The investigators recruited 56 recently diagnosed OSA patients, confirmed by full polysomnography (PSG), referred to Sleep Laboratory of Psychobiology Department of Federal University of Sao Paulo, Brazil, according to the following inclusion criteria: both genders aging from 29 to 70 years old, with apnea-hypopnea index (AHI) >5 events/hour of sleep. Control group comprised 50 healthy community subjects without OSA confirmed by full PSG, matched by age, gender, and BMI.