Is incretin-based therapy ready for the care of hospitalized patients with type 2 diabetes?: The time has come for GLP-1 receptor agonists!

Randomised comparison of intravenous and subcutaneous routes of glucagon-like peptide-1 administration for lowering plasma glucose in hyperglycaemic subjects with type 2 diabetes

AIM

To perform a direct, double-blind, randomised, crossover comparison of subcutaneous and intravenous glucagon-like peptide-1 (GLP-1) in hyperglycaemic subjects with type 2 diabetes naïve to GLP-1-based therapy.

MATERIALS AND METHODS

Ten fasted, hyperglycaemic subjects (1 female, age 63 ± 10 years [mean ± SD], glycated haemoglobin 73.5 ± 22.0 mmol/mol [8.9% ± 2.0%], both mean ± SD) received subcutaneous GLP-1 and intravenous saline, or intravenous GLP-1 and subcutaneous saline. Infusion rates were doubled every 120 min (1.2, 2.4, 4.8 and 9.6 pmol·kg-1·min-1 for subcutaneous, and 0.3, 0.6, 1.2 and 2.4 pmol·kg-1·min-1 for intravenous). Plasma glucose, total and intact GLP-1, insulin, C-peptide, glucagon and gastrointestinal symptoms were evaluated over 8 h. The results are presented as mean ± SEM.

RESULTS

Plasma glucose decreased more with intravenous (by ~8.0 mmol/L [144 mg/dL]) than subcutaneous GLP-1 (by ~5.6 mmol/L [100 mg/dL]; p < 0.001). Plasma GLP-1 increased dose-dependently, but more with intravenous than subcutaneous for both total (∆max 154.2 ± 3.9 pmol/L vs. 85.1 ± 3.8 pmol/L; p < 0.001), and intact GLP-1 (∆max 44.2 ± 2.2 pmol/L vs. 12.8 ± 2.2 pmol/L; p < 0.001). Total and intact GLP-1 clearance was higher for subcutaneous than intravenous GLP-1 (p < 0.001 and p = 0.002, respectively). The increase in insulin secretion was greater, and glucagon was suppressed more with intravenous GLP-1 (p < 0.05 each). Gastrointestinal symptoms did not differ (p > 0.05 each).

CONCLUSIONS

Subcutaneous GLP-1 administration is much less efficient than intravenous GLP-1 in lowering fasting plasma glucose, with less stimulation of insulin and suppression of glucagon, and much less bioavailability, even at fourfold higher infusion rates.

Management of Hyperglycemia in the Noncritical Care Setting: A Real-World Case-Based Approach With Alternative Insulin- and Noninsulin-Based Strategies

Insulin remains the mainstay of treatment for inpatient hyperglycemia in the United States and Canada. However, some other countries commonly use noninsulin agents such as metformin and sulfonylureas, and several trials have demonstrated the efficacy and safety of incretin-based agents in patients with type 2 diabetes who are admitted to noncritical care medicine and surgery services. There is a high degree of interest in alternative glucose-lowering strategies to achieve favorable glycemic outcomes with lower risks of hypoglycemia. In this case series, we highlight the challenges of inpatient glycemic management and the need for alternatives to the traditional basal-bolus insulin regimen. Additional investigation will be imperative to validate the safety and efficacy of appropriate insulin and noninsulin treatments and to further develop guidelines that are applicable in real-world hospital settings.

COVID-19 and Diabetes

Diabetes mellitus (DM) is one of the most common comorbid conditions in persons with COVID-19 and a risk factor for poor prognosis. The reasons why COVID-19 is more severe in persons with DM are currently unknown although the scarce data available on patients with DM hospitalized because of COVID-19 show that glycemic control is inadequate. The fact that patients with COVID-19 are usually cared for by health professionals with limited experience in the management of diabetes and the need to prevent exposure to the virus may also be obstacles to glycemic control in patients with COVID-19. Effective clinical care should consider various aspects, including screening for the disease in at-risk persons, education, and monitoring of control and complications. We examine the effect of COVID-19 on DM in terms of glycemic control and the restrictions arising from the pandemic and assess management of diabetes and drug therapy in various scenarios, taking into account factors such as physical exercise, diet, blood glucose monitoring, and pharmacological treatment. Specific attention is given to patients who have been admitted to hospital and critically ill patients. Finally, we consider the role of telemedicine in the management of DM patients with COVID-19 during the pandemic and in the future.

