Comparison of pioglitazone and gliclazide in sustaining glycemic control over 2 years in patients with type 2 diabetes

A consensus statement from the Japan Diabetes Society: A proposed algorithm for pharmacotherapy in people with type 2 diabetes - 2nd edition (English version)

This algorithm was issued for the appropriate use of drugs for the treatment of type 2 diabetes mellitus in Japan. The revisions include safety considerations, fatty liver disease as a comorbidity to be taken into account and the position of tirzepatide.

Associations among diabetes medication use, serum magnesium, and insulin resistance in a cohort of older Puerto Rican adults

BACKGROUND

Hypomagnesemia is commonly observed in individuals with diabetes, but how diabetes medications alter magnesium (Mg) status remains unclear.

OBJECTIVES

We aimed to examine the association between diabetes medication and hypomagnesemia and evaluate whether serum Mg mediates the association between diabetes medication and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) in a prospective cohort.

METHODS

Adults from the Boston Puerto Rican Health Study were included (n = 1106). Multivariable logistic regression models were used to estimate odds ratio (OR) and 95% confidence interval (CI) for cross-sectional association between diabetes medication and hypomagnesemia (serum Mg <0.75 mmol/L). Longitudinal mediation analysis was performed to evaluate the direct and indirect (via serum Mg) associations between diabetes medication and 4-y HOMA-IR in 341 participants with baseline hemoglobin A1c (HbA1c) of ≥6.5%.

RESULTS

Mean age at baseline was 59.0 ± 7.6 y, with 28.0% male and 45.8% with hypomagnesemia. Use of metformin [OR (95% CI) = 3.72 (2.53, 5.48)], sulfonylureas [OR (95% CI) = 1.68 (1.00, 2.83)], and glitazones [OR (95% CI) = 2.09 (1.10, 3.95)], but not insulin, was associated with higher odds of hypomagnesemia. Use of multiple diabetes medications and longer duration of use were associated with higher odds of hypomagnesemia. Serum Mg partially mediated the association between metformin and HOMA-IR [indirect association: β (95% CI) = 1.11 (0.15, 2.07)], which weakened the direct association [β (95% CI) = -5.16 (-9.02, -1.30)] by 22% [total association: β (95% CI) = -4.05 (-7.59, -0.51)]. Similarly, serum Mg mediated 17% of the association between sulfonylureas and elevated HOMA-IR. However, the mediation by serum Mg was weak for insulin and glitazones.

CONCLUSIONS

Diabetes medication, especially metformin, was associated with elevated odds of hypomagnesemia, which may weaken the association between metformin and lowering of HOMA-IR. The causal inference needs to be confirmed in further studies.

Bayesian model averaging of longitudinal dose-response models

Selecting a safe and clinically beneficial dose can be difficult in drug development. Dose justification often relies on dose-response modeling where parametric assumptions are made in advance which may not adequately fit the data. This is especially problematic in longitudinal dose-response models, where additional parametric assumptions must be made. This paper proposes a class of longitudinal dose-response models to be used in the Bayesian model averaging paradigm which improve trial operating characteristics while maintaining flexibility a priori. A new longitudinal model for non-monotonic longitudinal profiles is proposed. The benefits and trade-offs of the proposed approach are demonstrated through a case study and simulation.

Non-monotone Exponential Time (NEXT) Model for the Longitudinal Trend of a Continuous Outcome in Clinical Trials

The dose-response curve has been studied extensively for decades. However, most of these methods ignore intermediate measurements of the response variable and only use the measurement at the endpoint. In early phase trials, it is crucial to utilize all available data due to the smaller sample size. Simulation studies have shown that the longitudinal dose-response surface model provides a more precise parameter estimation compared to the traditional dose response using only data from the primary time point. However, the current longitudinal models with parametric assumptions assume the treatment effect increases monotonically over time, which may be controversial to reality. We propose a parametric non-monotone exponential time (NEXT) model, an enhanced longitudinal dose-response model with greater flexibility, capable of accommodating non-monotonic treatment effects and making predictions for longer-term efficacy. In addition, the estimator for the time to maximum treatment effect and its asymptotic distribution have been derived from NEXT. Extensive simulation studies using known data-generating models and using real clinical data showed the NEXT model outperformed the existing monotone longitudinal models.

Medical management of obesity

Obesity is a global epidemic that has worsened over the past few decades. It is strongly associated with multiple health conditions, including type 2 diabetes mellitus, cardiovascular diseases, obstructive sleep apnoea, certain malignancies and has an increased mortality risk. The annual cost of obesity to the NHS is around £6 billion, projected to increase to just under £10 billion by 2050. In 2020-2021, obesity was cited as a factor in over 1 million hospital admissions. An early and pragmatic approach to the management of obesity would reduce obesity-associated multiple health conditions and result in cost savings for the NHS. Here, we discuss current management strategies for obesity, including dietary intervention, pharmacological therapies and optimisation, and bariatric surgery.

Effects of glucose-lowering agents on cardiovascular and renal outcomes in subjects with type 2 diabetes: An updated meta-analysis of randomized controlled trials with external adjudication of events

AIMS

To investigate the effects of glucose-lowering agents on all-cause mortality, and cardiovascular and renal outcomes in adults with type 2 diabetes.

METHODS

A MEDLINE and EMBASE search was performed to identify randomized controlled trials, published up to 28 February 2022, with a follow-up ≥52 weeks, in which glucose-lowering drugs were compared with either placebo or active comparators. We included only trials reporting formal external adjudication of events. All-cause mortality, 3-point MACE (major cardiovascular events), and hospitalization for heart failure (HHF) were considered as principal outcomes. Doubling of serum creatinine, worsening albuminuria, and renal death were considered as secondary endpoints.

RESULTS

We included randomized controlled trials performed on metformin (n = 17), pioglitazone (n = 20), alpha-glucosidase inhibitors (n = 9), insulin secretagogues (n = 42), dipeptidyl-peptidase-4 inhibitors (n = 67), glucagon-like peptide-1 receptor agonists (n = 45) or sodium-glucose co-transporter-2 inhibitors (SGLT-2i; n = 42) and insulin (n = 18). Glucagon-like peptide-1 receptor agonist and SGLT-2i were associated with a significant reduction in all-cause mortality [Mantel-Haenszel odds ratio (MH-OR), 95% confidence interval: 0.88 (0.83; 0.95) and 0.85 (0.79; 0.91), respectively] and MACE [MH-OR, 95% confidence interval: 0.89 (0.84; 0.94) and 0.90 (0.84; 0.96), respectively]. SGLT-2i was associated with a reduced risk of HHF [MH-OR 0.68 (0.62; 0.75)], worsening albuminuria [MH-OR 0.67 (0.55; 0.80)] and doubling of serum creatinine [MH-OR 0.58 (0.44; 0.79)]. Metformin and pioglitazone were associated with a significantly lower risk of MACE [MH-OR 0.60 (0.47; 0.80) and 0.85 (0.74; 0.97), respectively] and pioglitazone with a higher risk of HHF [MH-OR 1.30 (1.04; 1.62)]. Insulin secretagogues were associated with increased risk of all-cause mortality [MH-OR 1.12 (1.01; 1.24)] and MACE [MH-OR 1.19 (1.02; 1.39)].

CONCLUSIONS

The results of this updated meta-analysis need to be considered in the choice of drug treatment for type 2 diabetes mellitus, which cannot be merely based on the effect of glucose-lowering drugs on long-term glycaemic control.

