Fractional Exhaled Nitric Oxide In Patients Research Articles

Association between triglyceride-glucose index and fractional exhaled nitric oxide in adults with asthma from NHANES 2007–2012

BackgroundSeveral studies have shown a potential relationship between triglyceride-glucose index (TGI) and asthma. However, limited research has been conducted on the relationship between TGI and fractional exhaled nitric oxide (FeNO).MethodsA total of 1,910 asthmatic individuals from the National Health and Nutrition Examination Survey (NHANES) database were included in this study. Linear regression analyses were used to investigate the relationship between TGI and FeNO in patients with asthma. Subsequently, a trend test was applied to verify whether there was a linear relationship between the TGI and FeNO. Finally, a subgroup analysis was performed to confirm the relationship among the different subgroup populations.ResultsMultivariable linear regression analyses showed that TGI was linearly related to FeNO in the asthmatic population. The trend test additionally validated the positive linear relationship between TGI and FeNO. The result of XGBoost revealed the five most influential factors on FeNO in a ranking of contrasted importance: eosinophil (EOS), body mass index (BMI), poverty-to-income ratio (PIR), TGI, and white blood cell count (WBC).ConclusionsThis investigation revealed a positive linear relationship between TGI and FeNO in patients with asthma. This finding suggests a potential relationship between TGI and airway inflammation in patients with asthma, thereby facilitating the prompt identification of irregularities and providing a basis for clinical decision making. This study provides a novel perspective on asthma management.

Correlation of fractional exhaled nitric oxide (FeNO) and clinical outcomes in patients with chronic obstructive pulmonary disease: A prospective cohort study

BackgroundFractional exhaled nitric oxide (FeNO) is an acceptable and noninvasive marker for defining eosinophilic airway inflammation. Further study is necessary to clarify the role of FeNO in patients with chronic obstructive pulmonary disease (COPD). This study aimed to determine the association between FeNO levels and clinical outcomes. MethodsA prospective observational study was conducted at Songklanagarind Hospital from October 2020 to November 2022. FeNO testing and spirometry were performed at the initial visit and 12-month follow-up. Exacerbation, hospitalization, lung function decline, and all-cause mortality were analyzed to determine the association between FeNO levels and clinical outcomes. ResultsA total of 60 patients with COPD were enrolled, 88.3 % of whom were male, with a mean age of 71.3 ± 9.5 years. There were 18 patients (30 %) in the high FeNO group (≥25 ppb) and 42 patients (70 %) in the low (<25 ppb) FeNO group. The mean blood eosinophil count (BEC) was significantly higher in the high FeNO group (p < 0.001). After a 12-month follow-up period, high FeNO group had higher exacerbation events (HR of 1.26, 95 % confidence interval (CI), 1.10–1.97, p= 0.025). Hospitalization and mortality rates were significantly higher in the high FeNO group. Regardless of the inhaled corticosteroids used, patients with high BEC and FeNO levels tended to have a greater risk of exacerbation. ConclusionIn patients with COPD, FeNO levels are strongly correlated with BEC. Poor clinical outcomes were reported in patients with high FeNO levels. FeNO may be a useful biomarker for predicting clinical outcomes in patients with COPD.

Sex differences of small airway function and fractional exhaled nitric oxide in patients with mild asthma

BackgroundSex differences of small airway function (SAF) and fractional exhaled nitric oxide (FeNO) in patients with mild asthma remain unclear. ObjectiveTo evaluate sex differences of SAF and FeNO in patients with mild asthma confirmed by positive methacholine challenge test (MCT) result. MethodsThis cross-sectional, double-centered, observational study enrolled 1609 adult patients with forced expiratory volume in 1 second greater than or equal to 80% and suspected asthma symptoms. Data of spirometry, FeNO, impulse oscillometry measurements, and peripheral blood test result were compared between males and females. The receiver-operating characteristic curves of SAF parameters and FeNO in predicting positive MCT result were also calculated. ResultsIn patients with mild asthma matched by age, males had better SAF but higher FeNO levels than females (60 [29.27%] vs 187 [46.75%] for small airway dysfunction, 78.6% vs 72.0% for forced expiratory flow [FEF]50%, 67.5% vs 60.1% for FEF75%, 73.7% vs 67.4% for FEF25%-75%, and 42.0 ppb vs 29.0 ppb for FeNO, respectively, all P ≤ .001). The FeNO levels in male current smokers were considerably lower than those of nonsmokers. SAF and FeNO values declined more rapidly with age among female than male patients with asthma. The optimal cutoff values of FEF25%-75%, FEF50%, and FeNO for predicting a positive MCT result were 81.5%, 86.4%, and 41.0 ppb in males vs 73.7%, 76.9%, and 35.0 ppb in females. ConclusionIn patients with mild asthma, the female patients have worse SAF, lower FeNO levels, and a more prominent decline trend of those parameters with age than males. Sex-specific cutoff values should be considered when SAF parameters (FEF25%-75%, FEF50%), alone or combined with FeNO, are used to predict positive MCT result in asthma diagnosis.

