Baseline characteristics of the patient population in the Saxagliptin Assessment of Vascular Outcomes Recorded in patients with diabetes mellitus (SAVOR)-TIMI 53 trial

Cardiovascular and renal safety of metformin in patients with diabetes and moderate or severe chronic kidney disease: Observations from the EXSCEL and SAVOR-TIMI 53 cardiovascular outcomes trials

AIM

To provide evidence on the cardiovascular and renal safety of metformin in chronic kidney disease (CKD) stages 3 to 4.

MATERIALS AND METHODS

This post hoc analysis compared participants with an estimated glomerular filtration rate (eGFR) of 15 to 59 mL/min/1.73m² in the Exenatide Study of Cardiovascular Event Lowering (EXSCEL) and the Saxagliptin and Cardiovascular Outcomes in Patients With Type 2 Diabetes Mellitus (SAVOR-TIMI 53) trials taking metformin, with those not exposed to metformin during these trials, using a propensity-matching approach. Adjusted Cox proportional hazards models were used to assess risk of major adverse cardiovascular events (MACE) and all-cause mortality (ACM). Metformin effect on eGFR slope was calculated using a mixed-model repeated measures analysis, and the number of lactic acidosis events was tabulated.

RESULTS

No strong trend for lower metformin doses with lower eGFR values was observed in either the EXSCEL or SAVOR-TIMI 53 trials. In the 1745 metformin-using participants matched to non-metformin users, metformin had neutral effects on MACE (hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.76-1.08; P = 0.28) and ACM (HR 0.86, 95% CI 0.70-1.07; P = 0.18), with no interaction by CKD stage, or with use of exenatide or saxagliptin. An improvement in eGFR slope was observed with metformin in the CKD stage 3B cohort in SAVOR-TIMI 53, but not in other groups.

CONCLUSIONS

This analysis of participants with CKD stages 3 to 4 from two cardiovascular outcomes trials supports the cardiorenal safety of metformin, but does not suggest a consistent benefit on MACE, ACM, or eGFR slope across this population.

Effects of anti-diabetes medications on cardiovascular and kidney outcomes in Asian patients with type 2 diabetes: a rapid evidence assessment and narrative synthesis

BACKGROUND

The cardiovascular and kidney safety of glucose-lowering drugs is a key concern in type 2 diabetes (T2D). We evaluated cardiorenal outcomes with glucose-lowering drugs in Asian patients, who comprise over half of T2D cases globally.

RESEARCH DESIGN AND METHODS

A rapid evidence assessment was conducted for phase III or IV, double-blind, randomized clinical trials of glucose-lowering drugs reporting cardiovascular or kidney outcomes for Asian T2D patients (Embase, Medline, Cochrane Library databases: 1 January 2008-14 June 2020).

RESULTS

Fifty-four publications reported exploratory data for Asians from 18 trials of dipeptidyl peptidase-4 (DPP-4) inhibitors, sodium-glucose co-transporter-2 (SGLT2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and insulin analogs. SGLT2 inhibitors and several GLP-1 receptor agonists were associated with reduced cardiovascular risk in Asian T2D patients, while DPP-4 inhibitors exhibited cardiovascular safety. SGLT2 inhibitors also appeared to reduce renal risk; however, kidney outcomes were lacking for DPP-4 inhibitors other than linagliptin and GLP-1 receptor agonists in Asian patients. Insulin data were inconclusive as the only trial conducted used different types of insulin as both treatment and comparator.

CONCLUSIONS

Cardiorenal outcomes with glucose-lowering drugs in Asian T2D patients were similar to outcomes in the overall multinational cohorts of these trials. DPP-4 inhibitors appear to demonstrate cardiovascular safety in Asians, while SGLT2 inhibitors and some GLP-1 receptor agonists may reduce cardiorenal and cardiovascular risk, respectively.

Optimizing the treatment of newly diagnosed type 2 diabetes mellitus with combination of dipeptidyl peptidase-4 inhibitors and metformin: An expert opinion

The expanding burden of Type 2 Diabetes Mellitus (T2DM) in today's world, with respect to incidence, prevalence, and cost incurred, is an existential risk to society. Various guidelines recommend individualization of treatment. This expert opinion aims to review the recent evidences and reach a consensus on the preferable combination therapy for use in newly diagnosed Indian T2DM patients with HbA_1C >7.5%. The core committee included seventeen diabetes specialists. Three statements were developed, discussed, and rated by specialists and recommendations were noted. Specialists were requested to rate the statements using a 9-point Likert's scale with score of 1 being “Strongly Disagree” and 9 being “Strongly Agree”. Statement-specific scores of all the specialists were added and mean score of ≥7.00 was considered to have achieved a consensus. Statements used to meet the consensus were: Statement 1. Majority of newly-diagnosed Indian diabetics have HbA_1C >7.5%; Statement 2. Patients with HbA_1C >7.5% may be initiated with dual therapy of dipeptidyl peptidase-4 inhibitors (DPP4Is) + Metformin; and Statement 3. In Indian patients with HbA_1C >7.5% at diagnosis, DPP4Is + Metformin may be considered as a first-line therapy. Literature review revealed that HbA_1C level at the time of diagnosis in majority of Indian T2DM patients is >7.5%. Consensus was reached that dual anti-diabetic therapy should be initiated in patients with HbA_1C >7.5%. DPP4Is + Metformin is the preferred cost-effective option and may be considered as a first-line therapy in Indian T2DM patients with HbA_1C >7.5% at diagnosis.

Dipeptidyl peptidase-4 inhibitors as new tools for cardioprotection

Previous studies have demonstrated that individuals with type 2 diabetes mellitus (T2DM) have a two- to fourfold propensity to develop cardiovascular disease (CVD) than nondiabetic population, making CVD a major cause of death and disability among people with T2DM. The present treatment options for management of diabetes propose the earlier and more frequent use of new antidiabetic drugs that could control hyperglycaemia and reduce the risk of cardiovascular events. Findings from basic and clinical studies pointed out DPP-4 inhibitors as potentially novel pharmacological tools for cardioprotection. There is a growing body of evidence suggesting that these drugs have ability to protect the heart against acute ischaemia-reperfusion injury as well as reduce the size of infarction. Consequently, the prevention of degradation of the incretin hormones by the use of DPP-4 inhibitors represents a new strategy in the treatment of patients with T2DM and reduction of CV events in these patients. Here, we discuss the cardioprotective effects of DPP-4 inhibitors as well as proposed pathways that these hypoglycaemic agents target in the cardiovascular system.

Pleiotropic effects of anti-diabetic drugs: A comprehensive review

Diabetes mellitus characterized by hyperglycaemia presents an array of comorbidities such as cardiovascular and renal failure, dyslipidemia, and cognitive impairments. Populations above the age of 60 are in an urgent need of effective therapies to deal with the complications associated with diabetes mellitus. Widely used anti-diabetic drugs have good safety profiles and multiple reports indicate their pleiotropic effects in diabetic patients or models. This review has been written with the objective of identifying the widely-marketed anti-diabetic drugs which can be efficiently repurposed for the treatment of other diseases or disorders. It is an updated, comprehensive review, describing the protective role of various classes of anti-diabetic drugs in mitigating the macro and micro vascular complications of diabetes mellitus, and differentiating these drugs on the basis of their mode of action. Notably, metformin, the anti-diabetic drug most commonly explored for cancer therapy, has also exhibited some antimicrobial effects. Unlike class specific effects, few instances of drug specific effects in managing cardiovascular complications have also been reported. A major drawback is that the pleiotropic effects of anti-diabetic drugs have been mostly investigated only in diabetic patients. Thus, for effective repurposing, more clinical trials devoted to analyse the effects of anti-diabetic drugs in patients irrespective of their diabetic condition, are required.

Metformin Use and Clinical Outcomes Among Patients With Diabetes Mellitus With or Without Heart Failure or Kidney Dysfunction

Background:

Metformin is first-line therapy for type 2 diabetes mellitus, although its effects on the cardiovascular system are unproved.

