Effect of metformin and rosiglitazone combination therapy in patients with type 2 diabetes mellitus: a randomized controlled trial

Rosiglitazone and bezafibrate modulate gene expression in a rat model of non-alcoholic fatty liver disease--a historical prospective

Background

Genetic factors implicated in the pathogenesis of non-alcoholic fatty liver disease are poorly understood. Our aim was to characterize three genes involved in a rat model of non-alcoholic fatty liver disease and investigate the effect of rosiglitazone and bezafibrate.

Method

Five rats were fed a chow diet (controls) and 18 a fructose-enriched diet (FED) for 5 weeks: 6 were administered rosiglitazone and 6 bezafibrate during the last 2 weeks and 6 were not treated at all. Livers were examined by reverse transcription-PCR for the genes encoding peroxisome proliferator-activated receptors (PPAR), PPAR-α, PPAR-γ, and Mn superoxide dismutase2 (Mn SOD2). Western blot was used for proteins levels.

Result

The FED rats showed a decrease in mRNA of MnSOD2, PPAR-α, and PPAR-γ (3, 3.5 fold, and 27%, respectively) (p<0.05). The 3 genes normalized in response to rosiglitazone and bezafibrate. The proteins of MnSOD2, PPAR-α and PPAR-γ in the FED rats decreased (2.5, 2, and 2.2, respectively) (p<0.05). Following administration of rosiglitazone, proteins of MnSOD2, PPAR-α and PPAR-γ in the FED rats increased (reaching 1.5-fold, a 20% increase and normalization, respectively), (p<0.05). Administration of bezafibrate to the FED rats restored the proteins of 3 genes to baseline.

Conclusion

A consistent reduction in hepatic expression of MnSOD2, PPAR-α and PPAR-γ in the FED rats compared with controls was observed. Administration of either rosiglitazone or bezafibrate to the FED rats restored these genes to a pre-morbid state.

Effect of pharmacological treatments for diabetes on homocysteine

Hyperhomocysteinemia is a well-established risk factor for cardiovascular disease. The association of hyperhomocysteinemia with diabetes mellitus is complex and may explain some of the risk of CVD in diabetics not explained by traditional risk factors. Both modifiable and non-modifiable factors interact with homocysteine metabolism and determine the plasma homocysteine concentrations. These include genetic abnormalities, age, sex, and various nutritional and hormonal determinants, all of which play a role in atherosclerosis and accelerated peripheral and cardio-vascular disease (CVD). Several medications modulate homocysteine metabolism and hence may play a role in the pathogenesis of CVD. Changes in renal function and interference with the homocysteine metabolism account for some of these drug effects. While a few of these drugs raise plasma homocysteine concentrations, others are beneficial and may counter some of the deleterious effects of hyperhomocysteinemia. Treatment of hyperhomocysteinemia with vitamins lowers plasma homocysteine concentrations and also reverses many of these drug effects. Little data is available on the effect of this intervention on cardiovascular outcomes. This review briefly outlines the effect of various medications used in the management of type 2 diabetes mellitus and metabolic syndrome.

Phase I trial of exemestane in combination with metformin and rosiglitazone in nondiabetic obese postmenopausal women with hormone receptor-positive metastatic breast cancer

PURPOSE

Obese women with breast cancer have worse prognosis than women with normal body mass index. Endocrine therapy resistance is in part mediated by insulin resistance in obese women with breast cancer. We investigated the tolerability and pharmacokinetics of exemestane in combination with metformin and rosiglitazone in nondiabetic overweight and obese postmenopausal women with hormone receptor-positive metastatic breast cancer.

METHODS

Patients had previously received chemotherapy and endocrine therapy for breast cancer. Exemestane was given as 25 mg orally per day. Metformin (M) and rosiglitazone (R) were given twice daily. Dose level 1 consisted of M 1,500 mg/day and R 6 mg/day. Dose level 2 consisted of M 2,000 mg/day and R 8 mg/day. Plasma concentrations of exemestane were measured on days 1, 8, and 15.

RESULTS

Twenty patients were enrolled. Fourteen patients received exemestane, metformin, and rosiglitazone. Six patients received exemestane with metformin only (2,000 mg/day). Both regimens were well tolerated at the highest doses tested, and there were no notable changes in plasma exemestane levels. Six patients (30%) had stable disease for 6 months or longer.

CONCLUSIONS

Oral daily administration of exemestane (25 mg) and metformin (2,000 mg) with and without rosiglitazone (8 mg) daily was well tolerated. Exemestane pharmacokinetics were not altered by metformin and rosiglitazone.

Resveratrol ameliorates diabetes-related metabolic changes via activation of AMP-activated protein kinase and its downstream targets in db/db mice

SCOPE

This study investigated the effects of resveratrol (RV) on diabetes-related metabolic changes in a spontaneous model of type 2 diabetes, as well as activation of AMP-activated protein kinase (AMPK) and downstream targets.

METHODS AND RESULTS

C57BL/KsJ-db/db mice were fed a normal diet with RV (0.005% and 0.02%, w/w) or rosiglitazone (RG, 0.001%, w/w) for 6 weeks. Both doses of RV significantly decreased blood glucose, plasma free fatty acid, triglyceride, apo B/apo AІ levels and increased plasma adiponectin levels. RV activated AMPK and downstream targets leading to decreased blood HbA1c levels, hepatic gluconeogenic enzyme activity, and hepatic glycogen, while plasma insulin levels, pancreatic insulin protein, and skeletal muscle GLUT4 protein were higher after RV supplementation. The high RV dose also significantly increased hepatic glycolytic gene expression and enzyme activity, along with skeletal muscle glycogen synthase protein expression, similar to RG. Furthermore, RV dose dependently decreased hepatic triglyceride content and phosphorylated I kappa B kinase (p-IKK) protein expression, while hepatic uncoupling protein (UCP) and skeletal muscle UCP expression were increased.

CONCLUSION

RV potentiates improving glycemic control, glucose uptake, and dyslipidemia, as well as protecting against pancreatic β-cell failure in a spontaneous type 2 diabetes model. Dietary RV has potential as an antidiabetic agent via activation of AMPK and its downstream targets.

