Dyspnea perception in asthma: role of airways inflammation, age and emotional status

Relevance of individual bronchial symptoms for asthma diagnosis and control in patients with rhinitis: A MASK-air study

RATIONALE

It is unclear how each individual asthma symptom is associated with asthma diagnosis or control.

OBJECTIVES

To assess the performance of individual asthma symptoms in the identification of patients with asthma and their association with asthma control.

METHODS

In this cross-sectional study, we assessed real-world data using the MASK-air® app. We compared the frequency of occurrence of five asthma symptoms (dyspnea, wheezing, chest tightness, fatigue and night symptoms, as assessed by the Control of Allergic Rhinitis and Asthma Test [CARAT] questionnaire) in patients with probable, possible or no current asthma. We calculated the sensitivity, specificity and predictive values of each symptom, and assessed the association between each symptom and asthma control (measured using the e-DASTHMA score). Results were validated in a sample of patients with a physician-established diagnosis of asthma.

MEASUREMENT AND MAIN RESULTS

We included 951 patients (2153 CARAT assessments), with 468 having probable asthma, 166 possible asthma and 317 no evidence of asthma. Wheezing displayed the highest specificity (90.5%) and positive predictive value (90.8%). In patients with probable asthma, dyspnea and chest tightness were more strongly associated with asthma control than other symptoms. Dyspnea was the symptom with the highest sensitivity (76.1%) and the one consistently associated with the control of asthma as assessed by e-DASTHMA. Consistent results were observed when assessing patients with a physician-made diagnosis of asthma.

CONCLUSIONS

Wheezing and chest tightness were the asthma symptoms with the highest specificity for asthma diagnosis, while dyspnea displayed the highest sensitivity and strongest association with asthma control.

Relationship of computed tomography-based measurements with symptom perception and quality of life in patients with severe asthma

BACKGROUND

Symptom perception and quality of life (QOL) are important domains for properly managing severe asthma. This study aimed to assess the relationship between airway structural and parenchymal variables measured using chest computed tomography (CT) and subjective symptom perception and QOL in patients with severe asthma enrolled in the Korean Severe Asthma Registry.

METHODS

This study used CT-based objective measurements, including airway wall thickness (WT), hydraulic diameter, functional small airway disease (fSAD), and emphysematous lung (Emph), to assess their association with subjective symptom (cough, dyspnea, wheezing, and sputum) perception measured using the visual analog scale, and QOL measured by the Severe Asthma Questionnaire (SAQ).

RESULTS

A total of 94 patients with severe asthma were enrolled in this study. The WT and fSAD% were significantly positively associated with cough and dyspnea, respectively. For QOL, WT and Emph% showed significant negative associations with the SAQ. However, there was no significant association between lung function and symptom perception or between lung function and QOL.

CONCLUSION

Overall, WT, fSAD%, and Emph% measured using chest CT were associated with subjective symptom perception and QOL in patients with severe asthma. This study provides a basis for clarifying the clinical correlates of imaging-derived metrics and for understanding the mechanisms of respiratory symptom perception.

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

BACKGROUND

It 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.

METHODS

This 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.

RESULTS

We 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.

CONCLUSIONS

Non-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.

Relationship between Multimorbidity and Quality of Life in a Primary Care Setting: The Mediating Role of Dyspnea

