Clinical Hemorheology and Microcirculation - Volume 59, issue 1

Authors: Soliman, Amr A. | Csorba, Roland | Yilmaz, Asli | Tsikoaras, Panagioti | von Tempelhoff, Georg-Friedrich

Article Type: Research Article

Abstract: Previous study have shown an association between failure of physiological hemodilution during 2nd trimester and an increased risk for the development of subsequent pregnancy complications such as early birth, birth of a growth retarded newborn (IUGR), low fetal birth weight and preeclampsia. The latter complication in particular goes along with dramatic changes in the placental perfusion as well as systemic maternal blood flow. Severity of preeclampsia may be preceded by distinct impaired hemodilution and reflected by the results of rheological parameters. A subgroup analysis was performed in a community based retrospective study of 4,985 consecutively recorded singleton pregnant women of …whom 423 had preeclampsia. Mean 2nd trimester hemoglobin levels and blood rheological results at the time of delivery were assessed and compared in women with moderate and severe preeclampsia. Mean 2nd trimester hemoglobin levels were calculated from the maternal records. Rheological variables included plasma viscosity (KSPV 1 Fresenius) and Red blood cell aggregation in stasis and under low shear conditions (MA1-Aggregometer; Myrenne). According to the definition of the German Society of Gynecology and Obstetrics (DGGG) 314 women had moderate preeclampsia (74.2%), while 109 had severe preeclampsia due to the presence of a blood pressure >170/110 mmHg (n = 41; 9.7%), and/or IUGR <5th percentile (n = 28; 6.6%), and/or HELLP-Syndrome (n = 10; 2.4%), and/or proteinuria ≥5 g/24 h (n = 30; 7.1%). Age, BMI, smoking, and maternal weight were comparable in the groups, while gestational age at delivery as well as fetal outcome parameter were statistically significant unfavourable in patients with severe preeclampsia. Mean 2nd trimester hemoglobin level were statistically significantly higher in women who developed severe vs. moderate preeclampsia (m = 12.75 ± 0.99 g/dL vs. m = 12.50 ± 1.05 g/dL; p = 0.033). However, in the ROC calculations a hemoglobin value of 12.05 g/dL revealed best sensitivity (78%) and specificity (33.8%) in women with subsequent diagnosis of severe preeclampsia, whereas sensitivity was 100% for a value >10.95 g/dL. There were no statistically significant differences for none of the rheological parameters at the time of delivery between groups of patient with moderate v.s severe preeclampsia. Severe preeclampsia and IUGR, however, was associated with statistically significantly higher RBC aggregation as compared to patients with moderate preeclampsia. Plasma viscosity was statistically significantly (p < 0.05) correlated with Fibrinogen values (r = 0.16), leukocyte-(r = 0.11) and platelets-count (r = 0.127), and hemoglobin/hematocrit values in particular (r = 0.23/0.26). Although mean 2nd trimester hemoglobin concentration are higher in patients with subsequent development of severe preeclampsia, due to the low sensitivity and specificity of this parameter clinical use for identifying women at risk is of limited value. On the other hand, a hemoglobin value below 11.0 g/dL excluded the risk for severe preeclampsia to 100%. Blood rheological parameters at the time of delivery in the absence of IUGR are not markedly influenced by severity of preeclampsia. Show more

Keywords: Blood fluidity, haemostasis, pregnancy, preeclampsia

DOI: 10.3233/CH-2012-1625

Citation: Clinical Hemorheology and Microcirculation, vol. 59, no. 1, pp. 1-15, 2015

Authors: Sinnapah, Stéphane | Cadelis, Gilbert | Waltz, Xavier | Lamarre, Yann | Connes, Philippe

