Obesity and asthma: current knowledge and future needs

Asthma and Hyperglycemia: Exploring the Interconnected Pathways

The interplay between asthma and glucose metabolism disorders, such as hyperglycemia, has gained increasing attention due to the potential exacerbation of asthma symptoms and severity. This review explores the complex relationship between hyperglycemia and asthma, emphasizing the pathophysiological links, the impact of glucose metabolism disorders on asthma, and the effects of asthma medications on glucose levels. Hyperglycemia, often induced by asthma treatments like corticosteroids, has been associated with an increased risk of asthma exacerbations. This review delves into the pathophysiology underlying this association, highlighting the role of insulin resistance, metabolic syndrome, and obesity in both the development and management of asthma. Metabolic syndrome, characterized by abdominal obesity and hyperglycemia, independently increases the risk of worsening respiratory symptoms and asthma. Furthermore, this review examines the influence of various antidiabetic medications on asthma outcomes. Biguanides, like metformin, have shown promise in improving asthma outcomes in patients with type 2 diabetes mellitus and asthma. However, other medications have mixed results regarding their impact on asthma control and lung function. Considering these findings, this review advocates for further research into the role of metabolic pathways in asthma management. It calls for comparative studies and the inclusion of asthma-related outcomes in clinical trials of antidiabetic drugs to better understand their potential benefits for individuals with obesity and concurrent asthma.

Pre-asthma: a useful concept for prevention and disease-modification? A EUFOREA paper. Part 1-allergic asthma

Asthma, which affects some 300 million people worldwide and caused 455,000 deaths in 2019, is a significant burden to suffers and to society. It is the most common chronic disease in children and represents one of the major causes for years lived with disability. Significant efforts are made by organizations such as WHO in improving the diagnosis, treatment and monitoring of asthma. However asthma prevention has been less studied. Currently there is a concept of pre- diabetes which allows a reduction in full blown diabetes if diet and exercise are undertaken. Similar predictive states are found in Alzheimer's and Parkinson's diseases. In this paper we explore the possibilities for asthma prevention, both at population level and also investigate the possibility of defining a state of pre-asthma, in which intensive treatment could reduce progression to asthma. Since asthma is a heterogeneous condition, this paper is concerned with allergic asthma. A subsequent one will deal with late onset eosinophilic asthma.

Obesity and Insulin Resistance in Asthma Pathogenesis and Clinical Outcomes

Common inflammatory ground links obesity, insulin resistance, and asthma. As recognition of their interplay, one worsening the natural course of the other, is recognised, questions remain about how to adequately address them altogether to improve clinical outcomes. The present manuscript sheds light on the problem, describing possible pathophysiological links, clinical views, and therapeutic challenges, raising questions about what remains to be done, and calling for multidisciplinary treatment of these patients to detect diseases early and adequately address them before they become full-blown and deteriorate their health and quality of life.

Predicting the risk of acute respiratory failure among asthma patients-the A2-BEST2 risk score: a retrospective study

Objectives

Acute respiratory failure (ARF) is a common complication of bronchial asthma (BA). ARF onset increases the risk of patient death. This study aims to develop a predictive model for ARF in BA patients during hospitalization.

Methods

This was a retrospective cohort study carried out at two large tertiary hospitals. Three models were developed using three different ways: (1) the statistics-driven model, (2) the clinical knowledge-driven model, and (3) the decision tree model. The simplest and most efficient model was obtained by comparing their predictive power, stability, and practicability.

Results

This study included 398 patients, with 298 constituting the modeling group and 100 constituting the validation group. Models A, B, and C yielded seven, seven, and eleven predictors, respectively. Finally, we chose the clinical knowledge-driven model, whose C-statistics and Brier scores were 0.862 (0.820-0.904) and 0.1320, respectively. The Hosmer-Lemeshow test revealed that this model had good calibration. The clinical knowledge-driven model demonstrated satisfactory C-statistics during external and internal validation, with values of 0.890 (0.815-0.965) and 0.854 (0.820-0.900), respectively. A risk score for ARF incidence was created: The A2-BEST2 Risk Score (A2 (area of pulmonary infection, albumin), BMI, Economic condition, Smoking, and T2(hormone initiation Time and long-term regular medication Treatment)). ARF incidence increased gradually from 1.37% (The A2-BEST2 Risk Score ≤ 4) to 90.32% (A2-BEST2 Risk Score ≥ 11.5).

Conclusion

We constructed a predictive model of seven predictors to predict ARF in BA patients. This predictor's model is simple, practical, and supported by existing clinical knowledge.

