Hypoglycemic disorders

Hypoglycemia in non-diabetic in-patients at a teaching referral hospital in Iran

Purpose

This study aims to investigate comorbidities, clinical features, laboratory values, and diagnoses in non-diabetic patients experiencing hypoglycemic episodes.

Methods

A retrospective observational study was conducted at Shariati Hospital in Iran from 2016 to 2023. Seventy-four non-diabetic patients admitted with a diagnosis of hypoglycemia were included, while patients with diabetes were excluded. Demographic data, symptoms, and biochemical assessments were obtained from the hospital information system. Hypoglycemic episodes were identified based on low measured blood glucose, recorded medications for hypoglycemia treatment, or recorded codes indicating hypoglycemia. Hypoglycemia was defined as blood glucose below 70 mg/dL (3.9 mmol/L) along with two other criteria of the Whipple triad. Statistical analysis was performed using SPSS software (version 26).

Results

Among the enrolled patients, 63.5% were female, and 13.5% were elderly (≥ 65 years). The most common comorbidities observed were cardiovascular disease (20.3%), psychological disorders (20.3%), hypothyroidism (14.9%), and hypertension (8.1%). The prevalent symptoms included weakness, loss of consciousness, sweating, palpitations, dizziness, and tremors. Non-diabetic hypoglycemia was caused by factitious disorders, insulinoma, organ failure, and infection, respectively.

Conclusion

Due to the diverse range of clinical symptoms, hypoglycemia in non-diabetic patients may be diagnosed late, leading to misdiagnoses such as psychological disorders or seizures. It is crucial to consider the possibility of hypoglycemia in non-diabetic patients and determine its underlying cause. Given the poor prognosis associated with hypoglycemia, timely interventions are essential.

A rare case report of reversible glucose counterregulation in an insulinoma patient with type 2 diabetes

CONTEXT

Insulinoma is a neuroendocrine tumor derived from pancreatic β -cells whose clinical manifestation is recurrent hypoglycemia. Insulinoma in a patient with preexisting diabetes is extraordinarily rare, and the unmasking of type 2 diabetes (T2DM) after insulinoma surgery is even rarer.

CASE REPORT

This article reports a 49-year-old male patient with insulinoma that masked the diagnosis of T2DM. The patient was admitted to the hospital with symptoms of hypoglycemia, such as repeated sweating, palpitations, and asthenia for over 4 years. The patient was diagnosed with insulinoma after completing relevant examinations. The emergence of hyperglycemia after the removal of insulinoma is attributable to the coexistence of T2DM. Surprisingly, a reversible decrease in cortisol levels was observed during the diagnostic process. We searched the previously published reports of this type of case from PubMed to determine why type 2 diabetes was covered by insulinoma and why glucocorticoids decreased.

CONCLUSIONS

The diagnosis of T2DM in the patient after surgery may be related to increased food intake and insulin resistance induced by hyperinsulinemia caused by long-term hypoglycemia. The reversible decrease in cortisol levels, not adrenocortical insufficiency during the diagnostic process, may be caused by a transient abnormality in glucose counterregulation.

Approach to the Patient: Insulinoma

Insulinomas are hormone-producing pancreatic neuroendocrine neoplasms with an estimated incidence of 1 to 4 cases per million per year. Extrapancreatic insulinomas are extremely rare. Most insulinomas present with the Whipple triad: (1) symptoms, signs, or both consistent with hypoglycemia; (2) a low plasma glucose measured at the time of the symptoms and signs; and (3) relief of symptoms and signs when the glucose is raised to normal. Nonmetastatic insulinomas are nowadays referred to as "indolent" and metastatic insulinomas as "aggressive." The 5-year survival of patients with an indolent insulinoma has been reported to be 94% to 100%; for patients with an aggressive insulinoma, this amounts to 24% to 67%. Five percent to 10% of insulinomas are associated with the multiple endocrine neoplasia type 1 syndrome. Localization of the insulinoma and exclusion or confirmation of metastatic disease by computed tomography is followed by endoscopic ultrasound or magnetic resonance imaging for indolent, localized insulinomas. Glucagon-like peptide 1 receptor positron emission tomography/computed tomography or positron emission tomography/magnetic resonance imaging is a highly sensitive localization technique for seemingly occult, indolent, localized insulinomas. Supportive measures and somatostatin receptor ligands can be used for to control hypoglycemia. For single solitary insulinomas, curative surgical excision remains the treatment of choice. In aggressive malignant cases, debulking procedures, somatostatin receptor ligands, peptide receptor radionuclide therapy, everolimus, sunitinib, and cytotoxic chemotherapy can be valuable options.

Spontaneous hypoglycemia: should we mind the gap? Long-term follow-up of healthy people who met Whipple's triad criteria

CONTEXT

Patients discharged as "healthy" with the symptoms of spontaneous hypoglycemia, commonly known as Whipple's triad, need more attention.

OBJECTIVE

Characterization and long-term follow-up of symptom development in patients with spontaneous hypoglycemia discharged as "healthy". The objective was to ascertain whether any conditions related to the symptoms were diagnosed during the follow-up period.

METHODS

Retrospective analysis of patient data and evaluation of a specific questionnaire on the development of symptoms of spontaneous hypoglycemia. In addition, patient questionnaires were evaluated and primary care physicians were asked about possible diseases not recorded at baseline that occurred during the follow-up period.

SETTING

Center for Endocrinology, Diabetology, and Osteology at the University Hospital Marburg, Inpatient Department, Germany.

PATIENTS

All patients who presented to our center for the 72-hour fast between 2005 and 2018 and were discharged without an internal medicine diagnosis were included.

INTERVENTIONS

Survey by questionnaire, via telephone interview.

MAIN OUTCOME MEASURES

Patient-reported information on current symptoms compared to original symptoms, diagnosis of insulinoma or diabetes mellitus during follow-up, matched with primary care physician data, and metabolic and biometric data such as body mass index (BMI), homeostasis model assessment for insulin resistance (HOMA IR), insulin sensitivity Matsuda Index (ISI-M), and area under the curve.

RESULTS

A total of 41 datasets were evaluated at baseline and 38 patients were followed for an average of approximately 10 years. In total, 61% of respondents still reported the same symptoms as at baseline. No insulinoma was missed in these patients. Only two of the 38 patients developed diabetes mellitus.

CONCLUSION

The high percentage of patients who are discharged as "healthy" and still have symptoms after many years is disturbing. It is possible that the symptoms are not due to low blood glucose. We urge caution with use of the term "healthy". We advocate a multidisciplinary therapeutic approach after an organic cause of hypoglycemia has been ruled out. Psychosomatic treatment seems to be useful. In addition, more research should be conducted on this topic.

