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OBJECTIVE: The carotid stiffness is an important factor in the pathogenesis of cerebrovascular small vessel disease. Our study aimed to evaluate the relation of the local arterial stiffness of the common carotid artery (CCA) to the hemodynamic forces and blood viscosity in patients with cerebral lacunar infarctions (LI). METHODS: Twenty-two patients with chronic LI and 15 age-matched controls were examined. An ultrasound examination of the CCA intima-media thickness (IMT), the parameters of local CCA stiffness: distensibility (DC) and compliance coefficients (CC), α and β stiffness indices and pulse wave velocity (PWV) was performed. The local hemodynamic forces were calculated: circumferential wall tension (CWT) and wall shear stress (WSS). Whole blood viscosity (WBV) and shear stresses at shear rates of 0.277 s- 1 to 94.5 s- 1 were measured in patients and controls. RESULTS: Higher values of IMT, a significant decrease of DC and CC and an increase of α and β stiffness indices and PWV in the LI patients compared to the controls were obtained. A parallel significant increase in CWT and a decrease in WSS was found. An increase in WBV and a significant increase in shear stresses were detected. In the LI patients, the increased stiffness indices were associated with an increase in age, cholesterol and WBV at higher shear rates in the left CCA. In the controls, the IMT and stiffness indices correlated significantly with the hemodynamic factors and WBV in both CCAs, while the stiffness indices correlated with the hemodynamic forces in the left CCA. CONCLUSION: The results of the present study demonstrate different associations of the local carotid stiffness indices with the hemodynamic forces and WBV in patients with LI and controls. [ABSTRACT FROM AUTHOR]

Existing effective treatments for ischemic stroke restore blood supply to the ischemic region using thrombolysis or mechanical removal of clot. However, it is increasingly recognized that successful removal of occlusive thrombus from the large artery—recanalization, may not always be accompanied by successful restoration of blood flow to the downstream tissues—reperfusion. Ultimately, brain tissue survival depends on cerebral perfusion, and a functioning microcirculation. Because capillary diameter is often equal to or smaller than an erythrocyte, microcirculation is largely dependent on erythrocyte rheological (hemorheological) factors such as whole blood viscosity (WBV). Several studies in the past have demonstrated elevated WBV in stroke compared with healthy controls. Also, elevated WBV has shown to be an independent risk factor for stroke. Elevated WBV leads to endothelial dysfunction, decreases nitric oxide-dependent flow-mediated vasodilation, and promotes hemostatic alterations/thrombosis, all leading to microcirculation sludging. Compromised microcirculation further leads to decreased cerebral perfusion. Hence, modulating WBV through pharmacological agents might be beneficial to improve cerebral perfusion in stroke. This review discusses the effect of elevated WBV on endothelial function, hemostatic alterations, and thrombosis leading to reduced cerebral perfusion in stroke. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pregnancy is a dynamic process associated with changes in vascular and rheological resistance. Maternal maladaptation to these changes is the leading cause of pregnancy complications such as preeclampsia. OBJECTIVE: This study aimed to assess the hemorheological alterations in pregnancies with a high risk for preeclampsia in the first trimester. METHODS: Ninety-two pregnant women were allocated into the high preeclampsia risk group (37 cases) and control groups (55 cases). Plasma and whole blood viscosity and red blood cell morphodynamic properties, including deformability and aggregation were assessed by Brookfield viscometer and laser-assisted optical rotational cell analyzer (LORRCA) at 11–14 gestational weeks. RESULTS: Whole blood viscosity was significantly higher in the high-risk group at all shear rates. Plasma viscosity and hematologic factors showed no differences between the groups. Hematocrit levels positively correlated with high blood viscosity only in the high-risk group. There were no significant changes in the other deformability and aggregation parameters. CONCLUSIONS: Changes in the whole blood viscosity of pregnant women with high preeclampsia risk refer to impaired microcirculation beginning from the early weeks of gestation. We suggest that the whole blood viscosity is consistent with the preeclampsia risk assessment in the first trimester, and its measurement might be promising for identifying high-preeclampsia-risk pregnancies. [ABSTRACT FROM AUTHOR]

Simple Summary: Blood viscosity, an essential hemorheological parameter, signifies the inherent resistance encountered during blood circulation within blood vessels. Assessing whole blood viscosity stands as an early diagnostic modality for an array of vascular conditions, encompassing cardiovascular, cerebrovascular, and microvascular ailments. Given the intricate challenge of early-stage diagnosis using conventional blood tests, blood viscosity emerges as a tool to gauge disease susceptibility. Recently, scanning capillary viscometers that can obtain blood viscosity values for a wide range of shear rates through a single measurement have been widely used. Using this, this study aimed to establish reference intervals in cats, representative companion animals, for further hemorheological study and the veterinary clinical field. The outcomes of this study yield essential reference intervals for normal whole blood viscosity in healthy feline subjects, encompassing a wide range of shear rates that hitherto lacked comprehensive establishment. Whole blood viscosity, a hemorheological factor, is currently used for diagnosis, as it is correlated with various vascular diseases that are difficult to diagnose early with a general blood test. It was determined that it was necessary to set reference intervals for further studies and utilization of whole blood viscosity in cats, a representative companion animal, and this study was conducted. Fifty healthy cats were recruited for the study, and whole blood viscosity, complete blood count, and serum chemistry tests were performed. The reference intervals of whole blood viscosity were 15.169 to 43.684 cP at a shear rate of 1 s−1 reflecting diastole, and 3.524 to 5.544 cP at a shear rate of 300 s−1 reflecting systole. Red blood cells, hematocrit, hemoglobin, white blood cells, and neutrophils in the complete blood count, and total protein, albumin, globulin, and cholesterol in the serum chemistry were significantly correlated with whole blood viscosity. The results of this study set the reference intervals of whole blood viscosity for healthy cats in a wide shear rate range that has not yet been fully established, and its correlation with other blood indicators investigated. [ABSTRACT FROM AUTHOR]