Fractional Exhaled Nitric Oxide in Teenagers and Adults with Atopic Dermatitis.

Fractional exhaled nitric oxide (FeNO) is a non-invasive biomarker of eosinophilic airway inflammation and therapeutic response to corticosteroid treatment of respiratory diseases. Atopic dermatitis (AD), one of the most common allergic conditions of the skin, is a factor influencing the increase of FeNO. The main aim of this study was to determine differences between levels of FeNO in patients with AD and healthy controls as measured by an electrochemical analyzer. In total, 54 teenagers and adults with AD were recruited and compared with 34 healthy volunteers. The measurements of FeNO were taken using the Hyp’Air FeNO in participants. FeNO was statistically significantly higher in patients with AD than in healthy controls (60.5 ± 35.1 vs. 14.8 ± 5.1 ppb, p < 0.001). We found a strong positive significant correlation between FeNO and the number of positive skin prick tests among AD patients (R = 0.754, p < 0.001). There was no correlation between FeNO and duration of disease as well as SCORAD index among patients. Moreover, we also found no FeNO difference between the mild and moderate forms of AD. The presence of AD and the increasing number of positive skin prick tests increase FeNO, so the results of this measurement should be interpreted with caution in patients with respiratory diseases suffering from AD.

Correlation of Atopy and FeNO in Allergic Rhinitis: An Indian Study

Fractional exhaled nitric oxide (FeNO) is a non-invasive marker of airway inflammation. Limited published data are available on the effect of atopy on FeNO in allergic rhinitis. To investigate the relationship between atopy and FeNO in patients with allergic rhinitis. Patients with allergic rhinitis were assessed for atopy and exhaled breath analysis of nitric oxide. Atopy was assessed by skin prick testing (SPT) against 58 common aero-allergens; a wheal size of 3mm or more as compared to buffer saline was considered positive. Patients were labelled to be atopic if they had at least one positive SPT result. The measurement of FeNO level was done by using NIOX chemiluminescence analyser. Forty-nine participants (26 males) aged between 8-50 years were studied and 31 of them were found to be atopic. The average value of FeNO in the subjects studied (n = 49) was 26.0 +/- 22.7 parts per billion (ppb) with significantly higher values being observed in atopic group as compared to non-atopic group (34.2 +/- 24.3 versus 11.9 +/- 9.0 ppb; p < 0.05). As FeNO is a marker of lower airway inflammation, significantly higher FeNO levels in atopic allergic rhinitis patients suggest that it may be a predictor for onset of asthma in these patients.

Use of Fractional Exhaled Nitric Oxide to Guide the Treatment of Asthma: An Official American Thoracic Society Clinical Practice Guideline.

Background: The fractional exhaled nitric oxide (FENO) test is a point-of-care test that is used in the assessment of asthma.Objective: To provide evidence-based clinical guidance on whether FENO testing is indicated to optimize asthma treatment in patients with asthma in whom treatment is being considered.Methods: An international, multidisciplinary panel of experts was convened to form a consensus document regarding a single question relevant to the use of FENO. The question was selected from three potential questions based on the greatest perceived impact on clinical practice and the unmet need for evidence-based answers related to this question. The panel performed systematic reviews of published randomized controlled trials between 2004 and 2019 and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) evidence-to-decision framework to develop recommendations. All panel members evaluated and approved the recommendations.Main Results: After considering the overall low quality of the evidence, the panel made a conditional recommendation for FENO-based care. In patients with asthma in whom treatment is being considered, we suggest that FENO is beneficial and should be used in addition to usual care. This judgment is based on a balance of effects that probably favors the intervention; the moderate costs and availability of resources, which probably favors the intervention; and the perceived acceptability and feasibility of the intervention in daily practice.Conclusions: Clinicians should consider this recommendation to measure FENO in patients with asthma in whom treatment is being considered based on current best available evidence.

