Effects of a dairy product (pecorino cheese) naturally rich in cis-9, trans-11 conjugated linoleic acid on lipid, inflammatory and haemorheological variables: a dietary intervention study.

BACKGROUND AND AIM: Some studies recently reported a favourable effect for cis-9, trans-11 conjugated linoleic acid (CLA) on plasma lipoprotein profile of healthy subjects. Aim of this crossover intervention study was to evaluate the influence of a short-term dietary intake of a cheese derived from sheep's milk naturally rich in CLA on several atherosclerotic biomarkers, in comparison with a commercially available cheese. METHODS AND RESULTS: Ten subjects (6 F; 4 M) with a median age of 51.5 followed for 10 weeks a diet containing 200 g/week of cheese naturally rich in CLA (intervention period) and for the same period a diet containing a commercially available cheese of the same quantity (placebo period). Consumption of the dairy product naturally rich in cis-9, trans-11 CLA determined a significant (p<0.05) reduction in inflammatory parameters such as interleukin-6 (pre: 8.08+/-1.57 vs. post: 4.58+/-0.94 pg/mL), interleukin-8 (pre: 45.02+/-5.82 vs. post: 28.59+/-2.64 pg/mL), and tumour necrosis factor-alpha (pre: 53.58+/-25.67 vs. post: 32.09+/-17.42 pg/mL) whereas no significant differences in the placebo period were observed. With regard to haemorheological parameters, the test period significantly ameliorated erythrocytes' filtration rate (pre: 7.61+/-0.71% vs. post: 9.12+/-0.97%; p=0.03) with respect to the placebo period. Moreover, a reduction in the extent of platelet aggregation, induced by arachidonic acid [pre: 87.8+/-1.76% vs. post: 77.7+/-3.56%; p=0.04] was observed during the test period in comparison with the placebo period. CONCLUSIONS: Dietary short-term intake of the tested dairy product naturally rich in cis-9, trans-11 CLA appeared to cause favourable biochemical changes of atherosclerotic markers.

[Role of hyperviscosity in cardiovascular and microvascular diseases]. / Ruolo dell'iperviscosita' nelle patologie cardiovascolari e nei disordini del microcircolo.

Blood viscosity plays a key role in regulating microvascular flow and alterations of hemorheological variables can lead to hyperviscosity, thus favoring the occurrence of occlusive thrombotic events. In the last few years an association between alterations in the hemorheologic profile and the severity of blood flow disturbances has been emphasized in several clinical and experimental conditions, possibly contributing to a better understanding of the pathophysiology of vascular disorders. The presence of alterations in hemorheological variables proved to be associated in several studies with an increased risk of cardiovascular disease and a higher mortality. The role of blood viscosity has also been analyzed in retrospective studies, which demonstrated that alterations in some hemorheological variables may increase the incidence of embolic events in patients with atrial fibrillation and may influence the responsiveness to antiplatelet drugs in patients with acute coronary syndromes. Recently, alterations of some hemorheological parameters were shown to be associated with complete occlusion of coronary arteries, favoring the occurrence of myocardial infarction with ST-segment elevation. In patients with this clinical condition, an increase in blood viscosity and some of its determinants was associated with increased infarct size and worse acute left ventricular dysfunction. Finally, the results of some observational clinical studies have shown that alterations of hemorheological variables may help to explain the pathophysiological mechanisms of some clinical disorders in which microvascular damage has been demonstrated, such as idiopathic sudden sensorineural hearing loss, retinal vein occlusion, and systemic sclerosis.

Erythrocyte oxidative stress is associated with cell deformability in patients with retinal vein occlusion.

Essentials Retinal vein occlusion (RVO), characterized by blood hyperviscosity, has an unclear pathogenesis. We aimed to find out if hemorheological profile is altered by oxidative stress in RVO patients. Red blood cell (RBC) oxidative stress is associated to whole blood viscosity and RBC deformability. Reactive oxygen species alter RBC membrane rigidity, playing a key role in RVO pathogenesis. SUMMARY: Background Retinal vein occlusion (RVO) is characterized by vision loss resulting from hypoperfusion and hypoxia of the retina. RVO pathogenesis is not yet fully understood, although blood hyperviscosity has been observed. Erythrocyte deformability plays a key role in determining blood viscosity, and it is critical to microvascular perfusion and oxygen delivery. It has been shown that oxidative stress-induced erythrocyte membrane fluidity alterations are linked to the progression of cardiovascular diseases. Objectives To determine whether erythrocytes from RVO patients show signs of oxidative stress, and whether this condition can modify the hemorheologic profile in these patients. Patients and Methods We analyzed the entire hemorheologic profile and erythrocyte oxidative stress - reactive oxygen species (ROS) production and membrane lipid peroxidation - in 128 RVO patients and 128 healthy subjects, matched for age and sex. Fluorescence anisotropy was used to evaluate the fluidity of erythrocyte membranes. Results In RVO patients, erythrocyte oxidative stress was present and positively correlated with whole blood viscosity and erythrocyte deformability. Multivariate linear regression analysis after adjustment for age, cardiovascular risk factors, medications, leukocyte number and mean corpuscular volume indicated that erythrocyte-derived ROS and erythrocyte lipid peroxidation were significantly and positively correlated with erythrocyte membrane viscosity and deformability. Moreover, in vitro experiments demonstrated that ROS have a key role in erythrocyte membrane fluidity. Conclusions Our findings indicate that erythrocyte oxidative stress plays a key role in the pathogenesis of RVO, and pave the way to new therapeutic interventions.

Blood viscosity and filtration abnormalities in mixed cryoglobulinemia patients.

