Skin Microcirculation Research Articles

Pregnancy-associated plasma protein-A is positively correlated with first-trimester skin microvascular reactivity.

To investigate the relationship between levels of circulating maternal pregnancy-associated plasma protein-A (PAPP-A) and first-trimester maternal vascular function. This was a cross-sectional study of 53 healthy, non-smoking, nulliparous pregnant women in Stockholm, Sweden. PAPP-A levels and vascular function were assessed during gestational weeks 11-14. Forearm skin microcirculation was investigated by laser Doppler perfusion imaging during iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) to assess endothelium-dependent and -independent microvascular vasodilatation, respectively. Microvascular endothelial function index was calculated as peak ACh/peak SNP. Endothelium-dependent and -independent vasodilatation in the brachial artery was evaluated, respectively, by postischemic hyperemia-induced flow-mediated vasodilatation (FMD) and by response to sublingual intake of glyceryl trinitrate (GTN). PAPP-A was correlated with skin microvascular endothelial function index (β = 1.008 (95% CI, 0.34-1.68), r2 = 0.17, P= 0.004). PAPP-A also correlated inversely with FMD (β = -0.052 (95% CI, -0.094 to -0.011), r2 = 0.13, P= 0.014) but did not relate to forearm endothelial function index (i.e. FMD/GTN). The results were retained in multivariate analyses including known confounding factors. First-trimester endothelium-dependent skin microvascular reactivity was positively related to PAPP-A levels. If confirmed, these novel findings suggest that first-trimester skin microvascular reactivity could be a useful early pregnancy marker of placental function. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Safety assessment of starch-based personal care products: Nanocapsules and pickering emulsions

The safety profile of the ingredients used in topical dosage forms and its evaluation is an issue of utmost importance. A suitable equilibrium between safety and efficacy is crucial before promoting a dermatological product. The aim of this work was to assess the safety and biological effects of starch-based vehicles (St-BV) used in such products. The hazard, exposure and dose-response assessment were used to characterize the risk of each ingredient. The EpiSkin™ assay and human repeat insult patch tests were performed to compare the theoretical safety assessment to in vitro and in vivo data. The efficacy of the St-BV was studied using biophysical measurements in human volunteers during 28 days, showing that all ingredients and their combinations were safe for the consumer. Tissue viability determined using the EpiSkin™ testing reached values between 84.0 ± 5.0% and 98.0 ± 8.6% after application of St-BV, which were considered as non-irritant to the skin. These observations were confirmed by the in vivo studies where the St-BV did not induce any sensitization on the volunteers, being safe for human use. Moreover, St-BV increased skin hydration and microcirculation, emerging as an attractive alternative to chemical raw materials.

The relationship between forearm skin speed-resolved perfusion and oxygen saturation, and finger arterial pulsation amplitudes, as indirect measures of endothelial function.

Endothelial function is important for regulating peripheral blood flow to meet varying metabolic demands and can be measured indirectly during vascular provocations. In this study, we compared the PAT finger response (EndoPAT) after a 5-minutes arterial occlusion to that from forearm skin comprehensive microcirculation analysis (EPOS). Measurements in 16 subjects with varying cardiovascular risk factors were carried out concurrently with both methods during arterial occlusion, while forearm skin was also evaluated during local heating. Peak values for EPOS skin Perfconv and speed-resolved total perfusion after the release of the occlusion were significantly correlated to the EndoPAT RHI (ρ=.68, P=.007 and ρ=.60, P=.025, respectively), mainly due to high-speed blood flow. During local heating, EPOS skin oxygen saturation, SO2, was significantly correlated to RHI (ρ=.62, P=.043). This indicates that SO2 may have diagnostic value regarding endothelial function. We have demonstrated for the first time a significant relationship between forearm skin microcirculatory perfusion and oxygen saturation and finger PAT. Both local heating and reactive hyperemia are useful skin provocations. Further studies are needed to understand the precise regulation mechanisms of blood flow and oxygenation during these tests.

