The FEF25–75and its Decline as a Predictor of Methacholine Responsiveness in Children

Respiratory pattern complexity in newly-diagnosed asthmatic patients

BACKGROUND

The intensity of respiratory symptoms and expiratory airflow limitations in asthma fluctuate over time. Some studies have reported variable complexity of the respiratory patterns in asthmatic patients. Thus, we conducted a novel study to assess the correlation between asthma severity and breathing pattern dynamics in newly-diagnosed asthmatic patients.

METHODS

A total of 20 newly-diagnosed asthmatic patients (7 male, 13 female) and 20 healthy cases (11 male, 9 female) were included. The respiratory patterns of all participants and the asthma severity for asthmatic patients were measured using a spirometer (before and after a bronchodilator exposure) and airflow recorder, respectively. The peak-to-peak intervals and the amplitude of peaks were considered as the inter-breath interval (IBI) and lung volume (LV) series. The Detrended Fluctuation Analysis (DFA), Sample Entropy (SampEn), Multi-scale Entropy (MSE), short-term (SD1) and long-term (SD2) variability, and IBI and LV Cross-Sample Entropy of the respiratory pattern dynamics were calculated using MATLAB (Mathwork, USA).

RESULTS

Asthma patients showed notable increase in the average of sample entropy in both IBI and LV parameters (p = 0.025 and p = 0.018, respectively) and also decreased synchronization between IBI and LV (p = 0.042). The multi-scale sample entropy of both IBI and LV was significantly higher in asthmatic patients (p < 0.05). Furthermore, SD1 and SD2 were higher in the patients with asthma (p < 0.05). Significant correlations were detected between spirometric (forced expiratory flow (FEF) change, pre FEF, pre forced expiratory volume in one second (FEV1) / forced vital capacity (FVC), FVC change) and respiratory pattern (mean-IBI, mean-LV, mean-respiratory rate (RR), coefficient of variation (CV)-IBI, CV-LV, cross-sample entropy) parameters (p < 0.05). Furthermore, we identified a negative correlation between CV of IBI and asthma severity (r = -0.52, p = 0.021).

CONCLUSION

Here, we took a novel approach and observed increased irregularity (more complexity) in the breathing pattern of patients newly-diagnosed with asthma. Remarkable correlations were detected between breathing complexity markers and spirometric indices along with disease severity in asthmatic patients. Thus, our data suggests respiratory pattern indices could be utilized as an indicator of asthma and its severity. However, more clinical data are required to support this conclusion.

Correlation between Reduced FEF25-75% and a Positive Methacholine Challenge Test in Adults with Nonobstructive Baseline Spirometry

Objective

To clarify whether in adults with a nonobstructive spirometry a reduced FEF25-75% is associated with a positive methacholine challenge test (MCT).

Methods

Data was collected for all the patients who had a MCT done between April 2014 and January 2020 but had nonobstructive baseline spirometry. Logistic regression was utilized to estimate the log odds of a positive methacholine test as a function of FEF25-75% and also for age, gender, BMI, FEV1, and FEV1/FVC.

Results

Out of 496 patients, 187 (38%) had a positive MCT. Baseline characteristics in two groups were similar except that patients with positive MCT were younger (32 ± 11.57 vs. 38 ± 13.25 years, respectively, p < 0.001). Mean FEF25-75% was lower in MCT positive (3.12 ± 0.99 L/s) vs. MCT negative (3.39 ± 0.97 L/s) patients, p = 0.003. Logistic regression results suggest that MCT outcome is inversely related to FEF25-75%, age, and gender. Specifically, as FEF25-75% percentage of predicted value increases, the log odds of a positive MCT decrease (odds ratio (OR) = 0.90, 95% confidence intervals (CI) = 0.84-0.96, p = 0.002). Also, as age increases, the log odds of a positive MCT decrease (OR = 0.95, 95%CI = 0.94-0.97, p < 0.001).

Conclusions

Reduced FEF25-75% in adults with nonobstructive spirometry can predict a positive response to MCT in younger patients. However, this relationship becomes weaker with increasing age.

