dimethylarginine and Stroke

Endothelial dysfunction is associated with increased levels of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) resulting in a decreased production of nitric oxide, which regulates the vascular tone.. Patients with acute ischemic stroke (AIS, n = 55) and asymptomatic significant carotid stenosis (AsCS, n = 44) were prospectively investigated. L-arginine, ADMA, SDMA, S100 B, and high-sensitivity C-reactive protein (hsCRP) were serially measured within 6 hours after the onset of stroke, at 24 and 72 poststroke hours. All markers were compared with healthy subjects (n = 45). The severity of AIS was daily assessed by National Institute of Health Stroke Scale scoring.. Even within 6 hours after the onset of stroke, L-arginine, ADMA, and SDMA were significantly higher in patients with AIS compared with both AsCS and healthy subjects. S100 B reflecting infarct size, positively correlated with the level of SDMA at 72 poststroke hours; changes in concentration of S100 B positively correlated with changes in the concentration of ADMA by 72 hours. Change in concentration of both ADMA and SDMA correlated with the change in concentration of hsCRP. Concentrations of L-arginine and hsCRP at 72 poststroke hours, respectively, were independent predictors of poststroke infection. S100 B level measured within 6 hours after the onset of AIS and hsCRP at 72 poststroke hours were independent predictors of death.. Metabolites of the L-arginine pathway were elevated in the very acute phase of ischemic stroke indicating a more pronounced endothelial dysfunction compared with AsCS. An increased basal L-arginine level in patients with AIS might be an adaptive mechanism; such transient elevation of the L-arginine/ADMA ratio at 24 poststroke hours may suggest that a temporary increase of L-arginine along with decrease of ADMA might be related to the protective role of L-arginine. Changes in the L-arginine pathway are predictive of poststroke infections.

Topics: Aged; Aged, 80 and over; Arginine; Biomarkers; C-Reactive Protein; Carotid Stenosis; Comorbidity; Female; Humans; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; S100 Calcium Binding Protein beta Subunit; Stroke

  Despite sharing some metabolic and pathological mechanisms, the reported association between total homocysteine (tHcy), asymmetric dimethylarginine (ADMA) and stroke remains controversial, particularly in Hispanic populations from developing countries in which genetic, socioeconomic, and nutritional factors are different to those described in developed countries. Our objectives were to determine the relationships of these factors to stroke and to each other independent of other cardiovascular risk factors, and to explore potential sex differences.. This national (Colombia) multicenter case-control study included 238 cases and 238 controls to evaluate traditional and emerging risk factors for ischemic stroke including tHcy and ADMA plasma levels.. The median plasma levels of tHcy were 8.48 μM for controls and 10.01 μM for cases (P<0.0001). Plasma levels of tHcy between 12 and 50μM were considered moderate hyperhomocysteinemia (HtHcy). There were no differences in plasma ADMA concentration between groups (P=0.40). Plasma levels of ADMA and creatinine were not correlated (P=0.47). After adjusting for confounding factors, the presence of HtHcy was strongly associated with stroke (OR 8.97; P<0.0001). The adjusted association between HtHcy and stroke in men (OR 9.98) was comparable to that in women (OR 8.98) (P=0.41).. In this Hispanic population, with relatively normal renal function, plasma levels of tHcy but not ADMA were associated with stroke independent of other cardiovascular risk factors.

Topics: Aged; Arginine; Case-Control Studies; Colombia; Female; Hispanic or Latino; Homocysteine; Humans; Male; Middle Aged; Risk Factors; Stroke

Increased levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, have been observed in patients with cardiovascular risk factors and atherosclerosis and in patients with a history of stroke. The role of ADMA and its analogue symmetric dimethylarginine (SDMA) in acute ischemic stroke is yet unclear. We hypothesized that plasma dimethylarginine levels increase in the hyper-acute phase after ischemic stroke and that their time course is related to stroke outcome.. Plasma dimethylarginines ADMA and SDMA and L-arginine levels were measured in 67 patients at 6, 12, 24 hours, as well as 3 and 7 days after stroke onset using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS). Data were compared to control data from 32 age-adjusted healthy volunteers. Clinical outcome was assessed using the modified Rankin Scale (mRS) at 90 days after stroke.. At baseline, plasma ADMA levels were higher in stroke patients than in controls, whereas plasma SDMA and L-arginine levels did not differ from control subjects. The time courses of ADMA and SDMA were related to the clinical outcome. Binary logistic regression analysis showed that ADMA levels of ≥ 0.566 µmol/L at day 3, ≥ 0.530 µmol/L at day 7 and SDMA levels of ≥ 0.59 µmol/L at 24 hours predicted an unfavorable clinical outcome.. An increase of both ADMA and SDMA plasma levels within the first 72 hours after the onset of ischemic stroke predicts a poor outcome.

