Metabolic effects of pioglitazone in combination with insulin in patients with type 2 diabetes mellitus whose disease is not adequately controlled with insulin therapy: results of a six-month, randomized, double-blind, prospective, multicenter, parallel-group study

Association of Pioglitazone With Major Adverse Cardiovascular Events, All-Cause Mortality, and Heart Failure Hospitalizations: A Systematic Review

Modern diabetic treatment has gone beyond glycemic control, with the choice of different medications to attain therapeutic targets also affected by the risk of long-term outcomes and safety profiles. The effect of diabetes on increased morbidity and mortality and its relationship to cardiovascular outcomes and coronary artery diseases have driven recent diabetes studies toward medications that improve cardiovascular outcomes and reduce all-cause mortality. This is attained by holistically treating cardiovascular complications in type 2 diabetic patients beyond glycemic control. Moreover, both diabetes and pre-diabetes are considered risk factors for both microvascular and macrovascular cardiac events. Despite the fact that initial research acknowledged fluid retention as a safety issue in pioglitazone use, clinical trial data have not presented conclusive proof of a positive or negative impact on cardiac function. This comprehensive literature review aims to evaluate the effect of pioglitazone on all-cause mortality, hospitalizations for heart failure, and major adverse cardiovascular outcomes, including the individual outcomes of non-fatal stroke, non-fatal myocardial infarction, and cardiovascular mortality.

Age, sex, disease severity, and disease duration difference in placebo response: implications from a meta-analysis of diabetes mellitus

BACKGROUND

The placebo response in patients with diabetes mellitus is very common. A systematic evaluation needs to be updated with the current evidence about the placebo response in diabetes mellitus and the associated factors in clinical trials of anti-diabetic medicine.

METHODS

Literature research was conducted in Medline, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for studies published between the date of inception and June 2019. Randomized placebo-controlled trials conducted in type 1and type 2 diabetes mellitus (T1DM/T2DM) were included. Random-effects model and meta-regression analysis were accordingly used. This meta-analysis was registered in PROSPERO as CRD42014009373.

RESULTS

Significantly weight elevation (effect size (ES) = 0.33 kg, 95% CI, 0.03 to 0.61 kg) was observed in patients with placebo treatments in T1DM subgroup while significantly HbA1c reduction (ES = - 0.12%, 95% CI, - 0.16 to - 0.07%) and weight reduction (ES = - 0.40 kg, 95% CI, - 0.50 to - 0.29 kg) were observed in patients with placebo treatments in T2DM subgroup. Greater HbA1c reduction was observed in patients with injectable placebo treatments (ES = - 0.22%, 95% CI, - 0.32 to - 0.11%) versus oral types (ES = - 0.09%, 95% CI, - 0.14 to - 0.04%) in T2DM (P = 0.03). Older age (β = - 0.01, 95% CI, - 0.02 to - 0.01, P < 0.01) and longer diabetes duration (β = - 0.02, 95% CI, - 0.03 to - 0.21 × 10^-2, P = 0.03) was significantly associated with more HbA1c reduction by placebo in T1DM. However, younger age (β = 0.02, 95% CI, 0.01 to 0.03, P = 0.01), lower male percentage (β = 0.01, 95% CI, 0.22 × 10^-2, 0.01, P < 0.01), higher baseline BMI (β = - 0.02, 95% CI, - 0.04 to - 0.26 × 10^-2, P = 0.02), and higher baseline HbA1c (β = - 0.09, 95% CI, - 0.16 to - 0.01, P = 0.02) were significantly associated with more HbA1c reduction by placebo in T2DM. Shorter diabetes duration (β = 0.06, 95% CI, 0.06 to 0.10, P < 0.01) was significantly associated with more weight reduction by placebo in T2DM. However, the associations between baseline BMI, baseline HbA1c, and placebo response were insignificant after the adjusted analyses.

CONCLUSION

The placebo response in diabetes mellitus was systematically outlined. Age, sex, disease severity (indirectly reflected by baseline BMI and baseline HbA1c), and disease duration were associated with placebo response in diabetes mellitus. The association between baseline BMI, baseline HbA1c, and placebo response may be the result of regression to the mean.

Pioglitazone Exposure Reduced the Risk of All-Cause Mortality in Insulin-Treated Patients with Type 2 Diabetes Mellitus

CONTEXT

The long-term safety and benefit of pioglitazone use in combination with insulin are still uncertain.

OBJECTIVE

This study compared the risks of all-cause mortality and major cardiovascular (CV) events between pioglitazone users and nonusers receiving insulin therapy.

DESIGN, SETTING AND PATIENTS

We conducted a 13-year retrospective cohort study by using data from the population-based National Health Insurance Research Database in Taiwan. A total of 20 376 patients with type 2 diabetes mellitus (T2DM) receiving insulin therapy were enrolled during 2000 to 2012. Overall, the incidence rates of all-cause mortality and CV events were compared between 2579 pioglitazone users and 2579 matched nonusers.

RESULTS

After adjustment for age, sex, comorbidities, Diabetes Complications Severity Index scores, and drugs used, mortality rates were 30.26 and 15.02 per 1000 person-years for pioglitazone nonusers and users, respectively. The adjusted hazard ratio (aHR) of mortality was 0.47 (95% confidence interval [CI]: 0.38-0.58, P < 0.001) for pioglitazone users compared with nonusers. The aHRs of CV and non-CV deaths were 0.78 (95% CI: 0.51-1.19) and 0.50 (95% CI: 0.38-0.66), respectively. The aHRs of hospitalized coronary artery disease, hospitalized stroke, and incident heart failure were not significantly different between pioglitazone users and nonusers.

CONCLUSIONS

This nationwide cohort study demonstrated that pioglitazone use reduced the risks of all-cause mortality and non-CV death for patients with T2DM undergoing insulin therapy.

Combating Obesity With Thermogenic Fat: Current Challenges and Advancements

Brown fat and beige fat are known as thermogenic fat due to their contribution to non-shivering thermogenesis in mammals following cold stimulation. Beige fat is unique due to its origin and its development in white fat. Subsequently, both brown fat and beige fat have become viable targets to combat obesity. Over the last few decades, most therapeutic strategies have been focused on the canonical pathway of thermogenic fat activation via the β3-adrenergic receptor (AR). Notwithstanding, administering β3-AR agonists often leads to side effects including hypertension and particularly cardiovascular disease. It is thus imperative to search for alternative therapeutic approaches to combat obesity. In this review, we discuss the current challenges in the field with respect to stimulating brown/beige fat thermogenesis. Additionally, we include a summary of other newly discovered pathways, including non-AR signaling- and non-UCP1-dependent mechanisms, which could be potential targets for the treatment of obesity and its related metabolic diseases.

GOALS FOR MEDICAL TREATMENT IN OBESITY AND PREDIABETES: IMPROVING OUTCOMES FOR BOTH

OBJECTIVE

The purpose of this review is to expose the surprising prevalence of diabetes-related complications in people with persistent prediabetes, and hence, to expand the paradigm of diabetes prevention to include the prevention of complications related to both hyperglycemia and obesity.

METHODS

Published literature was reviewed.

RESULTS

Approximately 84 million Americans have prediabetes, 85% of whom are overweight or obese. Although the incidence of diabetes-related complications is lower in people with prediabetes versus those with type 2 diabetes, the overall prevalence is virtually identical. Furthermore, many people with prediabetes not only suffer from the complications related to hyperglycemia, they also experience complications of obesity. Treating obesity as a disease has the potential to prevent complications of both hyperglycemia and obesity. Emerging data reveal the untapped potential for clinicians to enhance the effectiveness of anti-obesity medications through a mindful health care delivery style. This involves an understanding and ethical utilization of the placebo effect in conjunction with active medical therapy. This approach is not intended to mislead patients but rather to activate neurocircuitry that synergizes with the central action of the approved anti-obesity medications to potentiate weight loss.

CONCLUSION

Mindful administration of anti-obesity medications has the potential for widespread health benefits in people with obesity and prediabetes.

ABBREVIATIONS

ADA = American Diabetes Association; DPP = Diabetes Prevention Program; CVD = cardiovascular disease.

Addition of dipeptidyl peptidase-4 inhibitors to insulin treatment in type 2 diabetes patients: A meta-analysis

AIMS/INTRODUCTION

To evaluate the efficacy and safety of combining insulin therapy with dipeptidyl peptidase-4 (DPP-4) inhibitors compared with combining insulin therapy with a placebo or other antihyperglycemic agents.

MATERIALS AND METHODS

A literature search was carried out via electronic databases. The inclusion criteria were randomized controlled trials comparing the addition of DPP-4 inhibitors to insulin with the addition of a placebo or other active hypoglycemic agents to insulin therapy, study duration of no less than 12 weeks carried out in type 2 diabetes patients and the availability of outcome data to evaluate a change in the glycated hemoglobin.

