Lessons from SAVOR and EXAMINE: some important answers, but many open questions

Translating recent results from the Cardiovascular Outcomes Trials into clinical practice: recommendations from the Central and Eastern European Diabetes Expert Group (CEEDEG)

AIMS

These recommendations aim to improve care for patients with type 2 diabetes (T2D) at high cardiovascular (CV) risk in Central and Eastern Europe. Cardiovascular disease (CVD) and/or chronic kidney disease (CKD) are major interdependent comorbidities in patients with T2D, accounting for 50% of mortality. Following recent CV outcomes trial (CVOT) results, including those from EMPA-REG OUTCOME®, LEADER®, SUSTAIN™-6 and, most recently, the CANVAS study, it is essential to develop regional expert consensus recommendations to aid physicians in interpreting these newest data to clinical practice.

METHODS

The Central and Eastern European Diabetes Expert Group (CEEDEG) followed a Delphi method to develop treatment algorithms to aid physicians in the clinical management of patients with T2D at high CV risk.

RESULTS

In light of the latest CVOT results, and in particular the EMPA-REG OUTCOME® and LEADER® trials, the diagnosis, assessment, treatment choice and monitoring of patients with T2D and established CVD and/or CKD have been considered together with existing guidelines and presented in two reference algorithms. In addition, adherence, special prescribing considerations and a proposed multidisciplinary management approach have been discussed and are presented with the proposed algorithms.

CONCLUSIONS

The latest available high-level evidence on glucose-lowering drugs has enabled CEEDEG to develop practical consensus recommendations for patients with established CVD and/or CKD. These recommendations represent an update to international and country-level guidelines used for these patients, with the aim of providing a resource not only to endocrinologists, but to cardiologists, nephrologists and primary care physicians in the region.

Glucose, cholesterol, and blood pressure: is lower always better for type 2 diabetes?

Diabetes mellitus is a major risk factor for cardiovascular disease. However, the excess risk of death may vary substantially in subgroups of patients with type 2 diabetes, being highest in those younger than 55 years of age. A HbA1c value of 7.0 % or less is recommended for most patients with type 2 diabetes to reduce the incidence of microvascular disease, although individualized approaches that balance the benefits of glycemic control against the harms of hypoglycemia are encouraged. The selection of antidiabetic medications is of paramount importance, as the drug should not aggravate, and ideally even improve cardiovascular risk factors, with the hope to reduce cardiovascular morbidity and mortality. Patients with diabetes mellitus between 40 and 75 years of age with LDL-C between 70 and 189 mg/dL should be treated with a moderate-intensity statin. Implicit in this recommendation is the aim to reduce further LDL-C level in diabetes, in order to improve the cardiovascular outlook. The new PCSK9 inhibitors (evolocumab and arilocumab) are very promising, but, at present, their cost-effectiveness ratios exceed commonly accepted thresholds. For many people with diabetes mellitus and hypertension blood pressure should be <140/90 mmHg, although lower systolic targets (e.g., <130 mmHg) may be appropriate for certain individuals. With the likely exception of LDL-C, it is difficult to define a universal HbA1c and blood pressure target for all patients with type 2 diabetes mellitus. Ultimately, in the face of uncertainty in medicine, the final decision regarding a specific patient is best left to the clinician.

What Are We Learning from the FDA-Mandated Cardiovascular Outcome Studies for New Pharmacological Antidiabetic Agents?

Cardiovascular disease (CVD) is common in patients with diabetes. For these patients, clinicians should seek diabetes treatment that is beneficial rather than harmful in relation to CVD. Until recently, there have been many treatments for hyperglycemia, whose impact on CVD has been controversial. The aims of this review are to evaluate the effectiveness of antihyperglycemic medications on risk factors for CVD and to examine the impact of these drugs on CVD in cardiovascular (CV) outcome trials. In this article, we summarize current knowledge about the impacts of these drugs on various risk factors as well as CV outcomes. We identify the recent emergence of trials with antihyperglycemic agents showing newly discovered CV benefits as well as past trials with antihyperglycemic agents not showing much benefit on CV events. Rather than focusing on treatment strategies, we review the effects of individual drug classes on CV outcomes. We also briefly review goal-driven glycemia reduction and its impact on CVD. We conclude that antihyperglycemic agents are associated with improvement in CV risk factors in patients with diabetes and insulin resistance; in fact, a few drugs reduced CV events in randomized CV outcome trials. Therefore, the use of these drugs is appropriate for reducing glucose and decreasing CV event risk in a select subpopulation.

