Blood Pressure Control and Inflammatory Markers in Type 2 Diabetic Patients Treated with Pioglitazone or Rosiglitazone and Metformin

Rethinking pioglitazone as a cardioprotective agent: a new perspective on an overlooked drug

Since 1985, the thiazolidinedione pioglitazone has been widely used as an insulin sensitizer drug for type 2 diabetes mellitus (T2DM). Although fluid retention was early recognized as a safety concern, data from clinical trials have not provided conclusive evidence for a benefit or a harm on cardiac function, leaving the question unanswered. We reviewed the available evidence encompassing both in vitro and in vivo studies in tissues, isolated organs, animals and humans, including the evidence generated by major clinical trials. Despite the increased risk of hospitalization for heart failure due to fluid retention, pioglitazone is consistently associated with reduced risk of myocardial infarction and ischemic stroke both in primary and secondary prevention, without any proven direct harm on the myocardium. Moreover, it reduces atherosclerosis progression, in-stent restenosis after coronary stent implantation, progression rate from persistent to permanent atrial fibrillation, and reablation rate in diabetic patients with paroxysmal atrial fibrillation after catheter ablation. In fact, human and animal studies consistently report direct beneficial effects on cardiomyocytes electrophysiology, energetic metabolism, ischemia–reperfusion injury, cardiac remodeling, neurohormonal activation, pulmonary circulation and biventricular systo-diastolic functions. The mechanisms involved may rely either on anti-remodeling properties (endothelium protective, inflammation-modulating, anti-proliferative and anti-fibrotic properties) and/or on metabolic (adipose tissue metabolism, increased HDL cholesterol) and neurohormonal (renin–angiotensin–aldosterone system, sympathetic nervous system, and adiponectin) modulation of the cardiovascular system. With appropriate prescription and titration, pioglitazone remains a useful tool in the arsenal of the clinical diabetologist.

Assessing the need for pioglitazone in the treatment of patients with type 2 diabetes: a meta-analysis of its risks and benefits from prospective trials

The safety and usefulness of pioglitazone (Pio) is repeatedly called into question due to the contradictory information available about it. A meta-analysis and risk benefit assessment was conducted to address the various points of debate regarding Pio. Electronic database search (Cochrane library, Embase & PubMed) resulted in 10 citations eligible for this meta-analysis (prospective, randomised studies), which was conducted using CMA software version 3 (Biostat Inc., Englewood, NJ, USA). The meta-analysis was registered with PROSPERO (ID: CRD42019122403) and compared pioglitazone with a control (anti-hyperglycemic agents without pioglitazone) in patients with either established cardiovascular disease or having high cardiovascular risk. Sensitivity and subgroup analysis were conducted to differentiate the effect of Pio against active controls and placebo. The use of Pio compared to the control group that did not use Pio resulted in a 14% and 23% significant reduction in odds of major adverse cardiac events (MACE: MH-OR, 0.86; 95% CI 0.75–0.98), and stroke (MH-OR, 0.77; 95% CI 0.60–0.99), respectively. This reduction in stroke was not significant in comparison to placebo on subgroup analysis. However, Pio significantly increased odds of heart failure (HF) (MH-OR, 1.47; 95% CI 1.26–1.71) as well as hospitalization for heart failure (hHF) (MH-OR, 1.48; 95% CI 1.21–1.81). In addition, the use of Pio was associated with a significant increase in odds of fractures in women (MH-OR, 2.05; 95% CI 1.28–3.27) and anaemia (MH-OR, 2.56; 95% CI 1.55–4.21). Pio has no significant effect on bladder cancer nor macular oedema. Pio has salutary effects on MACE. The positive effects are completely offset by the harm they seem to cause by way of heart failure, fractures, and anaemia. Pio should therefore be reserved for treatment of T2D with high CV risk or established cardiovascular (CV) disease only in selected patients where other antidiabetics are precluded and not routinely.

Transcriptomic landscape profiling of metformin-treated healthy mice: Implication for potential hypertension risk when prophylactically used

Recently, the first-line anti-diabetic drug metformin shows versatile protective effects against several diseases and is potentially prescribed to healthy individual for prophylactic use against ageing or other pathophysiological processes. However, for healthy individuals, it remains unclear what effects metformin treatment will induce on their bodies. A systematic profiling of the molecular landscape of metformin treatment is expected to provide crucial implications for this issue. Here, we delineated the first transcriptomic landscape induced by metformin in 10 tissues (aorta, brown adipose, brain, eye, heart, liver, kidney, skeletal muscle, stomach and testis) of healthy mice by using RNA-sequencing technique. A comprehensive computational analysis was performed. The overrepresentation of cardiovascular disease-related gene sets, positive correlation with hypertension-related transcriptomic signatures and the associations of drugs with hypertensive side effect together indicate that although metformin does exert various beneficial effects, it would also increase the risk of hypertension in healthy mice. This prediction was experimentally validated by an independent animal experiments. Together, this study provided important resource necessary for investigating metformin's beneficial/deleterious effects on various healthy tissues, when it is potentially prescribed to healthy individual for prophylactic use.

The influence of anti-hyperglycemic drug therapy on cardiovascular and heart failure outcomes in patients with type 2 diabetes mellitus

Patients with type 2 diabetes mellitus (DM) are at a substantially increased risk of heart failure (HF) and HF mortality. Despite the lack of evidence that tight glycemic control reduces the incidence of cardiovascular (CV) events, a growing body of evidence suggests that the choice of glucose-lowering agents may influence outcomes including HF. Thiazolidinediones are associated with a significant risk of HF. For metformin, sulphonylureas and insulin, little data is available to indicate the impact on HF. The glucagon-like peptide-1 (GLP-1) agonists, liraglutide and semaglutide, have been shown to reduce major CV events, but did not affect rates of hospitalization for HF. Clinical trials have demonstrated diverse effects of Dipeptidyl peptidase-4 (DPP-4) inhibitors on HF; saxagliptin showed an increased risk of HF admissions, alogliptin was associated with higher rates of new HF admissions, while sitagliptin had a neutral effect. The sodium-glucose cotransporter 2 (SGLT2) inhibitors, empagliflozin and canagliflozin, have been recently shown to reduce the incidence of HF and cardiovascular mortality in patients with and without a history of HF. This review will summarize key findings of the impact of glucose-lowering agents on CV safety and HF-associated outcomes, present available data on the underlying mechanisms for the benefits of the SGLT2 inhibitors on HF, and discuss strategies to improve outcomes in patients with DM and high CV risk.

