Objective To investigate the effect of micronized fenofibrate on vascular endothelial function in patients with hypertriglyceridemia.Methods Using high-resolution ultrasound, we measured flow- and nitroglycerin-induced dilatation of the brachial artery in 30 patients with hypertriglyceridemia before and after treatment with micronized fenofibrate at a dose of 200 mg once daily for 4 weeks. Simultaneously, both serum lipid and plasma endothelin (ET) levels were determined.Results After micronized fenofibrate therapy, serum triglyceride (TG) levels decreased significantly (P<0. 05). Plasma ET levels also decreased markedly [(82.66 ±15.46) μg/L vs. (106.22 ±19.16) Mμg/L, P< 0.001]. Flow-induced vasodilatation was much improved (11.0% ±9.0% vs 2. 7%±2. 0% , P<0. 01). However, no significant changes in vasodilatation occurred in response to nitroglycerin (16. 2% ±6. 0% vs 15. 0% ±5. 0% , P>0. 05) in patients with hypertriglyceridemia.Conclusions Micronized fenofibrate can improve impaired endothelium Objective To investigate the effect of micronized fenofibrate on vascular endothelial function in patients with hypertriglyceridemia. Methods Using high-resolution ultrasound, we measured flow- and nitroglycerin-induced dilatation of the brachial artery in 30 patients with hypertriglyceridemia before and after treatment with micronized fenofibrate at Both plasma lipid and plasma endothelin (ET) levels were determined. Results After micronized fenofibrate therapy, serum triglyceride (TG) levels decreased significantly (P <0 05). Plasma ET (82.66 ± 15.46) μg / L vs. (106.22 ± 19.16) M μg / L, P <0.001]. Flow-induced vasodilatation was much improved (11.0% ± 9.0% vs 2.7% ± 2. 0%, P <0. 01). However, no significant changes in vasodilatation occurred in response to nitroglycerin (16.2% ± 6. 0% vs 15. 0% ± 5. 0%, P> 0.05) patients with hypertriglyceridemia. Confc Micronized fenofibrate can improve im paired endothelium