Micro- and macrocirculatory effects of apheresis in patients with familial hyperlipidemia

High lipid levels have been shown to coexist with a disturbed vascular endothelial function. Thus, acute lipid lowering could be expected to improve vascular reactivity. Patients with familial hyperlipidemia (FH) have substantial and rapid decreases in lipid levels after low-density lipoprotein apheresis. Thus, an opportunity exists to study acute effects of lipid lowering on vascular reactivity. Flow mediated vasodilation (FMD) is commonly used to assess endothelial function in conduit vessels, whereas vital capillary microscopy during the post-reactive hyperemia (PRH) phase is used to assess response at the microvascular level. It is not known whether endothelial dysfunction is a general phenomenon in all kinds of vessels or if there are differences between micro- and macrovessels. In the present study, we were not able to demonstrate an improved vascular response after acute lipid lowering in FH patients. This was true both in the microcirculation (PRH) and in the conduit vessels (FMD). However, the two methods gave concordant results, demonstrating disturbed vascular reactivity in the patients as compared with healthy subjects. We have found no previous report with parallel assessments at the microcirculatory and macrocirculatory levels.