Favorable effects of pioglitazone and metformin compared with gliclazide on lipoprotein subfractions in overweight patients with early type 2 diabetes

Effect of Pre-Meal Metformin With or Without an Acute Exercise Bout on Postprandial Lipemic and Glycemic Responses in Metabolic Syndrome Patients: A Randomized, Open Label, Crossover Study

INTRODUCTION

Both exercise and pre-meal metformin could lower postprandial glucose and lipid profiles.

AIMS

To explore whether pre-meal metformin administration is superior to metformin administration with the meal in reducing postprandial lipid and glucose metabolism, and whether its combination with exercise confer superior benefits in metabolic syndrome patients.

MATERIALS AND METHODS

In a randomized crossover design, 15 metabolic syndrome patients were assigned to 6 sequences including 3 experimental conditions: metformin administration with a test meal (met-meal), metformin administration 30 min prior to a test meal (pre-meal-met) with or without an exercise bout designed to expend 700 Kcal at 60% VO₂ peak performed the evening just before pre-meal-met condition. Only 13 participants (3 males, 10 females; age: 46 ± 9.86, HbA1c: 6.23 ± 0.36) were included in the final analysis.

RESULTS

Postprandial triglyceridemia was unaffected by any condition (all P > .05). However, both pre-meal-met (-7.1%, P = .009) and pre-meal-metx (-8.2%, P = .013) significantly reduced total cholesterol AUC with no significant differences between the two latter condition (P = .616). Similarly, LDL-cholesterol levels were significantly lower during both pre-meal-met (-10.1%, P = .013) and pre-meal-metx (-10.7%, P = .021) compared to met-meal with no difference between latter conditions (P = .822). Plasma glucose AUC was significantly reduced by pre-meal-metx compared to both pre-meal-met (-7.5%, P = .045) and met-meal (-8%, P = .03). Insulin AUC was significantly lower during pre-meal-metx compared to met-meal (-36.4%, P = .044).

CONCLUSIONS

Metformin administration 30 minutes prior to meal seems to exert favorable effects on postprandial TC and LDL-Cholesterol levels compared to its administration with meal. Addition of one exercise bout only improved postprandial glycemia and insulinemia.

TRIAL REGISTRY

Pan African clinical trial registry, Identifier PACTR202203690920424.

The Reciprocal Relationship between LDL Metabolism and Type 2 Diabetes Mellitus

Type 2 diabetes mellitus and insulin resistance feature substantial modifications of the lipoprotein profile, including a higher proportion of smaller and denser low-density lipoprotein (LDL) particles. In addition, qualitative changes occur in the composition and structure of LDL, including changes in electrophoretic mobility, enrichment of LDL with triglycerides and ceramides, prolonged retention of modified LDL in plasma, increased uptake by macrophages, and the formation of foam cells. These modifications affect LDL functions and favor an increased risk of cardiovascular disease in diabetic individuals. In this review, we discuss the main findings regarding the structural and functional changes in LDL particles in diabetes pathophysiology and therapeutic strategies targeting LDL in patients with diabetes.

Metformin, Macrophage Dysfunction and Atherosclerosis

Metformin is one of the most widely prescribed hypoglycemic drugs and has the potential to treat many diseases. More and more evidence shows that metformin can regulate the function of macrophages in atherosclerosis, including reducing the differentiation of monocytes and inhibiting the inflammation, oxidative stress, polarization, foam cell formation and apoptosis of macrophages. The mechanisms by which metformin regulates the function of macrophages include AMPK, AMPK independent targets, NF-κB, ABCG5/8, Sirt1, FOXO1/FABP4 and HMGB1. On the basis of summarizing these studies, we further discussed the future research directions of metformin: single-cell RNA sequencing, neutrophil extracellular traps (NETs), epigenetic modification, and metformin-based combination drugs. In short, macrophages play an important role in a variety of diseases, and improving macrophage dysfunction may be an important mechanism for metformin to expand its pleiotropic pharmacological profile. In addition, the combination of metformin with other drugs that improve the function of macrophages (such as SGLT2 inhibitors, statins and IL-1β inhibitors/monoclonal antibodies) may further enhance the pleiotropic therapeutic potential of metformin in conditions such as atherosclerosis, obesity, cancer, dementia and aging.

Metformin has no impact on nitric oxide production in patients with pre-diabetes

AIMS/INTRODUCTION

The authors evaluated the impact of different dose of metformin on NO (nitric oxide) production in subjects with pre-diabetes.

MATERIALS AND METHODS

The metformin-naïve patients from one Diabetic Center with newly diagnosed pre-diabetes, without cardio-vascular diseases, were randomized (based on the identification number, individual for each inhabitant in the country) for treatment with different doses of metformin (group A 3 × 500 mg, group B 3 × 1000 mg) for 12 weeks. Then, the subjects from group B were switched to dose 3 × 500 for the last 3 weeks. The wide panel of L-arginine/NO pathway metabolites concentrations was assessed using the liquid chromatography-mass spectrometry technique.

RESULTS

Between October 2017 and December 2018, 36 individuals were initially randomized to intervention groups. The study was completed with 25 subjects: 14 patients in group A, 11 in group B; also 11 healthy volunteers were recruited. There was no difference between participants with pre-diabetes and healthy volunteers as regards the baseline characteristics except for fasting glucose and fatty liver. The decrease of L-citrulline concentration only was reported for treatment groups during the intervention period, with no change for the other NO-production related substances.

CONCLUSION

It was the first study on the in vivo release of NO in humans with different metformin doses in patients with pre-diabetes. Metformin did not seem to increase NO production measured by the citrulline plasma levels, irrespective of the dose. The citrulline concentration change might indicate the drug impact on the condition of the enterocytes.

Long-term effect of pioglitazone vs glimepiride on lipoprotein oxidation in patients with type 2 diabetes: a prospective randomized study

AIMS

Type 2 diabetes (DM2) is associated to oxidative modifications of high-density lipoproteins (HDL), which can interfere with their function. Pioglitazone has proved effective in raising HDL cholesterol (HDL-C) and lowering small dense low-density lipoprotein (LDL), but no clinical studies have examined its effect on lipoprotein oxidation in patients with DM2.

METHODS

We assessed the effect of pioglitazone vs glimepiride after 1 year on HDL oxidation, expressed as relative abundance of peptides containing Met¹¹²O in ApoA-I (oxApoA-I) estimated by mass spectrometry (MALDI/TOF/TOF), in 95 patients with DM2. The oxLDL and AGE were quantified by ELISA.

RESULTS

Patients receiving pioglitazone showed a significant increase in the concentration of ApoA-I (Δ = 7.2 ± 14.8 mg/dL, p < 0.02) and a reduction in oxApoA-I (Δ = - 1.0 ± 2.6%, p < 0.02); this reduction was not significantly different from glimepiride. oxLDL showed a slight, but not significant increase in both treatment groups. Regression analysis showed a correlation between ΔoxApoA-I and ΔAGE (r = 0.30; p = 0.007) in all patients, while both of these parameters were unrelated to changes in HbA1c, HDL-C, duration of illness, or use of statins.

CONCLUSIONS

Long-term treatment with pioglitazone was effective in reducing the oxidation of HDL, but not LDL in patients with DM2, while glimepiride didn't. This finding seems to be associated to the change of glyco-oxidation status, not to any improvement in glycemic control or lipid profile.

TRIAL REGISTRATION

NCT00700856, ClinicalTrials.gov Registered June 18, 2008.

