Effects of subcutaneous, low-dose glucagon on insulin-induced mild hypoglycaemia in patients with insulin pump treated type 1 diabetes

Modeling the effect of glucagon on endogenous glucose production in type 1 diabetes: On the role of glucagon receptor dynamics

This paper validates a glucoregulatory model including glucagon receptors dynamics in the description of endogenous glucose production (EGP). A set of models from literature are selected for a head-to-head comparison in order to evaluate the role of glucagon receptors. Each EGP model is incorporated into an existing glucoregulatory model and validated using a set of clinical data, where both insulin and glucagon are administered. The parameters of each EGP model are identified in the same optimization problem, minimizing the root mean square error (RMSE) between the simulation and the clinical data. The results show that the RMSE for the proposed receptors-based EGP model was lower when compared to each of the considered models (Receptors approach: 7.13±1.71 mg/dl vs. 7.76±1.45 mg/dl (p=0.066), 8.45±1.38 mg/dl (p=0.011) and 8.99±1.62 mg/dl (p=0.007)). This raises the possibility of considering glucagon receptors dynamics in type 1 diabetes simulators.

American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update

OBJECTIVE

The objective of this clinical practice guideline is to provide updated and new evidence-based recommendations for the comprehensive care of persons with diabetes mellitus to clinicians, diabetes-care teams, other health care professionals and stakeholders, and individuals with diabetes and their caregivers.

METHODS

The American Association of Clinical Endocrinology selected a task force of medical experts and staff who updated and assessed clinical questions and recommendations from the prior 2015 version of this guideline and conducted literature searches for relevant scientific papers published from January 1, 2015, through May 15, 2022. Selected studies from results of literature searches composed the evidence base to update 2015 recommendations as well as to develop new recommendations based on review of clinical evidence, current practice, expertise, and consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RESULTS

This guideline includes 170 updated and new evidence-based clinical practice recommendations for the comprehensive care of persons with diabetes. Recommendations are divided into four sections: (1) screening, diagnosis, glycemic targets, and glycemic monitoring; (2) comorbidities and complications, including obesity and management with lifestyle, nutrition, and bariatric surgery, hypertension, dyslipidemia, retinopathy, neuropathy, diabetic kidney disease, and cardiovascular disease; (3) management of prediabetes, type 2 diabetes with antihyperglycemic pharmacotherapy and glycemic targets, type 1 diabetes with insulin therapy, hypoglycemia, hospitalized persons, and women with diabetes in pregnancy; (4) education and new topics regarding diabetes and infertility, nutritional supplements, secondary diabetes, social determinants of health, and virtual care, as well as updated recommendations on cancer risk, nonpharmacologic components of pediatric care plans, depression, education and team approach, occupational risk, role of sleep medicine, and vaccinations in persons with diabetes.

CONCLUSIONS

This updated clinical practice guideline provides evidence-based recommendations to assist with person-centered, team-based clinical decision-making to improve the care of persons with diabetes mellitus.

Vasodilatory effects of glucagon: A possible new approach to enhanced subcutaneous insulin absorption in artificial pancreas devices

Patients with diabetes mellitus type 1 depend on exogenous insulin to keep their blood glucose concentrations within the desired range. Subcutaneous bihormonal artificial pancreas devices that can measure glucose concentrations continuously and autonomously calculate and deliver insulin and glucagon infusions is a promising new treatment option for these patients. The slow absorption rate of insulin from subcutaneous tissue is perhaps the most important factor preventing the development of a fully automated artificial pancreas using subcutaneous insulin delivery. Subcutaneous insulin absorption is influenced by several factors, among which local subcutaneous blood flow is one of the most prominent. We have discovered that micro-doses of glucagon may cause a substantial increase in local subcutaneous blood flow. This paper discusses how the local vasodilative effects of micro-doses of glucagon might be utilised to improve the performance of subcutaneous bihormonal artificial pancreas devices. We map out the early stages of our hypothesis as a disruptive novel approach, where we propose to use glucagon as a vasodilator to accelerate the absorption of meal boluses of insulin, besides using it conventionally to treat hypoglycaemia.

