Flow‐mediated vasodilatation: variation and interrelationships with plasma lipids and lipoproteins

Abstract

Objective. Endothelial dysfunction is a critical, prerequisite step in atherosclerosis, and may be evaluated by flow‐mediated vasodilatation (FMD). The objective of this study was to examine interrelationships between FMD and plasma lipids and lipoproteins, and to determine the between‐operator and within‐subject variability associated with this technique. Material and methods. FMD, plasma lipids and lipoproteins, including small dense LDL (sdLDL), were measured twice in 40 healthy volunteers, 4 weeks apart. Interrelationships between mean FMD responses and plasma lipids and lipoproteins were examined by correlation analysis. FMD measurements were taken by two independent operators, allowing determination of between‐operator variability. Within‐subject variability was determined by obtaining two measurements, 4 weeks apart, in every subject, and carried out by the same operator. Results. FMD was inversely related to plasma triglycerides (r = −0.47, p = 0.002), total cholesterol/HDL cholesterol (r = −0.35, p = 0.03) and apolipoprotein B (r = −0.36, p = 0.02), but not to other plasma lipids and lipoproteins. When measuring variation in FMD, the following results were found: Between operators (SD = 4.0 FMD%) and within subjects (SD = 2.9 FMD%). Conclusions. The associations between FMD, plasma triglycerides and apoB provide evidence supporting a role for triglyceride‐rich lipoproteins in endothelial dysfunction.

• Atherosclerosis
• cholesterol
• endothelium
• lipoproteins
• triglycerides