Prolonged successful therapy for hyperinsulinaemic hypoglycaemia after gastric bypass: the pathophysiological role of GLP1 and its response to a somatostatin analogue

Post-Bariatric Hypoglycemia: an Impaired Metabolic Response to a Meal

AIMS/HYPOTHESIS

Post-bariatric hypoglycemia (PBH) is caused by postprandial hyperinsulinemia, due to anatomical alterations and changes in post-prandial metabolism after bariatric surgery. The mechanisms underlying the failing regulatory and compensatory systems are unclear. In this study, we investigated the differences in post-prandial hormones and metabolic profiles between patients with and without PBH.

METHODS

We performed a mixed meal test (MMT) in 63 subjects before and 1 year after Roux-en-Y gastric bypass (RYGB) surgery. Blood was withdrawn at 0, 10, 20, 30, 60, and 120 min after ingestion of a standardized meal. Glucose, insulin, GLP-1, FGF-19, and FGF-21 were measured and untargeted metabolomics analysis was performed on blood plasma to analyze which hormonal and metabolic systems were altered between patients with and without PBH.

RESULTS

Out of 63, a total of 21 subjects (33%) subjects developed PBH (glucose < 3.1 mmol/L) after surgery. Decreased glucose and increased insulin excursions during MMT were seen in PBH (p < 0.05). GLP-1, FGF-19, and FGF-21 were elevated after surgery (p < 0.001), but did not differ between PBH and non-PBH groups. We identified 20 metabolites possibly involved in carbohydrate metabolism which differed between the two groups, including increased carnitine and acylcholines in PBH.

CONCLUSION

Overall, 33% of the subjects developed PBH 1 year after RYGB surgery. While GLP-1, FGF-19, and FGF-21 were similar in PBH and non-PBH patients, metabolomics analysis revealed changes in carnitine and acyclcholines that are possibly involved in energy metabolism, which may play a role in the occurrence of PBH.

Proposed treatment strategy for reactive hypoglycaemia

Background/aim

Managing reactive hypoglycaemia (RH) poses challenges due to limited and often ineffective treatment options. We report a case series and draw on this to propose a stepwise treatment approach consisting of lifestyle modifications, metformin, GLP-1 analogues, and the use of flash glucose monitoring technology.

Method

A retrospective review was conducted to analyse the management of 11 cases presenting with recurrent RH symptoms.

Result

Two patients experienced successful resolution of symptoms through lifestyle modifications. Metformin alone was effective in treating seven out of nine patients who received pharmacological treatment. Two patients with previous upper gastrointestinal surgery showed a partial response to metformin and benefited further from additional long-acting GLP-1 analogue. Pharmacological intervention led to significant reductions in insulin and C-peptide levels in repeat mixed meal tolerance tests (P-values 0.043 for insulin and 0.006 for C-peptide). Finally, flash glucose monitoring technology was useful in early detection and preventing episodes of hypoglycaemia in one of these patients with persistent symptoms.

Conclusion

These findings highlight the potential efficacy of escalated treatment strategies for RH, including the use of metformin, GLP-1 analogues, and flash glucose monitoring technology.

Successful Treatment of Postprandial Hyperinsulinemic Hypoglycemia After Billroth-II Gastrojejunostomy Using Octreotide

Postprandial hyperinsulinemic hypoglycemia, although rare, is a well-documented complication that can manifest after upper gastrointestinal surgery. Despite its potential for severe morbidity, the underlying pathogenesis and optimal treatment strategies for this condition remain insufficiently understood. This report presents a compelling case of postprandial hypoglycemia following Billroth-II gastrojejunostomy, characterized by a marked increase in postprandial insulin levels, accompanied by the exaggerated response of incretin hormones. The incretin effect in this patient was found to be exceptionally high, measuring at approximately 90%. While nutritional interventions proved ineffective in alleviating the patient's symptoms, the administration of octreotide significantly attenuated the exaggerated postprandial insulin and incretin response, substantially ameliorating both the symptoms and postprandial hypoglycemia. Monthly subcutaneous injections of long-acting repeatable octreotide were initiated, resulting in the complete resolution of symptomatic postprandial hypoglycemia. Although the patient developed acalculous cholecystitis and gallstone cholangitis 2 years after commencing octreotide therapy, she has remained free from symptomatic postprandial hypoglycemia for more than 4 years. Our case underscores the efficacy of somatostatin analogs in the management of postprandial hyperinsulinemia after gastrointestinal surgery, shedding light on the potential involvement of incretin hormones in the pathophysiology of this condition.

Diagnosis and management of post-bariatric surgery hypoglycemia

INTRODUCTION

While bariatric surgery remains the most effective treatment for obesity that allows substantial weight loss with improvement and possibly remission of obesity-associated comorbidities, some postoperative complications may occur. Managing physicians need to be familiar with the common problems to ensure timely and effective management. Of these complications, postoperative hypoglycemia is an increasingly recognized complication of bariatric surgery that remains underreported and underdiagnosed.

AREA COVERED

This article highlights the importance of identifying hypoglycemia in patients with a history of bariatric surgery, reviews pathophysiology and addresses available nutritional, pharmacological and surgical management options. Systemic evaluation including careful history taking, confirmation of hypoglycemia and biochemical assessment is essential to establish accurate diagnosis. Understanding the weight-dependent and weight-independent mechanisms of improved postoperative glycemic control can provide better insight into the causes of the exaggerated responses that lead to postoperative hypoglycemia.

EXPERT OPINION

Management of post-operative hypoglycemia can be challenging and requires a multidisciplinary approach. While dietary modification is the mainstay of treatment for most patients, some patients may benefit from pharmacotherapy (e.g. GLP-1 receptor antagonist); Surgery (e.g. reversal of gastric bypass) is reserved for unresponsive severe cases. Additional research is needed to understand the underlying pathophysiology with a primary aim in optimizing diagnostics and treatment options.

Diffuse, Adult-Onset Nesidioblastosis/Non-Insulinoma Pancreatogenous Hypoglycemia Syndrome (NIPHS): Review of the Literature of a Rare Cause of Hyperinsulinemic Hypoglycemia

Differential diagnosis of hypoglycemia in the non-diabetic adult patient is complex and comprises various diseases, including endogenous hyperinsulinism caused by functional β-cell disorders. The latter is also designated as nesidioblastosis or non-insulinoma pancreatogenous hypoglycemia syndrome (NIPHS). Clinically, this rare disease presents with unspecific adrenergic and neuroglycopenic symptoms and is, therefore, often overlooked. A combination of careful clinical assessment, oral glucose tolerance testing, 72 h fasting, sectional and functional imaging, and invasive insulin measurements can lead to the correct diagnosis. Due to a lack of a pathophysiological understanding of the condition, conservative treatment options are limited and mostly ineffective. Therefore, nearly all patients currently undergo surgical resection of parts or the entire pancreas. Consequently, apart from faster diagnosis, more elaborate and less invasive treatment options are needed to relieve the patients from the dangerous and devastating symptoms. Based on a case of a 23-year-old man presenting with this disease in our department, we performed an extensive review of the medical literature dealing with this condition and herein presented a comprehensive discussion of this interesting disease, including all aspects from epidemiology to therapy.

Medical and surgical treatment of postbariatric hypoglycaemia: Retrospective data from daily practice

AIM

To evaluate medical and surgical treatment of postbariatric hypoglycaemia (PBH) in daily practice.