Impact of Metformin and Pioglitazone on Serum Level of Tumor Necrosis Factor-Alpha and Lipid Profiles during Implantation Window in Diabetic Rats

Background

The present study was designed to evaluate serum lipid profile and tumor necrosis factor-alpha (TNF-ɑ) level in diabetic rats at implantation time. Type 2 diabetes mellitus (T2DM) could affect various systems, including innate immune system and it causes chronic low-grade inflammation, increasing level of TNF-ɑ. Furthermore, T2DM is often accompanied by impaired lipid profile. Metformin and pioglitazone are used as the first and second lines of treatment for T2DM.

Materials and Methods

In this experimental study, 35 adult virgin female wistar rats, weighting 175-225 g, were randomly categorized into five groups: i. Control, ii. Sham, iii. Nicotinamide (NA)+streptozotocin (STZ) induced T2DM, iv. Diabetic+pioglitazone (20 mg/kg/day for 28 days oral administration), and v. Diabetic+metformin (100 mg/kg/day for 28 days oral administration). At the time of implantation, TNF-ɑ level in serum of rats was measured by ELISA kit. Glucose was measured using photometric method and lipid profiles were calculated by enzymatic methods.

Results

Level of TNF-ɑ in the diabetic group was significantly higher than other groups (P<0.001). In metformin treated group, TNF-ɑ serum level was also significantly higher than pioglitazone treated group (P<0.001). Fasting blood sugar (FBS) and lipid profiles were significantly higher in diabetic group.

Conclusion

Metformin and pioglitazone have similar effects on glucose, lipid profiles and TNF-ɑ serum levels. Among these drugs, pioglitazone has more efficient influence on TNF-α serum level, in comparison with metformin.

Metformin does not affect postabsorptive hepatic free fatty acid uptake, oxidation or resecretion in humans: A 3-month placebo-controlled clinical trial in patients with type 2 diabetes and healthy controls

AIMS

To explore whether the pre-clinical findings that metformin improves lipid metabolism, possibly through modulation of intrahepatic partitioning of fatty acids towards oxidation and away from re-esterification and resecretion as triglycerides (TGs), can be translated to a human setting.

MATERIALS AND METHODS

We performed a 3-month randomized, placebo-controlled, parallel-group clinical trial in patients with type 2 diabetes (T2D; n = 24) and healthy controls (n = 12). Patients with T2D received either placebo (placebo group) or 1000 mg metformin twice daily (metformin group), while healthy subjects were all treated with metformin (control group). Hepatic fatty acid metabolism was measured by [¹¹ C]palmitate positron-emission tomography, hepatic TG secretion and peripheral oxidation by ex vivo labelled [1-¹⁴ C]VLDL-TG and VLDL particle size by TG/apolipoprotein B ratio. Body composition was assessed by dual-energy X-ray and whole-body lipid oxidation by indirect calorimetry.

RESULTS

Metformin treatment for 3 months produced the anticipated decrease in fasting plasma glucose (FPG) in the metformin group (FPG 7.9 ± 1.8 mM [study day 1] vs 6.4 ± 1.1 mM [study day 2]), whereas patients in the placebo group and healthy controls had similar FPG levels before and after the trial (mixed model group vs time interaction; P = .003); however, contrary to our hypothesis, metformin treatment did not affect hepatic lipid metabolism or peripheral oxidation.

CONCLUSION

The observed beneficial effects on lipid metabolism during metformin treatment in humans appear to be secondary to long-term alterations in body composition or glucose homeostasis.

Canagliflozin, dapagliflozin and empagliflozin monotherapy for treating type 2 diabetes: systematic review and economic evaluation

BACKGROUND

Most people with type 2 diabetes are overweight, so initial treatment is aimed at reducing weight and increasing physical activity. Even modest weight loss can improve control of blood glucose. If drug treatment is necessary, the drug of first choice is metformin. However, some people cannot tolerate metformin, which causes diarrhoea in about 10%, and it cannot be used in people with renal impairment. This review appraises three of the newest class of drugs for monotherapy when metformin cannot be used, the sodium-glucose co-transporter 2 (SGLT2) inhibitors.

OBJECTIVE

To review the clinical effectiveness and cost-effectiveness of dapagliflozin (Farxiga, Bristol-Myers Squibb, Luton, UK), canagliflozin (Invokana, Janssen, High Wycombe, UK) and empagliflozin (Jardiance, Merck & Co., Darmstadt, Germany), in monotherapy in people who cannot take metformin.

SOURCES

MEDLINE (1946 to February 2015) and EMBASE (1974 to February 2015) for randomised controlled trials lasting 24 weeks or more. For adverse events, a wider range of studies was used. Three manufacturers provided submissions.

METHODS

Systematic review and economic evaluation. A network meta-analysis was carried out involving the three SGLT2 inhibitors and key comparators. Critical appraisal of submissions from three manufacturers.

RESULTS

We included three trials of dapagliflozin and two each for canagliflozin and empagliflozin. The trials were of good quality. The canagliflozin and dapagliflozin trials compared them with placebo, but the two empagliflozin trials included active comparators. All three drugs were shown to be effective in improving glycaemic control, promoting weight loss and lowering blood pressure (BP).

LIMITATIONS

There were no head-to-head trials of the different flozins, and no long-term data on cardiovascular outcomes in this group of patients. Most trials were against placebo. The trials were done in patient groups that were not always comparable, for example in baseline glycated haemoglobin or body mass index. Data on elderly patients were lacking.

CONCLUSIONS

Dapagliflozin, canagliflozin and empagliflozin are effective in improving glycaemic control, with added benefits of some reductions in BP and weight. Adverse effects are urinary and genital tract infections in a small proportion of users. In monotherapy, the three drugs do not appear cost-effective compared with gliclazide or pioglitazone, but may be competitive against sitagliptin (Januvia, Boehringer Ingelheim, Bracknell, UK).

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Is gliclazide a sulfonylurea with difference? A review in 2016

Sulfonylureas (SUs) remain the most commonly prescribed drug after metformin in the treatment of type 2 diabetes (T2DM), despite the availability of several newer agents. The primary reason of SUs being most popular is their quick glycemic response, time-tested experience and least cost. Although SUs are one amongst the several other second line agents after metformin in all major guidelines, the new Dutch type 2 guidelines specifically advise gliclazide as the preferred second line drug instead of SUs as a class. The World Health Organization (WHO) has also included gliclazide in their Model List of Essential Medicines 2013 motivated by its safety data in elderly patients. Specifically advising gliclazide may have been based on emerging evidence suggesting cardiovascular neutrality of gliclazide over other SUs. This prompted us to do a literature review of gliclazide efficacy and safety data compared to other SUs as well as oral anti-diabetic drugs.

Effects of sulfonylureas on lipids in type 2 diabetes mellitus: a meta-analysis of randomized controlled trials

OBJECTIVE

Previous studies suggested that dyslipidemia was potentially associated with anti-diabetic medications of sulfonylureas (SUs). The results were, however, inconsistent. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) to assess the effects of SUs on the level of lipids in patients with type 2 diabetes mellitus (T2DM).

METHODS

We searched PubMed, EMBASE, and CENTRAL databases for RCTs that addressed the effects of second- and/or third-generation SUs used in T2DM patients on lipids profiles with study duration of at least 12 weeks. Two reviewers independently screened literature, collected data, and assessed methodological quality of included studies. The meta-analysis was performed by using the RevMan5.1 software.

RESULTS

A total of 59 RCTs were included, of which 52 were included for final meta-analysis. The results suggested that SUs statistically increased the levels of FFA (SMD = 0.24, 95%CI 0.06 to 0.42) and TG (MD = 0.06, 95%CI 0.02 to 0.10), but decreased HDL-C (MD = -0.07, 95%CI -0.11 to -0.04) and LDL-C (MD = -0.11, 95%CI -0.17 to -0.04); but the SUs had no effect on TC (MD = 0.01, 95%CI -0.05 to 0.08), ApoA1 (MD = 0.01, 95%CI -0.03 to 0.04), and Apo B (MD = -0.01, 95%CI -0.05 to 0.03). When compared to metformin, SUs could increase TC and LDL-C; compared to glinides, SUs increased TC and lowered HDL-C; compared to thiazolidinediones, SUs reduced TC, LDL-C, HDL-C, and increase TG.

