Chest ACCP Career Connection
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Guest Access | Sign In via User Name/Password
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF) Free
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Article Archive
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (18)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Olin, A.-C.
Right arrow Articles by Torén, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Olin, A.-C.
Right arrow Articles by Torén, K.
(Chest. 2006;130:1319-1325.)
© 2006 American College of Chest Physicians

Height, Age, and Atopy Are Associated With Fraction of Exhaled Nitric Oxide in a Large Adult General Population Sample*

Anna-Carin Olin, MD; Annika Rosengren, MD; Dag S. Thelle, MD; Lauren Lissner, PhD; Björn Bake, MD and Kjell Torén, MD, FCCP

* From the Departments of Occupational and Environmental Medicine (Dr. Olin) and Respiratory Medicine and Allergology (Drs. Torén and Bake), Sahlgrenska University Hospital, Göteborg, Sweden; Department of Medicine (Dr. Rosengren), Sahlgrenska University Hospital/Östra, Göteborg, Sweden; Department of Community Medicine and Public Health (Drs. Thelle and Lissner), Sahlgrenska Academy, Göteborg University, Göteborg, Sweden; and Epigen (Dr. Thelle), Akerhus University Hospital, University of Oslo, Oslo, Norway.

Correspondence to: Anna-Carin Olin, MD, Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital, Box 414, SE 405 30 Göteborg, Sweden; e-mail Anna-Carin.Olin{at}amm.gu.se

Abstract

Study objectives: The fraction of exhaled nitric oxide (FENO) is elevated in subjects with asthma and atopy, and it has been proposed to be a noninvasive marker of airway inflammation. In addition to asthma and atopy, there is limited information about the determinants of FENO in a general population.

Design: Cross-sectional.

Setting: A random adult general population sample.

Participants: A total of 2,200 subjects, 1,111 women and 1,089 men, aged 25 to 75 years.

Interventions: The subjects were examined with regard to FENO, pulmonary function, anthropometric variables, and blood samples for Ig E, and completed a respiratory questionnaire. The associations between different determinants and FENO were analyzed with multiple linear regression models.

Results: The median value of FENO was 16.0 parts per billion (ppb), ranging from 2.4 to 199 ppb. Height, age, atopy, reporting of asthma symptoms in the last month, and reported use of inhaled steroids were positively associated with FENO. Current smokers had lower values of FENO. Gender was not associated with FENO.

Conclusions: In this random adult population sample, height, but not gender, was associated with FENO. Furthermore, asthma symptoms in the last month, reported use of inhaled steroids, and atopy were positively and independently associated with FENO, while there was a negative association with smoking.

Key Words: asthma • epidemiology • exhaled nitric oxide • gender

Fraction of exhaled nitric oxide (FENO) has been proposed to be a noninvasive marker of airway inflammation. Levels of FENO are elevated in subjects with asthma1 and atopy,2 and have been positively associated with eosinophils in BAL,3 with eosinophils in bronchial biopsy specimens,4 and with eosinophils in induced sputum.5 However, in addition to atopy, asthma, and respiratory symptoms, there are several other determinants of FENO. Their importance and interactions as determinant of FENO are incompletely understood.

Increased levels of IgE and positive skin-prick test results are clearly related to increased levels of FENO, but it is still unclear whether increased IgE, per se, is associated with increased levels of FENO, or if there is also a need for signs of airways inflammation.267 Smoking and the use of inhaled corticosteroids have been associated with decreased FENO levels,8 but whether the known determinants of FENO also are of importance among smokers is unclear.

There are studies91011 indicating an association between FENO and male gender. Age is related to FENO among subjects < 18 years old, and this may be due to an increase in the total airway mucosal surface area that produces nitric oxide.12 Among adults, conflicting results have been reported as to whether FENO is related to age and height.11131415 However, there are complex interactions between age, height, and gender, and each of these factors needs to be taken into account using multivariate techniques. Among adults, almost all studies assessing FENO and factors that may explain its variability have been performed either in clinical samples of patients with asthma or in samples of healthy subjects. Often, these samples have been limited in size. Studies on large, unselected, populations are therefore warranted in order to obtain as unbiased and valid results as possible.

In this article, we analyze FENO measured with exhalation flow of 50 mL/s among 2,200 randomly selected adults aged 25 to 75 years, with the aim to detect the determinants of FENO levels within a general population.

Materials and Methods

A general population sample of 25- to 75-year-old men and women was randomly selected from the population register in Göteborg, Sweden. From April 2001 to December 2003, 2,295 subjects were included. The study forms part of the Adult-Onset Asthma and Exhaled Nitric Oxide study, which is a joint study with the INTERGENE study.16 Further information on selection procedures and methods is available at www.sahlgrenska.gu.se/intergene/eng/methods.jsp.

All subjects received a postal questionnaire and an invitation to the clinical examination, as previously described.16 All subjects fasted for 4 h before the examination. The clinical examination comprised additional questionnaires, blood samples, anthropometric data, and lung function. FENO was measured using a chemiluminescence analyzer (NIOX-system; Aerocrine AB; Stockholm; Sweden) to measure exhaled nitric oxide during a slow single exhalation against an oral pressure of 5 cm H2O.2 It was measured for 10 s aiming at an exhalation flow rate of 50 mL/s (± 10%) during second 6 to second 10 of the exhalation phase. All measurements were performed in duplicate, all within 10% deviation, and the mean concentration in parts per billion (ppb) was registered.17 FENO was measured before spirometry.

Spirometry was performed with a dry-wedge spirometer (Vitalograph; Buckingham, UK). Results are presented as percent predicted.18 Blood samples were analyzed with regard to total amount of IgE (Phadiatop; Pharmacia; Uppsala; Sweden). Class 0 was regarded as negative, and class 1 was considered positive (atopic).19 The following definitions were used based on affirmative answers to the items in the questionnaire220: physician-diagnosed asthma: Have you ever had asthma diagnosed by a physician? ever (adult) wheezing: Have you since the age of 15 ever noticed wheezing or whistling in your chest? current asthma: Have you had an attack of asthma in the last 12 months? asthma symptoms during the previous month: Have you had an asthma attack during the past month? and rhinitis: Have you since the age of 15 had nasal congestion and/or attacks of sneezing or rhinorrhea without having a cold?21

Reported use of inhaled steroids was based on reporting of current regular use of medicines for asthma classified as inhaled steroids. Based on items in the questionnaire, subjects were classified as current smokers, ex-smokers, and never-smokers. A smoker who had refrained from smoking > 1 year was classified as ex-smoker.

All statistical calculations were performed using statistical software (SAS version 8.1; SAS Institute; Cary, NC). FENO values are presented as medians and interquartile ranges. The univariate analysis was generally based on nonparametric methods (Kruskal-Wallis).

The association between the different explanatory variables (gender, height, weight, smoking habits, atopy, physician-diagnosed asthma, asthma symptoms, and reported use of inhaled steroids) and rhinitis was examined in a multiple linear regression model using the procedure for general linear models with log-transformed FENO values as the dependent variable. Regarding age and height, the subjects were grouped into 10-year groups and into 10-cm intervals using the technique of dummy variables. In this model, all covariates have been included based on an a priori decision. After initial modeling, rhinitis was dropped because of low explanatory value. The models have also been stratified according to smoking habits, gender, and atopy. In one additional regression model, the raw unadjusted values of pulmonary function were used. All subjects gave their written consent to the study, and the protocol was approved by the ethical committee of Göteborg University.

Results

FENO level was measured in a total of 2,295 subjects. Seventy-seven measurements were not approved, and information on smoking habits was lacking in 18 subjects. Hence, 2,200 subjects were included in the present analysis, 1,111 women and 1,089 men. Basic data about the study population are presented in Table 1 .