Citrus unshiu peel extract ameliorates hyperglycemia and hepatic steatosis by altering inflammation and hepatic glucose- and lipid-regulating enzymes in db/db mice

Insulin resistance in Type 2 diabetes leads to hepatic steatosis that can accompanied by progressive inflammation of the liver. Citrus unshiu peel is a rich source of citrus flavonoids that possess anti-inflammatory, anti-diabetic and lipid-lowering effects. However, the ability of citrus unshiu peel ethanol extract (CPE) to improve hyperglycemia, adiposity and hepatic steatosis in Type 2 diabetes is unknown. Thus, we evaluated the effects of CPE on markers for glucose, lipid metabolism and inflammation in Type 2 diabetic mice. Male C57BL/KsJ-db/db mice were fed a normal diet with CPE (2 g/100 g diet) or rosiglitazone (0.001 g/100 g diet) for 6 weeks. Mice supplemented with the CPE showed a significant decrease in body weight gain, body fat mass and blood glucose level. The antihyperglycemic effect of CPE appeared to be partially mediated through the inhibition of hepatic gluconeogenic phosphoenolpyruvate carboxykinase mRNA expression and its activity and through the induction of insulin/glucagon secretion. CPE also ameliorated hepatic steatosis and hypertriglyceridemia via the inhibition of gene expression and activities of the lipogenic enzymes and the activation of fatty acid oxidation in the liver. These beneficial effects of CPE may be related to increased levels of anti-inflammatory adiponectin and interleukin (IL)-10, and decreased levels of pro-inflammatory markers (IL-6, monocyte chemotactic protein-1, interferon-γ and tumor necrosis factor-α) in the plasma or liver. Taken together, we suggest that CPE has the potential to improve both hyperglycemia and hepatic steatosis in Type 2 diabetes.

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.

Pioglitazone is a valid alternative to rosiglitazone

In 2000, two new thiazolidinediones, pioglitazone and rosiglitazone, were approved for the treatment of type 2 diabetes mellitus (T2DM). Administered as monotherapy or in combination with other antihyperglycemic agents, they represented an effective option for achieving or maintaining good glycemic control in patients with T2DM. Despite their efficacy, there was increasing concern regarding the potential of an increased cardiovascular risk with rosiglitazone. This resulted in the suspension of rosiglitazone from the European market by the European Medicines Agency in September 2010. This article focuses on the various steps that led to this important decision, and discusses a possible alternative for the treatment of patients receiving rosiglitazone.

Effect of lifestyle intervention plus rosiglitazone or placebo therapy on left ventricular mass assessed with cardiovascular magnetic resonance in the metabolic syndrome

BACKGROUND

To evaluate the effect of lifestyle intervention in conjunction with rosiglitazone or placebo therapy on left ventricular (LV) mass, using cardiovascular magnetic resonance (CMR) in the metabolic syndrome.

METHODS

The present study was a pre-specified substudy of a double-blind randomized controlled trial evaluating the effect of lifestyle intervention in conjunction with rosiglitazone or placebo therapy on carotid artery atherosclerosis in the metabolic syndrome. From this original study population, 10 subjects from the placebo group and 10 from the rosiglitazone group were randomly selected. At baseline and follow-up (52 weeks), clinical and laboratory measurements were assessed and a CMR-examination was performed to evaluate LV mass indexed for body surface area (LV mass-I). Subsequently, the effect of therapy (rosiglitazone vs. placebo) and clinical and laboratory variables on LV mass-I was evaluated.

RESULTS

In both groups, body mass index, waist circumference, systolic and diastolic blood pressure significantly decreased during follow-up. Interestingly, LV mass-I significantly decreased in the placebo group (48.9 ± 5.3 g/m2 vs. 44.3 ± 5.6 g/m2, p < 0.001) indicating reverse remodeling, whereas LV mass-I remained unchanged in the rosiglitazone group (54.7 ± 9.9 g/m2 vs. 53.7 ± 9.2 g/m2, p = 0.3). After correction for systolic and diastolic blood pressure and triglyceride, the kind of therapy (rosiglitazone vs. placebo) remained the only significant predictor of LV mass-I reduction.

CONCLUSIONS

Lifestyle intervention resulted in a reduction of LV mass-I in the metabolic syndrome, indicating reverse remodeling. However, rosiglitazone therapy may have inhibited this positive reverse remodeling.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN54951661.

Encounter frequency and serum glucose level, blood pressure, and cholesterol level control in patients with diabetes mellitus

BACKGROUND

More frequent patient-provider encounters may lead to faster control of hemoglobin A1c level, blood pressure (BP), and low-density lipoprotein (LDL) cholesterol (LDL-C) level (hereafter referred to as hemoglobin A1c, BP, and LDL-C) and improve outcomes, but no guidelines exist for how frequently patients with diabetes mellitus (DM) should be seen.

METHODS

This retrospective cohort study analyzed 26,496 patients with diabetes and elevated hemoglobin A1c, BP, and/or LDL-C treated by primary care physicians at 2 teaching hospitals between January 1, 2000, and January 1, 2009. The relationship between provider encounter (defined as a note in the medical record) frequency and time to hemoglobin A1c, BP, and LDL-C control was assessed.

RESULTS

Comparing patients who had encounters with their physicians between 1 to 2 weeks vs 3 to 6 months, median time to hemoglobin A1c less than 7.0% was 4.4 vs 24.9 months (not receiving insulin) and 10.1 vs 52.8 months (receiving insulin); median time to BP lower than 130/85 mm Hg was 1.3 vs 13.9 months; and median time to LDL-C less than 100 mg/dL was 5.1 vs 32.8 months, respectively (P<.001 for all). In multivariable analysis, doubling the time between physician encounters led to an increase in median time to hemoglobin A1c (not receiving [35%] and receiving [17%] insulin), BP (87%), and LDL-C (27%) targets (P<.001 for all). Time to control decreased progressively as encounter frequency increased up to once every 2 weeks for most targets, consistent with the pharmacodynamics of the respective medication classes.

CONCLUSIONS

Primary care provider encounters every 2 weeks are associated with fastest achievement of hemoglobin A1c, BP, and LDL-C targets for patients with diabetes mellitus.

The role of metformin and thiazolidinediones in the regulation of hepatic glucose metabolism and its clinical impact

Fasting hyperglycemia in type 2 diabetes mellitus (T2DM) results from elevated endogenous glucose production (EGP), which is mostly due to augmented hepatic gluconeogenesis. Insulin-resistant humans exhibit impaired insulin-dependent suppression of EGP and excessive hepatic lipid storage (steatosis), which relates to abnormal supply of free fatty acids (FFA) and energy metabolism. Only two glucose-lowering drug classes, the biguanide metformin and the thiazolidendiones (TZDs), exert insulin- and glucagon-independent hepatic effects. Preclinical studies suggest that metformin inhibits mitochondrial complex I. TZDs, as peroxisome proliferator-activated receptor (PPAR) γ-agonists, predominantly reduce the flux of FFA and cytokines from adipose tissue to the liver, but could also directly inhibit mitochondrial complex I. Although both metformin and TZDs improve fasting hyperglycemia and EGP in clinical trials, only TZDs decrease steatosis and peripheral insulin resistance. More studies are required to address their effects on hepatocellular energy metabolism with a view to identifying novel targets for the treatment of T2DM.

