Increased glycated albumin and decreased esRAGE concentrations are associated with in-stent restenosis in Chinese diabetic patients

Serum glycated albumin is associated with in-stent restenosis in patients with acute coronary syndrome after percutaneous coronary intervention with drug-eluting stents: An observational study

Background

Previous studies have confirmed the predicted value of serum glycated albumin (GA) in atherosclerotic cardiovascular disease. However, the relationship between GA and the development of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation has not been verified in patients with acute coronary syndrome (ACS).

Materials and methods

In this study, 797 patients diagnosed with ACS who underwent re-coronary angiography more than 6 months after the first successful DES-based percutaneous coronary intervention (PCI) were eventually included. Patients were categorized into two groups based on the median GA levels of 14.94%. Moreover, multivariate logistic regression analysis models and the net reclassification improvement and integrated differentiation improvement risk models were constructed to assess the relationship between the GA and DES-ISR in patients with ACS.

Results

The GA was significantly associated with an increased risk of DES-ISR, upon adjusting for confounding factors (as nominal variate: OR 1.868, 95% CI 1.191-2.932, P = 0.007; as continuous variate: OR 1.109, 95% CI 1.040-1.183, P = 0.002). The addition of GA to a baseline risk model had an incremental effect on the predictive value for DES-ISR (AUC: GA vs. baseline model, 0.714 vs. 0.692, comparison P = 0.017; category-free net reclassification improvement (NRI) 0.080, P = 0.035; integrated discrimination improvement (IDI) 0.023, P < 0.001).

Conclusion

GA level was significantly associated with a high risk of DES-ISR in patients with ACS treated with PCI. Moreover, the addition of the GA to a baseline risk model has an incremental effect on the predictive potential for DES-ISR.

Association of Circulating IgE and CML Levels with In-Stent Restenosis in Type 2 Diabetic Patients with Stable Coronary Artery Disease

Background: We investigated whether serum levels of immunoglobin (Ig) E and Nε-carboxymethyl-lysine (CML) are related to in-stent restenosis (ISR) in patients with stable coronary artery disease and type 2 diabetes mellitus (T2DM). Methods: Serum levels of IgE and CML were measured in 196 ISR patients and 220 non-ISR patients with stable angina and T2DM who received angiographic follow-up 12 months after percutaneous coronary intervention (PCI) with third-generation drug-eluting stent (DES) implantation for de novo lesions. Multivariate logistic regression analysis was performed to assess the association between IgE or CML and ISR. Results: Both IgE and CML levels were higher in patients with ISR compared with non-ISR patients (IgE: 187.10 (63.75−489.65) vs. 80.25 (30.65−202.50), p < 0.001; CML: 203.26 (164.50−266.84) vs. 174.26 (130.85−215.56), p < 0.001). The rate of ISR increased stepwise with increasing tertiles of IgE and CML levels (p for all trends < 0.001), and IgE correlated significantly with CML. After adjusting for potential confounders, IgE and CML levels remained independently associated with ISR. Moreover, IgE and CML levels improved the predictive capability of traditional risk factors for ISR, and there existed an interaction between IgE and CML in relation to ISR (p for interaction < 0.01). Conclusion: Elevated circulating IgE and CML levels confer an increased risk for ISR after DES-based PCI in type 2 diabetic patients with stable coronary artery disease.

Elevated Glycated Albumin in Serum Is Associated with Adverse Cardiac Outcomes in Patients with Acute Coronary Syndrome Who Underwent Revascularization Therapy

AIMS

The associations between increased glycated albumin (GA) in the serum and diabetic complications and mortality have been revealed in the general population. However, less is known regarding the prognostic value of GA in patients diagnosed with acute coronary syndrome (ACS).

METHODS

In this study, all patients admitted for ACS who underwent a successful percutaneous coronary intervention (PCI) at our center from January 2018 to February 2019 were retrospectively examined. Clinical characteristics, laboratory results (e.g., serum GA levels), and procedural details were collected. The primary outcome included a composite of major adverse cardio-cerebral events (MACCE), such as death, myocardial infarction, stroke, and unplanned revascularization. The association between serum GA levels and clinical outcomes was tested in three multivariable models using Cox proportional hazard analysis. Subgroup analysis was performed in patients who were diagnosed with diabetes versus patients without diabetes.

RESULTS

A total of 1,806 ACS patients (mean age of 59.4 years; 77.8% were men; 44.9% were diagnosed with diabetes) were enrolled in this study, where the majority exhibited unstable angina (81.6%) and showed preserved left ventricular systolic function. Patients in the high GA level group were commonly female and were more likely to have metabolic disorders and to exhibit severe CAD (all p＜0.05). MACCE occurred in 126 patients (7.0%) during a mean follow-up time of 17.2 months. The cumulative risk of MACCE at the 18-month follow-up visit significantly increased in a stepwise fashion along with increased GA levels (log-rank p=0.018) in the serum. The association between serum GA levels and MACCE was further determined after adjusting traditional risk factors and hemoglobin A1c (HbA1c) (GA, per 1% increase: hazard ratio [HR] 1.09, 95% confidence interval [CI] 1.06-1.13; GA, higher vs. lower tertial: HR 1.92, 95% CI 1.01-3.67). In a subgroup analysis, the prognostic role of serum GA only existed in diabetic patients, even when adjusting for traditional risk factors and HbA1c levels.

CONCLUSIONS

Elevated GA levels in the serum were associated with poor intermediate-term outcomes in low-risk ACS patients who underwent PCI, especially in patients with preexisting diabetes.

AGE-RAGE Stress and Coronary Artery Disease

Coronary artery atherosclerosis and atherosclerotic plaque rupture cause coronary artery disease (CAD). Advanced glycation end products (AGE) and its cell receptor RAGE, and soluble receptor (sRAGE) and endogenous secretory RAGE (esRAGE) may be involved in the development of atherosclerosis. AGE and its interaction with RAGE are atherogenic, while sRAGE and esRAGE have antiatherogenic effects. AGE-RAGE stress is a ratio of AGE/sRAGE. A high AGE-RAGE stress results in development and progression of CAD and vice-versa. AGE levels in serum and skin, AGE/sRAGE in patients with CAD, and expression of RAGE in animal model of atherosclerosis were higher, while serum levels of esRAGE were lower in patients with CAD compared with controls. Serum levels of sRAGE in CAD patients were contradictory, increased or decreased. This contradictory data may be due to type of patients used, because the sRAGE levels are elevated in diabetics and end-stage renal disease. AGE/sRAGE ratio is elevated in patients with reduced or elevated levels of serum sRAGE. It is to stress that AGE, RAGE, sRAGE, or esRAGE individually cannot serve as universal biomarker. AGE and sRAGE should be measured simultaneously to assess the AGE-RAGE stress. The treatment of CAD should be targeted at reduction in AGE levels, prevention of AGE formation, degradation of AGE in vivo, suppression of RAGE expression, blockade of RAGE, elevation of sRAGE, and use of antioxidants. In conclusion, AGE-RAGE stress would initiate the development and progression of atherosclerosis. Treatment modalities would prevent, regress, and slow the progression of CAD.

The role of advanced glycation end-products in the development of coronary artery disease in patients with and without diabetes mellitus: a review

Background

Traditional risk factors are insufficient to explain all cases of coronary artery disease (CAD) in patients with diabetes mellitus (DM). Advanced glycation end-products (AGEs) and their receptors may play important roles in the development and progression of CAD.

Body

Hyperglycemia is the hallmark feature of DM. An increase in the incidence of both micro-and macrovascular complications of diabetes has been observed with increased duration of hyperglycemia. This association persists even after glycemic control has been achieved, suggesting an innate mechanism of “metabolic memory.” AGEs are glycated proteins that may serve as mediators of metabolic memory due to their increased production in the setting of hyperglycemia and generally slow turnover. Elevated AGE levels can lead to abnormal cross linking of extracellular and intracellular proteins disrupting their normal structure and function. Furthermore, activation of AGE receptors can induce complex signaling pathways leading to increased inflammation, oxidative stress, enhanced calcium deposition, and increased vascular smooth muscle apoptosis, contributing to the development of atherosclerosis. Through these mechanisms, AGEs may be important mediators of the development of CAD. However, clinical studies regarding the role of AGEs and their receptors in advancing CAD are limited, with contradictory results.

