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INTRODUCTION: Essential thrombocythemia (ET) is an entity of classic Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), characterized by thrombocytosis with megakaryocytic hyperplasia where in the thrombocytes are increased with abnormal function. Thrombotic events are seen frequently and represent the main cause of morbidity and mortality in patients with MPNs, mainly polycythemia vera and ET. This study has aimed to research the effects of clonally increased thrombocytes on plasma viscosity (PV) levels among patients with ET and the relationship between PV and thromboembolism history, according to the hypotheses about the effects of PV in thromboembolic events among patients with ET. METHODS: A total of 55 patients were enrolled in the study group, 18 of who had been newly diagnosed with ET according to 2016 World Health Organization criteria and had not previously been treated. 37 of them had already been diagnosed with ET and had been treated. There were 47 healthy volunteers in the control group. 5 cc blood samples were taken from the patients into tubes including an anticoagulant to measure their PV levels. RESULTS: PV of the control group was found to be lower than in the study group and both each patient groups (p

Objective The aim of this study was to analyse the effects of dance movement therapy exercises (DMT) on the rheological properties of blood in elderly women. Methods The study encompassed group of women (mean aged: 67 years), who were subjected to three-month dance movement therapy programme (n = 20). Blood samples from all the women were examined for their haematological, rheological, and biochemical parameters both prior to the study and three months thereafter. Results DMT did not cause statistically significant differences in the number of erythrocytes, thrombocytes, leukocytes and the haematocrit value. DMT affected the rheological parameters of the blood in elderly women, improving the erythrocyte deformability at the lowest shear stress value and reducing the half-time of the total aggregation. Plasma viscosity and concentration of fibrinogen did not change after dance therapy. Conclusions DMT modulate rheological properties of blood of older women. The results of this study suggest that physical exercise program for older women can prevent unfavorable age-related changes. Some indicators such as the haematological parameters, plasma viscosity and fibrinogen level were not affected by DMT in older women, suggesting the maintenance of homeostasis.

Background COVID-19 associated hyperviscosity is a potential driver for the increased rates of thrombotic complications and multi-organ failure associated with severe COVID-19. Limited experience suggests a promising role for Therapeutic Plasma Exchange (TPE) in COVID-19 management based on the hypothesis that clinical benefit is derived from reduction in plasma viscosity. However, systematic study evaluating the safety and efficacy of TPE in these patients has not been done. Objective To evaluate the safety and efficacy of TPE in a subset of critically ill patients with COVID-19 and elevated blood viscosity in a randomized controlled trial (RCT). Study Design and Methods This study was conducted in the intensive care units (ICUs) of 3 hospitals in our health system, with a limited initial enrollment target of 20 patients. Participants included adult COVID-19 patients with moderate elevation in plasma viscosity (2.3-3.5 centipoise) or significant hyperfibrinogenemia (>800 mg/dL) that were not improving despite standard supportive care. Patients with bacterial or fungal coinfection or moribund patients were specifically excluded. Upon enrollment, patients were randomized 1:1 to the treatment group (1 plasma volume TPE with frozen plasma (FP) replacement on 2 consecutive days) or control group (continued standard of care (SOC)). Primary measures included the safety/tolerability of TPE and change in plasma viscosity levels after TPE versus SOC. Secondary measures included evaluation of various clinical and laboratory parameters, including fibrinogen and other coagulation-related markers, mortality, bleeding and thromboembolic complications, ICU length of stay and time to discharge after enrollment. Results Preliminary analysis of collected data demonstrates that TPE is safe and well-tolerated in these patients, with adverse events limited to one mild occurrence of tachycardia that improved upon decreasing the flow rate. There was significant decrease in plasma viscosity in the TPE treatment group, compared to the SOC control group. Secondary measures of select laboratory parameters also show a significant decrease in fibrinogen, von Willebrand factor (vWF), Factor VIII, and erythrocyte sedimentation rate in the TPE treatment group. No significant differences were seen in levels of fibrin monomer, total IgG, total IgM, total protein, or total albumin between the two groups. Data collection and analysis for clinical parameters are ongoing. Conclusions and Relevance Here we report preliminary results suggesting that TPE is safe and effective for normalizing plasma viscosity in critically ill COVID-19 patients. Concomitant removal of large plasma proteins (fibrinogen, vWF) hints at their role in driving the increased viscosity associated with severe disease, which may contribute to clotting and end-organ damage in COVID-19. Based on lack of change in total IgG/IgM levels, TPE is not anticipated to hinder the patient’s humoral immunity by removing existing anti-SARS-CoV-2 specific antibodies. These results warrant further studies on the utility of TPE to mitigate critical illness in COVID-19 patients.

In this case report, we examine the behavior of plasma viscosity, explored at high and low shear rates, and erythrocyte aggregation in two patients with congenital afibrinogenemia, a clinical disorder firstly described in 1920 and that has an estimated incidence of 1 : 1-200 0000. The two hemorheological parameters examined by us showed a marked decrease in both patients, in one of whom erythrocyte aggregation was even undetectable. Keeping in mind that spontaneous thrombosis (venous and arterial) has been often described in congenital afibrinogenemia, it can be hypothesized that the decrease in plasma viscosity and erythrocyte aggregation might cause a reduction of the endothelial synthesis and release of nitric oxide through the fall of the wall shear stress.

