Hemorheological Changes Research Articles

Hyperviscosity in plasma cell dyscrasias

Plasma cell dyscrasias are characterized by a malignant clonal proliferation of plasma cells. Due to the excessive production of abnormal clonal gammaglobulins, or paraproteins, there are major hemorheologic changes in the circulation. As a result, clinical manifestations of the hyperviscosity syndrome become a major cause of morbidity and mortality. Pathogenic factors for the hyperviscosity are due both to increased plasma viscosity and to increased erythrocyte aggregation, leading to increased whole blood viscosity. These changes are dependent on the plasma concentration as well as the molecular size of the paraprotein with the threshold for onset of hyperviscosity for IgG >15 g/dl, for polymerized IgG3 >4-5 g/dl, for IgA >10-11 g/dl; for polymerized IgA >6-7 g/dl and for IgM >3 g/dl. Correspondingly, the incidence of symptomatic hyperviscosity in Waldenstrom's macroglobulinemia is 10-30%, while that in IgG myeloma is 2-6%. Clinically, the syndrome has neurologic features of headache and dizziness, visual changes, renal failure, and cardiac failure from increased plasma volume. Thrombotic complications are frequent. Paradoxically, there can be bleeding complications due to impairment of platelet function. Removal of the paraprotein by plasma exchange (plasmapheresis) can effectively reduce the hyperviscosity. Long-term control of paraprotein production can be achieved by chemotherapy. The early recognition of the symptoms of hyperviscosity, confirmed by laboratory findings of increased paraproteins and of increased blood viscosity, is essential for the proper management of this group of disorders.

Hemorheological changes during experimental acute pancreatitis in male and female rats

Hemorheological changes during experimental acute pancreatitis in male and female rats

Does tobacco stimulate proliferation and migration of pancreatic stellate cells (PSC)?

Introduction: Although microcirculatory disturbances play pivotal role in the pathomechanism of acute pancreatitis (AP), very few papers can be found in which any of hemorheological parameters had been tested. The aim of our study was to analyze the hemorheological changes in cerulein-induced experimental acute pancreatitis in rat in two doses (5 and 10 mg/kg, s.c.), aiming to analyze the possible gender difference in hemorheological response, too. Methods: Male and female rats were subjected to Control group, or AP with 5 or 10 mg/kg cerulein groups. Blood samplings (lateral caudal vein) were completed before cerulein administration, and 1, 2 and 24 hours later. Hematological parameters, amylase activity, erythrocyte deformability (ektacytometry) and aggregation (light-transmission method) were tested.

Effects of Carbogen on Cochlear Blood Flow and Hearing Function Following Acute Acoustic Trauma in Guinea Pigs

Disturbances of microcirculation and hemorheological changes in the inner ear are the results of noise-induced hearing loss (NIHL). Both the disturbances of microcirculation and hemorheological changes are the etiologies of NIHL development, but they are also the results. Although previous reports that inhalation of high concentration of CO(2) may increase cochlear blood flow (CoBF), the effects of carbogen on the cochlear microcirculation and NIHL remain unclear. Changes induced by noise, carbogen and pure oxygen within the cochlear lateral wall microvasculature and in hearing thresholds were observed in guinea pigs using intravital microscopy and the auditory brainstem response. At the same time, arterial oxygen saturation and morphologic changes of cochlear hair cells were observed. Carbogen inhalation increased vessel diameters and blood flow velocities. Hearing thresholds elevation in the carbogen group was smaller than those in the control and oxygen group (p <0.05). Carbogen inhalation produced a trend toward less threshold shift after noise exposure, which reached statistical significance after day 3 (p <0.01). Respiratory acidosis was not found in our study. The segmented basal membranes of Corti in three groups indicated that no losses or discorders of hair cells were found. Carbogen inhalation can preserve hearing in animal models after acute acoustic trauma.

