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

DPP-4 inhibitors for treating T2DM - hype or hope? an analysis based on the current literature

DPP-4 inhibition is an interesting line of therapy for treating Type 2 Diabetes Mellitus (T2DM) and is based on promoting the incretin effect. Here, the authors have presented a brief appraisal of DPP-4 inhibitors, their modes of action, and the clinical efficiency of currently available drugs based on DPP-4 inhibitors. The safety profiles as well as future directions including their potential application in improving COVID-19 patient outcomes have also been discussed in detail. This review also highlights the existing queries and evidence gaps in DPP-4 inhibitor research. Authors have concluded that the excitement surrounding DPP-4 inhibitors is justified because in addition to controlling blood glucose level, they are good at managing risk factors associated with diabetes.

The role of Recent Pharmacotherapeutic Options on the Management of Treatment Resistant Type 2 Diabetes

INTRODUCTION

Type 2 diabetes mellitus is a complex progressive disease leading to chronic hyperglycemia due to insulin resistance and pancreatic beta-cell failure. Intensification of treatment regimens is often necessary due to the overall decline in insulin secretion. Unfortunately, many patients are unable to achieve optimal glycemic control despite the standard of care and thus may be classified as 'treatment resistant'.

AREAS COVERED

Newer pharmacotherapeutic agents, either injectable or oral, such as Glucagon-like-peptide-1 receptor agonists (GLP-1RA) and Sodium-glucose Cotransporter-2 (SGLT2) inhibitors are, herein, described. These agents can be used as single agents or fixed combinations that reduce glycemia while lessening the risk for hypoglycemia and renal and cardiovascular diseases.

EXPERT OPINION

If individualized target HbA1c is not obtained despite diet, lifestyle, and metformin therapy, then additional oral and injectable therapies should be considered. This may include newer agents such as GLP-1RA and SGLT2 inhibitors alone or in combination that provide renal protection and reduce cardiovascular and hypoglycemic risks. These newer agents have substantial potential for lowering HbA1c through differing but complementary mechanisms. Use of new insulin analogs with GLP-1RA preparations either alone or in fixed-ratio combinations, such as glargine/lixisenatide and degludec/liraglutide, can also reduce the multiple drug adherence burden while improving glycemic control.

Evaluation of Dipeptidyl Peptidase-4 Inhibitors versus Thiazolidinediones or Insulin in Patients with Type 2 Diabetes Uncontrolled with Metformin and a Sulfonylurea in a Real-World Setting

BACKGROUND

Guidelines do not make clear recommendations for third add-on agents to metformin plus a sulfonylurea. This study compared the effectiveness and safety of dipeptidyl peptidase-4 inhibitors (DPP4is) to thiazolidinedione (TZD) or insulin as a third add-on agent to metformin plus a sulfonylurea in an integrated health care setting.

METHODS

This retrospective database cohort study included adults with type 2 diabetes not at goal hemoglobin A1C (HbA1C) who initiated DPP4i, TZD, or insulin as a third add-on agent to metformin plus a sulfonylurea from January 2006 to June 2016. Primary outcomes were the proportion of patients who achieved goal HbA1C after starting the third add-on agent and change in HbA1C. Subgroup analysis was performed for patients with baseline HbA1C greater than 9%.

RESULTS

In this study, 2080 patients started on a DPP4i were matched to 8320 patients started on TZD and to 8320 patients taking insulin. A significantly higher percentage of patients taking TZD reached goal HbA1C (31.0% versus 23.6%; p < 0.05) and had a significantly larger HbA1C reduction (-0.94% ± 1.34% versus -0.79% ± 1.23%; p < 0.01) compared to patients taking a DPP4i. No difference in the percentage of patients meeting goal HbA1C nor in change in HbA1C was demonstrated between insulin versus DPP4i regimens. For patients with baseline HbA1C greater than 9%, insulin or TZD resulted in a significantly higher proportion of patients achieving goal HbA1C compared to DPP4i (17.3% and 19.0% versus 12.4%, respectively; p < 0.01).

CONCLUSION

TZD was more effective than DPP4i but DPP4i was as effective as insulin as a third add-on agent in the overall study population. Insulin was more effective than DPP4i only in the subgroup analysis of patients with baseline HbA1C greater than 9%.

