Hypoglycaemia in diabetes mellitus: epidemiology and clinical implications

Hypoglycemia and Cardiovascular Disease: Lessons from Outcome Studies

Severe hypoglycemia is recognized to be one of the strongest predictors of macrovascular events, adverse clinical outcomes, and mortality in patients with type 2 diabetes. Large clinical trials have reported an increased hazard ratio for all-cause mortality and cardiovascular events in patients with type 2 diabetes and severe hypoglycemia. However, these trials also reported an increased hypoglycemia-associated mortality rate in patients allocated to standard treatment by a factor of 1.5-2 despite a significant 50 % to 70 % lower incidence of hypoglycemia compared to the intensive treatment group. Although the potential for a causal relationship has been demonstrated in mechanistic studies, the evidence from large prospective studies suggest that other pre-existing cardiovascular risk factors in addition to hypoglycemia may be the major link to the final cardiovascular event, and that a low blood glucose level can trigger these events in patients with a high cardiovascular risk.

Risk of Hospitalization for Hypoglycemia in Older Patients with Diabetes Using Antipsychotic Drugs

OBJECTIVE

Antipsychotics may disrupt metabolic regulation in patients with diabetes mellitus. The risk of hypoglycemia in older users of antipsychotics with diabetes is largely unknown. Therefore, we investigated the association between the use of antipsychotic drugs and hypoglycemia requiring hospital admission in older patients with diabetes.

METHODS

In a nested case-control study using community pharmacy records linked to hospital admission data in the Netherlands (1998-2008), a cohort of 68,314 patients at least 65 years with diabetes was studied. Cases were patients from the study cohort with a first hospital admission for hypoglycemia; up to five comparison subjects were selected for each case. Exposure to antipsychotic drugs was the primary determinant of interest. Logistic regression analysis was performed to estimate the strength of the association between antipsychotic drug use and hypoglycemia, taking into account potential confounders.

RESULTS

Eight hundred fifteen patients were admitted to hospital for hypoglycemia. Current use of antipsychotic drugs was associated with an increased risk of hypoglycemia compared with non-use (adjusted OR: 2.26; 95% CI: 1.45-3.52; Wald χ(2) = 13.08, df = 1, p ≤0.001), especially in the first 30 days of treatment (adjusted OR: 7.65; 95% CI: 2.50-23.41; Wald χ(2) = 12.72, df = 1, p ≤0.001) and with higher doses (adjusted OR: 8.20; 95% CI: 3.09-21.75; Wald χ(2) = 17.90, df = 1, p ≤0.001).

CONCLUSION

Use of antipsychotic drugs by older patients with diabetes mellitus was associated with an increased risk of hospitalization for hypoglycemia. Our findings suggest that glucose levels should be monitored closely after initiation of antipsychotic drugs.

Hypoglycemia and Comorbidities in Type 2 Diabetes

Hypoglycemia is one of the major barriers in optimizing glycemic control. In type 2 diabetes, hypoglycemia is associated with multiple morbidities (eg, myocardial ischemia, cardiac arrhythmia, stroke, dementia, psychosocial dysfunction, obesity, microvascular complications, cancer, and diseases of respiratory, digestive, and dermatological systems). Risk factors associated with hypoglycemia in patients with type 2 diabetes include old age, long disease duration, low body mass index, high baseline glycated hemoglobin (HbA1c), treatment with insulin and sulphonylurea, renal dysfunction, albuminuria, reduced level of low density lipoprotein cholesterol, low triglyceride and depression. There are considerable overlaps between phenotypes associated with severe hypoglycemia and all-site cancer suggesting that hypoglycemia may be a marker of vulnerability. In patients with severe hypoglycemia, comprehensive assessment is recommended to detect silent conditions, such as renal dysfunction, cancer, depression as well as review of treatment strategies including drug use to prevent morbidities and mortality.

Surreptitious insulin overdosing in adolescents with type 1 diabetes

BACKGROUND

Hypoglycemia in children and adolescents with type 1 diabetes has diverse etiologies.

CASE CHARACTERISTICS

We report recurrent hypoglycemia in three children with type 1 diabetes because of insulin overdose.

INTERVENTION

Hospitalization and counselling by treating team and psychologist helped in resolving the recurrent hypoglycemia.

OUTCOME

Improvement in glycemic control was achieved.