Background Cryotherapy is a physiotherapy method used to treat back pain in older persons. Objective This study aims to evaluate the changes in the rheological parameters of blood in older women with spondyloarthrosis, who underwent whole-body cryotherapy. Methods The experimental group comprised 69 older women with lumbar spondyloarthrosis, aged between 65 and 70 years. Due to the methodology of the procedure, the experimental group was randomly divided into three groups. Each group underwent two weeks of different types of physiotherapy: only whole-body cryotherapy (22 women); only kinesitherapy (23 women); and both cryotherapy and kinesitherapy (24 women). The control group comprised 25 women who did not undergo any form of therapy. The evaluation of the rheological properties of the blood encompassed measurements of the plasma viscosity, the erythrocyte elongation and aggregation indices, and the level of fibrinogen. Results The conducted rheological tests revealed a significant decrease in the erythrocyte elasticity and aggregation indices only in the group of women who had undergone both whole-body cryotherapy and kinesitherapy. Conclusions Applying whole-body cryotherapy to older women with spondyloarthrosis decreases the elasticity of erythrocytes and, despite favourable changes in the aggregation parameters, problems with perfusion may still appear. For this reason, the benefit of using whole-body cryotherapy in these persons is debatable.

WOS: 000400599300001, PubMed ID: 27814281, AIM: To evaluate hemorheological parameters in patients with fibromyalgia syndrome (FMS) in order to elucidate the etiology of the disease. METHODS: Twenty-three adult FMS patients and 20 healthy controls were enrolled in the study. Diabetics, hypertensives and those with any rheumatological disorder or use drugs or smoking cigarette were excluded from the study. Following parameters were analyzed in each subject; erythrocyte deformability, erythrocyte aggregation, plasma viscosity, complete blood count, fasting blood glucose, fibrinogen, albumin, globulin and lipid profile. RESULTS: Erythrocyte elongation indices indicating deformability of erythrocytes were higher in FMS patients (0.564 +/- 0.002 at 16.87mPa and 0.605 +/- 0.002 at 30mPa shear rate) than controls (0.558 +/- 0.001 at 16.87mPa and 0.600 +/- 0.003 at 30mPa shear rate). Erythrocyte aggregation speed was higher in FMS patients (2.1 +/- 0.1 s) than controls (2.3 +/- 0.2 s). Erythrocyte aggregation index was also higher in FMS patients (65.5 +/- 1.3) than controls (62.9 +/- 1.5). Erythrocyte aggregation amplitude and plasma viscosity values were similar in both groups (both p > 0.05). Among the complete blood count and biochemical parameters, only albumin levels were lower in the FM patients than controls (p < 0.05). CONCLUSION: Our results indicate higher erythrocyte deformability and quicker erythrocyte aggregation in FM patients., Hacettepe University Scientific Research Administration, This study was supported by Hacettepe University Scientific Research Administration.

In order to determine the analytical precision and physiological fluctuation of a battery of blood tests (hematocrit, blood viscosity, plasma viscosity, blood filterability, red cell aggregation and blood cell counts) volunteers were tested at fortnightly intervals for weeks

Blood rheology measurements (whole blood viscosity, plasma viscosity, hematocrit and fibrinogen) and fibrinolytic and metabolic tests (plasma fibrinolytic activity, C-peptide, total cholesterol, triglycerides) were performed in 40 obese subjects before and after one year of hypocaloric diet

Background The diagnosis of prosthetic joint infection (PJI) is challenging because no single test has consistently demonstrated an adequate discriminative potential. The combination of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) with adequate thresholds is well established. This study sought to investigate the role of plasma viscosity (PV) in the diagnosis of PJI following painful total knee arthroplasty. Methods The medical notes, and hematological and microbiology results of 310 patients who underwent revision for a painful total knee arthroplasty were evaluated. Infection was confirmed using Musculoskeletal Infection Society criteria in 102 patients (32.9%), whereas 208 patients (67.1%) were classified as noninfected. Serum investigations including ESR, CRP, and PV were analyzed using receiver observer curves and optimal cutoff points identified. Results There was a strong correlation between PV and both ESR and CRP. The area under curve was 0.814 for PV and 0.812 for ESR. Statistical analysis showed noninferiority of PV as compared to ESR in diagnosing PJI. A PV value of ≥ 1.81 mPa.s. had the best efficiency of 82.1%. Combining a CRP ≥ 13.5 mg/L with a PV ≥ 1.81 mPa.s. in a serial test approach yielded the highest specificity of 97.9% and positive likelihood ratio of 22.8. Sensitivity was 47.9% and a negative likelihood ratio of 0.53. Conclusion PV is noninferior to ESR in diagnosing PJI. Its use is justified in clinical practice. It is cheaper, quicker, more efficient, and not influenced by hematocrit levels or medication. In this cohort, a PV value ≥ 1.81 mPa.s. would be an adequate cutoff to diagnose PJI in combination with CRP ≥ 13.5 mg/L.

Objectives: An ascending aortic aneurysm (AsAA) is fundamentally defined as the "ballooning" of the aorta at its exit site from the heart. the role of plasma viscosity (PV) and endothelial markers in AsAA is unknown. This study was designed to investigate AsAA in association with PV and the endothelial markers of fibrinogen, nitric oxide (NOx), and asymmetric dimethylarginine (ADMA). Methods: This study group consisted of 23 patients who underwent surgical repair for AsAA and 30 controls without diabetes, hypo- or hyperlipidemia, or heart disease. Several parameters, including plasma viscosity (PV), fibrinogen, NOx, and ADMA were assayed in both groups. Results: the preoperative PV in the patient group was significantly higher than that measured on postoperative day 7 and that of the control group (p

The aim of the study is to test the influence of in vivo magnetostimulation on the rheological properties of blood in neurological patients. Blood circulation in the body depends both on the mechanical properties of the circulatory system and on the physical and physicochemical properties of blood. The main factors influencing the rheological properties of blood are as follows: hematocrit, plasma viscosity, whole-blood viscosity, red cells aggregability, deformability, and the ability of red cells to orient in the flow. The blood samples were collected from neurological patients with pain. Blood samples were collected twice from each patient, that is, before the magnetostimulation and immediately after the therapy. For each blood sample, the hematocrit value was measured using the standard method. Plasma viscosity and whole-blood viscosity were measured by means of a rotary-oscillating rheometer Contraves LS40. Magnetic field was generated by the instrument Viofor JPS® and the magnetostimulation treatments were performed using M1P2 and M1P3 programs. The analysis of the results included estimation of the hematocrit value (Hct), plasma viscosity (ηp), whole-blood viscosity and rheological parameters of Quemada's model: k0, k∞, γ'c. Plasma viscosity values were obtained from the shear rate dependence of shear stress using the linear regression method. The results obtained in the study suggest that the blood rheological properties change in accord with applied magnetostimulation program.

