Association of peripheral microvascular dysfunction and erectile dysfunction.

PURPOSE: Increasing evidence of a link between erectile dysfunction and cardiovascular disease suggests a shared vascular etiology with endothelial dysfunction as a plausible underlying biological mechanism. To our knowledge whether this association is different for large arterial endothelium compared to microvascular endothelium has not yet been established. We investigated the association of erectile dysfunction with macrovascular and microvascular endothelial function.

MATERIALS AND METHODS: A sample of 390 men with a mean age of 55.5 years was recruited from the BACH survey, a population based survey of urological symptoms. Erectile dysfunction was assessed using IIEF-5. The percent of brachial artery flow mediated dilatation, a measure of macrovascular function, and hyperemic flow velocity in cm per second, a measure of microvascular function, were assessed by ultrasound. Linear regression was used to assess the association of erectile dysfunction and endothelial function, and adjust for potential confounders.

RESULTS: Reactive hyperemia was lower in men with vs without erectile dysfunction (mean ± SE 97.1 ± 2.5 vs 106.0 ± 1.6 cm per second, p = 0.003). However, the difference in flow mediated dilatation between men with vs without erectile dysfunction was statistically nonsignificant (mean 6.6% ± 0.33% vs 7.2% ± 0.24%, p = 0.147). The association of erectile dysfunction with reactive hyperemia was attenuated but it remained statistically significant in men with moderate to severe erectile dysfunction (IIEF-5 less than 12) after adjusting for traditional cardiovascular risk factors (p = 0.038).

CONCLUSIONS: These results provide evidence of greater microvascular than macrovascular endothelial dysfunction as a potential contributor to erectile dysfunction and an underlying mechanism linking erectile dysfunction and cardiovascular disease.