Addition of rosiglitazone to existing sulfonylurea treatment in chinese patients with type 2 diabetes and exposure to hepatitis B or C

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Standards of medical care for type 2 diabetes in China 2019

The prevalence of diabetes in China has increased rapidly from 0.67% in 1980 to 10.4% in 2013, with the aging of the population and westernization of lifestyle. Since its foundation in 1991, the Chinese Diabetes Society (CDS) has been dedicated to improving academic exchange and the academic level of diabetes research in China. From 2003 to 2014, four versions of Chinese diabetes care guidelines have been published. The guidelines have played an important role in standardizing clinical practice and improving the status quo of diabetes prevention and control in China. Since September 2016, the CDS has invited experts in cardiovascular diseases, psychiatric diseases, nutrition, and traditional Chinese medicine to work with endocrinologists from the CDS to review the new clinical research evidence related to diabetes over the previous 4 years. Over a year of careful revision, this has resulted in the present, new version of guidelines for prevention and care of type 2 diabetes in China. The main contents include epidemiology of type 2 diabetes in China; diagnosis and classification of diabetes; primary, secondary, and tertiary diabetes prevention; diabetes education and management support; blood glucose monitoring; integrated control targets for type 2 diabetes and treatments for hyperglycaemia; medical nutrition therapy; exercise therapy for type 2 diabetes; smoking cessation; pharmacologic therapy for hyperglycaemia; metabolic surgery for type 2 diabetes; prevention and treatment of cardiovascular and cerebrovascular diseases in patients with type 2 diabetes; hypoglycaemia; chronic diabetic complications; special types of diabetes; metabolic syndrome; and diabetes and traditional Chinese medicine.

Comparison of antidiabetic drugs added to sulfonylurea monotherapy in patients with type 2 diabetes mellitus: A network meta-analysis

AIMS

This study aimed to investigate the efficacy and safety of dual therapy comprising sulfonylurea (SU) plus antidiabetic drugs for the treatment of type 2 diabetes mellitus (T2DM).

METHODS

We searched the PubMed, Cochrane library, and Embase databases for randomized clinical trials (≥24 weeks) published up to December 28, 2017. Subsequently, we conducted pairwise and network meta-analyses to calculate the odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) of the outcomes.

RESULTS

The final analyses included 24 trials with a total of 10,032 patients. Compared with placebo, all treatment regimens were associated with a significantly higher risk of hypoglycemia, except the combinations of SU plus sodium-glucose co-transporter-2 inhibitor (SGLT-2i) [OR, 1.35 (95% CI: 0.81 to 2.25)] or alpha-glucosidase inhibitor (AGI) [OR, 1.16 (95% CI: 0.55 to 2.44)]. Notably, the combination of SU plus glucagon-like peptide-1 receptor agonist (GLP-1RA) was associated with the most significant increase in the risk of hypoglycemia. Furthermore, all SU-based combination regimens reduced the glycated hemoglobin (HbA1c) and fasting plasma glucose levels (FPG). However, only combinations containing SGLT-2i [MD, -1.00 kg (95% CI: -1.73 to -0.27)] and GLP-1RA [MD, -0.56 kg (95% CI: -1.10 to -0.02)] led to weight loss.

CONCLUSIONS

Our findings highlight the importance of considering the risk of hypoglycemia when selecting antidiabetic drugs to be administered concomitantly with SU. Although all classes of antidiabetic drugs improved glucose control when administered in combination with SU, SGLT-2i might be the best option with respect to factors such as hypoglycemia and body weight.

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.

Baseline differences in A1C explain apparent differences in efficacy of sitagliptin, rosiglitazone and pioglitazone

AIM

Published studies of patients treated with rosiglitazone or pioglitazone have reported greater reductions in HbA1c (A1C) than studies of patients treated with sitagliptin. However, studies of thiazolidinediones tended to enroll patients with higher baseline A1C levels. This meta-analysis investigates the relationship between baseline A1C and perceived efficacy of treatment.

