['To study effects of glomerular filtration rate (GFR) reduction on endothelial function in patients at early stages of chronic renal kidney (CKD).', 'Endothelial function of 101 patients with CKD of stage I-III was examined using reactive hyperemia test, dopplerography of skin vessels with ionophoresis of acetylcholin and nitroglycerin, lipidogram parameters, homocistein and annexin A5 levels, intima-media complex thickness of the common carotid artery, echocardiography findings.', 'Cardiovascular complications risk factors were found in all the patients: increased body mass index, arterial hypertension, dyslipoproteinemia, hyperhomocysteinemia. Reduced GFR (under 90 ml/min) is an independent factor of atherosclerosis risk.'] Is [ Glomerular filtration rate an indicator of endothelial function at early stages of chronic kidney disease ]?