Copyright of Firat Universitesi Sağlik Bilimleri Tip Dergisi is the property of Firat Universitesiu, Saglik Bilimleri Enstitusu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Turkish Journal of Trauma & Emergency Surgery / Ulusal Travma ve Acil Cerrahi Dergisi is the property of KARE Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective To investigate the effect of Tripterygium wilfordii polyglycosides(TWPS) on inflammatory response found in mouse models with Sjgren's syndrome(SS). Methods Mice were randomly divided into control group, Sjgren's syndrome model group, hydroxychloroquine sulfate treatment group (20 mg/kg hydroxychloroquine sulfate intragastric administration), TWPS low-dose, medium-dose and high-dose groups (10, 20, 30 mg/kg TWPS), TWPS + Wortmanin (PI3K/Akt/eNOS signaling pathway inhibitor) group (30 mg/kg TWPS and 0.6 mg/kg Wortmannin viajugular vein).Saliva flow rate, water intake, whole blood viscosity and plasma viscosity were recorded. Serum IL-6, IL-17, IgG and eNOS were detected by ELISA. Western blot was used to detect PI3K/Akt/eNOS pathway related proteins. Results Compared with control group, the saliva flow rate of the model group decreased and the quantity of drinking water increased(P＜0.05). Compared with model group, saliva flow rate increased and water consumption decreased in low, medium and high dose TWPS groups, which alleviated the change of model group(P＜0.05). Compared with the low, medium and high dose TWPS +Wortmanin groups, saliva flow rate decreased and water intake increased (P＜0.05). The whole blood and plasma viscosity of model group increased compared with control group(P＜0.05). The whole blood and plasma viscosity of TWPS low-dose, medium-dose and high-dose groups were lower than that of model group(P＜0.05). The whole blood and plasma viscosity of TWPS+Wortmanin group was higher than that of low, medium and high dose TWPS groups(P＜0.05). Compared with the control group, the levels of serum IL-6, IL-17 and IgG in model group were increased, while the level of eNOS was decreased(P＜0.05). The serum levels of IL-6, IL-17 and IgG in TWPS low-dose, medium-dose and high-dose groups were lower than those in model group, while the levels of eNOS were higher than those in model group(P＜0.05). The serum level of IL-6, IL-17 and IgG in TWPS +Wortmanin group increased as compared to those in low, medium and high dose TWPS +Wortmanin group, while the level of eNOS decreased as compared to those in low, medium and high dose TWPS +Wortmanin group(P＜0.05). The level of p-PI3K/PI3K, p-Akt/Akt and p-ENOS /eNOS in model group was lower than those in control group(P＜0.05). Compared with model group, p-PI3K/PI3K, p-Akt/Akt and p-ENOS/eNOS levels of TWPS in low, medium and high dose groups all increased(P＜0.05); The level of p-PI3K/PI3K, p-Akt/Akt and p-ENOS /eNOS in TWPS +Wortmanin group was lower than those in low, medium and high dose TWPS groups(P＜0.05). Conclusions TWPS alleviates inflammatory response and improves symptoms of mouse models with Sjgren's syndrome.

BACKGROUND: Complete atrioventricular block is most commonly caused by age-related degeneration and fibrosis in the cardiac conduction system and is called primary idiopathic complete atrioventricular (iCAVB). Although many factors affect this situation, which increases with age in the cardiac conduction system, the relationship between whole blood viscosity (WBV) and iCAVB has not been clarified until now. In this study, we aim to reveal the relationship between iCAVB and WBV. METHODS AND RESULTS: 141 patients with dual-chamber permanent pacemaker implanted for iCAVB and 140 age- and sex-matched subjects were included in this study. The WBV values of the study groups were compared in both high shear rate (HSR) and low shear rate (LSR). Both WBV at HSR and WBV at LSR were significantly higher in the iCAVB group compared to the control group (16.11 [15.14–16.89] vs 14.40 [13.62–15.58]; 39.82 [17.43–55.23] vs 1.38 [–13.14–26.73]; p < 0.001, respectively). The patient population was followed up for an median of 38 months for all-cause mortality. Higher mortality rates were found in higher WBV at HSR and WBV at LSR (p < 0.001,for both). CONCLUSIONS: In this study, WBV was found to be an independent predictor for iCAVB, and in these patients WBV was associated with poor clinical outcomes. [ABSTRACT FROM AUTHOR]

Whole blood viscosity (WBV) is the intrinsic resistance to flow developed due to the frictional force between adjacent layers of flowing blood. Elevated WBV is an independent risk factor for stroke. Poor microcirculation due to elevated WBV can prevent adequate perfusion of the brain and might act as an important secondary factor for hypoperfusion in acute ischaemic stroke. In the present study, we examined the association of WBV with basal cerebral perfusion assessed by CT perfusion in acute ischaemic stroke. Confirmed acute ischemic stroke patients (n = 82) presenting in hours were recruited from the single centre. Patients underwent baseline multimodal CT (non-contrast CT, CT angiography and CT perfusion). Where clinically warranted, patients also underwent follow-up DWI. WBV was measured in duplicate within 2 h after sampling from 5-mL EDTA blood sample. WBV was significantly correlated with CT perfusion parameters such as perfusion lesion volume, ischemic core volume and mismatch ratio; DWI volume and baseline NIHSS. In a multivariate linear regression model, WBV significantly predicted acute perfusion lesion volume, core volume and mismatch ratio after adjusting for the effect of occlusion site and collateral status. Association of WBV with hypoperfusion (increased perfusion lesion volume, ischaemic core volume and mismatch ratio) suggest the role of erythrocyte rheology in cerebral haemodynamic of acute ischemic stroke. The present findings open new possibilities for therapeutic strategies targeting erythrocyte rheology to improve cerebral microcirculation in stroke. [ABSTRACT FROM AUTHOR]

