Gender differences in cardiovascular risk, treatment, and outcomes: a post hoc analysis from the REWIND trial

Objectives. To assess whether the use of cardioprotective therapies for type 2 diabetes varies by gender and whether the risk of cardiovascular events is higher in women versus men in the REWIND trial, including an international type 2 diabetes patient population with a wide range of baseline risk. Design. Gender differences in baseline characteristics, cardioprotective therapy, and the achieved clinical targets at baseline and two years were analyzed. Hazards for cardiovascular outcomes (fatal/nonfatal stroke, fatal/nonfatal myocardial infarction, cardiovascular death, all-cause mortality, and heart failure hospitalization), in women versus men were analyzed using two Cox proportional hazard models, adjusted for randomized treatment and key baseline characteristics respectively. Time-to-event analyses were performed in subgroups with or without history of cardiovascular disease using Cox proportional hazards models that included gender, subgroup, randomized treatment, and gender-by-subgroup interactions. Results. Of 9901 participants, 46.3% were women. Significantly fewer women than men had a cardiovascular disease history. Although most women met treatment targets for blood pressure (96.7%) and lipids (72.8%), fewer women than men met the target for cardioprotective therapies at baseline and after two years, particularly those with prior cardiovascular disease, who used less renin-angiotensin-aldosterone system inhibitors, statins, and aspirin than men. Despite these differences, women had lower hazards than men for all outcomes except stroke. No significant gender and cardiovascular disease history interactions were identified for cardiovascular outcomes. Conclusions. In REWIND, most women met clinically relevant treatment targets, but in lower proportions than men. Women had a lower risk for all cardiovascular outcomes except stroke. Clinical trials.gov registration number: NCT01394952.

Biomarker Changes Associated With Both Dulaglutide and Cardiovascular Events in the REWIND Randomized Controlled Trial: A Nested Case-Control Post Hoc Analysis

OBJECTIVE

The glucagon-like peptide-1 receptor agonist dulaglutide reduced MACE in the Researching Cardiovascular Events with a Weekly Incretin in Diabetes (REWIND) trial. This article expores the relationship of selected biomarkers to both dulaglutide and major adverse cardiovascular events (MACE).

RESEARCH DESIGN AND METHODS

In this post hoc analysis, stored fasting baseline and 2-year plasma samples from 824 REWIND participants with MACE during follow-up and 845 matched non-MACE participants were analyzed for 2-year changes in 19 protein biomarkers. Two-year changes in 135 metabolites were also analyzed in 600 participants with MACE during follow-up and in 601 matched non-MACE participants. Linear and logistic regression models were used to identify proteins that were associated with both dulaglutide treatment and MACE. Similar models were used to identify metabolites that were associated with both dulaglutide treatment and MACE.

RESULTS

Compared with placebo, dulaglutide was associated with a greater reduction or lesser 2-year rise from baseline in N-terminal prohormone of brain natriuretic peptide (NT-proBNP), growth differentiation factor 15 (GDF-15), high-sensitivity C-reactive protein, and a greater 2-year rise in C-peptide. Compared with placebo, dulaglutide was also associated with a greater fall from baseline in 2-hydroxybutyric acid and a greater rise in threonine (P < 0.001). Increases from baseline in two of the proteins (but neither metabolite) were associated with MACE, including NT-proBNP (OR 1.267; 95% CI 1.119, 1.435; P < 0.001) and GDF-15 (OR 1.937; 95% CI 1.424, 2.634; P < 0.001).

CONCLUSIONS

Dulaglutide was associated with a reduced 2-year rise from baseline of NT-proBNP and GDF-15. Higher rises of these biomarkers were also associated with MACE.

Time-dependent event accumulation in a cardiovascular outcome trial of patients with type 2 diabetes and established atherosclerotic cardiovascular disease

BACKGROUND

Estimating cardiovascular (CV) event accrual is important for outcome trial planning. Limited data exist describing event accrual patterns in patients with type 2 diabetes (T2D). We compared apparent CV event accrual patterns with true event rates in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS).

METHODS

Centrally adjudicated event dates and accrual rates for a 4-point major adverse CV event composite (MACE-4; includes CV death, nonfatal myocardial infarction, nonfatal stroke, or unstable angina hospitalization), MACE-4 components, all-cause mortality (ACM), and heart failure hospitalization were compiled. We used three graphical methods (Weibull probability plot, plot of negative log of the Kaplan-Meier survival distribution estimate, and the Epanechnikov kernel-smoothed estimate of the hazard rate) to examine hazard rate morphology over time for the 7 outcomes.

RESULTS

Plots for all outcomes showed real-time constant event hazard rates for the duration of the follow-up, confirmed by Weibull shape parameters. The Weibull shape parameters for ACM (1.14, 95% CI 1.08-1.21) and CV death (1.08, 95% CI 1.01-1.16) were not sufficiently > 1 as to require non-constant hazard rate models to accurately depict the data. The time lag between event occurrence and event adjudication being completed, the adjudication gap, improved over the course of the trial.

CONCLUSIONS

In TECOS, the nonfatal event hazard rates were constant over time. Small increases over time in the hazard rate for fatal events would not require complex modelling to predict event accrual, providing confidence in traditional modelling methods for predicting CV outcome trial event rates in this population. The adjudication gap provides a useful metric to monitor within-trial event accrual patterns.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov NCT00790205.

Dulaglutide and cardiovascular and heart failure outcomes in patients with and without heart failure: a post-hoc analysis from the REWIND randomized trial

AIMS

People with diabetes are at high risk for cardiovascular events including heart failure (HF). We examined the effect of the glucagon-like peptide 1 agonist dulaglutide on incident HF events and other cardiovascular outcomes in those with or without prior HF in the randomized placebo-controlled Researching Cardiovascular Events with a Weekly Incretin in Diabetes (REWIND) trial.

METHODS AND RESULTS

The REWIND major adverse cardiovascular event (MACE) outcome was the first occurrence of a composite endpoint of non-fatal myocardial infarction, non-fatal stroke, or death from cardiovascular causes (including unknown causes). In this post-hoc analysis, a HF event was defined as an adjudication-confirmed hospitalization or urgent evaluation for HF. Of the 9901 participants studied over a median follow-up of 5.4 years, 213/4949 (4.3%) randomly assigned to dulaglutide and 226/4952 (4.6%) participants assigned to placebo experienced a HF event (hazard ratio [HR] 0.93, 95% confidence interval [CI] 0.77-1.12; p = 0.456). In the 853 (8.6%) participants with HF at baseline, there was no change in either MACE or HF events with dulaglutide as compared to participants without HF (p = 0.44 and 0.19 for interaction, respectively). Combined cardiovascular death and HF events were marginally reduced with dulaglutide compared to placebo (HR 0.88, 95% CI 0.78-1.00; p = 0.050) but unchanged in patients with and without HF at baseline (p = 0.31).

CONCLUSIONS

Dulaglutide was not associated with a reduction in HF events in patients with type 2 diabetes regardless of baseline HF status over 5.4 years of follow-up.

Novel Indices of Cognitive Impairment and Incident Cardiovascular Outcomes in the REWIND Trial

CONTEXT

Low cognitive scores are risk factors for cardiovascular outcomes. Whether this relationship is stronger using novel cognitive indices is unknown.

METHODS

Participants in the Researching Cardiovascular Events with a Weekly Incretin in Diabetes (REWIND) trial who completed both the Montreal Cognitive Assessment (MoCA) score and Digit Substitution Test (DSST) at baseline (N = 8772) were included. These scores were used to identify participants with baseline substantive cognitive impairment (SCI), defined as a baseline score on either the MoCA or DSST ≥ 1.5 SD below either score's country-specific mean, or SCI-GM, which was based on a composite index of both scores calculated as their geometric mean (GM), and defined as a score that was ≥ 1.5 SD below their country's average GM. Relationships between these measures and incident major adverse cardiovascular events (MACE), and either stroke or death were analyzed.

RESULTS

Compared with 7867 (89.7%) unaffected participants, the 905 (10.3%) participants with baseline SCI had a higher incidence of MACE (unadjusted hazard ratio [HR] 1.34; 95% CI 1.11, 1.62; P = 0.003), and stroke or death (unadjusted HR 1.60; 95% CI 1.33, 1.91; P < 0.001). Stronger relationships were noted for SCI-GM and MACE (unadjusted HR 1.61; 95% CI 1.28, 2.01; P < 0.001), and stroke or death (unadjusted HR 1.85; 95% CI 1.50, 2.30; P < 0.001). For SCI-GM but not SCI, all these relationships remained significant in models that adjusted for up to 10 SCI risk factors.

CONCLUSION

Country-standardized SCI-GM was a strong independent predictor of cardiovascular events in people with type 2 diabetes in the REWIND trial.

Glycaemic efficacy of an expanded dose range of dulaglutide according to baseline glycated haemoglobin (HbA1c) subgroup: Post hoc analysis of AWARD-11

The AWARD-11 trial demonstrated the safety and efficacy of dulaglutide 3.0 and 4.5 mg compared to dulaglutide 1.5 mg in patients with type 2 diabetes inadequately controlled with metformin. This post hoc analysis examined the change from baseline in glycated haemoglobin (HbA1c) and proportions of patients achieving HbA1c <7% at weeks 36 and 52 with dulaglutide 1.5 mg, 3.0 mg or 4.5 mg across clinically relevant baseline HbA1c subgroups (<8%; 8.0% to < 9.0%; 9.0% to < 10%; and ≥ 10%). Mean reductions in HbA1c were observed across all baseline HbA1c subgroups at 36 weeks (range of HbA1c change: 1.5 mg: -1.0% to -2.2%; 3.0 mg: -1.2% to -2.5%; and 4.5 mg: -1.2% to -3.2%). More patients randomized to 3.0 mg or 4.5 mg (vs. 1.5 mg) achieved HbA1c <7% at 36 weeks regardless of baseline HbA1c; the difference in proportions was greater at higher baseline HbA1c (P-interaction = 0.096). Similar patterns in glycaemic improvement and proportions achieving HbA1c <7% were observed at 52 weeks. Hypoglycaemia and gastrointestinal adverse events were similar among the HbA1c subgroups. Glycaemic control was improved with dulaglutide dose escalation from 1.5 mg to 3.0 mg or 4.5 mg across baseline HbA1c subgroups (<8%; 8.0% to < 9.0%; 9.0% to < 10%; and ≥ 10%).

