Erectile dysfunction in hypertensive men: sleep-related erections, penile blood flow and musculovascular events.

To explore how hypertension affects penile erection, we studied erectile hemodynamics during nocturnal penile tumescence in 3 groups of middle-aged men: hypertensive patients with and without erectile dysfunction, and normotensive controls without erectile problems. The hypertensive patients were not taking antihypertensive medication. Evaluations included standard monitoring of penile circumference change as well as noninvasive monitoring of penile segmental pulsatile blood flow and activity in the bulbocavernosus-ischiocavernosus muscles. Variables differed in how they discriminated among groups. Median amplitude of penile blood flow during rapid eye movement sleep differed significantly among all 3 study groups: controls had the highest amplitudes, patients without erectile problems had lower values and patients with erectile complaints had the lowest values. By contrast, standard measures of nocturnal penile tumescence (that is based on penile circumference change during sleep) only distinguished the patients with erectile problems from the 2 other groups. Density of musculovascular event clusters during rapid eye movement sleep (nearly simultaneous muscle activity burst, blood flow burst and circumference pulsation) distinguished the 2 groups of hypertensive men from controls. The sensitivity of the blood flow measure to changes in the hypertensive men without erectile complaints may indicate that the measure can reveal subclinical signs of developing vasculogenic erectile dysfunction.