Aspirin and decreased adult-onset asthma: randomized comparisons from the physicians' health study

Predicting Asthma Exacerbations Using Machine Learning Models

INTRODUCTION

Although clinical, functional, and biomarker data predict asthma exacerbations, newer approaches providing high accuracy of prognosis are needed for real-world decision-making in asthma. Machine learning (ML) leverages mathematical and statistical methods to detect patterns for future disease events across large datasets from electronic health records (EHR). This study conducted training and fine-tuning of ML algorithms for the real-world prediction of asthma exacerbations in patients with physician-diagnosed asthma.

METHODS

Adults with ≥ 2 ICD9/10 asthma codes within 1 year and at least 30 days apart were identified from the Optum Panther EHR database between 2016 and 2023. An emergency department (ED), urgent care, or inpatient visit for asthma, while on systemic administration of corticosteroids, was considered an exacerbation. To predict factors associated with exacerbations in a 6-month study period, clinical information from patients was retrieved in the preceding 6-month baseline period. Clinical information included demographics, lab results, diagnoses, medications, immunizations, and allergies. Three models built using Extreme Gradient Boosting (XGBoost), Long Short-Term Memory (LSTM), and Transformers algorithms were trained and tested on independent datasets. Predictions were explained using the SHAP (SHapley Additive exPlanations) library.

RESULTS

Of 1,331,934 patients with asthma, 16,279 (1.2%) experienced ≥ 1 exacerbation. XGBoost was the best predictive algorithm (area under the curve [AUC] = 0.964). Factors associated with exacerbations included a prior history of exacerbation, prednisone usage, high-dose albuterol usage, and elevated troponin I. Reduced probability of exacerbations was associated with receiving inhaled albuterol, vitamins, aspirin, statins, furosemide, and influenza vaccination.

CONCLUSION

This ML-based study on asthma in the real world confirmed previously known features associated with increased exacerbation risk for asthma, while uncovering not entirely understood features associated with reduced risk of asthma exacerbations. These findings are hypothesis-generating and should contribute to ongoing discussion of the strengths and limitations of ML and other supervised learning models in patient risk stratification.

Exposure to Proton Pump Inhibitors and the Risk of Incident Asthma in Patients with Coronary Artery Diseases: A Population-Based Cohort Study

We aimed to determine the association between proton pump inhibitor (PPI) use and incident asthma in patients with coronary artery disease (CAD). This nationwide cohort study collected claims data from the Taiwanese Bureau of National Health Insurance from 2004 to 2013. The primary outcome, i.e., the risk of incident asthma, was assessed by estimating hazard ratios (HRs) and 95% confidence intervals (CIs). The adjusted HR of asthma development was estimated using the Cox regression model. Sensitivity and subgroup analyses were also conducted. A total of 8894 PPI users and 12,684 H2-receptor antagonist (H2RA) users were included in patients with CAD. Compared with H2RA use, an increased risk of incident asthma was found between PPI use and the risk of incident asthma in patients with CAD after adjusting for sex, age, urbanization, and low income (HR: 1.41; 95% CI: 1.04-1.89). The sensitivity analysis results were consistent with the main analysis results. However, the subgroup analysis revealed no association of incident asthma in patients with diabetes mellitus, hyperlipidemia, stroke, allergic rhinitis, pneumonia, cancer, or depression in the PPI group compared with those in the H2RA group. In conclusion, PPI use increased the risk of asthma development in patients with CAD.

Emerging Roles of Platelets in Allergic Asthma

Allergic asthma is a complex chronic inflammatory disease of the airways, driven by Th2 immune responses and characterized by eosinophilic pulmonary inflammation, airway hyperresponsiveness, excessive mucus production, and airway remodeling. Overwhelming evidence from studies in animal models and allergic asthmatic patients suggests that platelets are aberrantly activated and recruited to the lungs. It has been established that platelets can interact with other immune cells and secrete various biochemical mediators to promote allergic sensitization and airway inflammatory response, and platelet deficiency may alleviate the pathological features and symptoms of allergic asthma. However, the comprehensive roles of platelets in allergic asthma have not been fully clarified, leaving attempts to treat allergic asthma with antiplatelet agents questionable. In this review, we summarize the role of platelet activation and pulmonary accumulation in allergic asthma; emphasis is placed on the different interactions between platelets with crucial immune cell types and the contribution of platelet-derived mediators in this context. Furthermore, clinical antiplatelet approaches to treat allergic asthma are discussed. This review provides a clearer understanding of the roles of platelets in the pathogenesis of allergic asthma and could be informative in the development of novel strategies for the treatment of allergic asthma.