Effect of bariatric surgery on lung function and asthma control after 8 years of follow-up

Background: Bariatric surgery has a proven beneficial effect on asthma symptoms and lung function in patients with class III obesity and asthma. The effects of bariatric surgery on asthma control and small airway function persist for at least 12 months after bariatric surgery. However, long-term follow-up data are lacking. Objectives: To evaluate the very-long term effects of bariatric surgery on asthma symptoms and lung function. Methods: In a prospective, longitudinal follow-up study, we planned an 8-year follow-up visit for patients previously included in the OBAS 1.0 trial, which evaluated the effects of bariatric surgery on asthma control and lung function in patients with asthma and class III obesity in The Netherlands. Results: Fifteen of 78 patients from the OBAS trial completed the 8-year follow-up visit. Nine patients underwent bariatric surgery, and six patients did not. After 8 years of follow-up, asthma control (Asthma Control Questionnaire [ACQ] score at 12 months of 0,4 versus an ACQ score of 0.7 at 8 years of follow-up; p = 0.075) and small airway function (R₅-R₂₀ (frequency-dependent resistance at 5Hz-20Hz); score at 12 months of 0,25 versus an ACQ score of 0.07 at 8 years of follow-up; p = 0.345) remained clinically stable compared with 12 months of follow-up. Patients who underwent bariatric surgery had a statistically significant weight regain between 12 months of follow-up and 8 years of follow-up (median [interquartile range] body mass index 30.2 kg/m² [23.9-43.4 kg/m²] versus 32.3 kg/m² [24.0-36.4 kg/m²]; p = 0.025). However, the impact of weight regain on asthma control, and asthma quality of life was clinically insignificant (ACQ, β (regression coefficient) = 0.04; 95% Confidence Interval [0.02; 0.06]; p < 0.001; and AQLQ; β = -0.04 CI [-0.07; -0.009]; p = 0.013). Conclusion: These results emphasize the importance of bariatric surgery in treating obesity-related asthma.

Indoor bacterial, fungal and viral species and functional genes in urban and rural schools in Shanxi Province, China-association with asthma, rhinitis and rhinoconjunctivitis in high school students

BACKGROUND

Studies in developed countries have reported that the prevalence of asthma and rhinitis is higher in urban areas than in rural areas, and this phenomenon is associated with urbanization and changing indoor microbiome exposure. Developing countries such as China have experienced rapid urbanization in past years, but no study has investigated microbiome exposure and urban-rural health effects in these countries.

METHODS

Nine high schools from urban and rural areas were randomly selected in Shanxi Province, China, and classroom vacuum dust was collected for shotgun metagenomic sequencing. A self-administered questionnaire was collected from 1332 students for personal information and health data. Three-level logistic regression was performed between microbial richness/abundance/functional pathways and the occurrence of asthma and rhinitis symptoms.

RESULTS

Consistent with developed countries, the prevalence of wheeze and rhinitis was higher in urban areas than in rural areas (p < 0.05). Metagenomic profiling revealed 8302 bacterial, 395 archaeal, 744 fungal, 524 protist and 1103 viral species in classroom dust. Actinobacteria (mean relative abundance 49.7%), Gammaproteobacteria (18.4%) and Alphaproteobacteria (10.0%) were the most abundant bacterial classes. The overall microbiome composition was significantly different between urban and rural schools (p = 0.001, Adonis). Species from Betaproteobactera, Gammaproteobacteria and Bacilli were enriched in urban schools, and species from Actinobacteria and Cyanobacteria were enriched in rural schools. Potential pathogens were present in higher abundance in urban schools than in rural schools (p < 0.05). Pseudoalteromonas, Neospora caninum and Microbacterium foliorum were positively associated with the occurrence of wheeze, rhinitis and rhinoconjunctivitis, and Brachybacterium was protectively (negatively) associated with rhinitis (p < 0.01). The abundance of human endocrine and metabolic disease pathways was positively associated with rhinitis (p = 0.008), and butyrate and propionate metabolic genes and pathways were significantly enriched in rural schools (p < 0.005), in line with previous findings that these short-chain fatty acids protect against inflammatory diseases in the human gut.

CONCLUSIONS

We conducted the first indoor microbiome survey in urban/rural environments with shotgun metagenomics, and the results revealed high-resolution microbial taxonomic and functional profiling and potential health effects. Video abstract.

ILC in chronic inflammation, cancer and targeting with biologicals

Since their discovery, Innate Lymphoid Cells (ILC) have emerged as important effector cells, serving multiple roles in maintaining tissue homeostasis and responding to tissue insults. As such, dysregulations of their function and distribution have been observed in a variety of immune-mediated diseases, suggesting a specific role for ILC in the pathophysiology of several disorders including chronic inflammation and cancer. Here, we provide an updated view on ILC biology dissecting their pathological or protective contribution in chronic inflammatory diseases such as multiple sclerosis, inflammatory bowel diseases, psoriasis, rheumatoid arthritis, asthma and COPD, atherosclerosis, also exploring ILC role in tumor surveillance and progression. Throughout the review, we will also highlight how the potential dual role of these cells for protective or pathogenic immunity in many inflammatory diseases makes them interesting targets for the development of novel therapeutic strategies, particularly promising.