MATERIALS AND METHODS

Retrospective data were extracted from medical records from four hospitals. PBH was defined by neuroglycopenic symptoms together with a documented glucose <3.0 mmol/L in the postprandial setting after previous bariatric surgery. Data were scored semiquantitatively on efficacy and side effects by two reviewers independently. Duration of efficacy and of use were calculated.

RESULTS

In total, 120 patients were included with a median follow-up of 27 months with a mean baseline age of 41 years, total weight loss of 33% and glucose nadir 2.3 mmol/L. Pharmacotherapy consisted of acarbose, diazoxide, short- and long-acting octreotide and glucagon-like peptide-1 receptor agonist analogues (liraglutide and semaglutide) with an overall efficacy in 45%-75% of patients. Combination therapy with two drugs was used by 30 (25%) patients. The addition of a second drug was successful in over half of the patients. Long-acting octreotide and the glucagon-like peptide-1 receptor agonist analogues scored best in terms of efficacy and side effects with a median duration of use of 35 months for octreotide. Finally, 23 (19%) patients were referred for surgical intervention. Efficacy of the surgical procedures, pouch banding, G-tube placement in remnant stomach and Roux-en-Y gastric bypass reversal, pooled together, was 79% with a median duration of initial effect of 13 months.

CONCLUSIONS

In daily practice, pharmacotherapy for PBH was successful in half to three quarters of patients. Combination therapy was often of value. One in five patients finally needed a surgical procedure, with overall good results.

Adult focal β-cell nesidioblastosis: A case report

BACKGROUND

Nesidioblastosis usually refers to a series of clinical manifestations caused by the proliferation of β-cells in pancreatic islets, and these clinical manifestations are hyperinsulinemia and persistent hypoglycemia. According to the size of the lesion, nesidioblastosis is divided into focal nesidioblastosis, diffuse nesidioblastosis and atypical nesidioblastosis, and its pathogenesis is still unclear. Nesidioblastosis is mainly seen in infants and rarely reported in adults, especially focal nesidioblastosis, which is difficult to distinguish from insulinoma.

CASE SUMMARY

We report a case of adult focal β-cell nesidioblastosis in which the preoperative diagnosis was insulinoma. The patient was a 48-year-old male who suffered from repeated morning and fasting palpitations, sweating, and severe disturbance of consciousness for 5 years. His blood glucose was found to be as low as 1.79 mmol/L during an attack. However, abdominal computed tomography showed no abnormalities. Magnetic resonance imaging and endoscopic ultrasonography demonstrated a nodular mass in the head of the pancreas, combined with hyperinsulinemia and high serum C-peptide. The patient was diagnosed with insulinoma and underwent Beger surgery; however, the postoperative pathological results showed nesidioblastosis.

CONCLUSION

Although surgical resection is the preferred option for nesidioblastosis, some cases can be treated non-surgically. In order to increase clinicians' understanding of nesidioblastosis, it is necessary to review the pathogenesis, diagnosis and treatment of this disease.

The efficacy of GLP-1RAs for the management of postprandial hypoglycemia following bariatric surgery: a systematic review

OBJECTIVE

Postprandial hyperinsulinemic hypoglycemia with neuroglycopenia is an increasingly recognized complication of Roux-en-Y gastric bypass and gastric sleeve surgery that may detrimentally affect patient quality of life. One likely causal factor is glucagon-like peptide-1 (GLP-1), which has an exaggerated rise following ingestion of carbohydrates after bariatric surgery. This paper sought to assess the role of GLP-1 receptor agonists (GLP-1RAs) in managing postprandial hypoglycemia following bariatric surgery.

METHODS

MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and Scopus were systematically and critically appraised for all peer-reviewed publications that suitably fulfilled the inclusion criteria established a priori. This systematic review was developed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols (PRISMA-P). It followed methods outlined in the Cochrane Handbook for Systematic Reviews of Interventions and is registered with PROSPERO (International Prospective Register of Systematic Reviews; identifier CRD420212716429).

RESULTS AND CONCLUSIONS

Postprandial hyperinsulinemic hypoglycemia remains a notoriously difficult to manage metabolic complication of bariatric surgery. This first, to the authors' knowledge, systematic review presents evidence suggesting that use of GLP-1RAs does not lead to an increase of hypoglycemic episodes, and, although this approach may appear counterintuitive, the findings suggest that GLP-1RAs could reduce the number of postprandial hypoglycemic episodes and improve glycemic variability.

Medical Nutrition Therapy and Other Approaches to Management of Post-bariatric Hypoglycemia: A Team-Based Approach

PURPOSE OF REVIEW

This manuscript provides a review of post-bariatric hypoglycemia (PBH) with a special focus on the role of the registered dietitian-nutritionist (RDN) and medical nutrition therapy (MNT) recommendations as foundational for management.

RECENT FINDINGS

As the number of bariatric surgeries rises yearly, with 256,000 performed in 2019, PBH is an increasingly encountered late complication. Following Roux-en-Y (RYGB) or vertical sleeve gastrectomy (VSG), about 1/3 of patients report symptoms suggestive of at least mild postprandial hypoglycemia, with severe and/or medically confirmed hypoglycemia in 1-10%. Anatomical alterations, changes in GLP1 and other intestinally derived hormones, excessive insulin response, reduced insulin clearance, impaired counterregulatory hormone response to hypoglycemia, and other factors contribute to PBH. MNT is the cornerstone of multidisciplinary treatment, with utilization of personal continuous glucose monitoring to improve safety when possible. While many individuals require pharmacotherapy, there are no currently approved medications for PBH. Increasing awareness and identification of individuals at risk for or with PBH is critical given the potential impact on safety, nutrition, and quality of life. A team-based approach involving the individual, the RDN, and other clinicians is essential in providing ongoing assessment and individualization of MNT in the long-term management of PBH.

Recommendations for the diagnosis and treatment of hypoglycaemia after bariatric surgery

Postprandial hyperinsulinaemic hypoglycaemia is a common complication of bariatric surgery. Although in general its evolution is mild and self-limited, it can lead to neuroglycopaenia and compromise the patient's safety and quality of life. The aim of this document is to offer some recommendations to facilitate the clinical care of these complex patients, reviewing the aetiopathogenesis, its diagnosis and treatment that, sequentially, will include dietary and pharmacological measures and surgery in refractory cases. In the absence of high-quality studies, the diagnostic and therapeutic approach proposed is based on the consensus of experts of the Grupo de Obesidad de la Sociedad Española de Endocrinología y Nutrición [Obesity Group of the Spanish Society of Endocrinology and Nutrition], GOSEEN. Those undergoing bariatric surgery should be informed of the possibility of developing this complication.

Pramlintide for post-bariatric hypoglycaemia

AIMS

The aim of this study was to examine the hypothesis that pramlintide would reduce hypoglycaemia by slowing gastric emptying and reducing postprandial glucagon secretion, thus limiting postprandial glycaemic excursions and insulin secretion, and thus to determine the efficacy of pramlintide on frequency and severity of hypoglycaemia in post-bariatric hypoglycaemia (PBH).

MATERIALS AND METHODS

Participants with PBH following gastric bypass were recruited from outpatient clinics at the Joslin Diabetes Center, Boston, Massachusetts for an open-label study of pramlintide efficacy over 8 weeks. Twenty-three participants were assessed for eligibility, 20 participants had at least one pramlintide dose, and 14 completed the study. A mixed-meal tolerance test (MMTT) was performed at baseline and after 8 weeks of subcutaneous pramlintide with a sequential dose increase to a maximum of 120 micrograms (mean 69 ± 32 mcg) three times daily. The primary endpoint was change in glucose excursions during the MMTT. Secondary measures included MMTT insulin response, satiety and dumping score, percentage time with sensor glucose (SG) <3.9 mM, and number of days with minimum SG <3 mM, during masked continuous glucose monitoring.

