Surfactant protein D concentration in a pediatric population with suspected sleep disorder.

Abstract

[eng] Obstructive sleep apnea (OSA) affects between 2% and 4% in children andthere is a search for new biomarkers that can be useful both in the diagnosis andin the evolution of the disease. The surfactant protein D (SP‐D) is a collectionthat is part of the innate immune system exerting an anti‐inflammatory andantimicrobial effect. Thus, the objective of this study was to evaluate theconcentration of SP‐D in the suspect OSA pediatric population. A total of 178children were recruited in this prospective study. Blood samples, sleep para-meters, feeding habits, anthropometric, sociodemographic, and family datawere collected. Specific biochemical determinations were made, and the plas-matic concentrations of SP‐D were measured by enzyme‐linked immunosorbentassay. We found no statistical correlation between the SP‐D concentration andthe apnea‐hypopnea index (AHI) from the data. Nevertheless, the changes inSP‐D levels could be correlated to a large extent by the arousals that often goalong with hypopneas (r = −0.258, p = 0.011 unadjusted; r = −0.258, p = 0.014adjusted by age and body mass inded [BMI] Z‐score). Intermittent hypoxia wascorrelated with C‐reactive protein levels (r = 0.547, p < 0.001 unadjusted;r = 0.542, p < 0.001 adjusted by age and BMI Z‐score). Although AHI and SP‐Ddid not appear to correlate, a secondary analysis suggests that sleep fragmen-tation, which is produced by arousals, may do, and further research is needed todetermine the mechanisms by which changes in SP‐D occur in OSA