Low-Dose Dasiglucagon Versus Oral Glucose for Prevention of Insulin-Induced Hypoglycemia in People With Type 1 Diabetes: A Phase 2, Randomized, Three-Arm Crossover Study

OBJECTIVE

To compare the efficacy of low-dose subcutaneous dasiglucagon with oral glucose for prevention of insulin-induced hypoglycemia in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Twenty adults with type 1 diabetes using multiple daily injection or insulin pump therapy completed a phase 2, randomized, three-arm crossover study. On each study visit, an individualized subcutaneous insulin bolus was administered aiming for a plasma glucose (PG) concentration of 3.0 mmol/L (54 mg/dL). When a PG concentration of 4.5 mmol/L (81 mg/dL) was reached, 15 g oral glucose (CHO) from dextrose tablets, 80 µg dasiglucagon (D80), or 120 µg dasiglucagon (D120) was administered. PG was measured frequently for the following 180 min.

RESULTS

Hypoglycemia (<3.9 mmol/L [70 mg/dL]) occurred in 10 participants after CHO, in 5 after D80, and in 4 after D120 (CHO vs. D80, P = 0.096; CHO vs. D120, P = 0.034). Time spent in hypoglycemia (<3.9 mmol/L [70 mg/dL]) was 14%, 7%, and 6% for CHO, D80, and D120, respectively (P = 0.273). The median time (95% CI) from intervention to first increase in PG of 1.1 mmol/L (20 mg/dL) was 30 (25-50), 15 (15-20), and 15 (15-20) minutes for CHO, D80, and D120, respectively (CHO vs. D80, P = 0.006; CHO vs. D120, P = 0.003). Episodes of nausea were numerically, but not significantly, higher after dasiglucagon administration. No significant differences in visual analog scale-assessed adverse effects were observed between interventions.

CONCLUSIONS

Low-dose dasiglucagon safely and effectively prevented insulin-induced hypoglycemia with a faster glucose-elevating profile than oral glucose.

Pharmacokinetics of Intraperitoneally Delivered Glucagon in Pigs: A Hypothesis of First Pass Metabolism

Background and Objective

Artificial pancreases administering low-dose glucagon in addition to insulin have the scope to improve glucose control in patients with diabetes mellitus type 1. If such a device were to deliver both hormones intraperitoneally, it would mimic normal physiology, which may be beneficial. However, the pharmacokinetic properties of glucagon after intraperitoneal administration are not well known. Hence, the current study aims to evaluate the relationship between the amount of intraperitoneally delivered glucagon and pharmacokinetic variables in a pig model.

Methods

Pharmacokinetic data was retrieved from experiments on 19 anaesthetised pigs and analysed post hoc. The animals received a single intraperitoneal bolus of glucagon ranging from 0.30 to 4.46 µg/kg. Plasma glucagon was measured every 2–10 min for 50 min.

Results

Peak plasma concentration and area under the time–plasma concentration curve of glucagon correlated positively with the administered dose, and larger boluses provided a relatively greater increase. The mean (standard deviation) time to maximum glucagon concentration in plasma was 11 (5) min, and the mean elimination half-life of glucagon in plasma was 19 (7) min.

Conclusions

Maximum plasma concentration and area under the time–plasma concentration curve of glucagon increase nonlinearly in relation to the intraperitoneally administered glucagon dose. We hypothesise that the results are compatible with a satiable first-pass metabolism in the liver. Time to maximum glucagon concentration in plasma and the elimination half-life of glucagon in plasma seem independent of the drug dose.

The effect of preceding glucose decline rate on low-dose glucagon efficacy in individuals with type 1 diabetes: A randomized crossover trial

Identifying determinants of low-dose glucagon efficacy is important to optimise its utilization for prevention and treatment of hypoglycaemia in individuals with type 1 diabetes. The study objective was to investigate whether the preceding glucose decline rate affects glucose response to low-dose glucagon administration. Ten adults with insulin pump-treated type 1 diabetes were included in this randomized, single-blind, two-way crossover study. Using a hyperinsulinaemic clamp technique, plasma glucose levels were reduced with either a rapid or slow decline rate while maintaining fixed insulin levels. When the plasma glucose level reached 3.9 mmoL/L, insulin and glucose infusions were discontinued and 150 μg subcutaneous glucagon was administered, followed by 120 minutes of plasma glucose monitoring. The positive incremental area under the glucose curve after administration of low-dose glucagon did not differ between the rapid-decline and slow-decline visits (mean ± SEM: 220 ± 49 vs. 174 ± 31 mmoL/L x min; P = 0.21). Similarly, no differences in total area under the glucose curve, peak plasma glucose, incremental peak plasma glucose, time-to-peak plasma glucose or end plasma glucose were observed. Thus, preceding glucose decline rate did not significantly affect the glucose response to low-dose glucagon.