Rosiglitazone lowers resting and blood pressure response to exercise in men with type 2 diabetes: A 1-year randomized study

AIMS

We aimed to determine the effect of 1-year treatment with the insulin sensitizer peroxisome proliferator-activated receptor (PPAR)-γ agonist rosiglitazone on exercise capacity and blood pressure (BP) response to exercise in men with coronary artery disease (CAD) and type 2 diabetes (T2D).

MATERIALS AND METHODS

A total of 116 men (age, 64 ± 7 years; body mass index, 30.0 ± 4.4 kg/m² ) with CAD and T2D were randomized to receive rosiglitazone or placebo for 1 year. Exercise capacity (VO_2peak ) and BP response to exercise were assessed with a maximal treadmill test, prior to the intervention and at 1-year follow-up. Exercise-induced hypertension (EIH) was defined as maximal systolic BP ≥ 220 mm Hg and/or diastolic BP ≥ 100 mm Hg.

RESULTS

PPAR-γ agonist-treated patients showed improvements in fasting glucose, HbA1c and insulin sensitivity (Homeostasis model assessment of insulin resistance [HOMA-IR]) (all P < .05). Resting BPs, maximal exercise diastolic BP and resting rate-pressure product (RPP) were all reduced in the PPAR-γ agonist group (P < .05). Maximal exercise duration was unchanged. T2D patients who displayed the greatest improvement in insulin sensitivity (HOMA-IR) under PPAR-γ agonist treatment experienced a greater reduction in exercise BP and RPP (P < .05). The proportion of men with EIH decreased in the PPAR-γ agonist group during follow-up (39.00% ± 0.06% vs 21.00% ± 0.05%). In the subgroup with EIH that was treated with a PPAR-γ agonist, resting and exercise diastolic BP, as well as resting RPP, were all reduced at 1-year follow-up (P < .05).

CONCLUSIONS

The insulin sensitizer rosiglitazone has a beneficial effect on resting and BP response to exercise in men with CAD and T2D, especially in those with an exaggerated BP response to exercise.

Interplay between the renin-angiotensin system, the canonical WNT/β-catenin pathway and PPARγ in hypertension

PURPOSE OF REVIEW

Heterogeneous causes can determinate hypertension.

RECENT FINDINGS

The renin-angiotensin system (RAS) has a major role in the pathophysiology of blood pressure. Angiotensin II and aldosterone are overexpressed during hypertension and lead to hypertension development and its cardiovascular complications. In several tissues, the overactivation of the canonical WNT/β-catenin pathway leads to inactivation of peroxisome proliferator-activated receptor gamma (PPARγ), while PPARγ stimulation induces a decrease of the canonical WNT/β-catenin pathway. In hypertension, the WNT/β-catenin pathway is upregulated, whereas PPARγ is decreased. The WNT/β-catenin pathway and RAS regulate positively each other during hypertension, whereas PPARγ agonists can decrease the expression of both the WNT/β-catenin pathway and RAS. We focus this review on the hypothesis of an opposite interplay between PPARγ and both the canonical WNT/β-catenin pathway and RAS in regulating the molecular mechanism underlying hypertension. The interactions between PPARγ and the canonical WNT/β-catenin pathway through the regulation of the renin-angiotensin system in hypertension may be an interesting way to better understand the actions and the effects of PPARγ agonists as antihypertensive drugs.

Pioglitazone Improves Left Ventricular Diastolic Function in Subjects With Diabetes

OBJECTIVE

To examine the effect of pioglitazone on myocardial insulin sensitivity and left ventricular (LV) function in patients with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Twelve subjects with T2D and 12 with normal glucose tolerance received a euglycemic insulin clamp. Myocardial glucose uptake (MGU) and myocardial perfusion were measured with [18F]fluoro-2-deoxy-d-glucose and [15O]H2O positron emission tomography before and after 24 weeks of pioglitazone treatment. Myocardial function and transmitral early diastolic relation/atrial contraction (E/A) flow ratio were measured with magnetic resonance imaging.

RESULTS

Pioglitazone reduced HbA1c by 0.9%; decreased systolic and diastolic blood pressure by 7 ± 2 and 7 ± 2 mmHg, respectively (P < 0.05); and increased whole-body insulin-stimulated glucose uptake by 71% (3.4 ± 1.3 to 5.8 ± 2.1 mg/kg · min; P < 0.01) in subjects with T2D. Pioglitazone enhanced MGU by 75% (0.24 ± 0.14 to 0.42 ± 0.13 μmol/min · g; P < 0.01) and myocardial perfusion by 16% (0.95 ± 0.16 to 1.10 ± 0.25 mL/min · g; P < 0.05). Measures of diastolic function, E/A ratio (1.04 ± 0.3 to 1.25 ± 0.4) and peak LV filling rate (349 ± 107 to 433 ± 99 mL/min), both increased (P < 0.01). End-systolic volume, end-diastolic volume, peak LV ejection rate, and cardiac output trended to increase (P not significant), whereas the ejection fraction (61 ± 6 to 66 ± 7%) and stroke volume increased significantly (71 ± 20 to 80 ± 20 L/min; both P < 0.05).

CONCLUSIONS

Pioglitazone improves whole-body and myocardial insulin sensitivity, LV diastolic function, and systolic function in T2D. Improved myocardial insulin sensitivity and diastolic function are strongly correlated.

Metformin in combination with rosiglitazone contribute to the increased serum adiponectin levels in people with type 2 diabetes mellitus

To evaluate how metformin plus rosiglitazone affect serum adiponectin levels in people suffering from type 2 diabetes mellitus (T2DM), 240 patients having T2DM were selected in this cohort study. Included subjects were randomly and equally separated into three subsets: i) Group A (rosiglitazone group); ii) group B (metformin group); and iii) group C (rosiglitazone + metformin group). Furthermore, meta-analysis of previous studies was performed by searching the general search engines and bibliographic databases. Compared with before treatment, the serum amount of adiponectin grew considerably in the three groups after treatment, and the levels in the group C was much greater than those of groups A and B (all P<0.05). Corresponding meta-analysis results suggested post-treatment serum adiponectin level to be greater than pretreatment level in T2DM patients (P<0.001). Further subgroup analyses indicated that combination therapy of metformin and rosiglitazone may increase the amount of serum adiponectin in T2DM sufferers among the majority subgroups (all P<0.05). The combination of metformin and rosiglitazone treatment increased serum adiponectin levels, suggesting that metformin plus rosiglitazone therapy is a suitable choice to treat T2DM.

