Serum ADMA concentration – an independent factor determining FMD impairment in cardiac syndrome X

Abstract

Mechanisms of decreased endogenous vascular reactivity in individuals with cardiac syndrome X (CSX) are not fully understood.

Aim. To evaluate the following serum markers: total nitric oxide (NO), asymmetric dimethylarginine (ADMA), platelet-derived growth factor (PDGF), and to establish their relation to ultrasound indexes of endothelial function and structural remodeling in CSX patients.

Method. The study group consisted of 43 CSX patients (mean age: 56.3 ± 9 years), while the control group included 21 healthy subjects (mean age: 54.86 ± 6.9 years). The high-resolution ultrasound was performed to measure: flow-mediated vasodilatation (FMD), nitroglycerine-mediated vasodilatation (NMD) and intima-media thickness (IMT) of carotid arteries.

Results. In CSX patients, significantly lower FMD (9.06 ± 3.2%) and significantly higher IMT (0.667 ± 0.14 mm) values were observed compared to healthy individuals (17.42 ± 8.4%, 0.571 ± 0.2 mm; P < 0.05). Mean total NO serum concentration was significantly higher in the CSX group (48.2 ± 18.2 μmol/L) as compared to controls (32.1 ± 1.4 μmol/L; P < 0.0001). There were no differences in serum ADMA and PDGF levels. In CSX patients, FMD values correlated with NO (r = 0.323; P = 0.039) and ADMA (r = -0.387; P = 0.012) serum levels; however, there were no significant correlations between NO and ADMA concentrations.

Conclusion. Serum ADMA concentration is the only independent factor determining FMD impairment.