Peripheral vascular response to inspiratory breath hold in paediatric homozygous sickle cell disease

New Findings• What is the central question of this study?Autonomic nervous dysfunction is implicated in complications of sickle cell anaemia (SCA). In healthy adults, a deep inspiratory breath hold (IBH) elicits rapid transient SNS- mediated vasoconstriction detectable using Laser Doppler Flux (LDF) assessment of the finger-tip cutaneous micovasculature.• What is the main finding and its importance?We demonstrate significantly increased resting peripheral blood flow and sympathetic activity in African children with SCA compared to sibling controls and increased sympathetic stimulation in response to vasoprovocation with DIG.This study is the first to observe an inverse association between resting peripheral blood flow and haemoglobin oxygen saturation (SpO2). These phenomena may be an adaptive response to the hypoxic exposure in SCA.There is increasing evidence that autonomic dysfunction in adults with homozygous sickle cell (haemoglobin SS) disease is associated with enhanced autonomic nervous system-mediated control of microvascular perfusion. However, it is unclear whether such differences are detectable in children with SS disease. We studied 65 children with SS disease [38 boys; median age 7.2 (interquartile range 5.1–10.6) years] and 20 control children without symptoms of SS disease [8 boys; 8.7 (5.5–10.8) years] and recorded mean arterial blood pressure (ABP) and daytime haemoglobin oxygen saturation (). Cutaneous blood flux at rest (RBF) and during the sympathetically activated vasoconstrictor response to inspiratory breath hold (IBH) were measured in the finger pulp of the non-dominant hand using laser Doppler fluximetry. Local factors mediating flow motion were assessed by power spectral density analysis of the oscillatory components of the laser Doppler signal. The RBF measured across the two study groups was negatively associated with age (r=−0.25, P < 0.0001), ABP (r=−0.27, P= 0.02) and daytime (r=−0.30, P= 0.005). Children with SS disease had a higher RBF (P= 0.005) and enhanced vasoconstrictor response to IBH (P= 0.002) compared with control children. In children with SS disease, higher RBF was associated with an increase in the sympathetic interval (r=−0.28, P= 0.022). The SS disease status, daytime and age explained 22% of the variance in vasoconstrictor response to IBH (P < 0.0001). Our findings suggest that blood flow and blood flow responses in the skin of young African children with SS disease differ from those of healthy control children, with increased resting peripheral blood flow and increased sympathetic stimulation from a young age in SS disease. They further suggest that the laser Doppler flowmetry technique with inspiratory breath hold manoeuvre appears to be robust for use in young children with SS disease, to explore interactions between , ABP and autonomic function with clinical complications, e.g. skin ulceration.

The Study of Interference with Ruyanneixiao Cream on Hemorheology and Mammary Microcirculation of Mammary Precancer Rats

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&lt;0.05) and the perfusion of mammary microcirculation was lower (P&lt;0.01). Compared with mammary precancer model group, the hemorheological parameters and perfusion of mammary microcirculation of each dose group of Ruyanneixiao cream were improved (P&lt;0.05). Conclusion: Ruyanneixiao cream can improve the status of hemorheology, increase the perfusion of mammary microcirculation. And it may be one of mechanism to treat and prevent mammary precancer disease.

Hemorheological consequences of hind limb ischemia-reperfusion differs in normal and gonadectomized male and female rats

It is known that hemorheological parameters show gender differences that might be altered by gonadectomy (GoE). Since micro-rheological parameters (erythrocyte deformability and aggregation) sensitively change during and after ischemia-reperfusion (I/R), the question arises whether the hemorheological effects of I/R may show gender differences and further changes might be expected when GoE and I/R are additive. Sprague-Dawley rats were divided into six groups: Control males and females, I/R males and females with 1-hour hind limb ischemia, GoE + I//R males and females when 3 months after bilateral gonadectomy the I/R was induced. Before and just after ischemia, and on the 1st-3rd-5th-7th postoperative days blood samples were taken (lateral tail vein, 0.3-0.5 mL) for analyzing hematological parameters, erythrocyte's deformability (slit-flow ektacytometer) and aggregation (light-transmission aggregometer). Leukocyte and platelet counts raised markedly in gonadectomized animals during the investigated days. Hemorheological changes of I/R showed gender differences: significant impairment of erythrocyte deformability was found on the 1st-3rd postoperative days, expressed mostly in females. In gonadectomized females the postischemic deformability values were impaired. Erythrocyte aggregation index significantly raised by the 1st postoperative day, dominantly in males. It is suggested that gonadectomy may act as an additional rheological 'risk factor' related to blood micro-rheological parameters in ischemia-reperfusion.

