ADMA Levels Research Articles

Endothelial Dysfunction and Nailfold Videocapillaroscopy Pattern as Predictors of Digital Ulcers in Systemic Sclerosis: a Cohort Study and Review of the Literature.

Raynaud's phenomenon and digital ulcers (DUs) are frequent among systemic sclerosis (SSc) patients. Our aim was to investigate the diagnostic and predictive value for DU of endothelial dysfunction biomarkers (flow-mediated dilatation (FMD), serum levels of endothelin-1 (ET-1), and ADMA), angiogenic/angiostatic biomarkers (vascular endothelial growth factor (VEGF), endoglin, and endostatin), and nailfold videocapillaroscopy (NVC). We compared our results with a literature review. In a cohort study of 77 SSc patients, we followed two groups of patients: (i) naïve DU patients (39) and (ii) active DU at baseline (38 patients) for 3 years. Telangiectasia (p < 0.001) and diffuse disease subset (p = 0.001) were significantly more frequent in patients with active DU at enrolment. Additionally, NVC late scleroderma pattern (AUC 0.846, 95%CI 0.760-0.932), lower values of FMD (AUC 0.754, 95%CI 0.643-0.864), increased serum levels of ET-1 (AUC 0.758, 95%CI 0.649-0.866), ADMA (AUC 0.634, 95%CI 0.511-0.757), and endoglin as well as low VEGF serum levels (AUC 0.705, 95%CI 0.579-0.830) were significantly associated to new DU events in the 3-year follow-up. Cox regression analysis showed that FMD > 9.41 % (HR 0.37, 95%CI 0.14-0.99); ET-1 >11.85 pmol/L (HR 3.81, 95%CI 1.41-10.26) and late NVC pattern (HR 2.29, 95%CI 0.97-5.38) were independent predictors of DU recurrence. When estimating the probability of occurrence of first DU in naïve DU patients, only late NVC pattern (HR 12.66, 95%CI 2.06-77.89) was an independent predictor factor. In conclusion, late scleroderma patterns in NVC are the best independent predictors of SSc patients who are at risk of developing DU. Endothelial dysfunction assessed by FMD and ET-1 was also found to be an independent predictor of DU recurrence in a 3-year follow-up.

PP.13.06

Objective: Increased arterial stiffness (AS) is an independent risk factor for cardiovascular disease. Endothelial nitric oxide (NO) is vasoprotective by decreasing not only vascular tone in resistance arteries, but also stiffness in conductance arteries. Asymmetric (ADMA) and symmetric (SDMA) dimethylarginines, endogenous inhibitors of NO synthesis from the precursor L-arginine (ARN), increase in conditions of oxidative stress and contribute to progression of endothelial dysfunction and arteriosclerosis. In essential hypertensives (EH) we investigated the relationship between systemic AS, as assessed by the ratio of pulse pressure (PP) to stroke volume (SV), with circulating levels of ADMA, SDMA, ARN and the activity of the renin-aldosterone system in resting conditions. Design and method: In 25 untreated grade I-II EH (age 50 ± 12 yrs, range 19–71, M/F = 15/10) blood pressure (BP, sphygmomanometer), heart rate (HR, EKG), stroke volume (SV, impedance cardiography) were measured after supine rest; venous blood was simultaneously sampled for plasma ADMA, SDMA, ARN (by HPLC), plasma renin activity (PRA) and aldosterone (Aldo)(by RIA). Results: Table shows means ± sd:Supine BP was 142/96 ± 15/8.4 mmHg, HR = 70.0 ± 9.5 bt/min; PRA was 0.3 ± 0.05 ng/ml/h (range 0.1–0.9) and Aldo 9.8 ± 0.7 ng/dl (range 3.7–17). AS (range 0.89–2.21 mmHg/ml) was directly related to age (r = 0.61, p < 0.05), to SDMA (r = 0.83, p < 0.01) and inversely to ARN/ADMA ratio, an indicator of NO production (r = -0.64, p < 0.05); AS was not related to PRA or Aldo. In a multiple regression analysis, SDMA was the best predictor of AS (p < 0.05). Conclusions: Systemic AS in EH was directly related to circulating levels of endogenous inhibitors of NO production. These data are compatible with an impaired activity of endothelial NO associated with increased stiffness of conductance arteries, a condition at higher cardiovascular risk in uncomplicated hypertensives.

