Effect of atorvastatin upon platelet activation in hypercholesterolemia, evaluated by flow cytometry

Hyperlipidemia is a well established risk factor for cardiovascular disease and atherothrombotic events, in which platelet activation also plays a significant role. However, very few studies have addressed platelet activation in hypercholesterolemia, the potential effect of lipid lowering drugs upon platelet hyperfunction, and the question of whether changes in the latter are correlated to normalization of plasma lipids. This study used whole blood flow cytometry to assess in vivo and in vitro platelet activation in a group of 33 patients with hypercholesterolemia, and also the ex vivo effect of atorvastatin (20 mg/day) upon such activation. A control group of 40 normolipidemic volunteers matched in terms of age, sex and added risk factors to the patient group was used. The results showed that hypercholesterolemic patients had in vivo a significantly greater percentage of GPIIb/IIIa- and phosphatidylserine-positive platelets compared with the control group (4.62+/-3.51% and 2.58+/-1.19% versus 2.73+/-1.08% and 1.54+/-0.68%, respectively). In vitro response of CD62 expression to thrombin was also greater in the patients than in the controls (92.51+/-6.00% versus 89.63+/-10.72%, p<0.05). Atorvastatin therapy normalized platelet hyperfunction in the patients studied and reduced GPIIb/IIIa response to ADP (from 82.65+/-6.43% to 75.84+/-4.89%, p<0.01). A significant correlation can be seen between such normalization and the decrease in plasma levels of total and LDL cholesterol.

Reliability of the E-test method for detection of colistin resistance in clinical isolates of Acinetobacter baumannii

We compared the E-test to the broth microdilution method for testing the susceptibility of 115 clinical isolates of Acinetobacter baumannii to colistin. Twenty-two (19.1%) strains were resistant to colistin and 93 (80.8%) strains were susceptible according to the reference broth microdilution method. A categorical agreement of 98.2% was found, with only two (1.7%) very major errors. Agreement within 1 twofold dilution between the E-test and the broth microdilution was 16.5%. Complete agreement was found for the strains for which MICs fell within the range of 0.25 to 1 microg of colistin/ml. However, there was poor concordance, particularly in extreme dilutions with higher MICs by the E-test method.

The multifunctional protein C system

The protein C pathway is a major regulator of blood coagulation, since it controls the conversion of prothrombin to thrombin through a feedback inhibition mechanism. Protein C circulates in plasma as an inactive zymogen and is activated on the surface of endothelial cells by the thrombin-thrombomodulin complex, a process that can be further enhanced when protein C binds to its membrane receptor, the endothelial-cell protein C receptor. Activated protein C (APC) is then released from the complex, binds protein S and inhibits thrombin formation by inactivating coagulation factors Va and VIIIa. The importance of the protein C anticoagulant pathway is emphasized by the increased risk of venous thromboembolism (VTE) associated with protein C and protein S deficiencies, the factor V Leiden mutation, and reduced circulating APC levels. The protein C pathway also plays a significant role in inflammatory processes, since it prevents the lethal effects of E. coli-associated sepsis in animal models and improves the outcome of patients with severe sepsis. APC seems to display anti-apoptotic and neuroprotective activities. Thus, it reduces organ damage in animal models of sepsis, ischemic injury, endothelial cell injury, or stroke. Further research will hopefully widen the current therapeutic perspectives in all these illnesses, where these effects might play a crucial role in their treatment. This review will summarize the mechanisms that contribute to these biological activities of the protein C pathway.

Erythrocyte aggregation in Behçet's disease determined with the Sefam and Myrenne aggregometer. Lack of association with thrombosis and uveitis

Behçet's disease (BD) is a chronic systemic vasculitis characterised by recurrent oral and genital ulcers and uveitis, in which 25-30% of patients develop thrombotic events of unknown etiology. In order to ascertain whether erythrocyte aggregation (EA) may be involved in thrombotic events and or uveitis in BD patients, we determined using two erythrocyte aggregometers i.e. Myrenne and Sefam (which provides the total disaggregation threshold, needed for erythrocytes to disaggregate), EA in 77 BD patients (42 male, 35 female, aged 44 +/- 12 years) and 77 controls (41 male, 36 female, aged 43 +/- 11 years). BD patients showed higher EA determined with both aggregometers: Myrenne (EA(0): P = 0.035; EA(1): P < 0.001) or the Sefam (Ta: P < 0.001, AI(10): P < 0.001, gammaD: P = 0.014) as well as higher fibrinogen and triglyceride levels (P < 0.001, P = 0.003, respectively) compared with the control group. However no differences were observed in any of the aggregation parameters determined either with the Myrenne (EA(0), EA(1)) or the Sefam (Ta, AI(10), gammaD) aggregometer when BD patients with thrombotic events (n = 23) or uveitis (n = 21) were compared with those who did not (P > 0.05). These results reinforce previous findings of our group, suggesting that EA does not seem to be involved in thrombotic events or in uveitis in BD patients.