The Most Important Metabolic Diseases in Dairy Cattle during the Transition Period

This review paper provides an in-depth analysis of three critical metabolic diseases affecting dairy cattle such as subacute ruminal acidosis (SARA), ketosis, and hypocalcemia. SARA represents a disorder of ruminal fermentation that is characterized by extended periods of depressed ruminal pH below 5.5-5.6. In the long term, dairy herds experiencing SARA usually exhibit secondary signs of the disease, such as episodes of laminitis, weight loss and poor body condition despite adequate energy intake, and unexplained abscesses usually 3-6 months after an episode of SARA. Depressed milk-fat content is commonly used as a diagnostic tool for SARA. A normal milk-fat test in Holstein dairy cows is >4%, so a milk-fat test of <3% can indicate SARA. However, bulk tank testing of milk fat is inappropriate to diagnose SARA at the herd level, so when >4 cows out of 12 and <60 days in milk are suspected to have SARA it can be considered that the herd has a problem. The rapid or abrupt introduction of fresh cows to high-concentrate diets is the most common cause of SARA. Changes in ruminal bacterial populations when exposed to higher concentrate rations require at least about 3 weeks, and it is recommended that concentrate levels increase by no more than 400 g/day during this period to avoid SARA. Ketosis, a prevalent metabolic disorder in dairy cattle, is scrutinized with a focus on its etiological factors and the physiological changes leading to elevated ketone bodies. In total mix ration-fed herds, an increased risk of mastitis and reduced fertility are usually the first clinical signs of ketosis. All dairy cows in early lactation are at risk of ketosis, with most cases occurring in the first 2-4 weeks of lactation. Cows with a body condition score ≥3.75 on a 5-point scale at calving are at a greater risk of ketosis than those with lower body condition scores. The determination of serum or whole blood acetone, acetoacetate, beta-hydroxybutyrate (BHB) concentration, non-esterified fatty acids (NEFA), and liver biopsies is considered the best way to detect and monitor subclinical ketosis, while urine or milk cowside tests can also be used in on-farm monitoring programs. Concentrations >1.0 mmol/L or 1.4 mmol/L blood or serum BHB are considered diagnostic of subclinical ketosis. The standard threshold used for blood is 1.2 mmol/L, which corresponds to thresholds of 100 mcmol/L for milk and 15 mg/dL for urine. Oral administration of propylene glycol (250-400 g, every 24 h for 3-5 days) is the standard and most efficacious treatment, as well as additional therapy with bolus glucose treatment. Hypocalcemia is a disease of adult dairy cows in which acute hypocalcemia causes acute to peracute, afebrile, flaccid paralysis that occurs most commonly at or soon after parturition. Dairy cows are at considerable risk for hypocalcemia at the onset of lactation, when daily calcium excretion suddenly increases from about 10 g to 30 g per day. Cows with hypocalcemia have a more profound decrease in blood calcium concentration-typically below 5.5 mg/dL. The prevention of parturient paresis has been historically approached by feeding cows low-calcium diets during the dry period. Negative calcium balance triggers calcium mobilization before calving and better equips the cow to respond to the massive calcium needs at the onset of lactation. Calcium intake must be limited to <20 g per day for calcium restriction to be effective. The most practical and proven method for monitoring hypocalcemia is by feeding cows an acidogenic diet for ~3 weeks before calving. Throughout the review, emphasis is placed on the importance of early diagnosis and proactive management strategies to mitigate the impact of these metabolic diseases on dairy cattle health and productivity. The comprehensive nature of this paper aims to serve as a valuable resource for veterinarians, researchers, and dairy farmers seeking a deeper understanding of these prevalent metabolic disorders in dairy cattle.

Unripe fruits of Litchi chinensis (Gaertn.) Sonn.: An overview of its toxicity

Litchi (Litchi chinensis) is a widely consumed fruit that has been used in many food and health-promoting products worldwide. Litchi is a good source of nutrients including vitamin and minerals, dietary fibers, proteins, and carbohydrates. Of note, several studies have reported that the constituents of litchi fruits elicit antioxidant properties and help to maintain blood pressure, and reduce the risk of stroke and heart attack. An unclearly explained outbreak occurred in June 2019 in Muzaffarpur (Bihar), India resulted in the death of more than 150 children in a week, followed by a total of 872 cases and 176 deaths. This outbreak was associated with the consumption of Litchi fruits and the occurrence of acute encephalitis syndrome. In this high Litchi production region, a huge number of acute encephalitis syndrome cases have been registered in children in the past two decades with high mortality due to these neurological disorders linked to the consumption of litchi. While finding out the causes for this recurrent outbreak, whether or not it is caused by a virus or the phytotoxins of litchi is to be considered critical. Amongst the probable causes were observed to be methylene cyclopropyl acetic acid and hypoglycin-A found in unripe Litchi fruits which can cause hypoglycemia and as a plausible cause of AES outbreaks. This review addresses this recurrent outbreak in-depth exploring the possible causes and discusses the possible mechanisms by which phytotoxins of litchi such as hypoglycin A and methylene cyclopropylglycine which may elicit such toxic effects.

Investigation and Causes of Spontaneous (Non-Diabetic) Hypoglycaemia in Adults: Pitfalls to Avoid

Although adult spontaneous (non-diabetic) hypoglycaemia is rare, its recognition is important for the preventative or curative treatment of the underlying cause. Establishing Whipple's triad-low blood glucose, neuroglycopaenia and resolution of neuroglycopaenia on increasing blood glucose levels to normal or above-is essential to verify hypoglycaemia. Awareness that hypoglycaemia may occur in severely ill patients is important for its prevention. Further investigation in such cases is unnecessary unless another cause of hypoglycaemia is suspected. Patients are often asymptomatic and normoglycaemic at review. Their history of medication, self-medication, access to hypoglycaemic drugs, alcohol use and comorbidity may provide aetiological clues. The investigation involves obtaining blood samples during symptoms for laboratory glucose measurement or provoking fasting or postprandial hypoglycaemia as directed by symptoms. If confirmed, insulin, c-peptide, proinsulin and beta-hydroxybutyrate are analysed in hypoglycaemic samples. These will classify hypoglycaemia due to non-ketotic hyperinsulinaemia, non-ketotic hypoinsulinaemia and ketotic hypoinsulinaemia, and direct investigations to identify the underlying cause. There are, however, many pitfalls that may mislabel healthy individuals as "hypoglycaemic" or misdiagnose treatable or preventable causes of spontaneous hypoglycaemia. Clinical acumen and appropriate investigations will mostly identify hypoglycaemia and its cause.

Pancreatic insulinoma: Diagnosis and treatment of a rare tumour with misleading symptoms - A case report

INTRODUCTION

Insulinomas are an uncommon occurrence, with an annual incidence of approximately 4 per million. These functional pancreatic neuroendocrine tumours can present with a myriad of nonspecific symptoms leading to frequent misdiagnoses.

PRESENTATION OF CASE

In this case report is presented a 55-year-old man who was misdiagnosed and managed for a seizure disorder with escalating antiepileptic treatments for 11 months. A thorough history after an attack was the main tool in solving the mystery of his refractory seizures, leading to the discovery of a pancreatic insulinoma. Biochemical tests revealed fasting hypoglycaemia and a relative hyperinsulinemia, and a distal pancreatic lesion measuring approximately 1.8 cm × 1.3 cm was detected on CT, MRI and endoscopic ultrasound. Successful laparoscopic pancreatic left resection led to complete resolution of symptoms and restoration of quality of life to pre-illness levels.

DISCUSSION AND CONCLUSION

Insulinomas have historically been difficult to diagnose because their symptoms mimic neurologic and psychiatric conditions. Patterns of symptom occurrence obtained from a carefully-taken history is the single most important tool in assessing patients with insulinomas, who usually present with unusual and refractory neuropsychiatric conditions.

An Uncommon Cause of Recurrent Presyncope, Dizziness, and Tachycardia: A Case Report of Diffuse, Adult-Onset Nesidioblastosis/Non-Insulinoma Pancreatogenous Hypoglycemia Syndrome (NIPHS)

Neurovegetative and autonomic symptoms are common presentations of various diseases, ranging from psychosomatic to severe organic disorders. A 23-year-old man presented with a history of recurrent presyncope, dizziness, and tachycardia. Repeated diagnostic work-up in various clinical settings could not identify any definite cause for approximately eight years. However, the incidental detection of postprandial and exercise-induced hypoglycemia was suggestive of an insulin-related disorder. A 72 h plasma glucose fasting test revealed endogenous hyperinsulinism. Upon imaging studies, no tumor mass potentially indicating insulinoma could be detected. ⁶⁸Ga-DOTA-Exendin-4 PET/CT showed diffuse tracer enrichment throughout the whole pancreas. A subtotal pancreatectomy was performed, and the diagnosis of diffuse, adult-onset nesidioblastosis was established histopathologically. This corresponds to the clinical findings of a functional β-cell disorder, also known as non-insulinoma pancreatogenous hypoglycemia syndrome (NIPHS). After nine months, the symptoms recurred, making complete pancreatectomy necessary. Postoperative laboratory evaluation exhibited no residual endogenous C-peptide production. This case illustrates the diagnostic challenges in patients presenting with unspecific, neurovegetative and autonomic symptoms with a severe and rare underlying cause.

