Effect of weight change on asthma-related health outcomes in patients with severe or difficult-to-treat asthma

Long-Term Weight Changes After Starting Anti-IL-5/5Ra Biologics in Severe Asthma: The Role of Oral Corticosteroids

BACKGROUND

Many patients with severe asthma are overweight or obese, often attributed to unintentional weight gain as a side effect of oral corticosteroids (OCSs). Anti-IL-5/5Ra biologics significantly reduce OCS use, but their long-term effects on weight are unknown.

OBJECTIVES

To examine (1) weight change up to 2 years after anti-IL-5/5Ra initiation in subgroups on the basis of maintenance OCS use at start of treatment and (2) whether cumulative OCS exposure before or changes in OCS exposure during treatment are related to weight change.

METHODS

Real-world data on weight and cumulative OCS dose from adults included in the Dutch Registry of Adult Patients with Severe asthma for Optimal DIsease management before and at least 2 years after starting anti-IL-5/5Ra were analyzed using linear mixed models and linear regression analyses.

RESULTS

For the included 389 patients (55% female; mean body mass index, 28 ± 5 kg/m2; 58% maintenance OCS), mean weight decreased -0.27 kg/y (95% CI, -0.51 to -0.03; P = .03), with more weight loss in patients with maintenance OCS use than in those without maintenance OCS use (-0.87 kg/y [95% CI, -1.21 to -0.52; P < .001] vs +0.54 kg/y [0.26 to 0.82; P < .001]). Greater weight loss at 2 years was associated with higher cumulative OCS dose in the 2 years before anti-IL-5/5Ra initiation (β = -0.24 kg/g; 95% CI, -0.38 to -0.10; P < .001) and, independently, greater reduction in cumulative OCS dose during follow-up (β = 0.27 kg/g; 95% CI, 0.11 to 0.43; P < .001).

CONCLUSIONS

Anti-IL-5/5Ra therapy is associated with long-term weight reduction, especially in patients with higher OCS exposure before treatment and those able to reduce OCS use during treatment. However, the effect is small and does not apply to all patients, and so additional interventions seem necessary if weight change is desired.

Acute Severe Asthma in Adolescent and Adult Patients: Current Perspectives on Assessment and Management

Asthma is a chronic airway inflammatory disease that is associated with variable expiratory flow, variable respiratory symptoms, and exacerbations which sometimes require hospitalization or may be fatal. It is not only patients with severe and poorly controlled asthma that are at risk for an acute severe exacerbation, but this has also been observed in patients with otherwise mild or moderate asthma. This review discusses current aspects on the pathogenesis and pathophysiology of acute severe asthma exacerbations and provides the current perspectives on the management of acute severe asthma attacks in the emergency department and the intensive care unit.

Susceptibility to exacerbations in Black adults with asthma

OBJECTIVE

Exacerbations account for much of the morbidity in asthma. In a large intervention study, we sought to test the hypothesis that a Black adult exacerbation-prone phenotype - a group of Black people with asthma who are at high risk of repeat exacerbation within one year - exists in asthma independent of clinical control.

METHODS

We analyzed exacerbation risk factors in 536 self-identified Black Americans with asthma eligible for, or on, Step 3 National Asthma Education and Prevention Program (NAEPP) therapy who participated in a randomized 6-18 month trial of tiotropium versus long acting beta agonist as add-on therapy to inhaled corticosteroids. Exacerbations were defined as events treated by oral or systemic corticosteroids. Clinical control was assessed by a validated asthma control questionnaire (ACQ5).

RESULTS

Exacerbations became more likely with loss of clinical control. The mean baseline ACQs for exacerbators and non-exacerbators were 2.41 and 1.91, respectively (p < 0.001). The strongest independent factor associated with exacerbations across all ACQ levels was an exacerbation in the preceding year (adjusted OR 3.26; p < 0.001). The severity of prior exacerbations did not correlate with the likelihood of a future exacerbation. Lower baseline FEV1/FVC was also associated with increased risk of exacerbations.

CONCLUSIONS

Even though exacerbations increase with loss of clinical control, an exacerbation susceptibility phenotype exists in Black adults with asthma, independent of clinical control. This phenotype requires precision therapeutic targeting.

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.

[Impact of obesity on response to therapy and pulmonary function in children with asthma]

OBJECTIVE

To investigate the effects of obesity on response to therapy and pulmonary function in children with asthma who receive inhaled corticosteroid (ICS) treatment.

