Perceived triggers of asthma: evaluation of a German version of the Asthma Trigger Inventory

Boosting nitric oxide in stress and respiratory infection: Potential relevance for asthma and COVID-19

Nitric oxide (NO) is a ubiquitous signaling molecule that is critical for supporting a plethora of processes in biological organisms. Among these, its role in the innate immune system as a first line of defense against pathogens has received less attention. In asthma, levels of exhaled NO have been utilized as a window into airway inflammation caused by allergic processes. However, respiratory infections count among the most important triggers of disease exacerbations. Among the multitude of factors that affect NO levels are psychological processes. In particular, longer lasting states of psychological stress and depression have been shown to attenuate NO production. The novel SARS-CoV-2 virus, which has caused a pandemic, and with that, sustained levels of psychological stress globally, also adversely affects NO signaling. We review evidence on the role of NO in respiratory infection, including COVID-19, and stress, and argue that boosting NO bioavailability may be beneficial in protection from infections, thus benefitting individuals who suffer from stress in asthma or SARS-CoV-2 infection.

Evaluation of a Spanish language version of the Asthma Trigger Inventory

Background: Perceptions of asthma triggers provide important guidance for patients' disease management. A psychometrically valid instrument, the Asthma Trigger Inventory (ATI), is available in English and German language versions, however, a version in Spanish as major world language has been missing.Method: A Spanish-language version of the ATI was evaluated in 339 adult patients with asthma, 223 of these in Peru and 107 in the USA. Principal Component analysis (PCA) with Varimax rotation was used to identify coherent trigger domains across and within samples. Resulting subscales were evaluated for internal consistency.Results: PCA suggested differences in factor structures between sites. Whereas the USA sample largely replicated original factors for animal allergens, pollen allergens, physical activity, air pollution/irritants, infections, and psychology, the initial analysis of the Peru sample suggested substantial overlap of air pollution/irritant, infection, and allergen items. Subsequent analysis of an expanded research form of the ATI for the Peru site culminated in extraction of five factors related to psychology, climate/temperature, combined pollen and animal allergens, physical activity, and infection. Internal consistencies were in an acceptable to excellent range (α = 0.74 to 0.94). Additional free trigger responses confirmed the importance of climate variables for patients in Peru. Psychological triggers were reported by 26% (Peru) and 31% (USA) of patients.Conclusion: Coherent trigger domains are readily identified and measured reliably by a Spanish-language ATI version. However, factor structures vary between samples from different Hispanic/Latino cultural and geographic domains. Culturally adapted versions of this instrument are therefore required for Hispanic/Latino population studies.

Towards an assessment of perceived COPD exacerbation triggers: Initial development and validation of a questionnaire

BACKGROUND AND OBJECTIVE

Prevention of exacerbations in chronic obstructive pulmonary disease (COPD) is important to decrease overall declines in functioning and improve quality of life. The present study sought to develop a psychometrically valid measure of perceived triggers of exacerbations in COPD patients, the COPD Exacerbation Trigger Inventory (CETI).

METHODS

Participants (n = 192) were recruited through local clinics and online to complete surveys of the CETI, demographic information, disease-specific information and the COPD Assessment Test (CAT). The CETI included a free response section on patients' individual top triggers, combined with ratings of their controllability.

RESULTS

Exploratory principal component analyses identified a stable 5-factor structure (33 items), from which trigger subscales for weather/climate, air pollution/irritants, exercise, infection/illness and psychological factors were formed (internal consistency Cronbach's α = 0.90-0.94). Trigger factors were associated with COPD functional status, exacerbation frequency and healthcare utilization. Participants found personal triggers related to dust, air pollution, smoking and physical activity to be the most easily controlled, whereas those related to psychological factors, climate, infection, respiratory symptoms and sleep to be more difficult to control. Greater perceived controllability of triggers was associated with lower CAT scores, indicating better health status and less impact of the disease on functioning.

