A review of the burden and management of mild asthma in adults - Implications for clinical practice

Asthma patients' and physicians' perspectives on the burden and management of asthma: Post-hoc analysis of APPaRENT 1 and 2 to assess predictors of treatment adherence

INTRODUCTION

Patient adherence to maintenance medication is critical for improving clinical outcomes in asthma and is a recommended guiding factor for treatment strategy. Previously, the APPaRENT studies assessed patient and physician perspectives on asthma care; here, a post-hoc analysis aimed to identify patient factors associated with good adherence and treatment prescription patterns.

METHODS

APPaRENT 1 and 2 were cross-sectional online surveys of 2866 adults with asthma and 1883 physicians across Argentina, Australia, Brazil, Canada, China, France, Italy, Mexico, and the Philippines in 2020-2021. Combined data assessed adherence to maintenance medication, treatment goals, use of asthma action plans, and physician treatment patterns and preferences. Multivariable logistic regression models assessed associations between patient characteristics and both treatment prescription (by physicians) and patient treatment adherence.

RESULTS

Patient and physician assessments of treatment goals and adherence differed, as did reporting of short-acting β2-agonist (SABA) prescriptions alongside maintenance and reliever therapy (MART). Older age and greater patient-reported severity and reliever use were associated with better adherence. Patient-reported prescription of SABA with MART was associated with household smoking, severe or poorly controlled asthma, and living in China or the Philippines.

CONCLUSIONS

Results revealed an important disconnect between patient and physician treatment goals and treatment adherence, suggesting that strategies for improving patient adherence to maintenance medication are needed, focusing on younger patients with milder disease. High reliever use despite good adherence may indicate poor disease control. Personalised care considering patient characteristics alongside physician training in motivational communication and shared decision-making could improve patient management and outcomes.

Mild asthma: Conundrums, complexities and the need to customize care

Mild and moderate asthma cover a wide range of asthma presentations, phenotypes and symptom burden, and account for the majority of people with asthma worldwide. Mild asthma has been difficult to define because of its heterogeneity and wide spectrum of impact and outcomes, including being associated with severe exacerbations. Assessment of mild-moderate asthma is best made by combining asthma symptom control and exacerbation risk as the principle means by which to determine treatment needs. Incontrovertible evidence and guidelines support treatment initiation with anti-inflammatory medication, completely avoiding reliever-only treatment of mild asthma. Shared decision making with patients and a treatable traits approach will ensure that a holistic approach is taken to maximize patient outcomes. Most importantly, mild asthma should be regarded as a reversible, potentially curable condition, remaining in long-term remission through minimizing triggers and optimizing care.

Mild asthma is not mild: risk factors and predictive biomarkers for severe acute exacerbations and progression in mild asthma

INTRODUCTION

Asthma is a common chronic respiratory disease characterized by chronic airway inflammation, airway hyperresponsiveness, reversible airflow limitation, and airway remodeling. Mild asthma is the most common type of asthma, but it is the most neglected. Sometimes mild asthma can lead to acute severe exacerbations or even death.

AREAS COVERED

This article reviews the epidemiology, risk factors, and possible predictors of acute severe exacerbations and disease progression in mild asthma to improve the understanding of mild asthma and its severe acute exacerbations and progression.

EXPERT OPINION

There is a necessity to improve asthma patient categorization and redefine mild asthma's concept to heighten patient and physician attention. Identifying mild asthma patients that are highly vulnerable to severe acute exacerbations and researching the mechanisms are future prioritizations.

Assessing the Effects of Changing Patterns of Inhaled Corticosteroid Dosing and Adherence with Fluticasone Furoate and Budesonide on Asthma Management

INTRODUCTION

Pharmacological asthma management focuses on the use of inhaled corticosteroid (ICS)-containing therapies, which reduce airway inflammation and provide bronchoprotection, improving symptom control and reducing exacerbation risk. ICS underuse due to poor adherence is common, leading to poor clinical outcomes including increased risk of mortality. This article reviews efficacy versus systemic activity profiles for various adherence patterns and dosing regimens of fluticasone furoate (FF)-containing and budesonide (BUD)-containing asthma therapies in clinical trials and real-world studies.