Regional myocardial function abnormalities are associated with macro- and microcirculation dysfunction in the metabolic syndrome: the RESOLVE study.

Abnormalities in myocardial and vascular function have been reported in the metabolic syndrome (MetS), but whether these alterations are related remains poorly documented. Our aim was accordingly to investigate interrelationships between macro- and microcirculatory vasoreactivity and left ventricular (LV) myocardial function in MetS patients. Eighty-eight MetS individuals and 44 age- and gender-matched healthy controls were enrolled. LV global longitudinal strain (GLS) was measured using Vector Velocity Imaging. Endothelial-dependent and independent reactivity in macro- and microcirculatory territories was established using flow-mediated dilation and nitrate-mediated dilation of the brachial artery and cutaneous blood flow measured with laser Doppler flowmetry in response to iontophoresis of acetylcholine and sodium nitroprusside, respectively. Carotid intima-media thickness (cIMT) was measured according to the Mannheim consensus. Compared to controls, MetS patients presented with reduced GLS (p<0.001) increased cIMT and impaired (p<0.001) endothelial and smooth muscle function of the brachial artery and the forearm skin microcirculation. Highly significant relationships (p<0.01) were noticed between GLS and vascular outcomes. In addition, cIMT (β=0.21, p=0.024) and microcirculatory endothelium-dependent reactivity (β=-0.20, p=0.035) were identified as independent predictors of GLS. In MetS, abnormalities in myocardial function and endothelial as well as smooth muscle function of small and large arteries co-exist and are closely associated. This study supports a role for microvascular dysfunction in the pathogenesis of LV myocardial dysfunction.

Whitening function of Chinese traditional medicine formula via laser Doppler technology

ABSTRACTFair skins are traditionally viewed as beautiful in Eastern regions of the world, and whitening effect is therefore eternally pursued. The aim of this study was to evaluate the whitening effectiveness of a traditional Chinese medicine (TCM) formula using laser Doppler technology. In addition, a melanin and erythema meter (Mexameter MX18/MPA-9, Courage&Kahazaka) and VISIA facial imaging booth (VISIA-CR, Canfield) were used to establish parallel comparisons. Pre- and post-treatment results showed that the TCM formula exhibits the best skin whitening effect. This was followed in effectiveness by the vitamin C group. The negative control and blank groups showed no whitening effect. The obtained results indicated that skin micro-circulation was enhanced in the TCM formula group. Therefore,this method could provide sufficient nutritive substances to fibroblasts and collagen, which in turn remove cell metabolic waste and other harmful substances such as superoxide anion in a timely manner. This improves the overall health of skin cells.

Pilot Assessment of the Angiosome Concept by Intra-operative Fluorescence Angiography After Tibial Bypass Surgery

The "angiosome" concept as a model for decision making in revascularisation of patients with critical limb ischaemia (CLI) has been subject to lively discussion in recent years. The aim of this prospective pilot study was to use intra-operative fluorescence angiography to provide further data on the angiosome concept on the level of microcirculation after tibial bypass surgery. This was a prospective analysis of 40 patients presenting with CLI Rutherford stage IV to VI before and after tibial bypass surgery. The macrocirculation was measured by the ankle brachial index. Skin microcirculation was assessed by intra-operative fluorescence angiography. The alteration of microcirculation was compared in direct and indirect revascularised angiosomes. Clinical follow-up investigations were performed and the wound healing rate was compared between the different revascularisation methods. Cumulated microcirculation parameters showed a significant improvement after surgery (ingress, ingress rate p<.001). Likewise, general microcirculatory improvement was observed in each foot angiosome after revascularisation, regardless of the tibial artery revascularised. Furthermore, a comparison of the direct (DR) and the indirect revascularised (IR) angiosomes did not show a significant difference concerning the improvement of microcirculation (difference DR-IR, ingress: 1.69, 95% CI 71.73-75.11; ingress rate: 0.08, 95% CI -12.91 to 13.07). The wound healing rate was similar in both groups, although the time to wound healing was faster by on average 2.5 months in the DR group (p=.083). Microcirculatory improvement was seen over the whole foot after tibial bypass. Therefore, fluorescence angiography is a promising tool to evaluate the angiosome concept in future larger studies. Clinicaltrials.gov: NCT03012750.