Glucagon for hypoglycaemia treatment in type 1 diabetes

To achieve strict glycaemic control and avoid chronic diabetes complications, individuals with type 1 diabetes (T1D) are recommended to follow an intensive insulin regimen. However, the risk and fear of hypoglycaemia often prevent individuals from achieving the treatment goals. Apart from early insulin suspension in insulin pump users, carbohydrate ingestion is the only option for preventing and treating non-severe hypoglycaemic events. These rescue treatments may give extra calories and cause overweight. As an alternative, the use of low-dose glucagon to counter hypoglycaemia has been proposed as a tool to raise glucose concentrations without adding extra calories. Previously, the commercially available glucagon formulations required reconstitution from powder to a solution before being injected subcutaneously or intramuscularly-making it practical only for treating severe hypoglycaemia. Several companies have developed more stable formulations that do not require the time-consuming reconstitution process before use. As well as treating severe hypoglycaemia, non-severe and impending hypoglycaemia can also be treated with lower doses of glucagon. Once available, low-dose glucagon can be either delivered manually, as an injection, or automatically, by an infusion pump. This review focuses on the role and perspectives of using glucagon to treat and prevent hypoglycaemia in T1D.

Intraperitoneal and subcutaneous glucagon delivery in anaesthetized pigs: effects on circulating glucagon and glucose levels

Glucagon is a pancreatic hormone and increases the blood glucose levels. It may be incorporated in a dual hormone artificial pancreas, a device to automatically and continuously control blood glucose levels of individuals with diabetes. Artificial pancreas systems have been developed for use in the subcutaneous tissue; however, the systems are not fully automated due to slow dynamics. The intraperitoneal space is therefore investigated as an alternative location for an artificial pancreas. Glucose dynamics after subcutaneous and intraperitoneal glucagon delivery in ten anaesthetized pigs were investigated. The pigs received intraperitoneal boluses of 0.3 µg/kg and 0.6 µg/kg and a subcutaneous bolus of 0.6 µg/kg in randomized order. They also received an intraperitoneal bolus of 1 mg given at the end of the experiments to test the remaining capacity of rapid glucose release. Six pigs were included in the statistical analysis. The intraperitoneal glucagon bolus of 0.6 µg/kg gave a significantly higher glucose response from 14 to 30 min compared with the subcutaneous bolus. The results indicate that glucagon induces a larger glucose response after intraperitoneal delivery compared with subcutaneous delivery and is encouraging for the incorporation of glucagon in an intraperitoneal artificial pancreas.

Glucagon-based therapy: Past, present and future

Diabesity and its related cardio-hepato-renal complications are of absolute concern globally. Last decade has witnessed a growing interest in the scientific community in investigating novel pharmaco-therapies employing the pancreatic hormone, glucagon. Canonically, this polypeptide hormone is known for its use in rescue treatment for hypoglycaemic shocks owing to its involvement in the counter-regulatory feedback mechanism. However, substantial studies in the recent past elucidated the pleiotropic effects of glucagon in diabesity and related complications like non-alcoholic steatohepatitis (NASH) and non-alcoholic fatty liver disease (NAFLD). Thus, the dual nature of this peptide has sparked the search for drugs that can modify glucagon signalling to combat hypoglycaemia or diabesity. Thus far, researchers have explored various pharmacological approaches to utilise this peptide in imminent modern therapies. The research endeavours in this segment led to explorations of stable glucagon formulations/analogues, glucagon receptor antagonism, glucagon receptor agonism, and incretin poly-agonism as new strategies for the management of hypoglycaemia or diabesity. This 'three-dimensional' research on glucagon resulted in the discovery of various drug candidates that proficiently modify glucagon signalling. Currently, several emerging glucagon-based therapies are under pre-clinical and clinical development. We sought to summarise the recent progress to comprehend glucagon-mediated pleiotropic effects, provide an overview of drug candidates currently being developed and future perspectives in this research domain.

Role of Glucagon in Automated Insulin Delivery

Treatment of type 1 diabetes with exogenous insulin often results in unpredictable daily glucose variability and hypoglycemia, which can be dangerous. Automated insulin delivery systems can improve glucose control while reducing burden for people with diabetes. One approach to improve treatment outcomes is to incorporate the counter-regulatory hormone glucagon into the automated delivery system to help prevent the hypoglycemia that can be induced by the slow pharmacodynamics of insulin action. This article explores the advantages and disadvantages of incorporating glucagon into dual-hormone automated hormone delivery systems.