Micro-rheological changes during experimental acute pancreatitis in the rat

Although microcirculatory disturbances play pivotal role in the pathomechanism of acute pancreatitis (AP), very few papers can be found which had been tested any of hemorheological parameters. The aim of our study was to analyze the hemorheological changes in cerulein-induced experimental acute pancreatitis in rat in two doses (5 and 10 μg/kg, s.c.). Male and female rats were subjected to Control group, or AP with 5 or 10 μg/kg cerulein groups. Blood samplings (lateral caudal vein) were completed before cerulein administration, and 1, 2 and 24 hours later. Hematological parameters, amylase activity, erythrocyte deformability (ektacytometry) and aggregation (light-transmission method) were tested. The presence of AP could be confirmed by amylase testing and histological examination. The earliest impairment of the red blood cell deformability could be observed 1 hour after cerulein administration in 10 μg/kg dosage. Female animals had the worst rheological results with high mortality. In conclusion, subcutaneously administrated cerulein in dosage of 5 and 10 μg/kg resulted in AP in rats, with significant changes in red blood cell deformability and alterations in erythrocyte aggregation. This model seems to be suitable for further comparative studies.

The effects of chronic long-term intermittent hypobaric hypoxia on blood rheology parameters

The effect of chronic long-term intermittent hypobaric hypoxia (CLTIHH) on blood rheology is not completely investigated. We designed this study to determine the effect of CLTIHH on blood rheology parameters. Present study was performed in 16 male Spraque-Dawley rats that divided into CLTIHH and Control groups. To obtain CLTIHH, rats were placed in a hypobaric chamber (430 mmHg; 5 hours/day, 5 days/week, 5 weeks). The control rats stayed in the same environment as the CLTIHH rats but they breathed room air. In the blood samples aspirated from the heart, hematocrit, whole blood viscosity, plasma viscosity, plasma fibrinogen concentration, erythrocyte rigidity index and oxygen delivery index were determined. The whole blood viscosity, plasma viscosity, hematocrit and fibrinogen concentration values in the CLTIHH group were found to be higher than those of the control group. However, no significant difference was found in erythrocyte rigidity index and oxygen delivery index between the groups. Our results suggested that CLTIHH elevated whole blood viscosity by increasing plasma viscosity, fibrinogen concentration and hematocrit value without effecting the erythrocyte deformability. Hence, CLTIHH that may occur in intermittent high altitude exposure and some severe obstructive sleep apnea (OSA) patients may be responsible for hemorheologic changes in those subjects.

Cardioprotection by resveratrol: A human clinical trial in patients with stable coronary artery disease

Several beneficial effects of resveratrol (RES), a natural antioxidant present in red wine have already been described. The aim of our study was to investigate if RES had a clinically measurable cardioprotective effect in patients after myocardial infarction. In this double-blind, placebo controlled trial 40 post-infarction Caucasian patients were randomized into two groups. One group received 10 mg RES capsule daily for 3 months. Systolic and diastolic left ventricular function, flow-mediated vasodilation (FMD), several laboratory and hemorheological parameters were measured before and after the treatment. Left ventricular ejection fraction showed an increasing tendency (ns) by RES treatment. However, left ventricular diastolic function was improved significantly (p < 0.01) by RES. A significant improvement in endothelial function measured by FMD was also observed (p < 0.05). Low-density lipoprotein (LDL) level significantly decreased (p < 0.05) in the RES treated group. Red blood cell deformability decreased and platelet aggregation increased significantly in the placebo group (p < 0.05), while resveratrol treatment has prevented these unfavourable changes. Concerning other measured parameters no significant changes were observed neither in placebo nor in RES group. Our results show that resveratrol improved left ventricle diastolic function, endothelial function, lowered LDL-cholesterol level and protected against unfavourable hemorheological changes measured in patients with coronary artery disease (CAD).

Following-up hemorheological consequences of gonadectomy in male and female rats

Growing number of clinical and experimental data reflect to the gender differences of hemorheological parameters. However, little is known about the potential hemorheological effect of gonadectomy and consequent changes in sex hormone concentration. Adult, same-aged male and female rats were involved in the study. In control male and female group no surgical intervention was performed. In gonadectomized (GoE) male and female groups bilateral orchidectomy or ovariectomy were completed. Body weight measurement and blood sampling were carried out in the 1st, 2nd and 3rd postoperative months. The GoE females had significant bodyweight augmentation and their plasma estrogen concentration decreased by 40-45% by the 1st postoperative month, while in males the testosterone level was not detectable after gonadectomy. Leukocyte and platelet counts moderately increased in GoE males. Elongation index values of erythrocytes slightly decreased in both genders after gonadectomy, showing converging values. Erythrocyte aggregation index values of GoE females significantly raised by the 2nd month. It can be concluded that gonadectomy in rats resulted in alteration (dominantly impairment) of blood microrheological parameters, by different manner in males and females. Supposedly decrease in estrogen can cause more expressed hemorheological changes than the cessation of testosterone.