Comparison of fractional exhaled nitric oxide, spirometry, and Asthma Control Test, in predicting asthma exacerbations: A prospective cohort study.

Context:Fractional exhaled nitric oxide (FeNO) is a noninvasive test for airway inflammation in asthma. The usefulness of FeNO in predicting exacerbations is uncertain.Aims:The study aims to assess and compare the ability of FeNO, spirometry, and asthma control test (ACT) in predicting future exacerbations of asthma and their correlation with each other.Settings and Design:This prospective, cohort study was conducted at the Department of Respiratory Medicine, Kasturba Medical College, Manipal.Materials and Methods:Adult asthma patients of age 18–65 years were included. Patients with a smoking history of >10 pack-years and those in whom spirometry was contraindicated were excluded. Patients who consented underwent FeNO and spirometry. The control of asthma was assessed using the ACT questionnaire. We captured the number of exacerbations in the follow-up period of 4 months.Statistical Analysis Used:Mann–Whitney test was used to compare the utility of FeNO, spirometry, ACT in predicting exacerbations and Spearman's correlation coefficient was used to ascertain the correlation among them.Results:Of 154 study patients, 28% had exacerbations. We found that there was no significant difference in FeNO in patients with and without exacerbations. The median (interquartile range [IQR]) FEV1% in the patients with and without exacerbations were 68 (55–79) and 75 (65–88), respectively (P = 0.013). The median (IQR) ACT score in patients with exacerbations was 12 (10–16) which was significantly lower than in those without exacerbation in whom it was 16 (14–18) (P = 0.003). There was a negative correlation of ACT with FeNO (Correlation coefficient: −0.167, P = 0.038). The median (IQR) FeNO level (ppb) was lower in patients who were on inhaled corticosteroid (ICS) than in the other group values being 22 (14–38) and 30 (17–58), respectively (P = 0.05).Conclusions:In our study, FEV1% and ACT score could predict exacerbations of asthma whereas FeNO could not. FeNO level correlated inversely with ACT score. FeNO level decreased with inhaled corticosteroid usage.

Lung Sound Analysis Provides A Useful Index For Both Airway Narrowing And Airway Inflammation In Patients With Bronchial Asthma.

BackgroundThe expiration-to-inspiration sound power ratio in a midfrequency range (E/I MF), a parameter of lung sound analysis (LSA), has been reported to be useful as an index of airway inflammation in patients with bronchial asthma. However, the E/I MF reflects airway narrowing caused by airway inflammation, and there is thus concern that it may not be an index of airway eosinophilic inflammation itself.MethodsA total of 131 patients with bronchial asthma were classified into four groups according to the presence or absence of airway narrowing and airway inflammation to examine whether the E/I MF could serve as an index of airway inflammation.ResultsThe E/I MF was significantly higher in patients with a normal forced expiratory volume in one second (FEV1) and high fractional exhaled nitric oxide (FeNO), those with a low FEV1 and normal FeNO, and those with a low FEV1 and high FeNO than in those with a normal FEV1 and normal FeNO (p < 0.05–0.01). In particular, the E/I MF was high even in the patients who had no airway narrowing but had airway inflammation (p < 0.01). The results of multivariate analysis of factors involved in FeNO in patients with a normal FEV1 revealed that the E/I MF was an independent factor (p = 0.0281).ConclusionThe E/I MF is a useful index of airway inflammation in the treatment of asthma, regardless of the presence or absence of airway narrowing.

Diagnostic value of fractional exhaled nitric oxide for asthma-chronic obstructive pulmonary disease overlap syndrome.

To examine the difference in the fractional exhaled nitric oxide (FeNO) between chronic obstructive pulmonary disease (COPD) patients with asthma-COPD overlap syndrome (ACOS) and patients with Non-ACOS COPD (Non-ACOS) and to investigate the correlation between FeNO levels and the differential cell counts of eosinophils in induced sputum, in order to explore the diagnostic value of FeNO in ACOS.A prospective, case-control study was performed on 53 cases of ACOS group and 53 cases of Non-ACOS group in the Respiratory Medicine Outpatient of Zhangzhou Municipal TCM Hospital, Affiliated to Fujian University of Traditional Chinese Medicine. The FeNO levels and induced sputum cell counts were determined and the correlation between FeNO levels and eosinophile percentage was analyzed by Pearson linear correlation analysis.The FeNO levels in patients with ACOS (37[24.5–53.0]) ppb were significantly higher than those of patients with Non-ACOS (20 [15.5–24.5] ppb) (P < .01). Also, the percentage of eosinophils in induced sputum in the ACOS group (5.70 [1.50–17.62]%) were significantly higher than those of the Non-ACOS group (0.50 [0.00–1.00]%) (P < .01). FeNO in both groups correlated positively with the percentage of eosinophils in induced sputum (P < .01), with a correlation coefficient r of 0.521. The area under the receiver operating curve of FeNO for the diagnosis of ACOS phenotype was 0.815 (P < .01), the sensitivity and specificity reach highest when the cut off value was 25.50 ppb.The FeNO in patients from the ACOS group were significantly higher than those in Non-ACOS group and were moderately correlated with the percentage of eosinophils in induced sputum. The results indicated that FeNO may be used as a diagnostic index for ACOS, in addition to the induced sputum.

Investigating fractional exhaled nitric oxide (FeNO) in chronic obstructive pulmonary disease (COPD) and asthma–COPD overlap (ACO): a scoping review protocol

IntroductionDuring the last decade, many articles have been published, including reviews on fractional exhaled nitric oxide (FeNO) use and utility in clinical practice and for monitoring and identifying eosinophilic airway...

Values in Elderly People for Exhaled Nitric Oxide Study.

Ageing population is constantly increasing due to rising life expectancy; consequently, the percentage of the elderly patients with asthma is increasing, as well. Fractional exhaled nitric oxide (FeNO) is a biomarker of lung inflammation, and currently it is widely used in clinical practice for asthma diagnosis and monitoring. Yet, there are no data about normal values of FeNO in patients of more than 65 years of age with normal lung function. The aim of this study was to establish adult FeNO reference values for subjects older than 65 years, according to the international guidelines. FeNO was measured in 303 healthy, nonsmoking adults more than 65 years of age, with normal spirometry values measured using the online single-breath technique. The results were analyzed by chemiluminescent detection. The FeNO levels obtained range from 5.00 to 29.9 ppb, with a mean value of 12.48 ± 2.80 ppb. A significant association of FeNO levels with age (p < 0.05) was observed. There was no difference in FeNO values between men and women unlike what was observed in younger patients. FeNO levels in healthy controls over 65 years of age are influenced by age as in younger adults. However, there is no difference in FeNO values in male and female seniors, in contrast with what was found in younger adults in other studies. These data can be useful for the clinician to interpret the values of FeNO assessed during clinical practice.

Aerobic training decreases bronchial hyperresponsiveness and systemic inflammation in patients with moderate or severe asthma: a randomised controlled trial

BackgroundThe benefits of aerobic training for the main features of asthma, such as bronchial hyperresponsiveness (BHR) and inflammation, are poorly understood. We investigated the effects of aerobic training on BHR...

Evaluation of exhaled nitric oxide in acute paraquat poisoning: A pilot study

BackgroundFractional exhaled nitric oxide (FENO) is nitric oxide (NO) in the lower airway measured by oral exhalation. FENO can be a useful non-invasive marker for asthma. Paraquat-mediated lung injury can be reflective of an ROS-induced lung injury. We aimed to verify if FENO is a clinical parameter of ROS formation and responsiveness to medical therapies in acute paraquat intoxication.Material/MethodsWe recruited 12 patients admitted with acute paraquat poisoning. A portable and noninvasive device called NIOX MINO™ (Aerocrine AB, Solna, Sweden) was used to measure FENO. Measurements were made at the time of hospital admission and at 24, 48, 72, 96, and 120 h after paraquat ingestion.ResultsSix out of the total 12 recruited patients had general conditions (e.g. oral pain) that made it difficult for them to exhale with adequate force. Mean plasma paraquat level was 1.4±2.5 μg/mL. We found no direct correlation between the paraquat levels (both ingestion amount and plasma concentration) and FENO (initial, maximal, and minimal values). All the measured FENO values were no greater than 20 ppb for the 2 patients who died. FENO did not vary more than 20% from the baseline. Compared to the above findings, FENO measurements were found to be greater than 20 ppb for the patients who survived. FENO tends to reach its peak value at between 50 h and 80 h.ConclusionsFENO did not predict mortality, and there was no increase of FENO in patients with severe paraquat intoxication.

