Peak expiratory flow variability adjusted by forced expiratory volume in one second is a good index for airway responsiveness in asthmatics

Executive summary: Japanese guidelines for adult asthma (JGL) 2021

Asthma is characterized by chronic airway inflammation, variable airway narrowing, and sensory nerve irritation, which manifest as wheezing, dyspnea, chest tightness, and cough. Longstanding asthma may result in airway remodeling and become intractable. Despite the increased prevalence of asthma in adults, asthma-associated deaths have decreased in Japan (0.94 per 100,000 people in 2020). The goals of asthma treatment include the control of symptoms and reduction of future risks. A functional partnership between physicians and patients is indispensable for achieving these goals. Long-term management with medications and the elimination of triggers and risk factors are fundamental to asthma treatment. Asthma is managed via four steps of pharmacotherapy ("controllers"), ranging from mild to intensive treatments, depending on disease severity; each step involves daily administration of an inhaled corticosteroid, which varies from low to high dosage. Long-acting β₂ agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonists are recommended as add-on drugs. Allergen immunotherapy is a new option that is employed as a controller treatment. Further, as of 2021, anti-IgE antibody, anti-IL-5 and anti-IL-5 receptor α-chain antibodies, and anti-IL-4 receptor α-chain antibodies are available for the treatment of severe asthma. Bronchial thermoplasty can be performed for asthma treatment, and its long-term efficacy has been reported. Algorithms for their usage have been revised. Comorbidities, such as allergic rhinitis, chronic rhinosinusitis, chronic obstructive pulmonary disease, and aspirin-exacerbated respiratory disease, should also be considered during the treatment of chronic asthma. Depending on the severity of episodes, inhaled short-acting β₂ agonists, systemic corticosteroids, short-acting muscarinic antagonists, oxygen therapy, and other approaches are used as needed ("relievers") during exacerbation.

Effect of 2-Hz Electroacupuncture Stimulation on Respiratory Function: A Randomized Controlled Trial

Objective: The autonomic nervous system is involved in the regulation of airway smooth muscle. This study examined the effect of acupuncture stimulation in the vicinity of the cervical-sympathetic ganglion on respiratory function in humans. Materials and Methods: Twenty-four healthy adults (19 males and 5 females) were randomly assigned to a no-treatment group, a leave-needle group, and an electroacupuncture (EA) group in a crossover trial. In all groups, respiratory function was initially tested. In both acupuncture groups, after 5 minutes of rest, a 5-minute acupuncture stimulus was delivered, followed by 5 minutes of rest. Thereafter, respiratory function was again tested in all groups. Acupuncture was delivered in the vicinity of the cervical ganglia at the height of the sixth cervical vertebra on the left side and the vertebral artery node; the EA stimulus was set to 2 Hz, and the stimulation intensity was set to a level at which no pain was felt by the participants. Results: The EA group had significant increases in peak expiratory flow (PEF) and vital capacity (VC) after the intervention, compared to before intervention. Additionally, the EA group had significant increases in these parameters, compared to the no-treatment group. Conclusions: These results indicated that stimulation with 2-Hz EA in the vicinity of the cervical-sympathetic trunk causes an increase in PEF and VC, and increased bronchial dilation.

Japanese Guideline for Adult Asthma 2014

Adult bronchial asthma (hereinafter, asthma) is characterized by chronic airway inflammation, reversible airway narrowing, and airway hyperresponsiveness. Long-standing asthma induces airway remodeling to cause intractable asthma. The number of patients with asthma has increased, and that of patients who die from asthma has decreased (1.5 per 100,000 patients in 2012). The aim of asthma treatment is to enable patients with asthma to lead a normal life without any symptoms. A good relationship between physicians and patients is indispensable for appropriate treatment. Long-term management with antiasthmatic agents and elimination of the causes and risk factors of asthma are fundamental to its treatment. Four steps in pharmacotherapy differentiate between mild and intensive treatments; each step includes an appropriate daily dose of an inhaled corticosteroid, varying from low to high. Long-acting 02-agonists, leukotriene receptor antagonists, and sustained-release theophylline are recommended as concomitant drugs, while anti-immunoglobulin E antibody therapy has been recently developed for the most severe and persistent asthma involving allergic reactions. Inhaled 02-agonists, aminophylline, corticosteroids, adrenaline, oxygen therapy, and others are used as needed in acute exacerbations by choosing treatment steps for asthma exacerbations depending on the severity of attacks. Allergic rhinitis, chronic obstructive pulmonary disease, aspirin-induced asthma, pregnancy, asthma in athletes, and coughvariant asthma are also important issues that need to be considered.

