Arterial erectile dysfunction: reliability of penile Doppler evaluation integrated with serum concentrations of late endothelial progenitor cells and endothelial microparticles.

We recently showed the diagnostic value of a new immunophenotype of blood endothelial progenitor cells (EPC) (CD45(-)/CD34(+)/CD144(+)) and endothelial microparticles (EMP) (CD45(-)/CD144(+)/annexin V(+)) in patients with arterial erectile dysfunction (AED), particularly in patients with associated late-onset hypogonadism and/or metabolic syndrome. In addition, we evaluated the effects of androgen replacement therapy, aerobic physical activity, and tadalafil administration on these markers. The aim of this study was to evaluate the serum concentrations of EPCs and EMPs in a large cohort of patients with AED according to severity of cavernous arterial insufficiency evaluated by penile Doppler. A total of 120 patients (aged 58.0 ± 6.0 years) with AED were enrolled in this study. Patients were classified into 3 groups based on value of peak systolic velocity (PSV). Group A: 37 patients with PSV <25 cm/s (severe arterial insufficiency); group B: 40 patients with PSV between 25 and 29 cm/s (moderate arterial insufficiency); group C: 43 patients with PSV between 30 and 34 cm/s (mild arterial insufficiency). Twenty patients (aged 60.0 ± 3.0 years) with psychogenic erectile dysfunction (PED) represented the control group. EPC and EMP blood concentrations were evaluated by flow cytometry. Patients with AED had significantly higher blood pressure, triglyceride levels, homeostasis model assessment index of insulin resistance, cavernous artery acceleration time, and intima-media thickness than those with PED, whereas International Index of Erectile Function score, high-density lipoprotein cholesterol level, and cavernous artery PSV were lower than those in PED. Both EPC and EMP levels were significantly higher in patients with AED compared with patients with PED. Among 3 groups of patients with AED, there were no significant differences in metabolic parameters examined, but group A showed significantly higher values of cavernous artery acceleration time and intima-media thickness than group B and group C. Finally, group A showed serum concentrations of EPCs and EMPs significantly higher compared with other groups with AED. Patients with AED showed worse metabolic parameters, cavernous artery parameters, and EPC and EMP levels compared with patients with PED. Among patients with AED, those with PSV <25 cm/s showed worse findings of endothelial dysfunction. This suggests that AED is an expression of endothelial damage and that this original immunophenotype of EPCs and EMPs may be considered a predictor of endothelial dysfunction in patients with AED. Finally, this study confirmed the reliability of penile Doppler evaluation integrated with these serum markers of endothelial dysfunction.