Epigenetic modification and therapeutic targets of diabetes mellitus

The prevalence of diabetes and its related complications are increasing significantly globally. Collected evidence suggested that several genetic and environmental factors contribute to diabetes mellitus. Associated complications such as retinopathy, neuropathy, nephropathy and other cardiovascular complications are a direct result of diabetes. Epigenetic factors include deoxyribonucleic acid (DNA) methylation and histone post-translational modifications. These factors are directly related with pathological factors such as oxidative stress, generation of inflammatory mediators and hyperglycemia. These result in altered gene expression and targets cells in the pathology of diabetes mellitus without specific changes in a DNA sequence. Environmental factors and malnutrition are equally responsible for epigenetic states. Accumulated evidence suggested that environmental stimuli alter the gene expression that result in epigenetic changes in chromatin. Recent studies proposed that epigenetics may include the occurrence of 'metabolic memory' found in animal studies. Further study into epigenetic mechanism might give us new vision into the pathogenesis of diabetes mellitus and related complication thus leading to the discovery of new therapeutic targets. In this review, we discuss the possible epigenetic changes and mechanism that happen in diabetes mellitus type 1 and type 2 separately. We highlight the important epigenetic and non-epigenetic therapeutic targets involved in the management of diabetes and associated complications.

Interactions between antihyperglycemic drugs and the renin-angiotensin system: Putative roles in COVID-19. A mini-review

BACKGROUND

Diabetes mellitus is associated with a more severe course of coronavirus disease 2019 (COVID-19). The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) utilizes angiotensin-converting enzyme II (ACE2) receptor for host cell entry. We aimed to assess the interactions between antihyperglycemic drugs and the renin-angiotensin system (RAS) and their putative roles in COVID-19.

METHODS

A literature search was performed using Pubmed to review the interrelationships between hyperglycemia, RAS and COVID-19, and the effects of antihyperglycemic medications.

RESULTS

The RAS has an essential role in glucose homeostasis and may have a role in COVID-19-induced lung injury. Some antihyperglycemic medications modulate RAS and might hypothetically alleviate the deleterious effect of angiotensin II on lung injury. Furthermore, most antihyperglycemic medications showed anti-inflammatory effects in animal models of lung injury.

CONCLUSIONS

Some antihyperglycemic medications might have protective effects against COVID-19-induced lung injury. Early insulin therapy seems very promising in alleviating lung injury.

Noninsulin medication therapy for hospitalized patients with diabetes mellitus

PURPOSE

Published evidence regarding the role of noninsulin antidiabetic therapies in glycemic management of hospitalized patients with diabetes mellitus is reviewed.

SUMMARY

The American Diabetes Association recommends against the routine use of noninsulin antidiabetic therapies during hospitalization and supports insulin use instead. There are significant risks associated with insulin therapy, including hypoglycemia, and use of alternative therapies may be considered in hospitalized patients. A MEDLINE literature search was conducted to find articles on studies evaluating the use of noninsulin antidiabetic therapies in the inpatient setting; all full-text English-language publications presenting observational and randomized clinical trial data on the topic of interest were considered for inclusion in the review, with 9 publications selected for review. The majority of the reviewed research focused on incretin-based therapies, and favorable safety and efficacy outcomes were reported with the use of dipeptidyl peptidase-4 (DPP-4) inhibitors. The available evidence indicates that the use of other noninsulin medications, including glucagon-like peptide-1 receptor agonists and sulfonylureas, to achieve and maintain glycemic control in the inpatient setting may be limited by adverse effects.

CONCLUSION

Optimal glycemic control in hospitalized patients with diabetes is necessary to avoid adverse effects. Insulin therapy is currently the primary medication recommended for this patient population. DPP-4 inhibitors have been demonstrated to be safe and effective for use in the inpatient setting in patients with well-controlled diabetes. Further research is needed to help define the role of noninsulin medications in the inpatient setting.