Whole blood viscosity (WBV) is considered as a reasonable proxy measure of blood flow, and it has been investigated in different cohort settings, including in patients with deep venous thrombosis, arterial thrombosis, acute stent thrombosis, and left ventricular apical thrombus formation following acute coronary syndrome. To determine the association between WBV and the presence of thrombus in the left atrium (LA) or left atrial appendage (LAA) in individuals who had transoesophageal echocardiography (TEE). The clinical data from 262 consecutive patients who had TEE at our facility were included in this retrospective cohort study. WBV was determined at both a high shear rate (HSR) and low shear rate (LSR) using hematocrit and total protein levels. In 22 cases (8.3%), the thrombus was detected. According to multivariable analyses, WBV at HSR and LSR were independently linked with thrombus detection in TEE. In a receiver operating characteristic (ROC) analysis, the area under curve (AUC) values of WBV at HSR and LSR were 0.77 and 0.76, respectively. To predict the presence of thrombus in TEE; the ideal value of WBV at HSR was > 16.6 with 81% sensitivity and 69% specificity and the ideal value of WBV at LSR was > 51.4 with 81% sensitivity and 70% specificity. This was the first study to indicate that significantly higher levels of WBV at both the HSR and LSR were linked to the presence of thrombus in the LA and LAA in cases who underwent TEE. [ABSTRACT FROM AUTHOR]

BACKGROUND: In the blood vessels the impaired hemorheological parameters in patients with type 2 diabetes mellitus (T2DM) could lead to elevated flow resistance, increased forces at the endothelial wall and to microvascular disturbances. OBJECTIVE: The aim of the study is to investigate the hemorheological variables and the changes of the skin blood flow responses to cold stress in T2DM patients. METHODS: The basic hemorheological parameters: hematocrit (Ht), fibrinogen (Fib), whole blood viscosity (WBV) and plasma viscosity (PV) were examined in 20 patients with T2DM and a control group of 10 healthy age and sex matched controls. The mechanisms of vascular tone regulation were investigated using the wavelet analysis of the skin temperature oscillations (WAST). The degrees of the microvascular tone changes were determined during a cold test in the endothelial (0.02–0.0095 Hz), neurogenic (0.05– 0.02 Hz) and myogenic (0.05– 0.14 Hz) frequency ranges. RESULTS: Significant increase of Fib and WBV in the patients in comparison to controls was found. The mean values of the amplitudes of the skin temperature (ST) pulsations decreased significantly during the cold stress only in the endothelial frequency range for the diabetic patients. CONCLUSIONS: The results of our study reveal parallel impairment of the blood rheological parameters and the cutaneous microcirculation in T2DM patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Psoriasis is associated with an increased risk for cardiovascular disease (CVD). Methotrexate (MTX) is often used as a first-line system therapy and there is a need to determine its effect on whole blood viscosity (WBV) and plasma viscosity (PV) in psoriasis. METHODS: A prospective, single-center, interventional study with a total of 111 psoriatic patients who received MTX therapy from October 22, 2018, to December 28, 2019, and 111 age- and sex-matched healthy controls. Changes in WBV, PV, blood counts, liver and renal function were evaluated. RESULTS: Psoriatic patients had significantly higher levels of WBV and relative viscosity (RV) at low shear rate (LSR), erythrocyte aggregation index (EAI), and PV than sex and age-matched healthy controls. PV was positively correlated with erythrocyte sedimentation rate (ESR), ESR was positively correlated with high sensitive C-reactive protein (hCRP). But only hCRP was positively associated with psoriasis area severity index (PASI) score. MTX significantly decreased the levels of PV, ESR, hCRP, and blood pressure (BP) in male patients, and the level of WBV in female patients. CONCLUSION: Sex-specific downregulation of MTX on WBV, PV, hCRP, and BP, indicating that the effect of MTX on the risk of cardiovascular disease was related with sex. [ABSTRACT FROM AUTHOR]

Background: Blood viscosity is a strong predictor of cardiovascular events. However, the relationship between blood viscosity and acute arterial occlusion (AAO) has not been studied adequately so far.

The association between whole blood viscosity (WBV) and metabolic syndrome (MetS) is still scarcely investigated in the population-based prospective cohort. We aim to explore the longitudinal effect of WBV on MetS, and to verify whether WBV measures can be used as early predictors for MetS. The longitudinal cohort consisted of 3,508 adults (2,350 males and 1,158 females) who visited the health check-up system twice. WBV were measured at four shear rate (200, 50, 10 and 1 s-1), and their values were classified into quartiles. Multivariate Cox models were used to estimate the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) in men and women, respectively. A total of 444 (12.66%) incident MetS were observed at follow-up period. The incidences of MetS significantly increased with increasing quartiles of WBVs at all of the shear rate in men. After adjusting for baseline age, smoking, obesity, hypertension, hyperglycemia, and hyperlipidemia status, all of the WBV measures were significantly associated with incident MetS in men, and the HRs showed clear increasing trend across the quartiles of baseline WBVs. There were no significant association between WBVs and incident MetS in women. These findings suggest that MetS has a hemodynamic basis, and WBVs could be used as independent early predictor for MetS in men. [ABSTRACT FROM AUTHOR]