Current study briefly shows the pathological changes of blood rheological properties in arterial hypertension and the impact of main rheological parameters is discussed (hematocrit, plasma viscosity, aggregation, erythrocyte deformity) on the development of blood hyperviscosity syndrome. The data is provided on the influence of antihypertension drugs (angiotensin converting enzyme inhibitors, calcium channel antagonists, andrenoblockers, diuretics and angiotensin II receptor blockers) on blood rheology in patients with arterial hypertension.

Background Preclinical studies report that higher plasma viscosity improves microcirculatory flow after haemorrhagic shock and resuscitation, but no clinical study has tested this hypothesis. Objective We investigated the relationship between plasma viscosity and sublingual microcirculatory flow in patients during resuscitation for traumatic haemorrhagic shock (THS). Methods Sublingual video-microscopy was performed for 20 trauma patients with THS as soon as feasible in hospital, and then at 24 h and 48 h. Values were obtained for total vessel density, perfused vessel density, proportion of perfused vessels, microcirculatory flow index (MFI), microcirculatory heterogeneity index (MHI), and Point of Care Microcirculation (POEM) scores. Plasma viscosity was measured using a Wells-Brookfield cone and plate micro-viscometer. Logistic regression analyses examined relationships between microcirculatory parameters and plasma viscosity, adjusting for covariates (systolic blood pressure, heart rate, haematocrit, rate and volume of fluids, and rate of noradrenaline). Results Higher plasma viscosity was not associated with improved microcirculatory parameters. Instead, there were weakly significant associations between higher plasma viscosity and lower (poorer) MFI (p = 0.040), higher (worse) MHI (p = 0.033), and lower (worse) POEM scores (p = 0.039). Conclusions The current study did not confirm the hypothesis that higher plasma viscosity improves microcirculatory flow dynamics in patients with THS. Further clinical investigations are warranted to determine whether viscosity is a physical parameter of importance during resuscitation of these patients.

Background. Yield shear stress (YSS) well characterizes the thixotropic status of blood, that exemplifies a reversible loss of blood fluidity due to a low shear rate. At the stable haematocrit ratio YSS depends mainly on the fibrinogen level.Aim. Since the role of other biochemical factors in the YSS phenomenon in cerebral ischaemia has not been well known, we have undertaken this problem in a group of stroke patients. Material and Methods. The study was carried out in 36 patients with acute ischaemic stroke and in 12 controls. YSS was estimated by means of microviscometric method. In all subjects the concentration of the following biochemical factors were assayed: albumin, IgG, IgA, IgM, apolipoprotein A, and B, cholesterol, triglycerides, LDL, HDL and fibrinogen. Then the thixotroipic effect of all biochemical factors and their correlations to fibrinogen were estimated by means of mathematical formulas.Results. We found a positive correlation in relation to the following thixotropic effects: for all subjects and separately for patients’ group: Alb(YSS) (p

Rheological blood parameters of neonates are different form those of adults. Many authors have studied changes in blood rheology in neonates in different clinical disorders. To-date, no one set the normal values for blood rheological parameters in healthy neonates. The aim of this study is to set the norm for rheological blood parameters in healthy newborns and to describe the changes in those parameters in common clinical disorders that affect the newborns. We recruited all the neonates born to mothers experiencing un eventful pregnancies, blood was taken from the umbilical cord right after the delivery. In this time period we recruited 4985 neonate. From this huge database we were able to set the standards for blood rheology in neonates, namely plasma viscosity of 1.06±0.072 mPa, erythrocyte aggregation at stasis of 2.41±2.74 s-1 and erythrocyte aggregation under low shear forces of 8.51±6.38 s-1. These values changed significantly in some diseased neonates. This is the largest study investigating normal rheological parameters and deviations from the norm in common clinical disorders occurring in this early stage of life.

Peripheral artery occlusive disease (PAOD) is associated with increased cardiovascular risk (CVR). Recently it has been reported that also the increased stiffness of lower limb arteries is associated with increased CVR. In particular, subjects with poorly compressible arteries (PCA) appear to have a CVR even higher than that of subjects with PAOD. Limited data are available on the role of hemorheological factors in determining increase in arterial stiffness. Our study aimed to investigate possible association between blood and plasma viscosity and elevated ankle brachial index (ABI).Subjects were free-living participants to a cardiovascular disease screening campaign. Sixty-two subjects with ABI ranging 1.3-1.4, and 20 with ABI1.4 were matched with 124 and 40 control subjects, respectively. Cardiovascular disease risk factors (blood pressure, blood lipids, glucose, cigarette smoking, obesity) were evaluated by routine methods. Blood and plasma viscosities were measured by a cone-plate viscometer. Ankle-brachial index was computed as measure of arterial stiffness.Compared with controls, who were carefully matched for age, sex and all cardiovascular risk factors, subjects with elevated ABI values had increased levels of plasma viscosity (1.42 ± 0.11 vs. 1.35 ± 0.10 cP, p 0.001, for subjects with ABI ranging 1.3-1.4, and 1.41 ± 0.10 vs. 1.33 ± 0.10 cP, p 0.01, for subjects with ABI1.4). No difference in blood viscosity was observed.The present investigation provides evidence that plasma viscosity is increased in subjects with elevated ABI values, independently of other cardiovascular risk factors. This finding contributes to explain the high CVR of patients with PCA.