FEF25-75% Is a More Sensitive Measure Reflecting Airway Dysfunction in Patients with Asthma: A Comparison Study Using FEF25-75% and FEV1

BACKGROUND

Reduced forced expiratory flow between 25% and 75% of vital capacity percent predicted (FEF_25-75%) representing small airway dysfunction (SAD) was associated with asthma development and progression.

OBJECTIVE

To investigate whether FEF_25-75% was superior to forced expiratory volume in 1 second in predicted (FEV₁%) in reflecting asthma features in adult patients.

METHODS

A retrospective spirometry dataset comprising 1801 adult patients with confirmed asthma and a subgroup of 332 patients having detailed clinical data were used to explore the association of FEF_25-75% and/or FEV₁% with clinical features of asthma.

RESULTS

Of the 1801 subjects, FEV₁% and FEF_25-75% ranged from 136.8% to 10.2% and 127.3% to 3.1%, respectively. FEF_25-75% < 65% was present in 1,478 (82.07%) of patients. FEF_25-75% was strongly correlated with matched FEV₁% (r = 0.900, P < .001). FEF_25-75% and FEV₁% were both correlated with airway hyperresponsiveness (r = 0.436, P < .001; r = 0.367, P < .001), asthma control test score (r = 0.329, P < .001; r = 0.335, P < .001), and sputum eosinophil count (r = -0.306, P < .001; r = -0.307, P < .001). Receiver-operating characteristic curves showed that FEF_25-75% had greater value in predicting severe asthma (area under the curve: 0.84 vs 0.81, P = .018), airflow obstruction (0.97 vs 0.89, P < .001), and severe bronchial hyperresponsiveness (0.74 vs 0.69, P = .012) as compared with FEV₁%. Patients with SAD (FEF_25-75% < 65%) in the presence of normal FEV₁% exhibited higher sputum eosinophil counts and had an increased dosage of daily inhaled corticosteroids (P < .001 and P = .010) than patients with normal lung function and their FEF_25-75% values correlated with sputum eosinophil count (r = -0.419, P = .015), but not FEV₁%.

CONCLUSION

FEF_25-75% represented small airway function and was more sensitive at reflecting airway hyperresponsiveness, inflammation, and disease severity as compared with FEV₁% in patients with asthma. Our data suggest further assessment of FEF_25-75% in asthma management, particularly for those with SAD who present normal FEV₁%.

Small-Airway Function Variables in Spirometry, Fractional Exhaled Nitric Oxide, and Circulating Eosinophils Predicted Airway Hyperresponsiveness in Patients with Mild Asthma

Purpose

Patients with variable symptoms suggestive of asthma but with normal forced expiratory volume in 1 second (FEV₁) often fail to be diagnosed without a bronchial provocation test, but the test is expensive, time-consuming, risky, and not readily available in all clinical settings.

Patients and Methods

A cross-sectional study was performed in 692 patients with FEV₁≥80% predicted; normal neutrophils and chest high-resolution computed tomography; and recurrent dyspnea, cough, wheeze, and chest tightness.

Results

Compared with subjects negative for AHR (n=522), subjects positive for AHR (n=170) showed increased FENO values, peripheral eosinophils (EOS), and R5-R20; decreased FEV₁, FEV₁/Forced vital capacity (FVC), and forced expiratory flow (FEFs) (P≤.001 for all). Small-airway dysfunction was identified in 104 AHR⁺ patients (61.17%), and 132 AHR⁻ patients (25.29%) (P<0.001). The areas under the curve (AUCs) of variables used singly for an AHR diagnosis were lower than 0.77. Using joint models of FEF_50%, FEF_75%, or FEF_25%-75% with FENO increased the AUCs to 0.845, 0.824, and 0.844, respectively, significantly higher than univariate AUCs (P <0.001 for all). Patients who reported chest tightness (n=75) had lower FEFs than patients who did not (P<0.001 for all). In subjects with chest tightness, the combination of FEF_50% or FEF_25%-75% with EOS also increased the AUCs substantially, to 0.815 and 0.816, respectively (P <0.001 for all versus the univariate AUCs).