RESULTS

The glycated hemoglobin-lowering efficacy was significantly greater with DPP-4 inhibitor/insulin (DPP-4i/INS) than with placebo/insulin (weighted mean difference -0.53%, 95% confidence interval -0.63, -0.43, P < 0.01). The postprandial plasma glucose-lowering efficacies was also significantly greater with DPP-4i/INS than with placebo/insulin (weighted mean difference -1.65 mmol/L, 95% CI: -2.34, -0.96, P < 0.05). The risk of hypoglycemia or severe hypoglycemia was similar for DPP4i/INS and placebo/insulin treatments. There was no significant difference in the glycemia-lowering efficacy between DPP-4i/INS and alpha-glucosidase inhibitors/insulin, thiazolidinedione/insulin and glucagon-like peptide-1 receptor agonist/insulin. Sodium-glucose cotransporter 2 inhibitor/insulin treatment achieved better placebo-corrected efficacy in lowering postprandial plasma glucose, with less weight gain and no higher risk of hypoglycemia.

CONCLUSIONS

Treatment with DPP-4 inhibitors combined with insulin improved glycemic control without an increased risk of hypoglycemia or weight gain compared with insulin treatment alone.

Comparison between sodium-glucose cotransporter 2 inhibitors and pioglitazone as additions to insulin therapy in type 2 diabetes patients: A systematic review with an indirect comparison meta-analysis

AIMS/INTRODUCTION

We aimed to evaluate the efficacy and safety of pioglitazone (PIO) and sodium-glucose cotransporter 2 inhibitors (SGLT2i) as additions to insulin therapy for the management of type 2 diabetes mellitus.

MATERIALS AND METHODS

We searched PubMed, EMBASE, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov through December 2016. Randomized controlled trials published in English that compared SGLT2i plus insulin (SGLT2i/INS) or PIO plus insulin (PIO/INS) with placebo plus insulin (PCB/INS) in type 2 diabetes mellitus patients were included. We compared the efficacy and safety between SGLT2i/INS and PIO/INS indirectly.

RESULTS

A total of 14 randomized controlled trials comparing 7,226 participants were included (8 SGLT2i and 6 PIO studies). SGLT2i/INS achieved similar reductions in hemoglobin A1c (weighted mean difference [WMD] -0.01% [-0.1 mmol/mol], 95% confidence interval [CI] -0.25 to 0.22% [-2.7 to -2.4 mmol/mol]; P = 0.896) and fasting plasma glucose (WMD -0.90 mg/dL, 95% CI: -15.50 to 13.71 mg/dL; P = 0.904), and a similar proportion of participants achieved hemoglobin A1c <7.0% (<53.0 mmol/mol; relative risk 0.98, 95% CI: 0.73 to 1.33; P = 0.917) as compared with the PIO/INS group, with greater weight reduction (WMD -4.54 kg, 95% CI: -5.67 to -3.41 kg; P < 0.001). PIO/INS showed non-significant trends toward a higher risk of hypoglycemia (relative risk 1.15, 95% CI: 0.97 to 1.35; P = 0.102) and higher reduction of total daily insulin doses (WMD -2.45 IU/day, 95% CI: -7.30 to 2.40 IU/day; P = 0.438).

CONCLUSIONS

Both PIO and SGLT2i are feasible adjunctive oral agents to pre-existing insulin therapy in individuals with inadequately controlled type 2 diabetes mellitus.

Insulin Monotherapy Versus Insulin Combined with Other Glucose-Lowering Agents in Type 2 Diabetes: A Narrative Review

CONTEXT

Insulin can be prescribed as a monotherapy or a combined therapy with other anti-diabetic medications. In this narrative review, the authors aimed to gather data related to comparison of insulin monotherapy versus combination of insulin and other anti-diabetic treatments with regards to different outcome measures in type 2 diabetes.

EVIDENCE ACQUISITION

This study searched and focused on the most recently published systematic reviews and their references investigating issues related to the primary aim.

RESULTS

The current data available on this topic is heterogeneous and suffers from low quality with respect to most combination treatments. Considering the efficacy and safety of combination therapy of insulin with older hypoglycemic agents, in general metformin and pioglitazone have the best and worst profiles, respectively. Compared to insulin monotherapy, combination of insulin and metformin is associated with better glycemic control, reduced daily insulin dose, less hypoglycemia, and weight gain; combination of insulin and pioglitazone results in greater hypoglycemia and weight gain and is associated with increased risk of edema and heart failure. Regarding sulphonylurea, there is some concern regarding hypoglycemia and weight gain. Addition of dipeptidyl peptidase-4 inhibitors to insulin seems to be beneficial with respect to glycemic control without any significant adverse effects. New drugs, including glucagon-like peptide-1 agonists and sodium glucose co-transporter 2 inhibitors, have acceptable profiles with significant benefits regarding weight reduction when added on insulin therapy.

CONCLUSIONS

Considering the quality and longevity of evidence, compared to insulin monotherapy, insulin combined with metformin and pioglitazone has the best and worst profiles, respectively. New anti-diabetic medications have acceptable profiles yet are expensive. It is important for clinicians to meticulously weigh the advantages of combination therapy against the possible adverse effects with each drug class in every patient, individually.

Comparison of non-insulin antidiabetic agents as an add-on drug to insulin therapy in type 2 diabetes: a network meta-analysis

We aimed to evaluate the comparative efficacy and safety of dipeptidyl peptidase-4 inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP-1RA), sodium-glucose co-transporter 2 inhibitors (SGLT2i), or thiazolidinedione (TZD) as an adjunctive treatment in patients with poorly controlled type 2 diabetes mellitus (T2DM) on insulin therapy. We searched Medline, Embase, the Cochrane Library, and ClinicalTrials.gov through April 2016. Bayesian network meta-analyses were performed with covariate adjustment. The primary outcome was the change in glycated hemoglobin A1c (HbA1c) from baseline. Fifty randomized controlled trials covering 15,494 patients were included. GLP-1RA showed the greatest HbA1c-lowering effect compared to the control (−0.84%; 95% credible interval, −1.00% to −0.69%), followed by TZD (−0.73%; −0.93 to −0.52%), SGLT2i (−0.66%; −0.84% to −0.48%), and DPP4i (−0.54%; −0.68% to −0.39%). SGLT2i showed the greatest fasting plasma glucose reduction. GLP-1RA and SGLT2i showed greater body weight reduction, whereas TZD increased body weight. TZD was ranked the highest in terms of insulin dose reduction. The risk of hypoglycemia was increased with TZD or GLP-1RA. The study provides the best available evidence on the comparative efficacy and safety of non-insulin anti-diabetic agents on top of pre-existing insulin therapy for inadequately controlled T2DM patients.

Protective effect of rosiglitazone on kidney function in high-fat challenged human-CRP transgenic mice: a possible role for adiponectin and miR-21?

Obesity-related albuminuria is associated with decline of kidney function and is considered a first sign of diabetic nephropathy. Suggested factors linking obesity to kidney dysfunction include low-grade inflammation, insulin resistance and adipokine dysregulation. Here, we investigated the effects of two pharmacological compounds with established anti-inflammatory properties, rosiglitazone and rosuvastatin, on kidney dysfunction during high-fat diet (HFD)-induced obesity. For this, human CRP transgenic mice were fed standard chow, a lard-based HFD, HFD+rosuvastatin or HFD+rosiglitazone for 42 weeks to study effects on insulin resistance; plasma inflammatory markers and adipokines; and renal pathology. Rosiglitazone but not rosuvastatin prevented HFD-induced albuminuria and renal fibrosis and inflammation. Also, rosiglitazone prevented HFD-induced KIM-1 expression, while levels were doubled with rosuvastatin. This was mirrored by miR-21 expression, which plays a role in fibrosis and is associated with renal dysfunction. Plasma insulin did not correlate with albuminuria. Only rosiglitazone increased circulating adiponectin concentrations. In all, HFD-induced albuminuria, and renal inflammation, injury and fibrosis is prevented by rosiglitazone but not by rosuvastatin. These beneficial effects of rosiglitazone are linked to lowered miR-21 expression but not connected with the selectively enhanced plasma adiponectin levels observed in rosiglitazone-treated animals.

Effects of pioglitazone therapy on blood parameters, weight and BMI: a meta-analysis

BACKGROUND

Type 2 diabetes mellitus (T2DM) is one of the most common diseases worldwide and insulin insufficiency and insulin resistance are two main metabolic issues connected with it. The dyslipidemia associated with insulin resistance and T2DM is characterized by higher triglycerides (TGs), higher very-low-density lipoprotein cholesterol and lower apo A1. Pioglitazone, a member of the thiazolidinedione class, with a proven antihyperglycemic effect, is known to positively influence insulin sensitivity and β-cell function and to have the potential to alter the lipid profile.