Blood, plasma and serum viscosity and blood filtration were investigated in 43 unselected mixed cryoglobulinemia patients. A hyperviscosity syndrome was present in only one patient, and rapidly improved after plasma exchange and cyclophosphamide therapy. A clear-cut increase in blood viscosity was infrequently observed in mixed cryoglobulinemia, although significant differences were present in the plasma and serum viscosity of patients and controls. In contrast, blood filtration was severely impaired in a high percentage of cases (51 and 72% of the values recorded at 37 degrees and 25 degrees C, respectively), and was on the average significantly higher in patients than in controls. Indirect evidence suggests that blood viscosity is at least in part related to cryoglobulins. In 19 patients studied before and after cryoglobulin removal, serum viscosity significantly decreased when the serum was deprived of cryoglobulins. In addition, the cryocrit correlated with all the hemorheological parameters with the exception of blood filtration. The hemorheological findings were compared with multisystemic features of the disease, i.e. liver, renal, lung, neurologic, vascular and funduscopic alterations. The potential clinical relevance of the hemorheological parameters was stressed by the close correlation between blood filtration parameters and serum creatinine. Furthermore, by discriminant analysis, viscosity and blood filtration changes were the serological parameters most significantly associated with the presence of renal, liver and neurological involvement. Thus, hemorheological parameters are frequently abnormal in mixed cryoglobulinemia patients, and seem to play a significant clinical role; they should therefore be included in the work-up of these patients.

[Hemorheologic and blood cell changes in humans during partial immersion, with a therapeutic method, in 38 C water]. / Modificazioni emoreologiche ed ematiche nell'uomo in corso di immersione parziale, con metodo terapeutico, in acqua a 38 degrees C.

This research was carried out to define the effects on man during head-out water immersion in a bath at 38.41 +/- 0.04 degrees C (mean +/- S.E.) with a method similar to that used for therapeutical rehabilitation and time of immersion of 30 minutes. Hemorheological, hematic and hemodynamic parameters were analysed. Seventeen healthy subjects (fourteen males and three females), between the ages of 21-65 years and mean age of 29.8 +/- 2.6 years were studied. Head-out water immersion resulted in: 1) decrease in blood viscosity, red blood cells count, C-Hct and M-Hct, without significant changes in leukocytes and platelets count, MCV, plasma viscosity, erythrocyte filtration time and RCDI; 2) an increase in heart rate and a decrease in systolic and diastolic blood pressure. Thirty minutes after the end of immersion, heart rate, diastolic blood pressure and blood viscosity, measured at 0.512 sec-1 shear rate, returned to pre-immersion values; systolic blood pressure showed a slight increase but was still significantly below the basal levels; erythrocytes count, C-Hct, M-Cct and blood viscosity, measured at 94.5 sec-1 shear rate, significantly exceeded pre-immersion values. The probable pathogenesis of these observations is suggested. A matter of great interest is the study of the same parameters in elderly subjects, with or without cardiovascular diseases, or in patients using drugs affecting blood pressure, blood viscosity or hemocoagulation process.

Alterations of haemorheological parameters in patients with peripheral arterial disease.

Peripheral arterial disease (PAD), is a common manifestation of systemic atherosclerosis. Advances on the development of such vascular disease have described with a number of novel risk factors. Hyperviscosity, due to alterations of blood cells and plasma components, may play a role on the pathogenesis of the disease. Aim of this study was to evaluate the possible association between hemorheological variables and PAD. The hemorheological variables [whole blood viscosity (WBV), erythrocyte deformability index (DI), plasma viscosity (PLV)] were analyzed in 90 patients and in 180 healthy subjects. WBV and PLV were measured by a Rotational Viscosimeter and DI by a filtrometer. DI and PLV were significantly different in patients as compared to controls. To investigate the possible association between these parameters and the disease we divided the study population into tertiles. At the univariate analysis, we found a significant association between the highest tertiles of PLV, of DI and the disease. A model adjusted for traditional risk factors showed an association between highest tertiles of PLV and PAD. After adjustment for confounding parameters highest tertiles of PLV remained to be significantly associated with the disease. Our data indicate that an alteration of plasma viscosity may modulate the predisposition to PAD.

Blood rheology and renal transplantation: an intriguing relationship for assessing cardiovascular risk.

Renal transplant recipients (RTRs) are at increased risk of cardiovascular complications. An altered hemorheological profile may determine both cardiovascular complications and progression of renal failure in RTRs. We performed this study to evaluate the rheologic status in 239 RTRs at least 12 months after transplantation with stable and normal renal function compared with 90 control subjects. In RTRs, a significantly higher hematocrit-adjusted, but not native, whole blood viscosity was found (P < .0001). Moreover, plasma viscosity and red blood cell deformability were significantly higher in patients than in control subjects (P < .0001), whereas no difference in erythrocyte aggregation between patients and control subjects was observed (P = .5). Fibrinogen, but not hematocrit, significantly increased in RTRs (P = .001). This preliminary study provides evidence of an altered hemorheologic profile in RTRs.

Haemorheological changes in mixed cryoglobulinaemia during apheresis treatment.

Thirty-four patients affected by mixed cryoglobulinaemia have been submitted to treatment by apheresis (plasma exchange or double cascade filtration). The authors have monitored clinical, laboratory and, above all, haemorheological changes following therapy. The final results have shown mainly a reduction of plasma viscosity and consequently an improvement of the haemorheology of the affected organs. In conclusion, apheresis may be considered a successful therapy in patients with severe renal or neurological diseases due to mixed cryoglobulinaemia.