Change In PEF Research Articles

Lung function parameters are associated with acute mountain sickness and are improved at high and extreme altitude

At altitude, factors such as decreased barometric pressure, low temperatures, and acclimatization might affect lung function.The effects of exposure and acclimatization to high-altitude on lung function were assessed in 39 subjects by repetitive spirometry up to 6022 m during a high-altitude expedition. Subjects were classified depending on the occurrence of acute mountain sickness (AMS) and summit success to evaluate whether lung function relates to successful climb and risk of developing AMS.Peak expiratory flow (PEF), forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) increased with progressive altitude (max. +20.2 %pred, +9.3 %pred, and +6.7 %pred, all p<0.05). Only PEF improved with acclimatization (BC1 vs. BC2, +7.2 %pred, p=0.044). At altitude FEV1 (p=0.008) and PEF (p<0.001) were lower in the AMS group.The risk of developing AMS was associated with lower baseline PEF (p<0.001) and longitudinal changes in PEF (p=0.008) and FEV1 (p<0.001). Lung function was not related to summit success (7126 m). Improvement in PEF after acclimatization might indicate respiratory muscle adaptation.

The physiological and physical benefits of two types of concurrent training: a randomized controlled trial

BackgroundIt is widely acknowledged that aerobic exercise and strength training are crucial components of most workout programs. However, there is no consensus as to whether the effectiveness of exercises is affected by the sequence in which they are performed. Therefore, the overarching aim of the study was to understand the optimal order of two types of concurrent training program for 13 weeks by comparing the effectiveness of the training on body composition, predicated maximal oxygen uptake (VO2max), dynamic respiratory parameters and muscle strength in healthy middle-aged people.MethodsThirty-three middle-aged individuals, who were categorized as moderately active based on their responses to International Physical Activity Questionnaires, underwent random allocation. The participants were randomly assigned into two groups: the Strength Training followed by Aerobic Training group (SAG, n = 16) and the Aerobic Training followed by Strength Training group (ASG, n = 17). Body composition, aerobic endurance, respiratory parameters, and upper and lower strength were assessed at baseline and after (post-test) a 13-week intervention. The chi-square test and the independent t-test were used to compare sociodemographic variables between the groups. A 2 × 2 analysis of variance (ANOVA) with repeated measures (group x measurement) was conducted. The study was retrospectively registered on clinicaltrials.gov in May of 2023 (clinicaltials.gov identifier: NCT05862415; in 04/25/2023).ResultsFindings showed no significant differences between the group in the VO2max, FVC or FEV1 (F = 1.122, 0.028, 0.06, 2.483; p > 0.05, respectively). Intragroup analysis revealed changes in PEF compared to baseline in the ASG (F = 5.895; p < 0.05). Increases were observed in all strength parameters for both training programs.ConclusionsThe concurrent training effect on muscle composition, oxygen consumption and muscle strength specifically 1RM, in middle-aged individuals are equivocal, regardless of the exercise order. The results indicate that both exercise sequences can elicit similar benefits in terms of cardiovascular fitness, muscular strength, and endurance. This lack of difference suggests that the order of exercise does not play a significant role in determining the effectiveness of the workout or the subsequent physiological adaptations.Clinicaltials.gov identifierNCT05862415. Date of registration: 04/25/2023

