Effect of angiotensin-converting enzyme inhibitor on serum asymmetric dimethylarginine and coronary circulation in patients with type 2 diabetes mellitus

Measurements of serum asymmetric dimethylarginine ( ADMA), an endogenous nitric oxide synthase inhibitor, and coronary flow velocity reserve (CFVR) using transthoracic Doppler echocardiography were performed at baseline and after 4 weeks of temocapril therapy ( 2 mg/day) in 18 patients with type 2 diabetes. Although blood pressure, fasting blood sugar and lipid profiles remained unchanged, serum ADMA concentrations decreased significantly (0.51 +/- 0.08 to 0.46 +/- 0.07 mu mol/1, p < 0.01) and CFVR increased significantly (2.78 +/- 0.36 to 3.35 +/- 0.46, p < 0.001) after the treatment. Moreover, a strong correlation was observed between the difference of ADMA and that of CFVR (r=- 0.80, p < 0.001). Temocapril reduced serum ADMA concentrations, improved CFVR beyond its blood pressure lowering effect. Our results suggest that decrease in ADMA by temocapril treatment is related to improvement of coronary circulation as determined by CFVR in patients with type 2 diabetes. (c) 2007 Elsevier Ireland Ltd. All rights reserved.