Glucose-Dependent Insulinotropic Polypeptide Stimulates Osteopontin Expression in the Vasculature via Endothelin-1 and CREB

Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone with extrapancreatic effects beyond glycemic control. Here we demonstrate unexpected effects of GIP signaling in the vasculature. GIP induces the expression of the proatherogenic cytokine osteopontin (OPN) in mouse arteries via local release of endothelin-1 and activation of CREB. Infusion of GIP increases plasma OPN concentrations in healthy individuals. Plasma endothelin-1 and OPN concentrations are positively correlated in patients with critical limb ischemia. Fasting GIP concentrations are higher in individuals with a history of cardiovascular disease (myocardial infarction, stroke) when compared with control subjects. GIP receptor (GIPR) and OPN mRNA levels are higher in carotid endarterectomies from patients with symptoms (stroke, transient ischemic attacks, amaurosis fugax) than in asymptomatic patients, and expression associates with parameters that are characteristic of unstable and inflammatory plaques (increased lipid accumulation, macrophage infiltration, and reduced smooth muscle cell content). While GIPR expression is predominantly endothelial in healthy arteries from humans, mice, rats, and pigs, remarkable upregulation is observed in endothelial and smooth muscle cells upon culture conditions, yielding a "vascular disease-like" phenotype. Moreover, the common variant rs10423928 in the GIPR gene is associated with increased risk of stroke in patients with type 2 diabetes.

Profile of saxagliptin in the treatment of type 2 diabetes: focus on Japanese patients

Saxagliptin is a selective and potent dipeptidyl peptidase (DPP)-4 inhibitor, approved as an adjunct to diet and exercise to improve glycemic control in type 2 diabetes mellitus (T2DM) in the USA on July 2009, and had been launched globally in over 86 countries by September 2013. In patients with T2DM, once-daily administration of saxagliptin before breakfast achieves sustained inhibition of plasma DPP-4 activity and reduction of postprandial hyperglycemia, including after dinner, associated with an increase in plasma glucagon-like peptide-1 levels. This paper reviews the safety and efficacy of saxagliptin in Japanese patients with T2DM. The clinical development study in Japan supported its usefulness for the disease. Saxagliptin 1, 2.5, and 5 mg led to significant improvements in glycated hemoglobin (HbA_1c), and was generally well tolerated. Treatment with saxagliptin 5 mg induced a sustained reduction in HbA_1c over 52 weeks. Long-term combination therapy with saxagliptin and other oral hypoglycemic agents also provided sustained glycemic control and was well tolerated for up to 52 weeks. Saxagliptin as add-on to sulfonylureas or glinides has a tendency to increase hypoglycemia, but not with other oral antidiabetic agents, such as α-glucosidase inhibitors, metformin, or thiazolidinediones. The results of clinical trials have confirmed the long-term efficacy and safety of saxagliptin monotherapy as well as its use as add-on combination therapy, and support its usefulness as a therapeutic agent for T2DM. Saxagliptin has less concern for hypoglycemia and weight gain, which often becomes problematic in routine care of T2DM. Meta-analysis of clinical trials in the USA showed no evidence of increased risk of cardiovascular events associated with saxagliptin, suggesting the superior of saxagliptin in terms of safety. Recently, investigators in the SAVOR-TIMI (Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction) 53 study suggested that DPP-4 inhibition with saxagliptin did not increase or decrease the rate of ischemic events, although the rate of hospitalization for heart failure was increased. Although saxagliptin improves glycemic control, other approaches are necessary to reduce cardiovascular risk in patients with diabetes. Saxagliptin is applicable for various pathological conditions, and is considered to be clinically significant as a new therapeutic option for Japanese patients with T2DM.