TNF-α gene polymorphisms and excessive daytime sleepiness in pediatric obstructive sleep apnea

Objective: To assess sleepiness, TNF-α plasma levels, and genomic variance in the TNF-α gene in children with obstructive sleep apnea (OSA). Study design: Children being evaluated for OSA (n = 60) and matched control children (n = 80) were assessed with a modified Epworth Sleepiness Scale questionnaire and underwent a blood draw the morning after nocturnal polysomnography. TNF-α plasma concentrations were assayed using ELISA, and genomic DNA was extracted. Genotyping and allelic frequencies were determined for 4 TNF-α single nucleotide polymorphisms using real-time polymerase chain reaction genotyping assays. Results: Morning TNF-α levels and Epworth Sleepiness Scale scores were increased in the presence of OSA, but substantial variability was present. Although TNF-α plasma concentrations were globally increased in OSA, most of the variance was attributable to the presence or absence of TNF-α -308G gene polymorphism. Conclusions: TNF-α levels are increased in a subset of children with OSA, particularly among those harboring the TNF-α -308G single nucleotide polymorphism. Among the latter, significant increases in excessive daytime sleepiness symptoms are also present. The relatively high variability of excessive daytime sleepiness in pediatric OSA may be related to underlying TNF-α gene polymorphisms, particularly -308G.