Background The aim of the study was to assess the influence of gender and hypertension on flow and reactivity of skin microcirculation at rest, during ischemia and heat stress.
Material and methods Studied population consisted of normotensive subjects and patients with newly diagnosed untreated hypertension. Body mass index (BMI) and blood pressure (BP) measurements, 24-hour monitoring (ABPM-SpaceLab 90207), pulse wave velocity (PWV-Complior), echocardiography (General Electrics Vivid 3), laboratory investigations were performed. Skin microcirculation was assessed by laser Doppler flowmetry (PeriFlux PF 5000). Rest flow (RF), minimal flow during ischemia (biological zero - BZ), peak flow after ischemia (PF) and heat flow (HF) after thermal stress (44°C) were presented as arbitrary units [U] and as cutaneous vascular conductance (CVC). Fast Fourier’s transformation of RF, BZ and HF were also performed. Power frequency oscillations [PU2/Hz] was evaluated in five frequency intervals of endothelial, neurogenic, miogenic, respiratory and heart origin. Data were analyzed in 4 groups subjects: 2 normotensives (NT M i NT K) and 2 hypertensives (HT M i HT K). Statistical analysis was performed with ANOVA Kruskal-Wallis, c2 tests and Spearman correlation.
Results Study population consisted of 74 persons aged 34.5 ± 8.9 years: 37 women and 37 men. Both gender were similar according to age and PWV, but women had lower values of BMI, hematocrit, glucose, uric acid, trigliceride, insulin, endothelin, and higher HDL cholesterol than men. Ejection fraction was similar, but other echocardiographic parameters were lower in female gender. Hypertensives had higher BP values than normotensives, but among normotensive and hypertensive groups BP values were comparable. Lower values of CVC BZ were observed in hypertensives (p = 0.01) with highest differences between NT K v. HT M (p = 0.03) and NT M v. HT K (p = 0.09). Highest HF was detected in normotensive women. Power of BZ oscillations of endothelial origin significantly differed (p = 0.03) among studied groups with the lowest values in K HT, especially v. M HT (p = 0.04). Among both gender negative correlation between CVC BZ and 24-BP values was observed. Power oscillations of BZ endothelial origin correlated negatively with ABPM BP values in women.
Conclusions Normotensive women in middle age mainly influence on increase vasodilatation and thermal skin flow. Hypertensive women reveal decrease of minimal skin flow during ischemia and weakness of endothelial origin flowmotion.