Pathophysiological mechanisms of chronic venous disease and their role in C0s clinical class

The aim of this review is to provide a clear understanding of the pathophysiological mechanisms of chronic venous disease (CVD) at different clinical stages and the possible role of these mechanisms in the development of symptoms in C0s clinical class of the Clinical, Etiologic, Anatomic, and Pathophysiologic classification, which consists of symptomatic patients without any visible or palpable signs of venous disease. The prevalence of C0s class in several epidemiological studies varies between 13% and 23% of the general population. Wall remodeling and valve destruction due to white cell endothelial interaction is the main cause of primary varicose veins, while deep vein thrombosis produces secondary changes leading to the postthrombotic syndrome. The underlying mechanism of the skin changes and ulceration is venous hypertension, which is transmitted to the skin microcirculation. Over the last 10 years, an improved videocapillaroscopic technique, the orthogonal polarization spectral imaging technique demonstrated that quantitative measurements in the skin microcirculation are progressively altered from C1 to C6 patients and that values in CVD patients are significantly different from healthy individuals (P < 0.05): capillary diameter increases and capillary morphology worsens from C2 to C5; diameter of the dermal papilla and diameter of the capillary bulk increase from C3 to C5; and functional capillary density (FCD) decreases from C4 to C5. In addition, significant changes have been shown between C0a and C0s patients despite the presence of normal conventional duplex scans in the latter: a decrease of FCD and an increase in the diameter of the dermal papilla. Functional abnormalities found to be present in C0s patients by recent studies include increased compliance of the venous wall (hypotonic phlebopathy), dilatation of deep veins in the calf producing an abnormally increased venous volume, reduction in emptying of venous reservoir, reduction in the venoarteriolar response on standing, and blood reflux in small venules despite a normal conventional duplex scan. However, most of the studies are small, and their findings need to be confirmed by larger series. It remains to be seen whether functional changes and microcirculatory changes respond to venoactive medications in parallel to the relief of symptoms.

The rationale for the application of photomagnetic therapy in the treatment of dermatitis

in spite of the fact that photomagnetic therapy with the use of the FotoSPOK device (Magnomed Ltd., Belarus) is already used in the medical practice, the application of this method for the management of many diseases remains to be substantiated on the scientifically sound grounds. The objective of the present study was to evaluate the effectiveness of photomagnetic therapy in the treatment of the local inflammatory process in the skin and to elaborate the rationale for the application of this technique in the treatment of contact dermatitis. The experiments were carried out on 168 outbred male rats. A modified model of experimental contact dermatitis was used in the work. The course of the treatment consisted of 8 procedures lasting 20 minutes each. The character and regression of dermatitis were estimated based on the general condition of the animals and dynamics of the skin processes. Simultaneously, the cutaneous temperature was recorded and skin microcirculation assessed. The morphological changes in the skin were evaluated in the rats with experimental dermatitis that received no treatment as well as in those given a course of photomagnetic therapy, before and after its application. The clinical, histochemical and histological data obtained in this study give evidence that the most effective tool currently available for the treatment of experimental dermatitis is photomagnetic therapy with the use a low-frequency magnetic field in the combination with the light of the blue and green spectral regions for the elimination of the inflammatory changes and oedema and with the light of the red and yellow spectral regions for the restoration of microcirculation and stimulation of regenerative processes in the skin. The results of the present study can serve as the basis for the differentiated application of the light of different wavelengths in dermatology; also, they can be used for the further development of the methods of photomagnetic therapy for the treatment of the inflammatory processes in the skin.