MESSAGE

Adolescents with type 1 diabetes may take extra insulin to consume more carbohydrates, or to seek attention. Parents should share the responsibility of care of adolescents during transition phase for better glycemic control.

Recognizing and minimizing hypoglycemia: The need for individualized care

Hypoglycemia is a condition known to disrupt many everyday activities and is associated with increased risks of hospitalization, falls, motor vehicle accidents and mortality. Many patients with diabetes have an increased risk of hypoglycemia due to interventions targeting glycemic control. In these patients, hypoglycemia and fear of hypoglycemia may further reduce adherence to glucose-lowering regimens, contributing to the further aggravation of diabetes-related complications. Avoiding hypoglycemia should be one of the principal goals of any treatment strategies employing agents that can induce hypoglycemia in order to prevent the occurrence of associated symptoms and consequences. The education of patients and their families is an important feature of individualized management strategies in order to prevent, mitigate and treat hypoglycemic episodes. Patients with diabetes need to be made aware of how to recognize the signs of hypoglycemia and of the simple, highly effective steps that they can take to self-manage hypoglycemic episodes. Clinicians should be familiar with the risk factors for hypoglycemia, especially the profiles of the different classes of glucose-lowering medications such as the sulfonylureas and insulin. This article aims to review the risk factors for hypoglycemia and its implications for patients and healthcare systems, and provide practical advice for minimizing the risk of hypoglycemia and its consequences.

Design and rationale of the IN CONTROL trial: the effects of real-time continuous glucose monitoring on glycemia and quality of life in patients with type 1 diabetes mellitus and impaired awareness of hypoglycemia

BACKGROUND

Hypoglycemia is the main side effect of intensified insulin therapy in type 1 diabetes and recognized as a limitation in achieving glycemic targets. Patients with impaired awareness of hypoglycemia have a threefold to sixfold increased risk of severe hypoglycemia. Real-time continuous glucose monitoring may help patients with type 1 diabetes to achieve better glycemic control with less hypoglycemic episodes. Accordingly, one may hypothesize that particularly type 1 diabetes mellitus patients with impaired awareness of hypoglycemia will profit most from this technology with improvements in their quality of life. However, this has not yet been established. This trial aims to study the effect of real-time continuous glucose monitoring on glycemia and quality of life specifically in type 1 diabetes mellitus patients with established impaired awareness of hypoglycemia.

METHODS/DESIGN

This is a two-center, randomized, cross-over trial with a 12-week wash-out period in between intervention periods. A total of 52 type 1 diabetes mellitus patients with impaired awareness of hypoglycemia according to Gold et al. criteria will be randomized to receive real-time continuous glucose monitoring or blinded continuous glucose monitoring for 16 weeks. After a wash-out period, patients will cross over to the other intervention. The primary outcome measure is time spent in euglycemia. Secondary outcomes include (diabetes-specific) markers of quality of life and other glycemic variables.

DISCUSSION

It remains unclear whether patients with type 1 diabetes and impaired awareness of hypoglycemia benefit from real-time continuous glucose monitoring in real-life. This study will provide insight into the potential benefits of real-time continuous glucose monitoring in this patient population.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT01787903.

Evidence-informed clinical practice recommendations for treatment of type 1 diabetes complicated by problematic hypoglycemia

Problematic hypoglycemia, defined as two or more episodes per year of severe hypoglycemia or as one episode associated with impaired awareness of hypoglycemia, extreme glycemic lability, or major fear and maladaptive behavior, is a challenge, especially for patients with long-standing type 1 diabetes. Individualized therapy for such patients should include a composite target: optimal glucose control without problematic hypoglycemia. Therefore, we propose a tiered, four-stage algorithm based on evidence of efficacy given the limitations of educational, technological, and transplant interventions. All patients with problematic hypoglycemia should undergo structured or hypoglycemia-specific education programs (stage 1). Glycemic and hypoglycemia treatment targets should be individualized and reassessed every 3-6 months. If targets are not met, one diabetes technology-continuous subcutaneous insulin infusion or continuous glucose monitoring-should be added (stage 2). For patients with continued problematic hypoglycemia despite education (stage 1) and one diabetes technology (stage 2), sensor-augmented insulin pumps preferably with an automated low-glucose suspend feature and/or very frequent contact with a specialized hypoglycemia service can reduce hypoglycemia (stage 3). For patients whose problematic hypoglycemia persists, islet or pancreas transplant should be considered (stage 4). This algorithm provides an evidence-informed approach to resolving problematic hypoglycemia; it should be used as a guide, with individual patient circumstances directing suitability and acceptability to ensure the prudent use of technology and scarce transplant resources. Standardized reporting of hypoglycemia outcomes and inclusion of patients with problematic hypoglycemia in studies of new interventions may help to guide future therapeutic strategies.

