Atopy influences exhaled nitric oxide levels in healthy schoolchildren

Aim ofthestudywastoinvestigatethefactorsinfluencingeNOlevelsina sample ofschoolchildrenwithorwithoutrespiratorydisease.Westudied767 schoolchildren, aged10-16years,randomlyselectedfrom16juniorhighschools of Palermo,Italy.Arespiratoryquestionnairewasfulfilled.Spirometry,skin tests, andoraleNOmeasureswereperformed.Amongsubjects,13.7%reported symptoms ofbronchialasthma(A),25.7%hadrhinitis(R),and60.6%were asymptomatic (C).TheFEV1/FVC%was88.8%(±6.1 SD)inA,90.5%(±6.0) in Rand90.9%(±6.6) inC(p<0.002). Atopicswere55.2%inA,43.9% in R,and35.9%inC.Amongatopicsubjects,194(62.4%)hadapositive skin testfordermatophagoides.MedianexhaledNO(andinterquartilerange) was19.5ppb(12.7-35.0)inatopicsand13.9ppb(10.6-18.4)innonatopics (p<0.0001). Amongasymptomatics,atopicshadsignificantlyhighereNOthan non atopics(p<0.0001). Doctordiagnosedasthmawasassociatedtoincreased eNO valuesonlyinatopicsubjects(p=0.0005).NaturallogofeNOwasstrongly correlatedtothetotalsumofwhealsizes(p <0.0001). Atopyandperennial allergenswerepredictorsofincreasedeNOinalogisticmodel,whenadjusted for FEV1/FVC%,FVCandheight.Ourstudypointsoutthattheatopicstatus(in particula