Pharmacological Management of Elderly Patients with Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome: Room for Speculation?

Asthma and chronic obstructive pulmonary disease (COPD) are two distinct diseases that share a condition of chronic inflammation of the airways and bronchial obstruction. In clinical settings, it is not rare to come across patients who present with clinical and functional features of both diseases, posing a diagnostic dilemma. The overlap condition has been termed asthma-COPD overlap syndrome (ACOS), and mainly occurs in individuals with long-standing asthma, especially if they are also current or former smokers. Patients with ACOS have poorer health-related quality of life and a higher exacerbation rate than subjects with asthma or COPD alone. Whether ACOS is a distinct nosological entity with genetic variants or rather a condition of concomitant diseases that overlap is still a matter of debate. However, there is no doubt that extended life expectancy has increased the prevalence of asthma and COPD in older ages, and thus the probability that overlap conditions occur in clinical settings. In addition, age-associated changes of the lung create the basis for the two entities to converge on the same subject. ACOS patients may benefit from a stepwise treatment similar to that of asthma and COPD; however, the proposed therapeutic algorithms are only speculative and extrapolated from studies that are not representative of the ACOS population. Inhaled corticosteroids are the mainstay of therapy, and always in conjunction with long-acting bronchodilators. The potential heterogeneity of the overlap syndrome in terms of inflammatory features (T helper-1 vs. T helper-2 pathways) may be responsible for the different responses to treatments. The interaction between respiratory drugs and concomitant diseases should be carefully evaluated. Similarly, the effect of non-respiratory drugs, such as aspirin, statins, and β-blockers, on lung function needs to be properly assessed.

Platelets constitutively express IL-33 protein and modulate eosinophilic airway inflammation

BACKGROUND

Although platelets play a key role in allergic inflammation in addition to their well-established role in hemostasis, the precise mechanisms of how platelets modulate allergic inflammation are not fully understood. IL-33 is an essential regulator of innate immune responses and allergic inflammation.

OBJECTIVE

We sought to determine the expression of IL-33 protein by platelets and its functional significance in airway inflammation.

METHODS

IL-33 protein in human platelets, the human megakaryocyte cell line MEG-01, and bone marrow-derived mouse megakaryocytes was detected by using Western blot analysis and fluorescent immunostaining. We examined the functional relevance of IL-33 protein in platelets by comparing platelet-intact and platelet-depleted groups in a murine model of IL-33-dependent airway eosinophilia elicited by intranasal administration of papain. We further compared the additive effect of administration of platelets derived from wild-type versus IL-33-deficient mice on the papain-induced eosinophilia.

RESULTS

Platelets and their progenitor cells, megakaryocytes, constitutively expressed IL-33 protein (31 kDa). Papain-induced IL-33-dependent airway eosinophilia in mice was significantly attenuated by platelet depletion. Conversely, concomitant administration of platelets derived from wild-type mice but not IL-33-deficient mice enhanced the papain-induced airway eosinophilia.

CONCLUSIONS

Our novel findings suggest that platelets might be important cellular sources of IL-33 protein in vivo and that platelet-derived IL-33 might play a role in airway inflammation. Therefore platelets might become an attractive novel therapeutic target for asthma and probably allergic inflammation.

The association between paracetamol use and asthma: causation or coincidence?

A better understanding of the causation of asthma and allergic disorders could potentially lead to intervention strategies that reduce their prevalence and severity. One potential causative factor is the use of paracetamol. Most of the evidence for the link with asthma is from non-experimental studies of paracetamol exposure in utero, infancy, childhood and adult life; however, it has been difficult to rule out confounding and bias in the associations observed. The two randomized clinical trials of the effect of paracetamol in patients with asthma have been difficult to interpret, due to methodological issues. There have been no randomized controlled trials of paracetamol use and the development of asthma. Both asthma and paracetamol use are common, and so even if there is a relatively small effect of paracetamol exposure on the development of asthma or its severity, then such an effect would be of major public health significance. It is proposed that randomized controlled trials of the effect of paracetamol on the development of asthma and its severity are a high research priority.