Icariin regulates PRMT/ADMA/DDAH pathway to improve endothelial function

Oxidative stress may affect PRMT/ADMA/DDAH (protein arginine methyltransferases/asymmetric dimethylarginine/dimethylarginine dimethylaminohydrolase) pathway to impair endothelial dysfunction. The present study was carried out to test the effect of icariin on endothelial function and the mechanisms responsible for this. Eighty mice at 12 weeks of age were separated randomly into four groups (n = 20): C57BL/6J control, untreated apolipoprotein E-deficient (ApoE(-/-)), two groups of icariin-treated (10 or 30 mg/kg body wt/day, intragastrically) ApoE(-/-). Primary human umbilical vein endothelial cells (HUVECs) were randomly divided into 7 groups: control group, vehicle of icariin (10 μmol/L) group, icariin (10 μmol/L) group, lysophosphatidylcholine (LPC) (10 μg/mL) group, LPC plus icariin (1 μmol/L) group, LPC plus icariin (3 μmol/L) group, and LPC plus icariin (10 μmol/L) group. In ApoE(-/-) mice and primary HUVECs, icariin treatment decreased reactive oxygen species production, PRMT I expression, ADMA level, half-maximum effective concentration of ApoE(-/-) mice aortic rings. Icariin increased DDAH II expression, DDAH activity, maximal relaxation value and endothelium-dependent vasorelaxation in aortic rings from ApoE(-/-) mice (p < 0.05 or p < 0.01). The present results suggest that icariin regulates PRMT/ADMA/DDAH pathway to improve endothelial function.

Abstract 437: Dysregulation of Cardiovascular Homeostasis by Proton Pump Inhibitors: Safety Concerns

Background: Proton pump inhibitors (PPIs) are commonly used drugs to treat gastric reflux. Recent retrospective cohorts have raised concern that the use of PPIs is associated with increased cardiovascular (CV) risk. In addition, we have recently reported seminal preclinical work demonstrating interference of the PPIs with CV homeostasis (Ghebremariam et al; Circulation 2013; 128:845-53). However, there is no prospective clinical study evaluating whether the use of PPIs directly causes CV harm. Methods: We conducted a controlled cross-over pilot study among 21 adults who are healthy (n = 11) or have established clinical cardiovascular disease (n = 10). Study subjects were assigned to receive a PPI (Prevacid) or a placebo pill once daily for 4 weeks. After a 2 week washout period, participants were crossed-over to receive the alternate treatment for the ensuing 4 weeks. Subjects underwent evaluation of vascular function (by the EndoPAT technique) and had plasma levels of asymmetric dimethylarginine (ADMA, an endogenous inhibitor of endothelial function) measured before and after treatment. In addition to the clinical study, we also carried out pharmacovigilance study of PPI use and CV harm using novel data mining approach from a dataset of 1.8 million patients. Results: In the clinical study, we observed a marginal inverse correlation between the EndoPAT score and plasma levels of ADMA (r = -0.364). Subjects experienced a greater worsening in plasma ADMA levels while on PPI than on placebo. However, these trends did not reach statistical significance, and PPI use was also not associated with impairment in flow mediated vasodilation during the course of this study. Nevertheless, our data mining study revealed increased association of PPI use with CV risk. Conclusions: In this open-label, cross-over pilot study, PPI use did not significantly influence vascular endothelial function. However, a positive association between PPI use and CV risk in our database study suggests that large number of participants may be needed to be followed up prospectively. Therefore, larger and longer-term trials are needed to mechanistically explain the correlation between PPI use and adverse clinical outcomes, which has increasingly been reported in retrospective cohorts.

