Risk of cardiovascular events and all-cause mortality in patients treated with thiazolidinediones in a managed-care population

Effects of expanding the look-back period to all available data in the assessment of covariates

BACKGROUND

A fixed baseline period has been a common covariate assessment approach in pharmacoepidemiological studies from claims but may lead to high levels of covariate misclassification. Simulation studies have recommended expanding the look-back approach to all available data (AAD) for binary indicators of diagnoses, procedures, and medications, but there have been few real data analyses using this approach.

OBJECTIVE

The objective of the study is to explore the impact on treatment effect estimates and covariate prevalence of expanding the look-back period within five validated studies in the Aetion system, a rapid cycle analytics platform.

METHODS

We reran the five studies and assessed covariates using (i) a fixed window approach (usually 180 days before treatment initiation), (ii) AAD prior to treatment initiation, and (iii) AAD with a categorized by recency approach, where the most recent occurrence of a covariate was labeled as recent (occurring within the fixed window) or past (before the start of the fixed window). For each covariate assessment approach, we adjusted for covariates via propensity score matching.

RESULTS

All studies had at least one covariate that had an increase in prevalence of 15% or higher from the fixed window to the AAD approach. However, there was little change in treatment effect estimates resulting from differing covariate assessment approaches. For example, in a study of acute coronary syndrome in high-intensity versus low-intensity statin users, the estimated hazard ratio from the fixed window approach was 1.11 (95% confidence interval 0.98, 1.25) versus 1.21 (1.07, 1.37) when using AAD and 1.19 (1.05, 1.35) using categorized by recency.

CONCLUSION

Expanding the baseline period to AAD improved covariate sensitivity by capturing data that would otherwise be missed yet did not meaningfully change the overall treatment effect estimates compared with the fixed window approach. Copyright © 2017 John Wiley & Sons, Ltd.

Uptake of new drugs in the early post-approval period in the Mini-Sentinel distributed database

PURPOSE

Several factors limit the statistical power of drug safety surveillance during the early post-approval period, including uptake of the drug and lag in data availability. This study characterized new drug uptake in the Mini-Sentinel Distributed Database and determined statistical power to detect levels of risk in post-launch safety assessments.

METHODS

The cumulative exposure among initiators of 46 new molecular entities approved from 2008 to 2011 was assessed. Using a Poisson estimation method, minimum incidence rate ratios (IRRs) detectable, with 80% power, were calculated under varying background incidence rates.

RESULTS

Twelve products (26.1%) had more than 15 000 new users after 2 years. With comparator group incidence rate of 1/1000 person-years, 16 (33.3%) products had enough exposure to detect an IRR of 5 with 24 months of data collected that would be available for assessment at 33 months post-launch. With an incidence rate of 5/1000 person-years, 23 (50%) products had enough exposure to detect an IRR of ≥3 with 2 years of data collected. At 33 months post-launch, only two (4.3%) of the drugs examined had enough data availability to detect IRR of <2, and eight (17.4%) of <3, with a background rate of 1/1000 person-years.

CONCLUSION

This study highlights the importance of drug uptake and data availability in early post-approval drug safety surveillance in Mini-Sentinel. There is limited ability to detect rate ratios below three for events with background rates of 1/1000 person-years or lower. This is largely due to low product uptake. Copyright © 2016 John Wiley & Sons, Ltd.

Risk of Bias in Systematic Reviews of Non-Randomized Studies of Adverse Cardiovascular Effects of Thiazolidinediones and Cyclooxygenase-2 Inhibitors: Application of a New Cochrane Risk of Bias Tool

BACKGROUND

Systematic reviews of the effects of healthcare interventions frequently include non-randomized studies. These are subject to confounding and a range of other biases that are seldom considered in detail when synthesizing and interpreting the results. Our aims were to assess the reliability and usability of a new Cochrane risk of bias (RoB) tool for non-randomized studies of interventions and to determine whether restricting analysis to studies with low or moderate RoB made a material difference to the results of the reviews.

