Relations between plasma asymmetric dimethylarginine (ADMA) and risk factors for coronary disease

Background Elevated plasma levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide production, are reported to be associated with coronary artery disease (CAD). Methods We measured plasma levels of ADMA and related compounds, nitrate + nitrite (NOx), total homocysteine (tHCY) and assessed renal function and lipid profiles in 145 patients—75 with triple vessel coronary disease and 70 with no detectable coronary disease. Results Levels of ADMA, l-arginine, l-arginine/ADMA and plasma NOx were not different in the two groups but smokers with triple vessel disease had higher ADMA and lower NOx levels than the non-smokers, relationships also present for all smokers and non-smokers in the two groups combined. In all 145 patients ADMA, symmetric dimethylarginine (SDMA) and tHCY levels were significantly higher in patients with glomerular filtration rate (GFR) <81 mL/min/1.73 m2 than in patients with GFR ≥ 81 mL/min/1.73 m2. There was a modest positive correlation between tHCY and ADMA and both were strongly correlated with SDMA which is excreted by the kidney. ADMA, SDMA and tHCY were negatively correlated with GFR. Conclusions We suggest that the reported ADMA increases in CAD patients are due to an associated reduction in renal function and to smoking habit.