Conclusion

FENO combined with FEF_50% and FEF_25%-75% predict AHR in patients with normal FEV₁. FEF_25%-75%, FEF_50%, or FEF_25%-75% together with EOS also can potentially suggest asthma in patients with chest tightness.

Determinants of response to bronchodilator in patients with cough variant asthma- A randomized, single-blinded, placebo-controlled study

BACKGROUND

Not all patients with cough variant asthma (CVA) show responsiveness to bronchodilators (RB) in clinic. Whether there are specific clinical and pathophysiological features can indicate RB in patients with CVA needs further investigation. Thus, we aimed to investigate the RB in patients with CVA and associated factors.

METHODS

Forty-two CVA patients were randomized in a 2:1 ratio to receive oral bambuterol hydrochloride (10 mg, once daily, for 3 days) or matched placebo, 36 patients (24 with bronchodilator and 12 with placebo) completed the study eventually. RB was considered when cough visual analogue scale (VAS) score decreased 30% or more after 3 days treatment. The baseline clinical and pathophysiological characteristics between patients with RB and patients without RB were compared. CRS was presented with the lowest concentration of capsaicin inducing at least 5 coughing (C5).

RESULTS

The responsive rate of patients with bronchodilator was significantly higher than that with placebo (62.5% vs 16.7%, p < 0.01). Patients with RB showed a significant greater mean decline of FEV₁% predicted after bronchial provocation (26.7% vs 22.4%, p < 0.05) and higher geometric mean of sputum eosinophils (1.37 vs 0.69, p < 0.05) as compared with these without RB. No significant differences in sputum neutrophil, Log C5 were found between patients with RB and patients without RB. There was a moderate correlation between the decline of FEV₁% pred and RB (r_s = 0.443, p < 0.05). The regression analysis showed that nocturnal cough was a predictor of RB (OR, 7.33, 95% CI: 1.11-48.26, p = 0.038). No adverse events were reported by all of the patients after the study.

CONCLUSION

More than one-third of patients with CVA do not respond to bronchodilator treatment, indicating that the response to bronchodilator should not be a diagnostic requirement of CVA. CVA patients with higher airway responsiveness will more likely respond to bronchodilator. Cough of CVA might be elicited by different mechanisms, which suggests that CVA could be divided into two phenotypes according to the response to bronchodilators.

Response to bronchodilator and clinical, pathophysiological features in patients with nonasthmatic eosinophilic bronchitis

INTRODUCTION

Whether nonasthmatic eosinophilic bronchitis (NAEB) shows response to bronchodilator (RB) remains unclear.

OBJECTIVES

To investigate the RB and its relationship with clinical and pathophysiological features in NAEB.

METHODS

Fifty-one patients with NAEB were assigned in a 2:1 ratio to receive oral bambuterol hydrochloride (n = 34, 10 mg, once daily, for 3 days) or matched placebo (n = 17) randomly, of whom 48 patients (32 with bronchodilator and 16 with placebo) completed the study. Sputum induction, spirometry and cough reflex sensitivity were measured. RB was considered when cough Visual analogue scale (VAS) score decreased 30% or more after treatment. Cough reflex sensitivity was defined as the lowest concentration of capsaicin inducing five coughings or more (C5), and presented as Log C5.

RESULTS

The responsive rate of patients with bronchodilator was significantly higher than that with placebo (34.4% vs 6.3%, P < 0.05). The VAS score decreased significantly in patients with bronchodilator (median: 6.0-3.0, P < 0.01). There was a significantly higher median Log C5 (2.7 vs 1.3, P < 0.05), and a higher trend of decline in FEV₁ % predicted and MMEF% predicted after bronchial provocation in patients with RB as compared with patients without RB. No significant differences in baseline percentages of sputum eosinophil were found between patients with RB and that without RB.

CONCLUSIONS

One third of patients with NAEB respond well to bronchodilator treatment, which are related with lower cough reflex sensitivity and increased airway responsiveness. The relationship between NAEB and asthma needs to be investigated further.