Article Type: Research Article

Abstract: Sleep apnea patients and obese subjects are overexposed to cardiovascular diseases. These two health conditions may be associated with hemorheological alterations which could increase the cardiovascular risk. The present study investigated the hemorheological characteristics in patients with overweight and/or sleep apnea to identify the main predictor of red blood cell (RBC) abnormalities in sleep apnea patients. Ninety-seven patients were subjected to one night sleep polygraphy to determine their sleep apnea status. Body mass index (BMI) and the apnea/hypopnea index (AHI) were determined for categorization of obesity and sleep apnea status. Blood was sampled for hematocrit, blood viscosity, RBC deformability, aggregation …and disaggregation threshold measurements. BMI and AHI were positively associated and were both positively associated with RBC aggregation. Analyses of covariance and multiple regression analyses revealed that BMI was more predictive of RBC aggregation than AHI. No association of BMI classes and AHI classes with RBC deformability or blood viscosity was observed. This study shows that increased RBC aggregation in sleep apnea patients is caused by overweight. Therapies to improve blood rheology in sleep apnea patients, and therefore reduce the risk for cardiovascular disorders, should focus on weight-loss. Show more

Keywords: Sleep apnea, obesity, blood rheology, apnea hypopnea index, body mass index, red blood cell aggregation

DOI: 10.3233/CH-121655

Citation: Clinical Hemorheology and Microcirculation, vol. 59, no. 1, pp. 17-26, 2015

Authors: Lo Presti, R. | Canino, B. | Cilluffo, P. | Calandrino, V. | Hopps, E. | Caimi, G.

Article Type: Research Article

Abstract: Physical exercise influences the body's oxidative status. The modifications can involve lipids, proteins and nucleic acids, and different effects seem to be induced by regular and acute exercise respectively. We examined protein oxidation, expressed as concentration of protein carbonyl groups (PC), in trained subjects before (time 0), 10 min (time 1) and 24 hours (time 2) after a cardiopulmonary test performed on a cycloergometer. We enrolled 38 trained subjects (26 men and 12 women), subdivided in two groups (A1 and B1) of 19 subjects each, according to the median value of VO2 max, and in two groups (A2 and B2) …of 19 subjects each, according to the median value of PC at baseline. PC concentration was measured by an enzyme-linked immunosorbent assay (ELISA). The groups A1 and B1 did not differ from each other as regards the basal PC level and groups A2 and B2 were not different as regards the VO2 max. At time 1 PC showed a significant increase in comparison with baseline in trained subjects as a whole group, as well as in each subgroup. At time 2, PC were decreased in comparison with both times 0 and 1 in the whole group and in subgroups A1 and B2, whereas in subgroups A2 and B1 the PC value at time 2 was not different compared to time 0. The percentage increase of PC at time 1 vs time 0, as well as the percentage decrease at time 2 vs time 1 and time 0 respectively, were not different between subgroups A1 and B1. On the contrary, the percentage variations observed at each interval were significantly different between subgroups A2 and B2. The results suggest a reaction of antioxidant systems to acute exercise in trained subjects, influenced by basal PC levels more than by aerobic fitness. Show more

DOI: 10.3233/CH-131721

Citation: Clinical Hemorheology and Microcirculation, vol. 59, no. 1, pp. 27-35, 2015

Authors: Waltz, Xavier | Hardy-Dessources, Marie-Dominique | Lemonne, Nathalie | Mougenel, Danièle | Lalanne-Mistrih, Marie-Laure | Lamarre, Yann | Tarer, Vanessa | Tressières, Benoit | Etienne-Julan, Maryse | Hue, Olivier | Connes, Philippe

Article Type: Research Article

Abstract: The hematocrit-to-viscosity ratio (HVR) has been widely used has an estimate of red blood cell (RBC) oxygen transport effectiveness into the microvasculature or as an oxygen delivery index. However, no study investigated the possibility of HVR to truly reflect RBC oxygen transport effectiveness or to be an oxygen delivery index. We measured blood viscosity at high shear rate (225 s−1 ), hematocrit, HVR, as well as the microvascular oxyhemoglobin saturation (TOI; tissue oxygen index) by spatial resolved near-infrared spectroscopy (NIRS) at cerebral and muscle levels in three population known to have various degrees of hemorheological abnormalities: healthy subjects (AA), patients …with sickle cell SC disease (SC) characterized by moderate anemia and patients with sickle cell anemia (SS) marked by severe anemia. At both the cerebral and muscle level, HVR was positively correlated with TOI (r = 0.28; p = 0.03 and r = 0.38; p = 0.003, at the cerebral and muscle level, respectively). These findings suggest that HVR probably play a key role in blood flow and hemodynamic regulation in the microvasculature, hence modulating the amount of oxygen available for tissues. Nevertheless, the strengths of the associations are weak (R2 < 0.50), suggesting that other determinants modulate microvascular blood flow and oxygenation, such as vascular geometry and vasomotor reserve. Show more