Multimorbidity is known to impair Quality of Life (QoL) in patients in a primary setting. Poor QoL is associated with higher dyspnea perception. How multimorbidity and dyspnea perception are related to QoL needs clarification. The aim of the present study is to evaluate the mediating role of dyspnea perception in the relationship between multimorbidity and QoL in adults with and without airflow obstruction in a primary care setting. Seventeen general practitioners participated in the study: a total of 912 adult patients attending the practitioner’s surgery for a generic consultation completed a preliminary respiratory screening; 566 of them answered a respiratory questionnaire between January and June 2014, and 259 of the latter (148 M, aged 40–88) agreed to go through all the of procedures including spirometry, the IMCA and QoL (SF-36 through Physical Health “PCS” and Mental Health components) questionnaires, evaluation of comorbidities and the mMRC Dyspnea Scale. For screening purpose, a cut-off of FEV₁/FVC < 70% was considered a marker of airflow obstruction (AO). Of the sample, 25% showed airflow obstruction (AO). No significant difference in mMRC score regarding the number of comorbidities and the PCS was found between subjects with and without AO. Multimorbidity and PCS were inversely related in subjects with (p < 0.001) and without AO (p < 0.001); mMRC and PCS were inversely related in subjects with (p = 0.001) and without AO (p < 0.001). A mediation analysis showed that the relation between number of comorbidities and PCS was totally mediated by mMRC in subjects with AO and partially in subjects without AO. We conclude that the effect of multimorbidity on PCS is totally mediated by mMRC only in AO. Detecting and monitoring mMRC in a primary care setting may be a useful indicator for evaluating a patient’s global health.

Estimating Respiratory Rate From Breath Audio Obtained Through Wearable Microphones

Respiratory rate (RR) is a clinical metric used to assess overall health and physical fitness. An individual's RR can change from their baseline due to chronic illness symptoms (e.g., asthma, congestive heart failure), acute illness (e.g., breathlessness due to infection), and over the course of the day due to physical exhaustion during heightened exertion. Remote estimation of RR can offer a cost-effective method to track disease progression and cardio-respiratory fitness over time. This work investigates a model-driven approach to estimate RR from short audio segments obtained after physical exertion in healthy adults. Data was collected from 21 individuals using microphone-enabled, near-field headphones before, during, and after strenuous exercise. RR was manually annotated by counting perceived inhalations and exhalations. A multi-task Long-Short Term Memory (LSTM) network with convolutional layers was implemented to process mel-filterbank energies, estimate RR in varying background noise conditions, and predict heavy breathing, indicated by an RR of more than 25 breaths per minute. The multi-task model performs both classification and regression tasks and leverages a mixture of loss functions. It was observed that RR can be estimated with a concordance correlation coefficient (CCC) of 0.76 and a mean squared error (MSE) of 0.2, demonstrating that audio can be a viable signal for approximating RR.Clinical relevance-The subject technology facilitates the use of accessible, aesthetically acceptable wearable headphones to provide a technologically efficient and cost-effective method to estimate respiratory rate and track cardio-respiratory fitness over time.

The Impact of Tobacco Smoking on Adult Asthma Outcomes

Background: Tobacco smoking is associated with more severe asthma symptoms, an accelerated decline in lung function, and reduced responses to corticosteroids. Our objective was to compare asthma outcomes in terms of disease control, exacerbation rates, and lung function in a population of asthmatic patients according to their smoking status. Methods: We compared patients’ demographics, disease characteristics, and lung-function parameters in current-smokers (CS, n = 48), former-smokers (FS, n = 38), and never-smokers (NS, n = 90), and identified predictive factors for asthma control. Results: CS had a higher prevalence of family asthma/atopy, a lower rate of controlled asthma, impaired perception of dyspnea, an increased number of exacerbations, and poorer lung function compared to NS. The mean asthma control questionnaire’s (ACQ) score was higher in CS vs. NS and FS (1.9 vs. 1.2, p = 0.02). Compared to CS, FS had a lower rate of exacerbations, a better ACQ score (similar to NS), a higher prevalence of dyspnea, and greater lung-diffusion capacity. Non-smoking status, the absence of dyspnea and exacerbations, and a forced expiratory volume in one second ≥80% of predicted were associated with controlled asthma. Conclusions: CS with asthma exhibit worse clinical and functional respiratory outcomes compared to NS and FS, supporting the importance of smoking cessation in this population.

Factors associated with discrepancies between poor dyspnea perception and abnormal lung function in 65 asthmatic patients

Background

Dyspnea is a subjective symptom of asthma whose perception is characterized by an interindividual variability. Poor dyspnea perception is usually associated with increased risk of exacerbation and may lead to inappropriate asthma management and under-treatment. We sought to identify factors associated with discrepancies between poor dyspnea perception and abnormal lung function in patients with moderate persistent asthma.