Influence of fibrinogen levels on erythrocyte aggregation determined with the Myrenne aggregometer and the Sefam erythro-aggregometer

Fibrinogen is one of the plasmatic proteins which has a major influence on erythrocyte aggregation. The level of fibrinogen at which erythrocyte aggregation does not further increase is not well established. Therefore we aim to determine erythrocyte aggregation with two devices: Myrenne aggregometer (M0 and M1) and Sefam erythro-aggregometer (Ta, AI10 and gammaD) in relation with fibrinogen levels, in patients with several diseases with fibrinogen levels ranging between 200-1100 mg/dl. With the Myrenne aggregometer a plateau can be observed for fibrinogen levels higher than 400 mg/dl, while with the Sefam erythro-aggregometer, aggregation increases proportionally with fibrinogen levels higher than 400 mg/dl. In addition, for fibrinogen values higher than 400 mg/dl, only statististically significant correlations could be observed between fibrinogen and erythrocyte aggregation parameters with the Sefam erythro-aggregometer: r(Ta)=-0.463; r(AI10)=0.624, r(gammaD)=0.817, p<0.01, but not with the Myrenne: r(M0)=0.01, r(M1)=0.02, ns. Although the Sefam erythro-aggregometer is a better tool for determining erythrocyte aggregation both at low and high fibrinogen levels, the Myrenne aggregometer may be useful for assessing the erythrocyte aggregation as an indicator of cardiovascular risk, as in such circumstances fibrinogen levels do not usually exceed values higher than 400 mg/dl.

Red blood cell deformability in iron deficiency anaemia

In patients with iron deficiency anaemia (IDA) it has been suggested that the shortened erythrocyte lifespan may be in part due to decreased erythrocyte deformability. In order to know whether erythrocyte deformability is decreased in IDA patients, we have determined the erythrocyte Elongation Index (EI) by means of ektacytometric techniques (Rheodyn SSD, Myrenne Gmbh, Germany), in 50 IDA patients and 100 well age and sex matched healthy controls. At the three shear stresses tested, 12, 30 and 60 Pa, IDA patients show statistically lower EI than controls (37.4+/-6.7 vs 48.6+/-2.9; 45.0+/-6.0 vs 54.5+/-2.8; 48.7+/-5.8 vs 57.0+/-2.9 mPa.s, respectively; p<0.001). A statistically significant correlation was found between EI at 12, 30, and 60 Pa and the hematimetric indices (MCV, MCH and MCHC), suggesting that the alteration in surface/volume ratio (shape) which characterizes this kind of microcytic hypocromic anaemia, accounts in part for the decreased EI. Rheodyn SSD, as an ektacytometric technique, is very sensitive to alterations in red blood cell geometry, for what seems to be a useful tool for detecting diminished erythrocyte deformability in IDA patients.

Contribution of polymorphisms in the endothelial protein C receptor gene to soluble endothelial protein C receptor and circulating activated protein C levels, and thrombotic risk

Endothelial cell protein C receptor (EPCR) enhances the generation of activated protein C (APC) by the thrombin-thrombomodulin complex. A soluble form of EPCR (sEPCR), which is generated by metalloprotease activity, is present in plasma. The distribution of sEPCR levels in healthy populations is bimodal. Previously, we described two polymorphisms in exon 4 of the EPCR gene, 4600A/G that encodes the substitution of Ser219 by Gly in the transmembrane region of EPCR and 4678G/C in the 3'-UT region. The aim of this study was to investigate the relationship between these two polymorphisms and plasma sEPCR and APC levels and risk of venous thrombosis. We genotyped 401 healthy controls from the Spanish population and measured their plasma sEPCR and APC levels. Carriers of the 4600AG genotype had significantly higher sEPCR levels than those with the AA genotype, while the 4678CC genotype was associated, to a lesser extent, with elevated APC levels. To assess the effect of these polymorphisms on the risk of thrombosis, we genotyped 405 patients with venous thromboembolism. The frequency of the 4600AG genotype was very similar in patients and controls (p=0.975), whereas the 4678CC genotype was significantly more frequent in controls than in patients (p=0.008). In multivariate analysis, carriers of the 4678CC genotype had a decreased risk of thrombosis (OR=0.61, p=0.009). These data indicate that individuals carrying the 4600AG genotype have high sEPCR levels but do not have an increased risk of thrombosis, whereas individuals carrying the 4678CC genotype have higher APC levels and lower risk of venous thromboembolism.