METHODS AND FINDINGS

We selected two systematic reviews of population-based, controlled non-randomized studies of the relationship between the use of thiazolidinediones (TZDs) and cyclooxygenase-2 (COX-2) inhibitors and major cardiovascular events. Two epidemiologists applied the Cochrane RoB tool and made assessments across the seven specified domains of bias for each of 37 component studies. Inter-rater agreement was measured using the weighted Kappa statistic. We grouped studies according to overall RoB and performed statistical pooling for (a) all studies and (b) only studies with low or moderate RoB. Kappa scores across the seven bias domains ranged from 0.50 to 1.0. In the COX-2 inhibitor review, two studies had low overall RoB, 14 had moderate RoB, and five had serious RoB. In the TZD review, six studies had low RoB, four had moderate RoB, four had serious RoB, and two had critical RoB. The pooled odds ratios for myocardial infarction, heart failure, and death for rosiglitazone versus pioglitazone remained significantly elevated when analyses were confined to studies with low or moderate RoB. However, the estimate for myocardial infarction declined from 1.14 (95% CI 1.07-1.24) to 1.06 (95% CI 0.99-1.13) when analysis was confined to studies with low RoB. Estimates of pooled relative risks of cardiovascular events with COX-2 inhibitors compared with no nonsteroidal anti-inflammatory drug changed little when analyses were confined to studies with low or moderate RoB. The exception was a rise in the relative risk associated with ibuprofen from 1.07 (95% CI 0.97-1.18) to 1.14 (95% CI 1.03-1.26). The main limitation of our study was testing the instrument on a narrow range of pharmacoepidemiological studies; we cannot assume our findings extend to a broader range of interventions and settings.

CONCLUSIONS

The Cochrane RoB tool highlighted a wide range of risks of bias in studies included in two widely cited reviews and had the potential to change the conclusions of the reviews. Systematic reviews that incorporate non-randomized studies of medical interventions should include a detailed assessment of RoB for each included study.

Cardiovascular risk associated with the use of glitazones, metformin and sufonylureas: meta-analysis of published observational studies

BACKGROUND

The results of observational studies evaluating and comparing the cardiovascular safety of glitazones, metformin and sufonylureas are inconsistent.To conduct and evaluate heterogeneity in a meta-analysis of observational studies on the risk of acute myocardial infarction (AMI) or stroke in patients with type 2 diabetes using non-insulin blood glucose-lowering drugs (NIBGLD).

METHODS

We systematically identified and reviewed studies evaluating NIBGLD in patients with type 2 diabetes indexed in Medline, Embase, or the Cochrane Library that met prespecified criteria. The quality of included studies was assessed with the RTI item bank. Results were combined using fixed- and random-effects models, and the Higgins I(2) statistic was used to evaluate heterogeneity. Sensitivity analyses by study quality were conducted.

RESULTS

The summary relative risk (sRR) (95% CI) of AMI for rosiglitazone versus pioglitazone was 1.13 (1.04-1.24) [I(2) = 55%]. In the sensitivity analysis, heterogeneity was reduced [I(2) = 16%]. The sRR (95% CI) of stroke for rosiglitazone versus pioglitazone was 1.18 (1.02-1.36) [I(2)  = 42%]. There was strong evidence of heterogeneity related to study quality in the comparisons of rosiglitazone versus metformin and rosiglitazone versus sulfonylureas (I (2) ≥ 70%). The sRR (95% CI) of AMI for sulfonylurea versus metformin was 1.24 (1.14-1.34) [I(2) = 41%] and for pioglitazone versus metformin was 1.02 (0.75-1.38) [I(2) = 17%]. Sensitivity analyses decreased heterogeneity in most comparisons.

CONCLUSION/INTERPRETATION

Sulfonylureas increased the risk of AMI by 24% compared with metformin; an imprecise point estimate indicated no difference in risk of AMI when comparing pioglitazone with metformin. The presence of heterogeneity precluded any conclusions on the other comparisons. The quality assessment was valuable in identifying methodological problems in the individual studies and for analysing potential sources of heterogeneity.

Observational studies of the association between glucose-lowering medications and cardiovascular outcomes: addressing methodological limitations

BACKGROUND

Recent years have witnessed a growing body of observational literature on the association between glucose-lowering treatments and cardiovascular disease. However, many of the studies are based on designs or analyses that inadequately address the methodological challenges involved.

METHODS

We reviewed recent observational literature on the association between glucose-lowering medications and cardiovascular outcomes and assessed the design and analysis methods used, with a focus on their ability to address specific methodological challenges. We describe and illustrate these methodological issues and their impact on observed associations, providing examples from the reviewed literature. We suggest approaches that may be employed to manage these methodological challenges.

