Hallmarks of EDCs among children in Southern China in Relation with obstructive sleep apnea

Childhood obstructive sleep apnea (OSA) is a common pediatric sleep disorder characterized by recurrent sleep-related upper airway dysfunction. China has the highest number of OSA sufferers (176 million) globally. Environmental endocrine-disrupting chemicals (EDCs) posed unrecognized threats to pediatric OSA are not clear. We examined the associations of 34 kinds of EDCs with childhood OSA in Southern China. We recruited 334 children aged ≤ 15 years (July-September 2022) from a tertiary sleep clinic in Shenzhen. Using HPLC-MS/MS, we quantified 7 organophosphate flame retardants (OPFRs), 3 parabens, 10 phthalate metabolites (PAEs), 4 benzophenones (BPs), 7 synthetic phenolic antioxidants (SPAs), and 3 bisphenols. Multivariable linear regression evaluated single-chemical associations with polysomnography-derived indices: apnea-hypopnea index (AHI), obstructive AHI (OAHI), oxygen desaturation index (ODI), and blood oxygen saturation (SpO₂) levels. Mixture effects were assessed through quantile-based g-computation (Qgcomp). Multiple EDCs demonstrated significant dose-response relationships with AHI, OAHI, and ODI (p < 0.05), while inversely associated with SpO₂. Qgcomp revealed each tertile increase in EDC mixture concentration corresponded to elevated AHI [18.53 % (95 % CI: 6.18 to 32.31)], OAHI [23.27 % (13.88 to 34.99)], and ODI [15.03 % (5.13 to 24.61)], along with decreased baseline SpO₂ [-0.25 (-0.49 to -0.01)], lowest SpO₂ [-1.09 (-2.17 to -0.01)], and mean SpO₂ [-0.39 (-0.70 to -0.07)], with DBP exhibiting the strongest negative effects on AHI, OAHI, and ODI, and BCIPP showing the greatest positive effects on baseline and mean SpO₂. This first biomonitoring study implicates EDC mixtures, particularly phthalates and OPFRs, in pediatric OSA pathogenesis. Our findings underscore the need for chemical policy reforms and longitudinal investigations elucidating biological mechanisms linking environmental exposures to sleep-disordered breathing.