CONCLUSION

The CETI is a psychometrically valid measure of perceived exacerbation triggers in patients with COPD. Perceived triggers are associated with clinical outcomes. Assessment of trigger classes and their controllability may prove useful in both research and clinical settings with COPD patients and to further our knowledge in prevention and disease management.

Asthma trigger perceptions are associated with work disability

OBJECTIVE

To study the association between perceptions of various triggers of asthma and employment status.

METHODS

A questionnaire was administered to all those adults living in the city of Tampere, Finland, who were entitled to special reimbursement for asthma medication by the Social Insurance Institution (n = 2613). The response rate was 79%. The study population (n = 1657) consisted of individuals who worked full-time (n = 967), were unemployed (n = 197), had all-cause work disability (n = 334), or were retired due to old age (n = 159). Given a list of potential asthma triggers, the respondents were asked how often (never/sometimes/often) the trigger caused or worsened their asthma symptoms during leisure time.

RESULTS

After adjusting for background variables (age, sex, smoking, and professional status), frequency of asthma symptoms, and the use of asthma medication during the last year, any individual trigger identified as asthma-relevant was associated with having work disability (vs. working full-time). The highest odds ratio (OR) was found for vehicle exhaust (OR 5.0, CI 2.2-11.4). We found similar but less consistent associations between asthma trigger perceptions and unemployment. No elevated ORs were found regarding asthma trigger perceptions for old-age retirement.

CONCLUSIONS

Perceptions of asthma triggers are associated with all-cause work disability. Our findings suggest that asthmatics have excess trigger perceptions that are not explained by asthma alone. Asthmatics need to be informed that inaccurate trigger perceptions may develop, and how they are induced, because unnecessary trigger avoidance may interfere with work life.

Asthma Trigger Reports Are Associated with Low Quality of Life, Exacerbations, and Emergency Treatments

RATIONALE

Despite the importance of trigger perceptions for asthma diagnosis and management, associations among asthma triggers, affective disorders, and asthma outcome have received little attention.

OBJECTIVES

Because anxiety and depression are known to influence patients' health reports, we measured and controlled for these affective disorders in analyzing associations among patient perceptions of asthma triggers and asthma treatment outcomes.

METHODS

Patients from a nationally representative sample of respiratory specialist practices (N = 459) were assessed for clinically significant anxiety and depression and completed questionnaires on asthma triggers, quality of life, and asthma control. Physicians recorded exacerbation and emergency treatment frequencies in the prior year, spirometric lung function, and allergy test results. Hierarchical multiple regressions examined associations among reported trigger factors, anxiety, depression, and asthma outcomes, including quality of life, asthma control, exacerbations, emergencies, and spirometry.

MEASUREMENTS AND MAIN RESULTS

Patients across asthma severity levels were well represented. Anxiety and depression were associated with more frequent nonallergic, in particular psychological, triggers. Controlling for demographics, asthma severity, anxiety, and depression, nonallergic asthma triggers (including psychological triggers) explained substantial portions of variance in asthma control (total of 19.5%, odds ratios [ORs] = 2.07-1.37 for individual triggers), asthma-related quality of life (total of 27.5%, ORs = 3.21-1.49), and general quality of life (total of 11.3%, ORs = 1.93-1.55). Psychological triggers were consistently associated with exacerbations and emergency treatments (ORs = 1.96-2.04) over and above other triggers and affective disorders. Spirometric lung function was largely unrelated to perceived asthma triggers.

CONCLUSIONS

Patients' perceptions of asthma triggers are important determinants of asthma outcomes, which can help identify individuals at risk for suboptimal asthma management.

Symptom-trigger factors other than allergens in asthma and allergy

Several environmental exposures of particular relevance for indoor air quality, such as exposure to odorants, may be associated with asthma and allergy. The aim of this study was to investigate attribution of symptoms and behavioral disruptions to various chemical and physical environmental sources in persons with self-reported asthma and allergy. Data from a population-based study, the Västerbotten Environmental Health Study, were used to compare persons with asthma, allergic rhinitis, allergic dermatitis, multiple diagnoses of asthma/allergy and no asthma or allergy. Persons with asthma and multiple diagnoses reported odorous/pungent and building-related environmental factors to trigger symptoms to a larger extent than did the reference group, mainly due to perfume and odors from flowers. They also reported behavioral disruptions and affective reactions to odorous/pungent environments. These findings increase the understanding of the role of odorants in symptom development and thereby the prevention of health problems in asthma and allergy in indoor air.