Impact of the use of anti-diabetic drugs on survival of diabetic dialysis patients: a 5-year retrospective cohort study in Taiwan

BACKGROUND

Type 2 diabetes mellitus (DM) and associated complications are common in patients with chronic kidney disease (CKD) and can increase morbidity and mortality. A longitudinal 5-year observational study was conducted to investigate whether the use of anti-diabetic medications or not affected survival rates of diabetic dialysis patients.

METHODS

Using a data sample of a million patients from Taiwan's National Health Insurance Database, a retrospective cohort study surveyed patients with type 2 DM who began dialysis between 2002 and 2007. The study population was classified into groups using or not using anti-diabetic drugs. The group using anti-diabetic drugs was then categorized into 3 subgroups, including use of only oral hypoglycemic agents (OHAs), only insulin, and OHAs-combined insulin groups. Subjects of these four groups were followed 5 years or to date of death. Three major areas were analyzed: (1) demographic data and medical history; (2) survival prognosis and causes of death; and (3) effects on survival prognosis of different classes of OHAs.

RESULTS

A total of 912 patients fitting inclusion criteria were enrolled and followed-up for 5 years or to date of death. A total 465 patients died, and those not using anti-diabetic drugs (67.34 %) had a higher mortality rate than those using anti-diabetic drugs (46.42 %). After the multivariate analysis, group of OHAs-combined insulin had the lowest risk of death (HR 0.36, 95 % CI 0.27-0.47), followed by OHAs alone (HR 0.49, 95 % CI 0.38-0.63) and then insulin alone (HR 0.67, 95 % CI 0.51-0.88). To clarify four classes of OHAs (sulfonylurea, α-glucosidase inhibitors, meglitinide, and thiazolidinedione) are used in Taiwan for uremia patient with type 2 DM, and in our study, there were no significant differences in survival prognosis for the four drugs. Finally, the most common cause of death was infectious disease and there were no significant differences among the four groups.

CONCLUSION

This 5-year observational study results suggested that diabetic dialysis patients with anti-diabetic drugs had a lower risk of death compared with those without anti-diabetic drugs. Despite insulin therapy, appropriate OHAs should play an important role in treating these patients.

Sildenafil does not enhance but rather attenuates vasorelaxant effects of antidiabetic agents

Type 2 diabetic men commonly experience erectile dysfunction for which phosphodiesterase-5 (PDE5) inhibitors like sildenafil (Viagra) are often recommended. By preventing degradation of cyclic guanosine monophosphate (cGMP) in vascular smooth muscle, these inhibitors also enhance arterial vasorelaxant effects of nitric oxide donors (which stimulate cGMP synthesis). In the present work, we confirmed this enhancing effect after co-administration of sildenafil with nitroprusside to freshly-isolated rat tail arterial tissues. However, in the same tissues we also observed that sildenafil does not enhance but rather attenuates vasorelaxant effects of three commonly-used antidiabetic drugs, i.e. the biguanide metformin and the thiazolidinediones pioglitazone and rosiglitazone. Indeed, sildenafil completely blocked vasorelaxant effects of low concentrations of these drugs. In addition, we found that this same novel anti-vasorelaxant interaction of sildenafil with these agents was abolished by either 1) omitting extracellular glucose or 2) inhibiting specific smooth muscle glycolytic pathways; pathways known to preferentially utilize extracellular glucose to fuel certain adenosine triphosphate (ATP)-dependent ion transporters: e.g. ATP-sensitive K channels, sarcoplasmic reticulum Ca-ATPase, plasma membrane Ca-ATPase and Na/K-ATPase. Accordingly, we suspect that altered activity of one or more of these ion transporters mediates the observed attenuating (anti-vasorelaxant) interaction of sildenafil with the antidiabetic drugs. The present results are relevant because hypertension is so common and difficult to control in Type 2 diabetes. The present data suggest that sildenafil might interfere with the known antihypertensive potential of metformin and the thiazolidinediones. However, they do not suggest that it will interact with them to cause life-threatening episodes of severe hypotension, as can occur when it is co-administered with nitrates.

Activation of central PPAR-γ attenuates angiotensin II-induced hypertension

Inflammation and renin-angiotensin system activity in the brain contribute to hypertension through effects on fluid intake, vasopressin release, and sympathetic nerve activity. We recently reported that activation of brain peroxisome proliferator-activated receptor (PPAR)-γ in heart failure rats reduced inflammation and renin-angiotensin system activity in the hypothalamic paraventricular nucleus and ameliorated the peripheral manifestations of heart failure. We hypothesized that the activation of brain PPAR-γ might have beneficial effects in angiotensin II-induced hypertension. Sprague-Dawley rats received a 2-week subcutaneous infusion of angiotensin II (120 ng/kg per minute) combined with a continuous intracerebroventricular infusion of vehicle, the PPAR-γ agonist pioglitazone (3 nmol/h) or the PPAR-γ antagonist GW9662 (7 nmol/h). Angiotensin II+vehicle rats had increased mean blood pressure, increased sympathetic drive as indicated by the mean blood pressure response to ganglionic blockade, and increased water consumption. PPAR-γ mRNA in subfornical organ and hypothalamic paraventricular nucleus was unchanged, but PPAR-γ DNA-binding activity was reduced. mRNA for interleukin-1β, tumor necrosis factor-α, cyclooxygenase-2, and angiotensin II type 1 receptor was augmented in both nuclei, and hypothalamic paraventricular nucleus neuronal activity was increased. The plasma vasopressin response to a 6-hour water restriction also increased. These responses to angiotensin II were exacerbated by GW9662 and ameliorated by pioglitazone, which increased PPAR-γ mRNA and PPAR-γ DNA-binding activity in subfornical organ and hypothalamic paraventricular nucleus. Pioglitazone and GW9662 had no effects on control rats. The results suggest that activating brain PPAR-γ to reduce central inflammation and brain renin-angiotensin system activity may be a useful adjunct in the treatment of angiotensin II-dependent hypertension.