RESULTS

From the evaluation of 81 publications of observational investigations assessing the association between glucose-lowering treatments and cardiovascular outcomes, we identified the following methodological challenges: 1) handling of temporality in administrative databases; 2) handling of risks that vary with time and treatment duration; 3) definitions of the exposure risk window; 4) handling of exposures that change over time; and 5) handling of confounding by indication. Most of these methodological challenges may be suitably addressed through application of appropriate methods.

CONCLUSIONS/INTERPRETATION

Observational research plays an increasingly important role in the evaluation of the clinical effects of diabetes treatment. Implementation of appropriate research methods holds the promise of reducing the potential for spurious findings and the risk that the spurious findings will mislead the medical community about risks and benefits of diabetes medications.

The risk of heart failure associated with the use of noninsulin blood glucose-lowering drugs: systematic review and meta-analysis of published observational studies

Background

Patients with type 2 diabetes mellitus (T2DM) are at high risk of heart failure. A summary of the effects of blood glucose-lowering drugs other than glitazones on the risk of heart failure in routine clinical practice is lacking. The objective of this study was to conduct a systematic review and meta-analysis of observational studies on the risk of heart failure when using blood glucose-lowering drugs.

Methods

We systematically identified and reviewed cohort and case–control studies in which the main exposure of interest was noninsulin blood glucose-lowering medications in patients with T2DM. We searched Medline, Embase, and the Cochrane Library to identify publications meeting prespecified eligibility criteria. The quality of included studies was assessed with the Newcastle-Ottawa Scale and the RTI item bank. Results were combined using fixed and random-effects models when at least 3 independent data points were available for a drug-drug comparison.

Results

The summary relative risk of heart failure in rosiglitazone users versus pioglitazone users (95% CI) was 1.16 (1.05-1.28) (5 cohort studies). Heterogeneity was present (I² = 66%). For new users (n = 4) the summary relative risk was 1.21 (1.14-1.30) and the heterogeneity was reduced (I² = 31%);. The summary relative risk for rosiglitazone versus metformin was 1.36 (95% CI, 1.17-1.59) (n = 3). The summary relative risk (95% CI) of heart failure in sulfonylureas users versus metformin users was 1.17 (95% CI, 1.06-1.29) (5 cohort studies; I² = 24%) and 1.22 (1.02-1.46) when restricted to new users (2 studies).

Information on other comparisons was very scarce. Information on dose and duration of treatment effects was lacking for most comparisons. Few studies accounted for disease severity; therefore, confounding by indication might be present in the majority of the within-study comparisons of this meta-analysis.

Conclusions

Use of glitazones and sulfonylureas was associated with an increased risk of heart failure compared with metformin use. However, indication bias cannot be ruled out. Ongoing large multidatabase studies will help to evaluate the risk of heart failure in treated patients with diabetes, including those using newer blood glucose-lowering therapies.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2261-14-129) contains supplementary material, which is available to authorized users.

Rivoglitazone: A New Thiazolidinedione for the Treatment of Type 2 Diabetes Mellitus

OBJECTIVE:

To review the pharmacology, pharmacokinetics, efficacy, and safety of the thiazolidinedione rivoglitazone, a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, to determine its potential role in the treatment of type 2 diabetes mellitus.

DATA SOURCES:

A MEDLINE search (1966-February 2013) was conducted for English-language studies in humans, using the terms rivoglitazone and CS011. Abstracts presented at the American Diabetes Association and European Association for the Study of Diabetes annual meetings from 2007 to 2012 were also evaluated for relevant data.

STUDY SELECTION AND DATA EXTRACTION:

Articles pertinent to the pharmacology, pharmacokinetics, efficacy, and safety of rivoglitazone were reviewed.

DATA SYNTHESIS:

Rivoglitazone has been shown, through small clinical studies, to decrease hemoglobin A1c (A1C) by 0.11-1.1% when compared with placebo and may provide greater A1C reduction than pioglitazone. Rivoglitazone reduces hyperglycemia, hyperinsulinemia, and hypertriglyceridemia by acting as an agonist of PPAR-γ. Rivoglitazone is the most potent PPAR-γ agonist; the initial recommended dose is 1 mg daily, with adjustment as needed to a maximum dose of 2 mg daily. Additionally, rivoglitazone has a longer half-life than other PPAR-γ agonists. Similar to those of the other PPAR-γ agonists, rivoglitazone's adverse effects include peripheral edema and weight gain.

