[Do passive smokers have an increased risk of thrombosis?]

In contrast to the proven association between active smoking and vascular injury, as well as hemostatic imbalance, such a relation is not jet proven for passive smoking. Vascular damage induced by smoking, however, can be seen in the materno-fetal circulation of smoking mothers, being much more pronounced in the umbilical system than in fetal vessels. These lesions show fast recovery after birth. In non-smokers acute exposure to passive smoke induces a short-lasting activation of platelet function and the prostaglandin system, followed by a quick recovery. Chronic exposure of non-smokers to passive smoke, however, results in changes of these parameters comparable to those seen in smokers, characterized by an activation of platelet function and a decrease in platelet sensitivity to the antiaggregatory prostaglandin I2. These results suggest that in non-smokers with atherogenic risk factors passive smoking may contribute to the incidence of atherosclerosis, as well as acute complications (thrombosis).