Effects of sexual arousal on vibrotactile detection thresholds in aged men with and without erectile dysfunction.

BACKGROUND Erectile dysfunction (ED) is a common problem in ageing men. Abnormalities in sexual arousal may contribute to its development, and to the failure of pharmacological therapies. However, there are few objective ways of assessing arousal. Sexual arousal has been shown to affect vibrotactile detection thresholds (VDT) in young, healthy men. The present study assessed the effects of sexual arousal on VDT in middle-aged men with and without ED in order to determine whether differences exist between the groups and if such differences may be useful in the evaluation of ED. METHODS VDT in the right index finger of 15 heterosexual men (mean age 74.3 +/- 6.0 years) who had been formally diagnosed with ED (ED group) and 16 men (mean age 68.0 +/- 6.6 years) who reported no sexual dysfunction in the past 6 months (erectile function (EF) group) were measured before and after watching erotic and control videos using a forced-choice, staircase method at frequencies of 30, 60 and 100 Hz. A mechanical stimulator was used to produce the vibratory stimulus. Results were analysed using repeated-measures analysis of variance. RESULTS There was no significant effect of watching the erotic video on VDT in subjects in the ED group. In the EF group, VDT was significantly lower at 60 and 100 Hz after watching the erotic video. There was no change in VDT after watching the control video in either group. CONCLUSION In response to sexual arousal, VDT in ageing men with normal erectile function decrease, whereas VDT in ageing men with ED remain unchanged.