mRNA analysis of several components of the plasminogen activator and matrix metalloproteinase systems in endometriosis using a real-time quantitative RT-PCR assay

BACKGROUND

The plasminogen activator (PA) and matrix metalloproteinase (MMP) systems are implicated in the establishment of endometriosis. The mechanisms by which these systems are involved in the pathogenesis of this disease are not well defined and controversial results have been published. The aim of this study was to analyse mRNA and protein levels of several components of the PA and MMP systems in endometriotic tissue and endometrium from women with and without endometriosis.

METHODS AND RESULTS

Real-time quantitative RT-PCR assays were developed to quantify mRNA levels of these components in 57 women with endometriosis and 32 controls. Endometrium of women with endometriosis showed higher mRNA and antigenic levels of urokinase type-PA (uPA) and MMP-3 than endometrium from controls. In these patients, ovarian endometriotic tissue had higher mRNA and antigenic levels of PA inhibitor type 1 (PAI-1) and MMP inhibitor type 1 (TIMP-1) than endometrium.

CONCLUSIONS

The increase in mRNA and protein levels of uPA and MMP-3 observed in endometrium of women with endometriosis may facilitate the attachment of endometrial tissue to the peritoneum and ovarian surface, as well as the invasion of the extracellular matrix. This process would lead to the formation of early endometriotic lesions. Once the ovarian endometriotic cyst is developed, PAI-1 and TIMP-1 would increase which could explain the frequent clinical finding of an endometrioma without invasion of the adjacent ovarian tissue.

Influence of plasma and erythrocyte factors on red blood cell aggregation in survivors of acute myocardial infarction

Increased erythrocyte aggregation (EA) has been observed in patients with ischaemic heart disease (IHD), although most of these studies have been performed in the acute phase when reactant proteins may account for this increase. Little is known about the role played by the erythrocyte itself in this aggregation process. To ascertain the contribution of both plasma and erythrocyte factors to EA in IHD, we investigated the following parameters in 78 survivors of acute myocardial infarction (AMI) and in a well-matched control group of 98 subjects: EA, glucose, total cholesterol (T-Chol), low-density lipoprotein-cholesterol (LDL-Chol), high-density lipoprotein-cholesterol (HDL-Chol), triglycerides, apolipoproteins A(1) and B, protein and functional fibrinogen, plasma sialic acid, membrane sialic acid, and the cholesterol and phospholipid content of the erythrocyte membrane. AMI survivors showed higher glucose (p<0.001), a borderline increase in triglycerides (p = 0.043), and a statistical decrease in Apo A(1) (p= 0.003) relative to controls. EA, functional fibrinogen, and plasma sialic acid were statistically higher in AMI survivors than in controls (p= 0.001; p<0.001; p= 0.011, respectively). Membrane sialic acid content was statistically lower in AMI patients than in controls (p= 0.026). No differences were observed in either membrane cholesterol or phospholipids. Multivariate logistic regression analysis, in which EA was dichotomized as higher or lower than 8.7, demonstrated that triglyceride levels higher than 175 mg/dL (OR= 7.7, p= 0.001) and functional fibrinogen levels higher than 320 mg/dL (OR= 3.7, p= 0.004) were independently associated with a greater risk of erythrocyte hyperaggregability. Our results suggest that plasma lipids, predominantly triglycerides, and fibrinogen may not only enhance the development of ischaemic events by their recognized atherogenic mechanisms, but also by increasing EA.