Conclusion

AGEs and their receptors may be useful biomarkers for the presence and severity of CAD. Further studies are needed to evaluate the utility of circulating and tissue AGE levels in identifying asymptomatic patients at risk for CAD or to identify patients who may benefit from invasive intervention.

Endogenous Secretory Receptor for Advanced Glycation End Products Protects Endothelial Cells from AGEs Induced Apoptosis

Endogenous secretory receptor for advanced glycation end products (esRAGE) binds extracellular RAGE ligands and blocks RAGE activation on the cell surface, protecting endothelial cell function. However, the underlying mechanism remains unclear. Endothelial cells overexpressing the esRAGE gene were generated using a lentiviral vector. Then, quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to assess esRAGE mRNA and protein levels, respectively. Hoechst-PI double staining was used to assess apoptosis. Western blot and qRT-PCR were used to assess the expression levels of apoptosis-related factors and the proinflammatory cytokine NF-кB. Compared with the control group, AGEs significantly induced endothelial cell apoptosis, which was significantly reduced by esRAGE overexpression. Incubation with AGEs upregulated the proapoptotic factor Bax and downregulated the antiapoptotic factor Bcl-2. Overexpression of esRAGE reduced Bax expression induced by AGEs and increased Bcl-2 levels. Furthermore, AGEs increased the expression levels of proinflammatory cytokine NF-кB, which were reduced after esRAGE overexpression. esRAGE protects endothelial cells from AGEs associated apoptosis, by downregulating proapoptotic (Bax) and inflammatory (NF-кB) factors and upregulating the antiapoptotic factor Bcl-2.

Relationship between RAGE gene polymorphisms and cardiovascular disease prognosis in the Chinese Han population

Cardiovascular disease (CVD) is the leading cause of death in China. This study aimed to investigate whether RAGE gene polymorphisms are associated with the prognosis of various cardiovascular diseases in the Chinese Han population. This study was conducted from July 2004 to December 2005 and a total of 425 subjects from Guangdong province were enrolled. Genotyping of the three polymorphisms (-429T/C, 1704G/T, and G82S) in the RAGE gene was performed with polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP). Patients were followed for 6.5 years to watch for the development of cardiovascular events and mortality. Subjects with the S mutation of the G82S polymorphism had a significantly higher risk of all-cause mortality and acute myocardial infarction (AMI) than did those with wild-type homozygosity. Logistic regression analysis and Kaplan-Meier analysis all revealed that the G82S polymorphism of the RAGE gene was associated with a significantly increased risk of all-cause mortality and AMI. However, the -429T/C and 1704G/T polymorphisms were not shown to have any effect on prognosis. In conclusion, the G82S variant of the RAGE gene was significantly associated with an increased risk of all-cause mortality and AMI in the Chinese Han population.

Association of RAGE gene Gly82Ser polymorphism with coronary artery disease and ischemic stroke: A systematic review and meta-analysis

BACKGROUND

The receptor for advanced glycosylation end products (RAGE) has been widely linked to diabetic atherosclerosis, but its effects on coronary artery disease (CAD) and ischemic stroke (IS) remain controversial. The Gly82Ser polymorphism is located in the ligand-binding V domain of RAGE, suggesting a possible influence of this variant on RAGE function. The aim of the present study is to clarify the association between the RAGE Gly82Ser polymorphism and susceptibility to CAD and IS.

METHODS

Eligible studies were identified through a comprehensive literature search. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the association of Gly82Ser polymorphism with CAD and IS risk. Fixed- or random-effects model was used depending on the heterogeneity between studies. A funnel plot and Egger linear regression test were applied to assess publication bias. We also performed subgroup analyses to investigate potential sources of heterogeneity.