Use of incretin-based therapy in hospitalized patients with hyperglycemia

OBJECTIVE

Hyperglycemia is common in hospitalized patients with and without prior history of diabetes and is an independent marker of morbidity and mortality in critically and noncritically ill patients. Tight glycemic control using insulin has been shown to reduce cardiac morbidity and mortality in hospitalized patients, but it also results in hypoglycemic episodes, which have been linked to poor outcomes. Thus, alternative treatment options that can normalize blood glucose levels without undue hypoglycemia are being sought. Incretin-based therapies, such as glucagon-like peptide (GLP)-1 receptor agonists (RAs) and dipeptidyl peptidase (DPP)-4 inhibitors, may have this potential.

METHODS

A PubMed database was searched to find literature describing the use of incretins in hospital settings. Title searches included the terms "diabetes" (care, management, treatment), "hospital," "inpatient," "hypoglycemia," "hyperglycemia," "glycemic," "incretin," "dipeptidyl peptidase-4 inhibitor," "glucagon-like peptide-1," and "glucagon-like peptide-1 receptor agonist."

RESULTS

The preliminary research experience with native GLP-1 therapy has shown promise, achieving improved glycemic control with a low risk of hypoglycemia, counteracting the hyperglycemic effects of stress hormones, and improving cardiac function in patients with heart failure and acute ischemia. Large, randomized controlled clinical trials are necessary to determine whether these favorable results will extend to the use of GLP-1 RAs and DPP-4 inhibitors.

CONCLUSIONS

This review offers hospitalist physicians and healthcare providers involved in inpatient diabetes care a pathophysiologic-based approach for the use of incretin agents in patients with hyperglycemia and diabetes, as well as a summary of benefits and concerns of insulin and incretin-based therapy in the hospital setting.

A Randomized Controlled Trial on the Safety and Efficacy of Exenatide Therapy for the Inpatient Management of General Medicine and Surgery Patients With Type 2 Diabetes

OBJECTIVE

This multicenter, open-label, randomized trial examined the safety and efficacy of exenatide alone or in combination with basal insulin in non-critically ill patients with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

A total of 150 patients with blood glucose (BG) between 140 and 400 mg/dL, treated at home with diet, oral agents, or insulin at a total daily dose <0.5 units/kg, were randomized to exenatide alone (5 μg twice daily), exenatide plus basal insulin, or a basal-bolus insulin regimen. The primary end point was difference in mean daily BG concentration among groups.

RESULTS

Mean daily BG was similar between patients treated with exenatide plus basal and a basal-bolus regimen (154 ± 39 vs. 166 ± 40 mg/dL, P = 0.31), and exenatide plus basal resulted in lower daily BG than did exenatide alone (177 ± 41 mg/dL, P = 0.02). Exenatide plus basal resulted in a higher proportion of BG levels in target range between 70 and 180 mg/dL compared with exenatide and basal-bolus (78% vs. 62% vs. 63%, respectively, P = 0.023). More patients in the exenatide and exenatide plus basal groups experienced nausea or vomiting than in the basal-bolus group (10% vs. 11% vs. 2%, P = 0.17), with three patients (6%) discontinued exenatide owing to adverse events. There were no differences in hypoglycemia <54 mg/dL (2% vs. 0% vs. 4%, P = 0.77) or length of stay (5 vs. 4 vs. 4 days, P = 0.23) among basal plus exenatide, exenatide, and basal-bolus groups.

CONCLUSIONS

The results of this pilot study indicate that exenatide alone or in combination with basal insulin is safe and effective for the management of hospitalized general medical and surgical patients with T2D.