유산소 운동 시 마스크 타입에 따라 호흡 기능에 미치는 효과

Purpose: This study aimed to explore the effects of the type of mask worn during aerobic exercise on respiratory function. Methods: A total of 30 people were included in this study. The subjects were randomly assigned to two groups: the dental mask group (wearing dental masks during aerobic exercise, n=15) and the KF94 mask group (wearing KF94 masks during aerobic exercise, n=15). Aerobic exercise was performed using a sedentary cycle with eight levels of intensity control three times a week for 4 weeks. Respiratory function (forced vital capacity [FVC], forced expiratory volume in one second [FEV1], FEV1-to-FVC ratio [FEV1/FVC%], and peak expiratory flow [PEF]) was assessed using a spirometer at 0, 2, and 4 weeks. Results: A significant difference in all respiratory function parameters, including FVC, FEV1, FEV1/FVC%, and PEF, was observed between the two groups (p&lt;.05). The change in respiratory function was not statistically significantly different between the two groups. However, a significant difference in the amount of change in PEF was observed between the two groups at 4 weeks (p&lt;.05). Conclusion: The dental and KF94 mask groups showed increased respiratory function. However, no significant difference was observed between the two groups. Furthermore, no difference was observed in the amount of increase in respiratory function during aerobic exercise according to the mask type. Thus, we recommend wearing a dental mask that is easy to breathe during aerobic exercise.

키네지오 테이핑 적용이 둥근어깨증후군 대상자의 폐활량에 미치는 영향

The purpose of this study was to find out the effect of kinesio taping on vital capacity of subjects with rounded shoulder syndrome. 26 of 20s men and women in their with round shoulder syndrome were randomly assigned to an experimental and a control group. All subjects measured their vital capacity before starting the experiment, and rested for an hour. The experimental group applied kinesio taping while resting, and the control group did not take any intervention. After an hour, subjects were measured vital capacity again to compare the amount of change. The experimental group showed significant changes in FVC, FEV1, and PEF after an hour. In the control group, there were no significant changes in vital capacity. In comparison between groups, the experimental group showed significant differences in FVC, FEV1, and PEF compared to the control group. Kinesio taping is effective in improving vital capacity for subjects who have rounded shoulder syndrome.

Effect of compression of fourth ventricle on the respiratory capacity in the post COVID patients

Introduction and Aim: Post-covid syndrome is the group of nonspecific symptoms which are seen among the patients who have been recovered from COVID-19 and that persist over 4 weeks. Symptoms involve fatigue, breathlessness, cough, cognitive disturbances, depression and anxiety, many organs related symptoms, and the prominent features involve shortness of breath and inability to return to baseline activity level. Studies show that Pneumonia which is associated with the COVID-19 infections can lead to long-standing damage to the alveoli in the lungs and as a result scar tissues may develop which in the future can lead to long-term breathing problems. The aim of this study is to assess the effectiveness of osteopathic CV4 technique in post covid patients.&#x0D; &#x0D; Materials and Methods: This is a pre-test and post-test experimental study conducted at Sri Sri University. In this study, 20 subjects both male and female, having mean age of 23.3 ± 2.81 years were taken. After assessment of all inclusion and exclusion criteria, a brief history regarding COVID-19 and if present other respiratory disorders was taken. Following this, a 5 minutes window period was given to all participants before the collection of pre-test data.&#x0D; &#x0D; Results: When CV4 osteopathic technique was given to post-covid patients, there was a significant change in FVC, FEV1, PEF and pulse rate when compared to the pretest intervention data. However, the changes in oxygen saturation levels were not statistically significant.&#x0D; &#x0D; Conclusion: The results show that osteopathic CV4 technique alters the respiratory capacity in post covid patients.

Efectos de la suplementación con vitamina D en el control del asma en pacientes adultos: una revisión sistemática

Background: Asthma is an airway chronic disease, with an important inflammatory component within its pathogenesis, driven by a dysregulated immune response. Vitamin D is an immunomodulator that regulates cell proliferation, differentiation and cytokine secretion profile. An association between vitamin D sufficiency and improvement in pulmonary function, asthma control and a decrease in exacerbations have been proposed in the adult population, which falls into importance given the high prevalence of vitamin D insufficiency globally. Objective: To know vitamin D supplementation effects in asthma control in adults. Methods: Through a PubMed and EMBASE database search, a systematic review of the literature was conducted. Primary outcomes were: changes in FEV1, symptomatic control, exacerbation frequency and PEF and adverse events as secondary outcomes. Outcome evidence quality assessment was made using the GRADE model. Results: Seven studies were selected after taking out duplicates, applying inclusion and exclusion criteria. In all cases, evidence quality assessed by the GRADE system yielded very low quality. Conclusions: No statistically significant differences were found after vitamin D supplementation in the overall evaluated outcomes. Nonetheless, a cautious interpretation of studies is mandatory, because evidence quality was very low and no serious adverse events were reported. Hence this treatment usefulness as an ancillary therapy for vitamin D deficient asthmatic patients cannot be dismissed.

