Comparison of two exhaled biomarkers in children with and without sleep disordered breathing.
OBJECTIVE
Airway oxidative stress and inflammation are likely to be involved in sleep disordered breathing (SDB) in children. We aimed to measure concentrations of 8-isoprostane (8-IsoP) in the exhaled breath condensate (EBC) and exhaled nitric oxide (FENO) in patients with SBD and healthy children, in order to assess the relationship between these two biomarkers, disease severity, and overnight changes.


METHODS
Patients with SDB (n = 46) and healthy controls (n = 20) aged 4.5-15.1 years (M/F: 36/30) underwent exhaled measurements. Patients with SDB underwent standard polysomnography to define primary snoring (PS: AHI < 1) and obstructive sleep apnea (OSA). Upon awakening the following morning, FENO was measured and EBC was collected for the measurement of EBC 8-IsoP.


RESULTS
OSA patients yielded higher awakening levels of 8-IsoP in EBC than PS patients and control subjects. The 8-IsoP levels, though not FENO, correlated with AHI (r = 0.40, p = 0.003) and SaO2 (r = -0.50, p = 0.001). Cut-off levels of 8-IsoP predicted OSA with a high AUC value (0.84, p = 0.000). Sensitivity and specificity for 8-IsoP levels above the percentile 50 (33.3 pg/mL) were 76.5% and 78.1%, respectively. 8-IsoP levels did not change from the evening to morning session, whereas morning FENO levels rose significantly only in patients with mild OSA (p = 0.03).


CONCLUSION
Levels of 8-IsoP, though not FENO, distinguish children with OSA from those with PS or healthy, correlate with disease severity and closely predict OSA in the whole sample.
['Barreto|Mario|M|', 'Montuschi|Paolo|P|', 'Evangelisti|Melania|M|', 'Bonafoni|Susanna|S|', 'Cecili|Manuela|M|', 'Shohreh|Rugia|R|', 'Santini|Giuseppe|G|', 'Villa|Maria Pia|MP|']
D000293:Adolescent D015415:Biomarkers D002648:Child D002675:Child, Preschool D015237:Dinoprost D005260:Female D006801:Humans D008297:Male D009569:Nitric Oxide D017286:Polysomnography D012680:Sensitivity and Specificity D012720:Severity of Illness Index D012891:Sleep Apnea Syndromes D012913:Snoring
Biomarkers Children Sleep disordered breathing Inflammation Snoring