Methods:

In this post hoc analysis, patients in SAVOR-TIMI 53 (Saxagliptin and Cardiovascular Outcomes in Patients With Type 2 Diabetes Mellitus) with baseline biomarker samples (n=12 156) were classified as ever versus never taking metformin during the trial period. Associations between metformin exposure and outcomes were estimated with inverse probability of treatment weighting Cox modeling for the composite end point of cardiovascular death, myocardial infarction, or ischemic stroke, as well as cardiovascular death and all-cause mortality, with biomarkers included as covariates. Additional sensitivity analyses included propensity score matching and Cox multivariable models.

Results:

Of the 12 156 patients with baseline biomarker samples, 8971 (74%) had metformin exposure, 1611 (13%) had prior heart failure, and 1332 (11%) had at least moderate chronic kidney disease (estimated glomerular filtration rate ≤45 mL·min −1 ·1.73 m −2 ). Metformin use was associated with no difference in risk for the composite end point (hazard ratio for inverse probability of treatment weighting, 0.92 [95% CI, 0.76–1.11]) but lower risk of all-cause mortality (hazard ratio for inverse probability of treatment weighting, 0.75 [95% CI, 0.59–0.95]). There was no significant relationship between metformin use and these end points in patients with prior heart failure or moderate to severe chronic kidney disease.

Conclusions:

In a cohort of 12 156 patients with type 2 diabetes mellitus and high cardiovascular risk, metformin use was associated with lower rates of all-cause mortality, including after adjustment for clinical variables and biomarkers, but not lower rates of the composite end point of cardiovascular death, myocardial infarction, or ischemic stroke. This association was most apparent in patients without prior heart failure or moderate to severe chronic kidney disease.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT01107886.

Prevalence and Outcomes of Polyvascular (Coronary, Peripheral, or Cerebrovascular) Disease in Patients With Diabetes Mellitus (From the SAVOR-TIMI 53 Trial)

We sought to assess the prevalence of polyvascular disease in patients with type 2 diabetes mellitus (T2DM) and its impact on ischemic events. Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus (SAVOR)-Thrombolysis in Myocardial Infarction (TIMI) 53, a large contemporary, randomized trial, evaluated the effect of saxagliptin versus placebo in 16,492 patients with T2DM and a history of or at risk for cardiovascular (CV) events. Polyvascular disease was defined as a history of clinical events involving 2 or more vascular beds (coronary, peripheral, or cerebrovascular system) at the time of randomization. The primary composite endpoint of CV death, myocardial infarction, or ischemic stroke was compared according to the number of diseased arterial beds. At the time of randomization, 3,667 (22.2%) patients had risk factors for CV events; 11,423 (69.3%) had established 1 arterial bed disease; 1,298 (7.9%) had 2 bed disease; and 104 (0.6%) had 3 bed disease. Compared with diabetic patients with no established atherosclerosis, the adjusted hazard ratio for the composite primary end point in 1, 2, or 3 diseased beds was 1.95, 3.54, and 4.64, respectively (trend p < 0.0001). The adjusted risk for overall mortality increased in a similar stepwise fashion from 1.47 to 2.33 to 3.12, respectively (trend p = 0.0001) with each additional diseased arterial territory. In conclusion, in patients with confirmed atherosclerosis enrolled in SAVOR-TIMI 53, 11% had polyvascular disease; and compared with diabetic patients with single bed disease, the risk of ischemic events and overall mortality was substantially higher in patients with T2DM and polyvascular disease.

Clinical Use of DPP-4 Inhibitors

DPP-4 inhibitors were introduced for the treatment of type 2 diabetes in 2006. They stimulate insulin secretion and inhibit glucagon secretion by elevating endogenous GLP-1 concentrations without an intrinsic hypoglycaemia risk. Their efficacy potential to lower HbA1c is in the range between 0.5 and 1.0% and their safety profile is favorable. DPP-4 inhibitors are body weight neutral and they have demonstrated cardiovascular safety. Most compounds can be used in impaired renal function. Guidelines suggest the additional use of DPP-4 inhibitors after metformin failure in patients that do not require antidiabetic therapy with proven cardiovascular benefit. Recently, DPP-4 inhibitors have increasingly replaced sulfonylureas as second line therapy after metformin failure and many metformin/DPP-4 inhibitor fixed dose combinations are available. In later stages of type 2 diabetes, DPP-4 inhibitors are also recommended in the guidelines in triple therapies with metformin and SGLT-2 inhibitors or with metformin and insulin. A treatment with DPP-4 inhibitors should be stopped when GLP-1 receptor agonists are used. DPP-4 inhibitors can be used as monotherapy when metformin is contraindicated or not tolerated. Some studies have shown value of initial metformin-DPP-4 inhibitor combination therapy in special populations. This article gives an overview on the clinical use of DPP-4 inhibitors.

Managing Diabetes and Preventing Heart Disease: Have We Found a Safe and Effective Agent?

OBJECTIVE

While improving glycemic control with antihyperglycemics has been demonstrated to reduce microvascular complications, the benefits of reduction in cardiovascular diseases (CVDs) have not been demonstrated with older agents. This article reviews current evidence of the CV outcomes of newer antihyperglycemics approved since 2008.

DATA SOURCES

Peer-reviewed articles were identified from MEDLINE (1966 to October 31, 2018) using search terms exenatide, liraglutide, lixisenatide, dulaglutide, semaglutide, alogliptin, linagliptin, saxagliptin, sitagliptin, canagliflozin, dapagliflozin, empagliflozin, mortality, myocardial infarction (MI), heart failure (HF), and stroke.

STUDY SELECTION AND DATA EXTRACTION

A total of 12 pertinent double-blinded randomized controlled trials were included.

DATA SYNTHESIS

Liraglutide, empagliflozin, and canagliflozin have been shown in patients with CV diseases and high risk of developing CV disease to be superior to placebo in improving CV outcomes. Saxagliptin and alogliptin have both been demonstrated to increase HF hospitalization, whereas sitagliptin has not. Relevance to Patient Care and Clinical Practice: In contrast to older-generation antihyperglycemics, selected new antihyperglycemic agents have been shown to be superior to placebo in improving CV outcomes. Clinicians may now be able to provide high-risk patients agents that not only help in providing glycemic control, but also prevent both macrovascular and microvascular complications.

CONCLUSION

Liraglutide, empagliflozin, and canagliflozin have been shown to be superior to placebo in improving CV outcomes. However, there are differences among agents in terms of HF and peripheral arterial disease outcomes. Future studies should focus on evaluating other clinical CV outcomes in patients without existing CVD and perhaps single drug regimens for diabetes.

Insulin and glucose-lowering agents for treating people with diabetes and chronic kidney disease

BACKGROUND

Diabetes is the commonest cause of chronic kidney disease (CKD). Both conditions commonly co-exist. Glucometabolic changes and concurrent dialysis in diabetes and CKD make glucose-lowering challenging, increasing the risk of hypoglycaemia. Glucose-lowering agents have been mainly studied in people with near-normal kidney function. It is important to characterise existing knowledge of glucose-lowering agents in CKD to guide treatment.

OBJECTIVES

To examine the efficacy and safety of insulin and other pharmacological interventions for lowering glucose levels in people with diabetes and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 12 February 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs looking at head-to-head comparisons of active regimens of glucose-lowering therapy or active regimen compared with placebo/standard care in people with diabetes and CKD (estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2) were eligible.