Thiazolidinedione drugs in the treatment of type 2 diabetes mellitus: past, present and future

Thiazolidinedione (TZD) drugs used in the treatment of type 2 diabetes mellitus (T2DM) have proven effective in improving insulin sensitivity, hyperglycemia, and lipid metabolism. Though well tolerated by some patients, their mechanism of action as ligands of peroxisome proliferator-activated receptors (PPARs) results in the activation of several pathways in addition to those responsible for glycemic control and lipid homeostasis. These pathways, which include those related to inflammation, bone formation, and cell proliferation, may lead to adverse health outcomes. As treatment with TZDs has been associated with adverse hepatic, cardiovascular, osteological, and carcinogenic events in some studies, the role of TZDs in the treatment of T2DM continues to be debated. At the same time, new therapeutic roles for TZDs are being investigated, with new forms and isoforms currently in the pre-clinical phase for use in the prevention and treatment of some cancers, inflammatory diseases, and other conditions. The aims of this review are to provide an overview of the mechanism(s) of action of TZDs, a review of their safety for use in the treatment of T2DM, and a perspective on their current and future therapeutic roles.

Pioglitazone utilization, efficacy & safety in Indian type 2 diabetic patients: A systematic review & comparison with European Medicines Agency Assessment Report

Background & objectives:

With pioglitazone ban and subsequent revoking in India along with varying regulatory decisions in other countries, it was decided to carry out a systematic review on its safety, efficacy and drug utilization in patients with type 2 diabetes mellitus (T2DM) in India and compare with the data from the European Medicines Agency Assessment Report (EMA-AR).

Methods:

Systematic review was performed as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching Medline/PubMed, Google Scholar and Science Direct databases using ‘pioglitazone AND India AND human’ and ‘pioglitazone AND India AND human AND patient’ and compared with EMA-AR. Spontaneous reports in World Health Organization VigiBase from India were compared with VigiBase data from other countries.

Results:

Sixty six publications, 26 (efficacy), 32 (drug utilization) and eight (safety), were retrieved. In India, pioglitazone was used at 15-30 mg/day mostly with metformin and sulphonylurea, being prescribed to 26.7 and 8.4 per cent patients in north and south, respectively. The efficacy in clinical trials (CTs) was similar to those in EMA-AR. Incidence of bladder cancer in pioglitazone exposed and non-exposed patients was not significantly different in an Indian retrospective cohort study. There were two cases and a series of eight cases of bladder cancer published but none reported in VigiBase.

Interpretation & conclusions:

In India, probably due to lower dose, lower background incidence of bladder cancer and smaller sample size in epidemiological studies, association of bladder cancer with pioglitazone was not found to be significant. Reporting of CTs and adverse drug reactions to Clinical Trials Registry of India and Pharmacovigilance Programme of India, respectively, along with compliance studies with warning given in package insert and epidemiological studies with larger sample size are needed.

Pharmacotherapy of 'treatment resistant' type 2 diabetes

INTRODUCTION

Despite type 2 diabetes (T2D) management offers a variety of pharmacological interventions targeting different defects, numerous patients remain with persistent hyperglycaemia responsible for severe complications. Unlike resistant hypertension, treatment resistant T2D is not a classical concept although it is a rather common observation in clinical practice. Areas covered: This article proposes a definition for 'treatment resistant diabetes', analyses the causes of poor glucose control despite standard therapy, briefly considers the alternative approaches to glucose-lowering pharmacotherapy and finally describes how to overcome poor glycaemic control, using innovative oral or injectable combination therapies. Expert opinion: Before considering intensifying the pharmacotherapy of a patient with poorly controlled T2D, it is important to verify treatment adherence, target obesity and consider various non pharmacological improvement quality interventions. If treatment resistant diabetes is defined as not achieving glycated haemoglobin target despite oral triple therapy with a third glucose-lowering agent added to metformin-sulfonylurea dual treatment, the combination of a dipeptidyl peptidase-4 (DPP-4) inhibitor and a sodium glucose cotransporter type 2 (SGLT2) inhibitor may offer new opportunities before considering injectable therapies. Insulin basal therapy (± metformin) may be optimized by the addition of a SGLT2 inhibitor or a glucagon-like peptide-1 (GLP-1) receptor agonist.

Comparison of charges and resource use associated with saxagliptin and sitagliptin

OBJECTIVES

Saxagliptin and sitagliptin are two commonly used dipeptidyl peptidase-4 (DPP-4) inhibitors. Little is known about their comparative effectiveness in the real world, particularly their impact on cost and resources use. The objective of this study was to analyze charges and resource use associated with saxagliptin and sitagliptin to understand the impact of these DPP-4 inhibitor treatment options in a real-world setting.