METHODS

The aim of our meta-analysis is to summarize and determine the influence of pioglitazone on the glycemic profile and lipoprotein metabolism as well as on weight and BMI in order to highlight the benefit of pioglitazone therapy in patients with T2DM. A comprehensive literature search was conducted through the electronic databases PubMed, MEDLINE, Scopus, PsyInfo, eLIBRARY.ru (from 2000 until February 2016) to identify studies that investigate the effect of pioglitazone on the glycemic and lipid profile and on the weight and BMI. We chose the random-effects method as the primary analysis. Forest plots depict estimated results from the studies included in the analysis and funnel plots are used to evaluate publication bias. Sensitivity analyses were performed in order to evaluate the degree of influence of the consequent elimination of each individual study on the final result.

RESULTS

Of the 1536 identified sources only 15 randomised trials were included in the meta-analysis. Pioglitazone treatment was associated with improvement in the glycemic profile. It reduced FPG levels by a mean of 1.1-2 mmol/l and HbA1c by a mean of 0.9-1.3%. Our results reaffirmed the hypothesis that pioglitazone has a positive influence on the lipid profile of T2DM patients with increase in TC and HDL, no significant changes in LDL and notable decrease in TGs. Results also showed that pioglitazone therapy led to increase in both weight and BMI (WMD 1.755, 95% CI 0.674 to 2.837 and 1.145, 95% CI 0.389 to 1.901 respectively).

CONCLUSION

Our results prove that the PPAR γ agonist pioglitazone has the potential to be beneficial to patients with T2DM.

Insulin monotherapy compared with the addition of oral glucose-lowering agents to insulin for people with type 2 diabetes already on insulin therapy and inadequate glycaemic control

BACKGROUND

It is unclear whether people with type 2 diabetes mellitus on insulin monotherapy who do not achieve adequate glycaemic control should continue insulin as monotherapy or can benefit from adding oral glucose-lowering agents to the insulin therapy.

OBJECTIVES

To assess the effects of insulin monotherapy compared with the addition of oral glucose-lowering agents to insulin monotherapy for people with type 2 diabetes already on insulin therapy and inadequate glycaemic control.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and reference lists of articles. The date of the last search was November 2015 for all databases.

SELECTION CRITERIA

Randomised controlled clinical trials of at least two months' duration comparing insulin monotherapy with combinations of insulin with one or more oral glucose-lowering agent in people with type 2 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias, extracted data and evaluated overall quality of the evidence using GRADE. We summarised data statistically if they were available, sufficiently similar and of sufficient quality. We performed statistical analyses according to the statistical guidelines in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We included 37 trials with 40 treatment comparisons involving 3227 participants. The duration of the interventions ranged from 2 to 12 months for parallel trials and two to four months for cross-over trials.The majority of trials had an unclear risk of bias in several risk of bias domains. Fourteen trials showed a high risk of bias, mainly for performance and detection bias. Insulin monotherapy, including once-daily long-acting, once-daily intermediate-acting, twice-daily premixed insulin, and basal-bolus regimens (multiple injections), was compared to insulin in combination with sulphonylureas (17 comparisons: glibenclamide = 11, glipizide = 2, tolazamide = 2, gliclazide = 1, glimepiride = 1), metformin (11 comparisons), pioglitazone (four comparisons), alpha-glucosidase inhibitors (four comparisons: acarbose = 3, miglitol = 1), dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) (three comparisons: vildagliptin = 1, sitagliptin = 1, saxagliptin = 1) and the combination of metformin and glimepiride (one comparison). No trials assessed all-cause mortality, diabetes-related morbidity or health-related quality of life. Only one trial assessed patients' treatment satisfaction and showed no substantial differences between the addition of either glimepiride or metformin and glimepiride to insulin compared with insulin monotherapy.Insulin-sulphonylurea combination therapy (CT) compared with insulin monotherapy (IM) showed a MD in glycosylated haemoglobin A1c (HbA1c) of -1% (95% confidence interval (CI) -1.6 to -0.5); P < 0.01; 316 participants; 9 trials; low-quality evidence. Insulin-metformin CT compared with IM showed a MD in HbA1c of -0.9% (95% CI -1.2 to -0.5); P < 0.01; 698 participants; 9 trials; low-quality evidence. We could not pool the results of adding pioglitazone to insulin. Insulin combined with alpha-glucosidase inhibitors compared with IM showed a MD in HbA1c of -0.4% (95% CI -0.5 to -0.2); P < 0.01; 448 participants; 3 trials; low-quality evidence). Insulin combined with DPP-4 inhibitors compared with IM showed a MD in HbA1c of -0.4% (95% CI -0.5 to -0.4); P < 0.01; 265 participants; 2 trials; low quality evidence. In most trials the participants with CT needed less insulin, whereas insulin requirements increased or remained stable in participants with IM.We did not perform a meta-analysis for hypoglycaemic events because the included studies used different definitions.. In most trials the insulin-sulphonylurea combination resulted in a higher number of mild episodes of hypoglycaemia, compared to the IM group (range: 2.2 to 6.1 episodes per participant in CT versus 2.0 to 2.6 episodes per participant in IM; low-quality evidence). Pioglitazone CT also resulted in more mild to moderate hypoglycaemic episodes compared with IM (range 15 to 90 episodes versus 9 to 75 episodes, respectively; low-quality evidence. The trials that reported hypoglycaemic episodes in the other combinations found comparable numbers of mild to moderate hypoglycaemic events (low-quality evidence).The addition of sulphonylureas resulted in an additional weight gain of 0.4 kg to 1.9 kg versus -0.8 kg to 2.1 kg in the IM group (220 participants; 7 trials; low-quality evidence). Pioglitazone CT caused more weight gain compared to IM: MD 3.8 kg (95% CI 3.0 to 4.6); P < 0.01; 288 participants; 2 trials; low-quality evidence. Metformin CT was associated with weight loss: MD -2.1 kg (95% CI -3.2 to -1.1), P < 0.01; 615 participants; 7 trials; low-quality evidence). DPP-4 inhibitors CT showed weight gain of -0.7 to 1.3 kg versus 0.6 to 1.1 kg in the IM group (362 participants; 2 trials; low-quality evidence). Alpha-glucosidase CT compared to IM showed a MD of -0.5 kg (95% CI -1.2 to 0.3); P = 0.26; 241 participants; 2 trials; low-quality evidence.Users of metformin CT (range 7% to 67% versus 5% to 16%), and alpha-glucosidase inhibitors CT (14% to 75% versus 4% to 35%) experienced more gastro-intestinal adverse effects compared to participants on IM. Two trials reported a higher frequency of oedema with the use of pioglitazone CT (range: 16% to 18% versus 4% to 7% IM).

AUTHORS' CONCLUSIONS

The addition of all oral glucose-lowering agents in people with type 2 diabetes and inadequate glycaemic control who are on insulin therapy has positive effects on glycaemic control and insulin requirements. The addition of sulphonylureas results in more hypoglycaemic events. Additional weight gain can only be avoided by adding metformin to insulin. Other well-known adverse effects of oral glucose-lowering agents have to be taken into account when prescribing oral glucose-lowering agents in addition to insulin therapy.

Continuation or discontinuation of pioglitazone when starting bedtime insulin in patients with poorly controlled type 2 diabetes in an inner-city population

OBJECTIVE

We studied the impact of continuing versus discontinuing pioglitazone on hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and weight when starting bedtime insulin in patients with poor glycemic control.

METHODS

We retrospectively analyzed data from a 13-month randomized control trial on 77 patients with type 2 diabetes mellitus (DM), who despite maximum doses of three oral diabetes medications (metformin, sulfonylurea and pioglitazone) had HbA1C levels above 7.5%. Patients were randomized to either continuing or discontinuing pioglitazone in addition to starting and up-titrating bedtime insulin. HbA1C, FPG, and weight were assessed at baseline, 3months, 7months and 13months with the differences from baseline for the two groups compared at each of the three time points using the Wilcoxon rank sum test.

RESULTS

We found that HbA1c was significantly lower at the 7-month (p=0.01) and 13-month time points (p=0.036), and FPG was significantly lower at all three time points in the group continuing pioglitazone compared with those discontinuing pioglitazone. Continuing pioglitazone resulted in a greater increase in weight at the 3-month (p=0.002), 7-month (p=0.0001) and 13-month (p=0.00003) time points. Patients with the lowest HbA1c (<8.2%) at baseline were more likely to benefit from continuing pioglitazone than those with higher baseline HbA1c. Patients who started insulin and discontinued pioglitazone had similar HbA1c, FPG and weight at the three time points as at baseline, suggesting that pioglitazone and bedtime insulin has similar glycemic effect in this population.