DATA COLLECTION AND ANALYSIS

Four authors independently assessed study eligibility, risk of bias, and quality of data and performed data extraction. Continuous outcomes were expressed as post-treatment mean differences (MD). Adverse events were expressed as post-treatment absolute risk differences (RD). Dichotomous clinical outcomes were presented as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Forty-four studies (128 records, 13,036 participants) were included. Nine studies compared sodium glucose co-transporter-2 (SGLT2) inhibitors to placebo; 13 studies compared dipeptidyl peptidase-4 (DPP-4) inhibitors to placebo; 2 studies compared glucagon-like peptide-1 (GLP-1) agonists to placebo; 8 studies compared glitazones to no glitazone treatment; 1 study compared glinide to no glinide treatment; and 4 studies compared different types, doses or modes of administration of insulin. In addition, 2 studies compared sitagliptin to glipizide; and 1 study compared each of sitagliptin to insulin, glitazars to pioglitazone, vildagliptin to sitagliptin, linagliptin to voglibose, and albiglutide to sitagliptin. Most studies had a high risk of bias due to funding and attrition bias, and an unclear risk of detection bias.Compared to placebo, SGLT2 inhibitors probably reduce HbA1c (7 studies, 1092 participants: MD -0.29%, -0.38 to -0.19 (-3.2 mmol/mol, -4.2 to -2.2); I2 = 0%), fasting blood glucose (FBG) (5 studies, 855 participants: MD -0.48 mmol/L, -0.78 to -0.19; I2 = 0%), systolic blood pressure (BP) (7 studies, 1198 participants: MD -4.68 mmHg, -6.69 to -2.68; I2 = 40%), diastolic BP (6 studies, 1142 participants: MD -1.72 mmHg, -2.77 to -0.66; I2 = 0%), heart failure (3 studies, 2519 participants: RR 0.59, 0.41 to 0.87; I2 = 0%), and hyperkalaemia (4 studies, 2788 participants: RR 0.58, 0.42 to 0.81; I2 = 0%); but probably increase genital infections (7 studies, 3086 participants: RR 2.50, 1.52 to 4.11; I2 = 0%), and creatinine (4 studies, 848 participants: MD 3.82 μmol/L, 1.45 to 6.19; I2 = 16%) (all effects of moderate certainty evidence). SGLT2 inhibitors may reduce weight (5 studies, 1029 participants: MD -1.41 kg, -1.8 to -1.02; I2 = 28%) and albuminuria (MD -8.14 mg/mmol creatinine, -14.51 to -1.77; I2 = 11%; low certainty evidence). SGLT2 inhibitors may have little or no effect on the risk of cardiovascular death, hypoglycaemia, acute kidney injury (AKI), and urinary tract infection (low certainty evidence). It is uncertain whether SGLT2 inhibitors have any effect on death, end-stage kidney disease (ESKD), hypovolaemia, fractures, diabetic ketoacidosis, or discontinuation due to adverse effects (very low certainty evidence).Compared to placebo, DPP-4 inhibitors may reduce HbA1c (7 studies, 867 participants: MD -0.62%, -0.85 to -0.39 (-6.8 mmol/mol, -9.3 to -4.3); I2 = 59%) but may have little or no effect on FBG (low certainty evidence). DPP-4 inhibitors probably have little or no effect on cardiovascular death (2 studies, 5897 participants: RR 0.93, 0.77 to 1.11; I2 = 0%) and weight (2 studies, 210 participants: MD 0.16 kg, -0.58 to 0.90; I2 = 29%; moderate certainty evidence). Compared to placebo, DPP-4 inhibitors may have little or no effect on heart failure, upper respiratory tract infections, and liver impairment (low certainty evidence). Compared to placebo, it is uncertain whether DPP-4 inhibitors have any effect on eGFR, hypoglycaemia, pancreatitis, pancreatic cancer, or discontinuation due to adverse effects (very low certainty evidence).Compared to placebo, GLP-1 agonists probably reduce HbA1c (7 studies, 867 participants: MD -0.53%, -1.01 to -0.06 (-5.8 mmol/mol, -11.0 to -0.7); I2 = 41%; moderate certainty evidence) and may reduce weight (low certainty evidence). GLP-1 agonists may have little or no effect on eGFR, hypoglycaemia, or discontinuation due to adverse effects (low certainty evidence). It is uncertain whether GLP-1 agonists reduce FBG, increase gastrointestinal symptoms, or affect the risk of pancreatitis (very low certainty evidence).Compared to placebo, it is uncertain whether glitazones have any effect on HbA1c, FBG, death, weight, and risk of hypoglycaemia (very low certainty evidence).Compared to glipizide, sitagliptin probably reduces hypoglycaemia (2 studies, 551 participants: RR 0.40, 0.23 to 0.69; I2 = 0%; moderate certainty evidence). Compared to glipizide, sitagliptin may have had little or no effect on HbA1c, FBG, weight, and eGFR (low certainty evidence). Compared to glipizide, it is uncertain if sitagliptin has any effect on death or discontinuation due to adverse effects (very low certainty).For types, dosages or modes of administration of insulin and other head-to-head comparisons only individual studies were available so no conclusions could be made.

AUTHORS' CONCLUSIONS

Evidence concerning the efficacy and safety of glucose-lowering agents in diabetes and CKD is limited. SGLT2 inhibitors and GLP-1 agonists are probably efficacious for glucose-lowering and DPP-4 inhibitors may be efficacious for glucose-lowering. Additionally, SGLT2 inhibitors probably reduce BP, heart failure, and hyperkalaemia but increase genital infections, and slightly increase creatinine. The safety profile for GLP-1 agonists is uncertain. No further conclusions could be made for the other classes of glucose-lowering agents including insulin. More high quality studies are required to help guide therapeutic choice for glucose-lowering in diabetes and CKD.

Blood pressure and cardiovascular outcomes in patients with diabetes and high cardiovascular risk

Aims

Optimal blood pressure for prevention of cardiovascular (CV) events in patients with Type 2 diabetes mellitus (T2DM) remains uncertain and there is concern for increased risk with low diastolic blood pressure (DBP). This study analysed the association between blood pressure and CV outcomes in high-risk patients with T2DM.

Methods and results

Patients with T2DM and elevated CV risk were enrolled in the Saxagliptin Assessment of Vascular Outcomes Recorded in patients with diabetes mellitus-Thrombolysis in Myocardial Infarction 53 trial. Cardiovascular outcomes were compared in the biomarker subgroup (n = 12 175) after stratification by baseline systolic blood pressure (SBP) and DBP. Adjusted risk was calculated by blood pressure stratum using clinical covariates plus N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponin-T (hsTnT). Trends were tested using linear and quadratic models. Adjusted risk of the composite endpoint of CV death, myocardial infarction (MI), or ischaemic stroke showed U-shaped relationships with baseline SBP and DBP (Pquadratic ≤ 0.01) with nadirs at SBP 130-140 or DBP 80-90 mmHg. Diastolic blood pressure <60 mmHg was associated with increased risk of MI (adjusted hazard ratio 2.30; 95% confidence interval 1.50-3.53) relative to DBP 80-90 mmHg. Adjusted odds of hsTnT concentration ≥14 ng/L showed U-shaped relationships with SBP and DBP (Pquadratic ≤ 0.01). The relationships between low DBP, elevated hsTnT, and increased MI remained after exclusion of patients with prior heart failure or NT-proBNP >median, suggesting that the relationship was not due to confounding from diagnosed or undiagnosed heart failure.

Conclusions

In patients with diabetes and elevated CV risk, even after extensive adjustment for underlying disease burden, there was a persistent association for low DBP with subclinical myocardial injury and risk of MI.

Risk Assessment in Patients With Diabetes With the TIMI Risk Score for Atherothrombotic Disease

OBJECTIVE

Improved risk assessment for patients with type 2 diabetes and elevated cardiovascular (CV) risk is needed. The Thrombolysis in Myocardial Infarction (TIMI) Risk Score for Secondary Prevention (TRS 2°P) predicts a gradient of risk in patients with prior myocardial infarction (MI) but has not been evaluated in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

CV event rates were compared by baseline TRS 2°P in 16,488 patients enrolled in SAVOR-TIMI 53 (Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53) with type 2 diabetes and high CV risk or established CV disease. Calibration was tested in the diabetes cohort from the REACH (REduction of Atherothrombosis for Continued Health) Registry.

RESULTS

TRS 2°P revealed a robust risk gradient for the composite of CV death, MI, and ischemic stroke in the full trial population, with 2-year event rates of 0.9% in the lowest- and 19.8% in the highest-risk groups (P_trend < 0.001). A clear risk gradient was present within the subgroups of all coronary artery disease (CAD), CAD without prior MI, CAD with prior MI, peripheral artery disease, and prior stroke (P_trend < 0.001 for each), with consistent risk relationships across subgroups. The C-statistic (0.71 for CV death and 0.66 for the composite end point) was consistent in each subgroup. There was close calibration with the type 2 diabetes cohort from the REACH Registry (goodness-of-fit P = 0.78).

CONCLUSIONS

The expanded TRS 2°P provides a practical and well-calibrated risk prediction tool for patients with type 2 diabetes.

The cardiovascular effect of incretin-based therapies among type 2 diabetes: a systematic review and network meta-analysis

OBJECTIVE

To evaluate the comparative cardiovascular safety of incretin-based therapies in patients with type 2 diabetes mellitus (T2DM).

METHODS

Medline, Embase, the Cochrane Library and www.clinicaltrials.gov were searched for randomized controlled trials (RCTs) with duration≥12 weeks. Network meta-analysis was performed, followed by subgroup analysis and meta-regression. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of evidence. The outcome of interest was a composite of cardiovascular death, myocardial infarction, stroke and heart failure. Odds ratio (OR) with 95% confidence interval (CI) was calculated as the measure of effect size.

RESULTS

281 RCTs (76.9% double-blinded) with 180,000 patients were included, comparing incretin-based therapies with other six classes of anti-diabetic drugs or placebo. A statistically significant reduction in the risk of cardiovascular events was found in favour of GLP-1RAs when compared with placebo (OR 0.89, 95%CI: 0.80-0.99) and sulfonylurea (OR 0.76, 95%CI: 0.59-0.99), whereas DPP-4 inhibitors showed a neutral effect compared with placebo (OR 0.92, 95%CI: 0.83-1.01).

CONCLUSIONS

Incretin-based therapies show similar cardiovascular risk in comparison with metformin, insulin, thiazolidinediones, alpha-glucosidase inhibitor and sodium-glucose co-transporter 2. GLP-1RA could decrease the risk compared with sulfonylurea or placebo, while DPP-4I appears to have neutral effect on cardiovascular risk.

The cardiovascular safety trials of DPP-4 inhibitors, GLP-1 agonists, and SGLT2 inhibitors

In this paper, we review the results of large, double-blind, placebo-controlled randomized trials mandated by the US Food and Drug Administration to examine the cardiovascular safety of newly-approved antihyperglycemic agents in patients with type 2 diabetes. The cardiovascular effects of dipeptidyl peptidase-4 (DPP-4) inhibitors remain controversial: while these drugs did not reduce or increase the risk of primary, pre-specified composite cardiovascular outcomes, one DPP-4 inhibitor (saxagliptin) increased the risk of hospitalization for heart failure in the overall population; another (alogliptin) demonstrated inconsistent effects on heart failure hospitalization across subgroups of patients, and a third (sitagliptin) demonstrated no effect on heart failure. Evidence for cardiovascular benefits of glucagon-like peptide-1 (GLP-1) agonists has been similarly heterogeneous, with liraglutide and semaglutide reducing the risk of composite cardiovascular outcomes, but lixisenatide having no reduction or increase in cardiovascular risk. The effect of GLP-1 agonists on retinopathy remains a potential concern. In the only completed trial to date to assess a sodium-glucose cotransporter-2 (SGLT2) inhibitor, empagliflozin reduced the risk of composite cardiovascular endpoints, predominantly through its impact on cardiovascular mortality and heart failure hospitalization.

Effect of Saxagliptin on Renal Outcomes in the SAVOR-TIMI 53 Trial

OBJECTIVE

Dipeptidyl peptidase 4 inhibitors may have a protective effect in diabetic nephropathy.

RESEARCH DESIGN AND METHODS

We studied renal outcomes of 16,492 patients with type 2 diabetes, randomized to saxagliptin versus placebo and followed for a median of 2.1 years in the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53 (SAVOR-TIMI 53) trial.

RESULTS

At baseline, 9,696 (58.8%) subjects had normoalbuminuria (albumin/creatinine ratio [ACR] <30 mg/g), 4,426 (26.8%) had microalbuminuria (ACR 30-300 mg/g), and 1,638 (9.9%) had macroalbuminuria (ACR >300 mg/g). Treatment with saxagliptin was associated with improvement in and/or less deterioration in ACR categories from baseline to end of trial (EOT) (P = 0.021, P < 0.001, and P = 0.049 for individuals with baseline normoalbuminuria, microalbuminuria, and macroalbuminuria, respectively). At 2 years, the difference in mean ACR change between saxagliptin and placebo arms was -19.3 mg/g (P = 0.033) for estimated glomerular filtration rate (eGFR) >50 mL/min/body surface area per 1.73 m² (BSA), -105 mg/g (P = 0.011) for 50 ≥ eGFR ≥ 30 mL/min/BSA, and -245.2 mg/g (P = 0.086) for eGFR <30 mL/min/BSA. Analyzing ACR as a continuous variable showed reduction in ACR with saxagliptin (1 year, P < 0.0001; 2 years, P = 0.0143; and EOT, P = 0.0158). The change in ACR did not correlate with that in HbA_1c (r = 0.041, 0.052, and 0.036; 1 year, 2 years, and EOT, respectively). The change in eGFR was similar in the saxagliptin and placebo groups. Safety renal outcomes, including doubling of serum creatinine, initiation of chronic dialysis, renal transplantation, or serum creatinine >6.0 mg/dL, were similar as well.

CONCLUSIONS

Treatment with saxagliptin improved ACR, even in the normoalbuminuric range, without affecting eGFR. The beneficial effect of saxagliptin on albuminuria could not be explained by its effect on glycemic control.

Predisposing Factors for Any and Major Hypoglycemia With Saxagliptin Versus Placebo and Overall: Analysis From the SAVOR-TIMI 53 Trial

OBJECTIVE

To analyze the impact of adding saxagliptin versus placebo on the risk for hypoglycemia and to identify predictors of any and major hypoglycemia in patients with type 2 diabetes included in the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53 (SAVOR-TIMI 53) study.

RESEARCH DESIGN AND METHODS

Patients with type 2 diabetes (n = 16,492) were randomized to saxagliptin or placebo and followed for a median of 2.1 years. Associations between any hypoglycemia (symptomatic or glucose measurement <54 mg/dL) or major hypoglycemia (requiring extended assistance) and patient characteristics overall and by treatment allocation were studied.

RESULTS

At least one hypoglycemic event was reported in 16.6% of patients, and 1.9% reported at least one major event. Patients allocated to saxagliptin versus placebo experienced higher rates of any (hazard ratio [HR] 1.16 [95% CI 1.08, 1.25]; P < 0.001) or major (HR 1.26 [1.01, 1.58]; P = 0.038) hypoglycemia. Hypoglycemia rates (any or major) were increased with saxagliptin in patients taking sulfonylureas (SURs) but not in those taking insulin. Rates were increased with saxagliptin in those with baseline HbA1c ≤7.0% and not in those with baseline HbA1c >7.0%. Multivariate analysis of the overall population revealed that independent predictors of any hypoglycemia were as follows: allocation to saxagliptin, long duration of diabetes, increased updated HbA1c, macroalbuminuria, moderate renal failure, SUR use, and insulin use. Predictors of major hypoglycemia were allocation to saxagliptin, advanced age, black race, reduced BMI, long duration of diabetes, declining renal function, microalbuminuria, and use of short-acting insulin. Among SURs, glibenclamide was associated with increased risk of major but not any hypoglycemia.

CONCLUSIONS

The identification of patients at risk for hypoglycemia can guide physicians to better tailor antidiabetic therapy.

