Noninvasive assessment of endothelial function and vascular parameters in patients with familial and nonfamilial hypercholesterolemia

INTRODUCTION Endothelial dysfunction is one of the markers of atherosclerosis.
OBJECTIVES The aim of the study was to evaluate endothelial function by assessing flow‑mediated dilation (FMD) and to measure the parameters of brachial arterial stiffness in patients with familial hypercholesterolemia (FH) and those with high low‑density lipoprotein (LDL) cholesterol levels without FH mutations (nonfamilial hypercholesterolemia – non‑FH).

PATIENTS AND METHODS The study involved 60 patients (mean age, 41.9 ±7.7 y) without documented cardiovascular events and clinical symptoms of cardiovascular diseases: 21 patients with elevated

plasma LDL cholesterol levels and genetically confirmed FH, 19 patients with elevated LDL cholesterol levels and without FH mutations, and 20 healthy controls. In each patient, ultrasound imaging was used to assess endothelium‑dependent FMD and nitroglycerin‑induced endothelium‑independent dilation (EID) in the brachial artery. In addition, echo‑tracking and photoplethysmography were used to assess the parameters of arterial stiffness.

RESULTS FMD was significantly lower in patients with FH (11.0% ±9.9% vs. 21.0% ±14.3%, P <0.01) and non‑FH (14.2% ±10.1% vs. 21.0% ±14.3%, P <0.05) compared with controls. EID and arterial stiffness parameters were similar between the groups.

CONCLUSIONS Reduced FMD may suggest endothelial dysfunction. A lack of significant differences in arterial stiffness parameters may indicate that vascular remodeling is not advanced in patients with elevated LDL cholesterol levels. A lack of significant differences in FMD and arterial stiffness between patients with and without FH may indicate that FH mutation itself is not the main determinant of endothelial dysfunction and vascular remodeling in younger patients with hypercholesterolemia.