RESULTS

There were no differences in MMTT glucose, glucagon or insulin between baseline and post treatment. We observed no significant change in satiety or dumping scores. The overall frequency of low SG values did not change, although there was substantial inter-individual variability.

CONCLUSIONS

In PBH, pramlintide does not modulate glycaemic or insulin responses, satiety, or dumping scores during an MMTT and does not impact glycaemic excursions or decrease low SG levels in the outpatient setting.

In patients with controlled acromegaly, indices of glucose homeostasis correlate with IGF-1 levels rather than with type of treatment

OBJECTIVE

Acromegaly is accompanied by abnormalities in glucose and lipid metabolism which improve upon treatment. Few studies have investigated whether these improvements differ between treatment modalities. This study aimed to compare glucose homeostasis, lipid profiles and postprandial gut hormone response in patients with controlled acromegaly according to actual treatment.

DESIGN

Cross-sectional study at a tertiary care centre.

PATIENTS

Twenty-one patients with acromegaly under stable control (ie insulin growth factor 1 [IGF1] levels below sex- and age-specific thresholds and a random growth hormone level <1.0 µg/L) after surgery (n = 5), during treatment with long-acting somatostatin analogues (n = 10) or long-acting somatostatin analogues + pegvisomant (n = 6) were included.

MEASUREMENTS

Glucose, insulin, total cholesterol and high-density lipoprotein-cholesterol were measured in fasting serum samples. Glucose, insulin, triglycerides, glucose-dependent insulinotropic polypeptide and glucagon-like peptide 1 were measured during a mixed meal test. Insulin sensitivity was evaluated by a hyperinsulinaemic-euglycaemic clamp.

RESULTS

There were no significant differences in glucose tolerance, insulin sensitivity or postprandial gut hormone responses between the three groups. Positive correlations between IGF1 levels and HbA1c, fasting glucose and insulin levels and postprandial area under the curve (AUC) of glucose and insulin and also an inverse association between IGF1 and glucose disposal rate were found in the whole cohort (all p < .05, lowest p = .001 for postprandial AUC glucose with r_s  = 0.660).

CONCLUSION

In this cross-sectional study in patients with controlled acromegaly, there were no differences in glucose homeostasis or postprandial substrate metabolism according to treatment modality. However, a lower IGF1 level seems associated with a better metabolic profile.

Symptomatic Hypoglycemia After Gastric Bypass: Incidence and Predictive Factors in a Cohort of 1,138 Consecutive Patients

OBJECTIVE

After Roux-en-Y gastric bypass (RYGB), postprandial hyperinsulinemic hypoglycemia (PPHH) is particularly critical because of the risk of trauma. The aim of this study was to assess the incidence and identify risk factors for symptomatic PPHH.

METHODS

Patients with RYGB were classified into moderate PPHH (MH) or severe hypoglycemia (SH), which is defined as patients with neuroglycopenic symptoms. Logistic multivariate linear regressions were performed to identify predictive factors for symptomatic PPHH and more specifically for SH with neuroglycopenic symptoms. Patients with diabetes and those with a follow-up shorter than 2 years were excluded.

RESULTS

Among the 1,138 patients, 44.2% had at least one episode of hypoglycemia with a mean delay of 25.5 (21.3) months, 32.6% had MH, and 11.6% had SH. The annual incidence rate of SH was 2.5% the first year, 3.7% the second year, and 1.5% the third year. Independent predictive factors for higher risk of SH were: younger age (odds ratio [OR] = 1.01; 95% CI: 1.05-16.69; P = 0.0007), lower BMI after RYGB (OR = 1.61; 95% CI: 1.17-2.22; P = 0.0035), and maximal weight loss (OR = 1.04; 95% CI = 1.39-1.23; P = 0.0106), whereas higher preoperative BMI was protective (OR = 0.78; 95% CI: 0.64-0.95; P = 0.0112).

CONCLUSIONS

This observational cohort study showed that the incidence of severe PPHH with neuroglycopenic symptoms after RYGB was higher than expected.

Hypoglycemia Worsened by Glucose Administration: A Case of Hypoglycemia Years After Gastric Surgery

BACKGROUND

Noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS) is a rare syndrome characterized by postprandial hypoglycemia with neuroglycopenic symptoms occurring 1 to 3 h after a meal. Diagnosis can be elusive, as the vast majority of patients have normal fasting blood glucose levels, and onset of hypoglycemic episodes can be a late complication of gastric surgery.

CASE REPORT

We report the case of a 45-year-old woman presenting to the Emergency Department (ED) with new-onset seizures and hypoglycemia worsened by glucose administration. Surgical history is pertinent for a Roux-en-Y gastric bypass approximately 10 years prior to presentation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although rare, it is important for emergency physicians to be vigilant of this disease process as a traditional treatment approach for hypoglycemia may be detrimental. Although cases of NIPHS have been documented in literature, its presence in emergency medicine-specific literature is seemingly nonexistent. Noninvasive imaging techniques will be normal, and diagnosis is dependent on awareness of this disease entity coupled with a detailed history.

Somatostatin analogues for the treatment of hyperinsulinaemic hypoglycaemia

Hyperinsulinaemic hypoglycaemia (HH) is a biochemical finding of low blood glucose levels due to the dysregulation of insulin secretion from pancreatic β-cells. Under normal physiological conditions, glucose metabolism is coupled to β-cell insulin secretion so that blood glucose levels are maintained within the physiological range of 3.5-5.5 mmol/L. However, in HH this coupling of glucose metabolism to insulin secretion is perturbed so that insulin secretion becomes unregulated. HH typically occurs in the neonatal, infancy and childhood periods and can be due to many different causes. Adults can also present with HH but the causes in adults tend to be different. Somatostatin (SST) is a peptide hormone that is released by the delta cells (δ-cells) in the pancreas. It binds to G protein-coupled SST receptors to regulate a variety of location-specific and selective functions such as hormone inhibition, neurotransmission and cell proliferation. SST plays a potent role in the regulation of both insulin and glucagon secretion in response to changes in glucose levels by negative feedback mechanism. The half-life of SST is only 1-3 min due to quick degradation by peptidases in plasma and tissues. Thus, a direct continuous intravenous or subcutaneous infusion is required to achieve the therapeutic effect. These limitations prompted the discovery of SST analogues such as octreotide and lanreotide, which have longer half-lives and therefore can be administered as injections. SST analogues are used to treat different forms of HH in children and adults and therapeutic effect is achieved by suppressing insulin secretion from pancreatic β-cells by complex mechanisms. These treatments are associated with several side effects, especially in the newborn period, with necrotizing enterocolitis being the most serious side effect and hence SS analogues should be used with extreme caution in this age group.

Guidelines for gastrostomy tube placement and enteral nutrition in patients with severe, refractory hypoglycemia after gastric bypass

BACKGROUND

Postbariatric hypoglycemia (PBH) affects up to 38% of Roux-en-Y gastric bypass (RYGB) patients. Severe cases are refractory to diet and medications. Surgical treatments including bypass reversal and pancreatectomy are highly morbid and hypoglycemia often recurs. We have developed a highly effective method of treatment by which enteral nutrition administered through a gastrostomy (G) tube placed in the remnant stomach replaces oral diet: if done correctly this reverses hyperinsulinemia and hypoglycemia, yielding substantial health and quality of life benefits for severely affected patients.