Mini-doses of glucagon to prevent hypoglycemia in children with type 1 diabetes refusing food: a case series

AIMS

Hypoglycemia in small children with type 1 diabetes is difficult to manage if nausea, vomit or food refusal occurs. If oral carbohydrate cannot be used, there is a hypothetical risk of severe hypoglycemia. The present article describes the effect on glucose of small doses of subcutaneous glucagon to revert hypoglycemia and prevent severe events in small children with type 1 diabetes using a continuous glucose monitoring.

METHODS

We analyzed 4 episodes of impending or mild hypoglycemia in 3 children with type 1 diabetes who refused to eat carbohydrates. Using a standard U-100 insulin syringe, children received one "unit" (10 μg) of glucagon subcutaneously for every year of age up to 15 units (150 μg). If the blood glucose did not increase within 30 min, the initial dosage was repeated at that time. Instructions were given by phone from the physician. At the following visit data from continuous glucose monitoring devices, insulin pump and glucometer were downloaded and reviewed retrospectively from the physician.

RESULTS

Blood glucose from continuous glucose monitoring after one and 2 h was 127 ± 80 mg/dl and 165 ± 78 mg/dl, respectively. After a glucagon injection, there was a single recurrence of hypoglycemia, requiring another shot. The glucagon was well tolerated, except for nausea, present before the injection. None of the children were taken to our hospital because of concerns for hypoglycemia.

CONCLUSION

Mini-doses of glucagon given subcutaneously were effective and safe in preventing frank or impending hypoglycemia in type 1 diabetes children refusing food.

Preference for Subcutaneously Administered Low-Dose Glucagon Versus Orally Administered Glucose for Treatment of Mild Hypoglycemia: A Prospective Survey Study

INTRODUCTION

Intensive insulin treatment for type 1 diabetes is associated with high risk of mild hypoglycemia. Mild hypoglycemia is usually treated orally with glucose, which may contribute to weight gain. Subcutaneous injection of low-dose glucagon may be a new treatment option for some occasions of mild hypoglycemia in individuals aiming for optimal glycemic control without gaining weight. We investigated under which occasions patients were interested to use low-dose glucagon.

METHODS

In a prospective 2-week event-driven survey, participants registered every event of mild hypoglycemia (sensor or blood glucose ≤ 3.9 mmol/l and/or hypoglycemia symptoms). For each hypoglycemia event, participants registered whether they would have preferred to use low-dose glucagon if the treatment had been available.

RESULTS

A total of 51 participants (13 men, mean ± SD age 43.6 ± 12.5 years, HbA1c 7.3 ± 0.7% (57 ± 8 mmol/mol), BMI 24.9 ± 3 kg/m²) were included. Each participant had on average 10 (range 3-23) mild hypoglycemia events during the 2-week survey period. Glucagon was preferred in 58% of the 514 mild hypoglycemia events (p > 0.05). Twelve percent of the participants had no desire to use glucagon for any hypoglycemia event. The preference pattern did not differ between sex, patient treatment modalities, and possible causes for hypoglycemia (all p > 0.05).

CONCLUSION

This study showed that a majority of our participants with type 1 diabetes were interested in using low-dose glucagon for the treatment of mild hypoglycemia.

FUNDING

This work was funded by a research grant from the Copenhagen University Hospital Hvidovre and by the Danish Diabetes Academy supported by the Novo Nordisk Foundation.

New uses and formulations of glucagon for hypoglycaemia

Hypoglycaemia is the more frequent complication of insulin therapy and the main barrier to tight glycaemic control. Injectable glucagon and oral intake of carbohydrates are the recommended treatments for severe and non-severe hypoglycaemia episodes, respectively. Nasal glucagon is currently being developed as a ready-to-use device, to simplify severe hypoglycaemia rescue. Stable forms of liquid glucagon could open the field for different approaches for mild to moderate hypoglycaemia treatment, such as mini-doses of glucagon or continuous subcutaneous glucagon infusion as a part of dual-hormone closed-loop systems. Pharmaceutical companies are developing stable forms of native glucagon or glucagon analogues for that purpose.

Glucagon Receptor Signaling and Glucagon Resistance

Hundred years after the discovery of glucagon, its biology remains enigmatic. Accurate measurement of glucagon has been essential for uncovering its pathological hypersecretion that underlies various metabolic diseases including not only diabetes and liver diseases but also cancers (glucagonomas). The suggested key role of glucagon in the development of diabetes has been termed the bihormonal hypothesis. However, studying tissue-specific knockout of the glucagon receptor has revealed that the physiological role of glucagon may extend beyond blood-glucose regulation. Decades ago, animal and human studies reported an important role of glucagon in amino acid metabolism through ureagenesis. Using modern technologies such as metabolomic profiling, knowledge about the effects of glucagon on amino acid metabolism has been expanded and the mechanisms involved further delineated. Glucagon receptor antagonists have indirectly put focus on glucagon's potential role in lipid metabolism, as individuals treated with these antagonists showed dyslipidemia and increased hepatic fat. One emerging field in glucagon biology now seems to include the concept of hepatic glucagon resistance. Here, we discuss the roles of glucagon in glucose homeostasis, amino acid metabolism, and lipid metabolism and present speculations on the molecular pathways causing and associating with postulated hepatic glucagon resistance.

Preserved glucose response to low-dose glucagon after exercise in insulin-pump-treated individuals with type 1 diabetes: a randomised crossover study

AIMS/HYPOTHESIS

This study aimed to compare the increase in plasma glucose after a subcutaneous injection of 200 μg glucagon given after 45 min of cycling with resting (study 1) and to investigate the effects of glucagon when injected before compared with after 45 min of cycling (study 2). We hypothesised that: (1) the glucose response to glucagon would be similar after cycling and resting; and (2) giving glucagon before the activity would prevent the exercise-induced fall in blood glucose during exercise and for 2 h afterwards.

METHODS

Fourteen insulin-pump-treated individuals with type 1 diabetes completed three visits in a randomised, placebo-controlled, participant-blinded crossover study. They were allocated by sealed envelopes. Baseline values were (mean and range): HbA_1c 54 mmol/mol (43-65 mmol/mol) or 7.1% (6.1-8.1%); age 45 years (23-66 years); BMI 26 kg/m² (21-30 kg/m²); and diabetes duration 26 years (8-51 years). At each visit, participants consumed a standardised breakfast 2 h prior to 45 min of cycling or resting. A subcutaneous injection of 200 μg glucagon was given before or after cycling or after resting. The glucose response to glucagon was compared after cycling vs resting (study 1) and before vs after cycling (study 2).

RESULTS

The glucose response to glucagon was higher after cycling compared with after resting (mean ± SD incremental peak: 2.6 ± 1.7 vs 1.8 ± 2.0 mmol/l, p = 0.02). As expected, plasma glucose decreased during cycling (-3.1 ± 2.8 mmol/l) but less so when glucagon was given before cycling (-0.9 ± 2.8 mmol/l, p = 0.002). The number of individuals reaching glucose values ≤3.9 mmol/l was the same on the 3 days.

CONCLUSIONS/INTERPRETATION

Moderate cycling for 45 min did not impair the glucose response to glucagon compared with the glucose response after resting. The glucose fall during cycling was diminished by a pre-exercise injection of 200 μg glucagon; however, no significant difference was seen in the number of events of hypoglycaemia.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02882737 FUNDING: The study was funded by the Danish Diabetes Academy founded by Novo Nordisk foundation and by an unrestricted grant from Zealand Pharma.

Low doses of dasiglucagon consistently increase plasma glucose levels from hypoglycaemia and euglycaemia in people with type 1 diabetes mellitus

AIM

To characterize the pharmacokinetic and pharmacodynamic properties of dasiglucagon, a novel, stable and liquid formulated glucagon analogue, during hypoglycaemic and euglycaemic conditions in adult patients with type 1 diabetes mellitus.

RESEARCH DESIGN AND METHODS

In this randomized double-blind trial, 17 patients received four single subcutaneous doses (0.03, 0.08, 0.2 and 0.6 mg) of dasiglucagon (4 mg/mL formulation) under euglycaemic (plasma glucose [PG] 5.6 mmol/L [100 mg/dL]) or hypoglycaemic (PG 3.1-3.7 mmol/L [56-66 mg/dL]) conditions. For comparison, three doses (0.03, 0.08 and 0.2 mg) of a commercial glucagon formulation (Eli Lilly) were investigated at euglycaemia.