RESULTS

A total of 16 eligible articles containing 18 studies were analyzed. The pooled analysis indicated that the Gly82Ser polymorphism significantly increased CAD risk in recessive and homozygous genetic models (SS vs GS + GG: OR = 1.34, 95% CI = 1.09-1.64; SS vs GG: OR = 1.38, 95% CI = 1.12-1.71). A significant association between the Gly82Ser polymorphism and IS risk was observed in all tested models except the heterozygous genetic model (GS + SS vs GG: OR = 1.20, 95% CI = 1.04-1.38; SS vs GS + GG: OR = 2.20, 95% CI = 1.74-2.78; SS vs GG: OR = 2.23, 95% CI = 1.72-2.91; S vs G: OR = 1.32, 95% CI = 1.05-1.65). Subgroup analysis suggested an association between CAD and IS risk and the Gly82Ser polymorphism in the Chinese population, but not in the non-Chinese population.

CONCLUSIONS

The current meta-analysis suggests that the RAGE Gly82Ser polymorphism is associated with an increased risk of CAD and IS, especially in the Chinese population. However, better-designed studies with larger sample sizes are needed to validate the results.

Elevated glycated albumin and reduced endogenous secretory receptor for advanced glycation endproducts levels in serum predict major adverse cardio-cerebral events in patients with type 2 diabetes and stable coronary artery disease

BACKGROUND AND AIM

Glycated albumin (GA) and the endogenous secretory receptor for advanced glycation endproducts (esRAGE) may modulate risk related to atherosclerosis. We tested the hypothesis that elevated GA and reduced esRAGE in serum are associated with adverse clinical outcomes in patients with type 2 diabetes and stable coronary artery disease (CAD).

METHODS

We determined GA and esRAGE serum levels in 576 consecutive patients with type 2 diabetes and stable CAD undergoing sirolimus-eluting stent (SES)-PCI. The primary endpoint was the incidence of major adverse cardio-cerebral events (MACCE) including cardiac death, non-fatal myocardial infarction, and non-fatal stroke during a 2-year follow-up. The secondary endpoint was the occurrence of clinically driven repeat revascularization during a 2-year follow-up. The prognostic value of GA and esRAGE was determined with the Cox-proportional hazard model after adjustment for covariates.

RESULTS

A total 40 patients (6.9%) experienced MACCE, and 108 (18.8%) patients underwent repeat coronary revascularization during the follow-up. Serum GA (HR=1.22, 95% CI 1.16-1.28; HR=1.15, 95% CI 1.11-1.19, respectively; for both p<0.001) and esRAGE (HR=0.60, 95% CI 0.40-0.87; HR=0.75, 95% CI 0.61-0.92, respectively; for both p<0.01) levels remained independent predictors of the primary and secondary endpoints after adjustment for possible confounders.

CONCLUSIONS

Serum GA and esRAGE are novel predictors of long-term clinical outcomes in patients with type 2 diabetes and stable CAD. Increased serum GA and decreased esRAGE are associated with a poor prognosis in such patients.

Association between the receptor for advanced glycation end products gene polymorphisms and coronary artery disease

Receptor for advanced glycation end products (RAGE) is a cell-surface molecule member of the immunoglobulin superfamily and thought to play a critical role in diabetic atherosclerosis. A growing body of studies has been conducted to determine the extent to which the variants of RAGE gene influence the risk of coronary artery disease (CAD). However, these have reported conflicting results. To investigate this inconsistency, we performed a comprehensive meta-analysis on the associations between the RAGE -374T/A, -429T/C, and Gly82Ser polymorphisms and the risk of CAD. A total of 4,402 cases and 6,081 controls from 17 published case-control studies were included. The overall odds ratio (OR) of CAD was 0.99 (95 % CI 0.87-1.13), 1.06 (95 % CI 0.95-1.18) and 1.12 (95 % CI 0.90-1.39) for -374A, -429C, and the minor S allele of the Gly82Ser polymorphism, respectively. Similarly, no significant results were observed for these polymorphisms using dominant model. However, when stratified by diabetic/non-diabetic status of the CAD patients, we found significant association among Caucasian type two diabetic CAD patients with the -374A allele [OR 1.39, 95 % CI 1.10-1.76, P(Z) = 0.006], while no association was detected between the -374T/A polymorphism and non-diabetic CAD in Caucasians [OR 0.79, 95 % CI 0.58-1.07, P(Z) = 0.13]. In conclusion, this meta-analysis suggested that possession of the -374A allele may be a risk factor in CAD among Caucasian patients with type two diabetes.

