title: Multiple-flow exhaled nitric oxide, allergy, and asthma in a population of older children.
abstract: "Extended" (multiple-flow) measurements of exhaled nitric oxide (FeNO) potentially can distinguish proximal and distal airway inflammation, but have not been evaluated previously in large populations. We performed extended NO testing within a longitudinal study of a school-based population, to relate bronchial flux (J'awNO) and peripheral NO concentration (CalvNO) estimates with respiratory health status determined from questionnaires. We measured FeNO at 30, 50, 100, and 300 ml/sec in 1,640 subjects aged 12-15 from eight communities, then estimated J'awNO and CalvNO from linear and nonlinear regressions of NO output versus flow. J'awNO, as well as FeNO at all flows, showed influences of asthma, allergy, Asian or African ancestry, age, and height (positive), and of weight (negative), generally corroborating past findings. By contrast, CalvNO results were inconsistent across different extended NO regression models, and appeared more sensitive to small measurement artifacts.
  
  
  CONCLUSIONS
  Extended NO testing is feasible in field surveys of young populations. In interpreting results, size, age, and ethnicity require attention, as well as instrumental and environmental artifacts. J'awNO and conventional FeNO provide similar information, probably reflecting proximal airway inflammation. CalvNO may give additional information relevant to peripheral airway, alveolar, or systemic pathology. However, it needs additional research, including testing of populations with independently verifiable peripheral or systemic pathology, to optimize measurement technique and interpretation.
authors.affiliation: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089, USA. linn@usc.edu
authors.forename: William S
authors.initials: WS
authors.lastname: Linn
authors.forename: Edward B
authors.initials: EB
authors.lastname: Rappaport
authors.forename: Sandrah P
authors.initials: SP
authors.lastname: Eckel
authors.forename: Kiros T
authors.initials: KT
authors.lastname: Berhane
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Muhammad T
authors.initials: MT
authors.lastname: Salam
authors.forename: Tracy M
authors.initials: TM
authors.lastname: Bastain
authors.forename: Frank D
authors.initials: FD
authors.lastname: Gilliland
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D001249:Asthma / Q000276:immunology / Q000378:metabolism*; D001827:Body Height / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D001944:Breath Tests / Q000379:methods*; D002140:California; D002648:Child; D005006:Ethnicity / Q000706:statistics & numerical data; D045853:Exhalation / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006304:Health Status; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology / Q000378:metabolism*; D007249:Inflammation / Q000276:immunology / Q000378:metabolism; D008137:Longitudinal Studies; D008297:Male; D009569:Nitric Oxide / Q000276:immunology / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000276:immunology / Q000378:metabolism; D011795:Surveys and Questionnaires
chemical_list: D009569:Nitric Oxide
keywords: airway inflammation; airways; allergy; asthma; epidemiology; exhaled nitric oxide; population survey; public health