Association of personal PM2.5 exposure with lung function alternation and mediating role of oxidative damage in general urban adults

Background: The association and mechanism of PM2.5 exposure in personal level with lung function alternation are rarely reported among urban adults in China. Objectives: To evaluate potential effects of personal PM2.5 exposure on lung function in general urban adults and explore mediating role of oxidative stress in the association. Methods: A total of 7685 measurements were obtained from the Wuhan-Zhuhai cohort. Personal PM2.5 exposure levels were estimated through an estimated model developed in Wuhan. Mixed linear model with subject-specific random intercept was used to evaluated the association between personal PM2.5 exposure and lung function, as well as PM2.5 exposure and oxidative damage biomarkers (urinary 8-isoprostane and 8-hydroxy-2′-deoxyguanosine (8-OHdG)). Mediation analysis was conducted to investigate the role of urinary 8-isoprostane and 8-OHdG in the association between PM2.5 and lung function. Results: Each 10 μg/m3 increase of the previous-day personal PM2.5 was significantly associated with a -2.94 mL, -2.02 mL and -16.14 mL/s change in FVC, FEV1 and PEF, respectively (all P&lt;0.05). The associations were more obvious among never smokers compared with current smokers. Seven days moving average of PM2.5 exposure showed the strongest effects on lung function parameters. Non-linear association was observed between 8-isoprostane and lung function. Among participants with low 8-isoprostane level (&lt;73.02 ng/mmol Cr), each 10 μg/m3 increase of 7 days average PM2.5 was associated with 1.06% (0.17, 1.96) increase in urinary 8-isoprostane level, and 8-isoprotane meditated 5.24%, 12.05% and 5.21% of the association with FVC, FEV1 and PEF, respectively. No significant association or mediation effect was observed among participants with high 8-isoprostane level. No significant mediation effect of 8-OHdG was observed. Conclusion: Personal exposure to PM2.5 is associated with reduced pulmonary ventilation function. PM2.5-related declines in both FEV1 and FVC were stronger among never smokers than those among current smokers. And urinary 8-isoprostane partly mediated the associations.

A Phase 2a Study of DP2 Antagonist GB001 for Asthma

GB001, a DP2 antagonist, may inhibit recruitment and activation of inflammatory cells in patients with asthma, consequently reducing airway inflammation. Explore the efficacy and safety of GB001 in adults with mild to moderate asthma. During a 4-week run-in period, adult patients with asthma (N= 158) received medium-dose inhaled corticosteroid and placebo and were then randomized to treatment once daily with GB001 5 mg, 20 mg, or placebo for 16 weeks or until asthma worsening/exacerbation. Patients were tapered to and then discontinued from low-dose inhaled corticosteroid at randomization and at 4 weeks postrandomization, respectively. Primary end point was change in morning peak expiratory flow (AM PEF); secondary end points included measures of asthma control. Safety was also assessed. Baseline characteristics were similar among GB001 5 mg, 20 mg, and placebo groups. Changes in AM PEF in 5 mg and 20 mg groups versus placebo showed mean differences (95% CI) of 15.2 (3.1-27.4) L/min (P= .02) and 13.7 (1.5-25.8) L/min (P= .03), respectively. The changes in forced expiratory volume in 1 second of 55 mL and 32 mL, respectively, were not significant. There was a significant difference between GB001 20 mg and placebo for the secondary end points of time to asthma worsening/exacerbation (hazard ratio, 0.29), 5-item Asthma Control Questionnaire score (-0.60 point), the percentage of days without asthma symptoms (26%), and the percentage of rescue-free days (22%). Patients with baseline eosinophil levels greater than or equal to 300/μL had larger differences between GB001 20 mg and placebo for changes in AM PEF. Similar effects were seen in a post hoc analysis for time to worsening/exacerbations and 5-item Asthma Control Questionnaire score. The most common nonserious adverse event in the GB001 groups compared with the placebo group was nasopharyngitis. GB001 was well tolerated and although not associated with clinically meaningful changes in lung function, improvements in asthma worsening/exacerbations and markers of asthma control were demonstrated. In addition, greater treatment effects were observed in patients with high baseline blood eosinophils. Further studies are needed to confirm these findings in the context of standard of care treatment.