Risk factors for asthma: is prevention possible?

Asthma is one of the most common diseases in the world, resulting in a substantial burden of disease. Although rates of deaths due to asthma worldwide have reduced greatly over the past 25 years, no available therapeutic regimens can cure asthma, and the burden of asthma will continue to be driven by increasing prevalence. The reasons for the increase in asthma prevalence have not been defined, which limits the opportunities to develop targeted primary prevention measures. Although associations are reported between a wide range of risk factors and childhood asthma, substantiation of causality is inherently difficult from observational studies, and few risk factors have been assessed in primary prevention studies. Furthermore, none of the primary prevention intervention strategies that have undergone scrutiny in randomised controlled trials has provided sufficient evidence to lead to widespread implementation in clinical practice. A better understanding of the factors that cause asthma is urgently needed, and this knowledge could be used to develop public health and pharmacological primary prevention measures that are effective in reducing the prevalence of asthma worldwide. To achieve this it will be necessary to think outside the box, not only in terms of risk factors for the causation of asthma, but also the types of novel primary prevention strategies that are developed, and the research methods used to provide the evidence base for their implementation. In the interim, public health efforts should remain focused on measures with the potential to improve lung and general health, such as: reducing tobacco smoking and environmental tobacco smoke exposure; reducing indoor and outdoor air pollution and occupational exposures; reducing childhood obesity and encouraging a diet high in vegetables and fruit; improving feto-maternal health; encouraging breastfeeding; promoting childhood vaccinations; and reducing social inequalities.

Mechanisms of aspirin desensitization

Aspirin-exacerbated respiratory disease is a clinical syndrome characterized by severe, persistent asthma, hyperplastic eosinophilic sinusitis with nasal polyps, and reactions to aspirin and other nonsteroidal antiinflammatory drugs that preferentially inhibit cyclooxygenase 1. The mechanisms behind the therapeutic effects of aspirin desensitization remain poorly understood. Recent studies suggest that the clinical benefits may occur through direct inhibition of tyrosine kinases and the signal transducer and activator of transcription 6 signaling pathway, which results in inhibition of interleukin 4 production. In this article, the current understanding of the mechanisms of aspirin desensitization is reviewed and future areas of investigation are discussed.

Acetaminophen and asthma

Acetaminophen is a widely used medication for the treatment of pain and fever in children and pregnant women. There is substantial epidemiological evidence in adults and children that acetaminophen use is associated with asthma symptoms. There is also a considerable body of evidence that supports a modest but consistent association of acetaminophen use in pregnancy and early infancy with asthma in later childhood. This relationship is robust to adjustment for a large range of potential confounding factors and, in some studies, shows clear evidence of a dose-dependent association but the possibility of confounding by indication has remained a concern. However, the epidemiological evidence is now compelling and there is a clear need to establish causation so that appropriate advice and interventions can be developed for children at risk of asthma. This requires randomised trials of analgesics and antipyretics, including acetaminophen, in a variety of clinical settings.

Adult-onset asthma: is it really different?

Asthma that starts in adulthood differs from childhood-onset asthma in that it is often non-atopic, more severe and associated with a faster decline in lung function. Understanding of the underlying mechanism of adult-onset asthma and identification of specific phenotypes may further our understanding of pathophysiology and treatment response, leading to better targeting of both existing and new approaches for personalised management. Pivotal studies in past years have led to sustained progress in many areas, ranging from risk factors for development, identification of different phenotypes, and introduction of new therapies. This review highlights and discusses literature on adult-onset asthma, with special focus on the differences from childhood-onset asthma, risk factors for development, phenotypes of adult-onset asthma and new approaches for personalised management.

Effects of Acetaminophen consumption in asthmatic children

BACKGROUND

Acetaminophen exposure might be associated with increasing risk of asthma prevalence and other atopic disorders over recent decades. The present study aimed to investigate the association between acetaminophen exposure and the risk of developing childhood asthma.

METHODS

A case - control study was undertaken between March and September 2010 in Urmia district north west of Iran. Subjects were children aged between 2 - 8 years old. Cases were asthmatic children diagnosed based on GINA criteria (n=207) and controls were children without asthma symptoms (n=414) using 1:2 sampling method. Cases and controls were matched for age and gender. Clinical data including Acetaminophen exposure was collected by a questionnaire which completed by interviewing with parents/ guardians.

RESULTS

Using Acetaminophen during the first year of life had no any effect on the risk of asthma (p=0.19), but amongst 2-8 years old children, this association was observed (p<0.001). There was also a doseresponseassociation between Acetaminophen consumption and risk of asthma (OR: 3.8; 95% CI; 2.15 6.59 for once per 2 to 3 month and OR: 4.2; 2.50 - 7.3 for at least one per month).

CONCLUSIONS

Using Acetaminophen increases risk of asthma among 2 - 8 years old children. However stronger evidences are required to design evidence-based guidelines to reduce acetaminophen consumption following post - vaccination and other febrile disorders.

The role of paracetamol in the pathogenesis of asthma

Paracetamol use represents a putative risk factor for the development of asthma. There is convincing epidemiological evidence that the risk of asthma may be increased with exposure to paracetamol in the intrauterine environment, infancy, later childhood and adult life. A dose-dependent association has also been observed in these different age groups in different populations world-wide. An association has also been shown between paracetamol use in both rhinoconjunctivitis and eczema. There is biological plausibility with paracetamol use leading to decreased glutathione levels resulting in increased oxidant-induced inflammation and potentially enhanced T-helper type 2 responses. At the population level, patterns of paracetamol use might explain, to some extent, the world-wide variation in the prevalence of asthma and related disorders, particularly the high rates in English-speaking countries, which have high per capita prescription and over-the-counter use of paracetamol. A temporal association also exists between the international trends of increasing paracetamol use and increasing prevalence of asthma over recent decades. Further research is urgently required, in particular randomized-controlled trials (RCTs) into the long-term effects of frequent paracetamol use in childhood, to determine the magnitude and characteristics of any such risk. Importantly, RCTs will also enable evidence-based guidelines for the recommended use of paracetamol to be developed.

Advances in adult asthma diagnosis and treatment and health outcomes, education, delivery, and quality in 2008

In 2008 the Journal reported new findings in management of asthma. Dosing schedules of inhaled steroids have been modified and individualized. New, more costly propellants are replacing ozone-depleting chlorofluorocarbons. An association of asthma with pneumococcal disease has been observed. Smoking bans in public places are eliminating second-hand smoke and reducing asthma-related emergency department visits among adults. In contrast with these advances, however, disparity in asthma morbidity persists: black persons compared with white persons have a 4-fold greater risk of an asthma-related emergency department visit.

Efficacy of sulphasalazine on lung histopathology in a murine model of chronic asthma

Sulphasalazine is a specific inhibitor of nuclear factor kappa B (NF-kappa B) which plays a key role in asthma. To determine the impact of sulphasalazine in the treatment of chronic asthma, BALB/c mice were sensitized and challenged with ovalbumin. Mice with experimentally induced asthma in group I received saline, group II sulphasalazine 200 mg/kg, group III sulphasalazine 300 mg/kg, and group IV dexamethasone 1 mg/kg intraperitoneally once a day in the last 7 days of the challenge period. Histological findings of the airways were evaluated by light and electron microscopies. Dexamethasone and sulphasalazine in both doses significantly improved all airway histopathologic parameters of asthma except numbers of goblet cells. Both doses of sulphasalazine improved thicknesses of basement membrane better than dexamethasone. Dexamethasone reduced the number of mast cells better than sulphasalazine (200 mg/kg). Further studies are needed to evaluate the efficacy of sulphasalazine in the treatment of asthma.

Intake of paracetamol and risk of asthma in adults

Intake of paracetamol has been associated with development of asthma. The aim of this study was to address a possible association between intake of paracetamol and risk of adult-onset asthma. Using a multidisciplinary postal questionnaire survey concerning health and lifestyle we prospectively studied 19,349 adult twins enrolled in the nationwide Danish Twin Registry. There was a higher prevalence of new-onset asthma in subjects who reported frequent intake of paracetamol at baseline compared with subjects without this determinant (12.0% vs. 4.3%), OR = 3.03 (1.51-6.11), p = 0.005. The result remained significant after adjusting for sex, age, smoking, BMI, hay fever, eczema, and intake of medications other than paracetamol, OR = 2.16 (1.03-4.53), p = 0.041. Frequent intake of paracetamol is an independent risk factor for adult-onset asthma.

Randomised aspirin assignment and risk of adult-onset asthma in the Women's Health Study

BACKGROUND

Randomised data in men show a small but significant reduction in the risk of adult-onset asthma among those given aspirin. The results from an observational study in women suggest that frequent use of aspirin decreases the risk of adult-onset asthma, but randomised data in women are lacking. A study was undertaken to test the effect of 100 mg aspirin or placebo on alternate days on the risk of adult-onset asthma in the Women's Health Study.

METHODS

A randomised, double-blind, placebo-controlled clinical trial of aspirin and vitamin E was performed in apparently healthy women with no indication or contraindication to aspirin therapy and no history of asthma at study entry. Female health professionals self-reported an asthma diagnosis on yearly questionnaires.

RESULTS

Among 37 270 women with no reported history of asthma prior to randomisation and during 10 years of follow-up, there were 872 new cases diagnosed with asthma in the aspirin group and 963 in the placebo group (hazard ratio 0.90; 95% CI 0.82 to 0.99; p = 0.027). This apparent 10% lower relative risk of incident adult-onset asthma among those assigned to aspirin was significantly modified by body mass index, with no effect in women with a body mass index of >/=30 kg/m2. The effect of aspirin on adult-onset asthma was not significantly modified by age, smoking status, exercise levels, postmenopausal hormone use or randomised vitamin E assignment.

CONCLUSIONS

In this large randomised clinical trial of apparently healthy adult women, administration of 100 mg aspirin on alternate days reduced the relative risk of a newly reported diagnosis of asthma.

Effect of aspirin on airway inflammation and pulmonary function in patients with persistent asthma

BACKGROUND

Aspirin can cause bronchoconstriction in some asthmatic patients through increased production of proinflammatory mediators, particularly leukotrienes. However, recent in vivo evidence has suggested that aspirin also triggers the production of lipoxins, which act as natural antagonists of prostaglandins and leukotrienes. Aside from patients with known aspirin-sensitive asthma, physicians have avoided the use of aspirin in asthmatic patients in general because it was believed that this agent might precipitate worsening of their condition.

OBJECTIVE

We sought to establish the effect of aspirin on pulmonary inflammation and function in patients with persistent asthma.

METHODS

After withdrawal of their usual anti-inflammatory medication, patients with mild-to-moderate persistent asthma undertook double-blind, randomized, crossover treatment with 75 mg/d aspirin and placebo for 3 weeks each. Treatment evaluation included histamine challenge, spirometry, impulse oscillometry, total and alveolar exhaled nitric oxide measurement, and serum thromboxane B2 and 15-epilipoxin A4 levels.

RESULTS

Fifteen patients completed the trial. Compared with placebo, there were no differences in histamine PC(20) values (0.17 doubling-dilution shift; 95% CI, -0.38 to 0.73; P = 1), exhaled nitric oxide levels (0.95-fold change; 95% CI, 0.45-2.00; P = 1), or any other inflammatory, spirometric, or oscillometry measurements. Aspirin led to a significant decrease in thromboxane B2 levels (17.53-fold difference; 95% CI, 5.46-56.49; P < .001). Baseline 15-epilipoxin A4 levels were increased at 4.88 ng/mL, and there was no increase with aspirin versus placebo (0.99-fold difference; 95% CI, 0.79-1.24; P = 1).

CONCLUSION

In this preliminary study of 15 patients, low-dose aspirin did not lead to increased 15-epilipoxin A4 synthesis or alter inflammatory markers in patients with mild-to-moderate persistent asthma.

Endogenous lipid mediators in the resolution of airway inflammation

Acute inflammation in the lung is fundamentally important to host defence, but chronic or excessive inflammation leads to several common respiratory diseases, including asthma and acute respiratory distress syndrome. The resolution of inflammation is an active process. In health, events at the onset of acute inflammation establish biosynthetic circuits for specific chemical mediators that later serve as agonists to orchestrate a return to tissue homeostasis. In addition to an overabundance of pro-inflammatory stimuli, pathological inflammation can also result from defects in resolution signalling. The understanding of anti-inflammatory, pro-resolution molecules and their counter-regulatory signalling pathways is providing new insights into the molecular pathophysiology of lung disease and opportunities for the design of therapeutic strategies. In the present review, the growing family of lipid mediators of resolution is examined, including lipoxins, resolvins, protectins, cyclopentenones and presqualene diphosphate. Roles are uncovered for these compounds, or their structural analogues, in regulating airway inflammation.

Tetranor PGDM, an abundant urinary metabolite reflects biosynthesis of prostaglandin D2 in mice and humans

Prostaglandin D(2) (PGD(2)) is a cyclooxygenase (COX) product of arachidonic acid that activates D prostanoid receptors to modulate vascular, platelet, and leukocyte function in vitro. However, little is known about its enzymatic origin or its formation in vivo in cardiovascular or inflammatory disease. 11,15-dioxo-9alpha-hydroxy-2,3,4,5-tetranorprostan-1,20-dioic acid (tetranor PGDM) was identified by mass spectrometry as a metabolite of infused PGD(2) that is detectable in mouse and human urine. Using liquid chromatography-tandem mass spectrometry, tetranor PGDM was much more abundant than the PGD(2) metabolites, 11beta-PGF(2alpha) and 2,3-dinor-11beta-PGF(2alpha), in human urine and was the only endogenous metabolite detectable in mouse urine. Infusion of PGD(2) dose dependently increased urinary tetranor PGDM > 2,3-dinor-11beta-PGF(2alpha) > 11beta-PGF(2alpha) in mice. Deletion of either lipocalin-type or hemopoietic PGD synthase enzymes decreased urinary tetranor PGDM. Deletion or knockdown of COX-1, but not deletion of COX-2, decreased urinary tetranor PGDM in mice. Correspondingly, both PGDM and 2,3-dinor-11beta-PGF(2alpha) were suppressed by inhibition of COX-1 and COX-2, but not by selective inhibition of COX-2 in humans. PGD(2) has been implicated in both the development and resolution of inflammation. Administration of bacterial lipopolysaccharide coordinately elevated tetranor PGDM and 2,3-dinor-11beta-PGF(2alpha) in volunteers, coincident with a pyrexial and systemic inflammatory response, but both metabolites fell during the resolution phase. Niacin increased tetranor PGDM and 2,3-dinor-11beta-PGF(2alpha) in humans coincident with facial flushing. Tetranor PGDM is an abundant metabolite in urine that reflects modulated biosynthesis of PGD(2) in humans and mice.

Aspirin and decreased adult-onset asthma: randomized comparisons from the physicians' health study

RATIONALE

In an observational cohort study, women who self-selected for frequent aspirin use developed less newly diagnosed asthma than women who did not take aspirin.

OBJECTIVE

To explore whether low-dose aspirin decreased the risk of newly diagnosed asthma in a randomized, double-blind, placebo-controlled trial.

METHODS

The Physicians' Health Study randomized 22,071 apparently healthy male physicians, aged 40-84 yr at baseline and tolerant of aspirin, over an 18-wk run-in period, to 325 mg aspirin or placebo on alternate days. The aspirin component was terminated after 4.9 yr due principally to the emergence of a statistically extreme 44% reduction in risk of first myocardial infarction among those randomly assigned to aspirin.

MEASUREMENTS

Physicians could self-report an asthma diagnosis on questionnaires at baseline, 6 mo, and annually thereafter. Asthma was not an a priori endpoint of the trial.

RESULTS

Among 22,040 physicians without reported asthma at randomization, there were 113 new asthma diagnoses in the aspirin group and 145 in the placebo group. The hazard ratio was 0.78 (95% confidence interval, 0.61-1.00; p = 0.045). This apparent 22% lower risk of newly diagnosed asthma among those assigned to aspirin was not modified by baseline characteristics including smoking, body mass index, or age.

CONCLUSIONS

Aspirin reduced the risk of newly diagnosed adult-onset asthma in a large, randomized clinical trial of apparently healthy, aspirin-tolerant men. This result requires replication in randomized trials designed a priori to test this hypothesis; it does not imply that aspirin improves symptoms in patients with asthma.