Efficacy and Safety of Pioglitazone Monotherapy in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Pioglitazone, the only thiazolidinedione drug in clinical practice is under scrutiny due to reported adverse effects, it's unique insulin sensitising action provides rationale to remain as a therapeutic option for managing type 2 diabetes mellitus (T2DM). We conducted a systematic review and meta-analysis comparing pioglitazone monotherapy with monotherapies of other oral antidiabetic drugs for assessing its efficacy and safety in T2DM patients. Mean changes in glycated haemoglobin (HbA1c), and mean changes in fasting blood sugar (FBS) level, body weight (BW) and homeostasis model assessment-insulin resistance (HOMA-IR) were primary and secondary outcomes, respectively. Safety outcomes were changes in lipid parameters, blood pressure and incidences of adverse events. Metafor package of R software and RevMan software based on random-effects model were used for analyses. We included 16 randomised controlled trials. Pioglitazone monotherapy showed equivalent efficacy as comparators in reducing HbA1c by 0.05% (95% CI: -0.21 to 0.11) and greater efficacy in reducing FBS level by 0.24 mmol/l (95% CI: -0.48 to -0.01). Pioglitazone showed similar efficacy as comparators in reducing HOMA-IR (WMD: 0.05, 95% CI: -0.49 to 0.59) and increasing high-density lipoprotein level (WMD: 0.02 mmol/l, 95% CI: -0.06 to 0.10). Improved blood pressure (WMD: -1.05 mmHg, 95% CI: -4.29 to 2.19) and triglycerides level (WMD: -0.71 mmol/l, 95% CI: -1.70 to 0.28) were also observed with pioglitazone monotherapy. There was a significant association of pioglitazone with increased BW (WMD: 2.06 kg, 95% CI: 1.11 to 3.01) and risk of oedema (RR: 2.21, 95% CI: 1.48 to 3.31), though the risk of hypoglycaemia was absolutely lower (RR: 0.51, 95% CI: 0.33 to 0.80). Meta-analysis supported pioglitazone as an effective treatment option for T2DM patients to ameliorate hyperglycaemia, adverse lipid metabolism and blood pressure. Pioglitazone is suggested to prescribe following individual patient's needs. It can be a choice of drug for insulin resistant T2DM patients having dyslipidaemia, hypertension or history of cardiovascular disease.

Physical exercise and non-insulin glucose-lowering therapies in the management of Type 2 diabetes mellitus: a clinical review

In the UK the National Institute of Health and Care Excellence (NICE) advocates intensive lifestyle programmes that attain the levels of daily physical activity set out by the Chief Medical Officer as a first-line strategy for improving the health of people at risk of developing diabetes or reducing the risk of development of Type 2 diabetes. For people with Type 2 diabetes, lifestyle measures complement pharmacological treatments that include both oral and injectable therapies. In line with this, NICE guidelines also support intensification of efforts to improve patient lifestyle along with these glucose-lowering therapies. There is a paucity of evidence, however, in the available published literature examining the association between glucose-lowering therapies and exercise metabolism. In the present review we explore the current knowledge with regard to the potential interactions of oral and non-insulin injectable therapies with physical activity in people at risk of, or who have, Type 2 diabetes, and present evidence that may inform healthcare professionals of the need to monitor patients more closely in their adaptation to both pharmacological therapy and physical activity.

Medications that cause weight gain and alternatives in Canada: a narrative review

BACKGROUND

The cause of the obesity epidemic is multifactorial, but may, in part, be related to medication-induced weight gain. While clinicians may strive to do their best to select pharmacotherapy(ies) that has the least negative impact on weight, the literature regarding the weight effects of medication is often limited and devoid of alternative therapies.

RESULTS

Antipsychotics, antidepressants, antihyperglycemics, antihypertensives and corticosteroids all contain medications that were associated with significant weight gain. However, there are several medication alternatives within the majority of these classes associated with weight neutral or even weight loss effects. Further, while not all of the classes of medication examined in this review have weight-favorable alternatives, there exist many other tools to mitigate weight gain associated with medication use, such as changes in dosing, medication delivery or the use of adjunctive therapies.

CONCLUSION

Medication-induced weight gain can be frustrating for both the patient and the clinician. As the use of pharmaceuticals continues to increase, it is pertinent for clinicians to consider the weight effects of medications prior to prescribing or in the course of treatment. In the case where it is not feasible to make changes to medication, adjunctive therapies should be considered.

Pioglitazone — an oral antidiabetic agent and metabolic syndrome modulator. Can theory translate into practice?

The metabolic syndrome, associated with insulin resistance, is a cluster of cardiovascular risk factors which results in premature morbidity and mortality from atherosclerotic vascular disease. Pioglitazone, a peroxisome-proliferator-activated receptor gamma (PPARγ) agonist, is an insulin sensitiser with the ability to address key features of the metabolic syndrome: glucose intolerance including type 2 diabetes, hypertension, dyslipidaemia, the pro-coagulant state, endothelial dysfunction, inflammation and atherosclerosis. The greatest potential benefit of pioglitazone is to influence atherogenesis itself through its pleiotrophic effects on vascular risk factors. This has been tested by the PROactive study, results of which are published in September 2005.

Efficacy and safety of pioglitazone added to alogliptin in Japanese patients with type 2 diabetes mellitus: a multicentre, randomized, double-blind, parallel-group, comparative study

A phase IV, multicentre, randomized, double-blind, parallel-group, comparative study was conducted in Japanese subjects with type 2 diabetes mellitus (T2DM) who had inadequate glycaemic control, despite treatment with alogliptin in addition to diet and/or exercise therapy. Subjects with glycated haemoglobin (HbA1c) concentrations of 6.9-10.5% were randomized to receive 16 weeks' double-blind treatment with pioglitazone 15 mg, 30 mg once daily or placebo added to alogliptin 25 mg once daily. The primary endpoint was the change in HbA1c from baseline at the end of treatment period (week 16). Both pioglitazone 15 and 30 mg combination therapy resulted in a significantly greater reduction in HbA1c than alogliptin monotherapy [-0.80 and -0.90% vs 0.00% (the least squares mean using analysis of covariance model); p < 0.0001, respectively]. The overall incidence rates of treatment-emergent adverse events were similar among the treatment groups. Pioglitazone/alogliptin combination therapy was effective and generally well tolerated in Japanese subjects with T2DM and is considered to be useful in clinical settings.

WITHDRAWN: Sulphonylurea monotherapy for patients with type 2 diabetes mellitus

The Cochrane Metabolic and Endocrine Disorders Group withdrew this review as of Issue 7, 2015 because of the involvement of one author (SS Lund) being employed in a pharmaceutical company. The authors of the review and the Cochrane Metabolic and Endocrine Disorders Group did not find that this was a breach of the rules of the Cochrane Collaboration at the time when it was published. However, after the publication of the review, the Cochrane Collaboration requested withdrawal of the review due to the employment of the author. A new protocol for a review to cover this topic will be published. This will have a new title and a markedly improved protocol fulfilling new and important developments and standards within the Cochrane Collaboration as well as an improved inclusion and search strategy making it necessary to embark on a completely new review project.

The editorial group responsible for this previously published document have withdrawn it from publication.

Emerging treatments for post-transplantation diabetes mellitus

Post-transplantation diabetes mellitus (PTDM), also known as new-onset diabetes mellitus (NODM), occurs in 10-15% of renal transplant recipients and is associated with cardiovascular disease and reduced lifespan. In the majority of cases, PTDM is characterized by β-cell dysfunction, as well as reduced insulin sensitivity in liver, muscle and adipose tissue. Glucose-lowering therapy must be compatible with immunosuppressant agents, reduced glomerular filtration rate (GFR) and severe arteriosclerosis. Such therapy should not place the patient at risk by inducing hypoglycaemic episodes or exacerbating renal function owing to adverse gastrointestinal effects with hypovolaemia. First-generation and second-generation sulphonylureas are generally avoided, and caution is currently advocated for the use of metformin in patients with GFR <60 ml/min/1.73 m(2). DPP-4 inhibitors do not interact with immunosuppressant drugs and have demonstrated safety in small clinical trials. Other therapeutic options include glinides and glitazones. Evidence-based treatment regimens used in patients with type 2 diabetes mellitus cannot be directly implemented in patients with PTDM. Studies investigating the latest drugs are required to direct the development of improved treatment strategies for patients with PTDM. This Review outlines the modern principles of glucose-lowering treatment in PTDM with specific reference to renal transplant recipients.

Evidence-based practice use of incretin-based therapy in the natural history of diabetes

The incretin class of anti-hyperglycemic agents, including glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-inhibitors, is an important addition to the therapeutic armamentarium for the management of appropriate patients with type 2 diabetes mellitus as an adjunct to diet and exercise and/or with the agents metformin, sulfonylureas, thiazolidinediones, or any combination thereof. More recently, US Food and Drug Administration (FDA)-approved indications for incretins were expanded to include use with basal insulin. This review article takes an evidence-based practice approach in discussing the importance of aggressive treatment for diabetes, the principles of incretin physiology and pathophysiology, use of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, and patient types and contexts where incretin therapy has been found beneficial, from metabolic syndrome to overt diabetes.