OBJECTIVES

To provide clinical guidelines for placement of a G-tube to treat postRYGB hypoglycemia, including candidate selection, preoperative evaluation, surgical considerations, and post-RYGB management.

SETTING

Stanford University Hospital and Clinics.

METHODS

Based on our relatively large experience with placing and managing G-tubes for PBH treatment, an interdisciplinary task force developed guidelines for practitioners.

RESULTS

A team approach (endocrinologist, dietitian, surgeon, psychologist) is recommended. Appropriate candidates have a history of RYGB, severe hypoglycemia refractory to medical-nutrition therapy, and significantly affected quality of life. Preoperative requirements include education and expectation setting, determination of initial enteral feeding program, and establishing service with a home enteral provider. Close postoperative follow-up is needed to ensure success and may require adjustments in formula and mode/rate of delivery to optimize tolerance and meet nutritional goals. G-tube nutrition must fully replace oral nutrition to prevent hypoglycemia.

CONCLUSIONS

G-tube placement in the remnant stomach represents a relatively well-tolerated and effective treatment for severe, refractory hypoglycemia after RYGB.

Potential contribution of the gut microbiota to hypoglycemia after gastric bypass surgery

Obesity has become a global health problem. Lifestyle modification and medical treatment only appear to yield short-term weight loss. Roux-en-Y gastric bypass (RYGB) is the most popular bariatric procedure, and it sustains weight reduction and results in the remission of obesity-associated comorbidities for obese individuals. However, patients who undergo this surgery may develop hypoglycemia. To date, the diagnosis is challenging and the prevalence of post-RYGB hypoglycemia (PRH) is unclear. RYGB alters the anatomy of the upper gastrointestinal tract and has a combined effect of caloric intake restriction and nutrient malabsorption. Nevertheless, the physiologic changes after RYGB are complex. Although hyperinsulinemia, incretin effects, dysfunction of β-cells and α-cells, and some other factors have been widely investigated and are reported to be possible mediators of PRH, the pathogenesis is still not completely understood. In light of the important role of the gut microbiome in metabolism, we hypothesized that the gut microbiome might also be a critical link between RYGB and hypoglycemia. In this review, we mainly highlight the current possible factors predisposing individuals to PRH, particularly related to the gut microbiota, which may yield significant insights into the intestinal regulation of glucose metabolic homeostasis and provide novel clues to improve the treatment of type 2 diabetes mellitus.

Safety, efficacy and pharmacokinetics of repeat subcutaneous dosing of avexitide (exendin 9-39) for treatment of post-bariatric hypoglycaemia

AIM

To evaluate the safety, efficacy and pharmacokinetics of repeat dosing of two formulations of subcutaneous (SC) avexitide (exendin 9-39) in patients with post-bariatric hypoglycaemia (PBH).

METHODS

In this phase 2, multiple-ascending-dose study conducted at Stanford University, 19 women with PBH underwent a baseline oral glucose tolerance test (OGTT), with metabolic and symptomatic assessments. Fourteen were then sequentially assigned to receive one of four ascending-dose levels of twice-daily lyophilized (Lyo) avexitide by SC injection for 3 days. On the basis of safety, efficacy and tolerability, five additional participants then received a novel liquid formulation (Liq) of avexitide by SC injection at a fixed dose of 30 mg twice daily for 3 days. All 19 participants underwent a repeat OGTT on day 3 of dosing to quantify metabolic, symptomatic and pharmacokinetic responses.

RESULTS

Treatment with Lyo avexitide reduced the magnitude of symptomatic hyperinsulinaemic hypoglycaemia at all dose levels, with dose-dependent improvements in glucose nadir, insulin peak and symptom score; doses ≥20 mg twice daily did not require glycaemic rescue (administered at glucose <2.8 mmol/L). Participants receiving Liq avexitide 30 mg twice daily did not require any glycaemic rescue, and on average achieved a 47% increase in glucose nadir, a 67% reduction in peak insulin, and a 47% reduction in overall symptom score. Equivalent doses of Liq versus Lyo avexitide yielded higher and more sustained plasma concentrations. Both formulations were well tolerated.

CONCLUSIONS

In patients with PBH, twice-daily administration of SC avexitide effectively raised the glucose nadir and prevented severe hypoglycaemia requiring rescue intervention. Avexitide may represent a viable therapy for PBH.

Common and Rare Complications of Bariatric Surgery

As the prevalence of obesity has increased, bariatric surgery has become more common because of its proven efficacy at promoting weight loss and improving weight-related medical comorbidities. Although generally successful, bariatric surgery may also lead to complications and negatively affect health. This article highlights some common and rare complications of bariatric surgery. Specifically, it discusses the risk of nutrient deficiencies (which is influenced by surgery type) and their downstream effects, including ill-effects on bone health. Rarer complications, such as postbypass hypoglycemia and alcohol use disorder, are also discussed.

Hypoglycemia After Upper Gastrointestinal Surgery: Clinical Approach to Assessment, Diagnosis, and Treatment

CONTEXT

Post-bariatric hypoglycemia (PBH) is an increasingly encountered complication of upper gastrointestinal surgery; the prevalence of this condition is anticipated to rise given yearly increases in bariatric surgical procedures. While PBH is incompletely understood, there is a growing body of research describing the associated factors, mechanisms, and treatment approaches for this condition.

EVIDENCE ACQUISITION

Data are integrated and summarized from studies of individuals affected by PBH and hypoglycemia following upper gastrointestinal surgery obtained from PubMed searches (1990-2020).

EVIDENCE SYNTHESIS

Information addressing etiology, incidence/prevalence, clinical characteristics, assessment, and treatment were reviewed and synthesized for the practicing physician. Literature reports were supplemented by clinical experience as indicated, when published data were not available.

CONCLUSION

PBH can be life-altering and severe for a subset of individuals. Given the chronic nature of this condition, and sequelae of both acute and recurrent episodes, increasing provider awareness of both the condition and associated risk factors is critical for assessment, prompt diagnosis, treatment, and preoperative identification of individuals at risk.

Postprandial hypoglycaemia after Roux-en-Y gastric bypass and the effects of acarbose, sitagliptin, verapamil, liraglutide and pasireotide

AIM

To investigate the effects of acarbose, sitagliptin, verapamil, liraglutide and pasireotide on post-bariatric hypoglycaemia (PBH) after Roux-en-Y gastric bypass.

MATERIALS AND METHODS

In a randomized crossover study, 11 women who had undergone Roux-en-Y gastric bypass and had documented hypoglycaemia were each evaluated during a baseline period without treatment and during five treatment periods with the following interventions: acarbose 50 mg for 1 week, sitagliptin 100 mg for 1 week, verapamil 120 mg for 1 week, liraglutide 1.2 mg for 3 weeks and pasireotide 300 μg as a single dose. Treatment effects were evaluated by a mixed-meal tolerance test (MMTT) and, for all treatment periods except pasireotide, by 6 days of continuous glucose monitoring (CGM).

RESULTS

Treatment with acarbose and treatment with pasireotide both significantly lifted nadir glucose levels (mean ± SEM 3.9 ± 0.2 and 7.9 ± 0.4 vs 3.4 ± 0.2; P < .03) and reduced time in hypoglycaemia during the MMTTs. Acarbose reduced peak glucose levels and time in hyperglycaemia, whereas pasireotide greatly increased both variables. Acarbose and pasireotide reduced insulin and C-peptide levels, and pasireotide also diminished glucagon-like peptide-1 levels. Sitagliptin lowered nadir glucose values, while verapamil and liraglutide had no effect on hypoglycaemia. During the CGM periods, the treatments had no impact on hypoglycaemia, whereas acarbose and liraglutide reduced hyperglycaemia and glycaemic variability.