METHODS

This report describes a Bayesian random effects analysis of 23 published studies. We constructed a random effects model including a factor adjusting for between-study differences in baseline A1C levels.

RESULTS

The random effects model correctly predicts post-treatment A1C levels from baseline A1C within a 95% confidence interval (CI) for each of the 23 studies included in the meta-analysis. After applying the model to adjust for differences in baseline A1C, we found that the difference in efficacy between rosiglitazone and sitagliptin was not significantly different from zero (0.12; 95% CI -0.09 to 0.34). Similarly, no significant differences are observed between the effects of pioglitazone and sitagliptin (0.01; 95% CI -0.21 to 0.22) or between rosiglitazone and pioglitazone (0.11; 95% CI -0.37 to 0.146). When baseline values are omitted from the Bayesian model, the findings suggest that rosiglitazone is superior to pioglitazone or sitagliptin.

CONCLUSIONS

These results illustrate the necessity for careful application of appropriate methodology when comparing results of different studies. When between-study differences in treatment effects are adjusted for baseline differences, then the findings suggest that none of the treatments has an effect that is superior to any of the other treatments.

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.

Addition of Thiazolidinedione or Exenatide to Oral Agents in Type 2 Diabetes: A Meta-Analysis

Background:

The introduction of several new therapeutic agents for the treatment of type 2 diabetes mellitus has led to significant challenges for providers in deciding which agent to select during the disease course.

Objective:

To provide a relative comparison of the efficacy and safety of adding thiazolidinediones (TZDs) or exenatide to oral agents for the management of type 2 diabetes mellitus by performing meta-analyses of relevant published studies.

Methods:

We systematically searched PubMed, MEDLINE, CINHAL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, EMBASE (inception to March 2008 for all databases), and abstracts presented at the 2006 and 2007 American Diabetes Association conferences to identify all relevant publications. Studies were included in the analysis if they (1) were published in English, (2) were prospective, randomized, and controlled with placebo or comparator, (3) were at least 24 weeks' duration, (4) included nonpregnant adults with type 2 diabetes, (5) were full-text, peer-reviewed articles examining the efficacy of either TZDs (rosiglitazone or pioglitazone) or exenatide in combination with other oral drugs, and (6) included hemoglobin A1C (AIC) outcomes in a manner that allowed data analysis. We evaluated mean change in A1C levels, proportion of subjects reaching A1C goals of less than 7%, mean change in fasting plasma glucose (FPG) and body weight, and the occurrence of nonsevere hypoglycemia and gastrointestinal adverse events.

Results:

A total of 5212 TZD and 3562 exenatide publications were identified. After critical evaluation, 22 publications met all of the inclusion criteria for the meta-analysis. A1C was reduced from baseline for TZDs (weighted mean difference –0.80%; 95% CI –1.10 to –0.50) and exenaiide (weighted mean difference –0.60%; 95% CI –1.04 to –0.16), Compared with controls, TZD- and exenatide-based therapies had odds ratios greater than 1 for reaching A1C targets of less than 7% (TZD OR 2.27; 95% CI 1.22 to 4.24 and exenatide OR 2.90; 95% CI 1.28 to 6.55). FPG concentrations were reduced significantly from baseline in the TZD-based regimens (weighted mean difference –29.58 mg/dL; 95% CI –39.27 to –19.89), but did not achieve significance in the exenatide trials (weighted mean difference –8.77 mg/dL; 95% CI –28.85 to 11.31). Body weight was reduced with exenatide (weighted mean difference –2.74 kg; 95% CI –4.85 to –0.64) and increased in subgroup analyses for TZDs (weighted mean difference 2.19 kg; 95% CI 1.24 to 3.14). There was no significant association between TZD or exenatide therapy and the risk of nonsevere hypoglycemia. The odds ratios for nausea, vomiting, and diarrhea with exenatide relative to controls were 9.02 (95% CI 3.66 to 22.23), 4.56 (95% CI 3.13 to 6.65), and 2.96 (95% CI 2.05 to 4.26), respectively.

