Language
Discrepant findings have been reported in studies investigating the impact of pediatric SDB on language. In comparison to normative data, children with SDB have average expressive language abilities.11,16-17 These findings are consistent across multiple language measures, including but not limited to the WISC-III,16,23 Expressive Vocabulary Test,11,31 and NEPSY: A Developmental Neuropsychological Assessment32 Language Domain.17Findings regarding receptive language in this population are mixed. The majority of studies reported average receptive language abilities across multiple measures, including but not limited to the Peabody Picture Vocabulary Test11,33 and NEPSY32receptive language tasks.11,18,34-35
Despite broadly average performance on language tasks in children with SDB compared to normative data, differences emerge when comparing language abilities in children with SDB to control groups. Multiple studies reported greater language impairment in children with SDB on expressive29 and receptive9,17-18,29-30,34 language tasks compared to controls. One study that followed infants with SDB over time reported that at two years of age, children with persistent SDB symptoms scored 5.3 points lower on a measure of language compared to children without SDB symptoms.29 Other studies reported no differences on language performance across pediatric SDB and control groups.18,34
Limited research has investigated differences in expressive and receptive language performance across multiple SDB severity levels in children. Hunter et al11 reported that children with moderate to severe SDB (AHI >5) performed worse on a NEPSY receptive language task than children with less severe SDB. The same study reported no differences across SDB severity levels on other language tasks.11 Biggs et al18similarly reported no significant differences across SDB severity level and language performance.
To determine the impact of SDB on language, research has explored the associations between respiratory status and language performance. Results indicate that a number of respiratory indicators, including the respiratory disturbance index,18 oxygen desaturation,36 sleep duration,29and frequency of snoring9 were associated with poorer expressive29,36 and receptive9,18,29language performance in children with SDB.
The studies reviewed above are limited by their examination of language as a broad construct. Future studies should expand on language profiles in children with SDB by incorporating measures of articulation, auditory processing, and social pragmatics. In addition, the literature reviewed above is characterized by discrepancies regarding language development in children with SDB. Definitions of SDB and SDB severity varied across studies. For example, one study measured SDB with a composite score that combined respiratory variables,17 while another measured SDB according to AHI.18 Without consistent SDB indicators and severity categories, it is challenging to meaningfully compare results across studies. Additionally, not all studies measured important covariates such as SES11,36and BMI,16,36 which are known to influence SDB and cognitive performance.