Structural and functional state of upper limb skin microvessels of healthy normotensive working-age individuals depending on body mass index and metabolic status

Aim . To study the structural and functional state of various components of the upper limb skin microcirculation in healthy normotensive working-age individuals depending on body mass index (BMI) and metabolic status. Material and methods . The study included 227 healthy normotensive volunteers (43±6 years old, 120/107 men/women). They underwent a comprehensive examination of various cardiovascular system sections using non-invasive methods. Left upper limb skin microcirculation was assessed using videocapillaroscopy, 2-channel laser Doppler flowmetry (LDF), and transmission photoplethysmography (PPG). Results . When dividing subjects into groups based on BMI (normal weight (18,5 kg/m 2 ≤ BMI <25 kg/m 2 , n=114) and overweight (25 kg/m 2 ≤ BMI <35 kg/m 2 , n=113) based on videocapillaroscopy, LDF, and PPG revealed no differences between the groups for any of the analyzed parameters. When dividing the subjects (n=227) into groups by metabolic status, the group with a metabolically healthy obesity (MHO) phenotype consisted of 53 (23%) subjects, and the group with a metabolically unhealthy obesity (MUO) phenotype included 174 (77%) individuals. In the MHO group, 29 (55%) overweight individuals relative to individuals with normal BMI values (n=24, 45%) had a decrease in the perfusion contribution of endothelial (7,15 and 4,53%), neurogenic (6,12 and 4,12%) and myogenic (5 and 2,97%) mechanisms of precapillary arteriole regulation, respectively. In the MUO group, the opposite situation was noted — subjects with normal weight (n=90, 52%) relative to individuals with overweight and class 1 obesity (n=84, 48%) had higher values of the contribution of regulatory mechanisms to the total precapillary arteriole tone from the endothelial (3,04 and 2,73), neurogenic (2,9 and 2,51), and myogenic (3,33 and 3,08) tone-forming regulatory mechanisms, respectively. Conclusion . BMI, as a microcirculation disorder biomarker in obesity, demonstrates logical/expected patterns only in individuals with MHO. In healthy normotensive individuals with MUO, the opposite state of resistive skin microvessels is observed, which requires further research in this area.