Priorities for future research into asthma diagnostic tools: A PAN-EU consensus exercise from the European asthma research innovation partnership (EARIP)

The diagnosis of asthma is currently based on clinical history, physical examination and lung function, and to date, there are no accurate objective tests either to confirm the diagnosis or to discriminate between different types of asthma. This consensus exercise reviews the state of the art in asthma diagnosis to identify opportunities for future investment based on the likelihood of their successful development, potential for widespread adoption and their perceived impact on asthma patients. Using a two-stage e-Delphi process and a summarizing workshop, a group of European asthma experts including health professionals, researchers, people with asthma and industry representatives ranked the potential impact of research investment in each technique or tool for asthma diagnosis and monitoring. After a systematic review of the literature, 21 statements were extracted and were subject of the two-stage Delphi process. Eleven statements were scored 3 or more and were further discussed and ranked in a face-to-face workshop. The three most important diagnostic/predictive tools ranked were as follows: "New biological markers of asthma (eg genomics, proteomics and metabolomics) as a tool for diagnosis and/or monitoring," "Prediction of future asthma in preschool children with reasonable accuracy" and "Tools to measure volatile organic compounds (VOCs) in exhaled breath."

Dose omission to shorten methacholine challenge testing: clinical consequences of the use of a 10% fall in FEV1 threshold

Introduction

In methacholine challenge testing (MCT), skipping a methacholine dose is suggested if FEV₁ falls by < 5%. Using a larger threshold may further shorten test duration, but data supporting this hypothesis is lacking. We evaluated the safety and consequences of using a 10% FEV₁ fall as threshold to skip the next dose of methacholine in patients undergoing MCT.

Methods

We reviewed MCTs performed in our center in 2017–2018. A ≤ 10% FEV₁ fall allowed the omission of the next methacholine dose. Patients of interest were those in which a dose was skipped after a previous FEV₁ fall outside the usual range (5–10%, termed “skip_5–10%”). Adverse events [AE; mild: > 1 nebulized salbutamol dose (2.5 mg) to reach basal FEV₁, palpitations; severe: hypoxemia and/or need for medical attention or intervention] were compared in the skip_5–10% group and others. Regression analysis was used to identify predictors of AE.

Results

208 MCTs were analysed (135 males, age 52 ± 15 years). Skip_5–10% occurred 111 times in 90 tests. Prevalence of AE was 5% and all were mild. Patients who developed AEs had lower FEV₁, FVC and FEV₁/FVC ratio, and higher lung volume values (all p < 0.05), but similar prevalence of skip_5–10% (36 vs. 44%, p = 0.64). Overall, MCTs in which at least one skip_5–10% occurred had a lower mean number of doses (3.1 ± 0.6 vs. 3.5 ± 1.3 doses, p = 0.007). Baseline residual volume was independently related to the development of AEs (OR 1.05, 95% CI 1.01–1.10, p = 0.01), but not the presence of a skip_5–10%, even when the skipped dose directly led to the reaching of PC₂₀ (OR 5.40, 95% CI 0.73–39.22, p = 0.10).

Conclusion

Omitting a methacholine dose based on a ≤ 10% fall in FEV₁ occurs frequently and has the potential to shorten test duration. AE are rare, but patients with worse baseline lung function and gas trapping are at increased risk of mild side effects.

The Value of Fractional Exhaled Nitric Oxide and Forced Mid-Expiratory Flow as Predictive Markers of Bronchial Hyperresponsiveness in Adults with Chronic Cough

BACKGROUND

Bronchial provocation tests are standard for diagnosing the etiology of chronic cough, but they are time consuming and can induce severe bronchospasm. A safer and faster clinical examination to predict bronchial hyperresponsiveness (BHR) is needed.

OBJECTIVE

The objective of this study was to investigate whether small-airway function tests can predict BHR in adult patients with chronic cough.