Study of efficacy and safety of levosalbutamol versus racemic salbutamol delivered by metered dose inhaler in children with moderate persistent asthma

Aim: To compare the efficacy and safety of Levosalbutamol versus racemic Salbutamol delivered by metered dose inhaler in children with moderate persistent asthma. Materials and Methods: Children enrolled in the study were randomized to receive MDI Levosalbutamol 2 puff thrice daily, 50 µgm/puff (group A) or MDI Racemic Salbutamol 2 puff thrice daily. 100 µgm/puff (group B).Baseline characteristics of both groups were comparable. The FEV1 % and PEF % were assessed at baseline, at 15 minutes following the first dose on day 1 and on day 8. In children who remained symptomatic on day 8, an additional evaluation on day 15 was performed. Asthma symptom score were calculated from symptom score card. Results: There was significant improvement in PEF % and FEV1 % within each group. But there was no statistically significant inter-group difference in PEF % change and FEV1 % change except mean change in PEF % and ∆PEF % of initial on day 8 (at the end of 1 week).Asthma symptom score improved significantly in both groups but there was no inter group difference. Incidence of side effects like decrease in serum potassium level and increase in heart rate were comparable in between the two groups. Conclusion: Levosalbutamol administered via MDI improved PEF % significantly more in comparison of racemic Salbutamol after regular use of one week. However, no significant differences were observed in between the two drugs with respect to pulmonary function test on day 1, FEV1 % on day 8 and asthma symptom score. The side effect profile of the two drugs was comparable. This suggests that Levosalbutamol is at least as efficacious as conventional Salbutamol in terms of clinical efficacy.

Pulmonary and respiratory muscle function in response to 10 marathons in 10 days

Marathon and ultramarathon provoke respiratory muscle fatigue and pulmonary dysfunction; nevertheless, it is unknown how the respiratory system responds to multiple, consecutive days of endurance exercise. Nine trained individuals (six male) contested 10 marathons in 10 consecutive days. Respiratory muscle strength (maximum static inspiratory and expiratory mouth-pressures), pulmonary function (spirometry), perceptual ratings of respiratory muscle soreness (Visual Analogue Scale), breathlessness (dyspnea, modified Borg CR10 scale), and symptoms of Upper Respiratory Tract Infection (URTI), were assessed before and after marathons on days 1, 4, 7, and 10. Group mean time for 10 marathons was 276 ± 35min. Relative to pre-challenge baseline (159 ± 32 cmH2O), MEP was reduced after day 1 (136 ± 31 cmH2O, p = 0.017), day 7 (138 ± 42 cmH2O, p = 0.035), and day 10 (130 ± 41 cmH2O, p = 0.008). There was no change in pre-marathon MEP across days 1, 4, 7, or 10 (p > 0.05). Pre-marathon forced vital capacity was significantly diminished at day 4 (4.74 ± 1.09 versus 4.56 ± 1.09L, p = 0.035), remaining below baseline at day 7 (p = 0.045) and day 10 (p = 0.015). There were no changes in FEV1, FEV1/FVC, PEF, MIP, or respiratory perceptions during the course of the challenge (p > 0.05). In the 15-day post-challenge period, 5/9 (56%) runners reported symptoms of URTI, relative to 1/9 (11%) pre-challenge. Single-stage marathon provokes acute expiratory muscle fatigue which may have implications for health and/or performance, but 10 consecutive days of marathon running does not elicit cumulative (chronic) changes in respiratory function or perceptions of dyspnea. These data allude to the robustness of the healthy respiratory system.

