Does age impact the obese asthma phenotype? Longitudinal asthma control, airway function, and airflow perception among mild persistent asthmatics

Altered Symptom Perception in Children With Asthma Is Associated With Poor Childhood Opportunity and Adverse Outcomes

BACKGROUND

Effective asthma self-management requires that children recognize their asthma symptoms when they occur. However, some children have altered symptom perception, which impairs their ability to respond to their asthma symptoms in a timely manner.

OBJECTIVE

To characterize the prevalence and features of altered symptom perception in children aged 5 to 18 years. We hypothesized that children with altered symptom perception would have more features of uncontrolled asthma, more health inequity, and poorer longitudinal asthma outcomes over 12 months.

METHODS

Children (N = 371) completed an outpatient research visit for clinical characterization. Altered symptom perception was defined by discordance between child responses on the 6-item Asthma Control Questionnaire and medical provider-elicited symptoms. Electronic medical records were reviewed for 12 months for the occurrence of an asthma exacerbation treated with systemic corticosteroids and an asthma exacerbation prompting an emergency department visit.

RESULTS

Approximately 15% of children had altered symptom perception and their asthma features were similar to those of children with uncontrolled asthma. Children with altered symptom perception were uniquely distinguished by non-White race and more severe prior exacerbations. These children also resided in ZIP codes with the poorest childhood opportunity (ie, poorest education, health and environmental features, and socioeconomic features). Outcomes of children with altered symptom perception were equally disparate with approximately 2-fold higher odds of a future exacerbation and approximately 3-fold higher odds of an emergency department visit for asthma.

CONCLUSIONS

Altered symptom perception is present in a small but significant number of children with asthma and is related to poorer childhood opportunity and other health inequities that require additional intervention.

Asthma and Rhinitis Through the Lifespan of Nonpregnant Women

Increasingly, clinical practice guidelines advocate a precision medicine-based approach to care for asthma. This focus requires knowledge of not only different asthma phenotypes and their associated biomarkers but also sex and gender differences through the lifespan. Evidence continues to build in favor of different lifetime prevalence, clinical presentations, responses to management, and long-term prognosis of asthma. Women transition through many biological and psychosocial phases in their lives, all of which may interact with, and influence, their health and well-being. Historically, explanations have focused on hormonal effects on asthma in reproductive life, but a greater understanding of mechanisms starting before birth and changing over a lifetime is now possible, with immunologic, inflammatory, and hormonal factors playing a role. This article describes the evidence for the differences in asthma and rhinitis between men and women at different stages of life, the potential underlying mechanisms that contribute to this, and the implications for management and research. Future research studies should systematically report sex differences in asthma so that this knowledge can be used to develop a personalized approach to care, to achieve best possible outcomes for all.

Early-immune development in asthma: A review of the literature

This review presents a comprehensive examination of the various factors contributing to the immunopathogenesis of asthma from the prenatal to preschool period. We focus on the contributions of genetic and environmental components as well as the role of the nasal and gut microbiome on immune development. Predisposing genetic factors, including inherited genes associated with increased susceptibility to asthma, are discussed alongside environmental factors such as respiratory viruses and pollutant exposure, which can trigger or exacerbate asthma symptoms. Furthermore, the intricate interplay between the nasal and gut microbiome and the immune system is explored, emphasizing their influence on allergic immune development and response to environmental stimuli. This body of literature underscores the necessity of a comprehensive approach to comprehend and manage asthma, as it emphasizes the interactions of multiple factors in immune development and disease progression.

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

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

Asthma Prevalence and Phenotyping in the General Population: The LEAD (Lung, hEart, sociAl, boDy) Study

Background

Asthma is a chronic heterogeneous respiratory disease involving differential pathophysiological pathways and consequently distinct asthma phenotypes.