GLP1 Receptor Agonist Liraglutide Is an Effective Therapeutic Option for Perioperative Glycemic Control in Type 2 Diabetes within Enhanced Recovery After Surgery (ERAS) Protocols

BACKGROUND

Enhanced Recovery After Surgery (ERAS) protocols are multimodal perioperative care pathways designed to achieve early recovery after surgical procedures by maintaining preoperative organ function and reducing profound stress responses following surgery [Wilmore and Kehlet: BMJ 2001; 322(7284): 473-6]. Glucagon-like peptide-1 receptor agonists (GLP-1RAgs), such as liraglutide, have recently been widely used as antidiabetic agents in patients with type 2 diabetes (T2D) because they maintain blood glucose at an ideal level throughout the day, including during postprandial periods, thereby improving hypoglycemia and body weight more than insulin therapies. Additionally, the administration of liraglutide may exert cardiovascular, renal, and cerebral protective effects in T2D patients. The use of GLP-1RAgs for perioperative glycemic control is sometimes considered to be controversial.

METHODS

The efficacy and safety of liraglutide therapy during perioperative glycemic control in elective surgery patients within ERAS protocols were compared with those of insulin therapy. Ninety adult T2D patients scheduled to undergo elective surgery within ERAS protocols were randomized and analyzed. Forty-nine subjects were prescribed liraglutide and 41 insulin therapy. Procedures comprised orthopedic, thoracic, urological, otolaryngological, hepatic resection, and gynecological breast surgeries.

RESULTS

Liraglutide was shown to be a more effective option than insulin therapy because (1) glycemic levels were more stable; (2) the number of patients requiring additional insulin according to the insulin sliding scale was significantly smaller (Fisher's exact test, p = 0.005); (3) the insulin dosage required on the day of surgery was significantly smaller (Fisher's exact, p = 0.004); (4) the additional insulin volume required was significantly less for patients throughout the perioperative period (Fisher's exact test, p = 0.001); and (5) while lean body mass remained the same, body fat measurements, particularly visceral fat, tended to decrease.

CONCLUSIONS

Based on the results of the present study and a recent large-scale clinical study showing cardiovascular and renal protective effects in T2D patients, we consider the administration of liraglutide within ERAS protocols for T2D patients to represent a more comprehensive suite of patient protection measures as a perioperative non-insulin agent, particularly in patients with limited exercise ability and those at risk of hypoglycemia.

Manejo de pacientes diabéticos hospitalizados

La diabetes es una enfermedad con importante prevalencia en todo el mundo. Se calcula que cerca de 415 millones de personas la padecen en la actualidad y que para el año 2040 esta cifra aumentará poco más del 50%. Debido a esto, se estima que gran parte de los ingresos por urgencias serán de pacientes diabéticos o sujetos a los cuales esta patología se les diagnosticará en dicha hospitalización; esta situación hace necesario conocer los lineamientos y las recomendaciones de las guías para el manejo intrahospitalario de los pacientes con hiperglucemia.El pilar fundamental del manejo hospitalario de diabetes es la monitorización intensiva, junto con la educación al paciente y la administración de insulina. El control glicémico es clave debido a que disminuye complicaciones intrahospitalarias. Cabe resaltar que el control estricto puede llevar a hipoglucemias, por lo que los episodios deben ser debidamente documentados y su causa corregida de inmediato.

Bridging technology and clinical practice: innovating inpatient hyperglycaemia management in non-critical care settings

Emerging evidence shows that suboptimal glycaemic control is associated with increased morbidity and length of stay in hospital. Various guidelines for safe and effective inpatient glycaemic control in the non-critical care setting have been published. In spite of this, implementation in practice remains limited because of the increasing number of people with diabetes admitted to hospital and staff work burden. The use of technology in the outpatient setting has led to improved glycaemic outcomes and quality of life for people with diabetes. There remains an unmet need for technology utilisation in inpatient hyperglycaemia management in the non-critical care setting. Novel technologies have the potential to provide benefits in diabetes care in hospital by improving efficacy, safety and efficiency. Rapid analysis of glucose measurements by point-of-care devices help facilitate clinical decision-making and therapy adjustment in the hospital setting. Glucose treatment data integration with computerized glucose management systems underpins the effective use of decision support systems and may streamline clinical staff workflow. Continuous glucose monitoring and automation of insulin delivery through closed-loop systems may provide a safe and efficacious tool for hospital staff to manage inpatient hyperglycaemia whilst reducing staff workload. This review summarizes the evidence with regard to technological methods to manage inpatient glycaemic control, their limitations and the future outlook, as well as potential strategies by healthcare organizations such as the National Health Service to mediate the adoption, procurement and use of diabetes technologies in the hospital setting.