Intravital Observation of Microvascular Remodeling During Chronic Exposure to Hypoxia in Mice.

It is well known that chronic hypoxia elevates hematocrit levels to maintain oxygen supply to tissues. Although such high hematocrit levels might lead to hypertension due to an increase in blood viscosity, the morbidity rate of hypertension is reportedly lower in populations residing at high altitudes. The present study aimed to clarify how chronic hypoxia affects the cardiovascular system by direct observation of the microcirculation. Mouse dorsal skin chamber was used to observe arteriolar responses and capillary angiogenesis during 1-week exposure to hypoxia. Furthermore, total peripheral vascular resistance (TPR) was evaluated by measuring blood pressure (BP) and blood flow (BF) in rat carotid arteries before and after 1-week exposure to hypoxia. After 1-week exposure to hypoxia, TPR showed no significant difference compared with normoxic conditions. Observation of dorsal skin microcirculation after 1-week exposure to hypoxia, showed that the arteriolar diameter increased by 29% and the vascular area expanded by 37% compared with measures before hypoxia. These results suggest that the effects of high blood viscosity on TPR would be modified by inducing microvascular remodeling.

Telemonitoring of Capillary Blood Flow in the Human Skin: New Opportunities and Prospects

The oscillatory nature of cutaneous perfusion is fundamental and is caused by the functional activity of various regulatory mechanisms, which is confirmed by various methods of studying microcirculatory blood flow in humans. A conceptually new method for assessing skin microcirculation reviewed here is based on the analysis of video fragments of capillary blood flow in the skin registered with a conventional web camera (smartphone, tablet and others). The method makes it possible to evaluate the character of blood flow on the opposite to the heart “pole” of the greater (systemic) circulation - in the transitional part of the capillaries. Simplicity and usability of capillary blood flow telemonitoring in humans open way for a personalized approach to patient treatment as well as telemedical control of treatment effectiveness in a variety of pathological conditions. The following mini-review offers further insight into the subject.

Microcirculation of the human skin as an object of research

The possibilities of modern non-invasive methods of studying microcirculation in humans allow you to immerse yourself in the world of fundamental physiological processes on the opposite heart to the «pole» of the cardiovascular system and to obtain data that were previously inaccessible to researchers. For example, laser Doppler flowmetry and computer capillaroscopy make it possible to obtain information on the vasomotor activity of resistive precapillary arterial and capillary sphincters that regulate the flow of blood to the exchange unit. This mechanism ensures the exchange of water-soluble and low-molecular substances and is determined by parameters of hemodynamics. The review briefly analyzes the main structural and functional aspects of the microvascular bed of the skin, which must be taken into account when conducting non-invasive studies of the microcirculation system in humans.

Functionality of skin microhemocirculation in patients with obliterating atherosclerosis of lower extremity arteries as per laser Doppler flowmetry

Introduction. High prevalence and a poor prognosis of obliterating atherosclerosis of lower extremity arteries make the comprehensive study of the disease as a pressing issue. Aim of the study. To reveal features of functional state of lower extremities skin microcirculation (MC) in patients with intermittent claudication (IC). Material and methods. Microcirculation in 75 patients with IC and 15 healthy subjects was assessed by laser Doppler flowmetry. Results. In IC patients compared to healthy people significant decrease in nutritive blood flow by 25.9 % was detected as well as activation of arterio-venous blood shunting (+45.6 %) with venous congestion that causes worsening in blood rheology abnormalities. Conclusion. The detected shifts in MC lead to the progression of functional insufficiency in peripheral blood flow.

Acute exhaustive rowing exercise reduces skin microvascular dilator function in young adult rowing athletes.