Trigger factors in asthma and chronic obstructive pulmonary disease: a single-centre cross-sectional survey

INTRODUCTION

The presence of trigger factors may help to distinguish asthma from chronic obstructive pulmonary disease (COPD). Knowing and avoiding trigger factors for both asthma and COPD can facilitate the design of comprehensive management programmes that can aid disease control. This study aimed to describe the relative frequency and range of various trigger factors in asthma and COPD.

METHODS

We conducted a telephone-based survey involving asthma and COPD patients on follow-up at a university hospital in Singapore.

RESULTS

A total of 779 asthma patients and 129 COPD patients participated in this study. Among these patients, 93.8% of those with asthma and 42.6% of those with COPD had trigger factors (p < 0.001). The median number of trigger factors was greater among asthma patients than among those with COPD (3 vs. 0, p < 0.001). Trigger factors found to be significantly more prevalent among asthma patients compared to those with COPD include tobacco smoke, alcohol, upper respiratory tract infections, incense smoke, perfume, laughter, a dusty environment, air-conditioning, heavy rain, heavy traffic fumes, citrus fruits, gastro-oesophageal reflux, household pets, flowers/pollen, medications and psychological triggers. Trigger factors that were not previously described, such as bathing, fatigue, insufficient sleep, crowded places and overeating, were also reported.

CONCLUSION

Trigger factors, although found in both groups of patients, were more common among asthma patients. Knowledge of these trigger factors may be useful in distinguishing between the two diseases and optimising disease management.

Effects of Symptom Perception Interventions on Trigger Identification and Quality of Life in Children with Asthma

BACKGROUND

Management of individual triggers is suboptimal in practice. In this project, we investigated the impact of symptom perception interventions on asthma trigger identification and self-reported asthma quality of life.

METHODS

Children with asthma (n=227) participated in three asthma education sessions and then were randomized first to one of three home monitoring conditions (symptom monitoring and peak flow training with feedback, peak flow training without feedback, or no peak flow training) and then subsequently to one of three resistive load discrimination training conditions (signal detection training with feedback, signal detection training without feedback, or no training). Triggers were reported at enrollment, following home monitoring, and following discrimination training; quality of life was measured after home monitoring and after resistive load testing.

RESULTS

Symptom perception interventions resulted in increases in reported triggers, which increased reliably as a function of home monitoring, and increased further in participants who completed discrimination training with feedback. Increases in the number of reported asthma triggers were associated with decreases in quality of life.

DISCUSSION

Patients may benefit from strategies that make trigger-symptom contingencies clear. Complementary strategies are needed to address changes in the perceived burden of asthma which comes from awareness of new asthma triggers.

Types, frequency and impact of asthma triggers on patients' lives: a quantitative study in five European countries

OBJECTIVE

To identify the types, frequency and impact of asthma triggers and the relationship to asthma control among adults with asthma in Europe.

METHODS

Adults with self-reported physician-diagnosed asthma receiving maintenance asthma treatment and self-reported exposure to known asthma triggers completed an online questionnaire; a subset completed a diary over 3-4 weeks. Information on asthma control (Asthma Control Test™ [ACT]), asthma triggers, frequency of exposure and behaviours in response or to avoid asthma triggers and the perceived impact on daily life was captured. A post-hoc analysis evaluated the impact of high trigger burden on the frequency of severe asthma exacerbations, hospitalisations and days lost at work/study.