Methodology

65 patients, who attended their scheduled follow-up pulmonology consultation at Ibn Sina Hospital (Rabat - Morocco), underwent interrogation including modified Medical Research Council (mMRC) scale for dyspnea, physical examination and spirometry. Two groups, those with mMRC < 2 (poor dyspnea perceivers) and those with mMRC scale ≥ 2 were compared.

Results

Poor dyspnea perception was found in 21 patients (32.3%). Associated factors were male sex (p : 0.03), low socio-economic income (p : 0.01), an onset of symptoms greater than 10 years (p : 0.01), BMI ≥ 25 Kg/m2 (p : 0.04) and depression (p : 0.04).

Conclusion

The results revealed factors significantly associated with poor dyspnea perception despite an obstructive ventilatory disorder. These factors could usefully be considered to successfully manage asthma as well as the regular prescription of an objective test like spirometry.

Symptoms and perception of airway obstruction in asthmatic patients: Clinical implications for use of reliever medications

BACKGROUND

Asthma causes the unpleasant sensation of breathlessness (dyspnea) caused by airway obstruction. Patients with poor perception of airway obstruction are at risk of delay in seeking medical attention and undertreatment, which can lead to avoidable deaths. Conversely, those with heightened perception are at risk of overtreatment and iatrogenic adverse effects with reliever medications, anxiety, and unnecessary use of health care resources.

OBJECTIVE

We sought to review evidence about symptom misperception in asthmatic patients and how to identify and manage affected patients, particularly with regard to reliever medications.

METHODS

We conducted a systematic literature search for studies of perception of airway function in asthmatic patients. We searched the OVID (Medline and Medline [R] in process [PubMed]), Embase, and Adisearch/Odyssey databases, restricting our search to human studies published in English from 1990-2018, with no restrictions on age, sex, or racial origin.

RESULTS

We found that both underperception and overperception assessed during induced bronchoconstriction or bronchodilation or during changes in airway resistance were common across all age groups and that aging, disease severity, smoking, sex, ethnicity, psychologic factors, and medication are all associated with differences in perception. Importantly, airway inflammation was associated with impaired perception and a history of severe or near-fatal asthma. We also identified knowledge gaps, such as whether an individual patient's perception varies over time and the influence perception has on patients' use of reliever medication.

CONCLUSION

We found that abnormal perception of airway obstruction has important clinical implications for the management of patients with asthma.

Factors Associated with Physician-Patient Discordance in the Perception of Asthma Control

BACKGROUND

Physicians' perception of asthma control has a direct impact on treatment options and patients' outcomes.

OBJECTIVE

To analyze the differences between patients and their physicians in the perception of asthma control. Moreover, factors associated with this discordance were explored.

METHODS

A multicenter, cross-sectional survey was conducted in patients visiting primary or secondary facilities for routine asthma reviews. Before the review, patients completed the 5-iteam Asthma Control Questionnaire (ACQ) under the supervision of a medical staff. Physicians recorded their perception of the patients' asthma control without viewing the ACQ results. After the review, physicians completed the demographic and clinical data.

RESULTS

A total of 1697 patients were included. ACQ results showed that asthma was well controlled in 52.2% of the patients, but physicians perceived that 79.6% of patients were well controlled. The concordance analyzed by the kappa index was weak (0.27). The discordant physician-patient pairs had significantly worse ACQ scores than the concordant pairs (P < .0001), but the use of neither inhaled corticosteroids nor other controller medications showed any differences between the groups. In a multivariate model, ACQ score of 0.75 or more and lack of lung function assessment within the previous 6 months were independently associated with the physician-patient discordance in the perception of asthma control.

CONCLUSIONS

The subjective perception of the physicians did not show a good agreement with the patients' asthma control based on validated ACQ scores, with increased rates of discordance among patients whose asthma was not well controlled and patients who had not received lung function assessment.