Abstract 167: High Dietary Fructose Does not Exacerbate the Detrimental Consequences of a HF Diet on Basilar Artery Function

There is a strong correlation between the consumption of sugar- or fructose-enriched products and obesity. Moreover, high dietary fructose without added fat and in the absence of obesity induces leptin resistance and exacerbates subsequent HF-induced obesity. Elevated leptin is associated with arterial stiffness. Thus, we hypothesized that the consequences of a high-fat/high-fructose (HF/F) diet would be more detrimental than a high-fat (HF) or chow diet on functional and structural changes in the basilar arteries. Male Sprague Dawley rats were fed either with chow, HF (30%) or HF/F (30%/44%) diets for 12 weeks (N=8-10/group). The basilar artery was cannulated in a pressurized system (90cm H2O) and vascular contractile responses to KCl (30-120 mM) and endothelin (10-11-10-7 M), and relaxation to acetylcholine (ACh) (10-10-10-4 M), and diethylamine (DEA)-NONO-ate (10-10-10-4 M) evaluated and artery wall thickness and eNOS immunofluroescence determined. At death, leptin, blood lipids, and asymetricaldiamethyl arginine level (ADMA) were assayed in serum. Basilar artery contractility was unchanged, but both HF and HF/F diets resulted in decreased relaxation responses compared with chow to endothelium dependent (Ach logEC50: -6.48, chow; -5.65, HF; 5.79HF/F, p&lt;0.05) and endothelium independent relaxation (DEA: -5.94;-4.45;-4.49, p&lt;.05). Increased basilar artery wall thickness was observed only in HF group (22±1.2 vs 27±1.6μm, p&lt;.05). Both diets increased serum ADMA levels (.36±.03 HF; .42±.05 HF/F vs .26±.02 chow, p&lt;.05), 50% decreased eNOS immunofluorescence (arbitrary units, p&lt;.05), and increased adipose tissue (10.7±.5 HF; 12.7±.8 HF/F vs 7.8±.3 chow, p&lt;.05). HF/F increased triglycerides (157±32 mg/dl) and leptin (10.4±1.8ng/ml) greater than with HF (65±15; 6.6±.6) or chow diet (63±14; 4.1±.3). In conclusion, both HF diets impaired basilar artery relaxation, potentially due to decreased eNOS synthesis and increased ADMA. Although, leptin and triglycerides were greater with HF/F diet only the HF increased wall thickness. These data suggest that the presence of high fructose in a HF diet does not exacerbate the detrimental consequences of a HF diet on basilar artery function.

CT-1 induces angiogenesis by regulating the ADMA/DDAH Pathway.

Cardiotrophin-1 (CT-1), a member of the IL-6 superfamily, is elevated in the serum of patients with ischemic and valvular heart disease. In this study, we hypothesized that CT-1 induces endothelial cell angiogenesis and that the ADMA/DDAH pathway plays an important role in the process. pEGFP-N1-CTF1-GFP and pEGFP-N1 were constructed and used to transiently transfect to HUVECs, mediated by LipofectamineTM 2000. After transfection, the expression of CT-1 was examined by qRT-PCR and western blotting. Endothelial cell proliferation assay was evaluated using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide (MTT) method. Migration assay was performed using transwell, tube formation test was examined on Matrigel, eNOSmRNA expression was assayed by qRT-PCR, DDAH I, DDAHII and VEGF expression were detected by western blotting, the level of ADMA and the activity of DDAH were measured by High Performance Liquid Chromatography, NOS activity and the concentration of NO were assayed by L-[3H] citrulline production from L-[3H]arginine. Overexpression of CT-1, increased endothelial cell proliferation, migration and formation of blood vessels, upregulated the expression of eNOSmRNA, DDAHI, DDAHII and VEGF, elevated the activity of DDAH and NOS, decreased the level of ADMA and promoted NO synthesis. In contrast, ADMA partially inhibited the effects of CT-1 induction. Overexpression of CT-1 increases cell proliferation, migration and formation of blood vessels. This result also suggests that CT-1 may regulate angiogenesis through the ADMA/DDAH pathway.

