Correlation of plasma levels of asymmetric dimethylarginine with carotid intima - Media thickness in hypertensive patients with endothelial dysfunction

Abstract

Background: Hypertension is one of the major risk factors in cardiovascular disease and the endothelial dysfunction in hypertensive patients is a major factor for cardiovascular complications. Asymmetric dimethylarginine (ADMA) has evolved in recent years as an important regulator of nitric oxide (NO) synthesis. The relationship between ADMA and essential hypertension is a rather new field of research. Carotid intima-media thickness (IMT) is an important marker in subclinical vascular lesion. An increased carotid IMT is considered by some authors a marker of subclinical atherosclerosis and blood pressure plays and important role in increasing the IMT. Aim: This study is aiming to investigate the relationship between plasma ADMA levels and carotid IMT in essential hypertensive patients with / without endothelial dysfunction. Material and method: The prospective present study was conducted during a period of 18 months and included a number of 62 patients with essential hypertension. They followed a series of clinical and laboratory investigations, including determination of plasma ADMA levels and respective carotid ITM Plasma ADMA levels were measured by highperformance liquid chromatography and carotid ITM by high-resolution ultrasonography system. Results: Mean plasma ADMA levels were significantly higher in the premier group (0,96 ± 0, 06 μmol/L) in comparison with that second group (0, 67 ± 0, 11 μmol/L; p < 0,001) and the third group (0, 54 ± 0, 06; p < 0,001). In regards to the mean value of carotid IMT, its distribution in the study group is as follows: in the third group the mean value of carotid IMT was between normal limit (0,6 – 0,9; 0.73 ± 0,05), for the second group the mean value of carotid IMT were also between normal limit (0,7 – 0,9; 0,82 ± 0,03) but for the first group the mean value of carotid IMT was higher (1,0 – 1,3 mm; 1,15 ± 0,09). This value, for premier group, was significantly higher compared with the other two groups (p < 0,001). Conclusions: Plasma ADMA levels are significantly high in mild – to – moderate hypertensive patients. Elevated ADMA levels are associated with endothelial dysfunction in these patients. High plasma ADMA levels was observed and significantly positively correlated with carotid IMT. The results obtained support the idea that, the correlation of the plasma ADMA levels and carotid IMT is maintained regardless of the degree of endothelial dysfunction.