Gastrointestinal Tolerability of Once-Weekly Dulaglutide 3.0 mg and 4.5 mg: A Post Hoc Analysis of the Incidence and Prevalence of Nausea, Vomiting, and Diarrhea in AWARD-11

BACKGROUND

Gastrointestinal (GI) events are the most frequent treatment-emergent adverse events (TEAEs) reported for glucagon-like peptide-1 receptor agonist therapies. This post hoc analysis of the AWARD-11 phase 3 trial assessed the GI tolerability of dulaglutide at once-weekly doses of 1.5, 3.0, and 4.5 mg.

METHODS

The AWARD-11 trial randomized patients to once-weekly dulaglutide 1.5 mg (n = 612), 3.0 mg (n = 616), or 4.5 mg (n = 614) for 52 weeks. Patients started on dulaglutide 0.75 mg for 4 weeks before escalating stepwise every 4 weeks until the final randomized dose was reached. This study analyzes the onsets, incidences, prevalences, and severities of nausea, vomiting, and diarrhea events reported through 52 weeks.

RESULTS

The highest incidences of nausea (≤ 8%), vomiting (≤ 2%), and diarrhea (≤ 4%) were primarily observed soon after the initiation of dulaglutide treatment at 0.75 mg. Incidence then declined throughout the remainder of the study, even with dose escalation to 1.5, 3.0, and 4.5 mg. Most of these GI TEAEs were mild to moderate in severity, with severe nausea, vomiting, or diarrhea events occurring in ≤ 0.6% of patients. Treatment discontinuation due to nausea was low across treatment groups (≤ 1.5%).

CONCLUSIONS

The tolerability profiles of dulaglutide 3.0 mg and 4.5 mg were consistent with that of the 1.5-mg dose. Patients experiencing GI events were most likely to do so within 2 weeks of treatment initiation, and few patients experienced a new GI event after escalating to the 3.0-mg or 4.5-mg dose. Severe events were infrequent, and when they did occur, no relationship with dose at time of event was observed. Supplementary file1 (MP4 33880 kb).

Efficacy and safety of dulaglutide 3.0 and 4.5 mg in patients aged younger than 65 and 65 years or older: Post hoc analysis of the AWARD-11 trial

AIM

To evaluate the efficacy and safety of dulaglutide 3.0 and 4.5 mg versus 1.5 mg when used as an add-on to metformin in subgroups defined by age (<65 and ≥65 years).

MATERIALS AND METHODS

Of 1842 patients included in this post hoc analysis, 438 were aged 65 years or older and 1404 were younger than 65 years. The intent-to-treat (ITT) population, while on treatment without rescue medication, was used for all efficacy analyses; the ITT population without rescue medication was used for hypoglycaemia analyses; all other safety analyses used the ITT population.

RESULTS

Patients aged 65 years or older and those younger than 65 years had a mean age of 69.5 and 53.2 years, respectively. In each age subgroup, the reduction from baseline in HbA1c and body weight (BW), and the proportion of patients achieving a composite endpoint of HbA1c of less than 7% (<53 mmol/mol) with no weight gain and no documented symptomatic or severe hypoglycaemia, were larger for dulaglutide 3.0 and 4.5 mg compared with dulaglutide 1.5 mg, but the treatment-by-age interactions were not significant. The safety profile for the additional dulaglutide doses was consistent with that of dulaglutide 1.5 mg and was similar between the age subgroups.

CONCLUSION

Dulaglutide doses of 3.0 or 4.5 mg provided clinically relevant, dose-related improvements in HbA1c and BW with no significant treatment-by-age interactions, and with a similar safety profile across age subgroups.

Risk Factors Associated with COVID-19 Hospitalization and Mortality: A Large Claims-Based Analysis Among People with Type 2 Diabetes Mellitus in the United States

INTRODUCTION

Diabetes has been identified as a high-risk comorbidity for COVID-19 hospitalization. We evaluated additional risk factors for COVID-19 hospitalization and in-hospital mortality in a nationwide US database.

METHODS

This retrospective study utilized the UnitedHealth Group Clinical Discovery Database (January 1, 2019-July 15, 2020) containing de-identified nationwide administrative claims, SARS-CoV-2 laboratory test results, and COVID-19 inpatient admissions data. Logistic regression was used to understand risk factors for hospitalization and in-hospital mortality among people with type 2 diabetes (T2D) and in the overall population. Robustness of associations was further confirmed by subgroup and sensitivity analyses in the T2D population.

RESULTS

A total of 36,364 people were identified who were either SARS-CoV-2⁺ or hospitalized for COVID-19. T2D was associated with increased COVID-19-related hospitalization and mortality. Factors associated with increased hospitalization risk were largely consistent in the overall population and the T2D subgroup, including age, male sex, and these top five comorbidities: dementia, metastatic tumor, congestive heart failure, paraplegia, and metabolic disease. Biguanides (mainly metformin) were consistently associated with lower odds of hospitalization, whereas sulfonylureas and insulins were associated with greater odds of hospitalization among people with T2D.

CONCLUSION

In this nationwide US analysis, T2D was identified as an independent risk factor for COVID-19 complications. Many factors conferred similar risk of hospitalization across both populations; however, particular diabetes medications may be markers for differential risk. The insights on comorbidities and medications may inform population health initiatives, including prevention efforts for high-risk patient populations such as those with T2D.

Efficacy and Safety of Dulaglutide 3.0 mg and 4.5 mg Versus Dulaglutide 1.5 mg in Metformin-Treated Patients With Type 2 Diabetes in a Randomized Controlled Trial (AWARD-11)

OBJECTIVE

To compare efficacy and safety of dulaglutide at doses of 3.0 and 4.5 mg versus 1.5 mg in patients with type 2 diabetes inadequately controlled with metformin.

RESEARCH DESIGN AND METHODS

Patients were randomly assigned to once-weekly dulaglutide 1.5 mg, 3.0 mg, or 4.5 mg for 52 weeks. The primary objective was determining superiority of dulaglutide 3.0 mg and/or 4.5 mg over 1.5 mg in HbA_1c reduction at 36 weeks. Secondary superiority objectives included change in body weight. Two estimands addressed efficacy objectives: treatment regimen (regardless of treatment discontinuation or rescue medication) and efficacy (on treatment without rescue medication) in all randomly assigned patients.

RESULTS

Mean baseline HbA_1c and BMI in randomly assigned patients (N = 1,842) was 8.6% (70 mmol/mol) and 34.2 kg/m², respectively. At 36 weeks, dulaglutide 4.5 mg provided superior HbA_1c reductions compared with 1.5 mg (treatment-regimen estimand: -1.77 vs. -1.54% [-19.4 vs. -16.8 mmol/mol], estimated treatment difference [ETD] -0.24% (-2.6 mmol/mol), P < 0.001; efficacy estimand: -1.87 vs. -1.53% [-20.4 vs. -16.7 mmol/mol], ETD -0.34% (-3.7 mmol/mol), P < 0.001). Dulaglutide 3.0 mg was superior to 1.5 mg for reducing HbA_1c, using the efficacy estimand (ETD -0.17% [-1.9 mmol/mol]; P = 0.003) but not the treatment-regimen estimand (ETD -0.10% [-1.1 mmol/mol]; P = 0.096). Dulaglutide 4.5 mg was superior to 1.5 mg for weight loss at 36 weeks for both estimands (treatment regimen: -4.6 vs. -3.0 kg, ETD -1.6 kg, P < 0.001; efficacy: -4.7 vs. -3.1 kg, ETD -1.6 kg, P < 0.001). Common adverse events through 36 weeks included nausea (1.5 mg, 13.4%; 3 mg, 15.6%; 4.5 mg, 16.4%) and vomiting (1.5 mg, 5.6%; 3 mg, 8.3%; 4.5 mg, 9.3%).

CONCLUSIONS

In patients with type 2 diabetes inadequately controlled by metformin, escalation from dulaglutide 1.5 mg to 3.0 mg or 4.5 mg provided clinically relevant, dose-related reductions in HbA_1c and body weight with a similar safety profile.

HbA1c Change and Diabetic Retinopathy During GLP-1 Receptor Agonist Cardiovascular Outcome Trials: A Meta-analysis and Meta-regression

BACKGROUND

Long-term glycemic control reduces retinopathy risk, but transient worsening can occur with glucose control intensification. Glucagon-like peptide 1 receptor agonists (GLP-1RA) lower glucose, but the long-term impact on retinopathy is unknown. GLP-1RA cardiovascular outcome trials (CVOTs) provide long-term follow-up, allowing examination of retinopathy outcomes.

PURPOSE

To examine the associations between retinopathy, HbA_1c, systolic blood pressure (SBP), and weight in GLP-1RA CVOTs.

DATA SOURCES

Systematic review identified six placebo-controlled GLP-1RA CVOTs reporting prespecified retinopathy outcomes.

STUDY SELECTION

Published trial reports were used as the primary data sources.

DATA EXTRACTION

HbA_1c, SBP, and weight data throughout follow-up by treatment group were extracted.