Case report: Thyroid storm in a three-year-old girl presenting with febrile status epilepticus and hypoglycemia

Thyroid storm, though extremely rare in toddlers, requires prompt diagnosis and treatment because it can be fatal if left untreated. However, thyroid storm is not often considered in the differential diagnosis of a febrile convulsion due to its rarity in children. Herein, we report the case of a 3-year-old girl with thyroid storm who presented with febrile status epilepticus. Although the seizure was stopped by diazepam administration, her tachycardia and widened pulse pressure persisted, and severe hypoglycemia was observed. Based on the findings of thyromegaly, a history of excessive sweating and hyperactivity, and a family history of Graves' disease, she was eventually diagnosed with a thyroid storm. The patient was successfully treated with thiamazole, landiolol, hydrocortisone, and potassium iodide. Propranolol, a non-selective β-blocker, has been used to manage tachycardia during thyroid storm. However, a cardio-selective β1-blockers, landiolol hydrochloride, was used in our case to avoid worsening hypoglycemia. Febrile status epilepticus is one of the most common medical emergencies in childhood; it is necessary to rule out treatable underlying critical diseases such as septic meningitis and encephalitis. Thyroid storm should be considered in children presenting with prolonged febrile convulsion accompanied by findings that are not usually observed with febrile convulsions.

Effects of Hypoglycemia on Cardiovascular Function in Patients with Diabetes

Hypoglycemia is common in patients with type 1 and type 2 diabetes (T1D, T2D), treated with insulin or sulfonylureas, and has multiple short- and long-term clinical implications. Whether acute or recurrent, hypoglycemia significantly affects the cardiovascular system with the potential to cause cardiovascular dysfunction. Several pathophysiological mechanisms have been proposed linking hypoglycemia to increased cardiovascular risk, including hemodynamic changes, myocardial ischemia, abnormal cardiac repolarization, cardiac arrhythmias, prothrombotic and proinflammatory effects, and induction of oxidative stress. Hypoglycemia-induced changes can promote the development of endothelial dysfunction, which is an early marker of atherosclerosis. Although data from clinical trials and real-world studies suggest an association between hypoglycemia and cardiovascular events in patients with diabetes, it remains uncertain whether this association is causal. New therapeutic agents for patients with T2D do not cause hypoglycemia and have cardioprotective benefits, whereas increasing the use of new technologies, such as continuous glucose monitoring devices and insulin pumps, has the potential to reduce hypoglycemia and its adverse cardiovascular outcomes in patients with T1D.

Pancreatic Dysfunction Masquerading as an Insulinoma

Insulinoma is a rare neuroendocrine tumor that overproduces insulin, resulting in hypoglycemic symptoms. Elevated C-peptide levels in the absence of sulfonylurea use indicate insulinoma. Treatment is usually glucose administration and if the tumor size is large, surgery may be warranted. We present a case of a young man who had a one-year continuing episode of hypoglycemic symptoms that resolve after consuming high-glucose solids and liquids. Although symptoms pointed toward insulinoma, the 72-hour fasting test failed to show insulinoma. This case shows how following the algorithm accurately will prevent an inaccurate diagnosis.

Clinical Presentation and Diagnostic Approach to Hypoglycemia in Adults Without Diabetes Mellitus

OBJECTIVE

To review the clinical presentation, causes, and diagnostic approach to spontaneous hypoglycemia in adults without diabetes mellitus.

METHODS

A literature review was performed using the PubMed and Google Scholar databases.

RESULTS

Hypoglycemia is uncommon in people who are not on glucose-lowering medications. Under normal physiologic conditions, multiple neural and hormonal counterregulatory mechanisms prevent the development of abnormally low levels of plasma glucose. If spontaneous hypoglycemia is suspected, the Whipple triad should be used to confirm hypoglycemia before pursuing further diagnostic workup. The Whipple criteria include the following: (1) low levels of plasma glucose, (2) signs or symptoms that would be expected with low levels of plasma glucose, and (3) improvement in those signs or symptoms when the level of plasma glucose increases. Spontaneous hypoglycemia can be caused by conditions that cause endogenous hyperinsulinism, including insulinoma, postbariatric hypoglycemia, and noninsulinoma pancreatogenous hypoglycemia. Spontaneous hypoglycemia can also be seen with critical illness, hepatic or renal dysfunction, hormonal deficiency, non-diabetes-related medications, and non-islet cell tumors. The initial diagnostic approach should begin by obtaining a detailed history of the nature and timing of the patient's symptoms, medications, underlying comorbid conditions, and any acute illness. A laboratory evaluation should be conducted at the time of the spontaneous symptomatic episode. Supervised tests such as a 72-hour fast or mixed-meal test may be needed to recreate the situation under which the patient is likely to experience symptoms.

CONCLUSION

We provide an overview of the physiology of counterregulatory response to hypoglycemia, its causes, and diagnostic approaches to spontaneous hypoglycemia in adults.

Insulin murder and the case of Colin Norris

Although insulin is an essential medicine and a life-saving drug, it has also been incriminated in many poisoning deaths; accidental, suicidal and some with malicious intent. Overdosing with insulin precipitates a life-threatening state of hypoglycemia and if untreated leads to coma, irreversible brain damage and death. Normally, the pancreatic β-cells secrete equimolar amounts of insulin and C-peptide into the portal venous blood, although under physiological conditions the plasma concentration ratio (insulin/C-peptide) is less than unity, because insulin is more susceptible to hepatic first-pass metabolism. A high ratio of insulin/C-peptide in plasma from a poisoned patient is compelling evidence that pharmaceutical insulin was administered, which does not contain C-peptide. The analysis of insulin and C-peptide was traditionally done by immunoassay methods (RIA and/or ELISA), although high resolution LC-MS/MS is more suitable for forensic purposes and permits the identification of insulin analogues. Use of insulin as a murder weapon is exemplified by the case of Colin Norris, a male nurse found guilty of murdering four elderly patients and the attempted murder of a fifth by injecting them with insulin. However, the prosecution evidence against Norris was mainly circumstantial and hearsay. Toxicological evidence against Norris consisted of a high insulin/C-peptide concentration ratio in plasma from one of the victims. This analysis was done by an immunoassay method at a clinical laboratory and not a forensic laboratory. Analytical procedures, including chain-of-custody routines, are more stringent at forensic laboratories. Since his conviction, some of the medical evidence against Norris has been called into question, especially the prevalence of spontaneous attacks of hypoglycemia in elderly and frail patients with co-morbidities.

Pitfalls in Diagnosing Hypoglycemia Due to Exogenous Insulin: Validation and Utility of an Insulin Analog Assay

OBJECTIVE

To overcome the limitations of commercially available insulin immunoassays which have variable detection of analog insulin and can lead to clinically discordant results and misdiagnosis in the workup of factitious hypoglycemia.

PATIENTS AND METHODS

We performed analytical validation of a liquid chromatography high resolution accurate mass (LC-HRAM) immunoassay to detect insulin analogs. We completed clinical assessment using a large cohort of human serum samples from 78 unique individuals, and subsequently used the assay in the evaluation of eight individuals with high diagnostic suspicion for factitious hypoglycemia.

