Effects of atorvastatin on apelin, visfatin (nampt), ghrelin and early carotid atherosclerosis in patients with type 2 diabetes

Drug discovery targeting nicotinamide phosphoribosyltransferase (NAMPT): Updated progress and perspectives

Nicotinamide phosphoribosyltransferase (NAMPT) is a key rate-limiting enzyme in the nicotinamide adenine dinucleotide (NAD+) salvage pathway, primarily catalyzing the synthesis of nicotinamide mononucleotide (NMN) from nicotinamide (NAM), phosphoribosyl pyrophosphate (PRPP), and adenosine triphosphate (ATP). Metabolic diseases, aging-related diseases, inflammation, and cancers can lead to abnormal expression levels of NAMPT due to the pivotal role of NAD+ in redox metabolism, aging, the immune system, and DNA repair. In addition, NAMPT can be secreted by cells as a cytokine that binds to cell membrane receptors to regulate intracellular signaling pathways. Furthermore, NAMPT is able to reduce therapeutic efficacy by enhancing acquired resistance to chemotherapeutic agents. Recently, a few novel activators and inhibitors of NAMPT for neuroprotection and anti-tumor have been reported, respectively. However, NAMPT activators are still in preclinical studies, and only five NAMPT inhibitors have entered the clinical stage, unfortunately, three of which were terminated or withdrawn due to safety concerns. Novel drug design strategies such as proteolytic targeting chimera (PROTAC), antibody-drug conjugate (ADC), and dual-targeted inhibitors also provide new directions for the development of NAMPT inhibitors. In this perspective, we mainly discuss the structure, biological function, and role of NAMPT in diseases and the currently discovered activators and inhibitors. It is our hope that this work will provide some guidance for the future design and optimization of NAMPT activators and inhibitors.

Targeting the apelin system for the treatment of cardiovascular diseases

Cardiovascular disease is the leading cause of death worldwide. Its prevalence is rising due to ageing populations and the increasing incidence of diseases such as chronic kidney disease, obesity, and diabetes that are associated with elevated cardiovascular risk. Despite currently available treatments, there remains a huge burden of cardiovascular disease-associated morbidity for patients and healthcare systems, and newer treatments are needed. The apelin system, comprising the apelin receptor and its two endogenous ligands apelin and elabela, is a broad regulator of physiology that opposes the actions of the renin-angiotensin and vasopressin systems. Activation of the apelin receptor promotes endothelium-dependent vasodilatation and inotropy, lowers blood pressure, and promotes angiogenesis. The apelin system appears to protect against arrhythmias, inhibits thrombosis, and has broad anti-inflammatory and anti-fibrotic actions. It also promotes aqueous diuresis through direct and indirect (central) effects in the kidney. Thus, the apelin system offers therapeutic promise for a range of cardiovascular, kidney, and metabolic diseases. This review will discuss current cardiovascular disease targets of the apelin system and future clinical utility of apelin receptor agonism.

Visfatin and Subclinical Atherosclerosis in Type 2 Diabetes: Impact of Cardiovascular Drugs

Background and Objectives: The role of adipokines in the development of atherosclerosis in type 2 diabetes (T2DM) has not yet been fully elucidated. The effects of drugs on adipokine concentrations have only been evaluated in very few studies, although they may be of clinical importance. This study aimed to assess whether the concentrations of circulating adipokines could predict subclinical atherosclerosis in patients with T2DM, as well as their interactions with commonly used cardiovascular drugs. Materials and Methods: Our population-based cross-sectional multicentric study included 216 participants with T2DM but without previously diagnosed atherosclerosis. The carotid artery intima-media thickness (IMT), plaque and ankle-brachial index (ABI) metrics were measured. Resistin, visfatin, retinol-binding protein 4, high molecular weight adiponectin and leptin levels were evaluated using Luminex's xMAP technology. Results: Visfatin and resistin concentrations correlated positively with IMT (p = 0.002 and p = 0.009, respectively). The correlation of visfatin to IMT ≥ 1.0 mm was significant in males (p < 0.001). Visfatin had a positive correlation with IMT ≥ 1.0 mm or plaque (p = 0.008) but resistin only correlated with plaque (p = 0.049). Visfatin predicted IMT ≥ 1.0 mm or plaque in patients on β-blocker monotherapy (p = 0.031). Visfatin lost its ability to predict subclinical atherosclerosis in patients taking angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers or statins. After adjustments for risk factors for atherosclerosis and cardiovascular drugs, visfatin maintained an independent association with mean IMT (p = 0.003), IMT ≥ 1.0 mm or plaque (p = 0.005) and ABI ≤ 0.9 (p = 0.029). Conclusions: Visfatin could be used as a marker of subclinical atherosclerosis in patients with T2DM, especially in males. The assessment of visfatin concentration could aid in identifying individuals who could benefit from implementing preventive measures against atherosclerosis.