Efficacy of mepolizumab add-on therapy on health-related quality of life and markers of asthma control in severe eosinophilic asthma (MUSCA): a randomised, double-blind, placebo-controlled, parallel-group, multicentre, phase 3b trial

BACKGROUND

Mepolizumab, an anti-interleukin-5 monoclonal antibody approved as add-on therapy to standard of care for patients with severe eosinophilic asthma, has been shown in previous studies to reduce exacerbations and dependency on oral corticosteroids compared with placebo. We aimed to further assess mepolizumab in patients with severe eosinophilic asthma by examining its effect on health-related quality of life (HRQOL).

METHODS

We did a randomised, double-blind, placebo-controlled, parallel-group, multicentre, phase 3b trial (MUSCA) in 146 hospitals or research centres in 19 countries worldwide. Eligible participants were patients aged 12 years or older with severe eosinophilic asthma and a history of at least two exacerbations requiring treatment in the previous 12 months before screening despite regular use of high-dose inhaled corticosteroids plus other controller medicines. Exclusion criteria included current smokers or former smokers with a history of at least ten pack-years. We randomly assigned participants (1:1) by country to receive a subcutaneous injection of either mepolizumab 100 mg or placebo, plus standard of care, every 4 weeks for 24 weeks (the final dose was given at week 20). We did the randomisation using an interactive voice response system and a centralised, computer-generated, permuted-block design of block size six. The two treatments were identical in appearance and administered in a masked manner; patients, investigators, other site staff and the entire study team including those assessing outcomes data were also masked to group assignment. The primary endpoint was the mean change from baseline in the St George's Respiratory Questionnaire (SGRQ) total score at week 24 in the modified intention-to-treat (modified ITT) population (analysed according to their randomly assigned treatment). Safety was assessed in all patients who received at least one dose of trial medication (analysed according to the actual treatment received). This trial is registered with ClinicalTrials.gov, number NCT02281318.

FINDINGS

We recruited patients between Dec 11, 2014, and Nov 20, 2015, and the study was undertaken between Dec 11, 2014, and June 10, 2016. The modified ITT population comprised 274 patients assigned to mepolizumab 100 mg and 277 assigned to placebo. Mepolizumab versus placebo showed significant improvements at week 24 from baseline in SGRQ total score (least squares mean [SE] change from baseline -15·6 (1·0) vs -7·9 (1·0), a treatment difference of -7·7 (95% CI -10·5 to -4·9; p<0·0001). No deaths occurred during the study. 192 (70%) of 273 patients who received mepolizumab and 207 (74%) of 278 who received placebo reported at least one on-treatment adverse event, the most common of which were headache (in 45 [16%] given mepolizumab vs 59 [21%] given placebo) and nasopharyngitis (in 31 [11%] given mepolizumab vs 46 [17%] given placebo). 15 (5%) and 22 (8%) patients had an on-treatment serious adverse event in the mepolizumab and placebo groups, respectively; the most common was asthma in both groups (in three [1%] given mepolizumab vs nine [3%] given placebo).

INTERPRETATION

Mepolizumab was associated with significant improvements in HRQOL in patients with severe eosinophilic asthma, and had a safety profile similar to that of placebo. These results add to and support the use of mepolizumab as a favourable add-on treatment option to standard of care in patients with severe eosinophilic asthma.

FUNDING

GlaxoSmithKline.

The Interpretation of Dyspnea in the Patient with Asthma

Physicians have noted dyspnea in severely ill asthmatic patients to be associated with fright or panic; in more stable patients dyspnea may reflect characteristics including lung function, personality and behavioral traits. This study evaluates the symptom of dyspnea in 32 asthmatic patients twice: first when acutely ill and again after an initial response to therapy. Spirometry was performed, dyspnea quantified (Borg scale), and panic assessed with a specialized measure of acute panic (the acute panic inventory (API)) in the 32 patients before and again after treatment. After treatment, questionnaires to evaluate somatization and panic disorder were also administered. When acutely ill, both the API and all spirometric measures (PEFR; FEV1; IC) correlated with dyspnea. Multiple linear regression showed that measures of the API, the peak expiratory flow rate, and female sex taken together accounted for 41% of dyspnea in acute asthma. After treatment, the API again predicted dyspnea while spirometric data did not. Those subjects who described themselves as having chronic panic disorder reported high grades of dyspnea after treatment also. We conclude that interpretations of the self-report of asthma differ between acutely ill and stable asthmatic patients.