CONCLUSIONS

In an experimental setting, treatment with acarbose and pasireotide reduced PBH. Acarbose appears to have an overall glucose-stabilizing effect, whereas pasireotide leads to increased and sustained hyperglycaemia.

Diazoxide for the Treatment of Hypoglycemia Resulting From Dumping Syndrome in a Child

Dumping syndrome-associated hypoglycemia is caused by an exaggerated hyperinsulinemic response to glucose absorption in the small intestine. Diazoxide acts on the ATP-sensitive potassium channels and prevents insulin secretion and, thus, should be beneficial for the treatment of hypoglycemia secondary to dumping syndrome. We report on the efficacy of diazoxide in a pediatric patient with dumping syndrome. A 6-year-old girl born at 32 weeks' gestation age with resultant short gut syndrome and liver failure, who had undergone liver, small bowel, and pancreas transplantation at 1 year of age, developed late dumping-like symptoms with postprandial hypoglycemia, headaches, tremors, and irritability. She experienced relief of symptoms with oral intake. An oral glucose tolerance test showed a fasting and 2-hour blood glucose of 3.9 and 2.8 mmol/L, respectively. A gastric emptying study confirmed the diagnosis of dumping. A diet with 2 g of fiber and cornstarch and antimotility medications failed to improve the dumping symptoms. Diazoxide was started orally at a dose of 3 mg/kg/d and was increased to 5 mg/kg/d, divided every 8 hours, after 1 month, with improvement of postprandial blood glucose values (3.6 to 5.0 mmol/L). No hypertrichosis, fluid retention, respiratory concerns, or other side effects were noted. Several duodenal dilations were performed, with resultant improvement of gastric emptying. She was eventually weaned from diazoxide, and no further episodes of substantial hypoglycemia occurred. In conclusion, diazoxide was efficacious and safe for the treatment of hypoglycemia secondary to dumping syndrome in children. It could be of particular use as a bridging therapy for children awaiting more definitive surgical interventions.

Hypoglycemia After Gastric Bypass Successfully Treated With Calcium Channel Blockers: Two Case Reports

Postprandial hyperinsulinemic hypoglycemia is an uncommon yet well-established complication of Roux-en-Y gastric bypass (RYGB) that can result in serious morbidity and adversely affect quality of life. It is often unrecognized and may be difficult to diagnose. Management is challenging. As the number of bariatric procedures increases in parallel with the obesity epidemic, clinicians will be tasked to offer effective medical therapies for this complication. Two patients presented several years after RYGB with severe postprandial hypoglycemia. In one of the patients, we were able to document simultaneous postprandial hypoglycemia and hyperinsulinemia. Conventional treatment approaches, including medical nutrition therapy, acarbose, diazoxide, and octreotide, were either ineffective or limited by poor tolerance. Nifedipine and verapamil were used adjunctively with dietary modification, resulting in resolution of symptomatic hypoglycemic episodes. These agents are therapeutic options that can be used for some patients refractory to more traditional treatments. They should be tried before surgical procedures are considered for affected patients. These two cases demonstrate that calcium channel blockers may be efficacious and appropriate for select patients refractory to dietary interventions alone.

Changes in gut hormones, glycaemic response and symptoms after oesophagectomy

BACKGROUND

Oesophagectomy is associated with reduced appetite, weight loss and postprandial hypoglycaemia, the pathophysiological basis of which remains largely unexplored. This study aimed to investigate changes in enteroendocrine function after oesophagectomy.

METHODS

In this prospective study, 12 consecutive patients undergoing oesophagectomy were studied before and 10 days, 6, 12 and 52 weeks after surgery. Serial plasma total fasting ghrelin, and glucagon-like peptide 1 (GLP-1), insulin and glucose release following a standard 400-kcal mixed-meal stimulus were determined. CT body composition and anthropometry were assessed, and symptom scores calculated using European Organisation for Research and Treatment of Cancer (EORTC) questionnaires.

RESULTS

At 1 year, two of the 12 patients exhibited postprandial hypoglycaemia, with reductions in bodyweight (mean(s.e.m.) 17·1(3·2) per cent, P < 0·001), fat mass (21.5(2.5) kg versus 25.5(2.4) kg before surgery; P = 0·014), lean body mass (51.5(2.2) versus 54.0(1.8) kg respectively; P = 0·003) and insulin resistance (HOMA-IR: 0.84(0.17) versus 1.16(0.20); P = 0·022). Mean(s.e.m.) fasting ghrelin levels decreased from postoperative day 10, but had recovered by 1 year (preoperative: 621·5(71·7) pg/ml; 10 days: 415·1(59·80) pg/ml; 6 weeks: 309·0(42·0) pg/ml; 12 weeks: 415·8(52·1) pg/ml; 52 weeks: 547·4(83·2) pg/ml; P < 0·001) and did not predict weight loss (P = 0·198). Postprandial insulin increased progressively at 10 days, 6, 12 and 52 weeks (mean(s.e.m.) insulin AUC_{0-30 min} : fold change 1·7(0·4), 2·0(0·4), 3·5(0·7) and 4·0(0·8) respectively; P = 0·001). Postprandial GLP-1 concentration increased from day 10 after surgery (P < 0·001), with a 3·3(1·8)-fold increase at 1 year (P < 0·001). Peak GLP-1 level was inversely associated with the postprandial glucose nadir (P = 0·041) and symptomatic neuroglycopenia (Sigstad score, P = 0·017, R²  = 0·45). GLP-1 AUC predicted loss of weight (P = 0·008, R²  = 0·52) and fat mass (P = 0·010, R²  = 0·64) at 1 year.

CONCLUSION

Altered enteroendocrine physiology is associated with early satiety, weight loss and postprandial hypoglycaemia after oesophagectomy.

Hypoglycemia After Gastric Bypass Surgery: Current Concepts and Controversies

CONTEXT

Hypoglycemia, occurring after bariatric and other forms of upper gastrointestinal surgery, is increasingly encountered by clinical endocrinologists. The true frequency of this condition remains uncertain, due, in part, to differences in the diagnostic criteria and in the affected populations, as well as relative lack of patient and physician awareness and understanding of this condition. Postbariatric hypoglycemia can be severe and disabling for some patients, with neuroglycopenia (altered cognition, seizures, and loss of consciousness) leading to falls, motor vehicle accidents, and job and income loss. Moreover, repeated episodes of hypoglycemia can result in hypoglycemia unawareness, further impairing safety and requiring the assistance of others to treat hypoglycemia.

OBJECTIVE

In this review, we summarize and integrate data from studies of patients affected by hypoglycemia after Roux-en-Y gastric bypass (RYGB) surgery, obtained from PubMed searches (1990 to 2017) and reference searches of relevant retrieved articles. Whereas hypoglycemia can also be observed after sleeve gastrectomy and fundoplication, this review is focused on post-RYGB, given the greater body of published clinical studies at present.

OUTCOME MEASURES

Data addressing specific aspects of diagnosis, pathophysiology, and treatment were reviewed by the authors; when not available, the authors have provided opinions based on clinical experience with this challenging condition.

CONCLUSIONS

Hypoglycemia, occurring after gastric bypass surgery, is challenging for patients and physicians alike. This review provides a systematic approach to diagnosis and treatment based on the underlying pathophysiology.