In Patients with Sickle Cell Disease on Chronic Transfusion Therapy, Viscosity and Aggregation Are Increased After a Single Transfusion, Negatively Affecting Low Shear Rate Blood Flow

Abstract 1259The ability for hemoglobin S to polymerize causes increased viscosity, decreased RBC deformability and increased RBC aggregation. Chronic transfusion therapy (CTT) in patients with sickle cell disease (SCD) decreases the percentage of hemoglobin S in the bloodstream. The hematocrit to viscosity ratio (HVR) has been used to estimate red cell oxygen transport effectiveness, a property of blood flow. There are undeniable benefits from CTT, however, there are patients on CTT who still suffer from acute crises. Acute hemorheologic changes after transfusion might contribute to these episodes. We hypothesize that viscosity and aggregation will increase post transfusion. Furthermore, we believe that these changes will result in lower oxygen transport effectiveness as measured by HVR.To test this hypothesis we enrolled 26 patients on chronic transfusion therapy in a prospective study to evaluate blood viscosity and aggregation changes with transfusion. We measured both oxygenated and deoxygenated whole blood viscosity at shear rates from 1s−1 to 1000s−1 and RBC aggregation at native hematocrit using a Rheolog viscometer (Rheologics Co). We also obtained pre and post transfusion blood counts, chemistry panels and markers of inflammation and hemolysis.14 females and 12 males were enrolled with one patient who was excluded due to incomplete data. The ages and reasons for starting transfusion were similar for male and female patients. As expected, transfusion resulted in significant increases of hemoglobin and hematocrit with a concomitant decrease of percent hemoglobin S and reticulocyte count. There was a trend toward decreased platelet count. Male patients had a significantly higher percent hemoglobin S, reticulocyte count, plasma free hemoglobin and platelet count compared to females. Viscosity increased significantly across all shear rates with transfusion and with deoxygenation. There was no sex difference in viscosity. Deoxygenation and transfusion increased the aggregation index. Change in viscosity positively correlated with increased hematocrit and aggregation index. There was no correlation of viscosity change with change in hemoglobin S, markers of inflammation or hemolysis.Deoxygenation lowered HVR at all shear rates. HVR was significantly lower post transfusion at low shear rates of 1s−1, 2s−1 and 5s−1 (Figure 1). At mid to high shear rates there was no difference in HVR, although as the shear rate increased, the HVR curves crossed with apparently increasing improvement in HVR post transfusion at the highest shear rates. The significant decrease in HVR at low shear correlated with increased aggregation index but not increased hematocrit.In this population of patients on CTT, blood viscosity and RBC aggregation increased post transfusion, thus predisposing them to impaired perfusion in low flow vascular beds. The decrease in HVR at low shear rates correlated with RBC aggregation, providing further evidence for post-transfusion risk of impaired perfusion. These results support our hypothesis and indicate potential adverse effects of transfusion on microvascular blood flow. [Display omitted] Disclosures:Wood:Novartis: Research Funding; Ferrokin Biosciences: Consultancy; Cooleys Anemia Foundation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Sanqi-Tongshu capsule's effect on hemodynamics in patients with acute cerebral infarction

Objective To observe the effects of Sanqi-Tongshu capsule on the hemodynamics in patients with acute cerebral infarction (blood rheology, blood lipids), and to explore the clinical efficacy.Methods 60 patients diagnosed of cerebral infarction by clinical and CT scan were randomized into a contrast group and a treatment group, with 30 patients in each group. The contrast group was treated with conventional western medicine the treatment group was treated with Sanqi-Tongshu capsule based on the contrast group. Hemorheology and blood lipid changes were observed before and after treatment. Results After the treatment,the treatment group's blood rheology [high shear whole blood (3.89±0.16) mpa·s, low-shear whole blood (8.12±0.06) mpa·s, erythrocyte aggregation index (1.164±0.24), erythrocyte rigidity index (3.53±0.40) ] and blood lipids [cholesterol (5.84± 0.92) mmol/L, triglycerides (1.54± 0.23) mmmmol/L, low-density lipoprotein (2.12 ± 0.54) mmol/L] showed statistical significance(all P＜0.05)compared with the contrast group.Conclusion Sanqi-Tongshu capsule can effectively improve the blood theology and lipid metabolism It is an effective drug for the treatment of acute cerebral infarction. Key words: Sanqi-Tongshucapsule; Infarction; Rheology; Lipids