Keywords: Microvascular oxygenation, sickle cell syndromes, hemorheology

DOI: 10.3233/CH-131742

Citation: Clinical Hemorheology and Microcirculation, vol. 59, no. 1, pp. 37-43, 2015

Authors: Canino, Baldassare | Hopps, Eugenia | Calandrino, Vincenzo | Montana, Maria | Lo Presti, Rosalia | Caimi, Gregorio

Article Type: Research Article

Abstract: Our aim was to evaluate nitric oxide metabolites (nitrite and nitrate), expressed as NOx, and erythrocyte deformability, expressed as elongation index, in a group of subjects with obstructive sleep apnea syndrome (OSAS). We enrolled 48 subjects (36 men and 12 women; mean age 50.3 ± 14.68 yrs) with OSAS diagnosed after a 1-night cardiorespiratory sleep study. OSAS severity was assessed evaluating the apnea/hypopnea index (AHI) and subjects were subdivided in two subgroups: Low (L = AHI <30) and High (H = AHI >30). NOx was examined converting nitrate into nitrite with a nitrate reductase and then assessing nitrite with spectrophotometry …after the addition of Griess reagent. The elongation index was obtained using the diffractometer Rheodyn SSD of Myrenne at shear stresses of 30 and 60 Pa and it was expressed as elongation index (EI). We found no difference in NOx among the entire group of OSAS subjects and normal controls, while we observed a NOx decrease in the H subgroup in comparison with L subgroup, but not in comparison with normal controls. We noted a significant decrease in EI at each shear stress in the entire group and also in the two subgroups in comparison with controls. The decrease in NO bioavailability and in erythrocyte deformability might contribute to explain the increased cardiovascular risk in OSAS subjects. Show more

Keywords: Nitric oxide metabolites, erythrocyte deformability, OSAS

DOI: 10.3233/CH-141815

Citation: Clinical Hemorheology and Microcirculation, vol. 59, no. 1, pp. 45-52, 2015

Authors: Gayda, Mathieu | Juneau, Martin | Tardif, Jean-Claude | Harel, François | Levesque, Sylvie | Nigam, Anil

Article Type: Research Article

Abstract: We studied the relationship between cardiovascular status (CV) and risk factor numbers, macrovascular (flow mediated dilatation: FMD) and microvascular function using near-infrared spectroscopy (NIRS) in adults with different CV status. Seventy adults with different CV status (27 controls, 18 metabolic syndrome (MetS) and 25 coronary heart disease (CHD) patients) underwent a 5-min forearm arterial occlusion in supine position. High-resolution ultrasound examination of the brachial artery was performed during 1 minute at rest and 45 to 120 seconds after cuff release. Oxy, de-oxy and total hemoglobin signals (O2 Hb, HHb and tHb) were measured continuously with NIRS on brachio-radialis muscle. FMD …was reduced in CHD patients (P < 0.05) compared to controls. Max. amplitude of O2 Hb and Hmax of tHb were reduced (P < 0.05) in MetS patients vs. controls. Post-deflation area under the curve (A.U.C) of O2 Hb was lower in CHD (P < 0.01) patients vs. controls and MetS patients. Independent predictors of microvascular function (A.U.C of O2 Hb) were abdominal obesity and LDL-cholesterol whereas macrovascular function (FMD) was predicted by CV status. Only A.U.C of O2 Hb related to CV risk numbers whereas FMD was not. Although macro and microvascular function were impaired in MetS and CHD patients, microvascular function was more strongly related to CV risk factors. Show more

Keywords: Macrovascular function, microvascular reactivity, cardiovascular risk factors