CONCLUSIONS:

Rivoglitazone is the fourth agent in the thiazolidinedione class of antidiabetes drugs. Although rivoglitazone appears to be more potent in its ability to lower A1C levels compared with other thiazolidinediones, further studies of longer duration are needed to fully assess the risks associated with this drug. Until these can be completed, we cannot recommend rivoglitazone over currently approved drugs in this class.

Chemical proteomics-based analysis of off-target binding profiles for rosiglitazone and pioglitazone: clues for assessing potential for cardiotoxicity

Drugs exert desired and undesired effects based on their binding interactions with protein target(s) and off-target(s), providing evidence for drug efficacy and toxicity. Pioglitazone and rosiglitazone possess a common functional core, glitazone, which is considered a privileged scaffold upon which to build a drug selective for a given target--in this case, PPARγ. Herein, we report a retrospective analysis of two variants of the glitazone scaffold, pioglitazone and rosiglitazone, in an effort to identify off-target binding events in the rat heart to explain recently reported cardiovascular risk associated with these drugs. Our results suggest that glitazone has affinity for dehydrogenases, consistent with known binding preferences for related rhodanine cores. Both drugs bound ion channels and modulators, with implications in congestive heart failure, arrhythmia, and peripheral edema. Additional proteins involved in glucose homeostasis, synaptic transduction, and mitochondrial energy production were detected and potentially contribute to drug efficacy and cardiotoxicity.

Thiazolidinedione drugs promote onset, alter characteristics, and increase mortality of ischemic ventricular fibrillation in pigs

PURPOSE

Despite favorable metabolic and vascular effects, thiazolidinedione (TZD) drugs have not convincingly reduced cardiovascular mortality in clinical trials, raising the possibility of countervailing, off-target effects. We previously showed that TZDs block cardiac ATP-sensitive potassium (K(ATP)) channels in pigs. In this study, we investigated whether TZDs affect onset, spectral characteristics, and mortality of ischemic ventricular fibrillation (VF) and whether such effects are recapitulated by a non-selective K(ATP) blocker (glyburide) or a mitochondrial K(ATP) blocker (5-hydroxydecanoate).

METHODS

A total of 121 anesthetized pigs were pre-treated with TZD (pioglitazone or rosiglitazone, 1 mg/kg IV, resulting in clinically relevant plasma concentrations), glyburide (1 mg/kg IV), 5-hydroxydecanoate (5 mg/kg IV) or inert vehicle. Ischemia was produced by occlusion of the left anterior descending coronary artery. In a subset of pigs treated with rosiglitazone or vehicle, ischemic preconditioning was performed.

RESULTS

VF developed in all but 6 pigs. In non-preconditioned pigs, onset of VF occurred sooner with pioglitazone (11±3 min, p<0.05) or rosiglitazone (14±3 min, p=0.06) than with vehicle (20±2 min). Defibrillation of VF was successful in 44% of pigs treated with vehicle, compared with 0% with pioglitazone (p=0.057) and 33% with rosiglitazone (NS). After ischemic preconditioning, defibrillation was successful in 62% of pigs treated with vehicle, compared with 26% treated with rosiglitazone (p=0.03). TZDs attenuated slowing of conduction due to ischemia and shifted ECG power spectra during VF toward higher frequencies. All effects of TZDs were recapitulated by glyburide, but not by 5-hydroxydecanoate, supporting an interaction of TZDs with the sarcolemmal K(ATP) channel.

CONCLUSION

In a porcine model, TZDs promote onset and increase mortality of ischemic VF, associated with alterations of conduction and VF spectral characteristics. Similar effects in a clinical setting might adversely impact cardiovascular mortality.

Insulin sensitization therapy and the heart: focus on metformin and thiazolidinediones

Chronic heart failure (CHF) is an insulin-resistant (IR) state and the degree of IR is related to disease severity and poor clinical outcome in CHF. IR may be pathophysiologically linked with CHF. Therefore, IR may represent a new target for treatment in CHF. Metformin and thiazolidinediones (TZDs) are effective diabetic therapies that are insulin sensitizers. TZDs are contraindicated in CHF because their use is associated with increased incidence of CHF as a result of their effects on renal sodium reabsorption and vascular permeability. There is evidence to suggest that metformin may be both safe and useful in CHF.

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.