Analyses of Results From Cardiovascular Safety Trials With DPP-4 Inhibitors: Cardiovascular Outcomes, Predefined Safety Outcomes, and Pooled Analysis and Meta-analysis

The U.S. Food and Drug Administration requires that the cardiovascular (CV) safety of all new drugs for diabetes be demonstrated through pooled analyses of phase III studies or specifically designed trials. This requirement prompted several placebo-controlled, noninferiority CV safety trials in high-risk patients; to date, all completed trials showed that dipeptidyl peptidase (DPP)-4 inhibitors do not increase or reduce the risk of major CV events. These results apparently contrast with those of pooled analyses and meta-analyses of previous, smaller trials with metabolic end points, which had suggested a reduction of risk. However, the design of CV trials, which were required to demonstrate safety, is not adequate (for duration, management of concurrent therapies, etc.) for the assessment of potential therapeutic benefits. In addition, CV safety trials enroll patients at high risk of CV events, who are different from those included in earlier trials with metabolic end points. Differences in characteristics of patients enrolled probably account for most of the discrepancy in CV outcomes between CV safety studies and earlier trials. The availability of several large-scale trials with longer duration provides the unique opportunity for assessment of the safety of DPP-4 inhibitors not only with respect to major CV events but also with reference to other safety issues. For example, CV safety trials can be a source of information for pancreatitis, cancer, or hypoglycemia.

Combination therapy for the improvement of long-term macrovascular and microvascular outcomes in type 2 diabetes: Rationale and evidence for early initiation

Diabetes is a leading cause of macrovascular and microvascular complications that can increase the risk of mortality if not properly managed. Proper glucose control can reduce the incidence of these complications, in particular those of the microvasculature. Over the last~10years, the cardiovascular safety of glucose-lowering drugs has come to the forefront of diabetes management and clinical trial design. While early combination therapy improves glycemic control, its impact on long-term outcomes, is not as clearly understood. The objective of this review is to examine the evidence of early combination therapy for the treatment of type 2 diabetes mellitus as it relates to studies of long-term microvascular and macrovascular outcomes.

LEADER-4: blood pressure control in patients with type 2 diabetes and high cardiovascular risk: baseline data from the LEADER randomized trial

OBJECTIVE

As glucagon-like peptide-1 receptor agonists lower blood pressure (BP) in type 2 diabetes mellitus (T2DM), we examined BP control in relation to targets set by international bodies prior to randomization in the Liraglutide Effect and Action in Diabetes: Evaluation of cardiovascular outcome Results (LEADER) trial.

METHODS

We analyzed baseline data from LEADER (NCT01179048), an ongoing phase 3B, randomized, double-blind, placebo-controlled cardiovascular outcomes trial examining the cardiovascular safety of the glucagon-like peptide-1 receptor agonist liraglutide in 9340 people with T2DM from 32 countries [age (all mean ± SD) 64 ± 7.2 years, BMI 32.5 ± 6.3 kg/m, duration of diabetes 12.7 ± 8.0 years], all of whom were at high risk for cardiovascular disease (CVD).

RESULTS

A total of 81% (n = 7592) of participants had prior CVD and 90% (n = 8408) had a prior history of hypertension. Despite prescription of multiple antihypertensive agents at baseline, only 51% were treated to a target BP of less than 140/85 mmHg and only 26% to the recommended baseline BP target of less than 130/80 mmHg. In univariate analyses, those with prior CVD were prescribed more agents (P < 0.001) and had lower BP than those without (137 ± 18.8/78 ± 10.6 mmHg versus 140 ± 17.7/80 ± 9.9 mmHg; P < 0.001). In logistic regression analyses, residency in North America (64% treated to <140/85 mmHg; 38% treated to <130/80 mmHg) was the strongest predictor of BP control.

CONCLUSION

These contemporary data confirm that BP remains insufficiently controlled in a large proportion of individuals with T2DM at high cardiovascular risk, particularly outside North America. Longitudinal data from the LEADER trial may provide further insights into BP control in relation to cardiovascular outcomes in this condition.

Cardiovascular Outcomes of Patients in SAVOR-TIMI 53 by Baseline Hemoglobin A1c

BACKGROUND

The effect of saxagliptin on cardiovascular outcomes according to different hemoglobin A1c (HbA1c) levels has not been described. Thus, we analyzed the SAVOR-TIMI 53 trial to compare the cardiovascular effects of saxagliptin vs placebo according to baseline HbA1c.

METHODS

A total of 16,492 patients with type 2 diabetes (HbA1c 6.5%-12.0% in the 6 months before randomization) and either a history of established cardiovascular disease or multiple risk factors for atherosclerosis were randomized to saxagliptin or placebo in addition to usual care. Patients were followed for a median of 2.1 years. The primary endpoint was cardiovascular death, myocardial infarction, or ischemic stroke.

RESULTS

Patients were stratified by HbA1c at randomization into the following prespecified groups: <7%, 7%-<8%, 8%-<9%, and ≥9%. Baseline HbA1c ≥7% was associated with increased risk of cardiovascular death, myocardial infarction, or ischemic stroke (adjusted hazard ratio [HR(adj)] 1.35; 95% confidence interval [CI], 1.17-1.58) but not hospitalization for heart failure (HR(adj) 1.09; 95% CI, 0.88-1.36). Saxagliptin neither increased nor decreased the risk of cardiovascular death, myocardial infarction, or ischemic stroke in patients with HbA1c <7% (HR 1.01; 95% CI, 0.78-1.31), 7%-<8% (HR 0.98; 95% CI, 0.80-1.20), 8%-<9% (HR 1.09; 95% CI, 0.85-1.39), ≥9% (HR 0.95; 95% CI, 0.77-1.18) (P-interaction = .89).

CONCLUSIONS

Baseline HbA1c is associated with increased risk of macrovascular events but not hospitalization for heart failure. There was no heterogeneity in the effect of saxagliptin on cardiovascular events by baseline HbA1c, with cardiovascular death, myocardial infarction, or ischemic stroke neither increased nor decreased across the spectrum of baseline HbA1c values.

Clinical trial simulation methods for estimating the impact of DPP-4 inhibitors on cardiovascular disease

Introduction

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of oral antidiabetic agents for the treatment of type 2 diabetes mellitus, which lower blood glucose without causing severe hypoglycemia. However, the first cardiovascular (CV) safety trials have only recently reported their results, and our understanding of these therapies remains incomplete. Using clinical trial simulations, we estimated the effectiveness of DPP-4 inhibitors in preventing major adverse cardiovascular events (MACE) in a population like that enrolled in the SAVOR-TIMI (the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus – Thrombolysis in Myocardial Infarction) 53 trial.

Methods

We used the Archimedes Model to simulate a clinical trial of individuals (N=11,000) with diagnosed type 2 diabetes and elevated CV risk, based on established disease or multiple risk factors. The DPP-4 class was modeled with a meta-analysis of HbA_1c and weight change, pooling results from published trials of alogliptin, linagliptin, saxagliptin, sitagliptin, and vildagliptin. The study treatments were added-on to standard care, and outcomes were tracked for 20 years.

Results

The DPP-4 class was associated with an HbA_1c drop of 0.66% (0.71%, 0.62%) and a weight drop of 0.14 (−0.07, 0.36) kg. These biomarker improvements produced a relative risk (RR) for MACE at 5 years of 0.977 (0.968, 0.986). The number needed to treat to prevent one occurrence of MACE at 5 years was 327 (233, 550) in the elevated CV risk population.

Conclusion

Consistent with recent trial publications, our analysis indicates that DPP-4 inhibitors do not increase the risk of MACE relative to the standard of care. This study provides insights about the long-term benefits of DPP-4 inhibitors and supports the interpretation of the published CV safety trial results.

Efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in black/African American patients with type 2 diabetes: Pooled analysis from eight Phase III trials

BACKGROUND

The prevalence of type 2 diabetes in black/African Americans from North and South America is high; yet data evaluating antidiabetic agents in this population is scarce. To address this gap, we pooled data from the clinical development program for linagliptin.

