The Association Between Fractional Exhaled Nitric Oxide (FeNO) and Allergic Diseases and Asthma at Age Six Years in a High Risk Birth Cohort

Abstract

RationaleTo determine whether FeNO levels are associated with the development of eczema, allergic sensitization, elevated total IgE levels, and/or asthma.MethodsThe relationship between FeNO levels and the development of allergic diseases was evaluated in children enrolled in the COAST (Childhood Origins of ASThma) study. FeNO was measured at age six years using the NIOX® online technique (Aerocrine, AB, Stockholm, Sweden); values were determined from three maneuvers that were within 2.5 ppb or 10%. Skin prick testing was performed at 5 years, and both allergen-specific IgE and total IgE levels were obtained at age 6 years. Asthma and eczema were diagnosed at 6 years of age.Results88% of children (199/227) successfully performed FeNO maneuvers at age six. There was no association between FeNO levels and active eczema (p = 0.13). FeNO levels were higher in subjects with at least one positive skin prick test compared to patients without any positive tests (geometric mean 9.9 vs 7.3 ppb, p = 0.005). A similar association was found between FeNO levels and a positive RAST test (geometric mean 10.9 vs 6.5 ppb, p < 0.0001). A positive correlation was demonstrated between FeNO levels and total IgE (r = 0.40, p < 0.0001). FeNO levels were higher in subjects with asthma (geometric mean 10.1 vs 8.0 ppb, p = 0.02); however, this association did not remain significant after adjusting for allergic sensitization in a multivariate model (p = 0.33).ConclusionsElevated FeNO levels at age six years are present in children with allergic sensitization and correlate with total IgE levels; eczema and asthma are not independently associated with increased FeNO. RationaleTo determine whether FeNO levels are associated with the development of eczema, allergic sensitization, elevated total IgE levels, and/or asthma. To determine whether FeNO levels are associated with the development of eczema, allergic sensitization, elevated total IgE levels, and/or asthma. MethodsThe relationship between FeNO levels and the development of allergic diseases was evaluated in children enrolled in the COAST (Childhood Origins of ASThma) study. FeNO was measured at age six years using the NIOX® online technique (Aerocrine, AB, Stockholm, Sweden); values were determined from three maneuvers that were within 2.5 ppb or 10%. Skin prick testing was performed at 5 years, and both allergen-specific IgE and total IgE levels were obtained at age 6 years. Asthma and eczema were diagnosed at 6 years of age. The relationship between FeNO levels and the development of allergic diseases was evaluated in children enrolled in the COAST (Childhood Origins of ASThma) study. FeNO was measured at age six years using the NIOX® online technique (Aerocrine, AB, Stockholm, Sweden); values were determined from three maneuvers that were within 2.5 ppb or 10%. Skin prick testing was performed at 5 years, and both allergen-specific IgE and total IgE levels were obtained at age 6 years. Asthma and eczema were diagnosed at 6 years of age. Results88% of children (199/227) successfully performed FeNO maneuvers at age six. There was no association between FeNO levels and active eczema (p = 0.13). FeNO levels were higher in subjects with at least one positive skin prick test compared to patients without any positive tests (geometric mean 9.9 vs 7.3 ppb, p = 0.005). A similar association was found between FeNO levels and a positive RAST test (geometric mean 10.9 vs 6.5 ppb, p < 0.0001). A positive correlation was demonstrated between FeNO levels and total IgE (r = 0.40, p < 0.0001). FeNO levels were higher in subjects with asthma (geometric mean 10.1 vs 8.0 ppb, p = 0.02); however, this association did not remain significant after adjusting for allergic sensitization in a multivariate model (p = 0.33). 88% of children (199/227) successfully performed FeNO maneuvers at age six. There was no association between FeNO levels and active eczema (p = 0.13). FeNO levels were higher in subjects with at least one positive skin prick test compared to patients without any positive tests (geometric mean 9.9 vs 7.3 ppb, p = 0.005). A similar association was found between FeNO levels and a positive RAST test (geometric mean 10.9 vs 6.5 ppb, p < 0.0001). A positive correlation was demonstrated between FeNO levels and total IgE (r = 0.40, p < 0.0001). FeNO levels were higher in subjects with asthma (geometric mean 10.1 vs 8.0 ppb, p = 0.02); however, this association did not remain significant after adjusting for allergic sensitization in a multivariate model (p = 0.33). ConclusionsElevated FeNO levels at age six years are present in children with allergic sensitization and correlate with total IgE levels; eczema and asthma are not independently associated with increased FeNO. Elevated FeNO levels at age six years are present in children with allergic sensitization and correlate with total IgE levels; eczema and asthma are not independently associated with increased FeNO.