RESULTS

The performance characteristics show that the LC-HRAM immunoassay can be applied to detect five commonly used synthetic insulin analogs (lispro, glulisine, aspart, glargine metabolite, and detemir) in human serum. Our clinical cases show that this assay could be used in the diagnosis of factitious hypoglycemia by identifying the analog insulin(s) in question.

CONCLUSION

The LC-HRAM immunoassay reported here overcomes a gap in our diagnostic pathway for hypoglycemia. The results obtained from our studies suggest that this method is appropriate for use in clinical laboratories when factitious hypoglycemia is considered as a differential diagnosis.

Is the Size of Insulinoma Predictive for its Endocrine Behavior? An Endoscopic Ultrasound Study

OBJECTIVE

Insulinoma is a rare tumor of the pancreas that can lead to spontaneous hypoglycemia due to excessive insulin secretion. Seventy-two-hour fast is the gold standard for finding the correct diagnosis. Endoscopic ultrasound (EUS) is an established examination method to identify the suspicious lesion. Previous studies correlate the measured size of insulinoma and their endocrine behavior. This study was designed to find a relation between these variables.

METHODS

We took the data of patients who had a histologically confirmed insulinoma after receiving an endoscopic ultrasound in our department. Size and echogenicity were correlated with the endpoint of the 72-hour fast and hormone levels.

RESULTS

A total of 45 patients were identified. Most insulinomas were small with a volume of<2 cm³ (median 1.15 cm³). There was no correlation between the duration of fasting, hormone levels, and the size of the insulinoma. In addition, in a subgroup analysis, no connection could be established between the size of the insulinoma and the amount of insulin released after oral glucose exposure. We found that homogeneous tumors were significantly smaller and had a lower Ki-67 index. Furthermore, there was a tendency towards a shorter duration for the 72-hour fast for the small tumors.

DISCUSSION

This data suggests that the measured size of insulinoma by EUS is not related to the time until termination of the 72-hour fast and measured hormone levels. The echogenicity seems more important, showing that homogenous tumors are an indicator of a higher differentiation, which can result in a shorter duration of the fasting period. The differences in the secretion behavior of the insulinomas could complicate the correlation of size and the 72-hour fast period.

Pancreatic neuroendocrine tumour-insulinoma masquerading as a psychiatric illness

A female patient in her early sixties had problems of recurrent syncopal attacks and panic attacks over the last 5 years. She had been initially managed for an anxiety disorder with psychiatric medications. During one of those episodes, she was brought to our hospital in an unconscious state with a low blood sugar level of 43 mg/dL. She was suspected to have a neuroendocrine tumour and diagnosis was established by supervised fasting up to 72 hours and imaging. Her recorded blood sugar during fasting was 37 mg/dL. She underwent surgery and presently remains asymptomatic. Physicians should have a high suspicion of insulinoma in patients presenting with repeated episodes of hypoglycaemic symptoms in the absence of any cognizable cause.

A Rare Case of Insulinoma in a Thin, Lean Adult Male: A Case Report

Insulinoma is an insulin-secreting tumor that causes hypoglycemia due to inappropriately high insulin secretion. The Whipple's triad, which comprises indications of hypoglycemia (tremor, sweating, irritability, uneasiness, and weakness), plasma glucose concentration <55 mg/dL (3.0 mmol/L), and resolution of symptoms after administration of glucose, is utilized for the determination of insulinoma. In this report, we present the case of a thin, lean, adult male with a BMI of 22, who presented with repetitive episodes of tremor, sweating, weariness, and perplexity that occurred amid fasting and settled with meals, fulfilling Whipple's triad criteria for the determination of insulinoma. The episodes frequently led to seizures. Supervised fasting was carried out, which revealed raised C-peptide levels, low blood glucose, and negative sulfonylurea screen. A computed tomography (CT) scan localized the tumor, and surgical resection was planned.

The optimal diagnostic criteria of endogenous hyperinsulinemic hypoglycemia based on a large cohort of Chinese patients

PURPOSE

An end-of-fast insulin level ≥ 3 µIU/ml, C-peptide level ≥ 0.6 ng/ml, and proinsulin level ≥ 5 pmol/l with end-of-fast glucose level ≤ 3.0 mmol/l have been established as the criteria for endogenous hyperinsulinemic hypoglycemia. However, all these criteria have been proposed based on patients in Western populations. This study aimed to determine the optimal criteria using a large series of Chinese patients.

METHODS

This retrospective study comprised 144 patients with surgically proven insulinoma and 40 controls who underwent a 72-h fasting test at the Peking Union Medical College Hospital(PUMCH) from 2000 to 2020. Receiver operating characteristic curves were used for analysis.

RESULTS

In this series of patients, the optimal diagnostic criteria for endogenous hyperinsulinemic hypoglycemia were insulin  ≥ 5.5 μIU/ml, C-peptide ≥ 0.7 ng/ml, and proinsulin ≥ 12 pmol/l with end-of-fast glucose ≤ 2.8 mmol/l; the sensitivity and specificity were 99% and 100% for insulin, 100% and 100% for C-peptide, and 93% and 100% for proinsulin, respectively. The diagnostic efficacy of the criteria based on Western populations was then tested. The sensitivity and specificity of end-of-fast insulin ≥ 3 μIU/ml, C-peptide ≥ 0.6 ng/ml, and proinsulin ≥ 5 pmol/l with end-of-fast glucose ≤ 3.0 mmol/l were 100% and 83%, 100% and 80%, and 97% and 78%, respectively.

CONCLUSIONS

New and optimized diagnostic criteria for endogenous hyperinsulinemic hypoglycemia in Chinese populations have been proposed, and these criteria yield satisfactory accuracy.

A critical analysis of laparoscopic and open approaches to sporadic pancreatic insulinoma resection in the modern era

BACKGROUND

A single center experience with sporadic pancreatic insulinoma was analyzed to develop an algorithm for modern surgical management.

METHODS

Thirty-four patients undergoing surgery from 2001 to 2019 were reviewed.

RESULTS

The majority underwent enucleation (10 laparoscopic, 15 open). Laparoscopy was performed in 22 patients with conversion to open in 11, mostly related to the proximity of the tumor to the pancreatic duct (n = 4). Tumors on the anterior and posterior surface of the pancreas in all anatomic locations were completed with laparoscopic enucleation. Overall, the clinically-relevant postoperative pancreatic fistula (CR-POPF) rate was 21%, with no difference between laparoscopic versus open enucleation (10% vs 20%, p = 0.50) or enucleation versus resection (16% vs 33%, p = 0.27). Laparoscopic enucleation had shorter median hospital length of stay (LOS) compared with open (4 vs 7 days, p = 0.02).

CONCLUSIONS

Laparoscopic enucleation does not increase the CR-POPF risk and provides an advantage with a shorter hospital LOS in select patients. Tumor location and relationship to the pancreatic duct guide surgical decision-making. These findings highlight tumor-specific criteria that would benefit from a minimally invasive approach.

[Spontaneous Hypoglycemia: A Diagnostic Challenge]

HISTORY

A 59-year-old woman presented for an endocrinological evaluation of recurrent spontaneous hypoglycemia. The complaints always regressed after carbohydrate intake. Due to classic congenital adrenal hyperplasia, the patient received substitution therapy with hydrocortisone for decades.

FINDINGS AND DIAGNOSIS

The patient was in good general condition and slightly overweight. The blood glucose at the time of admission was 87 mg/dl. The cortisol and adrenocorticotropic hormone (ACTH) under substitution with delayed-release hydrocortisone were unremarkable. The mixed-meal tolerance test (MMTT, standardized breakfast test) showed no reactive hypoglycemia. In the subsequent 72-hour fast, symptomatic hypoglycemia of 46 mg/dl was demonstrated after 36 hours. The insulin secretion was suppressed. The low cortisol as well as the high ACTH indicated an undersupply of hydrocortisone at this time.