Comparison of the effects of long-term pioglitazone and rosiglitazone therapy on liver enzymes in type 2 diabetes

Aims

Insulin resistance is a major factor influencing the progression of non-alcoholic fatty liver disease (NAFLD). Hence, insulin sensitisers such as thiazolidinediones (TZDs) are a potential treatment for NAFLD although their long-term benefits remain unknown.

Methods

We retrospectively studied 396 and 364 type 2 diabetes patients who received pioglitazone and rosiglitazone therapy respectively from diabetes clinics between May 2001 and November 2007.

Results

One hundred and seventy-seven pioglitazone-treated and 152 rosiglitazone-treated patients were included. After a year of treatment, significant improvement in glycated haemoglobin A1C (HbA1C), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) was observed in both groups despite weight gain. Changes in HbA1C and liver function test (LFT) were positively correlated in pioglitazone-treated (ALT p=0.01; GGT p<0.001; ALP p=0.006) and rosiglitazone-treated (GGT p= 0.01, ALP p=0.002) groups. Multiple regression showed no significant difference in the changes in ALT (p=0.43) and GGT (p=0.13) between the groups but a larger reduction in ALP (p=0.03) was noted in rosiglitazone-treated patients. Sixty patients remained on pioglitazone and 46 patients continued on rosiglitazone after four years. Sustained improvement in ALT, GGT and HbA 1C was observed in both groups despite weight gain over four years.

Low HDL-cholesterol: a strong predictor of glycemic response to glitazone treatment in patients with type 2 diabetes

We performed a study in 102 people with type 2 diabetes aiming to determine "easy-to-use" predictive factors for glycemic response to glitazones. We found that low baseline HDL-cholesterol (<40 mg/L [1.04 mmol/L] in males, <50 mg/L [1.30 mmol/L] in females) was a strong independent predictor of glycemic response to glitazones (OR=2.67 [2.02-3.52], p=0.0004).

Advances in the treatment of type 2 diabetes mellitus

There is a rising worldwide prevalence of diabetes, especially type 2 diabetes mellitus (T2DM), which is one of the most challenging health problems in the 21st century. The associated complications of diabetes, such as cardiovascular disease, peripheral vascular disease, stroke, diabetic neuropathy, amputations, renal failure, and blindness result in increasing disability, reduced life expectancy, and enormous health costs. T2DM is a polygenic disease characterized by multiple defects in insulin action in tissues and defects in pancreatic insulin secretion, which eventually leads to loss of pancreatic insulin-secreting cells. The treatment goals for T2DM patients are effective control of blood glucose, blood pressure, and lipids (if elevated) and, ultimately, to avert the serious complications associated with sustained tissue exposure to excessively high glucose concentrations. Prevention and control of diabetes with diet, weight control, and physical activity has been difficult. Treatment of T2DM has centered on increasing insulin levels, either by direct insulin administration or oral agents that promote insulin secretion, improving sensitivity to insulin in tissues, or reducing the rate of carbohydrate absorption from the gastrointestinal tract. This review presents comprehensive and up-to-date information on the mechanism(s) of action, efficacy, pharmacokinetics, pleiotropic effects, drug interactions, and adverse effects of the newer antidiabetic drugs, including (1) peroxisome proliferator-activated-receptor-γ agonists (thiazolidinediones, pioglitazone, and rosiglitazone); (2) the incretin, glucagon-like peptide-) receptor agonists (incretin-mimetics, exenatide. and liraglutide), (3) inhibitors of dipeptidyl-peptidase-4 (incretin enhancers, sitagliptin, and vildagliptin), (4) short-acting, nonsulfonylurea secretagogue, meglitinides (repaglinide and nateglinide), (5) amylin anlog-pramlintide, (6) α-glucosidase inhibitors (miglitol and voglibose), and (7) colesevelam (a bile acid sequestrant). In addition, information is presented on drug candidates in clinical trials, experimental compounds, and some plants used in the traditional treatment of diabetes based on experimental evidence. In the opinion of this reviewer, therapy based on orally active incretins and incretin mimetics with long duration of action that will be efficacious, preserve the β-cell number/function, and block the progression of diabetes will be highly desirable. However, major changes in lifestyle factors such as diet and, especially, exercise will also be needed if the growing burden of diabetes is to be contained.

PPARγ: a molecular link between systemic metabolic disease and benign prostate hyperplasia

The emergent epidemic of metabolic syndrome and its complex list of sequelae mandate a more thorough understanding of benign prostatic hyperplasia and lower urinary tract symptoms (BPH/LUTS) in the context of systemic metabolic disease. Here we discuss the nature and origins of BPH, examine its role as a component of LUTS and review retrospective clinical studies that have drawn associations between BPH/LUTS and type II diabetes, inflammation and dyslipidemia. PPARγ signaling, which sits at the nexus of systemic metabolic disease and BPH/LUTS through its regulation of inflammation and insulin resistance, is proposed as a candidate for molecular manipulation in regard to BPH/LUTS. Finally, we introduce new cell and animal models that are being used to study the consequences of obesity, diabetes and inflammation on benign prostatic growth.

Combination lipid therapy in type 2 diabetes mellitus

INTRODUCTION

A significant drop in cardiovascular risk has been seen in patients with type 2 diabetes treated with statins. However, this cardiovascular risk remains high, compared with nondiabetic individuals. This is partly due to the typical abnormalities of diabetic dyslipidemia - hypertriglyceridemia and decreased high-density lipoprotein cholesterol (HDL-C) - that are uncontrolled by statins. For this reason, combination lipid therapy may be considered in patients with type 2 diabetes.

AREAS COVERED

This review presents the main reasons for a combination lipid therapy in type 2 diabetes and the effects of several drugs, including fibrates, pioglitazone, niacin and omega 3, on diabetic dyslipidemia and the prevention of cardiovascular events. The real cardiovascular benefit of fibrates in patients with type 2 diabetes is not totally clear, but they may produce a significant benefit in patients with type 2 diabetes and diabetic dyslipidemia (hypertriglyceridemia, low HDL-C). Pioglitazone, which reduces triglycerides and increases HDL-C, has been shown to reduce the risk for major cardiovascular events in type 2 diabetes. Niacin and omega 3 fatty acids have a positive effect on diabetic dyslipidemia, but warrants clinical trials to demonstrate a clear cardiovascular benefit in type 2 diabetes.

