Relationship between rapid eye movement sleep and testosterone secretion in normal men

The relation between the pituitary-gonadal hormones' rhythm and sleep physi ology in men is not fully elucidated. To examine whether the reproductive h ormones are correlated with sleep architecture, we determined the nocturnal serum levels of testosterone, luteinizing hormone (LH), and follicle-stimu lating hormone (FSH) in six healthy young men. Serum hormone levels were ob tained every 15 minutes from 1900 to 0700 hours with simultaneous polysomno graphic sleep recordings. Hourly testosterone levels were lowest when subje cts were awake (1900-2200 hours) than during sleep (2300-0700 hours). Testo sterone nocturnal rise antedated the first REM by about 90 minutes. The ris e in testosterone levels was slower when REM latency was longer. Mean noctu rnal testosterone levels did not correlate with the number of rapid eye mov ment (REM) episodes. Also, pre-non-REM (NREM) testosterone levels were high er as compared with the pre-REM periods and lower during the first NREM per iod as compared with other nocturnal NREM periods. Serum LH levels disclose d a nocturnal rise that preceeded a similar rise in testosterone by about a n hour. We conclude that in young adult men, testosterone levels begin to r ise on falling asleep, peak at about the time of first REM, and remain at t he same levels until awakening.