Hypoglycaemia

Intestinal glucagon-like peptide-1: A new player associated with impaired counterregulatory responses to hypoglycaemia in type 1 diabetic mice

BACKGROUND

Impaired hypoglycaemic counterregulation has emerged as a critical concern for diabetic patients who may be hesitant to medically lower their blood glucose levels due to the fear of potential hypoglycaemic reactions. However, the patho-genesis of hypoglycaemic counterregulation is still unclear. Glucagon-like peptide-1 (GLP-1) and its analogues have been used as adjunctive therapies for type 1 diabetes mellitus (T1DM). The role of GLP-1 in counterregulatory dys-function during hypoglycaemia in patients with T1DM has not been reported.

AIM

To explore the impact of intestinal GLP-1 on impaired hypoglycaemic counterregulation in type 1 diabetic mice.

METHODS

T1DM was induced in C57BL/6J mice using streptozotocin, followed by intraperitoneal insulin injections to create T1DM models with either a single episode of hypoglycaemia or recurrent episodes of hypoglycaemia (DH5). Immunofluorescence, Western blot, and enzyme-linked immunosorbent assay were employed to evaluate the influence of intestinal GLP-1 on the sympathetic-adrenal reflex and glucagon (GCG) secretion. The GLP-1 receptor agonist GLP-1(7-36) or the antagonist exendin (9-39) were infused into the terminal ileum or injected intraperitoneally to further investigate the role of intestinal GLP-1 in hypoglycaemic counterregulation in the model mice.

RESULTS

The expression levels of intestinal GLP-1 and its receptor (GLP-1R) were significantly increased in DH5 mice. Consecutive instances of excess of intestinal GLP-1 weakens the sympathetic-adrenal reflex, leading to dysfunction of adrenal counterregulation during hypoglycaemia. DH5 mice showed increased pancreatic δ-cell mass, cAMP levels in δ cells, and plasma somatostatin concentrations, while cAMP levels in pancreatic α cells and plasma GCG levels decreased. Furthermore, GLP-1R expression in islet cells and plasma active GLP-1 levels were significantly increased in the DH5 group. Further experiments involving terminal ileal infusion and intraperitoneal injection in the model mice demonstrated that intestinal GLP-1 during recurrent hypoglycaemia hindered the secretion of the counterregulatory hormone GCG via the endocrine pathway.

CONCLUSION

Excessive intestinal GLP-1 is strongly associated with impaired counterregulatory responses to hypoglycaemia, leading to reduced appetite and compromised secretion of adrenaline, noradrenaline, and GCG during hypo-glycaemia.

A case of insulinoma misidentified as schizophrenia due to its manifestation in neuropsychiatric symptoms

Insulinomas can present with neuroglycopenic symptoms suggesting neuropsychiatric disorders, delaying diagnosis and treatment. We recently treated a 65-year-old woman with insulinoma who was misdiagnosed at her nearby psychiatric clinic as having schizophrenia because of personality changes and memory impairment; she was treated with brexpiprazole, which was discontinued due to persistence of the symptoms. Despite her relatively low casual plasma glucose (70 mg/dL), the physician at the psychiatric clinic did not investigate the possibility of hypoglycemia, partly because her HbA1c level (5.2%) was within normal range. After skipping lunch one day, she was found by her family to be unable to communicate properly. She was transported to the emergency room of our hospital, where intermittently scanning continuous glucose monitoring (isCGM) use permitted detection of the hypoglycemia and led to a diagnosis of insulinoma and successful resection. A 72-h fasting test established hyperinsulinemic hypoglycemia. Contrast-enhanced computed-tomography and endoscopic ultrasonography together with selective arterial calcium stimulation test revealed an insulin-secreting tumor in the tail of the pancreas. Surgical resection of the tumor corrected her glucose and insulin levels as well as eliminated the insulinoma neuropsychiatric symptoms. Pathological examination showed that the tumor was positive for chromogranin A, synaptophysin and insulin. It is, therefore, important for physicians to be aware that insulinomas can manifest as neuroglycopenic symptoms and to consider the possibility of hypoglycemia by careful medical interview and isCGM, especially when patients suspected of psychiatric disorders do not show the expected response to antipsychotic drugs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-024-00722-9.

