The use of microvascular endothelial function indicators to calculate functional age of the microcirculation system

Aim. To find out the possibility of using microvascular endothelial function indicators to determine the biological age (BA) of a person. Materials and methods. 390 patients aged 20–29 years (n = 31), 30–39 (n = 22), 40–49 (n = 45), 50–59 years (n = 72), 60–69 years (n = 129) and 70–79 years (n = 91) were examined. The functional state of the microvascular endothelium was analyzed by laser Doppler flowmetry on a BLF-21D (Transonic Systems Inc, USA) at the internal surface of the middle third of the forearm. Platelet aggregation activity was measured on a two-channel laser platelet aggregation analyzer 23 LA (Biola, Russia) by turbidimetric method, blood viscosity – using a rotational viscometer AKR-2 (Russia) at a shear rate of 10–200 s-1 with the deformation index and erythrocyte aggregation index calculation. Results. There was a statistically significant decrease in the volumetric rate of the skin blood flow (SBF) at rest and at the peak of post-occlusion reactive hyperemia, a reduced recovery time of SBF to baseline values from the age of 50–59 years, indicating endothelial dysfunction with aging. A progression of endothelial dysfunction in persons older than 60 years was accompanied by hemostatic parameters deterioration: increased blood viscosity, increased both spontaneous and induced platelet aggregation activity. Blood viscosity was statistically significantly increased from the age of 40. The formula for calculating BA using indicators of the microvascular endothelium functional state, platelet aggregation capacity and anthropometric indicators was obtained. Conclusions. The formula for calculating human BA using indicators of the microvascular endothelium functional state, platelet aggregation capacity and anthropometric indicators has been developed. Sufficiently high accuracy determination of the microcirculation system functional age based on the developed method has been shown.