BSTRACT A limited number of studies has been carried out concerning the combined effects of resistance training and saffron supplementation on cardiovascular risk factors. The aim of this study was to assess the effects of circuit resistance training with Crocus sativus (saffron) supplementation on plasma viscosity and fibrinogen. For this purpose, 44 healthy male subjects, based on individual characteristics and after homogenization, were divided into four groups, including water-training (WT; n=11), petal sweat–training (PST; n=10), bottom part of flower-training (BFT; n=11), and upper part of flower-training (UFT; n=12). Resistance training consisted of 12 stations (each station for 30 seconds with 40% of one repetition maximum) for 2 weeks (5 sessions per week). Saffron in the amount of 500 mg was used twice daily, i.e. in the morning and immediately after exercise. Blood samples were taken before and 48 hours after the last exercise session and were analyzed for fibrinogen and plasma viscosity. Significant differences were observed between groups in plasma levels of fibrinogen (P=0.01). The post hoc test showed significant differences between the UFT and PST groups and the UFT and BFT groups (respectively, P=0.04 and P=0.014). In the post-test, plasma fibrinogen had significantly decreased in the WT (P=0.005), PWT (P=0.003), and UFT (P=0.001) groups compared with pre-test data (within group difference). Moreover, plasma viscosity was significantly changed among groups (F3, 37=3.52, P=0.024). The post hoc test showed significant differences between the UFT and WT groups (P=0.037). In post-test data, plasma viscosity had significantly decreased in the WT (P=0.015) and UFT (P

Objective The aim of this study was to analyze the effects of dance therapy on selected hematological and rheological indicators in older women. Methods The study included 30 women (aged 71.8±7.4), and the control group comprised of 10 women of corresponding age. Women from the experimental group were subjected to a five-month dance therapy program (three 45-minute sessions per week); women from the control group were not involved in any regular physical activity. Blood samples from all the women were examined for hematological, rheological, and biochemical parameters prior to the study and five months thereafter. Results The dance therapy program was reflected by a significant improvement of erythrocyte count and hematocrit. Furthermore, the dance therapy resulted in a significant increase in the plasma viscosity, while no significant changes in glucose and fibrinogen levels were noted. Conclusions Dance therapy modulates selected hematological parameters of older women; it leads to increase in erythrocyte count and hematocrit level. Dance therapy is reflected by higher plasma viscosity. Concentrations of fibrinogen and glucose are not affected by the dance therapy in older women, suggesting maintenance of homeostasis. Those findings advocate implementation of dance therapy programs in older women.

The current work examines the effects of electromagnetic radiation on the hemorheology to provide an experimental basis for radiation protection. Electromagnetic radiation was generated by a Helmholtz coil constructed from copper wire. There were six rats altogether: three rats in the experimental group, and three rats in the control group. The rats in the experimental group were continuously exposed to radiation for 10 hours every day, and rats in the control group remained in a normal environment. After 30 days, the characteristics of hemorheology of the two groups were compared. The average plasma viscosity, whole blood high shear velocity, and whole blood low shear viscosity were lower in rats in the experimental group than in rats in the control group, while the whole blood shear viscosity was higher in the experimental group than in the control group. Results suggest that long term exposure to electromagnetic radiation does have certain impacts on the cardiovascular system, deeming it necessary to take preventative measures.

We recently proposed a unifying hypothesis to reconcile unexpected findings in exercise hemorheology and the classical concepts of “hemorheologic fitness” and the “triphasic effects of exercise”, based on the “healthy primitive lifestyle” paradigm. This paradigm assumes that evolution has selected genetic polymorphisms leading to insulin resistance as an adaptative strategy to cope with continuous low intensity physical activity and a special alimentation moderately high in protein, rich in low glycemic index carbohydrates, and poor in saturated fat. According to this protocol the true physiological picture would be that of an individual whose exercise and nutritional habits are close from this lifestyle, both sedentary subjects and trained athletes representing situations on the edge of this model. Unfortunately samples of people truly adhering to this ancestral lifestyle are hard to obtain. In order to address this picture we tried to compare databases obtained with our preceding published studies. As a model of the “healthy primitive lifestyle” we selected patients trained at low intensity (LI) and given an advice of protein intake around 1.2 g/kg/day. Results show a continuum for plasma viscosity which seems to be lower in athletes than LI-trained and even more sedentaries. When sedentary subjects become obese the most obvious characteristic is an increase in red blood cell (RBC) aggregation correlated to the size of fat stores. It is clear that 3 months of LI are not a perfect model of “healthy primitive lifestyle”, but these data suggest that the most important effect of LI regular exercise is to decrease plasma viscosity and that sedentarity increases RBC aggregation mostly when it results in increased fat storage.

To study the kinematic mechanics in exposure to heat and blood pressure among steelworkers. 403 heat-exposed male steelworkers and 102 non-heat-exposed male workers at the same workshop were studied. WBGT index, blood pressure were measured and hemorheology was detected. The results of this study show that blood viscosity, plasma viscosity, and hematocrit were positively correlated with systolic and diastolic blood pressure (P

Background: Endothelial nitric oxide synthase (eNOS) is generally expressed in endocardial cells, vascular endothelial cells and ventricular myocytes. However, there is no experimental study elucidating the relationship between cardiac eNOS expression and elevated plasma viscosity in low oxygen delivery pathological conditions such as hemorrhagic shock-resuscitation and hemodilution. This study tested the hypothesis that elevated plasma viscosity increases cardiac eNOS expression in a hemodilution model, leading to positive effects on cardiac performance. Materials and Methods: Two groups of golden Syrian hamster underwent an acute isovolemic hemodilution where 40% of blood volume was exchanged with 2% (low-viscogenic plasma expander [LVPE]) or 6% (high-viscogenic plasma expander [HVPE]) of dextran 2000 kDa. In control group, experiment was performed without hemodilution. All groups were performed in awake condition. Experimental parameters, i.e., mean arterial blood pressure (MAP), heart rate, hematocrit, blood gas content and viscosity, were measured. The eNOS expression was evaluated by eNOS Western blot analysis. Results: After hemodilution, MAP decreased to 72% and 93% of baseline in the LVPE and HVPE, respectively. Furthermore, pO 2 in the LVPE group increased highest among the groups. Plasma viscosity in the HVPE group was significantly higher than that in control and LVPE groups. The expression of eNOS in the HVPE group showed higher intensity compared to other groups, especially compared with the control group. Conclusion: Our results demonstrated that cardiac eNOS has responded to plasma viscosity modulation with HVPE and LVPE. This particularly supports the previous studies that revealed the positive effects on cardiac function in animals hemodiluted with HVPE.