Impact of glucose-lowering drugs on cardiovascular disease in type 2 diabetes

Type 2 diabetes mellitus (T2DM) is characterized by multiple pathophysiologic abnormalities. With time, multiple glucose-lowering medications are commonly required to reduce and maintain plasma glucose concentrations within the normal range. Type 2 diabetes mellitus individuals also are at a very high risk for microvascular complications and the incidence of heart attack and stroke is increased two- to three-fold compared with non-diabetic individuals. Therefore, when selecting medications to normalize glucose levels in T2DM patients, it is important that the agent not aggravate, and ideally even improve, cardiovascular risk factors (CVRFs) and reduce cardiovascular morbidity and mortality. In this review, we examine the effect of oral (metformin, sulfonylureas, meglitinides, thiazolidinediones, DPP4 inhibitors, SGLT2 inhibitors, and α-glucosidase inhibitors) and injectable (glucagon-like peptide-1 receptor agonists and insulin) glucose-lowering drugs on established CVRFs and long-term studies of cardiovascular outcomes. Firm evidence that in T2DM cardiovascular disease can be reversed or prevented by improving glycaemic control is still incomplete and must await large, long-term clinical trials in patients at low risk using modern treatment strategies, i.e., drug combinations designed to maximize HbA1c reduction while minimizing hypoglycaemia and excessive weight gain.

Effects of exenatide and metformin in combination on some adipocytokine levels: a comparison with metformin monotherapy

The aim of this study was to evaluate the effects of exenatide on levels of serum adipocytokines and on β-cell function. The study was conducted between 2008 and 2012. After a run-in period with metformin, 174 patients with type-2 diabetes were randomly distributed to either a group receiving exenatide at 10 μg twice daily, or a group receiving the placebo, for 12 months. We evaluated body mass index (BMI), blood pressure, glycemic control, lipid profile, fasting plasma insulin (FPI), HOMA-IR, HOMA-β, fasting plasma proinsulin (FPPr), proinsulin : fasting plasma insulin ratio (Pr/FPI ratio), C-peptide, glucagon, retinol binding protein-4 (RBP-4), visfatin, omentin-1, and microalbuminuria. We used ELISA methods to assess the various parameters. Patients also underwent a combined euglycemic-hyperinsulinemic and hyperglycemic clamp, with subsequent arginine stimulation. After 12 months, a combination of exenatide and metformin produced a better decrease in body mass, BMI, glycemic control, FPI, FPPr, FPPr/FPI ratio, HOMA-IR, and glucagon level. Treatment with exenatide + metformin was superior to the placebo + metformin in increasing HOMA-β, C-peptide, and β-cell function. Significant negative correlations were found between M value, an index of insulin sensitivity, and measured adipocytokines. In conclusion, the combination of exenatide + metformin plays a role in improving some adipocytokine levels, and is better than metformin alone. The significant negative correlation between M value and measured adipocytokines is another confirmation of the positive effects linked to the improvement in insulin sensitivity.

Setting the record straight on TIDE: a lost opportunity for patients with diabetes

Much has been written regarding the recently discontinued Thiazolidinedione Intervention with Vitamin D Evaluation (TIDE) trial (ClinicalTrials.gov NCT00879970; Diabetologia 55: 36-45) and a variety of opinions have been advanced regarding its purpose, context and design (N Engl J Med 397: 959-964). As such, we deemed it appropriate to clarify TIDE's objectives, research questions and design and the clinical equipoise regarding its research questions.

Influence of fibrinogen and C-RP on progression of peripheral arterial disease in type 2 diabetes: a preliminary report

Background

Limited studies have suggested that inflammatory biomarkers play a role in the initiation and progression of atherosclerosis in diabetic patients. This study assesses the effect of inflammatory biomarkers: fibrinogen and C-reactive protein (C-RP) on the progression of peripheral arterial disease (PAD) in type 2 diabetic (T2D) patients.

Methods

Sixty two patients with T2D and PAD (mean age 60.28 ± 27 years and diabetes duration of 8.58 ± 6.17 years) were enrolled in a cohort prospective study of 36 months. Ankle-brachial index (ABI) was measured in all patients at baseline and after 36 months. Multiple linear regression analysis was used to determine the predictivity of variables for fibrinogen, C-RP, plasma lipid fractions, fasting plasma glucose, Body Mass Index (BMI), duration of diabetes status and the age on changes in ABI value.

Results

Linear regression analysis defined F as a predictor for endpoint value of ABI (β = 0.469, p = 0.007). Value of C-RP determinates change of minimal value of ABI (β = 0.449, p = 0.037) and change of mean ABI per year (β = 0.442, p = 0.025).

Conclusion

Our data indicate that plasma determination of fibrinogen and C-RP might have a clinical implication in defining the process of progression of PAD in T2D population.

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.

Cardiovascular comorbidities of type 2 diabetes mellitus: defining the potential of glucagonlike peptide-1-based therapies

The global epidemic of diabetes mellitus (~95% type 2 diabetes) has been fueled by a parallel increase in obesity and overweight. Together, these metabolic disease epidemics have contributed to the increasing incidence and prevalence of cardiovascular disease. The accumulation of metabolic and cardiovascular risk factors in patients with type 2 diabetes--risk factors that may exacerbate one another--complicates treatment. Inadequate treatment, treatment that fails to achieve goals, increases the risk for cardiovascular morbidity and mortality. From a clinical perspective, type 2 diabetes is a cardiovascular disease, an observation that is supported by a range of epidemiologic, postmortem, and cardiovascular imaging studies. Vascular wall dysfunction, and particularly endothelial dysfunction, has been posited as a "common soil" linking dysglycemic and cardiovascular diseases. Vascular wall dysfunction promoted by environmental triggers (e.g., sedentary lifestyle) and metabolic triggers (chronic hyperglycemia, obesity) has been associated with the upregulation of reactive oxygen species and chronic inflammatory and hypercoagulable states, and as such with the pathogenesis of type 2 diabetes, atherosclerosis, and cardiovascular disease. Glucagon-like peptide-1 (GLP)-1, an incretin hormone, and synthetic GLP-1 receptor agonists represent promising new areas of research and therapeutics in the struggle not only against type 2 diabetes but also against the cardiovascular morbidity and mortality associated with type 2 diabetes. In a number of small trials in humans, as well as in preclinical and in vitro studies, both native GLP-1 and GLP-1 receptor agonists have demonstrated positive effects on a range of cardiovascular disease pathologies and clinical targets, including such markers of vascular inflammation as high-sensitivity C-reactive protein, plasminogen activator inhibitor-1, and brain natriuretic peptide. Reductions in markers of dyslipidemia such as elevated levels of triglycerides and free fatty acids have also been observed, as have cardioprotective functions. Larger trials of longer duration will be required to confirm preliminary findings. In large human trials, GLP-1 receptor agonists have been associated with significant reductions in both blood pressure and weight.