CONCLUSIONS

We conclude that in patients with uncontrolled type 2 DM, continuing pioglitazone while concurrently starting bedtime insulin within a 13-month period led to a significant decrease in both HbA1c and FPG levels compared with those who did not receive pioglitazone; however weight increased during this period.

Effect of pioglitazone therapy on high sensitive C-reactive protein and lipid profile in diabetic patients with renal transplantation; a randomize clinical trial

Background: Inflammation has a major role in disease lead to renal failure and diabetes mellitus, controlling inflammation in diabetic kidney receivers could decrease morbidity and mortality.

Objectives: This study designed for evaluating the efficacy of pioglitazone on C-reactive protein and lipid profile in diabetic kidney transplant receivers.

Patients and Methods: In this double blinded clinical trial, 58 diabetic renal transplant receivers, in first month after transplantation, randomized into two groups; receiving insulin and pioglitazone (15 mg tablet daily, group A); and insulin and placebo (group B). Blood pressure, weight, body mass index (BMI) and laboratory data compared in before and after 4-month treatment in two groups by SPSS.

Results: Fifty-eight patients with mean age of 44.15 ± 2 years included. There were no significant difference between groups in demographic data and other baseline measured variables (P > 0.05) .The mean weigh and BMI were slightly increased in group A and decreased in group B. The mean hs-CRP was decreased 4.82 mg/dL in group A and 1.93 mg/dL in group B (P = 0.007). The mean total serum cholesterol was significantly decreased 34 mg/dL in group A and 18.07 mg/dL in group B (P = 0.027). The mean serum HDL-C was significantly increased 13.31 mg/dL in group A and 5.89 mg/dl in group B (P < 0.001).

Conclusions: Pioglitazone seems to be a safe drug for reducing serum lipids and CRP in kidney transplant receivers with diabetes mellitus in short term. Long term effect of this drug could be evaluated in future studies.

Impact of Bromocriptine-QR Therapy on Glycemic Control and Daily Insulin Requirement in Type 2 Diabetes Mellitus Subjects Whose Dysglycemia Is Poorly Controlled on High-Dose Insulin: A Pilot Study

BACKGROUND

The concurrent use of a postprandial insulin sensitizing agent, such as bromocriptine-QR, a quick release formulation of bromocriptine, a dopamine D2 receptor agonist, may offer a strategy to improve glycemic control and limit/reduce insulin requirement in type 2 diabetes (T2DM) patients on high-dose insulin. This open label pilot study evaluated this potential utility of bromocriptine-QR.

METHODS

Ten T2DM subjects on metformin (1-2 gm/day) and high-dose (TDID ≥ 65 U/day) basal-bolus insulin were enrolled to receive once daily (morning) bromocriptine-QR (1.6-4.8 mg/day) for 24 weeks. Subjects with at least one postbaseline HbA1c measurement (N = 8) were analyzed for change from baseline HbA(1c), TDID, and postprandial glucose area under the curve of a four-hour mixed meal tolerance test (MMTT).

RESULTS

Compared to the baseline, average HbA1c decreased 1.76% (9.74 ± 0.56 to 7.98 ± 0.36, P = 0.01), average TDID decreased 27% (199 ± 33 to 147 ± 31, P = 0.009), and MMTT AUC(60-240) decreased 32% (P = 0.04) over the treatment period. The decline in HbA(1c) and TDID was observed at 8 weeks and sustained over the remaining 16-week study duration.

CONCLUSION

In this study, bromocriptine-QR therapy improved glycemic control and meal tolerance while reducing insulin requirement in T2DM subjects poorly controlled on high-dose insulin therapy.

Efficacy of pioglitazone on glycemic control and carotid intima-media thickness in type 2 diabetes patients with inadequate insulin therapy

Aims/Introduction:  The present study was designed to determine the effects of pioglitazone on glycemic control and atherosclerosis in patients with poorly controlled type 2 diabetes on insulin therapy.

Materials and Methods:  The study was a prospective, randomized controlled trial involving 48 patients with inadequately controlled type 2 diabetes treated with insulin. We assigned patients to oral pioglitazone titrated from 15–30 mg (n = 22) or no pioglitazone (n = 26), to be taken in addition to their glucose‐lowering drugs and other medications. Daily insulin doses and numbers were recorded during the study period.

Results:  The adjusted mean glycosylated hemoglobin (HbA_1c) values decreased significantly by 1.13 ± 1.50% and 0.55 ± 0.76% in the pioglitazone and control groups, respectively. Significant decrease of HbA_1c level was observed in the pioglitazone group compared with the control group (P < 0.05). The insulin dose lowered by 0.04 ± 0.10 units/kg/day in the pioglitazone group and increased by 0.03 ± 0.10 units/kg/day in the control group (P < 0.05). The number of insulin injections decreased by 0.1 ± 0.6 times/day in the pioglitazone group and increased by 0.2 ± 0.4 times/day in the control group (P < 0.05). The carotid intima‐media thickness estimated by B‐mode echography was carried out in both groups and decreased significantly at the end‐point only in the pioglitazone group, relative to the baseline.

Conclusions:  These findings show that pioglitazone is useful in improving glycemic control and preventing the progression of atherosclerosis in poorly‐controlled type 2 diabetics on insulin therapy. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00064.x, 2010)

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.

Complementing insulin therapy to achieve glycemic control

INTRODUCTION

Most patients with type 2 diabetes mellitus (T2DM) will need incrementally more complex therapeutic regimens to control hyperglycemia as the disease progresses. Insulin is very effective in reducing hyperglycemia and may improve β-cell function in patients with T2DM. However, insulin therapy is associated with weight gain and increased risk of hypoglycemia. Adding other antidiabetes medications to insulin can improve glycemic control and potentially lower the required insulin dose, resulting in less weight gain and lower risk for hypoglycemia. This article summarizes the advantages and disadvantages of different classes of commonly used antidiabetes agents, with emphasis on newer classes, for use as add-on therapy to insulin in patients with T2DM inadequately controlled on insulin therapy.

METHODS

A PubMed search from July 1, 2003 to April 15, 2013 for peer-reviewed clinical and review articles relevant to insulin combination or add-on therapy in T2DM was conducted. Search terms included "insulin combination therapy," "add-on therapy diabetes," "dipeptidyl peptidase-4 (DPP-4) inhibitors," "glucagon-like peptide-1 (GLP-1) receptor agonist," "sodium-glucose cotransporter 2 (SGLT2) inhibitors", "insulin metformin," "insulin sulfonylurea," and "insulin thiazolidinedione." Bibliographies from retrieved articles were also searched for relevant articles. Study design, clinical relevance, and effect on insulin combination therapy were analyzed.

RESULTS

Therapies used as add-on to insulin include agents associated with weight gain (thiazolidinediones and sulfonylureas) and/or hypoglycemia (sulfonylureas), which, therefore, may exacerbate risks already present with insulin. GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors improve glycemic control when added to insulin and have a low propensity for hypoglycemia and cause no change (DPP-4 inhibitors) or a reduction (GLP-1 receptor agonists, SGLT2 inhibitors) in body weight.

CONCLUSION

GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors improve glycemic control when combined with insulin. They also have low propensity for weight gain and hypoglycemia and so may be preferred treatment options for insulin combination when compared with traditional therapies.

Effect of pioglitazone versus metformin on cardiovascular risk markers in type 2 diabetes

INTRODUCTION

Besides its critical role in metabolic homeostasis, peroxisome proliferator-activated receptor (PPAR)-γ modulates several cellular responses involved in atherothrombosis. This multicenter, double-blind, randomized study investigated the effects of two oral hypoglycemic agents on markers of inflammation, platelet activation, thrombogenesis, and oxidative stress in patients with type 2 diabetes.

METHODS AND RESULTS

The primary objective of this study was to evaluate the effect on C-reactive protein (CRP) after a 16-week treatment period with either pioglitazone or metformin. Additionally, markers of vascular inflammatory response, platelet activation, thrombogenesis, oxidative stress, glucose, and lipid metabolism, as well as liver function, were measured. In total, 50 patients completed the study. Pioglitazone-treated patients were found to have statistically significantly larger decreases in mean CRP levels (-0.4 mg/dL) compared to those treated with metformin (-0.2 mg/dL) (P=0.04), as well as greater reductions in levels of mean fasting plasma glucose (-27 vs. -9 mg/dL; P=0.01), serum insulin (-2 vs. -1.9 mU/L; P=0.014), homeostatic model assessment (HOMA) (-1.2 vs. -0.9; P=0.015), and E-selectin (-12.4 vs. +3.4 μg/mL; P=0.01). Mean glycated hemoglobin (HbA1c) levels decreased in both treatment groups from baseline to week 16 (-0.4% in the pioglitazone group, -0.2% in the metformin group; P=0.36). Pioglitazone treatment was also found to be associated with a statistically significant increase in total cholesterol levels (+10 mg/dL in the pioglitazone arm, -3 mg/dL in the metformin arm; P=0.05) and a decrease in liver enzyme levels.

