Association Between Hospitalization for Heart Failure and Dipeptidyl Peptidase 4 Inhibitors in Patients With Type 2 Diabetes: An Observational Study

Second line initiation of insulin compared with DPP-4 inhibitors after metformin monotherapy is associated with increased risk of all-cause mortality, cardiovascular events, and severe hypoglycemia

AIMS

The objective of this nationwide study was to compare the risk of all-cause mortality, fatal and nonfatal cardiovascular disease (CVD), and severe hypoglycemia in patients with type 2 diabetes (T2D) on metformin monotherapy treatment starting second-line treatment with either insulin or dipeptidyl peptidase-4 inhibitor (DPP-4i).

METHODS

All patients with T2D in Sweden who initiated second-line treatment with insulin or DPP-4i after metformin monotherapy during 2007-2014 identified in the Swedish Prescribed Drug Register were followed for outcome in the Cause of Death and National Patient Registers. Insulin and DPP-4i patients were matched 1:1 using propensity-score matching. Comparisons between groups were performed using unadjusted Cox regression models. Additionally, multivariate adjusted survival models were used to test the results using the full population without matching.

RESULTS

Of 27,767 mono-metformin-treated patients, 55.7% started insulin and 44.3% a DPP-4i, and after matching both groups had 9278 patients each. Median follow-up (patients years) times were 3.84 (37,578) and 3.93 (37,983) for insulin and DPP-4i-groups, respectively. Insulin compared with DPP-4i was associated with higher risk of subsequent all-cause mortality, fatal and nonfatal CVD, and severe hypoglycemia; adjusted HR (95% CI): 1.69 (1.45-1.96); 1.39 (1.21-1.61); and 4.35 (2.26-8.35), respectively. When performing multivariate adjusted analyses on the full population similar results were found.

CONCLUSIONS

Initiation of insulin, compared with DPP-4i treatment, was associated with an increased risk of subsequent all-cause mortality, fatal and nonfatal CVD, and severe hypoglycemia. Results from randomized trials will be important to elucidate causal relationships.

Practical combination therapy based on pathophysiology of type 2 diabetes

Type 2 diabetes is a complex, chronic, and progressive condition that often necessitates the use of multiple medications to achieve glycemic goals. Clinical guidelines generally recommend intensifying pharmacotherapy if glycemic goals are not achieved after 3 months of treatment. However, for many patients with type 2 diabetes, treatment intensification is delayed or does not occur. Initiating combination therapy early in the disease course has the potential to delay disease progression and improve patient outcomes. Guidelines generally provide a list of agents that may be used in combination regimens and emphasize individualization of treatment. The purpose of this review is to discuss the rationale for combination therapy, considering treatment effects on pathophysiologic aspects of type 2 diabetes and individual drug profiles. The combination of newer antidiabetes therapies with complementary mechanisms of action provides the opportunity to target multiple sites of tissue, organ, and cellular dysfunction.

Dipeptidyl peptidase-4 inhibitors and cardiovascular risks in patients with pre-existing heart failure

BACKGROUND

Although recent clinical trials raised concerns about the risk for heart failure (HF) in dipeptidyl peptidase-4 (DPP-4) inhibitor use, data on the cardiovascular risks in the patients with pre-existing HF are still lacking.

METHODS

We used Taiwan's National Health Insurance Research Database to identify 196 986 patients diagnosed with type 2 diabetes mellitus (T2DM) who had previous history of HF between 2009 and 2013. This population included 30 204 DPP-4 inhibitor users and 166 782 propensity score-matched DPP-4 inhibitor non-users. The outcomes of interest were all-cause mortality, combination of myocardial infarction (MI) and ischaemic stroke, and hospitalisation for HF.

RESULTS

The incidence in DPP-4 users compared with non-users was 67.02 vs 102.85 per 1000 person-years for all-cause mortality, 37.89 vs 47.54 per 1000 person-years for the combination of MI and ischaemic stroke, 12.70 vs 16.18 per 1000 person-years for MI and 26.37 vs 32.46 per 1000 person-years for ischaemic stroke. The risk of all-cause mortality was lower in DPP-4 inhibitor users (HR 0.67, 95% CI 0.64 to 0.70), combination of MI and stroke (HR 0.81, 95% CI 0.76 to 0.87), MI (HR 0.80, 95% CI 0.71 to 0.89) and ischaemic stroke (HR 0.83, 95% CI 0.76 to 0.89) than in non-users. Notably, the risk of hospitalisation for HF did not differ significantly between groups. The results were similar after accounting for death as a competing risk.

