Conjugated Linoleic Acid’s Lack of Attenuation of Hyperpnea-Induced Bronchoconstriction in Asthmatic Individuals in the Short Term

Author(s):  
Jonathon L. Stickford ◽  
Timothy D. Mickleborough ◽  
Alyce D. Fly ◽  
Joel M. Stager

Purpose:Conjugated linoleic acid (CLA) has been reported to modify the inflammatory response associated with allergic airway disease, primarily in animal models. To extend these observations to humans, the effect of short-term CLA supplementation on the severity of exercise-induced bronchoconstriction (EIB) was investigated in asthmatics.Methods:Six subjects with physician-diagnosed asthma and EIB began the study on their usual diet, to which was added 4.8 g CLA/d for 8 wk. Pulmonary-function tests were administered before and after eucapnic voluntary hyperventilation (EVH) challenge at the commencement (Week 0) and conclusion of the treatment period (Week 8). Pre- and 90 min post-EVH challenge, urine was assayed for the presence of cysteinyl leukotrienes (LT) C4−E4 and 9α,11β-prostaglandin (PG) F2.Results:Pre- to post- EVH forced expiratory volume in 1 s (FEV1) did not significantly differ (p > .05) from Week 8 to Week 0. The pre- to post-EVH decline in FEV1 at Week 8 (–29.6% ± 6.6%) was not significantly different (p > .05) from that at Week 0 (–32.0% ± 5.5%). Area under the curve of FEV1 plotted against time from zero to 60 min (AUC0–60) was unaltered at Week 8 (–931% ± 350% change per minute) compared with Week 0 (−1,090% ± 270% change per minute). CLA supplementation did not alter forced midexpiratory flow, forced vital capacity (FVC), or FEV1/FVC. In addition, post-EVH urinary LTC4–E4 and 9α,11β-PGF2 were unchanged after CLA supplementation.Conclusion:Daily supplementation of 4.8 g CLA for 8 wk does not attenuate airway inflammation or hyperpnea-induced bronchoconstriction in asthmatic individuals.

PEDIATRICS ◽  
1975 ◽  
Vol 56 (5s) ◽  
pp. 923-926
Author(s):  
Gall G. Shapiro ◽  
William E. Pierson ◽  
C. Warren Blerman

This study was designed to assess the effectiveness of comolyn sodium in modifying exercise-induced bronchospasm (EIB). Twenty children and adolescents with EIB were given either cromolyn or placebo in a prerandomized double-blind fashion. They then performed a free running maneuver. Pulmonary function tests were obtained before and after this exercise. Patients returned one week later to repeat the same procedure. This time subjects took placebo if they had previously taken cromolyn and vice versa. Significant beneficial effects of cromolyn were noted in forced vital capacity and forced expiratory volume in one second measurements but not in forced expiratory flow between 25% and 75% of the flow-volume curve) (FEF 25%-75%). This suggests that larger airway disease is preferentially helped by cromolyn when subjects are stressed maximally as with a free running system. Subjects who received placebo on study day 1 and cromolyn on study day 2 showed the most striking benefit from cromolyn. This may be related to the better baseline status of subjects on day 2 as well as to familiarity with the procedure and medication.


2020 ◽  
Vol 6 (2) ◽  
pp. 00271-2019
Author(s):  
Anna R. Jackson ◽  
J.H. Hull ◽  
James G. Hopker ◽  
Hannah Fletcher ◽  
William Gowers ◽  
...  

Respiratory symptoms, including cough, are prevalent in individuals with asthma when exercising. This study investigates whether a heat and moisture exchanger (HME) face mask is effective in modulating exercise-induced bronchoconstriction (EIB) and post-exercise cough in a cold, dry environment in individuals with asthma.Twenty-six participants diagnosed with asthma (20 males, 6 females) completed three cycling exercise challenges at 8°C and 24% relative humidity in a randomised order. Participants wore either an HME mask (MASK), sham mask (SHAM), or no mask (CONT). Following a 3-min warm-up, participants completed 6-min cycling at 80% peak power output. Before and after exercise, maximal flow-volume loops were recorded. Post-exercise cough was monitored with a Leicester Cough Monitor (LCM) for 24 h. Results were analysed using repeated-measures ANOVA and Friedman's tests and data were presented as the mean±sd or median (interquartile range (IQR)).Eleven participants failed to demonstrate EIB (i.e. >10% fall in forced expiratory volume in 1 s after exercise) and were removed from analysis. The percentage fall in forced expiratory volume in 1 s following exercise in CONT was greater than MASK (MASK: −6% (7%), SHAM: −11% (11%), CONT: −13% (9%); p<0.01). No difference was found between exercise in cough count per hour over the 24-h monitoring period or the number of coughs in the first hour after exercise.HME masks can attenuate EIB when exercising in cold, dry environments. The SHAM mask may not have been entirely inert, demonstrating the challenges of running randomised control trials utilising control and sham conditions.


