Glucagon Infusion Research Articles

Chronic late gestation fetal hyperglucagonaemia results in lower insulin secretion, pancreatic mass, islet area and beta- and α-cell proliferation.

Fetal glucagon concentrations are elevated in the presence of a compromised intrauterine environment, as in cases of placental insufficiency and perinatal acidaemia. Our objective was to investigate the impact of late gestation fetal hyperglucagonaemia on in vivo insulin secretion and pancreatic islet structure. Chronically catheterized late gestation fetal sheep received an intravenous infusion of glucagon at low (5ng/kg/min; GCG-5) or high (50ng/kg/min; GCG-50) concentrations or a vehicle control (CON) for 8-10days.Glucose-stimulated fetal insulin secretion (GSIS) was measured following 3h (acute response) and 8-10days (chronic response) of experimental infusions. Insulin, glucose and amino acid concentrations were measured longitudinally. The pancreas was collected at the study end for histology and gene expression analysis. Acute exposure (3h) to GCG-50 induced a 3-fold increase in basal insulin concentrations with greater GSIS. Meanwhile, chronic exposure to both GCG-5 and GCG-50 decreased basal insulin concentrations 2-fold by day 8-10. Chronic GCG-50 also blunted GSIS at the study end. Fetal amino acid concentrations were decreased within 24h of GCG-5 and GCG-50, while there were no differences in fetal glucose. Histologically, GCG-5 and GCG-50 had lower β- and α-cell proliferation, as well as lower α-cell mass and pancreas weight, while GCG-50 had lower islet area. This study demonstrates that chronic glucagon elevation in late gestation fetuses impairs β-cell proliferation and insulin secretion, which has the potential to contribute to later-life diabetes risk. We speculate that the action of glucagon in lower circulating fetal amino acid concentrations may have a suppressive effect on insulin secretion. KEY POINTS: We have previously demonstrated in a chronically catheterized fetal sheep model that experimentally elevated glucagon in the fetus impairs placental function, reduces fetal protein accretion and lowers fetal weight. In the present study, we further characterized the effects of elevated fetal glucagon on fetal physiology with a focus on pancreatic development and β-cell function. We show that experimentally elevated fetal glucagon results in lower β- and α-cell proliferation, as well as decreased insulin secretion after 8-10days of glucagon infusion. These results have important implications for β-cell reserve and later-life predisposition to diabetes.

7213 Severe IGF-2 Mediated Hypoglycemia In A Patient With Adrenocortical Carcinoma: A Case Report

Abstract Disclosure: M. Camelo Pereira: None. P. Itersky: None. S. Sternlieb: None. N. Manuel: None. J. Dendy: None. Background: Hypoglycemia has been rarely described as a complication of adrenocortical carcinoma (ACC). Tumor cells produce insulin-like growth factor II, causing a paraneoplastic syndrome with severe refractory hypoglycemia. We report the unusual case of a patient with known ACC presented with seizures and severe IGF-2 mediated hypoglycemia. Clinical case: A 21-year-old man presented to a regional hospital due to new onset seizures in September 2023. He had been diagnosed with ACC in July 2022, when he presented to the hospital with frank Cushing’s syndrome. CT scan of his chest and abdomen at that time revealed a large left suprarenal mass and multiple lung and liver masses; a biopsy from the liver lesion confirmed the diagnosis of ACC and he was started on treatment with mitotane, levoketoconazole and hydrocortisone. Oncology attempted treatment with 3 cycles of cisplatin and etoposide, with no significant response; subsequently, treatment with Keytruda initially decreased tumor size, but ultimately his CT scan showed progression of disease and mitotane was stopped in August 2023. When brought to the hospital in September 2023 due to seizures and altered mental status, the patient’s blood glucose (BG) was 25 mg/dL (70-110 mg/dL) on point of care testing, so he was started on IV 10% dextrose with improvement in BG and mental status. He underwent endotracheal intubation and was taken to the intensive care unit, showed improvement and was eventually transferred to the general medical floor, where the dextrose infusion was discontinued. However, the following day, he had another hypoglycemic episode complicated with a seizure and had to be reintubated, returning to intensive care. The patient was subsequently transferred to a large tertiary hospital. Evaluation showed undetectable point-of-care BG (< 5 mg/dL) as well as hypokalemia. Fasting labs showed undetectable BHB, undetectable insulin, C-peptide of 0.32 ng/mL (0.78 - 5.19 ng/mL), and negative insulin antibodies. IGF-2/IGF-1 ratio was elevated at 15.6, suggesting IGF-2 mediated hypoglycemia. He was started on IV glucose 20% and glucagon infusions. Mitotane was restarted aiming to decrease tumor burden and consequently IGF-2 levels. Given his hypokalemia, his levoketoconazole dose had to be increased; he was also treated with stress dose steroids. His BG levels improved, and he had partial neurologic recovery, however ultimately curative treatment was not possible given the extent of his disease, so he was transitioned to comfort-focused care. Conclusion: This case illustrates the importance of appropriate workup of IGF-2 mediated hypoglycemia, allowing for the best possible therapeutic approach. In our case, reducing tumor burden was not feasible since the patient had widely metastatic disease, leading to a poor outcome. Presentation: 6/3/2024