DATA SYNTHESIS

Random-effects model meta-analysis showed no association between GLP-1RA treatment and retinopathy (odds ratio [OR] 1.10; 95% CI 0.93, 1.30), with high heterogeneity between studies (I ² = 52.2%; Q statistic P = 0.063). Univariate meta-regression showed an association between retinopathy and average HbA_1c reduction during the overall follow-up (slope = 0.77, P = 0.007), but no relationship for SBP or weight. Sensitivity analyses for HbA_1c showed a relationship at 3 months (P = 0.006) and 1 year (P = 0.002). A 0.1% (1.09 mmol/mol) increase in HbA_1c reduction was associated with 6%, 14%, or 8% increased Ln(OR) for retinopathy at the 3-month, 1-year, and overall follow-up, respectively.

LIMITATIONS

CVOTs were not powered to assess retinopathy outcomes and differed in retinopathy-related criteria and methodology. The median follow-up of 3.4 years is short compared with the onset of retinopathy.

CONCLUSIONS

HbA_1c reduction was significantly associated with increased retinopathy risk in meta-regression for GLP-1RA CVOTs. The magnitude of HbA_1c reduction was correlated with retinopathy risk in people with diabetes and additional cardiovascular risk factors, but the long-term impact of improved glycemic control on retinopathy was unmeasured in these studies. Retinopathy status should be assessed when intensifying glucose-lowering therapy.

Prediction and validation of exenatide risk marker effects on progression of renal disease: Insights from EXSCEL

AIM

To assess whether the previously developed multivariable risk prediction framework (PRE score) could predict the renal effects observed in the EXSCEL cardiovascular outcomes trial using short-term changes in cardio-renal risk markers.

MATERIALS AND METHODS

Changes from baseline to 6 months in HbA1c, systolic blood pressure (SBP), body mass index (BMI), haemoglobin, total cholesterol, and new micro- or macroalbuminuria were evaluated. The renal outcomes were defined as a composite of a sustained 30% or 40% decline in estimated glomerular filtration rate (eGFR) or end-stage renal disease (ESRD). Relationships between risk markers and long-term renal outcomes were determined in patients with type 2 diabetes from the ALTITUDE study using multivariable Cox regression analysis, and then applied to short-term changes in risk markers observed in EXSCEL to predict the exenatide-induced impact on renal outcomes.

RESULTS

Compared with placebo, mean HbA1c, BMI, SBP and total cholesterol were lower at 6 months with exenatide, as was the incidence of new microalbuminuria. The PRE score predicted a relative risk reduction for the 30% eGFR decline + ESRD endpoint of 11.3% (HR 0.89; 95% CI 0.83-0.94), compared with 12.7% (HR 0.87; 0.77-0.99) observed risk reduction. For the 40% eGFR decline + ESRD endpoint, the predicted and observed risk reductions were 11.0% (HR 0.89; 0.82-0.97) and 13.7% (HR 0.86, 0.72-1.04), respectively.

CONCLUSIONS

Integrating short-term risk marker changes into a multivariable risk score predicted the magnitude of renal risk reduction observed in EXSCEL.

Confirming the Bidirectional Nature of the Association Between Severe Hypoglycemic and Cardiovascular Events in Type 2 Diabetes: Insights From EXSCEL

OBJECTIVE

We sought to confirm a bidirectional association between severe hypoglycemic events (SHEs) and cardiovascular (CV) event risk and to characterize individuals at dual risk.

RESEARCH DESIGN AND METHODS

In a post hoc analysis of 14,752 Exenatide Study of Cardiovascular Event Lowering (EXSCEL) participants, we examined time-dependent associations between SHEs and subsequent major adverse cardiac events (CV death, nonfatal myocardial infarction [MI] or stroke), fatal/nonfatal MI, fatal/nonfatal stroke, hospitalization for acute coronary syndrome (hACS), hospitalization for heart failure (hHF), and all-cause mortality (ACM), as well as time-dependent associations between nonfatal CV events and subsequent SHEs.

RESULTS

SHEs were uncommon and not associated with once-weekly exenatide therapy (hazard ratio 1.13 [95% CI 0.94-1.36], P = 0.179). In fully adjusted models, SHEs were associated with an increased risk of subsequent ACM (1.83 [1.38-2.42], P < 0.001), CV death (1.60 [1.11-2.30], P = 0.012), and hHF (2.09 [1.37-3.17], P = 0.001), while nonfatal MI (2.02 [1.35-3.01], P = 0.001), nonfatal stroke (2.30 [1.25-4.23], P = 0.007), hACS (2.00 [1.39-2.90], P < 0.001), and hHF (3.24 [1.98-5.30], P < 0.001) were all associated with a subsequent increased risk of SHEs. The elevated bidirectional time-dependent hazards linking SHEs and a composite of all CV events were approximately constant over time, with those individuals at dual risk showing higher comorbidity scores compared with those without.

CONCLUSIONS

These findings, showing greater risk of SHEs after CV events as well as greater risk of CV events after SHEs, validate a bidirectional relationship between CV events and SHEs in patients with high comorbidity scores.

Exploring the Possible Impact of Unbalanced Open-Label Drop-In of Glucose-Lowering Medications on EXSCEL Outcomes

BACKGROUND

EXSCEL (Exenatide Study of Cardiovascular Event Lowering) assessed the impact of once-weekly exenatide 2 mg versus placebo in patients with type 2 diabetes mellitus, while aiming for glycemic equipoise. Consequently, greater drop-in of open-label glucose-lowering medications occurred in the placebo group. Accordingly, we explored the potential effects of their unbalanced use on major adverse cardiovascular events (MACE), defined as cardiovascular death, nonfatal myocardial infarction or nonfatal stroke, and all-cause mortality (ACM), given that some of these agents are cardioprotective.

METHODS

Cox hazard models were performed by randomized treatment for drug classes where >5% open-label drop-in glucose-lowering medication occurred, and for glucagon-like peptide-1 receptor agonists (GLP-1 RAs; 3.0%) using three methodologies: drop-in visit right censoring, inverse probability for treatment weighting (IPTW), and applying drug class risk reductions.

RESULTS

Baseline glucose-lowering medications for the 14 752 EXSCEL participants (73.1% with previous cardiovascular disease) did not differ between treatment groups. During median 3.2 years follow-up, open-label drop-in occurred in 33.4% of participants, more frequently with placebo than exenatide (38.1% versus 28.8%), with metformin (6.1% versus 4.9%), sulfonylurea (8.7% versus 6.9%), dipeptidyl peptidase-4 inhibitors (10.6% versus 7.5%), SGLT-2i (10.3% versus 8.1%), GLP-1 RA (3.4% versus 2.4%), and insulin (13.8% versus 9.4%). The MACE effect size was not altered meaningfully by right censoring, but the favorable HR for exenatide became nominally significant in the sulfonylurea and any glucose-lowering medication groups, while the ACM HR and p-values were essentially unchanged. IPTW decreased the MACE HR from 0.91 (P=0.061) to 0.85 (P=0.008) and the ACM HR from 0.86 (P=0.016) to 0.81 (P=0.012). Application of literature-derived risk reductions showed no meaningful changes in MACE or ACM HRs or P values, although simulations of substantially greater use of drop-in cardioprotective glucose-lowering agents demonstrated blunting of signal detection.

CONCLUSIONS

EXSCEL-observed HRs for MACE and ACM remained robust after right censoring or application of literature-derived risk reductions, but the exenatide versus placebo MACE effect size and statistical significance were increased by IPTW. Effects of open-label drop-in cardioprotective medications need to be considered carefully when designing, conducting, and analyzing cardiovascular outcome trials of glucose-lowering agents under the premise of glycemic equipoise. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01144338.

Microvascular and Cardiovascular Outcomes According to Renal Function in Patients Treated With Once-Weekly Exenatide: Insights From the EXSCEL Trial

OBJECTIVE

To evaluate the impact of once-weekly exenatide (EQW) on microvascular and cardiovascular (CV) outcomes by baseline renal function in the Exenatide Study of Cardiovascular Event Lowering (EXSCEL).

RESEARCH DESIGN AND METHODS

Least squares mean difference (LSMD) in estimated glomerular filtration rate (eGFR) from baseline between the EQW and placebo groups was calculated for 13,844 participants. Cox regression models were used to estimate effects by group on incident macroalbuminuria, retinopathy, and major adverse CV events (MACE). Interval-censored time-to-event models estimated effects on renal composite 1 (40% eGFR decline, renal replacement, or renal death) and renal composite 2 (composite 1 variables plus macroalbuminuria).

RESULTS

EQW did not change eGFR significantly (LSMD 0.21 mL/min/1.73 m² [95% CI -0.27 to 0.70]). Macroalbuminuria occurred in 2.2% of patients in the EQW group and in 2.5% of those in the placebo group (hazard ratio [HR] 0.87 [95% CI 0.70-1.07]). Neither renal composite was reduced with EQW in unadjusted analyses, but renal composite 2 was reduced after adjustment (HR 0.85 [95% CI 0.74-0.98]). Retinopathy rates did not differ by treatment group or in the HbA_1c-lowering or prior retinopathy subgroups. CV outcomes in those with eGFR <60 mL/min/1.73 m² did not differ by group. Those with eGFR ≥60 mL/min/1.73 m² had nominal risk reductions for MACE, all-cause mortality, and CV death, but interactions by renal function group were significant for only stroke (HR 0.74 [95% CI 0.58-0.93]; P for interaction = 0.035) and CV death (HR 1.08 [95% CI 0.85-1.38]; P for interaction = 0.031).

CONCLUSIONS

EQW had no impact on unadjusted retinopathy or renal outcomes. CV risk was modestly reduced only in those with eGFR ≥60 mL/min/1.73 m² in analyses unadjusted for multiplicity.

Within-Trial Evaluation of Medical Resources, Costs, and Quality of Life Among Patients With Type 2 Diabetes Participating in the Exenatide Study of Cardiovascular Event Lowering (EXSCEL)

OBJECTIVE

To compare medical resource use, costs, and health utilities for 14,752 patients with type 2 diabetes who were randomized to once-weekly exenatide (EQW) or placebo in addition to usual diabetes care in the Exenatide Study of Cardiovascular Event Lowering (EXSCEL).