Validity of mental and physical stress models

Different stress models are employed to enhance our understanding of the underlying mechanisms and explore potential interventions. However, the utility of these models remains a critical concern, as their validities may be limited by the complexity of stress processes. Literature review revealed that both mental and physical stress models possess reasonable construct and criterion validities, respectively reflected in psychometrically assessed stress ratings and in activation of the sympathoadrenal system and the hypothalamic-pituitary-adrenal axis. The findings are less robust, though, in the pharmacological perturbations' domain, including such agents as adenosine or dobutamine. Likewise, stress models' convergent- and discriminant validity vary depending on the stressors' nature. Stress models share similarities, but also have important differences regarding their validities. Specific traits defined by the nature of the stressor stimulus should be taken into consideration when selecting stress models. Doing so can personalize prevention and treatment of stress-related antecedents, its acute processing, and chronic sequelae. Further work is warranted to refine stress models' validity and customize them so they commensurate diverse populations and circumstances.

Ketogenic diet attenuates cognitive dysfunctions induced by hypoglycemia via inhibiting endoplasmic reticulum stress-dependent pathways

Hypoglycemia can potentially cause severe damage to the central nervous system. The ketogenic diet (KD), characterized by high-fat and extremely low-carbohydrate content, can modulate homeostasis and nutrient metabolism, thereby influencing body health. However, the effects and underlying mechanisms of KD on hypoglycemia-induced brain injury have not been thoroughly investigated. We aimed to explore the modulating effects of KD on cognitive functions and elucidate the underlying mechanisms. In this study, one-month-old mice were fed with KD for 2 weeks, and the changes in the gut microbiota were detected using the 16S rRNA gene amplicon sequencing method. The hypoglycemic model of mice was established using insulin, and the potential protective effect of KD on hypoglycemia-induced brain injury in mice was evaluated through immunofluorescence staining, western blotting, transmission electron microscopy, and Golgi staining. Our results showed that the intestinal flora of Dorea increased and Rikenella decreased in KD-fed mice. KD can not only alleviate anxiety-like behavior induced by hypoglycemia, but also increase the proportion of mushroom dendritic spines in the hippocampus by modulating changes in the gut microbiota. KD regulated synaptic plasticity by increasing the levels of SPN, PSD95, and SYP, which relieve cognitive impairment caused by hypoglycemia. Moreover, KD can promote the proliferation and survival of adult neural stem cells in the hippocampus, while reducing apoptosis by suppressing the activation of the IRE1-XBP1 and ATF6 endoplasmic reticulum stress pathways in mice with hypoglycemia. This study provides new evidence for demonstrating that KD may alleviate cognitive dysfunctions caused by hypoglycemia by modulating the gut microbiota.

Current and future therapies to treat impaired awareness of hypoglycemia

In order to achieve optimal glycemic control, intensive insulin regimes are needed for individuals with Type 1 Diabetes (T1D) and insulin-dependent Type 2 Diabetes (T2D). Unfortunately, intensive glycemic control often results in insulin-induced hypoglycemia. Moreover, recurrent episodes of hypoglycemia result in both the loss of the characteristic warning symptoms associated with hypoglycemia and an attenuated counterregulatory hormone responses. The blunting of warning symptoms is known as impaired awareness of hypoglycemia (IAH). Together, IAH and the loss of the hormonal response is termed hypoglycemia associated autonomic failure (HAAF). IAH is prevalent in up to 25% in people with T1D and up to 10% in people with T2D. IAH and HAAF increase the risk of severe hypoglycemia 6-fold and 25-fold, respectively. To reduce this risk for severe hypoglycemia, multiple different therapeutic approaches are being explored that could improve awareness of hypoglycemia. Current therapies to improve awareness of hypoglycemia include patient education and psychoeducation, the use of novel glycemic control technology, pancreas/islet transplantation, and drug therapy. This review examines both existing therapies and potential therapies that are in pre-clinical testing. Novel treatments that improve awareness of hypoglycemia, via improving the counterregulatory hormone responses or improving hypoglycemic symptom recognition, would also shed light on the possible neurological mechanisms that lead to the development of IAH. To reduce the risk of severe hypoglycemia in people with diabetes, elucidating the mechanism behind IAH, as well as developing targeted therapies is currently an unmet need for those that suffer from IAH.