Update on Glucose Management Among Noncritically Ill Patients Hospitalized on Medical and Surgical Wards

Hyperglycemia is a common issue affecting inpatient care. Although this is in part because of the higher rate of hospitalization among patients with preexisting diabetes, multiple factors complicate inpatient glucose management, including acute stress from illness or surgery, erratic dietary intake, and contribution of medications. It has been repeatedly demonstrated that poorly controlled blood glucose levels are associated with negative clinical outcomes, such as increased mortality, higher rate of surgical complications, and longer length of hospital stay. Given these concerns, there has been extensive study of the optimal strategy for management of glucose levels, with the bulk of existing literature focusing on insulin therapy in the intensive care unit setting. This review shifts the focus to the general adult medical and surgical wards, using clinical guidelines and sentinel studies to describe the scientific basis behind the current basal-bolus insulin-based approach to blood sugar management among noncritically ill inpatients. Patient-centered clinical trials looking at alternative dosing regimens and insulin analog and noninsulin agents, such as glucagon-like peptide-1 agonist therapies, introduce safe and effective options in the management of inpatient hyperglycemia. Data from these studies reveal that these approaches are of comparable safety and efficacy to the traditional basal-bolus insulin regimen, and may offer additional benefit in terms of less monitoring requirements and lower rates of hypoglycemia. Although existing data are encouraging, outcome studies will be needed to better establish the clinical impact of these more recently proposed approaches in an effort to broaden and improve current clinical practices in inpatient diabetes care.

Liraglutide as an Alternative to Insulin for Glycemic Control in Intensive Care Unit: A Randomized, Open-label, Clinical Study

Background:

Intravenous insulin is the cornerstone in the management of hyperglycemia in the Intensive Care Unit (ICU). We studied the efficacy of liraglutide compared with insulin in the ICU.

Materials and Methods:

In this prospective, open-labeled, randomized study, we included 120 patients (15–65 years, either sex) admitted to ICU with capillary blood glucose (CBG) between 181 and 300 mg/dl. We excluded patients with secondary diabetes and APACHE score >24. The patients were divided into two groups (n = 60) based on the CBG: Group 1 (181–240) and Group 2 (241–300). They were randomized further into four subgroups (n = 30) to receive insulin (Groups 1A and 2A), liraglutide (Group 1B), and insulin with liraglutide (Group 2B). The primary outcome was the ability to achieve CBG below 180 mg/dL at the end of 24 h. The secondary outcomes include mortality at 1 month and hospital stay. Data and results were analyzed using Mann-Whitney U-test, paired t- test, and Chi-square tests.

Results:

The mean age of the patients (93M and 27F) was 57.1 ± 13.9 years, hospital stay (16.9 ± 7.5 days), and CBG was 240.5 ± 36.2 mg/dl. The primary outcome was reached in 26, 27, 25, and 28 patients of Groups 1A, 2A, 1B, and 2B, respectively. The 30-day mortality and hospital stay were similar across all the four groups. Hypoglycemia was common with insulin and gastrointestinal side effects were more common with liraglutide (P < 0.001).

Conclusion:

Liraglutide is a viable alternative to insulin for glycemic control in the ICU. Further studies with a larger number of patients are required to confirm our findings.

Dulaglutide (Trulicity): The Third Once-Weekly GLP-1 Agonist

Dulaglutide (Trulicity): the third once-weekly GLP-1 agonist for type-2 diabetes.

The potential role of incretin therapy in the hospital setting

Hyperglycemia has been associated with increased morbidity and mortality in hospitalized patients. Insulin has traditionally been the drug of choice for managing hyperglycemia in this setting, but carries a significant risk of hypoglycemia. Incretin-based therapies, including glucagon-like peptide-1, glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, have potential use in the hospital. These agents have a relatively low risk of hypoglycemia, favorable short-term side effect profile, and can be used alone or in combination with insulin. Several small studies have supported the safety and efficacy of incretin therapies in the inpatient setting with the majority of data coming from the intensive care setting. Large-scale clinical studies are needed to further evaluate the potential role of incretins in the management of inpatient hyperglycemia.

