Relationship of asymmetric dimethylarginine with flow-mediated dilatation in subjects with newly detected severe hypercholesterolemia

Background: Little is know about the relationship between asymmetric dimethylarginine (ADMA) and percent flow-mediated dilatation (%FMD) in subjects with severe hypercholesterolemia (HH). Aim: The aim the present study was the evaluation of the relationship of ADMA to %FMD, as well as to lipid parameters and other markers of endothelial dysfunction in newly detected subjects with severe HH. Methods: One hundred and twenty asymptomatic patients with severe, newly detected HH and 100 controls were evaluated. The plasma level of ADMA was tested by ELISA and total homocysteine (tHcy) - through fluid chromatographic analysis. The %FMD was evaluated by the diameter of brachial artery with 7.5 MHz transducer of HP SONOS 5500. Results: Significant difference was found between patients and controls, (P < 0.05) regarding lipid total cholesterol, triglycerides, high-density lipoprotein, low-dencity lipoprotein, atherogenic indices) and non-lipid markers (ADMA, sICAM-1, sVCAM-1), as well as the endothelium dependent %FMD in contrast to flow independent vasodilation. (P > 0.05) No significant difference was found between the groups with respect to tHcy, P-selectine and E-selectine. (P > 0.05) A strong negative correlation was found between %FMD and ADMA. (r(xy) = -0.895; P < 0.001), Apolipoprotein-B (r(xy) = -0.687; P < 0.0001, tHcy (r(xy) = -0.560; P < 0.001) and Apolipoprotein index -B/A1 (r(xy) = -0.518; P < 0.001). The subsequent linear and multiple regression analysis selected ADMA as the most significant factor in relation to %FMD. Conclusion: It is concluded that ADMA is the basic modulator of %FMD among all tested atherogenic risk biomarkers in in newly detected subjects with severe HH.