REM Sleep Deprivation and Decrease of Nocturnal Penile Tumescence (NPT) in Young Healthy Males: The Significance of NPT Measurements.

REM Sleep Deprivation and Decrease of Nocturnal Penile Tumescence (NPT) in Young Healthy Males: The Significance of NPT Measurements, Stefan Kamp, Richard Ott, Thomas Knoll, Klaus-Peter Juenemann, Maurice-Stephan Michel, Peter Aiken, and Stephan Bross, Mannheim University Hospital, Germany

Measurement of Nocturnal Penile Tumescences (NPT) is an established tool in the diagnostics of erectile dysfunction. This study was performed to determine the influence of a disturbance of the physiological sleep pattern on NPT in young healthy males and to evaluate the significance of NPT measurement for the diagnosis of erectile dysfunction under inpatient conditions. Ten healthy young males, mean age 25.2 years (range 25-32), were examined during three nights under sleep laboratory conditions. A 12-channel polysomnography was performed to record the sleep stages, and NPT were continuously measured with the RigiScan[TM] device in all three nights. During the second night, we performed additional measurement of vital parameters such as heart rate and blood pressure. In night 3, sleep was interrupted and blood was drawn via an IV line every two hours to determine the serum levels of testosterone, FAI (free androgene index), estradiole, LH, FSH, prolactine, DHEA-S, and SHBG. We found a significant decrease of REM sleep in night 3 versus night 1 and a significant reduction of the overall duration of erections. Phase 3 and 4 sleep was also decreased, whereas $1 and $2 sleep was increased. Analog, the total number of events was significantly decreased during night 3. The amount of NPT, correlated to REM sleep, decreased from 80% in night 1 to 53% in night 3. There was no impairment of the circadian rhythm and pulsatile secretion of the measured sexual hormones seen in this study. We concluded that a normal sleep pattern is crucial for the evaluation of NPT measurements in the diagnostics of erectile dysfunction, and a combination with polysomnography should be performed to exclude false positive results.