CONCLUSIONS

In this nationwide T2DM cohort, the risks of mortality and the combination of MI and ischaemic stroke were lower for patients receiving DPP-4 inhibitors than for those who did not receive such treatment. DPP-4 inhibitor use was not associated with a higher risk of hospitalisation for HF even in patients with pre-existing HF.

Safety and efficacy of linagliptin in patients with type 2 diabetes mellitus and coronary artery disease: Analysis of pooled events from 19 clinical trials

AIMS

To examine the safety and efficacy of linagliptin in patients with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD) using pooled data from the global clinical trials program.

METHODS

Patient-level data were pooled from randomized, placebo-controlled clinical trials of linagliptin (5mg, monotherapy or combination therapy). Safety/efficacy analyses were conducted for patients with CAD and ≥12 and ≥24weeks of treatment, respectively.

RESULTS

The safety analysis included 19 trials (linagliptin, n=451; placebo, n=272) and the efficacy analysis, 12 trials (linagliptin, n=328; placebo, n=198); mean (± standard deviation) exposure to study treatment was 212 (144) days linagliptin and 245 (171) days placebo. Occurrence of cardiac adverse events (AEs) was similar for linagliptin- and placebo-treated patients (9.1% and 9.2%, respectively); exposure-adjusted incidence rates (per 100 patient-years) were 16.6 and 14.0, respectively. Overall incidence of AEs was numerically lower with linagliptin than placebo. After 24weeks, mean adjusted change (standard error) from baseline glycosylated hemoglobin was -0.64% (0.04) with linagliptin vs. -0.08% (0.05) with placebo (P<.001).

CONCLUSIONS

This comprehensive pooled analysis showed that addition of linagliptin to treatment regimens of patients with T2DM and CAD was not associated with an increased incidence of cardiac AEs, was well tolerated, and was effective.

Comparative risk for cardiovascular diseases of dipeptidyl peptidase-4 inhibitors vs. sulfonylureas in combination with metformin: Results of a two-phase study

AIMS

The aim was to assess whether the use of additional data from the Disease Management Program (DMP) diabetes mellitus type 2 to minimize the potential for residual confounding will alter the estimated risk of either myocardial infarction, ischemic stroke or heart failure in patients with type 2 diabetes using sulfonylureas compared to dipeptidyl peptidase-4 (DPP-4) inhibitors in addition to metformin based on routine health care data.

METHODS

We conducted a nested two-phase case-control study using claims data of one German health insurance from 2004 to 2013 (phase 1) and data of the DMP from 2010 to 2013 (phase 2). Adjusted odds ratios (ORs) for the combined cardiovascular event myocardial infarction, ischemic stroke or heart failure were calculated using a two-phase logistic regression.

RESULTS

Phase 1 comprised 3179 patients (289 cases; 2890 controls) and phase 2 comprised 1968 patients (168 cases; 1800 controls). We observed an adjusted OR of 0.83 for the combined cardiovascular event (95% CI: 0.61-1.13).

CONCLUSIONS

We observed a non-significantly reduced risk for cardiovascular diseases in patients using DPP-4 inhibitors compared to sulfonylureas in addition to metformin. This finding was not altered by the inclusion of additional information of the DMP in the analysis. However, due to the low power of this study, further studies are needed to reproduce our findings.

PERS&O (PERsistent Sitagliptin treatment & Outcomes): observational retrospective study on cardiovascular risk evolution in patients with type 2 diabetes on persistent sitagliptin treatment

OBJECTIVES

The UK Prospective Diabetes Study (UKPDS) Risk Engine (RE) provides the best risk estimates available for people with type 2 diabetes (T2D), so it was applied to patients on persistent sitagliptin treatment.

DESIGN

A 'real-world' retrospective, observational, single-center study.

SETTING

The study was performed in a general hospital in Northern Italy in order: (1) to validate UKPDS RE in a cohort of Italian participants with T2D without prespecified diabetes duration, with/without cardiovascular (CV) disease, treated with sitagliptin; (2) to confirm CV risk gender difference; (3) to evaluate the effect on metabolic control and on CV risk evolution obtained by 'add-on' persistent sitagliptin treatment.

PARTICIPANTS

Sitagliptin 100 mg once a day was taken by 462 participants with T2D: 170 of them (males: 106; age: 63.6±8.8; T2D duration: 11.58±7.33; females: 64; age: 65.6±7.95; T2D duration 13.5±7.9) were treated for 48 months with the same dosage.