Critical evaluation of the role of acarbose in the treatment of diabetes: patient considerations

The alpha-glucosidase inhibitor acarbose has been used for more than 20 years in the management of hyperglycemia. Owing to its unique mode of action in the gastrointestinal tract, its properties are very different from other antidiabetic medications. Patients on long-term treatment to control a chronic disease are not only interested in good treatment efficacy, but are also even more interested in the safety and side effects of their medications. Significant aspects of acarbose predominantly regarding safety and tolerability in the management of type 2 diabetes and prediabetes are reviewed. It is concluded that acarbose is a convenient long-term treatment option, with benefits for both type 2 diabetics and patients in a prediabetic state.

Risk of death and cardiovascular outcomes with thiazolidinediones: a study with the general practice research database and secondary care data

Objective

To describe the likely extent of confounding in evaluating the risks of cardiovascular (CV) events and mortality in patients using diabetes medication.

Methods

The General Practice Research Database was used to identify inception cohorts of insulin and different oral antidiabetics. An analysis of bias and incidence of mortality, acute coronary syndrome, stroke and heart failure were analysed in GPRD, Hospital Episode Statistics and death certificates.

Results

206,940 patients were identified. The bias analysis showed that past thiazolidinedione users had a lower mortality risk compared to past metformin users. There were no differences between past users of rosiglitazone and pioglitazone (adjusted RR of 1.04; 95% CI 0.93–1.18). Current rosiglitazone users had an increased risk of death (adjusted RR 1.20; 95% CI 1.08–1.34) and of hospitalisation for heart failure (adjusted RR of 1.73; 95% CI 1.19–2.51) compared to current pioglitazone users. Risk of mortality was increased two-fold shortly after starting rosiglitazone. Excess risk of death over 3 years with rosiglitazone was 0.3 per 100 in those aged 50–64 years, 2.0 aged 65–74, 3.0 aged 75–84, and 7.0 aged 85+. The cause of death with rosiglitazone was more likely to be due to a disease of the circulatory system.

Conclusions

Higher risks for death (overall and due to cardiovascular disease) and heart failure were found for rosiglitazone compared to pioglitazone. These excess risks were largest in patients aged 65 years or older. The European regulatory decision to suspend rosiglitazone is supported by this study.

Management of diabetes across the course of disease: minimizing obesity-associated complications

Obesity increases the risk for developing type 2 diabetes mellitus (T2DM) and this in turn correlates with an elevated probability of long-term diabetes complications once diabetes is established. Interventions aimed at lowering weight via changes in diet and lifestyle have repeatedly been shown to improve glycemic control in patients with T2DM and even to reverse early disease. Weight gain, a potential side effect of treatment for patients with T2DM, is also an important concern, and it has been noted that weight increases associated with antidiabetes therapy may blunt cardiovascular risk reductions achieved by decreasing blood glucose. Among older agents, metformin and acarbose have the lowest risk for weight gain, while sulfonylureas, meglitinides, and thiazolidinediones are all associated with weight increases. Clinical trial results have also consistently demonstrated that treatment with glucagon-like peptide-1 receptor agonists and amylin lowers weight, and that dipeptidyl peptidase-4 inhibitors are weight neutral in patients with T2DM. Conventional human insulin formulations are known to increase weight in patients with T2DM. However, some insulin analogs, particularly insulin detemir, have lower liability for this adverse event. The use of both pharmacologic and surgical therapies aimed at treating obesity rather than lowering blood glucose have the potential to improve glycemic control and even resolve T2DM in some patients.

Antidiabetic prescribing trends and predictors of thiazolidinedione discontinuation following the 2007 rosiglitazone safety alert

This study aimed to examine the change in antidiabetic medication prescribing trends and predictors of thiazolidinedione (TZD) discontinuation six months after the 2007 rosiglitazone safety alert. We performed a retrospective cohort analysis. Patients with two prescriptions for a TZD between 1 January and 21 May 2007, including one covering 21 May 2007, and continuous enrolment during 2006-2007 were identified from the MarketScan database. Multivariate logistic regression analysis was used to compare characteristics between patients who continued and discontinued each TZD. We identified 40,836 and 37,183 individuals with a current prescription for rosiglitazone and pioglitazone, respectively. Significantly more rosiglitazone (53.5%) compared to pioglitazone users (21.4%) discontinued initial therapy six months after the alert (p<0.001). Approximately 23% of patients who discontinued rosiglitazone were switched to pioglitazone, while <1% was switched from pioglitazone to rosiglitazone. Notably, 19.4% of patients who discontinued rosiglitazone and 36.1% of those who discontinued pioglitazone did not have evidence of any antidiabetic drug at follow-up. There was a significant decrease in metformin and an increase in sitagliptin prescribing in patients who discontinued TZDs. Age, sex, region, cardiovascular comorbidities and physician specialty predicted TZD discontinuation. These findings suggest that FDA advisories may be associated with substantial changes in medication use.