Elevated plasma viscosity (PV) is observed in patients with vascular risk factors, such as diabetes mellitus or arterial hypertension. In this study we investigated the association of plasma viscosity and the different clinical and radiological entities of cerebral ischemia.PV of 465 consecutively admitted patients with clinical symptoms of acute cerebral ischemia without radiological signs of bleeding was measured. Data is expressed as median [range] unless stated otherwise. p0.05 was considered statistically significant.Patients with acute cerebral ischemia (TIA or Stroke) showed increased PV (TIA 1.27mPas [1.07-1.53], stroke 1.27mPas [1.07-1.56]) compared to patients without cerebral ischemia (Mimics) (1.23mPas [1.06-1.42]). The group with radiologically proven small vessel disease (SVD) had a significantly higher mean values of PV (1.29mPas [1.06-1.54]) compared to those with signs of large vessel disease or cardioembolic events (1.22mPas [1.07-1.56], p0.001). Patients with chronic heart failure (p=0.007), arterial hypertension (p0.001) and diabetes mellitus (p=0.002) had higher PV compared to patients without these cardiovascular risk factors. Hyperlipidemia or nicotine abuse showed no relation to PV.Elevated PV is not only associated TIA and Stroke but is also found in patients with radiological signs of cerebral SVD. High levels of PV could be an underestimated risk for TIA and Stroke and participate in the complex pathophysiology of SVD. Prospective observational and interventional studies are warranted for further evaluation of PV in neurological ischemic diseases.

In the “Sicilian study on juvenile myocardial infarction,” we had evaluated plasma viscosity (PV) and neutrophil/lymphocyte ratio (NLR) in patients with acute myocardial infarction (AMI) at the age of ⩽45 years. Now, we examined the relationship between these 2 parameters in 120 subjects (109 men and 11 women) aged ⩽45 years with recent AMI. The patients were classified according to the number of cardiovascular risk factors, the electrocardiographic criteria (ST-segment elevation myocardial infarction [STEMI] or non-ST-segment elevation myocardial infarction [NSTEMI]), and the extent of coronary stenosis, evaluated with coronary angiography. On fasting venous blood, we measured PV at the shear rate of 450 s −1 and NLR. The control group included 50 healthy subjects (mean age = 35.1 ± 7.8 years). At the initial stage, PV and NLR were significantly increased in comparison with controls. Subdividing AMI patients according to the median value of NLR, in the group with high NLR PV was significantly higher, whereas subdividing the patients according to the PV median value, NLR was not different between the 2 groups; 3 and 12 months after AMI, we observed only a significant decrease in NLR. Only PV was discriminant regarding the cardiovascular complications registered during an 18-month follow-up. The evaluation of PV may be of prognostic value in juvenile AMI.

Hyperviscosity syndrome was described in Brattleboro rats. The aim of this study was to investigate the possibility of Brattleboro rats using, as a test system for the study of agents with hemorheological activity. Under conditions of this model of high blood viscosity syndrome in Brattleboro rats, Lychnis chalcedonica L. extract (150 mg/kg) administered intragastrically for 10 days exhibited hemorheological activity by modulating macro- (plasma viscosity, fibrinogen concentration) and microrheological (erythrocyte aggregation and deformability parameters. Hence, Brattleboro rats are an adequate model of hyperviscosity syndrome that can be used for search and testing of substances with hemorheological activity.

Tobacco use is widely spread throughout the world, from countries with low income economics to the most influential industrialized nations. The effect of smoking on human health are serious and in many cases, deadly. This study aimed at estimating the haemorheological parameters and examining the effects of this social behavior on them with a view to educate the smokers and the society. This study was carried out among the regular smokers that smoke not less than two sticks of cigarettes per day. Ninety (90) subjects were studied, comprising of sixty (60) smokers subjects, willingly volunteered to participate in the study and thirty (30) nonsmoker subjects that served as control for the study. The haemorheological parameters determined were packed cell volume (PCV), Erythrocyte sedimentation rate (ESR), Fibrinogen concentration (FIBC), Whole blood viscosity (WBV) and Plasma viscosity (PV). It was observed that there were statistically significant difference in WBC, ESR, FIB, and PCV (p0.05). In the correlation results, WBC correlate negatively with PLT and PV (r=-0.142, r=-0.042), PLT correlate negatively with ESR and PCV (r=-0.124, r=-0.172), and ESR correlate negatively with WBV(r=-0.065). The correlation between FIBC and WBV, PV, (r=-0.304, r=-0.077), WBV and PV(r=-0.333) were negative and all these were not statistically significant (p>0.05). The negative correlation that exist between the PV and PCV(r=-0.846) was statistically significant ( Conclusion: Smoking exerts negative influence on the haemorheological parameters and these are the contributing factors that lead to cardiovascular and atherosclerosis that usually occur in cigarette smokers and cause of their death. Also smokers are more prone to infection more than nonsmokers because of their low level of immunity.