Beyond HbA1c and glucose: the role of nontraditional glycemic markers in diabetes diagnosis, prognosis, and management

Fasting glucose and hemoglobin A1c (HbA1c) are the standard measures for diagnosis and monitoring of diabetes. There has been recent interest in nontraditional markers of hyperglycemia, including fructosamine, glycated albumin, and 1,5-anhydroglucitol (1,5-AG), as alternatives or adjuncts to standard measures. There is a growing literature linking these nontraditional markers with microvascular and macrovascular complications. Fructosamine and glycated albumin have also been shown to improve identification of persons with diabetes. However, long-term prospective studies with clinical outcomes are lacking. Some modern laboratory assays for fructosamine, glycated albumin, and 1,5-AG have excellent performance. Expanded use of these tests has the potential to improve diabetes care as these measures may overcome limitations of HbA1c in certain patients, complement traditional measures by providing additional information on shorter-term glycemic control, and improve risk stratification for diabetes and its complications. Nonetheless, studies are needed to demonstrate if their routine use will benefit patients and improve outcomes.

Association of four genetic polymorphisms of AGER and its circulating forms with coronary artery disease: a meta-analysis

Background

Considerable efforts have been devoted to evaluating the association of the receptor for advanced glycation end-products (gene AGER and protein: RAGE) genetic variants to coronary artery disease (CAD); the results, however, are often irreproducible. To generate more information, we sought to explore four common polymorphisms of AGER and its circulating forms associated with the risk of CAD via a meta-analysis.

Methodology/Principal Findings

Articles were identified by searching PubMed, EMBASE, Wanfang and CNKI databases before March 2013. Qualified articles had case-control designs and investigated AGER four polymorphisms (T-429C, T-374A, Gly82Ser, G1704A) or circulating soluble RAGE (sRAGE) or endogenous secretory RAGE (esRAGE) levels associated with CAD. Twenty-seven articles involving 39 independent groups fulfilled the predefined criteria. Overall, no significance was observed for all examined polymorphisms under allelic and dominant models. When restricting groups to CAD patients with diabetes mellitus or renal disease, deviations of risk estimates from the unity were stronger than overall estimates for all polymorphisms except for G1704A due to limited available studies. For example, under dominant model, having -429C allele increased the odds of developing CAD in diabetic patients by 1.22-fold (95% confidence interval (95% CI) 0.99–1.51; P = 0.06; I² = 6.7%) compared with that of overall estimate of 1.15-fold (95% CI: 0.97–1.36; P = 0.111; I² = 18.0%). Circulating sRAGE levels were non-significantly lower in CAD patients than in controls, whereas this reduction was totally and significantly reversed in CAD patients with diabetes mellitus (weighted mean difference: 185.71 pg/ml; 95% CI: 106.82 to 264.61 pg/ml). Circulating esRAGE levels were remarkably lower in CAD patients, as well as in subgroups with or without diabetes mellitus and without renal disease.

Conclusions

Our findings demonstrated that association of AGER genetic polymorphisms with CAD was potentiated in patients with diabetes mellitus or renal disease. Practically, circulating esRAGE might be a powerful negative predictor for the development of CAD.

Usefulness of preprocedural levels of advanced glycation end products to predict restenosis in patients with controlled diabetes mellitus undergoing drug-eluting stent implantation for stable angina pectoris (from the Prospective ARMYDA-AGEs Study)