Scientific Prize Papers

Objective Recent interest has focused on the role of the methyl-arginines, endogenous inhibitors of nitric oxide, as adverse prognostic indicators. To date, few studies have assessed the role of symmetric dimethyl-arginine (SDMA) in patients with peripheral arterial disease. We aimed to determine the relationship, if any, of SDMA to all-cause mortality and disease severity as assessed by the ankle-brachial index (ABI) in patients with symptomatic peripheral arterial disease (PAD). Methods In 238 patients with symptomatic PAD and an ABI of Results The median follow-up was 6 years 11 months (interquartile range [IQR], 4 years 5 months-7 years 10 months). SDMA and ADMA levels were higher in those who died compared with those who survived (0.51 [IQR, 0.44-0.66] μmol/L vs 0.46 [IQR, 0.39-0.55] μmol/L, P ≤ .001; and 0.48 [IQR, 0.41-0.55] μmol/L vs 0.45 [IQR, 0.39-0.50] μmol/L, P = .007, respectively). l-arginine levels were similar in the two groups. On multivariate analysis, SDMA and ADMA as continuous variable were significantly associated with mortality ( P = .001). For SDMA and ADMA, the highest compared with the lowest quartile levels were significantly associated with mortality (SDMA: hazard ratio, 3.855; 95% confidence interval, 1.625-9.143; P = .002; ADMA: hazard ratio, 2.277; 95% confidence interval, 1.114-4.654; P = .024). ADMA and SDMA showed a negative correlation with severity of PAD as assessed by ABI ( r = −0.236, N = 216, P r = −0.209, N = 208, P = .002, respectively). Conclusions The novel finding of this study is that SDMA levels were predictive of all cause-mortality and correlated with disease severity. Further studies should assess the role of nitric oxide donors in patients with high levels of SDMA.

Complementariness of experimental approaches to address research questions in older people

Vascular disease has been involved in the pathophysiology of frailty. However, the role of endothelial dysfunction, an obligatory step preceding vascular disease, is unknown. We addressed this issue in two phases: – searching if aging per se is accompanied by endothelial dysfunction in microvessels from human beings of different ages (range 18-89) free of cardiovascular risk factors or cardiovascular disease; – searching if endothelial dysfunction (assessed by high ADMA levels) is associated to frailty in older people enrolled in a cohort study (Toledo Study of Healthy Aging). Results Endothelial dysfunction is present in older people due to an increased oxidative stress and the presence of inflammation in the vascular wall (Rodriguez Manas et al., Aging Cell 2009) and ADMA levels are higher in frail people, in people without cardiovascular disease and after adjustment by Ankle-Brachial Index as a biomarker of subclinical disease (Alonso-Bouzon et al., Age 2013). Conclusion Different experimental approaches (from the bench to the population-based studies) exhibit a nice complementariness to ask research questions in older people. These findings have raised new hypotheses that are now being tested in EU funded projects (FRAILOMIC, FRAILCLINIC) led by our group to test biomarkers useful for the diagnosis and prognosis of frailty.

Endogenous Asymmetric Dimethylarginine Pathway in High Altitude Adapted Yaks.

Hypoxia-induced and high altitude pulmonary hypertension are a major problem in the mountain areas of the world. The asymmetric methylarginines (ADMA) inhibit nitric oxide (NO) synthesis by competing with L-arginine, and high levels of plasma ADMA predict adverse outcomes in pulmonary hypertension. However, little is known about the regulation of the ADMA-NO pathway in animals adapted to high altitudes. We measured the plasma ADMA concentration, endothelial NO synthase (eNOS), dimethylarginine dimethylaminohydrolases (DDAH) protein expression, and DDAH activities in the lungs from yaks. Although the yaks are hypoxemic, cardiac function and pulmonary arterial pressures are almost normal, and we found decreased DDAH expression and activity in association with reduced plasma ADMA concentrations. The eNOS expression was significantly higher in yaks. These results indicate that augmented endogenous NO activity in yaks through the ADMA-DDAH pathway and eNOS upregulation account for the low pulmonary vascular tone observed in high altitude adapted yaks.