Activated protein C levels in Behçet's disease and risk of venous thrombosis

Behçet's disease is a multi-systemic inflammatory disorder of unknown cause. Most abnormalities have been associated with endothelial injury caused by vasculitis. Thrombosis occurs in about 25% of patients, although the mechanism is unknown. The objective of this study was to evaluate the protein C activation system in Behçet's disease and its correlation with venous thromboembolism (VTE). Thirty-nine patients (12 with VTE) and 78 age- and sex-matched controls were included in the study, and levels of protein C, protein S, activated protein C (APC), protein C inhibitor (PCI), soluble thrombomodulin (TM), antithrombin (AT), alpha(1)-antitrypsin, fibrinogen, factor VIII, von Willebrand factor (VWF) and C-reactive protein (CRP) were measured. APC and TM levels were significantly lower in patients than in controls, whereas protein S, AT, alpha(1)-antitrypsin, fibrinogen, factor VIII, VWF and CRP levels were significantly higher in patients than in controls. APC, PCI and TM levels were lower in patients with VTE (0.65 +/- 0.19 ng/ml, 86% +/- 22% and 15.5 +/- 7.1 ng/ml respectively) than in those without VTE (0.78 +/- 0.17 ng/ml, 100% +/- 15% and 22.1 +/- 15.3 ng/ml) (P < 0.05). In patients, APC levels below 0.75 ng/ml (10th percentile of the control group) increased the risk of VTE about fivefold (odds ratio = 5.1; 95% confidence interval = 1.1-23.4). These results show that reduced APC levels are associated with the high incidence of VTE in Behçet's disease.

Homozygous Deficiency of Heparin Cofactor II

Background— Heparin cofactor II (HCII) is a hepatic serpin with significant antithrombin activity that has been implicated in coagulation, inflammation, atherosclerosis, and wound repair. Recent data obtained in mice lacking HCII suggest that this serpin might inhibit thrombosis in the arterial circulation. However, the clinical relevance and molecular mechanisms associated with deficiency of HCII in humans are unclear.

Methods and Results— We studied the first family with homozygous HCII deficiency, identifying a Glu428Lys mutation affecting a conserved glutamate at the hinge (P17) of the reactive loop. No carrier reported arterial thrombosis, and only 1 homozygous HCII-deficient patient developed severe deep venous thrombosis, but she also had a de novo Glu100Stop nonsense truncation in the antithrombin gene.

Conclusions— Our results confirm the key structural role of the P17 glutamate in serpins. The same mutation causes conformational instability and polymerization in 3 serpins: Drosophila necrotic, human α1-antitrypsin, and human HCII, which explains their plasma deficiency. In the family under study here, however, plasma HCII deficiency was not associated with a significant clinical phenotype.

Effect of eprosartan on cytoplasmic free calcium mobilization, platelet activation, and microparticle formation in hypertension

BACKGROUND

Hypertensive patients show greater platelet activation than do normotensive individuals. Platelet activation is characterized by increased phosphatidylserine (PS) exposure in the external hemilayer of the membrane, a larger number of platelet microparticles (PMP), and changes in intraplatelet-free calcium kinetics. This study evaluated whether eprosartan can protect against undesirable platelet activation.

METHODS

A total of 30 hypertensive patients (systolic blood pressure [SBP] 140 to 189 mm Hg; diastolic blood pressure [DBP] 90 to 109 mm Hg) without renal, liver, or cardiac organic lesions and with a mean age of 47.6 +/- 9.4 years and mean body mass index (BMI) of 27.9 +/- 3.9 kg/m2 received eprosartan (600 mg/day). They were compared with 31 normotensive individuals with a mean age of 43.3 +/- 6.7 years and a mean BMI of 26.8 +/- 3.9 kg/m2. Blood pressure measurements and platelet function changes were assessed at baseline (control and hypertensive patients) and after 1 and 2 months of eprosartan monotherapy (hypertensive patients only).

RESULTS

Significant baseline to endpoint (month 2) changes in SBP and DBP were noted in the eprosartan group (SBP: baseline 152.2 +/- 16.8 mm Hg, endpoint 142.2 +/- 16.9 mm Hg, P <.01; DBP: baseline 93.5 +/- 9.9 mm Hg, endpoint 85.8 +/- 11.9 mm Hg, P <.001). Native circulating activated platelets increased in both groups after shear stress or Ca2+ ionophore activation, and were reduced by eprosartan (after shear exposure from 104% at month 1 to 76% after 2 months of therapy). Eprosartan therapy normalized the number of microparticles after blood shear exposure (P <.01) and after exposure to Ca2+ ionophore activation (P <.05) and significantly reduced the trend for platelets to be more readily activated in hypertensive compared with normotensive subjects (baseline to endpoint change P <.001; increase/shear versus baseline P <.001). Eprosartan partially normalizes cytoplasmic-free calcium mobilization in platelets.