THERAPY AND COURSE

Initially, the morning dose of delayed-release hydrocortisone was increased. However, this had no effect on blood glucose. Therefore, hydrocortisone was also prescribed at night.

CONCLUSION

In addition to endogenous hyperinsulinism, a disturbance of the contrainsulinergic hormones can also be responsible for spontaneous hypoglycemia.The MMTT and the 72-hour fast test should be used for diagnosis. It is important to ensure that hormone analysis is carried out immediately in hypoglycemia. The ratio of insulin, C-peptide and proinsulin to blood glucose and the constellation of counter-regulatory hormones such as cortisol, ACTH, growth hormone, Insulin-like growth factor 1 (IGF-1) and catecholamines can provide information about the etiology of hypoglycemia.

Impaired glucose tolerance with neurological manifestations in insulinoma

Insulinoma may have an atypical presentation and it should be suspected in patients with neurological manifestations in spite of an atypical insulin and proinsulin levels associated with hypoglycemia. Fast test is an important tool to reach the diagnosis.

Case report of a pancreatic insulinoma misdiagnosed as epilepsy

A 55-year-old patient had spent 12 years with unexplained seizures, initially diagnosed as epilepsy and then as a psychiatric disorder. When she was admitted with hypoglycaemia, a fasting test was performed showing blood sugar levels as low as 1 mmol/L with symptoms of neuroglycopenia. Insulinoma was suspected and an MRI showed a large tumour in the tail region of the pancreas. A Dodecanetetraacetic acid-Tyr3-octreotate (DOTATATE) positron emission tomography CT indicated no malignancy and showed no signs of metastasis. The patient underwent surgery, leaving her asymptomatic.

Prognosis after surgery for multiple endocrine neoplasia type 1-related pancreatic neuroendocrine tumors: Functionality matters

BACKGROUND

Metastasized pancreatic neuroendocrine tumors are the leading cause of death in patients with multiple endocrine neoplasia type 1. Aside from tumor size, prognostic factors of pancreatic neuroendocrine tumors are largely unknown. The present study aimed to assess whether the prognosis of patients with resected multiple endocrine neoplasia type 1-related nonfunctioning pancreatic neuroendocrine tumors differs from those with resected multiple endocrine neoplasia type 1-related insulinomas and assessed factors associated with prognosis.

METHODS

Patients who underwent resection of a multiple endocrine neoplasia type 1-related pancreatic neuroendocrine tumors between 1990 and 2016 were identified in 2 databases: the DutchMEN Study Group and the International MEN1 Insulinoma Study Group databases. Cox regression was performed to compare liver metastases-free survival of patients with a nonfunctioning pancreatic neuroendocrine tumors versus those with an insulinoma and to identify factors associated with liver metastases-free survival.

RESULTS

Out of 153 patients with multiple endocrine neoplasia type 1, 61 underwent resection for a nonfunctioning pancreatic neuroendocrine tumor and 92 for an insulinoma. Of the patients with resected lymph nodes, 56% (18/32) of nonfunctioning pancreatic neuroendocrine tumors had lymph node metastases compared to 10% (4/41) of insulinomas (P = .001). Estimated 10-year liver metastases-free survival was 63% (95% confidence interval 42%-76%) for nonfunctioning pancreatic neuroendocrine tumors and 87% (72%-91%) for insulinomas. After adjustment for size, World Health Organization tumor grade, and age, nonfunctioning pancreatic neuroendocrine tumors had an increased risk for liver metastases or death (hazard ratio 3.04 [1.47-6.30]). In pancreatic neuroendocrine tumors ≥2 cm, nonfunctioning pancreatic neuroendocrine tumors (2.99 [1.22-7.33]) and World Health Organization grade 2 (2.95 [1.02-8.50]) were associated with liver metastases-free survival.

CONCLUSION

Patients with resected multiple endocrine neoplasia type 1-related nonfunctioning pancreatic neuroendocrine tumors had a significantly lower liver metastases-free survival than patients with insulinomas. Postoperative counseling and follow-up regimens should be tumor type specific and at least consider size and World Health Organization grade.

Essentials of Insulinoma Localization with Selective Arterial Calcium Stimulation and Hepatic Venous Sampling

Insulinomas are the most common functional pancreatic neuroendocrine tumor. Most insulinomas can be localized non-invasively with cross-sectional and nuclear imaging. Selective arterial calcium stimulation and hepatic venous sampling is an effective and safe minimally-invasive procedure for insulinoma localization that may be utilized when non-invasive techniques are inconclusive. The procedure’s technical success and proper interpretation of its results is dependent on the interventional radiologist’s knowledge of normal and variant pancreatic arterial perfusion. Accurate pre-operative localization aids in successful surgical resection. Technical and anatomic considerations of insulinoma localization with selective arterial calcium stimulation and hepatic venous sampling are reviewed.

Surgery for multiple endocrine neoplasia type 1-related insulinoma: long-term outcomes in a large international cohort

Background

Insulinomas are found in 10–15 per cent of patients with multiple endocrine neoplasia type 1 (MEN1) and lead to life‐threatening hypoglycaemia. Surgical outcome and the optimal surgical strategy for MEN1‐related insulinoma are unknown.

Methods

Patients with MEN1‐related insulinomas were identified in 46 centres in Europe and North America between 1990 and 2016. Insulinomas were considered localized if the lesion was in the pancreatic head or body/tail. Patients with pancreatic neuroendocrine tumours throughout the pancreas were suspected of having multifocal insulinoma. The primary outcome was postoperative hypoglycaemia, defined as persistent hypoglycaemia, or recurrent hypoglycaemia caused by a new insulinoma or insulin‐producing liver metastases. Hypoglycaemia‐free survival was estimated by the Kaplan–Meier method.

Results

Ninety‐six patients underwent resection for MEN1‐related insulinoma. Sixty‐three and 33 patients had localized and multifocal insulinomas respectively. After a median follow‐up of 8 (range 1–22) years, one patient (1 per cent) had persistent disease and six (6 per cent) had developed recurrent disease, of whom four had a new insulinoma. The 10‐year hypoglycaemia‐free survival rate was 91 (95 per cent c.i. 80 to 96) per cent. Of those with localized disease, 46 patients underwent pancreatic resection and 17 enucleation. One of these patients had persistent disease and one developed recurrent insulinoma. Among patients with multifocal disease, three developed new insulinomas and two developed insulin‐producing liver metastases.

Conclusion

Surgery for MEN1‐related insulinoma is more successful than previously thought.

Long-standing Sporadic Pancreatic Insulinoma: Report of a Rare Case

Insulinomas are rare, functional pancreatic neuroendocrine tumors arising from the pancreatic multipotent stem cells or neuroendocrine islet, occurring with a higher proportion in females. Majority of insulinomas have a sporadic etiology; however, only 5%-10% develop as a part of multiple endocrine neoplasm type 1 syndrome. They usually present with symptoms of hypoglycemia including disturbance in orientation, tremors, diaphoresis, altered mental state, seizures and visual changes among others. The diagnosis is based on appreciation of the classic Whipple triad, i.e. neuroglycopenic symptoms and sympathetic drive along with low serum glucose levels (<50 mg/dL) and a complete reversibility of these symptoms with prompt administration of glucose. The gold standard treatment for insulinoma involves complete surgical excision (i.e. enucleation), which is curative in 90% of the patients. Health care physicians should have a high index of suspicion for this tumor in patients presenting with neurological and sympathetic symptoms, particularly if they are resolved after eating. Here, we report the case of a 48-year-old female with the history of multiple episodes of hypoglycemic symptoms for the past two years which improved on glucose intake. Furthermore, we also summarized the discussion regarding diagnosis and management of pancreatic insulinoma.