View this table:
[in this window]
[in a new window]

  		Table 1. Basic Data of 2,200 Subjects in a Random Population Study Classified According to Smoking Habits*

 
The median value of FENO was 16.0 ppb (range, 2.4 to 199 ppb), with 25th and 75th percentiles being 11.0 ppb and 22.3 ppb, respectively. In the univariate analysis (Table 2 ), FENO was lower among current smokers than among never-smokers. FENO levels were higher in men than in women, among subjects with atopy, and among never-smokers with asthma. Increased levels of FENO were also observed among subjects with asthma symptoms during the previous month (22.5 ppb vs 17.0 ppb) or wheezing (19.5 ppb vs 16.7 ppb). This was not observed among ex-smokers or current smokers.


View this table:
[in this window]
[in a new window]

  		Table 2. Values of FENO Among 2,200 Subjects in a Random Population Study by Smoking Habits, Gender, and Atopy*

 
In a multiple linear regression model, FENO was independently and positively associated with atopy, height, age, smoking, asthma symptoms in the last month, and reported use of inhaled steroids (Table 3 ). There was no association with gender.


View this table:
[in this window]
[in a new window]

  		Table 3. Coefficients Obtained From Multiple Linear Regression Models With FENO (Logarithm Transformed) as the Dependent Variable in Relation to Different Independent Variables Among 2,200 Subjects in a Random Population Study*

 
With other variables equal, the mean levels of FENO among subjects with atopy were 23% (e0.21 = 1.23) higher compared to subjects without atopy. The initial model (all subjects) in Table 3 showed that taller subjects have higher FENO. For example, subjects taller than 189 cm have 40% (e0.32 = 1.4) higher FENO compared to subjects shorter than 160 cm. Stratifying for smoking gave similar results (Table 4 ). Stratifying for atopy showed that the mean level of FENO among atopic subjects taller than 189 cm is 1.9 times (e0.63) higher compared to atopic subjects shorter than 160 cm. We also performed multiple linear regression modeling in two different strata of height (separated by the median height of 172 cm) and found that height still predicted FENO independently of gender. In one additional model, FVC was introduced as an additional explanatory variable, but height was still a significant predictor of FENO.


View this table:
[in this window]
[in a new window]

  		Table 4. Coefficients Obtained From Multiple Linear Regression Models With FENO (Logarithm Transformed) as the Dependent Variable in Relation to Different Independent Variables Among 2,200 Subjects in a Random Population Study Classified According to Smoking*

 
Age was also independently and positively associated with FENO (Table 3). In the initial model (including all subjects), the oldest group (> 64 years) had a 40% higher FENO value as compared to the youngest group (Table 3). When the models were stratified according to gender, similar observations were found. Results were also similar when stratification was by presence or absence of asthma. An FENO increase with age was seen among in different smoking groups (Table 4), as well as among atopic and nonatopic subjects (Table 5 ).


View this table:
[in this window]
[in a new window]

  		Table 5. Coefficients Obtained From Multiple Linear Regression Models With FENO (Logarithm Transformed) as the Dependent Variable in Relation to Different Independent Variables Among 2,200 Subjects in a Random Population Study Classified According to Atopy*

 
Current smokers have 70% lower levels of FENO (Table 3). The estimate was – 0.36 (e–0.36 = 0.7) compared with nonsmokers (never-smokers and ex-smokers). The influence of pack-years and total smoking time was further modeled among current smokers. In a regression model with the same covariates as previously, pack-year was negatively associated with FENO. Duration of smoking was not associated with FENO.

Atopy was independently and positively associated with FENO (Table 3). If we excluded all subjects with asthma and current asthma symptoms during the previous month, atopy was still a significant predictor of FENO.

In contrast to the results of the univariate analyses, physician-diagnosed asthma was not associated with increased FENO in the different regression models. However, asthma symptoms during the last month were associated with increased levels of FENO. When current asthma (ie, asthma symptoms during the last 12 months) was used as a covariate, similar results were obtained. Current use of inhaled steroids was positively associated with increased levels of FENO among never-smokers (Table 4).