Diabetes mellitus (DM) remains the main predictor of restenosis rates and cardiovascular events following successful percutaneous coronary intervention (PCI) despite the use of drug-eluting stents (DES). HbA1c <6.0% is considered an index of optimized metabolic control in patients with DM, but several studies are downsizing its role in the clinical management of these patients. Increasing evidence points at the role of advanced glycation end products (AGEs) in restenosis pathogenesis independently on Hb1AC levels. Thus, we investigated the predictive value of preprocedural AGE levels for in-stent restenosis in a population of euglycaemic diabetic patients undergoing PCI with DES implantation. One hundred twenty-five consecutive patients with DM in optimized glycemic control admitted for stable angina pectoris and treated with elective DES implantation at a tertiary hospital were prospectively included. The primary end point of the ARMYDA-AGEs study was to compare rates of angiographic ISR at 6 months after the intervention according to pre-PCI levels of AGEs. Secondary end points were the correlations of AGE levels with occurrence of periprocedural myocardial damage, major adverse cardiac events, and in-stent late loss at 6-month control coronary angiography. AGE levels >17 μM was found to be an independent predictor of ISR at 6 months and stent lumen loss. AGEs failed to predict occurrence of secondary endpoints. In conclusion, elevated AGE levels predict occurrence of in-stent restenosis after DES implantation in patients with DM on optimized glycemic control and might represent a dosable marker of adverse outcome after PCI.

Screening for significant atherosclerotic renal artery stenosis with a regression model in patients undergoing transradial coronary angiography/intervention

OBJECTIVE

Early detection of atherosclerotic renal artery stenosis (ARAS) is clinically important with respect to blood pressure control, prevention of renal insufficiency, and even improving survival. We investigated whether the presence of significant ARAS (luminal diameter narrowing ≥70%) could be predicted using a logistic regression model before coronary angiography/intervention.

METHODS

Initially, we developed a logistic regression model for detecting significant ARAS based upon clinical and angiographic features and biochemical measurements in a cohort of 1813 patients undergoing transfemoral coronary and renal angiography. This model was then prospectively applied to an additional 495 patients who received transradial renal angiography to ascertain its predictive accuracy for the presence of significant ARAS.

RESULTS

Multivariate regression analysis revealed that older age (≥65 years), resistant hypertension, type 2 diabetes, creatinine clearance (Ccr) ≤60 ml/min, and multivessel coronary disease were independent predictors for significant ARAS. A logistic regression model for detecting ARAS by incorporating conventional risk factors and multivessel coronary disease was generated as: P/(1-P)=exp(-2.618+1.112[age≥65 years]+1.891[resistant hypertension]+0.453[type 2 diabetes]+0.587[Ccr≤60 ml/min]+2.254[multivessel coronary disease]). When this regression model was prospectively applied to the additional 495 patients undergoing transradial coronary and renal angiography, significant ARAS could be detected with a sensitivity of 81.2%, specificity of 88.9%, and positive and negative predictive accuracies of 53.8% and 96.7%, respectively.

CONCLUSIONS

The logistic regression model generated in this study may be useful for screening for significant ARAS in patients undergoing transradial coronary angiography/intervention.

Meta-analysis of RAGE gene polymorphism and coronary heart disease risk

Background

Recent data from human and animal studies have shown an upregulated expression of advanced glycosylation end product–specific receptor (RAGE) in human atherosclerotic plaques 1 and in retina, messangial, and aortic vessels, suggesting an important role of RAGE in the pathogenesis of atherothrombotic diseases. In the past few years, the relationship between RAGE polymorphisms (−429T/C, −374T/A, and G82S) and coronary heart disease (CHD) has been reported in various ethnic groups; however, these studies have yielded contradictory results.

Methods

PubMed, ISI web of science, EMBASE and the Chinese National Knowledge Infrastructure databases were systematically searched to identify relevant studies. Data were abstracted independently by two reviewers. A meta-analysis was performed to examine the association between RAGE polymorphisms and susceptibility to CHD. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

Results

A total of 17 studies including 4343 patients and 5402 controls were involved in this meta-analysis. Overall, no significant results were observed for −429T/C (OR  = 1.01, 95% CI: 0.92–1.12, P  = 0.78), −374T/A (OR  = 1.11, 95% CI: 0.98–1.26, P  = 0.09) and G82S (OR  = 1.12, 95% CI: 0.86–1.45, P  = 0.41) polymorphism. In the stratified analyses according to ethnicity, sample size, CHD endpoint and Hardy-Weinberg status, no evidence of any gene-disease association was obtained.

Conclusions

This meta-analysis demonstrates that there is no association between the RAGE −429T/C, −374T/A and G82S polymorphisms and CHD.