Cerebral anatomical changes in female asthma patients with and without depression compared to healthy controls and patients with depression

BACKGROUND

Population-based studies have demonstrated that asthma patients with depression symptoms are more likely to have poor asthma control and worse asthma outcomes. However, the underlying mechanism of the relationship between asthma and depression is still unclear. The present study aimed to examine the cerebral anatomical changes in female asthma patients with and without depression.

METHODS

Using structural magnetic resonance imaging (MRI) and a voxel-based morphometry technique, the primary effects of and the interaction between asthma and depression were analyzed. The cerebral gray matter volume (GMV) was compared between the groups. Correlation analyses between the GMV value of the brain regions and the clinical parameters were completed.

RESULTS

The interaction effect of asthma and depression was found on the right superior temporal gyrus (STG) and the left middle temporal gyrus. Patients with both asthma and depression showed less GMV in the right STG, the bilateral precuneus, and the right superior frontal gyrus compared to patients with asthma only. The GMV of the right STG showed a decrement form among the asthma only group, healthy controls and asthma plus depression group. In patients with asthma and depression, the volume of the right STG was positively correlated with PD20 (r = 0.714, p = 0.047) and negatively correlated with the nocturnal awakening score in the Asthma Control Test (r = -0.061, p = 0.038).

CONCLUSION

Current findings provided convergent evidence to support the critical role of the right STG in the brain mechanism that mediates asthma and depression.

Perception of bronchoconstriction following methacholine and eucapnic voluntary hyperpnea challenges in elite athletes

OBJECTIVE

Self-reported respiratory symptoms are poor predictors of exercise-induced bronchoconstriction (EIB) in athletes. The objective of this study was to determine whether athletes have an inadequate perception of bronchoconstriction.

METHODS

One hundred thirty athletes and 32 nonathletes completed a standardized questionnaire and underwent eucapnic voluntary hyperpnea (EVH) and methacholine inhalation test. Perception scores were quoted on a modified Borg scale before each spirometry measurement for cough, breathlessness, chest tightness, and wheezing. Perception slope values were also obtained by plotting the variation of perception scores before and after the challenges against the fall in FEV1 expressed as a percentage of the initial value [(perception scores after - before)/FEV1].

RESULTS

Up to 76% of athletes and 68% of nonathletes had a perception score of ≤0.5 at 20% fall in FEV1 following methacholine. Athletes with EIB/airway hyperresponsiveness (AHR) had lower perception slopes to methacholine than nonathletes with asthma for breathlessness only (P=.02). Among athletes, those with EIB/AHR had a greater perception slope to EVH for breathlessness and wheezing (P=.02). Female athletes had a higher perception slope for breathlessness after EVH and cough after methacholine compared with men (P<.05). The age of athletes correlated significantly with the perception slope to EVH for each symptom (P<.05).

CONCLUSIONS

Minimal differences in perception of bronchoconstriction-related symptoms between athletes and nonathletes were observed. Among athletes, the presence of EIB/AHR, older age, and female sex were associated with slightly higher perception scores.

Asthma and depression: the Cooper Center Longitudinal Study

BACKGROUND

Prior research suggests a possible association between asthma and depression.

OBJECTIVE

To examine the association between asthma and depressive symptoms, controlling for asthma medications, lung function, and overall health.