RESULTS

Dasiglucagon led to a dose-dependent and rapid increase in PG levels across all doses tested (mean increases 30 minutes post-dosing of 2.2 to 4.4 mmol/L [39-80 mg/dL] from euglycaemia and 1.3 to 5.2 mmol/L [24-94 mg/dL] from hypoglycaemia), which was higher than the rises elicited by similar doses of commercial glucagon (1.7-3.9 mmol/L [30-71 mg/dL]). The median time (range) to an increase in PG of >1.1 mmol/L (20 mg/dL) was <20 (18-19.5) minutes with 0.03 mg dasiglucagon and, with higher doses, the median times ranged from 9 to 15 minutes (commercial glucagon 13-14 minutes). In hypoglycaemia, 0.03 and 0.08 mg dasiglucagon re-established normoglycaemia (PG ≥3.9 mmol/L [70 mg/dL]) within median times of 14 and 10 minutes, respectively. Nausea and vomiting occurred more frequently with dasiglucagon than with commercial glucagon at identical doses which might be attributable to dasiglucagon's higher potency.

CONCLUSION

Dasiglucagon rapidly increased PG at doses of 0.03 to 0.6 mg in a dose-dependent manner and, therefore, is a good candidate for use in dual-hormone artificial pancreas systems.

Dual-hormone artificial pancreas: benefits and limitations compared with single-hormone systems

Technological advances have made the artificial pancreas a reality. This has the potential to improve the lives of individuals with Type 1 diabetes by reducing the risk of hypoglycaemia, achieving better overall glucose control, and enhancing quality of life. Both single-hormone (insulin-only) and dual-hormone (insulin and glucagon) systems have been developed; however, a focused review of the relative benefits of each artificial pancreas system is needed. We reviewed studies that directly compared single- and dual-hormone systems to evaluate the efficacy of each system for preventing hypoglycaemia and maintaining glycaemic control, as well as their utility in specific situations including during exercise, overnight and during the prandial period. We observed additional benefits with the dual-hormone artificial pancreas for reducing the risk of hypoglycaemic events overall and during exercise over the study duration. The single-hormone artificial pancreas was sufficient for maintenance of euglycaemia in the overnight period and for preventing late-onset post-exercise hypoglycaemia. Future comparative studies of longer duration are required to determine whether one system is superior for improving mean glucose control, eliminating severe hypoglycaemia, or improving quality of life.

Effects of Preceding Ethanol Intake on Glucose Response to Low-Dose Glucagon in Individuals With Type 1 Diabetes: A Randomized, Placebo-Controlled, Crossover Study

OBJECTIVE

This study investigated whether preceding ethanol intake impairs glucose response to low-dose glucagon in individuals with type 1 diabetes.

RESEARCH DESIGN AND METHODS

This was a randomized, crossover, placebo-controlled study in 12 insulin pump-treated individuals (median [interquartile range] age, 37 [31-51] years; HbA_1c, 57 [51-59] mmol/mol or 7.3% [6.8-7.5]; and BMI, 23.9 [22-25] kg/m²). During two overnight study visits, a 6 p.m. dinner (1 g carbohydrates/kg) was served with diet drink (placebo) or diet drink and ethanol (0.8 g/kg). After 8-9 h, ethanol was estimated to be metabolized, and a subcutaneous (s.c.) insulin bolus was given to induce mild hypoglycemia. When plasma glucose (PG) was ≤3.9 mmol/L, 100 µg glucagon was given s.c., followed by another s.c. 100 µg glucagon 2 h later. Primary end point was incremental peak PG induced by the first glucagon bolus.

RESULTS

Ethanol was undetectable before insulin administration at both visits. The insulin doses (mean ± SEM: 2.5 ± 0.4 vs. 2.7 ± 0.4 IU) to induce hypoglycemia (3.7 ± 0.1 vs. 3.9 ± 0.1 mmol/L) did not differ and caused similar insulin levels (28.3 ± 4.6 vs. 26.1 ± 4.0 mU/L) before glucagon administration on ethanol and placebo visits (all, P > 0.05). The first glucagon bolus tended to cause lower incremental peak PG (2.0 ± 0.5 vs. 2.9 ± 0.3 mmol/L, P = 0.06), lower incremental area under the curve (87 ± 40 vs. 191 ± 37 mmol/L × min, P = 0.08), and lower 2-h PG level (3.6 ± 1.0 vs. 4.8 ± 0.4 mmol/L, P = 0.05) after ethanol compared with placebo. The second glucagon bolus had similar responses between visits, but PG remained 1.8 ± 0.7 mmol/L lower after ethanol compared with placebo.

CONCLUSIONS

The ability of low-dose glucagon to treat mild hypoglycemia persisted with preceding ethanol intake, although it tended to be attenuated.