Objectives: Fractional flow reserve (FFR), which is an invasive technique, is appraised as the gold standard for physiological valuation of intermediate coronary disease. Because it is a pressure-linked measure, FFR can be influenced by whole blood viscosity (WBV). We aimed to evaluate the relationship between FFR and WBV, which can be calculated by a confirmed formula using only hematocrit and total serum protein levels. Materials and Methods: We involved 226 patients who were implemented FFR after interpreting coronary artery angiogram. We separated the patients into two groups accordingly with the FFR cutoff value of 0.80: 96 patients (77.1% male, mean age 62.84±9.90 years) with critical stenosis as FFR <0.80 group and 130 patients (76.9% male, mean age 63.32±11.0 years) non-critical stenosis as FFR≥0.80 group. WBV at both low shear rate (L-SR) (0.5 sec-1) and high shear rate (H-SR) (208 sec-1) was computed by using total serum protein levels and hematocrit. Results: Critical stenosis group had a remarkable increased WBV for both L-SR (52.85±21.23 vs. 43.90±22.30, p=0.003) and H-SR (16.89±1.03 vs. 16.45±1.09, p=0.002). In the multivariate regression models, WBV both for L-SR [Odds ratio (OR): 1.018, 95% confidence interval (CI): 1.004-1.032, p=0.010] and for H-SR (OR: 1.446, 95% CI: 1.094-1.912, p<0.010) was shown as an independent predictor of FFR value. Conclusion: This study showed that high WBV was significantly associated with FFR values in the critical stenosis group. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM) is a complex, chronic metabolic disorder characterized by impaired regulation of blood glucose levels. Zinc (Zn) is an essential trace elements that plays a role in various physiological processes within the body, including those related to diabetes. The current study was investigated the effect of Zn supplementation on hemorheological parameters in a rat model of DM. After induction of DM, 32 male Wistar albino rats were divided into four groups: control, Zn, DM, and Zn+DM. Whole blood viscosity (WBV) was determined by using digital cone and plate viscometer and plasma viscosity (PV) was determined by a Coulter Harkness capillary viscometer. The rats in the DM Group showed a decrease in both Zn levels and body weight, as well as an increase in glucose levels when compared to the control group. Diabetic rats supplemented with Zn displayed lower blood glucose levels and higher concentrations of Zn compared to the DM Group. The higher PV and lower hematocrit level were measured in DM Group than control group and lower PV, higher hematocrit level were measured in Zn+DM group than DM Group. The WBV was measured at four different shear rates (57.6–115.2 - 172.8–230.4 s −1). A statistically significant increase was observed in the DM group compared to the control group. Additionally, a statistically significant decrease was observed in the Zn+DM Group compared to the DM Group at a shear rate of 230.4 s−1. Erythrocyte rigidity index (T k) and oxygen delivery index (ODI) were computed under conditions of high shear rate. The rats in the DM group exhibited a reduction in ODI and an elevation in T k in comparison to the control group. Conversely, the diabetic rats supplemented with Zn exhibited decreased T k and increased ODI compared to the DM Group. Zn supplementation seems to have a potential beneficial effect for protecting adverse affect of diabetes on hemorheogical parameters and for maintaining vascular health. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background Warfarin is evidence-based therapy for the prevention of cardioembolic stroke, but has not been studied for its effects on whole blood viscosity (WBV). This study investigated the effect of warfarin versus aspirin on WBV in patients presenting with non-valvular atrial fibrillation (NVAF) and acute cardioembolic stroke. Methods We enrolled patients with acute cerebral infarction, aged 56–90 years who had NVAF, CHADS2 score ≥ 2, presenting with mild-to-moderate stroke (National Institute of Health Stroke Scale (NIHSS) score

Objectives: This study aims to evaluate the relationship of echocardiographic measurements, whole blood viscosity, and other hematological markers with short-term (0-30 days after the diagnosis) and long-term (31st day -12th month after the diagnosis) mortality in acute pulmonary embolism (APE). Patients and methods: This retrospective study included a total of 80 patients (35 males, 45 females; mean age 68.0±17.1 years; range, 22 to 92 years) with the definitive diagnosis of APE between January 2015 and December 2017. The patients were divided into three study groups as follows: short-term mortality group (n=20; 25.0%), long-term mortality group (n=15; 18.8%), and alive group (n=45; 56.2%) surviving beyond one year during follow-up. The demographic data, Pulmonary Embolism Severity Index, simplified Pulmonary Embolism Severity Index, complete blood count, N-terminal pro-brain natriuretic peptide (NT-proBNP), D-dimer, C-reactive protein, whole blood viscosity values, and echocardiographic measurements of the patients were recorded. Results: The increased levels of high shear rate-whole blood viscosity, low shear rate-whole blood viscosity, and the decreased levels of tricuspid annular plane systolic excursion were found to be associated with short-term mortality in APE. The red blood cell distribution width and NT-proBNP levels and pulmonary artery and right ventricular diameters were found to be associated with early and late mortality. Conclusion: Whole blood viscosity levels appear to estimate the patients susceptible to early mortality in APE, while late mortality seems to be predictable in the presence of increased red cell distribution width. Echocardiographic measurements seem to be applicable indicators of increased early and late mortality in APE. [ABSTRACT FROM AUTHOR]

