Background: Endothelial dysfunction is a key event in the pathophysiology of erectile dysfunction (ED) and generalized vascular disease. C-type natriuretic peptide (CNP) is a paracrine molecule that effects endothelial integrity and vascular tone.
Objective: To determine the role of CNP in men with vasculogenic ED.
Design, setting, and participants: Fifty-two consecutive men (age: 57+/-10 yr) with nonpsychogenic and nonhormonal ED for >6 mo and free of cardiovascular disease who were referred to the Cardiovascular Diseases and Sexual Health Unit of our Department for evaluation of ED were compared with 31 subjects with normal erectile function matched for age, body mass index, and traditional risk factors.
Measurements: Vasculogenic ED was diagnosed according to comprehensive history, physical examination, Sexual Health Inventory for Men (SHIM-5) scoring, hormonal testing, and penile color-Doppler ultrasound. Amino-terminal proCNP (NT-proCNP) was measured in plasma with enzyme-linked immunosorbent assay (ELISA).
Results and limitations: Compared to controls, ED patients had significantly lower NT-proCNP levels (0.21+/-0.08 pmol/l in ED patients vs 0.34+/-0.07 pmol/l in control subjects; p<0.001). NT-proCNP levels were associated with erectile performance as expressed by SHIM-5 score (r=0.57; p<0.001), even after adjusting for confounders. There was also an inverse linear relationship between ED duration and NT-proCNP levels (p<0.05). In patients with arteriogenic ED, there was a positive correlation of NT-proCNP levels with peak systolic velocity (PSV) (r=0.51; p=0.01).
Conclusions: CNP levels are associated with the presence, severity, and duration of ED. These findings provide further insight into the role of CNP in the pathophysiology of ED.