The relationship between components of hypoglycemia worries and avoiding hypoglycemia behavior in type 2 diabetes mellitus with hypoglycemia: a network analysis

BACKGROUND

The fear of hypoglycemia in type 2 diabetes mellitus (T2DM) patients with hypoglycemia has seriously affected their quality of life. They are always afraid of hypoglycemia and often take excessive action to avoid it. Yet, researchers have investigated the relationship between hypoglycemia worries and excessive avoiding hypoglycemia behavior using total scores on self-report measures. However, network analysis studies of hypoglycemia worries and excessive avoiding hypoglycemia behavior in T2DM patients with hypoglycemia are lacking.

PURPOSE

The present study investigated the network structure of hypoglycemia worries and avoiding hypoglycemia behavior in T2DM patients with hypoglycemia and aimed to identify bridge items to help them correctly treat hypoglycemia and properly deal with hypoglycemia fear.

METHODS

A total of 283 T2DM patients with hypoglycemia were enrolled in our study. Hypoglycemia worries and avoiding hypoglycemia behavior were evaluated with the Hypoglycemia Fear Scale. Network analyses were used for the statistical analysis.

RESULTS

B9 "Had to stay at home for fear of hypoglycemia" and W12 "I am worried that hypoglycemia will affect my judgment" have the highest expected influences in the present network. In the community of hypoglycemia worries, W17 "I worry about hypoglycemia during sleep" has the highest bridge expected influence. And in the community of avoiding hypoglycemia behavior, B9 "Had to stay at home for fear of hypoglycemia" has the highest bridge expected influence.

CONCLUSION

Complex patterns of associations existed in the relationship between hypoglycemia worries and avoiding hypoglycemia behavior in T2DM patients with hypoglycemia. From the perspective of network analysis, B9 "Had to stay at home for fear of hypoglycemia" and W12 "I am worried that hypoglycemia will affect my judgment" have the highest expected influence, indicating their highest importance in the network. W17 "I worry about hypoglycemia during sleep" aspect of hypoglycemia worries and B9 "Had to stay at home for fear of hypoglycemia" aspect of avoiding hypoglycemia behavior have the highest bridge expected influence, indicating they have the strongest connections with each community. These results have important implications for clinical practice, which provided potential targets for interventions to reduce hypoglycemia fear and improve the quality of life in T2DM patients with hypoglycemia.

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.

Evaluation of Support, a self-guided online type 1 diabetes self-management education and support web application-a mixed methods study

Background

Type 1 diabetes requires making numerous daily decisions to maintain normoglycemia. Support is an evidence-based self-guided web application for type 1 diabetes diabetes self-management.

Objective

Evaluate users' satisfaction with Support and investigate changes in self-reported frequency of-, fear of- hypoglycemia, and diabetes-related self-efficacy.

Methods

Adults from a Quebec type 1 diabetes registry used Support. Data was collected through online surveys or extracted from the registry at 0, 6, and 12 months (number of episodes and fear of hypoglycemia). At 6 months, participants reported satisfaction with Support and diabetes-related self-efficacy. A sub-group of 16 users was interviewed about their experience. Transcripts were analyzed using inductive and deductive approaches.

Results

In total, 207 accounts were created (35% men, 96% White, mean age and diabetes duration: 49.3 ± 13.8 and 25.2 ± 14.7 years). At 6 months, the median [Q1; Q3] satisfaction was 40/49 [35; 45] with a mean decrease in hypoglycemia frequency of 0.43 episodes over 3 days (95% CI: -0.86; 0.00, p = 0.051) and of -1.98 score for fear (95% CI: -3.76; -0.20, p = 0.030). Half of the participants reported increased diabetes-related self-efficacy.