Hypoglycemic risk exposures in relation to low serum glucose values in ambulatory patients

This study aimed to correlate hypoglycemic risk exposures (HREs) with low blood glucose value (BGV) in ambulatory patients to inform selection of a glucose critical action value (CAV).This was a retrospective study of ambulatory patients with at least 1 serum glucose ≤70 mg/dL obtained at 2 laboratories within the Johns Hopkins Health System over 3.8 years. Multivariable logistic regression was used to evaluate association of BGV cut-offs of <60, <54, <50, and <45 mg/dL with HREs. HREs were classified as "high hypoglycemic risk" (HHR), "moderate hypoglycemic risk" (MHR), "low hypoglycemic risk" (LHR), and "no hypoglycemic risk" (NHR).A total of 5404 patient samples of BG ≤70 mg/dL were analyzed, of which 30.3%, 23.2%, 28.5%, 18.0% occurred in NHR, LHR, MHR, and HHR groups, respectively. An inverse relationship was noted between BGV cut-offs and HHR, but no association was observed for LHR or MHR. After adjusting for age, sex, and race, there was an inverse association between BG thresholds and the odds of HHR. For classification of HHR, BGV cut-offs of <60, <54, <50, and <45 mg/dL correctly classified 71.2%, 69.8%, 68.8%, and 67.2% of BG samples, achieved false-positive rates of 13.6%, 4.7%, 1.7%, and 0.5% and positive likelihood ratios of 3.3, 6.0, 11.2, and 23.4, respectively.Nearly 70% of low BGVs occurred in patients with at least 1 HRE, but only ∼20% occurred in HHR patients. Given their high positive likelihood ratios, BGVs <54 or <50 mg/dL are reasonable candidates for CAVs that would allow sufficient clinician response time while minimizing false-positive alerts.

Hypoglycemia, Malnutrition and Body Composition

Hypoglycemia is one of the most significant factors to affect prognosis, and is detrimental to patients regardless of diabetes mellitus (DM) status. The classical paradigms dictate that hypoglycemia is a result of overtreatment with glucose lowering agents (iatrogenic hypoglycemia), or, as among patients without DM, this condition is attributed to disease severity. New information shows that hypoglycemia occurs among patients that have a tendency for it. Incident hypoglycemia is very prevalent in the hospital setting, occurring in 1:6 patients with DM and in 1:17 patients without DM (Leibovitz E, Khanimov I, Wainstein J, Boaz M; Diabetes Metab Syndr Clin Res Rev. 13:222-226, 2019).One of the major factors associated with incidence of hypoglycemia is the nutritional status on hospital admission and during the hospitalization. Assessment of nutritional status using questionnaires and biomarkers might be helpful in determining risk of hypoglycemia. Moreover, administration of oral nutritional supplements was shown to decrease this risk.It is also well known that a high burden of comorbidities is associated with an increased risk of hypoglycemia. For example, kidney disease, whether acute or chronic, was shown to increase the risk for hypoglycemia, as well as some endocrine disorders.In this review we elaborate on specific findings that are characteristic of patients at risk for developing hypoglycemia, as well as treatment aimed at preventing its occurrence.

Peripherally administered KP-10 prevents development of insulin-induced hypoglycemic shock in diabetic rhesus monkeys

AIM

This study investigated whether kisspeptin-10 (KP-10) prevents diabetic rhesus monkeys from insulin-induced hypoglycemic shock.

MATERIALS AND METHODS

Thirty-six adult male rhesus monkeys were used, six in each group. Diabetes was induced with streptozotocin (45 mg/kg b.w.; single dose i.v.). Groups were as: saline control, insulin alone, pre-insulin (treated with KP-10, 30 min before insulin), post-insulin (treated with KP-10, 30 min after insulin), treated with premix dose of KP-10 (50 μg) and insulin, and the group treated with the kisspeptin antagonist P234 (50 μg). Following an overnight fast, each animal was subjected to respective treatment, and blood glucose concentrations were recorded every 30-min interval for 3 h.

RESULTS

Intergroup comparisons demonstrated that treatment with KP-10 prior to insulin administration and kisspeptin-insulin premix treatment allowed blood glucose levels to rise to significantly higher levels (p < 0.001) by 180 min in diabetic and healthy animals compared to treatment with insulin alone. However, intragroup comparisons revealed a significant decrease in blood glucose level in diabetic animals only. Treatment with P234 antagonist followed by insulin administration abolished the preventive action of kisspeptin, whereby blood glucose decreased significantly (p < 0.001) in both diabetic and healthy animals. KP-10 post-insulin treatment, however, remained ineffective and led, instead, to significantly decreased glucose concentrations by 180 min in both diabetic and healthy animals when compared to animals treated with insulin alone.

CONCLUSIONS

KP-10 bears therapeutic potential to prevent hypoglycemic shock that may sometimes occur during intensive insulin therapy. Several pharmacological aspects of its interaction with insulin and other drugs, however, remain to be investigated.

Hypoglycemic symptoms in the absence of diabetes: Pilot evidence of clinical hypoglycemia in young women

Aims

Clinical visits of non-diabetic patients reporting hypoglycemic symptoms are common in endocrinology practices, but remain understudied and lack clinical definition and evidence-based recommendations for diagnosis or treatment. Our goal was to pilot test the concordance of hypoglycemic symptoms with low glucose values in young non-diabetic individuals.

Methods

We recruited eight individuals who reported regularly experiencing symptoms consistent with hypoglycemia to wear a blinded Dexcom continuous glucose monitor and report symptoms for seven days. We excluded individuals with diabetes or other known causes of hypoglycemia or similar symptoms.

Results

Participants were all women with an average age of 29 years. 25% were African American and 25% had obesity. All participants experienced glucose values ≤ 70 mg/dL and half (4/8) experienced glucose ≤ 54 mg/dL for at least 15 min or 3 consecutive readings. Average time between last meal and reported symptoms was 4.4 h. Lower glucose values were significantly associated with higher odds of experiencing hypoglycemic symptoms 1.15 (CI: 1.07-1.24) for every -5mg/dL, (p < 0.001) from mixed effects models for repeated measures adjusted for age, race, and body mass index. All participants also reported engaging in potentially obesogenic behaviors in order to avoid symptoms.

Conclusions

Individuals with hypoglycemic symptoms in the absence of diabetes experience clinical hypoglycemia, indicating the need to understand the etiology, behavioral responses, and other health risks that might be associated with this understudied condition.

Medical therapy in patients with endogenous hypoglycaemia: Is euglycaemia achievable?

CONTEXT

While the only curative treatment for patients with endogenous hypoglycaemia related to inappropriate insulin or to insulin growth factor 2 (IGF2) secretion is surgery, medical treatment to normalize plasma glucose levels can be useful.

OBJECTIVE

The aim of this prospective single centre study was to assess whether patients with endogenous hypoglycaemia, considered euglycaemic with medical treatments, experienced asymptomatic hypo- or hyperglycaemic excursions.

PATIENTS AND METHODS

All patients with endogenous hypoglycaemia related to inappropriate insulin or to IGF2 secretion between 2012 and 2016 and considered normoglycaemic with medical treatment (absence of clinical hypoglycaemia and self-monitoring blood glucose in the normal range) were enroled and underwent a six-day continuous glucose monitoring (CGM) recording.

RESULTS

Twenty-seven patients (inappropriate insulin secretion n = 25 and IGF2 secretion n = 2), treated with diazoxide (n = 16), somatostatin analogues (n = 7), glucocorticoids (n = 3) or a combination of these treatments (n = 1) were enroled. Twenty-five CGMs were analysed. CGM confirmed normoglycaemia in 11/25 patients (44%). Hypoglycaemias below 0.60 g/L were present in seven patients (28%) and were associated with hyperglycaemic excursions above 1.40 g/L in five patients. Seven patients (28%) had only hyperglycaemic excursions. Based on these results, treatment was modified in 14 patients (56%).