How to Use Statins in Secondary Prevention of Atherosclerotic Diseases: from the Beneficial Early Initiation to the Potentially Unfavorable Discontinuation

Statins, a class of lipid-lowering drugs, reduce morbidity and mortality in patients with established atherosclerosis-related cardiovascular disease. Early initiation of statin therapy after admission for acute coronary syndromes (ACS), stroke, or transient ischemic attack (TIA) is associated with improved cardiovascular outcomes. Moreover, high-dose statin treatment prior to coronary or carotid revascularization has been shown to reduce cardiovascular events in these patients. However, many patients may be undertreated, and a residual cardiovascular risk remains in current clinical practice. Despite the beneficial role of statins, their discontinuation rate among patients is still elevated leading to severe adverse cardiovascular events due to atherosclerotic plaque destabilization. In this review, we summarized the impact of statin treatment among patients, focusing on the initiation time-points as well as the potential harm derived by their discontinuation.

The interplay between statins and adipokines. Is this another explanation of statins' 'pleiotropic' effects?

Statin therapy comprises an integral part of secondary and to a lesser extent of primary cardiovascular disease prevention. This is attributed not only to their lipid-lowering properties, but as well to a plethora of pleiotropic actions. Recently, the cytokines secreted by adipose tissue, the so-called adipokines, have been proved to play a critical role in various pathophysiological functions, among which inflammation and atherosclerosis development and vulnerability. The aim of this literature review was to summarize the effects of statins and the underlying mechanisms on the circulating levels of the most common adipokines regulating atherosclerosis process, as a part of their pleiotropic function. Up to now, robust evidence implicates a significant statin-induced reduction of pro-inflammatory adipokines IL-6, TNF-a and visfatin. Weak evidence from limited, small and mostly non-randomized studies suggest increased levels of anti-inflammatory adipokines apelin, vaspin and omentin-1 after statin therapy. In the rest of most known adipokines, statins have shown either controversial (adiponectin, retinol binding protein-4 and fetuin-A) or negligible effects (leptin and resistin) on their circulating levels. Therefore, statins may favourably alter the balance of inflammatory/anti-inflammatory adipokines, implicating a novel atheroprotective mechanism. However, the interplay between statins and adipokines is still not fully elucidated and its potential clinical relevance is warranted.

Overweight and obesity in type 1 diabetes is not associated with higher ghrelin concentrations

BACKGROUND

Several studies have demonstrated suppressed levels of acylated (AG) and unacylated ghrelin (UAG) in patients with type 2 diabetes. However, the role of these hormones in type 1 diabetes has not been extensively studied. This study assessed the relationship between AG and UAG levels and body composition in patients with type 1 diabetes.

METHODS

We selected eighteen patients with type 1 diabetes and divided them into two groups: non-obese (BMI < 25 kg/m²) and overweight (BMI ≥ 25 kg/m²). Demographics, parameters of body composition and serum parameters including AG and UAG, were assessed.

RESULTS

The patients with a BMI ≥ 25 kg/m² were older and had a longer duration of diabetes. AG and UAG levels were not significantly different between non-obese and overweight groups (mean AG non-obese ± SD: 44.5 ± 29.4 pg/ml and mean UAG non-obese 42.4 ± 20.7 pg/ml vs mean AG overweight ± SD: 46.1 ± 29.6 pg/ml and mean UAG overweight 47.2 ± 18.2 pg/ml). AG/UAG ratios did not discriminate between these groups. There was a positive association of insuline dose/kg bodyweight with BMI (r² = 0.45, p = 0.002).

CONCLUSIONS

Surprisingly, unlike non-diabetics and in T2D, we did not observe a difference in plasma levels of AG and UAG between normal weight and overweight adult type 1 diabetics. However, we did observe a positive correlation between BMI and insuline dose/kg bodyweight, suggesting that exogenous insulin is more important than the ghrelin system in the development of obesity in type 1 diabetes.

Targeting Small GTPases and Their Prenylation in Diabetes Mellitus

A fundamental role of pancreatic β-cells to maintain proper blood glucose level is controlled by the Ras superfamily of small GTPases that undergo post-translational modifications, including prenylation. This covalent attachment with either a farnesyl or a geranylgeranyl group controls their localization, activity, and protein–protein interactions. Small GTPases are critical in maintaining glucose homeostasis acting in the pancreas and metabolically active tissues such as skeletal muscles, liver, or adipocytes. Hyperglycemia-induced upregulation of small GTPases suggests that inhibition of these pathways deserves to be considered as a potential therapeutic approach in treating T2D. This Perspective presents how inhibition of various points in the mevalonate pathway might affect protein prenylation and functioning of diabetes-affected tissues and contribute to chronic inflammation involved in diabetes mellitus (T2D) development. We also demonstrate the currently available molecular tools to decipher the mechanisms linking the mevalonate pathway’s enzymes and GTPases with diabetes.

Omentin-1 and vaspin serum levels in patients with pre-clinical carotid atherosclerosis and the effect of statin therapy on them

BACKGROUND

Omentin-1 and vaspin are novel adipokines, and their association with atherosclerosis is still under investigation. The present study aimed to assess the relationship of those adipokines with preclinical, non-significant carotid atherosclerosis and the impact of statin therapy on their levels, suggesting a link between adiposity and atherosclerosis.

METHODS

Eighty-four statin-free subjects with non-significant, preclinical carotid atherosclerosis and elevated LDL- cholesterol levels (>130 mg/dl) were recruited to receive atorvastatin (from 10 to 80 mg per day) (atorvastatin group - AG group). Forty-six age- and gender-matched healthy individuals, without any chronic disease served as controls (control group - CG). Clinical parameters, metabolic profile, serum omentin-1, vaspin concentrations and ultrasound measurements of carotid thickening were obtained at the beginning and after 12 months.

RESULTS

At baseline, AG showed lower omentin-1 and vaspin serum levels than CG (p ≤ 0.001). Along the entire study population at baseline, omentin-1 levels were independently related to LDL-cholesterol, while vaspin levels were independently associated with hsCRP and the presence of carotid atherosclerosis (p < 0.05). Within AG, 12-months atorvastatin treatment significantly increased omentin-1 (from 202.79 ± 91.41 ng/ml to 262.56 ± 101 ng/ml, p < 0.001) and vaspin concentrations (from 1.29 ± 0.51 ng/ml to 1.70 ± 0.5 ng/ml, p = 0.002). In standard multiple regression analysis, the presence of carotid atherosclerosis related to baseline vaspin levels (β = -0.232, p < 0.001), while the atorvastatin-induced increase of vaspin was independently associated with hsCRP reduction (β = -0.198, p = 0.045).

CONCLUSION

Low omentin-1 and vaspin serum levels associated with preclinical, non-significant carotid atherosclerosis. Notably, atorvastatin administration significantly increased both adipokines, but the underlying mechanisms and the clinical impact of those changes requires further investigation.

High-dose atorvastatin improves vascular endothelial function in patients with leukoaraiosis

Objective

Leukoaraiosis (LA), as an age‐related white matter degeneration, is mainly caused by chronic ischemia. Our study aims to explore the efficacy of different doses of atorvastatin (ATV) in the vascular endothelial function in patients with LA.

Methods

Our study enrolled 402 LA patients who were then randomly included as control or treated with ATV (10 mg), ATV (20 mg), or ATV (30 mg). The total cholesterol (TC), triglycerides (TG), high‐density lipoprotein cholesterol (HDL‐C), and low‐density lipoprotein cholesterol (LDL‐C) were detected by enzyme colorimetric assay. The high‐sensitivity C‐reactive protein (hs‐CRP) level, reactive hyperemia index (RHI), endothelin‐1 (ET‐1) content, and nitric oxide (NO) level were tested by latex agglutination test, peripheral arterial tonometry technology, radioimmunoassay, and nitrate reductase assay, respectively.

Results

After 8 weeks of ATV treatment, the levels of TC, LDL‐C, and HS‐CRP decreased significantly, and the trends were demonstrated in a more significant way with the increases of dose of ATV. The treatment with ATV at different doses elevated NO level and RHI and declined ET‐1 content. Gastrointestinal reaction, muscular pain, and increased aminopherase were observed after treatment with the ATV at different doses with more obvious symptoms detected accompanied by the increase of the dose. The RHI was in negative correlation with the ET‐1 and HS‐CRP while in positive correlation with NO.

Conclusion

Our study demonstrates that ATV can significantly improve the vascular endothelial function in LA patients with a dose‐dependent effect.