Altered Plasticity of Glycogen Phosphorylase in Forebrain Gliosomes Obtained from Insulinoma Patients

We investigated a control model of hypoglycemia-exposed brain tissues from a small series of patients with insulinoma, immediately dissect them, and perform a differential cold centrifugation to obtain gliosomes and examine alterations of glycogenolytic mechanisms. The BB as well as MM isoforms of glycogen phosphorylase enzymatic protein expression remained unaltered between insulinoma and control subjects within the gliosomes. However, the glycogen phosphorylase remained in a form that was potentially activated several folds on placing the gliosomes in a glucose-free medium. This was examined by its increased interaction with protein kinase A. Inhibitors of glycogen phosphorylase was used as controls. Furthermore, we demonstrated that glucose-depleted medium enhanced production of both ATP and lactate by the gliosomes. It is possible that a portion of glucose obtained from glycogen breakdown was circuited through glycolytic pathways to generate ATP. It has been reported earlier that ATP within gliosomes plays a major role in glutamate uptake, thus potentially preventing seizure during active bouts of hypoglycemia. Lactate shuttle from astrocytes is a potential mechanism to balance neuronal bioenergetics during events of hypoglycemia. Newer approaches to pharmacologically modulate glycogen phosphorylase may prove to be rational approach for neuroprotective therapy in this common clinical syndrome of hypoglycemia.

Avoiding or coping with severe hypoglycemia in patients with type 2 diabetes

Hypoglycemia is a major barrier to achieving the glycemic goal in patients with type 2 diabetes. In particular, severe hypoglycemia, which is defined as an event that requires the assistance of another person to actively administer carbohydrates, glucagon, or take other corrective actions, is a serious clinical concern in patients with diabetes. If severe hypoglycemia is not managed promptly, it can be life threatening. Hypoglycemia-associated autonomic failure (HAAF) is the main pathogenic mechanism behind severe hypoglycemia. Defective glucose counter-regulation (altered insulin secretion, glucagon secretion, and an attenuated increase in epinephrine during hypoglycemia) and a lack of awareness regarding hypoglycemia (attenuated sympathoadrenal activity) are common components of HAAF in patients with diabetes. There is considerable evidence that hypoglycemia is an independent risk factor for cardiovascular disease. In addition, hypoglycemia has a significant influence on the quality of life of patients with diabetes. To prevent hypoglycemic events, the setting of glycemic goals should be individualized, particularly in elderly individuals or patients with complicated or advanced type 2 diabetes. Patients at high-risk for the future development of severe hypoglycemia should be selected carefully, and intensive education with reinforcement should be implemented.

Preclinical and Clinical Studies for Sodium Tungstate: Application in Humans

Diabetes is a complex metabolic disorder triggered by the deficient secretion of insulin by the pancreatic β-cell or the resistance of peripheral tissues to the action of the hormone. Chronic hyperglycemia is the major consequence of this failure, and also the main cause of diabetic problems. Indeed, several clinical trials have agreed in that tight glycemic control is the best way to stop progression of the disease. Many anti-diabetic drugs for treatment of type 2 diabetes are commercially available, but no ideal normoglycemic agent has been developed yet. Moreover, weight gain is the most common side effect of many oral anti-diabetic agents and insulin, and increased weight has been shown to worsen glycemic control and increase the risk of diabetes progression. In this sense, the inorganic salt sodium tungstate (NaW) has been studied in different animal models of metabolic syndrome and diabetes, proving to have a potent effect on normalizing blood glucose levels and reducing body weight, without any hypoglycemic action. Although the liver has been studied as the main site of NaW action, positive effects have been also addressed in muscle, pancreas, brain, adipose tissue and intestine, explaining the effective anti-diabetic action of this salt. Here, we review NaW research to date in these different target organs. We believe that NaW deserves more attention, since all available anti-diabetic treatments remain suboptimal and new therapeutics are urgently needed.