Airway Obstruction In Subjects Research Articles

Evaluating the effect of antidepressants on the relationship between depression and asthma

BackgroundIt is unclear if depression is associated with impaired lung function in subjects with asthma, while few studies evaluated the effect of antidepressants on the relationship between depression and asthma. We designed this study to investigate if subjects with concomitant asthma and depression not taking antidepressants have worse asthma outcomes compared to asthmatic subjects without depression, and to evaluate whether antidepressants modify this association. MethodsThis is a cross-sectional study. We included non-smokers with asthma, 18 years old or above. Study subjects attended an appointment with a chest physician, answered study questionnaires and underwent a spirometry test. We performed crude and adjusted binary logistic regression analyses. ResultsWe enrolled 309 subjects with asthma, of whom 48 with depression taking antidepressants, 52 with depression not taking antidepressants, and 209 without depression (control group). Asthmatic subjects with depression who had not used antidepressants before enrollment were more likely to have uncontrolled symptoms of asthma [adjusted OR 3.10, 95CI (1.56–6.15)] and airway obstruction [adjusted OR 2.41, 95CI (1.24–4.69)] compared to the control group. Subjects who had used antidepressants had higher odds of uncontrolled symptoms of asthma [adjusted OR 3.02, 95CI (1,50–6.07)], but similar odds of airway obstruction [adjusted OR 1.24, 95CI (0.87–1.77)] compared to the control group. ConclusionsNon-treated depression is associated with airway obstruction in subjects with asthma, but antidepressants modify this association. Thus, we recommend regular screening of depression in subjects with asthma, and prescription of antidepressants whenever depression symptoms justify pharmacological therapy.

A Study to Assess the Effect of Non-asthmatic Allergic Rhinitis on Pulmonary Functions-A Prospective Case-control Study.

Allergic rhinitis, beginning from childhood, is a global health problem. According to the literature, allergic rhinitis has been found association with asthma and other allergic manifestations. In this study we like to find out the significance and prognostic importance of spirometry in allergic rhinitis. The study was carried out over a period of 2years, with 63 cases and controls each. Subjects in the age of 20-55years with allergic rhinitis and SFAR score of > / = 7 were included as a case. Participants were interviewed and sent for spirometry. Controls were recruited from the retrospective data of healthy individuals with spirometry parameters done for health checkup. These controls had an SFAR score of < 7. All the data obtained were analyzed and compared between cases and controls. The mean age of the cases and controls were 33.17 ± 10.817 and 44.41 ± 7.4, respectively. Majority of cases and controls were males (60.3% and 57.1%). A statistically significant difference in FEF25-75% among cases and controls was noted (p = 0.00), thus proving probability of developing small airway obstruction in subjects with allergic rhinitis. Subjects with allergic rhinitis have a probability of developing small airway obstruction with subclinical changes, hence necessitating the need of regular follow-up.

Airway Clearance Management with Vaküm Technology in Subjects with Ineffective Cough: A Pilot Study on the Efficacy, Acceptability Evaluation, and Perception in Children with Cerebral Palsy.

Background: In the medical complexity of a children with cerebral palsy, impaired airway clearance represents a major problem, leading to significative respiratory morbidity and mortality. Its management is difficult because of limited cooperation and poor tolerance to invasive treatments. Free Aspire® (FA) is a device designed to remove bronchial secretions noninvasively, without generating cough. Methods: The aim of our pilot prospective study is to assess the efficacy and acceptability of FA in removing airway obstruction in subjects with cerebral palsy and ineffective cough. We enrolled 11 subjects. At enrollment and after 3, 6, and 12 months, we collected data regarding health care resources use for respiratory exacerbations, perceived efficacy, and acceptability of treatment. Results: We observed a reduction in emergency room (ER) accesses, home pharmacological treatment, hospitalizations number, and hospital stay length. In particular after 12 months we observed a reduction of 74% in ER accesses and home pharmacological treatment, 38% in hospitalizations number, and 17% in hospital stay length for respiratory exacerbations. The 100% of caregivers considered the treatment effective and simple to use and noted an improvement in subjects' general condition. They also reported good treatment tolerance of subjects, with an overall good compliance. Conclusion: The study demonstrates that FA is an effective device for the removal of bronchial secretions, with a positive caregivers' perception, that favored a good long-term compliance.

Gamma-glutamyl transferase activity as a predictive marker for severity of obstructive sleep apnea syndrome and concomitant hypertension.