Beyond metformin: safety considerations in the decision-making process for selecting a second medication for type 2 diabetes management: reflections from a diabetes care editors' expert forum

The trend toward personalized management of diabetes has focused attention on the differences among available pharmacological agents in terms of mechanisms of action, efficacy, and, most important, safety. Clinicians must select from these features to develop individualized therapy regimens. In June 2013, a nine-member Diabetes Care Editors' Expert Forum convened to review safety evidence for six major diabetes drug classes: insulin, sulfonylureas (SUs), thiazolidinediones (TZDs), glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, and sodium glucose cotransporter 2 inhibitors. This article, an outgrowth of the forum, summarizes well-delineated and theoretical safety concerns related to these drug classes, as well as the panelists' opinions regarding their best use in patients with type 2 diabetes. All of the options appear to have reasonably wide safety margins when used appropriately. Those about which we know the most-metformin, SUs, insulin, and perhaps now also TZDs-are efficacious in most patients and can be placed into a basic initial algorithm. However, these agents leave some clinical needs unmet. Selecting next steps is a more formidable process involving newer agents that are understood less well and for which there are unresolved questions regarding risk versus benefit in certain populations. Choosing a specific agent is not as important as implementing some form of early intervention and advancing rapidly to some form of combination therapy as needed. When all options are relatively safe given the benefits they confer, therapeutic decision making must rely on a personalized approach, taking into account patients' clinical circumstances, phenotype, pathophysiological defects, preferences, abilities, and costs.

Causal inference in longitudinal comparative effectiveness studies with repeated measures of a continuous intermediate variable

We propose a principal stratification approach to assess causal effects in nonrandomized longitudinal comparative effectiveness studies with a binary endpoint outcome and repeated measures of a continuous intermediate variable. Our method is an extension of the principal stratification approach originally proposed for the longitudinal randomized study "Prevention of Suicide in Primary Care Elderly: Collaborative Trial" to assess the treatment effect on the continuous Hamilton depression score adjusting for the heterogeneity of repeatedly measured binary compliance status. Our motivation for this work comes from a comparison of the effect of two glucose-lowering medications on a clinical cohort of patients with type 2 diabetes. Here, we consider a causal inference problem assessing how well the two medications work relative to one another on two binary endpoint outcomes: cardiovascular disease-related hospitalization and all-cause mortality. Clinically, these glucose-lowering medications can have differential effects on the intermediate outcome, glucose level over time. Ultimately, we want to compare medication effects on the endpoint outcomes among individuals in the same glucose trajectory stratum while accounting for the heterogeneity in baseline covariates (i.e., to obtain 'principal effects' on the endpoint outcomes). The proposed method involves a three-step model estimation procedure. Step 1 identifies principal strata associated with the intermediate variable using hybrid growth mixture modeling analyses. Step 2 obtains the stratum membership using the pseudoclass technique and derives propensity scores for treatment assignment. Step 3 obtains the stratum-specific treatment effect on the endpoint outcome weighted by inverse propensity probabilities derived from Step 2.

Drug treatment of type 2 diabetes mellitus in patients for whom metformin is contraindicated

Metformin is considered an initial drug of choice for type 2 diabetes mellitus by leading recommendations. When contraindications to its use exist or patients cannot tolerate it due to adverse effects, clinicians have a variety of other classes of agents to treat hyperglycemia associated with type 2 diabetes mellitus. Each class of agent has its own benefit and safety profile. There are numerous factors to consider when selecting another agent in lieu of metformin including, but not limited to, overall efficacy in A1c reduction, adverse effect profile, cost, and patient preference. The number of factors influencing the decision process presents challenges and often no one specific agent is ideal. Each pharmacotherapeutic class of agents alternative to metformin for the treatment of hyperglycemia in type 2 diabetes mellitus as initial monotherapy is reviewed.

Pioglitazone: an antidiabetic drug with cardiovascular therapeutic effects

The antidiabetic compound pioglitazone, an activator of the intracellular peroxisome proliferator-activated receptor-gamma, and decreases metabolic and vascular insulin resistance. The drug is well tolerated, and its metabolic effects include improvements in blood glucose and lipid control. Vascular effects consist of improvements in endothelial function and hypertension, and a reduction in surrogate markers of artherosclerosis. In a large, placebo-controlled, outcome study in secondary prevention, PROactive study, the use of pioglitazone in addition to an existing optimized macrovascular risk management resulted in a significant reduction of macrovascular endpoints within a short observation period that was comparable to the effect of statins and angiotensin converting enzyme inhibitors in other trials. These results underline the value of pioglitazone for managing the increased cardiovascular risk of patients with a metabolic syndrome or Type 2 diabetes mellitus.

Assessment of pancreatic β-cell function: review of methods and clinical applications

Type 2 diabetes mellitus (T2DM) is characterized by a progressive failure of pancreatic β-cell function (BCF) with insulin resistance. Once insulin over-secretion can no longer compensate for the degree of insulin resistance, hyperglycemia becomes clinically significant and deterioration of residual β-cell reserve accelerates. This pathophysiology has important therapeutic implications. Ideally, therapy should address the underlying pathology and should be started early along the spectrum of decreasing glucose tolerance in order to prevent or slow β-cell failure and reverse insulin resistance. The development of an optimal treatment strategy for each patient requires accurate diagnostic tools for evaluating the underlying state of glucose tolerance. This review focuses on the most widely used methods for measuring BCF within the context of insulin resistance and includes examples of their use in prediabetes and T2DM, with an emphasis on the most recent therapeutic options (dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists). Methods of BCF measurement include the homeostasis model assessment (HOMA); oral glucose tolerance tests, intravenous glucose tolerance tests (IVGTT), and meal tolerance tests; and the hyperglycemic clamp procedure. To provide a meaningful evaluation of BCF, it is necessary to interpret all observations within the context of insulin resistance. Therefore, this review also discusses methods utilized to quantitate insulin-dependent glucose metabolism, such as the IVGTT and the euglycemic-hyperinsulinemic clamp procedures. In addition, an example is presented of a mathematical modeling approach that can use data from BCF measurements to develop a better understanding of BCF behavior and the overall status of glucose tolerance.

Do thiazolidinediones still have a role in treatment of type 2 diabetes mellitus?

Thiazolidinediones have been introduced in the treatment of type 2 diabetes mellitus (T2DM) since the late 1990s. Although troglitazone was withdrawn from the market a few years later due to liver toxicity, both rosiglitazone and pioglitazone gained widespread use for T2DM treatment. In 2010, however, due to increased risk of cardiovascular events associated with its use, the European Medicines Agency recommended suspension of rosiglitazone use and the Food and Drug Administration severely restricted its use. Thus pioglitazone is the only thiazolidinedione still significantly employed for treating T2DM and it is the only molecule of this class still listed in the American Diabetes Association-European Association for the Study of Diabetes 2012 Position Statement. However, as for the other thiazolidinediones, use of pioglitazone is itself limited by several side effects, some of them potentially dangerous. This, together with the development of novel therapeutic strategies approved in the last couple of years, has made it questionable whether or not thiazolidinediones (namely pioglitazone) should still be used in the treatment of T2DM. This article will attempt to formulate an answer to this question by critically reviewing the available data on the numerous advantages and the potentially worrying shortcomings of pioglitazone treatment in T2DM.

Cardiovascular safety of sulfonylureas: a meta-analysis of randomized clinical trials

AIM

Cardiovascular safety of sulfonylurea has been questioned by some authors. This article aims at collecting all available data on this issue from randomized trials.

METHODS

A meta-analysis was performed including all trials with a duration of at least 6 months, comparing a sulfonylurea with a non-sulfonylurea agent in type 2 diabetes. Major cardiovascular events (MACE) and mortality were retrieved and combined to calculate Mantel-Haenzel odds ratio (MH-OR).