METHODS

This was a retrospective, new-user study approved by the Institutional Review Board at the University of Toledo. Data were collected from a US insurance claims dataset (OptumInsight) for patients newly initiating treatment with saxagliptin or sitagliptin between January 1, 2010 and December 31, 2011. ICD-9 code 250 was used to identify patients with T2D. Overall and diabetes-related medical and pharmacy charges were observed. Inpatient hospitalizations were also compared. Propensity score matching was used to balance the cohorts of patients prescribed saxagliptin and sitagliptin. Appropriate univariate statistical tests were applied to the propensity-matched sample to examine differences in resource utilization outcomes. Statistical significance was evaluated at P < 0.05.

RESULT

After the propensity score matching, each cohort included 7711 patients. Saxagliptin treatment was associated with lower overall charges ($13,292 vs $14,032; P = 0.0023) and overall medical charges ($9,540 vs $10,296; P = 0.0024) during the 6-month follow-up period compared with sitagliptin treatment. No significant differences were observed in the overall pharmacy charges ($3,751 vs $3,753; P = 0.6937) and the diabetes-related charges ($5,141 vs $5,232; P = 0.2957). All-cause and diabetes-related inpatient hospitalization rates were significantly lower with saxagliptin treatment (p = 0.0001 and p = 0.0019, respectively). All-caused inpatient charges were also significantly lower with saxagliptin ($2,917.26 vs $3445.89; P < 0.0001).

CONCLUSION

Compared with patients initiating sitagliptin treatment, patients initiating saxagliptin treatment reported lower overall and medical charges and lower overall and diabetes-related hospitalization rates. These findings may aid payers in managing patients with T2D.

Pharmacokinetics and clinical evaluation of the alogliptin plus pioglitazone combination for type 2 diabetes

INTRODUCTION

Type 2 diabetes is a complex disease with multiple defects, which generally requires a combination of several pharmacological approaches to reach glucose control targets. A unique fixed-dose combination combines a thiazolidinedione (pioglitazone) and a dipeptidyl peptidase-4 inhibitor (alogliptin).

AREA COVERED

An extensive literature search was performed to analyze the pharmacokinetics of pioglitazone and alogliptin when used separately and in combination as well as to summarize clinical and toxicological considerations about the combined therapy.

EXPERT OPINION

Pioglitazone, a potent insulin sensitizer, and alogliptin, an incretin-based agent that potentiates post-meal insulin secretion and reduces glucagon secretion, have complementary mechanisms of action. The clinical efficacy of a combined therapy is superior to any single therapy in patients treated with diet or with metformin (with or without sulphonylurea). These two drugs can be administered once daily, with or without a meal. No clinically relevant pharmacokinetic interactions between the two agents have been described and the fixed-dose combination has shown bioequivalence with alogliptin and pioglitazone given separately. Combining alogliptin with pioglitazone does not alter the safety profile of each compound. Weight gain observed with pioglitazone may be limited with the addition of alogliptin. The concern of an increased risk of heart failure remains to be better investigated.

Efficacy and safety of adding pioglitazone or sitagliptin to patients with type 2 diabetes insufficiently controlled with metformin and a sulfonylurea

OBJECTIVE

To evaluate the efficacy and safety of add-on pioglitazone versus sitagliptin in patients with type 2 diabetes inadequately controlled on metformin and a sulfonylurea (SU).

METHODS

This 24-week, randomized, open-label study compared pioglitazone (30 mg daily, n = 59) and sitagliptin (100 mg daily, n = 60) in patients with inadequate glycemic control (glycosylated hemoglobin [HbA1c] ≥7.0% to <11.0%) while receiving a stable dose of metformin (≥1,500 mg daily) and an SU (≥half-maximal dose).

RESULTS

The mean changes in HbA1c from baseline was -0.94 ± 0.12% with pioglitazone and -0.71 ± 0.12% with sitagliptin, for a between-groups difference of -0.23 ± 0.16% (P = .16). The mean change in fasting plasma glucose (FPG) were -35.7 ± 4.0 mg/dL with pioglitazone and -22.8 ± 4.0 mg/dL with sitagliptin, for a between-groups difference of -12.9 ± 5.7 mg/dL (P = .02). Pioglitazone was associated with a significant decrease in high-sensitive C-reactive protein (hs-CRP), but sitagliptin did not. The mean weight gain was higher in the pioglitazone group, with a between-group difference of 1.6 kg (P<.01). Overall adverse events (AEs) were similar in both groups. However, the incidence of edema was higher with pioglitazone, and the incidence of gastrointestinal AEs was higher with sitagliptin.