RESULTS

A total of 1202 adults participated and 177 completed the diary. Asthma was uncontrolled for the majority (76%) of participants and most (52%) reported exposure to 6-15 asthma triggers. As trigger burden increased, behavioural changes to manage trigger exposure had a significantly increased impact on daily life (p < 0.0001) and job choice (p = 0.002). Participants reporting a high trigger burden (>16) were more likely to report uncontrolled asthma than those with a low trigger burden (1-5). Participants with a high trigger burden had previously experienced on average two more severe asthma attacks during a lifetime (p < 0.001), two more hospitalisations (p < 0.001) and 3.5 more missed days at work or study in the last year due to their asthma (p < 0.001) than those with a low trigger burden.

CONCLUSIONS

Adults with asthma reporting a high trigger burden (>16 different triggers) experience more severe asthma attacks than those reporting lower trigger burdens.

Perceived triggers of asthma: key to symptom perception and management

Adequate asthma management depends on an accurate identification of asthma triggers. A review of the literature on trigger perception in asthma shows that individuals vary in their perception of asthma triggers and that the correlation between self-reported asthma triggers and allergy tests is only modest. In this article, we provide an overview of psychological mechanisms involved in the process of asthma triggers identification. We identify sources of errors in trigger identification and targets for behavioural interventions that aim to improve the accuracy of asthma trigger identification and thereby enhance asthma control.

Psychosocial factors and behavioral medicine interventions in asthma

OBJECTIVE

This review examines the evidence for psychosocial influences in asthma and behavioral medicine approaches to its treatment.

METHOD

We conducted a systematic review of the literature on psychosocial influences and the evidence for behavioral interventions in asthma with a focus on research in the past 10 years and clinical trials. Additional attention was directed at promising new developments in the field.

RESULTS

Psychosocial factors can influence the pathogenesis and pathophysiology of asthma, either directly through autonomic, endocrine, immunological, and central nervous system mechanisms or indirectly through lifestyle factors, health behaviors, illness cognitions, and disease management, including medication adherence and trigger avoidance. The recent decade has witnessed surging interest in behavioral interventions that target the various pathways of influence. Among these, self-management training, breathing training, and exercise or physical activation programs have proved particularly useful, whereas other essential or promising interventions, such as smoking cessation, dietary programs, perception and biofeedback training, and suggestive or expressive psychotherapy, require further, more rigorous evaluation. Given the high comorbidity with anxiety and mood disorders, further evaluation of illness-specific cognitive behavior therapy is of particular importance. Progress has also been made in devising community-based and culturally tailored intervention programs.

CONCLUSION

In concert with an essential medication treatment, behavioral medicine treatment of asthma is moving closer toward an integrated biopsychosocial approach to disease management.

Triggers of asthma and COPD: are they different?

BACKGROUND

Asthma symptoms can be triggered by a variety of factors commonly referred to as "triggers". Some of these factors can also induce severe asthma exacerbations. Thus, it can be assumed that actions taken against such triggers may prevent the progression of the disease. However, limited data exist on the clinical importance of these triggers in patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVE

To compare the effect of triggers on symptoms and actions taken against certain modifiable triggers in patients with asthma and COPD.

METHODS

The study was conducted in a university hospital between June 2009 and June 2010. Patients with asthma and COPD were asked to complete a questionnaire in which both the factors triggering symptoms and the actions taken against several triggers were assessed.

RESULTS

Three hundred consecutive adult patients (150 asthma, 150 COPD) were enrolled to the study. The frequency of triggering factors was similar in both groups. Vaccination rates for influenza and pneumococcus were significantly higher in patients with COPD. However, such anti-allergic approaches as the use of strategies to decrease dust exposure, the use of anti-mite bed sheets, and the removal of pets from the home were more commonly employed by asthmatic patients.

CONCLUSION

This study revealed that certain triggers affected COPD and asthma patients to the same degree. Therefore, triggers and strategies for controlling modifiable triggers should be more concentrated on during education in both groups. However, the preventive effect of these strategies on disease progression, particularly in patients with COPD, needs clarification.

