Sleep, breathing, and cephalometrics in older children and young adults .2. Response to nasal occlusion

Study objectives: We postulated that nasal occlusion would provide a challange enabling us to assess factors predisposing development of sleep apnea in older children/adolescents and young adults. Factors of interest included sex, age, body mass index (BMI), tonsillar hypertrophy, and cephalometric measurements. Design: Sleep and breathing variables were examined and compared for four groups of subjects between one baseline night and one night of nasal occlusion in a sleep research laboratory. Subjects: Healthy, normal boys (n=23, mean age= 13.3+/-2.1 years), girls (n=22, mean age=13.8+/-1.8 years), men (n=23, mean age=22.2+/-1.5 years), and women (n=24, mean age=22.4+/-1.8 years) were studied. Measurements and results: The following sleep and sleep-related breathing measures showed significant increases in all four groups from baseline to occlusion: percentage of stage 1, number of transient arousals, transient arousal index, apnea index, respiratory disturbance index (RDI), and mean apnea length. No significant relationships were found between occlusion-night RDI and tonsillar size, cephalometric variables, or BMI, either singly or in combination. Conclusions: Subjects' responses to nasal seclusion varied: most demonstrated a minimal and clinically insignificant increase in RDI; few showed a marked increase in RDI. Significant increases of sleep fragmentation-even in the absence of frankly disturbed breathing-indicate that nasal occlusion may secondarily affect waking function if prolonged over a series of nights.