CONCLUSION

Pioglitazone and sitagliptin achieved similar improvements in overall glycemic control in patients with type 2 diabetes inadequately controlled with metformin and an SU. However there were some differences in terms of FPG, hs-CRP, lipids, body-weight change, and AEs.

Outcomes and lessons from the PROactive study

Beyond improvement of glucose control, thiazolidinediones exert pleiotropic effects, which may contribute to some cardiovascular protection. PROactive ("PROspective pioglitAzone Clinical Trial In macroVascular Events") has provided valuable, although controversial, information on the impact of pioglitazone on cardiovascular outcomes in a high-risk population of patients with type 2 diabetes and established macrovascular disease. Since 2005, there has been much debate on the relative value of the statistically non-significant 10% reduction in the quite challenging primary composite endpoint (combining cardiovascular disease-driven and procedural events in all vascular beds) versus the statistically significant 16% decrease in the more robust and conventional main secondary endpoint (all-cause mortality, myocardial infarction, and stroke) observed with pioglitazone. Revisiting PROactive deserves much interest following the report of inconclusive results on cardiovascular efficacy and safety of rosiglitazone in RECORD, the withdrawal (limitation) of rosiglitazone because of cardiovascular safety concern, the recent publication of a statement positioning pioglitazone in type 2 diabetes and the near availability of cheaper generics of pioglitazone. Although subanalyses may have more limited value from a statistical viewpoint, they nonetheless can provide valuable information on the drug efficacy/safety profile and clinical insights into which patients might benefit most (in terms of cardiovascular outcomes) from pioglitazone therapy.

Comparison of hemoglobin A1c goal achievement with the addition of pioglitazone to maximal/highest tolerated doses of sulfonylurea and metformin combination therapy

OBJECTIVES

It has been proposed that the combination of thiazolidinedione (TZD) therapy to metformin and sulfonylurea is beneficial due to each medication having a unique mechanism of action. Within the Veterans Affairs Hospital, specific criteria of use define when TZD therapy can be initiated. Most patients who receive TZD therapy have failed other medications prior to use. The primary objective of this study was to determine the percentage of patients achieving the American Diabetes Association (ADA) goal hemoglobin A1c (A1c) of less than 7% with the addition of pioglitazone to the maximal/highest tolerated doses of sulfonylurea and metformin combination therapy.

METHODS

This was a six healthcare system retrospective, descriptive, analysis of type 2 diabetic patients (DM-2). Patients must have received the maximal/highest tolerated doses of sulfonylurea and metformin combination therapy and have been TZD naïve or off TZD therapy for a minimum of 6 months, a baseline A1c greater than 7%, a repeat A1c at 3 and 6 months available, and deemed medication compliant.

RESULTS

We evaluated 98 total patients. The percentage of veteran patients achieving ADA goal A1c of less than 7% after the addition of pioglitazone reached statistical significance at both 3 and 6 months post TZD initiation. The mean reduction in A1c post-pioglitazone initiation was 0.67% (SD ± 0.92) and 0.78% (SD ± 0.94) at 3 and 6 months, respectively.

CONCLUSION

The addition of pioglitazone to veteran patients who were already receiving maximal/highest tolerated doses of sulfonylurea was able to achieve a higher percentage in with the ADA goal A1c of less than 7%. Initiating pioglitazone in patients with an A1c of 9% or greater did not reach statistical significance in achieving an A1c less than 7%. The initial starting dose of pioglitazone 30 mg can be considered as compared to 15 mg daily if contraindications do not exist.

A review of gliptins in 2011

INTRODUCTION

Dipeptidylpeptidase-4 (DPP-4) inhibitors offer new options for the management of type 2 diabetes (T2DM).

AREAS COVERED

This paper is an updated review, providing an analysis of both the similarities and the differences between the various compounds known as gliptins, currently used in the clinic (sitagliptin, vildagliptin, saxagliptin, alogliptin and linagliptin). This paper discusses the pharmacokinetic and pharmacodynamic characteristics of gliptins; both the efficacy and safety profiles of gliptins in clinical trials (compared with classical glucose-lowering agents), given as monotherapy or in combination, including in special populations; the positioning of DPP-4 inhibitors in the management of T2DM in recent guidelines; and various unanswered questions and perspectives.