Pharmacokinetic and Pharmacodynamic Characteristics of Dasiglucagon, a Novel Soluble and Stable Glucagon Analog

OBJECTIVE

Treatment of severe hypoglycemia outside of the hospital setting is limited to glucagon formulations requiring reconstitution before use, which may lead to erroneous or delayed glucagon administration. We compared the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics and safety and tolerability of different doses of dasiglucagon, a novel soluble glucagon analog, with approved pediatric and full doses of GlucaGen in insulin-induced hypoglycemia in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

In this single-center, randomized, double-blind trial, 58 patients with type 1 diabetes received single subcutaneous injections of 0.1, 0.3, 0.6, or 1.0 mg dasiglucagon or 0.5 or 1.0 mg GlucaGen in a state of hypoglycemia (blood glucose target 55 mg/dL) induced by an intravenous insulin infusion.

RESULTS

Dasiglucagon demonstrated a dose-dependent and rapid increase in plasma concentrations, reaching a maximum at ∼35 min with a half-life of ∼0.5 h. Dasiglucagon rapidly increased plasma glucose (PG) by ≥20 mg/dL (9-14 min) to PG ≥70 mg/dL (within 6-10 min), similar to GlucaGen, but with a longer-lasting and greater effect on PG. All patients on both treatments reached these end points within 30 min (predefined success criteria). Both treatments were well tolerated. Nausea was the most frequent adverse event, occurring at a similar rate (44-56%).

CONCLUSIONS

Dasiglucagon was well tolerated and showed an early PD response similar to that of GlucaGen at corresponding doses, suggesting comparable clinical effects of the two glucagon formulations. Dasiglucagon has the potential to become an effective and reliable rescue treatment for severe hypoglycemia in a ready-to-use pen.

Design and Clinical Evaluation of a Novel Low-Glucose Prediction Algorithm with Mini-Dose Stable Glucagon Delivery in Post-Bariatric Hypoglycemia

BACKGROUND

Postbariatric hypoglycemia (PBH) is a complication of bariatric surgery with limited therapeutic options. We developed an event-based system to predict and detect hypoglycemia based on continuous glucose monitor (CGM) data and recommend delivery of minidose liquid glucagon.

METHODS

We performed an iterative development clinical study employing a novel glucagon delivery system: a Dexcom CGM connected to a Windows tablet running a hypoglycemia prediction algorithm and an Omnipod pump filled with an investigational stable liquid glucagon formulation. Meal tolerance testing was performed in seven participants with PBH and history of neuroglycopenia. Glucagon was administered when hypoglycemia was predicted. Primary outcome measures included the safety and feasibility of this system to predict and prevent severe hypoglycemia. Secondary outcomes included hypoglycemia prediction by the prediction algorithm, minimization of time below hypoglycemia threshold using glucagon, and prevention of rebound hyperglycemia.

RESULTS

The hypoglycemia prediction algorithm alerted for impending hypoglycemia in the postmeal state, prompting delivery of glucagon (150 μg). After observations of initial incomplete efficacy to prevent hypoglycemia in the first two participants, system modifications were implemented: addition of PBH-specific detection algorithm, increased glucagon dose (300 μg), and a second glucagon dose if needed. These modifications, together with rescue carbohydrates provided to some participants, contributed to progressive improvements in glucose time above the hypoglycemia threshold (75 mg/dL).

CONCLUSIONS

Preliminary results indicate that our event-based automatic monitoring algorithm successfully predicted likely hypoglycemia. Minidose glucagon therapy was well tolerated, without prolonged or severe hypoglycemia, and without rebound hyperglycemia.

Practical Approaches to Diagnosing, Treating and Preventing Hypoglycemia in Diabetes

Hypoglycemia in individuals with diabetes can increase the risk of morbidity and all-cause mortality in this patient group, particularly in the context of cardiovascular impairment, and can significantly decrease the quality of life. Hypoglycemia can present one of the most difficult aspects of diabetes management from both a patient and healthcare provider perspective. Strategies used to reduce the risk of hypoglycemia include individualizing glucose targets, selecting the appropriate medication, modifying diet and lifestyle and applying diabetes technology. Using a patient-centered care approach, the provider should work in partnership with the patient and family to prevent hypoglycemia through evidence-based management of the disease and appropriate education.