Association of lipid peroxidation and interleukin-6 with carotid atherosclerosis in type 2 diabetes

Enhanced lipid peroxidation and elevated interleukin-6 levels are common in type 2 diabetes mellitus patients. Atherosclerotic vascular complications greatly contribute to morbidity and mortality in diabetes. The aim of this study was to assess the relation of lipid peroxidation and interleukin-6 with carotid atherosclerosis in type 2 diabetes mellitus.

Methods

This cross-sectional study included 90 type 2 diabetes mellitus male patients with age ≥ 40 years and 30 healthy male subjects matched for age. All of them were subjected to measuring of 8-iso prostaglandin F2α as a marker of lipid peroxidation, interleukin-6 and carotid intima media thickness as a marker of carotid atherosclerosis.

Results

Both 8-iso prostaglandin F2α and interleukin-6 were found to have significant positive correlation with carotid intima media thickness (P < 0.001) and both were found to be significant predictors of the presence of subclinical carotid atherosclerosis in multiple regression analysis.

Conclusion

Lipid peroxidation and interleukin-6 may play an important role in atherogenesis in type 2 diabetes mellitus and limiting their effects may reduce atherosclerotic vascular complications in type 2 diabetes mellitus.

Association of fasting glucagon-like peptide-1 with oxidative stress and subclinical atherosclerosis in type 2 diabetes

AIM

Glucagon-like peptide-1(GLP-1) is a gut hormone that beside its main function in glucose homeostasis may play a role as an anti-oxidant and anti-atherosclerotic factor. The aim of this study was to estimate fasting total GLP-1 level in type 2 diabetes (T2DM) patients and to determine its relation with oxidative stress and atherosclerotic vascular changes.

METHODS

The study included 60 T2DM male patients with age ≥40 and 30 healthy male subjects matched for age. All of them were subjected to measuring of fasting total GLP-1, 8-iso prostaglandin F2α (8-iso PGF2α) as a marker of oxidative stress and carotid intima media thickness (CIMT) as a marker of subclinical atherosclerosis.

RESULTS

Fasting total GLP-1 was not significantly different in diabetics in comparison with healthy subjects (p = 0.52). Fasting total GLP-1 was found to have significant negative correlations with both 8-iso PGF2α (p < 0.05) and CIMT (p < 0.001).

CONCLUSION

Endogenous fasting GLP-1 appears to have anti-oxidant and anti-atherosclerotic effects in T2DM.

Protective effect of atorvastatin meditated by HMGCR gene on diabetic rats with atherosclerosis: An in vivo and in vitro study

BACKGROUND

Accelerated atherosclerosis in patients suffering from diabetes represents a major cause of morbidity and mortality. The aim of present study was to investigate the protective effects conferred by atorvastatin (AVT) meditated by the HMGCR gene in diabetic rats with atherosclerosis.

METHODS

Serum triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very-low-density lipoprotein cholesterol (VLDL-C), fasting blood glucose (FBG) and serum insulin (INS) were all determined by means of in vivo experiments. Following the establishment of the diabetic model of atherosclerosis, the expressions of HMGCR, low density lipoprotein receptor (LDLR), fatty acid synthase (FASN) were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis in the vitro experiments. Flow cytometry was adopted in order to detect cell cycle and apoptosis.

RESULTS

The in vivo experiments results indicated that FBG and INS among the diabetic arteriosclerosis rats exhibited markedly higher levels; after injected with AVT and HMGCR, decreased contents of TC, TG, LDL-C and VLDL-C, while increased contents of HDL-C as well as an increased positive rate of HMGCR protein expression were observed. In vitro experiment, the mRNA and protein expression of LDLR were increased and FASN were decreased in cells transfected with HMGCR and AVT; with a greater number of cells arrested at the S phase and less in the G0/G1 phase, as well as data indicating the rate of apoptosis was inhibited after HMGCR and AVT transfection processes.

CONCLUSION

The key findings of the present study suggested that the protective effect conferred by AVT in diabetic rats with atherosclerosis was associated with the overexpression of the HMGCR gene, thus presenting a novel target for atherosclerosis treatment.

Differential effect of metformin and/or glyburide on apelin serum levels in patients with type 2 diabetes mellitus: Concepts and clinical practice

Type 2 diabetes mellitus (T2DM) is a metabolic disorder associated with abundant adipocytokine changes which may play an important role in the progression of insulin resistance and micro- and macro-vascular complications. Therefore, the objective of this study was to assess the differential effect of metformin alone or in combination with glyburide on apelin serum levels in patients with T2DM. In this case–control study, fifty patients with T2DM in the age range of 45–65 years and twenty-five healthy controls matched for age and body weight were recruited from single endocrinology center, subdivided according to the diabetic pharmacotherapy into: Group I: healthy controls (n = 25), Group II: T2DM patients on metformin (n = 15), Group III: T2DM patients on glyburide (n = 17), and Group IV: T2DM patients on metformin plus glyburide (n = 28). Biochemical and anthropometric variables in relation to apelin serum levels were estimated. Apelin serum levels were low in normal healthy controls compared to T2DM patients (P < 0.01). The differential effect of diabetic pharmacotherapy on apelin serum level was statistically significant (P < 0.01) compared to the controls, but insignificant when compared among used drugs (P > 0.05). Apelin level was high in T2DM compared to the controls; both metformin and glyburide might play a role in this elevation.

Association between FTO gene polymorphisms and type 2 diabetes mellitus, serum levels of apelin and androgen hormones among Iranian obese women

BACKGROUND AND AIMS

Recent studies show that FTO single nucleotide polymorphisms (SNPs) are associated with obesity and type 2 diabetes mellitus (T2DM). On the other hand, many animal models and clinical studies have demonstrated that apelin, an adipocytokine, is related to the obesity and T2DM. Additionally, obese women are at risk of Hyperandrogenemia. So, the aim of this study was to investigate the relationship between FTO variants (rs763967273, rs759031579, rs141115189, rs9926289, rs76804286 and rs9939609) with T2DM, serum apelin and androgenic hormones in Iranian obese women.

SUBJECTS AND METHODS

197 obese women (123 women with T2DM and 74 women as healthy control) were participated in this study. Anthropometrical and biochemical characteristics were measured. Serum apelin and androgen hormones levels were determined in 66 subjects consisting of 33 cases and 33 controls. PCR were carried out and subsequently, the PCR production was genotyped by Sanger sequencing assay.

RESULTS

Our observations showed that all SNPs are related to T2DM. The rs9926289 FTO variant had a strong association with serum apelin and dehydroepiandrosterone-sulfate levels (P=0.04 and P=0.03, respectively) among SNPs. In addition, apelin and androgenic hormones were correlated with T2DM. Two polymorphisms including rs9939609 and rs9926289 had a strong Linkage disequilibrium (r²=1).

CONCLUSION

FTO variants not only were associated with T2DM, but also some variants had a strong association with apelin and androgenic hormones profile.

Effect of different doses of statins on the development of type 2 diabetes mellitus in patients with myocardial infarction

BACKGROUND

Cardiovascular diseases and type 2 diabetes mellitus (T2DM) may have common developmental mechanisms associated with lipid metabolism disorders. Dyslipidemia and progression of atherosclerosis in people with T2DM are accompanied by an increase in cardiovascular mortality. This study examined the dose-dependent action of atorvastatin on carbohydrate metabolism and adipokine status in patients within 12 months after myocardial infarction (MI).

METHODS

A total of 156 male MI patients who had received atorvastatin 20 mg/day (78 patients) or 40 mg/day (78 patients) starting from day 1 of onset were enrolled. Glucose, insulin, C-peptide, resistin, adiponectin, and ghrelin levels were measured at baseline, day 12, and months 3 and 12. Patients were monitored for new incidences of T2DM for 12 months after MI.

RESULTS

For acute phase MI, patients had moderate insulin resistance, hyperglycemia, and hyper-insulinemia, high leptin and resistin levels, and low ghrelin and adiponectin levels. Atorvastatin 20 mg/day was more effective at correcting the imbalances. Patients taking atorvastatin 40 mg/day (group 2) following MI showed increases in levels of glucose, insulin, and C-peptide and insulin resistance progression after 12 months of therapy, as evidenced by increased quantitative insulin sensitivity check index scores and detection of new T2DM cases.

CONCLUSION

Atorvastatin improved adipokine profiles and ghrelin levels, with low doses showing more significant effects. Atorvastatin dose prescribed for MI patients should take into account the degree of insulin resistance and adipokine status.

Consumption of extra-virgin olive oil rich in phenolic compounds improves metabolic control in patients with type 2 diabetes mellitus: a possible involvement of reduced levels of circulating visfatin

AIM

Phenolic compounds naturally contained in extra-virgin olive oil (EVOO) have demonstrated anti-inflammatory and antioxidant properties. The present study aimed at evaluating the effects of a polyphenol-rich extra-virgin olive oil (EVOO) (high-polyphenol EVOO, HP-EVOO) on the metabolic control and the production of specific pro-/anti-inflammatory adipokines in overweight patients with type 2 diabetes mellitus (T2D).

METHODS

Eleven overweight T2D patients not in treatment with insulin were invited to follow their habitual diet for a total of 8 weeks. During the first 4 weeks (wash-out period), they were asked to consume refined olive oil (ROO, polyphenols not detectable) and then to replace ROO with HP-EVOO (25 mL/day, 577 mg of phenolic compounds/kg) for the remaining 4 weeks. Anthropometric parameters, fasting glycaemia, glycated haemoglobin (HbA1c), high-sensitive C-reactive protein, plasma lipid profile, liver function and serum levels of TNF-α, IL-6, adiponectin, visfatin and apelin were assessed at the end of each 4-week period.

RESULTS

HP-EVOO consumption significantly reduced fasting plasma glucose (P = 0.023) and HbA1c (P = 0.039) levels as well as BMI (P = 0.012) and body weight (P = 0.012). HP-EVOO ingestion determined a reduction in serum level of aspartate aminotransferase (AST, P = 0.0056) and alanine aminotransferase (ALT, P = 0.024). Serum visfatin levels strongly decreased after HP-EVOO ingestion (P = 0.0021).

CONCLUSIONS

Daily consumption of polyphenol-rich EVOO might improve metabolic control and circulating inflammatory adipokines profile in overweight T2D patients.

Atorvastatin Treatment for Carotid Intima-Media Thickness in Chinese Patients With Type 2 Diabetes: A Meta-Analysis

Impact of atorvastatin on carotid intima-media thickness (CIMT) in patients with type 2 diabetes is still debating.The aim of our study is to investigate atorvastatin as adjuvant treatment on CIMT in Chinese patients with type 2 diabetes by conducting a meta-analysis based on the randomized controlled trials (RCTs).A systematic search of electronic database of the Pubmed, EMBASE, Cochrane Library, VIP database, China National Knowledge Infrastructure, and Wangfang up to January 2015 was conducted. Randomized controlled trials (RCTs) comparing atorvastatin adjuvant treatment to the hypoglycemic therapies or high-dose atorvastatin versus low-dose atorvastatin therapies for patients with type 2 diabetes were selected.A total of 14 RCTs involving 1345 patients were included. Adjuvant treatment with atorvastatin was associated with a significant reduction in CIMT (weighted mean difference [WMD] = -0.17 mm; 95% confidence interval [CI] -0.22 to -0.12). Compared with the low-dose atorvastatin, high-dose atorvastatin treatment was associated with a significant reduction in CIMT (WMD = -0.17 mm; 95% CI: -0.32 to -0.02). Adjuvant treatment with atorvastatin reduced serum total cholesterol, triglyceride, low-density lipoproteins, and high sensitivity C-reactive protein levels. However, atorvastatin had no significant impact on blood glucose levels.This meta-analysis demonstrated that treatment with atorvastatin significantly reduced CIMT in Chinese patients with type 2 diabetes. Moreover, high-dose atorvastatin appeared to have additional benefits in reducing CIMT than the low-dose atorvastatin.

The relation between apelin levels, echocardiographic findings and carotid intima media thickness in peritoneal dialysis patients

BACKGROUND

Cardiovascular disease (CVD) is the most important cause of morbidity and mortality in patients with end stage renal disease (ESRD). Apelin expressed in endothelial and other tissues including brain and kidney is an adipocytokine defined recently and is emerging an important mediator of cardiovascular homeostasis. The aim of this study was to test whether apelin levels might be associated with carotid artery atherosclerosis and left ventricular mass index (LVMI) in peritoneal dialysis patients.

PATIENTS AND METHODS

Fifty peritoneal dialysis patients (25 female, mean age 41.4 ± 11.9 years, mean dialysis vintage 65.0 ± 35.4 months) and 18 healthy individuals (9 female, mean age 41.7 ± 6.8 years) were included in this cross-sectional study. Serum apelin 12 levels, echocardiographic findings and carotid intima media thickness (CIMT) were recorded as well as clinical and laboratory data.

RESULTS

There were no differences between the patient and the control groups with regard to demographic characteristics. In patient group, LVMI, CIMT, CRP and apelin levels were elevated compared to control group. However there was no association between apelin, LVMI and CIMT. There was a positive correlation between apelin and CRP, which was not statistically significant. When patients were divided into two groups according to the mean serum apelin levels, LVMI, CIMT and CRP were higher in the high apelin group but this difference did not reach statistical significance.

CONCLUSION

We observed an increased inflammation and CVD risk in peritoneal dialysis patients. However, serum apelin levels seem not to be associated with cardiovascular risk in this group of patients.

Circulating apelin is increased in patients with type 1 or type 2 diabetes and is associated with better glycaemic control

CONTEXT

Apelin is an adipokine expressed in several tissues and it appears to be involved in energy metabolism.

OBJECTIVE

The aim of this study was to determine serum apelin levels in a large cohort of patients with type 1 and type 2 diabetes and control subjects and to correlate the results with glycaemic control.

DESIGN AND PARTICIPANTS

One hundred and thirty patients with type 1 diabetes, 98 patients with type 2 diabetes and 162 controls were enrolled in the study. Apelin levels were measured by enzyme-linked immunosorbent assay.

RESULTS

Serum apelin levels were significantly higher in type 1 and type 2 diabetic patients than in controls (P < 0·0001). Serum apelin levels were higher in type 1 than in type 2 diabetic patients (P = 0·02). In multivariate analysis, serum apelin levels were higher in patients with type 1 diabetes and in patients with type 2 diabetes versus controls. We found a negative correlation between glycosylated haemoglobin and serum apelin levels in all diabetic patients (r = -0·17, P = 0·008) and in patients with type 2 diabetes (r = -0·24 P = 0·01). No correlation was found in type 1 diabetic patients.

CONCLUSION

Our study showed that apelin concentrations were increased in diabetic patients. This rise, which was greater in type 1 than in type 2 diabetic patients, suggests that obesity is not the main determinant of plasma apelin levels. The negative correlation with glycosylated haemoglobin in patients with type 2 diabetes could indicate that apelin plays a role in glycaemic balance and even insulin sensitivity.

Serum levels of novel adipokines in patients with acute ischemic stroke: potential contribution to diagnosis and prognosis

This study evaluated serum levels of novel adipokines in acute ischemic stroke (AIS) and their association with prognosis. We enrolled 168 patients with AIS and 58 stroke-free age- and sex-matched individuals (controls). Clinical parameters, carotid ultrasound, metabolic profile, vaspin, apelin, visfatin, and ghrelin were assayed. Stroke-patients were sampled at hospital admission and were prospectively followed-up (median 16 months) for the cardiovascular endpoint (cardiovascular death/stroke/myocardial infarction). At admission, stroke-patients appeared with higher levels of systolic blood pressure, hsCRP and worse metabolic profile (p<0.05), (p>0.05). Compared to controls, AIS group had significantly higher serum concentrations of visfatin (22.92±9.72ng/ml vs 16.56±7.82ng/ml, p=0.006) and lower of vaspin (0.94±0.43ng/ml vs 1.84±0.82ng/ml, p=0.019) and ghrelin (3.47±1.44ng/ml vs 5.93±2.78ng/ml, p<0.001), while apelin did not differ between groups. Similar differences in adipokines were found between stroke subgroups with and without significant ipsilateral carotid stenosis (>50%) (p<0.05). In stepwise logistic regression analysis adjusted for diabetes, hypertension, dyslipidemia and age, visfatin (p=0.026) and ghrelin (p=0.012) proved to be independent predictors of AIS. During follow-up, 27 patients achieved cardiovascular endpoint. In addition to coronary artery disease and NIHSS score, visfatin serum levels was associated with cardiovascular endpoint (HR: 1.255, 95% CI: 1.025-1.576). Our results suggested the association of AIS with higher visfatin and lower vaspin and ghrelin serum levels. Visfatin levels can be a predictor of cardiovascular mortality and morbidity in AIS.

The effect of short-term simvastatin treatment on plasma adipokine levels in patients with isolated hypercholesterolemia: A preliminary report

BACKGROUND

Apart from reducing plasma lipids, statins produce numerous non-lipid-related pleiotropic effects. The aim of this study was to investigate whether short-term simvastatin treatment affects plasma adipokine levels in patients with isolated hypercholesterolemia.

METHODS

The study included 42 adult patients with untreated isolated hypercholesterolemia, complying throughout the study with lifestyle intervention, 23 of whom were treated with simvastatin (40 mg daily), as well as 18 healthy subjects with normal lipid profile. Plasma lipids, apolipoproteins, glucose metabolism markers, as well as plasma levels of C-reactive protein (CRP), free fatty acids (FFA), leptin, adiponectin, visfatin and tumor necrosis factor-α (TNF-α) were determined at baseline and after 30 days of treatment.

RESULTS

Compared with the control age-, sex-, and weight-matched healthy subjects, isolated hypercholesterolemic patients exhibited higher plasma levels of leptin, visfatin, TNF-α, FFA and CRP, as well as lower plasma levels of adiponectin. Apart from decreasing plasma total cholesterol, LDL cholesterol and apolipoprotein B-100 levels, simvastatin reduced plasma levels of FFA, leptin and TNF-α, as well as increased plasma levels of adiponectin, which was accompanied by a reduction in plasma CRP. There were no differences in simvastatin action on plasma adipokines and CRP between insulin-resistant and insulin-sensitive subjects.

CONCLUSIONS

Our results indicate that the presence of isolated hypercholesterolemia is associated with abnormal hormonal function of the adipose tissue. These changes are partially reversed by short-term simvastatin treatment, and this action may contribute to the clinical effectiveness of statins in the therapy of atherosclerosis-related disorders.

Obesity and metabolic syndrome as related to cardiovascular disease

The metabolic syndrome (MetS) constitutes a multifaceted disorder, including obesity, dyslipidemia, hyperglycemia and hypertension, associated with an increased propensity towards cardiovascular disease (CVD). Besides this, accumulating data suggest the involvement of nontraditional, novel, cardiovascular risk factors in MetS. Among them, insulin resistance seems to possess a predominant role in MetS-related CVD in obese patients. Furthermore, adipose tissue fatty acid metabolism, increased incidence of oxidative stress and endothelial dysfunction, and excessive production of adipocyte derivatives, known as adipokines, have all been proposed to contribute to the pathogenesis of CVD in obese patients with MetS. Lifestyle interventions, such as weight loss and increased physical activity, have long been the cornerstone for the treatment of obesity-related disorders. With the exception of obesity, pharmaceutical interventions targeting each disorder of MetS have yielded considerable improvement in cardiovascular morbidity and mortality. The long-term management of obesity and its complications seems promising but requires further investigation.

Apelin/APJ signaling is a critical regulator of statin effects in vascular endothelial cells--brief report

OBJECTIVE

The endothelial response elicited by the G-protein-coupled receptor pathway involving apelin and APJ predicts an overall vasoprotective effect. As a number of downstream endothelial targets of apelin/APJ signaling are also known to be targeted by statins (3-hydroxy-3-methyl-glutaryl [HMG]-CoA reductase inhibitors) as potential mediators of their known pleiotropic effects, we evaluated for the involvement of apelin/APJ signaling in statin endothelial effects.

METHODS AND RESULTS

We found that disruption of apelin/APJ signaling in endothelial cells leads to significantly decreased expression of Krűppel-like factor 2, endothelial nitric oxide synthase, and thrombomodulin. We found that statin-mediated induction of Krűppel-like factor 2, endothelial nitric oxide synthase, and thrombomodulin expression, as well as inhibition of monocyte-endothelial adhesion, was abrogated by concurrent apelin knockdown. Moreover, we found that statins can transcriptionally regulate APJ in a Krűppel-like factor 2-dependent manner, demonstrating the presence of a positive-feedback loop.

CONCLUSIONS

Our findings provide a novel mechanism by which the apelin/APJ pathway serves as a critical intermediary that links statin to its pleiotropic effects in regulating endothelial gene targets and function.

Role of SST, CORT and ghrelin and its receptors at the endocrine pancreas

Somatostatin (SST), cortistatin (CORT), and its receptors (sst1-5), and ghrelin and its receptors (GHS-R) are two highly interrelated neuropeptide systems with a broad range of overlapping biological actions at central, cardiovascular, and immune levels among others. Besides their potent regulatory role on GH release, its endocrine actions are highlighted by SST/CORT and ghrelin influence on insulin secretion, glucose homeostasis, and insulin resistance. Interestingly, most components of these systems are expressed at the endocrine pancreas and are actively involved in the modulation of pancreatic islet function and, consequently influence glucose homeostasis. In addition, some of them also participate in islet survival and regeneration. Furthermore, under severe metabolic condition as well as in endocrine pathologies, their expression profile is severely deregulated. These findings suggest that SST/CORT and ghrelin systems could play a relevant role in pancreatic function under metabolic and endocrine pathologies. Accordingly, these systems have been therapeutically targeted for the prevention or amelioration of certain metabolic conditions (obesity) as well as for tumor growth inhibition and/or hormonal regulation in endocrine pathologies (neuroendocrine tumors). This review focuses on the interrelationship between SST/CORT and ghrelin systems and their role in severe metabolic conditions and some endocrine disorders.