title: Inflammatory cytokines and childhood obstructive sleep apnoea.
abstract: OBJECTIVE
  To evaluate serum cytokine concentrations in children with and without obstructive sleep apnoea (OSA) and to investigate the effects of OSA treatment on cytokines.
  
  
  METHODS
  Consecutive children with habitual snoring and symptoms suggestive of OSA were recruited. They completed a sleep apnoea symptom questionnaire, underwent physical examination and overnight polysomnography (PSG). OSA was diagnosed if obstructive apnoea index (OAI) >1. A blood sample was collected for analysis of IL-6, IL-8, and TNF-alpha after PSG.
  
  
  RESULTS
  One hundred forty-two children (97 males) with a median (IQR) age of 11.1 years (9.0-12.8) were recruited. The commonest presenting symptoms were nocturnal mouth breathing, prone sleeping position and poor attention at school. Forty-seven children were found to have OSA and they had higher serum IL-6 [0.1 (0.1-0.4) vs 0.1 (0.1-0.1) pg/mL, P = 0.001] and IL-8 [1.7 (1.0-2.3) vs 1.3 (0.9-1.7) pg/mL, P = 0.029] concentrations compared to their non-OSA counterparts. Multiple regression analysis indicated that OAI was significantly associated with both IL-6 (r = 0.351, P <0.001) and IL-8 (r = 0.266, P = 0.002). Sixteen children underwent treatment and there was significant reduction in mean (SD) serum IL-8 after intervention [pre vs post levels of 1.9 (1.0) vs 1.1 (0.6) pg/mL, P = 0.001] independent of weight loss.
  
  
  CONCLUSIONS
  Children with OSA had elevated levels of pro-inflammatory cytokines that normalised following treatment suggesting that the inflammatory response is potentially reversible. Early detection and intervention may be beneficial.
authors.affiliation: Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.
authors.forename: Albert M
authors.initials: AM
authors.lastname: Li
authors.forename: Hugh S
authors.initials: HS
authors.lastname: Lam
authors.forename: Michael H M
authors.initials: MH
authors.lastname: Chan
authors.forename: Hung K
authors.initials: HK
authors.lastname: So
authors.forename: Siu K
authors.initials: SK
authors.lastname: Ng
authors.forename: Iris H S
authors.initials: IH
authors.lastname: Chan
authors.forename: Christopher W K
authors.initials: CW
authors.lastname: Lam
authors.forename: Yun K
authors.initials: YK
authors.lastname: Wing
mesh_terms: D002648:Child; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood; D008297:Male; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000628:therapy; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D016207:Cytokines; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha