All children were recruited at the Children’s Hospital atMontefiore (CHAM), Bronx, New York. The study was approvedby the Committee of Clinical Investigations at Albert EinsteinCollege of Medicine, Bronx, New York. Sixty-four obese childrenwith intact tonsils and adenoids in the age range of 8 to 17years (BMI >95th percentile for age and gender) were initiallyenrolled into the study. After an overnight polysomnography(PSG) study, each subject was classified as an OSAS or a control.Subjects were excluded if they had abnormal developmentor a known metabolic or endocrine disorder. Subjects were alsoexcluded if they had complete unilateral or bilateral nasalobstruction, which precludes measuring nasal resistance withanterior rhinomanometry. Thus, two of the OSAS subjects wereexcluded from final analysis due to unilateral nasal obstruction.Overnight PSGTo evaluate for the existence and severity of OSAS, overnightPSG (Xltek, Oakville, ON, Canada) was conducted at theSleep Disorders Center at the CHAM. OSAS was defined if theapnea index (AI) was 1/hour and/or the apnea-hypopnea index(AHI) was 5/hour. Sleep scoring was performed according tostandard criteria as defined by the American Academy of SleepMedicine.15Active aNRTo measure aNR we used the AAR technique.16 Accordingly,transnasal pressure and airflow were measured separately ineach nostril during quiet tidal breathing in the supine positionduring wakefulness. Airflow and pressure were collected by aresearch grade clinical rhinomanometer (NR6; GM Instruments,Kilwinning, UK) with a face mask. Patients were allowed to blowtheir nose prior to test if needed. We used disposable foam plugsfitted with a pressure-sensing tube inserted into one nostril tocarry out the pressure measurement while airflow through theother nostril was measured by a pneumotachometer. Measurementof the opposite nostril was performed in the same fashion.Thus, pressure measured in the occluded nostril is equivalent tothe driving pressure at the choanal junction, because the air columnin the occluded nostril is stagnated. Subjects maintained aclosed mouth during the measurement. Measurements includedfour breathing phases: ascending and descending phases duringinspiration and expiration.Unilateral nasal resistance. Unilateral nasal resistance(uNR) of each nostril was defined at the 150 Pa standard transnasalpressure value (Fig. 1). Twelve respiratory cycles wererecorded and averaged for each subject during inspiration andexpiration. Measurements were discarded if flow and pressurewaveforms were atypical of normal breathing.aNR. aNR was calculated using the two parallel resistancesaddition: (uNRR 3 uNRL)/(uNRR1uNRL), where uNRR anduNRL are right and left unilateral measurements, respectively.Statistical MethodsDemographics, polysomnographic, and rhinomanometrydata are presented as mean6standard deviation values forOSAS and control groups. End points between groups werecompared using two-tailed unpaired t tests, and Spearman correlationanalysis was performed to evaluate the associationbetween aNR and AHI, gender, and BMI z score for all subjects.P<.05 was considered significant. A commercial statistical softwarepackage (SigmaPlot version 12; Systat Software, San Jose,CA) was used for all statistical computations
การแปล กรุณารอสักครู่..
