Plasma asymmetric dimethylarginine level and extent of lesion at coronary angiography

Elevated asymmetric dimethylarginine level as biomarkers of adverse outcomes in individuals undergoing coronary angiography/percutaneous coronary interventions: a systematic review and meta-analysis

BACKGROUND

No previous systematic review and meta-analysis have comprehensively evaluated the association of asymmetric dimethylarginine (ADMA) level with adverse prognosis in individuals undergoing percutaneous coronary interventions (PCI)/coronary angiography (CAG). The aim of this systematic review and meta-analysis was to assess the predictive value of the elevated ADMA level in individuals undergoing CAG/PCI.

MATERIALS AND METHODS

Two authors independently searched PubMed and Embase databases (up to 31 October 2020) for observational studies investigating the association between circulating ADMA level and adverse outcomes in individuals undergoing CAG/PCI. The predictive value of ADMA was expressed by pooling the multivariable-adjusted risk ratio with 95% confidence intervals (CI) for the highest versus lowest ADMA level.

RESULTS

A total of nine prospective studies with 6374 participants were identified. Compared with those with the lowest ADMA level, patients with the highest ADMA level conferred an increased risk of all-cause mortality (risk ratio, 2.11; 95% CI, 1.38-3.21), cardiovascular mortality (risk ratio, 2.95; 95% CI, 1.14-7.68), major adverse cardiovascular events (risk ratio, 2.10; 95% CI, 1.35-3.27) and restenosis (risk ratio, 4.57; 95% CI, 2.52-8.30), respectively.

CONCLUSIONS

High level of ADMA level is possibly an independent predictor of mortality and cardiovascular events in individuals undergoing CAG/PCI. Detection of blood ADMA level before CAG/PCI may add valuable clinical prognosis information.

Atorvastatin protects endothelium by decreasing asymmetric dimethylarginine in dyslipidemia rats

Background

Asymmetric Dimethylarginine (ADMA) is an inhibitor of endogenous nitric oxide synthase, which is the key synthase for nitric oxide (NO) production. Whether statins could protect endothelium by reducing ADMA concentration is unclear, and whether this effect is associated with the dose of statins usage is also needed further studied.

Methods

Dyslipidemia rat model was produced by giving high-fat and high-cholesterol diet for 8 weeks. Thereafter, low-dose (5 mg/kg body weight/day) and high-dose (20 mg/kg body weight/day) atorvastatin were orally prescribed for 4 weeks. Parameters of interest including lipid profiles, inflammatory and oxidative markers, NO production and plasma levels of ADMA and ADMA concentration of myocardium were evaluated. Liver enzymes and creatinine kinase (CK) were also detected for safety concern.

Results

At baseline, all parameters were comparable between the sham and the dyslipidemia groups. At 8 weeks of dyslipidemia establishment, as compared to the sham group, body weight and lipid profiles were significantly elevated, and plasma levels of C-reactive protein (CRP), malondialdehyde (MDA) and ADMA were concomitantly increased in accompanying with NO reduction in the dyslipidemia groups. With 4 weeks of atorvastatin therapy, as compared to the control group, lipid disorders and NO production were improved, and plasma levels of CRP, MDA and ADMA were significantly decreased in the high-dose atorvastatin group. ADMA concentration of cardiac tissues was also significantly reduced in the high-dose atorvastatin group. Notably, there was a trend to similar effects which did not reach statistical significance in the low-dose atorvastatin group when compared to the control group. Liver enzyme and CK were comparable after 4 weeks of atorvastatin therapy between groups.

Conclusion

In rats with dyslipidemia, atorvastatin therapy could reduce plasma level of ADMA and ADMA concentration in cardiac tissues, and these effects are associated with the dose of atorvastatin therapy.

Serum Asymmetric Dimethylarginine, and Adiponectin as Predictors of Atherosclerotic Risk among Obese Egyptian Children

BACKGROUND: Obesity is associated with an increased risk of developing hyperinsulinemia, dyslipidemia, hypertension, premature atherosclerosis, and coronary artery disease in the future.AIM: This study is designed to assess the relationship between serum adiponectin, asymmetric dimethylarginine (ADMA), and lipid profile among Egyptian overweight and obese children.METHODS: This cross sectional case control study included 40 selected pre-pubertal overweight and obese children, 24 girls (60%) and 16 boys (40%) aged between 5 to 13 years (8.85 ± 2.7 years), from new cases attending the National nutrition institute clinic during 2013. Forty apparently healthy children of matched age and sex were recruited as a control group.RESULTS: Obese group showed highly significant higher levels of serum ADMA, triglycerides, and total cholesterol compared with healthy controls (P <0.000 in all). However, serum adiponectin levels were highly significant lower in obese children compared to healthy controls (P < 0.000). Serum ADMA showed significant positive correlations with height, serum total cholesterol and serum triglycerides levels and significant negative correlation with the body mass index and weight for age z score.  Serum adiponectin showed significant negative correlations with BMI, weight, and weight for age z score and significant positive correlation with serum triglycerides. By linear regression analysis; serum adiponectin, and serum triglycerides levels were significant predictors of high serum ADMA level (p =0.045 and 0.015 respectively). BMI, weight, height and serum triglycerides were significant predictors of low serum adiponectin levels (p = 0.005, 0.022, 0.026 and 0.015 respectively).CONCLUSIONS: Our results revealed that ADMA, Adiponectin and lipid profile can be considered as predictive biomarkers in prediction and prevention of atherosclerotic risk in the future among overweight and obese Egyptian children.