Comparative Effectıveness of Novokinin, Perindopril and Losartan on Blood Pressure, Adma, Nadph Oxidase and Rho Kinase at Renal Tissue in L-Name and Salt Induced Hypertension

There is no sufficiently investigation about the effects of novokinin, AT2 receptor agonist, on target molecules associated with organ pathology including ADMA, NADPH oxidase and Rho kinase. In this study we investigated the effects of novokinin, perindopril and losartan on Rho kinase, ADMA, NADPH oxidase at renal tissue blood pressure, in L-NAME and salt induced hypertension. Additionally, a1-adrenergic-induced contraction, ach-induced dilator responses in vessels obtained from hypertensive and pharmacological therapy groups were studied.In this study we investigated the effects of novokinin, perindopril and losartan on blood pressure, Rho kinase, ADMA, NADPH oxidase at renal tissue in L-NAME and salt induced hypertension. Additionally, a1-adrenergic-induced contraction, ach-induced dilator responses in vessels obtained from hypertensive and pharmacological therapy groups were studied. To develop hypertension, L-NAME was administrated intraperitoneally and drinking water with salt (1%) for 4 weeks. Perindopril, losartan, novokinin were administrated intraperitoneally for 2 weeks. Blood pressure was measured by using tail-cuff method; Rho kinase, ADMA and NADPH oxidase were measured by ELA°SA at renal tissues.Values are presented as means ± S.E.M.; compared by one way anova. Novokinin, perindopril and losartan diminished the level of NADPH oxidase and ADMA at renal tissue compared to hypertension group. Novokinin, perindopril and losartan decreased blood pressure. The greatest reduction of blood pressure was determined in perindopril treatment group In the hypertensive group, the acetylcholine EC50 value was significantly higher than in the control group and Emax value was significantly lower in hypertensive group compared to control. The application of novokinin, perindopril and losartan were improved the ach induced dilator responses in L-NAME and salt induced hypertension model. AT2 receptor agonist novokinin may offer protection of target organs such as the kidney. In this regard, further experimental studies are needed to exhibit potential benefits of novokinin in hypertension and end organ damage treatment for advanced clinical research.

Serum Asymmetric Dimethylarginine (ADMA) Levels Predict Steroid-Refractory Gvhd before Allogeneic Stem Cell Transplantion

Background: Graft-versus-host disease (GvHD) is the major complication of allogeneic stem cell transplantation (alloSCT) and its therapy-resistant form causes significant morbidity and mortality. The pathomechanism of steroid resistance is currently not completely understood, however, endothelial cell dysfunction seems to play an important role. Serum markers indicating endothelial cell distress such as angiopoetin-2 (Ang-2) and nitrates have been demonstrated to predict steroid-refractory GVHD already before alloSCT. In the current study we investigated ADMA, a strong indicator of endothelial dysfunction, as predictor of acute steroid-refractory GVHD.Methods: We performed a retrospective study of 521 patients who were treated by alloSCT between 3/2001-3/2013. Endothelial cell-associated serum markers were correlated with the course of GvHD, non relapse mortality and statin intake. Cut-offs were determined by maximally selected LogRank statistics.Results: During the post transplant period 114 patients developed a steroid-sensitive GvHD grade 1-2, 50 patients a steroid-sensitive GvHD grade 3-4, and 44 patients a steroid-refractory GvHD which had been always grade 3-4 maximum severity. 313 patients had no signs of GvHD. 266 patients were treated with pravastatin since 2010 when statin prophylaxis for cardiovascular long-term toxicity of calcineurin inhibitor immunosuppression was introduced as standard policy in our program. Median follow up of the whole cohort was 47 months. Median age was 53 years (range 17-75). High ADMA levels (>0.6 µM) significantly predicted steroid-refractory GVHD already before alloSCT (p=0.044, HR=3.5, 95% CI 1.1-11.8). In those patients who developed GVHD, high ADMA levels (>0.6 µM) were not only associated with an increased risk of steroid refractoriness, but also translated into increased non-relapse mortality (HR 2.2 CI 1.1-4.8, p=0.049). By multivariate analysis, the association of high ADMA levels with the risk of refractory GVHD remained significant in the whole cohort after adjusting for age, disease specific remission score, donor and conditioning (HR 6.4 CI 1.6-26.2, p=0.009).The ADMA cut-off was used to build a score along with the previously described predictors of GVHD refractoriness pretransplant Ang-2 (cut-off 1µg/ml) and nitrates (cut-off 26.5 µM). Serum levels of above the cut-off were counted as one point and 0-1 points were considered low risk, 2 points intermediate risk and 3 points high risk. The score was capable of separating risk groups of patients with a different likelihood to develop refractory GVHD (p=0.001, Figure 1) already before alloSCT. The highest risk group had also an increased NRM incidence (p= 0.02, Figure 1). Most interestingly, this endothelial risk score completely failed to predict outcome if patients were on statins (p=0.62).Conclusion: High serum ADMA predicts refractory GVHD already prior to alloSCT. Our results support the hypothesis that endothelial damage / vulnerability contribute to refractoriness of acute GVHD.Dept. Medicine V, University of Heidelberg, Germany [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Effects of rosuvastatin on ADMA, rhokinase, NADPH oxidase, caveolin-1, hsp 90 and NFkB levels in a rat model of myocardial ischaemia-reperfusion.