CONCLUSIONS

SUs have a small effect on lipids, although they may statistically increase the level of FFA and TG, and decrease LDL-C and HDL-C.

WITHDRAWN: Sulphonylurea monotherapy for patients with type 2 diabetes mellitus

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

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

Comparison of glucose lowering effect of metformin and acarbose in type 2 diabetes mellitus: a meta-analysis

BACKGROUND

Metformin is the first-line oral hypoglycemic agent for type 2 diabetes mellitus recommended by international guidelines. However, little information exists comparing it with acarbose which is also commonly used in China. This study expanded knowledge by combining direct and indirect evidence to ascertain the glucose lowering effects of both drugs.

METHODS

PubMed (1980- December 2013) and China National Knowledge Infrastructure databases (1994-January 2014) were systematically searched for eligible randomized controlled trials from Chinese and English literatures. Meta-analysis was conducted to estimate the glucose lowering effects of metformin vs. acarbose, or either of them vs. common comparators (placebo or sulphonylureas), using random- and fixed-effect models. Bucher method with indirect treatment comparison calculator was applied to convert the summary estimates from the meta-analyses into weighted-mean-difference (WMD) and 95% confidence intervals (CIs) to represent the comparative efficacy between metformin and acarbose.

RESULTS

A total of 75 studies were included in the analysis. In direct comparison (8 trials), metformin reduced glycosylated hemoglobin (HbA1c) by 0.06% more than acarbose, with no significant difference (WMD,-0.06%; 95% CI, -0.32% to 0.20%). In indirect comparisons (67 trials), by using placebo and sulphonylureas as common comparators, metformin achieved significant HbA1c reduction than acarbose, by -0.38% (WMD,-0.38%, 95% CI, -0.736% to -0.024%) and -0.34% (WMD, -0.34%, 95% CI, -0.651% to -0.029%) respectively.

CONCLUSION

The glucose lowering effects of metformin monotherapy and acarbose monotherapy are the same by direct comparison, while metformin is a little better by indirect comparison. This implies that the effect of metformin is at least as good as acarbose's.

Metformin inhibits food intake and neuropeptide Y gene expression in the hypothalamus

Metformin may reduce food intake and body weight, but the anorexigenic effects of metformin are still poorly understood. In this study, Sprague-Dawley rats were administered a single intracere-broventricular dose of metformin and compound C, in a broader attempt to investigate the regula-tory effects of metformin on food intake and to explore the possible mechanism. Results showed that central administration of metformin significantly reduced food intake and body weight gain, par-ticularly after 4 hours. A reduction of neuropeptide Y expression and induction of AMP-activated protein kinase phosphorylation in the hypothalamus were also observed 4 hours after metformin administration, which could be reversed by compound C, a commonly-used antagonist of AMP-activated protein kinase. Furthermore, metformin also improved lipid metabolism by reducing plasma low-density lipoprotein. Our findings suggest that under normal physiological conditions, central regulation of appetite by metformin is related to a decrease in neuropeptide Y gene expres-sion, and that the activation of AMP-activated protein kinase may simply be a response to the anorexigenic effect of metformin.

Sulfonylurea versus metformin monotherapy in patients with type 2 diabetes: a Cochrane systematic review and meta-analysis of randomized clinical trials and trial sequential analysis

BACKGROUND

Guidelines recommend metformin as the first-line oral treatment for type 2 diabetes. We conducted a systematic review to assess whether the use of second- and third-generation sulfonylurea agents is associated with benefits and harms in terms of patient-important outcomes compared with metformin.

METHODS

We searched several electronic databases and other sources for randomized clinical trials published to August 2011. We included trials that compared sulfonylurea versus metformin monotherapy among patients 18 years or older with type 2 diabetes and that had an intervention period of at least 24 weeks. We assessed risk of bias and extracted data related to interventions and outcomes. The risk of random errors was assessed by trial sequential analysis.

RESULTS

We included 14 trials (4560 participants). All trials were judged to be at high risk of bias. Data on patient-important outcomes were sparse. Compared with metformin, sulfonylurea did not significantly affect all-cause mortality (relative risk [RR] 0.98, 95% confidence interval [CI] 0.61 to 1.58) or cardiovascular mortality (RR 1.47, 95% CI 0.54 to 4.01). Sulfonylurea significantly decreased the risk of nonfatal macrovascular outcomes (RR 0.67, 95% CI 0.48 to 0.93). However, the definition of this outcome varied among trials, and trial sequential analysis showed that more trials are needed before reliable conclusions can be drawn. No differences between sulfonylurea and metformin were found for change in fasting blood glucose level or glycosylated hemoglobin concentration in the random-effects model. Sulfonylurea resulted in greater weight gain compared with metformin, a finding confirmed in the trial sequential analysis. Significantly more patients in the sulfonylurea arm than in the metformin arm had mild hypoglycemia (RR 2.95, 95% CI 2.13 to 4.07) and severe hypoglycemia (RR 5.64, 95% CI 1.22 to 26.00).

INTERPRETATION

Some evidence suggests that, compared with metformin, second- and third-generation sulfonylureas may not affect all-cause or cardiovascular mortality but may decrease the risk of nonfatal macrovascular outcomes among patients with type 2 diabetes. They may also increase the risk of hypoglycemia. In general, the available data were too few and inconsistent to provide firm evidence concerning patient-important outcomes in relation to the benefits and harms of sulfonylurea versus metformin monotherapy.

Safety and efficacy of gliclazide as treatment for type 2 diabetes: a systematic review and meta-analysis of randomized trials

Objective and Design

Gliclazide has been associated with a low risk of hypoglycemic episodes and beneficial long-term cardiovascular safety in observational cohorts. The aim of this study was to assess in a systematic review and meta-analysis of randomized controlled trials the safety and efficacy of gliclazide compared to other oral glucose-lowering agents (PROSPERO2013:CRD42013004156)

Data Sources

Medline, EMBASE, Clinicaltrials.gov, Trialregister.nl, Clinicaltrialsregister.eu and the Cochrane database.

Selection

Included were randomized studies of at least 12 weeks duration with the following outcomes: HbA1c change, incidence of severe hypoglycemia, weight change, cardiovascular events and/or mortality when comparing gliclazide with other oral blood glucose lowering drugs. Bias was assessed with the Cochrane risk of bias tool. The inverse variance random effects model was used.

Results

Nineteen trials were included; 3,083 patients treated with gliclazide and 3,155 patients treated with other oral blood glucose lowering drugs. There was a considerable amount of heterogeneity between and bias in studies. Compared to other glucose lowering agents except metformin, gliclazide was slightly more effective (−0.13% (95%CI: −0.25, −0.02, I² 55%)). One out of 2,387 gliclazide users experienced a severe hypoglycemic event, whilst also using insulin. There were 25 confirmed non-severe hypoglycemic events (2.2%) in 1,152 gliclazide users and 22 events (1.8%) in 1,163 patients in the comparator group (risk ratio 1.09 (95% CI: 0.20, 5.78, I² 77%)). Few studies reported differences in weight and none were designed to evaluate cardiovascular outcomes.

Conclusions

The methodological quality of randomized trials comparing gliclazide to other oral glucose lowering agents was poor and effect estimates on weight were limited by publication bias. The number of severe hypoglycemic episodes was extremely low, and gliclazide appears at least equally effective compared to other glucose lowering agents. None of the trials were designed for evaluating cardiovascular outcomes, which warrants attention in future randomized trials.