Unhealthy dietary fats are associated with faster kidney function decline. The cell membrane composition of phospholipid fatty acids (FAs) is a determinant of membrane fluidity and rheological properties. These properties, which have been linked to kidney damage, are thought to be reflected by the lipophilic index (LI). We prospectively investigated the associations of LI with kidney function and its decline.Observational study from the Prospective Investigation of Vasculature in Uppsala Seniors including 975 men and women with plasma phospholipid FAs composition and cystatin-C estimate glomerular filtration rate (eGFR). Of these, 780 attended re-examination after 5 years, and eGFR changes were assessed. Participants with a 5-year eGFR reduction ≥30% were considered chronic kidney disease (CKD) progressors (n = 198). LI was calculated as the sum of the products of the FA proportions with the respective FAs melting points. Blood rheology/viscosity measurements were performed in a random subsample of 559 subjects at baseline. Increased LI showed a statistically significant but overall weak association with blood, plasma viscosity (both Spearman rho = 0.16, p 0.01), and erythrocyte deformability (rho = -0.09, p 0.05). In cross-sectional analyses, LI associated with lower eGFR (regression coefficient 3.00 ml/min/1.73 mA high LI was associated with lower kidney function, kidney function decline, and CKD progression.

We previously reported that low intensity endurance training in sedentary patients suffering from the metabolic syndrome improves blood rheology, mostly due to a decrease in plasma viscosity correlated with an increase in cardiorespiratory fitness. We investigated whether these findings can be extended to type-2 diabetics. 22 diabetics (11 women and 10 men, age: 52.00 ± 2.9 yr, BMI: 32.47 ± 1.17 kg/m 2 ) were tested before and after 2 months. Eight of them were trained (2 to 3 × 45 min/wk) at the power intensity where lipid oxidation reaches a maximum (LIPOX max) and thirteen served as controls. Over this period the only significant hemorheological effect of training was a decrease in RBC aggregation "M" (−1.25 ± 0.357 p = 0.01) in the trained group. Subjects who lost weight exhibited a decrease in plasma viscosity (from 1.46 ± 0.013 to 1.38 ± 0.02 p < 0.01). Changes in waist circumference are associated with changes in hematocrit (r = −0.952 p = 0.01); plasma viscosity (r = −0.91; p = 0.03); RBC aggregation ("M" r = 0.940; p = 0.02). Subjects can also be divided into those who improved their aerobic capacity VO2max and those whose VO2max decreased or remained unchanged. An increase in VO2max is associated with a decrease in whole blood viscosity (r = −0.79 p = 0.06) explained by an improvement in RBC rigidity "Tk" (r = −0.963 p = 0.002). This study suggests that in Type 2 diabetic patients: (a) viscosity factors might be less responsive to training than in non diabetic individuals; (b) visceral fat loss is the main determinant of changes in hematocrit, plasma viscosity and RBC aggregation; (c) improvements in aerobic capacity improves blood viscosity via an increase in RBC deformability.

OBJECTIVE Structure and mechanical properties of red blood cells are markedly influenced by pathophysiology of many diseases which in turn potentially impair microcirculatory blood flow. The physiological association between blood rheological parameters and red blood cell indices was investigated in otherwise healthy unselected mid-age women prior to elective gynaecological surgery. METHODS Red Blood Cell-deformability (RBC 1.2, 3.0; 6.0, 12.0; 30.0, 60.0) during exposure to low (RBC 1.2, 3.0), moderate (RBC 16.0, 12.0) and high shear forces (RBC 30.0, 60.0; Rheodyn; Myrenne), -aggregation (MA1; Myrenne) during low shear (E1; 4-1 S) and in stasis (E0) and plasma viscosity (Pv; KSV 1; Fresenius) were correlated with red blood cell indices (RBC-I: MCV, MCH and MCHC) and subjects' characteristics in 286 healthy women the day before undergoing gynaecologic standard surgery. Women with known pregnancy, malign-, infective-, chronic-disease or extreme BMI ( 40 Kg/m2) were excluded from this trial. RESULTS From June 2014 to December 2014 a total of 286 healthy women (age: 46.5±17.6 y; BMI: 25.5±5.2 kg/m2) were eligible for inclusion into this prospective evaluation. Pv (mean±SD: 1.17±0.12 mPa s) and RBC aggregation (E0:12.6±6.3; E1:17.9±7.3) were not significantly correlated with RBC-I but with age and BMI. In contrast, RBC-deformability correlated significantly with MCV and MCH but significantly inversely correlated with MCHC. Deformability significantly increased with age but was unaffected by BMI of women. The correlation between RBC-I and RBC deformability was most remarkable during moderate shear force exposure. Neither haemoglobin nor haematocrit were correlated with RBC deformability or RBC-I. CONCLUSIONS Cell volume and haemoglobin content had a strong impact on deformability in apparently healthy mid age women, whereas low MCHC and large MCV were associated with an increase in deformability while high MCHC and small MCV correlated with increased rigidity of RBC. BMI had no impact on deformability while age was associated with an increase in all determinants of blood viscosity. RBC aggregability was not affected by MCV, MCHC or MCH in mid-age women.

Background: Subclinical hypothyroidism (SH) is defined as elevated serum thyroid-stimulating hormone (TSH) concentration associated with normal serum-free thyroxine levels. Effects of hypothyroidism on hemorheology had widely attracted the attention of researchers during the last decade. Objective: The purpose of this study is to determine alterations in hemorheological parameters and carotid intima-media thickness (CIMT) in children with SH. Methods: Fifty-three SH children and 31 healthy controls were enrolled. Erythrocyte deformability and aggregation were determined by an ektacytometer and plasma viscosity (PV) by a cone-plate rotational viscometer. CIMT was evaluated sonographically. Results: Erythrocyte deformability of the SH group measured at 0.53 and 1.69-30 Pa was lower than that of the control group. The erythrocyte aggregation index, aggregation half time and PV were not different between the groups. However, the aggregation amplitude and mean corpuscular hemoglobin concentration were significantly higher in SH compared to the control group. There was a negative correlation between TSH and deformability values measured at 5.33-30.0 Pa. CIMT in patients with SH was significantly higher than in the control group (p = 0.001; SH = 0.48 ± 0.04 mm, control group = 0.43 ± 0.03 mm). Conclusion: Impaired hemorheology and increased CIMT are well-known risk factors for developing cardiovascular pathologies. The results of the current study suggest the treatment of children with SH in order to avoid early circulatory problems.