Glucagon Clearance Is Decreased in Chronic Kidney Disease but Preserved in Liver Cirrhosis.

It is not completely clear which organs are responsible for glucagon elimination in humans, and disturbances in the elimination of glucagon could contribute to the hyperglucagonemia observed in chronic liver disease and chronic kidney disease (CKD). Here, we evaluated kinetics and metabolic effects of exogenous glucagon in individuals with stage 4 CKD (n =16), individuals with Child-Pugh A-C cirrhosis (n = 16) and matched control individuals (n = 16), before, during and after a 60-minute glucagon infusion (4 ng/kg/min). Individuals with CKD exhibited a significantly lower mean metabolic clearance rate of glucagon (14.0 [95% CI 12.2;15.7] mL/kg/min) both compared to individuals with cirrhosis (19.7 [18.1;21.3] mL/kg/min, P < 0.001) and to control individuals (20.4 [18.1;22.7] mL/kg/min, P < 0.001). Glucagon half-life was significantly prolonged in the CKD group (7.5 [6.9;8.2] minutes) compared to individuals with cirrhosis (5.7 [5.2;6.3] minutes, P = 0.002) and control individuals (5.7 [5.2;6.3] minutes, P < 0.001). No difference in the effects of exogenous glucagon on plasma glucose, amino acids, or triglycerides was observed between groups. In conclusion, chronic kidney disease, but not liver cirrhosis leads to a significant reduction in glucagon clearance, supporting the kidneys as a primary site for human glucagon elimination.

Analysis of Glucose Responsive Glucagon Therapeutics using Computational Models of the Glucoregulatory System.

Glucose-responsive glucagon (GRG) therapeutics are a promising technology for reducing the risk of severe hypoglycemia as a complication of diabetes mellitus. Herein, the performance of candidate GRGs in the literature by modeling the kinetics of activation and connecting them as input into physiological glucoregulatory models is evaluated and projected the two distinct GRG designs, experimental results reported in Wu etal. (GRG-I) and Webber etal. (GRG-II) is considered. Both are evaluated using a multi-compartmental glucoregulatory model (IMPACT) and used to compare in-vivo experimental data of therapeutic performance in rats and mice. For GRG-I and GRG-II, the total integrated glucose material balances are overestimated by 41.5% ± 14% and underestimated by 24.8% ± 16% compared to in-vivo time-course data, respectively. These large differences to the relatively simple computational descriptions of glucagon dynamics in the model, which underscores the urgent need for improved glucagon models is attributed. Additionally, therapeutic insulin and glucagon infusion pumps are modeled for type 1 diabetes mellitus (T1DM) human subjects to extend the results to additional datasets. These observations suggest that both the representative physiological and non-physiological models considered in this work require additional refinement to successfully describe clinical data that involve simultaneous, coupled insulin, glucose, and glucagon dynamics.

