Alteraciones hemorreológicas, fibrinolíticas e hipercoagulabilidad en la obesidad: Efecto de la pérdida ponderal.
Obesity is considered to be an independent risk factor for arterial and venous thrombosis. The mechanisms through which obesity increases cardiovascular risk independently of its association with other cardiovascular risks factors are not well established. Hemorheological factors could contribute to this prothrombotic state. Erythrocyte deformability, erythrocyte aggregation and lipidic membrane phosphatidylserine expression have been scarcely studied in these patients. Disturbances in C protein system could favour as well thrombotic events. An increase in plasminogen activator inhibitor type 1 levels (PAI-1), which can be related to 4G/5G polymorphism of its gene, can also contribute to this hypercoagulable state.
Our objective was to show that hemorheological, fibrynolitic and coagulation disturbances can contribute to the hypercoagulable state in obesity, and that these disturbances can improve with weight loss.
We studied 67 obese patients who were compared with a control group, and underwent a hypocaloric diet for three months. The results were as follows:
? Obese patients show a disturbed hemorheological profile, with an increase in fibrinogen, plasma and blood viscosity, and erythrocyte aggregability. This hyperaggregability is associated to insulin resistance.
? Erythrocyte deformability is not decreased in obese patients, and no changes in cholesterol and phospholipids membrane content are found. Nevertheless, obese patients with metabolic syndrome show lower erythrocyte deformability.
? High levels of fibrinogen and blood and plasma viscosity do not change with weight loss, but hyperaggregability improves.
? Phosphatidylserine expression in the outside lawyer of lipidic membrane is increased in obese patients.
? We have not found a state of activated protein C resistance in obese patients.
? Activated protein C levels are increased in obese patients, and decrease with weight loss.
? Obese patients show an increase in PAI-1 antigen and activity. We have not found a correlation between these levels and 4G allele.
? Obese patients with metabolic syndrome have non-significantly higher levels of PAI-1.
? After weight loss, PAI-1 levels decrease. Obese patients with 4G allele show a non significant lower decrease of PAI-1 levels.
We have confirmed hemorheological, fibrinolytic and coagulation disturbances associated to obesity. Some of these disturbances improve with weight loss.
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Advisor:Vayá Montaña, Amparo; Hernández Mijares, Antonio
School:Universitat de València
Source Type:Master's Thesis
Date of Publication:07/05/2007