The frequency of structural and functional changes in endothelium (decrease of endothelium dependent vasodilatation of brachial artery, thickness of intima-media of common carotid artery and the presence of
atherosclerotic plaques) and their relationship with traditional risk factors for cardiovascular complications in patients with antiphospholipid syndrome (APS) were studied. The study included 153 patients, among them 34
(22.2%) patients with primary APS (PAPS), 48 (31.4%) – with secondary APS (SAPS) and 71 (46.4%) systemic lupus erythematosus (SLE) patients without APS. Subclinical manifestations of atherosclerosis (thickness of
intima-media of common carotid artery, the presence of atherosclerotic plaques and dysfunction of the endothelium) were registered in 77.3% patients with SAPS, 46.9% patients with PAPS and 55.2% of SLE
patients without APS. High (76.5–81.2%) prevalence of traditional risk factors was revealed in patients with APS. Dyslipidemia was significantly more often (1.6 times) recorded in patients with SAPS. Both endothelial
dysfunction and severity of atherosclerosis in patients with PAPS and SAPS were associated with elderly age, arterial hypertension, dyslipidemia and obesity. There was no relationship of subclinical manifestations of
atherosclerotic lesions with male gender, physical inactivity and smoking.