In silico validation of a customizable fully-autonomous artificial pancreas with coordinated insulin, glucagon and rescue carbohydrates

Artificial pancreas systems should be designed considering different patient profiles, which is challenging from a control theory perspective. In this paper, a flexible-hybrid dual-hormone control algorithm for an artificial pancreas is proposed. The algorithm handles announced/unannounced meals by means of a non-interacting feedforward scheme that safely incorporates prandial boluses. Also, a coordination strategy is employed to distribute the counter-regulatory actions, which can be delivered as a continuous glucagon infusion via an automated pump, as an oral rescue carbohydrate recommendation, or as a rescue glucagon dose recommendation to be administrated through a glucagon pen. The different configurations of the proposed controller were evaluated in silico using a 14-day virtual scenario with random meal intakes and exercise sessions, achieving above 80% time-in-range and low time spent in hypoglycemia.

High-energy pacing inhibits slow-wave dysrhythmias in the small intestine.

The motility of the gastrointestinal tract is coordinated in part by rhythmic slow waves, and disrupted slow-wave patterns are linked to functional motility disorders. At present, there are no treatment strategies that primarily target slow-wave activity. This study assessed the use of pacing to suppress glucagon-induced slow-wave dysrhythmias in the small intestine. Slow waves in the jejunum were mapped in vivo using a high-resolution surface-contact electrode array in pigs (n = 7). Glucagon was intravenously administered to induce hyperglycemia. Slow-wave propagation patterns were categorized into antegrade, retrograde, collision, pacemaker, and uncoupled activity. Slow-wave characteristics such as period, amplitude, and speed were also quantified. Postglucagon infusion, pacing was applied at 4 mA and 8 mA and the resulting slow waves were quantified spatiotemporally. Antegrade propagation was dominant throughout all stages with a prevalence of 55 ± 38% at baseline. However, glucagon infusion resulted in a substantial and significant increase in uncoupled slow waves from 10 ± 8% to 30 ± 12% (P = 0.004) without significantly altering the prevalence of other slow-wave patterns. Slow-wave frequency, amplitude, and speed remained unchanged. Pacing, particularly at 8 mA, significantly suppressed dysrhythmic slow-wave patterns and achieved more effective spatial entrainment (85%) compared with 4 mA (46%, P = 0.039). This study defined the effect of glucagon on jejunal slow waves and identified uncoupling as a key dysrhythmia signature. Pacing effectively entrained rhythmic activity and suppressed dysrhythmias, highlighting the potential of pacing for gastrointestinal disorders associated with slow-wave abnormalities.NEW & NOTEWORTHY Glucagon was infused in pigs to induce hyperglycemia and the resulting slow-wave response in the intact jejunum was defined in high resolution for the first time. Subsequently, with pacing, the glucagon-induced dysrhythmias were suppressed and spatially entrained for the first time with a success rate of 85%. The ability to suppress slow-wave dysrhythmias through pacing is promising in treating motility disorders that are associated with intestinal dysrhythmias.

Glucagon infusion alters the circulating metabolome and urine amino acid excretion in dogs.

Glucagon plays a central role in amino acid (AA) homeostasis. The dog is an established model of glucagon biology, and recently, metabolomic changes in people associated with glucagon infusions have been reported. Glucagon also has effects on the kidney; however, changes in urinary AA concentrations associated with glucagon remain under investigation. Therefore, we aimed to fill these gaps in the canine model by determining the effects of glucagon on the canine plasma metabolome and measuring urine AA concentrations. Employing two constant rate glucagon infusions (CRI) - low-dose (CRI-LO: 3 ng/kg/min) and high-dose (CRI-HI: 50 ng/kg/min) on five research beagles, we monitored interstitial glucose and conducted untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) on plasma samples and urine AA concentrations collected pre- and post-infusion. The CRI-HI induced a transient glucose peak (90-120 min), returning near baseline by infusion end, while only the CRI-LO resulted in 372 significantly altered plasma metabolites, primarily reductions (333). Similarly, CRI-HI affected 414 metabolites, with 369 reductions, evidenced by distinct clustering post-infusion via data reduction (PCA and sPLS-DA). CRI-HI notably decreased circulating AA levels, impacting various AA-related and energy-generating metabolic pathways. Urine analysis revealed increased 3-methyl-l-histidine and glutamine, and decreased alanine concentrations post-infusion. These findings demonstrate glucagon's glucose-independent modulation of the canine plasma metabolome and highlight the dog's relevance as a translational model for glucagon biology. Understanding these effects contributes to managing dysregulated glucagon conditions and informs treatments impacting glucagon homeostasis.

