Adenotonsillectomy-related changes in systemic inflammation among children with obstructive sleep apnea

Background: Adenotonsillar hypertrophy is the most common cause of pediatric obstructive sleep apnea (OSA). Although adenotonsillectomy considerably reduces OSA and systemic inflammation, whether and how systemic inflammation influences the effects of adenotonsillectomy on OSA has yet to be determined. Methods: This study investigated the associations between changes in anatomical variables, % changes in subjective OSA-18 questionnaire scores, % changes in 11 polysomnographic parameters, and % changes in 27 systemic inflammatory biomarkers in 74 children with OSA. Results: Fifty-six (75.6%) boys and 18 (24.4%) girls with the mean age of 7.4 ± 2.2 years and apnea-hypopnea index (AHI) of 14.2 ± 15.9 events/h were included in the statistical analysis. The mean period between before and after adenotonsillectomy was 5.6 ± 2.6 months. After adenotonsillectomy, the OSA-18 score, eight of 11 polysomnographic parameters, and 20 of 27 inflammatory biomarkers significantly improved (all p < 0.005). Notably, there were significant associations between change in tonsil size and % change in AHI (r = 0.23), change in tonsil size and % changes in interleukin-8 (IL-8) (r = 0.34), change in tonsil size and % change in and IL-10 (r = -0.36), % change in IL-8 and % change in C-C chemokine ligand 5 (CCL5) (r = 0.30), and % change in CCL5 and % change in AHI (r = 0.38) (all p < 0.005). Interestingly, % change in IL-8 and % change in CCL5 serially mediated the relationship between change in tonsil size and % change in AHI (total effect: β = 16.672, standard error = 8.274, p = 0.048). Conclusion: These preliminary findings suggest that systemic inflammation is not only a complication of OSA but also that it mediates the surgical effects, which may open avenues for potential interventions to reduce tonsil size and OSA severity through the regulation of IL-8 and CCL5.