Intima-Media Thickness and Flow-Mediated Vasodilation in Asymptomatic Subjects with Newly Detected Severe Hypercholesterolemia

Background: The aim was to establish the predictors of early functional and structural vascular alterations (using intima-media thickness (IMT)) and flow-mediated vasodilation (%FMD) as well as to investigate the interrelationship between IMT and %FMD in asymptomatic, never-treated, severe hypercholesterolemia (HH). Methods: One hundred and twenty patients with asymptomatic, severe, untreated HH and 100 controls were included. ELISA was used for asymmetric dimethylarginine (ADMA) and cellular adhesion molecules, and fluid chromatography for total homocysteine (tHcy). Hewlett Packard SONOS 5500 with a 7.5 MHz transducer and MedicaSoft IMT software were used for evaluation of %FMD and IMT of common carotid artery (CCA). Results: Patients and controls differ with respect to all tested biomarkers (P < 0.05), except for P-selectin and E-selectin (P < 0.05). %FMD was lower in patients (P < 0.001). The IMT of the CCA was higher in patients (P < 0.001). Inverse correlations were found between %FMD and IMT mean and age, ADMA, Apo-B, Apo-B/Apo-A₁, and tHcy. ADMA was established as the most important factor related to %FMD. Age and Apo-B were established as the most important factors related to IMT mean. An inverse correlation was established between %FMD and IMT mean (r_xy= 0.546; P < 0.001)). If cases with IMT mean ≥1 were excluded, the correlation weakened. In patients with IMT mean ≥1 mm, the correlation did not change. Conclusion: In conclusion, asymptomatic, untreated patients with severe hypercholesterolemia are at high risk of having increased IMT of the CCA, especially if there is endothelial dysfunction, verified by %FMD of the brachial artery.