Psychological distress and substance use among young adults with comorbid asthma and obesity

This study examined psychosocial distress and substance use in young adults with asthma (A), obesity (O), comorbid asthma and obesity (AO), or neither (controls). Participants: Eight hundred eighty-one young adults were included in the A, O, AO, or control group. Methods: ANCOVA and logistic regression analyses were performed to compare responses to screeners for psychological distress and substance use among the four groups. Results: Levels of depressive symptoms, worry, nonsuicidal self-injury, emotion dysregulation, and chronic pain symptoms differed across groups, with the A and AO groups showing greater psychological distress than the O and control groups. The AO group exhibited the highest levels of cigarette and smokeless tobacco use, while the O group exhibited the least frequent binge drinking behaviors. Conclusions: Individuals with asthma or comorbid asthma and obesity appear to experience the poorest psychosocial functioning and highest use of tobacco products. Potential mechanisms and implications of these relationships are discussed.

Associations between overweight and obesity and asthma outcomes in urban adolescents

Objective: To examine the prevalence of overweight and obesity in urban adolescents with asthma and to investigate the relationships between anthropometric measures and asthma outcomes including quality of life, asthma control and lung function.Methods: Adolescents with an asthma diagnosis, 12-20 years-old, were recruited from three urban communities in the United States. Spirometry and anthropometric data including height, weight and waist circumferences were collected along with questionnaire data measuring quality of life, asthma control, and medication adherence. Body mass index (BMI) and waist-height ratio (WHtR) were computed.Results: The sample (N = 294) included 48% female and 80% African American. About 50% of the sample were either overweight or obese, and 41% had central obesity. No significant gender interactions with either BMI or WHtR on asthma outcomes were found. Neither BMI nor WHtR predicted quality of life, asthma control or medication adherence, while females had poorer quality of life and asthma control regardless of weight status (p < 0.001). Higher BMI or WHtR predicted higher spirometry values. Regardless of weight status, females had greater percent predicted spirometry values, while raw values (L) were significantly greater in males.Conclusions: High BMI is a common comorbidity among poor, primarily African American, urban adolescents with asthma. The negative impact of being overweight or obese on quality of life or asthma control is yet to be manifested in adolescents. The findings underscore adolescence as an ideal period to safely intervene to reduce excessive body weight, which can prevent the potentially harmful effects of obesity on future asthma outcomes.

Metabolic Dysfunction and Asthma: Current Perspectives

The increasing knowledge of the mechanisms involved in metabolism is shifting the paradigms by which the pathophysiology of many pulmonary diseases is understood. Metabolic dysfunction is recognized in obesity-associated asthma, but other metabolic conditions have been shown to be independently related to asthma. Novel insights have also recently been brought by metabolomics in this filed. The purpose of this review is to discuss current perspectives regarding metabolic dysfunction in asthma, from obesity-related asthma to other metabolic conditions and the role of current pharmacological therapeutic strategies and lifestyle interventions. Obesity is a well-recognized risk factor for asthma across the lifespan, which is generally associated with poorer response to current available treatments, rendering a more severe, refractory disease status. Besides the epidemiological and clinical link, untargeted metabolomics studies have recently supported the obesity-associated asthma phenotype at the molecular level. Not only obesity-related, but also other aspects of metabolic dysregulation can be independently linked to asthma. These include hyperinsulinemia, dyslipidemia and hypertension, which need to be taken into account, even in the non-obese patient. Untargeted metabolomics studies have further highlighted several other metabolic pathways that can be altered in asthma, namely regarding oxidative stress and systemic inflammation, and also suggesting the importance of microbiota in asthma pathogenesis. Considering the reduced response to corticosteroids, other pharmacologic treatments have been shown to be effective regardless of body mass index. Non-pharmacologic treatments (namely weight reduction and dietary changes) may bring substantial benefit to the asthmatic patient. Taken together, this evidence points towards the need to improve our knowledge in this filed and, in particular, to address the influence of environmental factors in metabolic dysfunction and asthma development. Personalized medicine is definitely needed to optimize treatment, including a holistic view of the asthmatic patient in order to set accurate pharmacologic therapy together with dietary, physical exercise and lifestyle interventions.

Development of self-assessed work ability among middle-aged asthma patients-a 10 year follow-up study

OBJECTIVE

The prevalence of asthma has been growing among working age people over the last decades. In this study, we examine the development of Work Ability Score (WAS) among middle-aged asthmatics in a longitudinal setting, in order to find risk factors for poor development.

METHODS

We followed the development of WAS trends during 10 years in a cohort of 529 middle-aged asthmatics, who were active in working life. Follow-up questionnaires were mailed in years 1, 2, 4, 6, 8, and 10. To study the development of WAS over time, we computed the discrete Frechet distance, which describes the similarity between the shapes of WAS curves.

RESULTS

Sixty-eight percent of the patients' WAS remained good or excellent throughout the follow-up period, while 24% of the patients WAS trend remained moderate. However, in 8%, the WAS was poor already in baseline and decreased further throughout the study. Using logistic regression, the moderate/poor development was associated significantly with high body mass index (BMI), pack years, adult onset asthma, physically strenuous work, number of co-morbidities, especially in psychiatric conditions, hypertension, and gastroesophageal reflux disease(GERD). When the model was adjusted for age and gender, adulthood onset of asthma and pack years lost their significance. Based on medication (high dose of inhaled corticosteroids (ICS) and second controller in use), 8% of the patients had severe asthma.

CONCLUSION

In the great majority of middle-aged asthma patients WAS remained stable throughout the follow-up period. However, 8% of the patients, who had more severe asthma and multiple co-morbidities, showed significantly poorer outcomes.

Insomnia symptoms and asthma control-Interrelations and importance of comorbidities

BACKGROUND

Insomnia symptoms are common with asthma. The aim of the study was to analyse the associations between insomnia symptoms and asthma control, asthma severity, and asthma-related comorbidity in a community-based population.

METHODS

Adults (n = 23 875, ages 18-45) from the community-based LifeGene study answered a questionnaire on insomnia symptoms, airway symptoms, asthma diagnosis, asthma medication, and asthma-related comorbidities (chronic rhinosinusitis, gastro-oesophageal reflux, anxiety, depression, or obesity).

RESULTS

Of the participants, 1272 (5.3%) had asthma. The prevalence of any insomnia symptom was higher in participants with uncontrolled asthma (n = 201) than with controlled or partially controlled asthma (32.2% vs 19.9% and 20.1%, respectively, P < .01). There was no significant difference in the prevalence of insomnia symptoms between subjects with controlled asthma and subjects without asthma. Subjects with asthma and any asthma-related comorbidity reported more insomnia symptoms (29.0% vs 22.4%, P < .01) compared to asthmatics without comorbidity. Moreover, the prevalence was highest among subjects reporting both uncontrolled asthma and any asthma-related comorbidity (45.1%, P < .01). Uncontrolled asthma remained significantly associated with insomnia symptoms (OR 1.72 (1.15-2.56)) after adjusting for age, sex, BMI, smoking history, comorbidities, physical activity, and educational level, while medication level was not. Among asthma-related comorbidities, chronic rhinosinusitis (OR 1.62 (1.20-2.19)), obesity (1.87 (1.07-3.25)), and depression (OR 1.85 (1.34-2.55)) were independently associated with insomnia symptoms.

CONCLUSION

Uncontrolled asthma was significantly associated with insomnia symptoms, while controlled or partially controlled asthma was not. Asthma-related comorbidity is of great importance, and asthma control seems to be more important than asthma severity for insomnia symptoms.

Obesity and adiposity indicators in asthma and allergic rhinitis in children

PURPOSE OF REVIEW

The prevalence of obesity and allergic diseases, such as asthma and allergic rhinitis, is increasing worldwide not only in adults, but also in children. Experimental and clinical studies have demonstrated the effect of obesity not only on asthma, but also on other allergic diseases.

RECENT FINDINGS

Allergic diseases, such as asthma and allergic rhinitis, are common chronic inflammatory diseases of the airways. Obesity is an increasingly common pediatric disease and is a risk factor for the development of asthma in that obese patients with asthma tend to have more severe asthma that does not respond well to standard asthma therapy. On the contrary, children with asthma maybe at a high risk of obesity, suggesting that the relationship of asthma and obesity seems to be interrelated. The role of obesity on the development of allergic rhinitis is not well defined, whereas allergic rhinitis may have an impact on obesity.

SUMMARY

Childhood obesity is often considered to be less serious than obesity in adults because of the greater risk of complications in obese adults. In this review, we discuss the allergic confounders of obesity and the impact of allergic diseases on obesity. Proper control of the BMI within the normal range in children with allergic diseases is important.

Serum levels of IL-5, IL-6, IL-8, IL-13 and IL-17A in pre-defined groups of adult patients with moderate and severe bronchial asthma

BACKGROUND

Bronchial asthma (BA) is a complex disease characterised by persistent inflammation. Exhaled nitric oxide (FeNO) and blood eosinophil count (b-Eos) are biomarkers for type 2 endotype of BA.

OBJECTIVE

To analyse a panel of serum interleukins and total IgE in predefined by FeNO and b-Eos groups of moderate and severe BA patients.

METHODS

Serum levels of IL-5, IL-6, IL-8, IL-13 and IL-17A (ELISA) were measured in 30 healthy controls (HC) and 80 adult BA patients. BA patients were split into 4 groups. Group 1:Low FeNO/Low b-Eos (n = 23; 28.8%); Group 2:Low FeNO/High b-Eos (n = 17; 21.3%); Group 3:High FeNO/Low b-Eos (n = 15; 18.8%); Group 4:High FeNO/High b-Eos (n = 25; 31.3%).

RESULTS

All interleukins and total IgE were significantly higher in patients with BA as compared with HC. IL-5 levels were highest in Group 2 (p < 0.05). IL-6, IL-13 and IL-17A levels were elevated in Groups 2, 3 and 4 as compared with HC (p < 0.05). Higher IL-8 levels were associated with a pattern of current smokers. Highest IL-17A levels were found in type 2 high groups with frequent exacerbations, mostly uncontrolled and severe BA. We have found a distinct pattern for each group based on demographic, clinical, functional, immunological and inflammatory characteristics.