EXPERT OPINION

The role of DPP-4 inhibitors in the therapeutic armamentarium of T2DM is evolving, as their potential strengths and weaknesses become better defined. Future critical issues may include the durability of glucose control, resulting from better β-cell protection, positive effects on cardiovascular outcomes and long-term safety issues.

DPP-4 inhibitors in the management of type 2 diabetes: a critical review of head-to-head trials

Dipeptidyl peptidase-4 (DPP-4) inhibitors offer new options for the management of type 2 diabetes. Direct comparisons with active glucose-lowering comparators in drug-naive patients have demonstrated that DPP-4 inhibitors exert slightly less pronounced HbA(1c) reduction than metformin (with the advantage of better gastrointestinal tolerability) and similar glucose-lowering effects as with a thiazolidinedione (TZD; with the advantage of no weight gain). In metformin-treated patients, gliptins were associated with similar HbA(1c) reductions compared with a sulphonylurea (SU; with the advantage of no weight gain, considerably fewer hypoglycaemic episodes and no need for titration) and a TZD (with the advantage of no weight gain and better overall tolerability). DPP-4 inhibitors also exert clinically relevant glucose-lowering effects compared with a placebo in patients treated with SU or TZD (of potential interest when metformin is either not tolerated or contraindicated), and as oral triple therapy with a good tolerability profile when added to a metformin-SU or pioglitazone-SU combination. Several clinical trials also showed a consistent reduction in HbA(1c) when DPP-4 inhibitors were added to basal insulin therapy, with no increased risk of hypoglycaemia. Because of the complex pathophysiology of type 2 diabetes and the complementary actions of glucose-lowering agents, initial combination of a DPP-4 inhibitor with either metformin or a glitazone may be applied in drug-naive patients, resulting in greater efficacy and similar safety compared with either drug as monotherapy. However, DPP-4 inhibitors were less effective than GLP-1 receptor agonists for reducing HbA(1c) and body weight, but offer the advantage of being easier to use (oral instead of injected administration) and lower in cost. Only one head-to-head trial demonstrated the non-inferiority of saxagliptin vs sitagliptin. Clearly, more trials of direct comparisons between different incretin-based therapies are needed. Because of their pharmacokinetic characteristics, pharmacodynamic properties (glucose-dependent glucose-lowering effect) and good overall tolerability profile, DPP-4 inhibitors may have a key role to play in patients with renal impairment and in the elderly. The role of DPP-4 inhibitors in the therapeutic armamentarium of type 2 diabetes is rapidly evolving as their potential strengths and weaknesses become better defined mainly through controlled clinical trials.

Efficacy and safety of the PPARγ partial agonist balaglitazone compared with pioglitazone and placebo: a phase III, randomized, parallel-group study in patients with type 2 diabetes on stable insulin therapy

BACKGROUND

Treatment of patients with perioxisome proliferator-activated receptor-γ full agonists are associated with weight gain, heart failure, peripheral oedema, and bone loss. However, the safety of partial perioxisome proliferator-activated receptor-γ agonists has not been established in a clinical trial. The BALaglitazone glucose Lowering Efficacy Trial aimed to establish the glucose-lowering effects and safety parameters of the perioxisome proliferator-activated receptor-γ partial agonist balaglitazone in diabetic patients on stable insulin therapy.

METHODS

Four hundred and nine subjects from three countries with type 2 diabetes on stable insulin therapy were randomized to 26 weeks of double-blind treatment with once daily doses of 10 or 20 mg balaglitazone, 45 mg pioglitazone, or matching placebo (n ≥ 99 in each group). The primary endpoint was the efficacy of balaglitazone 10 and 20 mg versus placebo on the absolute change in haemoglobin A(1c) . Secondary endpoints included levels of fasting serum glucose, and changes in body composition and bone mineral density as measured by dual energy X-ray absorptiometry, in comparison to pioglitazone 45 mg. This study is registered with Clinicaltrials.gov identifier: NCT00515632.

RESULTS

In the 10- and 20-mg balaglitazone groups, and in the 45-mg pioglitazone group, significant reductions in haemoglobin A(1c) levels were observed (−0.99, −1.11, and −1.22%, respectively; p < 0.0001) versus placebo. Fasting serum glucose was similarly reduced in all treatment arms. Dual energy X-ray absorptiometry analyses showed that, while balaglitazone at 10 mg caused weight gain and fluid retention compared to placebo, the magnitude of these effects was significantly smaller than that of pioglitazone 45 mg and balaglitazone 20mg. Balaglitazone at either dose did not appear to reduce bone mineral density, while Pioglitazone showed a trend towards a reduction.