Objective: To establish a novel cardiocentesis method for withdrawing venous blood from the right atrium, and to improve an acute blood stasis rat model using an ice bath and epinephrine hydrochloride (Epi) while considering the 3Rs (reduction, refinement, and replacement) of humane animal experimentation. Methods: An acute blood stasis model was established in male Sprague-Dawley rats by subcutaneous injection (s.c.) Epi (1.2 mg/kg) administration at 0 h, followed by a 5-min exposure to an ice-bath at 2 h and s.c. Epi administration at 4 h. Control rats received physiological saline. Rats were fasted overnight and treated with Angelicae Sinensis Lateralis Radix (ASLR) and Pheretima the following day. Venous blood was collected using our novel cardiocentesis method and used to test whole blood viscosity (WBV), prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (FIB) content. Results: The rats survived the novel cardiocentesis technique; WBV value returned to normal while hematological parameters such as hemoglobin level and red blood cell count were restored to >94% of the corresponding values in normal rats following a 14-day recovery. Epi (1.2 mg/kg, s.c.) combined with a 5-min exposure to the ice bath replicated the acute blood stasis rat model and was associated with the highest WBV value. In rats showing acute blood stasis, ASLR treatment [4 g/(kg·d) for 8 days] decreased WBV by 9.98%, 11.09%, 9.34%, 9.00%, 7.66%, and 7.03% (P<0.05), while Pheretima treatment [2.6 g/(kg·d), for 8 days] decreased WBV by 25.49%, 25.94%, 16.28%, 17.76%, 11.07%, and 7.89% (P<0.01) at shear rates of 1, 3, 10, 30, 100, and 180 s−1, respectively. Furthermore, Pheretima treatment increased APTT significantly (P<0.01). Conclusions: We presented a stable, reproducible, and improved acute blood stasis rat model, which could be applied to screen drugs for promoting blood circulation and eliminating blood stasis. [ABSTRACT FROM AUTHOR]

Objective: Our goal was to determine if whole blood viscosity (WBV) can be used to predict the risk of pulmonary arterial hypertension (PAH) in patients with systemic sclerosis (SSc). Methods: Patients with SSc were analyzed. Out of 107 patients, 26 patients, found to have confirmed diagnosis of PAH, were classified as those with (n = 26, PAH group) and without PAH (n = 81, non-PAH group). We calculated estimated WBV at both high (HSR) and low shear rates (LSR) from hematocrit and total serum protein levels. Results: Total protein levels were significantly higher and the anti-centromere antibody (ACA) was more frequent in the PAH group. Furthermore, anti-topoisomerase antibody (anti-scl-70) was significantly less frequent in the PAH group. The WBV values were significantly higher at HSR (16.68 ± 0.38 vs. 16.24 ± 0.58; p < 0.001) and at LSR (51.81 ± 7.21 vs. 42.97 ± 11.76; p < 0.001) in PAH group. The multivariate analysis revealed that the WBV at both shear rates independently designated the presence of PAH in SSc patients. The ROC curve showed that the sensitivity and specificity of LSR and HSR were 92.3% and 61.7% (AUC 0.759, p < 0.001), and 88.5% and 65.4% (AUC 0.770, p < 0.001) with a cutoff value of 43.56 and 16.32 for WBV, respectively. Conclusion: Higher WBV levels in SSc patients were an independent indicator for PAH development in this cohort. WBV-LSR and WBV-HSR values might help exclude the PAH possibility in patients diagnosed with SSc and remain as an independently associated biomarker for follow-up of these patients for future risk of PAH development. Findings remain to be confirmed by other cohorts. Key Points • The most important cause of morbidity and mortality in systemic sclerosis patients is considered to be pulmonary arterial hypertension. • When the symptoms of PAH are not recognized earlier in the course of the SSc, the prognosis might be worse. • Higher whole blood viscosity levels in scleroderma patients with PAH was an independent indicator for PAH development. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ankara University Faculty of Medicine / Ankara Üniversitesi Tip Fakültesi Mecmuasi is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Whole blood viscosity (WBV) is a group of important clinical indicators of cardio-cerebral vascular diseases. Existing detection methods for WBV are complex, making them inconvenient for large population screening. Blood viscosity is closely related to the deformability and aggregation of erythrocytes, which are associated with haemoglobin. Haemoglobin has obvious near-infrared (NIR) spectral absorption. Scattering occurs when NIR light enters a viscous blood sample, and its scattering degree is correlated with blood viscosity. Based on repeated spectral measurements and spectral similarity, spectral noise-to-signal ratio (NSR) was proposed to quantify the spectral scattering effect in the blood sample. A novel selection method of piecewise-continuous wavelengths, named NSR priority-partial least squares (NSRP-PLS), was proposed and applied for visible-NIR quantitative analysis of WBV with high, medium and low shear rates [WBV(H), WBV(M), WBV(L)]. Modelling was separately performed by gender to allow for systematic gender differences in blood viscosity. For the NIR-predicted and clinically measured values of the three WBV indicators in independent validation, the root mean square errors for prediction (SEP) were 0.498, 0.222 and 0.193 (mPa·s), respectively. And the correlation coefficients (R P) were 0.927, 0.934 and 0.927, respectively. Compared with the three current well-performing methods (MW-PLS, CARS-PLS and SPA-PLS), the proposed NSRP-PLS method achieved better predictive accuracy. Results indicated that visible-NIR spectroscopy combined with the NSRP-PLS method can be used for the quantitative analysis of WBV. The proposed analytical method is rapid, reagent-free and is scientific and meaningful for cardio-cerebral vascular diseases screening in large populations. Unlabelled Image • Noise-to-signal ratio priority-partial least squares • Piecewise-continuous NIR wavelength selection • Rapid and reagent-free analysis of whole blood viscosity • Multiple division modelling achieves parameter stability. • Independent modelling based on gender groups [ABSTRACT FROM AUTHOR]