RESULTS

Of the 115 selected trials, 62 reported information on MACE, and 30 reported at least one event. MH-OR for sulfonylurea was 1.08 [0.86-1.36], p = 0.52 (1.85 [1.20-2.87], p = 0.005, in the five trials vs. DPP4 inhibitors, no significant differences vs. other comparators). The MH-OR for myocardial infarction and stroke was 0.88 [0.75-1.04], p = 0.13 and 1.28 [1.03-1.60], p = 0.026, respectively. Mortality was significantly increased with sulfonylureas (MH-OR: 1.22 [1.01-1.49], p = 0.047).

CONCLUSIONS

In type 2 diabetes, the use of sulfonylureas is associated with increased mortality and a higher risk of stroke, whereas the overall incidence of MACE appears to be unaffected. Significant differences in cardiovascular risk could be present in direct comparisons with specific classes of glucose-lowering agents, such as DPP4 inhibitors, but this hypothesis needs to be confirmed in long-term cardiovascular outcomes trials. The results of this meta-analysis need to be interpreted with caution, mainly because of limitations in trial quality and under-reporting of information on cardiovascular events and mortality. However, the cardiovascular safety of sulfonylureas cannot be considered established unless it is evaluated in long-term cardiovascular outcomes trials.

Profile of vildagliptin in type 2 diabetes: efficacy, safety, and patient acceptability

Vildagliptin is a selective and potent dipeptidyl peptidase-4 inhibitor that improves glycemic control by inhibiting the degradation of both endogenous glucagon-like peptide-1 and glucose-dependent insulinotropic peptide. This article is a comprehensive review of the safety and efficacy of vildagliptin in patients with type 2 diabetes. Clinical evidence has proven that it effectively decreases hemoglobin A_1c with a low risk of hypoglycemia and is weight neutral. The addition of vildagliptin to metformin improves glucose control and significantly reduces gastrointestinal adverse events, particularly in patients inadequately controlled with metformin monotherapy. Its long-term advantages include preservation of β-cell function, reduction in total cholesterol, decrease in fasting lipolysis in adipose tissue, and triglyceride storage in non-fat tissues. Vildagliptin is well tolerated with a low incidence of AEs, and it does not increase the risk of cardiovascular/cerebrovascular (CCV) events. It can be taken before or after meals, and has little drug interaction, thus it will be well accepted.

Sulphonylurea monotherapy for patients with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a growing health problem worldwide. Whether sulphonylureas show better, equal or worse therapeutic effects in comparison with other antidiabetic interventions for patients with T2DM remains controversial.

OBJECTIVES

To assess the effects of sulphonylurea monotherapy versus placebo, no intervention or other antidiabetic interventions for patients with T2DM.

SEARCH METHODS

We searched publications in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, LILACS and CINAHL (all until August 2011) to obtain trials fulfilling the inclusion criteria for our review.

SELECTION CRITERIA

We included clinical trials that randomised patients 18 years old or more with T2DM to sulphonylurea monotherapy with a duration of 24 weeks or more.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias. The primary outcomes were all-cause and cardiovascular mortality. Secondary outcomes were other patient-important outcomes and metabolic variables. Where possible, we used risk ratios (RR) with 95% confidence intervals (95% CI) to analyse the treatment effect of dichotomous outcomes. We used mean differences with 95% CI to analyse the treatment effect of continuous outcomes. We evaluated the risk of bias. We conducted trial sequential analyses to assess whether firm evidence could be established for a 10% relative risk reduction (RRR) between intervention groups.

MAIN RESULTS

We included 72 randomised controlled trials (RCTs) with 22,589 participants; 9707 participants randomised to sulphonylureas versus 12,805 participants randomised to control interventions. The duration of the interventions varied from 24 weeks to 10.7 years. We judged none of the included trials as low risk of bias for all bias domains. Patient-important outcomes were seldom reported.First-generation sulphonylureas (FGS) versus placebo or insulin did not show statistical significance for all-cause mortality (versus placebo: RR 1.46, 95% CI 0.87 to 2.45; P = 0.15; 2 trials; 553 participants; high risk of bias (HRB); versus insulin: RR 1.18, 95% CI 0.88 to 1.59; P = 0.26; 2 trials; 1944 participants; HRB). FGS versus placebo showed statistical significance for cardiovascular mortality in favour of placebo (RR 2.63, 95% CI 1.32 to 5.22; P = 0.006; 2 trials; 553 participants; HRB). FGS versus insulin did not show statistical significance for cardiovascular mortality (RR 1.36, 95% CI 0.68 to 2.71; P = 0.39; 2 trials; 1944 participants; HRB). FGS versus alpha-glucosidase inhibitors showed statistical significance in favour of FGS for adverse events (RR 0.63, 95% CI 0.52 to 0.76; P = 0.01; 2 trials; 246 participants; HRB) and for drop-outs due to adverse events (RR 0.28, 95% CI 0.12 to 0.67; P = 0.004; 2 trials; 246 participants; HRB).Second-generation sulphonylureas (SGS) versus metformin (RR 0.98, 95% CI 0.61 to 1.58; P = 0.68; 6 trials; 3528 participants; HRB), thiazolidinediones (RR 0.92, 95% CI 0.60 to 1.41; P = 0.70; 7 trials; 4955 participants; HRB), insulin (RR 0.96, 95% CI 0.79 to 1.18; P = 0.72; 4 trials; 1642 participants; HRB), meglitinides (RR 1.44, 95% CI 0.47 to 4.42; P = 0.52; 7 trials; 2038 participants; HRB), or incretin-based interventions (RR 1.39, 95% CI 0.52 to 3.68; P = 0.51; 2 trials; 1503 participants; HRB) showed no statistically significant effects regarding all-cause mortality in a random-effects model. SGS versus metformin (RR 1.47; 95% CI 0.54 to 4.01; P = 0.45; 6 trials; 3528 participants; HRB), thiazolidinediones (RR 1.30, 95% CI 0.55 to 3.07; P = 0.55; 7 trials; 4955 participants; HRB), insulin (RR 0.96, 95% CI 0.73 to 1.28; P = 0.80; 4 trials; 1642 participants; HRB) or meglitinide (RR 0.97, 95% CI 0.27 to 3.53; P = 0.97; 7 trials, 2038 participants, HRB) showed no statistically significant effects regarding cardiovascular mortality. Mortality data for the SGS versus placebo were sparse. SGS versus thiazolidinediones and meglitinides did not show statistically significant differences for a composite of non-fatal macrovascular outcomes. SGS versus metformin showed statistical significance in favour of SGS for a composite of non-fatal macrovascular outcomes (RR 0.67, 95% CI 0.48 to 0.93; P = 0.02; 3018 participants; 3 trials; HRB). The definition of non-fatal macrovascular outcomes varied among the trials. SGS versus metformin, thiazolidinediones and meglitinides showed no statistical significance for non-fatal myocardial infarction. No meta-analyses could be performed for microvascular outcomes. SGS versus placebo, metformin, thiazolidinediones, alpha-glucosidase inhibitors or meglitinides showed no statistical significance for adverse events. SGS versus alpha-glucosidase inhibitors showed statistical significance in favour of SGS for drop-outs due to adverse events (RR 0.48, 95% CI 0.24 to 0.96; P = 0.04; 9 trials; 870 participants; HRB). SGS versus meglitinides showed no statistical significance for the risk of severe hypoglycaemia. SGS versus metformin and thiazolidinediones showed statistical significance in favour of metformin (RR 5.64, 95% CI 1.22 to 26.00; P = 0.03; 4 trials; 3637 participants; HRB) and thiazolidinediones (RR 6.11, 95% CI 1.57 to 23.79; P = 0.009; 6 trials; 5660 participants; HRB) for severe hypoglycaemia.Third-generation sulphonylureas (TGS) could not be included in any meta-analysis of all-cause mortality, cardiovascular mortality or non-fatal macro- or microvascular outcomes. TGS versus thiazolidinediones showed statistical significance regarding adverse events in favour of TGS (RR 0.88, 95% CI 0.78 to 0.99; P = 0.03; 3 trials; 510 participants; HRB). TGS versus thiazolidinediones did not show any statistical significance for drop-outs due to adverse events. TGS versus other comparators could not be performed due to lack of data.For the comparison of SGS versus FGS no meta-analyses of all-cause mortality, cardiovascular mortality, non-fatal macro- or microvascular outcomes, or adverse events could be performed.Health-related quality of life and costs of intervention could not be meta-analysed due to lack of data.In trial sequential analysis, none of the analyses of mortality outcomes, vascular outcomes or severe hypoglycaemia met the criteria for firm evidence of a RRR of 10% between interventions.