CONCLUSION

Patients treated with balaglitazone at 10 mg and 20 mg and pioglitazone at 45 mg showed clinically meaningful improvements in glucose levels and HbA(1c) . With the 10 mg dose, the benefits (glucose & HgA(1c) lowering) and untoward effects (fluid and fat accumulation) were less, results that encourage further studies of this drug candidate.

Efficacy and safety of saxagliptin in combination with metformin compared with sitagliptin in combination with metformin in adult patients with type 2 diabetes mellitus

BACKGROUND

Dipeptidyl peptidase-4 inhibitors improve glycaemic control in patients with type 2 diabetes mellitus when used as monotherapy or in combination with other anti-diabetic drugs (metformin, sulphonylurea, or thiazolidinedione). This 18-week, phase 3b, multicentre, double-blind, noninferiority trial compared the efficacy and safety of two dipeptidyl peptidase-4 inhibitors, saxagliptin and sitagliptin, in patients whose glycaemia was inadequately controlled with metformin.

METHODS

Adult type 2 diabetes mellitus patients (N = 801) with glycated haemoglobin (HbA(1c)) 6.5-10% on stable metformin doses (1500-3000 mg/day) were randomized 1 : 1 to add-on 5 mg saxagliptin or 100 mg sitagliptin once daily for 18 weeks. The primary efficacy analysis was a comparison of the change from baseline HbA(1c) at week 18 in per-protocol patients. Noninferiority was concluded if the upper limit of the two-sided 95% confidence interval of the HbA(1c) difference between treatments was < 0.3%.

RESULTS

The adjusted mean changes in HbA(1c) following the addition of saxagliptin or sitagliptin to stable metformin therapy were - 0.52 and - 0.62%, respectively. The between-group difference was 0.09% (95% confidence interval, - 0.01 to 0.20%), demonstrating noninferiority. Both treatments were generally well tolerated; incidence and types of adverse events were comparable between groups. Hypoglycaemic events, mostly mild, were reported in approximately 3% of patients in each treatment group. Body weight declined by a mean of 0.4 kg in both groups.

CONCLUSIONS

Saxagliptin added to metformin therapy was effective in improving glycaemic control in patients with type 2 diabetes mellitus inadequately controlled by metformin alone; saxagliptin plus metformin was noninferior to sitagliptin plus metformin, and was generally well tolerated.

Avoiding hypoglycaemia while achieving good glycaemic control in type 2 diabetes through optimal use of oral agent therapy

BACKGROUND

Patients with type 2 diabetes appear to be at relatively low risk of severe hypoglycaemia and hypoglycaemia unawareness in the early stages of disease. However, declining endogenous insulin secretory capacity due to beta-cell dysfunction/failure eventually produces vulnerability similar to type 1 diabetes. Severe hypoglycaemia itself is associated with serious morbidity and sometimes mortality, and represents an important barrier to achieving glycaemic goals and thus may reduce the protection from diabetes-related morbidity provided by good glycaemic control. Achieving an optimal balance of good glycaemic control and low risk of hypoglycaemia is key to providing optimum care in individuals with type 2 diabetes. This article discusses the issues related specifically to hypoglycaemia associated with oral agent therapy and how these agents may be best employed to provide an optimal balance between hypoglycaemia and good glycaemic control.

METHODS

Embase and Medline searches from 1998 to 2009 using the search terms DPP-4 inhibitors, metformin, oral agents, sulphonylureas, thiazolidinediones AND hypoglycaemia were conducted to identify relevant articles. The limitations inherent in this retrospective, narrative review of previously published publications chosen at the author's discretion are acknowledged.

FINDINGS

Failure to address even mild hypoglycaemia and glycaemic control early in the course of the disease may compromise the success of treatment in the longer term. Metformin, thiazolidinediones and DPP-4 inhibitors, either as monotherapy or in combination with each other, have a well-characterised low propensity to cause hypoglycaemia compared with other therapies.

CONCLUSIONS

Metformin, thiazolidinediones and DPP-4 inhibitors appear to be the most appropriate oral options for minimising the risk of hypoglycaemia. Early and ongoing attention to hypoglycaemia should form an integral part of any long-term glucose control strategy.

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.