Increased hepatic glucagon sensitivity in totally pancreatectomised patients.

The metabolic phenotype of totally pancreatectomised patients includes hyperaminoacidaemia and predisposition to hypoglycaemia and hepatic lipid accumulation. We aimed to investigate whether the loss of pancreatic glucagon may be responsible for these changes. Nine middle-aged, normal-weight totally pancreatectomised patients, nine patients with type 1 diabetes (C-peptide negative), and nine matched controls underwent two separate experimental days, each involving a 150-min intravenous infusion of glucagon (4 ng/kg/min) or placebo (saline) under fasting conditions while any basal insulin treatment was continued. Glucagon infusion increased plasma glucagon to similar high physiological levels in all groups. The infusion increased hepatic glucose production and decreased plasma concentration of most amino acids in all groups, with more pronounced effects in the totally pancreatectomised patients compared with the other groups. Glucagon infusion diminished fatty acid re-esterification and tended to decrease plasma concentrations of fatty acids in the totally pancreatectomised patients but not in the type 1 diabetes patients. Totally pancreatectomised patients were characterised by increased sensitivity to exogenous glucagon at the level of hepatic glucose, amino acid, and lipid metabolism, suggesting that the metabolic disturbances characterising these patients may be rooted in perturbed hepatic processes normally controlled by pancreatic glucagon.

Acute insulin-induced hypoglycemia in twin neonates

Twin neonates with a history of exogenous insulin administration by a mother suffering from post-partum psychosis are reported. Twin 1 presented with lethargy, while twin 2 presented with apnea and bradycardia, requiring vigorous resuscitation. During their neonatal intensive care unit stay, both the babies developed multiple episodes of symptomatic refractory hypoglycemia with seizures and were managed with intravenous dextrose boluses and infusion, glucagon infusion, octreotide, diazoxide, and glucocorticoids. Although short-acting regular insulin (Actrapid, Novo Nordisk™) preparation was administered to the neonates, its effects were seen for a duration of 3–4 days, probably due to the depot effect. We highlight the importance of history taking and physical examination for early diagnosis and appropriate management.

Unveiling the Downside of Glucagon Therapy for Neonatal Hypoglycemia: A Case Report

Here we report a case of a late preterm baby, noted to have asymptomatic hypoglycemia and developed transient metabolic acidosis with hyponatremia and hyperkalemia whilst being treated with continuous infusion of glucagon.

The effect of exogenous glucagon on circulating amino acids in individuals with and without type 2 diabetes and obesity.

In obesity and type 2 diabetes, hyperglucagonaemia may be caused by elevated levels of glucagonotropic amino acids due to hepatic glucagon resistance at the level of amino acid turnover. Here, we investigated the effect of exogenous glucagon on circulating amino acids in obese and non-obese individuals with and without type 2 diabetes. This was a post hoc analysis in a glucagon infusion study performed in individuals with type 2 diabetes (n = 16) and in age, sex, and body mass index-matched control individuals without diabetes (n = 16). Each group comprised two subgroups of eight individuals with and without obesity, respectively. All participants received a 1-h glucagon infusion (4 ng/kg/min) in the overnight fasted state. Plasma amino acid concentrations were measured with frequent intervals. Compared to the control subgroup without obesity, baseline total amino acid levels were elevated in the control subgroup with obesity and in the type 2 diabetes subgroup without obesity. In all subgroups, amino acid levels decreased by up to 20% in response to glucagon infusion, which resulted in high physiological steady-state glucagon levels (mean concentration: 74 pmol/L, 95% CI [68;79] pmol/L). Following correction for multiple testing, no intergroup differences in changes in amino acid levels reached significance. Obesity and type 2 diabetes status was associated with elevated fasting levels of total amino acids. The glucagon infusion decreased circulating amino acid levels similarly in all subgroups, without significant differences in the response to exogenous glucagon between individuals with and without obesity and type 2 diabetes. The hormone glucagon stimulates glucose production from the liver, which may promote hyperglycaemia if glucagon levels are abnormally elevated, as is often seen in type 2 diabetes and obesity. Glucagon levels are closely linked to, and influenced by, the levels of circulating amino acids. To further investigate this link, we measured amino acid levels in individuals with and without obesity and type 2 diabetes before and during an infusion of glucagon. We found that circulating amino acid levels were higher in type 2 diabetes and obesity, and that glucagon infusion decreased amino acid levels in both individuals with and without type 2 diabetes and obesity. The study adds novel information to the link between circulating levels of glucagon and amino acids.