Conclusions:

TZDs and exenatide have modest but beneficial effects on glycemic control and are relatively safe in regard to the adverse events studied. TZDs produce greater improvement in glycemic control, while exenatide Is associated with reduction in body weight.

A retrospective evaluation of congestive heart failure and myocardial ischemia events in 14,237 patients with type 2 diabetes mellitus enrolled in 42 short-term, double-blind, randomized clinical studies with rosiglitazone

PURPOSE

Retrospectively investigate potential associations between rosiglitazone and congestive heart failure (CHF) and, separately, events of myocardial ischemia.

METHODS

Data from 14 237 individuals in 42 short-term, double-blind, randomized studies of rosiglitazone versus placebo or active diabetes medications were analyzed across seven treatment comparisons using an exact logistic regression model, adjusted for number of major cardiovascular risk factors and duration of exposure.

RESULTS

CHF incidence ranged 0-1.27% (SAEs) and 0.12-2.42% (all AEs) with rosiglitazone versus 0.07-0.75% (SAEs) and 0.25-1.36% (all AEs) with control. Higher odds ratios (95%CI) were observed for CHF SAEs with sulfonylurea- and insulin-containing combinations: rosiglitazone monotherapy versus placebo, 0.25 (<0.01-4.75); rosiglitazone monotherapy versus sulfonylurea/metformin monotherapy, 0.23 (<0.01-2.14); sulfonylurea + rosiglitazone versus sulfonylurea monotherapy, 0.95 (0.01-75.20); metformin + rosiglitazone versus metformin monotherapy, 0.60 (0.00-8.28); metformin + rosiglitazone versus metformin + sulfonylurea, 1.04 (0.39-2.86); sulfonylurea + metformin + rosiglitazone versus sulfonylurea + metformin, 3.15 (0.35-150.52); insulin + rosiglitazone versus insulin monotherapy, 1.63 (0.52-6.01). Myocardial ischemia incidence ranged 0.75-1.40% (SAEs) and 1.49-2.77% (all AEs) with rosiglitazone versus 0.21-2.04% (SAEs) and 0.56-2.38% (all AEs) with control. Each comparison had an OR >1, with wide confidence intervals generally including unity. With data pooling, more events of myocardial ischemia were observed with rosiglitazone (2.00%) versus control (1.53%) (HR 1.30, 95%CI 1.004-1.69).

CONCLUSIONS

CHF incidence may be greater when rosiglitazone is combined with sulfonylureas or insulin. When data were pooled, more events of myocardial ischemia were observed with rosiglitazone versus control. Final results from RECORD will allow a more rigorous evaluation of the cardiovascular safety profile.

Lipids behavior and adverse effects for oral antidiabetic agents in patients with Type 2 diabetes treated with sulfonylureas alone based on systematic review

The secondary and adverse effects when biguanides, alpha-glycosidase inhibitor or thiazolidine derivative was used with sulphonylurea agent (SU) as compared with those with SU alone in Type 2 diabetes patients by using Systematic Review. Two-agent concurrent treatment groups, taken from studies in which subjects were assigned to a group given only a sulfonylurea agent and a group given a sulfonylurea agent with the other glycemic control agent (combination of a sulfonylurea agent and a biguanide agent (I), combination of a sulfonylurea agent and an alpha-glucosidase inhibitor (II), and combination of a sulfonylurea agent and thiazolidinedione (III)), were studied in a randomized controlled trial. The secondary efficacy outcome measures were total cholesterol (TC), triglyceride (TG), HDL-C, LDL-C, and change in body weight. The incidence of hypoglycemia, feeling of fullness, diarrhea, liver dysfunction, and edema was investigated as a safety outcome measure, and the clinical significance of concurrent treatment with a sulfonylurea agent in addition to the other glycemic control agent was investigated. With respect to (II), an antidiabetic effect was showed. As for (III), it had the disadvantage of increased body weight. Furthermore, increase of HDL-C levels, in particular, was observed. The improving effect of (III) on serum lipids may be clinically effective for considering the pathologic condition of diabetes, which is often complicated by hyperlipidemia.