METHODS

A total of 129 children with asthma were divided into two groups according to their body mass index: normal weight group (n=64) and obese group (n=65). The asthma control status and pulmonary function were compared between the two groups after one year of ICS treatment. The pulmonary function was expressed as percent forced expiratory volume in 1 second (FEV1%), percent predicted forced vital capacity (FVC%), peak expiratory flow (PEF), peak expiratory flow at 25% of vital capacity (PEF25), and peak expiratory flow at 50% of vital capacity (PEF50). The asthma control status was expressed as complete control rate, partial control rate, and uncontrolled rate. Sixty-eight healthy children were selected as the healthy control group.

RESULTS

There were significant differences in the indices of pulmonary function between the three groups before treatment (P<0.01); the healthy control group had the best values of pulmonary function, while the obese group had the worst values. After 1 year of treatment, the normal weight group showed significantly more improvements in FEV1% and FVC% than the obese group (P<0.01). However, there were no significant differences in improvements in PEF, PEF25, and PEF50 between the two groups. The complete control rate, partial control rate, and uncontrolled rate in the normal weight group were 72%, 19%, and 9%, respectively, while the rates in the obese group were 28%, 51%, and 22%, respectively; the normal weight group had a significantly better asthma control status than the obese group (P<0.01).

CONCLUSIONS

The asthmatic children with obesity have a significantly less improvement in large airway function and a poorer asthma control status after ICS treatment than those with the normal weight.

Asthma

Asthma is the most common inflammatory disease of the lungs. The prevalence of asthma is increasing in many parts of the world that have adopted aspects of the Western lifestyle, and the disease poses a substantial global health and economic burden. Asthma involves both the large-conducting and the small-conducting airways, and is characterized by a combination of inflammation and structural remodelling that might begin in utero. Disease progression occurs in the context of a developmental background in which the postnatal acquisition of asthma is strongly linked with allergic sensitization. Most asthma cases follow a variable course, involving viral-induced wheezing and allergen sensitization, that is associated with various underlying mechanisms (or endotypes) that can differ between individuals. Each set of endotypes, in turn, produces specific asthma characteristics that evolve across the lifecourse of the patient. Strong genetic and environmental drivers of asthma interconnect through novel epigenetic mechanisms that operate prenatally and throughout childhood. Asthma can spontaneously remit or begin de novo in adulthood, and the factors that lead to the emergence and regression of asthma, irrespective of age, are poorly understood. Nonetheless, there is mounting evidence that supports a primary role for structural changes in the airways with asthma acquisition, on which altered innate immune mechanisms and microbiota interactions are superimposed. On the basis of the identification of new causative pathways, the subphenotyping of asthma across the lifecourse of patients is paving the way for more-personalized and precise pathway-specific approaches for the prevention and treatment of asthma, creating the real possibility of total prevention and cure for this chronic inflammatory disease.

Airway Obstruction Worsens in Young Adults with Asthma Who Become Obese

BACKGROUND

Few studies have examined how developing obesity in early adulthood affects the course of asthma.

OBJECTIVE

We analyzed lung function and asthma impairment and risk among nonobese children with asthma, comparing those who were obese in young adulthood with those who remained nonobese.

METHODS

We carried out the post hoc analysis of 771 subjects with mild to moderate asthma who were not obese (pediatric definition, body mass index [BMI] < 95th percentile) when enrolled in the Childhood Asthma Management Program at ages 5-12 years. The subjects were then followed to age 20 years or more. For visits at ages 20 years or more, spirometry values as percent predicted and recent asthma symptom scores and prednisone exposure were compared between 579 subjects who were nonobese at all visits and 151 who were obese (adult definition of BMI ≥ 30 kg/m(2)) on at least 1 visit (median number of visits when obese = 4, IQR 2-7).

RESULTS

Compared with participants who were nonobese (BMI 23.4 ± 2.6 kg/m(2)), those who became obese (BMI 31.5 ± 3.8 kg/m(2)) had significant decreases in forced expiratory volume in the first second (FEV1)/forced vital capacity (FVC) (P < .0003) and FEV1 (P = .001), without differences in FVC (P = .15) during visits at ages 20 years or more. For each unit increase of BMI, FEV1 percent predicted decreased by 0.29 (P = .0009). The relationship between BMI and lung function was not confounded by sex or BMI at baseline. Asthma impairment (symptom scores) and risk (prednisone use) did not differ between the 2 groups.