METHODS

A retrospective, cross-sectional study of diagnoses made using spirometry and bronchial provocation test results was performed in 290 patients with chronic nonproductive cough. BHR-predictive values were analyzed via the area under receiver operating characteristic curves (AUCs). Optimal cutoff values were determined by maximizing the sum of sensitivity and specificity.

RESULTS

Patients with chronic cough with BHR showed lower forced expiratory flow between 25% and 75% (FEF_25%-75%), higher fractional exhaled nitric oxide (FENO), and a higher percentage of eosinophils in blood than patients without BHR (P < .0001 for all). The AUCs of FENO and FEF_25%-75% for a BHR diagnosis were 0.788 (95% CI, 0.725-0.851) and 0.702 (95% CI, 0.641-0.763), respectively. Optimal cutoff values were 43 ppb for FENO and 78.5% for FEF_25%-75%, with negative predictive values of 85.38% and 81.34%, respectively. The combined use of FENO and FEF_25%-75% increased the AUC to 0.843 (95% CI, 0.794-0.892), significantly higher than either FENO (P = .012) or FEF_25%-75% (P < .0001) alone.

CONCLUSIONS

Small-airway dysfunction is present in patients with chronic cough and BHR. FEF_25%-75% has value as a negative predictive parameter for BHR, especially when combined with FENO. FENO > 43 ppb and FEF_25%-75% < 78.5% strongly predicted a positive bronchial provocation test.

Current clinical diagnostic tests for asthma

Asthma involves variable airflow obstruction in both large and small airways. The physiological consequences of obstruction include increased airway resistance and decreased expiratory flow rates, which lead to air trapping and dynamic hyperinflation. This chapter reviews current methods for pulmonary function testing to detect these physiological changes for both diagnosis and monitoring.

Retrospective observations on the ability to diagnose and manage patients with asthma through the use of impulse oscillometry: comparison with spirometry and overview of the literature

Objective. Impulse oscillometry (IOS) is an evolving technology for the diagnosis and followup of patients with asthma. Our objective is to review the findings on patients who underwent both spirometry and IOS during clinical evaluations of their asthma. The goal was to retrospectively evaluate IOS during the initial diagnosis and followup of patients with asthma in comparison with spirometry. Methods. We routinely perform IOS and spirometry evaluation in patients with suspected asthma during baseline visits and at followup. We reviewed the data on 39 patients over the age of 13 with asthma at baseline and following treatment with inhaled corticosteroids. IOS and spirometry were both done at baseline, following short acting bronchodilator administration, and at followup after at least three months of inhaled corticosteroid treatment. Results. IOS showed improvement in airway function both initially, following short acting bronchodilator introduction, and later after initiation of long term inhaled corticosteroid treatment, even when the spirometry did not reveal improvement. We noted the IOS improvement in the reactance or AX as well as the resistance in smaller airways or R5. Conclusion. IOS may provide a useful measure towards identifying an asthma diagnosis and followup without inducing the extra respiratory effort spirometry requires.

Leukotriene receptor antagonists for small-airway abnormalities in asthmatics: a systematic review and meta-analysis

BACKGROUND

Airway inflammation that occurs in asthma is mainly distributed in the small airways. Leukotriene receptor antagonists (LTRAs) are systemically active drugs that may act on the small airways.

OBJECTIVES

The aim of our study was to assess the efficacy of LTRAs for small-airway abnormalities in asthmatics.

METHODS

We searched the databases of Cochrane Central, MEDLINE, and EMBASE from the time of the establishment of the databases to December 2012. The data were extracted using a pooled mean difference (MD) or standardized mean difference (SMD) with a 95% confidence interval (CI).