Comparative cardiovascular effects of thiazolidinediones: systematic review and meta-analysis of observational studies

OBJECTIVE

To determine the comparative effects of the thiazolidinediones (rosiglitazone and pioglitazone) on myocardial infarction, congestive heart failure, and mortality in patients with type 2 diabetes.

DESIGN

Systematic review and meta-analysis of observational studies.

DATA SOURCES

Searches of Medline and Embase in September 2010.

STUDY SELECTION

Observational studies that directly compared the risk of cardiovascular outcomes for rosiglitazone and pioglitazone among patients with type 2 diabetes mellitus were included.

DATA EXTRACTION

Random effects meta-analysis (inverse variance method) was used to calculate the odds ratios for cardiovascular outcomes with thiazolidinedione use. The I(2 )statistic was used to assess statistical heterogeneity.

RESULTS

Cardiovascular outcomes from 16 observational studies (4 case-control studies and 12 retrospective cohort studies), including 810,000 thiazolidinedione users, were evaluated after a detailed review of 189 citations. Compared with pioglitazone, use of rosiglitazone was associated with a statistically significant increase in the odds of myocardial infarction (n = 15 studies; odds ratio 1.16, 95% confidence interval 1.07 to 1.24; P < 0.001; I(2) = 46%), congestive heart failure (n = 8; 1.22, 1.14 to 1.31; P < 0.001; I(2) = 37%), and death (n = 8; 1.14, 1.09 to 1.20; P < 0.001; I(2) = 0%). Numbers needed to treat to harm (NNH), depending on the population at risk, suggest 170 excess myocardial infarctions, 649 excess cases of heart failure, and 431 excess deaths for every 100,000 patients who receive rosiglitazone rather than pioglitazone.

CONCLUSION

Among patients with type 2 diabetes, use of rosiglitazone is associated with significantly higher odds of congestive heart failure, myocardial infarction, and death relative to pioglitazone in real world settings.

The economics of diabetes prevention

In the United States, the costs associated with diabetes mellitus are increasing. Although people with diabetes comprise less than 6% of the US population, approximately 1 in 5 health care dollars is spent caring for people with diabetes. Healthy lifestyle interventions for the general population and intensive lifestyle and medication interventions for high-risk individuals present opportunities for diabetes prevention. This article describes the costs associated with glucose intolerance and diabetes, the effect of glucose intolerance and diabetes on the quality of life, and the cost-effectiveness of screening and primary prevention interventions for diabetes prevention.

Management of type 2 diabetes: evolving strategies for the treatment of patients with type 2 diabetes

The prevalence of type 2 diabetes continues to increase at an alarming rate around the world, with even more people being affected by prediabetes. Although the pathogenesis and long-term complications of type 2 diabetes are fairly well known, its treatment has remained challenging, with only half of the patients achieving the recommended hemoglobin A(1c) target. This narrative review explores the pathogenetic rationale for the treatment of type 2 diabetes, with the view of fostering better understanding of the evolving treatment modalities. The diagnostic criteria including the role of hemoglobin A(1c) in the diagnosis of diabetes are discussed. Due attention is given to the different therapeutic maneuvers and their utility in the management of the diabetic patient. The evidence supporting the role of exercise, medical nutrition therapy, glucose monitoring, and antiobesity measures including pharmacotherapy and bariatric surgery is discussed. The controversial subject of optimum glycemic control in hospitalized and ambulatory patients is discussed in detail. An update of the available pharmacologic options for the management of type 2 diabetes is provided with particular emphasis on newer and emerging modalities. Special attention has been given to the initiation of insulin therapy in patients with type 2 diabetes, with explanation of the pathophysiologic basis for insulin therapy in the ambulatory diabetic patient. A review of the evidence supporting the efficacy of the different preventive measures is also provided.