CONCLUSION

Despite the disappearance of hypoglycaemia-related clinical symptoms and normalization of blood glucose self-monitoring data, 56% of the patients with endogenous hypoglycaemia treated with medical therapy experienced asymptomatic hypo- and/or hyperglycaemia. Continuous glucose monitoring could be a useful approach to reveal and prevent hypo- or hyperglycaemic excursions.

Comparison of the diagnostic accuracy of the current guidelines for detecting insulinoma

Objective Insulinomas are rare pancreatic endocrine tumors characterized by hypoglycemia. Guidelines by the Endocrine Society (ES), the European (ENETS) and the North American (NANETS) Neuroendocrine Tumor Societies provide divergent diagnostic criteria. This study compared the diagnostic accuracy of these different criteria during the 72-h fasting test. Design Retrospective cohort study. Methods From 2000 to 2014, 64 patients with a suspected insulinoma underwent a 72-h fasting test and were included in the analysis. This study assessed the diagnostic sensitivity, specificity and accuracy based on venous blood glucose and corresponding insulin levels measured by electrochemiluminescence immunoassay (ECLIA). Results Based on 64 individuals (18 with, 46 without insulinoma), the ES criteria provided a diagnostic sensitivity of 0.94 (0.73-1.00), specificity of 0.89 (0.76-0.96) and accuracy of 0.91 (0.81-0.96). ENETS/NANETS criteria reached a diagnostic sensitivity of 0.78 (0.52-0.94), specificity of 1.00 (0.92-1.00) and accuracy of 0.94 (0.85-0.98). Conclusions These results point to a higher diagnostic sensitivity with less specificity for diagnosing insulinoma using ES criteria and a higher specificity at lower sensitivity by using ENETS/NANETS criteria. Before considering these results when applying the different criteria in clinical practice, the results should be confirmed in further studies comprising larger cohorts.

Paraneoplastic syndromes and other systemic disorders associated with neuroendocrine neoplasms

Neuroendocrine paraneoplastic syndromes (PNS) consist of metabolic disorders that accompany benign and malignant neoplasms but remain unrelated to mass effects or invasion by the primary tumor or its metastases. The underlying pathogenesis responsible for PNS usual clinical presentation relies on aberrant production of protein hormones, proteins and other substances by the tumor. Prompt recognition of characteristic signs and symptoms combined with serological identification of key substances may result in early diagnosis of PNS and its underlying malignancy. For these reasons, healthcare professionals should familiarize themselves with tumor-induced hypercalcemia, syndrome of inappropriate antidiuretic hormone, carcinoid syndrome, virilisation syndrome, gynecomastia, acromegaly, Cushing syndrome, osteogenic osteomalacia, tumor-induced hypoglycemia, necrolytic migratory erythema, and watery diarrhea, hypokalemia and achlorydria syndrome. Medical awareness for PNS can improve patient outcomes through earlier administration of cancer therapy and treatment, better symptomatic relief and prolong overall survival.

Insulinoma resembling a rapid eye movement sleep behavior disorder: a case report

Some patients with insulinoma present with neuropsychiatric symptoms and are often misdiagnosed with psychiatric disease. We present the case of a 72-year-old Japanese female who exhibited violent behavior while asleep and received a diagnosis of suspected rapid eye movement sleep behavior disorder (RBD). She was admitted to the psychiatry ward after receiving levomepromazine 25 mg intramuscularly. The patient’s blood glucose level was 27 mg/dL at the time of hospitalization, and a biochemical examination revealed that her insulin level was 9.1 µU/mL and C-peptide level was 2.16 ng/mL. A contrast-enhanced computed tomography revealed a mass 8 mm in diameter in the pancreatic head. The diagnosis was changed from RBD to insulinoma. The sleep behavior disorder disappeared after continuous glucose administration. After enucleation of the insulinoma, the administration of glucose was discontinued, and her blood glucose levels recovered. This case suggests that insulinoma should be considered by physicians and psychiatrists in the differential diagnosis of patients with symptoms presenting as RBD.

A case of hyperinsulinemic hypoglycemia related with a calcimimetic agent

We herein report a case of a 60-year-old female receiving hemodialysis who developed severe hyperinsulinemic hypoglycemia and lost her consciousness. A calcimimetic agent had been administered for the secondary hyperparathyroidism. The calcimimetic agent, mimicking the elevation of the extracellular calcium ion concentration, activates calcium-sensing receptors (CaSR) of the parathyroid cells and inhibits the parathyroid hormone secretions. The previous study suggested that the CaSR are also expressed in both human β cells and insulinoma cells, but the reactivity to change in the extracellular calcium ion concentration is different between normal β cells and insulinoma cells. After cessation of the calcimimetic agent, hypoglycemic symptoms disappeared and endogenous insulin secretion dropped to normal levels. However, the result of a prolonged fasting test indicated that she remained hyperinsulinemic even after its cessation, suggesting that she had insulinoma which could not be detected by the imaging examinations. The previous autopsy data showed that there were many cases of the insulinoma without the symptoms of hypoglycemia. We considered the possibility that she had the insulinoma and the pancreatic tumor was too small to promote the insulin secretion and cause hypoglycemia without activation by the calcimimetic agent. We should know that the calcimimetic agent could cause hyperinsulinemic hypoglycemia with the unidentified insulinoma.

Refractory Metastatic Insulinoma Treated with Everolimus, Complicated by Cryptogenic Organizing Pneumonia

Insulinoma is a rare neuroendocrine pancreatic islet cell tumor of which the majority are benign and solitary. Its estimated incidence is 2 to 4 cases per 1 million person-years. We report the case of an 82-year-old female who presented with metastatic insulinoma to the liver and retroperitoneal lymph nodes. It was diagnosed based on positive Whipple's triad, elevated insulin, elevated C-peptide, and negative insulin auto-antibody. Her disease was initially managed with diazoxide 100 mg orally every 8 hours, octreotide LAR 30 mg intramuscularly every month, and sunitinib 12.5 mg orally three times a day. However, patient had recurrent symptoms and imaging consistent with worsened metastatic insulinoma; and thus, treatment was changed to everolimus 10 mg PO daily. Over the subsequent 10 months, the patient developed progressive shortness of breath and hypoxemia with and oxygen saturation (SpO2) of 89% on room air. Computerized tomography (CT) and lung biopsy were consistent with cryptogenic organizing pneumonia (COP) temporally associated with the initiation of everolimus. She was started on prednisone 1 mg/kg/day and within 48 hours, her symptoms and hypoxemia improved to SpO2 of 98-99% at room air and her repeat CT chest showed marked disease improvement. Given her good response with everolimus, it was continued in conjunction with the prednisone and to this day, patient has had a significant therapeutic response with normoglycemia and stable, well-controlled symptoms. This case is unique because to our knowledge, it is the first reported case of a patient with metastatic insulinoma complicated by the development of cryptogenic organizing pneumonia. It reaffirms the causal association between everolimus and cryptogenic organizing pneumonia that has been reported numerous times in literature. However, there has been no reported cases showing that the COP can be managed with prednisone concurrently with everolimus for the metastatic insulinoma without diminished clinical benefit. While pulmonary complications have been cited as reasons for discontinuation of everolimus therapy, our case report highlights the use of steroids as a viable therapeutic strategy that allows successful therapy with everolimus to be continued. In addition to presenting this case, we will also do a thorough review of the literature surrounding the available therapeutic options of metastatic insulinoma. This will include surgery, somatostatin analogs, antimicrobials, potassium channel activators, VEGF-A inhibitors, alkylating agents and mTOR inhibitors to provide a more in-depth picture of how we treat metastatic insulinoma.