AUTHORS' CONCLUSIONS

There is insufficient evidence from RCTs to support the decision as to whether to initiate sulphonylurea monotherapy. Data on patient-important outcomes are lacking. Therefore, large-scale and long-term randomised clinical trials with low risk of bias, focusing on patient-important outcomes are required.

Pleiotropic effects of thiazolidinediones: implications for the treatment of patients with type 2 diabetes mellitus

Thiazolidinediones (TZDs) are insulin-sensitizing antidiabetes agents that act through the peroxisome proliferator-activated receptor-γ to cause a durable improvement in glycemic control in patients with type 2 diabetes mellitus. Although less well recognized, TZDs also exert a protective effect on β-cell function. In addition to their beneficial effects on glucose homeostasis, TZDs-especially pioglitazone-exert a number of other pleiotropic effects that make them ideal agents as monotherapy or in combination with other oral agents, glucagon-like peptide-1 analogs, or insulin. Pioglitazone improves endothelial dysfunction, reduces blood pressure, corrects diabetic dyslipidemia, and reduces circulating levels of inflammatory cytokines and prothrombotic factors. Pioglitazone also redistributes fat and toxic lipid metabolites in muscle, liver, β cells, and arteries, and deposits the fat in subcutaneous adipocytes where it cannot exert its lipotoxic effects. Consistent with these antiatherogenic effects, pioglitazone reduced major adverse cardiac event endpoints (ie, mortality, myocardial infarction, and stroke) in the Prospective Pioglitazone Clinical Trial in Macrovascular Events and in a meta-analysis of all other published pioglitazone trials. Pioglitazone also mobilizes fat out of the liver, improving liver function and histologic abnormalities in patients with nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Pioglitazone also reduces proteinuria, all-cause mortality, and cardiovascular events in patients with type 2 diabetes mellitus with a reduced glomerular filtration rate. These benefits must be weighed against the side effects of the drug, including weight gain, fluid retention, atypical fractures, and, possibly, bladder cancer. When low doses of pioglitazone are used (eg, 7.5-30 mg/d) with gradual titration, and physician recognition of the potential side effects are applied, the risk-to-benefit ratio is very favorable. Despite having similar effects on glycemic control, pioglitazone and rosiglitazone appear to have different effects on cardiovascular outcomes. Rosiglitazone has been associated with an increased risk of myocardial infarction, and its use in the United States is restricted because of cardiovascular safety concerns.

Contribution of insulin deficiency and insulin resistance to the development of type 2 diabetes: nature of early stage diabetes

At the time of diagnosis of type 2 diabetes (T2D), patients already have varying degrees of beta-cell dysfunction and insulin resistance and the defects continue to deteriorate despite treatment. We examined insulin secretion impairment and insulin resistance in overweight patients with T2D who had metformin failure, with elevated HbA1c at maximal metformin dose. Patients (N = 1,039) were examined at entry to the European Exenatide (EUREXA) clinical trial of add-on exenatide versus sulphonylurea. Mean (±SD) age was 57 ± 10 years, and BMI was 32.4 ± 4.1 kg/m(2). All patients underwent an oral glucose tolerance test; HOMA-IR, HOMA-B, ∆I(30)/∆G(30), disposition index and pro-insulin/insulin ratio were evaluated in relation to stratified HbA1c levels (≤7.3, >7.3-8.2, >8.2%) and duration of diabetes (<3, ≥3-<6, ≥6 years) using non-parametric analysis of variance. Patients overall had a wide range of impaired insulin secretion (HOMA-B: median 50.4, interquartile range 32.8-78.8) and insulin resistance (HOMA-IR: 4.8, 3.0-7.4). With increasing HbA1c levels, there was a statistically significant decrease in HOMA-B (P < 0.001), ∆I(30)/∆G(30) (P = 0.003) and disposition index (P < 0.001), and increase in pro-insulin/insulin (P < 0.001) and HOMA-IR (P < 0.001). With increasing duration since diabetes diagnosis, there was a significant decrease in HOMA-B (P < 0.001), but no significant trend in HOMA-IR, ∆I(30)/∆G(30), disposition index or pro-insulin/insulin. Metformin failure in these patients was associated with beta-cell dysfunction to a greater extent than insulin resistance. Loss of the first-phase insulin release, indicated by a low ∆I(30)/∆G(30), would indicate that this patient cohort requires add-on therapy that can maintain beta-cell function.

Second line therapy: type 2 diabetic subjects failing on metformin GLP-1/DPP-IV inhibitors versus sulphonylurea/insulin: for GLP-1/DPP-IV inhibitors

Following diagnosis, type 2 diabetic subjects are invariably treated with life style modifications and metformin. However, majority of these subjects require addition of another therapeutic agent singly or in combination; with or without insulin within few months to few years. For several decades, sulphonylureas and insulin have been the second line agent of choice. Clinical practice guidelines also suggest a similar approach. Subsequently thiazolidinediones, alpha glucose inhibitors and other agents were added to therapeutic armamentarium. Unfortunately, none of these treatment options could address the issue of progressive decline in beta cell function. Furthermore, they are responsible for unacceptable incidence of hypoglycaemia, weight gain and other side effects related to individual agents. Type 2 diabetic subjects have great propensity to develop cardiovascular complications. Sulphonylureas, insulin and thiazolidinediones have all been associated with adverse cardiovascular outcomes in differing magnitude. It has been made mandatory by regulatory agencies to ensure cardiovascular safety of any new anti-diabetic agent. Glucagon Like Peptide-1(GLP-1)-based therapies have been able to address several of these issues. Incretin mimetics and Di Peptidyl Dipeptidase IV (DPP-IV) inhibitors cause glucose-dependent insulin secretion and glucagon suppression from beta and alpha cells of the pancreas respectively. They owe this property to their binding with G-Protein-coupled receptors leading to an increased amount of c-AMP. They do not cause beta cell exhaustion. On the contrary such agents prevent beta cell apoptosis. Clinical trials have established the superiority of incretin mimetics particularly liraglutide against comparators including glimepiride, rosiglitazone and insulin Glargine in terms of efficacy. Furthermore, they have shown evidence towards beta cell protection, significant weight loss, minimal hypoglycaemia and favourable impact on surrogate markers of cardiovascular outcomes. DPP-IV inhibitors have limited ability to achieve glycaemic targets. However, they are weight neutral, cause minimal hypoglycaemia and have some beneficial effect on beta cell function. Finally, they are very well tolerated.

Novel therapeutics and targets for the treatment of diabetes

The microvascular complications of insufficiently controlled diabetes (neuropathy, retinopathy and nephropathy) and the marked increased risk of macrovascular events (e.g., stroke and myocardial infarction) have a dire impact on society in both human and economic terms. In Type 1 diabetes total β-cell loss occurs. In Type 2 diabetes, partial β-cell loss occurs before diagnosis, and the progressive β-cell loss during the life of the patient increases the severity of the disease. In patients with diabetes, increased insulin resistance in the muscle and liver are key pathophysiologic defects. In addition, defects in metabolic processes in the fat, GI tract, brain, pancreatic α-cells and kidney are detrimental to the overall health of the patient. This review addresses novel therapies for these deficiencies in clinical and preclinical evaluation, emphasizing their potential to address glucose homeostasis, β-cell mass and function, and the comorbidities of cardiovascular disease and obesity.

