The impact of daily sildenafil on levels of soluble molecular markers of endothelial function in plasma in patients with erectile dysfunction.

OBJECTIVE To investigate the impact of daily sildenafil on levels of soluble molecular markers of endothelial function in men with erectile dysfunction. METHODS Patients aged >18 years with erectile dysfunction of vascular etiology for >6 months, either alone or in combination with disease states strongly associated with endothelial dysfunction such as diabetes/metabolic syndrome, hypertension and coronary artery disease, received sildenafil 25 mg orally for 4 weeks. Markers of endothelial function were measured in plasma at baseline and at end of treatment using standard methods and commercially available kits. RESULTS Altogether, 112 men with mean (SD) age of 60.6 (7.3) years completed the protocol. Sildenafil 25 mg daily for 4 weeks significantly reduced endothelin-1 levels compared with baseline (2.83+/-1.63 vs 3.24+/-1.90 pg/ml, p<0.001). Significant changes were also observed for nitric oxide (35.12+/-21.14 vs 31.91+/-16.28 pmol/lt, p=0.01) and cyclic guanosine monophosphate (3.79+/-2.37 vs 2.70+/-1.34 pmol/ml, p<0.001) levels, but not for any of the other biomarkers measured. Erectile function was significantly improved. CONCLUSIONS Daily sildenafil ameliorates endothelial function as assessed by levels of biomarkers of endothelial function in patients with erectile dysfunction. This is in agreement with other studies showing similar benefits with phosphodiesterase-5 inhibitor treatment. The clinical implications of this finding warrant further investigation.