[Tobacco smoking and cardiovascular diseases].

Epidemiological studies have shown that chronic tobacco smoking is associated with a significant increase in risks of coronary disease (chiefly myocardial infarction and sudden death), occlusive arteriopathy of the lower limbs and cerebral vascular accident. The risk is strongly augmented by the presence of other vascular risk factors such as arterial hypertension, hypercholesterolaemia, diabetes and oral contraception. Nicotine and carbon monoxide seem to play a major role in the effect of smoking on vessels. In addition to its acute haemodynamic effects, tobacco not only has an atherogenic effect (endothelial toxicity and changes in lipid profile), but it also facilitates thrombosis (by alteration of platelet functions and elevation of fibrinogen level, haematocrit level and blood viscosity) and spasm (by modification of prostaglandin metabolism and action on catecholamines). All these isolated or associated mechanisms account for clinical and evolutive manifestations or coronary or peripheral arterial lesions. The progression of female smoking partly explains the frequency of vascular pathology in young women. Recent experimental data and epidemiological studies have confirmed the responsibility of passive smoking for coronary pathology, thus justifying the measures enforced to limit the exposure of non-smokers. To cease smoking is probably the most efficient primary or secondary preventive measure, as it results in a relatively rapid decrease in the risk of complications, and notably thrombosis. No effort should be spared to obtain these results and at the same time correct other vascular risk factors.