Practical implementation of incretin-based therapy in hospitalized patients with type 2 diabetes

Hyperglycemia in patients with and without a prior history of diabetes is an independent marker of morbidity and mortality in critically and noncritically ill patients. Improvement of glycemic control with insulin therapy has been shown to reduce hospital complications in patients with diabetes, but also results in increased rates of hypoglycemia, which have been linked to poor outcomes. Thus, alternative treatment options that can normalize blood glucose levels without undue hypoglycemia are being sought. Incretin-based therapies, such as glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, stimulate insulin secretion in a glucose-dependent fashion, thus not causing hypoglycemia. Alternative points of view exist regarding insulin versus incretin therapy for the care of these patients. We have brought together the authors on the opposite sides of this discussion with the objective of providing a rational synthesis on how to achieve the best possible control of glycemia in the hospital, using both standard insulin approaches and incretin-based therapies to improve patient outcomes. This review examines the benefits of incretin-based therapy in improving glycemic control in hospitalized patients with stress-induced diabetes and in diabetic patients in critical care and non-critical care settings.

Gastrointestinal metabolic surgery for the treatment of type 2 diabetes mellitus

Medical therapy for type 2 diabetes mellitus is ineffective in the long term due to the progressive nature of the disease, which requires increasing medication doses and polypharmacy. Conversely, bariatric surgery has emerged as a cost-effective strategy for obese diabetic individuals; it has low complication rates and results in durable weight loss, glycemic control and improvements in the quality of life, obesity-related co-morbidity and overall survival. The finding that glucose homeostasis can be achieved with a weight loss-independent mechanism immediately after bariatric surgery, especially gastric bypass, has led to the paradigm of metabolic surgery. However, the primary focus of metabolic surgery is the alteration of the physio-anatomy of the gastrointestinal tract to achieve glycemic control, metabolic control and cardio-metabolic risk reduction. To date, metabolic surgery is still not well defined, as it is used most frequently for less obese patients with poorly controlled diabetes. The mechanism of glycemic control is still incompletely understood. Published research findings on metabolic surgery are promising, but many aspects still need to be defined. This paper examines the proposed mechanism of diabetes remission, the efficacy of different types of metabolic procedures, the durability of glucose control, and the risks and complications associated with this procedure. We propose a tailored approach for the selection of the ideal metabolic procedure for different groups of patients, considering the indications and prognostic factors for diabetes remission.

Evidence-based practice use of incretin-based therapy in the natural history of diabetes

The incretin class of anti-hyperglycemic agents, including glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-inhibitors, is an important addition to the therapeutic armamentarium for the management of appropriate patients with type 2 diabetes mellitus as an adjunct to diet and exercise and/or with the agents metformin, sulfonylureas, thiazolidinediones, or any combination thereof. More recently, US Food and Drug Administration (FDA)-approved indications for incretins were expanded to include use with basal insulin. This review article takes an evidence-based practice approach in discussing the importance of aggressive treatment for diabetes, the principles of incretin physiology and pathophysiology, use of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, and patient types and contexts where incretin therapy has been found beneficial, from metabolic syndrome to overt diabetes.

Pharmacotherapy for Hyperglycemia in Noncritically Ill Hospitalized Patients

In Brief Hyperglycemia in the hospital setting affects 38-46% of noncritically ill hospitalized patients. Evidence from observational studies indicates that inpatient hyperglycemia, in patients with and without diabetes, is associated with increased risks of complications and mortality. Substantial evidence indicates that correction of hyperglycemia through insulin administration reduces hospital complications and mortality in critically ill patients, as well as in general medicine and surgery patients. This article provides a review of the evidence on the different therapies available for hyperglycemia management in noncritically ill hospitalized patients.

