Jennifer B. Green

Effect of Sitagliptin on Cardiovascular Outcomes in Type 2 Diabetes

BACKGROUND Data are lacking on the long-term effect on cardiovascular events of adding sitagliptin, a dipeptidyl peptidase 4 inhibitor, to usual care in patients with type 2 diabetes and cardiovascular disease. METHODS In this randomized, double-blind study, we assigned 14,671 patients to add either sitagliptin or placebo to their existing therapy. Open-label use of antihyperglycemic therapy was encouraged as required, aimed at reaching individually appropriate glycemic targets in all patients. To determine whether sitagliptin was noninferior to placebo, we used a relative risk of 1.3 as the marginal upper boundary. The primary cardiovascular outcome was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. RESULTS During a median follow-up of 3.0 years, there was a small difference in glycated hemoglobin levels (least-squares mean difference for sitagliptin vs. placebo, -0.29 percentage points; 95% confidence interval [CI], -0.32 to -0.27). Overall, the primary outcome occurred in 839 patients in the sitagliptin group (11.4%; 4.06 per 100 person-years) and 851 patients in the placebo group (11.6%; 4.17 per 100 person-years). Sitagliptin was noninferior to placebo for the primary composite cardiovascular outcome (hazard ratio, 0.98; 95% CI, 0.88 to 1.09; P<0.001). Rates of hospitalization for heart failure did not differ between the two groups (hazard ratio, 1.00; 95% CI, 0.83 to 1.20; P=0.98). There were no significant between-group differences in rates of acute pancreatitis (P=0.07) or pancreatic cancer (P=0.32). CONCLUSIONS Among patients with type 2 diabetes and established cardiovascular disease, adding sitagliptin to usual care did not appear to increase the risk of major adverse cardiovascular events, hospitalization for heart failure, or other adverse events. (Funded by Merck Sharp & Dohme; TECOS ClinicalTrials.gov number, NCT00790205.).

Rationale, design, and organization of a randomized, controlled Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) in patients with type 2 diabetes and established cardiovascular disease.

Sitagliptin, an oral dipeptidyl peptidase-4 inhibitor, lowers blood glucose when administered as monotherapy or in combination with other antihyperglycemic agents. TECOS will evaluate the effects of adding sitagliptin to usual diabetes care on cardiovascular outcomes and clinical safety. TECOS is a pragmatic, academically run, multinational, randomized, double-blind, placebo-controlled, event-driven trial recruiting approximately 14,000 patients in 38 countries who have type 2 diabetes (T2DM), are at least 50 years old, have cardiovascular disease, and have an hemoglobin A1c value between 6.5% and 8.0%. Eligible participants will be receiving stable mono- or dual therapy with metformin, sulfonylurea, or pioglitazone, or insulin alone or in combination with metformin. Randomization is 1:1 to double-blind sitagliptin or matching placebo, in addition to existing therapy in a usual care setting. Follow-up occurs at 4-month intervals in year 1 and then twice yearly until 1300 confirmed primary end points have occurred. Glycemic equipoise between randomized groups is a desired aim. The primary composite cardiovascular endpoint is time to the first occurrence of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina, with cardiovascular events adjudicated by an independent committee blinded to study therapy. TECOS is a pragmatic-design cardiovascular outcome trial assessing the cardiovascular effects of sitagliptin when added to usual T2DM management.

Association Between Sitagliptin Use and Heart Failure Hospitalization and Related Outcomes in Type 2 Diabetes Mellitus: Secondary Analysis of a Randomized Clinical Trial.

IMPORTANCE Previous trial results have suggested that dipeptidyl peptidase 4 inhibitor (DPP4i) use might increase heart failure (HF) risk in type 2 diabetes mellitus (T2DM). The DPP4i sitagliptin has been shown to be noninferior to placebo with regard to primary and secondary composite atherosclerotic cardiovascular (CV) outcomes in the Trial Evaluating Cardiovascular Outcomes With Sitagliptin (TECOS). OBJECTIVE To assess the association of sitagliptin use with hospitalization for HF (hHF) and related outcomes. DESIGN, SETTING, AND PARTICIPANTS TECOS was a randomized, double-blind, placebo-controlled study evaluating the CV safety of sitagliptin vs placebo, each added to usual antihyperglycemic therapy and CV care among patients with T2DM and prevalent atherosclerotic vascular disease. The median follow-up was 2.9 years. The setting was 673 sites in 38 countries. Participants included 14 671 patients with T2DM and atherosclerotic vascular disease. The study dates were December 2008 through March 2015. INTERVENTIONS Patients were randomized to sitagliptin vs placebo added to standard care. MAIN OUTCOMES AND MEASURES Prespecified secondary analyses compared the effect on hHF, hHF or CV death, and hHF or all-cause death composite outcomes overall and in prespecified subgroups. Supportive analyses included total hHF events (first plus recurrent) and post-hHF death. Meta-analyses evaluated DPP4i effects on hHF and on hHF or CV death. RESULTS Of 14 671 patients, 7332 were randomized to sitagliptin and 7339 to placebo. Hospitalization for HF occurred in 3.1% (n = 228) and 3.1% (n = 229) of the sitagliptin and placebo groups, respectively (unadjusted hazard ratio, 1.00; 95% CI, 0.83-1.19). There was also no difference in total hHF events between the sitagliptin (n = 345) and placebo (n = 347) groups (unadjusted hazard ratio, 1.00; 95% CI, 0.80-1.25). Post-hHF all-cause death was similar in the sitagliptin and placebo groups (29.8% vs 28.8%, respectively), as was CV death (22.4% vs 23.1%, respectively). No heterogeneity for the effect of sitagliptin on hHF was observed in subgroup analyses across 21 factors (P > .10 for all interactions). Meta-analysis of the hHF results from the 3 reported DPP4i CV outcomes trials revealed moderate heterogeneity (I2 = 44.9, P = .16). CONCLUSIONS AND RELEVANCE Sitagliptin use does not affect the risk for hHF in T2DM, both overall and among high-risk patient subgroups. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00790205.