Therapies for type 2 diabetes: lowering HbA1c and associated cardiovascular risk factors

OBJECTIVES

To summarize data supporting the effects of antidiabetes agents on glucose control and cardiovascular risk factors in patients with type 2 diabetes.

METHODS

Studies reporting on the effects of antidiabetes agents on glycemic control, body weight, lipid levels, and blood pressure parameters are reviewed and summarized for the purpose of selecting optimal therapeutic regimens for patients with type 2 diabetes.

RESULTS

National guidelines recommend the aggressive management of cardiovascular risk factors in patients with type 2 diabetes, including weight loss and achieving lipid and blood pressure treatment goals. All antidiabetes pharmacotherapies lower glucose; however, effects on cardiovascular risk factors vary greatly among agents. While thiazolidinediones, sulfonylureas, and insulin are associated with weight gain, dipeptidyl peptidase-4 inhibitors are considered weight neutral and metformin can be weight neutral or associated with a small weight loss. Glucagon-like peptide-1 receptor agonists and amylinomimetics (e.g. pramlintide) result in weight loss. Additionally, metformin, thiazolidinediones, insulin, and glucagon-like peptide-1 receptor agonists have demonstrated beneficial effects on lipid and blood pressure parameters.

CONCLUSION

Management of the cardiovascular risk factors experienced by patients with type 2 diabetes requires a multidisciplinary approach with implementation of treatment strategies to achieve not only glycemic goals but to improve and/or correct the underlying cardiovascular risk factors.

Omega 3 polyunsaturated fatty acids supplementation and blood pressure levels in hypertriglyceridemic patients with untreated normal-high blood pressure and with or without metabolic syndrome: a retrospective study

Recent evidence suggests that at least a part of the polyunsaturated fatty acids (PUFAs) heart protective effect is mediated by a relatively small but significant decrease in blood pressure level. We retrospectively evaluated the long-term effect of a PUFA supplementation on the blood pressure level of 111 hypertriglyceridemic subjects with untreated normal-high blood pressure that were prescribed a 2 grams PUFA supplementation in order to improve their plasma lipid pattern. After 12 months of treatment, systolic blood pressure (SBP) meanly decreased by 2.7 +/- 2.5 mmHg (p = 0.001) and diastolic blood pressure (DBP) by 1.3 +/- 3.3 mmHg (p < 0.001), while basal heart rate decreased by 4.0 +/- 4.4 bpm (p < 0.001). Both SBP and DBP reduction were significantly related to the baseline SBP (p < 0.001) and DBP (p < 0.001), respectively. Diastolic blood pressure change was also inversely related to the patient's age (p = 0.004). No significant difference was perceived in the metabolic syndrome subgroup. In our retrospective study, highly purified omega-3 PUFA long-term supplementation is associated with a significant reduction in SBP, DBP, Pulse pressure (PP), and basal heart rate in hypertriglyceridemic patients with normal-high blood pressure. No significant difference was perceived in the metabolic syndrome subgroup. The main determinants of the PUFA anti-hypertensive effect appear to be the basal blood pressure level and age.

PPARs in the Renal Regulation of Systemic Blood Pressure

Recent research has revealed roles for the peroxisome proliferator activated receptor (PPAR) family of transcription factors in blood pressure regulation, expanding the possible therapeutic use of PPAR ligands. PPARalpha and PPARgamma modulate the renin-angiotensin-aldosterone system (RAAS), a major regulator of systemic blood pressure and interstitial fluid volume by transcriptional control of renin, angiotensinogen, angiotensin converting enzyme (ACE) and angiotensin II receptor 1 (AT-R1). Blockade of RAAS is an important therapeutic target in hypertension management and attenuates microvascular damage, glomerular inflammation and left ventricular hypertrophy in hypertensive patients and also show antidiabetic effects. The mechanisms underlying the benefits of RAAS inhibition appear to involve PPARgamma-regulated pathways. This review summarizes current knowledge on the role of PPARs in the transcriptional control of the RAAS and the possible use of PPAR ligands in the treatment of RAAS dependent hypertension.

Effects of sitagliptin or metformin added to pioglitazone monotherapy in poorly controlled type 2 diabetes mellitus patients

The aim of the study was to compare the effects of the addition of sitagliptin or metformin to pioglitazone monotherapy in poorly controlled type 2 diabetes mellitus patients on body weight, glycemic control, beta-cell function, insulin resistance, and inflammatory state parameters. One hundred fifty-one patients with uncontrolled type 2 diabetes mellitus (glycated hemoglobin [HbA(1c)] >7.5%) in therapy with pioglitazone 30 mg/d were enrolled in this study. We randomized patients to take pioglitazone 30 mg plus sitagliptin 100 mg once a day, or pioglitazone 15 mg plus metformin 850 mg twice a day. We evaluated at baseline and after 3, 6, 9, and 12 months these parameters: body weight, body mass index, HbA(1c), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), homeostasis model assessment insulin resistance index (HOMA-IR), homeostasis model assessment beta-cell function index, fasting plasma proinsulin (Pr), Pr/FPI ratio, adiponectin, resistin (R), tumor necrosis factor-alpha (TNF-alpha), and high-sensitivity C-reactive protein. A decrease of body weight and body mass index was observed with metformin, but not with sitagliptin, at the end of the study. We observed a comparable significant decrease of HbA(1c), FPG, and PPG and a significant increase of homeostasis model assessment beta-cell function index compared with baseline in both groups without any significant differences between the 2 groups. Fasting plasma insulin, fasting plasma Pr, Pr/FPI ratio, and HOMA-IR values were decreased in both groups even if the values obtained with metformin were significantly lower than the values obtained with sitagliptin. There were no significant variations of ADN, R, or TNF-alpha with sitagliptin, whereas a significant increase of ADN and a significant decrease of R and TNF-alpha values were recorded with metformin. A significant decrease of high-sensitivity C-reactive protein value was obtained in both groups without any significant differences between the 2 groups. There was a significant correlation between HOMA-IR decrease and ADN increase, and between HOMA-IR decrease and R and TNF-alpha decrease in pioglitazone plus metformin group after the treatment. The addition of both sitagliptin or metformin to pioglitazone gave an improvement of HbA(1c), FPG, and PPG; but metformin led also to a decrease of body weight and to a faster and better improvement of insulin resistance and inflammatory state parameters, even if sitagliptin produced a better protection of beta-cell function.

