Pioglitazone produces rapid and persistent reduction of vascular inflammation in patients with hypertension and type 2 diabetes mellitus who are receiving angiotensin II receptor blockers

Cellular adhesion molecules in drug-naïve and previously medicated patients with schizophrenia-spectrum disorders

BACKGROUND

Endothelial inflammation may be involved in the pathogenesis of schizophrenia, and cellular adhesion molecules (CAMs) on endothelial cells may facilitate leukocyte binding and transendothelial migration of cells and inflammatory factors. The aim of the present study was to assess levels of soluble cellular adhesion molecules, including intercellular adhesion molecule (ICAM)-1, vascular adhesion molecule (VCAM)-1, mucosal addressin cell adhesion molecule (MADCAM), junctional adhesion molecule (JAM-A) and neural cadherin (N-CAD) in patients with schizophrenia compared to healthy controls.

METHODS

The study population consists of 138 patients with schizophrenia-spectrum disorder, of whom 54 were drug-naïve, compared to 317 general population controls. The potential confounders age, gender, smoking and body mass index (BMI) were adjusted for in linear regression models.

RESULTS

The total patient group showed significantly higher levels of ICAM-1 (p < 0.001) and VCAM-1 (p < 0.001) compared to controls. Previously medicated patients showed higher ICAM-1 levels compared to drug-naïve patients (p = 0.042) and controls (p < 0.001), and elevated VCAM-1 levels compared to controls (p < 0.001). Drug-naive patients had elevated levels of VCAM-1 (p = 0.031) compared to controls.

CONCLUSIONS

In our study, patients with schizophrenia - including the drug-naïve - have higher levels of soluble CAMs compared to healthy controls. These findings suggest activation of the endothelial system as in inflammation.

Dysregulation of Leukocyte Trafficking in Type 2 Diabetes: Mechanisms and Potential Therapeutic Avenues

Type 2 Diabetes Mellitus (T2DM) is a chronic inflammatory disorder that is characterized by chronic hyperglycemia and impaired insulin signaling which in addition to be caused by common metabolic dysregulations, have also been associated to changes in various immune cell number, function and activation phenotype. Obesity plays a central role in the development of T2DM. The inflammation originating from obese adipose tissue develops systemically and contributes to insulin resistance, beta cell dysfunction and hyperglycemia. Hyperglycemia can also contribute to chronic, low-grade inflammation resulting in compromised immune function. In this review, we explore how the trafficking of innate and adaptive immune cells under inflammatory condition is dysregulated in T2DM. We particularly highlight the obesity-related accumulation of leukocytes in the adipose tissue leading to insulin resistance and beta-cell dysfunction and resulting in hyperglycemia and consequent changes of adhesion and migratory behavior of leukocytes in different vascular beds. Thus, here we discuss how potential therapeutic targeting of leukocyte trafficking could be an efficient way to control inflammation as well as diabetes and its vascular complications.

Hepatocyte growth factor exerts beneficial effects on mice with type II diabetes‑induced chronic renal failure via the NF‑κB pathway