In vivo photoacoustic and photothermal cytometry for monitoring multiple blood rheology parameters

Alterations of blood rheology (hemorheology) are important for the early diagnosis, prognosis, and prevention of many diseases, including myocardial infarction, stroke, sickle cell anemia, thromboembolism, trauma, inflammation, and malignancy. However, real-time in vivo assessment of multiple hemorheological parameters over long periods of time has not been reported. Here, we review the capabilities of label-free photoacoustic (PA) and photothermal (PT) flow cytometry for dynamic monitoring of hemorhelogical parameters in vivo which we refer to as photoacoustic and photothermal blood rheology. Using phenomenological models, we analyze correlations between both PT and PA signal characteristics in the dynamic modes and following determinants of blood rheology: red blood cell (RBC) aggregation, deformability, shape (e.g., as in sickle cells), intracellular hemoglobin distribution, individual cell velocity, hematocrit, and likely shear rate. We present ex vivo and in vivo experimental verifications involving high-speed PT imaging of RBCs, identification of sickle cells in a mouse model of human sickle cell disease and in vivo monitoring of complex hemorheological changes (e.g., RBC deformability, hematocrit and RBC aggregation). The multi-parameter platform that integrates PT, PA, and conventional optical techniques has potential for translation to clinical applications using safe, portable, laser-based medical devices for point-of-care screening of disease progression and therapy efficiency.

Mild haemorheological changes induced by a moderate endurance exercise in patients with sickle cell anaemia

The levels and duration of physical activity that can be considered as completely safe in patients with sickle cell anaemia (SCA) is unknown. The present study compared the haemorheological and haematological profile, cell density distribution and basic biochemistry between a group of 17 patients with SCA and 21 healthy subjects before and after a 20 min duration submaximal cycling exercise at the same absolute workload. Blood was sampled at rest and 3 min after the end of exercise for measurement of biological parameters. Exercise did not affect the haematocrit and blood viscosity in the two groups. Plasma viscosity was not different between the two groups at rest and similarly increased with exercise. The proportion of intermediary dense cells (with density between 1·11 and 1·12 g/ml) decreased with exercise in the SCA group resulting in an increase in the proportion of red blood cells with a density >1·12 g/ml. No change was observed in the control group. The present study suggests that mild-moderate exercise is not very harmful for SCA patients. The haemorheological and haematological changes were very mild, except for the formation of dense cells but no clinically significant signs of medical complication were present in any of the patients.

Hemorheological changes and their clinical relevance in preeclampsia

This review summarizes the hemorheological changes during gestation and their clinical relevance in pre-eclampsia. The gestational disease named pre-eclampsia, characterized by proteinuria (more than 0.3 g/day) and hypertension (blood pressure above 140/90 mmHg), exists from the 20th gestational week until the sixth postpartum week. Its etiology is complex; the pathomechanism mainly involves disturbances in cross talks among the vegetative system, the placenta and the circulatory system. Soluble factors of placenta mediate circulatory changes, which result in adaptive responses in both vegetative and circulatory systems. Derailment of this adaption, however, leads to increased turbulence and local damages in cellular elements of the circulatory system. The initial local lesion progresses to a generalized form. Later, these events will continue to strengthen their own cycle. As a result, an unstable circulatory state will be established, which causes organ damages.

Hemorheological changes in patients with living-donor renal transplantation

Living-donor renal transplantation is the preferred treatment for patients with end stage renal disease since it affords earlier transplantation and better graft for long term survival. The aim of the present study was to explore the hemorheological changes in patients undergone living-donor renal transplantation. We investigated the dynamic changes in the hemorheological properties of blood taken from the patients before renal transplantation and at 1 week, 2 week, 3 week and >1 month after the operation. As compared with pre-operation, the whole blood viscosity at different shear rates decreased significantly; the erythrocyte aggregation index decreased; the erythrocyte deformation index (DI) and integrated deformation index (IDI) had a remarkable improvement; the erythrocyte electrophoresis rate was raised. We also found that the osmotic fragility of RBCs at 145 mOsm/kg was greatly decreased after renal transplantation. Importantly, the ratio of erythrocyte membrane protein 4.1 a to 4.1 b decreased, which may explain the changes in DI, IDI, and osmotic fragility. Our results suggest that these hemorheological changes may greatly improve the organ microcirculation, which would play a critical role in reduce the ischemia-reperfusion injury in the graft.