RESEARCH DESIGN AND METHODS

Medical resource use data and responses to the EuroQol 5-Dimension (EQ-5D) instrument were collected at baseline and throughout the trial. Medical resources and medications were assigned values by using U.S. Medicare payments and wholesale acquisition costs, respectively. Secondary analyses used English costs.

RESULTS

Patients were followed for an average of 3.3 years, during which time those randomized to EQW experienced 0.41 fewer inpatient days (7.05 vs. 7.46 days; relative rate ratio 0.91; P = 0.05). Rates of outpatient medical visits were similar, as were total inpatient and outpatient costs. Mean costs for nonstudy diabetes medications over the study period were ∼$1,600 lower with EQW than with placebo (P = 0.01). Total within-study costs, excluding study medication, were lower in the EQW arm than in the placebo arm ($28,907 vs. $30,914; P ≤ 0.01). When including the estimated cost of EQW, total mean costs were significantly higher in the EQW group than in the placebo group ($42,697 vs. $30,914; P < 0.01). With English costs applied, mean total costs, including exenatide costs, were £1,670 higher in the EQW group than the placebo group (£10,874 vs. £9,204; P < 0.01). There were no significant differences in EQ-5D health utilities between arms over time.

CONCLUSIONS

Medical costs were lower in the EQW arm than the placebo arm, but total costs were significantly higher once the cost of branded exenatide was incorporated.

Effect of Once-Weekly Exenatide on Clinical Outcomes According to Baseline Risk in Patients With Type 2 Diabetes Mellitus: Insights From the EXSCEL Trial

Background

In the EXSCEL (Exenatide Study of Cardiovascular Event Lowering), exenatide once‐weekly resulted in a nonsignificant reduction in major adverse cardiovascular events (MACEs) and a nominal 14% reduction in all‐cause mortality in 14 752 patients with type 2 diabetes mellitus (T2DM) with and without cardiovascular disease. Whether patients at increased risk for events experienced a comparatively greater treatment benefit with exenatide is unknown.

Methods and Results

In the EXSCEL population, we created risk scores for MACEs and all‐cause mortality using step‐wise selection of baseline characteristics. A risk score was calculated for each patient, and a time‐to‐event model for each end point was developed including the risk score, treatment assignment, and risk‐treatment interaction. Interaction P values evaluating for a differential treatment effect by baseline risk were reported. Over a median follow‐up of 3.2 years (interquartile range, 2.2, 4.4), 1091 (7.4%) patients died and 1744 (11.8%) experienced a MACE. Independent predictors of MACEs and all‐cause mortality included age, sex, comorbidities (eg, previous cardiovascular event), body mass index, blood pressure, hemoglobin A1c, and estimated glomerular filtration rate. The all‐cause mortality and MACE risk models had modest discrimination with optimism‐corrected c‐indices of 0.73 and 0.71, respectively. No interaction was observed between treatment effect and risk profile for either end point (both interactions, P>0.1).

Conclusions

Baseline characteristics (eg, age, previous cardiovascular events) and routine laboratory values (eg, hemoglobin A1c, estimated glomerular filtration rate) provided modest prognostic value for mortality and MACEs in a broad population of patients with type 2 diabetes mellitus. Exenatide's effects on mortality and MACEs were consistent across the spectrum of baseline risk.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01144338.

Meta-analysis of the impact of alpha-glucosidase inhibitors on incident diabetes and cardiovascular outcomes

Background

Alpha-glucosidase inhibitors (AGIs) have been shown to reduce incident type 2 diabetes but their impact on cardiovascular (CV) disease remains controversial. We sought to identify the overall impact of AGIs with respect to incident type 2 diabetes in individuals with impaired glucose tolerance (IGT), and CV outcomes in those with IGT or type 2 diabetes.

Methods

We used PubMed and SCOPUS to identify randomized controlled trials reporting the incidence of type 2 diabetes and/or CV outcomes that had compared AGIs with placebo in populations with IGT or type 2 diabetes, with or without established CV disease. Eligible studies were required to have ≥ 500 participants and/or ≥ 100 endpoints of interest. Meta-analyses of available trial data were performed using random effects models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident type 2 diabetes and CV outcomes.

Results

Of ten trials identified, three met our inclusion criteria for incident type 2 diabetes and four were eligible for CV outcomes. The overall HR (95% CI) comparing AGI with placebo for incident type 2 diabetes was 0.77 (0.67–0.88), p < 0.0001, and for CV outcomes was 0.98 (0.89–1.10), p = 0.85. There was little to no heterogeneity between studies, with I² values of 0.03% (p = 0.43) and 0% (p = 0.79) for the two outcomes respectively.

Conclusions

Allocation of people with IGT to an AGI significantly reduced their risk of incident type 2 diabetes by 23%, whereas in those with IGT or type 2 diabetes the impact on CV outcomes was neutral.

Changes in Serum Calcitonin Concentrations, Incidence of Medullary Thyroid Carcinoma, and Impact of Routine Calcitonin Concentration Monitoring in the EXenatide Study of Cardiovascular Event Lowering (EXSCEL)

OBJECTIVE

Increases in serum calcitonin, a tumor marker for medullary thyroid carcinoma (MTC), have been associated with glucagon-like peptide 1 receptor agonist use in some preclinical studies. We report calcitonin changes in exenatide-treated and placebo-administered participants and MTC incidence in the EXenatide Study of Cardiovascular Event Lowering (EXSCEL) and consider the impact of within-trial calcitonin monitoring.

RESEARCH DESIGN AND METHODS

EXSCEL participants were randomized 1:1 to once-weekly exenatide 2 mg or placebo. Serum calcitonin was measured at baseline (with trial medication discontinued if >40 ng/L) and annually thereafter (with trial medication discontinued if ≥50 ng/L). Median calcitonin concentrations were calculated at each time point, and thyroid malignancies were collected prospectively. Data regarding follow-up after an elevated calcitonin were collected retrospectively.

RESULTS

At baseline, 52 (30 exenatide and 22 placebo) participants had calcitonin >40 ng/L, and during follow-up an additional 23 participants (15 exenatide and 8 placebo) had calcitonin ≥50 ng/L in the intention-to-treat population. Median calcitonin concentrations were similar between treatment groups at baseline with no increase over time. Confirmed MTC occurred in three participants (2 exenatide and 1 placebo), all of whom had significantly elevated baseline calcitonin values (413, 422, and 655 ng/L).

CONCLUSIONS

During a median 3.2 years' follow-up, no change in serum calcitonin was seen with exenatide therapy. The three confirmed cases of MTC all occurred in participants with markedly elevated baseline calcitonin levels, measured prior to trial medication administration. Regular calcitonin monitoring identified no additional cases of MTC, suggesting no benefit of routine calcitonin monitoring during exenatide treatment.

Progression of glucose-lowering diabetes therapy in TECOS

AIMS

TECOS was a randomized, double-blind, placebo-controlled trial assessing the impact of sitagliptin vs. placebo on cardiovascular outcomes when added to usual care in patients with type 2 diabetes. We report the use of concomitant diabetes medications and the risk for progression to insulin during follow-up.

MATERIALS AND METHODS

TECOS enrolled 14 671 participants with HbA1c 6.5%-8.0% on monotherapy with metformin, pioglitazone, sulfonylurea (SU), or dual therapy with two oral agents or insulin with or without metformin. Subsequent diabetes management was by the participant's usual care physician. Time to initiation of insulin and risk of hypoglycaemia were estimated using Cox proportional hazards models.

RESULTS

The most common glucose-lowering regimens at baseline were metformin monotherapy (30.2%), SU monotherapy (8.5%), metformin/SU therapy (35.1%), and insulin with or without metformin (13.9% and 8.6%, respectively). Over a median 3.0 years' follow-up, diabetes therapy was intensified in 25.2% of participants (sitagliptin 22.0%, placebo 28.3%). Medications most commonly added were SU (8.3%) or insulin (8.8%). Insulin initiation in the usual care setting occurred at mean (standard deviation) HbA1c of 8.5 (1.5)%. Sitagliptin did not impact rates of severe hypoglycaemia, but delayed progression to insulin when added to metformin or metformin/SU regimens.

CONCLUSION

Consistent with the trial's pragmatic design, TECOS participants underwent typical progression of diabetes medications. Sitagliptin was associated with lower HbA1c, without increased risk for severe hypoglycaemia and was associated with delayed progression to insulin when added to metformin with or without SU.

Sex differences in management and outcomes of patients with type 2 diabetes and cardiovascular disease: A report from TECOS

AIM

To examine sex differences in baseline characteristics and outcomes in patients with type 2 diabetes and atherosclerotic vascular disease.

MATERIALS AND METHODS

Cox models were used to analyse the association between sex and outcomes in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), a randomized, placebo-controlled trial assessing the impact of sitagliptin on cardiovascular (CV) outcomes in patients with type 2 diabetes and atherosclerotic vascular disease.

RESULTS

A total of 4297 women and 10 374 men were followed for a median of 3.0 years. Women were slightly older and more often had cerebrovascular disease and peripheral arterial disease but less often coronary heart disease than men. At baseline, women were less likely to use aspirin or statins. The primary composite outcome of CV death, myocardial infarction, stroke, or hospitalization for unstable angina occurred in 418 women (9.7%) and 1272 men (12.3%; 3.48 vs 4.38 events/100 participant-years, crude hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.71-0.89, adjusted HR 0.64, 95% CI 0.55-0.74; P < .0001). Women also had a significantly lower risk of secondary CV outcomes and all-cause death.