Significance of fractional exhaled nitric oxide combined with serum procalcitonin and C-reactive protein in evaluation of elderly asthma

Bronchial asthma is a common chronic airway inflammatory disease. Asthma is associated with high mortality, especially in the elderly patients. Repeated exacerbations cause disease progression. Therefore, identifying the onset of acute elderly asthma as soon as possible and giving the effective treatment is crucial to improve the prognosis. This study was to investigate the significance of fractional exhaled nitric oxide (FeNO) combined with serum procalcitonin (PCT) and C-reactive protein (CRP) in the evaluation of elderly asthma. A total of 120 elderly patients with an acute attack of asthma from July, 2010 to May, 2012 were studied. On presentation, FeNO, serum PCT and CRP concentrations were measured and sputum culture was also performed. The elderly patients were re-evaluated when they had returned to their stable clinical state. The elderly patients were classified into two groups: positive bacterial culture group (A) and negative bacterial culture group (B). The results showed that: (1) In patients with an acute exacerbation of asthma, 48 (40%) patients had positive sputum bacterial culture and 72 (60%) had negative sputum bacterial culture. (2) The levels of FeNO in patients with acute exacerbation of asthma were significantly higher than in those with no acute exacerbation state (63.8±24.6 vs. 19±6.5 ppb, P<0.05). There was no significant difference in FeNO between group A and group B (P>0.05). (3) The levels of PCT and CRP in group A patients with an acute exacerbation of asthma were significantly higher (P<0.05) than in group B (for PCT: 27.46±9.32 vs. 7.85±3.52 ng/mL; for CRP: 51.25±11.46 vs. 17.11±5.87 mg/L, respectively). When they had returned to stable clinical state, the levels of PCT and CRP in group A were decreased significantly (P<0.05), and those in group B had no significant change (P>0.05) when compared with the exacerbation group. There were no significant differences in the levels of PCT and CRP between the two groups in non-acute exacerbation state (P>0.05). These results suggest that the increase in FeNO indicates the acute exacerbation of asthma, and the elevation of serum PCT and CRP levels may be associated with bacterial infection.

Effects of Aerobic Training on Airway Inflammation in Asthmatic Patients

there is evidence suggesting that physical activity has anti-inflammatory effects in many chronic diseases; however, the role of exercise in airway inflammation in asthma is poorly understood. We aimed to evaluate the effects of an aerobic training program on eosinophil inflammation (primary aim) and nitric oxide (secondary aim) in patients with moderate or severe persistent asthma. sixty-eight patients randomly assigned to either control (CG) or aerobic training (TG) groups were studied during the period between medical consultations. Patients in the CG (educational program + breathing exercises; N = 34) and TG (educational program + breathing exercises + aerobic training; N = 34) were examined twice a week during a 3-month period. Before and after the intervention, patients underwent induced sputum, fractional exhaled nitric oxide (FeNO), pulmonary function, and cardiopulmonary exercise testing. Asthma symptom-free days were quantified monthly, and asthma exacerbation was monitored during 3 months of intervention. at 3 months, decreases in the total and eosinophil cell counts in induced sputum (P = 0.004) and in the levels of FeNO (P = 0.009) were observed after intervention only in the TG. The number of asthma symptom-free days and VO(2max) also significantly improved (P < 0.001), and lower asthma exacerbation occurred in the TG (P < 0.01). In addition, the TG presented a strong positive relationship between baseline FeNO and eosinophil counts as well as their improvement after training (r = 0.77 and r = 0.9, respectively). aerobic training reduces sputum eosinophil and FeNO in patients with moderate or severe asthma, and these benefits were more significant in subjects with higher levels of inflammation. These results suggest that aerobic training might be useful as an adjuvant therapy in asthmatic patients under optimized medical treatment.