Efficacy and safety of exenatide once weekly versus metformin, pioglitazone, and sitagliptin used as monotherapy in drug-naive patients with type 2 diabetes (DURATION-4): a 26-week double-blind study

OBJECTIVE

To test the safety and efficacy of exenatide once weekly (EQW) compared with metformin (MET), pioglitazone (PIO), and sitagliptin (SITA) over 26 weeks, in suboptimally treated (diet and exercise) drug-naive patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Patients were randomized to subcutaneous (SC) EQW 2.0 mg + oral placebo (n = 248), MET 2,000 mg/day + SC placebo (n = 246), PIO 45 mg/day + SC placebo (n = 163), or SITA 100 mg/day + SC placebo (n = 163) for 26 weeks. MET and PIO therapies were increased to maximum-tolerated dosages. Injections with EQW or placebo were administered weekly, while oral medication or placebo was administered daily.

RESULTS

Baseline characteristics were as follows: 59% men, 67% Caucasian, mean age 54 years, HbA(1c) 8.5%, fasting serum glucose 9.9 mmol/L, body weight 87.0 kg, and diabetes duration 2.7 years. HbA(1c) reductions (%) at 26 weeks (least-squares means) with EQW versus MET, PIO, and SITA were -1.53 vs. -1.48 (P = 0.620), -1.63 (P = 0.328), and -1.15 (P < 0.001), respectively. Weight changes (kg) were -2.0 vs. -2.0 (P = 0.892), +1.5 (P < 0.001), and -0.8 (P < 0.001), respectively. Common adverse events were as follows: EQW, nausea (11.3%) and diarrhea (10.9%); MET, diarrhea (12.6%) and headache (12.2%); PIO, nasopharyngitis (8.6%) and headache (8.0%); and SIT, nasopharyngitis (9.8%) and headache (9.2%). Minor (confirmed) hypoglycemia was rarely reported. No major hypoglycemia occurred.

CONCLUSIONS

EQW was noninferior to MET but not PIO and superior to SITA with regard to HbA(1c) reduction at 26 weeks. Of the agents studied, EQW and MET provided similar improvements in glycemic control along with the benefit of weight reduction and no increased risk of hypoglycemia.

New oral antidiabetic agents

The pathophysiology of hyperglycemia in type 2 diabetes (T2DM) involves 3 main defects: insulin deficiency, excess hepatic glucose output, and insulin resistance. Oral anti-diabetic agents act in a variety of ways. These include agents that stimulate insulin secretion, reduce hepatic glucose production, delay digestion and absorption of intestinal carbohydrate or improve insulin action. Because of improved knowledge of pathophysiology, new drugs with mechanisms of action focussed on specific pathophysiological alterations have appeared, in order to utilize all the possibilities of treating this condition. Here, we focus on the new agents used in the latest years and the overcoming ones in future, in particular incretin-based therapies, drugs inhibiting kidney glucose reabsorption (SGLT2 inhibitors), and glucokinase activators. The strategy for new drug development advocated here is to establish a broad range of anti-diabetic medicines with different mechanisms of action and potential opportunities for effective combination therapies.

Pioglitazone: beyond glucose control

Pioglitazone is an oral antidiabetic agent that decreases insulin resistance in adipose tissue, liver and muscles. This action is mediated by its link to a nuclear receptor called peroxisome proliferator-activated receptor-gamma. By improving insulin sensitivity, hepatic glucose production decreases and glucose uptake increases in the peripheral tissues. Beyond these effects on glucose metabolism, pioglitazone has positive effects on lipid metabolism, blood pressure, endothelial function, adiponectin and C-reactive protein levels. These make pioglitazone treatment effective beyond glucose control. In this article, current evidence concerning pioglitazone in the treatment of Type 2 diabetes will be reviewed.

Pioglitazone and alogliptin combination therapy in type 2 diabetes: a pathophysiologically sound treatment

Insulin resistance and islet (beta and alpha) cell dysfunction are major pathophysiologic abnormalities in type 2 diabetes mellitus (T2DM). Pioglitazone is a potent insulin sensitizer, improves pancreatic beta cell function and has been shown in several outcome trials to lower the risk of atherosclerotic and cardiovascular events. Glucagon-like peptide-1 deficiency/resistance contributes to islet cell dysfunction by impairing insulin secretion and increasing glucagon secretion. Dipeptidyl peptidase-4 (DPP-4) inhibitors improve pancreatic islet function by augmenting glucose-dependent insulin secretion and decreasing elevated plasma glucagon levels. Alogliptin is a new DPP-4 inhibitor that reduces glycosylated hemoglobin (HbA_1c), is weight neutral, has an excellent safety profile, and can be used in combination with oral agents and insulin. Alogliptin has a low risk of hypoglycemia, and serious adverse events are uncommon. An alogliptin–pioglitazone combination is advantageous because it addresses both insulin resistance and islet dysfunction in T2DM. HbA_1c reductions are significantly greater than with either monotherapy. This once-daily oral combination medication does not increase the risk of hypoglycemia, and tolerability and discontinuation rates do not differ significantly from either monotherapy. Importantly, measures of beta cell function and health are improved beyond that observed with either monotherapy, potentially improving durability of HbA_1c reduction. The alogliptin–pioglitazone combination represents a pathophysiologically sound treatment of T2DM.

Targeting beta-cell function early in the course of therapy for type 2 diabetes mellitus

OBJECTIVE

This report examines current perspectives regarding likely mechanisms of beta-cell failure in type 2 diabetes and their clinical implications for protecting or sparing beta-cells early in the disease progression. In addition, it considers translation strategies to incorporate relevant scientific findings into educational initiatives targeting clinical practice behavior.

PARTICIPANTS

On January 10, 2009, a working group of basic researchers, clinical endocrinologists, and primary care physicians met to consider whether current knowledge regarding pancreatic beta-cell defects justifies retargeting and retiming treatment for clinical practice. Based on this meeting, a writing group comprised of four meeting participants subsequently prepared this consensus statement. The conference was convened by The Endocrine Society and funded by an unrestricted educational grant from Novo Nordisk.

EVIDENCE

Participants reviewed and discussed published literature, plus their own unpublished data.

CONSENSUS PROCESS

The summary and recommendations were supported unanimously by the writing group as representing the consensus opinions of the working group.

CONCLUSIONS

Workshop participants strongly advocated developing new systems to address common barriers to glycemic control and recommended several initial steps toward this goal. These recommendations included further studies to establish the clinical value of pharmacological therapies, continuing basic research to elucidate the nature and mechanisms of beta-cell failure in type 2 diabetes mellitus, and exploring new educational approaches to promote pathophysiology-based clinical practices. The Endocrine Society has launched a new website to continue the discussion between endocrinologists and primary care physicians on beta-cell pathophysiology in type 2 diabetes and its clinical implications. Join the conversation at http://www.betacellsindiabetes.org

Simple pharmacometric tools for oral anti-diabetic drug development: competitive landscape for oral non-insulin therapies in type 2 diabetes

The objectives were to develop a translational model that will help select doses for Phase-3 trials based on abbreviated Phase-2 trials and understand the competitive landscape for oral anti-diabetics based on efficacy, tolerability and ability to slow disease progression. Data for eight anti-diabetics with temporal profiles for fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) from 12 publications were digitized. The monotherapy data consisted of FPG and HbA1c profiles that were modeled using a transit compartment model. Evaluation of the competitive landscape utilized HbA1c literature data for 11 drugs. For the safety metric, tolerability issues with anti-diabetic drug classes were tabulated. For disease progression, the coefficient of failure method was used for assessing data from two long-term trials. The transit rate constants were remarkably consistent across 12 trials and represent system-specific/drug-independent parameters. The competitive landscape analysis showed that the primary efficacy metric fell into two groups of DeltaHbA1c: >0.8% or approximately 0.8%. On the safety endpoints, older agents showed some tolerability issues while the new agents were relatively safe. Among the different drug classes, only the thiazolidinediones appeared to slow disease progression but may also increase heart failure risk. In conclusion, the ability of system-specific parameters to predict HbA1c provides a tool to predict the expected efficacy profile from abbreviated dose-finding trials. To be commercially viable, new drugs should improve DeltaHbA1c by about 0.8% or more and possess safety profiles similar to newer anti-diabetic agents. Thus, this study proposes a suite of simple yet powerful tools to guide type-2-diabetes drug development.