Type II diabetes is associated with a low quality of life and inflammation, and is often accompanied by varying degrees of chronic renal failure. Chronic renal failure is considered one of the most important factors that aggravates diabetes and contributes to renal insufficiency in patients with diabetes though cellular fibrosis. It has previously been reported that hepatocyte growth factor (HGF) serves extensive biological roles, and is a multifunctional antifibrotic factor that is involved in kidney development, acute injury and regeneration. The present study aimed to investigate whether HGF exerts beneficial effects on type II diabetes‑induced chronic renal failure in a mouse model. Plasma concentration levels of HGF, tumor necrosis factor (TNF)‑α, monocyte chemoattractant protein (MCP)‑1, interleukin (IL)‑1 and IL‑6 were analyzed prior to and following treatment with HGF. Blood urea nitrogen, plasma creatinine concentrations, and electrolyte, total serum protein, parathyroid hormone and C‑reactive protein levels were analyzed by ELISA. The mechanism underlying the effects of the HGF‑mediated signaling pathway was also investigated in mice with type II diabetes‑induced chronic renal failure. Histological analysis was used to determine the therapeutic effects of HGF on mice with type II diabetes‑induced chronic renal failure. The results indicated that HGF exhibited lower plasma concentrations in mice with type II diabetes‑induced chronic renal failure compared with in healthy mice. In addition, treatment with HGF relieved chronic renal failure via inhibition of inflammation. The results indicated that TNF‑α, MCP‑1 and IL‑1 serum concentration levels were downregulated following treatment with HGF. Conversely, IL‑6 and vascular endothelial growth factor concentration was increased in the HGF‑treated mice compared with in the control mice. The results also demonstrated that HGF treatment downregulated the expression of nuclear factor (NF)‑κB molecules, and target molecules C‑C motif chemokine ligand (Ccl)2, Ccl5, intercellular adhesion molecule 1 and TNF‑α. The present study demonstrated that HGF markedly improved renal failure induced by type II diabetes in a mouse model; histological analyses revealed that renal cell injury was improved following treatment with HGF. In conclusion, these results suggested that HGF may exert beneficial effects on type II diabetes‑induced chronic renal failure via regulation of the NF‑κB signaling pathway.

Resveratrol provides benefits in mice with type II diabetes-induced chronic renal failure through AMPK signaling pathway

Type II diabetes-induced ischemic injuries are known to lead to the rapid degeneration of the kidneys as a result of chronic renal failure. Chronic renal failure is a condition, which typically manifests with symptoms including cardiovascular system and left ventricular hypertrophy, atherosclerosis as well as arterial and aortic stiffness. Resveratrol is a multifunctional compound that has been reported to produce beneficial outcomes for patients with type-II diabetes due to prevention of oxidative stress and apoptosis. However, the beneficial effects of resveratrol in chronic renal failure and the underlying mechanisms have remained to be fully elucidated. The present study investigated the therapeutic effects of resveratrol in mice with chronic renal failure induced by type-II diabetes and assessed the mechanism of action. Oxidative stress, apoptosis and adenosine monophosphate-activated protein kinase (AMPK) in the renal cells of the model mice were assessed. Changes in inflammatory factors renal cells from experimental mice as well as insulin resistance were also analyzed. Morphological changes and immunocytes in renal cells were determined by immunostaining. The results demonstrated that resveratrol treatment decreased the apoptotic rate of renal cells from experimental mice. Oxidative stress also improved in renal cells, as indicated by inhibition of superoxide dismutase and reduced glutathione and 4-hydroxy-2-nonenal levels. In addition, insulin resistance was improved after an 8-week treatment with resveratrol. Inflammatory factors were decreased and factors promoting kidney function were increased after resveratrol treatment. Furthermore, morphological changes were observed to be ameliorated, indicating the therapeutic efficacy of resveratrol. In addition, immunocyte precipitation in renal cells was markedly decreased in resveratrol-treated mice. Importantly, the AMPK signaling pathway was found to be involved in the beneficial effect of resveratrol on the model mice. In conclusion, the present study suggested that resveratrol may be an ideal agent for the treatment of chronic renal failure induced by type-II diabetes through regulation of the AMPK signaling pathway, which should be further investigated in clinical trials.

Thiazolidinediones improve flow-mediated dilation: a meta-analysis of randomized clinical trials

AIMS

Thiazolidinediones administration is assumed to be related with an improvement of endothelial dysfunction (ED); nevertheless, previous studies have been inconsistent. For this reason, the present meta-analysis was directed to estimate if thiazolidinediones were related to endothelial dysfunction improvement by using flow-mediated dilation (FMD) measurement.

METHODS

Literature search of the PubMed, the Cochrane Library, the Web of Science, and the Scopus databases was performed covering the period until July 01, 2015, for randomized clinical trials that investigated an influence of thiazolidinediones on FMD. For the calculation of the pooled overall effect, a random effect model was used. Meta-regression and subgroup analyses were performed to evaluate the impact of study characteristics on the effect of thiazolidinediones administration on FMD.