METHODS

We conducted a cross-sectional study of 12,944 adults who completed physician-based preventive health examinations at the Cooper Clinic from 2000 to 2012. Information on medical histories, including asthma and depression, and medications were collected. Participants reported overall health status, completed spirometry testing, and underwent depression screening using the 10-item Center for Epidemiologic Studies Depression Scale (CES-D). Dependent variables of current depressive symptoms (CES-D scores ≥10) and lifetime history of depression were separately modeled using logistic regression with independent variables, including demographics, spirometry, asthma controller medications, and patient-reported health status.

RESULTS

The sample was predominantly white and well educated. The prevalence of asthma was 9.0%. Asthma was associated with an odds ratio (OR) of 1.41 (95% CI, 1.16-1.70; P < .001) of current depressive symptoms based on CES-D score. Asthma was also associated with lifetime history of depression (OR, 1.66; 95% CI, 1.40-1.95; P < .001). Neither lung function nor asthma controller medications were significantly associated with depression.

CONCLUSION

Asthma was associated with increased prevalence of current depressive symptoms and lifetime depression in a large sample of relatively healthy adults. These findings suggest that the increased likelihood of depression among patients with asthma does not appear to be exclusively related to severe or poorly controlled asthma. People with asthma, regardless of severity, may benefit from depression screening in clinical settings.

Could FEV₁ decline have a role in daily clinical practice for asthma monitoring?

OBJECTIVE

The aim of this review was to understand whether FEV1 decline measured during the follow-up of asthmatic subjects (FEV1 variation between two different measurements at a distance of at least 5 years) may have a role in their management.

METHODS

Articles, commentaries and reviews relating to the topic were searched in PubMed.

RESULTS

Patients with an accelerated FEV1 decline (>30 ml/year) may be either steroid-resistant/difficult-to-treat asthmatics or not adequately treated because they are either under-perceivers or poorly adherent to their therapy. Sometimes they may be unable to use devices correctly. Untreated rhinitis and incorrect lifestyle (obesity status, a high-fat diet and lack of exercise) must be considered when facing a pulmonary function decline. Identifying asthmatics with an accelerated FEV1 decline, even with well controlled symptoms, may allow us to make possible treatment adjustments or to remove potentially harmful environmental exposure and suggest a correct lifestyle. Depending on FEV1 decline severity, we may detect different asthma phenotypes. One type is characterized by no/low lung function reduction. Among moderate/severe 'declining' subjects, there may be a group that might be responsive to treatment and a second one with a quicker loss in lung function that may be unresponsive to therapy.

CONCLUSION

FEV1 decline calculation should be assessed early in clinical practice over the course of time in order to make all possible variations in treatment, environmental exposure and lifestyle more efficacious overall for declining subjects responsive to anti-inflammatory therapy. Further studies are necessary to validate this approach to asthma.

Discrepancies between lung function and asthma control: asthma perception and association with demographics and anxiety

Understanding asthma symptom perception is necessary for reducing unnecessary costs both for asthma sufferers and society and will contribute to improving asthma management. The primary aim of this study was to develop and test a standardized method for classification of asthma perceiver categories into under-, normal, and overperceiver groups based on the comparison between self-report and lung function components of asthma control. Additionally, the degree to which demographic variables and anxiety contributed to the classification of patients into perceiver groups was examined. Patients underwent methacholine or reversibility testing to confirm asthma diagnosis. Next, participants completed lung function testing over 3 days before their next appointment. Finally, patients filled out demographic and self-report measures including the Asthma Control Test (ACT). Each self-report category of control assessed by the ACT (interference, shortness of breath, nighttime awakenings, rescue inhaler usage, and a composite total score) was compared with lung function measurements using a modified version of the asthma risk grid. Using the modified asthma risk grid to determine perceiver categorization, this sample included 14 underperceivers, 29 normal perceivers, and 36 overperceivers. A discriminant analysis was performed that indicated that a majority of underperceivers were characterized by being African American and having low asthma-specific anxiety. Normal perceivers in this sample tended to be older. Overperceivers tended to be female. Our findings encourage further research using the reported method of classifying asthma patients into perceiver categories.