Cross-Validation of a Glucose-Insulin-Glucagon Pharmacodynamics Model for Simulation Using Data From Patients With Type 1 Diabetes

BACKGROUND

Currently, no consensus exists on a model describing endogenous glucose production (EGP) as a function of glucagon concentrations. Reliable simulations to determine the glucagon dose preventing or treating hypoglycemia or to tune a dual-hormone artificial pancreas control algorithm need a validated glucoregulatory model including the effect of glucagon.

METHODS

Eight type 1 diabetes (T1D) patients each received a subcutaneous (SC) bolus of insulin on four study days to induce mild hypoglycemia followed by a SC bolus of saline or 100, 200, or 300 µg of glucagon. Blood samples were analyzed for concentrations of glucagon, insulin, and glucose. We fitted pharmacokinetic (PK) models to insulin and glucagon data using maximum likelihood and maximum a posteriori estimation methods. Similarly, we fitted a pharmacodynamic (PD) model to glucose data. The PD model included multiplicative effects of insulin and glucagon on EGP. Bias and precision of PD model test fits were assessed by mean predictive error (MPE) and mean absolute predictive error (MAPE).

RESULTS

Assuming constant variables in a subject across nonoutlier visits and using thresholds of ±15% MPE and 20% MAPE, we accepted at least one and at most three PD model test fits in each of the seven subjects. Thus, we successfully validated the PD model by leave-one-out cross-validation in seven out of eight T1D patients.

CONCLUSIONS

The PD model accurately simulates glucose excursions based on plasma insulin and glucagon concentrations. The reported PK/PD model including equations and fitted parameters allows for in silico experiments that may help improve diabetes treatment involving glucagon for prevention of hypoglycemia.

Low-Carbohydrate Diet Impairs the Effect of Glucagon in the Treatment of Insulin-Induced Mild Hypoglycemia: A Randomized Crossover Study

OBJECTIVE

This study compared the ability of glucagon to restore plasma glucose (PG) after mild hypoglycemia in patients with type 1 diabetes on an isocaloric high-carbohydrate diet (HCD) versus a low-carbohydrate diet (LCD).

RESEARCH DESIGN AND METHODS

Ten patients with insulin pump-treated type 1 diabetes randomly completed 1 week of the HCD (≥250 g/day) and 1 week of the LCD (≤50 g/day). After each week, mild hypoglycemia was induced by a subcutaneous insulin bolus in the fasting state. When PG reached 3.9 mmol/L, 100 µg glucagon was given subcutaneously, followed by 500 µg glucagon 2 h later.

RESULTS

Compared with the HCD, the LCD resulted in lower incremental rises in PG after the first (mean ± SEM: 1.3 ± 0.3 vs. 2.7 ± 0.4 mmol/L, P = 0.002) and second glucagon bolus (4.1 ± 0.2 vs. 5.6 ± 0.5 mmol/L, P = 0.002). No differences were observed between the diets regarding concentrations of insulin, glucagon, and triglycerides.

CONCLUSIONS

The LCD reduces the treatment effect of glucagon on mild hypoglycemia. Carbohydrate intake should be considered when low-dose glucagon is used to correct hypoglycemia.

Glucagon in artificial pancreas systems: Potential benefits and safety profile of future chronic use

The role of glucagon in the pathophysiology of diabetes has long been recognized, although its approved clinical use has so far been limited to the emergency treatment of severe hypoglycaemia. A novel use of glucagon as intermittent mini-boluses is proposed in the dual-hormone version (insulin and glucagon) of the external artificial pancreas. Short-term studies suggest that the incorporation of glucagon into artificial pancreas systems has the potential to further decrease hypoglycaemic risk and improve overall glucose control; however, the potential long-term safety and benefits also need to be investigated given the recognized systemic effects of glucagon. In the present report, we review the available animal and human data on the physiological functions of glucagon, as well as its pharmacological use, according to dosing and duration (acute and chronic). Along with its main role in hepatic glucose metabolism, glucagon affects the cardiovascular, renal, pulmonary and gastrointestinal systems. It has a potential role in weight reduction through its central satiety function and its role in increasing energy expenditure. Most of the pharmacological studies investigating the effects of glucagon have used doses exceeding 1 mg, in contrast to the mini-boluses used in the artificial pancreas. The available data are reassuring but comprehensive human studies using small but chronic glucagon doses that are close to the physiological ranges are lacking. We propose a list of variables that could be monitored during long-term trials of the artificial pancreas. Such trials should address the questions about the risk-benefit ratio of chronic glucagon use.