Impact of therapeutic advances on hypoglycaemia in type 2 diabetes

Insulin actions on hypothalamic glucose-sensing neurones

Subsequent to the discovery of insulin 100 years ago, great strides have been made in understanding its function, especially in the brain. It is now clear that insulin is a critical regulator of the neuronal circuitry controlling energy balance and glucose homeostasis. This review focuses on the effects of insulin and diabetes on the activity and glucose sensitivity of hypothalamic glucose-sensing neurones. We highlight the role of electrophysiological data in understanding how insulin regulates glucose-sensing neurones. A brief introduction describing the benefits and limitations of the major electrophysiological techniques used to investigate glucose-sensing neurones is provided. The mechanisms by which hypothalamic neurones sense glucose are discussed with an emphasis on those glucose-sensing neurones already shown to be modulated by insulin. Next, the literature pertaining to how insulin alters the activity and glucose sensitivity of these hypothalamic glucose-sensing neurones is described. In addition, the effects of impaired insulin signalling during diabetes and the ramifications of insulin-induced hypoglycaemia on hypothalamic glucose-sensing neurones are covered. To the extent that it is known, we present hypotheses concerning the mechanisms underlying the effects of these insulin-related pathologies. To conclude, electrophysiological data from the hippocampus are evaluated aiming to provide clues regarding how insulin might influence neuronal plasticity in glucose-sensing neurones. Although much has been accomplished subsequent to the discovery of insulin, the work described in our review suggests that the regulation of central glucose sensing by this hormone is both important and understudied.

Prescription patterns of antihyperglycemic drugs in elderly patients in Spain: A national cross-sectional study

BACKGROUND AND OBJECTIVE

Elderly patients with type 2 diabetes represent a growing and heterogeneous group of subjects where treatment targets and antihyperglycemic drugs prescriptions should be tailored according to coexisting illnesses, functional and social domains.

METHODS

We carried-out a national cross-sectional study (from February 2014 to December 2014) to assess prescription patterns and treatment inadequacy in patients with type 2 diabetes older than 65 years with at least 6 months of treatment with antihyperglycemic drugs.

RESULTS

We included a total of 4,917 patients cared by 2,100 family physicians and 450 specialists. Diabetes prescriptions were monotherapy (21.2%), dual therapy (58.1%) and triple therapy (20.6%). The most common prescription patterns were metformin in monotherapy (66.5%), metformin plus DPP4 inhibitors in dual therapy (77.3%) and, in triple therapy, oral drugs (45.5%) and oral drugs plus insulin (45.8%). A total of 1,272 (25.9%) patients were at risk of serious hypoglycemia, 643 of them due to treatment with secretagogues (25%) or treatment with human insulin types (25.6%).

CONCLUSIONS

Elderly patients with type 2 diabetes often receive antihyperglycemic therapy with higher risk of hypoglycemia. Substitution of secretagogues and human insulin therapy for safer medication could significantly reduce the adverse effects of diabetes treatment in this population.

Hypoglycemia: The neglected complication

Hypoglycemia is an important complication of glucose-lowering therapy in patients with diabetes mellitus. Attempts made at intensive glycemic control invariably increases the risk of hypoglycemia. A six-fold increase in deaths due to diabetes has been attributed to patients experiencing severe hypoglycemia in comparison to those not experiencing severe hypoglycemia Repeated episodes of hypoglycemia can lead to impairment of the counter-regulatory system with the potential for development of hypoglycemia unawareness. The short- and long-term complications of diabetes related hypoglycemia include precipitation of acute cerebrovascular disease, myocardial infarction, neurocognitive dysfunction, retinal cell death and loss of vision in addition to health-related quality of life issues pertaining to sleep, driving, employment, recreational activities involving exercise and travel. There is an urgent need to examine the clinical spectrum and burden of hypoglycemia so that adequate control measures can be implemented against this neglected life-threatening complication. Early recognition of hypoglycemia risk factors, self-monitoring of blood glucose, selection of appropriate treatment regimens with minimal or no risk of hypoglycemia and appropriate educational programs for healthcare professionals and patients with diabetes are the major ways forward to maintain good glycemic control, minimize the risk of hypoglycemia and thereby prevent long-term complications.

Liraglutide: clinical pharmacology and considerations for therapy

Liraglutide is a United States Food and Drug Administration (FDA)-approved glucagon-like peptide-1 (GLP-1) analog that is 97% homologous to native human GLP-1. The additional 16-carbon fatty acid chain causes noncovalent binding to albumin, which slows absorption from the injection site and protects the molecule from degradation by the enzyme dipeptidyl peptidase-4, allowing for protraction of action. Albumin binding and an elimination half-life of 13 hours combine to allow for once-daily dosing. Liraglutide 1.2 and 1.8 mg/day given as monotherapy for up to 52 weeks produced mean reductions in hemoglobin A1c (A1C) of 0.6-1.6%; combination therapy of liraglutide with oral antidiabetic agents demonstrated mean A1C reductions up to 1.5%. The satiety effect of GLP-1 receptor agonists and documented weight loss as great as 3.38 kg in clinical trials may make liraglutide ideal for obese patients with type 2 diabetes mellitus. Like other incretin-based agents, preliminary studies suggest liraglutide may also increase β-cell mass and function. Hypoglycemia is rare with liraglutide and tends to occur when used in combination with sulfonylureas; liraglutide in combination with insulin is not yet FDA approved. The pharmacokinetic parameters of liraglutide are unaffected by age, sex, race, or ethnicity, and no special recommendations for altered dosing of liraglutide need apply to populations with hepatic or renal impairment. Results from clinical trials have not shown an increased risk of medullary thyroid cancer, pancreatitis, or poor cardiovascular outcomes with liraglutide treatment. Ongoing, long-term monitoring studies continue to evaluate the safety of liraglutide treatment in these outcomes.

Medically minimising the impact of hypoglycaemia in type 2 diabetes: a review

INTRODUCTION

Some therapies for type 2 diabetes (T2DM) are limited by hypoglycaemia, and this underestimated side effect carries an associated morbidity and financial burden. Large trials that have examined strict glycaemic control and cardiovascular outcomes in T2DM have highlighted the potential harm of exposure to hypoglycaemia in people with coronary heart disease.

AREAS COVERED

The responses to, and the morbidity associated with, hypoglycaemia in T2DM are discussed with identification of people most at risk of severe hypoglycaemia. The evidence base for non-pharmacological strategies and the risks of hypoglycaemia associated with various treatment modalities are examined. This review provides the clinician with a rational approach to the selection of different anti-diabetes drugs to minimize the risk of hypoglycaemia.

EXPERT OPINION

When managing T2DM, insulin and insulin secretagogues should be used judiciously and glycaemic targets individualized to avoid hypoglycaemia. Incretin mimetics present a lower risk of hypoglycaemia with similar efficacy as traditional agents in treating hyperglycaemia. The potential relationship between hypoglycaemia and precipitation of acute cardiovascular events is a highly topical area of research and may help determine what glycaemic targets are appropriate in people with T2DM.

Clinical inertia in management of T2DM

Diabetes is highly prevalent and serious chronic debilitating disease and reported to be the fourth main cause of death in Europe. Despite extensive evidence of benefits of tight glycemic control, large proportions of people with diabetes do not achieve target glycemic control. One major reason for this is clinical inertia which is "recognising the problem but failure to act" by health care professionals in primary care. The key issues in the management of people with T2DM include early detection of problems, realistic goal setting, improved patient adherence, better knowledge and understanding of pharmacotherapeutic treatment options and prompt intervention. Health care professionals must need to overcome clinical inertia and need to intensify therapy in an appropriate and timely manner.

Avoiding hypoglycaemia while achieving good glycaemic control in type 2 diabetes through optimal use of oral agent therapy

BACKGROUND

Patients with type 2 diabetes appear to be at relatively low risk of severe hypoglycaemia and hypoglycaemia unawareness in the early stages of disease. However, declining endogenous insulin secretory capacity due to beta-cell dysfunction/failure eventually produces vulnerability similar to type 1 diabetes. Severe hypoglycaemia itself is associated with serious morbidity and sometimes mortality, and represents an important barrier to achieving glycaemic goals and thus may reduce the protection from diabetes-related morbidity provided by good glycaemic control. Achieving an optimal balance of good glycaemic control and low risk of hypoglycaemia is key to providing optimum care in individuals with type 2 diabetes. This article discusses the issues related specifically to hypoglycaemia associated with oral agent therapy and how these agents may be best employed to provide an optimal balance between hypoglycaemia and good glycaemic control.

METHODS

Embase and Medline searches from 1998 to 2009 using the search terms DPP-4 inhibitors, metformin, oral agents, sulphonylureas, thiazolidinediones AND hypoglycaemia were conducted to identify relevant articles. The limitations inherent in this retrospective, narrative review of previously published publications chosen at the author's discretion are acknowledged.

FINDINGS

Failure to address even mild hypoglycaemia and glycaemic control early in the course of the disease may compromise the success of treatment in the longer term. Metformin, thiazolidinediones and DPP-4 inhibitors, either as monotherapy or in combination with each other, have a well-characterised low propensity to cause hypoglycaemia compared with other therapies.

CONCLUSIONS

Metformin, thiazolidinediones and DPP-4 inhibitors appear to be the most appropriate oral options for minimising the risk of hypoglycaemia. Early and ongoing attention to hypoglycaemia should form an integral part of any long-term glucose control strategy.