Relationship of Asymmetric Dimethylarginine With Penile Doppler Ultrasound Parameters in Men with Vasculogenic Erectile Dysfunction▪

Abstract: Background: Asymmetric dimethylarginine (ADMA), a selective endogenous nitric oxide synthase inhibitor, is elevated in many conditions associated with erectile dysfunction (ED), such as hypertension, diabetes, hyperlipidemia, and renal failure; it is also increased in men with coronary artery disease and ED. The dynamic penile colour Doppler ultrasound is considered the gold standard for the evaluation of penile vascular damage. Objective: We investigated whether the extent of ultrasonographically documented penile vascular disease is associated with higher ADMA levels. Design, setting, and participants: One hundred four consecutive ED patients (mean age: 56±9 yr) without manifest cardiovascular/atherosclerotic disease and 31 subjects with normal erectile function matched for age and traditional risk factors were studied. Measurements: We evaluated penile dynamic colour Doppler parameters of arterial insufficiency (peak systolic velocity) and veno-occlusive dysfunction (end diastolic velocity) and measured systemic inflammatory markers/mediators. Results and limitations: Compared to men without ED, ED patients had significantly higher ADMA levels (p <0.001). ADMA was significantly increased in patients with severe arterial insufficiency (PSV<25cm/s) compared to subjects with borderline insufficiency and men with normal penile arterial function (p <0.001, by analysis of variance). Multivariable analysis adjusting for age, mean pressure, other risk factors, high-sensitivity C-reactive protein, testosterone, and treatment showed independent inverse association between ADMA level and peak systolic velocity (p <0.01). The combination of higher ADMA level with arterial insufficiency showed greater impact on 10-yr risk of a cardiovascular event compared to either parameter alone. Conclusions: ADMA level is independently associated with ultrasonographically documented poor penile arterial inflow. This finding underlines the important role of ADMA as a marker of penile arterial damage and implies a contribution of this compound to the pathophysiology of generalised vascular disease associated with ED. [Copyright &y& Elsevier]