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Simultaneously elevated Fe NO and blood eosinophils relate to asthma morbidity in asthmatics from NHANES 2007‐12
Author(s) -
Mogensen I.,
Alving K.,
Jacinto T.,
Fonseca J.,
Janson C.,
Malinovschi A.
Publication year - 2018
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/cea.13137
Subject(s) - asthma , medicine , exhaled nitric oxide , eosinophil , wheeze , odds ratio , national health and nutrition examination survey , population , gastroenterology , immunology , spirometry , environmental health
Summary Background Fraction of exhaled nitric oxide (Fe NO ) and blood eosinophil (B‐Eos) count are biomarkers for type 2 inflammation. However, they signal different inflammatory pathways. Simultaneously elevated, they are related to more asthma events in a general population and among younger asthmatics. Objective To investigate if simultaneously elevated Fe NO and B‐Eos relate to asthma outcomes and lung function among subjects with asthma at a wide age span, and how different cut‐offs for the markers affect these relations. Method Fe NO , B‐Eos and forced expiratory volume in 1 second ( FEV 1 ) were assessed in 1419 subjects with asthma, aged 6‐79 years old, from the National Health and Nutrition Examination Survey ( NHANES ) 2007‐12. Elevated levels were defined as Fe NO ≥20 p.p.b. for children <12 years and ≥25 p.p.b. for subjects ≥12 years and B‐Eos count ≥300 cells/μL. Additional analyses were performed for the cut‐offs Fe NO >35/30 and >50/35 p.p.b., and for B‐Eos ≥400 and ≥ 500 cells/μL, as well as for different age subgroups (6‐17, 18‐44, >44 years old). Asthma events during the past year were self‐reported. Results Subjects with simultaneously elevated Fe NO and B‐Eos compared with normal levels of both markers had a higher adjusted odds ratio ( aOR (95% CI )) for having FEV 1 <80% of predicted (2.15 (1.28‐3.59), wheeze disturbing sleep (1.88 (1.27, 2.78)) but did not differ regarding asthma attacks past year. Elevated B‐Eos, but not Fe NO , was related to higher aOR for asthma attack (1.57 (1.14, 2.18) or emergency room ( ER ) visit due to asthma (1.88 (1.33, 2.64) when elevated Fe NO and elevated B‐Eos were studied as independent predictors. Conclusion Simultaneously elevated Fe NO and B‐Eos related to reduced lung function in asthmatics, wheezing symptoms, but not to a history of asthma attacks. Asthma attacks and ER ‐visit due to asthma were related to increased B‐Eos levels.