Browsing by Author "Alving, K"
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- Exhaled nitric oxide levels and blood eosinophil counts independently associate with wheeze and asthma events in National Health and Nutrition Examination Survey subjectsPublication . Malinovschi, A; Fonseca, JA; Jacinto, T; Alving, K; Janson, CBACKGROUND: Fraction of exhaled nitric oxide (Feno) and blood eosinophil count (B-Eos) values, markers of local and systemic eosinophilic inflammation, respectively, are increased in asthmatic patients. Little is known about the relation of these markers to reported wheeze and asthma events in a random population sample. OBJECTIVES: We sought to determine the individual and independent values of B-Eos and Feno in relation to wheeze, asthma diagnosis, and asthma events in a cross-sectional study. METHODS: Feno and B-Eos values were measured in 12,408 subjects aged 6 to 80 years from the National Health and Nutrition Examination Survey 2007-2008 and 2009-2010. Current wheeze and asthma diagnosis, as well as asthma attacks and asthma-related emergency department (ED) visits within the last 12 months, were assessed by means of questionnaires. RESULTS: Intermediate or high Feno values and intermediate or high B-Eos values were independently associated with having asthma, wheeze, and asthma attacks. However, only intermediate and high B-Eos values were independently associated with asthma-related ED visits. High Feno (≥ 50 ppb) and B-Eos (≥ 500 cells/mm(3)) values rendered an adjusted odds ratio of 4.5 of having wheeze, 5.1 of having asthma, 5.4 for asthma attacks, and 2.9 for asthma-related ED visits compared with normal Feno (<25 ppb) and B-Eos (<300 cells/mm(3)) values. CONCLUSIONS: Exhaled nitric oxide and B-Eos values offered independent information in relation to the prevalence of wheeze, asthma diagnosis, and asthma events in this random population sample. The clinical importance of these findings in asthmatic patients with regard to phenotyping and individualized treatment, considering both local and systemic eosinophilic inflammation, needs to be determined.
- Inflammatory patterns in fixed airflow obstruction are dependent on the presence of asthmaPublication . Mogensen, I; Jacinto, T; Alving, K; Fonseca, JA; Janson, C; Malinovschi, ARationale: Fixed airflow obstruction (FAO) can complicate asthma. Inflammation is a proposed underlying mechanism. Objective: Our aim in this cross-sectional investigation was to evaluate the blood leucocyte pattern and level of exhaled nitric oxide in asthmatics and non-asthmatics with or without FAO. Methods: A total of 11,579 individuals aged ≥20 years from the US National Health and Nutrition Examination Survey were included. They were grouped as: controls without asthma and FAO (n = 9,935), asthmatics without FAO (n = 674), asthmatics with FAO (n = 180) and non-asthmatics with FAO (n = 790). FAO was defined as post-bronchodilator FEV1/FVC < lower limit of normal. Exhaled nitric oxide ≥ 25ppb, blood eosinophil levels ≥300 cells/μL, and blood neutrophil levels ≥5100 cells/μL were defined as elevated. Stratified analyses for smoking and smoking history were performed. Results: Elevated blood eosinophil levels were more common in all groups compared to the controls, with the highest prevalence in the group with asthma and fixed airflow obstruction (p<0.01). In a multiple logistic regression model adjusted for potential confounders including smoking, the asthma groups had significantly higher odds ratios for elevated B-Eos levels compared to the control group (odds ratio 1.4, (confidence interval: 1.1-1.7) for the asthma group without fixed airflow obstruction and 2.5 (1.4-4.2) for the asthma group with fixed airflow obstruction). The group with fixed airflow obstruction without asthma had higher odds ratio for elevated blood neutrophil levels compared to the controls: 1.4 (1.1-1.8). Smoking and a history of smoking were associated to elevated B-Neu levels. Conclusion: Fixed airflow obstruction in asthma was associated with elevated blood eosinophil levels, whereas fixed airflow obstruction without asthma was associated with elevated blood neutrophil levels..
- Setting reference values for exhaled nitric oxide: a systematic reviewPublication . Jacinto, T; Alving, K; Correia, R; Costa-Pereira, A; Fonseca, JABACKGROUND: The values obtained when the fraction of exhaled nitric oxide (FeNO) is measured are affected by several factors that are specific to the individual patient, making interpretation difficult, especially in the initial assessment of patients with respiratory symptoms. METHODS: Systematic review of studies on FeNO reference values and individual-specific factors that influence them. RESULTS: From 3739 references, 15 studies were included. Four studies included children and adolescents. In nine studies, samples were selected from the general population. Most studies reported objective measures for atopy (nine studies), but not for smoking status (one). Significant determinants of FeNO values reported were age and height (seven studies), atopy (six), smoking (four), weight (four), sex (three) and race (three). Additional factors were included in eight studies. R(2) was reported in only five studies. The logarithmic transformation of FeNO was inadequately described in seven studies. CONCLUSION: There are several equations for FeNO reference values that may be used in clinical practice, although the factors they include and the statistical methods they use vary considerably. We recommend the development of standard methods for the evaluation of normal FeNO data and that reference equations should be formulated based on a predetermined physiological model.