Efficacy and safety of exenatide once weekly versus sitagliptin or pioglitazone as an adjunct to metformin for treatment of type 2 diabetes (DURATION-2): a randomised trial

BACKGROUND

Most patients with type 2 diabetes begin pharmacotherapy with metformin, but eventually need additional treatment. We assessed the safety and efficacy of once weekly exenatide, a glucagon-like peptide 1 receptor agonist, versus maximum approved doses of the dipeptidyl peptidase-4 inhibitor, sitagliptin, or the thiazolidinedione, pioglitazone, in patients treated with metformin.

METHODS

In this 26-week randomised, double-blind, double-dummy, superiority trial, patients with type 2 diabetes who had been treated with metformin, and at baseline had mean glycosylated haemoglobin (HbA(1c)) of 8.5% (SD 1.1), fasting plasma glucose of 9.1 mmol/L (2.6), and weight of 88.0 kg (20.1), were enrolled and treated at 72 sites in the USA, India, and Mexico. Patients were randomly assigned to receive: 2 mg injected exenatide once weekly plus oral placebo once daily; 100 mg oral sitagliptin once daily plus injected placebo once weekly; or 45 mg oral pioglitazone once daily plus injected placebo once weekly. Primary endpoint was change in HbA(1c) between baseline and week 26. Analysis was by intention to treat, for all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT00637273.

FINDINGS

170 patients were assigned to receive once weekly exenatide, 172 to receive sitagliptin, and 172 to receive pioglitazone. 491 patients received at least one dose of study drug and were included in the intention-to-treat analysis (160 on exenatide, 166 on sitagliptin, and 165 on pioglitazone). Treatment with exenatide reduced HbA(1c) (least square mean -1.5%, 95% CI -1.7 to -1.4) significantly more than did sitagliptin (-0.9%, -1.1 to -0.7) or pioglitazone (-1.2%, -1.4 to -1.0). Treatment differences were -0.6% (95% CI -0.9 to -0.4, p<0.0001) for exenatide versus sitagliptin, and -0.3% (-0.6 to -0.1, p=0.0165) for exenatide versus pioglitazone. Weight loss with exenatide (-2.3 kg, 95% CI-2.9 to -1.7) was significantly greater than with sitagliptin (difference -1.5 kg, 95% CI -2.4 to -0.7, p=0.0002) or pioglitazone (difference -5.1 kg, -5.9 to -4.3, p<0.0001). No episodes of major hypoglycaemia occurred. The most frequent adverse events with exenatide and sitagliptin were nausea (n=38, 24%, and n=16, 10%, respectively) and diarrhoea (n=29, 18%, and n=16, 10%, respectively); upper-respiratory-tract infection (n=17, 10%) and peripheral oedema (n=13, 8%) were the most frequent events with pioglitazone.

INTERPRETATION

The goal of many clinicians who manage diabetes is to achieve optimum glucose control alongside weight loss and a minimum number of hypoglycaemic episodes. Addition of exenatide once weekly to metformin achieved this goal more often than did addition of maximum daily doses of either sitagliptin or pioglitazone.

FUNDING

Amylin Pharmaceuticals and Eli Lilly.

Clinical evaluation of combined therapy for type 2 diabetes

OBJECTIVE

Therapeutic guidelines recommend the combination of drugs as necessary to control type 2 diabetes (T2D). This research assessed the effectiveness of pioglitazone (Pio), metformin (Met) and sulfonylurea (SU) combinations in the routine clinical practice.

RESEARCH DESIGN AND METHODS

A nationwide, 12-month prospective, observational cohort study was performed in 2294 patients with T2D (50.3% females, mean age: 61.1 years, mean body mass index: 30.2 kg/m(2), mean time since diagnosis: 8.5 years) who started, at the discretion of treating physician, oral antihyperglycaemic treatment with either Pio + SU, Pio + Met or SU + Met because of inadequate control with previous therapy. Fasting plasma glucose (FPG), glycohaemoglobin (HbA1c), lipids, blood pressure, and anthropometric parameters were measured, and 10-year cardiovascular risk was estimated.

RESULTS

FPG, HbA1c and total cholesterol at baseline had mean values (184.6 mg/dl, 8.5% and 246.0 mg/dl, respectively) associated with an excess of micro- and macrovascular risk. The mean changes from baseline in the Pio + SU, Pio + Met and SU + Met cohorts were, respectively, -37.9, -32.7 and -25.8 mg/dl for FPG; -1.1, -1.0 and -0.7% for HbA1c; -30.7, -38.7 and -17.1 mg/dl for triglycerides; and +2.3, +2.5 and +0.6 mg/dl for HDL cholesterol. In consequence, the estimated 10-year cardiovascular risk decreased more in the Pio cohorts, particularly with Pio + Met (1.7% versus 1.4% Pio + SU and 1.0% SU + Met -Framingham equation- and 0.6% versus 0.4% SU + Met - Systematic Coronary Risk Evaluation model-). Related adverse events were significantly (p = 0.016) more frequent in Pio cohorts (4.7% with Pio + SU, 5.1% with Pio + Met) than in the SU + Met cohort (2.4%).

CONCLUSIONS

In patients with T2D failing therapy, mostly SU or Met monotherapy, pioglitazone add-on treatment was associated with a significant improvement of micro- and macrovascular risk estimations. These results from real-life clinical conditions support the findings of prior randomised trials, although they should be interpreted with caution because of the observational, nonrandomised design.

Long-term glycaemic effects of pioglitazone compared with placebo as add-on treatment to metformin or sulphonylurea monotherapy in PROactive (PROactive 18)

AIMS

To assess the long-term glycaemic effects, concomitant changes in medications and initiation of permanent insulin use (defined as daily insulin use for a period of > or = 90 days or ongoing use at death/final visit) with pioglitazone vs. placebo in diabetic patients receiving metformin or sulphonylurea monotherapy at baseline in the PROspective pioglitAzone Clinical Trial in macroVascular Events (PROactive).

METHODS

In PROactive, patients with Type 2 diabetes and macrovascular disease were randomized to pioglitazone (force titrated to 45 mg/day) or placebo, in addition to other existing glucose-lowering therapies. In a post-hoc analysis, we categorized patients not receiving insulin at baseline and treated by oral monotherapy into two main cohorts: add-on to metformin alone (n = 514) and sulphonylurea alone (n = 1001). The follow-up averaged 34.5 months.

RESULTS

There were significantly greater reductions in glycated haemoglobin (HbA(1c)) with pioglitazone than with placebo and more pioglitazone-treated patients achieved HbA(1c) targets, irrespective of the baseline oral glucose-lowering regimen and despite a decrease in the use of other glucose-lowering agents. Approximately twice as many in the placebo groups progressed to permanent insulin use than in the pioglitazone groups across the two cohorts: 3.4% for pioglitazone and 6.5% for placebo when added to metformin monotherapy and 6.3% and 14.8%, respectively, when added to sulphonylurea monotherapy. The overall safety of both dual therapies was good.

CONCLUSIONS

Intensifying an existing oral monotherapy regimen to a dual oral regimen by adding pioglitazone resulted in sustained improvements in glycaemic control and reduced progression to insulin therapy. The efficacy and safety of adding pioglitazone to either metformin monotherapy or sulphonylurea monotherapy were good.

Long-term glycaemic control with metformin-sulphonylurea-pioglitazone triple therapy in PROactive (PROactive 17)

AIMS

We assessed the long-term glycaemic effects and the safety profile of triple therapy with the addition of pioglitazone vs. placebo in patients with Type 2 diabetes treated with combined metformin-sulphonylurea therapy in the PROspective pioglitAzone Clinical Trial In macroVascular Events (PROactive).

METHODS

In a post-hoc analysis, we identified patients treated with metformin plus sulphonylurea combination therapy and not receiving insulin at baseline (n = 1314). In those patients, we compared the effects of pioglitazone (force-titrated to 45 mg/day, n = 654) vs. placebo (n = 660) on glycated haemoglobin (HbA(1c)) reduction, concomitant changes in medications and initiation of permanent insulin use (defined as daily insulin use for a period of > or = 90 days or ongoing use at death/final visit).

RESULTS

Significantly greater reductions in HbA(1c) and greater proportions of patients with HbA(1c) at target were noted with pioglitazone vs, placebo, despite a decrease in the use of other oral glucose-lowering agents. There was an approximate twofold increase in progression to permanent insulin use in the placebo group vs. the pioglitazone group: 31.1 vs. 16.1%, respectively, when added to combination therapy. The overall safety of the metformin-sulphonylurea-pioglitazone triple therapy was good.