Combining Rosuvastatin With Angiotensin-Receptor Blockers of Different PPARγ-Activating Capacity

The effects of combining angiotensin-receptor blockers of different peroxisome proliferator-activated receptor γ-activating capacity with rosuvastatin on high-density lipoprotein (HDL) subfractions and associated enzymes in patients with mixed dyslipidemia, hypertension, and prediabetes were assessed. Patients (n = 151) were randomly allocated to rosuvastatin (10 mg/d) plus telmisartan 80 mg/d (RT group, n = 52) or irbesartan 300 mg/d (RI group, n = 48) or olmesartan 20 mg/d (RO group, n = 51). Total and intermediate HDL cholesterol (HDL-C) levels did not change in any group. Large HDL-C increased, while small HDL-C decreased significantly in all the groups ( P = not significant between the groups). The mass of HDL lipoprotein-associated phospholipase A2 (HDL-Lp-PLA2) and the activities of paraoxonase 1 remained unchanged in all the groups. However, HDL-Lp-PLA2 activity increased only in the RT group (+21.4%; P < .01 vs baseline) and did not change in the RI (−4.3%; P = .005 vs RT group) and RO (+3.2%; P = .01 vs RT) groups. In conclusion, only the combination of rosuvastatin with telmisartan increased the possibly antiatherosclerotic HDL-Lp-PLA2 activity.

Sulphonylurea monotherapy for patients with type 2 diabetes mellitus

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Lipoprotein subfractions in metabolic syndrome and obesity: clinical significance and therapeutic approaches

Small, dense low density lipoprotein (sdLDL) represents an emerging cardiovascular risk factor, since these particles can be associated with cardiovascular disease (CVD) independently of established risk factors, including plasma lipids. Obese subjects frequently have atherogenic dyslipidaemia, including elevated sdLDL levels, in addition to elevated triglycerides (TG), very low density lipoprotein (VLDL) and apolipoprotein-B, as well as decreased high density lipoprotein cholesterol (HDL-C) levels. Obesity-related co-morbidities, such as metabolic syndrome (MetS) are also characterized by dyslipidaemia. Therefore, agents that favourably modulate LDL subclasses may be of clinical value in these subjects. Statins are the lipid-lowering drug of choice. Also, anti-obesity and lipid lowering drugs other than statins could be useful in these patients. However, the effects of anti-obesity drugs on CVD risk factors remain unclear. We review the clinical significance of sdLDL in being overweight and obesity, as well as the efficacy of anti-obesity drugs on LDL subfractions in these individuals; a short comment on HDL subclasses is also included. Our literature search was based on PubMed and Scopus listings. Further research is required to fully explore both the significance of sdLDL and the efficacy of anti-obesity drugs on LDL subfractions in being overweight, obesity and MetS. Improving the lipoprotein profile in these patients may represent an efficient approach for reducing cardiovascular risk.

Lipoprotein subfractions in metabolic syndrome and obesity: clinical significance and therapeutic approaches

Small, dense low density lipoprotein (sdLDL) represents an emerging cardiovascular risk factor, since these particles can be associated with cardiovascular disease (CVD) independently of established risk factors, including plasma lipids. Obese subjects frequently have atherogenic dyslipidaemia, including elevated sdLDL levels, in addition to elevated triglycerides (TG), very low density lipoprotein (VLDL) and apolipoprotein-B, as well as decreased high density lipoprotein cholesterol (HDL-C) levels. Obesity-related co-morbidities, such as metabolic syndrome (MetS) are also characterized by dyslipidaemia. Therefore, agents that favourably modulate LDL subclasses may be of clinical value in these subjects. Statins are the lipid-lowering drug of choice. Also, anti-obesity and lipid lowering drugs other than statins could be useful in these patients. However, the effects of anti-obesity drugs on CVD risk factors remain unclear. We review the clinical significance of sdLDL in being overweight and obesity, as well as the efficacy of anti-obesity drugs on LDL subfractions in these individuals; a short comment on HDL subclasses is also included. Our literature search was based on PubMed and Scopus listings. Further research is required to fully explore both the significance of sdLDL and the efficacy of anti-obesity drugs on LDL subfractions in being overweight, obesity and MetS. Improving the lipoprotein profile in these patients may represent an efficient approach for reducing cardiovascular risk.

Pioglitazone protects HDL(2&3) against oxidation in overweight and obese men

BACKGROUND

The worldwide epidemic of obesity is a major public health concern and is persuasively linked to the rising prevalence of diabetes and cardiovascular disease. Obesity is often associated with an abnormal lipoprotein profile, which may be partly negated by pioglitazone intervention, as this can influence the composition and oxidation characteristics of low-density lipoprotein (LDL). However, as pioglitazone's impact on these parameters within high-density lipoprotein (HDL), specifically HDL(2&3), is absent from the literature, this study was performed to address this shortcoming.

METHODS

Twenty men were randomized to placebo or pioglitazone (30 mg/day) for 12 weeks. HDL(2&3) were isolated by rapid-ultracentrifugation. HDL(2&3)-cholesterol and phospholipid content were assessed by enzymatic assays and apolipoprotein AI (apoAI) content by single-radial immunodiffusion. HDL(2&3) oxidation characteristics were assessed by monitoring conjugated diene production and paraoxonase-1 activity by spectrophotometric assays.

RESULTS

Compared with the placebo group, pioglitazone influenced the composition and oxidation potential of HDL(2&3). Specifically, total cholesterol (P < 0.05), phospholipid (P < 0.001) and apoAI (P < 0.001) were enriched within HDL(2). Furthermore, the resistance of HDL(2&3) to oxidation (P < 0.05) and the activity of paroxonase-1 were also increased (P < 0.001).

CONCLUSIONS

Overall, these findings indicate that pioglitazone treatment induced antiatherogenic changes within HDL(2&3), which may help reduce the incidence of premature cardiovascular disease linked with obesity.

Cardiovascular risk factors in a patient with diabetes mellitus and coronary artery disease: therapeutic approaches to improve outcomes: perspectives of a preventive cardiologist

In patients with diabetes mellitus (DM), a cardiovascular event is of critical concern because of the impact on long-term survival. Cardiovascular disease (CVD) is the leading cause of death for patients with DM, which makes the modification of risk factors in the patient with DM and CVD a primary focus of the preventive cardiologist. Management of this patient population should include pharmacologic interventions, such as antidyslipidemics (mainly statins) and oral anti-DM (or insulin) agents, as well as diet control, physical exercise, and smoking cessation. It is hoped that focus on the ABCs of treatment--hemoglobin A(1c), blood pressure, and cholesterol-lipid profile--along with ongoing and future studies on the effects of these interventions will help to reduce the significant morbidity and mortality from microvascular and macrovascular complications in these high-risk patients with DM.

Metabolic syndrome: a brain disease

Recent research indicates an association between brain dysfunction and the pathogenesis of metabolic syndrome. To investigate this, we created a Medline search (up to December 2011) of articles in PubMed. The results indicated that refined carbohydrates, saturated and total fat, high levels of ω-6 fatty acids, and low levels of ω-3 fatty acids and other long chain polyunsaturated fatty acids (PUFA), all in conjunction with sedentary behaviour and mental stress can predispose to inflammation. Increased sympathetic activity, with increased secretion of catecholamine, cortisol, and serotonin can cause oxidative stress, which may damage the arcuate nucleus as well as the hypothalamus and macrophages, and the liver may release pro-inflammatory cytokines. These, in conjunction with an underlying deficiency in long chain PUFA, may damage the arcuate nucleus as well as neuropeptide-Y and pro-opiomelanocortin neurons and insulin receptors in the brain, especially during fetal life, infancy, and childhood, resulting in their dysfunction. Of the fatty acids in the brain, 30%-50% are long chain PUFA, which are incorporated in the cell membrane phospholipids. Hence, ω-3 fatty acids, which are also known to enhance parasympathetic activity and increase the secretion of anti-inflammatory cytokines interleukin (IL)-4 and IL-10 as well as acetylcholine in the hippocampus, may be protective. Therefore, treatment with ω-3 fatty acids may be applied for the prevention of metabolic syndrome.