Intensive Glycemic Control Is Not Associated With Fractures or Falls in the ACCORD Randomized Trial

OBJECTIVE Older adults with type 2 diabetes are at high risk of fractures and falls, but the effect of glycemic control on these outcomes is unknown. To determine the effect of intensive versus standard glycemic control, we assessed fractures and falls as outcomes in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) randomized trial. RESEARCH DESIGN AND METHODS ACCORD participants were randomized to intensive or standard glycemia strategies, with an achieved median A1C of 6.4 and 7.5%, respectively. In the ACCORD BONE ancillary study, fractures were assessed at 54 of the 77 ACCORD clinical sites that included 7,287 of the 10,251 ACCORD participants. At annual visits, 6,782 participants were asked about falls in the previous year. RESULTS During an average follow-up of 3.8 (SD 1.3) years, 198 of 3,655 participants in the intensive glycemia and 189 of 3,632 participants in the standard glycemia group experienced at least one nonspine fracture. The average rate of first nonspine fracture was 13.9 and 13.3 per 1,000 person-years in the intensive and standard groups, respectively (hazard ratio 1.04 [95% CI 0.86–1.27]). During an average follow-up of 2.0 years, 1,122 of 3,364 intensive- and 1,133 of 3,418 standard-therapy participants reported at least one fall. The average rate of falls was 60.8 and 55.3 per 100 person-years in the intensive and standard glycemia groups, respectively (1.10 [0.84–1.43]). CONCLUSIONS Compared with standard glycemia, intensive glycemia did not increase or decrease fracture or fall risk in ACCORD.

Baseline Characteristics of Patients with Diabetes and Coronary Artery Disease Enrolled in the BARI 2D Trial

BACKGROUND The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial was undertaken to determine whether early revascularization intervention is superior to deferred intervention in the presence of aggressive medical therapy and whether antidiabetes regimens targeting insulin sensitivity are more or less effective than regimens targeting insulin provision in reducing cardiovascular events among patients with type 2 diabetes mellitus and stable coronary artery disease (CAD). METHODS The BARI 2D trial is a National Institutes of Health-sponsored randomized clinical trial with a 2 x 2 factorial design. Between 2001 and 2005, 49 clinical sites in North America, South America, and Europe randomized 2,368 patients. At baseline, the trial collected data on clinical history, symptoms, and medications along with centralized evaluations of angiograms, electrocardiograms, and blood and urine specimens. RESULTS Most of the BARI 2D patients were referred from the cardiac catheterization laboratory (54%) or cardiology clinic (27%). Of the randomized participants, 30% were women, 34% were minorities, 61% had angina, and 67% had multiregion CAD. Moreover, 29% had been treated with insulin, 58% had hemoglobin A(1c) >7.0%, 41% had low-density lipoprotein cholesterol >or=100 mg/dL, 52% had blood pressure >130/80 mm Hg, and 56% had body mass index >or=30 kg/m(2). CONCLUSIONS Baseline characteristics in BARI 2D are well balanced between the randomized treatment groups, and the clinical profile of the study cohort is representative of the target population. As a result, the BARI 2D clinical trial is in an excellent position to evaluate alternative treatment approaches for diabetes and CAD.