DMD CLINICAL THERAPIES II: P.134Comparing home-based respiratory function monitoring to hospital-based spirometry in Duchenne muscular dystrophy

In Duchenne muscular dystrophy (DMD), respiratory function decline leads to a high disease burden and early mortality. Data comparing the similarity and reliability of home-based respiratory assessments to hospital-based spirometry assessments had been lacking. In DELOS, respiratory function data were prospectively collected from 64 DMD patients aged 10-18 years, not taking glucocorticoids. All patients had established respiratory function decline (defined as peak expiratory flow <80%p) at baseline, and were treated with idebenone (900 mg/day) or placebo. Hospital-based spirometry was conducted during hospital visits at baseline and at 3-month intervals thereafter over the 12-month study period. Patients also measured peak expiratory flow and forced expiratory volume in 1 second, expressed as percent of predicted (PEF%p, FEV1%p), weekly, at home, using the ASMA-1 device (Vitalograph). Data were analyzed using a mixed model for repeated measures. The mean age of DELOS participants was 14.3 years. A majority (92%) were non-ambulatory and showed signs of significant upper limb weakness at baseline (59% had a Brooke's score of ≥ 5). The weekly changes in PEF%p measured at home compared well with hospital-based measurements, showing a 5.6 ± 1.7% (95% CI, 2.16–9.04; p = 0.002) overall treatment difference from placebo in favor of idebenone across all weekly visits, compared to a 6.27% difference from placebo at last visit using standard hospital spirometry (95% CI, 0.61–11.93; p = 0.031). The weekly ASMA-1 data indicated a stabilization of PEF%p in the idebenone group versus a natural history-consistent decline in the placebo group – a result that was replicated by the hospital-based data. Home-based respiratory function monitoring is reliable in pediatric and adolescent patients with DMD, and may prove useful and convenient in combination with hospital-based monitoring. These data further support the efficacy of idebenone in slowing respiratory function decline in DMD.

Rapid and Consistent Improvements in Morning PEF in Patients with Severe Eosinophilic Asthma Treated with Mepolizumab.

Previous studies showed that mepolizumab significantly reduces exacerbations and oral corticosteroid use in patients with severe eosinophilic asthma. However, early studies reported inconsistent effects on lung function. This study specifically assessed the onset of clinical effect and the relationship of baseline blood eosinophil count of mepolizumab 100mg subcutaneous (SC) administration on morning peak expiratory flow (AM PEF). Post hoc analysis of data from two randomized, double-blind, placebo-controlled studies (MENSA, NCT01691521; MUSCA, NCT02281318) of 4-weekly mepolizumab 100mg versus placebo in patients with severe eosinophilic asthma. Individual study results were generated using a mixed model repeated measures model controlling for multiple covariates and were combined using a fixed effects meta-analysis via inverse-variance weighting. Significant improvements in AM PEF after the first dose of mepolizumab 100mg SC vs. placebo were seen as early as week 1 and continued to improve further with subsequent doses. The mean change in AM PEF was 26L/min in the mepolizumab group compared to 4L/min in the placebo group, p < 0.001. When the population was stratified by blood eosinophil thresholds the mean difference from placebo was 24L/min (≥ 150 cells/µL), 27L/min (≥ 300 cells/µL), and 34L/min (≥ 500 cells/µL), p < 0.001 for all subgroups. The < 150 cells/µL (≥ 300 cells/µL in the previous year) group increased 13L/min, while both 150 to < 300 cells/µL and 300 to < 500 cells/µL ranges demonstrated comparable changes (19L/min and 17L/min), respectively. Our analysis has shown early and consistent improvements in lung function measured by AM PEF using the study enrollment criterion of ≥ 150 eosinophils/µL. We also identified a relationship between baseline blood eosinophils and improvements in AM PEF with mepolizumab in patients with severe eosinophilic asthma. GlaxoSmithKline (study ID 208091).