Metabolomics reveals reduction of metabolic oxidation in women with polycystic ovary syndrome after pioglitazone-flutamide-metformin polytherapy

Polycystic ovary syndrome (PCOS) is a variable disorder characterized by a broad spectrum of anomalies, including hyperandrogenemia, insulin resistance, dyslipidemia, body adiposity, low-grade inflammation and increased cardiovascular disease risks. Recently, a new polytherapy consisting of low-dose flutamide, metformin and pioglitazone in combination with an estro-progestagen resulted in the regulation of endocrine clinical markers in young and non-obese PCOS women. However, the metabolic processes involved in this phenotypic amelioration remain unidentified. In this work, we used NMR and MS-based untargeted metabolomics to study serum samples of young non-obese PCOS women prior to and at the end of a 30 months polytherapy receiving low-dose flutamide, metformin and pioglitazone in combination with an estro-progestagen. Our results reveal that the treatment decreased the levels of oxidized LDL particles in serum, as well as downstream metabolic oxidation products of LDL particles such as 9- and 13-HODE, azelaic acid and glutaric acid. In contrast, the radiuses of small dense LDL and large HDL particles were substantially increased after the treatment. Clinical and endocrine-metabolic markers were also monitored, showing that the level of HDL cholesterol was increased after the treatment, whereas the level of androgens and the carotid intima-media thickness were reduced. Significantly, the abundance of azelaic acid and the carotid intima-media thickness resulted in a high degree of correlation. Altogether, our results reveal that this new polytherapy markedly reverts the oxidant status of untreated PCOS women, and potentially improves the pro-atherosclerosis condition in these patients.

Clinical applications of advanced lipoprotein testing in diabetes mellitus

Traditional lipid profiles often fail to fully explain the elevated cardiovascular risk of individuals with diabetes mellitus. Advanced lipoprotein testing offers a novel means to evaluate dyslipidemia and refine risk estimation. Numerous observational studies have demonstrated a characteristic pattern of elevated levels of small, dense LDL particles, out of proportion to traditional lipid levels, in patients with both diabetes mellitus and the metabolic syndrome. Commonly used glucose and lipid-lowering agents have varied effects in patients with diabetes on both LDL and HDL subfractions. The exact role of advanced lipoprotein testing in patients with diabetes mellitus and the metabolic syndrome remains unclear but may offer improved assessment of cardiovascular risk compared with traditional lipid measurements.

Relationships between cholesterol efflux and high-density lipoprotein particles in patients with type 2 diabetes mellitus

BACKGROUND

High-density lipoprotein (HDL) encompasses a heterogeneous population of lipoproteins with differences in functionality. The impact of HDL heterogeneity on its ability to support HDL-mediated cholesterol efflux has not been previously studied in patients with type 2 diabetes mellitus (T2DM).

OBJECTIVES

To examine the relationships between various HDL subtypes and cholesterol efflux from macrophages in patients with T2DM.

METHODS

Lipoprotein molecular profiles of 44 patients were studied by NMR spectroscopy. Cholesterol efflux was expressed as percentage efflux of radioactivity from lipid-laden THP-1 macrophages preincubated with (3)H-cholesterol and then incubated with serum depleted of apolipoprotein B to provide an HDL-enriched acceptor medium.

RESULTS

There was a predominance of small HDL particles (59%) and small putatively atherogenic low-density lipoprotein particles (56%). Neither HDL-C nor ApoA-I concentrations showed statistically significant correlations with percentage cholesterol efflux, but a significant positive relationship was found with the total HDL particle concentration (r = 0.41, P = .005) contributed to largely by medium HDL particles (r = 0.41, P = .006). The correlation between medium-sized HDL particle concentration remained significantly associated with cholesterol efflux when assessed with the use of a linear regression model that included all the HDL lipoprotein subclass concentrations as well as apolipoprotein A-I. Importantly, no statistically significant association was observed between the number of small HDL particles and cholesterol efflux. Hemoglobin A1c showed a significant inverse correlation with cholesterol efflux (r = -0.31, P = .04).

CONCLUSION

In patients with moderately controlled type 2 diabetes mellitus, cholesterol efflux from macrophages incubated with apolipoprotein B-depleted plasmas correlated significantly and positively with the concentration of total and medium-sized HDL and not with that of the smallest particles.

Gene activation regresses atherosclerosis, promotes health, and enhances longevity

Background

Lifestyle factors and pharmacological compounds activate genetic mechanisms that influence the development of atherosclerotic and other diseases. This article reviews studies on natural and pharmacological gene activation that promotes health and enhances longevity.

Results

Living habits including healthy diet and regular physical activity, and pharmacotherapy, upregulate genes encoding enzymes and apolipoprotein and ATP-binding cassette transporters, acting in metabolic processes that promote health and increase survival. Cytochrome P450-enzymes, physiological factors in maintaining cholesterol homeostasis, generate oxysterols for the elimination of surplus cholesterol. Hepatic CTP:phosphocholine cytidylyltransferase-α is an important regulator of plasma HDL-C level. Gene-activators produce plasma lipoprotein profile, high HDL-C, HDL₂-C and HDL-C/cholesterol ratio, which is typical of low risk of atherosclerotic disease, and also of exceptional longevity together with reduced prevalence of cardiovascular, metabolic and other diseases. High HDL contributes to protection against inflammation, oxidation and thrombosis, and associates with good cognitive function in very old people. Avoiding unhealthy stress and managing it properly promotes health and increases life expectancy.

Conclusions

Healthy living habits and gene-activating xenobiotics upregulate mechanisms that produce lipoprotein pattern typical of very old people and enhance longevity. Lipoprotein metabolism and large HDL₂ associate with the process of living a very long life. Major future goals for health promotion are the improving of commitment to both wise lifestyle choices and drug therapy, and further the developing of new and more effective and well tolerated drugs and treatments.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

BACKGROUND

Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age.

OBJECTIVES

To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies.

SEARCH STRATEGY

A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators.

SELECTION CRITERIA

Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy.

DATA COLLECTION AND ANALYSIS

The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data.

MAIN RESULTS

Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies.

AUTHORS' CONCLUSIONS

There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.

Pioglitazone and mechanisms of CV protection

BACKGROUND AND AIM

Pioglitazone has diverse multiple effects on metabolic and inflammatory processes that have the potential to influence cardiovascular disease pathophysiology at various points in the disease process, including atherogenesis, plaque inflammation, plaque rupture, haemostatic disturbances and microangiopathy.

RESULTS

Linking the many direct and indirect effects on the vasculature to the reduction in key macrovascular outcomes reported with pioglitazone in patients with type 2 diabetes presents a considerable challenge. However, recent large-scale clinical cardiovascular imaging studies are beginning to provide some mechanistic insights, including a potentially important role for improvements in high-density lipoprotein cholesterol with pioglitazone. In addition to a role in prevention, animal studies also suggest that pioglitazone may minimize damage and improve recovery during and after ischaemic cardio- and cerebrovascular events.

DESIGN AND METHODS

In this review, we consider potential cardiovascular protective mechanisms of pioglitazone by linking preclinical data and clinical cardiovascular outcomes guided by insights from recent imaging studies.