Effects of glucagon as a neurohormone on the central nervous system and glucose homeostasis.

This study aimed to elucidate the possible effects of the acute/long-term infusion of glucagon in the brain as the regulatory role on the endocrine secretions of the pancreas. Ninety male Wistar albino rats were divided as Control, artificial Cerebrospinal Fluid (aCSF) (120 min), Glucagon (120 min), pancreatic denervation (PD)+aCSF (120 min), PD+Glucagon (120 min), aCSF (7 days), Glucagon (7 days), PD+aCSF (7 days) and PD+Glucagon (7 days). Glucagon and solvent (aCSF) were administered after pancreatic denervation (PD) by Hamilton syringe and osmotic mini pump (1 µg/10 µl/min) in the third ventricle of the brain. Acute intracerebroventricular (icv) administration of glucagon resulted in an elevation of glucagon levels and a concurrent reduction in blood glucose levels. Furthermore, in both the PD+aCSF (7 days) and PD+Glucagon (7 days) groups, there was a notable decrease in propiomelanocortin (POMC) and agouti-related protein (AgRP). Significant changes were observed in feed consumption and body weight, as well as pancreatic glucagon levels, with a simultaneous decrease in insulin levels in the PD (7 days), Glucagon (7 days), and PD+Glucagon (7 days) groups. These alterations were statistically significant when compared to the control group (p<0.05). The research outcomes established that pancreas-secreted glucagon functions as a neurohormone within the brain, activating central pathways linked to blood glucose regulation. The presence of glucagon led to a decrease in POMC levels. Surprisingly, this reduction in POMC resulted in the suppression of AgRP. Contrary to expectations, the suppression of AgRP led to an increase in food intake rather than a decrease. As already highlighted in the results section, it was emphasized that POMC may play a more significant role than AgRP in influencing feeding behavior.

Anaphylaxis and Cardiac Arrest in a Patient during the 14th Transarterial Chemo-embolization for Hepatocellular Carcinoma

Transarterial chemo-embolization (TACE) is a valid and recommended treatment for patients with Barcelona Clinic Liver Cancer (BCLC) Stage B hepatocellular carcinoma (HCC). It is considered a safe procedure and the treatment-related mortality rate is less than 1%, mostly associated with acute liver failure, sepsis, renal failure or liver abscess. We reported a rare case of anaphylaxis and cardiac arrest during TACE, followed by successful cardiopulmonary resuscitation (CPR) and the management per anaphylaxis guideline, including epinephrine injection and glucagon infusion. The patient recovered well from this event and continued his treatment for HCC. The diagnosis, management and laboratory analysis of anaphylaxis is also reviewed in discussion. To our knowledge, it is the first case report of anaphylaxis-related cardiac arrest during TACE.

High Doses of Exogenous Glucagon Stimulate Insulin Secretion and Reduce Insulin Clearance in Healthy Humans.