The predictors of FENO differed among subjects with atopy and no atopy (Table 5). The coefficients for asthma symptoms during the last month were positive among atopics, 0.33, but were not significantly different from zero among nonatopic subjects. Regarding current use of inhaled steroids, the coefficients were positive among nonatopic subjects but not significantly different from zero among atopic subjects.

Discussion

The main novel results of the present population-based, cross-sectional study of adults are that FENO was positively related to height and age, and that there was no association with gender. These results were found among both atopic and nonatopic subjects. There was no increased FENO in the group with physician-diagnosed asthma, but subjects with asthma symptoms during the last month had increased levels of FENO. The strength of the present study is that we have used a large random population sample that allowed us to control for confounding and interaction using multiple linear regression models.

Several studies9101122 have reported an association between FENO and male gender. In children, it has been reported that girls have higher FENO,11 but among older children there appears to be no gender difference.71323 In some studies,1113 a positive relation was found between height and FENO. As men are generally taller then women, it has been unclear whether increased FENO among men is an independent effect of gender or of height. In the study by Franklin et al,11 the presented logistic regression models also included height as a covariate, but male gender was still associated with increased FENO. However, this was a small study, and the estimate for height was not presented. Tsang et al10 used analysis of covariance including body mass index and body surface area but still observed a higher FENO among men. In the study by Nordvall et al,22 multiple linear regression modeling was used, but whether height was included as a covariate is not clear from the presented data.

In the present study, FENO was clearly height dependent. When both gender and height were included in the regression models, the contribution of gender was not significant. This relation with height was observed among both men and women, as well as in different height strata. In neither strata was there any relation between gender and FENO. Hence, we conclude from our study that FENO is height dependent, with no obvious relation to gender. The positive association between FENO and height is probably due to a height-dependent increase in the total airway mucosal surface area that produces nitric oxide.12

Previous studies show conflicting results with respect to whether FENO is age dependent. Baraldi et al24 found no correlation to age (r < 0.2) in a study of 159 healthy children. In a study of 157 healthy children in Australia, Franklin et al7 found that FENO increased with age both in analyses with univariate methods, as well as in multiple linear regression models. Buchvald et al25 found a clear age dependency of FENO among healthy children aged 4 to 17 years using log-transformed values in a multiple linear regression model. Among adults, a study10 from Hong Kong found no correlation (r = 0.12) between age and FENO; however, no multivariate analyses were presented. In a study14 from Israel on 87 subjects with asthma aged 2 to 41 years, there was a significant increase in FENO with age; the authors used log-transformed values in a linear regression model. Finally, in a study of a random population sample of 115 adults,11 there was a weak correlation between age and FENO in univariate analyses, but whether this remained in the logistic regression model was not reported.

In the present study, FENO was clearly age dependent. This was observed in all different models, both among asthmatics and among nonasthmatics. This consistent result has previously not been found among adults. Published studies725 on children using similar methods to the ones used here, log transformation and regression modeling, have also observed a relation between FENO and age. However, among children there is a clear relation between age and body size. Why FENO increases with increasing age among adults remains unclear. However, only 15 to 20% of the variation is explained by the regression models. Hence, other factors that may be related to age, such as presence of subclinical airway inflammation, diet,26 and increased cumulative exposure to air pollution,27 may play a role. It has also been shown that airway closure, which increases with age, is associated with airway inflammation.28

Consistent with many other studies, we observed that current smokers have decreased FENO levels, and subjects with atopy have increased FENO levels. However, based on our large sample we were able to demonstrate that also among current smokers and former smokers, increased FENO was found in subjects with atopy.

In the univariate analyses, never-smoking subjects with physician-diagnosed asthma had higher levels of FENO. However, in the full regression model, this relation did not remain significant, nor did it remain significant when the models were stratified according to smoking, atopy, or gender. Among subjects with asthma, it has been shown that FENO is increased among atopic subjects but not among nonatopic subjects.293031 Franklin at al11 reported that increased FENO was associated with atopy and increased airway hyperreactivity but not with asthma per se. This is in line with our findings that atopy but not asthma is an independent predictor for FENO. We also observed that atopy was a determinant of FENO even among subjects without respiratory symptoms. This is contradictory to what we have seen in a previous study,2 but that study was performed in a selected population, pulp-mill workers.

It is well established that use of inhaled corticosteroids decreases FENO levels. In the present study, we found, somewhat surprisingly, that subjects reporting the use of inhaled steroids had increased levels of FENO. This was observed in the full regression model, and when the population was further stratified it was mostly evident among nonatopic subjects. We made a more detailed descriptive analysis of the material, and among the nonatopic subjects, 18 individuals reported use of inhaled steroids. Their mean FENO was 22.5 ppb. Among them, 15 subjects (83%) reported physician-diagnosed asthma. Current asthma symptoms were reported by 15 subjects (83%), and 12 subjects (67%) reported asthma symptoms during the previous month. The most plausible explanation for this observation is that subjects with asthma are prescribed steroids but do not use them. An alternative explanation is that these nonatopic subjects do not respond to their inhaled steroids.

This study confirms the well-established association between atopy, smoking, and FENO.31 In addition, the present study also finds an independent association between age, height, and FENO. The impact of height and age on FENO is in some strata similar to that of atopy. If these results are confirmed by others, it will underline the need for reference values among adults for FENO, which in addition to smoking and atopy also takes height and age into account.

This study was performed in an unselected population, and the participation rate was approximately 40%. In agreement with previous findings,16 nonparticipation was most frequent in the younger age groups and among men. Possibly, subjects with asthma or respiratory symptoms might be less likely to take part in the study. However, the prevalence in the present study of atopy and physician-diagnosed asthma was in the same range as described previously.3233 Selection bias may affect the results, for instance if short subjects with high FENO are accumulated among the dropouts, but this seems unlikely. Hence, we consider our results as probably representative of an adult general population.

In this random adult population sample, height, but not gender, was associated with FENO. Furthermore, asthma symptoms in the last month, reported use of inhaled steroids, and atopy were positively and independently associated with FENO, while there was a negative association with smoking.

Footnotes

Abbreviations: FENO = fraction of exhaled nitric oxide; ppb = parts per billion

The study was supported by the Swedish Council for Worklife and Social Research (FAS), the Swedish Heart and Lung Foundation, and Astra-Zeneca, Sweden.

None of the authors have any conflicts of interest to disclose.

Received for publication January 13, 2006. Accepted for publication May 20, 2006.