Association study of polymorphisms in the receptor for advanced glycation end-products (RAGE) gene with susceptibility and prognosis of heart failure

BACKGROUND

Functional polymorphisms in the receptor for advanced glycation end-products (RAGE) gene have been implicated in several vascular diseases. However, to date, no study investigated the association of RAGE polymorphisms with heart failure (HF).

OBJECTIVE

In this study we tested the hypothesis that the 63-bp insertion/deletion, the -374T>A (rs1800624) and the -429T>C (rs1800625) polymorphisms in the RAGE gene might be associated with susceptibility to HF and could predict all-cause mortality in Brazilian outpatients with left ventricular systolic dysfunction.

METHODS

A total of 273 consecutive HF patients (196 Caucasian- and 77 African-Brazilians) and 334 healthy blood donors (260 Caucasian- and 74 African-Brazilians) were enrolled in a tertiary care university hospital. Genotyping of RAGE polymorphisms was done by polymerase chain reaction (PCR) or PCR followed by enzyme restriction analysis.

RESULTS

The allele, genotype and haplotype frequencies of -374T>A and -429T>C polymorphisms were not significantly different between HF patients and healthy blood donors in both ethnic groups. However, among African-Brazilians, the frequency of carriership of the del allele was lower in HF patients than in blood donors (2.6% vs 12.2%, respectively, p=0.008). Patients were followed-up for a median of 38 months and the survival analysis did not reveal a consistent association between RAGE polymorphisms and all-cause death in both ethnic groups.

CONCLUSION

The -374T>A and -429T>C polymorphisms in the RAGE gene were not associated with the susceptibility and prognosis of HF. Notwithstanding, the 63-bp ins/del polymorphism might be involved in the susceptibility to HF in African-Brazilians.

Identification of haplotype tag single nucleotide polymorphisms within the receptor for advanced glycation end products gene and their clinical relevance in patients with major trauma

INTRODUCTION

The receptor for advanced glycation end products (RAGE) has been considered as one of the major pattern recognition receptors and plays an important role in the development of sepsis and multiple organ dysfunction in critical illnesses. Although genetic variants of the RAGE gene have been shown to be well associated with susceptibility to some inflammatory diseases, little is known about their clinical relevance in the development of sepsis in critical ill patients.

METHODS

Four genetic variants were selected from the entire RAGE gene and genotyped using pyrosequencing and polymerase chain reaction-length polymorphism methods. Association studies were performed in two independent Chinese Han populations.

RESULTS

Among the four genetic variants, only the rs1800625 polymorphism was significantly associated with sepsis morbidity rate and multiple organ dysfunction (MOD) scores in patients with major trauma both in Chongqing (n = 496) and Zhejiang (n = 232) districts, respectively. Results from ex vivo responsiveness of peripheral blood leukocytes indicated that the rs1800625 polymorphism was well associated with decreased production of TNFα. In addition, the rs1800625 polymorphism could significantly inhibit the promoter activities of the RAGE gene.

CONCLUSIONS

The rs1800625 polymorphism is a functional variant, which might be used as a relevant risk estimate for the development of sepsis and multiple organ dysfunction syndrome in patients with major trauma.

Association between sRAGE, esRAGE levels and vascular inflammation: analysis with (18)F-fluorodeoxyglucose positron emission tomography

BACKGROUND

The receptor for advanced glycation end-products (RAGE) and its diverse ligands play a pivotal role in the development of cardiovascular disease. Soluble forms of RAGE (sRAGE), including the splice variant endogenous secretory RAGE (esRAGE), may neutralize AGE-RAGE mediated vascular damage by acting as a decoy. (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a novel imaging technique for detecting vascular inflammation.

METHODS

We examined vascular inflammation measured using FDG-PET in 41 type 2 diabetes patients and 41 healthy control subjects in the right carotid artery. Vascular (18)F-FDG uptake was measured as the blood-normalized standardized uptake value (SUV), known as the target-to-background ratio (TBR). In addition, their relationship with carotid intima-media thickness (CIMT), estimated GFR (eGFR), and other cardiovascular risk factors was evaluated.