RESULTS

Eight studies were included. The outcomes were the conventional parameters for the detection of small-airway abnormalities. Eight studies were included. The outcomes were the conventional parameters for the detection of small-airway abnormalities. LTRAs compared to placebo improved small-airway abnormalities, as indicated by a number of radiological and physiological parameters, such as lung attenuation (MD, 61.00; 95% CI, 26.32 to 95.68) and residual volume (SMD, -0.85; 95% CI, -1.29 to -0.42). Conventional inhaled corticosteroids (ICSs) compared to LTRAs improved small-airway abnormalities, as indicated by the reactance area (p = 0.028). Compared with conventional treatment alone, a combination of LTRAs and conventional treatment improved small-airway abnormalities, as indicated by a number of radiological and physiological parameters, such as airway wall thickness (p < 0.05), alveolar nitric oxide concentration (p = 0.04), a decrease in resistance from 5 to 20 hertz (p = 0.032), reactance area (p = 0.014), eosinophil cationic protein levels (p = 0.045) and number of eosinophils (p = 0.035) in the late-phase induced sputum. However, there was no significant improvement in forced expiratory flow between 25% and 75% of forced vital capacity in any of the comparisons.

CONCLUSIONS

LTRAs may improve most of the conventional parameters for the detection of small-airway abnormalities in asthmatics. However, there is no evidence of the superiority of LTRAs over ICSs in improving functional parameters related to the small airways.

Concave pattern of a maximal expiratory flow-volume curve: a sign of airflow limitation in adult bronchial asthma

Background. In patients with bronchial asthma, spirometry could identify the airflow limitation of small airways by evaluating the concave shape of the maximal expiratory flow-volume (MEFV) curve. As the concave shape of the MEFV curve is not well documented, we reevaluated the importance of this curve in adult asthmatic patients. Methods. We evaluated spirometric parameters, the MEFV curve, and its concave shape (scoop between the peak and endpoint of expiration) in 27 nonsmoking asthmatic patients with physician-confirmed wheeze and positive bronchial reversibility after a short-acting β2-agonist inhalation. We also calculated angle β and shape factors (SF_25% and SF_50%) to quantitate the curvilinearity of the MEFV curve. Results. The MEFV curve was concave in all patients. Along with improvements in standard spirometric parameters, curvilinear parameters, angle β, SF_25%, and SF_50% were significantly improved after bronchodilator inhalation. There were significant correlations between improvements in angle β, and FEF_50%, and FEF_25-75%, and between improvements in SF_25%, and SF_50%, and FEF_75%. Conclusions. The bronchodilator greatly affected the concave shape of the MEFV curve, correlating with spirometric parameters of small airway obstructions (FEF_50%, FEF_75%, and FEF_25-75%). Thus, the concave shape of the MEFV curve is an important indicator of airflow limitation in adult asthmatic patients.

The interest of FEF(25-75) in evaluating bronchial hyperresponsiveness with the methacholine test

BACKGROUND

Bronchial hyperresponsiveness is the pathogenic basis of asthma, and measurement of its intensity is investigated using the methacholine provocation test, which not only and particularly evaluates the reduction in FEV1 (PD20) but also takes forced mid-expiratory flow or FEF(25-75) (PD40) into account. The present study aims to evaluate the usefulness of both parameters.

MATERIAL AND METHODS

Provocation testing was carried out in 151 patients between 7 and 22 years of age diagnosed with asthma, tracheobronchitis and/or rhinitis, using a short method that allows quantification of the methacholine administered. The subjects were divided into three groups according to the amount of methacholine needed to obtain the mentioned parameters (group 1: ≤1000μg; group 2: 1001-2000μg; group 3: ≥2001μg).

RESULTS

Greater variability was recorded for FEF(25-75) than for FEV1. Paired comparison among the three groups for FEV1 proved significant, in the same way as for FEF(25-75) between groups 2 and 3, and 1 and 3, but not between groups 1 and 2. Calculation was made of the amount of methacholine required to obtain PD20 and PD40 from the same dose. Only the significant differences corresponded to the comparison of group 1 versus the rest, with no differences between the means of the total mean values.

CONCLUSIONS

The utility of PD20 is more evident, considering the variability of PD40; the latter may be useful in patients with rhinitis or tracheobronchitis when PD20 proves scantly demonstrative.