Glucose control in non-critically ill inpatients with diabetes: towards closed-loop

Inpatient glycaemic control remains an important issue due to the increasing number of patients with diabetes admitted to hospital. Morbidity and mortality in hospital are associated with poor glucose control, and cost of hospitalization is higher compared to non-diabetes patients. Guidelines for inpatient glycaemic control in the non-critical care setting have been published. Current recommendations include basal-bolus insulin therapy, regular glucose monitoring, as well as enhancing healthcare provider's role and knowledge. In spite of growing focus, implementation in practice is limited, mainly due to increasing workload burden on staff and fear of hypoglycaemia. Advances in healthcare technology may contribute to an improvement of inpatient diabetes care. Integration of glucose measurements with healthcare records and computerized glycaemic control protocols are currently being used in some institutions. Recent interests in continuous glucose monitoring have led to studies assessing its utilization in inpatients. Automation of glucose monitoring and insulin delivery may provide a safe and efficacious tool for hospital staff to manage inpatient hyperglycaemia, whilst reducing staff workload. This review summarizes the evidence on current approaches to managing inpatient glycaemic control; its utility and limitations. We conclude by discussing the evidence from feasibility studies to date, on the potential use of closed loop in the non-critical care setting and its implication for future studies.

A fusion protein derived from plants holds promising potential as a new oral therapy for type 2 diabetes

The incretin hormone glucagon-like peptide-1 (GLP-1) is recognized as a promising candidate for the treatment of type 2 diabetes (T2D), with one of its mimetics, exenatide (synthetic exendin-4) having already been licensed for clinical use. We seek to further improve the therapeutic efficacy of exendin-4 (Ex-4) using innovative fusion protein technology. Here, we report the production in plants a fusion protein containing Ex-4 coupled with human transferrin (Ex-4-Tf) and its characterization. We demonstrated that plant-made Ex-4-Tf retained the activity of both proteins. In particular, the fusion protein stimulated insulin release from pancreatic β-cells, promoted β-cell proliferation, stimulated differentiation of pancreatic precursor cells into insulin-producing cells, retained the ability to internalize into human intestinal cells and resisted stomach acid and proteolytic enzymes. Importantly, oral administration of partially purified Ex-4-Tf significantly improved glucose tolerance, whereas commercial Ex-4 administered by the same oral route failed to show any significant improvement in glucose tolerance in mice. Furthermore, intraperitoneal (IP) injection of Ex-4-Tf showed a beneficial effect in mice similar to IP-injected Ex-4. We also showed that plants provide a robust system for the expression of Ex-4-Tf, producing up to 37 μg prEx-4-Tf/g fresh leaf weight in transgenic tobacco and 137 μg prEx-4-Tf/g freshweight in transiently transformed leaves of N. benthamiana. These results indicate that Ex-4-Tf holds substantial promise as a new oral therapy for type 2 diabetes. The production of prEx-4-Tf in plants may offer a convenient and cost-effective method to deliver the antidiabetic medicine in partially processed plant food products.

Understanding hypoglycemia in hospitalized patients

Controlling blood glucose in hospitalized patients is important as both hyperglycemia and hypoglycemia are associated with increased cost, length of stay, morbidity and mortality. A limiting factor in stringent control is the concern of iatrogenic hypoglycemia. The association of hypoglycemia with mortality has led to clinical guideline changes recommending more conservative glycemic control than had previously been suggested, with the use of patient specific approaches when appropriate. Healthier, stable patients may be managed with stricter control while the elderly and severely ill may be managed less aggressively. While the avoidance of hypoglycemia is essential in clinical practice, recent studies suggest that a higher mortality rate occurs in spontaneous rather than iatrogenic hypoglycemia. Therefore, inpatient hypoglycemia may be viewed more as a biomarker of disease rather than a true cause of fatality.

Incretins and the intensivist: what are they and what does an intensivist need to know about them?

Hyperglycaemia occurs frequently in the critically ill, even in those patients without a history of diabetes. The mechanisms underlying hyperglycaemia in this group are complex and incompletely defined. In health, the gastrointestinal tract is an important modulator of postprandial glycaemic excursions and both the rate of gastric emptying and the so-called incretin hormones, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, are pivotal determinants of postprandial glycaemia. Incretin-based therapies (that is, glucagon-like peptide- 1 agonists and dipeptidyl-peptidase-4 inhibitors) have recently been incorporated into standard algorithms for the management of hyperglycaemia in ambulant patients with type 2 diabetes and, inevitably, an increasing number of patients who were receiving these classes of drugs prior to their acute illness will present to ICUs. This paper summarises current knowledge of the incretin effect as well as the incretin-based therapies that are available for the management of type 2 diabetes, and provides suggestions for the potential relevance of these agents in the management of dysglycaemia in the critically ill, particularly to normalise elevated blood glucose levels.