CONCLUSION

Becoming obese in early adulthood was associated with increased airway obstruction, without impact on asthma impairment or risk.

Role of weight management in asthma symptoms and control

Obesity and asthma have increasingly been linked with an increased risk of developing asthma associated with increasing body mass index. Overweight/obese patients with asthma have more symptoms, poor asthma control, and decreased response to conventional asthma therapies. Weight loss may be associated with improvements in asthma control, response to medications, and overall asthma-related quality of life. This article discusses the effect of weight loss via dietary modifications and surgical interventions on asthma symptoms and control. Weight loss should be encouraged as a means of improving asthma control but there are insufficient data to recommend surgical interventions solely for this purpose.

Impact of asthma exacerbations and asthma triggers on asthma-related quality of life in patients with severe or difficult-to-treat asthma

BACKGROUND

Few data are available that evaluate the relationship among asthma exacerbations, asthma triggers, and asthma-related quality of life (QoL).

OBJECTIVE

To evaluate the impact of asthma exacerbations and asthma triggers on QoL.

METHODS

Patients with severe or difficult-to-treat asthma, ages ≥ 13 years (n = 2679) from the TENOR (The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens) 3-year observational study were included. Exacerbations were defined hierarchically in descending order of severity (hospitalization, emergency department [ED] visit, steroid burst, no exacerbation) by using data from months 6 and 12. The total number (frequency) of exacerbations was assessed. Asthma-related QoL was measured at month 12 by using the Mini-Asthma QoL Questionnaire (Mini-AQLQ); self-reported asthma triggers were collected at baseline and annually. We used 1-way ANOVA to test for differences in Mini-AQLQ domain scores across asthma exacerbation severity, the total number of asthma exacerbations, and the number of asthma triggers.

RESULTS

A significant decrease (P < .001) in Mini-AQLQ domain scores was seen with increasing severity of asthma exacerbation (no exacerbation, steroid burst, ED visit, and hospitalization); symptom (5.5, 4.8, 4.3, and 4.2), activity (5.8, 5.2, 4.6, and 4.4), emotional (5.6, 5.0, 4.4, and 4.2), exposure (5.0, 4.5, 4.0, and 3.9); and overall (5.5, 4.9, 4.3, and 4.1). Increasing exacerbation frequency and the number of baseline asthma triggers also were associated with significant decreases in Mini-AQLQ domain scores. An increasing number of asthma triggers were associated with an increase in severity and frequency of exacerbations.

CONCLUSION

Avoidance of asthma triggers may reduce exacerbation rates and improve asthma-related QoL in patients with severe or difficult-to-treat asthma. Interventional studies are warranted to further explore these outcomes.

Factors associated with severe uncontrolled asthma and the perception of control by physicians and patients

INTRODUCTION

Despite current treatments, more than half of patients with asthma are not controlled. The objective was to evaluate the correlation between control perceived by patients and physicians, compared with control evaluated according to criteria of the Spanish Guidelines for Asthma Management (GEMA), and to investigate the factors associated with that control.

METHODS

Multicenter, cross-sectional, observational study including 343 patients with severe persistent asthma according to GEMA criteria seen in the Department of Pulmonology and Allergology. The correlation between asthma control perceived by the patient, the physician and according to clinical judgment based on the GEMA criteria was calculated, and a multivariate analysis was used to determine variables related to the perception of asthma control.

RESULTS

According to GEMA criteria, only 10.2% of patients were well controlled, 27.7% had partial control and 62.1% were poorly controlled. Both the physicians and the patients overestimated control: 75.8% and 59.3% of patients had controlled asthma according to the patient and the physician, respectively, and were not controlled according to GEMA (P<.0001). Patients with uncontrolled asthma according GEMA had higher body mass index (P=.006) and physical inactivity (P=.016). Factors associated with a perceived lack of control by both physicians and patients were: nocturnal awakenings (≥ 1 day/week), frequent use of rescue medication (≥ 5 days/week) and significant limitation in activities. Discrepant factors between physicians and patients were dyspnea and emergency room visits (patients only), FEV1 ≤ 80% and a poorer understanding of the disease by the patient (physicians only).