The effect of nephrostomy tract infiltration of ketamine on postoperative pain and peak expiratory flow rate in patients undergoing tubeless percutaneous nephrolithotomy: a prospective randomized clinical trial.

Ketamine, as a systemic and local analgesic, has been used to reduce postoperative pain in many studies. The present study was designed to assess the analgesic efficacy of nephrostomy tract infiltration of ketamine in postoperative pain after tubeless percutaneous nephrolithotomy (PCNL). Sixty-six patients with renal stone who were candidates for PCNL were randomized to two groups with 33 patients in each group. In group K, 20mL saline solution containing 1.5mg/kg ketamine was infiltrated into the nephrostomy tract and in group C, 20mL saline solution was infiltrated into the nephrostomy tract at the end of surgery. The postoperative pain scores, sedation scores, time to first rescue analgesia, rescue analgesic requirement, peak expiratory flow rate (PEF), and hemodynamic parameters were compared between two groups. Sixty-six patients with a mean age of 45.29 ± 15years and an age range of 18-60years participated in this study. There was no significant difference in the demographic data and duration of surgery between the two groups. The mean VAS scores were significantly lower in the intervention group compared with the control group at the recovery, and 4 and 6h postoperatively (p = 0.001). The mean time to first rescue analgesia in the postoperative period was significantly lower in the control group (64.5 ± 8.1min) compared with the intervention group (122 ± 18.4min). The trend of first opioid administration was significantly lower in the ketamine group p < 0.009. There was no significant differences in PEF between the two groups in the postoperative period (p = 0.622). In conclusion infiltration of ketamine into the nephrostomy tract provides superior analgesic and sedative effects in PCNL surgery without significant changes in PEF.

OP40 – 2251: Idebenone as a new therapy to treat respiratory function loss in Duchenne muscular dystrophy: from preclinical studies to phase III trial outcome

Based on its dual mode of action (reducing oxidative stress and improving mitochondrial respiratory chain function), we hypothesized idebenone as a potential therapeutic strategy for DMD. Here we summarize the development program which was executed between 2004 and 2014. A preclinical observer-blinded and placebo-controlled study in the mdx mouse model of DMD showed a significant cardioprotective and voluntary exercise performance effect for presymptomatic-initiated and long-term idebenone treatment. Next, a phase 2 randomized placebo-controlled clinical trial (DELPHI) was performed in 21 DMD boys aged 8–16 years, demonstrating trends for beneficial effects of idebenone on early functional cardiac and respiratory parameters. An important finding was that patients treated for 12 months with idebenone stabilized in peak expiratory flow percent predicted (PEF%p, marker of expiratory muscle strength), compared to patients receiving placebo who declined. Next we investigated the efficacy and tolerability of idebenone in a multicenter phase 3 trial (DELOS) in 64 DMD patients aged 10–18 years not taking concomitant glucocorticoid steroids. The majority of patients (92%) were non-ambulatory at baseline. The primary endpoint was change in PEF%p over the 12 month treatment period. Other respiratory outcome measures included forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), weekly home-based PEF measurements, peak cough flow (PCF) and maximal static airway pressures. Idebenone significantly reduced the decline in PEF%p. A significant treatment effect was also observed in PEF (L/min), weekly home-based PEF as well as analyses of FVC and FEV1. The outcomes were comparable between patients with previous glucocorticoid steroid use and steroid naive patients. Results of respiratory function analyses were supported by responder analyses and clinical observations. In conclusion, our data consistently demonstrated that Idebenone was safe and well tolerated, significantly preserved respiratory function, and represents a new treatment option for patients with DMD.