METHODS

A retrospective pooled analysis of eight completed randomized, placebo-controlled Phase III trials of linagliptin identified 336 patients with type 2 diabetes who self-identified their ethnicity as black or African American. Participants received linagliptin (n = 173, 5 mg/day) or placebo (n = 163) as monotherapy, or as add-on to other antidiabetic agents, including insulin. The primary end point was the change in glycated hemoglobin (HbA1c) from baseline to week 18 or 24.

RESULTS

The placebo-adjusted mean change (95% confidence interval [CI]) in HbA1c from baseline was -0.69% (-0.92 to -0.46; p < 0.0001) at week 18 (eight trials), and -0.64% (-0.90 to -0.39; p < 0.0001) at week 24 (six trials). The placebo-adjusted mean change (95% CI) in fasting plasma glucose from baseline was -11.7 mg/dL (-23.1 to -0.3; p = 0.0446) at week 18 and -14.7 mg/dL (-25.7 to -3.8; p = 0.0087) at week 24. Incidence of investigator-defined hypoglycemia was similar between the two groups (linagliptin, 12.1%; placebo, 11.7%). Overall, the safety profile of linagliptin in this patient group was comparable to that of placebo, with comparable incidence of adverse events; linagliptin was weight-neutral in this patient population.

CONCLUSION

Linagliptin provided clinically significant improvements in glycemic control without increased risk of hypoglycemia and without weight gain, representing a useful type 2 diabetes therapy option for the black/African American population.

Efficacy and safety of saxagliptin in older participants in the SAVOR-TIMI 53 trial

OBJECTIVE

To examine the safety and cardiovascular (CV) effects of saxagliptin in the predefined elderly (≥65 years) and very elderly (≥75 years) subpopulations of the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53 (SAVOR-TIMI 53) trial.

RESEARCH DESIGN AND METHODS

Individuals ≥40 years (n = 16,492; elderly, n = 8,561; very elderly, n = 2,330) with HbA1c ≥6.5% (47.5 mmol/mol) and ≤12.0% (107.7 mmol/mol) were randomized (1:1) to saxagliptin (5 or 2.5 mg daily) or placebo in a double-blind trial for a median follow-up of 2.1 years.

RESULTS

The hazard ratio (HR) for the comparison of saxagliptin versus placebo for the primary end point (composite of CV mortality, myocardial infarction, or ischemic stroke) was 0.92 for elderly patients vs. 1.15 for patients <65 years (P = 0.06) and 0.95 for very elderly patients. The HRs for the secondary composite end points in the entire cohort, elderly cohort, and very elderly cohort were similar. Although saxagliptin increased the risk of hospitalization for heart failure in the overall saxagliptin population, there was no age-based treatment interaction (P = 0.76 for elderly patients vs. those <65 years; P = 0.34 for very elderly patients vs. those <75 years). Among saxagliptin-treated individuals with baseline HbA1c ≥7.6% (59.6 mmol/mol), the mean change from baseline HbA1c at 2 years was -0.69%, -0.64%, -0.66%, and -0.66% for those ≥65, <65, ≥75, and <75 years old, respectively. The incidence of overall adverse events (AEs) and serious AEs was similar between saxagliptin and placebo in all cohorts; however, hypoglycemic events were higher for saxagliptin versus placebo regardless of age.

CONCLUSIONS

The SAVOR-TIMI 53 trial supports the overall CV safety of saxagliptin in a robust number of elderly and very elderly participants, although the risk of heart failure hospitalization was increased irrespective of age category. AEs and serious AEs as well as glycemic efficacy of saxagliptin in elderly patients are similar to those found in younger patients.

Asymmetric dimethylarginine, a biomarker of cardiovascular complications in diabetes mellitus

Cardiovascular (CV) complications are an essential causal element of prospect in diabetes mellitus (DM), with carotid atherosclerosis being a common risk factor for prospective crisis of coronary artery diseases and/or cerebral infarction in DM subjects. From another point of view, asymmetric dimethylarginine (ADMA) has been established as an inhibitor of endogenous nitric oxide synthesis and the relationship between ADMA and arteriosclerosis has been reported. In our study with 87 type 2 DM (T2DM) patients, we have examined whether ADMA and other CV risk factors are the useful predictors of DMCV complications. After the measurement of the respective CV risk factors, we have followed the enrolled T2DM patients for 5 years. We have finally analyzed 77 patients. DMCV complications developed in 15 cases newly within 5 years, and 4 cases recurred. The concentrations of ADMA in plasma were markedly more elevated in 19 DM patients with CV complications than in 58 DM patients without CV complications. Urinary albumin (U-Alb), mean intimal-medial thickness (IMT) and ankle brachial index (ABI) were also higher in patients with CV complications. Multiple regression analyses showed that U-Alb had an influence on the high level of ADMA (standardized β = 6.59, P = 0.00014) independently of age, systolic BP, fibrinogen, mean IMT, plaque score, and ABI. The review indicates what is presently known regarding plasma ADMA that might be a new and meaningful biomarker of CV complications in DM subjects.

Impact of treatment with saxagliptin on glycaemic stability and β-cell function in the SAVOR-TIMI 53 study

AIMS

To study the effects of saxagliptin, a dipeptidyl peptidase-4 inhibitor, on glycaemic stability and β-cell function in the SAVOR-TIMI 53 trial.

METHODS

We randomized 16,492 patients with type 2 diabetes (T2D) to saxagliptin or placebo, added to current antidiabetic medications, and followed them for a median of 2.1 years. Glycaemic instability was defined by: (i) a glycated haemoglobin (HbA1c) increase of ≥ 0.5% post-randomization; (ii) the initiation of new antidiabetic medications for ≥ 3 months; or (iii) an increase in dose of oral antidiabetic medication or ≥ 25% increase in insulin dose for ≥ 3 months. β-cell function was assessed according to fasting homeostatic model 2 assessment of β-cell function (HOMA-2β) values at baseline and at year 2 in patients not treated with insulin.

RESULTS

Compared with placebo, participants treated with saxagliptin had a reduction in the development of glycaemic instability (hazard ratio 0.71; 95% confidence interval 0.68-0.74; p < 0.0001). In participants treated with saxagliptin compared with placebo, the occurrence of an HbA1c increase of ≥ 0.5% was reduced by 35.2%; initiation of insulin was decreased by 31.7% and the increases in doses of an oral antidiabetic drug or insulin were reduced by 19.5 and 23.5%, respectively (all p < 0.0001). At 2 years, HOMA-2β values decreased by 4.9% in participants treated with placebo, compared with an increase of 1.1% in those treated with saxagliptin (p < 0.0001).

CONCLUSIONS

Saxagliptin improved glycaemia and prevented the reduction in HOMA-2β values. Saxagliptin may reduce the usual decline in β-cell function in T2D, thereby slowing diabetes progression.

Saxagliptin and cardiovascular outcomes in patients with type 2 diabetes and moderate or severe renal impairment: observations from the SAVOR-TIMI 53 Trial

OBJECTIVE

The glycemic management of patients with type 2 diabetes mellitus (T2DM) and renal impairment is challenging, with few treatment options. We investigated the effect of saxagliptin in the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus (SAVOR)-Thrombolysis in Myocardial Infarction (TIMI) 53 trial according to baseline renal function.

RESEARCH DESIGN AND METHODS

Patients with T2DM at risk for cardiovascular events were stratified as having normal or mildly impaired renal function (estimated glomerular filtration rate [eGFR] >50 mL/min/1.73 m(2); n = 13,916), moderate renal impairment (eGFR 30-50 mL/min/1.73 m(2); n = 2,240), or severe renal impairment (eGFR <30 mL/min/1.73 m(2); n = 336) and randomized to receive saxagliptin or placebo. The primary end point was cardiovascular death, myocardial infarction, or ischemic stroke.