Clinical expert panel on monitoring potential lung toxicity of inhaled oligonucleotides: consensus points and recommendations

Oligonucleotides (ONs) are an emerging class of drugs being developed for the treatment of a wide variety of diseases including the treatment of respiratory diseases by the inhalation route. As a class, their toxicity on human lungs has not been fully characterized, and predictive toxicity biomarkers have not been identified. To that end, identification of sensitive methods and biomarkers that can detect toxicity in humans before any long term and/or irreversible side effects occur would be helpful. In light of the public's greater interests, the Inhalation Subcommittee of the Oligonucleotide Safety Working Group (OSWG) held expert panel discussions focusing on the potential toxicity of inhaled ONs and assessing the strengths and weaknesses of different monitoring techniques for use during the clinical evaluation of inhaled ON candidates. This white paper summarizes the key discussions and captures the panelists' perspectives and recommendations which, we propose, could be used as a framework to guide both industry and regulatory scientists in future clinical research to characterize and monitor the short and long term lung response to inhaled ONs.

Lung function changes in asthmatic children treated with HFA-BDP

STUDY OBJECTIVES

Asthma guidelines suggest that normal or near normal lung function should be one of the goals for good asthma control. Therefore, children with chronic persistent asthma and reduced peripheral airway function were assessed after the replacement of conventional inhaled corticosteroids (ICS) with an extrafine aerosol formulation, hydrofluoroalkane-134a beclomethoasone diproprionate (HFA-BDP).

DESIGN AND SETTING

Lung function and clinical details were studied in children with moderate persistent asthma who regularly attended the pediatric pulmonary outpatient clinic at Kosair Children's Hospital, Louisville, Kentucky, USA.

SUBJECTS

A total of 20 children, 7 girls and 13 boys, with stable asthma but reduced forced expiratory flows between 25% and 75% of vital capacity (FEF(25-75) ) were included in the study.

INTERVENTION

After the initial assessment, each subject was switched from conventional ICS to HFA-BDP. All other medications remained the same. Reassessment of lung function and clinical status was performed at least 3 weeks after the intervention.

RESULTS

FEF(25-75) increased from a mean of 50.75% to 68.85% predicted (P < 0.001). Forced expiratory volume in 1 sec (FEV(1)) also increased significantly from 84.6% to 93.8% predicted (P = 0.001). No changes asthma symptoms were observed.

CONCLUSION

Compared to conventional ICS, the use of HFA-BDP in asthmatic children significantly improves airflow in both the large and the peripheral airways without loss of asthma control.

The reciprocal influences of asthma and obesity on lung function testing, AHR, and airway inflammation in prepubertal children

Although asthma and obesity are among the major chronic disorders their reciprocal or independent influences on lung function testing, airways hyperresponsiveness (AHR) and bronchial inflammation has not been completely elucidated. In 118 pre-pubertal Caucasian children anthropometric measurements functional respiratory parameters (flow/volume curves at baseline and after 6-minute walk test [6MWT]) together with bronchial inflammatory index (FeNO) were assessed. The study population was divided into four groups according to BMI and the presence or absence of asthma: Obese asthmatic (ObA) Normal-weight asthmatic (NwA), Obese non-asthmatic (Ob), non-asthmatic normal-weight children (Nw). Baseline PEF and MEF(75) (%-expected) were significantly different across the four groups with significantly lower values of MEF(75) in ObA and Ob children when compared to Nw children (P = 0.004 and P = .0001, respectively) and this independent role of obesity on upper respiratory flows was confirmed by multiple analysis of covariance. After 6 MWT respiratory parameters decreased only in ObA and NwA children and 12 children presented a positive fall in FEV(1), in contrast no changes of respiratory function testing were detected in Ob and Nw children, and only 2 Ob children presented a significant fall in FEV(1). FeNO analysis demonstrated significantly higher values in ObA and NwA children when compared to Ob (P = 0.008 and P = 0.0002, respectively) and Nw children (P = 0.0001 and P = 0.0003, respectively), although a significant difference was found between Ob and Nw children (P = 0.0004). Multiple analysis of covariance confirmed an independent role of asthma on this parameter. In conclusion while AHR and airway inflammation are clearly associated with an asthmatic status, obesity seems to induce reduction of upper airways flows associated with a certain degree of pro-inflammatory changes.