Topics: Aged; Arginine; Case-Control Studies; Chromatography, High Pressure Liquid; Female; Humans; Male; Middle Aged; Prospective Studies; Reproducibility of Results; Stroke; Tandem Mass Spectrometry

Patients with diabetes mellitus (DM) have been shown to have higher levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of endothelial nitric oxide (NO) synthase. Higher plasma levels of ADMA have been implicated in the pathogenesis of endothelial dysfunction and atherosclerosis by lowering NO levels. High baseline plasma levels of ADMA in patients with DM have been shown to predict diabetes related complications. However, there are limited data on the prognostic significance of baseline ADMA levels in patients with established DM.. The present study investigated the long-term prognostic significance of baseline plasma ADMA levels in a well-characterized cohort of 170 high-risk diabetic men with known or suspected coronary artery disease who were referred for coronary angiography. All patients were followed prospectively for the development of vascular outcomes, including all-cause mortality.. After controlling for a variety of baseline variables (including established biomarkers such as hs-CRP and fibrinogen), plasma ADMA levels (analyzed as the upper tertile of baseline values compared with the lower two tertiles) were a strong and independent predictor of all-cause mortality (HR 2.63, 95% CI 1.13-6.11, p=0.0247) when using a Cox proportional hazards model. In addition, baseline ADMA values were also an independent predictor of the composite outcome of all-cause mortality or MI (fatal or non-fatal) (HR 2.44, 95% CI 1.26-4.72, p=0.0079), as well as the composite outcome of all-cause mortality, MI (fatal or nonfatal), or stroke (HR 2.00, 95% CI 1.10-3.62, p=0.0232).. These data demonstrate that elevated baseline levels of ADMA are a strong and independent predictor of cardiovascular outcomes (including all-cause mortality) in patients with DM.

Topics: Aged; Arginine; Coronary Angiography; Coronary Disease; Diabetes Complications; Humans; Male; Myocardial Infarction; Prognosis; Proportional Hazards Models; Stroke

The objective of this study was to determine whether the long-term administration of an HMG-CoA reductase inhibitor, atorvastatin, confers protective effects against stroke events in stroke-prone spontaneously hypertensive rats (SHRSPs). Atorvastatin (2 mg/kg, 20 mg/kg) or vehicle was orally administered to 8-week-old SHRSPs for 11 weeks. The survival ratio and stroke incidence were calculated, and plasma lipids and plasma levels of asymmetric dimethylarginine (ADMA), a circulating endogenous competitive inhibitor of NO synthase, were measured after sacrifice. The effect of atorvastatin on local cerebral blood flow (l-CBF) was also determined in 13-week-old SHRSPs after treatment with 20 mg/kg atorvastatin daily for 5 weeks. The survival ratios at 19 weeks of age were 15, 30, and 50% in the vehicle, low-dose (2 mg/kg), and high-dose groups (20 mg/kg), respectively. The survival ratio was significantly higher in the high-dose group than in the vehicle group. The incidence of stroke was significantly lower in the high-dose group than in the vehicle group. The levels of ADMA were 0.81+/-0.18 (mean+/-S.D.), 0.62+/-0.09, and 0.61+/-0.06 micromol/l in the vehicle, low-dose, and high-dose groups, respectively. Atorvastatin administration significantly reduced the ADMA levels without affecting the levels of plasma lipids. The level of l-CBF tended to be higher in the treated group, but not to a significant extent. Thus, atorvastatin was determined to confer a protective effect against hypertension-based stroke. The data suggest that the efficacy of the statin for stroke protection may be partially involved in the improvement of endothelial function via NO production and reduction of ADMA. Statins may confer useful protection against not only atherosclerosis-based stroke, but also hypertension-based stroke.

Topics: Animals; Arginine; Atorvastatin; Brain; Cerebral Arteries; Cerebrovascular Circulation; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Endothelial Cells; Heptanoic Acids; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Lipid Metabolism; Male; Neuroprotective Agents; Nitric Oxide; Nitric Oxide Synthase; Pyrroles; Rats; Rats, Inbred SHR; Stroke; Survival Rate; Time; Time Factors; Treatment Outcome

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, has been shown to be involved in the pathogenesis of atherosclerosis. The present study was initiated to investigate the role of ADMA as a risk marker of acute cerebrovascular disease (CVD). We examined 363 CVD patients and 48 controls. The ADMA concentration (mean+/-S.D., mumol/L) in controls was 0.50 +/- 0.06. Compared to controls, increased concentrations of ADMA were observed in cardio-embolic infarction (0.55 +/- 0.08; p < 0.001; n = 71), and TIA (0.54 +/-0 .05; p < 0.001; n = 31), but not in non-cardio-embolic infarction (0.51 +/- 0.07; p = 0.56; n = 239) and haemorrhagic stroke (0.51 +/- 0.11; p = 0.77; n = 22). In multivariate logistic regression models, CVD increased across quartiles of ADMA in all subgroups, but this association was only significant in the TIA group (odds ratio for highest versus lowest quartile 13.1; 95% CI: 2.9-58.6; p trend 0.001) A decreased arginine/ADMA ratio was significantly associated with CVD in the entire study population (p < 0.01). Our results indicate that ADMA is a weak independent marker for acute stroke and a strong marker for TIA and that relative arginine deficiency, measured as the l-arginine/ADMA ratio, is present in acute CVD.

Topics: Acute Disease; Aged; Arginine; Biomarkers; Cerebral Hemorrhage; Cerebral Infarction; Enzyme Inhibitors; Female; Glycated Hemoglobin; Humans; Ischemic Attack, Transient; Male; Multivariate Analysis; Nitric Oxide Synthase; Odds Ratio; Risk Factors; Stroke