CONCLUSIONS

Eprosartan significantly reduces blood pressure and normalizes undesirable changes in platelet function.

Erythrocyte aggregability and disaggregability in thalassemia trait carriers analyzed by a laser backscattering technique

Erythrocyte aggregability was determined by a laser backscattering light technique in 23 beta minor thalassemia carriers and in 36 age and sex matched controls. The aggregation time (Ta) was statistically higher in cases than in controls (2.8 +/- 1.0 vs 2.3 +/- 0.4, p < 0.05) and the aggregation index at 10 sec (AI10) was statistically lower (25.1 +/- 5.7 vs 28.2 +/- 3.8, p < 0.05), suggesting both parameters a statistically lower erythrocyte aggregability tendency. However, the total disaggregation threshold (gammaD) was statistically higher in cases than in controls (134.4 +/- 34.1 vs 105.1 +/- 33.1, p < 0.05), indicating that once aggregates are formed a higher shear rate is needed to break them up. No differences were observed in plasmatic factors, i.e., fibrinogen, total cholesterol and triglycerides, that could have influenced erythrocyte aggregation. A negative statistically significant correlation was found between erythrocyte indexes and the total disaggregation threshold. The lower erythrocyte aggregation found in minor thalassemia carriers could be attributed in part to the morphological alterations, although others mechanisms such as modifications in the membrane structure of the RBC can not be ruled out.

Do hemorheological alterations play any role in the development of thrombotic events in Behçet's disease?

Behçet's disease (BD) is associated with an increased thrombotic risk, although the prothrombotic mechanisms are not clearly defined. Alterations in blood rheology, specially increased erythrocyte aggregation has been suggested to play an important role in the development of thrombotic events in patients with Behçet's disease. In order to ascertain whether any rheological parameter could be involved in the pathogenesis of thrombotic events in Behçet's disease we have determined plasmatic lipids, fibrinogen, hematocrit, erythrocyte aggregation (Myrenne aggregometer), erythrocyte deformability (Rheodyn SSD), blood viscosity (Brookfield viscosimeter), plasma viscosity (Fresenius capillary viscosimeter) and erythrocyte indexes in Behçet's patients with a non-active disease when sampling, and a well matched control group. The patient group was made up of 40 Behçet's patients (20 male, 20 female aged 43+/-12 years) and the control group comprised 70 healthy volunteers (24 male, 46 female aged 45+/-13 years). Twelve of the 40 Behçet's patients have had a previous documented history of deep vein thrombosis at least six months before entering the study, and the other 28 did not. When patients and controls were compared, patients showed a statistically higher fibrinogen level (p=0.002), plasma viscosity (p=0.003), blood viscosity (p=0.021) and erythrocyte aggregation (p=0.049), the other rheological parameters not being statistically significant. No differences were observed in the rheological parameters when patients with and without a previous thrombotic episode were compared. Our results suggest that rheological alterations do not seem to play any role in the development of thrombotic events in patients with Behçet's disease.

Rheological profile in severe and morbid obesity. Preliminary results

The association of hemorheological alterations with morbid obesity remains a question of debate. In order to ascertain whether morbid obese subjects show certain hemorheological alterations which might be involved in the higher thrombotic risk which characterizes these subjects, we determine glucose, plasma lipids, apolipoproteins, fibrinogen, hematocrit, blood viscosity (Brookfield DVIII viscosimeter), both at native and corrected hematocrit of 45%, plasma viscosity (Fresenius capillary viscosimeter), erythrocyte aggregation (Myrenne aggregometer), both at stasis and at 3 s(-1) at 45% hematocrit and erythrocyte indexes in 41 morbid obese subjects (32 female, 9 male aged 33+/-10 years), and in a well matched non-obese control group (40 female, 15 male, aged 32+/-10 years). Mean BMI in the morbid obese group was 44.9+/-6.7 kg/m2 vs 23.5+/-4.8 kg/m2 in the control group (p<0.001). Morbid obese subjects when compared with the control group showed a statistically higher glucose level (p<0.001), LDL-cholesterol (p=0.019), triglycerides (p<0.001), apoB (p=0.019), apoB/A1 (p<0.001), fibrinogen (p<0.001), erythrocyte aggregation (p<0.001), and a statistically lower HDL-cholesterol (p<0.001). No differences between both groups were observed regarding total-cholesterol, plasma viscosity, blood viscosity and hematocrit (p=0.109; p=0.690; p=0.510; p=0.950), respectively. After the adjustment for BMI, differences in glucose, LDL-cholesterol, triglycerides, apoB, apoB/A1, and erythrocyte aggregation did not reach the statistical significance, and differences in fibrinogen were borderline significant (p=0.051), showing a direct effect of BMI on the detected differences between obese and non-obese. Our results suggest that in morbid obese subjects the increased fibrinogen levels and the altered lipid profile associated with their higher BMI, could in addition to its known mechanisms on haemostasis, favour both venous and arterial thrombotic events by enhancing erythrocyte aggregation.