The effect of acute exhaustive exercise session on skin microvascular reactivity was assessed in professional rowers and sedentary subjects. A potential involvement of altered hemodynamic parameters and/or oxidative stress level in the regulation of skin microvascular blood flow by acute exercise were determined. Anthropometric, biochemical, and hemodynamic parameters were measured in 18 young healthy sedentary men and 20 professional rowers who underwent a single acute exercise session. Post-occlusive reactive hyperemia (PORH), endothelium-dependent acetylcholine (ACh), and endothelium-independent sodium nitroprusside (SNP) microvascular responses were assessed by laser Doppler flowmetry in skin microcirculation before and after acute exercise. Serum lipid peroxidation products and plasma antioxidant capacity were measured using spectrophotometry. At baseline, rowers had significantly lower diastolic blood pressure (DBP) and heart rate (HR), and higher stroke volume (SV), PORH, and endothelium-dependent vasodilation than sedentary. Acute exercise caused a significant increase in systolic blood pressure, DBP, HR, and SV and a decrease in total peripheral resistance in both groups. Acute exercise induced a significant impairment in PORH and ACh-induced response in rowers, but not in sedentary, whereas the SNP-induced vasodilation was not affected by acute exercise in any group. Antioxidant capacity significantly increased only in sedentary after acute exercise. Single acute exercise session impaired microvascular reactivity and endothelial function in rowers but not in sedentary, possibly due to (1) more rowing grades and higher exercise intensity achieved by rowers; (2) a higher increase in arterial pressure in rowers than in sedentary men; and (3) a lower antioxidant capacity in rowers.

Evaluation of a pointwise microcirculation assessment method using liquid and multilayered tissue simulating phantoms.

.A fiber-optic probe-based instrument, designed for assessment of parameters related to microcirculation, red blood cell tissue fraction (), oxygen saturation (), and speed resolved perfusion, has been evaluated using state-of-the-art tissue phantoms. The probe integrates diffuse reflectance spectroscopy (DRS) at two source–detector separations and laser Doppler flowmetry, using an inverse Monte Carlo method for identifying the parameters of a multilayered tissue model. Here, we characterize the accuracy of the DRS aspect of the instrument using (1) liquid blood phantoms containing yeast and (2) epidermis-dermis mimicking solid-layered phantoms fabricated from polydimethylsiloxane, titanium oxide, hemoglobin, and coffee. The root-mean-square (RMS) deviations for for the two liquid phantoms were 11% and 5.3%, respectively, and 11% for the solid phantoms with highest hemoglobin signatures. The RMS deviation for was 5.2% and 2.9%, respectively, for the liquid phantoms, and 2.9% for the solid phantoms. RMS deviation for the reduced scattering coefficient (), for the solid phantoms was 15% (475 to 850 nm). For the liquid phantoms, the RMS deviation in average vessel diameter () was . In conclusion, the skin microcirculation parameters and , as well as, and are estimated with reasonable accuracy.

Prospects of Laser Doppler flowmetry application in assessment of skin microcirculation in diabetes

This review includes results of scientific and clinical use of laser Doppler flowmetry (LDF) in patients with diabetes mellitus. LDF is a non-invasive method for the quantitative evaluation of microcirculation, which can assess microcirculatory rhythms and conduct functional tests with various impacts, allowing the exploration of regulatory mechanisms of microcirculation.&#x0D; LDF reveals specific diabetes changes in the regulatory function of microcirculation. Microcirculation disturbances, which are traditionally associated with the pathogenesis of complications, also occur in patients with early disorders of carbohydrate metabolism and may precede the manifestation of diabetes. However, this method is still not applied in clinical practice. In this review, we analysed factors limiting the implementation of LDF in practical medicine and suggest ways to improve its clinical significance.