Roux en Y gastric bypass hypoglycemia resolves with gastric feeding or reversal: Confirming a non-pancreatic etiology

OBJECTIVE

Postprandial hypoglycemia is an infrequent but disabling complication of Roux-en-Y gastric bypass (RYGB) surgery. Controversy still exists as to whether the postprandial hyperinsulinemia observed is due to inherent changes in pancreatic β-cell mass or function or to reversible alterations caused by RYGB anatomy. We aimed to determine if gastric feeding or reversal of RYGB would normalize postprandial glucose and hormone excursions in patients with symptomatic hypoglycemia.

METHODS

We completed a prospective study of six patients with severe symptomatic RYGB hypoglycemia who underwent RYGB reversal. An additional subject without hypoglycemia who underwent RYGB reversal was also studied prospectively. Mixed meal tolerance testing (MTT) was done orally (RYGB anatomy), via gastrostomy tube in the excluded stomach in the setting of RYGB, and several months after RYGB reversal.

RESULTS

All subjects reported symptomatic improvement of hypoglycemia after reversal of RYGB. Weight gain after reversal was moderate and variable. Postprandial glucose, insulin, and GLP-1 excursions were significantly diminished with gastric feeding and after reversal. Insulin secretion changed proportional to glucose levels and insulin clearance increased after reversal. Glucagon/insulin ratios were similar throughout study. We further compared the impact of modified sleeve gastrectomy reversal surgery to those with restoration of complete stomach and found no significant differences in weight regain or in postprandial glucose or hormone levels.

CONCLUSIONS

Reversal of RYGB is an effective treatment option for severe postprandial hypoglycemia. The pathophysiology of this disorder is primarily due to RYGB anatomy resulting in altered glucose, gut, and pancreatic hormone levels and decreased insulin clearance, rather than inherent β-cell hyperplasia or hyperfunction.

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.

Hyperinsulinemic hypoglycemia after gastric bypass surgery: what's up and what's down?

Obesity is a global public health problem and attempts to treat this condition using life style with and without pharmacological interventions have not been successful in majority of obese individuals. To date, the most effective treatment for obesity is weight loss surgery. One of the most widely used procedures to treat obesity worldwide, Roux-en-Y gastric bypass surgery (RYGB), has shown to induce diabetes remission in addition to significant and sustainable weight loss. As the number of this procedure performed over the last two decades increased, it has become clear that a subgroup of individuals develop postprandial hypoglycemia several years after surgery. This debilitating late complication of RYGB is often associated with loss of consciousness or seizures, and in severe cases, it is only partially responsive to diet modification or other available therapeutic options. The diagnosis is often a challenge resulting in delays in receiving care in the affected individuals. Although the underlying mechanisms are under current investigations, growing evidence suggest that a combination of exaggerated meal-derived nutrient appearance to systemic circulation and altered islet and gut hormone response after eating have a role in pathogenesis of this condition. The goal of this review is to highlight new perspectives regarding this life-threatening complication of RYGB. The etiology, diagnosis, recommendation on how to distinguish from classic dumping and current available treatment based on literature review will be discussed. In addition, physiologic changes after gastric bypass predisposing to hypoglycemia syndrome will be highlighted.International Journal of Obesity advance online publication, 31 October 2017; doi:10.1038/ijo.2017.257.

Incidence and Predictive Factors of Postprandial Hyperinsulinemic Hypoglycemia After Roux-en-Y Gastric Bypass: A Five year Longitudinal Study

BACKGROUND

Postprandial hyperinsulinemic hypoglycemia (PHH) is often reported after Roux-en-Y gastric bypass (RYGB). In the absence of a prospective study, the clinical and biological determinants of PHH remain unclear.

OBJECTIVE

To determine the incidence and predictive factors of PHH after RYGB.

METHODS

Participants were 957 RYGB patients enrolled in an ongoing longitudinal cohort study. We analyzed the results of an oral glucose tolerance test (OGTT) routinely performed before surgery and 1 and/or 5 years after. PHH was defined as blood glucose < 50 mg/dL AND plasma insulin > 3 mU/L at 120 minutes post glucose challenge. Validated indices of insulin sensitivity (Matsuda index), beta-cell function (Insulinogenic index), and beta-cell mass (fasting C-peptide: glucose ratio) were calculated, from glucose, insulin, and c-peptide values measured during OGTT.

RESULTS

OGTT results were available in all patients at baseline, in 85.6% at 12 months and 52.8% at 60 months. The incidence of PHH was 0.5% at baseline, 9.1% * and 7.9%* at 12 months and 60 months following RYGB (*: P < 0.001). In multivariate logistic regression analysis, PHH after RYGB was independently associated with lower age (P = 0.005), greater weight loss (P = 0.031), as well as higher beta-cell function (P = 0.002) and insulin sensitivity (P < 0.001), but not with beta-cell mass (P = 0.381). A preoperative elevated beta-cell function was an independent predictor of PHH after RYGB (receiver operating characteristics curve area under the curve 0.68, P = 0.04).

CONCLUSIONS:

The incidence of PHH significantly increased after RYGB but remained stable between 1 and 5 years. The estimation of beta-cell function with an OGTT before surgery can identify patients at risk for developing PHH after RYGB.

The Impact of Bariatric Surgery on Type 2 Diabetes Mellitus and the Management of Hypoglycemic Events

Recent studies discussed the benefit of bariatric surgery on obese patients diagnosed with type 2 diabetes mellitus (T2DM). Several factors play an essential role in predicting the impact of bariatric surgery on T2DM, such as ABCD score (age, BMI, C-peptide, and duration of the disease), HbA1c, and fasting blood glucose, incretins [glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP)]. DiaRem score known to include factors such as age, HbA1c, medication, and insulin usage used to predict the remission of T2DM, but it has some limitations. An extensive literature search was conducted on PubMed and Google Scholar using keywords such as gastric bypass, T2DM, bariatric surgery, GLP-1, GIP, and post bariatric hypoglycemia. Restrictive-malabsorptive procedures are most effective in treating T2DM patients based on changes induced in appetite through regulation of gastrointestinal hormones, with decreased hunger and increased satiation. We provide a review of bariatric surgery influence on T2DM and management of post-intervention hypoglycemic events. Post-bariatric surgery hypoglycemia is a serious complication especially when patients develop life-threatening neuroglycopenia with loss of consciousness and seizure. The avoidance of this adverse event may be achieved by strict dietary modification including a restriction on carbohydrates as well as foods with high glycemic index. Further research will provide more information on post-bariatric surgery hyperinsulinemic hypoglycemia pathophysiology and management.

Pregnancy Following Bariatric Surgery-Medical Complications and Management

Bariatric surgery is most commonly carried out in women of childbearing age. Whilst fertility rates are improved, pregnancy following bariatric surgery poses several challenges. Whilst rates of many adverse maternal and foetal outcomes in obese women are reduced after bariatric surgery, pregnancy is best avoided for 12-24 months to reduce the potential risk of intrauterine growth retardation. Dumping syndromes are common after bariatric surgery and can present diagnostic and therapeutic challenges in pregnancy. Early dumping occurs due to osmotic fluid shifts resulting from rapid gastrointestinal food transit, whilst late dumping is characterized by a hyperinsulinemic response to rapid absorption of simple carbohydrates. Dietary measures are the mainstay of management of dumping syndromes but pharmacotherapy may sometimes become necessary. Acarbose is the least hazardous pharmacological option for the management of postprandial hypoglycemia in pregnancy. Nutrient deficiencies may vary depending on the type of surgery; it is important to optimize the nutritional status of women prior to and during pregnancy. Dietary management should include adequate protein and calorie intake and supplementation of vitamins and micronutrients. A high clinical index of suspicion is required for early diagnosis of surgical complications of prior weight loss procedures during pregnancy, including small bowel obstruction, internal hernias, gastric band erosion or migration and cholelithiasis.

