Nocturnal penile tumescence and penile responses in the waking state in diabetic and nondiabetic sexual dysfunctionals.

This study compared diabetics with sexual dysfunction, nondiabetics with sexual dysfunction, and a group of controls on nocturnal penile tumescence (NPT) during three nights in a sleep laboratory, and penile response to erotic stimulation in the waking state on one of the nights. Both diabetic and nondiabetic dysfunctionals showed less erectile response to erotic films and tape than controls but did not differ from each other. In contrast, the diabetic dysfunctionals showed significantly weaker NPT response than both the nondiabetic dysfunctionals and the controls, and 58% of them (contrasted with 23% of nondiabetic dysfunctionals and 0% of controls) would be classified as organic using minimal NPT (less than 11.5 mm maximal increase in penile circumference during any nocturnal erection) as the sole criterion. There was a significant relationship between NPT and waking erections in response to erotic stimuli, especially in the diabetic dysfunctionals and the controls.