Chronic intermittent hypia, inflammation and oxidative stress are involved in resultant obstructive sleep apnea syndrome (OSAS), which may affect numerous regulatory mechanisms that play a role in the regulation of blood pressure. Gamma-glutamyl transferase (GGT) is a novel marker in the prediction of cardiovascular risk. The objective of this study was to investigate the correlation of serum levels of GGT with hypertension and the degree of the upper airway obstruction in subjects with OSAS. A total of 270 subjects that met the inclusion criteria were enrolled in the study. The subjects were divided into four separate groups according to the apnea-hypopnea index (AHI) scores as the control group (AHI<5), mild OSAS group (AHI 5-15), moderate OSAS group (AHI 16-30) and severe OSAS group (AHI >30). A further classification of the OSAS subjects was made in two groups based on the presence of hypertension. The study included 43 control individuals and 59 subjects with mild, 54 subjects with moderate and 114 subjects with severe OSAS. The serum levels of GGT were found to be significantly correlated with OSAS severity (control group: 18±3.3, mild OSAS: 23.6±7.3, moderate OSAS: 26.4±7.5 and severe OSAS: 39.8±12). Serum levels of GGT were found to be significantly higher in OSAS subjects with concomitant hypertension than in the group without associated hypertension (P<.05). The results showed that the adjusted mean GGT under OSA without hypertension (Madj =28.76, SE=0.71) was significantly lower than in cases with OSA with hypertension (Madj =42.79, SE=1.19). The present study indicated a strong correlation between high serum levels of GGT and concomitant hypertension in subjects with obstructive sleep apnea. This biomarker may be helpful in grading the severity of obstructive sleep apnea and correlated with hypertension in this population.

Asymptomatic subjects with airway obstruction have significant impairment at exercise

BackgroundThe relevance of screening for airway obstruction in subjects not complaining of COPD symptoms may depend on the definition of airway obstruction. Response to exercise in asymptomatic subjects with persistent...

Interaction between asthma and smoking increases the risk of adult airway obstruction.

The aim of the present study was to analyse the interaction between asthma and smoking in the risk of adult airway obstruction, accounting for atopy. In the European Community Respiratory Health Survey, 15 668 persons aged 20-56 years underwent spirometry in 1991-1993 and 9 years later (n=8916). Risk of airway obstruction and lung function decline associated with smoking and early-onset (<10 years of age) and late-onset (>10 years of age) asthma were analysed with generalised estimating equation models and random-effect linear models, adjusting for covariates. Interaction of asthma with smoking was expressed as relative excess risk due to interaction (RERI). A 20-fold increase in adult airway obstruction was found among those with early-onset asthma independently of smoking status (never-smokers: OR 21.0, 95% CI 12.7-35; current smokers: OR 23.7, 95% CI 13.9-40.6). Late-onset asthma was associated with airway obstruction, with a stronger association among current smokers (OR 25.6, 95% CI 15.6-41.9) than among never-smokers (OR 11.2, 95% CI 6.8-18.6) (RERI 12.02, 95% CI 1.96-22.07). Stratifying by atopy, the association between smoking and asthma was most pronounced among nonatopics. Early- and late-onset asthma were associated with 10-20-fold increased risk of adult airway obstruction. Smoking increased the risk of adult airway obstruction in subjects with asthma onset after age 10 years. Investigation of measures potentially preventive of chronic obstructive pulmonary disease development following asthma is urgently needed.

An RGS4-Mediated Phenotypic Switch of Bronchial Smooth Muscle Cells Promotes Fixed Airway Obstruction in Asthma

In severe asthma, bronchodilator- and steroid-insensitive airflow obstruction develops through unknown mechanisms characterized by increased lung airway smooth muscle (ASM) mass and stiffness. We explored the role of a Regulator of G-protein Signaling protein (RGS4) in the ASM hyperplasia and reduced contractile capacity characteristic of advanced asthma. Using immunocytochemical staining, ASM expression of RGS4 was determined in endobronchial biopsies from healthy subjects and those from subjects with mild, moderate and severe asthma. Cell proliferation assays, agonist-induced calcium mobilization and bronchoconstriction were determined in cultured human ASM cells and in human precision cut lung slices. Using gain- and loss-of-function approaches, the precise role of RGS proteins was determined in stimulating human ASM proliferation and inhibiting bronchoconstriction. RGS4 expression was restricted to a subpopulation of ASM and was specifically upregulated by mitogens, which induced a hyperproliferative and hypocontractile ASM phenotype similar to that observed in recalcitrant asthma. RGS4 expression was markedly increased in bronchial smooth muscle of patients with severe asthma, and expression correlated significantly with reduced pulmonary function. Whereas RGS4 inhibited G protein-coupled receptor (GPCR)-mediated bronchoconstriction, unexpectedly RGS4 was required for PDGF-induced proliferation and sustained activation of PI3K, a mitogenic signaling molecule that regulates ASM proliferation. These studies indicate that increased RGS4 expression promotes a phenotypic switch of ASM, evoking irreversible airway obstruction in subjects with severe asthma.

