Nasal obstruction as a risk factor for sleep apnoea syndrome

Nasal obstruction has frequently been mentioned as a possible risk factor i n obstructive sleep apnoea syndrome (OSAS). Over a 2-yr period, 541 unselected consecutive snorers referred for suspect ed breathing disorders during sleep were included to undergo posterior rhin omanometry, In addition cephalometric landmarks and body mass index (BMI) w ere obtained. Polysomnography was used to determine the number of abnormal respiratory events that occurred during sleep, OSAS was defined as 15 episo des, or more, of apnoea or hypopnoea per hour of sleep (AHI). Of the 541 consecutive snorers 528 underwent nasal resistance measurement b y posterior rhinomanometry (failure rate: 2.4%), Patients with OSAS (259 pa tients) had higher nasal resistance than patients without OSAS (2.6+/-1.6 h Pa.s(-1) versus 2.2+/-1.0 hPa.L.s(-1), respectively, p<0.005). A stepwise multiple regression analysis showed that BMI, male sex, nasal re sistance, and cephalometric parameters were contributing factors to the AHI . The r(2)-value of the multiple regression analysis was 0.183. Nasal resis tance contributed 2.3% of the variance (p<0.0001), whereas mandibular plane -hyoid distance, EMI, male sex and age contributed 6.2%, 4.6%, 3% and 1.3% of the variance, respectively. To conclude, daytime nasal obstruction is an independent risk factor for OS AS.