Abstract
RATIONALE: Sleep-disordered breathing (SDB) in children is associated with cognitive challenges. However, potential associations between SDB severity and neurocognitive function, as well as the presence of an SDB cutoff, have not been fully explored. OBJECTIVES: To determine whether SDB-associated adverse changes in neurocognitive functioning are severity dependent. METHODS: A total of 1,010 snoring and nonsnoring children ages 5-7 years were prospectively recruited from public schools and underwent polysomnography and neurocognitive assessments of intellectual, attention, memory, language, and executive function development. The children were subdivided into four severity groups on the basis of apnea-hypopnea index (AHI), followed by comparisons of cognitive function, with a particular focus on standardized subtests of intellectual, language, attention, memory, and executive function. MEASUREMENT AND MAIN RESULTS: Differential Ability Scales Verbal (P < 0.001) and Nonverbal (P = 0.002) performance, as well as global conceptual ability (IQ) (P < 0.001) scores, differed significantly across the groups, with individuals with higher AHI showing worse performance. Additionally, specific NEPSY (a Developmental Neuropsychological Assessment) subscores focused on attention and executive skills differed across the groups, indicating differences in levels of engagement and problem solving. Children with higher AHI (>5 per hour of total sleep time) were significantly more impaired than all three lower AHI groups, indicating a dose-response impact of SDB. CONCLUSIONS: This large community-based sample of children highlights the significant deleterious impact of SDB, particularly in children with moderate to severe obstructive sleep apnea, and also that even snoring alone affects neurocognitive function. By affecting developing capabilities, as illustrated by cognitive measures in a severity-graded manner, SDB could adversely impact children's capacity to attain academic and adaptive goals, ultimately hampering their ability to reach independence. Our findings support the need for increased awareness of SDB, with particular emphasis on children with more severe obstructive sleep apnea.