CONCLUSION

Pioglitazone may influence CVD pathophysiology at multiple points in the disease process, including atherogenesis, plaque inflammation, plaque rupture and haemostatic disturbances (i.e. thrombus/embolism formation), as well as microangiopathy.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

BACKGROUND

Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age.

OBJECTIVES

To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies.

SEARCH STRATEGY

A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators.

SELECTION CRITERIA

Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy.

DATA COLLECTION AND ANALYSIS

The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data.

MAIN RESULTS

Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies.

AUTHORS' CONCLUSIONS

There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.

Effects of telmisartan on insulin resistance in Japanese type 2 diabetic patients

OBJECTIVE

PPARgamma agonists are widely used in type 2 diabetic patients to reduce insulin resistance. Recently, telmisartan, an AT1 receptor antagonist, was reported to function as a partial agonist of PPARgamma based on in vitro experiments. The aim of the present study was to investigate whether the PPARgamma enhancing activity of telmisartan is exerted clinically in diabetic patients.

METHODS

We compared the effects of telmisartan with those of candesartan, on insulin sensitivity, the serum levels of various adipocytokines and oxidative stress.

PATIENTS

In total, 85 Japanese type 2 diabetic patients with hypertension, maintained on 8 mg per day of candesartan, were randomly assigned to the TM group (candesartan switched to 40 mg of telmisartan, n=38) or the CD group (no treatment change, n=47).

RESULTS

After 3 months, oxidized lipids were significantly decreased only in the TM group. Although the homeostasis assessment model of insulin resistance (HOMA-R) tended to be improved and serum concentrations of HDL-cholesterol and HMW adiponectin tended to be increased only in the TM group, these alterations were too small to be significant by unpaired t-test. Interestingly, in subgroup analysis, the alterations of HOMA-R, serum concentrations of oxidized lipids, and HMW adiponectin were more apparent in obese TM group subjects and the changes reached statistical significance.

CONCLUSION

Switching from candesartan to telmisartan in obese subjects increases serum adiponectin and improves both insulin resistance and oxidative stress, while these effects were not statistically apparent in the total patient population. These results support the idea that telmisartan exerts its PPARgamma enhancing activity clinically in obese type 2 diabetic patients.

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.

Factors associated with results and conclusions of trials of thiazolidinediones

Background

When a sponsor funds a study of two competing drugs in a head-to-head comparison, the results and conclusions are likely to favor the sponsor’s drug. Thiazolidinediones, oral medications used for the treatment of type 2 diabetes, are one of the most costly choices of oral anti-diabetic medications, yet they do not demonstrate clinically relevant differences in achieving lower glycosylated hemoglobin levels compared to other oral antidiabetic drugs. Our aim is to examine associations between research funding source, study design characteristics aimed at reducing bias, and other factors with the results and conclusions of randomized controlled trials (RCTs) of thiazolidinediones compared to other oral hypoglycemic agents.

Methods and Findings

This is a cross-sectional study of 61 published RCTs comparing a thiazolidinedione (glitazone) to another anti-diabetic drug or placebo for treatment of type 2 diabetes. Data on study design characteristics, funding source, author’s financial ties, results for primary outcomes, and author conclusions were extracted. Univariate logistic regression identified associations between independent variables and results and conclusions that favored the glitazone. Of the RCTs, 59% (36/61) were funded by industry, 39% (24/61) did not disclose any funding. Common study design weaknesses included inadequate blinding and lack of concealment of allocation. Trials that reported favorable glycemic control results for the glitazone were more likely to have adequate blinding (OR (95% CI)  = 5.42 (1.46, 21.19), p = 0.008) and have a corresponding author with financial ties to the glitazone manufacturer (OR (95% CI)  = 4.12 (1.05, 19.53); p = 0.04). Trials with conclusions favoring the glitazone were less likely to be funded by a comparator drug company than a glitazone company (OR (95% CI)  = 0.026 (0, 0.40), p = 0.003) and less likely to be published in journals with higher impact factors (OR (95% CI)  = 0.79 (0.62, 0.97), p = 0.011). One limitation of our study is that we categorized studies as funded by industry based on each article’s disclosure which could underestimate the number of industry sponsored studies and personal ties of investigators. Additionally, our study did not include any head-to-head comparisons of one glitazone to another.

Conclusions

Published RCT comparisons of glitazones with other anti-diabetic drugs or placebo are predominantly industry supported and this support, as well as the financial ties of study authors, appears to be associated with favorable findings.

Rosiglitazone is associated with mortality in chronic hemodialysis patients

Recent studies have associated rosiglitazone, a thiazolidinedione drug, with adverse cardiovascular outcomes in the general population with diabetes. Using data from the Dialysis Outcomes and Practice Patterns Study in the United States, we examined cardiovascular hospitalization and mortality associated with prescription of rosiglitazone, compared with other oral hypoglycemic agents, among 2393 long-term hemodialysis patients who were followed for a median of 1.1 yr. We assessed mortality risk using Cox models in patient-level and dialysis facility-level analyses that used the facility proportion of patients on rosiglitazone as the predictor (instrumental variable approach) and adjusted the models for demographics, comorbid conditions, laboratory values, and achieved dialysis dosage. Compared with patients prescribed other oral hypoglycemic agents, patients prescribed rosiglitazone had significantly higher all-cause (hazard ratio [HR] 1.38; 95% confidence interval [CI] 1.05 to 1.82) and cardiovascular (HR 1.59; 95% CI 1.14 to 2.22) mortality, and their adjusted HR for hospitalization with myocardial infarction was 3.5-fold higher (P = 0.02). We did not observe similar associations in a secondary analysis evaluating pioglitazone. By the instrumental variable approach, facilities with more than the median adjusted percentage (6.2%) of patients who had diabetes and were prescribed rosiglitazone had significantly higher all-cause mortality (HR 1.36; 95% CI 1.15 to 1.62) and cardiovascular mortality (HR 1.42; 95% CI 1.07 to 1.88) than facilities with less than the median expected percentage prescribed rosiglitazone. Our practice-based findings suggest significant associations of rosiglitazone use with higher cardiovascular and all-cause mortality among hemodialysis patients with diabetes.

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.

Pioglitazone and cardiovascular risk. A comprehensive meta-analysis of randomized clinical trials

AIM

The aim of this meta-analysis of randomized clinical trials (RCT) was to assess whether pioglitazone is also associated with increased cardiovascular risk, as recently reported for rosiglitazone.

METHODS

RCT of pioglitazone were retrieved from Medline (any date up to 31 August 2007; English language only). Unpublished RCT were identified through http://www.clinicaltrials.gov or http://www.fda.gov websites, and results on cardiovascular outcomes were retrieved from investigators and/or sponsors, whenever possible. RCT were included in meta-analysis if pioglitazone was compared with other treatments (placebo, active comparators or no treatment) for at least 4 weeks. Ninety-four trials, 10 of which were unpublished, were retrieved; those included in the analysis, which excluded PROspective PioglitAzone Clinical Trial In MacroVascular Events (PROACTIVE), enrolled 11 268 and 9912 patients in the pioglitazone and comparator groups respectively. Data for analysis, extracted independently by two observers, included all-cause and cardiovascular mortality and incidence of non-fatal coronary events and heart failure. Proportions of outcome measures across treatment groups were compared by odds ratios (ORs) and 95% confidence interval.

RESULTS

Pioglitazone was associated with reduced all-cause mortality [OR 0.30 (0.14-0.63); p < 0.05], with no relevant effect on non-fatal coronary events. The observed increase in incidence of non-fatal heart failure was not statistically significant [OR 1.38 (0.90-2.12)].

CONCLUSION

The use of pioglitazone does not appear to be harmful in terms of cardiovascular events and all-cause deaths.