CONCLUSION

FeNO and b-Eos are useful in the identification of severe type 2 BA subgroups with frequent exacerbations. IL-5, IL-6, IL-13 and IL-17A are involved in the persistent type 2 immune response in moderate and severe BA. We have identified a pattern of refractory, severe type 2/IL-17A high BA in the real clinical practice.

Elucidation of causal direction between asthma and obesity: a bi-directional Mendelian randomization study

BACKGROUND

Observational associations between asthma and obesity are well established, but inferring causality is challenging. We leveraged publicly available summary statistics to ascertain the causal direction between asthma and obesity via Mendelian randomization in European-ancestry adults.

METHODS

We performed two-sample bi-directional Mendelian randomization analysis using publicly available genome-wide association studies summary statistics. Single nucleotide polymorphisms associated with asthma and body mass index at genome-wide significance were combined using a fixed effect meta-analysis in each direction. An extensive sensitivity analysis was considered.

RESULTS

There was evidence in support of increasing causal effect of body mass index on risk of asthma (odds ratio 1.18 per unit increase, 95% confidence interval (CI) (1.11, 1.25), P = 2 × 10-8. No significant causal effect of asthma on adult body mass index was observed [estimate -0.004, 95% CI (-0.018, 0.009), P = 0.553].

CONCLUSIONS

Our results confirmed that in European-ancestry populations, adult body mass index is likely to be causally linked to the risk of asthma; yet the effect of asthma on body mass index is small, if present at all.

Asthma alleviates obesity in males through regulating metabolism and energy expenditure

Many epidemiological studies suggested a correlation between obesity and asthma. However, little is known about the molecular details explaining this correlation. Here, we show that asthma decreased body weight of asthmatic male mice fed with high fat diet via increasing energy expenditure and insulin sensitivity. The increase of energy expenditure was mainly due to upregulation of pAMPK and Sirt1. The activation of AMPK/Sirt1/PGC1α signaling promoted the expression of the thermogenic genes like ucp1, PRDM16, cidea, Elovl3, PPARα, which occurred in brown adipocyte tissue and subcutaneous white adipose tissue. Besides, by activating IL33/ILC2/AAMac pathway in subcutaneous white adipose tissue, asthma promoted subcutaneous white adipose tissue into beige fat. In addition, insulin sensitivity was improved in the asthmatic male mice by decreasing the expression of G6Pase in the liver, which was recapitulated in HepG2. In human, we found that Body Mass Index (BMI) and waist circumference were significantly lower in males suffering asthma compared with the control in the National Health and Nutrition Examination Survey (NHANES) cohort. These data together suggest asthma in males decreases obesity by improving the metabolism function of brown and subcutaneous adipose tissue, and decreasing insulin resistant in the liver.

Emerging roles of innate lymphoid cells in inflammatory diseases: Clinical implications

Innate lymphoid cells (ILC) represent a group of lymphocytes that lack specific antigen receptors and are relatively rare as compared to adaptive lymphocytes. ILCs play important roles in allergic and nonallergic inflammatory diseases due to their location at barrier surfaces within the airways, gut, and skin, and they respond to cytokines produced by activated cells in their local environment. Innate lymphoid cells contribute to the immune response by the release of cytokines and other mediators, forming a link between innate and adaptive immunity. In recent years, these cells have been extensively characterized and their role in animal models of disease has been investigated. Data to translate the relevance of ILCs in human pathology, and the potential role of ILCs in diagnosis, as biomarkers and/or as future treatment targets are also emerging. This review, produced by a task force of the Immunology Section of the European Academy of Allergy and Clinical Immunology (EAACI), encompassing clinicians and researchers, highlights the role of ILCs in human allergic and nonallergic diseases in the airways, gastrointestinal tract, and skin, with a focus on new insights into clinical implications, therapeutic options, and future research opportunities.

Allergic airway inflammation: key players beyond the Th2 cell pathway

Allergic asthma is characterized by eosinophilic airway inflammation, mucus hyperproduction, and airway hyperreactivity, causing reversible airway obstruction. Accumulating evidence indicates that antigen-specific Th2 cells and their cytokines such as IL-4, IL-5, and IL-13 orchestrate these pathognomonic features of asthma. However, over the past decade, the understanding of asthma pathogenesis has made a significant shift from a Th2 cell-dependent, IgE-mediated disease to a more complicated heterogeneous disease. Recent studies clearly show that not only Th2 cytokines but also other T cell-related cytokines such as IL-17A and IL-22 as well as epithelial cell cytokines such as IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) are involved in the pathogenesis of asthma. In this review, we focus on the roles of these players beyond Th2 pathways in the pathogenesis of asthma.

Pediatric severe asthma: a case series report and perspectives on anti-IgE treatment

Background

The primary goal of asthma management is to achieve disease control for reducing the risk of future exacerbations and progressive loss of lung function. Asthma not responding to treatment may result in significant morbidity. In many children with uncontrolled symptoms, the diagnosis of asthma may be wrong or adherence to treatment may be poor. It is then crucial to distinguish these cases from the truly “severe therapy-resistant” asthmatics by a proper filtering process. Herein we report on four cases diagnosed as difficult asthma, detail the workup that resulted in the ultimate diagnosis, and provide the process that led to the prescription of omalizumab.

Case presentation

All children had been initially referred because of asthma not responding to long-term treatment with high-dose inhaled steroids, long-acting β₂-agonists and leukotriene receptor antagonists. Definitive diagnosis was severe asthma. Three out four patients were treated with omalizumab, which improved asthma control and patients’ quality of life. We reviewed the current literature on the diagnostic approach to the disease and on the comorbidities associated with difficult asthma and presented the perspectives on omalizumab treatment in children and adolescents. Based on the evidence from the literature review, we also proposed an algorithm for the diagnosis of pediatric difficult-to-treat and severe asthma.

Conclusions

The management of asthma is becoming much more patient-specific, as more and more is learned about the biology behind the development and progression of asthma. The addition of omalizumab, the first targeted biological treatment approved for asthma, has led to renewed optimism in the management of children and adolescents with atopic severe asthma.

Pulmonary function, exhaled nitric oxide and symptoms in asthma patients with obesity: a cross-sectional study

Background

Obesity is a risk factor for the development of asthma. In patients with obesity the diagnosis of asthma is often based on symptoms, but without objective measurements. Nevertheless, obesity-associated asthma is recognized as a distinct asthma phenotype. Therefore, this study explores lung function and symptoms in asthma patients with and without obesity.

Methods

The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort study with 6671 participants (aged 45–65 years) of whom 472 had asthma. Of this latter group, linear regression analysis was used to examine differences in lung function and symptoms between asthma patients with (n = 248) and without obesity (n = 224), and between asthma patients with and without increased Fe_NO. Analyses were adjusted for confounders.

Results

Asthma patients with obesity had lower predicted FEV₁ and FVC values than patients without obesity [adjusted mean difference (MD) -3.3% predicted, 95% CI -6.5, −0.2; adjusted MD −5.0% predicted, 95% CI -7.8, −2.1]. The prevalence of symptoms was higher in patients with obesity. Asthma patients with obesity and with increased Fe_NO had lower FEV₁ and FEV₁/FVC values compared with those with low Fe_NO (adjusted MD −6.9% predicted, 95% CI -11.7, −2.0; −2.4%, 95% CI -4.6, −0.2).

Conclusion

Asthma patients with obesity had lower FEV₁ and FVC values than patients without obesity. This suggests that patients with obesity have restrictive lung function changes, rather than obstructive changes. Asthma patients with obesity and increased Fe_NO showed more obstructive changes. Fe_NO might help to identify patients with eosinophilic inflammation-driven asthma, whereas patients with low Fe_NO might have an obesity-associated asthma phenotype in which symptoms are partly caused by the obesity.

Electronic supplementary material

The online version of this article (10.1186/s12931-017-0684-9) contains supplementary material, which is available to authorized users.

More than a decade follow-up in patients with severe or difficult-to-treat asthma: The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) II

BACKGROUND

The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR I) study demonstrated high morbidity in patients with severe or difficult-to-treat asthma despite standard-of-care treatment.

OBJECTIVE

We sought to determine the long-term natural history of disease and outcomes in patients in TENOR I after more than a decade.

METHODS

TENOR I was a multicenter observational study (2001-2004) of 4756 patients with severe or difficult-to-treat asthma. TENOR II was a follow-up study of TENOR I patients using a single cross-sectional visit in 2013/2014. Overall, the sites participating in TENOR II originally enrolled 1230 patients in TENOR I. Clinical and patient-reported outcomes were assessed, including very poorly controlled asthma based on National Heart, Lung, and Blood Institute guidelines.

RESULTS

A total of 341 (27.7%) patients were enrolled in TENOR II and were representative of the TENOR I cohort. The most frequent comorbidities were rhinitis (84.0%), sinusitis (47.8%), and gastroesophageal reflux disease (46.3%). Mean percent predicted prebronchodilator and postbronchodilator FEV₁ were 72.7% (SD, 21.4%) and 78.2% (SD, 20.7%), respectively. A total of 231 (72.9%) of 317 patients had positive test responses to 1 or more allergen-specific IgEs. The mean blood eosinophil count was 200/μL (SD, 144/μL). Eighty-eight (25.8%) patients experienced an asthma exacerbation in the prior 3 months requiring hospital attention, oral corticosteroids, or both. More than half (197/339 [58.1%]) had very poorly controlled asthma. Medication use suggested undertreatment.

CONCLUSION

TENOR II provides longitudinal data to characterize disease progression, heterogeneity, and severity in patients with severe or difficult-to-treat asthma. Findings show continued morbidity, including a high degree of comorbid conditions, allergic sensitization, exacerbations, and very poorly controlled asthma, including reduced lung function.

The role of airway hyperresponsiveness measured by methacholine challenge test in defining asthma severity in asthma-obesity syndrome

PURPOSE OF REVIEW

Asthma is a complex disease defined by chronic inflammation of the airways. In research and clinical practice measures used for diagnosis, an assessment of control and severity of asthma are varied and there exists no gold standard. To date, several studies have explored the link between obesity and asthma although the exact mechanism is not yet fully understood. A study undertaken by our research group in 2015, on the effects of weight loss on asthma severity in obese asthmatics, demonstrated that an improvement in airway hyperresponsiveness could be achieved after significant weight reduction with a weight loss program. The objective of this article is to review the current literature for the primary and secondary outcomes studied to estimate the effects of weight loss on asthma severity in adults with obesity and asthma.

RECENT FINDINGS

A review of the most recent research conducted since 2014 demonstrates that effects of weight loss on asthma severity in adults with obesity and asthma has not been the focus of majority of the studies. Apart from our study published in 2015, very few studies used airway hyperresponsiveness as the primary or secondary outcome measure. The literature reveals that significant weight loss does, however, lead to improvement in asthma severity and control in adults with obesity and asthma.

SUMMARY

The current literature suggests that improvement in lung function requires moderate to significant (5-10%) weight loss in adults with obesity and asthma. However, with a few exceptions, the majority of these studies were small and used variable and questionable asthma severity outcome measures. There is an urgent need for standardization of diagnosis of asthma, study inclusion criteria, and outcome measures to assess asthma severity in research setting. Long-term effects of weight loss interventions on asthma severity and control, in adults with obesity and asthma, also remain unanswered.

Addressing unmet needs in understanding asthma mechanisms: From the European Asthma Research and Innovation Partnership (EARIP) Work Package (WP)2 collaborators

Asthma is a heterogeneous, complex disease with clinical phenotypes that incorporate persistent symptoms and acute exacerbations. It affects many millions of Europeans throughout their education and working lives and puts a heavy cost on European productivity. There is a wide spectrum of disease severity and control. Therapeutic advances have been slow despite greater understanding of basic mechanisms and the lack of satisfactory preventative and disease modifying management for asthma constitutes a significant unmet clinical need. Preventing, treating and ultimately curing asthma requires co-ordinated research and innovation across Europe. The European Asthma Research and Innovation Partnership (EARIP) is an FP7-funded programme which has taken a co-ordinated and integrated approach to analysing the future of asthma research and development. This report aims to identify the mechanistic areas in which investment is required to bring about significant improvements in asthma outcomes.

Quality of Life and Health Outcomes in Overweight and Non-Overweight Children With Asthma

BACKGROUND

During the past two decades, the number of children and adolescents who are obese has more than doubled. Following this trend in childhood obesity, there has been an alarming increase in the number of children with asthma who are overweight.

OBJECTIVE

The aim of this study was to examine the differences in quality of life (QOL) and health outcomes of obese and overweight children with asthma compared with normal-weight children with asthma using a descriptive comparative survey design.

METHODS

This comparative study consisted of 90 overweight and normal-weight 9- to 14-year-olds with asthma. Health outcomes examined included asthma-related missed number of school days, emergency department (ED) visits, hospitalizations, number of days wheezing, and number of night awakenings. QOL was measured using the Pediatric Asthma Quality of Life Questionnaire.

RESULTS

The obese group reported the highest percentage of ED visits, hospitalizations, and number of days wheezing compared with the normal-weight group. A risk ratio analysis showed that the obese group had an overall 2.73 (95% confidence interval [CI] 2.15, 3.63) times higher likelihood of going to the ED and a 2.46 (95% CI 1.97, 3.19) times higher likelihood of hospitalization than the overweight and normal-weight groups. Asthma severity was a significant predictor of overall QOL (β = -23.737, p = .002).

CONCLUSIONS

The study results are consistent with other investigations that demonstrate that obese persons are at higher risk of experiencing severe asthma symptoms and support obesity as a potentially modifiable risk factor for asthma mitigation and prevention.

Patient stratification and the unmet need in asthma

Asthma is often described as an inflammatory disease of the lungs and in most patients symptomatic treatment with bronchodilators or inhaled corticosteroids is sufficient to control disease. Unfortunately there are a proportion of patients who fail to achieve control despite treatment with the best current treatment. These severe asthma patients have been considered a homogeneous group of patients that represent the unmet therapeutic need in asthma. Many novel therapies have been tested in unselected asthma patients and the effects have often been disappointing, particularly for the highly specific monoclonal antibody-based drugs such as anti-IL-13 and anti-IL-5. More recently, it has become clear that asthma is a syndrome with many different disease drivers. Clinical trials of anti-IL-13 and anti-IL-5 have focused on biomarker-defined patient groups and these trials have driven the clinical progression of these drugs. Work on asthma phenotyping indicates that there is a group of asthma patients where T helper cell type 2 (Th2) cytokines and inflammation predominate and these type 2 high (T2-high) patients can be defined by biomarkers and response to therapies targeting this type of immunity, including anti-IL-5 and anti-IL-13. However, there is still a subset of T2-low patients that do not respond to these new therapies. This T2-low group will represent the new unmet medical need now that the T2-high-targeting therapies have made it to the market. This review will examine the current thinking on patient stratification in asthma and the identification of the T2-high subset. It will also look at the T2-low patients and examine what may be the drivers of disease in these patients.

Emerging Comorbidities in Adult Asthma: Risks, Clinical Associations, and Mechanisms

Asthma is a heterogeneous disease with many phenotypes, and age at disease onset is an important factor in separating the phenotypes. Most studies with asthma have been performed in patients being otherwise healthy. However, in real life, comorbid diseases are very common in adult patients. We review here the emerging comorbid conditions to asthma such as obesity, metabolic syndrome, diabetes mellitus type 2 (DM2), and cardiac and psychiatric diseases. Their role as risk factors for incident asthma and whether they affect clinical asthma are evaluated. Obesity, independently or as a part of metabolic syndrome, DM2, and depression are risk factors for incident asthma. In contrast, the effects of comorbidities on clinical asthma are less well-known and mostly studies are lacking. Cross-sectional studies in obese asthmatics suggest that they may have less well controlled asthma and worse lung function. However, no long-term clinical follow-up studies with these comorbidities and asthma were identified. These emerging comorbidities often occur in the same multimorbid adult patient and may have in common metabolic pathways and inflammatory or other alterations such as early life exposures, systemic inflammation, inflammasome, adipokines, hyperglycemia, hyperinsulinemia, lung mechanics, mitochondrial dysfunction, disturbed nitric oxide metabolism, and leukotrienes.

Diet-induced obesity alters myeloid cell populations in naïve and injured lung

BACKGROUND

There are pulmonary consequences to obesity, including increased prevalence of asthma, greater susceptibility to influenza, and possibly reduced susceptibility to lung injury. Although it is well established that obesity is associated with alterations to the immune system, little is known about obesity-associated changes to pulmonary immune cells.

OBJECTIVES

We hypothesized that obesity would alter the inflammatory milieu in the unchallenged lung and circulation; thereby contributing to altered susceptibility to lung injury.

METHODS

We used a murine model of diet-induced obesity and evaluated bone marrow and blood leukocytes at 3 months, and pulmonary leukocytes at 3 and 6 months for changes in their adhesion and chemokine receptors, markers of activation states, and cell numbers. We also evaluated the inflammatory response to LPS in obese mice.

RESULTS

In the lung, diet-induced obesity was associated with increased leukocyte numbers over-time. Adhesion receptors were increased in a cell- and site-specific fashion, and there was an evolution of macrophage and neutrophil polarization toward M1 and N1, respectively. After LPS-challenge, obesity was associated with increased neutrophil recruitment to the lung with impaired migration into the alveolar space. Associated with these changes, obesity increased LFA-1 and ICAM-1 neutrophil expression and altered CXCL1 gradients.

CONCLUSION

Our results highlight the effects of diet-induced obesity on the murine blood and lung leukocyte populations, including increases in adhesion receptor expression that may contribute to altered recruitment or retention within the lung. Translation of these findings to people with obesity will be critical for determining the basic inflammatory underpinnings of pulmonary disease susceptibility.

Asthma and obesity: is weight reduction the key to achieve asthma control?

PURPOSE OF REVIEW

Obesity has significant negative impact on asthma control and risk of exacerbations. The purpose of this review is to discuss recent studies evaluating the effects of weight reduction on asthma control in obese adults.

RECENT FINDINGS

Clinical studies have shown that weight reduction in obese patients is associated with improvements in symptoms, use of controller medication, and asthma-related quality of life together with a reduction in the risk for severe exacerbations. Furthermore, several studies have also revealed improvements in lung function and airway responsiveness, and more recently it has been shown that weight reduction following bariatric surgery has positive impact on small airway function, systemic inflammation and bronchial inflammation in this group of patients, which may explain the observed improvements in symptom control and lung function.

SUMMARY

Weight reduction in obese adults with asthma leads to an overall improvement in asthma control, including airway hyperresponsiveness and inflammation. Weight reduction should be a cornerstone in the management of obese patients with asthma.

Asthma symptoms in obese adults: The challenge of achieving asthma control

The association between asthma and obesity is well-described, but not straightforward, and according to current guidelines asthma control is more difficult to achieve in obese patients. The currently available studies evaluating response to pharmacological asthma therapy in obese patients show that these patients have an altered, in general less favorable, response to both reliever and controller medication compared to normal weight patients. However, at present, the limited available evidence precludes evidence-based recommendations. The 'obesity-related asthma' phenotype has different characteristics, including association with atopy and type of airway inflammation, compared to 'classic' asthma. Furthermore, weight loss in patients with this phenotype leads to an improvement in symptoms, lung function, and airway responsiveness, as well as a reduction in medication utilization and hospital admissions. Obese patients, who present with symptoms suggesting a diagnosis of asthma, may have a distinct phenotype or a disease mimicking asthma, likely to have a potentially higher remission rate. And by that, our approach to this group of patients should combine pharmacologic and non-pharmacologic therapies, including exercise, weight loss and dietary interventions, instead of primarily focusing on disease control by stepping up asthma therapy.