Objective: The accompanying thrombocytosis is referred to as the major factor associated with thromboembolism in iron deficiency anemia (IDA). Increased viscosity may increase the risk of thrombosis. We hypothesized that increased platelet count -with reactive thrombocytosis- might also affect plasma viscosity. We planned to evaluate the influence of normal and high platelet count on plasma viscosity in IDA patients. Material and Methods: The patient population consisted of fifty-three newly diagnosed and untreated women aged between 18 and 62 years with IDA. Group 1 consisted of 33 patients, platelet levels below 400 x 109/L. Group 2 consisted of 20 patients, platelet levels above 400 x 109/L. Measurements of plasma viscosity were performed using Brookfield viscometer. Results: Mean plasma viscosity was found as 1.05 ± 0.08 mPa.s. in Group 1, and 1.03 ± 0.06 mPa.s. in Group 2. Mean plasma viscosity was not statistically different. White blood cell count was significantly higher in Group 2. Vitamin B12 levels were significantly higher in Group 2, while folic acid levels were higher in Group 1 (p=0.011 and p=0.033). Plasma viscosity was correlated with erythrocyte sedimentation rate (r=0.512 p=0.002) in Group 1 and inversely correlated with vitamin B12 (r=−0.480 p=0.032) in Group 2. Conclusion: Despite the significant difference between groups in terms of platelet count, no significant difference was detected in plasma viscosity and this finding could be explained as the following; 1-These platelets were not thrombocythemic platelets; 2-Similar to the theory about leukocytes, higher platelet counts – even non-thrombocythemic – may increase plasma viscosity; 3-Evaluating platelet count alone is not sufficient and the associating red-cell deformability should also be taken into account; and 4-Although other diseases that could affect viscosity are excluded, some definitely proven literature criteria such as fibrinogen, hyperlipidemia, and the inflammatory process should also be evaluated by laboratory and clinical measures.

Purpose The aim of our study is to define the association between microvascular complications and plasma viscosity (PV) in the diabetic elderly and to determine whether PV measurement can be used as a potential marker for microvascular complications of diabetes. Methods In this cross-sectional study consisted of people aged 65 or over, 226 of them had diabetes and 59 of them did not. Those with inflammatory disease, infection and organ failure were not included in the study as they could affect PV. Diabetic cases are categorized into groups according to their microvascular complications. The PV of all the cases was measured by Brookfield DV-II viscometer. Results PV is significantly higher in diabetic patients when compared to the non-diabetic control group (1.71±0.17 mPas and 1.48±0.06 mPas respectively, P P P P Conclusion PV is clearly elevated in the diabetic elderly, particularly in patients with microvascular complications. These elevations are significantly correlated with the duration of diabetes, metabolic control level and the number of microvascular complications. Studies are needed to show the cause and effect relationship between diabetic complications and PV in the elderly.

It is well known that hemostatic-thrombotic mechanisms are influenced by hemodynamic factors, such as shear forces affecting platelets or red blood cell aggregation, in turn affecting flow in stenotic regions. Endothelial cell function is also significantly influenced by shear forces acting on the vessel wall. Further, the distribution of shear forces in the vasculature is complex and closely associated with factors determining the flow properties of blood. Therefore, there is a link among alterations in the rheological properties of blood and its elements and the risk for thrombosis, with this linkage confirmed by numerous clinical studies. After discussing relevant rheological and hemodynamic concepts, this review focuses on selected drug-induced conditions that are known to be associated with both hyperviscosity conditions and increased thrombotic risk: oral contraceptives, diuretics, intravenous immunoglobulin, erythropoiesis-stimulating agents, chemotherapy, and radio-contrast media. Alterations of relationships between blood rheology and thrombotic risk related to artificial circulatory environments and physical exercise are also briefly discussed., NA

Objective: to probe the interference of Ruyanneixiao cream for hemorheology and mammary microcirculation of mammary precancer rats. Methods: 48 virginal female SD rats were randomly allocated into 6 groups, A: Blank control group (8); B: Mammary precancer model group (8); C: Tamoxifen (TAM) group (8); D: High dose group of Ruyanneixiao cream (8); E: Middle dose group of Ruyanneixiao cream (8); F: Low dose group of Ruyanneixiao cream (8). The changes of hemorheology and mammary microcirculation were recorded when the rats were executed after 60d. Result: compared with the Blank control group, the whole blood viscosity and plasma viscosity of mammary precancer model group was higher (P

In order to improve the speed and accuracy of the existing product, a new automated hemorheology analyzer is designed and implementation in this paper. In the new analyzer, the whole blood and plasma with different characteristics are tested by different systems, which work in parallel and independently. The design and implementation of the new hemorheology analyzer including hardware and software design are put forward. Experimental results show that the performance of the new instrument, such as efficiency and test speed are both improved in the new instrument.

Background: Diagnosis of giant cell arteritis (GCA) is based on criteria of the American College of Rheumatology. However, not all GCA patients meet these criteria and treatment may be delayed in individual patients, leading to an increased risk of complications. Methods: In an observational study, we investigated acute phase response markers in GCA and non-GCA patients matched for erythrocyte sedimentation rate and CRP levels. Results: Plasma viscosity (PV) was significantly elevated in all GCA patients, but normal in non-GCA patients. Conclusions: Our data suggest that PV may reflect a more specific component of the acute inflammatory response in patients with GCA. Analysis of PV may significantly contribute to a reliable diagnosis early in the course of the disease, particularly in patients with suspected GCA that do not meet current diagnostic criteria.