RESULTS

Both mean and maximum TBR values were significantly higher in patients with type 2 diabetes compared to healthy subjects. After adjusting for age and gender, sRAGE levels were significantly correlated with both mean and maximum TBR values, but not with CIMT values. Multiple linear regression analysis showed that maximum TBR values were independently associated with sRAGE levels in addition to HbA1c and eGFR.

CONCLUSIONS

Circulating sRAGE showed significant association with TBR values measured using FDG-PET, which reflect vascular inflammation.

Association of AGER gene G82S polymorphism with the severity of coronary artery disease in Chinese Han population

BACKGROUND AND OBJECTIVE

Advanced glycosylation end-product receptor (AGER) plays an important role in the development and progression of atherosclerosis. The G82S polymorphism (rs2070600) is located in the ligand-binding V-domain of AGER suggesting a possible influence of this variant on AGER function. The aim of this study is to evaluate the association of the G82S polymorphism with the severity of coronary artery disease (CAD) in patients with or without type 2 diabetes mellitus (T2DM).

DESIGN AND METHODS

The AGER gene G82S polymorphism was analysed in 270 nondiabetic and 270 type 2 diabetic Chinese Han patients with angiographically proven CAD (luminal stenosis ≥ 50%). The number of diseased vessels and Gensini score were used to determine the severity of CAD. Genotyping for the G82S polymorphism was performed by PCR-RFLP using restriction enzymes AluI.

RESULTS

The frequency of 82S allele was significantly lower in the diabetic CAD patients with multi-vessel disease than in those with single-vessel disease (P = 0·015). When controlled for confounding variables, the 82S allele was associated with decreased risk of multi-vessel disease [P = 0·038, adjusted OR = 0·565 (0·329-0·972)]. The protective effect of the 82S allele against the severity of CAD was not observed in patients with nondiabetic CAD.

CONCLUSIONS

AGER 82S allele showed a protective effect on CAD severity in the presence of T2DM in Chinese Han population.

Soluble forms of RAGE in internal medicine

The receptor for advanced glycation end-products (RAGE) and its ligands are intimately involved in the pathobiology of a wide range of diseases that share common features, such as enhanced oxidative stress, immune/inflammatory responses, and altered cell functions. Soluble forms of RAGE (sRAGE), including the splice variant endogenous secretory (es)RAGE, have been found circulating in plasma and tissues. Experimental data suggest that these isoforms may neutralize the ligand-mediated damage by acting as a decoy. Moreover, evidence is mounting to support a role for both sRAGE and esRAGE as biomarkers or endogenous protection factors against RAGE-mediated pathogenesis. In this review, we will focus on clinical and therapeutical implications arising from studies investigating the significance of soluble RAGE isoforms in several clinical settings, including cardiovascular disease, diabetes mellitus, hypercholesterolemia, chronic renal failure, immune/inflammatory diseases, pulmonary diseases, neurodegeneration, and cancer.

Decreased serum esRAGE level is associated with angiographically determined coronary plaque progression in diabetic patients

OBJECTIVE

This study evaluated the relationship between serum levels of endogenous secretory receptor for advanced glycation endproducts (esRAGE) and coronary plaque progression in diabetic and nondiabetic patients.

DESIGN AND METHODS

Serum esRAGE level was measured and quantitative coronary angiography (QCA) was performed in 265 consecutive patients at baseline and 1-year follow-up.

RESULTS

Comparing to baseline, serum esRAGE level was significantly increased during follow-up in nondiabetic patients without plaque progression (p=0.014), unchanged in nondiabetic patients with plaque progression and diabetic patients without plaque progression, and decreased in diabetic patients with plaque progression (p=0.011). Moreover, change of esRAGE levels correlated with change of QCA measurements. Multivariable regression analyses revealed that high-density lipoprotein cholesterol (OR=0.214, p=0.037), hypertension (OR=2.755, p=0.011), high-sensitivity C-reactive protein (OR=1.083, p<0.001) and change of esRAGE (OR=23.477, p<0.001) were independent risk factors for plaque progression in diabetic patients.

CONCLUSIONS

This study demonstrated an association of decreased serum esRAGE level with coronary plaque progression in patients with diabetes.