Airway responsiveness to psychological processes in asthma and health

Psychosocial factors have been found to impact airway pathophysiology in respiratory disease with considerable consistency. Influences on airway mechanics have been studied particularly well. The goal of this article is to review the literature on airway responses to psychological stimulation, discuss potential pathways of influence, and present a well-established emotion-induction paradigm to study airway obstruction elicited by unpleasant stimuli. Observational studies have found systematic associations between lung function and daily mood changes. The laboratory-based paradigm of bronchoconstrictive suggestion has been used successfully to elicit airway obstruction in a substantial proportion of asthmatic individuals. Other studies have demonstrated modulation of airway responses to standard airway challenges with exercise, allergens, or pharmacological agents by psychological factors. Standardized emotion-induction techniques have consistently shown airway constriction during unpleasant stimulation, with surgery, blood, and injury stimuli being particularly powerful. Findings with various forms of stress induction have been more mixed. A number of methodological factors may account for variability across studies, such as choice of measurement technique, temporal association between stimulation and measurement, and the specific quality and intensity of the stimulus material, in particular the extent of implied action-orientation. Research has also begun to elucidate physiological processes associated with psychologically induced airway responses, with vagal excitation and ventilatory influences being the most likely candidate pathways, whereas the role of specific central nervous system pathways and inflammatory processes has been less studied. The technique of emotion-induction using films has the potential to become a standardized challenge paradigm for the further exploration of airway hyperresponsiveness mediated by central nervous system processes.

History of symptom triggers in patients presenting to the emergency department for asthma

OBJECTIVES

Understanding triggers is important for managing asthma particularly for patients who seek emergency department (ED) care for exacerbations. The objectives of this analysis were to delineate self-reported triggers in ED patients and to assess associations between triggers and asthma knowledge, severity, and quality of life.

METHODS

At the time of an ED visit, 296 patients were asked what were their usual asthma triggers based on a checklist of 25 potential items, and what they thought specifically precipitated their current ED visit. Using standardized scales, patients also were asked about asthma knowledge, severity, and quality of life.

RESULTS

The mean age was 44 years and 72% were women. Patients cited a mean of 12 triggers; most patients had diverse triggers spanning respiratory infections, environmental irritants, emotions, allergens, weather, and exercise. Patients with more triggers were more likely to be women (odds ratio (OR) = 2.0, confidence interval (CI) = 1.3, 3.2, p = .002), obese (OR = 1.7, CI = 1.1, 2.5, p = .01), and to not have a smoking history (OR = 1.9, CI = 1.3, 2.9, p = .001). There were no associations between number of triggers and current age, age at diagnosis, education, socioeconomic status, or race/ethnicity. Patients who cited more triggers had more frequent flares (OR = 1.1, CI = 1.1, 1.2, p < .0001), worse quality of life scores (OR 1.6, CI = 1.1, 2.4, p = .02), and were more likely to have been previously hospitalized for asthma (OR = 1.9, CI = 1.3, 2.9, p = .003) and to have previously required oral corticosteroids (OR = 2.9, CI = 1.6, 5.1, p = .003). There was little clustering of specific triggers according to the variables we considered except for more frequent animal allergy in patients diagnosed at a younger age (OR = 2.8, CI = 1.7, 4.5, p < .0001) and worse quality of life in patients citing emotional stress as a trigger (OR = 2.5, CI = 1.5, 4.0, p = .0002). Patients attributed their current ED visit to multiple precipitants, particularly respiratory infections and weather, and these were concordant with what they reported were known triggers.

CONCLUSIONS

Patients presenting to the ED for asthma reported multiple triggers spanning diverse classes of precipitants and having more triggers was associated with worse clinical status. ED patients should be instructed that although it may not be possible to eliminate all triggers, mitigating even some triggers can be helpful.

Poor asthma control and exposure to traffic pollutants and obesity in older adults

BACKGROUND

Environmental and host predictors of asthma control in older asthmatic patients (>65 years old) are poorly understood.