CONCLUSIONS

Intensifying an existing dual oral therapy regimen to a triple oral regimen by adding pioglitazone to the classical metformin-sulphonylurea combination resulted in sustained improvements in glycaemic control and reduced progression to insulin therapy. The advantages and disadvantages of adding pioglitazone instead of adding basal insulin should be assessed further.

The backbone of oral glucose-lowering therapy: time for a paradigm shift?

The complex array of metabolic abnormalities associated with type 2 diabetes provides a number of new targets for therapeutic intervention. Although the established oral glucose-lowering therapies, metformin and the sulfonylureas, continue to provide the backbone of therapeutic approaches, the thiazolidinediones (TZDs) also play an important role. Further, a new class of oral agents, the dipeptidyl peptidase-IV (DPP-IV) inhibitors, has recently become available with apparent utility in decreasing postprandial glucose excursions. This review examines how the TZDs and the DPP-IV inhibitors might integrate into current treatment strategies, considering not only glycemic goals, but also longer-term benefits such as durability of glycemic control, effect on metabolic parameters and cardiovascular outcomes. A practical approach is taken, reflecting potential clinical situations in which therapeutic intervention is required.

Redefining the role of thiazolidinediones in the management of type 2 diabetes

There is a need to evaluate oral glucose-lowering agents not only for their value in achieving glycemic control but also for their impact on cardiac risk factor modification. This article reviews the evidence base for the two thiazolinediones currently available, pioglitazone and rosiglitazone. These drugs exert their effects through actions affecting metabolic control, lipid profiles, and the vascular wall. They have been shown to be as efficacious in establishing glycemic control, in both monotherapy and combination therapy regimens, as more traditional oral agents, and may be able to sustain that control in the long term. Both thiazolidinediones have demonstrated favorable effects on markers of cardiovascular disease. Evidence from the large PROactive outcomes study suggests that pioglitazone may exert protective effects in patients with type 2 diabetes and macrovascular disease. Thiazolidinediones are generally well tolerated but they can cause weight gain, induce fluid retention, and may contribute to bone loss in postmenopausal women. The place of thiazolidinediones in the management of type 2 diabetes is well established. The potential for additional benefits in reducing macrovascular risk encourages further long-term study of these agents.

Impact of incretin therapy on islet dysfunction: an underlying defect in the pathophysiology of type 2 diabetes

Glucose homeostasis is governed by a complex interplay of hormonal signaling and modulation. Insulin, glucagon, amylin, the incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), and other hormones and enzymes interact to maintain glucose homeostasis and normal cellular metabolism. Derangements in these hormonal interactions, particularly insulin deficits and impaired insulin action, result in the development of type 2 diabetes-but only in individuals who have experienced significant dysfunction or loss of beta-cells, located in the pancreatic islets of Langerhans. Much less is known about the impact of alpha-cell dysregulation on glucose homeostasis, although it has been demonstrated that glucagon-secreting alpha-cells, also located in the pancreatic islets, play an important role in glucose metabolism. Because beta-cell dysfunction occurs early in the course of type 2 diabetes and is progressive, early intervention with therapies that improve beta-cell function is desirable. In addition to reducing HbA1c and fasting plasma glucose, the recently developed diabetes therapies GLP-1 receptor agonists (eg, exenatide, liraglutide) and dipeptidyl peptidase-4 (DPP-4) inhibitors (eg, sitagliptin, vildagliptin) appear to have beneficial effects on beta-cell dysfunction and, possibly, on alpha-cell dysregulation.

Thiazolidinediones: effects on the development and progression of type 2 diabetes and associated vascular complications

In addition to reducing hyperglycaemia, the metabolic actions of TZDs (pioglitazone and rosiglitazone) in theory might improve the prognosis of patients with type 2 diabetes. However, it appears from recent data that pioglitazone and rosiglitazone have different cardiovascular risk profiles. The scope of this paper is to examine the benefits and risks of pioglitazone and rosiglitazone. Three large clinical studies (DREAM, and ADOPT with rosiglitazone; PROactive with pioglitazone) have recently been reported. A lower annual rate of decline of ss-cell function observed with rosiglitazone in the ADOPT study, compared with metformin and glyburide (glibenclamide), along with a reduced progression to insulin use seen with pioglitazone in the PROactive study, provides evidence that TZDs are effective in treating progressive hyperglycaemia. In PROactive, although the primary endpoint was not met, pioglitazone was associated with a reduction in a secondary composite endpoint of clinical cardiovascular events in high-risk patients with existing macrovascular disease who were already receiving other glycaemic and cardiovascular medications. Further evidence supporting an anti-atherogenic effect of pioglitazone was gained from the PERISCOPE study of carotid intima-media thickness. Recent controversy concerning a possible increased risk of myocardial infarction associated with rosiglitazone has fuelled uncertainty about the risk-benefit profile of this agent. In 2008, an update of an American Diabetes Association-European Association for the Study of Diabetes consensus statement on initiation and adjustment of therapy in patients with type 2 diabetes advised clinicians against using rosiglitazone. Skeletal fractures have recently emerged as a side effect of both TZDs. Available data suggest that cardiovascular benefits observed with pioglitazone might not be a class effect of TZDs.

The IRIS V study: pioglitazone improves systemic chronic inflammation in patients with type 2 diabetes under daily routine conditions

BACKGROUND

The peroxisome proliferator-activated receptor-gamma agonist pioglitazone is established as a drug to treat patients with type 2 diabetes mellitus. In addition to lowering blood glucose levels, one of the favorable effects of pioglitazone is improvement of systemic chronic inflammation particularly affecting vessel walls. The effect can be monitored by the measurement of the biomarker C-reactive protein in the range of 0-10 mg/L (high-sensitivity C-reactive protein [hsCRP]). This observational trial was performed to evaluate the effects of pioglitazone on hsCRP values in a large population under daily life conditions.

METHODS

A total of 1,170 subjects could be included into the final analysis (633 men, 537 women; age [mean +/- SD], 63.5 +/- 10.4 years, body mass index, 31.0 +/- 5.5 kg/m2; duration of diabetes, 6.9 +/- 8.1 years; glycosylated hemoglobin [HbA1c], 7.5 +/- 1.1%). All patients were glitazone-naive prior to study entry. The patients received pioglitazone alone or in combination with their previous treatment (acarbose, sulfonylurea drugs, and/or metformin). Patients were evaluated at baseline and after 10 +/- 2 weeks and 20 +/- 2 weeks of treatment. Observation parameters were fasting blood glucose, lipids, and blood pressure. The level of hsCRP was determined in a central laboratory at baseline and at end point.

RESULTS

All markers showed a significant improvement at trial end point. A decrease of hsCRP (baseline 3.3 +/- 1.0 mg/L vs. end point 2.8 +/- 2.3 mg/L, P < 0.01), HbA1c (7.5 +/- 1.1% vs. 6.8 +/- 0.9%, P < 0.001), fasting blood glucose (8.7 +/- 2.6 mM vs. 7.2 +/- 2.1 mM, P < 0.001), low-density lipoproteins (3.3 +/- 1.0 mM vs. 3.2 +/- 0.9 mM, P < 0.001), and triglycerides (2.4 +/- 2.0 mM vs. 2.2 +/- 2.5 mM, P < 0.001) and an increase in high-density lipoproteins (1.3 +/- 0.4 mM vs. 1.4 +/- 0.4 mM, P < 0.001) was observed. Parallel to the metabolic improvement, both systolic and diastolic blood pressure values were reduced (141 +/- 17 mm Hg vs. 137 +/- 15 mm Hg and 83 +/- 9 mm Hg vs. 80 +/- 9 mm Hg, respectively; P < 0.001 in both cases).

CONCLUSIONS

These observational results, obtained from a nonselected patient population under daily routine conditions, confirm the benefits of pioglitazone treatment on blood glucose, lipid metabolism, and blood pressure. The results show that pioglitazone treatment improves chronic vascular inflammation, which may be associated with reduced cardiovascular risk.