CONCLUSIONS

Only 10% of patients with severe asthma evaluated in this study are controlled according to GEMA criteria. Patients and physicians overestimate control and the overestimation by patients is greater. Physical inactivity and obesity are associated with a lack of control according to GEMA.

Asthma exacerbations: predisposing factors and prediction rules

PURPOSE OF REVIEW

Asthma is a multifaceted disease that is associated with decreased lung function, multiple symptoms, varying levels of asthma control, and risk of acute exacerbations. The ability to predict the risk of developing acute exacerbations may improve the management of asthmatics and facilitate identification of these patients for interventional studies.

RECENT FINDINGS

Factors that are associated with different manifestations of asthma differ. Biomarkers that are correlated with airways hyper-responsiveness do not necessarily correlate with risk of future exacerbations. Genetic factors that segregate with exacerbation risk are beginning to emerge. Outcome measures that demonstrate predictive validity have been developed and may facilitate patient management and provide novel clinically meaningful endpoints in clinical trials.

SUMMARY

This review will emphasize underlying factors associated with asthma exacerbations and clinical prediction rules that correlate with the risk of developing severe exacerbations of asthma.

Linking obesity and asthma

A growing body of literature suggests that obesity has a significant impact on asthma risk, phenotype, and prognosis. Epidemiological studies have clearly demonstrated that asthma is more likely to occur in obese patients, and health status is impaired in obese individuals with asthma, with obese asthmatics experiencing more symptoms, worse quality of life, increased healthcare use, and increased asthma severity. However, obesity has well-described effects on lung function and mechanics that can lead to symptoms of dyspnea without causing the pathophysiologic changes of asthma. Adding to the challenges of evaluating this association, some studies have failed to demonstrate a robust relationship between obesity and traditional biomarkers of airway inflammation in adult asthmatics, leading to the conclusion that obesity does not necessarily worsen airway inflammation in asthma. In this regard, emerging data suggest that nonatopic mechanisms may be relevant in obese asthmatics, and that these mechanisms may have a direct impact on the response of obese asthmatics to asthma therapies, most notably inhaled glucocorticoids. This article will review selected aspects of the contributions of obesity-related airway and systemic inflammation to asthma, with a focus on the impact of obesity as a modifier of risk, prognosis, and therapeutic response in asthma.

Elevated sputum interleukin-5 and submucosal eosinophilia in obese individuals with severe asthma

RATIONALE

The relationship between airway inflammation and obesity in severe asthma is poorly understood.

OBJECTIVES

We sought to determine the relationship between sputum mediator profiles and the distribution of eosinophilic inflammation and obesity in people with severe asthma.

METHODS

Clinical parameters and eight mediators in sputum were assessed in 131 subjects with severe asthma from a single center categorized into lean, overweight, and obese groups defined by their body mass index. In an independent group of people with severe asthma (n = 45) and healthy control subjects (n = 19) eosinophilic inflammation was enumerated in bronchial submucosa, blood, and sputum and related to their body mass index.

MEASUREMENTS AND MAIN RESULTS

Sputum IL-5 geometric mean (95% confidence interval) (pg/ml) was elevated in the obese (1.8 [1.2-2.6]) compared with overweight (1.1 [0.8-1.3]; P = 0.025) and lean (0.9 [0.6-1.2]; P = 0.018) subjects with asthma and was correlated with body mass index (r = 0.29; P < 0.001). There was no relationship among body mass index, the sputum cell count, or other sputum mediators. In the bronchoscopy group the submucosal eosinophil number in the subjects with asthma was correlated with body mass index (Spearman rank correlation, rs = 0.38; P = 0.013) and the median (interquartile range) number of submucosal eosinophils was increased in obese (19.4 [11.8-31.2]) (cells per square millimeter) versus lean subjects (8.2 [5.4-14.6]) (P = 0.006). There was no significant association between sputum or peripheral blood eosinophil counts and body mass index.

CONCLUSIONS

Sputum IL-5 and submucosal eosinophils, but not sputum eosinophils, are elevated in obese people with severe asthma. Whether specific antieosinophilic therapy is beneficial, or improved diet and lifestyle in obese asthma has antiinflammatory effects beyond weight reduction, requires further study.