SummaryAimEndothelial dysfunction, oxidative stress and inflammation are among the most important mechanisms of ischaemia–reperfusion (I/R) injury. Besides their cholesterol-lowering effects, statins are known to provide protection against myocardial dysfunction and vascular endothelial injury via nitric oxide-dependent mechanisms. The aim of this study was to investigate the effects of rosuvastatin on certain intermediates involved in the generation of nitric oxide (asymmetrical dimethyl arginin, ADMA, caveolin-1 and hsp 90), oxidative stress (rhokinase, NADPH oxidase) and inflammation (NFkB), using an in vivo model of myocardial infarction in the rat.MethodsAdult male Sprague Dawley rats were divided into three groups (control, I/R and I/R after 15 days of rosuvastatin administration). Reperfusion was applied for 120 min following left anterior descending coronary artery ischaemia for 30 min. Caveolin-1, hsp 90 and NFkB levels were evaluated with the quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and ADMA, rhokinase and NADPH oxidase levels were evaluated with ELISA.ResultsWhile NFkB and hsp 90 levels were higher in the I/R group, their levels were significantly lower in the rosuvastatin group. While ADMA and NADPH oxidase levels significantly increased with I/R, they were lower in the rosuvastatin-treated group, but not statistically significant. Rhokinase levels were significantly lower in the rosuvastatin group. Caveolin-1 levels were not different between the groups.ConclusionOur results suggest that ADMA, rhokinase, NADPH oxidase, hsp 90 and NFkB could facilitate I/R injury, and rosuvastatin significantly reduced levels of these parameters. These results indicate that rosuvastatin may have a protective role in I/R injury via mechanisms targeting inflammation, endothelial dysfunction and oxidative stress.

S251: Nitric oxide and asymmetric dimethyl arginine (adma) levels in an experimental hydronephrotic kidney caused by unilateral partial ureteral obstruction

S251: Nitric oxide and asymmetric dimethyl arginine (adma) levels in an experimental hydronephrotic kidney caused by unilateral partial ureteral obstruction

Associations of Methylarginines and Homoarginine With Diastolic Dysfunction and Cardiovascular Risk Factors in Patients With Preserved Left Ventricular Ejection Fraction

BackgroundAsymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and homoarginine are considered to modulate nitric oxide synthesis. We evaluated whether ADMA, SDMA, and homoarginine are associated with diastolic dysfunction. Methods and ResultsWe investigated primary care patients at cardiovascular risk with preserved left ventricular ejection fraction from the multicenter DIAST-CHF study. We measured serum concentrations of ADMA, SDMA, and homoarginine and performed standardized echocardiographic examinations. Among 1,396 patients (mean age 65.3 ± 8.3 y, 54.6% women), diastolic dysfunction was ruled out in 261 patients (18.7%). Mild and moderate/severe grades of diastolic dysfunction were present in 900 (64.5%) and 235 (16.8%) study participants, respectively. After adjustments for cardiovascular risk factors, ADMA and SDMA were positively and homoarginine negatively associated with N-terminal pro–B-type natriuretic peptide and midregional pro-adrenomedullin (P < .05 for all). Lower homoarginine levels were associated with diastolic dysfunction, and higher ADMA and SDMA levels were associated with the severity of diastolic dysfunction (P < .05 for all). ConclusionsHigher levels of ADMA and SDMA and lower levels of homoarginine are associated with an adverse cardiovascular risk profile and diastolic dysfunction. Further studies should clarify the potential of these amino acid derivatives for the therapy of cardiovascular diseases.