CONCLUSIONS

The favorable changes in markers of systemic and vascular inflammatory response with pioglitazone suggest that it may positively influence the atherothrombotic process in type 2 diabetes.

A comparative study on the effects of diet and exercise, metformin and metformin+pioglitazone treatment on NIDDM patients

A comparative study on two groups of newly diagnosed nonobese and obese NIDDM patients who were 15 in each group and treated by diet cum exercise and metfromin monotherapy respectively and a third group of 15 obese NIDDM patients whose hyperglycemia was not first controlled by a combination therapy of metformin and sulfonylurea and therefore changed over to a different combination therapy of metformin and ploglitazone, was carried out before and after a period of three months treatment. The mild hyperglycemia in the 1(st) group and the moderate or severe hyperglycemia with accompanied disorders of serum enzymes such as AST, ALT, GGT and the level of HBA(10) observed with 2(nd) and 3(rd) groups of obese NIDDM patients were significantly ameliorated by the respective mode of treatments. Here the efficacies of the three types of treatment are substantiated and further it specifically depicts the success with the choice of combination therapy with metformin and pioglitazone in the third group of obese diabetics.

Plakilactones from the marine sponge Plakinastrella mamillaris. Discovery of a new class of marine ligands of peroxisome proliferator-activated receptor γ

In this paper we report the isolation and the molecular characterization of a new class of PPARγ ligands from the marine environment. Biochemical characterization of a library of 13 oxygenated polyketides isolated from the marine sponge Plakinastrella mamillaris allowed the discovery of gracilioether B and plakilactone C as selective PPARγ ligands in transactivation assays. Both agents covalently bind to the PPARγ ligand binding domain through a Michael addition reaction involving a protein cysteine residue and the α,β-unsaturated ketone in their side chains. Additionally, gracilioether C is a noncovalent agonist for PPARγ, and methyl esters 1 and 2 are noncovalent antagonists. Structural requirements for the interaction of these agents within the PPARγ ligand binding domain were obtained by docking analysis. Gracilioether B and plakilactone C regulate the expression of PPARγ-dependent genes in the liver and inhibit the generation of inflammatory mediators by macrophages.

Effects on lipid profile of dipeptidyl peptidase 4 inhibitors, pioglitazone, acarbose, and sulfonylureas: meta-analysis of placebo-controlled trials

INTRODUCTION

Lipid profile is an important determinant of cardiovascular risk in type 2 diabetes. It is well known that patients with type 2 diabetes are more likely to be dyslipidemic than the general population. Given the observed connection between glucose and lipid metabolism in patients with type 2 diabetes, it is conceivable that different glucose-lowering agents can have a varying impact on the lipid profile. When metformin monotherapy fails, other drugs can be added to achieve sufficient glycemic control. Available oral agents include pioglitazone, acarbose, dipeptidyl peptidase 4 (DPP-4) inhibitors, and insulin secretagogs. The present meta-analysis was designed to assess the effect of DPP-4 inhibitors, pioglitazone, insulin secretagogs, and acarbose on blood lipids when compared to placebo.

METHODS

An extensive search (any date up to November 1, 2011) was performed for all trials performed on the following classes of drugs: gliptin, insulin secretagogs, pioglitazone, and acarbose. The following endpoints were considered: endpoint total, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) and triglycerides.

RESULTS

The difference in mean total cholesterol values at endpoint versus baseline was significantly higher in patients on pioglitazone, sulfonylureas, and DPP-4 inhibitor treatment (but not on acarbose) than those on placebo, demonstrating that treatment with these drugs (except acarbose) is associated with a significant reduction in total cholesterol. With respect to triglycerides, a significant reduction could be observed with acarbose, pioglitazone, and DPP-4 inhibitors, but not with sulfonylureas. HDL-C appeared to be increased by treatment with acarbose and pioglitazone, and decreased by sulfonylureas.

CONCLUSION

The present meta-analysis shows that available glucose-lowering drugs may have varying effects on the lipid profile. DPP-4 inhibitors, acarbose, and pioglitazone seem to have a more favorable effect on the lipid profile than sulfonylureas.

Thiazolidinedione safety

INTRODUCTION

Thiazolidinediones (TZDs) initially showed great promise as unique receptor-mediated oral therapy for type 2 diabetes, but a host of serious side effects, primarily cardiovascular, have limited their utility. It is crucial at this point to perform a risk-benefit analysis to determine what role TZDs should play in our current treatment of type 2 diabetes and where the future of this class of drugs is headed.

AREAS COVERED

This review provides a comprehensive overview of the literature from 2000 onward reporting the known side effects of rosiglitazone and pioglitazone, with commentary on the quality of the data available, putative mechanism of each side effect and clinical significance. Finally, a perspective on the future of the TZDs as a class is provided.

EXPERT OPINION

The current TZDs are first-generation, non-specific activators of peroxisome proliferator-activated receptor (PPAR) gamma, resulting in a wide array of deleterious side effects that currently limit their use. However, the development of highly targeted selective PPAR gamma modulators (SPPARγMs) and dual PPAR gamma/alpha agonists is on the horizon.

Thiazolidinediones and PPARγ agonists: time for a reassessment

Thiazolidinediones (TZDs) are anti-diabetic drugs that act as insulin sensitizers and are used in the management of type 2 diabetes mellitus. TZDs, which are ligands for the transcription factor peroxisome proliferator-activated receptor PPARγ, have a wide spectrum of action, including modulation of glucose and lipid homeostasis, inflammation, atherosclerosis, bone remodeling and cell proliferation. Randomized clinical trials have demonstrated the efficacy and durability of the anti-hyperglycemic action of TZDs, and have suggested that the TZD pioglitazone also exerts cardioprotective action. However, the clinical use of TZDs is limited by the occurrence of several adverse events, including body-weight gain, congestive heart failure, bone fractures and possibly bladder cancer. Therefore, there is an unmet need for the development of new safer PPARγ-modulating drugs.

Effect of saxagliptin as add-on therapy in patients with poorly controlled type 2 diabetes on insulin alone or insulin combined with metformin

OBJECTIVE

To evaluate efficacy and safety of saxagliptin as add-on therapy in patients with type 2 diabetes (T2D) with inadequate glycemic control on insulin alone or combined with metformin.

METHODS

Adults (n = 455) with HbA(1c) 7.5-11% on stable insulin therapy (30-150 U/day ± metformin) for at least 8 weeks were stratified by metformin use and randomly assigned 2:1 to receive saxagliptin 5 mg or placebo once daily for 24 weeks. Patients were to maintain stable insulin doses but these could be decreased to reduce risk of hypoglycemia. Patients with hyperglycemia or substantially increased insulin use were rescued with a flexible insulin regimen and remained in the study. Metformin doses were kept stable. The primary efficacy endpoint was change in HbA(1c) from baseline to week 24 (or rescue).

RESULTS

Patients treated with saxagliptin versus placebo had significantly greater reductions in adjusted mean HbA(1c) (difference: -0.41%, p < 0.0001), postprandial glucose (PPG) 180-minute area under the curve (-3829.8 mg·min/dL, p = 0.0011), and 120-minute PPG (-23.0 mg/dL, p = 0.0016) at 24 weeks. Treatment with saxagliptin resulted in similar reductions in HBA(1c) relative to placebo, irrespective of metformin treatment. At 24 weeks, difference in adjusted mean fasting plasma glucose for saxagliptin versus placebo was -4.02 mg/dL (p = 0.3958); 17.3% and 6.7% of patients in the saxagliptin and placebo groups, respectively, achieved HbA(1c) < 7%. Mean change from baseline in body weight at week 24 was 0.39 kg for saxagliptin and 0.18 kg for placebo. Hypoglycemia was reported in 18.4% and 19.9% of patients in the saxagliptin and placebo groups, respectively (confirmed hypoglycemia: 5.3%, 3.3%). Other adverse events reported in at least 5% of patients were urinary tract infection (saxagliptin, placebo: 5.9%, 6.0%), influenza (3.0%, 6.6%), and pain in extremity (1.6%, 6.0%).

CONCLUSIONS

Saxagliptin 5-mg once-daily add-on therapy improves glycemic control in T2D patients on insulin alone or combined with metformin and is generally well-tolerated. NCT00757588.

Thiazolidinediones and risk of heart failure in patients with or at high risk of type 2 diabetes mellitus: a meta-analysis and meta-regression analysis of placebo-controlled randomized clinical trials

BACKGROUND

Recent meta-analyses of randomized clinical trials (RCTs) demonstrated a higher risk of heart failure (HF) with the use of thiazolidinediones (TZDs). However, this effect may have been diluted by including active controls. Also, it is uncertain whether the risk of HF is similar with rosiglitazone and pioglitazone.