Toxicological and Biochemical Analyses of an Autopsy Case Involving Oral Overdose of Multiple Antidiabetic and Antihypertensive Drugs

Oral antidiabetics can cause fatal hypoglycemia; although they can be chemically identified and quantified, biochemical investigations are important for assessing the biological consequences of an overdose. Such cases of overdose involving oral antidiabetics may involve other drugs for treating lifestyle-related diseases, particularly antihypertensives. Here, we report a toxicological and biochemical investigation of drugs and biochemical profiles in a fatal overdose involving multiple oral antidiabetics and antihypertensives. A 55-year-old woman died about 2 days after the ingestion of around 110 tablets of antidiabetics and antihypertensives that had been prescribed for her husband. A forensic autopsy and histological analysis demonstrated no evident pathology as the cause of death. A toxicological analysis suggested hypoglycemia and an overdose of antihypertensives as well as the retention of antidiabetics and diuretics in the pericardial fluid. A relatively low pericardial amlodipine concentration was observed, which may have been the result of its long half-life (slower distribution and reduction rate) and/or possible affinity with the myocardium. In addition, a biochemical analysis indicated hypoglycemia, without increased serum insulin and C-peptide, but with increased glucagon levels, as the possible influence of glibenclamide overdose. These observations suggest the usefulness of a combination of toxicological and biochemical analyses in postmortem investigations involving a fatal overdose of such drugs.

Factitious hypoglycemia in children and adolescents with diabetes

BACKGROUND

Factitious hypoglycemia is a condition of self-induced hypoglycemia due to surreptitious administration of insulin or oral hypoglycemic agents. In adults, it is an uncommon, but well known clinical entity observed in individuals with and without diabetes.

OBJECTIVES

To report a case of factitious hypoglycemia highlighting diagnostic pitfalls, to identify common characteristics of children and adolescents with factitious hypoglycemia, and to examine whether the information on long-term outcome exists.

METHODS

We present a case of an adolescent with type 1 diabetes who had self-induced hypoglycemia of several years' duration; and we conducted a systematic literature review on factitious hypoglycemia in pediatric patients with diabetes.

RESULTS

We identified a total of 83 articles of which 14 met the inclusion criteria (describing 39 cases). All but 1 individual had type 1 diabetes and the majority was female (63%). Average age was 13.5 ± 2.0 years with the youngest patient presenting at the age 9.5 years. Blood glucose control was poor (hemoglobin A1c: 12.1 ± 4.0%). In 35%, psychiatric disorders were mentioned as contributing factors. Only 3 reports provided follow-up beyond 6 months.

CONCLUSIONS

Factitious hypoglycemia typically occurs in adolescents with type 1 diabetes who use insulin to induce hypoglycemia. Awareness of this differential diagnosis and knowledge of potentially misleading laboratory results may facilitate earlier recognition and intervention. Little information exists on effective treatments and long-term outcome.

A Randomized Clinical Trial of Metformin to Treat Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Metformin inhibits cyclic AMP generation and activates AMP-activated protein kinase (AMPK), which inhibits the cystic fibrosis transmembrane conductance regulator and Mammalian Target of Rapamycin pathways. Together these effects may reduce cyst growth in autosomal dominant polycystic kidney disease (ADPKD).

METHODS

A phase II, double-blinded randomized placebo-controlled trial of 26 months duration. Participants will include nondiabetic adults (n = 96) aged 18-60 years, with an estimated glomerular filtration rate (eGFR) ≥50 mL/min/1.73 m2 and ADPKD, recruited from university-based practices in Baltimore and Boston. Participants will be randomized in 1: 1 ratio to metformin or placebo at 500 mg once daily, increased every 2 weeks to a maximum of 1,000 mg twice daily as tolerated. Dose is decreased if eGFR falls to 30-45 mL/min/1.73 m2 and discontinued at eGFR < 30 mL/min/1.73 m2.

RESULTS

The primary outcomes are safety, assessed by the rates of hypoglycemia, elevated lactic acid levels, adverse events, and tolerability assessed by the Gastrointestinal Severity Rating Scale and maximum tolerated dose of study medication. Secondary outcomes include changes in total kidney and liver volumes, pain, and health-related quality of life, and changes in urinary metabolomic biomarkers.

CONCLUSIONS

Results of this trial will provide important information on the feasibility, safety, and tolerability of long-term use of metformin in patients with -ADPKD and provide preliminary information regarding its efficacy in slowing disease progression. Furthermore, results may support or refute the hypothesis that metformin effects on disease progression are mediated through the activation of the AMPK pathway. These results will be essential for the justification and design of a full-scale efficacy trial.

Hypoinsulinemic hypoglycemia triggered by liver injury in elderly subjects with low body weight: case reports

Hypoglycemia is induced by many causes, especially over-dose of insulin or oral hypoglycemic agents in diabetic subjects. In such a case, hyperinsulinemic hypoglycemia is usually observed. On the other hand, it is important to classify secondary hypoglycemia and hypoinsulinemic hypoglycemia. Liver injury-induced hypoglycemia is one of the causes of hypoinsulinemic hypoglycemia but rarely observed in clinical practice. Herein, we experienced similar 2 cases of non-diabetic hypoinsulinemic hypoglycemia. Both of them were elderly subjects with low body weight. Furthermore, it is likely that hypoinsulinemic hypoglycemia in both subjects was triggered by severe liver injury, at least in part, due to possible limited liver glycogen store. In elderly subjects with low body weight and/or malnutrition, metabolism in the liver is reduced and glycogen accumulation is decreased. Such alteration brings out acute and marked liver injury, which finally leads to the onset of severe hypoglycemia. It is known that not only liver injury but also multiple organ failure could be induced due to extreme emaciation in subjects. It is likely that in elderly subjects with low body weight and/or malnutrition, multiple organ failure including liver failure could be induced due to the similar reason. Therefore, we should be very careful of such subjects in order to avoid the development of multiple organ failure which leads to life-threatening situations. In conclusion, we should keep in mind the possibility of hypoinsulinemic hypoglycemia when we examine severe liver injury, especially in elderly or starving subjects with low body weight and limited liver glycogen stores.

Patient Understanding of Hypoglycemia in Tertiary Referral Centers

BACKGROUND

Hypoglycemia is an important complication in the treatment of patients with diabetes. We surveyed the insight by patients with diabetes into hypoglycemia, their hypoglycemia avoidance behavior, and their level of worry regarding hypoglycemia.

METHODS

A survey of patients with diabetes, who had visited seven tertiary referral centers in Daegu or Gyeongsangbuk-do, Korea, between June 2014 and June 2015, was conducted. The survey contained questions about personal history, symptoms, educational experience, self-management, and attitudes about hypoglycemia.

RESULTS

Of 758 participants, 471 (62.1%) had experienced hypoglycemia, and 250 (32.9%) had experienced hypoglycemia at least once in the month immediately preceding the study. Two hundred and forty-two (31.8%) of the participants had received hypoglycemia education at least once, but only 148 (19.4%) knew the exact definition of hypoglycemia. Hypoglycemic symptoms identified by the participants were dizziness (55.0%), sweating (53.8%), and tremor (40.8%). They mostly chose candy (62.1%), chocolate (37.7%), or juice (36.8%) as food for recovering hypoglycemia. Participants who had experienced hypoglycemia had longer duration of diabetes and a higher proportion of insulin usage. The mean scores for hypoglycemia avoidance behavior and worry about hypoglycemia were 21.2±10.71 and 23.38±13.19, respectively. These scores tended to be higher for participants with higher than 8% of glycosylated hemoglobin, insulin use, and experience of emergency room visits.

CONCLUSION

Many patients had experienced hypoglycemia and worried about it. We recommend identifying patients that are anxious about hypoglycemia and educating them about what to do when they develop hypoglycemic symptoms, especially those who have a high risk of hypoglycemia.