CONCLUSIONS

In this large prospective study of people with type 2 diabetes and CV disease, women had different CV disease burden, worse CV risk factor profiles, and less use of indicated medications than men. Despite this, women had significantly lower risk of CV events, suggesting that the cardioprotective effects of female sex extend to populations with type 2 diabetes.

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.

Metformin in non-diabetic hyperglycaemia: the GLINT feasibility RCT

BACKGROUND

The treatment of people with diabetes with metformin can reduce cardiovascular disease (CVD) and may reduce the risk of cancer. However, it is unknown whether or not metformin can reduce the risk of these outcomes in people with elevated blood glucose levels below the threshold for diabetes [i.e. non-diabetic hyperglycaemia (NDH)].

OBJECTIVE

To assess the feasibility of the Glucose Lowering In Non-diabetic hyperglycaemia Trial (GLINT) and to estimate the key parameters to inform the design of the full trial. These parameters include the recruitment strategy, randomisation, electronic data capture, postal drug distribution, retention, study medication adherence, safety monitoring and remote collection of outcome data.

DESIGN

A multicentre, individually randomised, double-blind, parallel-group, pragmatic, primary prevention trial. Participants were individually randomised on a 1 : 1 basis, blocked within each site.

SETTING

General practices and clinical research facilities in Cambridgeshire, Norfolk and Leicestershire.

PARTICIPANTS

Males and females aged ≥ 40 years with NDH who had a high risk of CVD.

INTERVENTIONS

Prolonged-release metformin (500 mg) (Glucophage® SR, Merck KGaA, Bedfont Cross, Middlesex, UK) or the matched placebo, up to three tablets per day, distributed by post.

MAIN OUTCOME MEASURES

Recruitment rates; adherence to study medication; laboratory results at baseline and 3 and 6 months; reliability and acceptability of study drug delivery; questionnaire return rates; and quality of life.

RESULTS

We sent 5251 invitations, with 511 individuals consenting to participate. Of these, 249 were eligible and were randomised between March and November 2015 (125 to the metformin group and 124 to the placebo group). Participants were followed up for 0.99 years [standard deviation (SD) 0.30 years]. The use of electronic medical records to identify potentially eligible individuals in individual practices was resource intensive. Participants were generally elderly [mean age 70 years (SD 6.7 years)], overweight [mean body mass index 30.1 kg/m2 (SD 4.5 kg/m2)] and male (88%), and the mean modelled 10-year CVD risk was 28.8% (SD 8.5%). Randomisation, postal delivery of the study drug and outcome assessment using registers/medical records were feasible and acceptable to participants. Most participants were able to take three tablets per day, but premature discontinuation of the study drug was common (≈30% of participants by 6 months), although there were no differences between the groups. All randomised participants returned questionnaires at baseline and 67% of participants returned questionnaires by the end of the study. There was no between-group difference in Short Form questionnaire-8 items or EuroQol-5 Dimensions scores. Compared with placebo, metformin was associated with small improvements in the mean glycated haemoglobin level [-0.82 mmol/mol, 95% confidence interval (CI) -1.39 to -0.24 mmol/mol], mean estimated glomerular filtration rate (2.31 ml/minute/1.73 m2, 95% CI -0.2 to 4.81 ml/minute/1.73 m2) and mean low-density lipoprotein cholesterol level (-0.11 mmol/l, 95% CI -0.25 to 0.02 mmol/l) and a reduction in mean plasma vitamin B12 level (-16.4 ng/l, 95% CI -32.9 to -0.01 ng/l). There were 35 serious adverse events (13 in the placebo group, 22 in the metformin group), with none deemed to be treatment related.

LIMITATIONS

Changes to sponsorship reduced the study duration, the limited availability of information in medical records reduced recruitment efficiency and discontinuation of study medication exceeded forecasts.

CONCLUSIONS

A large, pragmatic trial comparing the effects of prolonged-release metformin and placebo on the risk of CVD events is potentially feasible. However, changes to the study design and conduct are recommended to enable an efficient scaling up of the trial. Recommendations include changing the inclusion criteria to recruit people with pre-existing CVD to increase the recruitment and event rates, using large primary/secondary care databases to increase recruitment rates, conducting follow-up remotely to improve efficiency and including a run-in period prior to randomisation to optimise trial adherence.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN34875079.

FUNDING

The project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 18. See the NIHR Journals Library website for further project information. Merck KGaA provided metformin and matching placebo.

Cardiovascular outcomes with glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes: a meta-analysis

BACKGROUND

Glucagon-like peptide-1 (GLP-1) receptor agonists are effective glucose-lowering drugs. Findings from cardiovascular outcome trials showed cardiovascular safety of GLP-1 receptor agonists, but results for cardiovascular efficacy were varied. We aimed to examine overall cardiovascular efficacy for lixisenatide, liraglutide, semaglutide, and extended-release exenatide.

METHODS

In this systematic review and meta-analysis, we analysed data from eligible trials that assessed the safety and efficacy of GLP-1 receptor agonists compared with placebo in adult patients (aged 18 years or older) with type 2 diabetes and had a primary outcome including, but not limited to, cardiovascular mortality, non-fatal myocardial infarction, and non-fatal stroke. We searched PubMed and MEDLINE without language restrictions up to Sept 18, 2017, for eligible trials. We did a meta-analysis of available trial data using a random-effects model to calculate overall hazard ratios (HRs) for cardiovascular efficacy outcomes and odds ratios for key safety outcomes.

FINDINGS

Of 12 articles identified in our search and screened for eligibility, four trials of cardiovascular outcomes of GLP-1 receptor agonists were identified: ELIXA (lixisenatide), LEADER (liraglutide), SUSTAIN 6 (semaglutide), and EXSCEL (extended-release exenatide). Compared with placebo, GLP-1 receptor agonist treatment showed a significant 10% relative risk reduction in the three-point major adverse cardiovascular event primary outcome (cardiovascular mortality, non-fatal myocardial infarction, and non-fatal stroke; HR 0·90, 95% CI 0·82-0·99; p=0·033), a 13% RRR in cardiovascular mortality (0·87, 0·79-0·96; p=0·007), and a 12% relative risk reduction in all-cause mortality (0·88, 0·81-0·95; p=0·002), with low-to-moderate between-trial statistical heterogeneity. No significant effect of GLP-1 receptor agonists was identified on fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, hospital admission for unstable angina, or hospital admission for heart failure. Overall, no significant differences were seen in severe hypoglycaemia, pancreatitis, pancreatic cancer, or medullary thyroid cancer reported between GLP-1 receptor agonist treatment and placebo.

INTERPRETATION

Our findings show cardiovascular safety across all GLP-1 receptor agonist cardiovascular outcome trials and suggest that drugs in this class can reduce three-point major adverse cardiovascular events, cardiovascular mortality, and all-cause mortality risk, albeit to varying degrees for individual drugs, without significant safety concerns. GLP-1 receptor agonists have a favourable risk-benefit balance overall, which should allow the choice of drug to be individualised to each patient's needs.

FUNDING

Amylin Pharmaceuticals (AstraZeneca).

Modelling incremental benefits on complications rates when targeting lower HbA1c levels in people with Type 2 diabetes and cardiovascular disease

AIM

Glucose-lowering interventions in Type 2 diabetes mellitus have demonstrated reductions in microvascular complications and modest reductions in macrovascular complications. However, the degree to which targeting different HbA_1c reductions might reduce risk is unclear.

METHODS

Participant-level data for Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) participants with established cardiovascular disease were used in a Type 2 diabetes-specific simulation model to quantify the likely impact of different HbA_1c decrements on complication rates. Ten-year micro- and macrovascular rates were estimated with HbA_1c levels fixed at 86, 75, 64, 53 and 42 mmol/mol (10%, 9%, 8%, 7% and 6%) while holding other risk factors constant at their baseline levels. Cumulative relative risk reductions for each outcome were derived for each HbA_1c decrement.

RESULTS

Of 5717 participants studied, 72.0% were men and 74.2% White European, with a mean (sd) age of 66.2 (7.9) years, systolic blood pressure 134 (16.9) mmHg, LDL-cholesterol 2.3 (0.9) mmol/l, HDL-cholesterol 1.13 (0.3) mmol/l and median Type 2 diabetes duration 9.6 (5.1-15.6) years. Ten-year cumulative relative risk reductions for modelled HbA_1c values of 75, 64, 53 and 42 mmol/mol, relative to 86 mmol/mol, were 4.6%, 9.3%, 15.1% and 20.2% for myocardial infarction; 6.0%, 12.8%, 19.6% and 25.8% for stroke; 14.4%, 26.6%, 37.1% and 46.4% for diabetes-related ulcer; 21.5%, 39.0%, 52.3% and 63.1% for amputation; and 13.6%, 25.4%, 36.0% and 44.7 for single-eye blindness.

CONCLUSIONS

These simulated complication rates might help inform the degree to which complications might be reduced by targeting particular HbA_1c reductions in Type 2 diabetes.

Relationship between baseline physical activity assessed by pedometer count and new-onset diabetes in the NAVIGATOR trial

OBJECTIVE

Physical activity is related to clinical outcomes, even after adjusting for body mass, but is rarely assessed in randomized clinical trials.

RESEARCH DESIGN AND METHODS

We conducted an observational analysis of data from the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research trial, in which a total of 9306 people from 40 countries with impaired glucose tolerance and either cardiovascular disease or cardiovascular risk factors were randomized to receive nateglinide or placebo, in a 2-by-2 factorial design with valsartan or placebo. All were asked to also participate in a detailed lifestyle modification programme and followed-up for a median of 6.4 years with progression to diabetes as a co-primary end point. Seven-day ambulatory activity was assessed at baseline using research-grade pedometers. We assessed whether the baseline amount of physical activity was related to subsequent development of diabetes in individuals with impaired glucose tolerance.