OBJECTIVES

This study quantified the risks of HF with the use of TZDs in patients with or at high risk of developing type 2 diabetes mellitus (DM), and evaluated differential effects by type of TZD. Secondarily, we evaluated risks of peripheral edema.

METHODS

We performed a systematic review and meta-analysis of placebo-controlled RCTs evaluating the effect of rosiglitazone or pioglitazone on investigator-reported HF and edema. Articles published before 31 December 2009 were searched in MEDLINE, The Web of Science, and Scopus, and the data were extracted by three investigators. RCTs with ≥100 patients and ≥3 months of follow-up were included. We quantified the effect of TZDs as odds ratios (ORs) by using the Mantel-Haenzel and alternative models. We further evaluated the risk of serious/severe HF, and the effect of several trial characteristics on HF risk by subgroup analysis and meta-regression analysis.

RESULTS

29 trials (n = 20 254) were evaluated. TZDs were significantly associated with HF (TZD 360/6807 [5.3%] vs placebo 234/6328 [3.7%], OR 1.59; 95% CI 1.34, 1.89; p < 0.00001). The risk of HF was higher with rosiglitazone than with pioglitazone (2.73 [95% CI 1.46, 5.10] vs 1.51 [1.26, 1.81]; p = 0.06). TZDs were associated with a similar risk of serious/severe HF (OR 1.47; 95% CI 1.16, 1.87; p = 0.002). Use of TZDs was also associated with edema (OR 2.04; 95% CI 1.85, 2.26; p < 0.00001). HF and edema risks were consistent using Peto and random effects models. Risks of HF were significantly high for the subgroups of trials including patients with or at high risk for type 2 DM, and for the subgroup of trials with ≥12 months of follow-up. Meta-regression analysis showed that trials with lower overall baseline risk had higher HF risks.

CONCLUSION

In placebo-controlled trials of adult patients with or at high risk for type 2 DM, TZD therapy is significantly and consistently associated with a higher risk of HF. The risk of serious/severe HF is also increased with the use of TZDs. HF risks are similar to those of meta-analyses combining active- and placebo-controlled trials. The benefit/risk profile of TZDs should be considered when treating diabetic patients with or without prior HF.

Which is the eligible patient to be treated with pioglitazone? The expert view

Pioglitazone has an important role in the treatment of patients with Type 2 diabetes. The drug can help patients to achieve sustained glycemic control and may delay the requirement for insulin. Pioglitazone may provide benefits beyond its effects on glycemia, with data suggesting it may confer anti-atherosclerotic and cardioprotective properties. Attention should be given to possible side effects relating to class effects of TZD, and selection of appropriate patients to be prescribed pioglitazone will enable optimum benefits to be derived from pioglitazone treatment.

Double-blind, randomized, multicentre, and active comparator controlled investigation of the effect of pioglitazone, metformin, and the combination of both on cardiovascular risk in patients with type 2 diabetes receiving stable basal insulin therapy: the PIOCOMB study

BACKGROUND

We analyzed specific effects of an add-on therapy with pioglitazone compared to metformin and their combination in patients with basal insulin treatment on biomarkers of CV risk.

METHODS

In this double-blind, randomized, multicentre, active comparator controlled trial, 121 patients with type 2 diabetes were enrolled. Inclusions: treatment with basal insulin, HbA(1C) 6.5%-8.5%, age 30-75 years. After glargine therapy over 2 weeks for titration towards FBG ≤ 7.8 mmol/L, patients received either (A) bid 850 mg metformin (n = 42), (B) bid 15 mg pioglitazone (n = 40), or (C) 30 mg pioglitazone plus 1.7 g metformin (n = 39) over 6 months. Matrix Metal Proteinase 9 (MMP-9) was primary objective, together with biomarkers of CV risk.

RESULTS

Pioglitazone (B) reduced MMP-9 versus baseline by 54.1 ± 187.1 ng/mL, with metformin (A) it was increased by 49.6 ± 336.2 ng/mL (p = 0.0345; B vs. A), and with the combination of both (C) it was decreased by 67.8 ± 231.4 ng/mL (A vs. C: p = 0.0416; B vs. C: p = 0.8695). After logarithmic transformation due to high variances the exploratory results showed significance for A vs. B (p = 0.0043) and for A vs. C (p = 0.0289).Insulin dosage was reduced by 7.3 units in group B (p < 0.0001), by 6.0 units in C (p = 0.0004), but was increased by 2.5 units (p = 0.1539) in A at follow up. Reduction in hs-CRP was significant within treatment groups for B (p = 0.0098) and C (p < 0.0001), and between the groups for A vs. C (p = 0.0124). All three single regimens reduced PAI-1. Adiponectin was significantly elevated in B and C (p < 0.0001) and between-groups. HbA(1C) was only significantly decreased in the combination group. No significant effects were observed for NFkB and PGFα. peripheral edema were seen in 11.9% vs. 40.0% vs. 20.5%, and weight change was -0.7 kg vs. +4.3 kg vs. +2.7 kg (A vs. B vs. C).

CONCLUSIONS

Addition of pioglitazone but not of metformin reduces MMP-9, hs-CRP and increased insulin sensitivity and adiponectin in this study. The combination of both had no additional effect on inflammation. Pioglitazone is suggested to be a rational add-on therapy to basal insulin in patients with high CV risk.

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.

Fat redistribution preferentially reflects the anti-inflammatory benefits of pioglitazone treatment

Thiazoledinedione is known to have an anti-inflammatory effect besides a hypoglycemic effect. We investigated changes in high-sensitivity C-reactive protein (hsCRP), a proinflammatory marker, after pioglitazone treatment in association with the resulting changes in various metabolic and anthropometric parameters. A total of 93 type 2 diabetes mellitus patients (47 men and 46 women; mean age, 50.0 ± 10.8 years) who were being treated with a stable dose of sulfonylurea or metformin were enrolled in the study. Pioglitazone (15 mg/d) was added to their treatment regimen for 12 weeks, and metabolic and anthropometric measurements were taken before and after pioglitazone treatment. Pioglitazone treatment for 12 weeks decreased serum hsCRP levels (0.83 [1.14] to 0.52 [0.82] mg/L, P < .001) and improved glycemic control (fasting glucose, P < .001; glycosylated hemoglobin, P < .001) and lipid profiles (triglyceride, P = .016; high-density lipoprotein cholesterol, P < .001). Between responders and nonresponders to the hsCRP-lowering effect of pioglitazone, there were significant differences in baseline hsCRP levels and changes in the postprandial glucose and the ratio of visceral fat thickness (VFT) to subcutaneous fat thickness (SFT) (P = .004, .011, and .001, respectively). The percentage change in hsCRP levels after treatment was inversely correlated with baseline hsCRP levels (r = -0.497, P < .001) and directly correlated with the change in postprandial glucose (r = 0.251, P = .021), VFT (r = 0.246, P = .030), and VFT/SFT ratio (r = 0.276, P = .015). Logistic regression analysis revealed that the hsCRP-lowering effect of pioglitazone was affected by baseline hsCRP levels (odds ratio [OR] = 7.929, P = .007) as well as changes in postprandial 2-hour glucose (OR = 0.716, P = .025) and VFT/SFT ratio (OR = 0.055, P = .009). In conclusion, treatment with pioglitazone produced an anti-inflammatory effect, decreasing serum hsCRP levels; and a decrease in the VFT/SFT ratio was independently and most strongly associated with the hsCRP-decreasing effect. These results suggest that abdominal fat redistribution preferentially reflects the anti-inflammatory benefits of pioglitazone treatment.

Hypoglycaemia with pioglitazone: analysis of data from the Prescription-Event Monitoring study

AIMS AND OBJECTIVES

To investigate the relationship between patients' characteristics, use of concomitant anti-diabetic therapies and the incidence of hypoglycaemia, an acute complication of the treatment of diabetes mellitus reported by general practitioners (GPs) during the first 9 months of the treatment with pioglitazone.

METHODS

We used data collected for the Prescription-Event Monitoring (PEM) study conducted by the Drug Safety Research Unit for patients prescribed pioglitazone between November 2000 and June 2001 by their GP in England. A Cox proportional-hazards regression model was used to assess this relationship.

RESULTS

The original pioglitazone PEM cohort included 12,772 patients (mean age 60.9 years); 53% (6777) were male. A total of 77 patients experienced at least one hypoglycaemic episode (9.64 per 1000 patient-years). Women were estimated to have twice the hazard of having a hypoglycaemic event compared with men [hazard ratio (HR) 2.05; confidence interval (CI) 1.24, 3.41]. Patients taking combination therapy with sulfonylurea or insulin were estimated to have approximately three and four times the hazard of having an event compared with those who were not taking these adjunctive therapies [HR=3.11 (CI 1.64, 5.88); HR=4.15 (CI 1.74, 9.91), respectively]. Patients treated with adjunctive metformin were 25% less likely to experience hypoglycaemia than those who did not take concomitant metformin (HR=0.75; CI 0.44, 1.27).