Abstract 228: Apolipoprotein E (ApoE) Genetic Polymorphism Modulation Of Endothelial Dysfunction In Hypertensive Patients Is Determined By Renal Function.

INTRODUCTION: ADMA, an endogenous inhibitor of nitric oxide synthase, is an independent marker of progression of renal dysfunction, vascular complications and death. Overexpression of the ADMA degrading enzyme dimethylarginine dimethylaminohydrolase 1 (DDAH1) ameliorates atherosclerosis in genetic ApoE deficient mice. Once ApoE polymorphism is a key player on lipid metabolism, it is possible that it brings on individual susceptibility to endothelial dysfunction. OBJECTIVE: The aim of this study was to assess the effect of the ApoE genetic polymorphism on ADMA levels in a cohort of hypertensive patients stratified by renal function. PATIENTS AND METHODS: Patients were stratified into 3 groups according to GFR using the CKD-EPI: I &gt; 60ml/min, II ≤ 60 ml/min and &gt; 15 ml/min, and III ≤ 15 ml/min. HPLC was used for the measurement of ADMA. Polymorphic ApoE analysis performed by PCR amplification and allele frequency compared in each group between first and third tertile of ADMA as epidemiological, clinical and laboratorial characteristics. Statistical analysis performed using the software IBM SPSS Statistics 20.0. RESULTS: Mean age of the patients was 60.1± 14.1 years, 318 (50.7%) were male, mean BMI was 28.0 ± 5.3, 396 (63.2%) were Caucasians, 244 (38.9%) had DM, 316 (50.4%) had dyslipidemia, 223 (35.6%) had cardiovascular disease (CVD). Groups were composed respectively of 189, 229 and 202 patients. E2 allele was present in 67 (10.7%) patients, E3 allele in 588 (93.8%), E4 allele in 116 (18.5%). In group III, the frequency of E4 allele of ApoE was lower in the third tertile of ADMA (p = .000, Pearson Chi-Square). This link remained significant even after control for confounders like age, sex, BMI, DM, CVD, PCR and LDL (OR 0.127, CI: 0.35 - 0.468, p = .002). CONCLUSION: ApoE E4 allele independent association with lower levels of ADMA is pronounced among those patients with advanced stage of renal disease. This association may represent an unknown genetic pathway that modulates ADMA levels on this population.

Physical activity below the minimum international recommendations improves oxidative stress, ADMA levels, resting heart rate and small artery endothelial function

BackgroundA moderate level of physical activity (PA), such as a daily 30-min walk, reduces cardiovascular risk. There is a lack of evidence about the cardiovascular benefits of PA below this recommendation of minimum PA level. ObjectiveWe aimed to study the impact of a lower level of PA on cardiovascular health. DesignSixty-four overweight/obese men and women were enrolled in a community programme consisting of 4 months of 1h, low-intensity PA two days per week. Before and after the intervention, PA level (METs/h/wk), endogenous antioxidant status (SOD and GPX concentration and activity and oxidised LDL), ADMA concentrations, endothelial function by small artery reactive hyperaemia index (saRHI), and resting heart rate (RHR) were assessed. ResultsAfter the intervention, significant increases in saRHI (P=0.031), SOD and GPX activities, and a decrease in ADMA plasma concentrations, and RHR (P<0.001 for all) were observed. Increases in PA were positively associated with increases in saRHI (r=0.341, P=0.022), GPx (r=0.303, P=0.047) and decreases in RHR (r=−0.302, P=0.047). Multivariate analyses showed that independent predictors of saRHI improvement were an increase in PA (2.65, 95%CI: 1.21–4.01), decrease in RHR (1.91, 95%CI: 1.01–4.98), and an increase in GPx (2.61, 95%CI: 1.16–5.01). ConclusionIn obese and overweight men and women, an increase in PA, even below the minimal international recommendations, improves antioxidant capacity, RHR and peripheral small artery reactivity.

Successful catheter ablation decreases platelet activation and improves endothelial function in patients with atrial fibrillation.