METHODS

We performed a structured literature review (1 January 2000-3 March 2022) and mathematical modelling analysis of FF-containing and BUD-containing regular daily dosing in patients with mild-to-severe asthma, as-needed BUD/formoterol (FOR) in mild asthma, and BUD/FOR maintenance and reliever therapy (MART) dosing in moderate-to-severe asthma, to assess efficacy (bronchoprotection) and systemic activity (cortisol suppression) profiles of dosing patterns of ICS use in multiple adherence scenarios.

RESULTS

A total of 22 manuscripts were included in full-text review and 18 in the model simulations. Focusing on FF-containing or BUD-containing treatments at comparable adherence rates, regular daily FF or FF/vilanterol (VI) dosing provided more prolonged bronchoprotection and fewer systemic effects than daily BUD, daily BUD/FOR, or BUD/FOR MART dosing, especially in low adherence scenarios. In model simulations and the real-world setting, FF/VI generally provided longer bronchoprotection, lower systemic activity, and greater clinical benefits over BUD/FOR as well as consistently higher adherence.

CONCLUSION

In this literature review and modelling analysis, FF/VI was found to show clinical advantages on asthma control over BUD/FOR. These findings have implications for helping clinicians select the most suitable inhaled therapy for their patients with asthma.

Questions in Mild Asthma: An Official American Thoracic Society Research Statement

Background: Patients with mild asthma are believed to represent the majority of patients with asthma. Disease-associated risks such as exacerbations, lung function decline, and death have been understudied in this patient population. There have been no prior efforts from major societies to describe research needs in mild asthma. Methods: A multidisciplinary, diverse group of 24 international experts reviewed the literature, identified knowledge gaps, and provided research recommendations relating to mild asthma definition, pathophysiology, and management across all age groups. Research needs were also investigated from a patient perspective, generated in conjunction with patients with asthma, caregivers, and stakeholders. Of note, this project is not a systematic review of the evidence and is not a clinical practice guideline. Results: There are multiple unmet needs in research on mild asthma driven by large knowledge gaps in all areas. Specifically, there is an immediate need for a robust mild asthma definition and an improved understanding of its pathophysiology and management strategies across all age groups. Future research must factor in patient perspectives. Conclusions: Despite significant advances in severe asthma, there remain innumerable research areas requiring urgent attention in mild asthma. An important first step is to determine a better definition that will accurately reflect the heterogeneity and risks noted in this group. This research statement highlights the topics of research that are of the highest priority. Furthermore, it firmly advocates the need for engagement with patient groups and for more support for research in this field.

Sex differences of small airway function and fractional exhaled nitric oxide in patients with mild asthma

BACKGROUND

Sex differences of small airway function (SAF) and fractional exhaled nitric oxide (FeNO) in patients with mild asthma remain unclear.

OBJECTIVE

To evaluate sex differences of SAF and FeNO in patients with mild asthma confirmed by positive methacholine challenge test (MCT) result.

METHODS

This cross-sectional, double-centered, observational study enrolled 1609 adult patients with forced expiratory volume in 1 second greater than or equal to 80% and suspected asthma symptoms. Data of spirometry, FeNO, impulse oscillometry measurements, and peripheral blood test result were compared between males and females. The receiver-operating characteristic curves of SAF parameters and FeNO in predicting positive MCT result were also calculated.

RESULTS

In patients with mild asthma matched by age, males had better SAF but higher FeNO levels than females (60 [29.27%] vs 187 [46.75%] for small airway dysfunction, 78.6% vs 72.0% for forced expiratory flow [FEF]_50%, 67.5% vs 60.1% for FEF_75%, 73.7% vs 67.4% for FEF_25%-75%, and 42.0 ppb vs 29.0 ppb for FeNO, respectively, all P ≤ .001). The FeNO levels in male current smokers were considerably lower than those of nonsmokers. SAF and FeNO values declined more rapidly with age among female than male patients with asthma. The optimal cutoff values of FEF_25%-75%, FEF_50%, and FeNO for predicting a positive MCT result were 81.5%, 86.4%, and 41.0 ppb in males vs 73.7%, 76.9%, and 35.0 ppb in females.

CONCLUSION

In patients with mild asthma, the female patients have worse SAF, lower FeNO levels, and a more prominent decline trend of those parameters with age than males. Sex-specific cutoff values should be considered when SAF parameters (FEF_25%-75%, FEF_50%), alone or combined with FeNO, are used to predict positive MCT result in asthma diagnosis.

Novel genetic variants in long non-coding RNA MEG3 are associated with the risk of asthma

Background

Asthma is the most common chronic inflammatory airway disease worldwide. Asthma is a complex disease whose exact etiologic mechanisms remain elusive; however, it is increasingly evident that genetic factors play essential roles in the development of asthma. The purpose of this study is to identify novel genetic susceptibility loci for asthma in Taiwanese. We selected a well-studied long non-coding RNA (lncRNA), MEG3, which is involved in multiple cellular functions and whose expression has been associated with asthma. We hypothesize that genetic variants in MEG3 may influence the risk of asthma.

Methods

We genotyped four single nucleotide polymorphisms (SNPs) in MEG3, rs7158663, rs3087918, rs11160608, and rs4081134, in 198 patients with asthma and 453 healthy controls and measured serum MEG3 expression level in a subset of controls.

Results

The variant AG and AA genotypes of MEG3 rs7158663 were significantly over-represented in the patients compared to the controls (P = 0.0024). In logistic regression analyses, compared with the wild-type GG genotype, the heterozygous variant genotype (AG) was associated with a 1.62-fold [95% confidence interval (CI) [1.18-2.32], P = 0.0093] increased risk and the homozygous variant genotype (AA) conferred a 2.68-fold (95% CI [1.52-4.83], P = 0.003) increased risk of asthma. The allelic test showed the A allele was associated with a 1.63-fold increased risk of asthma (95% CI [1.25-2.07], P = 0.0004). The AG plus AA genotypes were also associated with severe symptoms (P = 0.0148). Furthermore, the AG and AA genotype carriers had lower serum MEG3 expression level than the GG genotype carriers, consistent with the reported downregulation of MEG3 in asthma patients.

Conclusion

MEG3 SNP rs7158663 is a genetic susceptibility locus for asthma in Taiwanese. Individuals carrying the variant genotypes have lower serum MEG3 level and are at increased risks of asthma and severe symptoms.

Consensus on mild asthma management: results of a modified Delphi study

OBJECTIVE

In order to understand the role of regular controller inhaled corticosteroids (ICS) versus as-needed ICS-formoterol in managing mild asthma, we performed a modified Delphi procedure.

METHODS

Opinions from 16 respiratory experts to three surveys and during a virtual scientific workshop helped to develop final consensus statements (pre-defined as 70% agreement).

RESULTS

Thirteen participants completed all rounds (response rate 81%). At the end of the procedure, there was final consensus on: regular daily ICS being the recommended treatment approach in mild persistent asthma, with better symptom control and robust long-term clinical data compared with as-needed ICS-formoterol (85%); to avoid noncompliance, frequently seen in mild asthma patients, regular ICS dosing should be accompanied by ongoing education on treatment adherence (100%); treatment aims should be targeting asthma control (92%) and reduction of exacerbation risk (85%). No consensus was reached on whether GINA or national guidelines most influence prescribing decisions.

CONCLUSIONS

It is important to encourage patients to be adherent and to target both asthma control and exacerbation risk reduction. There is robust clinical evidence to support proactive regular dosing with ICS controller therapy plus as-needed short-acting beta-agonists for the management of patients with mild asthma.

ABBREVIATIONS.

Supplemental data for this article is available online at https://doi.org/10.1080/02770903.2022.2034850 .

Derivation of asthma severity from electronic prescription records using British thoracic society treatment steps

Background:

Asthma severity is typically assessed through a retrospective assessment of the treatment required to control symptoms and to prevent exacerbations. The joint British Thoracic Society and Scottish Intercollegiate Guidelines Network (BTS/SIGN) guidelines encourage a stepwise approach to pharmacotherapy, and as such, current treatment step can be considered as a severity categorisation proxy. Briefly, the steps for adults can be summarised as: no controller therapy (Step 0), low-strength Inhaled Corticosteroids (ICS; Step 1), ICS plus Long-Acting Beta-2 Agonist (LABA; Step 2), medium-dose ICS + LABA (Step 3), and finally either an increase in strength or additional therapies (Step 4). This study aimed to investigate how BTS/SIGN Steps can be estimated from across a large cohort using electronic prescription records, and to describe the incidence of each BTS/SIGN Step in a general population.

Methods:

There were 41,433,707 prescriptions, for 671,304 individuals, in the Asthma Learning Health System Scottish cohort, between 1/2009 and 3/2017. Days on which an individual had a prescription for at least one asthma controller (preventer) medication were labelled prescription events. A rule-based algorithm was developed for extracting the strength and volume of medication instructed to be taken daily from free-text data fields. Asthma treatment regimens were categorised by the combination of medications prescribed in the 120 days preceding any prescription event and categorised into BTS/SIGN treatment steps.

Results:

Almost 4.5 million ALHS prescriptions were for asthma controllers. 26% of prescription events had no inhaled corticosteroid prescriptions in the preceding 120 days (Step 0), 16% were assigned to BTS/SIGN Step 1, 7% to Step 2, 21% to Step 3, and 30% to Step 4. The median days spent on a treatment step before a step-down in treatment was 297 days, whereas a step-up only took a median of 134 days.

Conclusion

We developed a reproducible methodology enabling researchers to estimate BTS/SIGN asthma treatment steps in population health studies, providing valuable insights into population and patient-specific trajectories, towards improving the management of asthma.

Factors associated with medication adherence among adults with asthma

OBJECTIVE

Asthma medication adherence is of crucial importance for successful disease management. The aim of this study was to identify and rank factors associated with medication adherence among adults with asthma in the general population.

METHODS

We used data on physician-diagnosed asthma, medication adherence, and factors associated with asthma medication adherence from the Danish General Suburban Population Study using a cross-sectional study design. We ranked factors associated with asthma medication adherence based on the magnitude of odds ratios, and the population attributable fractions.

RESULTS

Among 20,032 individuals from the general population, 1,128 (6%) suffered from asthma and 822 (73%) of these were adherent to asthma medications. Based on odds ratios, the three top-ranked factors associated with asthma medication adherence were asthma attacks within the past year (4.0; 95% CI: 2.9-5.5), allergy medication use (3.8; 2.6-5.6), and age above median (3.4; 2.4-4.7), followed by asthma severity markers like airway obstruction, and coughing with mucus. Based on population attributable fractions, the three top-ranked factors associated with adherence to asthma medications were asthma attacks within the past year (70%), age above median (57%), and use of allergy medication (49%).

CONCLUSIONS

The study showed that in the general population recent asthma attacks, higher age, and taking allergy medication were the three most important factors associated with asthma medication adherence. The importance of maintaining adherence to asthma medications even in the absence of severe disease or expressed asthma symptoms should be better communicated to the general population.

Genetic variants in miR-145 gene are associated with the risk of asthma in Taiwan

Asthma is a chronic airway inflammation disease and the diagnosis and treatment strategies remain difficult. MicroRNAs play important roles in many biological and pathological processes including asthma development. There is no study confirming the contribution of genetic variants in miR-145 to asthma etiology. We hypothesize that single nucleotide polymorphisms (SNPs) in the promoter region of miR-145 may be associated with the risk of asthma in Taiwanese. We used a case–control study to test this hypothesis. In 198 asthma patients and 453 healthy controls, the genotypes of miR-145 rs4705342 and rs4705343 were determined, and the associations of miR-145 genotypes with asthma risk and severity were evaluated. The distribution of miR-145 rs4705342 genotypes between asthma patients and non-asthmatic control groups were significantly different (p = 0.0187). In multivariable logistic regression analysis, compared with the wild-type TT genotype, individuals carrying the variant genotypes had progressively decreased risks of asthma: the odds ratio (OR) for the heterogeneous variant genotype (CT) and homozygous variant genotype (CC) was 0.77 (95% CI 0.55–1.10, p = 0.1788) and 0.41 (95% CI 0.21–0.79, p = 0.0102), respectively (p for trend = 0.0187). In allelic test, the C allele was associated with a 31% reduced risk of asthma (OR = 0.69, 95% CI 0.53–0.90, p = 0.0070). In addition, the rs4705342 variant genotypes were correlated with the symptom severity (p = 3 × 10^–5). Furthermore, the variant genotypes correlated with lower miR-145-5p expression level in serum (p = 0.0001). As for rs4705343, there was no differential distribution of genotypes between cases and controls. Our data provide evidence for miR-145 rs4705342 to serve as a novel biomarker for asthma risk prediction.

Expert Opinion on Practice Patterns in Mild Asthma After the GINA 2019 Updates: A Major Shift in Treatment Paradigms from a Long-Standing SABA-Only Approach to a Risk Reduction-Based Strategy with the Use of Symptom-Driven (As-Needed) Low-Dose ICS/LABA

PURPOSE OF REVIEW

This expert opinion, prepared by a panel of chest disease specialists, aims to review the current knowledge on practice patterns in real-life management of mild asthma and to address the relevant updates in asthma treatment by The Global Initiative for Asthma (GINA) to guide clinicians for the best clinical practice in applying these new treatment paradigms.

RECENT FINDINGS

On the basis of the emerging body of evidence suggesting the non-safety of short-acting β2-agonists (SABA)-only therapy and comparable efficacy of the as-needed inhaled corticosteroids (ICS)-formoterol combinations with maintenance ICS regimens, GINA recently released their updated Global Strategy for Asthma Management and Prevention Guide (2019). The new GINA 2019 recommendations no longer support the SABA-only therapy in mild asthma but instead includes new off-label recommendations such as symptom-driven (as-needed) low-dose ICS-formoterol and "low dose ICS taken whenever SABA is taken." The GINA 2019 asthma treatment recommendations include a major shift from long-standing approach of clinical practice regarding the use of symptom-driven SABA treatment alone in the management of mild asthma. This expert opinion supports the transition from a long-standing SABA-only approach to a risk reduction-based strategy, with the use of symptom-driven (as-needed) low-dose ICS/LABA in mild asthma patients, particularly in those with poor adherence to controller medications. The thoughtful and comprehensive approach of clinicians to these strategies is important, given that the exact far-reaching impact of this major change in management of mild asthma in the real-world settings will only be clarified over time.

Association between Interleukin-4-590C>T Polymorphism and the Susceptibility to Asthma: A Meta-Analysis of Case-Control Study

This study was aimed to investigate the relationship between the interleukin-4-590C > T gene polymorphism and the susceptibility to asthma by meta-analysis. To explore the underlying relationship between the polymorphism of IL-4-590C > T and the susceptibility to asthma, this study systematically retrieved the literature including cohort studies and case-control studies published before June 2019 in PubMed, Embase, and Cochrane Library. Data on the odds ratio (OR) and 95% confidence interval (CI) of the literature were included in the relative studies. Subsequently, the included data were weighted by an inverse variance and then analyzed by the fixed or random effects model. Overall, 818 asthma patients and 831 healthy individuals participated in the 8 independent case-control studies in the current meta-analysis. There was no correlation between IL-4-590C > T TT genotype and the increased susceptibility to asthma (dominant model: OR = 1.31, 95% CI = 0.68-2.53). Subgroup analysis by ethnicity showed no significant results in the Asians (OR = 1.28, 95% CI = 0.24-6.80); however, IL-4-590C > T TT genotype significantly elevated the susceptibility to asthma in the Caucasians (OR = 1.43, 95%CI = 1.03-1.98). Meanwhile, subgroup analysis was performed by source of control. A statistically significant result was found in the population-based control group (OR = 1.33, 95% CI = 1.01-1.76), but not in the hospital-based control group (OR = 1.22, 95% CI = 0.27-5.46). The results demonstrated that IL-4-590C > T TT genotype could significantly enhance the susceptibility to asthma in Caucasians without increasing that in Asian populations. However, it still required a large sample of high-quality studies in multicentral hospital to further confirm its reliability.

Pharmacology Versus Convenience: A Benefit/Risk Analysis of Regular Maintenance Versus Infrequent or As-Needed Inhaled Corticosteroid Use in Mild Asthma

INTRODUCTION

This study compared the bronchoprotective and benefit/risk profiles of various inhaled corticosteroid (ICS) dosing regimens in mild asthma.

METHODS

A pharmacokinetic/pharmacodynamic model was developed and validated describing the relationship between ICS dose and time-course for airway bronchoprotection, [provocative concentration of adenosine monophosphate (AMP) causing ≥ 20% decline in forced expiratory volume in 1 s (FEV1) (AMP PC20)], for fluticasone furoate (FF), fluticasone propionate (FP) and budesonide (BUD). For regular ICS maintenance therapy (100% and 50% adherence) and infrequent or as-needed use (dosing 3-4 times per week), treatment effectiveness was expressed as percent time during 28 days when bronchoprotection exceeded either the threshold for a treatment-related bronchoprotective effect (AMP PC20 ≥ 0.25 doubling dose) or the threshold for a clinically significant bronchoprotective effect (AMP PC20 ≥ 1.0 doubling dose). This value was divided by the total ICS dose administered expressed in prednisolone equivalents to give a therapeutic index (TI).

RESULTS

The model-predicted time course of ICS-induced bronchoprotection with regular daily maintenance dosing and 100% adherence showed that all ICS at the highest recommended doses for mild asthma exceeded the threshold for clinically significant bronchoprotective effect for all or most of the 28-day dosing period, mean (90% CI); 100% (96.1-100), 99.9% (8.0-100) and 100% (58.2-100) with TI values of 16.9, 6.6 and 5.4 for FF 100 µg OD, FP 200 µg BID and BUD 200 µg BID, respectively. For simulated poor adherence (50%) to regular daily maintenance therapy, corresponding mean (90% CI) values were; 75.7% (39.4-89.1), 52.3% (0.7-69.2) and 51.3% (28.6-58.3) with TI values of 25.7, 6.9 and 5.6. For simulated infrequent/as needed use the corresponding values were; 77.0% (37.6-87.0), 25.5% (0.0-38.0) and 26.2% (14.3-31.5) with TI values of 26.1, 6.7 and 5.7. For all regimen/scenarios, FF had the most sustained efficacy and favourable TI followed by FP and BUD.

CONCLUSIONS

At doses recommended for mild asthma, all ICS regimens provide sustained bronchoprotective efficacy when dosed regularly with high adherence. With poor adherence or use 3-4 times per week (infrequent/as needed), longer-acting ICS molecules will more likely provide sustained protection and a better TI versus shorter duration of action molecules (FF > FP ≥ BUD). These data highlight the benefits of using ICS as regular daily maintenance dosing in mild asthma and the potential risks of under-treatment with ICS (which may occur with ICS/formoterol as-needed approach in mild persistent asthma) associated with reduced levels of bronchoprotection.