RESULTS

After a median duration of 2 years, saxagliptin neither increased nor decreased the risk of the primary and secondary composite end points compared with placebo, irrespective of renal function (all P for interactions ≥ 0.19). Overall, the risk of hospitalization for heart failure among the three eGFR groups of patients was 2.2% (referent), 7.4% (adjusted hazard ratio [HR] 2.38 [95% CI 1.95-2.91], P < 0.001), and 13.0% (adjusted HR 4.59 [95% CI 3.28-6.28], P < 0.001), respectively. The relative risk of hospitalization for heart failure with saxagliptin was similar (P for interaction = 0.43) in patients with eGFR >50 mL/min/1.73 m(2) (HR 1.23 [95% CI 0.99-1.55]), eGFR 30-50 mL/min/1.73 m(2) (HR 1.46 [95% CI 1.07-2.00]), and in patients with eGFR <30 (HR 0.94 [95% CI 0.52-1.71]). Patients with renal impairment achieved reductions in microalbuminuria with saxagliptin (P = 0.041) that were similar to those of the overall trial population.

CONCLUSIONS

Saxagliptin did not affect the risk of ischemic cardiovascular events, increased the risk of heart failure hospitalization, and reduced progressive albuminuria, irrespective of baseline renal function.

Cardiovascular effects of incretins in diabetes

Recent years have seen an enormous increase in the number of therapeutic agents available for lowering blood glucose levels in people with type 2 diabetes. Among these agents, the incretin mimetics glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonists and dipeptidyl peptidase 4 (DPP4) inhibitors have received particular attention for the potential of these interventions to positively impact on cardiovascular outcomes. Although the results of large-scale cardiovascular outcome trials eagerly are anticipated, an increasing body of literature from preclinical and early phase clinical studies has indicated that both GLP-1R agonists and DPP4 inhibitors may exert glucose-independent cardiovascular effects. Despite its role in glucose homeostasis, the GLP-1R is surprisingly widely distributed throughout the body, including in the heart. GLP-1 may exert its effects through both receptor-dependent and receptor-independent mechanisms and through the actions of both the intact peptide and its metabolites. In addition, DPP4 inhibition not only augments the circulating levels of incretin hormones, but it also holds the capacity to augment the activity of other biologically important substrates, most notably the small protein stromal cell-derived factor 1 alpha. Whether these collective functions will act to reduce cardiovascular events in patients remains to be determined.

Cardiovascular event rates and healthcare resource utilisation among high-risk adults with type 2 diabetes mellitus in a large population-based study

OBJECTIVE

This study ascertained the incidence and resource utilisation of non-fatal myocardial infarction (MI), stroke, coronary bypass surgery or angioplasty among adults with type 2 diabetes mellitus (T2DM) at high risk for cardiovascular disease (CVD) over 3 and 5 years.

METHODS

Respondents from the US, population-based SHIELD study with T2DM and at cardiovascular risk were stratified into an established CVD cohort and a risk factors cohort. Proportion of respondents self-reporting a new MI, stroke or revascularisation was calculated. Multivariate discrete logistic hazards models were utilised.

RESULTS

Incidence rate in the established CVD cohort (n = 1198) was 26.3% over 3 years (31.2%, 5 years) and in the risk factors cohort (n = 924) 18.8% over 3 years (26.0%, 5 years). Healthcare resource use was significantly greater among respondents who had a new CV event than among those not experiencing an event (p < 0.001).

CONCLUSIONS

Individuals with T2DM at risk for CVD had a high incidence of CV events in this large US study, which represents a significant burden on the healthcare system.

Antihyperglycaemic therapies and cancer risk

AIMS

This review is aimed at highlighting the potential mitogenic/tumour growth-promoting or antimitogenic/tumour growth-inhibiting effects of the main antihyperglycaemic drug classes.

METHODS

We review and discuss the most current studies evaluating the association between antidiabetic medications used in clinical practice and malignancies as described so far.

RESULTS

Metformin seems to be the only antidiabetic drug to exert protective effects both on monotherapy and also when combined with other oral antidiabetic drugs or insulins in several site-specific cancers. In contrast, several other drug classes may increase cancer risk. Some reason for concern remains regarding sulphonylureas and also the incretin-based therapies regarding pancreas and thyroid cancers and the sodium glucose cotransporter-2 inhibitors as well as pioglitazone regarding bladder cancer. The majority of meta-analyses suggest that there is no evidence for a causal relationship between insulin glargine and elevated cancer risk, although the studies have been controversially discussed. For α-glucosidase inhibitors and glinides, neutral or only few data upon cancer risk exist.

CONCLUSION

Although the molecular mechanisms are not fully understood, a potential risk of mitogenicity and tumour growth promotion cannot be excluded in case of several antidiabetic drug classes. However, more large-scale, randomized, well-designed clinical studies with especially long follow-up time periods are needed to get reliable answers to these safety issues.

Safety of saxagliptin: events of special interest in 9156 patients with type 2 diabetes mellitus

BACKGROUND

A post hoc pooled analysis was undertaken to evaluate the safety of saxagliptin in patients with type 2 diabetes mellitus, with attention to events of special interest for dipeptidyl peptidase-4 inhibitors.

METHODS

Pooled analyses were performed for 20 randomized controlled studies (N = 9156) of saxagliptin as monotherapy or add-on therapy, and a subset of 11 saxagliptin + metformin studies. Adverse events and events of special interest (gastrointestinal adverse events, infections, hypersensitivity, pancreatitis, skin lesions, lymphopenia, thrombocytopenia, hypoglycaemia, bone fracture, severe cutaneous adverse reactions, opportunistic infection, angioedema, malignancy, worsening renal function, and specific laboratory events) were assessed; incidence rates (events/100 person-years) and incidence rates ratios (saxagliptin/control) were calculated (Mantel-Haenszel method).

RESULTS

In both pooled datasets, the incidence rates for deaths, serious adverse events, discontinuations due to adverse events, pancreatitis, malignancy, and most other events of special interest, excepting bone fractures and hypersensitivity, were similar between treatments, with 95% confidence intervals (CIs) for incidence rates ratios including 1. In the 20-study pool, the incidence rates per 100 person-years was higher with saxagliptin versus control for bone fractures [1.1 vs 0.6; incidence rates ratio (95% CI), 1.81 (1.04-3.28)] and hypersensitivity adverse events [1.3 vs 0.8; 1.67 (1.01-2.87)].

CONCLUSIONS

Pooled data from 20 studies confirm that saxagliptin has a favourable safety and benefit-risk profile.

Incidence of pancreatitis and pancreatic cancer in a randomized controlled multicenter trial (SAVOR-TIMI 53) of the dipeptidyl peptidase-4 inhibitor saxagliptin

OBJECTIVE

To determine the incidence of pancreatitis and pancreatic cancer in the SAVOR-TIMI 53 trial.

RESEARCH DESIGN AND METHODS

A total of 16,492 type 2 diabetic patients ≥40 years old with established cardiovascular (CV) disease or CV risk factors were randomized to saxagliptin or placebo and followed for 2.1 years. Outcome measures were investigator reported with blinded expert adjudication of total pancreatitis (acute and chronic) and reported cases of pancreatic cancer.

RESULTS

Trial investigators reported 35 events of pancreatitis in each treatment arm in 63 patients (33 [0.40%] in the saxagliptin arm and 30 [0.37%] in control arm), with a hazard ratio (HR) of 1.09 (95% CI 0.66-1.79, P = 0.80). Adjudication confirmed pancreatitis in 24 patients (26 events) in the saxagliptin arm (0.29%) and 21 patients (25 events) in placebo arm (0.26%), with an HR of 1.13 (0.63-2.06, P = 0.77). Cases of definite acute pancreatitis were confirmed in 17 (0.2%) vs. 9 (0.1%) (HR 1.88 [0.86-4.41], P = 0.17), definite plus possible pancreatitis in 22 vs. 16 (HR 1.36 [0.72-2.64], P = 0.42), and chronic pancreatitis in 2 vs. 6 (HR 0.33 [0.05-1.44], P = 0.18) in the saxagliptin and placebo arms, respectively. No differences in time to event onset, concomitant risk factors for pancreatitis, investigator-reported causality from study medication or disease severity, and outcome were found between treatment arms. The investigators reported 5 and 12 cases of pancreatic cancer in the saxagliptin and placebo arms, respectively (HR 0.42 [0.13-1.12], P = 0.09).

