Hypoglycemia

Recurrent hypoglycemia dampens functional regulation mediated via Neurexin-1, Neuroligin-2 and Mint-1 docking proteins: Intensified complications during diabetes

Glycemic regulation is important for maintaining critical physiological functions. Extreme variation in levels of circulating glucose are known to affect insulin secretion. Elevated insulin levels result in lowering of circulating glycemic levels culminating into hypoglycemia. Recurrence of hypoglycemia are often noted owing to fasting conditions, untimely meals, irregular dietary consumption, or as a side-effect of disease pathophysiology. Such events of hypoglycemia threaten to hamper the patterns of insulin secretion in diabetic condition. Insulin vesicle docking is a prerequisite phase which ensures anchoring of the vesicles to the β-cell membrane in order to expel the insulin cargo. Neurexin and Neuroligin are the marker docking proteins which assists in the tethering of the insulin granules to the secretory membrane. However, these cell adhesion molecules indirectly affect the glycemic levels by regulating insulin secretion. The effect of extreme levels of glycemic fluctuations on these molecules, and how it affects the docking machinery remains obscure. Our current study demonstrates down-regulated expression of Neurexin-1, Neuroligin-2 and Mint-1 molecules during hyperglycemia, hypoglycemia and diabetic hypoglycemia in rodents as well as for an in-vitro system using MIN6 cell-line. Studies with fluorescently labelled insulin revealed presence of lessened functional insulin secretory granules, concomitant with the alterations in morphology and as a result of hypoglycemia in control and diabetic condition which was found to be further deteriorating. Our studies indicate towards a feeble vesicular anchorage, which may partly be responsible for dwindled insulin secretion during diabetes. However, hypoglycemia poses as a potent diabetic complication in further deteriorating the docking machinery. To the best of our knowledge this is the first report which demonstrates the effect of hypoglycemic events in affecting insulin secretion by weakening insulin vesicular anchorage in normal and diabetic individuals.

Intensive insulin therapy in sepsis patients: Better data enables better intervention

In clinics, sepsis is a critical disease that often develops into shock and multiple organ dysfunction, leading to a serious threat of death. Patients with sepsis are often accompanied by stress hyperglycemia which is an independent risk factor for poor prognosis in sepsis. Thus, the treatment for stress hyperglycemia has attracted more and more attention, among which intensive insulin therapy is widely concerned. However, the benefits and harms of intensive insulin therapy for sepsis patients remain controversial. What the existing literature discusses mostly are the clinical benefit and hypoglycemia risk of intensive insulin therapy, but there is no conclusion on the target range of blood glucose control, the applicable patients, the timing of treatment initiation, and how to avoid the risk. In this study, we have analyzed and summarized the existing literature, hoping to determine the adverse and clinical benefit of intensive insulin therapy in sepsis. And we attempt to assemble better evidence to propose a better recommendation on hyperglycemia intervention for sepsis patients.

Case Report: Artifactual Hypoglycemia: A Condition That Should Not Be Forgotten

BACKGROUND

Hypoglycemia is uncommon in people who are not being treated for diabetes mellitus and, when present, the differential diagnosis is broad. Artifactual hypoglycemia describes discrepancy between low capillary and normal plasma glucose levels regardless of symptoms and should be considered in patients with Raynaud's phenomenon.

CASE PRESENTATION

A 46-year-old female patient with a history of a sleeve gastrectomy started complaining about episodes of lipothymias preceded by sweating, nausea, and dizziness. During one of these episodes, a capillary blood glucose was obtained with a value of 24 mg/dl. She had multiple emergency admissions with low-capillary glycemia. An exhaustive investigation for possible causes of hypoglycemia was made for 18 months. The 72h fasting test was negative for hypoglycemia. A Raynaud's phenomenon was identified during one appointment.

CONCLUSION

Artifactual hypoglycemia has been described in various conditions including Raynaud's phenomenon, peripheral arterial disease, Eisenmenger syndrome, acrocyanosis, or hypothermia. With this case report, we want to reinforce the importance of being aware of this diagnosis to prevent anxiety, unnecessary treatment, and diagnostic tests.

Improvement of Blood Samples Preanalytic Management Alters the Clinical Results of Glucose Values: Population Study

BACKGROUND

Prolonged time elapsing between the blood drawing and separation of the cell mass may result in decreased sample glucose levels due to continuous glycolysis. This can lead to underdiagnoses of hyperglycemic states and overdiagnosis of hypoglycemia. We aimed to evaluate the clinical impact of shortened transit time and earlier centrifugation of laboratory specimens on reported glucose results and diagnosis of clinically significant hypoglycemia (<50 mg/dL) or elevated glucose levels (>100 mg/dL).

METHODS

We assessed all fasting-serum glucose tests from the adult population (190 767 subjects) without known diabetes residing in Southern Israel. Before and after intervention periods were compared: 268 359 blood tests were performed during 2009-2010, and 317 336 during 2012-2013.

RESULTS

While glucose levels were 94.17 mg/dL ± 14.12 in 2012-2013 versus 83.53 mg/dL ± 14.50 in 2009-2010 (12.75% ± 0.88 increase, P < .001), the difference in glycated hemoglobin levels was statistically significant but clinically negligible: 5.84% ± 0.56 in 2012-2013 versus 5.88% ± 0.56 in 2009-2010 (0.53% ± 0.78 decrease, P < .01). There was an increased likelihood of a glucose result to be above 100 mg/dL following intervention: 9.80% versus 25.90%, P < .001. For clinics distanced over 40 km from the laboratory, age-adjusted odds ratio value was 1.26 (95% CI 1.13, 1.41). The proportion of samples with hypoglycemia values decreased from 0.33% to 0.03% (P < .001).

CONCLUSIONS

We demonstrated an important change in glucose values over a two-year period following an improvement of the preanalytic processes. The intervention was related to an increase in the frequency of hyperglycemia results and a decrease in the number of hypoglycemia results. Future administrative projects should consider clinical consequences with involvement of all relevant stakeholders.

Inhibitory effects of selected antibiotics on the activities of α-amylase and α-glucosidase: In-vitro, in-vivo and theoretical studies

Antibiotics are effective drugs that are used to treat infectious diseases either by killing bacteria or slowing down their growth. The well-adapted structural features of antibiotics for the inhibition/activation of enzymes include several available hydrogen bond (H-bond) acceptors and donors, flexible backbone and hydrophobic nature. The substrates of α-amylase and α-glucosidase, known as key absorbing enzymes, have functional groups (OH groups) rembling antibiotics. Given the possibility of developing in diabetics and the significant association between diabetes and infection, the present study was conducted to investigate the influences of tetracycline (TET), kanamycin (KANA), lincomycin (LIN), erythromycin (ERM) and azithromycin (AZM) on α-glucosidase and α-amylase activities with calculating IC₅₀ and K_i values. Also, the efficacy of antibiotics after oral administration was evaluated by analysis of blood glucose concentrations in rats, as well as a molecular docking analysis was explored. α-glucosidase and α-amylase activities were inhibited in a dose dependent fashion by TET with an IC₅₀ of 38.7 ± 1.4 and 47.8 ± 3.2 μM respectively, by KANA with an IC₅₀ of 46.2 ± 1.6 and 65.1 ± 1.6, by LIN with an IC₅₀ of 59.1 ± 2.1 and 51.3 ± 4.1, by ERM with an IC₅₀ of 94.9 ± 4.7 and 65.7 ± 3.8 and by AZM with an IC₅₀ of 69.4 ± 4.4 and 103.6 ± 6.2. Moreover, the K_i values of TET were calculated as 4.4 ± 0.6 and 8.4 ± 0.8 μM for α-glucosidase and α-amylase in a competitive-mode and mixed-mode inhibition. In addition, to communicate with the active site of α-glucosidase and α-amylase respectively, TET presented a binding energy of -9.8 and -8.8 kcal/mol, KANA -7.9 and -7.1, LIN -7.8 and -6.7, ERM -6.8 and -6.4, and AZM -6.4 and -7.5 kcal/mol. In-vivo studies also suggested a decrease in the blood glucose concentration after administering TET compared to the positive controls (P < 0.01). The results obtained from the present research can therefore help the scientific community explore the possible interconnection between the clinical side-effects of antibiotics and their α-glucosidase and α-amylase inhibitory properties, as the target enzymes in hypoglycemia conditions.

Intranasal glucagon for hypoglycaemia in diabetic patients. An old dream is becoming reality?

In 1983 it was shown that glucagon administered intranasally (IN) was absorbed through the nasal mucosa and increased blood glucose in healthy subjects. Shortly thereafter, it was shown that IN glucagon counteracts with hypoglycaemia in insulin-treated diabetic patients. In spite of this evidence, IN glucagon was not developed by any pharmaceutical company before 2010, when renewed interest led to intensive evaluation of a possible remedy for hypoglycaemia in insulin-treated diabetic adults and children. IN glucagon is now being developed as a needle-free device that delivers glucagon powder for treatment of severe hypoglycaemia; the ease of using this device stands in stark contrast to the difficulties encountered in use of the current intramuscular glucagon emergency kits. Studies have demonstrated the efficacy, safety and ease-of-use of this IN glucagon preparation, and suggest IN glucagon as a promising alternative to injectable glucagon for treating severe hypoglycaemia in children and adults who use insulin. This would meet the unmet medical need for an easily administered glucagon preparation.

Hypoglycaemia without diabetes encountered by emergency medical services: a retrospective cohort study

BACKGROUND

The current study investigates the incidence, aetiology, and outcome of hypoglycaemia of patients without diabetes in the EMS.

METHODS

The study was a retrospective cohort study that utilized electronic EMS patient record system (population of one million). All patients encountered by EMS with plasma glucose ≤3.9 mmol/l from 2009 to 2015 were included in the study and hospital records were screened manually to detect possible reasons for hypoglycaemia. Data from the governmental health insurance agency for all residents in Finland was used to reveal the diabetes status of the patients. Survival of the patients was followed from Population register centre up to six years. Serious hypoglycaemia was defined as plasma glucose ≤3.0 mmol/l.

RESULTS

From EMS cases with a plasma glucose measurement a total of 5467 hypoglycaemic patients without diabetes were encountered by EMS during the study period with an incidence of 1082 (CI95% 1019-1148) per 100,000 inhabitants per year, corresponding 41.6%, (CI95% 40.8-42.3) of all hypoglycaemic patients. Of those patients, 3856 [71.6%, (CI95% 70.4-72.8)] were transported to hospital and 910 [23.2%, (CI95% 22.0-24.6)] had serious hypoglycaemia. The three main diagnosis groups that appeared in the subsequent hospital treatment associated with hypoglycaemia in all transported cases without diabetes as well with serious hypoglycaemia cases were: alcohol abuse [41.2%, (CI95% 39.7-42.8) and 42.2%, (CI95% 39.0-45.4)], hypothermia [17.2%, (CI95% 16.0-18.4) and 27.4%, (CI95% 24.6-30.4)], and malnutrition [16.9%, (CI95% 15.8-18.1) and 25.1%, (CI95% 22.4-28.0)]. Mortality ranged from 0.6-65.4% depending of admission reason and increased significantly at long-term. Non-Diabetics survival was less than with diabetics, when serious hypoglycaemia was present.

DISCUSSION

The most common possible hypoglycaemia related aetiological causes encountered in the EMS, alcohol abuse, hypothermia, and malnutrition, although frequent are often relatively benign conditions. These possible causes of hypoglycaemia can often be treated at scene or need only short hospital admissions. Hence they are not so prevalent in hospital studies.

CONCLUSIONS

Hypoglycaemia without diabetes is commonly observed among the hypoglycaemic EMS cases. Main causes for it are alcohol abuse, hypothermia, and malnutrition. Mortality correlated with age, higher priority dispatch codes, and plasma glucose rate in multivariate logistic regression analysis. Some of the etiological subgroups carry a markedly high mortality rate.

MANAGEMENT OF ENDOCRINE DISEASE: Pathogenesis and management of hypoglycemia

Glucose is the main substrate utilized by the brain and as such multiple regulatory mechanisms exist to maintain glucose concentrations. When these mechanisms fail or are defective, hypoglycemia ensues. Due to these robust mechanisms, hypoglycemia is uncommon and usually occurs in the setting of the treatment of diabetes using glucose-lowering agents such as sulfonylureas or insulin. The symptoms of hypoglycemia are non-specific and as such it is important to confirm hypoglycemia by establishing the presence of Whipple's triad before embarking on an evaluation for hypoglycemia. When possible, evaluation of hypoglycemia should be carried out at the time of spontaneous occurrence of symptoms. If this is not possible then one would want to create the circumstances under which symptoms occur. In cases where symptoms occur in the post absorptive state, a 72-h fast should be performed. Likewise, if symptoms occur after a meal then a mixed meal study may be the test of choice. The causes of endogenous hyperinsulinemic hypoglycemia include insulinoma, post-bariatric hypoglycemia and noninsulinoma pancreatogenous hypoglycemia syndrome. Autoimmune hypoglycemia syndrome is clinically and biochemically similar to insulinoma but associated with high levels of insulin antibodies and plasma insulin. Other important causes of hypoglycemia include medications, non-islet cell tumors, hormonal deficiencies, critical illness and factitious hypoglycemia. We provide an overview of the pathogenesis and management of hypoglycemia in these situations.

Insulinoma Due to Multiple Pancreatic Microadenoma Localized by Multimodal Imaging

CONTEXT

Insulinomas are usually due to a solitary tumor, but they can be challenging to localize.

CASE DESCRIPTION

A 66-year-old woman presented with a 1-year history of episodic neuroglycopenic hypoglycemia and was suspected of having an insulinoma. On a supervised fast, she was found to be hypoglycemic at 39 mg/dL, with an insulin of 40 μU/mL 26 hours into the fast and a proinsulin of 35 pmol/L. Contrast-enhanced computed tomography and magnetic resonance imaging did not localize a pancreatic lesion. Intra-arterial calcium stimulation testing showed a step-up of venous insulin levels at injection of the superior mesenteric artery and proximal and mid-splenic artery, and a ⁶⁸Ga-DOTATATE positron emission tomography/computed tomography showed focal uptake in the neck of the pancreas with a standardized uptake value of 12. Despite negative intraoperative pancreatic palpation and ultrasound, the patient underwent an extended distal pancreatectomy with normalization of biochemical levels and resolution of her symptoms. Pathology showed four subcentimeter neuroendocrine tumors that were positive for insulin, consistent with a diagnosis of multiple microadenomas.

CONCLUSIONS

Multiple microadenomas are a rare cause of hyperinsulinemic hypoglycemia and localization, and resection of these tumors may be facilitated by multimodal imaging.

Spontaneous hypoglycemia: diagnostic evaluation and management

Spontaneous hypoglycemia is a puzzling clinical problem and an important reason for referral to endocrinologists. Several clinical conditions such as insulinomas, non-insulinoma pancreatogenous hypoglycemia syndrome, insulin autoimmune syndrome, postprandial hypoglycemia (reactive hypoglycemia), non-islet cell tumor hypoglycemia, primary adrenal insufficiency, hypopituitarism, and critical illness can be associated with spontaneous hypoglycemia. Rarely, in patients with mental health issues, factious hypoglycemia from extrinsic insulin use or ingestion of oral hypoglycemic agents can obfuscate the clinical picture for clinicians trying to identify an organic cause. In those presenting with Whipple's triad (symptoms ± signs of hypoglycemia, low plasma glucose, and resolution symptoms ± signs after hypoglycemia correction), a 72-h supervised fast test with measurement of plasma insulin, c-peptide, pro-insulin, and beta-hydroxybutyrate levels, coupled with plasma/urine sulphonylurea screen, forms the first step in diagnostic evaluation. A mixed meal test is preferable for those with predominantly postprandial symptoms. Additional non-invasive and/or invasive diagnostic evaluation is necessary if an organic hypoglycemic disorder is suspected. With the aid of a few brief clinical case scenarios, we discuss the diagnostic evaluation and management of spontaneous hypoglycemia through this comprehensive article.

Non-linear associations of risk factors with mild hypoglycemia among Chinese patients with type 2 diabetes

AIMS

The present study aimed to examine the nonlinear associations between risk factors and mild hypoglycemia in Chinese patients with type 2 diabetes mellitus (T2DM).

METHODS

From May 2013 to August 2013, we conducted a cross sectional survey of 6633 inpatients with T2DM and without severe hypoglycemia, aged 21-77 years, from 81 top tertiary hospitals in China. Mild hypoglycemia was defined as having hypoglycemia with symptoms in one month. Binary logistic regression analysis with restricted cubic splines was used to estimate odds ratio curves of non-linear risk factors for mild hypoglycemia.

RESULTS

Increasing body mass index was associated with decreasing risk of mild hypoglycemia in a linear manner while age, duration of diabetes, glycated hemoglobin (HbA1c), mean artery pressure and lipids were associated with mild hypoglycemia in non-linear manners. Age ≥40 years, duration ≥2 years, HbA1c ≥7.0-<11.5% (≥53-<102 mmol/mol), triglyceride ≥1.7-<3.6 mmol/L, low-density lipoprotein cholesterol (LDL-C) ≥2.6-<4.8 mmol/L, and high-density lipoprotein cholesterol (HDL-C) ≥1.2-<4.8 mmol/L were associated with increased risks of mild hypoglycemia.

CONCLUSIONS

Chinese T2DM patients with age≥40 years, duration of diabetes ≥2-<6 years, HbA1c ≥7.0-<11.5% (≥53-<102 mmol/mol), LDL-C ≥2.6-<4.8mmol/L, HDL-C ≥1.2-<4.8 mmol/L or triglyceride ≥1.7-<3.6 mmol/L were at particularly high risk for mild hypoglycemia.

Preoperative localization of an insulinoma: selective arterial calcium stimulation test performance

PURPOSE

Preoperative localization of an insulinoma is recommended to improve the cure rate, but non-invasive procedures can fail to detect the tumour. The objective of the study was to assess the performance of a selective arterial calcium stimulation test in the preoperative localization of insulinomas that were not detected by conventional imaging procedures.

METHODS

We conducted a monocenter retrospective case review of 13 patients who had endogenous hyperinsulinism and were treated between 1994 and 2013. Patients were selected on the basis of negative or doubtful non-invasive preoperative imaging. A selective arterial calcium stimulation test was performed by pancreatic and hepatic arteriography with selective intra-arterial calcium stimulation and hepatic venous sampling in order to obtain the plasma insulin measurement. We evaluated the efficacy of the test by comparing the results with an endoscopic ultrasound.

RESULTS

Twelve of the 13 patients underwent surgery, and the presence of an insulinoma was proven in 11 patients by pathological analysis of the tumour. An endoscopic ultrasound was consistent with surgery in 71.4 % of cases, while selective arterial calcium stimulation was consistent with surgery in 90.9 % and allowed detection of an insulinoma in two additional patients with a negative endoscopic ultrasound. One false-negative and one false-positive arterial calcium test were observed. No adverse events were recorded except transient skin flush following calcium injection in one patient.

CONCLUSION

The selective arterial calcium stimulation test is a sensitive diagnostic procedure for localizing insulinomas and may be considered when non-invasive radiological imaging does not allow the detection of an occult insulinoma.

Role of the Entero-Insular Axis in the Pathogenesis of Idiopathic Reactive Hypoglycemia: A Pilot Study

CONTEXT

Idiopathic reactive hypoglycemia (IRH) is characterized by recurrent episodes of symptomatic hypoglycemia occurring within 4 hours after meals. The underlying mechanisms remain obscure.

OBJECTIVE

This study aimed to investigate the response of the glucoregulatory and gastrointestinal hormones to an oral glucose load (OGTT) in individuals with documented IRH.

DESIGN AND SETTING

This was a cross-sectional study composed of outpatients referred to "Federico II" University of Naples.

PATIENTS

We enrolled subjects with IRH documented by a mixed meal under ordinary life conditions and healthy subjects as controls.

MAIN OUTCOME MEASURE

We measured plasma glucose, insulin, glucagon-like peptide 1 (GLP-1), GIP, and glucagon response to a 75-g OGTT in cases and controls.

RESULTS

Ten IRH and eight control subjects were enrolled. During the OGTT, mean plasma glucose tended to be lower in IRH than in control subjects, reaching a statistically significant difference at 240 minutes (T240) (43 ± 1.6 vs 72 ± 0.3 mg/dL; P = .001). Accordingly, the insulin response was higher in IRH than in control subjects (P < .019) with a statistically significant difference (46%) at T90 (P = .045) and was associated with significantly lower glucagon levels in the late phase of the OGTT: at T120 (P = .031) and T180 (P = .048) in IRH than in control subjects. A greater GLP-1 response was found among IRH compared with control subjects (P = .005); GLP-1 peak was 2-fold higher in IRH individuals (9.77 ± 2.52 pmol/L) than in the control group (4.19 ± 0.53 pmol/L; P = .041). In the IRH group, GLP-1 peak inversely correlated with the nadir of plasma glucose (r = -0.66; P = .039). A multivariate analysis confirmed that GLP-1 peak independently predicted the plasma glucose nadir (β = -0.593; P = .026).

CONCLUSIONS

GLP-1 may play a significant role in the pathogenesis of idiopathic IRH.

Increasing trend in emergency department visits for hypoglycemia from patients with type 2 diabetes mellitus in Taiwan

AIMS

We analyze the time trends of hypoglycemia-related emergency department visits in Taiwan between 2000 and 2010, focusing on type 2 diabetic patients receiving antidiabetic agents.

METHODS

From a national dataset containing longitudinal medical claims of one million persons, we ascertained 4479 hypoglycemia-related emergency department visits from 3184 type 2 diabetic patients for analysis. We used negative binomial regression to calculate the incidence rate ratios (IRRs) for comparing event rates of hypoglycemia-related emergency department visits in different study periods.

RESULTS

Rates of hypoglycemia-related emergency department visits increased 4.8 folds from year 2000 to 2010 (adjusted IRR 4.88, 95% CI 3.94-6.05, P<0.001). Severe hypoglycemia requiring emergency department visits prevailed among women, older patients (≥ 65 years), and those not lived in the urban areas.

CONCLUSIONS

Within a 10-year period, there was a substantial increase in the rates of hypoglycemia-related emergency department visits from type 2 diabetic patients in Taiwan. Appropriate risk management plans should be developed to prevent the occurrence of severe hypoglycemia in patients with type 2 diabetes in Taiwan.

Exhaustion of food budgets at month's end and hospital admissions for hypoglycemia

One in seven US households cannot reliably afford food. Food budgets are more frequently exhausted at the end of a month than at other points in time. We postulated that this monthly pattern influenced health outcomes, such as risk for hypoglycemia among people with diabetes. Using administrative data on inpatient admissions in California for 2000-08, we found that admissions for hypoglycemia were more common in the low-income than the high-income population (270 versus 200 admissions per 100,000). Risk for hypoglycemia admission increased 27 percent in the last week of the month compared to the first week in the low-income population, but we observed no similar temporal variation in the high-income population. These findings suggest that exhaustion of food budgets might be an important driver of health inequities. Policy solutions to improve stable access to nutrition in low-income populations and raise awareness of the health risks of food insecurity might be warranted.

Glucagon for hypoglycemic episodes in insulin-treated diabetic patients: a systematic review and meta-analysis with a comparison of glucagon with dextrose and of different glucagon formulations

AIMS

Glucagon is used as an emergency drug in hypoglycemia, mainly when the patient is unconscious. A few studies report on ineffectiveness of glucagon in relieving hypoglycemia. The present systematic review and meta-analysis evaluate the effectiveness of glucagon alone and in comparison with dextrose and the effectiveness of intranasal glucagon in comparison with injected glucagon.

METHODS

Studies were grouped into three groups: (1) reports on glucagon ineffectiveness; (2) comparison of glucagon and dextrose; (3) comparison of intranasal glucagon and injected glucagon. In groups 2 and 3, only controlled studies were included in the analysis, whether randomized or non-randomized studies. Appropriate methodology (PRISMA statement) was adhered to, and publication bias was formally assessed. Sixteen studies, published in any language as full papers, were analysed to identify predictors of ineffectiveness, and they were included in a meta-analysis (random effects model) to study the effect of different strategies. Intervention effect (number of failures) was expressed as odds ratio (OR), with 95 % confidence intervals.

RESULTS

Failure rate ranged from 0.0 to 2.31 %, to 7.6 %, to 14.4 %, and to 59 %. Comparing glucagon and dextrose, the OR was 0.53 (0.20-1.42); comparing intranasal and intramuscular glucagon, the OR was 1.40 (0.18-10.93). Heterogeneity was low and not statistically significant. Publication bias was absent.

CONCLUSIONS

These data indicate that ineffectiveness of glucagon is unfrequent, not different from dextrose; in addition, intranasal and injected glucagon are similarly effective. In the case of failure, a second dose can be administered.

The Intersection between Food Insecurity and Diabetes: A Review

Access to sufficient, safe, and nutritious food not only affects the health of people who experience food insecurity, but also their ability to manage health conditions, such as diabetes. When people find it difficult to access sufficient food, tailoring their food selection to a diabetes regimen is even more difficult. Food insecurity in North America is consistently more prevalent among households with a person living with diabetes, and similarly, diabetes is also more prevalent in food-insecure households. Diabetes management can be stressful due to the many required responsibilities; when compounded with food insecurity, it becomes an even greater challenge. As a result, many food-insecure diabetics find themselves caught between competing priorities such as procuring food, prescribed medications and supplies for diabetes, and managing other living expenses, potentially worsening their condition and overall health. Healthcare providers should be aware and informed about the significant role that food security can play in the prevention and management of diabetes.

Treatment of endocrine disorders in the neuroscience intensive care unit

OPINION STATEMENT

This review discusses concepts and treatments associated with the most clinically relevant areas of acute endocrine dysfunction amongst patients with common diseases in neuroscience intensive care units (Neuro ICUs). We highlight the following points:• While a thorough work-up for hyponatremia when it is present is always warranted, subarachnoid hemorrhage (SAH) patients who are in a time window concerning for cerebral vasospasm and who are hyponatremic with high urine output are generally thought to have cerebral salt wasting. These patients are typically treated with a combination of continuous hypertonic saline infusion and fludrocortisone.• Diabetes insipidus (DI) is often seen in patients fulfilling death by neurological criteria, as well as in patients with recent pituitary surgery and less often in SAH and traumatic brain injury patients who are not brain dead. Patients with DI in the Neuro ICU often cannot drink to thirst and may require a combination of desmopression/vasopressin administration, aggressive fluid repletion, and serum sodium monitoring.• Diagnosing adrenal insufficiency immediately following pituitary injury is complicated by the fact that the expected atrophy of the adrenal glands, due to lack of a stimulus from pituitary adrenocorticotropic hormone, may take up to 6 weeks to develop. Cosyntropin testing can be falsely normal during this period.• Both hyperglycemia (glucose >200 mg/dL) and hypoglycemia (glucose <50 mg/dL) are strongly associated with neurological morbidity and mortality in ICUs and should be avoided. Glucose concentrations between 120-160 mg/dL can serve as a reasonable target for insulin infusion protocols.• There is no data to suggest that treatment of abnormal thyroid function tests in nonthyroidal illness syndrome/sick euthyroid leads to benefits in either mortality or morbidity. True myxedema coma is a rare clinical diagnosis that is treated with intravenous levothyroxine accompanied by stress-dose steroids.

Glucose fluctuations in subjects with normal glucose tolerance, impaired glucose regulation and newly diagnosed type 2 diabetes mellitus

OBJECTIVE

Glycemic variability is poorly studied in the nondiabetic individuals and newly diagnosed patients with type 2 diabetes. The aim of the study is to investigate the characteristics of glucose fluctuations in subjects with normal glucose tolerance (NGT), impaired glucose regulation (IGR) and newly diagnosed, drug-naïve type 2 diabetes mellitus (DM-2).

DESIGN AND PATIENTS

This is a cross-sectional study of three groups including 53 subjects with IGR, 56 DM-2 patients and 53 NGT individuals. Monitoring by a continuous glucose monitoring system (CGMS(®) System Gold(™)) was performed for three consecutive days.

MEASUREMENTS

Mean blood glucose (MBG), standard deviation of MBG (SDBG), largest amplitude of glycemic excursions (LAGE) and mean amplitude of glycemic excursions (MAGE) were calculated to estimate intraday blood glucose variability. Interday variability of glucose was evaluated by absolute means of daily differences (MODD). Postprandial glucose excursion (PPGE) was calculated to assess the influence of meals on glucose fluctuation.

RESULTS

Twenty-two percentage of NGT and 33.9% of IGR individuals experienced blood glucose ≥ 11.1 mmol/l; 49.1% of NGT, 50.9% of IGR and 30.8% of DM-2 participants had hypoglycemic episodes (CGM values <3.9 mmol/l). The IGR and DM-2 groups had greater SDBG (P = 0.010 and P < 0.001), LAGE (P = 0.014 and P < 0.001) and MAGE (P = 0.044 and P < 0.001) compared with the NGT group. Significantly greater MODD and PPGEs were found in the DM-2 groups than in the IGR and NGT groups (P < 0.001). The DM-2 patients had higher 72-MBG and glucose levels overnight than the NGT and IGR subjects (P < 0.001). In the patients with diabetes, MAGE was positively associated with MODD (r = 0.558, P < 0.001) and PPGEs (r = 0.738-0.843, P < 0.001).

CONCLUSIONS

Glucose variability is present to an increasing degree from NGT to IGR and IGR to DM-2. Compared with the NGT individuals, the IGR and DM-2 subjects show more predominant intraday glucose fluctuations. The DM-2 patients demonstrate increased PPGEs, higher glucose levels overnight and greater interday fluctuations.

Idiopathic accelerated gastric emptying presenting in adults with post-prandial diarrhea and reactive hypoglycemia: a case series

INTRODUCTION

We have previously reported the association of gastrointestinal and hypoglycemic symptoms, with idiopathic accelerated gastric emptying. We now report the first series of six similar cases.

CASE PRESENTATIONS

Patient 1: A 24-year-old Caucasian man presented to our facility with a six-month history of post-prandial nausea, flatulence, bloating, abdominal discomfort and associated diarrhea. He had associated episodes of fatigue, sweating, anxiety, confusion and craving for sweet foods. Patient 2: A 52-year-old Caucasian woman presented to our facility with a 15-year history of post-prandial bloating, abdominal pain and diarrhea, often associated with nausea, severe sweating, and fatigue. Patient 3: An 18-year-old Caucasian woman presented to our facility with a nine-year history of post-prandial diarrhea, abdominal bloating and pain. There was associated nausea, tremor, lethargy, and craving for sweet foods. Patient 4: A 77-year-old Caucasian woman presented to our facility with a four-month history of epigastric distension, pain after eating and a change in bowel habit. She experienced intermittent severe diarrhea and marked fatigue, nausea and sweating. Patient 5: A 23-year-old Caucasian woman presented to our facility with a two-year history of early satiety, and diarrhea after eating. She also complained of feeling faint and weak between meals, when she became cold and clammy, and on several occasions lost consciousness during these episodes. Patient 6: A 64-year-old Caucasian woman presented to our facility with a 10-year history of nausea, early satiety and profound bloating followed by diarrhea. All symptoms predominantly occurred in the first three hours after eating, when she felt faint, lethargic, and had a craving for sweet foods. In all cases, symptoms were alleviated or resolved by taking sweet food or drink and response to treatment was 90% or greater in all cases.

CONCLUSIONS

This series extends our description of this new clinical syndrome. All patients responded well to treatment for accelerated gastric emptying. Clinicians in the disciplines of endocrinology, gastroenterology, neurology and general practice are likely to find this information useful as they will consult patients with some or all of these symptoms and in a proportion of these patients idiopathic accelerated gastric emptying may be present and provide a useful avenue for therapeutic intervention.

Stress induced Salmonella Typhimurium recrudescence in pigs coincides with cortisol induced increased intracellular proliferation in macrophages

Salmonella Typhimurium infections in pigs often result in the development of carriers that intermittently excrete Salmonella in very low numbers. During periods of stress, for example transport to the slaughterhouse, recrudescence of Salmonella may occur, but the mechanism of this stress related recrudescence is poorly understood. Therefore, the aim of the present study was to determine the role of the stress hormone cortisol in Salmonella recrudescence by pigs. We showed that a 24 h feed withdrawal increases the intestinal Salmonella Typhimurium load in pigs, which is correlated with increased serum cortisol levels. A second in vivo trial demonstrated that stress related recrudescence of Salmonella Typhimurium in pigs can be induced by intramuscular injection of dexamethasone. Furthermore, we found that cortisol, but not epinephrine, norepinephrine and dopamine, promotes intracellular proliferation of Salmonella Typhimurium in primary porcine alveolar macrophages, but not in intestinal epithelial cells and a transformed cell line of porcine alveolar macrophages. A microarray based transcriptomic analysis revealed that cortisol did not directly affect the growth or the gene expression or Salmonella Typhimurium in a rich medium, which implies that the enhanced intracellular proliferation of the bacterium is probably caused by an indirect effect through the cell. These results highlight the role of cortisol in the recrudescence of Salmonella Typhimurium by pigs and they provide new evidence for the role of microbial endocrinology in host-pathogen interactions.

Hypoglycemia revisited in the acute care setting

Hypoglycemia is a common finding in both daily clinical practice and acute care settings. The causes of severe hypoglycemia (SH) are multi-factorial and the major etiologies are iatrogenic, infectious diseases with sepsis and tumor or autoimmune diseases. With the advent of aggressive lowering of HbA1c values to achieve optimal glycemic control, patients are at increased risk of hypoglycemic episodes. Iatrogenic hypoglycemia can cause recurrent morbidity, sometime irreversible neurologic complications and even death, and further preclude maintenance of euglycemia over a lifetime of diabetes. Recent studies have shown that hypoglycemia is associated with adverse outcomes in many acute illnesses. In addition, hypoglycemia is associated with increased mortality among elderly and non-diabetic hospitalized patients. Clinicians should have high clinical suspicion of subtle symptoms of hypoglycemia and provide prompt treatment. Clinicians should know that hypoglycemia is associated with considerable adverse outcomes in many acute critical illnesses. In order to reduce hypoglycemia-associated morbidity and mortality, timely health education programs and close monitoring should be applied to those diabetic patients presenting to the Emergency Department with SH. ED disposition strategies should be further validated and justified to achieve balance between the benefits of euglycemia and the risks of SH. We discuss relevant issues regarding hypoglycemia in emergency and critical care settings.

[Influence of pre-operative fasting time on blood glucose in older patients]

PURPOSE

This study was performed to identify changes in blood glucose at preoperative fasting time in surgical patients over 60 yr.

METHODS

Data collection was performed from July, 2008 through July, 2009. Participants consisted of 80 nondiabetic surgical patients. Blood glucose was checked from 3 to 5 times. The 5 times were 2-hr fasting on the pre-operative day (T1, n=80), 8 hr (T2, n=80), 10 hr (T3, n=17), 12 hr (T4, n=34) and 14 hr fasting on the day of the operation (T5, n=29).

RESULTS

Of the patients, 27.5% had a blood glucose level of less than 79 mg/dL at T2; 17.6% at T3; 32.4% at T4; and 17.2% at T5. Mean blood glucose levels were 93.8 mg/dL at T1; 88.4 mg/dL at T2; 91.7 mg/dL at T3; 87.4 mg/dL at T4: and 94.1 mg/dL at T5. Blood glucose was the lowest at T2 (p<.001).

CONCLUSION

As 17.6-32.4% of the patients showed the blood glucose level of less than 79 mg/dL at 8-14 hr pre-operative fasting, the authors recommend that surgical patients >60 yr-of-age be observed for hypoglycemia during pre-operative fasting of more than 10 hr and that surgical patients >60 yr-of-age with risks for hypoglycemia be scheduled for operation within 10 hr preoperative fasting.

Drug-induced hypoglycaemia: an update

Drugs are the most frequent cause of hypoglycaemia in adults. Although hypoglycaemia is a well known adverse effect of antidiabetic agents, it may occasionally develop in the course of treatment with drugs used in everyday clinical practice, including NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, antidepressants and other miscellaneous agents. They induce hypoglycaemia by stimulating insulin release, reducing insulin clearance or interfering with glucose metabolism. Several drugs may also potentiate the hypoglycaemic effect of antidiabetic agents. Administration of these agents to individuals with diabetes mellitus is of most concern. Many of these drugs, and depending on clinical setting, may also induce hyperglycaemia. Drug-induced hepatotoxicity and nephrotoxicity may lead in certain circumstances to hypoglycaemia. Some drugs may also induce hypoglycaemia by causing pancreatitis. Drug-induced hypoglycaemia is usually mild but may be severe. Effective clinical management can be handled through awareness of this drug-induced adverse effect on blood glucose levels. Herein, we review pertinent clinical information on the incidence of drug-induced hypoglycaemia and discuss the underlying pathophysiological mechanisms, and prevention and management.

SIRT6 deficiency results in severe hypoglycemia by enhancing both basal and insulin-stimulated glucose uptake in mice

Glucose homeostasis in mammals is mainly regulated by insulin signaling. It was previously shown that SIRT6 mutant mice die before 4 weeks of age, displaying profound abnormalities, including low insulin, hypoglycemia, and premature aging. To investigate mechanisms underlying the pleiotropic phenotypes associated with SIRT6 deficiency, we generated mice carrying targeted disruption of SIRT6. We found that 60% of SIRT6(-/-) animals had very low levels of blood glucose and died shortly after weaning. The remaining animals, which have relatively higher concentrations of glucose, survived the early post-weaning lethality, but most died within one year of age. Significantly, feeding the mice with glucose-containing water increased blood glucose and rescued 83% of mutant mice, suggesting that the hypoglycemia is a major cause for the lethality. We showed that SIRT6 deficiency results in more abundant membrane association of glucose transporters 1 and 4, which enhances glucose uptake. We further demonstrated that SIRT6 negatively regulates AKT phosphorylation at Ser-473 and Thr-308 through inhibition of multiple upstream molecules, including insulin receptor, IRS1, and IRS2. The absence of SIRT6, consequently, enhances insulin signaling and activation of AKT, leading to hypoglycemia. These data uncover an essential role of SIRT6 in modulating glucose metabolism through mediating insulin sensitivity.

Risk factors for recurrent hypoglycemia in hospitalized diabetic patients admitted for severe hypoglycemia

PURPOSE

Severe hypoglycemia can result in neural damage, impaired cognitive function, coma, seizures, or death. The decision to admit diabetic patients after initial treatment in the emergency department remains unclear. Our purpose is to identify risk factors for developing recurrent hypoglycemia in diabetic patients admitted for severe hypoglycemia.

MATERIALS AND METHODS

We reviewed the records of 233 subjects (92 males, 141 females; mean age, 74.1 +/- 9.8 years) with type 2 diabetes treated at a tertiary care teaching hospital and hospitalized for severe hypoglycemia.

RESULTS

Seventy-four (31.8%) patients were categorized with recurrent hypoglycemia and 159 (68.2%) with non-recurrent. Multivariate logistic regression analysis revealed that patients with loss of a recent meal, coronary artery disease, infection, and poor renal function (lower estimated glomerular filtration rate) were at risk for recurrent hypoglycemia. The use of calcium-channel blockers appeared to be a protective factor for the development of recurrent hypoglycemia.

CONCLUSION

There may be a subset of patients with severe hypoglycemia and certain risk factors for recurrent hypoglycemia that should be admitted.

An autopsy case presenting repetitive hypoglycemia and unique cortical dysplasia

In epileptic patients, focal cortical dysplasia (FCD) is pathologically characterized by irregular cortical lamination, blurring of the grey and white matter border and the occurrence of dysplastic cells in the cerebral cortex. Here, we report the case of a 42-year-old male showing developmental delay, transient repetition of hypoglycemic attack and cortical dysplasia, partly mimicking FCD. He had no family history of neurological disorders. He had never been able to stand independently and had always been unable to speak. He developed generalized convulsion in infancy, and then, in the absence of predisposing factors, suffered from repetitive hypoglycemic attacks between the ages of 27 and 38. Various endocrine tests, abdominal CT and brain MRI failed to demonstrate abnormalities. He died of peritonitis. At autopsy, no changes were observed in the pancreas, liver, kidneys, endocrine organs or hypothalamus. In the insular and frontal cortices, many large bizarre cells in the deep layer were observed and perivascular oligodendrocyte satellitosis was present in the adjacent white matter. Unlike FCD, the cortical lamination and the grey-white matter interface were preserved. A well-demarcated pilocytic astrocytoma was present in the brainstem. The cortical dysplasia, consisting of the diffuse occurrence of bizarre cells and the preservation of cortical lamination, is unique and has not been previously reported. Repetition of hypoglycemic attacks within a certain period is also noteworthy, although the relationship of this with the cortical dysplasia is unknown.

Insulin secretion and insulin-producing tumors

Insulinomas are rare neuroendocrine tumors of pancreatic islet cells that retain the ability to produce and secrete insulin. In contrast to normally differentiated β-cells, insulinoma cells continue to secrete insulin and proinsulin at low blood glucose. This deregulated insulin secretion manifests clinically as fasting hypoglycemia. The molecular pathways that characterize normal insulin secretion and β-cell growth are reviewed and contrasted to the biology of insulinomas. The second half of this review summarizes the clinical approach to the disorder. The diagnosis of insulinoma is established by demonstrating inappropriately high insulin levels with coincident hypoglycemia at the time of a supervised fast. Localization of insulinomas is challenging owing to their small size but should be attempted to maximize the chance for successful surgical resection and avoid risks associated with reoperation. In the majority of cases, successful surgical resection leads to lifelong cure.

Diabetes-Related Medication-Induced Hypoglycemia

Hypoglycemia is a common adverse event in patients with both type 1 and type 2 diabetes and may be a barrier to patients achieving tight glycemic control. It is diagnosed either biochemically, as a blood glucose value, or clinically based on symptoms caused by an autonomic response to changes in blood glucose. Patients that experience repeated episodes of hypoglycemia lose the counterregulatory response that produces symptoms and results in hypoglycemia unawareness. Medications account for the most frequent cause of hypoglycemia in both the inpatient and outpatient setting. Treatment of hypoglycemia may be accomplished via the oral or parenteral route with 15 to 20 g of carbohydrate. Following treatment of the episode, it is important to evaluate for the cause and, if medication related, adjust the patient’s treatment regimen.

Use of therapeutic responses to glucose replacement to predict glucose patterns in diabetic patients presenting with severe hypoglycaemia

OBJECTIVE

The purpose of this study was to determine whether initial serum glucose levels, therapeutic responses to intravenous glucose replacement and changes in serum glucose levels over time could predict serum glucose patterns.

METHODS

The patients enrolled in this retrospective chart review had been previously diagnosed with diabetes mellitus and were later hospitalised for severe hypoglycaemia (SH). They were all admitted to the emergency department (ED) during a 4-year period between January 2003 and December 2006. Comparison of the therapeutic responses to glucose replacement according to the serum glucose patterns [categorised into recurrent hypoglycaemia (RH), overshoot hyperglycaemia (OH) and favourable groups] during the first 48 h was performed.

RESULTS

Compared with the favourable group, therapeutic responses to glucose replacement were significantly lower in the RH group and higher in the OH group; the changes in serum glucose levels over time were also significantly lower in the RH group and higher in the OH group.

CONCLUSION

Therapeutic responses to glucose replacement and changes in serum glucose levels over time can differentiate diabetic patients with RH and OH from those with favourable glucose patterns during the first 48 h after presentation in the ED with SH. We believe that a 'response-to-treatment' based strategy is useful in determining the ED disposition of diabetic patients presenting with SH.

Hemangiopericytoma-associated hypoglycemia improved by glucocorticoid therapy: a case report

A 59-year-old man was admitted because of recurrent, severe hypoglycemia. He had multiple metastases from a meningeal hemangiopericytoma, which had been operated on 12 years earlier. The results of laboratory testing at the time of hypoglycemia showed very low serum levels of insulin, C-peptide, and growth hormone, with slightly high levels of insulin-like growth factor-II, and a normal level of insulin-like growth factor-I. The diagnosis of hemangiopericytoma-associated hypoglycemia was proposed. The patient was given corticosteroid therapy, which ameliorated symptoms of hypoglycemia.

Evaluation and management of adult hypoglycemic disorders: an Endocrine Society Clinical Practice Guideline

OBJECTIVE

The aim is to provide guidelines for the evaluation and management of adults with hypoglycemic disorders, including those with diabetes mellitus.

EVIDENCE

Using the recommendations of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system, the quality of evidence is graded very low (plus sign in circle ooo), low (plus sign in circle plus sign in circle oo), moderate (plus sign in circle plus sign in circle plus sign in circle o), or high (plus sign in circle plus sign in circle plus sign in circle plus sign in circle).

CONCLUSIONS

We recommend evaluation and management of hypoglycemia only in patients in whom Whipple's triad--symptoms, signs, or both consistent with hypoglycemia, a low plasma glucose concentration, and resolution of those symptoms or signs after the plasma glucose concentration is raised--is documented. In patients with hypoglycemia without diabetes mellitus, we recommend the following strategy. First, pursue clinical clues to potential hypoglycemic etiologies--drugs, critical illnesses, hormone deficiencies, nonislet cell tumors. In the absence of these causes, the differential diagnosis narrows to accidental, surreptitious, or even malicious hypoglycemia or endogenous hyperinsulinism. In patients suspected of having endogenous hyperinsulinism, measure plasma glucose, insulin, C-peptide, proinsulin, beta-hydroxybutyrate, and circulating oral hypoglycemic agents during an episode of hypoglycemia and measure insulin antibodies. Insulin or insulin secretagogue treatment of diabetes mellitus is the most common cause of hypoglycemia. We recommend the practice of hypoglycemia risk factor reduction--addressing the issue of hypoglycemia, applying the principles of intensive glycemic therapy, and considering both the conventional risk factors and those indicative of compromised defenses against falling plasma glucose concentrations--in persons with diabetes.

Structural basis of GLUT1 inhibition by cytoplasmic ATP

Cytoplasmic ATP inhibits human erythrocyte glucose transport protein (GLUT1)–mediated glucose transport in human red blood cells by reducing net glucose transport but not exchange glucose transport (Cloherty, E.K., D.L. Diamond, K.S. Heard, and A. Carruthers. 1996. Biochemistry. 35:13231–13239). We investigated the mechanism of ATP regulation of GLUT1 by identifying GLUT1 domains that undergo significant conformational change upon GLUT1–ATP interaction. ATP (but not GTP) protects GLUT1 against tryptic digestion. Immunoblot analysis indicates that ATP protection extends across multiple GLUT1 domains. Peptide-directed antibody binding to full-length GLUT1 is reduced by ATP at two specific locations: exofacial loop 7–8 and the cytoplasmic C terminus. C-terminal antibody binding to wild-type GLUT1 expressed in HEK cells is inhibited by ATP but binding of the same antibody to a GLUT1–GLUT4 chimera in which loop 6–7 of GLUT1 is substituted with loop 6–7 of GLUT4 is unaffected. ATP reduces GLUT1 lysine covalent modification by sulfo-NHS-LC-biotin by 40%. AMP is without effect on lysine accessibility but antagonizes ATP inhibition of lysine modification. Tandem electrospray ionization mass spectrometry analysis indicates that ATP reduces covalent modification of lysine residues 245, 255, 256, and 477, whereas labeling at lysine residues 225, 229, and 230 is unchanged. Exogenous, intracellular GLUT1 C-terminal peptide mimics ATP modulation of transport whereas C-terminal peptide-directed IgGs inhibit ATP modulation of glucose transport. These findings suggest that transport regulation involves ATP-dependent conformational changes in (or interactions between) the GLUT1 C terminus and the C-terminal half of GLUT1 cytoplasmic loop 6–7.