Cardiovascular outcomes in trials of oral diabetes medications: a systematic review

BACKGROUND

A wide variety of oral diabetes medications are currently available for the treatment of type 2 diabetes mellitus, but it is unclear how these agents compare with respect to long-term cardiovascular risk. Our objective was to systematically examine the peer-reviewed literature on the cardiovascular risk associated with oral agents (second-generation sulfonylureas, biguanides, thiazolidinediones, and meglitinides) for treating adults with type 2 diabetes.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials, from inception through January 19, 2006. Forty publications of controlled trials that reported information on cardiovascular events (primarily myocardial infarction and stroke) met our inclusion criteria. Using standardized protocols, 2 reviewers serially abstracted data from each article. Trials were first described qualitatively. For comparisons with 4 or more independent trials, results were pooled quantitatively using the Mantel-Haenszel method. Results are presented as odds ratios (ORs) and corresponding 95% confidence intervals (CIs).

RESULTS

Treatment with metformin hydrochloride was associated with a decreased risk of cardiovascular mortality (pooled OR, 0.74; 95% CI, 0.62-0.89) compared with any other oral diabetes agent or placebo; the results for cardiovascular morbidity and all-cause mortality were similar but not statistically significant. No other significant associations of oral diabetes agents with fatal or nonfatal cardiovascular disease or all-cause mortality were observed. When compared with any other agent or placebo, rosiglitazone was the only diabetes agent associated with an increased risk of cardiovascular morbidity or mortality, but this result was not statistically significant (OR, 1.68; 95% CI, 0.92-3.06).

CONCLUSIONS

Meta-analysis suggested that, compared with other oral diabetes agents and placebo, metformin was moderately protective and rosiglitazone possibly harmful, but lack of power prohibited firmer conclusions. Larger, long-term studies taken to hard end points and better reporting of cardiovascular events in short-term studies will be required to draw firm conclusions about major clinical benefits and risks related to oral diabetes agents.

Therapeutical effects of PPAR agonists assessed by biomarker modulation

The metabolic syndrome is defined as the clustering of cardiovascular risk factors, such as glucose intolerance, hyperinsulinemia, dyslipidemia, coagulation disturbances and hypertension. Activators of the nuclear receptors peroxisome proliferator-activated receptors (PPARs) modulate several of the metabolic risk factors pre-disposing to atherosclerosis. Fibrates are hypolipidemic drugs operating through activation of PPARalpha, whereas glitazones are insulin sensitizers activating PPARgamma. In addition, these drugs exert pleiotropic and anti-inflammatory actions. This review will focus on the different effects of fibrates and glitazones, as measured by biomarker modulation, on the development of atherosclerosis and cardiovascular disease.

Metformin increases HDL3-cholesterol and decreases subcutaneous truncal fat in nondiabetic patients with HIV-associated lipodystrophy

The purpose of this study was to assess metformin effects on high-density lipoprotein (HDL) composition of patients with HIV-associated lipodystrophy (LDHIV). Twenty-four adult outpatients were enrolled to receive metformin (1700 mg/d) during 6 months, but 2 were lost to follow-up and 6 stopped the drug due to adverse events (gastrointestinal in 5, and excessive weight loss in 1). From the 16 subjects who completed the study, 69% were female. At baseline, 3 and 6 months, we assessed: weight, waist and hip circumferences, blood pressure, fasting glucose and insulin, homeostasis model assessment of insulin resistance (HOMA2-IR), lipids, and HDL subfractions by microultracentrifugation. At 0 and 6 months, body fat distribution was assessed by computed tomography (CT) scan (L4 and middle femur). Metformin use was associated with reduction of mean weight (-2.4Kg at 6 months; p < 0.001), body mass index, waist, waist-to-hip ratio and a marked decrease in blood pressure (p < 0.001). Subcutaneous (p = 0.01) and total abdominal fat (p = 0.002) were reduced, but no change was found in visceral or thigh fat. No difference was detected on plasma glucose, insulin, HOMA2-IR, cholesterol or triglycerides, except for an increase in HDL3-cholesterol (from 21 mg/dL to 24 mg/dL, p = 0.002) and a reduction of nascent HDL (the fraction of plasma HDL-cholesterol not associated to subfractions HDL2 or HDL3) (p = 0.008). Adverse effects were very common, but most were gastrointestinal and mild. Thus, metformin use in LDHIV increases HDL3-cholesterol (probably due to improved maturation of HDL) and decreases blood pressure, weight, waist, and subcutaneous truncal fat, making this an attractive option for preventing cardiovascular disease in this population.

Performing meta-analysis with incomplete statistical information in clinical trials

BACKGROUND

Results from clinical trials are usually summarized in the form of sampling distributions. When full information (mean, SEM) about these distributions is given, performing meta-analysis is straightforward. However, when some of the sampling distributions only have mean values, a challenging issue is to decide how to use such distributions in meta-analysis. Currently, the most common approaches are either ignoring such trials or for each trial with a missing SEM, finding a similar trial and taking its SEM value as the missing SEM. Both approaches have drawbacks. As an alternative, this paper develops and tests two new methods, the first being the prognostic method and the second being the interval method, to estimate any missing SEMs from a set of sampling distributions with full information. A merging method is also proposed to handle clinical trials with partial information to simulate meta-analysis.

METHODS

Both of our methods use the assumption that the samples for which the sampling distributions will be merged are randomly selected from the same population. In the prognostic method, we predict the missing SEMs from the given SEMs. In the interval method, we define intervals that we believe will contain the missing SEMs and then we use these intervals in the merging process.

RESULTS

Two sets of clinical trials are used to verify our methods. One family of trials is on comparing different drugs for reduction of low density lipprotein cholesterol (LDL) for Type-2 diabetes, and the other is about the effectiveness of drugs for lowering intraocular pressure (IOP). Both methods are shown to be useful for approximating the conventional meta-analysis including trials with incomplete information. For example, the meta-analysis result of Latanoprost versus Timolol on IOP reduction for six months provided in 1 was 5.05 +/- 1.15 (Mean +/- SEM) with full information. If the last trial in this study is assumed to be with partial information, the traditional analysis method for dealing with incomplete information that ignores this trial would give 6.49 +/- 1.36 while our prognostic method gives 5.02 +/- 1.15, and our interval method provides two intervals as Mean in [4.25, 5.63] and SEM in [1.01, 1.24].

CONCLUSION

Both the prognostic and the interval methods are useful alternatives for dealing with missing data in meta-analysis. We recommend clinicians to use the prognostic method to predict the missing SEMs in order to perform meta-analysis and the interval method for obtaining a more cautious result.

Metformin: effects on micro and macrovascular complications in type 2 diabetes

INTRODUCTION

The antihyperglycaemic agent metformin is widely used in the treatment of type 2 diabetes. Data from the UK Prospective Diabetes Study and retrospective analyses of large healthcare databases concur that metformin reduces the incidence of myocardial infarction and increases survival in these patients. This apparently vasoprotective effect appears to be independent of the blood glucose-lowering efficacy.

EFFECTS OF METFORMIN

Metformin has long been known to reduce the development of atherosclerotic lesions in animal models, and clinical studies have shown the drug to reduce surrogate measures such as carotid intima-media thickness. The anti-atherogenic effects of metformin include reductions in insulin resistance, hyperinsulinaemia and obesity. There may be modest favourable effects against dyslipidaemia, reductions in pro-inflammatory cytokines and monocyte adhesion molecules, and improved glycation status, benefiting endothelial function in the macro- and micro-vasculature. Additionally metformin exerts anti-thrombotic effects, contributing to overall reductions in athero-thrombotic risk in type 2 diabetic patients.

Thiazolidinediones-improving endothelial function and potential long-term benefits on cardiovascular disease in subjects with type 2 diabetes

Endothelial dysfunction, which leads to impaired vasodilation, is an early event in the development of atherosclerosis. A number of mechanisms involving, for example, cell adhesion molecules, chemokines, and cytokines, contribute to this inflammatory disease, and insulin resistance plays a cardinal role in accelerating these processes. Hyperglycemia and other metabolic abnormalities that are commonly associated with insulin resistance also contribute to impaired endothelial function. In addition, the important role of the endothelium in damage repair following a cardiovascular event is emerging. The combination of proatherogenic factors in patients with type 2 diabetes results in blunted endothelial function and an increased risk of cardiovascular disease. Insulin-sensitizing agents such as thiazolidinediones have demonstrated a number of clinical benefits, including anti-inflammatory and antithrombotic properties, which may impact on the course of atherosclerosis. Recent studies have demonstrated that thiazolidinediones improve endothelial function in subjects with and without type 2 diabetes.

Measuring biomarkers to assess the therapeutic effects of PPAR agonists?

The metabolic syndrome is defined as a clustering of cardiovascular risk factors with insulin resistance, including dyslipidemia, coagulation disturbances and hypertension. Activators of the peroxisome proliferator-activated receptors (PPARs) modulate several of the metabolic risk factors predisposing to atherosclerosis. Fibrates are hypolipidemic drugs acting through activation of PPARα, whereas glitazones are insulin sensitizers activating PPARγ. In addition, these drugs exert pleiotropic anti-inflammatory actions. In this review, we will focus on the effects of fibrates and glitazones on biomarker modulation and their usefulness in the treatment of cardiovascular disease.

Treatment of the dyslipidemia of insulin resistance

The increase in ischemic cardiovascular mortality and morbidity in persons with insulin resistance has been adequately documented elsewhere in this issue. Some of the most important risk factors for this increased mortality and morbidity are the lipid abnormalities, which form two out of five criteria for defining the metabolic syndrome, a definition focusing on risk factors for ischemic cardiovascular disease. This article explores the description, pathophysiology, and treatment of these atherogenic lipid abnormalities.

Pioglitazone and rosiglitazone have different effects on serum lipoprotein particle concentrations and sizes in patients with type 2 diabetes and dyslipidemia

OBJECTIVE

Associated with insulin resistance in type 2 diabetes are increased serum triglycerides, decreased HDL cholesterol, and a predominance of large VLDL, small LDL, and small HDL particles. The comparative effects of thiazolidinedione insulin sensitizers on serum lipoprotein particle concentrations and sizes in type 2 diabetes are not known. We studied the effects of pioglitazone (PIO) and rosiglitazone (ROSI) treatments on serum lipoprotein particle concentrations and sizes in type 2 diabetic patients with dyslipidemia.

RESEARCH DESIGN AND METHODS

This is a prospective, randomized, double-blind, multicenter, parallel-group study. After a 4-week placebo washout period, patients randomized to PIO (n = 369) were treated with 30 mg q.d. for 12 weeks followed by 45 mg q.d. for another 12 weeks, while patients randomized to ROSI (n = 366) were treated with 4 mg q.d. followed by 4 mg b.i.d. for the same intervals. Lipoprotein subclass particle concentrations and sizes were determined by proton nuclear magnetic resonance spectroscopy at baseline and end point (PIO [n = 333] and ROSI [n = 325] patients).

RESULTS

PIO treatment increased total VLDL particle concentration less than ROSI treatment and decreased VLDL particle size more than ROSI. PIO treatment reduced total LDL particle concentration, whereas ROSI treatment increased it. Both treatments increased LDL particle size, with PIO treatment having a greater effect. Whereas PIO treatment increased total HDL particle concentration and size, ROSI treatment decreased them; both increased HDL cholesterol levels.

CONCLUSIONS

PIO and ROSI treatments have different effects on serum lipoprotein subclass particle concentrations and sizes in patients with type 2 diabetes and dyslipidemia.

Hepatic safety profile and glycemic control of pioglitazone in more than 20,000 patients with type 2 diabetes mellitus: postmarketing surveillance study in Japan

The prospective observational study was designed to identify factors affecting glycemic control with pioglitazone and to confirm the hepatic safety of the drug in patients with type 2 diabetes. Baseline patient characteristics, changes in serum hemoglobin A1c (A1c) and alanine aminotransferase (ALT), other treatments for diabetes mellitus, and hepatobiliary adverse reactions were examined. In total, 24,993 patients, representing 28,008 patient-years, were included in the safety evaluation and 20,447 patients in the efficacy evaluation. No case of hepatic failure was reported, and neither temporal nor dose relations were found between pioglitazone and ALT abnormalities. Serum A1c was clearly reduced in patients with baseline body mass index <25 kg/m(2) or baseline fasting immunoreactive insulin <5.0 microU/mL. Among the patients treated for more than 6 months, the change in A1c was -1.0% at 6 months with both monotherapy and combination therapy and remained stable up to 18 months. The overall rate of achievement of A1c<7% in patients with baseline A1c above 7% was 34.1%; notably, the achievement rate of A1c<7% was approximately 30% even in patients with high baseline A1c (mean 8.8%) taking multiple antidiabetic medications, including sulfonylurea, for whom insulin therapy is usually indicated in Japan.

The effect of pioglitazone on recurrent myocardial infarction in 2,445 patients with type 2 diabetes and previous myocardial infarction: results from the PROactive (PROactive 05) Study

OBJECTIVES

This analysis from the PROactive (PROspective pioglitAzone Clinical Trial In macroVascular Events) study assesses the effects of pioglitazone on mortality and macrovascular morbidity in patients with type 2 diabetes and a previous myocardial infarction (MI).

BACKGROUND

People with type 2 diabetes have an increased incidence of MI compared with the general population. Those with diabetes and MI have a worse prognosis than nondiabetic patients with cardiovascular disease.

METHODS

The PROactive study was a prospective, multicenter, double-blind, placebo-controlled trial of 5,238 patients with type 2 diabetes and macrovascular disease. Patients were randomized to either pioglitazone or placebo in addition to their other glucose-lowering and cardiovascular medication. Treatment of diabetes, dyslipidemia, and hypertension was encouraged according to the International Diabetes Federation guidelines. Patients were followed for a mean of 2.85 years. The primary end point was the time to first occurrence of macrovascular events or death. Of the total cohort, the subgroup of patients who had a previous MI (n = 2,445 [46.7%]; n = 1,230 in the pioglitazone group and n = 1,215 in the placebo group) was evaluated using prespecified and post-hoc analyses.

RESULTS

Pioglitazone had a statistically significant beneficial effect on the prespecified end point of fatal and nonfatal MI (28% risk reduction [RR]; p = 0.045) and acute coronary syndrome (ACS) (37% RR; p = 0.035). There was a 19% RR in the cardiac composite end point of nonfatal MI (excluding silent MI), coronary revascularization, ACS, and cardiac death (p = 0.033). The difference in the primary end point defined in the main PROactive study did not reach significance in the MI population (12% RR; p = 0.135). The rates of heart failure requiring hospitalization were 7.5% (92 of 1,230) with pioglitazone and 5.2% (63 of 1,215) with placebo. Fatal heart failure rates were similar (1.4% [17 of the 92] with pioglitazone versus 0.9% [11 of the 63] with placebo).

CONCLUSIONS

In high-risk patients with type 2 diabetes and previous MI, pioglitazone significantly reduced the occurrence of fatal and nonfatal MI and ACS. (PROspective pioglitAzone Clinical Trial In macroVascular Events; http://www.clinicaltrials.gov/ct/show/NCT00174993?order = 1; ISRCTN NCT00174993).