CONCLUSIONS

This study has shown that the treatment with pioglitazone was associated with a low incidence of hypoglycaemia. The factors possibly increasing the risk of hypoglycaemia were concomitant therapy with sulfonylurea or insulin and female gender.

The addition of pioglitazone in type 2 diabetics poorly controlled on insulin therapy: a meta-analysis

AIM

To quantify the effect of a pioglitazone on glycemic control and lipid parameters, as well as the risk of adverse events when incorporated into the treatment regimen of patients with type 2 diabetes inadequately controlled on insulin.

METHODS

The electronic databases PubMed, Embase and The Cochrane Library were searched systematically to identify randomized controlled trials (RCTs) of pioglitazone therapy in patients with type 2 diabetes mellitus (DM) inadequately controlled after treatment with insulin. Data on change of haemoglobin A1C (HbA1c), fasting plasma glucose (FPG), lipid parameters and risk of hypoglycemic, edema events were extracted from each study and pooled according to fixed effect model or random effect model in meta-analyses.

RESULTS

Four RCTs including 1767 patients were included. The pooled estimate of change in HbA1c from baseline was 1.22% (95% CI 1.01-1.44, p<0.001 vs. baseline) and of change in FPG from baseline was 1.63 mmol/l (95% CI 0.75-2.50, p<0.001 vs. baseline). Pioglitazone significantly increased high-density lipoprotein cholesterol (HDL-c) level (0.2 mmol/L, 95%CI: 0.13-0.28) and low-density lipoprotein cholesterol (LDL-c) level (0.10 mol/L, 95%CI: 0.09-0.17), and lowered triglyceride (TG) level (0.05 mmol/L, 95%CI: 0.01-0.09). The odds of experiencing a hypoglycemic event in pioglitazone-treated arms was significantly higher than comparator treatments (RR=1.57, 95% CI 1.12-2.20, p<0.001). The case was the same with edema (RR=2.42, 95% CI 1.67-3.50, p<0.001).

CONCLUSIONS

Our study implied that in patients with type 2 DM whose control is inadequate on insulin therapy, the additional pioglitazone could significantly improve glucose metabolism and might have a positive effect on important components of the lipid profile, which may have important implications in reducing the risk of cardiovascular disease, a major long-term complication in type 2 diabetes mellitus. Besides, the adverse events (AEs) were well tolerated.

Pioglitazone for the treatment of type 2 diabetes in patients inadequately controlled on insulin

Insulin resistance and impaired beta-cell function are primary defects that occur early in the course of development of type 2 diabetes. Insulin resistance leads to hyperinsulinemia in order to maintain normal glucose tolerance. In most cases of type 2 diabetes, beta-cell dysfunction develops subsequent to the development of insulin resistance, and it is not until such beta-cell dysfunction develops that any abnormality in glucose tolerance is seen. Insulin resistance is a primary defect in type 2 diabetes. The risk of coronary heart disease is significantly increased in patients with type 2 diabetes. Cardiovascular disease causes 80% of all diabetic mortality, and in 75% of those cases, it is a result of coronary atherosclerosis. These points provide a rationale for early and aggressive management of cardiovascular risk in patients with diabetes. Thiazolidinediones represent an effective tool for targeting some features of this increased risk as they decrease insulin resistance and can prevent and/or delay diabetes progression.

Key considerations around the risks and consequences of hypoglycaemia in people with type 2 diabetes

Hypoglycaemia and its consequences represent a significant risk for many people who have type 2 diabetes, and hypoglycaemia is currently under-recognised and commonly avoidable. Current clinical guidelines recommend the targeting of tight glycaemic control and this strategy may also be associated with an increased risk of hypoglycaemia. Hypoglycaemia impacts on morbidity, mortality and quality of life of people with type 2 diabetes, and improved recognition of the symptoms of hypoglycaemia will allow effective treatment and reduce the risk of progression to more severe episodes. A common cause of hypoglycaemia in people with type 2 diabetes is glucose-lowering medication, in particular, those which raise insulin independently of ambient glucose concentration such as sulphonylureas and exogenous insulin. The recently published National Institute for Health and Clinical Excellence guideline recommends the use of Dipeptidyl peptidase-4 inhibitors or thiazolidinediones (glitazones) as alternative second-line therapy instead of a sulphonylurea in those patients who are at significant risk of hypoglycaemia and its consequences.

Concomitant therapy with pioglitazone and insulin for the treatment of type 2 diabetes

To prevent hyperinsulinemia, which may cause atherosclerosis, thiazolidinediones (TZDs), also known as insulin sensitizers, are often added to the therapeutic regimen of patients with type 2 diabetes who are receiving insulin. The combination of insulin with pioglitazone, a TZD, reduces glycoated hemoglobin (HbA(1c)) by 0.6%-2.1%. The higher the HbA(1c) baseline the larger the therapeutic reduction of HbA(1c). This combination therapy has been shown to be beneficial even in lean Japanese patients with diabetes. It should be noted that such combination therapy is much more useful when the main clinical aim is lowering not postprandial, but fasting and nocturnal glycemia. The glycemic-lowering effects of pioglitazone alone occur slowly, whereas the addition of insulin to pioglitazone often shows a dramatic glucose-lowering effect. Thus, such combination therapy increases the possibility of frequent hypoglycemia within 1 to 2 months of combining the drugs. Severe hypoglycemia in patients using this therapy is rare. Patients treated with combination therapy who show a predominant reduction of glycemia often have severe edema; in 10%-20% of patients, combination therapy leads to drug-related congestive heart failure (CHF). However, this phenomenon is usually weakened if low doses of pioglitazone which are added to insulin therapy (ie, 15 mg/day or even 7.5 mg/day for women). It is well known that pioglitazone has an anti-atherosclerotic effect, although it is unclear if hyperinsulinemia induces atherogenic changes, either directly or indirectly, by the promotion of obesity. Until now, we have not confirmed whether the anti-atherosclerotic effects of pioglitazone exceed the supposed disadvantageous action of insulin when used in combination therapy. The addition of pioglitazone tends to reduce daily insulin dosages, but study findings have not been consistent. Improvement of lipid profiles has also been weak with this combination therapy. Long-term trials are needed before any conclusions can be reached concerning atherogenic effects of treatment for type 2 diabetes. Combination therapy of even small doses of pioglitazone with insulin should be primarily used for patients who achieve insufficient reduction in glycemia with insulin monotherapy.

Earlier triple therapy with pioglitazone in patients with type 2 diabetes

AIMS

This study assessed the efficacy of add-on pioglitazone vs. placebo in patients with type 2 diabetes uncontrolled by metformin and a sulphonylurea or a glinide.

METHODS

This multicentre, double-blind, parallel-group study randomized 299 patients with type 2 diabetes to receive 30 mg/day pioglitazone or placebo for 3 months. After this time, patients continued with pioglitazone, either 30 mg [if glycated haemoglobin A1c (HbA(1c)) <or=6.5%] or titrated up to 45 mg (if HbA(1c) >6.5%), or placebo for a further 4 months. The primary efficacy end-point was improvement in HbA(1c) (per cent change). Secondary end-points included changes in fasting plasma glucose (FPG), insulin, C-peptide, proinsulin and lipids. The proinsulin/insulin ratio and homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of beta-cell function (HOMA-B) were calculated.

RESULTS

Pioglitazone add-on therapy to failing metformin and sulphonylurea or glinide combination therapy showed statistically more significant glycaemic control than placebo addition. The between-group difference after 7 months of triple therapy was 1.18% in HbA(1c) and -2.56 mmol/l for FPG (p < 0.001). Almost half (44.4%) of the patients in the pioglitazone group who had a baseline HbA(1c) level of <8.5% achieved the HbA(1c) target of < 7.0% by final visit compared with 4.9% in the placebo group. When the baseline HbA(1c) level was >or= 8.5%, 13% achieved the HbA(1c) target of < 7.0% in the pioglitazone group and none in the placebo group. HOMA-IR, insulin, proinsulin and C-peptide decreased and HOMA-B increased in the pioglitazone group relative to the placebo group.

CONCLUSIONS

In patients who were not well controlled with dual combination therapy, the early addition of pioglitazone improved HbA(1c), FPG and surrogate measures of beta-cell function. Patients were more likely to reach target HbA(1c) levels (< 7.0%) with pioglitazone treatment if their baseline HbA(1c) levels were < 8.5%, highlighting the importance of early triple therapy.