Macro- and microrheological parameters of blood in patients with cerebral and peripheral atherosclerosis: The molecular change mechanisms after pentoxifylline treatment

This study was designed to evaluate hemorheological changes in patients with cerebrovascular disease (CVD) and peripheral arterial disease (PAD) after 4 weeks of pentoxifylline therapy as well as to study red blood cell microrheological variables after the cell incubation with pentoxifylline and some phosphodiesterase (PDE) activity inhibitors. The patients with CVD (n = 50) and PAD (n = 33) were treated with pentoxifylline (400 mg, thrice a day) for 4 weeks. Before and after drug therapy the hemorheological measurements including plasma and whole blood viscosity, red blood cell aggregation (RBCA) and deformability (RBCD) were completed. In vitro study RBCs were incubated with: 1) Vinpocetine--inhibitor PDE-1, 10 μM; 2) Rolipram--PDE-4, 10 μM; 3) Isobutyl-methylxanthine (IBMX)--nonselective PDE inhibitor, 100 μM and with pentoxifylline, 10 μM The cell incubation was performed at 37 °C for 15 min. There were the positive changes of hemorheological profile after 4 weeks of the pentoxifylline therapy both in CVD and PAD patients. The marked RBCD changes were observed after the in vitro cell pentoxifylline treatment as well. Perhaps it is connected with the inhibition of the phosphodiesterase activity in RBCs. An application of drugs and chemicals that can inhibit the PDE activity resulted in RBCD rise and RBCA decrease. The experiments with the use of selective PDE inhibitors have revealed the similar red cell deformability changes. Vinpocetine increased RBCD significantly (p < 0.05). PDE-4 inhibitor--Rolipram stimulated RBCD by 15% (p < 0.05). Some more effective was IBMX. After cell incubation with it a significant rise of the deformability (by 27%; p < 0.05) was found. All drugs, having PDE activity decreased RBCA, but the most pronounced effect had Vinpocetine (50%; p < 0.05). Thus, administered pentoxifylline, daily (1200 mg), during four weeks improves hemorheological profile and especially its microrheological part as well as the blood transport capacity in subjects with cerebral and peripheral vascular disorders. It is most probably red cell microrheological control mechanisms may be associated with the phosphodiesterase activity alterations.

Endurance running trial in tropical environment: A blood rheological study

The aim of this study was to clarify whether exercising in a tropical climate induces blood rheology alterations despite ad libitum hydration. Hematological, biochemical and hemorheological changes were investigated in young healthy adults (N = 9 men, 20.7 ± 0.8 yrs) after a 10-km race in hot and humid conditions. Subjects' maximal aerobic abilities were tested using a maximal ramp exercise. Blood was sampled at rest (TR), at the end of the race (TEx), and after 24 hours of recovery (T24). Ad libitum hydration was allowed during the race. Blood viscosity (ηb), red blood cell deformability (EI), aggregation (AI) and disaggregation shear rate (γ) were measured. Hematocrit, hemoglobin and plasma concentration of chlorine, sodium and potassium did not change in response to exercise. No functional consequence was observed on RBC deformability since EI remained unchanged. Percentages of echinocytes, schizocytes and stomatocytes remained in the subclinical range at all times. AI, γ and ηb did not present change. Running exercise in tropical climate with ad libitum hydration does not alter the main rheological properties of blood.

Hemorheological changes with strontium ranelate treatment do not seem to be related to its claimed prothrombotic effects

Strontium ranelate is claimed to be related with increased risk of thromboembolic events. No explanation of this increased incidence of thromboembolism has been identified. However, growing evidence has clearly demonstrated the involvement of blood rheology in any thrombotic process. The aim of this study was to assess hemorheological changes with strontium ranelate treatment in elderly women with osteoporosis. This study was designed in a prospective manner. Twenty-two elderly women diagnosed with osteoporosis were included. During a 2-month treatment period, participants received strontium ranelate 2 g/day. Hemorheological parameters including erythrocyte deformability, erythrocyte aggregation and plasma viscosity were measured before and after 2 months therapy with strontium ranelate. The median age of the patients was 70.0 (range = 65–80) years. After 60 days of treatment, there was no statistically significant change in hemorheological parameters. None of the subjects developed clinical venous thromboembolic event (VTE) during the 2-month period of strontium ranelate treatment. Our study demonstrated that in elderly women, treatment of osteoporosis with strontium ranelate did not change hemorheological parameters over 2 months of time. However, its long-term effects on hemorheologic parameters should be evaluated further with a larger sample.