Correlation of 8-isoprostane, interleukin-6 and cardiac functions with clinical score in childhood obstructive sleep apnoea

Objective: Adeno-tonsillar hypertrophy is the commonest cause of childhood obstructive sleep apnoea (OSA). Our aim of the study is to correlate the severity of OSA with levels of 8-isoprostane and interleukin-6 (IL-6) and with cardiac diastolic dysfunctions. Methods: Forty children with adenoidal hypertrophy and 20 control children were recruited. The OSA clinical score was evaluated and IL-6 and 8-isoprostane were measured in exhaled breath condensate. The cardiac functions were evaluated by conventional and tissue Doppler echocardiography (TDE). Results: Higher concentrations of isoprostane-8 and IL-6 were found in group with clinical score > 40 (58.595 +/- 2.86 pg/mL and 38 +/- 1.77 pg/mL, respectively) than in control group (34.9 +/- 1.5 pg/mL and 7.02 +/- 0.3 pg/mL, respectively) {p < 0.0001*}. There was positive correlation between level of isoprostane-8 and IL-6 and value of clinical score {p < 0.0001*} and also with the degree of the cardiac dysfunction in those children. Conclusion: The severity of OSA as indicated by clinical score was positively correlated with degree of elevation of 8-Isoprostane and IL-6 in breath condensate of children with OSA and also with degree of cardiac dysfunction. Echocardiography and tissue Doppler modality are advised to examine these children.