References

  1. Alving, K, Weitzberg, E, Lundberg, JM (1993) Increased amount of nitric oxide in exhaled air of asthmatics. Eur Respir J 6,1368-1370[Abstract]
  2. Olin, A-C, Alving, K, Torén, K Exhaled nitric oxide: relation to sensitization and respiratory symptoms. Clin Exp Allergy 2004;34,221-236[CrossRef][ISI][Medline]
  3. Warke, TJ, Fitch, PS, Brown, V, et al Exhaled nitric oxide correlated with airway eosinophils in childhood asthma. Thorax 2002;57,383-387[Abstract/Free Full Text]
  4. Riise, GC, Olin, AC, Torén, K Subjects in a population study with high levels of FENO have signs of eosinophil airway inflammation in BAL [abstract]. Proc Am Thorac Soc 2005;2,A930
  5. Berry, MA, Shaw, RH, Green, CE, et al The use of exhaled nitric oxide concentration to identify eosinophilic airway inflammation: an observational study in adults with asthma. Clin Exp Allergy 2005;35,1175-1179[CrossRef][ISI][Medline]
  6. Van den Toorn, LM, Prins, J-B, Overbeek, SE, et al Adolescents in clinical remission of atopic asthma have elevated exhaled nitric oxide levels and bronchial hyperresponsiveness. Am J Respir Crit Care Med 2000;162,953-957[Abstract/Free Full Text]
  7. Franklin, PJ, Taplin, R, Stick, SM A community study of exhaled nitric oxide in healthy children. Am J Respir Crit Care Med 1999;159,69-73[Abstract/Free Full Text]
  8. Kharitonov, S, Barnes, PJ Exhaled markers of pulmonary disease. Am J Respir Crit Care Med 2001;163,1693-1722[Free Full Text]
  9. Jilma, B, Kastner, J, Mensik, C, et al Sex differences in concentrations of exhaled nitric oxide and plasma nitrate. Life Sci 1996;6,469-476
  10. Tsang, KW, Ip, SK, Tipoe, GL, et al Exhaled nitric oxide: the effects of age, gender and body size. Lung 2001;179,83-91[CrossRef][ISI][Medline]
  11. Franklin, PJ, Stick, SM, Turner, SW, et al Measuring exhaled nitric oxide levels in adults: the importance of atopy and airway responsiveness. Chest 2004;126,1540-1545[Abstract/Free Full Text]
  12. Pedroletti, C, Högman, M, Merilainen, P, et al Nitric oxide airway diffusing capacity and mucosal concentration in asthmatic schoolchildren. Pediatr Res 2003;54,496-501[CrossRef][ISI][Medline]
  13. Franklin, PJ, Turner, SW, Le Souef, PN, et al Exhaled nitric oxide and asthma: complex interactions between atopy, airway hyperresponsiveness, and symptoms in a community population of children. Thorax 2003;58,1048-1052[Abstract/Free Full Text]
  14. Avital, A, Uwyyed, K, Berkman, N, et al Exhaled nitric oxide is age-dependent in asthma. Pediatr Pulmonol 2003;36,433-438[CrossRef][ISI][Medline]
  15. Malmberg, LP, Turpeinen, H, Rytilä, P, et al Determinants of increased exhaled nitric oxide in patients with suspected asthma. Allergy 2005;60,464-468[CrossRef][ISI][Medline]
  16. Berg, C, Lissner, L, Aires, N, et al Trends in blood lipid levels, blood pressure, alcohol and smoking habits from 1985 to 2002: results from INTERGENE and GOT-MONICA. Eur J Cardiovasc Prev Rehabil 2005;12,115-125[CrossRef][ISI][Medline]
  17. ATS/ERS recommendations for standardized procedures for the on-line and off-line measurement of exhaled lower respiratory nitric oxide and nasal nitric oxide. Am J Respir Crit Care Med 2005;171,912-930[Free Full Text]
  18. Langhammer, A, Johnsen, R, Gulsvik, A, et al Forced spirometry reference values for Norwegian adults: the bronchial obstruction in Nord-Trøndelag study. Eur Respir J 2001;18,770-779[Abstract/Free Full Text]
  19. Matricardi, PM, Nisini, R, Pizzolo, JG, et al The use of Phadiatop in mass-screening programmes of inhalant allergies: advantages and limitations. Clin Exp Allergy 1990;20,151-155[CrossRef][ISI][Medline]
  20. Torén, K, Brisman, J, Järvholm, B Asthma and asthma-like symptoms in adults assessed by questionnaires. Chest 1993;104,600-608[Abstract/Free Full Text]
  21. Hellgren, J, Lillienberg, L, Jarlstedt, J, et al Population-based study of non-infectious rhinitis in relation to occupational exposure, age, sex and smoking. Am J Ind Med 2002;42,23-28[CrossRef][ISI][Medline]
  22. Nordvall, SL, Janson, C, Palm-Stephens, P, et al Exhaled nitric oxide in a population-based study of asthma and allergy in schoolchildren. Allergy 2005;60,469-475[CrossRef][ISI][Medline]
  23. Kiissoon, N, Duckworth, LJ, Blake, KV, et al FENO50: relationship to exhalation rates and online versus bag collection in healthy adolescents. Am J Respir Crit Care Med 2000;162,539-545[Abstract/Free Full Text]
  24. Baraldi, E, Azzolin, NM, Cracco, A, et al Reference values of exhaled nitric oxide for healthy children 6–15 years old. Pediatr Pulmonol 1999;27,54-58[ISI][Medline]
  25. Buchvald, F, Baraldi, E, Carraro, E, et al Measurement of exhaled nitric oxide in healthy subjects age 4 to 17 years. J Allergy Clin Immunol 2005;115,1130-1136[CrossRef][ISI][Medline]
  26. Olin, A-C, Aldenbratt, A, Ekman, A, et al Increased nitric oxide in exhaled air after intake of a nitrate rich meal. Respir Med 2001;95,153-158[CrossRef][ISI][Medline]
  27. Adamkiewicz, G, Ebelt, S, Syring, M, et al Association between air pollution exposure and exhaled nitric oxide in an elderly population. Thorax 2004;59,204-209[Abstract/Free Full Text]
  28. D’Angelo, E, Pecchiari, M, Della Valle, P, et al Effects of mechanical ventilation at low lung volume on respiratory mechanics and nitric oxide in normal rabbits. J Appl Physiol 2005;99,433-444[Abstract/Free Full Text]
  29. Ludvigsdottir, D, Janson, C, Högman, M, et al Exhaled nitric oxide and its relationship to airway responsiveness and atopy in asthma: BHR study group. Respir Med 1999;93,552-556[CrossRef][ISI][Medline]
  30. Gratziou, C, Lignos, M, Dassiou, M, et al Influence of atopy on exhaled nitric oxide in patients with stable asthma and rhinitis. Eur Respir J 1999;14,897-901[Abstract/Free Full Text]
  31. Ho, L-P, Wood, FT, Robson, A, et al Atopy influences exhaled nitric oxide levels in adult asthmatics. Chest 2000;118,1327-1331[Abstract/Free Full Text]
  32. Torén, K, Hermansson, B-A Incidence rate of adult-onset asthma in relation age, gender, smoking and atopy: a Swedish population-based study of 15,813 adults. Int J Tuberc Lung Dis 1999;3,192-197[ISI][Medline]
  33. Torén, K, Gislason, T, Omenaas, E, et al Incidence of asthma in relation to age, sex and respiratory symptoms: a prospective longitudinal study from Northern Europe (RHINE-study). Eur Respir J 2004;24,942-946[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
 ChestHome page
K. G. Lim and C. Mottram
The Use of Fraction of Exhaled Nitric Oxide in Pulmonary Practice
Chest, May 1, 2008; 133(5): 1232 - 1242.
[Abstract] [Full Text] [PDF]