Pharmacological Characterization of Adenosine Receptors on Isolated Human Bronchi

Adenosine induces airways obstruction in subjects with asthma, but the receptor subtype responsible remains unknown. The objectives of this study were to determine the pharmacological profile of adenosine receptor subtypes mediating contraction and to investigate the mechanism in normal and passively sensitized human airway tissues. Contraction of bronchial rings isolated from resected lung tissue of patients with lung carcinoma was measured in response to nonselective adenosine receptor agonists, 5-AMP and 5'-(N-Ethylcarboxamido)adenosine, and A(1) receptor agonist, N(6)-cyclopentyladenosine, in the absence and presence of selective adenosine receptor antagonists. Pharmacological antagonists, chemical ablation of airway sensory nerves using capsaicin, and passive sensitization of tissue with serum from subjects with atopy and asthma was used to investigate the mechanism of contraction. Human bronchial tissue contracted in a concentration-dependent manner to adenosine agonists that showed a rank order of activity of A(1) > A(2B) >> A2(A) = A3. The maximum contractile response to N(6)-cyclopentyladenosine (231.0 ± 23.8 mg) was significantly reduced in tissues chemically treated with capsaicin to desensitize sensory nerves (desensitized: 101.6 ± 15.2 mg; P < 0.05). Passive sensitization significantly augmented the contraction induced by adenosine A(1) receptor activation (sensitized: 389.7 ± 52.8 mg versus nonsensitized; P < 0.05), which was linked to the release of leukotrienes, and not histamine (MK571: 25.5 ± 1.7 mg; epinastine 260.0 ± 22.2 mg versus control; P < 0.05). This study provides evidence for a role for adenosine A(1) receptors in eliciting human airway smooth muscle constriction, which, in part, is mediated by the action of capsaicin sensitive sensory nerves.

Sleep magnetic resonance imaging: Dynamic characteristics of the airway during sleep in obstructive sleep apnea syndrome

To determine the dynamic characteristics of airway obstruction in subjects with obstructive sleep apnea (OSA) syndrome. A prospective cohort study of 20 OSA patients and 19 control subjects who underwent real-time magnetic resonance imaging (MRI) evaluation between 2006 and 2008. The dynamics of the upper airway were visualized using real-time MRI (RTHawk system, Stanford, CA) during natural sleep. Respiratory and desaturation events were correlated to polysomnogram results, and anatomic site of obstruction was determined from the real-time MRI sequences. The relation between visually observed airway obstructions and autonomic system changes was quantified and reliability calculated (Cronbach α, Aabel 2009; Gigawiz, Ltd., Tulsa, OK). An automated analysis tool was developed to determine which respiratory event is associated with the longest duration and location of obstruction in the posterior airway space (Matlab 2009; Mathworks, Inc., Natick, MA). Airway obstructions visualized on Sleep MRI during natural sleep included retropalatal, retroglossal, and combined obstruction. Respiratory events (mean rate of 31.9 per hour per subject) and desaturations (mean rate of 19.4 per hour per subject) temporally coincided with airway obstructive events. Intrarater reliability coefficients ranged from a low of 0.95 to a high of 1.0 for each rater. Inter-rater reliability coefficients ranged from a low of 0.85 to a high of 1.0. Sleep MRI is a novel and reliable approach to simultaneously evaluate airway obstructions and respiratory events in real time during natural sleep. Sleep MRI can define the dynamic characteristics of airway obstruction in both surgically naive and postsurgical OSA patients.