2016 ◽  
Vol 41 (7) ◽  
pp. 735-740 ◽  
Author(s):  
Enrico Heffler ◽  
Matteo Bonini ◽  
Luisa Brussino ◽  
Paolo Solidoro ◽  
Giuseppe Guida ◽  
...  

Exercise-induced dyspnea is common among adolescents and young adults and often originates from exercise-induced bronchoconstriction (EIB). Sometimes, dyspnea corresponds to exercise-induced laryngospasm (EILO), which is a paradoxical decrease in supraglottic/glottic area. Vitamin D deficiency, which occurs frequently at northern latitudes, might favor laryngospasm by impairing calcium transport and slowing striate muscle relaxation. The aim of this study was to evaluate whether vitamin D status has an influence on bronchial and laryngeal responses to exercise in young, healthy athletes. EIB and EILO were investigated during winter in 37 healthy competitive rowers (24 males; age range 13–25 years), using the eucapnic voluntary hyperventilation test (EVH). EIB was diagnosed when forced expiratory volume in the first second decreased by 10%, EILO when maximum mid-inspiratory flow (MIF50) decreased by 20%. Most athletes (86.5%) had vitamin D deficiency (below 30 ng/mL), 29 mild-moderate (78.4%) and 3 severe (8.1%). EVH showed EIB in 10 subjects (27%), EILO in 16 (43.2%), and combined EIB and EILO in 6 (16.2%). Athletes with EILO had lower vitamin D (19.1 ng/mL vs. 27.0 ng/mL, p < 0.001) and higher parathyroid hormone (30.5 pg/mL vs. 19.2 pg/mL, p = 0.006) levels. The degree of laryngoconstriction (post-EVH MIF50 as a percentage of pre-EVH MIF50) was related directly with vitamin D levels (r = 0.51; p = 0.001) and inversely with parathyroid hormone levels (r = –0.53; p = 0.001). We conclude that vitamin D deficiency is common during winter in young athletes living above the 40th parallel north and favors laryngospasm during exercise, probably by disturbing calcium homeostasis. This effect may negatively influence athletic performance.


Author(s):  
José Rizzo ◽  
Edil Rodrigues Filho ◽  
Adriana Gonçalves ◽  
Laienne Albuquerque ◽  
Eduardo Albuquerque ◽  
...  

BACKGROUND: Exercise-induced respiratory symptoms are frequently reported by asthmatics and exercise-induced bronchospasm (EIB) is a frequent cause that requires objective testing for diagnosis. Eucapnic voluntary hyperventilation (EVH) is recommended as an exercise surrogate stimulus for this purpose, but its short-term reproducibility is not yet established in young asthmatics. OBJECTIVE: To evaluate the short-term test-retest agreement and reproducibility of FEV1 changes after EVH in young asthmatics. METHODS: Asthmatics aged between 10 and 20 years underwent EVH for EIB diagnosis on two occasions 2-4 days apart at a specialized university clinic. FEV1 was measured 5, 15 and 30 minutes after EVH with a target ventilation rate 21 times baseline FEV1. EIB was diagnosed as a decrease >10% in FEV1 from baseline. RESULTS: Twenty-six of 62 recruited individuals tested positive for EIB on both visits (positive group) and 17 on one visit only (divergent group); and 19 tested negative on both visits (negative group). The overall agreement was 72.5% (95%CI 61.6%, 83.6%) and positive and negative agreement was 41.9% and 30.6% respectively. Despite overall low bias in FEV1 response between test days (0.87%), the limits of agreement were wide (+20.72%). There were no differences in pre-challenge FEV1 or achieved ventilation rate, between visits either between groups (p=0.097 and p=0.461) or within groups, (p=0.828 and p=0.780). No test was interrupted by symptoms and there were no safety issues. CONCLUSIONS: More than one EVH test should be performed in young asthmatics with a negative test to exclude EIB and minimize misdiagnosis and mistreatment.


