Impact of Catheter Arteriography on the Serum Level of Asymmetric Dimethylarginine, an Endogenous Inhibitor of Nitric Oxide Synthase

ADMA predicts major adverse renal events in patients with mild renal impairment and/or diabetes mellitus undergoing coronary angiography

Asymmetric dimethylarginine (ADMA) is a competitive inhibitor of the nitric oxide (NO)-synthase and a biomarker of endothelial dysfunction (ED). ED plays an important role in the pathogenesis of contrast-induced nephropathy (CIN). The aim of our study was to evaluate serum ADMA concentration as a biomarker of an acute renal damage during the follow-up of 90 days after contrast medium (CM) application.Blood samples were obtained from 330 consecutive patients with diabetes mellitus or mild renal impairment immediately before, 24 and 48 hours after the CM application for coronary angiography. The patients were followed for 90 days. The composite endpoints were major adverse renal events (MARE) defined as occurrence of death, initiation of dialysis, or a doubling of serum creatinine concentration.Overall, ADMA concentration in plasma increased after CM application, although, there was no differences between ADMA levels in patients with and without CIN. ADMA concentration 24 hours after the CM application was predictive for dialysis with a specificity of 0.889 and sensitivity of 0.653 at values higher than 0.71 μmol/L (area under the curve: 0.854, 95% confidential interval: 0.767-0.941, P < 0.001). This association remained significant in multivariate Cox regression models adjusted for relevant factors of long-term renal outcome. 24 hours after the CM application, ADMA concentration in plasma was predictive for MARE with a specificity of 0.833 and sensitivity of 0.636 at a value of more than 0.70 μmol/L (area under the curve: 0.750, 95% confidence interval: 0.602-0.897, P = 0.004). Multivariate logistic regression analysis confirmed that ADMA and anemia were significant predictors of MARE. Further analysis revealed that increased ADMA concentration in plasma was highly significant predictor of MARE in patients with CIN. Moreover, patients with CIN and MARE had the highest plasma ADMA levels 24 hours after CM exposure in our study cohort. The impact of ADMA on MARE was independent of such known CIN risk factors as anemia, pre-existing renal failure, pre-existing heart failure, and diabetes.ADMA concentration in plasma is a promising novel biomarker of major contrast-induced nephropathy-associated events 90 days after contrast media exposure.

Determination of oxidative stress and cellular inflammation in patients with diabetic nephropathy and non-diabetic nephropathy being administered hemodialysis treatment due to chronic renal failure

OBJECTIVES

We aimed to evaluate oxidative stress [8-hydroxydeoxyguanosine (8-OHdG), malondialdehyde (MDA)] endothelial damage [asymmetric dimethylarginine (ADMA)] and markers of cellular inflammation [interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), neopterin (NP) and high-sensitivity C-reactive protein (hsCRP)] in patients with diabetic nephropathy (DN) and non-diabetic nephropathy who were being administered hemodialysis treatment because of chronic renal failure.

METHODS

In determining 8-OHdG, IL-6 and TNF-α levels, Enzyme-Linked Immuno-Sorbent Assay method was used. Serum MDA, ADMA and NP levels were determined by using high performance liquid chromatography (HPLC). And hs-CRP values were measured with nephelometric method.

RESULTS

Serum 8-OHdG and MDA levels were found statistically to have increased when compared with those of the control group in patients groups after dialysis. However, serum ADMA and neopterin levels were observed statistically to have decreased when compared with those of the control group in patients groups after dialysis. But, decreases on ADMA and neopterin levels are still much higher than those of control. IL-6 and TNF-α levels were found to have increased when compared with those of control group in patients groups before dialysis.

CONCLUSION

The oxidative stress in patients with DN, who were being treated with hemodialysis due to chronic renal failure, was higher than that of non-DN patients who were being treated with hemodialysis. In contrast with this, inflammation occurring in non-DN patients was found to have been higher than that of in patients with DN.

Relations between concentrations of asymmetric dimethylarginine and neopterin as potential risk factors for cardiovascular diseases in haemodialysis-treated patients

OBJECTIVES

To investigate the correlation between concentrations of asymmetric dimethylarginine (ADMA) and neopterin (NP) as potential risk factors for cardiovascular diseases in chronic renal failure patients.

METHOD

In this study, 33 patients with renal failure before and after haemodialysis were compared with healthy control subjects. Serum ADMA and NP levels were measured using high performance liquid chromatography (HPLC).

RESULTS

When ADMA and NP concentrations in renal failure patients were compared before and after dialysis, before dialysis ADMA and NP concentrations were higher than those in the control group. However, ADMA and NP levels showed a falling mean and clear after dialysis. While there is no correlation between ADMA and NP levels before dialysis, there is a mean and positive correlation between ADMA and NP levels after dialysis.

CONCLUSION

Potential risk factors for cardiovascular diseases include high concentrations of both ADMA and NP levels in chronic renal failure patients. A correlation mean between ADMA and NP levels after dialysis was found, but no correlation between ADMA and NP levels before haemodialysis was discovered. These can be evaluated as two different risk factors independent from each other.