L-arginine, asymmetric dimethylarginine, and symmetric dimethylarginine in plasma and synovial fluid of patients with knee osteoarthritis

BACKGROUND

The aim of this study was to investigate the involvement of the nitric oxide (NO) pathway in osteoarthritis (OA).

MATERIAL AND METHODS

The study groups consisted of 32 patients with knee OA and 31 healthy controls. In peripheral venous blood samples (from the OA patients and the controls) and in synovial fluid samples (from the OA patients), the concentrations of L-arginine (ARN), asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) were evaluated. In plasma samples, thiobarbituric acid reactive substances (TBARS) were also measured.

RESULTS

Plasma ARN concentrations were lower in the OA patients than in controls (53.55 ± 16.37 vs. 70.20 ± 25.68 µmol/l) (P<0.05), while plasma ADMA concentrations were similar. Accordingly, the ARN/ADMA ratio was lower in the OA patients than in the control group (80.85 ± 29.58 vs. 110.51 ± 30.48, P<0.05). Plasma SDMA and TBARS concentrations were higher in the OA patients than in controls (0.69 ± 0.15 vs. 0.60 ± 0.10 µmol/l, P<0.05 and 1.21 ± 0.29 vs. 0.55 ± 0.12, respectively) (P<0.001). In the OA patients, ADMA concentrations were significantly higher in the synovial fluid than in plasma (0.75 ± 0.09 vs. 0.69 ± 0.14 µmol/l, P<0.05), as were ARN concentrations (76.96 ± 16.73 vs. 53.55 ± 16.73 µmol/l) (P<0.00001). Conclusions These results indicate a poor availability of NO in the synovial fluid of the OA patients, which may contribute to the progression of OA. The decreased ARN/ADMA ratio and the increased SDMA and TBARS in the plasma of the OA patients suggest an impairment of endothelial function in these subjects.

Changes in ADMA and TAFI levels after stenting in coronary artery disease patients

The aim of this study was to examine the contribution of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS) and a novel marker of vascular endothelial dysfunction, and thrombin-activatable fibrinolysis inhibitor (TAFI), a risk factor for venous thrombosis, to the predisposition of coronary restenosis following stent implantation in coronary artery disease (CAD) patients. Thirty-seven patients with CAD were recruited from the Kobry El Obba Military Hospital, Cairo, Egypt. The patients were hospitalized for coronary angiography and coronary stenting (CS). Overnight fasting blood samples were collected from patients prior to CS and four months later for the determination of plasma ADMA and TAFI levels. The patients underwent follow-up coronary angiography to reveal in-stent restenosis. The results showed that plasma ADMA levels in CAD patients were significantly higher than those reported for healthy subjects. ADMA levels were significantly increased by 30% in CAD patients four months following CS. CAD patients who developed in-stent restenosis had a 35% increase in ADMA levels following CS. TAFI levels were not significantly changed after CS in CAD patients or in any of the subgroups. In conclusion, ADMA, but not TAFI, is linked to the predisposition of in-stent restenosis following CS.

Relationship between L-arginine/asymmetric dimethylarginine, homocysteine, folic acid, vitamin B levels, and coronary artery ectasia

BACKGROUND

Coronary artery ectasia (CAE) is characterized by an abnormal dilatation of the coronary arteries. The ratio of L-arginine/asymmetric dimethylarginine (ADMA) and homocysteine are important factors for endothelial function. In this study, we investigate the ratio of L-arginine/ADMA, homocysteine, and folic acid/vitamin B levels in patients with CAE.

METHODS

Forty patients diagnosed with CAE using coronary angiography were included in the study (24 male; mean age, 56 ± 11 years). The control group consisted of 30 patients who had normal coronary arteries as determined by coronary angiography (11 male; mean age, 54 ± 8 years). The ratio of L-arginine/ADMA and plasma homocysteine was measured using high-performance liquid chromatography.

RESULTS

The L-arginine/ADMA ratio and L-arginine levels were significantly lower in the CAE group compared with the control group (110 ± 27 vs. 149 ± 77, P=0.02 and 157 ± 32 μmol/l vs. 187 ± 59 μmol/l, P=0.02, respectively). Plasma ADMA levels were similar in the two groups. Patients with CAE had higher plasma homocysteine levels (P=0.01). Plasma folic acid, vitamin B6, and vitamin B12 levels were similar between the two groups.