INTERVENTIONS

An analysis of normality was performed both for continuous, and for groups variables on UKPDS RE percentage values, defining the requirement of a base log10 transformation to normalize risk factor values for analysis validation.

RESULTS

The evaluation of CV risk evolution by gender (t-test) confirmed the expected statistical difference (p<0.0001). Sitagliptin obtained significant results after 12 months, and at the end of the observation, both on metabolic control (expressed by glycated hemoglobin) and on UKPDS RE. Analysis of variance test revealed a significant effect on CV risk after 12 months (p=0.003), and after 48 months (p=0.04). A bivariate correlation analysis revealed a correlation index (r)=0.2 between the two variables (p<0.05).

CONCLUSIONS

These 'real-world' data obtained applying UKPDS RE may reflect patients' and clinicians' interest in realizing individual CV risk, and its evolution. Sitagliptin-persistent treatment for a medium-long period obtained an improvement on metabolic control, as well as a reduction on CV risk.

Risk for Hospitalized Heart Failure Among New Users of Saxagliptin, Sitagliptin, and Other Antihyperglycemic Drugs: A Retrospective Cohort Study

BACKGROUND

Recent postmarketing trials produced conflicting results about the risk for hospitalized heart failure (hHF) associated with dipeptidyl peptidase-4 (DPP-4) inhibitors, creating uncertainty about the safety of these antihyperglycemic agents.

OBJECTIVE

To examine the associations of hHF with saxagliptin and sitagliptin.

DESIGN

Population-based, retrospective, new-user cohort study.

SETTING

18 health insurance and health system data partners in the U.S. Food and Drug Administration's Mini-Sentinel program.

PATIENTS

Patients aged 18 years or older with type 2 diabetes who initiated therapy with saxagliptin, sitagliptin, pioglitazone, second-generation sulfonylureas, or long-acting insulin products from 2006 to 2013.

MEASUREMENTS

Hospitalized HF, identified by International Classification of Diseases, Ninth Revision, Clinical Modification codes 402.x1, 404.x1, 404.x3, and 428.xx recorded as the principal discharge diagnosis.

RESULTS

78 553 saxagliptin users and 298 124 sitagliptin users contributed an average of 7 to 9 months of follow-up data to 1 or more pairwise comparisons. The risk for hHF was not higher with DPP-4 inhibitors than with the other study drugs. The hazard ratios from the disease risk score (DRS)-stratified analyses were 0.83 (95% CI, 0.70 to 0.99) for saxagliptin versus sitagliptin, 0.63 (CI, 0.47 to 0.85) for saxagliptin versus pioglitazone, 0.69 (CI, 0.54 to 0.87) for saxagliptin versus sulfonylureas, and 0.61 (CI, 0.50 to 0.73) for saxagliptin versus insulin. The DRS-stratified hazard ratios were 0.74 (CI, 0.64 to 0.85) for sitagliptin versus pioglitazone, 0.86 (CI, 0.77 to 0.95) for sitagliptin versus sulfonylureas, and 0.71 (CI, 0.64 to 0.78) for sitagliptin versus insulin. Results from the 1:1 propensity score-matched analyses were similar. Results were also similar in subgroups of patients with and without prior cardiovascular disease and in a subgroup defined by the 2 highest DRS deciles.

LIMITATION

Residual confounding and short follow-up.

CONCLUSION

In this large cohort study, a higher risk for hHF was not observed in users of saxagliptin or sitagliptin compared with other selected antihyperglycemic agents.

PRIMARY FUNDING SOURCE

U.S. Food and Drug Administration.

Effects of dipeptidyl peptidase-4 inhibitor in insulin-resistant rats with myocardial infarction