Glucagon is generally defined as a counter-regulatory hormone with a primary role to raise blood glucose concentrations by increasing endogenous glucose production (EGP) in response to hypoglycemia. However, glucagon has long been known to stimulate insulin release, and recent preclinical findings support a paracrine action of glucagon directly on islet β-cells that augments secretion. In mice, the insulinotropic effect of glucagon is glucose dependent and not present during basal euglycemia. To test the hypothesis that the relative effects of glucagon on hepatic and islet function were also varied with blood glucose, a group of healthy subjects received glucagon (100 ng/kg) during fasting glycemia or experimental hyperglycemia (~150 mg/dl) on two separate days. During fasting euglycemia, administration of glucagon caused blood glucose to rise due to increased EGP, with a delayed increase of insulin secretion. When given during experimental hyperglycemia, glucagon caused a rapid, 3-fold increase in insulin secretion, as well as a more gradual increase in EGP. Under both conditions, insulin clearance was decreased in response to glucagon infusion. The insulinotropic action of glucagon, which is proportional to elevated levels of blood glucose, suggests distinct physiologic roles in the fasting and prandial states.

Signs of Glucagon Resistance After a 2-Week Hypercaloric Diet Intervention.

Hyperglucagonemia is observed in individuals with obesity and contributes to the hyperglycemia of patients with type 2 diabetes. Hyperglucagonemia may develop due to steatosis-induced hepatic glucagon resistance resulting in impaired hepatic amino acid turnover and ensuing elevations of circulating glucagonotropic amino acids. We evaluated whether glucagon resistance could be induced in healthy individuals by a hypercaloric diet intervention designed to increase hepatic fat content. We recruited 20 healthy male individuals to follow a hypercaloric diet and a sedentary lifestyle for 2 weeks. Amino acid concentrations in response to infusion of glucagon were assessed during a pancreatic clamp with somatostatin and basal insulin. The reversibility of any metabolic changes was assessed 8 weeks after the intervention. Hepatic steatosis was assessed by magnetic resonance spectroscopy. The intervention led to increased hepatic fat content (382% [206%; 705%], P < .01). Glucagon infusion led to a decrease in the concentration of total amino acids on all experimental days, but the percentage change in total amino acids was reduced (-2.5% ± 0.5% vs -0.2% ± 0.7%, P = .015) and the average slope of the decline in the total amino acid concentration was less steep (-2.0 ± 1.2 vs -1.2 ± 0.3 μM/min, P = .016) after the intervention compared to baseline. The changes were normalized at follow-up. Our results indicate that short-term unhealthy behavior, which increases hepatic fat content, causes a reversible resistance to the effect of glucagon on amino acid concentrations in healthy individuals, which may explain the hyperglucagonemia associated with obesity and diabetes.

FRI610 Phosphatidylinositol 3-kinase Inhibition With Alpelisib Is Safe And Effective In Treating Refractory Hypoglycemia Associated With Malignant Insulinoma