OBJECTIVE

To examine the effects of residential exposure to traffic exhaust and other environmental and host predictors on asthma control in older adults.

METHODS

One hundred four asthmatic patients 65 years of age or older from allergy and pulmonary clinics in greater Cincinnati, Ohio, completed the validated Asthma Control Questionnaire (ACQ), pulmonary function testing, and skin prick testing to 10 common aeroallergens. Patients had a physician's diagnosis of asthma, had significant reversibility in forced expiratory volume in 1 second or a positive methacholine challenge test result, and did not have chronic obstructive pulmonary disease. The mean daily residential exposure to elemental carbon attributable to traffic (ECAT) was estimated using a land-use regression model. Regression models were used to evaluate associations among independent variables, ACQ scores, and the number of asthma exacerbations, defined as acute worsening of asthma symptoms requiring prednisone use, in the past year.

RESULTS

In the adjusted model, mean daily residential exposure to ECAT greater than 0.39 μg/m(3) was significantly associated with poorer asthma control based on ACQ scores (adjusted β = 2.85; 95% confidence interval [CI], 0.58-5.12; P = .02). High ECAT levels were also significantly associated with increased risk of asthma exacerbations (adjusted odds ratio, 3.24; 95% CI, 1.01-10.37; P = .05). A significant association was found between higher body mass index and worse ACQ scores (adjusted β = 1.15; 95% CI, 0.53-1.76; P < .001). Atopic patients (skin prick test positive) had significantly better ACQ scores than nonatopic patients (adjusted β = -0.39; 95% CI, -0.67 to -0.11; P < .01).

CONCLUSION

Higher mean daily residential exposure to traffic exhaust, obesity, and nonatopic status are associated with poorer asthma control among older asthmatic patients.

Airway constriction in asthma during sustained emotional stimulation with films

BACKGROUND

Individuals with asthma have been shown to respond to unpleasant stimuli with bronchoconstriction, but little is known about the time course of responding during sustained emotional stimulation and whether it varies with patients' experience.

OBJECTIVE

To examine the time course of oscillatory resistance (R(os)) during emotionally evocative films in 15 asthma patients and 14 healthy controls.

METHODS

Participants viewed unpleasant, surgery, and neutral films, each ranging 3-5min in duration. R(os) and the respiratory pattern (respiration rate, tidal volume, minute ventilation) were monitored continuously. Following each film, participants rated their affective response and symptoms. The time course of R(os) during films was explored using multilevel modeling.

RESULTS

Compared to neutral film sequences, unpleasant films (including those with surgery scenes) elicited a uniform pattern of initial increases in R(os) with peaks within the first 1-2min, followed by a gradual decline. Increases were more pronounced in asthma and during surgery films. Including additional respiratory parameters as time-varying covariates did not affect the temporal course of R(os) change. The rate of decline in R(os) (after the initial increase) was less in participants who experienced greater arousal and in patients who reported more shortness of breath. Patients more susceptible to psychological triggers in daily life showed slower rates of decline in R(os).

CONCLUSION

The temporal course of bronchoconstriction to unpleasant stimulation is highly uniform in asthma, with strong constriction in early stages of stimulation. More sustained constriction in emotion-induced asthma could be a risk factor for developing asthma exacerbation in daily life.

Airway response to emotional stimuli in asthma: the role of the cholinergic pathway