EXPERT OPINION

Although combination lipid therapy seems to be useful to control diabetic dyslipidemia, the efficacy of such combined therapies on significantly reducing cardiovascular risk has still to be confirmed by additional clinical trials.

Diabetes mellitus: new drugs for a new epidemic

The prevalence of diabetes mellitus (DM) is increasing rapidly in the 21st century as a result of obesity, an ageing population, lack of exercise, and increased migration of susceptible patients. This costly and chronic disease has been likened recently to the 'Black Death' of the 14th century. Type 2 DM is the more common form and the primary aim of management is to delay the micro- and macrovascular complications by achieving good glycaemic control. This involves changes in lifestyle, such as weight loss and exercise, and drug therapy. Increased knowledge of the pathophysiology of diabetes has contributed to the development of novel treatments: glucagon-like peptide-1 (GLP-1) mimetics, dipeptidyl peptidase-4 (DPP-4) inhibitors, thiazolidinediones (TZDs), and insulin analogues. GLP-1 agonists mimic the effect of this incretin, whereas DPP-4 inhibitors prevent the inactivation of the endogenously released hormone. Both agents offer an effective alternative to the currently available hypoglycaemic drugs but further evaluation is needed to confirm their safety and clinical role. The past decade has seen the rise and fall in the use of the TZDs (glitazones), such that the only glitazone recommended is pioglitazone as a third-line treatment. The association between the use of rosiglitazone and adverse cardiac outcomes is still disputed by some authorities. The advent of new insulin analogues, fast-acting, and basal release formulations, has enabled the adoption of a basal-bolus regimen for the management of blood glucose. This regimen aims to provide a continuous, low basal insulin release between meals with bolus fast-acting insulin to limit hyperglycaemia after meals. Insulin therapy is increasingly used in type 2 DM to enhance glycaemic control. Recently, it has been suggested that the use of the basal-release insulins, particularly insulin glargine may be associated with an increased risk of cancer. Although attention is focused increasingly on newer agents in the treatment of diabetes, metformin and the sulphonylureas are still used in many patients. Metformin, in particular, remains of great value and may have novel anti-cancer properties.

Comparative effectiveness and safety of medications for type 2 diabetes: an update including new drugs and 2-drug combinations

BACKGROUND

Given the increase in medications for type 2 diabetes mellitus, clinicians and patients need information about their effectiveness and safety to make informed choices.

PURPOSE

To summarize the benefits and harms of metformin, second-generation sulfonylureas, thiazolidinediones, meglitinides, dipeptidyl peptidase-4 (DPP-4) inhibitors, and glucagon-like peptide-1 receptor agonists, as monotherapy and in combination, to treat adults with type 2 diabetes.

DATA SOURCES

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched from inception through April 2010 for English-language observational studies and trials. The MEDLINE search was updated to December 2010 for long-term clinical outcomes.

STUDY SELECTION

Two reviewers independently screened reports and identified 140 trials and 26 observational studies of head-to-head comparisons of monotherapy or combination therapy that reported intermediate or long-term clinical outcomes or harms.

DATA EXTRACTION

Two reviewers following standardized protocols serially extracted data, assessed applicability, and independently evaluated study quality.

DATA SYNTHESIS

Evidence on long-term clinical outcomes (all-cause mortality, cardiovascular disease, nephropathy, and neuropathy) was of low strength or insufficient. Most medications decreased the hemoglobin A(1c) level by about 1 percentage point and most 2-drug combinations produced similar reductions. Metformin was more efficacious than the DPP-4 inhibitors, and compared with thiazolidinediones or sulfonylureas, the mean differences in body weight were about -2.5 kg. Metformin decreased low-density lipoprotein cholesterol levels compared with pioglitazone, sulfonylureas, and DPP-4 inhibitors. Sulfonylureas had a 4-fold higher risk for mild or moderate hypoglycemia than metformin alone and, in combination with metformin, had more than a 5-fold increased risk compared with metformin plus thiazolidinediones. Thiazolidinediones increased risk for congestive heart failure compared with sulfonylureas and increased risk for bone fractures compared with metformin. Diarrhea occurred more often with metformin than with thiazolidinediones.

LIMITATIONS

Only English-language publications were reviewed. Some studies may have selectively reported outcomes. Many studies were small, were of short duration, and had limited ability to assess clinically important harms and benefits.

CONCLUSION

Evidence supports metformin as a first-line agent to treat type 2 diabetes. Most 2-drug combinations similarly reduce hemoglobin A(1c) levels, but some increased risk for hypoglycemia and other adverse events.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Second-line therapy in patients with type 2 diabetes inadequately controlled with metformin monotherapy: a systematic review and mixed-treatment comparison meta-analysis

BACKGROUND

Although there is general agreement that metformin should be used as first-line pharmacotherapy in patients with type 2 diabetes, uncertainty remains regarding the choice of second-line therapy once metformin is no longer effective. We conducted a systematic review and meta-analysis to assess the comparative safety and efficacy of all available classes of antihyperglycemic therapies in patients with type 2 diabetes inadequately controlled on metformin monotherapy.

METHODS

MEDLINE, EMBASE, BIOSIS Previews, PubMed and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials published in English from 1980 to October 2009. Additional citations were obtained from grey literature and conference proceedings and through stakeholder feedback. Two reviewers independently selected studies, extracted data and assessed risk of bias. Key outcomes of interest were hemoglobin A1c, body weight, hypoglycemia, quality of life, long-term diabetes-related complications, serious adverse drug events and mortality. Mixed-treatment comparison and pairwise meta-analyses were conducted to pool trial results, when appropriate.

RESULTS

We identified 49 active and non-active controlled randomized trials that compared 2 or more of the following classes of antihyperglycemic agents and weight-loss agents: sulfonylureas, meglitinides, thiazolidinediones (TZDs), dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) analogues, insulins, alpha-glucosidase inhibitors, sibutramine and orlistat. All classes of second-line antihyperglycemic therapies achieved clinically meaningful reductions in hemoglobin A1c (0.6% to 1.0%). No significant differences were found between classes. Insulins and insulin secretagogues were associated with significantly more events of overall hypoglycemia than the other agents, but severe hypoglycemia was rarely observed. An increase in body weight was observed with the majority of second-line therapies (1.8 to 3.0 kg), the exceptions being DPP-4 inhibitors, alpha-glucosidase inhibitors and GLP-1 analogues (0.6 to -1.8 kg). There were insufficient data available for diabetes complications, mortality or quality of life.

INTERPRETATION

DPP-4 inhibitors and GLP-1 analogues achieved improvements in glycemic control similar to those of other second-line therapies, although they may have modest benefits in terms of weight gain and overall hypoglycemia. Further long-term trials of adequate power are required to determine whether newer drug classes differ from older agents in terms of clinically meaningful outcomes.

Thiazolidinediones plus metformin association on body weight in patients with type 2 diabetes

There are different studies about the efficacy and safety and tolerability of thiazolidinediones added to metformin. The reported improved glycemic control with thiazolidinediones use seems to be associated with an increase in weight with an estimated 2-3 kg weight gain suggesting that maybe thiazolidinediones are not safe for the clinical use. Other authors reported that thiazolidinediones give an improvement in the glycemic without giving weight gain. With our review, we want to evaluate the effects of thiazolidinediones plus metformin combination in diabetic patients on the body weight. From the data emerged from our review we can conclude that even if a small increase in mean body weight was observed in patients treated with thiazolidinediones plus metformin therapy, the weight gain was less than previously reported and it was also considerably less than what might have been expected given the large improvements in glycemic control. For these reasons we can safely say that thiazolidinediones in combination with metformin are effective and well tolerated in patients with type 2 diabetes.

Fructose-1, 6-bisphosphatase inhibitors for reducing excessive endogenous glucose production in type 2 diabetes

Fructose-1,6-bisphosphatase (FBPase), a rate-controlling enzyme of gluconeogenesis, has emerged as an important target for the treatment of type 2 diabetes due to the well-recognized role of excessive endogenous glucose production (EGP) in the hyperglycemia characteristic of the disease. Inhibitors of FBPase are expected to fulfill an unmet medical need because the majority of current antidiabetic medications act primarily on insulin resistance or insulin insufficiency and do not reduce gluconeogenesis effectively or in a direct manner. Despite significant challenges, potent and selective inhibitors of FBPase targeting the allosteric site of the enzyme were identified by means of a structure-guided design strategy that used the natural inhibitor, adenosine monophosphate (AMP), as the starting point. Oral delivery of these anionic FBPase inhibitors was enabled by a novel diamide prodrug class. Treatment of diabetic rodents with CS-917, the best characterized of these prodrugs, resulted in a reduced rate of gluconeogenesis and EGP. Of note, inhibition of gluconeogenesis by CS-917 led to the amelioration of both fasting and postprandial hyperglycemia without weight gain, incidence of hypoglycemia, or major perturbation of lactate or lipid homeostasis. Furthermore, the combination of CS-917 with representatives of the insulin sensitizer or insulin secretagogue drug classes provided enhanced glycemic control. Subsequent clinical evaluations of CS-917 revealed a favorable safety profile as well as clinically meaningful reductions in fasting glucose levels in patients with T2DM. Future trials of MB07803, a second generation FBPase inhibitor with improved pharmacokinetics, will address whether this novel class of antidiabetic agents can provide safe and long-term glycemic control.

Updated review: improved glycemic control with repaglinide-metformin in fixed combination for patients with type 2 diabetes

As the prevalence of type 2 diabetes continues to rise, new drug therapies will need to be explored to prevent morbidity and mortality associated with diabetes as well as growing health care costs. Type 2 diabetes is characterized by decreased insulin secretion and sensitivity. Numerous oral medications are currently approved for the treatment of type 2 diabetes. A treat-to-failure approach has traditionally been adopted with step-wise additions of oral medications; however, a growing frequency of treatment failures with monotherapy has led to the use of combination therapies earlier in the treatment of type 2 diabetes. One such combination regimen is repaglinide (a prandial glucose optimizer that increases insulin release) plus metformin (an insulin sensitizer that inhibits hepatic glucose output and increases peripheral glucose uptake while minimizing weight gain). Findings from several clinical trials have shown repaglinide plus metformin combination therapy to be superior to either monotherapy with significant reductions in hemoglobin A1C and fasting glucose values. Repaglinide used in combination also has shown less incidence of hypoglycemia compared with other combination therapies such as sulphonylureas plus metformin. Repaglinide plus metformin combination therapy appears to be a valuable therapeutic option for type 2 diabetic patients seeking a less complex drug regimen while potentially achieving better glucose control if currently inadequately controlled on monotherapy.

Glucagon-like peptide analogues for type 2 diabetes mellitus: systematic review and meta-analysis

BACKGROUND

Glucagon-like peptide (GLP-1) analogues are a new class of drugs used in the treatment of type 2 diabetes. They are given by injection, and regulate glucose levels by stimulating glucose-dependent insulin secretion and biosynthesis, suppressing glucagon secretion, and delaying gastric emptying and promoting satiety. This systematic review aims to provide evidence on the clinical effectiveness of the GLP-1 agonists in patients not achieving satisfactory glycaemic control with one or more oral glucose lowering drugs.

METHODS

MEDLINE, EMBASE, the Cochrane Library and Web of Science were searched to find the relevant papers. We identified 28 randomised controlled trials comparing GLP-1 analogues with placebo, other glucose-lowering agents, or another GLP-1 analogue, in patients with type 2 diabetes with inadequate control on a single oral agent, or on dual therapy. Primary outcomes included HbA1c, weight change and adverse events.

RESULTS

Studies were mostly of short duration, usually 26 weeks. All GLP-1 agonists reduced HbA1c by about 1% compared to placebo. Exenatide twice daily and insulin gave similar reductions in HbA1c, but exenatide 2 mg once weekly and liraglutide 1.8 mg daily reduced it by 0.20% and 0.30% respectively more than glargine. Liraglutide 1.2 mg daily reduced HbA1c by 0.34% more than sitagliptin 100 mg daily. Exenatide and liraglutide gave similar improvements in HbA1c to sulphonylureas. Exenatide 2 mg weekly and liraglutide 1.8 mg daily reduced HbA1c by more than exenatide 10 μg twice daily and sitagliptin 100 mg daily. Exenatide 2 mg weekly reduced HbA1c by 0.3% more than pioglitazone 45 mg daily.Exenatide and liraglutide resulted in greater weight loss (from 2.3 to 5.5 kg) than active comparators. This was not due simply to nausea. Hypoglycaemia was uncommon, except when combined with a sulphonylurea. The commonest adverse events with all GLP-1 agonists were initial nausea and vomiting. The GLP-1 agonists have some effect on beta-cell function, but this is not sustained after the drug is stopped.

CONCLUSIONS

GLP-1 agonists are effective in improving glycaemic control and promoting weight loss.

A systems biology approach to identify effective cocktail drugs

BACKGROUND

Complex diseases, such as Type 2 Diabetes, are generally caused by multiple factors, which hamper effective drug discovery. To combat these diseases, combination regimens or combination drugs provide an alternative way, and are becoming the standard of treatment for complex diseases. However, most of existing combination drugs are developed based on clinical experience or test-and-trial strategy, which are not only time consuming but also expensive.

RESULTS

In this paper, we presented a novel network-based systems biology approach to identify effective drug combinations by exploiting high throughput data. We assumed that a subnetwork or pathway will be affected in the networked cellular system after a drug is administrated. Therefore, the affected subnetwork can be used to assess the drug's overall effect, and thereby help to identify effective drug combinations by comparing the subnetworks affected by individual drugs with that by the combination drug. In this work, we first constructed a molecular interaction network by integrating protein interactions, protein-DNA interactions, and signaling pathways. A new model was then developed to detect subnetworks affected by drugs. Furthermore, we proposed a new score to evaluate the overall effect of one drug by taking into account both efficacy and side-effects. As a pilot study we applied the proposed method to identify effective combinations of drugs used to treat Type 2 Diabetes. Our method detected the combination of Metformin and Rosiglitazone, which is actually Avandamet, a drug that has been successfully used to treat Type 2 Diabetes.

CONCLUSIONS

The results on real biological data demonstrate the effectiveness and efficiency of the proposed method, which can not only detect effective cocktail combination of drugs in an accurate manner but also significantly reduce expensive and tedious trial-and-error experiments.

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

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

A model for glucose, insulin, and beta-cell dynamics in subjects with insulin resistance and patients with type 2 diabetes

Type 2 diabetes mellitus (T2DM) is a progressive, metabolic disorder characterized by reduced insulin sensitivity and loss of beta-cell mass (BCM), resulting in hyperglycemia. Population pharmacokinetic-pharmacodynamic (PKPD) modeling is a valuable method to gain insight into disease and drug action. A semi-mechanistic PKPD model incorporating fasting plasma glucose (FPG), fasting insulin, insulin sensitivity, and BCM in patients at various disease stages was developed. Data from 3 clinical trials (phase II/III) with a peroxisome proliferator-activated receptor agonist, tesaglitazar, were used to develop the model. In this, a modeling framework proposed by Topp et al was expanded to incorporate the effects of treatment and impact of disease, as well as variability between subjects. The model accurately described FPG and fasting insulin data over time. The model included a strong relation between insulin clearance and insulin sensitivity, predicted 40% to 60% lower BCM in T2DM patients, and realistic improvements of BCM and insulin sensitivity with treatment. The treatment response on insulin sensitivity occurs within the first weeks, whereas the positive effects on BCM arise over several months. The semi-mechanistic PKPD model well described the heterogeneous populations, ranging from nondiabetic, insulin-resistant subjects to long-term treated T2DM patients. This model also allows incorporation of clinical-experimental studies and actual observations of BCM.

Comparative evaluation of incretin-based antidiabetic medications and alternative therapies to be added to metformin in the case of monotherapy failure

Aims/Introduction:  To compare clinical consequences of using inretin-based medications versus conventional antidiabetic agents as add-on to metformin in case of monotherapy failure in patients with type 2 diabetes.

MATERIALS AND METHODS

  The medical literature including recent abstracts from international diabetes conferences was searched for reports from clinical trials with incretin mimetics (GLP-1 receptor agonists), inhibitors of dipeptidyl peptidase-4 (DPP-4, incretin enhancers) and conventional antidiabtic drugs coadministered with metformin after monotherapy failure. A scoring system is suggested to compare the clinical utility of using incretin-based versus conventional antidiabetic agents in this situation.

RESULTS

  Incretin mimetics and DPP-4 inhibitors on top of metformin treatment help achieve glycaemic control comparable to other efficient antidiabetic drugs, both if separate or head-to-head trials were considered. Incretin-based antidiabetic drugs did not cause hypoglycaemia (different from sulfonylureas, meglitinides and insulin) and weight gain (different from sulfonylureas, meglitinides, thiazolidinediones, and insulin). DPP-4 inhibitors were weight neutral, incretin mimetics lead to weight loss. The clinical profile of incretin-based medications received the highest scores, followed by α-glucosidase inhibitors, with far lower scores assigned to insulin, glitazones, and sulfonyureas (in this order).

CONCLUSIONS

  Based on the results from clinical trials, incretin-based medications have been shown to be efficacious antidiabetic drugs with a favourable adverse event and tolerability profile. This leads to high scores using a novel system paying attention to multiple facets contributing to the selection of antidiabetic drugs for general recommendation and individual treatment choices.

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.

Treatment of type 2 diabetes mellitus with orally administered agents: advances in combination therapy

OBJECTIVE

To discuss the effects and clinical benefit provided by combining various orally administered antidiabetic drugs (OADs) for the treatment of type 2 diabetes and to examine the advantages of single-tablet combinations with respect to targeting hyperglycemia and adherence.

METHODS

A review of randomized controlled trials that studied OAD combinations for the treatment of type 2 diabetes was conducted by using search terms in PubMed.

RESULTS

Reported data have documented that OAD combination therapies have additional benefits over monotherapy in terms of glycemic efficacy. Results from randomized controlled trials on a range of OAD combinations have demonstrated differences in safety and efficacy. The use of single-tablet OAD combinations has been shown to improve adherence in patients.

CONCLUSION

The development of single-tablet OAD combinations that can address all aspects of glycemia with a favorable tolerability profile has the potential to help patients manage their glycemic control more effectively and to minimize the risk of long-term diabetes-related complications. In addition, single-tablet combinations of agents offer improved convenience for patients as well as potential cost benefits. Thus, they represent an important treatment option for type 2 diabetes.

Long-term efficacy of rosiglitazone in nonalcoholic steatohepatitis: results of the fatty liver improvement by rosiglitazone therapy (FLIRT 2) extension trial

Short-term trials of glitazones in nonalcoholic steatohepatitis (NASH) yielded controversial histological results. Longer treatment might result in additional improvement. After a 1-year randomized trial, 53 patients underwent a control liver biopsy and were enrolled in an open-label extension trial of rosiglitazone (RSG), 8 mg/day for 2 additional years. In all, 44 completed the extension phase including 40 with a third liver biopsy. Of these, 22 received placebo (PLB) in the randomized phase (PLB-RSG), and 18 RSG (RSG-RSG). During the 2-year extension phase serum insulin decreased by 26%, homeostasis model assessment (HOMA) by 30%, and alanine aminotransferase (ALT) by 24%. However, there was no significant change in the mean NASH activity score (NAS) (3.8 +/- 2.11 versus 3.68 +/- 1.8), ballooning score, fibrosis stage (1.76 +/- 1.18 versus 1.85 +/- 1.19), or area of fibrosis by micromorphometry (4.43% +/- 0.68 to 5.54% +/- 0.68). In the PLB-RSG group steatosis significantly decreased after 2 years of RSG (median decrease of 15%); in the RSG-RSG group, after an initial decline in the first year of 20%, 2 additional years of RSG did not result in further improvement. Likewise, there was no improvement in the NAS score, ballooning, intralobular inflammation, fibrosis stage, or area of fibrosis with 2 additional years of RSG in the RSG-RSG group.

CONCLUSION

Rosiglitazone has a substantial antisteatogenic effect in the first year of treatment without additional benefit with longer therapy despite a maintained effect on insulin sensitivity and transaminase levels. This suggests that improving insulin sensitivity might not be sufficient in NASH and that additional targets of therapy for liver injury should be explored.

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 pioglitazone and rosiglitazone combined with metformin on body weight in people with diabetes

Currently, pioglitazone and rosiglitazone are the thiazolidinediones available for clinical use. In the literature, there are different studies concerning the efficacy, safety and tolerability of thiazolidinediones as add-on therapy to metformin in patients with type 2 diabetes inadequately controlled with metformin alone. Metformin and thiazolidinediones are both antihyperglycaemic drugs, both lower blood glucose concentrations in type 2 diabetes without causing overt hypoglycaemia and both require the presence of insulin to generate their therapeutic effects, but act without stimulating insulin secretion. Some authors reported that the improved glycaemic control obtained with thiazolidinediones is associated with an increase in body weight with an estimated 2-3 kg weight gain for every 1% decrease in HbA(1c) which could negate some of the benefits of the improved metabolic control. Some other authors, instead, reported that thiazolidinediones give a better improvement in the glycaemic control compared with metformin alone without giving weight gain. The emerging discrepancies from these studies could be because of the study design, the patient selection, the degree of glycaemic control and/or the methods to measure body weight. We have undertaken a thorough literature search on Medline and Embase to evaluate the effects of thiazolidinediones plus metformin combination in people with diabetes on the body weight.

The European Exenatide study of long-term exenatide vs. glimepiride for type 2 diabetes: rationale and patient characteristics

AIM

To describe the rationale for the European Exenatide (EUREXA) clinical study and describe the characteristics of the patient cohort.

METHODS

EUREXA is a multinational study of long-term effects of add-on exenatide vs. glimepiride in patients with type 2 diabetes and failure of diet/lifestyle plus metformin monotherapy. Metformin failure was defined as hemoglobin A1c (HbA1c) > or = 6.5% and patients were overweight/obese (BMI > or = 25 to < 40 kg/m(2)). The primary end point is time to failure of combination treatment, defined from HbA1c concentration according to current criteria. At baseline, an oral glucose tolerance test (OGTT) was performed, fasting blood was taken for lipid profile and patients were randomized to add-on exenatide (5 microg b.i.d. for 4 weeks then 10 microg b.i.d.) or glimepiride (1 mg/day titrated to maximum dose).

RESULTS

A total of 1039 patients were entered in the study, with mean (+/- s.d.) age 57.2 +/- 9.6 years, body mass index (BMI) 32.4 +/- 4.1 kg/m(2), duration of diabetes 5.6 +/- 4.5 years and HbA1c 7.4 +/- 0.7%. A history of cardiovascular disease (CVD) was present for 64.8% of patients overall and duration of diabetes was statistically significantly longer for patients with CVD than without (p = 0.010). Lipid abnormalities were reported for 48.9% of patients and 40.9% were taking at least one lipid-lowering medication.

CONCLUSION

Patients included in the EUREXA study had early failure of glucose control with metformin and presented typical features of type 2 diabetes: overweight/obesity and high prevalence of lipid abnormalities and CVD. In this population, the effects of exenatide vs. glimepiride will be evaluated over at least 2.5 years.

Self-monitoring of blood glucose in diabetes mellitus: arguments for an individualized approach

BACKGROUND

The utility of glucose self-monitoring in different types and stages of diabetes is controversial, as there is only sparse relevant evidence from randomized controlled clinical trials. In this analysis, the authors aim to develop individualized recommendations based on clinical needs and the available literature.

METHODS

The PubMed database was searched for articles that appeared up to 30 September 2008 containing the terms "measurement," "control","monitoring," and "hypoglycemia"; the retrieved articles were supplemented by other articles that were cited in them. A directed search was also made for the recommendations of the German, European, American, and international diabetological societies. Conclusions were then drawn about the useful modalities and extent of glucose self-monitoring on the basis of the clinical features of the major types of diabetes and the main treatment strategies for them.

RESULTS

With the exception of intensified treatment strategies (which rely on blood-sugar regulation with insulin), only a few evidence-based recommendations can be derived from randomized clinical trials and meta-analyses. Nonetheless, a strategy for self-monitoring according to the patient's individual needs can be derived from the characteristics of therapeutic regimens: depending on the type of diabetes from which the patient suffers, the predicted number of glucometer strips required for self-monitoring will vary from almost none to roughly 400 per month.

CONCLUSIONS

The decision to use glucose self-monitoring, as well as the type and extent of self-monitoring that will be used, should be based on the individual patient's type of diabetes, treatment regimen, and clinical characteristics. Like any other type of therapeutic intervention, self-monitoring should have a well-documented, rational justification.

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.

Diabetes medications and body weight

Tight diabetes control sometimes comes with a price: weight gain and hypoglycemia. Two of the three major recent trials that looked at the relationship between intensive diabetes control and cardiovascular events reported significant weight gain among the intensively treated groups. There is a growing concern that the weight gain induced by most diabetes medications diminishes their clinical benefits. On the other hand, there is a claim that treating diabetes with medications that are weight neutral or induces weight loss or less weight gain while minimizing those that increase body weight may emerge as the future direction for treating overweight and obese patients with diabetes. This review clarifies the weight effect of each of the currently available diabetes medications, and explains the mechanism of action behind this effect. Despite the great variability among reviewed clinical trials, the currently available evidence is quite sufficient to demonstrate the change in body weight in association with most of the currently available medications. This review also provides some guidelines on using diabetes medications during weight management programs.