Objective: We aimed to investigate whether increased whole blood viscosity (WBV) could be an important factor for the occurrence of aortic valve sclerosis (AVS). Subjects and Methods: A total of 209 patients were enrolled in the study. WBV was calculated using the hematocrit and total plasma protein at a low shear rate (LSR) and a high shear rate (HSR). AVS was defined as irregular valve thickening and calcification (without evidence of outflow obstruction) documented by a peak transvalvular velocity < 2.5 m/s on echocardiographic examination. The patient group consisted of 109 patients with AVS (77 females, 32 males), and 100 subjects without AVS (65 females, 35 males) were assigned to the control group. Results: In the AVS group, WBV values were significantly higher for HSR (17.4 ± 0.5 vs. 17.1 ± 0.7 208 s–1, p < 0.001) and LSR (65.9 ± 12.5 vs. 59.7 ± 16.7 0.5 s–1, p = 0.002). In multivariate logistic regression analysis, WBV at HSR and LSR were independent predictors of AVS (odds ratio, OR: 2.24, 95% confidence interval, CI: 1.38–3.64, p = 0.001; OR: 1.026, 95% CI: 1.006–1.046, p = 0.01, respectively). Receiver-operating characteristic (ROC) curve analysis indicated that a WBV cutoff value of 65.4 at LSR had a sensitivity of 46.8% and a specificity of 60.0% (area under the ROC curve, AUC: 0.615, 95% CI: 0.535–0.696, p = 0.004), and a WBV cutoff value of 17.1 at HSR had a sensitivity of 61.5% and specificity of 53% (AUC: 0.648, 95% CI: 0.571–0.725, p < 0.001) for the prediction of AVS. Conclusion: This study demonstrated that WBV was independently associated with AVS. WBV could be an indicator of inflammation and vessel remodeling without evidence of outflow obstruction. [ABSTRACT FROM AUTHOR]

Background: Obesity affects all major organ systems and leads to increased morbidity and mortality. Whole blood viscosity is an important independent regulator of cerebral blood flow. The aim of the present study was to evaluate the effect of whole blood viscosity on cerebral artery blood flow velocities using transcranial Doppler ultrasound in pediatric patients with obesity compared to healthy controls and analyze the effect of whole blood viscosity and blood pressure status to the cerebral artery blood flow velocities. Methods: Sixty patients with obesity diagnosed according to their body mass index (BMI) percentiles aged 13–18 years old were prospectively enrolled. They were grouped as hypertensive or normotensive according to their ambulatory blood pressure monitoring. Whole blood viscosity and middle cerebral artery velocities by transcranial Doppler ultrasound were studied and compared to 20 healthy same aged controls. Results: Whole blood viscosity values in hypertensive (0.0619±0.0077 poise) and normotensive (0.0607±0.0071 poise) groups were higher than controls (0.0616±0.0064 poise), with no significance. Middle cerebral artery blood flow velocities were higher in the obese hypertensive (73.9±15.0 cm/s) and obese normotensive groups (75.2±13.5 cm/s) than controls (66.4±11.5 cm/s), but with no statistical significance. Conclusions: Physiological changes in blood viscosity and changes in blood pressure did not seem to have any direct effect on cerebral blood flow velocities, the reason might be that the cerebral circulation is capable of adaptively modulating itself to changes to maintain a uniform cerebral blood flow. [ABSTRACT FROM AUTHOR]

A rapid analytical method of human whole blood viscosity with low, medium, and high shear rates [WBV(L), WBV(M), and WBV(H), respectively] was developed using visible and near-infrared (Vis-NIR) spectroscopy combined with a moving-window partial least squares (MW-PLS) method. Two groups of peripheral blood samples were collected for modeling and validation. Separate analytical models were established for male and female groups to avoid interference in different gender groups and improve the homogeneity and prediction accuracy. Modeling was performed for multiple divisions of calibration and prediction sets to avoid over-fitting and achieve parameter stability. The joint analysis models for three indicators were selected through comprehensive evaluation of MW-PLS. The selected joint analysis models were 812-1278 nm for males and 670-1146 nm for females. The root-mean-square errors (SEP) and the correlation coefficients of prediction (R) for all validation samples were 0.54 mPa•s and 0.91 for WBV(L), 0.25 mPa•s and 0.92 for WBV(M), and 0.22 mPa•s and 0.90 for WBV(H). Results indicated high prediction accuracy, with prediction values similar to the clinically measured values. Overall, the findings confirmed the feasibility of whole blood viscosity quantification based on Vis-NIR spectroscopy with MW-PLS. The proposed rapid and simple technique is a promising tool for surveillance, control, and treatment of cardio-cerebrovascular diseases in large populations. [ABSTRACT FROM AUTHOR]

Aim: The role of elevated whole blood viscosity (WBV) in the pathogenesis of atherosclerosis is well known. We sought to investigate the gender differences in the association between WBV, coronary blood flow and tissue oxygen delivery index (TODI) in cardiac syndrome X (CSX). Methods: Forty-six CSX patients and 14 healthy volunteers were enrolled. The coronary flow parameters were obtained with transthoracic Doppler echocardiography and WBV was measured (at high-shear and low-shear rates of 300s-1 and 5s-1, respectively) using a scanning capillary tube viscometer. TODI was determined from the ratio of hematocrit to WBV measured at a low-shear rate of 5s-1. Results: In male patients, the mean diastolic coronary flow velocity (CFV) and diastolic velocity time integral (VTI) were significantly decreased compared to control group (all p<0.05) and the WBV showed significant negative correlation with peak systolic CFV (r = -0.559 at 300s-1, r = -0.438 at 5s-1), mean systolic CFV (r = -0.577 at 300s-1, r = -0.488 at 5s-1), systolic VTI (r = -0.576 at 300s-1, r = -0.530 at 5s-1) and diastolic VTI (r = -0.553 at 300s-1, r = -0.551 at 5s-1) (all p<0.01). Meanwhile, although female patients showed no significant relationships between WBV and coronary flow parameters, TODI were significantly decreased compared to the control group (3.64 ± 0.34 vs. 4.07 ± 0.38%/centipoises (cP), respectively, p=0.008). Conclusion: Our study suggests that there are gender-related differences in the pathogenesis of microvascular angina and gender-specific approaches for CSX patients might be needed. [ABSTRACT FROM AUTHOR]