In asthma, airways constrict in response to emotion and stress, but underlying mechanisms, potential extrathoracic contributions, and associations with airway pathophysiology have not been elucidated. We therefore investigated the role of the cholinergic pathway in emotion-induced airway responses in patients with asthma and the association of these responses with airway pathophysiology. Patients with asthma (n=54) and healthy participants (n=25) received either 40 microg ipratropium bromide or a placebo in a double-blind double-dummy cross-over design in two laboratory sessions with experimental emotion induction. Stimuli were preevaluated films and pictures of pleasant, unpleasant, and neutral quality. Respiratory resistance and reactance at 5 and 20 Hz were measured continuously before and during presentations, together with respiration by impedance plethysmography and end-tidal PCO2 by capnometry. In addition, measures of airway inflammation (fraction of exhaled nitric oxide), airway hyperreactivity (methacholine challenge), and reversibility of obstruction were obtained. Respiratory resistance at 5 and 20 Hz increased during unpleasant stimuli in asthma patients. This response was blocked by ipratropium bromide and was not substantially associated with asthma severity, airway inflammation, hyperreactivity and reversibility, or pattern of ventilation and PCO2. Under the placebo condition, changes in resistance during unpleasant films were positively correlated with patients' reports of psychological asthma triggers. In conclusion, airway constriction to unpleasant stimuli in asthma depends on an intact cholinergic pathway, is largely due to the central airways, and is not substantially associated with other indicators of airway pathology. Its link to the perceived psychological triggers in patients' daily lives suggests a physiological basis for emotion-induced asthma.

Emotional reactivity of the airways in asthma: consistency across emotion-induction techniques and emotional qualities

Considerable individual differences exist in asthma patients' airway responses to emotional stimuli, but little is known about the generalization of such responses across situations or states of airways constriction. Fifty-four asthma patients and 25 healthy controls viewed in two separate sessions, films and blocks of pictures from each of three emotional qualities, pleasant, unpleasant, and neutral. At the beginning of each session, patients received a placebo or anti-cholinergic bronchodilator (ipratropium bromide), respectively, in a randomized double-blind design. Respiratory resistance, reactance and impedance were recorded throughout stimulus presentations with impulse oscillometry. Resistance increases showed a moderate degree of generalization across unpleasant films and pictures, unpleasant and pleasant pictures, as well as cholinergic blockade and placebo. Thus, the intensity of airway responses to unpleasant emotional stimuli is a moderately stable characteristic of asthma patients. In addition to the central airway, peripheral and extrathoracic airways may also contribute the consistency of such responses.

Triggers in adult asthma: are patients aware of triggers and doing right?

BACKGROUND

As triggers have a potential to induce asthma exacerbations, awareness of the patients to individual triggers as well as protective measures might be helpful to prevent asthma attacks. Though allergens and allergen avoidance have been studied extensively, there are only few studies on non-allergic triggers and their avoidance for adult patients with asthma. In this study, we wanted to investigate asthma triggers and compliance to the preventive measures in an adult population.

METHODS

One hundred and thirty one adult asthma patients were enrolled into the study. A face to face interview was done by using a questionnaire including individual asthma triggers, prevention measures against major modifiable triggers and knowledge sources of the cases.

RESULTS

Regardless of asthma severity, 59.5 % of the subjects reported to be triggered by more than 10 factors. The most common triggers were air pollutants (89.3 %) and weather changes (81.7 %). Severe group was more frequently affected by medications, emotional stress, weather changes and indoor pollutants than other severity groups (p=0.017, 0.014, 0.049 and 0.018, respectively) whereas stress was reported more frequently by females than males. Prevention measures were insufficient regarding some major triggers.

CONCLUSION

Adult patients are vulnerable to several triggers regardless from underlying severity of the illness. Insufficient compliance to the major preventive measures indicates that new strategies are needed to prevent asthma attacks caused by modifiable triggers.

Traffic exposure associated with allergic asthma and allergic rhinitis in adults. A cross-sectional study in southern Sweden

Background

There is conflicting evidence that traffic-related air pollution is a risk factor for allergic conditions. Few studies have investigated this in adults. In adults, a high proportion of asthma, rhinitis and eczema is triggered by non-allergic factors. We investigated traffic as a risk factor for allergic versus non-allergic asthma and rhinitis, and eczema, in adults.

A questionnaire from 2000 (n = 9319, 18–77 years) provided individual data about disease outcome and self-reported traffic exposure. Additional exposure assessments were obtained using Geographical Informations Systems (GIS). Residential addresses were linked to the national Swedish Road Database and to a pollutant database with modelled annual means of NO_x (Nitrogen Oxids).