(Poly)peptide-based therapy for diabetes mellitus: insulins versus incretins

Insulin therapy remains the standard of care for achieving and maintaining adequate glycemic control, especially in hospitalized patients with critical and noncritical illnesses. Insulin therapy is more effective against elevated fasting glycaemia but less in the reduction of postprandial hyperglycaemia. It is associated with a high incidence of hypoglycemia and weight gain. Contrary, GLP-1 mimetic therapy improves postprandial glycaemia without the hypoglycaemia and weight gain associated with aggressive insulin therapy. Moreover, it has the potential to reduce cardiovascular related morbidity. However, its increased immunogenicity and severe gastrointestinal adverse effects present a huge burden on patients. Thus, a right combination of basal insulin which has lowering effect on fasting plasma glucose and GLP-1 mimetic with its lowering effect on postprandial plasma glucose with minimal gastrointestinal adverse effects, seems the right therapy choice from a clinical point of view for some diabetic patients. In this article, we discuss the pros and cons of the use of insulin analogues and GLP-1 mimetics that are associated with the treatment of type 2 diabetes.

Hyperglycemia in the intensive care unit: is insulin the only option?

Current guidelines advocate the use of insulin for the management of hyperglycemia in the hospital setting. However, insulin is limited by a narrow therapeutic window, frequent errors, a need for expertise and systems-based monitoring, and lack of specificity for metabolic abnormalities that occur during critical illness. As a result, non-insulin alternatives have garnered increasing interest for managing hyperglycemia in the hospital. However, non-insulin therapies have had safety and tolerability concerns, patients may still need insulin for glycemic control, and there have been limited outcomes data supporting their use. In the study by Christiansen and colleagues in the previous issue of Critical Care, pre-admission metformin therapy was associated with reduced mortality in critically ill patients with type 2 diabetes. The mortality benefit persisted after controlling for other variables, and was particularly prominent when metformin was continued during admission. Furthermore, the reduction in mortality was observed despite a slightly increased prevalence of lactic acidosis in metformin users. The protective effects of metformin are purported to be related to pleiotropic, possibly anti-inflammatory mechanisms, raising the question of benefit in patients without diabetes. Thus, the findings warrant a re-appraisal of the risks and benefits of metformin use during critical illness. However, in order to justify the revision of multiple guidelines and changes in product labeling, clinical trials in carefully selected patient populations are indicated.

Pathways to quality inpatient management of hyperglycemia and diabetes: a call to action

Currently patients with diabetes comprise up to 25-30% of the census of adult wards and critical care units in our hospitals. Although evidence suggests that avoidance of hyperglycemia (>180 mg/dL) and hypoglycemia (<70 mg/dL) is beneficial for positive outcomes in the hospitalized patient, much of this evidence remains controversial and at times somewhat contradictory. We have recently formed a consortium for Planning Research in Inpatient Diabetes (PRIDE) with the goal of promoting clinical research in the area of management of hyperglycemia and diabetes in the hospital. In this article, we outline eight aspects of inpatient glucose management in which randomized clinical trials are needed. We refer to four as system-based issues and four as patient-based issues. We urge further progress in the science of inpatient diabetes management. We hope this call to action is supported by the American Diabetes Association, The Endocrine Society, the American Association of Clinical Endocrinologists, the American Heart Association, the European Association for the Study of Diabetes, the International Diabetes Federation, and the Society of Hospital Medicine. Appropriate federal research funding in this area will help ensure high-quality investigations, the results of which will advance the field. Future clinical trials will allow practitioners to develop optimal approaches for the management of hyperglycemia in the hospitalized patient and lessen the economic and human burden of poor glycemic control and its associated complications and comorbidities in the inpatient setting.