Nonvalvular atrial fibrillation (AF) confers a five-fold increased risk of stroke. Whether catheter ablation (CA) subsequently decreases prothrombotic risk is unknown. The purpose of this study was to assess the long-term effects of CA for AF on prothrombotic risk. Fifty-seven patients undergoing CA for AF were prospectively studied. Platelet activation (CD62P [platelet P-selectin] and PAC-1 [glycoprotein IIb/IIIa] expression) and endothelial function (asymmetric dimethylarginine [ADMA] levels) were measured at baseline and 6-months postablation. Thirty-seven (65%) patients remained in sinus rhythm (SR group) and 20 (35%) sustained AF recurrence (AF recurrence group) at 6-months. Patients with AF-recurrence were older, had a higher proportion of hypertension and long-standing persistent AF. There were no significant differences in CD62P (P = .3), PAC-1 (P = .1) and ADMA (P = .7) levels at baseline between the two groups. In the SR group, markers of platelet activation decreased significantly at 6-month follow-up compared to baseline; log CD62P % 0.79 ± 0.28 vs 1.03 ± 0.27 (P <.05) and log PAC-1 % 0.22 ± 0.58 vs 0.89 ± 0.31 (P <.01). This was not significant in the AF-recurrence group (P = .8, log CD62P; P = .1, log PAC-1). For endothelial function, ADMA levels decreased significantly at 6-months compared to baseline in the SR group (log ADMA μM/L 0.15 ± 0.02 vs 0.17 ± 0.04; P <.05), but did not alter significantly in the AF-recurrence group (P = .4, log ADMA). Catheter ablation and successful maintenance of SR leads to a decrease in platelet activation and improvement in endothelial function in patients with AF. These findings suggest that AF is an important determinant of the prothrombotic state and that this may be reduced by successful catheter ablation.

Short-term rosuvastatin therapy influence on restored endothelial function in hypertensive patients

Objectives: We proposed to investigate the effects of rosuvastatin therapy in 10 or 20 mg on endothelial function, plasma ADMA levels and values ??of carotid intima-media thickness (IMT), in patients with essential hypertension and endothelial dysfunction, after 6 month of treatment.

Role of alanine:glyoxylate aminotransferase 2 in metabolism of asymmetric dimethylarginine in the settings of asymmetric dimethylarginine overload and bilateral nephrectomy.

Asymmetric and symmetric dimethylarginines (ADMA and SDMA) predict complications and mortality in cardiovascular and renal diseases. Alanine:glyoxylate aminotransferase 2 (AGXT2) can metabolize both ADMA and SDMA; however, this metabolic pathway is still poorly understood. The goal of our study was to test the hypothesis that AGXT2 is compensatory upregulated in the settings of ADMA overload and bilateral nephrectomy. ADMA was infused for 3 days using osmotic minipumps in mice. Half of the mice underwent bilateral nephrectomy 24 h before the end of the infusion. Infusion of ADMA caused a 3- to 4-fold increase in plasma and urine ADMA levels and a 2- to 3-fold increase in plasma and urine levels of the ADMA-specific metabolite of AGXT2 α-keto-δ-(N,N-dimethylguanidino)valeric acid (DMGV). Bilateral nephrectomy led to an ∼4-fold increase of plasma SDMA levels, but did not change plasma ADMA levels. Interestingly, plasma levels of DMGV were elevated 32-fold in the mice, which underwent bilateral nephrectomy. Neither bilateral nephrectomy nor ADMA infusion caused upregulation of AGXT2 expression or activity. Our data demonstrate that short-term elevation of systemic levels of ADMA leads to a dramatic increase of DMGV formation without upregulation of AGXT2 expression or activity, which suggests that AGXT2-mediated pathway of ADMA metabolism is not saturated under normal conditions and may play a major role in the maintenance of ADMA homeostasis in the setting of local or systemic elevation of ADMA levels.

AB0574 A Prospective Follow-Up of Young, Male Patients with Behcet's Disease without Major Organ Involvement

ObjectivesVascular involvement, especially in young males, is one of the main causes of mortality and morbidity in Behcet's Disease (BD). However, the prognosis and predictors of vascular involvement is unsufficiently...