Skin Blood Flow and Vascular Endothelium Function in Uremia

Prevalence of dermatological disorder in patients with end-stage kidney disease is estimated as 50% to 100% in various studies. Some of the skin lesions are specific for the diseases causing chronic kidney disease (CKD), some are associated with CKD, and still others are the dermatological manifestation of uremia. Microangiopathy was also found in both arterioles and venule in the skin biopsy of "normal looking" skin in patients with end-stage kidney disease. In a cross-sectional study in patients on dialysis, we measured skin blood flow (SBF) using laser Doppler device in a standardized way at various areas of lower extremities at 2 different local skin temperatures: 35°C and 44°C. Local heating increases skin perfusion by mechanisms dependent on nitric oxide (NO). SBF was impaired in CKD patients Stage 5 on HD, particularly in those with diabetes mellitus as a cause of CKD. The reduced response in the SBF to the heat in our patients may be due to decreased generation of NO in uremia. Endothelium-dependent vasodilatation in patients on dialysis and the response of the skin microcirculation to acetylcholine was diminished in hypertensive patients on dialysis. Similarly, patients with diabetes mellitus had decreased SBF during intradermal microdialysis with a NO synthase inhibitor. Multiple uremic toxins have been studied invitro and show to cause various degree of endothelial cell dysfunction. Unfortunately, no clear benefit has been described in CKD patients to different intervention aimed to reduce uremic toxin effect on endothelium. There are no long-term data on the factors which can modify endothelium function in uremia, but non pharmacologic interventions, diet, and several pharmacologic approaches could be beneficial. Measurement of SBF can be useful in evaluation of vasculopathy in CKD population and can potentially be used for assessment of vascular response during specific clinical intervention.

Effect of Electroacupuncture at The Zusanli Point (Stomach-36) on Dorsal Random Pattern Skin Flap Survival in a Rat Model.

Random skin flaps are commonly used for wound repair and reconstruction. Electroacupuncture at The Zusanli point could enhance microcirculation and blood perfusion in random skin flaps. To determine whether electroacupuncture at The Zusanli point can improve the survival of random skin flaps in a rat model. Thirty-six male Sprague Dawley rats were randomly divided into 3 groups: control group (no electroacupuncture), Group A (electroacupuncture at a nonacupoint near The Zusanli point), and Group B (electroacupuncture at The Zusanli point). McFarlane flaps were established. On postoperative Day 2, malondialdehyde (MDA) and superoxide dismutase were detected. The flap survival rate was evaluated, inflammation was examined in hematoxylin and eosin-stained slices, and the expression of vascular endothelial growth factor (VEGF) was measured immunohistochemically on Day 7. The mean survival area of the flaps in Group B was significantly larger than that in the control group and Group A. Superoxide dismutase activity and VEGF expression level were significantly higher in Group B than those in the control group and Group A, whereas MDA and inflammation levels in Group B were significantly lower than those in the other 2 groups. Electroacupuncture at The Zusanli point can effectively improve the random flap survival.

Volume loading augments cutaneous vasodilatation and cardiac output of heat stressed older adults.