Adverse cardiac remodeling after myocardial infarction (MI) leads to progressive heart failure. Obese-insulin resistance increases risks of MI and heart failure. Although dipeptidyl peptidase-4 (DPP4) inhibitor is known to exert cardioprotection, its effects on adverse remodeling after MI in obese-insulin-resistant rats are unclear. We hypothesized that DPP4 inhibitor reduces adverse left ventricular (LV) remodeling and LV dysfunction in obese-insulin-resistant rats with MI. Rats were fed either normal diet (ND) or high-fat diet (HFD) for 12 weeks to induce obese-insulin resistance, followed by left anterior descending coronary artery ligation to induce MI. Then, rats in each dietary group were divided into five subgroups to receive vehicle, enalapril (10mg/kg/day), metformin (30mg/kg/day), DPP4 inhibitor vildagliptin (3mg/kg/day), or combined metformin and vildagliptin for 8 weeks. Heart rate variability (HRV), LV function, pathological and biochemical studies for LV remodeling, and cardiomyocyte apoptosis were determined. Obese-insulin-resistant rats had severe insulin resistance and LV dysfunction. HFD rats had a higher mortality rate than ND rats, and all treatments reduced the mortality rate in obese-insulin-resistant rats. Although all drugs improved insulin resistance, HRV, LV function as well as reduced cardiac hypertrophy and fibrosis, vildagliptin effectively reduced cardiomyocyte cross-sectional areas more than enalapril and was related to markedly decreased ERK1/2 phosphorylation. In ND rats with MI, metformin neither improved LV ejection fraction nor reduced cardiac fibrosis. The infarct size and transforming growth factor-β expression were not different among groups. In obese-insulin-resistant rats with chronic MI, DPP4 inhibitor vildagliptin exerts better cardioprotection than enalapril in attenuating adverse LV remodeling.

EMPA-REG and Other Cardiovascular Outcome Trials of Glucose-lowering Agents: Implications for Future Treatment Strategies in Type 2 Diabetes Mellitus

During the last decade, the armamentarium for glucose-lowering drugs has increased enormously by the development of DPP-4 inhibitors, GLP-1 receptor agonists and SGLT2 inhibitors, allowing individualization of antidiabetic therapy for patients with type 2 diabetes (T2DM). Some combinations can now be used without an increased risk for severe hypoglycemia and weight gain. Following a request of the US Food and Drug Administration, many large cardiovascular (CV) outcome studies have been performed in patients with longstanding disease and established CV disease. In the majority of CV outcome studies, CV risk factors were well controlled and a high number of patients were already treated with ACE inhibitors/angiotensin receptor blockers, statins and antiplatelet drugs. Most studies with insulin glargine and newer glucose-lowering drugs (saxagliptin, alogliptin, sitagliptin, lixisenatide) demonstrated safety of newer glucose-lowering agents but did not show superiority in the CV outcomes compared with placebo. By contrast, in the EMPA-REG OUTCOME (Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients) study, CV death, all-cause mortality, and hospitalization for heart failure were significantly decreased when empagliflozin was added instead of placebo to therapy for patients with high CV risk and T2DM already well treated with statins, glucose-lowering drugs, and blood pressure-lowering drugs as well as antiplatelet agents. In addition, renal endpoints including endstage renal disease were also significantly reduced when empagliflozin was added instead of placebo. Interestingly, the reduction of these clinically relevant end points was observed after a few months, making antiatherogenic effects an unlikely cause. The fact that the incidence of myocardial infarction (MI) and stroke were not reduced is in line with the hypothesis that hemodynamic factors in particular have contributed to the impressive improvement of the prognosis. To reduce the CV burden of patients with T2DM, drugs influencing factors involved in atherogenesis (eg, insulin resistance, chronic inflammation, increase of HDL, prothrombotic state) are more promising. The recent IRIS (Insulin Resistance Intervention after Stroke) study documented a significant reduction in stroke and MI when pioglitazone instead of placebo was given to nondiabetic patients presenting with both stroke/transient ischemic attack and insulin resistance, confirming results from the PROactive (Prospective Pioglitazone Clinical Trial in Macrovascular Events) study in patients with T2DM. Based on these new data, we suggest that the addition of both empagliflozin and pioglitazone to metformin might be the relative best option to reduce the high CV morbidity and mortality of patients with T2DM and already established CV complications. The very recent announcement that the CV outcome study with liraglutide (LEADER) also demonstrated a significant reduction of the composite endpoint (cardiovascular death, non-fatal myocardial infarction or non-fatal stroke) gives new hope for further beneficial treatment options for T2DM patients with established CVD.

Glucose-lowering therapy in type 2 diabetes. New hope after the EMPA-REG outcome trial

Prevention of cardiovascular morbidity and mortality remains the key factor in the treatment of type 2 diabetes (T2DM). In the early phase of T2DM, multifactorial intervention is mandatory and glucose levels should be near normal, in particular in younger patients presenting with the highest cardiovascular risk. Anti-diabetic drugs without any risk for hypoglycaemia should be preferred in order to reduce clinical inertia and increase the long-term adherence to the treatment. In patients already presenting with cardiovascular disease, the best outcome may be expected with the triple oral therapy of metformin, pioglitazone, and empagliflozin, although a controlled prospective study versus insulin therapy is needed to confirm the expectation.