CONCLUSIONS

In the SAVOR-TIMI 53 trial, within 2.1 years of follow-up, risk for pancreatitis in type 2 diabetic patients treated with saxagliptin was low and apparently similar to placebo, with no sign of increased risk for pancreatic cancer. Further studies are needed to completely resolve the pancreatic safety issues with incretin-based therapy.

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.

Comparative effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors and human glucagon-like peptide-1 (GLP-1) analogue as add-on therapies to sulphonylurea among diabetes patients in the Asia-Pacific region: a systematic review

The prevalence of diabetes mellitus is rising globally, and it induces a substantial public health burden to the healthcare systems. Its optimal control is one of the most significant challenges faced by physicians and policy-makers. Whereas some of the established oral hypoglycaemic drug classes like biguanide, sulphonylureas, thiazolidinediones have been extensively used, the newer agents like dipeptidyl peptidase-4 (DPP-4) inhibitors and the human glucagon-like peptide-1 (GLP-1) analogues have recently emerged as suitable options due to their similar efficacy and favorable side effect profiles. These agents are widely recognized alternatives to the traditional oral hypoglycaemic agents or insulin, especially in conditions where they are contraindicated or unacceptable to patients. Many studies which evaluated their clinical effects, either alone or as add-on agents, were conducted in Western countries. There exist few reviews on their effectiveness in the Asia-Pacific region. The purpose of this systematic review is to address the comparative effectiveness of these new classes of medications as add-on therapies to sulphonylurea drugs among diabetic patients in the Asia-Pacific countries. We conducted a thorough literature search of the MEDLINE and EMBASE from the inception of these databases to August 2013, supplemented by an additional manual search using reference lists from research studies, meta-analyses and review articles as retrieved by the electronic databases. A total of nine randomized controlled trials were identified and described in this article. It was found that DPP-4 inhibitors and GLP-1 analogues were in general effective as add-on therapies to existing sulphonylurea therapies, achieving HbA1c reductions by a magnitude of 0.59-0.90% and 0.77-1.62%, respectively. Few adverse events including hypoglycaemic attacks were reported. Therefore, these two new drug classes represent novel therapies with great potential to be major therapeutic options. Future larger-scale research should be conducted among other Asia-Pacific region to evaluate their efficacy in other ethnic groups.

Effects of alogliptin in chronic kidney disease patients with type 2 diabetes

OBJECTIVE

Diabetes is a major risk factor for chronic kidney disease (CKD). In this study, we examined the effects of alogliptin on blood glucose control and the renal function in type 2 diabetes CKD patients.

METHODS

We recruited 36 CKD patients with type 2 diabetes. The patients were followed up for six months after adding alogliptin. Blood biochemical, urine test and office BP values were obtained six months before and after the start of treatment.

RESULTS

The mean HbA1c value was not decreased; however, the 1,5-AG values tended to improve (p=0.1023). The mean eGFR was unchanged. There were no significant changes in the patients with an eGFR of 60 mL/min/1.73 m2 or more (25 patients) or in the patients with an eGFR less than 60 mL/min/1.73 m2 (11 patients). A total of 15 patients were identified to have rapidly declining diabetic nephropathy, with an annual reduction in eGFR of 5 mL/min/1.73 m2 or more. The slope of the regression line for eGFR (-1.296 before starting treatment with alogliptin) was positive, increasing up to 0.08786. The eGFR values appeared to stop decreasing and positively reversed. The urinary albumin-to-creatinine ratio exhibited a downward trend. The effect on the renal function was independent of the levels of blood sugar, blood pressure and lipids.

CONCLUSION

We examined the ability of alogliptin to maintain the renal function in patients with CKD complicated by type 2 diabetes. Our study suggests that alogliptin can be safely administered in patients with CKD. However, although we expected alogliptin to demonstrate renal protective effects, were unable to detect statistically significant differences. One reason for this finding is that there are few registered cases.

Incretin-based therapies: focus on effects beyond glycemic control alone

Type 2 diabetes is associated with a high prevalence of comorbidities resulting from hypertension, dyslipidemia, and hyperglycemia. Inadequate management of these risk factors will eventually result in detrimental health consequences. Thus, the effect of a drug on factors such as weight, cardiovascular (CV) risk factors, and adherence is important to consider. A review was undertaken of the recent medical literature describing the extraglycemic characteristics of the two classes of incretin-based therapies-glucagon-like peptide-1 receptor agonists (GLP-1RA) and dipeptidyl peptidase-4 (DPP-4) inhibitors. PubMed searches were performed to identify published data on incretin therapies that describe their effects on CV risk factors, CV events, and factors related to medication adherence. The maintenance or loss of weight associated with the use of GLP-1RAs and DPP-4 inhibitors is well described in the medical literature. These agents also appear to be associated with a modest decrease in blood pressure and a reduced risk of CV events. In addition, several characteristics of incretin therapies may improve rates of medication adherence, such as generally favorable tolerability profiles (particularly with DPP-4 inhibitors), the availability of formulations that simplify treatment regimens, and a low risk for hypoglycemia. The literature on incretin therapies describes a number of clinical characteristics that are relevant to the management of extraglycemic risk factors. As part of a holistic treatment strategy, these properties constitute important considerations for tailoring therapy to individual patients with type 2 diabetes.

Saxagliptin and cardiovascular outcomes in patients with type 2 diabetes mellitus

BACKGROUND

The cardiovascular safety and efficacy of many current antihyperglycemic agents, including saxagliptin, a dipeptidyl peptidase 4 (DPP-4) inhibitor, are unclear.

METHODS

We randomly assigned 16,492 patients with type 2 diabetes who had a history of, or were at risk for, cardiovascular events to receive saxagliptin or placebo and followed them for a median of 2.1 years. Physicians were permitted to adjust other medications, including antihyperglycemic agents. The primary end point was a composite of cardiovascular death, myocardial infarction, or ischemic stroke.

RESULTS

A primary end-point event occurred in 613 patients in the saxagliptin group and in 609 patients in the placebo group (7.3% and 7.2%, respectively, according to 2-year Kaplan-Meier estimates; hazard ratio with saxagliptin, 1.00; 95% confidence interval [CI], 0.89 to 1.12; P=0.99 for superiority; P<0.001 for noninferiority); the results were similar in the "on-treatment" analysis (hazard ratio, 1.03; 95% CI, 0.91 to 1.17). The major secondary end point of a composite of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, coronary revascularization, or heart failure occurred in 1059 patients in the saxagliptin group and in 1034 patients in the placebo group (12.8% and 12.4%, respectively, according to 2-year Kaplan-Meier estimates; hazard ratio, 1.02; 95% CI, 0.94 to 1.11; P=0.66). More patients in the saxagliptin group than in the placebo group were hospitalized for heart failure (3.5% vs. 2.8%; hazard ratio, 1.27; 95% CI, 1.07 to 1.51; P=0.007). Rates of adjudicated cases of acute and chronic pancreatitis were similar in the two groups (acute pancreatitis, 0.3% in the saxagliptin group and 0.2% in the placebo group; chronic pancreatitis, <0.1% and 0.1% in the two groups, respectively).

CONCLUSIONS

DPP-4 inhibition with saxagliptin did not increase or decrease the rate of ischemic events, though 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. (Funded by AstraZeneca and Bristol-Myers Squibb; SAVOR-TIMI 53 ClinicalTrials.gov number, NCT01107886.).