title: Combined use of fractional exhaled nitric oxide and bronchodilator response in predicting future loss of asthma control among children with atopic asthma.
abstract: Recognition of patients at risk of asthma exacerbation is important for future asthma care and improved outcome. The aim of the present study was to see whether measurements of bronchodilator response (BDR) and fractional exhaled nitric oxide (FeNO) in combination provide prognostic information superior to either measurement alone in children with atopic asthma.
  
  
  
  A total of 201 atopic children aged 8-16 years with intermittent or mild persistent asthma were included. Pulmonary function tests including BDR and FeNO were serially monitored 10 times or more over 2 years when subjects were not receiving controller medications. After completion of monitoring, 1-year observation for a loss of asthma control was performed.
  
  
  
  During the monitoring period, positive BDRs (≥12% in forced expiratory volume in 1 s (FEV1) from pre-bronchodilator value) and FeNO higher than 35 parts per billion (ppb) were observed at least once in 59% and 77% of participants. When analysed as continuous variables, both BDR (hazard ratio (HR): 1.21; 95% CI: 1.04-1.41; P = 0.014) and FeNO (HR: 1.27; 95% CI: 1.09-1.49; P = 0.003) were associated with increased risks for a control loss. Compared with patients showing either positive BDRs (HR: 3.19; 95% CI: 1.05-9.64) or FeNO higher than 35 ppb (HR: 4.70; 95% CI: 1.68-13.11), patients with both findings (HR: 7.08; 95% CI: 2.57-19.49) had greater risks for a control loss.
  
  
  
  These data support that combined use of BDR and FeNO measurements can modify predictive risk obtained from either measurement alone.
authors: Department of Pediatrics, Chungbuk National University, Cheongju, Republic of Korea.
authors: Je-Kyung
authors: JK
authors: Kim
authors: Department of Pediatrics, Chungbuk National University, Cheongju, Republic of Korea.
authors: Jae-Yub
authors: JY
authors: Jung
authors: Department of Preventive Medicine, College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, Republic of Korea.
authors: Heon
authors: H
authors: Kim
authors: Department of Preventive Medicine, College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, Republic of Korea.
authors: Sang-Yong
authors: SY
authors: Eom
authors: Department of Pediatrics, Chungbuk National University, Cheongju, Republic of Korea.
authors: Youn-Soo
authors: YS
authors: Hahn
mesh_terms: D001249:Asthma / Q000188:drug therapy / Q000276:immunology / Q000503:physiopathology* / Q000517:prevention & control; D001944:Breath Tests; D001980:Bronchi / Q000187:drug effects*; D001993:Bronchodilator Agents / Q000494:pharmacology*; D002648:Child; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000150:complications; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D011237:Predictive Value of Tests; D011379:Prognosis
chemical_list: D001993:Bronchodilator Agents; D009569:Nitric Oxide
keywords: asthma; atopy; bronchodilator response; child; fractional exhaled nitric oxide; loss of asthma control