New combination treatments in the management of diabetes: focus on sitagliptin – metformin

Type 2 diabetes mellitus is an increasingly prevalent condition worldwide. The complications of this disease are known to significantly increase the morbidity and mortality of those affected, resulting in substantial direct and indirect costs. Although good glycemic control has been shown to reduce the incidence and progression of diabetes-related microvascular complications, blood glucose levels are not adequately controlled in most individuals with diabetes. The reasons for this are many, and include issues such as poor adherence to complex medication regimes; costs of prescribed therapies; and the failure of traditionally prescribed medications to preserve beta cell function over time. However, our armamentarium of glucose-lowering drugs has expanded recently with the development of medications that act via the incretin pathway. Sitagliptin, the first commercially available dipeptidyl peptidase-4 inhibitor, inhibits the metabolism and inactivation of the incretin hormones GLP-1 and GIP. The subsequent elevation in levels of these hormones and associated prolongation of their actions has been shown to increase insulin secretion and suppress glucagon secretion in a glucose-appropriate fashion. Sitagliptin therapy in individuals with type 2 diabetes has been found to lower significantly hemoglobin A1c (Hb1c) levels with a minimum of adverse side effects such as weight gain or hypoglycemia. Use of sitagliptin in conjunction with the insulin-sensitizing medication metformin has been shown to decrease HbA1c levels more significantly than does either drug alone. This combination of medications is generally well tolerated, with no adverse effects on weight and a very low likelihood of treatment-related hypoglycemia. Use of both drugs will positively affect many of the underlying metabolic abnormalities associated with type 2 diabetes, including the disordered secretion of insulin and glucagon as well as impaired sensitivity to insulin which are known to accompany this disease. Animal studies also suggest that dipeptidyl peptidase-4 inhibitor treatment may help to preserve beta cell mass; however, it is unclear at present whether or not this will prove to be the case in humans.

The potential role and rationale for treatment of heart failure with sodium–glucose co‐transporter 2 inhibitors

Heart failure (HF) and type 2 diabetes mellitus (T2DM) are both growing public health concerns contributing to major medical and economic burdens to society. T2DM increases the risk of HF, frequently occurs concomitantly with HF, and worsens the prognosis of HF. Several anti‐hyperglycaemic medications have been associated with a concern for worse HF outcomes. More recently, the results of the EMPA‐REG OUTCOME trial showed that the sodium–glucose co‐transporter 2 (SGLT2) inhibitor empagliflozin was associated with a pronounced and precocious 38% reduction in cardiovascular mortality in subjects with T2DM and established cardiovascular disease [Correction added on 8 September 2017, after first online publication: “32%” in the previous sentence was corrected to “38%”]. These benefits were more related to a reduction in incident HF events rather than to ischaemic vascular endpoints. Several mechanisms have been put forward to explain these benefits, which also raise the possibility of using these drugs as therapies not only in the prevention of HF, but also for the treatment of patients with established HF regardless of the presence or absence of diabetes. Several large trials are currently exploring this postulate.

Cardiovascular Outcomes Trials in Type 2 Diabetes: Where Do We Go From Here? Reflections From a Diabetes Care Editors’ Expert Forum

In December 2008, the U.S. Food and Drug Administration issued guidance to the pharmaceutical industry setting new expectations for the development of antidiabetes drugs for type 2 diabetes. This guidance expanded the scope and cost of research necessary for approval of such drugs by mandating long-term cardiovascular outcomes trials (CVOTs) for safety. Since 2008, 9 CVOTs have been reported, 13 are under way, and 4 have been terminated. Reassuringly, each of the completed trials demonstrated the noninferiority of their respective drugs to placebo for their primary cardiovascular (CV) composite end point. Notably, four additionally provided evidence of CV benefit in the form of significant decreases in the primary CV composite end point, two suggested reductions in CV death, and three suggested reductions in all-cause mortality. Although these trials have yielded much valuable information, whether that information justifies the investment of time and resources is controversial. In June 2016, a Diabetes Care Editors’ Expert Forum convened to review the processes and challenges of CVOTs, discuss the benefits and limitations of their current designs, and weigh the merits of modifications that might improve the efficiency and clinical value of future trials. Discussion and analysis continued with the CVOT trial results released in June 2017 at the American Diabetes Association’s Scientific Sessions and in September 2017 at the European Association for the Study of Diabetes scientific meeting. This article summarizes the discussion and findings to date.

Enhanced fitness: a randomized controlled trial of the effects of home-based physical activity counseling on glycemic control in older adults with prediabetes mellitus.

To determine whether a home‐based multicomponent physical activity counseling (PAC) intervention is effective in reducing glycemic measures in older outpatients with prediabetes mellitus.

Regional, age and sex differences in baseline characteristics of patients enrolled in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS)

To report baseline characteristics and cardiovascular (CV) risk management by region, age, sex and CV event type for 14 724 participants in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), a randomized, double‐blind, placebo‐controlled trial exploring whether sitagliptin added to usual type 2 diabetes (T2DM) care affects time to first event in the composite endpoint of CV death, non‐fatal myocardial infarction (MI), non‐fatal stroke or unstable angina hospitalization.