Laser Doppler flowmetry evaluation of skin microvascular endothelial function in patients with metabolic syndrome

Metabolic syndrome (MetS) is associated with high cardiovascular morbidity and mortality, and endothelial dysfunction is an early pathogenetic event in the MetS. Lifestyle changes and pharmacological intervention might partly restore endothelial function in MetS. Whereas an optimal non-invasive test for endothelial dysfunction is still being sought, the aim of this study was to assess the relationship between changes in skin microvascular endothelial function, detected by Laser Doppler flowmetry, and cardiovascular risk factors (CVRFs) of patients with MetS.

3081 patients (1865 women and 1216 men, mean age 53 ± 6 years) with MetS were enrolled in the study, which was conducted during the period of 2010-2014 at Vilnius University Hospital Santaros Klinikos. Skin microvascular endothelial function was evaluated using the Laser Doppler flowmetry in combination with the post-occlusive reactive hyperaemia test. The percentage change of flow from peak to the rest flow (PF-RF) was calculated and used as the main measure of endothelial function.

The study showed that decrease in flow-mediated dilatation reflected by PF-RF was associated with increased triglycerides (p = 0.002), male sex (p < 0.001), and diabetes (p = 0.002). Patients with quite a few CVRFs (body mass index ≥25 kg/m², smoking, diabetes, arterial hypertension, a positive history of dyslipidaemia) had significantly lower PF-RF score than patients only with one of these risk factors (p < 0.001).

Changes in skin microvascular endothelial function are significantly associated with most CVRFs and depend on the number of CVRFs.