Obese mice are resistant to eosinophilic airway inflammation induced by diesel exhaust particles

Particulate matter can exacerbate respiratory diseases such as asthma. Diesel exhaust particles are the substantial portion of ambient particulate matter with a <2.5 µm diameter in urban areas. Epidemiological data indicate increased respiratory health effects of particulate matter in obese individuals; however, the association between obesity and diesel exhaust particle-induced airway inflammation remains unclear. We aimed to investigate the differences in susceptibility to airway inflammation induced by exposure to diesel exhaust particles between obese mice (db/db) and lean mice (db/+m). Female db/db and db/+m mice were intratracheally administered diesel exhaust particles or vehicle every 2 weeks for a total of seven times. The cellular profile of bronchoalveolar lavage fluid and histological changes in the lungs were assessed and the lungs and serum were analyzed for the generation of cytokines, chemokines and soluble intercellular adhesion molecule 1. Diesel exhaust particle exposure-induced eosinophilic infiltration in db/+m mice accompanied by T-helper 2 cytokine, chemokine and soluble intercellular adhesion molecule 1 expression in the lungs. In contrast, it induced mild neutrophilic airway inflammation accompanied by elevated cytokines and chemokines in db/db mice. The lungs of db/db mice exhibited decreased expression of eosinophil activators/chemoattractants such as interleukin-5, interleukin-13 and eotaxin compared with those of db/+m mice. In addition, serum eotaxin and monocyte chemotactic protein-1 levels were significantly higher in db/db mice than in db/+m mice. In conclusion, obesity can affect susceptibility to diesel exhaust particle-induced airway inflammation, which is possibly due to differences in local and systemic inflammatory responses between lean and obese individuals.

Assessing the risk of attack in the management of asthma: a review and proposal for revision of the current control-centred paradigm

Asthma guidelines focus on day-to-day control of symptoms. However, asthma attacks remain common. They continue to cause mortality and considerable morbidity, and are a major financial burden to the UK National Health Service (NHS) and the wider community. Asthma attacks have chronic consequences, being associated with loss of lung function and significant psychological morbidity. In this article we argue that addressing daily symptom control is only one aspect of asthma treatment, and that there should be a more explicit focus on reducing the risk of asthma attacks. Management of future risk by general practitioners is already central to other conditions such as ischaemic heart disease and chronic renal impairment. We therefore propose a revised approach that separately considers the related domains of daily control and future risk of asthma attack. We believe this approach will have advantages over the current 'stepwise' approach to asthma management. It should encourage individualised treatment, including non-pharmacological measures, and thus may lead to more efficacious and less harmful management strategies. We speculate that this type of approach has the potential to reduce morbidity and healthcare costs related to asthma attacks.

The asthma phenotype in the obese: distinct or otherwise?

Asthma is a heterogenous disorder that can be classified into several different phenotypes. Recent cluster analyses have identified an “obese-asthma” phenotype which is characterized by late onset, female predominance and lack of atopy. In addition, obesity among early-onset asthmatics clearly exists and heightens the clinical presentation. Observational studies have demonstrated that asthma among the obese has a clinical presentation that is more severe, harder to control, and is not as responsive to standard controller therapies. While weight loss studies have demonstrated improvement in asthma outcomes, further studies need to be performed. The current knowledge of the existence of two obesity-asthma phenotypes (early- versus late-onset asthma) should encourage investigators to study these entities separately since just as they have distinct presentations, their course, response to therapies, and weight loss strategies may be different as well.

Role of obesity in asthma control, the obesity-asthma phenotype

Asthma is a disease with distinct phenotypes that have implications for both prognosis and therapy. Epidemiologic studies have demonstrated an association between asthma and obesity. Further studies have shown that obese asthmatics have poor asthma control and more severe asthma. This obese-asthma group may represent a unique phenotype. The mechanisms behind poor asthma control in obese subjects remain unclear, but recent research has focused on adipokines and their effects on the airways as well as the role of oxidative stress. Both surgical and nonsurgical weight loss therapy have shown promising results with improvements in asthma control and decreased asthma severity. Comorbid conditions such as gastroesophageal reflux disease and obstructive sleep apnea may also have a role in poor asthma control in obese asthmatics. Further research is needed to define the mechanisms behind this phenotype which will guide the development of targeted therapies.

