In this study will be recruited volunteers 25-50 years of age with a body mass index (BMI) 20-25 kg/m2 (normal) that after performing polysomnography, will be distributed in the following groups: healthy or diagnosed with obstructive sleep apnea syndrome (OSA). Volunteers without OSA will be submitted to total sleep deprivation (SD) or selective REM sleep deprivation for 48 hours. After SD, these volunteers will be allowed to sleep for 48 hours (period rebound). Blood samples will be taken for hormonal analysis (testosterone, luteinizing hormone, follicle-stimulating hormone, progesterone and cortisol)and gene expression. The semen collection for evaluation of sperm count (concentration, viability and sperm morphology) in three different periods, baseline collection, after SD protocols and the end of rebound period. Individuals diagnosed with OSA also have three collections of blood and semen samples for analyzes.