Home page
 ChestHome page
K. Kostikas, A. I. Papaioannou, K. Tanou, A. Koutsokera, M. Papala, and K. I. Gourgoulianis
Portable Exhaled Nitric Oxide as a Screening Tool for Asthma in Young Adults During Pollen Season
Chest, April 1, 2008; 133(4): 906 - 913.
[Abstract] [Full Text] [PDF]

Home page
 ChestHome page
M. Olivieri, M. Malerba, G. Talamini, and M. Corradi
Reference Values for Exhaled Nitric Oxide in the General Population
Chest, March 1, 2008; 133(3): 831 - 832.
[Full Text] [PDF]

Home page
 ChestHome page
T. Kovesi, R. Kulka, and R. Dales
Exhaled Nitric Oxide Concentration Is Affected by Age, Height, and Race in Healthy 9- to 12-Year-Old Children
Chest, January 1, 2008; 133(1): 169 - 175.
[Abstract] [Full Text] [PDF]

Home page
 ChestHome page
M. Olivieri, M. Corradi, and M. Malerba
Gender and Exhaled Nitric Oxide
Chest, October 1, 2007; 132(4): 1410 - 1410.
[Full Text] [PDF]

Home page
 ChestHome page
A.-C. Olin, B. Bake, and K. Toren
Exhaled Nitric Oxide and Gender
Chest, October 1, 2007; 132(4): 1410 - 1410.
[Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF) Free
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Article Archive
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (18)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Olin, A.-C.
Right arrow Articles by Torén, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Olin, A.-C.
Right arrow Articles by Torén, K.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS