New perspectives in type 2 diabetes, cardiovascular risk, and treatment goals

Efficacy and safety of glucagon-like peptide-1 receptor agonists in type 2 diabetes: A systematic review and mixed-treatment comparison analysis

AIMS

To compare efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in people with type 2 diabetes.

MATERIALS AND METHODS

We electronically searched, up to June 3, 2016, published randomized clinical trials lasting between 24 and 32 weeks that compared a GLP-1RA (albiglutide, dulaglutide, twice-daily exenatide and once-weekly exenatide, liraglutide, lixisenatide, semaglutide and taspoglutide) with placebo or another GLP-1RA. Data on cardiometabolic and safety outcomes were analysed using a mixed-treatment comparison meta-analysis.

RESULTS

A total of 34 trials (14 464 participants) met the inclusion criteria; no published data for semaglutide were available. Compared with placebo, all GLP-1RAs reduced glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) levels (reductions ranged from -0.55% and -0.73 mmol/L, respectively, for lixisenatide to -1.21% and -1.97 mmol/L, respectively, for dulaglutide). There were no differences within short-acting (twice-daily exenatide and lixisenatide) or long-acting (albiglutide, dulaglutide, once-weekly exenatide, liraglutide and taspoglutide) groups. Compared with twice-daily exenatide, dulaglutide treatment was associated with the greatest HbA1c and FPG reduction (0.51% and 1.04 mmol/L, respectively), followed by liraglutide (0.45% and 0.93 mmol/L, respectively) and once-weekly exenatide (0.38% and 0.85 mmol/L, respectively); similar reductions were found when these 3 agents were compared with lixisenatide. Compared with placebo, all GLP-1RAs except albiglutide reduced weight and increased the risk of hypoglycaemia and gastrointestinal side effects, and all agents except dulaglutide and taspoglutide reduced systolic blood pressure. When all GLP-1RAs were compared with each other, no clinically meaningful differences were observed in weight loss, blood pressure reduction or hypoglycaemia risk. Albiglutide had the lowest risk of nausea and diarrhoea and once-weekly exenatide the lowest risk of vomiting.

CONCLUSIONS

The RCTs in the present analysis show that all GLP-1RAs improve glycaemic control, reduce body weight and increase the risk of adverse gastrointestinal symptoms compared with placebo. Although there were no differences when short-acting agents were compared with each other or when long-acting agents were compared with each other, dulaglutide, liraglutide and once-weekly exenatide were superior to twice-daily exenatide and lixisenatide at lowering HbA1c and FPG levels. There were no differences in hypoglycaemia between these 3 agents, whilst once-weekly exenatide had the lowest risk of vomiting. These results, along with patient's preferences and individualized targets, should be considered when selecting a GLP-1RA.

Efficacy and safety of insulin-GLP-1 receptor agonists combination in type 2 diabetes mellitus: a systematic review

INTRODUCTION

Attaining optimal glycemic targets in patients with type 2 diabetes is often hard and compromised by the shortcomings of the several treatments. Areas covered: When glycemic levels are not adequately controlled, an association of GLP-1 receptor agonists and insulin therapy can be adopted. In order to assess the benefit/risk profile of this combination therapy, a literature search of randomized clinical trials was performed.Eighteen trials matched the inclusion criteria. In 10 studies, GLP-1 receptor agonists were added on to an existing regimen, whereas insulin added to an existing GLP-1 receptor agonists regimen occurred in 2 studies. Six studies compared GLP-1 receptor agonists with short acting insulin as a treatment strategy to intensify basal insulin therapy. Expert opinion: Clinical trials herein reviewed demonstrated the safety and the efficacy of combining GLP-1 receptor agonists with basal insulin, with most studies showing equal or slightly superior efficacy, as compared with the addition of prandial insulin, associated with weight loss and less hypoglycemia.

Sodium-glucose cotransporter 2 inhibitors and cardiovascular outcomes

Type 2 diabetes mellitus (T2DM) is associated with an elevated risk of cardiovascular (CV) morbidity and mortality. Furthermore, many patients with T2DM have comorbidities that are risk factors for CV disease. While intensive glucose control reduces the risk of diabetic microvascular complications, its relationship to CV outcomes remains unclear. Consequently, the management of CV risk factors in patients with T2DM is complex, and factors other than blood glucose must be considered. Sodium-glucose cotransporter 2 (SGLT2) inhibitors, a class of oral glucose-lowering agents, are associated with reductions in blood pressure and body weight, in addition to decreasing hyperglycemia, and therefore have the potential to reduce CV risk in patients with T2DM. The clinical trial results of SGLT2 inhibitors regarding CV safety and outcomes are discussed, including data from the recently published EMPA-REG OUTCOME study. This trial was the first dedicated CV outcomes study to demonstrate that a glucose-lowering agent lowered CV mortality and all-cause mortality, and reduced hospitalization for heart failure in patients with T2DM at high risk of CV events.

Real-world glycemic outcomes in patients with type 2 diabetes initiating exenatide once weekly and liraglutide once daily: a retrospective cohort study

AIM

The glucagon-like peptide-1 receptor agonists exenatide once weekly (QW) and liraglutide once daily (QD) have demonstrated improvements in glycemic outcomes in patients with type 2 diabetes mellitus in randomized clinical trials. However, little is known about their real-world comparative effectiveness. This retrospective cohort study used the Quintiles Electronic Medical Record database to evaluate the 6-month change in glycated hemoglobin (A1C) for patients initiating exenatide QW or liraglutide QD.

METHODS

Patients with type 2 diabetes mellitus prescribed exenatide QW (n=664) or liraglutide QD (n=3,283) between February 1, 2012 and May 31, 2013 were identified. Baseline A1C measures were from 75 days before to 15 days after initiating exenatide QW or liraglutide QD, with follow-up measures documented at 6 months (±45 days). Adjusted linear regression models compared the difference in mean A1C change. A priori defined sensitivity analysis was performed in the subgroup of patients with baseline A1C ≥7.0% and no prescription for insulin during the 12-month pre-index period.

RESULTS

For exenatide QW and liraglutide QD, respectively, mean (SD) age of the main study cohort was 58.01 (10.97) and 58.12 (11.05) years, mean (SD) baseline A1C was 8.4% (1.6) and 8.4% (1.6), and 48.2% and 54.2% of patients were women. In adjusted models, change in A1C did not differ between exenatide QW and liraglutide QD during 6 months of follow-up. Results were consistent in the subgroup analyses.

CONCLUSION

In a real-world setting, A1C similarly improves in patients initiating exenatide QW or liraglutide QD.

Impact of clinical inertia on cardiovascular risk factors in patients with diabetes

AIMS

To determine whether clinical inertia is associated with simpler interventions occurring more often than complex changes and the association between clinical inertia and outcomes.

METHODS

Prevalence of clinical inertia over a 30 month period for hyperglycaemia, hypertension and dyslipidaemia was calculated in a random sample (n=334) of patients attending a diabetes clinic. Comparisons between prevalence of clinical inertia and outcomes for each condition were examined using parametric tests of association.

RESULTS

There was less clinical inertia in hyperglycaemia (29% of consultations) compared with LDL (80% of consultations) and systolic BP (68% of consultations). Consultations where therapy was intensified had a greater reduction in risk factor levels than when no change was made. No association was found between treatment intensity scores and changes in HbA1c, LDL or blood pressure over 30 months.

CONCLUSIONS

Physicians are no more likely to intervene in conditions where simple therapeutic changes are necessary as opposed to complex changes. Greater clinical inertia leads to poorer outcomes. There continues to be substantial clinical inertia in routine clinical practice. Physicians should adopt a holistic approach to cardiovascular risk reduction in patients with diabetes, adhere more closely to established management guidelines and emphasize personal individualized target setting.

Insulin plus incretin: A glucose-lowering strategy for type 2-diabetes

There are many advantages of combining incretin therapy [glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors] with insulin therapy as a glucose-lowering strategy in type 2 diabetes. One important advantage is the complementary mode of the mechanistic action of incretin and insulin therapy. Another advantage is the reduction in risk of hypoglycemia and weight gain when adding incretin therapy to insulin. Several clinical trials have studied the addition of GLP-1 receptor agonists [exenatide BID (twice daily), lixisenatide, albiglutide] or DPP-4 inhibitors (vildagliptin, sitagliptin, saxagliptin, alogliptin, linagliptin) to ongoing insulin therapy or adding insulin to ongoing therapy with a GLP-1 receptor agonist (liraglutide). These studies show improved glycemia in the presence of limited risk for hypoglycemia and weight gain with the combination of incretin therapy with insulin. This article reviews the background and clinical studies on this combination.

Combination therapy with GLP-1 receptor agonists and basal insulin: a systematic review of the literature

Treatment algorithms for type 2 diabetes call for intensification of therapy over time as the disease progresses and glycaemic control worsens. If diet, exercise and oral antihyperglycaemic medications (OAMs) fail to maintain glycaemic control then basal insulin is added and ultimately prandial insulin may be required. However, such an intensification strategy carries risk of increased hypoglycaemia and weight gain, both of which are associated with worse long-term outcomes. An alternative strategy is to intensify therapy by the addition of a short-acting glucagon-like peptide-1 receptor agonist (GLP-1 RA) rather than prandial insulin. Short-acting GLP-1 RAs such as exenatide twice daily are particularly effective at reducing postprandial glucose while basal insulin has a greater effect on fasting glucose, providing a physiological rationale for this complementary approach. This review analyzes the latest randomized controlled clinical trials of insulin/GLP-1 RA combination therapy and examines results from 'real-world' use of the combinations as reported through observational and clinical practice studies. The most common finding across all types of studies was that combination therapy improved glycaemic control without weight gain or an increased risk of hypoglycaemia. Many studies reported weight loss and a reduction in insulin use when a GLP-1 RA was added to existing insulin therapy. Overall, the relative degree of benefit to glycaemic control and weight was influenced by the insulin titration employed in conjunction with the GLP-1 RA. The greatest glycaemic benefits were observed in studies with structured titration of insulin to glycaemic targets while the greatest weight benefits were observed in studies with a protocol-specified focus on insulin sparing. The adverse event profile of GLP-1 RAs in the reviewed trials was similar to that reported with GLP-1 RAs as monotherapy or in combination with OAMs with gastrointestinal events being the most commonly reported.

Demonstrating the burden of hypoglycemia on patients' quality of life in diabetes clinical trials: measurement considerations for hypoglycemia

OBJECTIVES

To evaluate the association between hypoglycemia and health-related quality of life (HRQoL) in the context of a clinical trial using both an objectively confirmed and a patient-reported measure of hypoglycemia.

METHODS

During a phase III, double-arm, randomized study, patients completed the short form 36 health survey (SF-36), a generic HRQoL questionnaire, at baseline and at weeks 24, 52, and 104. The objectively confirmed measure of hypoglycemia was based on a combination of plasma glucose measure and presence of hypoglycemia-related symptoms. The patient-reported frequency of hypoglycemia was defined as the following item: "How often have you felt that your blood sugars have been unacceptably low recently?" The association between hypoglycemia and HRQoL was evaluated in intent-to-treat patients (N = 3059) by using repeated-measurements analyses, with SF-36 scores used as explained variables and baseline SF-36 score, age, sex, country, time, and either number of objectively confirmed hypoglycemic events (0, ≥1) or patient-reported frequency of hypoglycemia (continuous variable 0-6) as explanatory variables.

RESULTS

During study duration, less than 6% of patients experienced at least one objectively confirmed hypoglycemic event and about half the patients reported unacceptably low blood sugars "none of the time." The association between the number of objectively confirmed hypoglycemic events and HRQoL was not statistically significant, while the patient-reported frequency of hypoglycemia was statistically significantly related to all SF-36 scores (P < 0.001), except physical functioning; patients reporting greater perceived frequency of hypoglycemia had worse HRQoL.

CONCLUSIONS

Using a patient-reported measure of hypoglycemia in the context of a clinical trial could enable the burden of hypoglycemia for patients to be demonstrated.

Cardiovascular benefits of exogenous insulin

CONTEXT

Recent studies on mediators of inflammation, experimental models of atherosclerosis, and acute ischemia have identified novel mechanisms through which insulin may exert cardiovascular protective effects. This review aims to summarize current knowledge regarding the cardiovascular, antiinflammatory, and antiatherogenic effects of insulin, and the effect of intensive glycemic control in acute cardiovascular disease.

EVIDENCE ACQUISITION

Publications of interest were identified using preselected MeSH terminology and keywords to search online databases such as PubMed and OVID for the period January 1988 to February 2012. Relevant publications were obtained and reviewed by two independent observers, then evaluated a priori against the following criteria: study quality, main clinical outcomes, and applicability to clinical practice.

EVIDENCE SYNTHESIS

Insulin has been shown to exert vasodilatory, antiinflammatory, and antiatherogenic effects in experimental models, independent of its glucose-lowering effects. Additionally, glucose is known to exert potent proinflammatory, prothrombotic, and proapoptotic effects during myocardial infarct, indicative that hyperglycemia is likely to be injurious to the heart. In this context, through its nonmetabolic and metabolic (glucose-lowering) effects, insulin is likely to be cardioprotective and to improve clinical outcomes in acute myocardial infarction.

CONCLUSIONS

Despite promising experimental data and evidence of benefit from single-center randomized clinical trials, clinical evidence supporting the cardioprotective effects of insulin from a multicenter randomized clinical trial is still lacking. Future prospective studies with insulin infused at adequate concentrations, individually titrated to achieve and maintain euglycemia (blood glucose < 140 mg/dl) and minimize hypoglycemia, are required to investigate the role of insulin in the management of patients with acute cardiovascular disease.

Best approaches in the battle against Globesity? Learning lessons from our experience tackling HIV-AIDS and tobacco smoking

In 2008, two-thirds of the annual global death toll was attributable to non-communicable diseases (NCDs). Defined as chronic conditions often caused or exacerbated by non-obligated lifestyle behaviours, the NCD epidemic has been fuelled by a combination of risk factors, including tobacco use, an unhealthy diet combined with lack of physical activity and overweight-obesity, and harmful alcohol use. The health consequences are mainly seen as cardiovascular diseases, diabetes, cancers and chronic respiratory problems. Generally associated with the West, they are now recognized as a global threat to public health. They are also an unsupportable global health economic burden. NCDs incidence can be significantly reduced through the adoption of proven and affordable interventional measures which are complementary to global health efforts already underway. To head off the certain future surge in morbidity and mortality, at record costs to health budgets worldwide, there is a pressing need to change global population's behaviours and choices in relation to these risk factors. The most pressing challenge in NCD prevention is combating the rise in overweight-obesity, which threatens individuals, communities and countries as never before. If not overcome, this may undo much of the progress seen in reducing the incidence of myocardial infarctions, strokes and some cancers evident from the 1960s onwards.

Overview of the guidelines and evidence for the pharmacologic management of type 2 diabetes mellitus

The number of novel treatment options for type 2 diabetes mellitus, including those with distinctive mechanisms of action, has risen sharply this decade, and health care providers must be aware of the drugs' safety and efficacy in order to provide patients with the best care possible. Guidelines for type 2 diabetes provide recommendations for initiating and continuing treatment that will enable patients to achieve glycemic control and maintain it over time. Several recently completed, large clinical trials have provided information pertaining to potential benefits and risks of achieving specific treatment goals, and medical professionals should consider applying the insights from these trials when optimizing care for their patients. The pharmacist plays an essential role in helping patients achieve and maintain tight glycemic control by assisting other health care providers in understanding and utilizing the guidelines as part of individualized treatment regimens.

A critical review of diabetes, glycemic control, and dental implant therapy

OBJECTIVES

To systematically examine the evidence guiding the use of implant therapy relative to glycemic control for patients with diabetes and to consider the potential for both implant therapy to support diabetes management and hyperglycemia to compromise implant integration.

MATERIAL AND METHODS

A systematic approach was used to identify and review clinical investigations directly assessing implant survival or failure for patients with diabetes. A MEDLINE (PubMED) database search identified potential articles for inclusion using the search strategy: (dental implants OR oral implants) AND (diabetes OR diabetic). Inclusion in this review required longitudinal assessments including at least 10 patients, with included articles assessed relative to documentation of glycemic status for patients.

RESULTS

Although the initial search identified 129 publications, this was reduced to 16, for inclusion. Reported implant failure rates for diabetic patients ranged from 0% to 14.3%. The identification and reporting of glycemic control was insufficient or lacking in 13 of the 16 studies with 11 of these enrolling only patients deemed as having acceptable glycemic control, limiting interpretation of findings relative to glycemic control. Three of the 16 studies having interpretable information on glycemic control failed to demonstrate a significant relationship between glycemic control and implant failure, with failure rates ranging from 0% to 2.9%.

CONCLUSIONS

Clinical evidence is lacking for the association of glycemic control with implant failure while support is emerging for implant therapy in diabetes patients with appropriate accommodations for delays in implant integration based on glycemic control. The role for implants to improve oral function in diabetes management and the effects of hyperglycemia on implant integration remain to be determined.

Non-peptidic glucose-like peptide-1 receptor agonists: aftermath of a serendipitous discovery

Glucagon-like peptide-1 (GLP-1) receptor is an ideal target in the development of incretin-based therapies for diabetes and obesity. Two approaches have been adopted: GLP-1 receptor agonists that mimic the effects of native GLP-1 and dipeptidyl peptidase-4 inhibitors that increase endogenous GLP-1 levels. During the past two decades, search for orally active, non-peptidic GLP-1 receptor agonists has been the focal point of research and development activities in many multinational pharmaceutical companies. Such efforts have not resulted in any success thus far. Serendipitous discovery of substituted cyclobutanes represented by Boc5 as a new class of GLP-1 receptor agonists led us to believe that a small molecule approach to class B G-protein coupled receptor agonism is no longer a fantasy but a reality. However, major obstacles still pose great challenges, and the reasons of which are discussed in this perspectives.