DOI: 10.3233/CH-141816

Citation: Clinical Hemorheology and Microcirculation, vol. 59, no. 1, pp. 53-65, 2015

Authors: Karmakar, Tanusri | Mallick, Sanjaya K. | Chakraborty, Arpita | Maiti, Animesh | Chowdhury, Subhankar | Bhattacharyya, Maitree

Article Type: Research Article

Abstract: Platelet signatures indicating differential dysfunction, hyperactivation, aggregation or adhesion are capable of expressing their characters during the journey of a disease process, and can be utilized as cost effective biomarkers with immense clinical value. Type 2 diabetes mellitus (T2DM) is a major lifestyle disease of contemporary world with progression to diabetes associated cardiovascular diseases (DM-CVD). We identified a few potential biomarkers in platelets of T2DM to analyze the thrombotic risk in diabetes subjects by utilizing flow cytometric quantification with different flurochrome conjugated monoclonal antibodies. Our study describes interesting correlations (p < 0.0001) for different clinical parameters of concurrent threat for …vessel occlusion and the status of indices like reactive oxygen species, von Willebrand factor and mitochondrial membrane potential using western blotting and fluorescence techniques. Our study involved 32 T2DM, and 31 T2DM - CVD subjects compared to 29 healthy controls without any history of T2DM or CVD. An altered expression of platelet surface markers P-selectin (CD62p) and GpIIb/IIIa (CD 41/61, PAC1) along with changes in the platelet size due to agonist induced activation contributed to the enhanced thrombotic potential in the patients. This work elucidates the prospect of platelet biomarkers as diagnostic tool to predict cardiovascular risk in DM subjects. Show more

Keywords: Platelets, ROS, mitochondrial membrane potential, flow cytometry, surface markers, vWF

DOI: 10.3233/CH-141818

Citation: Clinical Hemorheology and Microcirculation, vol. 59, no. 1, pp. 67-81, 2015

Authors: Hodges, Gary J. | Nawaz, Shah | Tew, Garry A.

Article Type: Research Article

Abstract: Peripheral arterial disease (PAD) is associated with cutaneous microvascular dysfunction and an increased risk of arterial ulceration in the affected lower-limb(s). The purpose of this study was to investigate the role of nitric oxide (NO) in cutaneous microvascular dysfunction in patients with PAD. Using laser-Doppler flowmetry, we measured skin blood flow (SkBF) in 5 patients with unilateral symptomatic PAD and 10 age-matched healthy controls at baseline and during 40 min of local skin heating to 42°C at 1) untreated lower-leg sites, and 2) lower-leg sites treated with 20 mM N(G)-nitro-L-arginine methyl ester (L-NAME) to inhibit NO synthase activity. SkBF was …expressed as laser-Doppler flux (LDF) and normalized to maximal LDF (%LDF(max)) achieved through localized heating to 44°C and concomitant infusion of 56 mM sodium nitroprusside. Pharmacological agents and control treatments (lactated Ringer's) were administered using intradermal microdialysis. The plateau LDF response to local skin warming at the untreated skin sites was significantly (P < 0.05) lower in the diseased limb of the PAD patients (70.3 ± 13.6 %max) compared to the non-diseased contralateral limb (85.0 ± 10.2 %max) and the response observed for the control participants (89.0 ± 5.2 %max). The NO contribution to the plateau SkBF response tended to be lower in the diseased limb of the PAD patients (45.1 ± 16.4% versus 56.1 ± 10.7% [P = 0.12] and 55.4 ± 11.5% [P = 0.13], respectively). The results suggest that PAD impairs downstream cutaneous microvascular vasodilatory function and that the microvascular dysfunction is probably explained, at least in part, by a reduced NO signal. Show more

Keywords: Laser Doppler flowmetry, skin blood flow, vascular function, vasodilation, ulcer, L-NAME, microvascular dysfunction, claudication, peripheral vascular disease

DOI: 10.3233/CH-141838

Citation: Clinical Hemorheology and Microcirculation, vol. 59, no. 1, pp. 83-95, 2015