Improving cardiovascular risk--applying evidence-based medicine to glucose-lowering therapy with thiazolidinediones in patients with type 2 diabetes

BACKGROUND

The management of patients with type 2 diabetes aims to reduce the elevated risk of cardiovascular disease (CVD) by addressing established risk factors including hyperglycaemia, dyslipidaemia and hypertension. The thiazolidinediones are equally effective in improving glycaemic control when used in combination regimens in patients with type 2 diabetes, but have differing effects on the diabetic dyslipidaemia.

AIMS

To compare the effects of rosiglitazone and pioglitazone on inflammatory mediators associated with atherosclerosis and CVD, surrogate cardiovascular endpoints, and hard cardiovascular outcomes in patients with type 2 diabetes.

MATERIALS AND METHODS

A search of the PubMed database plus manual search of referenced papers for other relevant citations.

RESULTS

Both glitazones reduce inflammatory markers and other circulating markers of CV disease. Available data suggest that pioglitazone can delay progression of atherosclerosis in patients with type 2 diabetes, as shown by the PERISCOPE and CHICAGO studies, and that it can reduce the rate of clinical CV events as shown by PROactive. Clinical end-point data for rosiglitazone are inconclusive, providing no evidence of benefit and a possible increase in myocardial infarction.

DISCUSSION

There is a consistency of benefit with pioglitazone on markers, surrogate cardiovascular outcomes and clinical end-point trials.

CONCLUSION

Pioglitazone is the preferred thiazolidinedione to reduce cardiovascular risk in people with type 2 diabetes.

The role of pioglitazone in modifying the atherogenic lipoprotein profile

Pioglitazone, a thiazolidinedione, has established efficacy in improving glycaemic control in patients with type 2 diabetes. Pioglitazone also improves components of the mixed dyslipidaemia profile common in these patients, as typified by raised levels of plasma triglycerides, low levels of HDL cholesterol (HDL-C) and a raised proportion of LDL cholesterol (LDL-C) occurring as the small dense subfraction. In head-to-head trials, pioglitazone has consistently shown superior benefits on LDL-C and HDL-C as well as triglycerides compared with rosiglitazone and sulphonylureas. Pioglitazone used as monotherapy or combination therapy reduces levels of small dense LDL3 particles while raising levels of larger and less atherogenic LDL fractions. In addition, pioglitazone reduces cholesterol load and particle numbers of LDL3. Importantly, the differential effects of pioglitazone on LDL subfractions are complimentary and additive to those of simvastatin. Pioglitazone increases total HDL-C levels by 10-20%, mainly because of an increase in the larger HDL2 subfraction. Pioglitazone also significantly reduces plasma triglyceride levels by 10-25%. In recent studies, pioglitazone significantly reduced carotid and coronary atherosclerosis compared with the sulphonylurea glimepiride. The antidyslipidaemic effects of pioglitazone--in particular, improvements in HDL-C and reduction of small dense LDL3--may have contributed to these effects.

Adding pioglitazone to insulin containing regimens in type 2 diabetes: systematic review and meta-analysis

Background

Type 2 diabetes is treated in a stepwise manner, progressing from diet and physical activity to oral antidiabetic agents and insulin. The oral agent pioglitazone is licensed for use with insulin when metformin is contraindicated or not tolerated. This systematic review and meta-analysis investigates the extent to which adding pioglitazone to insulin-containing regimens produces benefits in terms of patient-relevant outcomes.

Methodology/Principal Findings

Medline, Embase, and the Cochrane Library were searched for randomised controlled trials comparing pioglitazone in combination with any insulin-containing regimen in comparison with the same insulin regimen alone in patients with type 2 diabetes. Outcomes investigated included HbA1c, hypoglycaemia, weight, and adverse events. Studies were selected, assessed and summarised according to standard systematic review methodology and in a meta-analysis. We included eight trials that examined the benefits of adding pioglitazone to an insulin regimen and studied a total of 3092 patients with type 2 diabetes. All studies included patients with previously inadequate glucose control. Trial duration was between 12 weeks and 34.5 months. The trials used pioglitazone doses of up to 45 mg/day. In our meta-analysis, the mean reduction in HbA1c was 0.58% (95% CI: −0.70, −0.46, p<0.00001). Hypoglycaemic episodes were slightly more frequent in the pioglitazone arms (relative risk 1.27; 95% CI: 0.99, 1.63, p = 0.06). Where reported, HDL-cholesterol tended to be increased with pioglitazone. Patients on pioglitazone tended to gain more weight than those who were not, with an average difference of almost 3 kg. Peripheral oedema was more frequent in the pioglitazone groups. None of the studies reported on fractures in women, and data on cardiovascular events were inconclusive, with most studies being too short or too small to assess these long-term outcomes.

Conclusions/Significance

When added to insulin regimens, pioglitazone confers a small advantage in terms of HbA1c in type 2 diabetes patients with previous inadequate glucose control, but at the cost of increased hypoglycaemia and weight gain. Other considerations include the risk of heart failure, fractures in women, a reduced insulin dose, and the net financial cost.

Pleiotropic effects of thiazolidinediones on traditional and non-traditional atherosclerotic risk factors

BACKGROUND

The thiazolidinediones pioglitazone and rosiglitazone have established efficacy in improving insulin sensitivity, glycaemic control, dyslipidaemia, hypertension and microalbuminuria in patients with type 2 diabetes. As specific agonists of peroxisome proliferator-activated receptor-gamma, thiazolidinediones have also demonstrated protective effects on a variety of atherosclerosis biomarkers and surrogate measures of cardiovascular disease.

AIM

This paper reviews the evidence for pleiotropic effects on a variety of non-traditional atherosclerotic risk factors.

DISCUSSION

Thiazolidinediones attenuate circulating levels of pro-inflammatory mediators in patients with type 2 diabetes, including C-reactive protein, interleukin-6, CD40L, monocyte chemoattractant protein-1 and metalloproteinase-9. These agents also increase levels of the vascular protective adipokine, adiponectin. The clinical significance of these findings is supported by evidence of improved endothelial dysfunction, reduced carotid intima media thickness and improvements in stenosis following coronary artery stent implantation in patients treated with thiazolidinediones. Limited data suggest that thiazolidinediones might also improve the circulating levels and functional activity of angiogenic endothelial progenitor cells, which independently predict the incidence of cardiovascular events and death. It should be noted that the US Food and Drug Administration and the European Medicines Agency have requested changes to the prescribing information for rosiglitazone to highlight the possibility of an increased risk with this agent in patients with ischaemic heart disease; on review, no such amendment was required for the pioglitazone prescribing information. Both agencies continue to suggest that the benefits of both thiazolidinediones outweight any possible detrimental effects. Further research remains to be conducted to elucidate the potentially differential vascular protective effects of thiazolidinediones. In the US, there are black box heart failure warnings for both agents.

CONCLUSION

In light of the established importance of reducing cardiovascular risk in patients with type 2 diabetes, current evidence continues to support the use of pioglitazone within multifactorial risk management strategies.

Insulin therapy in type 2 diabetes: what is the evidence?

AIM

To systematically review the literature regarding insulin use in patients with type 2 diabetes mellitus

METHODS

A Medline and Embase search was performed to identify randomized controlled trials (RCT) published in English between 1 January 2000 and 1 April 2008, involving insulin therapy in adults with type 2 diabetes mellitus. The RCTs must comprise at least glycaemic control (glycosylated haemoglobin (HbA1c), postprandial plasma glucose and /or fasting blood glucose (FBG)) and hypoglycaemic events as outcome measurements.

RESULTS

The Pubmed search resulted in 943 hits; the Embase search gave 692 hits. A total of 116 RCTs were selected by title or abstract. Eventually 78 trials met the inclusion criteria. The studies were very diverse and of different quality. They comprised all possible insulin regimens with and without combination with oral medication. Continuing metformin and/or sulphonylurea after start of therapy with basal long-acting insulin results in better glycaemic control with less insulin requirements, less weight gain and less hypoglycaemic events. Long-acting insulin analogues in combination with oral medication are associated with similar glycaemic control but fewer hypoglycaemic episodes compared with NPH insulin. Most of the trials demonstrated better glycaemic control with premix insulin therapy than with a long-acting insulin once daily, but premix insulin causes more hypoglycaemic episodes. Analogue premix provides similar HbA1c, but lower postprandial glucose levels compared with human premix, without increase in hypoglycaemic events or weight gain. Drawing conclusions from the limited number of studies concerning basal-bolus regimen seems not possible. Some studies showed that rapid-acting insulin analogues frequently result in a better HbA1c or postprandial glucose without increase of hypoglycaemia than regular human insulin.

CONCLUSION

A once-daily basal insulin regimen added to oral medication is an ideal starting point. All next steps, from one to two or even more injections per day should be taken very carefully and in thorough deliberation with the patient, who has to comply with such a regimen for many years.

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.

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.