Background: Delirium after cardiothoracic surgery is common and associated with impaired outcomes. Although several mechanisms have been proposed (including changes in cerebral perfusion), the pathophysiology of postoperative delirium remains unclear. Blood viscosity is related to cerebral perfusion and thereby might contribute to the development of delirium after cardiothoracic surgery. The aim of this study was to investigate whether whole blood viscosity differs between cardiothoracic surgery patients with and without delirium.Methods: In this observational study postoperative whole blood viscosity of patients that developed delirium (cases) were compared with non-delirious cardiothoracic surgery patients (controls). Cases were matched with the controls, yielding a 1:4 case-control study. Serial hematocrit, fibrinogen, and whole blood viscosity were determined pre-operatively and at each postoperative day. Delirium was assessed using the validated Confusion Assessment Method for the Intensive Care Unit or Delirium Screening Observation scale.Results: In total 80 cardiothoracic surgery patients were screened of whom 12 delirious and 48 matched non-delirious patients were included. No significant difference was found between both groups in fibrinogen (p = 0.36), hematocrit (p = 0.23) and the area under curve of the whole blood viscosity between shear rates 0.02 and 50 s(-1) (p = 0.80) or between shear rates 0.02 and 5 s(-1) (p = 0.78).Conclusion: In this case control study in cardiothoracic surgery patients changes in whole blood viscosity were not associated with the development of delirium. [ABSTRACT FROM AUTHOR]

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is an independent risk factor for increased cardiovascular disease. Altered hemorheological parameters have also been shown to play a crucial role in atherogenesis. Moreover, increased viscosity is observed in insulin resistance, metabolic syndrome, hypertension, diabetes, ischemic heart disease, and stroke. A recent study confirmed that whole blood viscosity (WBV) is a predictor of cardiovascular events. AIMS: This study aimed to investigate the association of WBV with NAFLD. METHODS: In this cross-sectional study, we investigated the relationship between WBV and NAFLD in 1329 subjects (962 men and 367 women) in a general health examination. RESULTS:WBVat lowshear stresswas elevated in patients withNAFLD. In addition, the prevalence of metabolic syndrome and NAFLD increased as WBV quartiles increased both in men and in women. Multiple regression analysis further identified WBV as an independent and significant determinant for NAFLD. CONCLUSIONS: The findings showed that WBV at low shear stress is increased in NAFLD. Moreover, WBV at low shear stress is independently associated with NAFLD even after adjusting other cardiovascular risk factors. [ABSTRACT FROM AUTHOR]

BACKGROUND: Various vascular risk factors such as smoking, obesity, and diabetes mellitus are associated with hyperviscosity and lumbar disc herniation (LDH). However, the changes of viscosity in LDH have not been examined. AIMS: The present study was to elucidate 1) the rheological parameter levels in patients with LDH, 2) the risk factors that were related to rheological parameters. METHODS: Our study evaluated the rheological parameters in 307 cases with LDH and in 307 control subjects. Multiple linear regression analysis was conducted to assess the significant factors for whole blood viscosity (WBV) at low shear rate. RESULTS: LDH patients had markedly lower physical activity and significantly higher WBV3 s-1 compared with non-LDH subjects (p < 0.001). Moreover, WBV (3 s-1) tended to increase as physical activity decreased. Multiple linear regression analysis revealed that reduced physical activity was a significant factor contributing to elevated WBV (3 s-1). CONCLUSIONS: WBV (3 s-1) is elevated in patients with LDH. In addition, reduced physical activity is a significant factor for WBV (3 s-1). Further studies are warranted to determine the role of WBV (3 s-1) in LDH. [ABSTRACT FROM AUTHOR]

The objective of the present study was to evaluate the effects and safety of sarpogrelate hydrochloride (sarpogrelate) in patients with elevated blood viscosity (BV), after 12 and 24 weeks of twice (BID) or thrice (TID) daily administrations of sarpogrelate (100 mg). The participants received oral sarpogrelate administration for 24 weeks and visited the hospital every 12 ± 2 week for blood viscosity measurements at shear rates of 5 and 300 s−1. The BV measured at shear rate of 5 s−1 in male patients decreased significantly from 18.91 cP at the baseline to 16.3 cP after 24 weeks of sarpogrelate administration (13.6 % drop, p < 0.001). The BV measured at 5 s−1 in female decreased more significantly from 17.5 cP at the baseline to 13.4 cP after 24 weeks of sarpogrelate administration (23.0 % drop, p < 0.001). In summary, sarpogrelate may be considered as a possible therapeutic option for improving BV in patients with elevated blood viscosity. In particular, the reduction of the low-shear BV with the help of a viscosity-reducing drug such as sarpogrelate may be considered as a potentially new pharmacological tool for microvascular disease. • BV at shear rate of 5 s-1 in male patients decreased by 13.6% after 24 weeks of sarpogrelate administration. • BV at shear rate of 5 s-1 in female decreased by 23.0% after 24 weeks of sarpogrelate administration. • Female patients derived greater benefit from sarpogrelate treatment on improving the blood viscosity. • Triglyceride level in female patients decreased by 30.4% after 24 weeks of sarpogrelate administration. [ABSTRACT FROM AUTHOR]

BACKGROUND: Postmenopausal women often develop hemorheological disorders which may affect the systemic blood circulation and present a cardiovascular risk factor. OBJECTIVE:We evaluated effects of secoisolariciresinol (SECO), a phytoestrogen, on hemorheological parameters and lipid peroxidation in a model of the age-related and/or surgical menopause induced by ovariectomy in rats. METHODS: Arterial blood was sampled from sham-operated female rats, ovariectomized rats (OVX), and OVX treated with SECO (OVXSECO) (20 mg/kg/day intragastrically for two weeks). Plasma estrogen concentration and the following hemorheological parameters were measured: RBC aggregation (half-time of aggregation, T1/2; amplitude of aggregation, AMP; aggregation index, AI), RBC deformability (elongation index, EI), whole blood viscosity at the shear rate of 3-300 s-1, plasma viscosity, hematocrit, plasma fibrinogen. Lipid peroxidation was evaluated by measuring conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS) in plasma. RESULTS: Ovariectomy in rats caused a 60% decrease in plasma estrogen level and triggered the development of macro- and microhemorheological abnormalities. Blood viscosity increased by 12-31%, RBC elongation index reduced by 16-28%, and T1/2 and AI increased by 35% and 29% respectively. The increase in blood viscosity correlated predominantly with reduced RBC deformability. Plasma CD and TBARS were elevated by 47% and 104% respectively. SECO therapy for OVX rats reduced blood viscosity by 9-18% and T1/2 by 32%, and increased EI by 4-17%. SECO therapy disrupted the correlation between blood viscosity and RBC deformability. Lipid peroxidation was significantly inhibited, as shown by the reduction in CD and TBARS plasma concentrations by 89% and 70% respectively. SECO did not affect plasma viscosity, estrogen or fibrinogen levels. CONCLUSIONS: SECO treatment for OVX rats improves blood macro- and microrheological parameters, possibly through antioxidant protection of RBC. [ABSTRACT FROM AUTHOR]

Rheohaemapheresis aims to normalize major rheological parameters and is used to treat patients with dry age-related macular degeneration (AMD). While effective, this approach is invasive and requires specially trained personnel. Therefore, the search for novel effective compounds with hemorheological properties that can be taken orally to treat AMD is justified. The use of a robust rodent model of AMD with high blood viscosity is crucial to test the efficacy of potential hemorheological drugs to treat this disease. The objective of this study was to investigate whether OXYS rats, generally used as an animal model of AMD, have hyperviscosity syndrome. The results of this study show that blood viscosity in OXYS rats at low (3-10 s-1) and high (45-300 s-1) shear rates were 14-20% and 7-10% higher than in Wistar rats, while hematocrit and plasma viscosity were not different. Red blood cells (RBCs) in OXYS rats were more prone to aggregation as shown by 39% shorter half-time than in Wistar rats. RBCs were also more rigid in OXYS than in Wistar rats as shown by 21-33% lower index of elongation at the shear stress of 1-7 Pa. These data indicate that OXYS rats have hyperviscosity syndrome as the result of abnormal RBC deformability and aggregation. We propose to use OXYS rats as an animal model for preclinical studies to test compounds with hemorheological properties aimed to treat AMD. [ABSTRACT FROM AUTHOR]

Objective We have shown increased whole blood viscosity (WBV), decreased erythrocyte deformability, and increased erythrocyte aggregation in metabolic syndrome (MetS) in our previous study. The objective of the study was to find out if the altered hemorheology shown in MetS in our previous study is associated with chronic inflammation and oxidative stress in the same subjects. Methods One hundred recruited participants were classified into three groups based on the number of the MetS components present following National Cholesterol Education Program, Adult Treatment Panel III definitions. WBV, erythrocyte aggregation, erythrocyte deformability, oxidative stress markers (erythrocyte reduced glutathione (GSH), superoxide dismutase (SOD), and urinary isoprostanes), inflammatory markers high-sensitivity C-reactive protein (hsCRP), and thrombotic marker D-dimer were measured. Data were analyzed by IBM SPSS 20 software. Results We found a significant association of altered hemorheology with chronic inflammation and oxidative stress in MetS. There was a linear increase in the level of hsCRP and a linear decrease in the level of SOD and GSH across the quartiles of erythrocyte aggregation. Similarly, the thrombotic marker D-dimer showed a linear increase and oxidative stress marker GSH showed a linear decrease trend across the quartiles of WBV. Discussion Alterations of hemorheology in MetS are probably due to the effect of chronic inflammation and oxidative stress. The negative effects of chronic inflammation and oxidative stress on the cardiovascular system could be due to the resulting altered hemorheology. [ABSTRACT FROM AUTHOR]

BACKGROUND: The presence of silent cerebral infarction (SCI) increases the risk of transient ischemia attack, symptomatic stroke, cardiovascular disease and dementia. Increased viscosity is associated with aging, obesity, carotid intima-media thickness, metabolic syndrome, hypertension, diabetes, ischemic heart disease, and stroke. AIMS: The purpose of the study was to assess the hemorheological parameters levels in SCI patients. METHODS: A cross-sectional study was conducted to evaluate the association between hemorheological parameters and SCI in 1487 subjects (868 men and 619 women) undergoing medical check-up. RESULTS: The participants with SCI had higher whole blood viscosity (WBV) levels at low shear rate than those without SCI (10.34±1.77mPa.s vs. 8.98±0.88mPa.s; P < 0.001). Moreover, the subjects with a high WBV had a higher prevalence of SCI. Logistic regression analysis revealed that a significant association of WBV levels with the risk of SCI after adjustment for confounding factors (OR: 2.025; 95% CI: 1.750-2.343; P < 0.001). CONCLUSIONS: Whole blood viscosity at low shear rate is a novel indicator for SCI regardless of classical cardiovascular risk factors. Early measurement of whole blood viscosity may be helpful to assess the risk of stroke. [ABSTRACT FROM AUTHOR]