Assessment of asthma control and asthma exacerbations in the epidemiology and natural history of asthma: outcomes and treatment regimens (TENOR) observational cohort

Patients with severe or difficult-to-treat asthma account for substantial asthma morbidity, mortality, and healthcare burden despite comprising only a small proportion of the total asthma population. TENOR, a multicenter, observational, prospective cohort study was initiated in 2001. It enrolled 4,756 adults, adolescents and children with severe or difficult-to-treat asthma who were followed semi-annually and annually for three years, enabling insight to be gained into this understudied population. A broad range of demographic, clinical, and patient self-reported assessments were completed during the follow-up period. Here, we present key findings from the TENOR registry in relation to asthma control and exacerbations, including the identification of specific subgroups found to be at particularly high-risk. Identification of the factors and subgroups associated with poor asthma control and increased risk of exacerbations can help physicians design individual asthma management, and improve asthma-related health outcomes for these patients.

The effect of bariatric surgery in the difficult asthma-obesity phenotype: a case report

INTRODUCTION

Obesity and asthma have become increasingly prevalent conditions in recent years; they often coexist and place a significant burden on the National Health Service. Asthma in the obese is more difficult to treat than in those with a normal body mass index (BMI) and is associated with resistance to traditional asthma therapies and increased use of healthcare resources. Weight loss can improve asthma control in such patients. The degree of weight loss achieved through dietary strategies, however, is often only modestly successful in this group. Bariatric surgery is increasingly used to achieve sustained significant weight loss in morbid obesity. It may offer under-recognized benefit in the difficult asthma-obesity phenotype.

CASE STUDY

We describe the case of a 32-year-old female with difficult asthma who had a BMI of 45 kg/m(2) at the time of referral to our clinic. Her asthma was uncontrolled despite maximal inhaled therapy, oral therapy with Zafirlukast, and daily high-dose (25 mg) oral prednisolone. Additional therapies (subcutaneous Terbutaline and the steroid-sparing agent Methotrexate) had little impact on asthma control and she remained morbidly obese. She underwent gastric bypass surgery and, over the following 18 months, her BMI dropped to 27.7 kg/m(2), her corticosteroid dose was reduced to 7.5 mg (adrenal insufficiency proven), and maintenance inhaled therapy and oral medications were stopped as she maintained good asthma control.

CONCLUSION

This case demonstrates the dramatic improvement that bariatric surgery can have on asthma symptoms and medication use in morbidly obese patients with very difficult to control asthma.

Key findings and clinical implications from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study

Patients with severe or difficult-to-treat asthma are an understudied population but account for considerable asthma morbidity, mortality, and costs. The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study was a large, 3-year, multicenter, observational cohort study of 4756 patients (n=3489 adults ≥ 18 years of age, n=497 adolescents 13-17 years of age, and n=770 children 6-12 years of age) with severe or difficult-to-treat asthma. TENOR's primary objective was to characterize the natural history of disease in this cohort. Data assessed semiannually and annually included demographics, medical history, comorbidities, asthma control, asthma-related health care use, medication use, lung function, IgE levels, self-reported asthma triggers, and asthma-related quality of life. We highlight the key findings and clinical implications from more than 25 peer-reviewed TENOR publications. Regardless of age, patients with severe or difficult-to-treat asthma demonstrated high rates of health care use and substantial asthma burden despite receiving multiple long-term controller medications. Recent exacerbation history was the strongest predictor of future asthma exacerbations. Uncontrolled asthma, as defined by the 2007 National Heart, Lung, and Blood Institute guidelines' impairment domain, was highly prevalent and predictive of future asthma exacerbations; this assessment can be used to identify high-risk patients. IgE and allergen sensitization played a role in the majority of severe or difficult-to-treat asthmatic patients.

Obesity and asthma disease phenotypes

PURPOSE OF REVIEW

The increasing prevalence of both asthma and obesity is associated with substantial morbidity and healthcare utilization. Herein, we review recent data suggesting that the obese asthmatic may represent a distinct clinical phenotype.

RECENT FINDINGS

Obesity is a major risk factor for asthma, and asthma in obese patients appears to be more difficult to control, with decreased responsiveness to controller therapies posing a significant public health issue, as the prevalence of both asthma and obesity continues to rise. Epidemiologic research has defined the association between obesity and asthma, an association in part influenced by physiologic abnormalities attendant to both disorders. Healthcare utilization is also increased in obese asthmatic individuals, with reduced response to asthma controller therapies, a finding likely mediated by specific aspects of systemic and airway inflammation. We end by reviewing the role of comorbid clinical disorders in the association and by highlighting evidence that weight loss is associated with improvement in clinical and physiologic parameters of asthma.