The Prevalence of Airway Obstruction in Subjects With a History of Pulmonary Tuberculosis in Mexico

The Prevalence of Airway Obstruction in Subjects With a History of Pulmonary Tuberculosis in Mexico

Chest Physiotherapy Does Not Induce Bronchospasm in Stable Asthma

Study objectives A recent systematic review concluded that it is not possible to judge manual chest physiotherapy safety in asthma. This study measured the effects of chest physiotherapy on pulmonary function and symptoms and safety in people with stable asthma. Design Prospective controlled study. Setting University general hospital. Patients Eighty-one asthma patients attending an asthma clinic with stable asthma, 62 adults and 19 children, and 15 adults without asthma recruited from members of staff of the hospital. Interventions Spirometry was performed before and five minutes after chest physiotherapy, which included postural drainage, percussion, vibratory-shaking and the forced expiration technique – ‘huffing'. Measurements and results There were no significant changes in FEV1 and FEF25-75% induced by chest physiotherapy in adults with mild and moderate or severe asthma and in children with mild and moderate asthma. After chest physiotherapy there was no decrease in FEV1 greater than 20%. Of the children 32% and of the adults 4% complained of worsening in asthma symptoms after physiotherapy manoeuvres. However, FEV1 did not decrease more than 10% in any of them. Eight hours after treatment, participants with moderate asthma did not show a significant change in FEV1. Conclusions Chest physiotherapy manoeuvres, including postural drainage, percussion, vibratory-shaking and ‘huffing', do not induce a significant worsening in airway obstruction in subjects with stable asthma, including patients with severe asthma. A recent systematic review concluded that it is not possible to judge manual chest physiotherapy safety in asthma. This study measured the effects of chest physiotherapy on pulmonary function and symptoms and safety in people with stable asthma. Prospective controlled study. University general hospital. Eighty-one asthma patients attending an asthma clinic with stable asthma, 62 adults and 19 children, and 15 adults without asthma recruited from members of staff of the hospital. Spirometry was performed before and five minutes after chest physiotherapy, which included postural drainage, percussion, vibratory-shaking and the forced expiration technique – ‘huffing'. There were no significant changes in FEV1 and FEF25-75% induced by chest physiotherapy in adults with mild and moderate or severe asthma and in children with mild and moderate asthma. After chest physiotherapy there was no decrease in FEV1 greater than 20%. Of the children 32% and of the adults 4% complained of worsening in asthma symptoms after physiotherapy manoeuvres. However, FEV1 did not decrease more than 10% in any of them. Eight hours after treatment, participants with moderate asthma did not show a significant change in FEV1. Chest physiotherapy manoeuvres, including postural drainage, percussion, vibratory-shaking and ‘huffing', do not induce a significant worsening in airway obstruction in subjects with stable asthma, including patients with severe asthma.

Experimental rhinovirus 16 infection causes variable airway obstruction in subjects with atopic asthma.

Exacerbations of asthma are often associated with rhinovirus infections. However, it has not been investigated whether rhinovirus infection can induce variable airway obstruction in asthma. We examined the effect of experimental rhinovirus 16 (RV16) infection on daily home recordings of FEV(1) in 27 subjects (nonsmoking, atopic, mildly asthmatic) who participated in a parallel placebo-controlled study. The subjects used a microspirometer to record FEV(1) three times daily from 4 d before until 10 d after RV16 (n = 19) or placebo (n = 8) inoculation. In addition, symptoms of asthma and symptoms of common cold were scored. Airway hyperresponsiveness to histamine was measured 3 d before and on Days 4 and 11 after RV16/placebo administration. Home recordings of FEV(1) decreased significantly after RV16 infection, reaching a minimum 2 d after inoculation (ANOVA, p </= 0.005), which was significantly different from placebo (p </= 0.004). In the RV16 group the lowest FEV(1) (expressed as a percentage of personal best) during Days 0-3 after infection (mean +/- SEM: 78.7 +/- 2.6% versus baseline: 85.6 +/- 1.2%, p = 0.008) correlated significantly with the cold score (r = -0.47, p = 0.04), asthma score (r = -0.47, p = 0.04), and with the decrease in airway hyperresponsiveness on Day 4 as compared with baseline (r = 0.50, p = 0.03). We conclude that experimental RV16 infection augments variable airway obstruction in subjects with asthma. This favors a causative role for rhinovirus colds in asthma exacerbations, and is in keeping with rhinovirus-induced worsening of airway inflammation.

Exhaled nitric oxide is higher both at day and night in subjects with nocturnal asthma.