Levels of soluble CD40 ligand and P-Selectin in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is linked to an increased risk of cardiovascular disease. We aimed to research whether the levels of soluble P-selectin (sP-selectin) and soluble CD40 ligand (sCD40L), markers of endothelial function, are altered in subjects with NAFLD having no confounding factors for atherosclerosis. sCD40L, sP-selectin, and high-sensitivity C-reactive protein (hsCRP) levels, and homeostasis model assessment of insulin resistance (HOMA-IR) indexes were measured in 50 NAFLD subjects and 30 healthy controls. sCD40L, sP-selectin, and hsCRP levels were not significantly different between two groups (P = 0.48, 0.51, and 0.34, respectively). Body mass index, waist circumference, and insulin levels and HOMA indexes were significantly higher in subjects with NAFLD (all P < 0.001). The present data show that sCD40L and sP-selectin may not contribute to the accelerated atherogenesis associated with this clinically relevant condition.

Combined pioglitazone and metformin treatment maintains the beneficial effect of short-term insulin infusion in patients with type 2 diabetes: results from a pilot study

BACKGROUND

The aim of our study was to examine the efficacy of short-term intravenous insulin intervention followed by oral pioglitazone/metformin therapy to prevent patients from continuous insulin application.

METHODS

This prospective, open-label, 4-month pilot study comprised of 14 diabetes patients (5 female, 9 male; age 60 +/- 2 years; body mass index 29 +/- 3.2 kg/m(2); hemoglobin A1c [HbA1c] 7.6 +/- 1.1%) with (1) insufficient glycemic control under a dose of metformin >or=1700 mg/day and/or metformin plus additional oral antidiabetes drugs (OADs) and (2) appropriate residual beta-cell function. Initially, an inpatient 34 h continuous intravenous insulin infusion was performed, and metformin was given (2x 850 mg/day). Insulin was stopped, and pioglitazone 30 mg/day was added at the second inpatient day. Patients were followed for four months. Efficacy parameters [change of HbA1c, fasting blood glucose [FBG], intact proinsulin, adiponectin, and high-sensitivity C-reactive protein (hsCRP)] were assessed after initial normalization of blood glucose values by intravenous insulin and at the study end point.

RESULTS

During the acute insulin intervention, FBG levels were stabilized in all study subjects. In the following OAD treatment period, five patients showed an improvement of HbA1c > 0.5% [35.7%; seven patients remained stable (50.0%), two patients were nonresponders (14.3%)]. Fasting glucose values dropped after insulin infusion (-17.7%; p < .001). This effect was maintained during the consecutive OAD treatment period (glucose +0.3%, not significant (NS); HbA1c -6.0%; p < .05). The initial decrease in fasting intact proinsulin levels was also maintained during the study (end value -41%, p < .05). Improvements in hsCRP values (postinsulin value, -15%, NS; end value -37%; p < .05) and adiponectin values (postinsulin value +15%, NS; end value +128%; p < .001) were demonstrated at end point only after continued glitazone intake.

CONCLUSIONS

Our pilot study demonstrated that a beneficial effect of a short-term intravenous insulin application on glycemic control was effectively maintained by pioglitazone/metformin treatment for at least 4 months. In addition, the oral therapy significantly improved cardiovascular risk parameters.

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

BACKGROUND

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

AIMS

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

MATERIALS AND METHODS

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

RESULTS

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

DISCUSSION

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

CONCLUSION

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

The role of pioglitazone in modifying the atherogenic lipoprotein profile

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

Relation of severe coronary artery narrowing to insulin or thiazolidinedione use in patients with type 2 diabetes mellitus (from the Bypass Angioplasty Revascularization Investigation 2 Diabetes Study)

Patients with diabetes continue to die of coronary artery disease (CAD) at rates 2 to 4 times higher than patients without diabetes, despite advances in treatment of cardiovascular disease. The role of glycemic control therapies, independent of their glucose-lowering effects, on cardiovascular disease is a recurring question. We examined the association of glycemic control therapies with extent of CAD as measured by coronary angiogram obtained at baseline in 1,803 subjects in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial who had type 2 diabetes mellitus, documented moderate to severe CAD, and no previous cardiac revascularization procedures. The association between glycemic control therapy use recorded at baseline and percent coronary artery stenosis and myocardial jeopardy index was analyzed by multiple regression models. Insulin use at study entry was associated with 23% fewer highly stenotic lesions (> or =70%) (p <0.001) and a significantly lower myocardial jeopardy index compared with subjects not on insulin, despite a worse cardiac risk factor profile, more unstable angina, and increased inflammatory markers in insulin users. Subjects taking thiazolidinediones (TZDs) for > or =6 months had 17% fewer highly stenotic lesions (p = 0.02) and significantly lower C-reactive protein, fibrinogen, and plasminogen activator inhibitor-1 levels compared with those not taking TZDs. In conclusion, this cross-sectional study of patients with type 2 diabetes mellitus and CAD showed that treatment with insulin or TZDs was associated with fewer highly stenotic lesions, independent of disease duration, glycemic control, and other risk factors.

Risk management in the treatment of type 2 diabetes with pioglitazone

INTRODUCTION

Type 2 diabetes mellitus is one of the most important cardiovascular risk factors. Insulin-resistance represents the common mechanism that leads to type 2 diabetes in obese subjects. Pioglitazone is an insulin-sensitizing agent available for treatment of type 2 diabetes. Large clinical trials have demonstrated the effectiveness of pioglitazone in achieving metabolic control and reducing cardiovascular morbidity and mortality.

AIM

The purpose of this article is to review the effectiveness and tolerability of pioglitazone in the prevention and management of atherosclerosis in patients with type 2 diabetes.

EVIDENCE REVIEW

We reviewed the main monotherapy and comparative studies of pioglitazone, and particularly the recent evidence in the field of atherosclerosis and cardiovascular prevention.

PLACE IN THERAPY

The current evidence shows that pioglitazone is an effective option in the treatment of type 2 diabetes. More studies are needed to establish a role for pioglitazone in atherosclerosis prevention beyond glycemic control.

