There are many researches that demonstrate that the position of the patient modified the apnea-hypopnea index(IAH). In supine position the IAH will increase comparing with lateral position during th sleep. However few studies were done with the elevation of the head of the bed.~First the investigators will do a standard polysomnography and see if the patients are included analysing the criteria like apnea-hypopnea index equal or more than 5. Within 2 weeks the patient will do the second polysomnography but this will be with a elevation of the head of the bed (15 cm of elevation of the bed doing a inclination). Then the investigators will compare the data of apnea-hypopnea index in the standard polysomnography versus the index with the elevation of the head of the bed.The main outcome will be to analyze the apnea hypopnea index comparing standard polysomnography (sPSG) with elevated polysomnography (ePSG).
The purpose of this study is to determine if the elevation of the head of the bed in patients with obstructive sleep apnea can decrease the apnea-hypopnea index. First the investigators will do a standard polysomnography and see if the patients are included analysing the criteria like apnea-hypopnea index equal or more than 5. Within 2 weeks the patient will do the second polysomnography but this will be with a elevation of the head of the bed (15 cm of elevation of the bed doing a inclination). Then the investigators will compare the data of apnea-hypopnea index in the standard polysomnography versus the index with the elevation of the head of the bed.