Age-related changes in cutaneous microvascular and cardiac functions limit the extent of cutaneous vasodilatation and the increase in cardiac output that healthy older adults can achieve during passive heat stress. However, it is unclear if these age-related changes in microvascular and cardiac functions maximally restrain the levels of cutaneous vasodilatation and cardiac output that healthy older adults can achieve during heat stress. We observed that rapid volume loading, performed during passive heat stress, augments both cutaneous vasodilatation and cardiac output in healthy older humans. These findings demonstrate that the microcirculation of healthy aged skin can further dilate during passive heat exposure, despite peripheral limitations to vasodilatation. Furthermore, healthy older humans can augment cardiac output when cardiac pre-load is increased during heat stress. Primary ageing markedly attenuates cutaneous vasodilatation and the increase in cardiac output during passive heating. However, it remains unclear if these responses are maximally restrained by age-related changes in cutaneous microvascular and cardiac functions. We hypothesized that rapid volume loading performed during heat stress would increase cardiac output in older adults without parallel increases in cutaneous vasodilatation. Twelve young (Y: 26±5years) and ten older (O: 69±3years) healthy adults were passively heated until core temperature increased by 1.5°C. Cardiac output (thermodilution), forearm vascular conductance (FVC, venous occlusion plethysmography) and cutaneous vascular conductance (CVC, laser-Doppler) were measured before and after rapid infusion of warmed saline (15mLkg-1 , ∼7min). While heat stressed, but prior to saline infusion, cardiac output (O: 6.8±0.4 vs. Y: 9.4±0.6Lmin-1 ), FVC (O: 0.08±0.01 vs. Y: 0.17±0.02mL(100mLmin-1 mmHg-1 )-1 ), and CVC (O: 1.29±0.34 vs. Y: 1.93±0.30unitsmmHg-1 ) were lower in older adults (all P<0.01). Rapid saline infusion increased cardiac output (O: +1.9±0.3, Y: +1.8±0.7Lmin-1 ), FVC (O: +0.015±0.007, Y: +0.048±0.013mL(100mLmin-1 mmHg-1 )-1 ), and CVC (O: +0.28±0.10, Y: +0.29±0.16unitsmmHg-1 ) in both groups (all P<0.01). The absolute increase in cardiac output and CVC were similar between groups, whereas FVC increased to a greater extent in young adults (P<0.01). These results demonstrate that healthy older adults can achieve greater levels of cutaneous vasodilatation and cardiac output during passive heating.

Impact of Leg Elevation and Compression Bandaging on Skin Microcirculation in Healthy Adults.

Impact of Leg Elevation and Compression Bandaging on Skin Microcirculation in Healthy Adults.

PP.19.13] POST OCCLUSIVE REACTIVE HYPEREMIC RESPONSE OF SKIN MICROCIRCULATION IN EXTREMELY OBESE HYPERTENSIVE AND NON-HYPERTENSIVE PATIENTS AFTER BARIATRIC SURGERY

Objective: Bariatric surgery is an effective therapeutic method to lose weight and improve metabolism in extremely obese patients. However, little is known about reactivity of skin microcirculation after bariatric surgery. The aim of this study was to assess changes of post occlusive reactive hyperemic (PORH) response in skin microcirculation among extremely obese patients after six months after bariatric surgery. Design and method: Study population consisted of patients with severe obesity who met the eligibility criteria and underwent bariatric surgery (sleeve gastrectomy and Roux-en-Y gastric bypass). Skin blood flow was measured using PeriFlux laser Doppler flowmetry (Periflux System 5000; Perimed, Järfälla/Stockholm, Sweden). Resting flow and PORH were registered before and six months after bariatric surgery. Fast Fourier Transformation of LDF signal of reactive hyperemia was also performed. Data were analyzed in two groups: without (group I) and with hypertension (group II). Statistical analysis was performed with median test. Results: Data from 89 patients (mean age 42.1 ± 11.2 years, 40,4% men) were analyzed. Age and weight loss were similar in group I (n=28) and in group II (n=61). Peak flow increased in group I [44,5 (35,5–64,7) vs 51,2 (33,4–71,6) AU, p < 0,02] after surgery, but it was unchanged in group II [35,0 (24,4–60,4) vs 45,7 (37,1–60,3) AU, p=0,24]. Power of endothelium activity significantly increased and power of neurogenic activity was unchanged in both groups. On the other hand, power of myogenic activity remained unchanged in group I [0,208 (0,144–0,470) vs 0,230 (0,148–0,441) AU2/Hz, p=0,72] and increased in hypertensive subjects [0,190 (0,114–0,257) vs 0,209 (0,162–0,354) AU2/Hz, p=0,001]. Conclusions: Reactivity of skin microcirculation improved in different way in hypertensive and non-hypertensive obese patients after bariatric surgery, but those changes were not associated with improvement of peak flow in patients with hypertension.