Conclusions

Participants reported a high level of satisfaction with Support. Its use has the potential to facilitate hypoglycemia management and increase diabetes-related self-efficacy.

Trial registration

This study is registered on ClinicalTrials.gov NCT04233138.

Fear of hypoglycemia and associated factors in hospitalized patients with type 2 diabetes: a cross‑sectional study

The present cross-sectional survey was performed to assess the prevalence and factors associated with fear of hypoglycemia (FoH) in hospitalized patients with type 2 diabetes (T2D). Between July and December 2020, 494 patients with T2D were evaluated via structured questionnaires containing sociodemographic information, clinical information, and the Fear of Hypoglycemia-15 scale (FH-15). Patients were divided into the FoH and non-FoH groups according to the FH-15 score. Univariate and multivariate logistic regression analyses were performed to determine factors associated with FoH. Variables with P values < 0.1 in the univariate model were included in the multivariate model. In this study, the prevalence of FoH was 17.4% (86/494). 247 (50.0%) patients experienced hypoglycemic episodes in the past year, and 15 (3.0%) patients experienced severe hypoglycemic episodes in the past year. The mean age was 60.04 ± 11.71 years old, and female patients accounted for 39.9% of the sample. The item with the highest average FH-15 scores was: how often are you afraid of having hypoglycemia while alone? Multivariate logistic regression analysis indicated that living alone (OR 2.48; 95% CI 1.20-5.14; P = 0.015), number of hypoglycemic episodes in the past year (OR 1.06; 95% CI 1.03-1.10; P < 0.001), number of severe hypoglycemic episodes in the past year (OR 2.61; 95% CI 1.20-5.69; P = 0.016), and duration of insulin use (OR 1.06; 95% CI 1.02-1.10; P = 0.006) were associated with FoH. The prevalence of FoH in hospitalized patients with T2D was high. FoH was associated with living alone, number of hypoglycemic episodes in the past year, number of severe hypoglycemic episodes in the past year, and duration of insulin use. These findings can contribute to early decision-making for preventing, identifying, and improving FoH in patients with T2D. In the future, interventions aimed at reducing FoH to improve the harmful effects of FoH are necessary, such as increasing diabetes-related knowledge and skills, increasing social support, reducing psychological fear, and minimizing risks for hypoglycemic episodes.

Relationship Between Glycosylated Hemoglobin and Short-Term Mortality of Spontaneous Intracerebral Hemorrhage

Background: The relationship between glycosylated hemoglobin (HbA1c) and prognosis of spontaneous intracerebral hemorrhage (SICH) patients has not been fully elucidated. This study aimed to reveal the relationship between HbA1c levels and short-term mortality after patient admission with SICH. Methods: It was a large-scale, multicenter, cross-sectional study. From August 1, 2015, to July 31, 2019, a total of 41910 SICH patients were included in the study from the Chinese Stroke Center Alliance (CSCA) program. Finally, we comprehensively analyzed the data from 21,116 patients with SICH. HbA1c was categorized into four groups by quartile. Univariate and multivariate logistic regression analyses were used to assess the association between HbA1c levels and short-term mortality in SICH patients. Results: The average age of the 21,116 patients was 62.8 ± 13.2 years; 13,052 (61.8%) of them were male, and 507 (2.4%) of them died. Compared to the higher three quartiles of HbA1c, the lowest quartile (≤5.10%) had higher short-term mortality. In subgroup analysis with or without diabetes mellitus (DM) patients, the mortality of the Q3 group at 5.60-6.10% was significantly lower than that of the Q1 group at ≤5.10%. After adjustment for potential influencing factors, the ROC curve of HbA1c can better predict the short-term mortality of patients with SICH (AUC = 0.6286 P < 0.001). Conclusions: Therefore, we concluded that low or extremely low HbA1c levels (≤5.10%) after stroke were associated with higher short-term mortality in SICH patients, with or without DM.