Nocturnal penile tumescent evaluation of erectile function in insulin-dependent diabetic men.

This study compared nocturnal penile erections in four age-matched groups of young subjects: diabetic patients with and without erectile problems, psychogenically impotent men and healthy control subjects. All men were assessed under similar conditions during three nights, each for a total of 156 study nights. Diabetic impotent men exhibited a significantly decreased number of erectile episodes (p less than 0.05) and episodes of maximum tumescence per night (p less than 0.01). They also spent significantly less time in tumescence (p less than 0.005) and in simultaneous rapid eye movement sleep and tumescence (p less than 0.005). Diabetic men without sexual problems, psychogenically impotent men, and normal control subjects did not differ. Diabetic men in both groups spent less sleep time in rapid eye movement sleep and had longer latencies to onset of rapid eye movement. The decreased time in erection noted in impotent diabetic patients was no longer significant when adjusted for differences in duration of rapid eye movement sleep. In comparison to healthy control subjects and psychogenically impotent men, non-impotent diabetic men did show significantly diminished circumferential increases during erections, similar in degree to impotent diabetic patients (p less than 0.05).