RESULTS

Pedometer data were obtained on 7118 participants and 35.0% developed diabetes. In an unadjusted analysis each 2000-step increment in the average number of daily steps, up to 10 000, was associated with a 5.5% lower risk of progression to diabetes (HR 0.95, 95%CI 0.92 to 0.97), with >6% relative risk reduction after adjustment.

CONCLUSIONS

Physical activity should be measured objectively in pharmacologic trials as it is a significant but underappreciated contributor to diabetes outcomes. It should be a regular part of clinical practice as well.

Effects of Once-Weekly Exenatide on Cardiovascular Outcomes in Type 2 Diabetes

BACKGROUND

The cardiovascular effects of adding once-weekly treatment with exenatide to usual care in patients with type 2 diabetes are unknown.

METHODS

We randomly assigned patients with type 2 diabetes, with or without previous cardiovascular disease, to receive subcutaneous injections of extended-release exenatide at a dose of 2 mg or matching placebo once weekly. The primary composite outcome was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The coprimary hypotheses were that exenatide, administered once weekly, would be noninferior to placebo with respect to safety and superior to placebo with respect to efficacy.

RESULTS

In all, 14,752 patients (of whom 10,782 [73.1%] had previous cardiovascular disease) were followed for a median of 3.2 years (interquartile range, 2.2 to 4.4). A primary composite outcome event occurred in 839 of 7356 patients (11.4%; 3.7 events per 100 person-years) in the exenatide group and in 905 of 7396 patients (12.2%; 4.0 events per 100 person-years) in the placebo group (hazard ratio, 0.91; 95% confidence interval [CI], 0.83 to 1.00), with the intention-to-treat analysis indicating that exenatide, administered once weekly, was noninferior to placebo with respect to safety (P<0.001 for noninferiority) but was not superior to placebo with respect to efficacy (P=0.06 for superiority). The rates of death from cardiovascular causes, fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, hospitalization for heart failure, and hospitalization for acute coronary syndrome, and the incidence of acute pancreatitis, pancreatic cancer, medullary thyroid carcinoma, and serious adverse events did not differ significantly between the two groups.

CONCLUSIONS

Among patients with type 2 diabetes with or without previous cardiovascular disease, the incidence of major adverse cardiovascular events did not differ significantly between patients who received exenatide and those who received placebo. (Funded by Amylin Pharmaceuticals; EXSCEL ClinicalTrials.gov number, NCT01144338 .).

Secondary Prevention of Cardiovascular Disease in Patients With Type 2 Diabetes Mellitus: International Insights From the TECOS Trial (Trial Evaluating Cardiovascular Outcomes With Sitagliptin)

BACKGROUND

Intensive risk factor modification significantly improves outcomes for patients with diabetes mellitus and cardiovascular disease. However, the degree to which secondary prevention treatment goals are achieved in international clinical practice is unknown.

METHODS

Attainment of 5 secondary prevention parameters-aspirin use, lipid control (low-density lipoprotein cholesterol <70 mg/dL or statin therapy), blood pressure control (<140 mm Hg systolic, <90 mm Hg diastolic), angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, and nonsmoking status-was evaluated among 13 616 patients from 38 countries with diabetes mellitus and known cardiovascular disease at entry into TECOS (Trial Evaluating Cardiovascular Outcomes With Sitagliptin). Logistic regression was used to evaluate the association between individual and regional factors and secondary prevention achievement at baseline. Cox proportional hazards regression analysis was used to determine the association between baseline secondary prevention achievement and cardiovascular death, myocardial infarction, or stroke.

RESULTS

Overall, 29.9% of patients with diabetes mellitus and cardiovascular disease achieved all 5 secondary prevention parameters at baseline, although 71.8% achieved at least 4 parameters. North America had the highest proportion (41.2%), whereas Western Europe, Eastern Europe, and Latin America had proportions of ≈25%. Individually, blood pressure control (57.9%) had the lowest overall attainment, whereas nonsmoking status had the highest (89%). Over a median 3.0 years of follow-up, a higher baseline secondary prevention score was associated with improved outcomes in a step-wise graded relationship (adjusted hazard ratio, 0.60; 95% confidence interval, 0.47-0.77 for those patients achieving all 5 measures versus those achieving ≤2).

CONCLUSIONS

In an international trial population, significant opportunities exist to improve the quality of cardiovascular secondary prevention care among patients with diabetes mellitus and cardiovascular disease, which in turn could lead to reduced risk of downstream cardiovascular events.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00790205.

Effect of valsartan on kidney outcomes in people with impaired glucose tolerance

AIMS

To examine the effect of valsartan on kidney outcomes in patients with impaired glucose tolerance (IGT).

METHODS

In a double-blind randomized trial, 9306 patients with IGT were assigned to valsartan (160 mg daily) or placebo. The co-primary endpoints were the development of diabetes and two composite cardiovascular outcomes. Prespecified renal endpoints included: the composite of renal death, end-stage renal disease (ESRD) or doubling of serum creatinine; estimated glomerular filtration rate (eGFR) ≤30 mL/min/1.73 m² ; hospitalization for renal failure; and progression from normoalbuminuria to microalbuminuria, microalbuminuria to macroalbuminuria, and normoalbuminuria to macroalbuminuria. The median follow-up was 6.2 years.

RESULTS

Valsartan reduced the incidence of diabetes but not cardiovascular events. In the valsartan group, 25/4631 patients (0.5%), vs 26/4675 (0.6%) patients in the placebo group, developed ESRD or experienced doubling of serum creatinine (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.55-1.66; P  = .87). Few patients in either group developed an eGFR of ≤30 mL/min/1.73 m² or had a renal hospitalization. Fewer patients on valsartan (237/4084 [5.8%]) than on placebo (342/4092 [8.4%]) developed microalbuminuria (HR 0.68, 95% CI 0.57-0.80; P  < .0001), and fewer valsartan-treated patients developed macroalbuminuria. Overall, urinary albumin-to-creatinine ratio (UACR) was 11% lower with valsartan (95% CI 8-13; P  < .0001) and 9% lower (95% CI 6-11; P  < .0001) after adjusting for both glucose and blood pressure.

CONCLUSIONS

The effect of valsartan on UACR was not wholly explained by change in blood pressure or glucose. Valsartan reduced the incidence of microalbuminuria in IGT without increasing the incidence of hyperkalaemia or renal dysfunction compared with placebo.

Baseline characteristics of patients enrolled in the Exenatide Study of Cardiovascular Event Lowering (EXSCEL)

BACKGROUND

EXSCEL is a randomized, double-blind, placebo-controlled trial examining the effect of exenatide once-weekly (EQW) versus placebo on time to the primary composite outcome (cardiovascular death, nonfatal myocardial infarction or nonfatal stroke) in patients with type 2 diabetes mellitus (DM) and a wide range of cardiovascular (CV) risk.

METHODS

Patients were enrolled at 688 sites in 35 countries. We describe their baseline characteristics according to prior CV event status and compare patients with those enrolled in prior glucagon-like peptide-1 receptor agonist (GLP-1RA) outcomes trials.

RESULTS

Of a total of 14,752 participants randomized between June 2010 and September 2015, 6,788 (46.0%) patients were enrolled in Europe; 3,708 (25.1%), North America; 2,727 (18.5%), Latin America; and 1,529 (10.4%), Asia Pacific. Overall, 73% had at least one prior CV event (70% coronary artery disease, 24% peripheral arterial disease, 22% cerebrovascular disease). The median (IQR) age was 63 years (56, 69), 38% were female, median baseline HbA1c was 8.0% (7.3, 8.9) and 16% had a prior history of heart failure. Those without a prior CV event were younger with a shorter duration of diabetes and better renal function than those with at least one prior CV event. Compared with prior GLP-1RA trials, EXSCEL has a larger percentage of patients without a prior CV event and a notable percentage who were taking a dipeptidyl peptidase-4 inhibitor at baseline (15%).

CONCLUSIONS

EXSCEL is one of the largest global GLP-1RA trials, evaluating the safety and efficacy of EQW with a broad patient population that may extend generalizability compared to prior GLP-1RA trials (ClinicalTrials.gov number, NCT01144338).

Assessing the Safety of Sitagliptin in Older Participants in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS)

OBJECTIVE

Limited data exist regarding safety and efficacy of antihyperglycemic drugs in older patients with type 2 diabetes. The Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) was a randomized, double-blind, placebo-controlled trial assessing the impact of sitagliptin on a primary composite outcome of cardiovascular death, nonfatal stroke, nonfatal myocardial infarction, or unstable angina hospitalizations in patients with type 2 diabetes (HbA_1c ≥6.5% [48 mmol/mol] and ≤8.0% [64 mmol/mol]) and cardiovascular disease. We analyzed baseline characteristics and clinical outcomes for TECOS participants aged ≥75 years.

RESEARCH DESIGN AND METHODS

Clinical and safety event summaries are presented for older versus younger participants and for the treatment groups within the older cohort.

RESULTS

Of 14,351 participants with age recorded, 2,004 (14%) were ≥75 years old (mean age 78.3 years [SD 3.1]), with 68% men and type 2 diabetes duration median 12.0 years (IQR 7, 21). During 2.9 years median follow-up, older participants had higher rates of the primary outcome (6.46 vs. 3.67 events per 100 person-years; hazard ratio 1.72 [95% CI 1.52-1.94]), death (2.52 [2.20-2.89]), severe hypoglycemia (1.53 [1.15-2.03]), and fractures (1.84 [1.44-2.35]). In the older cohort, sitagliptin did not significantly impact the primary composite (1.10 [0.89-1.36]), death (1.05 [0.83-1.32]), heart failure hospitalization (0.99 [0.65-1.49]), severe hypoglycemia (1.03 [0.62-1.71]), rates of acute pancreatitis and pancreatic cancer, or serious adverse events.

CONCLUSIONS

Among older patients with well-controlled type 2 diabetes and cardiovascular disease, sitagliptin had neutral effects on cardiovascular risk and raised no significant safety concerns.