Results

Living within 100 m from a road with a traffic intensity of >10 cars/min (24 hour mean) was associated with prevalence of current asthma reported to be triggered by allergic factors (OR = 1.83, 95% CI = 1.23–2.72) and with allergic rhinitis (OR = 1.30, 95%CI = (1.05–1.61). No relation was seen with asthma or rhinitis triggered by other factors. Living within 100 m of a road with >10 cars/min was also associated with hand-eczema during the last 12 months (OR = 1.63, 95% CI = 1.19–2.23), but not with allergic eczema or diagnosed hand-eczema. Consistent results were seen using self-reported traffic, but the associations with NO_x were less consistent.

Conclusion

Exposure to traffic was associated with a higher prevalence of allergic asthma and allergic rhinitis, but not with asthma or rhinitis triggered by non-allergic factors. This difference was suggested by the overall pattern, but only clear using GIS-measured traffic intensity as a proxy for traffic exposure. An association was also found with hand-eczema during the last 12 months. We suggest that asthma and rhinitis should not be treated as homogenous groups when estimating effects from traffic in adults.

Psychological triggers and hyperventilation symptoms in asthma

BACKGROUND

Anecdotal accounts have identified hyperventilation as one route through which psychological factors can trigger bronchoconstriction. However, little is known about the empirical association between psychological and other trigger factors and hyperventilation in asthma exacerbations.

OBJECTIVE

To study the cross-sectional association between perceived triggers and hyperventilation symptoms in 1 British and 1 German sample of patients with asthma who were recruited from the community and from primary care clinics.

METHOD

Patients completed relevant language versions of the Asthma Trigger Inventory and the Asthma Symptom Checklist.

RESULTS

After controlling for demographics and asthma severity, perceived asthma triggers measured by subscales of the Asthma Trigger Inventory explained 12.5% to 37.3% of the variance in Asthma Symptom Checklist hyperventilation-hypocapnia symptoms. Psychological triggers accounted for 10.6% to 26.7% of the variance alone and 4.3% to 11.0% of the variance over and above other trigger factors. In contrast, perceived animal and pollen allergen triggers did not contribute unique variance to the hyperventilation symptom report. Psychological triggers did not explain variance in classic airway obstruction symptoms, thus arguing against a general bias toward inflated symptom reports in patients with psychologically induced asthma.

CONCLUSION

Differences in perceived asthma triggers are substantially associated with hyperventilation symptoms, and patients with more frequent psychological triggers also tend to report that they experience more hyperventilation symptoms during their asthma symptom episodes.

Stress effects on lung function in asthma are mediated by changes in airway inflammation

OBJECTIVE

To examine the association of changes in current negative mood and long-term daily hassles with changes in lung function and airway inflammation in patients suffering from asthma and in healthy controls. Associations between psychological factors and asthma symptoms have been documented, but the relationship between airway inflammation and psychological factors has been largely unexplored.

METHOD

Data were analyzed from 46 asthma patients and 25 controls who completed questionnaires on current mood and daily hassles at two assessments 3 months apart. Lung function was measured by spirometry (forced expiratory volume in the first second (FEV(1))) and airway inflammation by the fraction of nitric oxide in exhaled air (FeNO). Regression analyses controlling for allergen load and air pollution (ozone) were calculated to study the association between changes in psychological factors and changes in lung function and airway inflammation, and to examine the mediational role of airway inflammation in the stress-lung function association.

RESULTS

In patients with asthma, increases in negative affect were associated with decreases in FEV(1) and increases in FeNO. For daily hassles, a reverse pattern of associations was found, with decreases in daily hassles linked to decreases in FEV(1) and increases in FeNO. Mediation analyses showed that FeNO was a significant mediator of the association of both negative affect and daily hassles with lung function changes. No significant associations were found for healthy controls.

CONCLUSION

Psychological variables are consistently associated with spirometric lung function and airway inflammation in asthma patients. For asthma patients, effects of acute negative affect must be distinguished from more chronic distress due to daily hassles.