Objective and Methods

In the LEAD Study, a general population cohort (n=11.423) in Vienna ranging from 6-82 years of age, we addressed the prevalence of asthma and explored inflammatory asthma phenotypes that included allergic and non-allergic asthma, and within these phenotypes, an eosinophilic (eosinophils ≥300 cells/µL, or ≥150 cells/µL in the presence of ICS medication) or non-eosinophilic (eosinophils <300 cells/µL, or <150 cells/µL in the presence of ICS) phenotype. In addition, we compared various factors related to biomarkers, body composition, lung function, and symptoms in control subjects versus subjects with current asthma (current doctor's diagnosis of asthma).

Results

An overall prevalence of 4.6% was observed for current asthma. Furthermore, an age-dependent shift from allergic to non-allergic asthma was found. The non-eosinophilic phenotype was more prominent. Obesity was a prevalent condition, and body composition including visceral adipose tissue (VAT), is affected in current asthma versus controls.

Conclusion

This broad-aged and large general population cohort identified differential patterns of inflammatory asthma phenotypes that were age-dependent. The presence of eosinophilia was associated with worse asthma control, increased asthma medication, increased VAT, and lower lung function, the opposite was found for the presence of an allergic asthma.

Differential gene expression in nasal airway epithelium from overweight or obese youth with asthma

BACKGROUND

The mechanisms underlying the known link between overweight/obesity and childhood asthma are unclear. We aimed to identify differentially expressed genes and pathways associated with obesity-related asthma through a transcriptomic analysis of nasal airway epithelium.

METHODS

We compared the whole transcriptome in nasal airway epithelium of youth with overweight or obesity and asthma with that of youth of normal weight and asthma, using RNA sequencing data from a cohort of 235 Puerto Ricans aged 9-20 years (EVA-PR) and an independent cohort of 66 children aged 6-16 years in Pittsburgh (VDKA). Differential expression analysis adjusting for age, sex, sequencing plate number, and sample sorting protocol, and the first five principal components were performed independently in each cohort. Results from the two cohorts were combined in a transcriptome-wide meta-analysis. Gene enrichment and network analyses were performed on top genes.

RESULTS

In the meta-analysis, 29 genes were associated with obesity-related asthma at an FDR-adjusted p <.05, including pro-inflammatory genes known to be differentially expressed in adipose tissue of obese subjects (e.g., CXCL11, CXCL10, and CXCL9) and several novel genes. Functional enrichment analyses showed that pathways for interferon signaling, and innate and adaptive immune responses were down-regulated in overweight/obese youth with asthma, while pathways related to ciliary structure or function were up-regulated. Upstream regulatory analysis predicted significant inhibition of the IRF7 pathway. Network analyses identified "hub" genes like GBP5 and SOCS1.

CONCLUSION

Our transcriptome-wide analysis of nasal airway epithelium identified biologically plausible genes and pathways for obesity-related asthma in youth.

Are wheezing, asthma and eczema in children associated with mother's health during pregnancy? Evidence from an Australian birth cohort

BACKGROUND

This study investigated the prevalence of wheezing, asthma, and eczema among Australian children using longitudinal data from birth to 15 years of age. This study also examined the association between maternal health status during pregnancy and their offspring's respiratory and allergic morbidities using sex-segregated data.

METHODS

This study used data from the Longitudinal Study of Australian Children (LSAC) where approximately 5000 children of a birth cohort across Australia were surveyed in 2004. These children were followed biennially in eight waves up to their age of 15 years until 2018. The status of the children's wheezing, asthma, and eczema were reported by the mothers upon doctors' diagnosis (for asthma) or self-assessment (for wheezing or eczema). Binomial logistic regression models were used to analyse associations between maternal health during pregnancy and their children's health outcomes.