Post-gastric bypass hypoglycaemia: a review

Bariatric surgery is a highly effective treatment for severe obesity, resulting in substantial weight loss and normalizing obesity-related comorbidities. However, long-term consequences can occur, such as postbariatric surgery hypoglycaemia. This is a challenging medical problem, and the number of patients presenting with it has been increasing. Roux-en-Y gastric bypass (RYGB) is the most popular bariatric procedure, and it is the surgery most commonly associated with the development of postbariatric surgery hypoglycaemia. To date, the pathogenesis of this condition has not been completely established. However, various factors - particularly increased postprandial glucagon-like peptide (GLP)-1 secretion - have been considered as crucial mediator. The mechanisms responsible for diabetic remission after bariatric surgery may be responsible for the development of hypoglycaemia, which typically occurs 1-3 h after a meal and is concurrent with inappropriate hyperinsulinaemia. Carbohydrate-rich foods usually provoke hypoglycaemic symptoms, which can typically be alleviated by strict dietary modifications, including carbohydrate restriction and avoidance of high glycaemic index foods and simple sugars. Few patients require further medical intervention, such as medications, but some patients have required a pancreatectomy. Because this option is not always successful, it is no longer routinely recommended. Clinical trials are needed to further determine the pathophysiology of this condition as well as the best diagnostic and treatment approaches for these patients.

Hypoglycaemia after gastric bypass: mechanisms and treatment

Hypoglycaemia after gastric bypass can be severe, but is uncommon, and is sometimes only revealed through monitoring glucose concentrations. The published literature is limited by the heterogeneity of the criteria used for diagnosis, arguing in favour of the Whipple triad with a glycaemia threshold of 55 mg/dl as the diagnostic reference. Women who lost most of their excess weight after gastric bypass, long after the surgery was performed, and who did not have diabetes before surgery are at the greatest risk. In this context, hypoglycaemia results from hyperinsulinism, which is either generated by pancreas anomalies (nesidioblastosis) and/or caused by an overstimulation of β cells by incretins, mainly glucagon-like peptide-1 (GLP-1). Glucose absorption is both accelerated and increased because of the direct communication between the gastric pouch and the jejunum. This is a post-surgical exaggeration of a natural adaptation that is seen in patients who have not undergone surgery in whom glucose is infused directly into the jejunum. There is not always a correspondence between symptoms and biological traits; however, hyperinsulinism is constant if hypoglycaemia is severe and there are neuroglucopenic symptoms. The treatment relies firstly on changes in eating habits, splitting food intake into five to six daily meals, slowing gastric emptying, reducing the glycaemic load and glycaemic index of foods, using fructose and avoiding stress at meals. Pharmacological treatment with acarbose is efficient, but other drugs still need to be validated in a greater number of subjects (insulin, glucagon, calcium channel blockers, somatostatin analogues and GLP-1 analogues). Lastly, if the surgical option has to be used, the benefits (efficient symptom relief) and the risks (weight regain, diabetes) should be weighed carefully.

Synchronous Nesidioblastosis, Endocrine Microadenoma, and Intraductal Papillary Mucinous Neoplasia in a Man Presenting With Hyperinsulinemic Hypoglycemia

Herein, we report the first case of concomitant nesidioblastosis, pancreatic neuroendocrine tumor, and intraductal papillary mucinous neoplasia. The combination is significant as each of these pathological entities is independently very rare. The patient was a 33-year-old man who presented with symptomatic hyperinsulinemic hypoglycemia and no risk factors for pancreatic disease. Abdominal imaging showed an isolated 12 mm pancreatic lesion, whilst selective arterial calcium stimulation testing demonstrated multiple territories of insulin excess. He proceeded to subtotal pancreatectomy. Histopathology revealed an endocrine microadenoma, α and β cell nesidioblastosis, and multifocal intraductal papillary mucinous neoplasia. The endocrine microadenoma and nesidioblastosis stained for insulin, suggesting both likely contributed to hypoglycemia. Glucagon immunohistochemistry was also positive, though there were no clinical features of glucagon excess. Hypoglycemia resolved postoperatively. This case and other evidence from the literature suggest that hyperplasia and neoplasia may occur sequentially in the pancreas, and that endocrine and exocrine tumorigenesis may be linked in some individuals. Further study is required to identify a unifying mechanism, and to elucidate potential ramifications in the management of patients with pancreatic neoplasms.

Hyperinsulinemic Hypoglycemia after Bariatric Surgery: Diagnosis and Management Experience from a Spanish Multicenter Registry

BACKGROUND

Severe postprandial hypoglycemia after bariatric surgery is a rare but invalidating complication. Our aim was to describe the different tests performed for its diagnosis and their outcomes as well as the response to the prescribed pharmacological and surgical treatments.

METHODS

Multicenter, retrospective systematic review of cases with recurrent severe postprandial hypoglycemia.

RESULTS

Over 11 years of follow-up, 22 patients were identified. The test most used to provoke hypoglycemia was the oral glucose load test followed by the mixed meal test which was the least standardized test. With pharmacological treatment, 3 patients were symptom-free (with octreotide) and in 12 patients hypoglycemic episodes were attenuated. Seven patients had persistent hypoglycemic episodes and underwent surgery. Partial pancreatectomy was performed in 3 patients who had positive selective arterial calcium stimulation, and nesidioblastosis was confirmed in 2 patients. Reconversion to normal anatomy was performed in 3 patients, and 1 patient underwent a resection of the 'candy cane' roux limb, with resolution of hypoglycemia in all cases.

CONCLUSIONS

There is high heterogeneity in the evaluation and treatment options for postoperative hypoglycemia. In patients that do not respond to pharmacological treatment, reconstruction of gastrojejunal continuity may be the safest and most successful procedure.

Recognition and management of hyperinsulinemic hypoglycemia after bariatric surgery

Hyperinsulinemic hypoglycemia with neuroglycopenia is an increasingly recognized complication of Roux-en-Y gastric bypass (RYGB) due to the changes in gut hormonal milieu. Physicians should be aware of this complication to ensure timely and effective treatment of post-RYGB patients, who present to them with hypoglycemic symptoms. Possible causes of hypoglycemia in these patients include late dumping syndrome, nesidioblastosis and rarely insulinoma. Systematic evaluation including history, biochemical analysis, and diagnostic testing might help in distinguishing among these diagnoses. Continuous glucose monitoring is also a valuable tool, revealing the episodes in the natural environment and can also be used to monitor treatment success. Treatment should begin with strict low carbohydrate diet, followed by medication therapy. Therapy with diazoxide, acarbose, calcium channel blockers and octreotide have been proven to be beneficial, but the response apparently is highly variable. When other treatment options fail, surgical options can be considered.

Hypoglycemia in everyday life after gastric bypass and duodenal switch

DESIGN

Gastric bypass (GBP) and duodenal switch (DS) in morbid obesity are accompanied by marked metabolic improvements, particularly in glucose control. In recent years, episodes of severe late postprandial hypoglycemia have been increasingly described in GBP patients; data in DS patients are scarce. We recruited three groups of subjects; 15 GBP, 15 DS, and 15 non-operated overweight controls to examine to what extent hypoglycemia occurs in daily life.