Nitric oxide in exhaled air is thought to reflect airway inflammation. No data have been reported so far on circadian changes in NO in subjects with nocturnal asthma. To determine whether exhaled NO shows a circadian rhythm inverse to the circadian rhythm in airway obstruction in subjects with nocturnal asthma, we conducted a study involving six healthy controls, eight individuals without nocturnal asthma (4-h to 16-h variation in peak expiratory flow [PEF] <= 15%), and six individuals with nocturnal asthma (4-h to 16-h PEF variation > 15%). Smoking, use of corticosteroids, and recent respiratory infections were excluded. NO concentrations were measured at 12, 16, 20, and 24 h, and at 4, 8, and 12 h of the next day, using the single-breath method. At the same times, FEV1 and PEF were also measured. Mean NO concentrations were significantly higher in subjects with nocturnal asthma than in subjects without nocturnal asthma, and higher in both groups than in healthy controls at all time points. Mean exhaled NO levels over 24 h correlated with the 4-h to 16-h variation in PEF (r = 0.61, p < 0.01). Exhaled NO did not show a significant circadian variation in any of the three groups as assessed with cosinor analysis, in contrast to the FEV1 in both asthma groups (p < 0.05). At 4 h, mean +/- SD NO levels were higher than at 16 h in subjects with nocturnal asthma; at 50 +/- 20 ppb versus 42 +/- 15 ppb (p < 0.05); other measurements at all time points were similar. Differences in NO and FEV1 from 4 h to 16 h did not correlate with one another. We conclude that subjects with nocturnal asthma exhale NO at higher levels both at night and during the day, which may reflect more severe diurnal airway-wall inflammation. A circadian rhythm in exhaled NO was not observed. NO levels did not correspond to the circadian rhythm in airway obstruction. The small increase in NO at 4 h may indicate an aspect of inflammation, but it is not associated with increased nocturnal airway obstruction.

Is reactive airways dysfunction syndrome a variant of occupational asthma?

Background: Reactive airways dysfunction syndrome (RADS) or irritant-induced asthma is a syndrome that leaves subjects with asthma-like symptoms after one or more exposures to a high concentration of an irritant substance. The degree of reversibility of airway obstruction in subjects with RADS is nevertheless unknown, as is the degree of associated lesions at the airway level. Methods: We compared the acute reversibility of forced expiratory volume in 1 second (FEV 1) after inhalation of albuterol (200 μg) in 15 subjects with RADS (12 cases caused by chlorine inhalation) with that of 30 subjects with occupational asthma (OA) caused by various agents. They were paired according to baseline airway obstruction (61% and 63% of predicted value in the RADS and OA groups), requirement for medication (bronchodilator only- 7 of 15 subjects with RADS and 14 of 30 subjects with OA-as compared with bronchodilator + inhaled steroids in 8 of 15 subjects with RADS and 16 of 30 subjects with OA, respectively), and interval since removal from exposure (means of 30 and 24 months in the RADS and OA groups). In addition, five nonsmokers with RADS who had not received inhaled steroids underwent bronchoscopy with lavage and bronchial biopsies less than 2 years after the exposure. Results: The percentage increase in FEV 1 over baseline after inhalation of albuterol was 10% ± 9% in the RADS group and 19% ± 16% in the OA group ( p = 0.005). Only 2 of 15 subjects (13%) with RADS and 12 of 30 subjects (40%) with OA showed an improvement in FEV 1 of 20% or greater after inhalation of albuterol. Bronchoalveolar lavage showed an increased number of cells with a predominance of lymphocytes, and biopsy specimens showed increased basement membrane thickness in the five subjects with RADS who underwent bronchoscopy. Conclusion: Subjects with RADS are generally left with less airway reversibility than those with OA. We suggest that this difference is secondary to distinct pathologic changes.

Abnormal inspiratory flow-volume curves in patients with sleep-disordered breathing.

Although flow-volume curves are valuable in detecting extrathoracic airway obstruction, their role in testing patients with sleep-disordered breathing is undefined. To determine whether patients with sleep-disordered breathing have abnormal flow-volume curves consistent with variable extrathoracic obstruction, 60 subjects referred with suspected sleep disorders prospectively underwent spirometry and assessment of flow-volume curves. These tests were interpreted independent of the outcome of polysomnography. Fourteen of 35 subjects (40%) with sleep-disordered breathing had abnormal flow-volume curves consistent with variable extrathoracic airway obstruction, and 2 of 25 (8%) with no breathing disorder had extrathoracic obstruction (p less than 0.02). The presence of extrathoracic airway obstruction in subjects with mixed or obstructive sleep apnea did not correlate with age, the presence of snoring, excessive daytime hypersomnolence, obesity, or the severity of sleep apnea. Abnormal flow-volume curves were found more frequently in women who had no obvious structural upper airway abnormality. Because of the high specificity (92%) of the flow-volume curve, the finding of extrathoracic obstruction in patients with a history consistent with sleep-disordered breathing substantially increases the likelihood that sleep apnea is present.