Evaluation of step-down therapy from an inhaled steroid to montelukast in childhood asthma

BackgroundAsthma guidelines allow antileukotriene medications to be used as an alternative to inhaled corticosteroids (ICSs) in second-step intensity therapy. The aim of this study was to determine whether asthma control can be maintained after reducing treatment from low-dose ICS to montelukast. MethodsIn this prospective, real-life 12-week trial, 84 young patients with asthma (7–18 years) controlled by low-dose ICS, had treatment switched to montelukast. Symptoms and PEF were monitored daily; exhaled nitric oxide (eNO) and spirometry every four weeks; sputum eosinophil (sEo) and bronchial hyperreactivity (BHR) assessed at the beginning and at the end of the study. The primary endpoint was number of patients discontinued from the study due to asthma exacerbations. ResultsEleven patients (13.1%) were discontinued due to asthma exacerbations. At the beginning, patients with elevated percentage of sEo had increased risk of exacerbations (relative risk RR, 6.6; 95% CI, 1.2–35.6), as well as those with augmented BHR (RR, 4.24; 95% CI, 1.1–16.2) as compared to patients who completed the study. An intensification of symptoms and increased use of beta-adrenergics were observed during the last visit before exclusion from the study, but not changes in spirometry, PEF, and eNO. No change in clinical parameters, inflammatory markers or BHR was observed in patients remaining in the study. ConclusionsAfter treatment switch from low-dose ICS to montelukast, asthma control was maintained in the majority of patients during the 12-week observation period. Sputum eosinophilia or BHR before the treatment switch was exacerbation risk factor.

Relation of bronchial and alveolar nitric oxide to exercise‐induced bronchoconstriction in atopic children and adolescents

Exercise challenge test is widely used in diagnostics and follow-up of childhood asthma, but the method is complex, time consuming, and expensive. In this study, we aimed to find out whether flow-independent nitric oxide (NO) parameters (bronchial NO flux [J'aw(NO)] and alveolar NO concentration [CA(NO)]) predict exercise-induced bronchoconstriction (EIB) in atopic children and adolescents with asthma-like symptoms. Also, the respective NO parameters corrected for axial backward diffusion (J'aw(NO) [TMAD] and CA(NO) [TMAD]) were calculated and included in the analysis. Thirty patients (6-19 yr old) with confirmed atopy (positive skin prick tests or allergen-specific IgE) and asthma-like respiratory symptoms were included in the study. Before the current investigations, none of the patients had been diagnosed to have asthma and none were on inhaled corticosteroids. Exhaled NO was measured at multiple exhalation flow rates, and exercise challenge test was carried out. Bronchial NO flux and alveolar NO concentration were calculated according to the linear method with and without correction for axial backward diffusion. Sixty-six healthy school children served as controls. The patients were divided into two groups according to EIB. Patients with EIB (EIB+ group, n = 18) had enhanced bronchial NO output as compared to patients without EIB (EIB- group, n = 12); but the EIB- group did not differ from healthy controls. EIB+ group had also higher alveolar NO concentration than EIB- group and healthy controls, but EIB- group did not differ from healthy controls. When bronchial NO flux and alveolar NO concentration were corrected for axial diffusion, J'aw(NO) (TMAD) had equal difference as J'aw(NO) between the groups as expected. However, only EIB+ had higher CA(NO) (TMAD) than healthy controls, and the patient groups did not differ from each other. In patients, bronchial NO output correlated with the magnitude of exercise-induced change in PEF (r(s) = -0.388, p = 0.034), FEV(1) (r(s) = -0.395, p = 0.031), and FEF(50%) (r(s) = -0.431, p = 0.020), i.e., the higher the bronchial NO output, the larger the decrease in PEF/FEV(1) /FEF(50%) . Alveolar NO concentrations correlated with the change in FEV(1) (r(s) = -0.439, p = 0.015), FEF(50%) (r(s) = -0.454, p = 0.013), FEF(75%) (r(s) = -0.447, p = 0.017), and FVC (r(s) = -0.375, p = 0.045). For J'aw(NO) (TMAD), the correlations and p-values were equal to those of J'aw(NO) , but, interestingly, CA(NO) (TMAD) had no significant correlations with any of the exercise-induced changes in lung function. The results showed that in atopic children and adolescents, increased bronchial NO output as well as J'aw(NO) (TMAD) were associated with EIB, while alveolar NO concentration (but not CA(NO) [TMAD]) correlated with the degree of obstruction in smaller airways induced by exercise challenge.