2021 ◽  
Vol 7 (2) ◽  
pp. 00917-2020
Author(s):  
Ulrika Käck ◽  
Elisabet Einarsdottir ◽  
Marianne van Hage ◽  
Anna Asarnoj ◽  
Anna James ◽  
...  

BackgroundThe clinical presentation of children sensitised to dog dander varies from asymptomatic to severe allergic airway disease, but the genetic mechanisms underlying these differences are not clear. The objective of the present study was to investigate nasal transcriptomic profiles associated with dog dander sensitisation in school children and to reveal clinical symptoms related with these profiles.MethodsRNA was extracted from nasal epithelial cell brushings of children sensitised to dog dander and healthy controls. Blood sample analyses included IgE against dog dander, dog allergen molecules, other airborne and food allergens, basophil activation and white blood cell counts. Clinical history of asthma and rhinitis was recorded, and lung function was assessed (spirometry, methacholine provocation and exhaled nitric oxide fraction).ResultsThe most overexpressed gene in children sensitised to dog dander compared to healthy controls was CST1, coding for Cystatin 1. A cluster of these children with enhanced CST1 expression showed lower forced expiratory volume in 1 s, increased bronchial hyperreactivity, pronounced eosinophilia and higher basophil allergen threshold sensitivity compared with other children sensitised to dog dander. In addition, multi-sensitisation to lipocalins was more common in this group.ConclusionsOverexpression of CST1 is associated with more severe allergic airway disease in children sensitised to dog dander. CST1 is thus a possible biomarker of the severity of allergic airway disease and a possible therapeutic target for the future treatment of airborne allergy.


1988 ◽  
Vol 64 (4) ◽  
pp. 1527-1536 ◽  
Author(s):  
C. S. Kim ◽  
G. A. Lewars ◽  
M. A. Sackner

Total aerosol deposition in the lung was measured in 100 subjects with various lung conditions. The subjects consisted of 40 normals (N), 15 asymptomatic smokers (S), 10 smokers with small airway disease (SAD), 20 with chronic simple bronchitis (SB), and 15 with chronic obstructive bronchitis (COPD), and a relationship of total aerosol deposition to degree of lung abnormality was investigated. The subjects were categorized by medical history and a battery of pulmonary function tests, including spirometry, body plethysmography, and single and multiple N2 washout measurements. Subjects repeatedly breathed a monodisperse test aerosol (1.0 micron diam) from a collapsible rebreathing bag (0.5 liter volume) at a rate of 30 breaths/min, while inhaled and exhaled aerosol concentrations were continuously monitored by a laser aerosol photometer in situ and recorded on a strip-chart recorder. The number of rebreathing breaths resulting in 90% aerosol loss from the bag (N90) was determined, and percent predicted N90 values were then determined from the results of computer simulation and used as a deposition index. The percent predicted N90 values were 99.7 +/- 14, 86.5 +/- 15, 66.9 +/- 17, 51 +/- 12, and 30.9 +/- 9, respectively, for N, S, SAD, SB, and COPD. All of these values were significantly different from each other (P less than 0.05). There was no difference between male and female but percent predicted N90 values were slightly higher in young than in old normals. Percent predicted N90 values showed a strong linear correlation with spirometric measurements of forced expiratory volume in 1 s and maximum midexpiratory flow rate. However, many of the SAD and SB with normal spirometry showed abnormal N90. These results suggest that total lung aerosol deposition is a sensitive index of lung abnormality and may be of potential use for nonspecific general patient screening.