RESULTS

This meta-analysis included 16 studies with 812 subjects. The obtained results demonstrated an improvement of endothelial dysfunction measured with FMD (16 studies, 812 subjects; WMD: 2.4 %, 95 % CI = 1.1 to 3.69 %; p = 0.0003). The significant heterogeneity was noted (I (2) = 95 %, p < 0.00001). Subgroup analysis demonstrated that pioglitazone and rosiglitazone were able to improve FMD. Also, thiazolidinediones improved FMD if treatment was longer than 12 weeks and if patients were younger than 65 years. Additionally, a lipid profile was found to influence thiazolidinediones effect on FMD.

CONCLUSION

The results of this meta-analysis demonstrated that thiazolidinediones were able to improve FMD, which in clinical terms can be further translated to the improvement of an impaired endothelial function. Nevertheless, the link between FMD and its predictive clinical relevance still requires further clarification.

Effect of Atorvastatin and Pioglitazone on Plasma Levels of Adhesion Molecules in Non-Diabetic Patients With Hypertension or Stable Angina or Both

BACKGROUND

It was to study the effect of atorvastatin, pioglitazone and their combination on plasma levels of adhesion molecules in patients with hypertension or stable angina or both.

METHODS

It was an open-label, randomized parallel-group study. Forty-five atorvastatin-naive patients with hypertension or stable angina or both, were randomized to receive either atorvastatin (19 patients; 10 mg OD for 12 weeks) or pioglitazone (26 patients; 30 mg OD for 12 weeks). Another group of 30 patients who were already on atorvastatin were put on add-on pioglitazone therapy (pioglitazone (15 mg OD) + atorvastatin (10 mg OD) for 12 weeks). Plasma high-sensitivity C-reactive protein (hsCRP), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) levels were measured at baseline and after 12 weeks of therapy.

RESULTS

Atorvastatin monotherapy significantly reduced plasma sICAM-1, but pioglitazone monotherapy did not produce any significant effect. Addition of pioglitazone in patients already receiving atorvastatin also significantly reduced plasma sICAM-1 level. However, there was no significant change in plasma hsCRP and sVCAM-1 levels in any of the groups after 12 weeks of therapy.

CONCLUSION

There is therapeutic advantage of combining pioglitazone and atorvastatin on plasma sICAM-1 levels.

From hypertension to stroke: mechanisms and potential prevention strategies

Stroke is a major cause of disability and death worldwide. Prevention aimed at risk factors of stroke is the most effective strategy to curb the stroke pandemic. Hypertension is one of the most important risk factors for stroke. Despite the substantial evidence of the benefits of lowering blood pressure, conventional treatment does not normalize the burden of major cardiovascular events in patients with hypertension. Fully understanding the factors involved in the hypertension-induced stroke helps to develop new strategies for stroke prevention. Antihypertensive therapies selected should have positive blood pressure-independent effects on stroke risk. This review summarizes the factors involved in the hypertension-induced stroke, such as oxidative stress, inflammation, and arterial baroreflex dysfunction, and potential strategies for its prevention, therefore, provides clues for clinicians.

Fat redistribution preferentially reflects the anti-inflammatory benefits of pioglitazone treatment

