BACKGROUND/AIM: Exercise can positively influence risk factors associated with cardiovascular disease. The mechanisms by which exercise reduces atherogenic risk remain unknown. The aim of the present study was to investigate the effect of acute exercise (cardiopulmonary exercise cycle ergometer test) on atherogenic lipids in untreated mild hypertensive patients with or without hypercholesterolemia. This testing allows determination of exercise capacity, peak heart rate, and ventilation per minute (VE), peak oxygen uptake (pVO2) and exercise time (ET). METHODS: The study group included 85 untreated mild hypertensive patients (according to VII Joint National Committee--JNC 7) divided into two subgroups: hypertensive hypercholesterolemic and hypertensive normocholesterolemic. The control grouip included 35 normotensive subjects divided into two subgroups: normotensive hypercholesterolemic and normotensive normocholesterolemic. Lipid profiles to determine were oxidized LDL (OxLDL)--a marker of oxidative stress, triglycerides, total cholesterol, LDL cholesterol, and HDL cholesterol, which were measured at rest and 30 minutes after the acute bout of cardiopulmonary exercise cycle ergometer test. Lipids profiles were measured by enzymatic methods. Oxidized LDL was determined by a commercially available sandwich ELISA (Mercodia AB, Uppsala, Sweden). C-reactive protein (CRP) was measured using chemiluminiscent methods (Immulite-DPC). RESULTS: In our study OxLDL was significantly higher in hypertensive patients with atherogenic lipid profiles in basal condition, compared to the hypertensive patients without atherogenic lipid profiles and controls. There was a significant difference in CRP (p