PEDIATRICS ◽  
1975 ◽  
Vol 56 (5s) ◽  
pp. 860-867
Author(s):  
Gerd J. A. Cropp ◽  
I. J. Schmultzler

Sixty asthmatic children were exercised on a bicycle ergometer and had pulmonary function tests performed before and repeatedly after exercise. Pulmonary function measurements included airway resistance (Raw), specific airway conductance (SGaw) functional residual capacity (FRC), peak expiratory flow rate (PEFR), maximum mid-expiratory flow (MMEF), forced expiratory volume during first second of expiration (FEV1), and forced vital capacity (FVC). At any one time during the post-exercise observation period decreases in SGaw were greater than changes in any other pulmonary function test, making SGaw the most sensitive test for the detection. of exercise-induced airway obstruction in asthmatics. Beyond five minutes after exercise PEFR and MMEF were reduced by exercise approximately equally, but somewhat less often and less markedly than SGaw. Exercise-induced reductions in FEV1 were less marked and less frequent than decreases in PEFR and MMEF, and reductions in FVC were the least severe and least often observed abnormality. Decreases in SGaw were significantly, but not linearly correlated with decreases in PEFR, MMEF, FEV1,, FVC, and FEV1/FVC. There were statistically significant linear correlations between exercise-induced increases in FRC and decreases in FVC and between increases in Raw and FRC. If we accept that increases in Raw and FRC indicate increases in large and small airway obstruction respectively, exercise-induced decreases in FVC may indirectly suggest acute hyperinflation and thus small airway obstruction. Although the positive correlation between Raw and FRC indicated that both large and small airway obstruction developed after exercise in many of our asthmatics, increases in Raw were usually greater than increases in FRC, suggesting that large airway obstruction tends to be greater than small airway obstruction in exercise-induced asthma.


PEDIATRICS ◽  
1981 ◽  
Vol 67 (4) ◽  
pp. 508-513
Author(s):  
Gail G. Shapiro ◽  
Joseph J. McPhillips ◽  
Kevin Smith ◽  
Clifton T. Furukawa ◽  
William E. Pierson ◽  
...  

Theophylline and terbutaline, alone and in combination, were evaluated for effectiveness in treating exercise-induced bronchospasm (EIB) when used at doses that should be tolerated by adolescents taking them intermittently: theophylline, 250 mg (fast release), and terbutaline, 2.5 mg. Twenty-one subjects, 12 to 19 years of age, with EIB performed standardized exercise tests on four separate days and received either theophylline, terbutaline, the combination, or placebo in a prerandomized double-blind manner prior to exercise. Exercise tests were performed two and five hours after each study drug administration. Blood samples were drawn before and again two and five hours after drug administration for theophylline level. Pulmonary function [forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and forced expiratory flow rate (FEF25% to 75%)] was recorded before and after exercise. All of the active treatments were better than placebo in diminishing EIB. The combination was statistically better than terbutaline or theophylline alone. The effect of theophylline was not significantly different from that of terbutaline. The combination induced significantly more tremor than either agent individually. Either drug alone or the two in combination is effective for diminishing EIB. Although the combination may have additive properties for some patients, the increased incidence of tremor may diminish its appeal. Either drug alone or in combination is effective in decreasing EIB for at least five hours, which makes them practical choices for treatment of school-aged children.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ümran Toru ◽  
Peri Meram Arbak ◽  
Kezban Özmen Süner ◽  
Özlem Yavuz ◽  
Naciye Karataş

Background and Aim. It was observed that occupation and smoking increased each other’s effects on the development of airway diseases. We aimed to search the relationship between respiratory symptoms, smoking, and occupation.Materials and Methods. 225 employees in Düzce, Turkey, were applied a survey questioning respiratory complaints, pulmonary function tests (PFTs) and cotinine measurements in urine.Results. Cough (26.7%), phlegm (30.7%), and chest tightness (21.3%) were encountered more in carpenters compared to other groups and phlegm was statistically higher at significant level compared to other groups. The complaints of cough (30.4%), phlegm (27.4%), and chest tightness (21.5%) were significantly higher in individuals whose cotinine level was above 500 ng/mL and forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio, maximum midexpiratory flow rate (MMFR) values were significantly lower. Dyspnea complaint of auto painters whose cotinine level was below 500 ng/mL was significantly higher and also expected MMFR% value of this group was significantly lower compared to other groups. While age had independent effect on respiratory function tests, type of the job was found to be independently effective on MMFR.Conclusion. Smoking increases respiratory complaints of employees. In auto painters, the occupation causes airway disease regardless of smoking.


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