Functional state of skin microvascular bed according to laser doppler flowmetry in patients with arterial hypertension combined with hypercholesterolemia

Abstract

Introduction. The great importance of risk factors, such as arterial hypertension (AH) and low-density lipoprotein cholesterol (LDL-H), for development of cardiovascular diseases, makes highly relevant to obtain the data of the nature of microcirculation (MC) changes that are a key link of maintaining homeostasis under their concomitant influence. Aim – to evaluate functional state of skin microvascular bed using laser Doppler flowmetry in patients with arterial hypertension (AH) and combined with hypercholesterolemia. Materials and Methods. The study involved 37 practically healthy volunteers and 94 patients with 2–3 stage of AH, which were divided into 2 groups: Gr.1 with LDL-CH level ≤3.5 mmol/l (n = 35) and Gr.2 with LDL-H level >3.5 mmol/l (n = 59). MC of the forearm skin was assessed by laser Doppler flowmetry. Parameters of basal blood flow, the amplitude-frequency spectrum of its fluctuations, nutritional MC, and parameters of occlusion test were evaluated. Results. Analyzing rhythm structure of blood flow fluctuations, statistically significant decrease in standardized parameters of their amplitude in endothelial and myogenic frequency ranges was revealed in patients with elevated LDL-CH levels compared to patients of Gr.1 by 19.7 % and 9.7 % (р = 0.045), respectively, which indicated weakening of endothelial function and constriction of precapillary segment of MC. These changes were accompanied by decrease in reserve of microvascular blood flow by 9.1 % in Gr.2 of patients (p = 0.044) with pronounced trend towards reduction of capillary perfusion and activation of blood flow through arteriolovenular shunts. Conclusion. More pronounced functional disorders of MC, characterized by endothelial dysfunction, constriction of precapillary segment, and decrease in reserve potential of tissue hemoperfusion were revealed in AH patients with atherogenic hyperlipidemia vs AH patients.