Pancreatic Safety of Sitagliptin in the TECOS Study

OBJECTIVE

We evaluated the incidence of acute pancreatitis and pancreatic cancer in patients with type 2 diabetes and cardiovascular disease who were treated with sitagliptin, a dipeptidyl peptidase-4 inhibitor (DPP-4i).

RESEARCH DESIGN AND METHODS

In the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) study, a cardiovascular safety study of sitagliptin, all suspected cases of acute pancreatitis and pancreatic cancer were collected prospectively for 14,671 participants during a median follow-up time of 3 years, and were adjudicated blindly.

RESULTS

Baseline differences were minimal between participants confirmed to have no pancreatic events, acute pancreatitis, or pancreatic cancer. Among those participants randomized to receive sitagliptin, 23 (0.3%) (vs. 12 randomized to receive placebo [0.2%]) had pancreatitis (hazard ratio 1.93 [95% CI 0.96-3.88], P = 0.065; 0.107 vs. 0.056/100 patient-years), with 25 versus 17 events, respectively. Severe pancreatitis (two fatal) occurred in four individuals allocated to receive sitagliptin. Cases of pancreatic cancer were numerically fewer with sitagliptin (9 [0.1%]) versus placebo (14 [0.2%]) (hazard ratio 0.66 [95% CI 0.28-1.51], P = 0.32; 0.042 vs. 0.066 events/100 patient-years). Meta-analysis with two other DPP-4i cardiovascular outcome studies showed an increased risk for acute pancreatitis (risk ratio 1.78 [95% CI 1.13-2.81], P = 0.01) and no significant effect for pancreatic cancer (risk ratio 0.54 [95% CI 0.28-1.04], P = 0.07).

CONCLUSIONS

Pancreatitis and pancreatic cancer were uncommon events with rates that were not statistically significantly different between the sitagliptin and placebo groups, although numerically more sitagliptin participants developed pancreatitis and fewer developed pancreatic cancer. Meta-analysis suggests a small absolute increased risk for pancreatitis with DPP-4i therapy.

Sitagliptin and risk of fractures in type 2 diabetes: Results from the TECOS trial

AIM

To examine fracture incidence among participants in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS).

RESEARCH DESIGN AND METHODS

We used data from 14 671 participants in the TECOS study who were randomized double-blind to sitagliptin (n = 7332) or placebo (n = 7339). Cumulative fracture incidence rates were calculated and their association with study treatment assignment was examined using multivariable Cox proportional hazards regression.

RESULTS

The baseline mean (standard deviation) participant age was 65.5 (8.0) years, diabetes duration was 11.6 (8.1) years and glycated haemoglobin level was 7.2 (0.5)% [55.2 (5.5) mmol/mol], and 29.3% of participants were women and 32.1% were non-white. During 43 222 person-years' follow-up, 375 (2.6%; 8.7 per 1000 person-years) had a fracture; 146 were major osteoporotic fractures (hip, n = 34; upper extremity, n = 81; and clinical spine, n = 31). Adjusted analyses showed fracture risk increased independently with older age (P < .001), female sex (P < .001), white race (P < .001), lower diastolic blood pressure (P < .001) and diabetic neuropathy (P = .003). Sitagliptin, compared with placebo, was not associated with a higher fracture risk [189 vs 186 incident fractures: unadjusted hazard ratio (HR) 1.01, 95% confidence interval (CI) 0.82 to 1.23, P = .944; adjusted HR 1.03, P = .745], major osteoporotic fractures (P = .673) or hip fractures (P = .761). Insulin therapy was associated with a higher fracture risk (HR 1.40, 95% CI 1.02-1.91; P = .035), and metformin with a lower risk (HR 0.76, 95% CI 0.59-0.98; P = .035).

CONCLUSION

Fractures were common among people with diabetes in the TECOS study, but were not related to sitagliptin therapy. Insulin and metformin treatment were associated with higher and lower fracture risks, respectively.

Randomized controlled trial comparing impact on platelet reactivity of twice-daily with once-daily aspirin in people with Type 2 diabetes

AIMS

Reduced aspirin efficacy has been demonstrated in people with Type 2 diabetes. Because increased platelet reactivity and/or turnover are postulated mechanisms, we examined whether higher and/or more frequent aspirin dosing might reduce platelet reactivity more effectively.

METHODS

Participants with Type 2 diabetes (n = 24) but without known cardiovascular disease were randomized in a three-way crossover design to 2-week treatment periods with aspirin 100 mg once daily, 200 mg once daily or 100 mg twice daily. The primary outcome was platelet reactivity, assessed using the VerifyNow(™) ASA method. Relationships between platelet reactivity and aspirin dosing were examined using generalized linear mixed models with random subject effects.

RESULTS

Platelet reactivity decreased from baseline with all doses of aspirin. Modelled platelet reactivity was more effectively reduced with aspirin 100 mg twice daily vs. 100 mg once daily, but not vs. 200 mg once daily. Aspirin 200 mg once daily did not differ from 100 mg once daily. Aspirin 100 mg twice daily was also more effective than once daily as measured by collagen/epinephrine-stimulated platelet aggregation and urinary thromboxane levels, with a similar trend measured by serum thromboxane levels. No episodes of bleeding occurred.

CONCLUSIONS

In Type 2 diabetes, aspirin 100 mg twice daily reduced platelet reactivity more effectively than 100 mg once daily, and numerically more than 200 mg once daily. Clinical outcome trials evaluating primary cardiovascular disease prevention with aspirin in Type 2 diabetes may need to consider using a more frequent dosing schedule.

Physical activity as a determinant of fasting and 2-h post-challenge glucose: a prospective cohort analysis of the NAVIGATOR trial

AIM

To investigate whether previous physical activity levels are associated with blood glucose levels in individuals with impaired glucose tolerance in the context of an international pharmaceutical trial.

METHODS

Data were analysed from the NAVIGATOR trial, which involved 9306 individuals with impaired glucose tolerance and high cardiovascular risk from 40 different countries, recruited in the period 2002-2004. Fasting glucose, 2-h post-challenge glucose and physical activity (pedometer) were assessed annually. A longitudinal regression analysis was used to determine whether physical activity levels 2 years (t-2 ) and 1 year (t-1 ) previously were associated with levels of glucose, after adjusting for previous glucose levels and other patient characteristics. Those participants with four consecutive annual measures of glucose and two consecutive measures of physical activity were included in the analysis.

RESULTS

The analysis included 3964 individuals. Change in physical activity from t-2 to t-1 and activity levels at t-2 were both associated with 2-h glucose levels after adjustment for previous glucose levels and baseline characteristics; however, the associations were weak: a 100% increase in physical activity was associated with a 0.9% reduction in 2-h glucose levels. In addition, previous physical activity only explained an additional 0.05% of the variance in 2-h glucose over the variance explained by the history of 2-h glucose alone (R(2)  = 0.3473 vs. 0.3468). There was no association with fasting glucose.

CONCLUSIONS

In the context of a large international clinical trial, previous physical activity levels did not meaningfully influence glucose levels in those with a high risk of chronic disease, after taking into account participants' previous trajectory of glucose control.

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.).

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

AIMS

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.

METHODS

TECOS enrolled patients aged ≥50 years, with T2DM and CV disease from 38 countries in five regions: North America, Eastern Europe, Western Europe, Asia Pacific and Latin America. Participants had a glycated haemoglobin concentration of 6.5-8.0% (48-64 mmol/mol) and were receiving oral and/or insulin-based antihyperglycaemic therapy. Analysis of variance or logistic regression was used to compare regional CV risk factors and treatments, referenced to North America.

RESULTS

Patients had a mean [1 standard deviation (SD)] age of 66 (8) years, a median (interquartile range) diabetes duration of 9.4 (4.9, 15.3) years, and a mean (SD) body mass index 30.2 (5.7) kg/m² . Compared with North America, blood pressure and lipids were higher in all regions. Statin use was lowest in Latin America (68%) and Eastern Europe (70%) and aspirin use was lower compared with North America in all regions except Asia Pacific. Achievement of treatment targets did not differ by age group or insulin usage, but men and participants with previous MI were more likely than women or those with previous stroke or peripheral arterial disease to reach most treatment goals.

CONCLUSION

The CV risk factors of participants in TECOS are reasonably controlled, but differences in CV risk management according to region, sex and history of disease exist. This diversity will enhance the generalizability of the trial results.

Pharmacological interventions for preventing or delaying onset of type 2 diabetes mellitus

Prevention or delay of onset of type 2 diabetes in individuals at varying risk across the dysglycaemia continuum before overt diabetes becomes clinically manifest constitutes a leading objective of global disease prevention schemes. Pharmacological intervention has been suggested as a means to help prevent diabetes and reduce the global burden of this chronic condition. However, there is no credible evidence that early pharmacological intervention leads to long-term benefit in reducing diabetes-related complications or preventing early mortality, compared to treating people with diagnosed diabetes who have crossed the glycaemic threshold. In this review, we examine published evidence from trials using pharmacological agents to delay or prevent progression to diabetes. We also explore the benefit/risk impact of such therapies, safety issues and relevant off-target effects. Current evidence suggests none of the drugs currently available sustainably lower cumulative diabetes incidence, none provides a durable delay in diabetes diagnosis and none provides a convincing concomitant excess benefit for microvascular or macrovascular risk.

Impact of baseline physical activity and diet behavior on metabolic syndrome in a pharmaceutical trial: results from NAVIGATOR

OBJECTIVE

The cardiometabolic risk cluster metabolic syndrome (MS) includes ≥3 of elevated fasting glucose, hypertension, elevated triglycerides, reduced high-density lipoprotein cholesterol (HDL-c), and increased waist circumference. Each can be affected by physical activity and diet. Our objective was to determine whether determine whether baseline physical activity and/or diet behavior impact MS in the course of a large pharmaceutical trial.