Effect of a hypocaloric diet on lipids and rheological profile in subjects with severe and morbid obesity. A follow-up study

Discrepant results have been published regarding modifications of rheological parameters in obese subjects after a low caloric diet (LCD). In order to ascertain whether a decrease in BMI associated to a LCD, is accompanied by changes in the hemorheological parameters, we determined in 41 morbid obese subjects (32 female, 9 male aged 33+/-10 years) BMI, glucose, plasmatic lipids and apolipoproteins, fibrinogen, blood viscosity (Brookfield viscosimeter), plasma viscosity (Fresenius capillary viscosimeter), erythrocyte aggregation (Myrenne aggregometer), hematocrit and erythrocyte indexes, before starting on a LCD and 1 and 3 months after. During the first month obese subjects received a very low caloric diet (VLCD) (Modifast) providing 458 kcal per day. The second and third month they received a LCD providing 1500 kcal/day for men and 1200 kcal/day for women. One month after starting on a VLCD, a statistical significant decrease in glucose (p<0.001), Total-cholesterol (p<0.001), LDL-cholesterol (p<0.001), triglycerides (p=0.012), apoB (p<0.001) and erythrocyte aggregation (p<0.001) were observed together with a concomitant decrease in BMI (p<0.001). The expected decrease in HDL-cholesterol associated with a low fat diet was also noted in these individuals. No changes in fibrinogen, hematocrit, blood viscosity or plasma viscosity were observed. At 3 months only a slight increase in BMI was observed regarding the one month period, glucose being the only parameter which remained statistically lower. All the other significant parameters returned to their basal values at 3 months. VLCD (Modifast) is associated to a significant decrease in BMI with the corresponding improvement in glucose, lipids and erythrocyte aggregation at one month. However a LCD alone does not produce a further decrease in weight and both lipids and erythrocyte aggregation return to the basal situation at three months.

Influence of plasmatic lipids on the hemorheological profile in healthy adults

Some hemorheological parameters constitute risk factors for ischemic cardiovascular events. Most of these hemorheological factors are determined by the erythrocyte intrinsic properties and the high molecular weight plasmatic proteins, especially fibrinogen. The contribution of the plasmatic lipids to hemorheological factors is not well established. With this aim we determined hemorheological parameters in 112 healthy volunteers (62 males, 50 females) aged 35+/-10 years, range 19-54 years, members of our hospital staff. A complete set of rheological test was performed. Blood viscosity (BV) 230 sec(-1), plasma viscosity (PV), erythrocyte aggregation index (EAI), erythrocyte elongation index (EEI), hematocrit and fibrinogen. We also determined plasmatic lipids including total cholesterol (T-Ch) and its fractions (HDL-Ch, LDL-Ch, VLDL-Ch), triglycerides, lipoproteins (Apo B, Apo A(1), B/A(1)). Exclusion criteria were concomitant cardiovascular risk factors or any other associated pathology. Our results show a positive correlation between BV 230 sec(-1) and triglycerides (r=0.335) and negative with HDL-Ch (r=-0.451) (p=0.01), respectively; PV shows a positive correlation with T-Ch (r=0.297), LDL-Ch (r=0.298) and Apo B/A (r=0.290) (p=0.01). The EEI was negatively correlated with TG (p=0.05). Of all the rheological parameters evaluated, EAI is the factor which shows the highest significant correlation with plasmatic lipids: T-Ch (r=0.515), TG (r=0.303), LDL-Ch (r=0.507) and Apo B/A ratio (r=0.403); (p=0.01). These results suggest that plasmatic lipids contribute to modulate the blood rheological properties, slowing blood flow, favouring the development of atherothrombotics events, especially in stenotic areas or bifurcations in the vascular tree.