Objective: The primary aim of this research is to systematically sort out and analyze available documents for yang deficiency syndrome in traditional Chinese medicine, providing innovative ideas and methods for statistical study of yang deficiency syndrome. Methods: Based on the China National Knowledge Internet (CNKI) and Chongqing VIP databases, using ”yang deficiency”, ”deficiency cold”, and ”patient” as keywords, we searched literature of clinical researches and used ”ratio-comparison” and ”integration-comparison” to analyze objective data after data preprocessing. Relative importance value of physiological and biochemical parameters were reflected by P value calculated by ratio-comparison or Q value by integration-comparison. Results: With calculation of relative importance values of clinical indicators among various systems, we got the ranking of relative importance of different indexes. Triiodothyronine and urine 17-hydorxycorticosteroid of endocrine system, immunoglobulin A of immune system, and the ratio of cyclic adenosine monophosphate to cyclic guanosine monophosphate, which had great |P|(or |Q|) values and negative P (or Q) values, had a clearly lower level in yang deficiency patients than in the control; hemorheological indicators such as plasma viscosity, whole blood reduced viscosity and erythrocyte electrophoresis time had small |P| (or |Q|) values. These indicators, however, showed less importance for reflecting yang deficiency. Conclusion: Ratio-comparison method and integration-comparison method employed in this study have merits of efficiency and robustness. After detailed compiling and mining of all available data, we have made reasonable advice on the most relevant index of yang deficiency for further study of the essence of this syndrome.

Background: Markers of platelet activation and haemorrheological indices have been demonstrated to play a role in the pathophysiology of atherosclerosis and cardiovascular events. In this study, we aimed at investigate the association between plasma viscosity and platelet indices in patients undergoing coronary angiography. Materials and methods: Three hundred and eighty four consecutive patients scheduled to undergo coronary angiography were included in the study. Prior to coronary angiography, blood samples were withdrawn to determine routine biochemical markers, blood cell analyses and viscosity measurements. According to the results of coronary angiography, patients were classified either in a subgroup with coronary artery disease (CAD; 1 or more stenoses > 50%) or normal coronary arteries (NCA; no stenoses or

To ascertain the effects of environmental temperature on blood rheology, ten subjects performed two exercise trials, in random order, at approximately 60% VO 2 max for 45-min. One trial was conducted in thermoneutral environment (20 ± 1°C), while the other was performed in hot dry condition (36 ± 1°C). Venous blood was removed at rest; following exercise and recovery. Blood was measured for lactate, haematocrit, and hemoglobin, while plasma was measured for viscosity, and fibrinogen. Plasma volume changes were estimated from Hct and Hb readings. Exercise was followed by a significant (P < 0.05) reduction in plasma volume in both test trials. Lactate increased significantly (P < 0.05) following exercise with no difference being observed between trials. When post exercise raw data were not adjusted for plasma volume changes, a significant increase (P < 0.05) in plasma viscosity (PV) and plasma fibrinogen (Fb) was found with no difference between thermoneutral and hot trials. When the raw data post exercise for PV and Fb were adjusted for plasma volume changes, no significant difference between rest and post exercise was demonstrated. Rheological variables returned to the pre-exercise level at the end of recovery. In conclusion, vigorous exercise transiently increased PV and Fb, and the added heat stress did not affect these responses more than exercise alone. The mechanism responsible for the increase in PV and Fb in response to vigorous exercise appears to be related to plasma shifts from intravascular to the extravascular spaces rather than plasma volume loss.

Purpose of review: Plasma expanders are reviewed to determine their ability to restore microvascular function as a means for extending the transfusion trigger and delaying the use of blood transfusions. This outcome is currently achievable because of the emergence of a new understanding of optimal tissue function that prioritizes maintenance of functional capillary density, which results from the normalization of blood viscosity via the increase in plasma viscosity with new viscogenic colloids. Recent findings: Use of viscous plasma expanders in experimental models of extreme hemodilution, hemorrhagic shock and endotoxemia shows that the limiting factor in anemia is not oxygen-carrying capacity but the decline of microvascular function due to the lowering of functional capillary density. In support of this hypothesis, we find that viscogenic colloids including high-molecular-weight starches, dextrans, polyvinylpyrrolidone, keratin and polyethylene glycol-conjugated albumin maintain or restore microvascular function in extreme hemodilution, polyethylene glycol-conjugated albumin yielding the best results. Summary: Preclinical studies show that polyethylene glycol-conjugated albumin at concentrations in the range of 2-4% extends the transfusion trigger, providing the more extended and complete microvascular and systemic recovery from hemorrhagic shock, extreme hemodilution and endotoxemia, postponing the need of reestablish intrinsic blood oxygen-carrying capacity to hemoglobin concentrations lower than those associated with accepted transfusion triggers.

Summary The erythrocyte sedimentation rate has previously been identified as an important prognostic factor in Hodgkin's disease. The plasma viscosity has replaced the ESR measurement in many laboratories, but doubts exist about its clinical relevance. In this study plasma viscosity at presentation/diagnosis was studied in 107 patients with Hodgkin's disease. A multivariate analysis of factors influencing prognosis and relapse-free survival identified plasma viscosity and number of disease sites as being highly significant. The risk of relapse increases initially with a rise in plasma viscosity, but after a value of about 2.0 mPa.s no further increase in risk is observed. When all of the prognostic factors are made available to the proportional hazards model, treatment modality and plasma viscosity are selected as the best set for predicting time to first relapse. This study demonstrates that measurement of plasma viscosity at presentation is an important prognostic factor in Hodgkin's disease, in terms of predicting outcome or risk of relapse.

Ten patients with ischaemic cerebrovascular accident were given pentoxifylline, 1.2-1.5 g daily parenterally for ten consecutive days. At the beginning of treatment, on the first and then every third day the following rheological measurements were made: yield shear stress, plasma viscosity, haematocrit, erythrocyte aggregation and deformability. In the course of treatment there was a highly significant improvement in the first and last functions. Plasma viscosity and erythrocyte aggregation did not change significantly. Haematocrit was changed in two patients by isovolaemic haemodilutions. Clinically there was improvement in nine patients; one patient died as a result of severe brainstem ischaemia.