SUMMARY

Obesity has a significant impact on asthma risk, severity and control. Additional studies are needed to define mechanisms by which airway physiologic and inflammatory phenotypes in asthma are modified by obesity.

Asthma and obesity: does weight loss improve asthma control? a systematic review

Aim and methods

Obesity is a major health problem, and obesity is associated with a high incidence of asthma and poor asthma control. The aim of the present paper is to systematically review the current knowledge of the effect on overall asthma control of weight reduction in overweight and obese adults with asthma.

Results

Weight loss in obese individuals with doctor-diagnosed asthma is associated with a 48%–100% remission of asthma symptoms and use of asthma medication. Published studies, furthermore, reveal that weight loss in obese asthmatics improves asthma control, and that especially surgically induced weight loss results in significant improvements in asthma severity, use of asthma medication, dyspnoea, exercise tolerance, and acute exacerbations, including hospitalizations due to asthma. Furthermore, weight loss in obese asthmatics is associated with improvements in level of lung function and airway responsiveness to inhaled methacholine, whereas no significant improvements have been observed in exhaled nitric oxide or other markers of eosinophilic airway inflammation.

Conclusion

Overweight and obese adults with asthma experience a high symptomatic remission rate and significant improvements in asthma control, including objective measures of disease activity, after weight loss. Although these positive effects of weight loss on asthma-related health outcomes seem not to be accompanied by remission or improvements in markers of eosinophilic airway inflammation, it has potentially important implications for the future burden of asthma.

Current control and future risk in asthma management

Despite international and national guidelines, poor asthma control remains an issue. Asthma exacerbations are costly to both the individual, and the healthcare provider. Improvements in our understanding of the therapeutic benefit of asthma therapies suggest that, in general, while long-acting bronchodilator therapy improves asthma symptoms, the anti-inflammatory activity of inhaled corticosteroids reduces acute asthma exacerbations. Studies have explored factors which could be predictive of exacerbations. A history of previous exacerbations, poor asthma control, poor inhaler technique, a history of lower respiratory tract infections, poor adherence to medication, the presence of allergic rhinitis, gastro-oesophageal reflux disease, psychological dysfunction, smoking and obesity have all been implicated as having a predictive role in the future risk of asthma exacerbation. Here we review the current literature and discuss this in the context of primary care management of asthma.

The effects of bariatric surgery on asthma severity

BACKGROUND

Excess body weight increases both the risk and severity of asthma. Several studies indicate that bariatric surgery decreases asthma severity, but either enrolled few patients or were not focused primarily on asthma. Furthermore, none compared the effects of different bariatric surgical procedures.

METHODS

Subjects underwent bariatric surgery at member institutions of the Michigan Bariatric Surgery Collaborative between 06/06/2006 and 5/14/2009. Patient records provided data on baseline demographics, asthma medication use, comorbidities, body mass index, type of procedure and perioperative complications. One year later, patients received a follow-up mail survey covering weight and use of asthma medications at that time.

RESULTS

Of the 13,057 bariatric surgery patients, 2,562 (18.6%) reported use of asthma medications at baseline. Several comorbidities were significantly more common in asthma patients, who also experienced significantly more perioperative wound and respiratory complications. Among 257 asthma patients who participated in a 1-year follow-up survey, 13 of 28 who had initially used oral corticosteroids for symptom control no longer required them, while use of inhaled corticosteroids decreased from 49.8% to 29.6%. Reduction in intensity of asthma therapy correlated with presence of sleep disorders and extent of weight loss on univariate analysis but not multivariate analysis. Patients who underwent laparoscopic adjustable gastric banding (LAGB), which was associated with less weight loss than other surgical modalities, were significantly less likely to reduce the intensity of their asthma therapy.

CONCLUSIONS

Bariatric surgery decreases the intensity of medication required to control patients' asthma symptoms, although LAGB appears to produce less significant effects.

