Comparative study of the upper and lower limb skin blood flow control mechanisms in patients with essential hypertension

Abstract

Objective: To investigate limb specific differences in cutaneous vascular function in patients (n=33) with essential hypertension (EHT). Methods: In this observational cross-sectional study, baseline skin blood flow and the response to local heating were measured with a laser Doppler flowmeter (LDF) from the volar region of the forearm and the gaiter area of the foot at supine rest. The fractal analysis, detrended fluctua- tion analysis (DFA), was used to calculate the correlation properties of skin blood flow, LDF signal. The paired t-test and repeated measures ANOVA were used to determine the response to local heating and compare the scaling exponents of different anatomical locations respectively. Results: We found three linear scaling regions that describe the fractal behavior of LDF signal with their slopes, scaling exponents. For cardiac (αC) and cardio-respiratory (αCR) scaling exponents, thermal hyperemia (T) induced greater change in the leg (αC=1.49±0.26; αCT=1.62±0.20 p