METHODS

Continuous glucose monitoring (CGM) was used during 3 days of normal activity. The glycemic variability was measured by mean amplitude of glycemic excursion and continuous overall net glycemic action. Fasting blood samples were drawn, and the patients kept a food and symptom log throughout the study.

RESULTS

The GBP group displayed highly variable CGM curves, and 2.9% of their time was spent in hypoglycemia (<3.3  mmol/l, or 60  mg/dl). The DS group had twice as much time in hypoglycemia (5.9%) and displayed CGM curves with little variation as well as lower HbA1c levels (29.3 vs 35.9 mmol/mol, P<0.05). Out of a total of 72 hypoglycemic episodes registered over the 3-day period, 70 (97%) occurred in the postprandial state and only about one-fifth of the hypoglycemic episodes in the GBP and DS groups were accompanied by symptoms. No hypoglycemias were seen in controls during the 3-day period.

CONCLUSION

Both types of bariatric surgery induce marked, but different, changes in glucose balance accompanied by frequent, but mainly unnoticed, hypoglycemic episodes. The impact and mechanism of hypoglycemic unawareness after weight-reduction surgery deserves to be clarified.

A case of severe anorexia, excessive weight loss and high peptide YY levels after sleeve gastrectomy

Sleeve gastrectomy (SG) is the second most commonly performed bariatric procedure worldwide. Altered circulating gut hormones have been suggested to contribute post-operatively to appetite suppression, decreased caloric intake and weight reduction. In the present study, we report a 22-year-old woman who underwent laparoscopic SG for obesity (BMI 46 kg/m²). Post-operatively, she reported marked appetite reduction, which resulted in excessive weight loss (1-year post-SG: BMI 22 kg/m², weight loss 52%, >99th centile of 1-year percentage of weight loss from 453 SG patients). Gastrointestinal (GI) imaging, GI physiology/motility studies and endoscopy revealed no anatomical cause for her symptoms, and psychological assessments excluded an eating disorder. Despite nutritional supplements and anti-emetics, her weight loss continued (BMI 19 kg/m²), and she required nasogastric feeding. A random gut hormone assessment revealed high plasma peptide YY (PYY) levels. She underwent a 3 h meal study following an overnight fast to assess her subjective appetite and circulating gut hormone levels. Her fasted nausea scores were high, with low hunger, and these worsened with nutrient ingestion. Compared to ten other post-SG female patients, her fasted circulating PYY and nutrient-stimulated PYY and active glucagon-like peptide 1 (GLP1) levels were markedly elevated. Octreotide treatment was associated with suppressed circulating PYY and GLP1 levels, increased appetite, increased caloric intake and weight gain (BMI 22 kg/m² after 6 months). The present case highlights the value of measuring gut hormones in patients following bariatric surgery who present with anorexia and excessive weight loss and suggests that octreotide treatment can produce symptomatic relief and weight regain in this setting.

Increased plasma incretin concentrations identifies a subset of patients with persistent congenital hyperinsulinism without KATP channel gene defects

Congenital hyperinsulinism causes profound hypoglycemia, which may persist or resolve spontaneously. Among 13 children with congenital hyperinsulinism, elevated incretin hormone concentrations were detected in 2 with atypical, persistent disease. We suggest that incretin biomarkers may identify these patients, and that elevated hormone levels may contribute to their pathophysiology.

Hypoglycemia after Roux-En-Y gastric bypass: detection rates of continuous glucose monitoring (CGM) versus mixed meal test

BACKGROUND

Neuroglucopenic hypoglycemia might be an underestimated threat for roux-en-Y gastric bypass (RYGB) patients leading to fatigue, syncope, seizures or even accidental deaths. Different measurements can assess hypoglycemia such as a finger-stick glucometer, an Oral Glucose Tolerance Test, a Mixed Meal-Test (MMT) or, as introduced recently, continuous glucose monitoring (CGM).

SETTING

University Hospital, Austria.

METHODS

To assess the incidence of hypoglycemic episodes under real life conditions, 5-day CGM was performed in a series of 40 patients at a mean of 86 months after RYGB. The detection rates were compared to a mixed meal-test.

RESULTS

CGM detected hypoglycemic episodes of <55 mg/dL or <3.05 mmol/L in 75% of the patients, while MMT indicated hypoglycemia in 29% of the patients. CGM also detected nocturnal hypoglycemic episodes in 15 (38%) of the patients. A mean of 3±1 hypoglycemic episodes per patient with a mean duration of 71±25 minutes were observed by CGM.

CONCLUSIONS

Assessed under real life conditions by CGM, post-RYGB hypoglycemia was found more frequently than expected. CGM revealed hypoglycemic episodes in 75% of the patients while MMT had a lower detection rate. Thus, CGM may have a role for screening but also for the evaluation of dietary modifications, drug therapy or surgical intervention for hypoglycemia after RYGB.

The somatostatin receptor in human pancreatic β-cells

The peptide hormone somatostatin (SST) is produced in the brain, the gut, and in δ-cells in pancreatic islets of Langerhans. SST secretion from δ-cells is stimulated by glucose, amino acids, and glucagon-like peptide-1. Exogenous SST strongly inhibits the secretion of the blood glucose-regulating hormones insulin and glucagon from pancreatic β-cells and α-cells, respectively. Endogenous SST secreted from δ-cells is a paracrine regulator of insulin and glucagon secretion, although the exact physiological significance of this regulation is unclear. Secreted SST binds to specific receptors (SSTRs), which are coupled to Gi/o proteins. In both β- and α-cells, activation of SSTRs suppresses hormone secretion by reducing cAMP levels, inhibiting electrical activity, decreasing Ca²⁺ influx through voltage-gated Ca²⁺ channels and directly reducing exocytosis in a Ca²⁺ and cAMP-independent manner. In rodents, β-cells express predominantly SSTR5, whereas α-cells express SSTR2. In human islets, SSTR2 is the dominant receptor in both β- and α-cells, but other isoforms also contribute to the SST effects. Evidence from rodent models suggests that SST secretion from δ-cells is dysregulated in diabetes mellitus, which may contribute to the metabolic disturbances in this disease. SST analogues are currently used for the treatment of hyperinsulinism and other endocrine disorders, including acromegaly and Cushing's syndrome.

Using miglitol at 30 min before meal is effective in hyperinsulinemic hypoglycemia after a total gastrectomy

A 45-year-old woman who had undergone total gastrectomy for gastric cancer presented with a history of postprandial hypoglycemic episodes with loss of consciousness after meals. Laboratory findings revealed marked hyperinsulinemia and hypoglycemia after a meal. We first treated the patient with octreotide; however, she was unable to continue the treatment because of adverse effects of the drug, such as nausea and headache. Diazoxide was used next for preventing hyperinsulinemia; however, this was not effective for suppressing the postprandial insulin secretion. Since hypoglycemia following gastrectomy is thought to be caused by rapid delivery of nutrients into the duodenum, we performed a meal tolerance test while varying the timing of administration of miglitol in relation to the meal. Miglitol was administered 30 min before, just before, or both 30 min and just before a meal. In the case of administration just before a meal, insulin secretion was suppressed, although hypoglycemia was not prevented. Administration of the drug 30 min before a meal prevented postprandial hypoglycemia by slowing the increase of the blood glucose and serum insulin levels following the meal to a greater degree than administration just before a meal. Miglitol administration both 30 min and just before a meal caused an even smoother increase in blood glucose and serum insulin levels following the meal. In this report, we propose a new therapeutic approach for reactive hypoglycemia after gastrectomy, namely, administration of miglitol 30 min before meals.