CONCLUSION

This study shows that patients with CAE have a lower L-arginine/ADMA ratio and higher plasma homocysteine levels. These results show a potential relationship between endothelial dysfunction and CAE.

The biochemistry, measurement and current clinical significance of asymmetric dimethylarginine

Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide synthase and an important cause of endothelial dysfunction. Its increased plasma concentration is associated with a variety of traditional cardiovascular risk factors, and may mediate their effects on the vascular endothelium. ADMA is also an independent predictor of cardiovascular events and mortality, and predicts outcomes in critically ill patients in the intensive care unit. This work has provided insights into the role of ADMA as an endogenous regulator of nitric oxide synthesis. At present there is no specific therapy to modify ADMA concentration, but increasing interest and work on protein arginine methyltransferases and dimethylarginine dimethylaminohydrolase, which synthesize and metabolize ADMA, respectively, might provide novel therapeutic targets.

Plasma asymmetric dimethylarginine and L-arginine levels in patients with cardiac syndrome X

BACKGROUND

Endothelial dysfunction and subsequently impaired microvascular circulation are the leading mechanisms in the development of cardiac syndrome X (CSX). The study evaluated the plasma asymmetric dimethylarginine (ADMA) and L-arginine levels of the patients with CSX and the control group and aimed to determine any relationship between these parameters and epicardial coronary blood flow and myocardial tissue perfusion.

METHODS

The study group consisted of 32 patients (mean age: 52.6+/-9.4 years, 14 men) with typical exertional angina, positive exercise test, and normal coronary arteries diagnosed as CSX. Plasma ADMA, L-arginine levels, and L-arginine/ADMA ratio were compared with the values of the control group, which consisted of 17 age-matched and sex-matched individuals. Concentrations of L-arginine and ADMA were measured by high-performance liquid chromatography. In all the coronary territories, epicardial coronary flow was assessed by thrombolysis in myocardial infarction (TIMI) frame count (TFC) method, and tissue level perfusion, by myocardial blush grade (MBG) method. A MBG score less than 3 was considered an impaired myocardial perfusion, and a MBG score of '3' in all the coronary territories, a normal myocardial perfusion.

RESULTS

The plasma ADMA levels of the study group were higher than those of the control group (0.83+/-0.38 vs. 0.55+/-0.44 micromol/l, P=0.03), whereas plasma L-arginine levels were similar in both groups (70.25+/-21.89 vs. 76.09+/-18.22 micromol/l, P=0.36), resulting in a diminished L-arginine/ADMA ratio in the patients with CSX [82.3 (60.2-128.8) vs. 242.2 (76.7-386.4), P=0.003]. In CSX group, the patients with abnormal myocardial tissue perfusion had increased plasma ADMA levels compared with those with normal tissue perfusion (0.99+/-0.37 vs. 0.69+/-0.34 micromol/l, P=0.02), whereas plasma L-arginine levels were similar in both groups. No correlations were observed between TFC values and plasma ADMA, L-arginine levels, and L-arginine/ADMA ratio. Plasma ADMA levels, however, were negatively correlated with MBG scores (r=-0.349, P=0.014).

CONCLUSION

We have shown for the first time that in the patients with CSX, increased plasma ADMA levels might be associated with impaired myocardial tissue perfusion when assessed by MBG.

Down-regulation of endogenous nitric oxide synthase inhibitors on endothelial SK3 expression

OBJECTIVES

To investigate role of endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) in down-regulation of the expression of endothelial SK3 in atherosclerosis.

METHODS

Apolipoprotein E deficient (apo E(-/-)) mice aged 11 approximately 12 weeks were treated with ADMA (5 mg/kg per day, subcutaneous injection) for 4 weeks. Cultured human umbilical venous endothelial cells (HUVECs) were treated with different concentrations of lysophosphatidylcholine (LPC) or ADMA for 48 h. Plasma levels of ADMA were determined by high performance liquid chromatogram (HPLC); protein and mRNA levels of SK3 in the aortas of mice and cultured cells were detected by immunofluorescence, western blot and RT-PCR, respectively.

RESULTS

Concomitantly with the elevated plasma levels of ADMA, the expressions of both SK3 protein and mRNA in aortas of apo E(-/-) mice were significantly reduced in comparison to those of the wild-type mice. Moreover, 4-week treatment of ADMA made levels of SK3 expression even lower. In cultured HUVECs, either LPC or ADMA notably decreased the expressions of both SK3 protein and mRNA in a concentration dependent manner.

CONCLUSIONS

Endogenous ADMA may be an important factor for down-regulation of the expression of endothelial SK3 in atherosclerotic animals.