Safety and efficacy of rosiglitazone in the elderly diabetic patient

Diabetes is an important health condition for the aging population; at least 20% of patients over the age of 65 years have diabetes, and this number can be expected to grow rapidly in the coming decades. Rosiglitazone, a drug in the thiazolidinedione class which targets insulin resistance, was approved by drug regulatory bodies based on its ability to improve glycemic control nearly ten years ago. The greatest long-term risk in diabetes is cardiovascular disease with macrovascular disease being the cause of as much as 80% of mortality. More recently the cardiovascular safety of rosiglitazone was brought to center stage following several meta-analyses and the unplanned interim analysis of the RECORD trial. As opposed to pioglitazone, current evidence points to rosiglitazone having a greater risk of myocardial ischemic events than placebo, metformin, or sulfonylureas. A thiazolidinedione class effect however seems apparent with respect to the increased risk for fractures and congestive heart failure. Clinical trial evidence on rosiglitazone therapy in the elderly is limited. The available evidence is mainly related to observational cohort studies. Most of the trial evidence relates to a younger population and therefore these data can not be directly extrapolated to an older population. The effects of the thiazolidinedione drug class remain incompletely understood.

Competact, a fixed combination of pioglitazone and metformin, improves metabolic markers in type 2 diabetes patients with insufficient glycemic control by metformin alone--results from a post-marketing surveillance trial under daily routine conditions

BACKGROUND

In patients with type 2 diabetes, glycemic control to target goals can only be achieved for a while by single-drug treatment. Antidiabetes therapy has to be adapted according to the individual course of the disease. This trial investigates the impact of Competact (Takeda Pharma, Aachen, Germany) (marketed as ActoplusMet in the United States)-a fixed combination of 850 mg of metformin with 15 mg of pioglitazone-for diabetes treatment in patients with insufficient glycemic control by metformin alone.

STUDY DESIGN

This observational drug monitoring trial was performed at 1,480 study sites in Germany, and 4,866 complete patient data sets were included into the final analyses. Mean +/- SD age was 60.8 +/- 9.6 years (2,171 women, 2,691 men; disease duration, 6.7 +/- 4.7 years; body mass index [BMI], 31.0 +/- 5.2 kg/m(2)). In total, 43.8% of the patients received lipid-lowering drugs (antihypertensive medication, 74.3%). Main inclusion criteria were type 2 diabetes, metformin monotherapy, and an initial hemoglobin A1c (HbA1c) value between 6.6% and 9.9%. Parameters of glycemic control (HbA1c, fasting blood glucose [FBG]), blood pressure (BP), inflammation (high-sensitivity C-reactive protein [hsCRP]), and lipid metabolism (total cholesterol, high-density lipoprotein [HDL]-cholesterol, non-HDL-cholesterol, and triglycerides) were collected at baseline and after 4 months.

RESULTS

All investigated parameters improved significantly (all P < 0.001) after 4 months of therapy with Competact (baseline vs. end point: systolic BP, 139.7 +/- 15.1 vs. 134.4 +/- 12.0 mm Hg; diastolic BP, 83.1 +/- 8.9 vs. 80.5 +/- 7.5 mm Hg; HbA1c, 7.8 +/- 1.0% vs. 7.0 +/- 0.8%; FBG, 9.0 +/- 2.6 vs. 7.0 +/- 1.7 mM; cholesterol, 5.7 +/- 1.1 mM vs. 5.3 +/- 0.9 mM; HDL-cholesterol, 1.2 +/- 0.4 mM vs. 1.3 +/- 0.4 mM; non-HDL-cholesterol, 4.5 +/- 1.2 mM vs. 4.0 +/- 0.9 mM; triglycerides, 2.5 +/- 1.0 mM vs. 2.1 +/- 0.8 mM; hsCRP, 3.2 +/- 2.6 mg/L vs. 2.7 +/- 2.3 mg/L). It is noteworthy that the BMI was not affected by Competact (31.0 +/- 5.2 kg/m(2) vs. 31.1 +/- 6.1 kg/m(2), P = 0.221).

CONCLUSIONS

These observational results, obtained from a non-selected patient population under daily routine conditions, show the beneficial effects of a pioglitazone/metformin combination for diabetes patients with insufficient glycemic control under daily routine conditions.

The backbone of oral glucose-lowering therapy: time for a paradigm shift?

The complex array of metabolic abnormalities associated with type 2 diabetes provides a number of new targets for therapeutic intervention. Although the established oral glucose-lowering therapies, metformin and the sulfonylureas, continue to provide the backbone of therapeutic approaches, the thiazolidinediones (TZDs) also play an important role. Further, a new class of oral agents, the dipeptidyl peptidase-IV (DPP-IV) inhibitors, has recently become available with apparent utility in decreasing postprandial glucose excursions. This review examines how the TZDs and the DPP-IV inhibitors might integrate into current treatment strategies, considering not only glycemic goals, but also longer-term benefits such as durability of glycemic control, effect on metabolic parameters and cardiovascular outcomes. A practical approach is taken, reflecting potential clinical situations in which therapeutic intervention is required.

Effects of rosiglitazone and pioglitazone on lipoprotein metabolism in patients with Type 2 diabetes and normal lipids

AIMS

Previous studies have suggested that plasma lipids are affected differently by the peroxisome proliferators-activated receptor (PPAR)-gamma agonists pioglitazone and rosiglitazone. The aim of this study was to perform a quantitative lipoprotein turnover study to determine the effects of PPAR-gamma agonists on lipoprotein metabolism.

METHODS

Twenty-four subjects with Type 2 diabetes treated with diet and/or metformin were randomized in a double-blind study to receive 30 mg pioglitazone, 8 mg rosiglitazone or placebo once daily for 3 months. Before and after treatment, absolute secretion rate (ASR) and fractional catabolic rate (FCR) of very low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) apolipoprotein B100 were measured with a 10-h infusion of 1-13C leucine.

RESULTS

There was a significant decrease in glycated haemoglobin (HbA(1c)) and non-esterified fatty acids with pioglitazone (P = 0.01; P = 0.02) and rosiglitazone (P = 0.04; P = 0.003), respectively, but no change in plasma triglyceride or high-density lipoprotein (HDL) cholesterol. Following rosiglitazone, there was a significant reduction in VLDL apolipoprotein B100 (apoB) ASR (P = 0.01) compared with baseline, a decrease in VLDL triglyceride/apoB (P = 0.01), an increase in LDL2 cholesterol (P = 0.02) and a decrease in LDL3 cholesterol (P = 0.02). There was a decrease in VLDL triglyceride/apoB (P = 0.04) in the pioglitazone group. There was no significant difference in change in VLDL ASR or FCR among the three groups.

CONCLUSIONS

In patients with Type 2 diabetes and normal lipids, treatment with rosiglitazone or pioglitazone had no significant effect on lipoprotein metabolism compared with placebo.