Thiazoledinedione is known to have an anti-inflammatory effect besides a hypoglycemic effect. We investigated changes in high-sensitivity C-reactive protein (hsCRP), a proinflammatory marker, after pioglitazone treatment in association with the resulting changes in various metabolic and anthropometric parameters. A total of 93 type 2 diabetes mellitus patients (47 men and 46 women; mean age, 50.0 ± 10.8 years) who were being treated with a stable dose of sulfonylurea or metformin were enrolled in the study. Pioglitazone (15 mg/d) was added to their treatment regimen for 12 weeks, and metabolic and anthropometric measurements were taken before and after pioglitazone treatment. Pioglitazone treatment for 12 weeks decreased serum hsCRP levels (0.83 [1.14] to 0.52 [0.82] mg/L, P < .001) and improved glycemic control (fasting glucose, P < .001; glycosylated hemoglobin, P < .001) and lipid profiles (triglyceride, P = .016; high-density lipoprotein cholesterol, P < .001). Between responders and nonresponders to the hsCRP-lowering effect of pioglitazone, there were significant differences in baseline hsCRP levels and changes in the postprandial glucose and the ratio of visceral fat thickness (VFT) to subcutaneous fat thickness (SFT) (P = .004, .011, and .001, respectively). The percentage change in hsCRP levels after treatment was inversely correlated with baseline hsCRP levels (r = -0.497, P < .001) and directly correlated with the change in postprandial glucose (r = 0.251, P = .021), VFT (r = 0.246, P = .030), and VFT/SFT ratio (r = 0.276, P = .015). Logistic regression analysis revealed that the hsCRP-lowering effect of pioglitazone was affected by baseline hsCRP levels (odds ratio [OR] = 7.929, P = .007) as well as changes in postprandial 2-hour glucose (OR = 0.716, P = .025) and VFT/SFT ratio (OR = 0.055, P = .009). In conclusion, treatment with pioglitazone produced an anti-inflammatory effect, decreasing serum hsCRP levels; and a decrease in the VFT/SFT ratio was independently and most strongly associated with the hsCRP-decreasing effect. These results suggest that abdominal fat redistribution preferentially reflects the anti-inflammatory benefits of pioglitazone treatment.

Rosiglitazone decreases C-reactive protein to a greater extent relative to glyburide and metformin over 4 years despite greater weight gain: observations from a Diabetes Outcome Progression Trial (ADOPT)

OBJECTIVE

C-reactive protein (CRP) is closely associated with obesity and cardiovascular disease in both diabetic and nondiabetic populations. In the short term, commonly prescribed antidiabetic agents have different effects on CRP; however, the long-term effects of those agents are unknown.

RESEARCH DESIGN AND METHODS

In A Diabetes Outcome Progression Trial (ADOPT), we examined the long-term effects of rosiglitazone, glyburide, and metformin on CRP and the relationship among CRP, weight, and glycemic variables in 904 subjects over 4 years.

RESULTS

Baseline CRP was significantly correlated with homeostasis model assessment of insulin resistance (HOMA-IR), A1C, BMI, waist circumference, and waist-to-hip ratio. CRP reduction was greater in the rosiglitazone group by -47.6% relative to glyburide and by -30.5% relative to metformin at 48 months. Mean weight gain from baseline (at 48 months) was 5.6 kg with rosiglitazone, 1.8 kg with glyburide, and -2.8 kg with metformin. The change in CRP from baseline to 12 months was correlated positively with change in BMI in glyburide (r = 0.18) and metformin (r = 0.20) groups but not in the rosiglitazone (r = -0.05, NS) group. However, there was no longer a significant correlation between change in CRP and change in HOMA-IR, A1C, or waist-to-hip ratio in any of the three treatment groups.

CONCLUSIONS

Rosiglitazone treatment was associated with durable reductions in CRP independent of changes in insulin sensitivity, A1C, and weight gain. CRP in the glyburide and metformin groups was positively associated with changes in weight, but this was not the case with rosiglitazone.

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.

Essential hypertension: is there a role for inflammatory mechanisms?

Inflammation is a key feature in the initiation, progression, and clinical implications of cardiovascular disorders, including essential hypertension. Increasing evidence shows that activation of renin-angiotensin-aldosterone system and enhanced local production of angiotensin II have been implicated in the pathophysiology of inflammation. Besides being a potent vasoactive peptide, angiotensin II regulates the inflammatory process. Specifically, it increases vascular permeability, participates in the recruitment of inflammatory cells and their adhesion to the activated endothelium, and regulates cell growth and fibrosis. Reactive oxygen species are implicated at every stage in inflammation and activate multiple intracellular signaling molecules and transcription factors associated with inflammatory responses, such as nuclear factor-kappa B and activator protein-1. Other components of the renin-angiotensin-aldosterone system, including aldosterone and/or mineralocorticoid receptor, induce the production of reactive oxygen species and participate in vascular inflammation. Several studies suggest a role of endothelin-1 as an important mediator of chronic inflammation and there is an increasing interest in the relationship between endothelin-1 and reactive oxygen species. These data may have great impact on future therapeutic strategies.