Comparative effect of pre‐coseasonal and continuous grass sublingual immunotherapy in children

One of the most important aspects of sublingual immunotherapy (SLIT) is the regimen of administration. The aim of the study was to compare the efficacy and the safety of SLIT given pre-coseasonally (starting before the pollen season and continuing until the end of it) and continuously (all year round, independent of the pollen season) in children allergic to grass pollen. Sixty children aged 6-18, sensitive only to grass pollen, with rhinitis (20 patients had concomitant asthma) participated in the 2-year prospective, randomized, double-blind, placebo-controlled trial. Both pre-coseasonal and continuous SLIT were associated with a substantial reduction in the combined symptoms/medication score when compared with placebo; there were no significant differences between the regimens (mean difference: 18.1 ± 12.4, P > 0.05). Similar changes were observed in the total symptoms score. Pre-coseasonal therapy, compared with continuous, was more effective in the reduction of nasal symptoms (mean difference: -18.0 ± 2.5, P = 0.006). We did not observe significant differences in medication, ocular, and asthma scores between the regimens. We did not observe changes in morning PEF, FEV1, and PD20 in any of the three groups nor between the groups throughout the study. We showed a significant decrease in FeNO level comparable in both active groups. There were no differences between groups in the induction of CD4CD25Foxp3-positive cells in peripheral blood during the study. Both protocols were effective compared with placebo and showed similar decreases for combined symptoms/medication score and all secondary endpoints, with the exception of nasal symptoms that were lower in the pre-coseasonal group.

Application of respiratory muscle training in patients with COPD in remission phase in primary hospitals

Objective To evaluate the efficacy of respiratory muscle training in patients with COPD in remission phase in primary hospitals. Methods 82 patients with COPD in remission phase received respiratory muscle training including pursed lip breathing, deep breathing, breathing exercises for 2 to 3 months, 20 to 30 minutes daily. The improvement in hypoxia and respiratory fatigue was observed; and the changes in VCmas(L), FEV1/FVC(%), FEV(L), and PEF(L/S)were determined. Results After 3 months of respiratory muscle training, hypoxia, respiratory fatigue, and indice of lung function tests were significantly improved; and the FEV1/FVC value, as compared with the baseline, differed significantly(P＜ 0.05). Conclusions It is of important significance for respiratory muscle training to improve lung function in patients with COPD in remission phase in primary hospitals. Key words: Chronic obstructive pulmonary disease; Respiratory muscle training; Remission; Evaluation

S159 Do occupational asthmatics with small changes in PEF at work have less FEV1 decline than those with larger changes?

BackgroundThe significance of consistent small changes in PEF related to work, or records with diurnal variation within the normal range, are disputed. We related PEF changes at diagnosis to longitudinal...

A technical report on exhaled nitric oxide measurement: asthma monitoring in athletes

Exhaled NO (FENO) measurements have been utilized as a marker to diagnose asthma as well as a non-invasive tool for monitoring airway inflammation and the response to anti-inflammatory medications. One area where this non-invasive monitoring may be helpful is for asthmatic athletes as they train for competitive events. We hypothesized that in the course of training an asthmatic individual may experience worsening of lung inflammation reflected in FENO levels that may be too subtle to detect by conventional methods like spirometry. Data were collected from an asthmatic patient (n = 1) over the course of endurance training using both the desktop (NIOX) and the portable NO (MINO) analyzers daily for eight weeks. We found that average NO levels measured in the desktop system correlated well with the two portable analyzers (r2 = 0.73, r2 = 0.74; p < 0.0001); additionally, there was a strong correlation between the two MINO devices (r2 = 0.88; p < 0.0001). A strong negative relationship existed between the number of miles run and NO, regardless of the device used. FEV1 and PEF, however, did not change significantly as the miles run increased. Exercise training in asthmatics was associated with a decrease (improvement) in NO levels but no significant change in FEV1 and PEF. This suggests that exhaled NO levels may be more sensitive to changes in the airway as a result of exercise than traditional pulmonary function testing.