Rosiglitazone and glimeperide: review of clinical results supporting a fixed dose combination

Type 2 diabetes has become a major burden to the health care systems worldwide. Among the drugs approved for this indication, glimepiride and rosiglitazone have gained substantial importance in routine use. While glimepiride stimulates β-cell secretion and leads to reduction of blood glucose values, rosiglitazone activates PPARγ and improves insulin resistance, at the vascular and metabolically active cells. Therefore, the combination of the two drugs may be an interesting approach to improve glycemic control and lower cardiovascular risk. A fixed combination of both drugs has been approved for clinical use in the US and EU. The combination of glimepiride and rosiglitazone is generally well tolerated and the use of a fixed combination may lead to improved adherence of the patients to their therapy. The purpose of this review is to evaluate the clinical data that have been published on this combination, appearing to represent a convenient way to obtain therapeutic targets in patients with type 2 diabetes mellitus.

Rosiglitazone for type 2 diabetes mellitus

BACKGROUND

Diabetes has long been recognised as a strong, independent risk factor for cardiovascular disease, a problem which accounts for approximately 70% of all mortality in people with diabetes. Prospective studies show that compared to their non-diabetic counterparts, the relative risk of cardiovascular mortality for men with diabetes is two to three and for women with diabetes is three to four. The two biggest trials in type 2 diabetes, the United Kingdom Prospective Diabetes Study (UKPDS) and the University Group Diabetes Program (UGDP) study did not reveal a reduction of cardiovascular endpoints through improved metabolic control. Theoretical benefits of the peroxisome proliferator activated receptor gamma (PPAR-gamma) activator rosiglitazone on endothelial function and cardiovascular risk factors might result in fewer macrovascular disease events in people with type 2 diabetes mellitus.

OBJECTIVES

To assess the effects of rosiglitazone in the treatment of type 2 diabetes.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE and The Cochrane Library.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials in adult people with type 2 diabetes mellitus and had a trial duration of at least 24 weeks.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Pooling of studies by means of fixed-effects meta-analysis could be performed for adverse events only.

MAIN RESULTS

Eighteen trials which randomised 3888 people to rosiglitazone treatment were identified. Longest duration of therapy was four years with a median of 26 weeks. Published studies of at least 24 weeks rosiglitazone treatment in people with type 2 diabetes mellitus did not provide evidence that patient-oriented outcomes like mortality, morbidity, adverse effects, costs and health-related quality of life are positively influenced by this compound. Metabolic control measured by glycosylated haemoglobin A1c (HbA1c) as a surrogate endpoint did not demonstrate clinically relevant differences to other oral antidiabetic drugs. Occurrence of oedema was significantly raised (OR 2.27, 95% confidence interval (CI) 1.83 to 2.81). The single large RCT (ADOPT - A Diabetes Outcomes Progression Trial) indicated increased cardiovascular risk. New data on raised fracture rates in women reveal extensive action of rosiglitazone in various body tissues.

AUTHORS' CONCLUSIONS

New studies should focus on patient-oriented outcomes to clarify the benefit-risk ratio of rosiglitazone therapy. Safety data and adverse events of all investigations (published and unpublished) should be made available to the public.

Effect of rosiglitazone on the risk of myocardial infarction and death from cardiovascular causes

BACKGROUND

Rosiglitazone is widely used to treat patients with type 2 diabetes mellitus, but its effect on cardiovascular morbidity and mortality has not been determined.

METHODS

We conducted searches of the published literature, the Web site of the Food and Drug Administration, and a clinical-trials registry maintained by the drug manufacturer (GlaxoSmithKline). Criteria for inclusion in our meta-analysis included a study duration of more than 24 weeks, the use of a randomized control group not receiving rosiglitazone, and the availability of outcome data for myocardial infarction and death from cardiovascular causes. Of 116 potentially relevant studies, 42 trials met the inclusion criteria. We tabulated all occurrences of myocardial infarction and death from cardiovascular causes.

RESULTS

Data were combined by means of a fixed-effects model. In the 42 trials, the mean age of the subjects was approximately 56 years, and the mean baseline glycated hemoglobin level was approximately 8.2%. In the rosiglitazone group, as compared with the control group, the odds ratio for myocardial infarction was 1.43 (95% confidence interval [CI], 1.03 to 1.98; P=0.03), and the odds ratio for death from cardiovascular causes was 1.64 (95% CI, 0.98 to 2.74; P=0.06).

CONCLUSIONS

Rosiglitazone was associated with a significant increase in the risk of myocardial infarction and with an increase in the risk of death from cardiovascular causes that had borderline significance. Our study was limited by a lack of access to original source data, which would have enabled time-to-event analysis. Despite these limitations, patients and providers should consider the potential for serious adverse cardiovascular effects of treatment with rosiglitazone for type 2 diabetes.

Factors associated with the effect-size of thiazolidinedione (TZD) therapy on HbA(1c): a meta-analysis of published randomized clinical trials

OBJECTIVE

To examine factors affecting the size of the HbA(1c) response to thiazolidinedione (TZD) therapy.

RESEARCH DESIGN AND METHODS

Meta-analysis of randomized TZD controlled trials which were identified using PubMed, EBSCO and Sci-lit databases and were published in English. Sociodemographic and clinical data were extracted from each trial. HbA(1c) effect size was defined as either a placebo-subtracted change in HbA(1c) or a change in HbA(1c) from baseline. Weighted multivariable regression was used to examine factors associated with changes in HbA(1c). Bootstrapped smearing estimates were computed to obtain reliable estimates of HbA(1c) effect size.

RESULTS

Forty-two trials yielded 60 trial arms which represented 8322 patients treated with thiazolidinediones. Weighted placebo-subtracted change in HbA(1c) was -0.99% +/- 0.02% with an average baseline HbA(1c) of 9.1% +/- 1.0%. Weighted bootstrapped smearing estimate of the placebo-subtracted change in HbA(1c) was -1.02% +/- 0.004%. After controlling for other variables, the baseline HbA(1c) level had a significant negative association with placebo-subtracted HbA(1c) change (p = 0.004) and also with change in HbA(1c) from baseline (p = 0.002). Longer trial duration was associated with greater placebo-subtracted HbA(1c) change (p = 0.01) but not with the change in HbA(1c) from baseline. The multivariable models explained 72% of the variation in placebo-subtracted HbA(1c) change. It was not possible to estimate effects of the run-in period and obesity on TZD effect size.

CONCLUSION

Baseline HbA(1c) and trial duration significantly impacted the effect size of TZD therapy on HbA(1c). Age, gender, duration of diabetes and prior use of anti-diabetic therapy were not associated with the TZD effect size.

Targeting insulin resistance and beta-cell dysfunction: the role of thiazolidinediones

Insulin resistance and beta-cell dysfunction are fundamental defects that contribute to the development of type 2 diabetes, and as such are targets for primary prevention of disease progression. The two parameters are linked by several factors, including glucotoxicity and lipotoxicity, and recent research has enlightened understanding of the molecular mechanisms underlying the development and progression of the disease. Historically, type 2 diabetes has been managed by controlling hyperglycemia, using agents that increase insulin levels or reduce hepatic glucose production, as exemplified by the United Kingdom Prospective Diabetes Study. The thiazolidinediones control hyperglycemia by targeting the fundamental defects of the disease, and have shown well-documented improvements in insulin sensitivity and beta-cell function, both in monotherapy and in combination with other oral antidiabetic agents. TRoglitazone In the Prevention Of Diabetes (TRIPOD) has demonstrated the potential for thiazolidinediones to delay progression to type 2 diabetes. Prospective studies such as Diabetes REduction Approaches with ramipril and rosiglitazone Medications (DREAM) are currently evaluating the long-term effects of thiazolidinediones on metabolic status and disease progression.