Change in hemoglobin A(1c) and C-reactive protein levels in patients with diabetes mellitus

The authors studied the effects on C-reactive protein (CRP) levels of an intensive intervention to reduce hemoglobin A(1c) (HbA(1c)) among 58 veterans with type 2 diabetes. Weekly group sessions of behavioral and pharmacologic intervention were conducted for 4 weeks at Providence Veterans Affairs Medical Center. Change in cardiovascular risk factors and CRP levels were compared at baseline and 3 months postintervention. There was a significant decrease in HbA(1c) (-0.7%+/-1.9%, P<.01), total cholesterol (-20.3+/-41.1 mg/dL, P=.01), low-density lipoprotein cholesterol (-11.7+/-31.4 mg/dL, P=.05), systolic blood pressure (-6.9+/-21.2 mm Hg, P=.03), and diastolic blood pressure (-6.0+/-10.6 mm Hg, P<.01) over 4 months. There was no significant change in CRP levels (1.1+/-6.6 mg/L, P=.2). These results suggest that CRP effects may not be adequate to predict changes in cardiovascular risk among diabetic patients and should not be a surrogate for achieving evidence-based goals in traditional cardiovascular risk factors.

The peroxisome proliferator-activated receptor-gamma agonist pioglitazone represses inflammation in a peroxisome proliferator-activated receptor-alpha-dependent manner in vitro and in vivo in mice

OBJECTIVES

Our aim was to investigate if the peroxisome proliferator-activated receptor (PPAR)-gamma agonist pioglitazone modulates inflammation through PPARalpha mechanisms.

BACKGROUND

The thiazolidinediones (TZDs) pioglitazone and rosiglitazone are insulin-sensitizing PPARgamma agonists used to treat type 2 diabetes (T2DM). Despite evidence for TZDs limiting inflammation and atherosclerosis, questions exist regarding differential responses to TZDs. In a double-blinded, placebo-controlled 16-week trial among recently diagnosed T2DM subjects (n = 34), pioglitazone-treated subjects manifested lower triglycerides and lacked the increase in soluble vascular cell adhesion molecules (sVCAM)-1 evident in the placebo group. Previously we reported PPARalpha but not PPARgamma agonists could repress VCAM-1 expression. Since both triglyceride-lowering and VCAM-1 repression characterize PPARalpha activation, we studied pioglitazone's effects via PPARalpha.

METHODS

Pioglitazone effects on known PPARalpha responses--ligand binding domain activation and PPARalpha target gene expression--were tested in vitro and in vivo, including in wild-type and PPARalpha-deficient cells and mice, and compared with the effects of other PPARgamma (rosiglitazone) and PPARalpha (WY14643) agonists.

RESULTS

Pioglitazone repressed endothelial TNFalpha-induced VCAM-1 messenger ribonucleic acid expression and promoter activity, and induced hepatic IkappaBalpha in a manner dependent on both pioglitazone exposure and PPARalpha expression. Pioglitazone also activated the PPARalpha ligand binding domain and induced PPARalpha target gene expression, with in vitro effects that were most pronounced in endothelial cells. In vivo, pioglitazone administration modulated sVCAM-1 levels and IkappaBalpha expression in wild-type but not PPARalpha-deficient mice.

CONCLUSIONS

Pioglitazone regulates inflammatory target genes in hepatic (IkappaBalpha) and endothelial (VCAM-1) settings in a PPARalpha-dependent manner. These data offer novel mechanisms that may underlie distinct TZD responses.

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.