MATERIALS/METHODS

This was an observational study from NAVIGATOR, a double-blind, randomized (nateglinide, valsartan, both, or placebo), controlled trial between 2002 and 2004. We studied data from persons (n=9306) with impaired glucose tolerance and cardiovascular disease (CVD) or CVD risk factors; 7118 with pedometer data were included in this analysis. Physical activity was assessed with 7-day pedometer records; diet behavior was self-reported on a 6-item survey. An MS score (MSSc) was calculated using the sum of each MS component, centered around the Adult Treatment Panel III threshold, and standardized according to sample standard deviation. Excepting HDL-c, assessed at baseline and year 3, MS components were assessed yearly. Follow-up averaged 6 years.

RESULTS

For every 2000-step increase in average daily steps, there was an associated reduction in average MSSc of 0.29 (95% CI (-)0.33 to (-)0.25). For each diet behavior endorsed, there was an associated reduction in average MSSc of 0.05 (95% CI (-)0.08 to (-)0.01). Accounting for the effects of pedometer steps and diet behavior together had minimal impact on parameter estimates with no significant interaction. Relations were independent of age, sex, race, region, smoking, family history of diabetes, and use of nateglinide, valsartan, aspirin, antihypertensive, and lipid-lowering agent.

CONCLUSIONS

Baseline physical activity and diet behavior were associated independently with reductions in MSSc such that increased attention to these lifestyle elements provides cardiometabolic benefits. Thus, given the potential to impact outcomes, assessment of physical activity and diet should be performed in pharmacologic trials targeting cardiometabolic risk.

Association between change in daily ambulatory activity and cardiovascular events in people with impaired glucose tolerance (NAVIGATOR trial): a cohort analysis

BACKGROUND

The extent to which change in physical activity can modify the risk of cardiovascular disease in individuals at high cardiovascular risk is uncertain. We investigated whether baseline and change in objectively-assessed ambulatory activity is associated with the risk of a cardiovascular event in individuals at high cardiovascular risk with impaired glucose tolerance.

METHODS

We assessed prospective data from the NAVIGATOR trial involving 9306 individuals with impaired glucose tolerance who were recruited in 40 countries between January, 2002, and January, 2004. Participants also either had existing cardiovascular disease (if age ≥50 years) or at least one additional cardiovascular risk factor (if age ≥55 years). Participants were followed-up for cardiovascular events (defined as cardiovascular mortality, non-fatal stroke, or myocardial infarction) for 6 years on average and had ambulatory activity assessed by pedometer at baseline and 12 months. Adjusted Cox proportional hazard models quantified the association of baseline and change in ambulatory activity (from baseline to 12 months) with the risk of a subsequent cardiovascular event, after adjustment for each other and potential confounding variables. This study is registered with ClinicalTrials.govNCT00097786.

FINDINGS

During 45,211 person-years follow-up, 531 cardiovascular events occurred. Baseline ambulatory activity (hazard ratio [HR] per 2000 steps per day 0·90, 95% CI 0·84-0·96) and change in ambulatory activity (0·92, 0·86-0·99) were inversely associated with the risk of a cardiovascular event. Results for change in ambulatory activity were unaffected when also adjusted for changes in body-mass index and other potential confounding variables at 12 months.

INTERPRETATION

In individuals at high cardiovascular risk with impaired glucose tolerance, both baseline levels of daily ambulatory activity and change in ambulatory activity display a graded inverse association with the subsequent risk of a cardiovascular event.

FUNDING

Novartis Pharmaceuticals.

Role of diuretics, β blockers, and statins in increasing the risk of diabetes in patients with impaired glucose tolerance: reanalysis of data from the NAVIGATOR study

OBJECTIVE

To examine the degree to which use of β blockers, statins, and diuretics in patients with impaired glucose tolerance and other cardiovascular risk factors is associated with new onset diabetes.

DESIGN

Reanalysis of data from the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial.

SETTING

NAVIGATOR trial.

PARTICIPANTS

Patients who at baseline (enrolment) were treatment naïve to β blockers (n=5640), diuretics (n=6346), statins (n=6146), and calcium channel blockers (n=6294). Use of calcium channel blocker was used as a metabolically neutral control.

MAIN OUTCOME MEASURES

Development of new onset diabetes diagnosed by standard plasma glucose level in all participants and confirmed with glucose tolerance testing within 12 weeks after the increased glucose value was recorded. The relation between each treatment and new onset diabetes was evaluated using marginal structural models for causal inference, to account for time dependent confounding in treatment assignment.

RESULTS

During the median five years of follow-up, β blockers were started in 915 (16.2%) patients, diuretics in 1316 (20.7%), statins in 1353 (22.0%), and calcium channel blockers in 1171 (18.6%). After adjusting for baseline characteristics and time varying confounders, diuretics and statins were both associated with an increased risk of new onset diabetes (hazard ratio 1.23, 95% confidence interval 1.06 to 1.44, and 1.32, 1.14 to 1.48, respectively), whereas β blockers and calcium channel blockers were not associated with new onset diabetes (1.10, 0.92 to 1.31, and 0.95, 0.79 to 1.13, respectively).

CONCLUSIONS

Among people with impaired glucose tolerance and other cardiovascular risk factors and with serial glucose measurements, diuretics and statins were associated with an increased risk of new onset diabetes, whereas the effect of β blockers was non-significant.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00097786.

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.

Incidence of atrial fibrillation in a population with impaired glucose tolerance: the contribution of glucose metabolism and other risk factors. A post hoc analysis of the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research trial

BACKGROUND

The role of dysglycemia as an additional risk factor for atrial fibrillation (AF) is controversial. Therefore, it was of interest to assess risk factors for incident AF in a large, representative population of patients with cardiovascular risk factors and impaired glucose tolerance but not overt diabetes in NAVIGATOR.

METHODS

Predictors of incident AF were analyzed in 8,943 patients without AF at baseline by Cox proportional hazards regression. Study treatments (valsartan vs no valsartan and nateglinide vs no nateglinide) and the time-dependent covariate for progression to type 2 diabetes mellitus were added separately to the model.

RESULTS

The median age of the 8,943 patients included in the present analysis of the NAVIGATOR trial was 63 years. Half of those patients were men, 6,922 (77.4%) had a history of hypertension, and 255 (2.9%) had heart failure. The median glycated hemoglobin was 6%. During the study, 613 of the 8,943 patients without AF at baseline presented with at least 1 episode of AF (6.9% 5-year incidence). Besides established predictors of incident AF, a 1 mmol/L increment of baseline fasting glucose, but not progression to diabetes, was found to be associated with a 33% increased risk of incident AF. Neither valsartan nor nateglinide affected AF incidence.

CONCLUSIONS

In a trial population with impaired glucose tolerance, fasting plasma glucose and well-known risk factors (age, hypertension, and elevated body weight), but not progression to diabetes, predict risk of AF.

A novel risk classification paradigm for patients with impaired glucose tolerance and high cardiovascular risk

We used baseline data from the NAVIGATOR trial to (1) identify risk factors for diabetes progression in those with impaired glucose tolerance and high cardiovascular risk, (2) create models predicting 5-year incident diabetes, and (3) provide risk classification tools to guide clinical interventions. Multivariate Cox proportional hazards models estimated 5-year incident diabetes risk and simplified models examined the relative importance of measures of glycemia in assessing diabetes risk. The C-statistic was used to compare models; reclassification analyses compare the models' ability to identify risk groups defined by potential therapies (routine or intensive lifestyle advice or pharmacologic therapy). Diabetes developed in 3,254 (35%) participants over 5 years median follow-up. The full prediction model included fasting and 2-hour glucose and hemoglobin A1c (HbA1c) values but demonstrated only moderate discrimination for diabetes (C = 0.70). Simplified models with only fasting glucose (C = 0.67) or oral glucose tolerance test values (C = 0.68) had higher C statistics than models with HbA1c alone (C = 0.63). The models were unlikely to inappropriately reclassify participants to risk groups that might receive pharmacologic therapy. Our results confirm that in a population with dysglycemia and high cardiovascular risk, traditional risk factors are appropriate predictors and glucose values are better predictors than HbA1c, but discrimination is moderate at best, illustrating the challenges of predicting diabetes in a high-risk population. In conclusion, our novel risk classification paradigm based on potential treatment could be used to guide clinical practice based on cost and availability of screening tests.

Evaluation of a self-administered oral glucose tolerance test

OBJECTIVE

To assess the feasibility of using a disposable, self-administered, capillary blood sampling oral glucose tolerance test (OGTT) device in a community setting.

RESEARCH DESIGN AND METHODS

Eighteen healthy and 12 type 2 diabetic volunteers underwent six 75-g OGTTs using a prototype device in the following three settings: unaided at home (twice); unaided but observed in clinic (twice); and performed by a nurse with simultaneous laboratory glucose assays of 0- and 120-min venous plasma samples (twice). The device displayed no results. A detachable data recorder returned to the clinic provided plasma-equivalent 0- and 120-min glucose values and key parameters, including test date, start and end times, and time taken to consume the glucose drink.

RESULTS

The device was universally popular with participants and was perceived as easy to use, and the ability to test at home was well liked. Device failures meant that 0- and 120-min glucose values were obtained for only 141 (78%) of the 180 OGTTs performed, independent of setting. Device glucose measurements showed a mean bias compared with laboratory-measured values of +0.9 at 5.0 mmol/L increasing to +4.4 at 15.0 mmol/L. Paired device glucose values were equally reproducible across settings, with repeat testing showing no training effect regardless of setting order.

CONCLUSIONS

Self-administered OGTTs can be performed successfully by untrained individuals in a community setting. With improved device reliability and appropriate calibration, this novel technology could be used in routine practice to screen people who might need a formal OGTT to confirm the presence of impaired glucose tolerance or diabetes.