Stratifying a risk for an increased variation of airway caliber among the clinically stable asthma

BACKGROUND

Recently, correlations of peak expiratory flow (PEF) variation have been shown to facilitate the prediction of later asthma symptoms and exacerbations. However, it has not been fully examined whether or not any patient characteristics are associated with the residual airway lability in treated asthmatics. The objective of this study is to examine a predictive marker for increased variation of PEF in patients with clinically stable asthma.

METHODS

We studied 297 asthmatic patients who were monitored for PEF twice a day. Asthma Control Questionnaire (ACQ), spirometry, and exhaled nitric oxide fraction (FENO) were measured. After the assessment of baseline values, PEF measuring was continued and associations between these clinical markers and later variation of PEF over a week (Min%Max) were investigated.

RESULTS

17.5% of the subjects showed increased PEF variability (Min%Max < 80%). ACQ, forced expiratory volume in 1 s % of predicted (%FEV1), and FENO were identified as independent predictors of Min%Max < 80%. An ACQ ≥ 0.4 yielded 96% sensitivity and 59% specificity, a %FEV1 ≤ 85% yielded 62% sensitivity and 89% specificity, and a FENO ≥ 40 ppb yielded 75% sensitivity and 90% specificity for identifying the subjects with high variability in PEF. When we combine %FEV1 ≤ 85% and FENO ≥ 40 ppb, this index showed the highest specificity (98%) for increased PEF variability.

CONCLUSIONS

These results indicate that ACQ, %FEV1 and FENO can stratify the risk for increased variation in airway caliber among patients with stable asthma. This may help identify subjects in whom further monitoring of lung function fluctuations is indicated.

Difference in time-course of improvement in asthma control measures between budesonide and budesonide/formoterol

Combinations of inhaled corticosteroids (ICS) and inhaled long-acting beta(2)-agonists (LABA) have become widely used for the initiation of maintenance treatment for asthma. However, it has not been fully elucidated whether ICS/LABA alters the time-course of different control outcome measures in steroid-naive patients with asthma compared to the treatment with ICS alone. We compared the time-response in Asthma Control Questionnaire (ACQ), forced expiratory volume in 1 s (FEV1), exhaled nitric oxide fraction (FE(NO)), and airway responsiveness to methacholine (PD(200)) between budesonide (BUD) and budesonide/formoterol (BUD/FM). BUD/FM therapy significantly improved the ACQ score at week 2 and week 4 (p < 0.01 and p < 0.05), and increased FEV1 and the methacholine threshold at week 8 and week 24 (all p < 0.05) compared to BUD alone. A logistic function model showed that the BUD/FM combination significantly improved ACQ, FEV1, FE(NO) and PD(200) at a faster rate than BUD over 24 weeks (p < 0.001 for ACQ, FEV1, PD(200), and p < 0.05 for FE(NO), z-test). A significant variance in the time-response was also found in the outcomes of the two treatment groups (FE(NO) and ACQ > FEV1 and PD(200), p < 0.001, z-test). The present study provides evidence that ICS/LABA combination therapy results in a more rapid improvement in asthma symptoms, lung function, and airway inflammation compared to ICS monotherapy in steroid-naive patients with asthma.

Molecular mechanism of the additive effects of leukotriene modifier in asthmatic patients receiving steroid therapy

BACKGROUND

The addition of leukotriene modifier (LM) may be a useful approach for uncontrollable asthma despite treatment with inhaled corticosteroid (ICS), especially in asthmatics comorbid with allergic rhinitis (AR), although little is known about its molecular mechanism. We evaluated the additive effects of LM with ICS on pulmonary function and airway inflammation in asthmatics with or without AR.

METHODS

Eighteen uncontrolled steroid-treated asthmatics, nine with and nine without AR, were enrolled. Spirometry, peak expiratory flow (PEF) measurements, and exhaled breath condensate sampling were performed before and 8 weeks after LM administration. The lowest PEF over the course of one week, expressed as a percentage of the highest PEF (Min%Max PEF), was used as an index of fluctuation of the airway caliber. Airway cytokine expression was analyzed with a protein array.

RESULTS

A significant improvement in forced expiratory volume in one second as a percentage of the predicted value (%FEV(1)) and Min%Max PEF was seen in the subgroup of asthma with AR. Although there was no significant difference in the baseline cytokine values between the groups, the exhaled RANTES level was significantly reduced by LM in the asthma with AR group. The changes in the RANTES level were significantly related to the changes in the %FEV(1) and Min%Max PEF values.

CONCLUSIONS

LM caused a greater improvement in pulmonary function and airway inflammation in asthmatics with AR. The RANTES-mediated pathway may be involved in the improvement of the airflow limitation and airway lability by LM additive therapy in asthmatics receiving steroid therapy.