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

BACKGROUND

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

AIM

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

DISCUSSION

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

CONCLUSION

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

Insulin sensitizers for women with polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is the most frequent endocrine disorder and most common cause of anovulation in women of reproductive age. It is a heterogeneous disorder, characterized by excess androgen, ovulatory dysfunction and/or polycystic ovaries. The syndrome is known for its association with several reproductive problems, including infertility and obstetric adverse effects. In addition, significant long-term health problems have been strongly linked to PCOS, with women suffering from the disorder having a significantly higher risk of diabetes, cardiovascular risk and some types of cancer, such as endometrial cancer. Although its etiology is unknown, insulin resistance is believed to play a pivotal role in its pathophysiology, with insulin sensitizers found to provide an exciting option in managing health problems associated with PCOS. Almost a decade ago, we proposed a non-insulin-sensitizing mechanism of action for insulin sensitizers through their effect on steroidogenesis. Accumulating evidence supported such an assumption, with solid evidence for a modulating effect on steroidogenesis by metformin and glitazones in the ovaries, adrenal glands and fat cells. Furthermore, other exciting positive roles for insulin sensitizers, in particular glitazones, have been reported at the level of endothelial function. Studying the value of insulin sensitizers in preventing long-term health problems in women with PCOS is still in the stage of infancy.

Evidence-based and potential benefits of metformin in the polycystic ovary syndrome: a comprehensive review

Metformin is an insulin sensitizer widely used for the treatment of patients affected by type 2 diabetes mellitus. Because many women with polycystic ovary syndrome (PCOS) are insulin resistant, metformin was introduced in clinical practice to treat these patients also. Moreover, metformin's effect has other targets beside its insulin-sensitizing action. The present review was aimed at describing all evidence-based and potential uses of metformin in PCOS patients. In particular, we will analyze the uses of metformin not only for the treatment of all PCOS-related disturbances such as menstrual disorders, anovulatory infertility, increased abortion, or complicated pregnancy risk, hyperandrogenism, endometrial, metabolic and cardiovascular abnormalities, but also for the prevention of the syndrome.

Comparison of the effect of lipophilic and hydrophilic statins on serum adiponectin levels in patients with mild hypertension and dyslipidemia: Kinki Adiponectin Interventional (KAI) Study

The plasma level of adiponectin, which is known as an anti-atherogenic adipocytokine, correlates inversely with the progression of atherosclerosis. An increase in the serum adiponectin level has been reported after the administration of hydrophilic pravastatin, but not after the administration of lipophilic statins thus far. We investigated whether hydrophilic pravastatin acts distinctly from simvastatin, which has the highest lipophilicity, on the favorable effect on adiponectin in dyslipidemic patients. A total of 27 dyslipidemic patients with mild hypertension were enrolled in this study. The patients were initially treated with simvastatin 10 mg/day for six months or more (mean 7.1 months), and then were switched to pravastatin 20 mg/day. The serum adiponectin, cholesterol fractionated components, and C-reactive protein (CRP) were evaluated after six-month intervals. Switching from simvastatin to pravastatin caused little change in the low-density lipoprotein cholesterol levels (103 mg/dl to 104 mg/dl, p = 0.782) and blood pressure (133/70 mmHg to 132/69 mmHg), while the serum adiponectin level significantly increased (11.9 mug/ml to 13.1 mug/ml, p = 0.009, respectively), and the serum CRP significantly decreased (0.078 mg/dl to 0.062 mg/dl, p = 0.040, respectively). Hydrophilic pravastatin increased the serum adiponectin level and decreased the CRP after switching from lipophilic simvastatin in the absence of any difference in the low-density lipoprotein cholesterol level and blood pressure. It remains possible, however, that this difference was due not only to pharmacologic lipophilicity, but also to some other specific characteristics such as the formula of statins, the subject characteristics, race, body size, high-density lipoprotein cholesterol, etc.

Pioglitazone metabolic effect in metformin-intolerant obese patients treated with sibutramine

OBJECTIVE

Metformin is the drug of choice to treat obese type 2 diabetes patients because it reduces either insulin-resistance and body weight. We aimed to comparatively test the efficacy and tolerability of pioglitazone and sibutramine in metformin-intolerant obese type 2 diabetic patients treated with sibutramine.

MATERIALS AND METHODS

Five hundred and seventy-six consecutive Caucasian obese type 2 diabetic patients were evaluated during a 12-months period and fifty-two patients were resulted intolerant to metformin at maximum dosage (3,000 mg/day). All intolerant patients to metformin received a treatment with pioglitazone (45 mg/day) and sibutramine (10 mg/day) and they were compared with fifty-three patients treated with metformin (3,000 mg/day) and sibutramine (10 mg/day) for 6 months in a single-blind controlled trial. We assessed body mass index, waist circumference, glycated hemoglobin, Fasting Plasma glucose, postprandial plasma glucose, fasting plasma insulin, postprandial plasma insulin, lipid profile, systolic blood pressure, diastolic blood pressure and heart rate at baseline and after 3, and 6 months.

RESULTS

No body mass index change was observed at 3, and 6 months in pioglitazone + sibutramine group, while a significant reduction of body mass index and waist circumference was observed after 6 months in metformin + sibutramine group (p<0.05). A significant decrease of glycated hemoglobin, Fasting Plasma glucose, postprandial plasma glucose, fasting plasma insulin, postprandial plasma insulin and HOMA index was observed after 3, and 6 months in both groups (p<0.05, and p<0.01, respectively). A significant Tg reduction was present after 6 months (p<0.05) in both groups respect to the baseline values. No systolic blood pressure, diastolic blood pressure and heart rate change was obtained after 3, and 6 months in both groups.

CONCLUSION

Pioglitazone and sibutramine combination appears to be a short-term equally efficacious and well-tolerated therapeutic alternative respect to metformin-intolerant obese type 2 diabetic patients treated with sibutramine.

Sibutramine effect on metabolic control of obese patients with type 2 diabetes mellitus treated with pioglitazone

