Gender Differences in Microvessular Bed Parameters according to High-Frequency Doppler Ultrasonography

The study is aimed at analyzing the differences in central hemodynamics and blood flow in the microcirculatory bed in men and women to identify specific gender characteristics of microcirculation. The study involved 84 women and 406 men. Three-fold measurement of arterial pressure on the brachial artery was performed using the MediTechMT-25 Palm device (United States). Blood flow parameters were measured at rest using high-frequency ultrasound dopplerography on the skin of the nail fold of the index finger of the right hand. The subjects were in a sitting position, the hand on which the measurement was performed was on a solid support at the level of the heart. The Minimax-Doppler-K dopplerograph (Russia) with a 20-MHz sensor was used for the study. Analysis of the results revealed statistically significant differences in microcirculation parameters between men and women. Women had higher values of blood flow velocity in the arteriolar (Vm: 0.98 versus 0.91 cm/s, p = 0.040; Vs: 1.55 versus 1.38 cm/s, p < 0.001; Vas: 0.81 versus 0.55 cm/s, p = 0.003) and venular links (Vad: 0.34 versus 0.25 cm/s, p = 0.002). In men, this is compensated by higher values of capillary blood flow, such as Vam: 0.16 versus 0.19 cm/s, p = 0.030, as well as volumetric blood flow in the capillaries (Qam: 0.08 versus 0.11 mL/min, p < 0.001). In addition, women have higher pulsatility indices (PI: 1.35 vs. 1.16, p = 0.014) and circulatory tension indices (RI: 0.80 vs. 0.73, p = 0.026).