TY - JOUR T1 - Nightly variability of obstructive sleep apnoea/hypopnoea syndrome measured over 2 nights JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P2275 AU - Meriem Mjid AU - Yassine Ouahchi AU - Sonia Toujani AU - Salma Mokkadem AU - Nozha Ben Salah AU - Abdelmajid Ben Hmida AU - Bechir Louzir AU - Nadia Mhiri AU - Jouda Cherif AU - Majed Beji Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P2275.abstract N2 - Apnoea/hypopnoea index (AHI) is the primary measurement used to characterize obstructive sleep apnoea/hypopnoea (OSAHS). Despite its popularity, there are limiting factors to its application as night-to-night variability. This study aims to evaluate variability of AHI and to determine its possible relationship with other clinical features. A prospective study was designed in a University Hospital's sleep unit. Adults with clinical suspicion of OSAHS underwent 2 consecutive nights of polygraphic recording. Then, population was divided in 2 groups (P1=AHI variation>10, P2=AHI variation<10). Exclusion criteria were clinical diseases or occupations that might result in sleep alterations, sleep deprivation or altered sleep/wake cycle. Twenty patients were enrolled (13women,7men). Mean age was 50.6 years±9,315. Mean Body Mass Index (BMI) was 36,35 kg/m2±9,051. Clinical manifestations were dominated by snoring and day time sleepiness. AHI values weren't significantly altered throughout the 2 recording nights (33.20event/h vs 31.85event/h). On the first night, 4 patients were classified as having light OSAHS, 6 were moderate and 8 presented severe apnea. AHI was lower than 5 in 2 patients. In the second night, classification has changed in 8 patients (40%). Among them, 4 changed to a more severe stage. Moreover, comparison between P1(n=7) and P2(n=10) showed no differences in regard to age and BMI (p<0.05). Our study demonstrates that AHI in OSAHS patients presented a good correlation among the 2 nights. However, a significant individual variability should be considered, especially when AHI is applied in OSAHS classification or as a criterion of therapeutic success. ER -