Thiazolidinediones are supposed to be the pharmacologic agents that more physiologically fight the insulin resistance, but a possible adverse effect may be a weight increase. The aim of the study was to test the efficacy and tolerability of sibutramine on the metabolic effect of pioglitazone in obese patients with type 2 diabetes mellitus. All enrolled patients were required to have been diagnosed as being diabetic for at least 6 months and did not have glycemic control with diet and oral hypoglycemic agents such as sulfonylureas or metformin, both to the maximum tolerated dose. After a run-in period in which the eligible patients took a fixed dose of pioglitazone (30 mg/d), the patients were randomized to receive also sibutramine (10 mg/d) or placebo for 6 months. We assessed body mass index, hemoglobin A(1c) (HbA(1c)), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), postprandial plasma insulin (PPI), lipid profile, lipoprotein parameters, and lipoprotein (a) at baseline and after 3 and 6 months. No body mass index change was observed after 3 and 6 months in the pioglitazone + placebo (pp) group. Significant decrease was present in the pioglitazone + sibutramine (ps) group after 3 (P < .05) and 6 months (P < .01) compared with the baseline values, and this variation was significant (P < .05) between groups. A significant HbA(1c) decrease was observed after 3 (P < .05) and 6 months (P < .01) in both groups with respect to the baseline values. There was no difference in HbA(1c) value between the 2 groups. No FPG, PPG, FPI, PPI, and homeostasis model assessment index change was observed at 3 months, whereas a significant decrease was present after 6 months (P < .05), in both groups with respect to the baseline values. There was no difference in FPG, PPG, FPI, PPI, and homeostasis model assessment index value between the pp and ps groups. No significant low-density lipoprotein cholesterol change was observed at 3 months, whereas a significant decrease was present after 6 months (P < .05), in both groups with respect to the baseline values. There was no difference in low-density lipoprotein cholesterol value between the pp and ps groups. No triglyceride variation was present at 3 and 6 months in the pp group and at 3 months in the ps group, whereas a significant decrease was observed at 6 months (P < .05) in the ps group with respect to the baseline values. There was no difference in triglyceride value between both groups. No high-density lipoprotein cholesterol, apolipoprotein A-I, apolipoprotein B, and lipoprotein (a) changes were present in both groups with respect to the baseline values. Sibutramine appears to be a tolerable and efficacious drug when added to pioglitazone for the global management of obese diabetic patients.

Thiazolidinediones in type 2 diabetes: a cardiology perspective

OBJECTIVE

To examine the cardiovascular effects of thiazolidinediones (TZDs), discuss concerns regarding this drug class and its relation to heart failure (HF) and myocardial infarction (MI), and address the clinical implications of HF and MI.

DATA SOURCES

Literature was accessed through MEDLINE (1979-April 2008) using the search terms type 2 diabetes mellitus, thiazolidinediones, cardiovascular events, heart failure, myocardial infarction, and edema. Reviews, meta-analyses, clinical trials, observational studies (case-control, cohort), and descriptive studies (case reports, case series) were included.

STUDY SELECTION AND DATA EXTRACTION

All articles that were written in English and identified from the data sources were reviewed.

DATA SYNTHESIS

The American Diabetes Association recommends metformin as first-line therapy for type 2 diabetes, with the subsequent addition of a TZD, sulfonylurea, or insulin if the target is not met. Beyond glucose lowering, TZDs improve various factors associated with cardiovascular risk. Whether the effects translate into beneficial cardiovascular outcomes is controversial. In PROactive (Prospective Pioglitazone Clinical Trial in Macrovascular Events), pioglitazone did not produce a significant reduction in the primary endpoint that included a composite of coronary and vascular deaths, but the secondary composite endpoint of all-cause mortality, MI, or stroke was significantly reduced. Concerns related to HF have led to warnings in the labeling of TZDs. The drugs are contraindicated in patients with New York Heart Association Class III or IV HF. Rosiglitazone, but not pioglitazone, is associated with an increased risk of myocardial ischemic events, although the absolute magnitude is extremely small.

CONCLUSIONS

Although the glycemic efficacy of TZDs is comparable to that of metformin, adverse effects and higher costs make TZDs less appealing for initial therapy. Among the TZDs, pioglitazone should be considered based on cardiovascular safety data. In combination with metformin, pioglitazone may be particularly beneficial for patients with diabetes and metabolic syndrome. For patients on rosiglitazone who are achieving glycemic goals and tolerating the therapy without apparent complications, rosiglitazone may be continued.

Time to insulin in type-2 diabetes: high hurdles or Santiago way?

The prevalence of obesity has been increasing dramatically in the last decades; the major metabolic complication of obesity is insulin resistance and type-2 diabetes because there are pathogenetic mechanisms linking obesity and type-2 diabetes. Diabetes is also rapidly increasing worldwide; such a description of the key stages in the evolution of type-2 diabetes may be of great interest for implementing antidiabetes treatment. In recent times, type-2 diabetes therapy has been based on drugs, which improve insulin sensibility or stimulate insulin secretion or slow down glucose absorption. Recently, an ADA and EASD consensus has been released to develop a common approach for the management of hyperglycaemia in adults. The development of new classes of blood-glucose-lowering medications to supplement the older therapies, such as lifestyle-directed interventions, insulin, sulfonylureas, and metformin, has increased the different possible options for the treatment of type-2 diabetes. Therapeutic approaches aiming to potentiate the biological effects of incretins include degradation-resistant GLP-1 receptor agonists (incretin mimetics), and inhibitors of dipeptidyl peptidase-IV (DPP-IV) activity (incretin enhancers) will be very useful to slow down type-2 diabetes progression. Weight-loss interventions, such as a hypocaloric diet and physical exercise, in addition to agents such as orlistat, sibutramine and cannabinoid receptor antagonists, may have favourable effects upon fat storage, nutrient metabolism and ultimately glucose tolerance or type-2 diabetes. When the therapeutic target is not achieved, insulin with metformin could be suggested, but is this approach the ideal one for all patients? Perhaps it is possible to delay the initiation of insulin therapy, therefore, the actual and future therapeutical options are considered in the present review.

Effects of antidiabetic and antihyperlipidemic agents on C-reactive protein

Type 2 diabetes mellitus (DM) increases the risk of cardiovascular disease, a major cause of morbidity and mortality. Central to type 2 DM is insulin resistance, a proinflammatory, hypercoagulable state that predisposes patients to develop cardiovascular disease and that is associated with risk factors for atherosclerosis including dyslipidemia, hypertension, inflammation, and altered hemostasis. Atherosclerosis is recognized as a chronic inflammatory disease of the arteries. C-reactive protein (CRP) is an acute-phase response protein that is considered both a marker of inflammation and a predictor of cardiovascular events including myocardial infarction, stroke, peripheral arterial disease, and sudden cardiac death. Evidence indicates that CRP has a direct proatherogenic effect through up-regulation of angiotensin II type 1 receptors and through the stimulation of other proinflammatory factors. Patients with type 2 DM tend to have higher CRP concentrations than do those without it, suggesting an increased role of inflammation in the accelerated atherosclerosis seen in these patients. Reducing CRP concentrations through lifestyle changes or pharmacotherapeutics could have clinical benefit; long-term studies are needed to determine whether reductions in CRP concentrations translate into improved cardiovascular outcomes. Because glucose and lipid levels as well as CRP concentrations are often elevated in patients with type 2 DM, an agent that positively affects multiple cardiovascular risk factors would be most beneficial. This article reviews available data on antidiabetic and antihyperlipidemic agents that reduce CRP concentrations in addition to their primary effect of lowering glucose or lipid levels.