SLEEP-DISORDERED BREATHING IN ADULTS AND CHILDREN WITH CYSTIC FIBROSIS

Abstract

Chronic airway obstruction may determine early hypoxaemia during exercise and sleep even in patients with normal diurnal blood gases. The aim of our study was to establish the occurrence of sleep-disordered breathing (SDB) in a cohort of patients with cystic fibrosis (CF), followed in our Cystic Fibrosis Unit. We therefore studied 55 patients (49% M; 36% children (mean age 4.3±3.9, SaO2 % awake 97.7±1.5); 64% adults (mean age 20.9±4.9, BMI 21.1±3.6, SaO2 % awake 97.1±1.1). All patients, in stable clinical conditions, underwent a nocturnal standard polysomnography (sleep monitoring system Compumedics S-Series) and respiratory functional evaluation during the day. Scoring of respiratory events was performed according to standard criteria. Polysomnographic monitoring revealed the occurrence of SDB, defined as an apnea-hypopnea index (AHI) >5, in 52% of adults and in 56% of children. In adults we found mean AHI 16.8±7.8, mean nocturnal SaO2 93.9%±2.3, mean SaO2 min 88.2%±2.2; in children we found mean AHI 12.5±5.8, mean nocturnal SaO2 93.7%±1.2, mean SaO2 min 89.2%±3.2. In both adults and children we found a similar prevalence of upper airways obstruction (sinusitis and rhinitis), a major cause of SDB, in groups with SDB and without SDB. In adults we found a lower mean FEV1% in the group with SDB as compared to the group without SDB (50% vs 64%, respectively). These data show a high prevalence of sleep-disordered breathing in patients with cystic fibrosis. In these patients SDB occurs in an early phase of life and in adulthood SDB seems to be associated to a lower respiratory function.