Sex features of cutaneous microvasculature in healthy working-age people

Aim. To study sex characteristics of cutaneous microvascular structure and function in a cohort of healthy working-age people without cardiovascular diseases. Material and methods . The study included 35 healthy men (42±4 years) and 34 women (41 ±5 years). The cardiovascular system was assessed in all patients. The microcirculatory bed of the skin was investigated by the following non-invasive methods: 1) computerized video capillaroscopy; 2) laser Doppler flowmetry; 3) photoplethysmography. Results. According to computerized video capillaroscopy in men, compared with women, there was a smaller number of both functioning capillaries (78 vs 86 capillaries/mm 2 , respectively (p<0,05)) and their total number (100 vs 120 capillaries/mm 2 , respectively (p<0,001)). Against the background of a decrease in capillary density in men, there was a higher skin interstitial hydration — 113 vs 96 gm (p<0,005) in men than in women. At the level of precapillary arterioles, where humoral tone regulation prevails. Laser Doppler flowmetry revealed lower pulse amplitude in men than in women — 0,87 vs 1,02 pf, respectively (p<0,05), which indicates a lower arterial blood inflow to exchange microvessels. Against this background, the constrictor response of precapillary arterioles to a sympathetic nervous system stimulation in men is higher than in women — 45% vs 40%, respectively (p<0,05). At the level of large arterioles, where neural tone regulation prevails, photoplethysmography revealed lower augmentation index standardized at a heart rate in men (-4,6 vs 1,7%, respectively, p<0,05), which indicates lower rigidity of muscular vessels in men. Conclusion. In working-age healthy people, sex differences are noted at all cutaneous microvascular levels, which must be taken into account when planning studies.