Penile tumescence monitoring during morning naps to assess male erectile functioning: an initial study of healthy men of varied ages.

Whether sleep erections occurred during morning naps (preceded by modest sleep deprivation) in healthy men whose ages were representative of clients in sexual health clinics was assessed. Subjects (N = 30) reduced their normal sleep time to increase the likelihood that they would experience rapid eye movement (REM) sleep [closely associated with nocturnal penile tumescence (NPT)]. They then reported to an outpatient psychophysiological laboratory for an early morning nap, during which sleep and penile tumescence measures were recorded continuously. All subjects were able to sleep during at least 1 of their 2 recorded sessions, 24 (80%) experienced REM sleep, and 22 (73%) experienced tumescence episodes consistent with previous NPT studies. The magnitude of these erections could reduce concerns about the presence of organic pathology, and obviate the need for an NPT study. Results suggest that monitoring tumescence during naps may be useful as an inexpensive and convenient screening approach in the assessment of male erectile functioning.