Body mass and fat mass in refractory asthma: an observational 1 year follow-up study

Background. Asthma and obesity are common; however the impact of obesity upon asthma remains uncertain. Objectives. To assess relationships between obesity and fat mass with airway inflammation, lung function, and disease control in patients with refractory asthma. Methods. 151 refractory asthma patients were characterised for measures of airway inflammation, lung function, Juniper asthma control questionnaire (JACQ), body mass index (BMI), and fat mass index (FMI) derived from dual energy X-ray absorptiometry. Patients were reassessed over 12 months. Results. 74% of patients had an elevated BMI. BMI and FMI correlated (r = 0.9, P < .001). FMI and JACQ correlated in men (r = 0.3, P = .01). After 12 months 23% lost weight. Weight change over 12 months correlated with FEV₁ change (r = −0.3, P = .03), but not with change in JACQ or exacerbations. Conclusion. Increased fat mass is common in refractory asthma and is associated with asthma symptom control in men. Loss of weight is associated with improvement in lung function in refractory asthma.

[Relationship between comorbidity and asthma control]

INTRODUCTION

The coexistence of potentially aggravating processes is common in asthmatics, particularly in patients with difficult control. The primary aim of this study is to ascertain whether comorbidity id more common in uncontrolled patients. As a secondary aim, we propose to evaluate the correlation between the asthma control test (ACT) and the fraction of exhaled nitric oxide (FENO).

PATIENT AND METHODS

A prospective, observational study comparing the function and clinical picture of two groups of asthmatics: controlled (ACT≥20) and uncontrolled (ACT<20). They were all assessed for, smoking, rhinosinusitis, obesity, anxiety, depression, vocal cord dysfunction, gastro-oesophageal reflux (GORD), allergic bronchopulmonary aspergillosis (ABPA), COPD and nasal polyps.

RESULTS

A total of 50 patients with controlled asthma and 102 with suboptimal control were included. The patients with an ACT≥20 had better lung function, less variation in PEF, less bronchial hyper-reactivity and lower FENO values. Comorbidities were found in 95% of the controlled asthmatics and in 97% of the uncontrolled. Only the presence of nasal polyps, GORD and ABPA was more frequent in the uncontrolled group. However, the simultaneous presence of 3 or more comorbidity factors was significantly more frequent in patients with sub-optimal control (P=0.01). There was no significant correlation between the FENO and the ACT values (rho=-0.08; P=0.32).

CONCLUSIONS

Aggravating comorbidities are more common in patients with sub-optimal control. There was no correlation between the FENO and the ACT values.

Recent insight into obesity and asthma

PURPOSE OF REVIEW

The worldwide pandemic of obesity is creating unique challenges for the diagnosis and treatment of asthma. A wealth of epidemiologic literature has established that whereas asthma can lead to obesity, obesity is a risk factor for asthma, but mechanisms are unclear. This review assesses the current understanding of the relationship between obesity and asthma.

RECENT FINDINGS

Recent studies are developing a more sophisticated understanding of the possible inflammatory, immunologic, genetic, and mechanical mechanisms underlying the association between obesity and asthma. Obese asthma may be a unique phenotype of asthma, with a more difficult clinical course and altered response to asthma controller therapy. Adipokines such as leptin and adiponectin are thought to be important, but there is new interest in other inflammatory mechanisms related to visceral obesity, insulin resistance, and the metabolic syndrome.

SUMMARY

There are still far more questions than answers as to how obesity might cause or worsen asthma. It is clear that weight gain and obesity are particularly troublesome in asthmatics, and clinicians should target these individuals for aggressive intervention. Randomized controlled trials are needed to determine the best treatment approaches for obese asthma, and prospective studies in which both obesity and asthma are well characterized are needed to better understand the underlying mechanisms.

Severe asthma: what makes it so hard to manage?

Severe asthma presents significant management challenges. Patients can be difficult to control despite use of current standard-of-care therapy, including inhaled corticosteroids and long-acting beta-agonists. Alternative diagnoses, noncompliance, and comorbidities all can influence asthma control, future risk, and response to currently available therapy. Definitions of severe asthma evaluate and address these confounding variables, and yet patients are still symptomatic despite aggressive, appropriate therapy. Severe asthma has a distinct pathophysiology including airway remodeling that contributes to the decreased effectiveness of standard therapy. Multiple phenotypes exist within severe asthma that likely require distinct therapeutic approaches to achieve control and improve long-term health outcomes. New therapeutic approaches to these distinct phenotypes will improve our understanding and treatment of this difficult-to-manage disease.