Abstract Disclosure: Y. Kang: None. D.A. Rubinson: None. I. Odintsov: None. A. Vaidya: None. J.S. Williams: None. G.K. Adler: None. M.E. McDonnell: None. M. Patti: Advisory Board Member; Self; Fractyl Laboratories. Consulting Fee; Self; AstraZeneca, Hanmi Pharmaceuticals, MBX. Grant Recipient; Self; Dexcom. N.E. Palermo: None. Background: Nonfunctioning malignant pancreatic neuroendocrine tumors (PNETs) can transform to functional PNETs. Transformation into insulin-secreting PNET (ISPNET) is associated with poor overall survival and refractory hypoglycemia, often requiring ICU care. We present a case of refractory hypoglycemia due to ISPNET, which was successfully treated with alpelisib, an inhibitor of phosphatidylinositol 3-kinase (PI3K) currently approved for breast cancer. Clinical Case: A 79-year-old man with a 5-year history of type 2 diabetes and 10-year history of grade II, well-differentiated, non-functioning PNET (Ki67 15%) with hepatic metastasis presented with worsening symptomatic hypoglycemia. He discontinued his antidiabetic agent 3 months ago due to hypoglycemia and was on lanreotide and everolimus as PNET treatment. Evaluation revealed plasma glucose 29 mg/dL, proinsulin &amp;gt;700 pmol/L (reference: 3.6-22), insulin 116 uIU/mL (2.6-24.9), C-peptide 12.0 ng/mL (1.1-4.4), beta-hydroxybutyrate 0.1 mmol/L (&amp;lt;0.3), and negative sulfonylurea panel. Imaging showed extensive progression of hepatic metastases, and debulking hepatectomy was performed. Pathology showed grade III PNET with positive insulin staining and mib-1 index of 22%. After 2 months of euglycemia post-surgery, he was readmitted to the ICU with refractory hypoglycemia. Evaluation showed plasma glucose 91 mg/dL, proinsulin, and insulin levels above-assay (&amp;gt;700 pmol/L and &amp;gt;930.0 uIU/mL, respectively) and C-peptide 71.8 ng/mL; imaging revealed hepatic tumor progression. Severe hypoglycemia as low as 34 mg/dL was noted despite therapy with IV dextrose (30%, up to 100 cc/hr), glucagon infusion (0.6 mg/hr), dexamethasone 20 mg QD, and diazoxide 30 mg TID. Debilitating anasarca developed despite aggressive diuresis, attributed to high-volume IV dextrose, diazoxide, and renal dysfunction. Two hours after 300 mg alpelisib administration, patient exhibited hyperglycemia, allowing discontinuation of dextrose infusion 8 hours later. Glucagon infusion was subsequently discontinued, and he was discharged to home. Within 20 days, the patient was able to discontinue all diuretics, dexamethasone, and cornstarch. Patient had no side effects related to alpelisib and performance status returned to baseline. Glucose ranged between 160-300 mg/dL without any hypoglycemia. On week 4 of alpelisib, plasma glucose was 340 mg/dL, proinsulin &amp;gt;700 pmol/L, insulin 181 uIU/mL, and C-peptide 20.2 ng/mL. Conclusion: To our knowledge, this is the first case demonstrating alpelisib as a safe and effective option in refractory hypoglycemia associated with insulinoma. While it is unclear whether this is mediated by anti-tumor effects or solely by blockade of insulin action, PI3-K inhibition should be considered as a treatment option in patients with ISPNET in whom hypoglycemia has failed to improve with conventional approaches. Presentation: Friday, June 16, 2023

FRI667 Profound And Persistent Hypoglycemia With Hepatocellular Carcinoma- A Non-islet Cell Tumor

Abstract Disclosure: A. Muneeb: None. M. Shahid: None. M. Raza: None. H. Zahoor: None. S. Sultan: None. Introduction: Tumor related hypoglycemia is rare and can be caused by islet cell tumors or non-islet cell tumors (NICT). Proposed mechanisms for non-islet cell tumor hypoglycemia (NICTH) include: increased big-IGF production (precursor of IGF2 which acts similar to insulin); increased insulin production; infiltration of liver/adrenals; and autoantibodies to insulin receptors. Clinical Case: A 78-year-old female with pertinent medical history of recently diagnosed locally advanced hepatocellular carcinoma (HCC) was found unresponsive at home. On arrival of EMS, the blood glucose (BG) level was in 30s. Dextrose water was administered that resulted in improvement of her mentation. She was alert and awake when brought to the hospital but was persistently hypoglycemic despite frequent feeding. She was started on dextrose infusion and was admitted for workup of persistent hypoglycemia. She denied history of diabetes, insulin or sulfonylurea use. She reported an admission to another facility for hypoglycemia 4 days ago where adrenal insufficiency was ruled out with normal morning cortisol levels. During this hospitalization, CBC and CMP were unremarkable except low BG. A CT scan of the abdomen/pelvis was consistent with locally advanced HCC. Fasting protocol was started and BG monitoring was performed every 30 minutes. When BG fell below 55 mg/dL; C-peptide, insulin and proinsulin levels were drawn which came back severely suppressed at 0.13 ng/mL, &amp;lt;1 mU/L, and 2.7 pmol/L respectively. IGF2 was low-normal at 339 ng/mL. Given aforementioned workup and exclusion of other causes including medications, insulinoma and adrenal insufficiency, hypoglycemia was attributed to big-IGF mediated NICTH. Dextrose infusion was re-initiated but the patient continued to have BG in 30s, which was verified by both finger-stick and serum chemistry. Dexamethasone was initiated and dextrose infusion was continued. Oncology deemed her a poor surgical candidate. She declined other therapies for HCC. BG stabilized after institution of steroids, dextrose infusion was weaned successfully, and patient was discharged. Conclusion: A high index of suspicion should be held for NICTH in patients with profound hypoglycemia refractory to dextrose infusions in the setting of NICT. The diagnosis of NICTH can be made with suppressed insulin and C-peptide, elevated big-IGF, and normal-reduced IGF2 levels. Management of NICTH related to HCC is tumor resection. However, local anti-tumor therapies can be considered in non-surgical candidates. Since NICTH can be refractory to dextrose infusion, steroids with or without GH are an effective option. In refractory cases, continuous glucagon infusion and parenteral nutrition can be considered. Further research is needed to help develop better treatment options. We hope to contribute to the current literature regarding NICTH and bring awareness to the medical community. Presentation: Friday, June 16, 2023

