drug administration. Drugs can cause endocrine abnormalities via different mechanisms, including direct alteration of hormone production, changes in the regulation of the hormonal axis, effects on hormonal transport, binding, and signalling, as well as similar changes to counter-regulatory hormone systems. Furthermore, drugs can affect the evaluation of endocrine parameters by causing interference with diagnostic tests. Common drug-induced endocrine and metabolic disorders include disorders of carbohydrate metabolism, electrolyte and calcium abnormalities, as well as drug-induced thyroid and gonadal disorders. An understanding of the proposed mechanisms of these drug effects and their evaluation and differential diagnosis may allow for more critical interpretation of the clinical observations associated with such disorders, better prediction of drug-induced adverse effects and better choices of and rationales for treatment.

Management of dyslipidemias in patients with diabetes and chronic kidney disease

Cardiovascular disease (CVD) is the leading cause of death in patients with stage 5 chronic kidney disease (CKD), and the mortality rate in stage 5 CKD is even higher in patients with diabetes. CVD risk reduction includes control of hyperglycemia, dyslipidemia, and BP. An LDL cholesterol goal of 70 mg/dl has been suggested for such high-risk patients. Most studies that have showed CVD risk reduction with statins have been in patients without CKD. However, some studies have had sufficient numbers of patients with CKD stages 2 to 3 to permit analysis, and these generally have shown CVD benefits similar to those found in patients without CKD. Studies that have shown benefit in patients who were on dialysis or after transplantation have been mixed, in part because CVD in such patients is far advanced and may not respond as well to intervention. As GFR falls, the dosages of many of the drugs that are used for the treatment of dyslipidemias need to be modified. In general, however, atorvastatin and fluvastatin dosages do not have to be modified. Drug interactions with cyclosporine also occur. In general, combinations of statins and fibrates should be avoided, and fenofibrate should be avoided in all patients with decreased GFR levels. Overall, on the basis of the very high risk for CVD in patients with diabetes and CKD, aggressive management of dyslipidemias is warranted, with an LDL goal of 70 mg/dl.