Challenges in the management of hyperinsulinemic hypoglycemia in a preterm neonate - A case report and literature review

Hyperinsulinemic hypoglycemia (HH) includes a diverse group of disorders characterized by dysregulated insulin secretion, exhibiting clinical, genetic, and morphological heterogeneity. It is associated with permanent brain damage. Hence, a timely diagnosis and prompt management are essential to safeguard against complications such as epilepsy, cerebral palsy, and neurodevelopmental deficits. We report the challenges faced in the management of HH in a preterm neonate. A baby girl was born to a G2A1 mother at 31 weeks of gestation due to preterm onset of labor with premature rupture of membranes. The baby had persistent and refractory hypoglycemia requiring oral and parenteral medications such as diazoxide, hydrochlorothiazide, hydrocortisone, nifedipine, glucagon infusion, and subcutaneous octreotide. Genetic testing unveiled a homozygous pathogenic mutation of the ABCC8 gene with autosomal recessive (AR) inheritance. As the AR inheritance always presents with diffuse lesions, a 18F-fluoro-dihydroxyphenylalanine positron emission computed tomography (18F-DOPA PET) scan was not done to differentiate focal and diffuse lesions. The baby underwent laparoscopic near-total pancreatectomy and was discharged on subcutaneous octreotide. Continuous intravenous glucagon infusion may help reduce the infusion rate of glucose needed to maintain normoglycemia. Diazoxide unresponsiveness in a baby with HH needs genetic studies. AR inheritance always presents as diffuse lesions. Hence, an 18F-DOPA PET scan can be deferred to differentiate the diffuse and focal forms.

Nonlinear Mixed Effects Modeling of Glucagon Kinetics in Healthy Subjects.

To date, the lack of a model of glucagon kinetics precluded the possibility of estimating and studying glucagon secretion in vivo, e.g., using deconvolution, as done for other hormones like insulin and C-peptide. Here, we used a nonlinear mixed effects technique to develop a robust population model of glucagon kinetics, able to describe both the typical population kinetics (TPK) and the between-subject variability (BSV), and relate this last to easily measurable subject characteristics. Thirty-four models of increasing complexity (variably including covariates and correlations among random effects) were identified on glucagon profiles obtained from 53 healthy subjects, who received a constant infusion of somatostatin to suppress endogenous glucagon production, followed by a continuous infusion of glucagon (65 ng/kg/min). Model selection was performed based on its ability to fit the data, provide precise parameter estimates, and parsimony criteria. A two-compartment model was the most parsimonious. The model was able to accurately describe both the TPK and the BSV of model parameters as function of body mass and body surface area. Parameters were precisely estimated, with central volume of distribution V1 = 5.46 L and peripheral volume of distribution V2 = 5.51 L. The introduction of covariates resulted in a significant shrinkage of the unexplained BSV and considerably improved the model fit. We developed a robust population model of glucagon kinetics. This model provides a deeper understanding of glucagon kinetics and is usable to estimate glucagon secretion in vivo by deconvolution of plasma glucagon concentration data.

Dual hormone fully closed loop in type 1 diabetes: a randomised trial in the Netherlands – study protocol

IntroductionThe management of type 1 diabetes (T1DM) has undergone significant advancements with the availability of novel technologies, notably continuous and flash glucose monitoring (CGM and FGM, respectively) and hybrid closed...