RESULTS

Asthma prevalence among 0-1-year aged children was 11.7%, increased to 15.4% when the children were 10-11 years old, and then decreased to 13.6% when they were 14-15 years old. Wheezing and eczema were most prevalent when the children were 2-3 years old (26.0 and 17.8% respectively) and were least prevalent when the children were 14-15 years old (7.3 and 9.5% respectively). Maternal asthma, smoking during pregnancy, and pre-pregnancy obesity were significantly associated with an increased risk of wheezing and asthma in Australian children. Childhood eczema was associated only with maternal asthma. These associations were stronger among male children up to age 10-11 and during adolescence (12-15 years of age), female children were more prone to wheezing, asthma, and eczema.

CONCLUSION

This is a comprehensive longitudinal study of Australian children (0-15 years of age) to assess the prevalence (with sex-specific differences) of wheezing, asthma and eczema as well as the association between these respiratory and allergic morbidities and maternal health during pregnancy. The study findings suggest that careful medical and obstetric monitoring, improved specific age-sex wise risk factor prevention for children and health promotion for pregnant women would help protect child health.

Pediatric Obesity-Related Asthma: The Role of Nutrition and Nutrients in Prevention and Treatment

Childhood obesity rates have dramatically risen in numerous countries worldwide. Obesity is likely a factor in increased asthma risk, which is already one of the most widespread chronic respiratory pathologies. The pathogenic mechanism of asthma risk has still not yet been fully elucidated. Moreover, the role of obesity-related inflammation and pulmonary overreaction to environmental triggers, which ultimately result in asthma-like symptoms, and the importance of dietary characteristics is well recognized. Diet is an important adjustable element in the asthma development. Food-specific composition of the diet, in particular fat, sugar, and low-quality nutrients, is likely to promote the chronic inflammatory state seen in asthmatic patients with obesity. An unbalanced diet or supplementation as a way to control asthma more efficiently has been described. A personalized dietary intervention may improve respiratory symptoms and signs and therapeutic response. In this narrative review, we presented and discussed more recent literature on asthma associated with obesity among children, focusing on the risk of asthma among children with obesity, asthma as a result of obesity focusing on the role of adipose tissue as a mediator of systemic and local airway inflammation implicated in asthma regulation, and the impact of nutrition and nutrients in the development and treatment of asthma. Appropriate early nutritional intervention could possibly be critical in preventing and managing asthma associated with obesity among children.

Asthma phenotypes and endotypes: a systematic review

INTRODUCTION

Asthma is a complex disorder characterized by expiratory airflow limitation, wheeze, shortness of breath, chest tightness and cough, which can vary over time and in intensity. Being highly heterogeneous, asthma was characterized and classified in several asthma phenotypes and endotypes from 1947 until today. The present systematic review aims to summarize and describe evidence that was published in the last ten years in the field of asthma phenotyping and endotyping.

EVIDENCE ACQUISITION

The systematic review resumed high-quality evidence (clinical trials and randomized control trials) retrieved on MEDLINE and EMBASE databanks and involving adult asthmatic populations. Analyses of literature were conducted according to PRISMA and CASP guidelines.

EVIDENCE SYNTHESIS

Querying MEDLINE and EMBASE databanks, 5019 and 12261 entries were retrieved, respectively. Applying limitations for year of publication, age of participants, and type of publication, the search results were reduced to 98 and 132 articles, respectively. After data abstraction and resolution of duplications, only 50 articles were further evaluated. The research products were then classified first in macro-areas of interest (phenotypes or endotypes) and then in detailed micro-areas.

CONCLUSIONS

This systematic review overviews the principal findings available from high-quality literature in the last decade concerning asthma phenotypes and endotypes. Asthma has been described from different points of view, characterizing symptoms, microbiota composition, comorbidities, viral infections, and airway and/or systemic inflammatory status. The comprehension of precise mechanisms underlying asthma pathogenesis is thereby the basis for the development of novel therapeutic strategies, likely essential to the development of precision medicine.

A comparative study of clinical profile and symptom control in overweight and normal weight school-age children with mild persistent asthma

OBJECTIVES

To find out the proportion of children with poor symptom control in overweight/obese and normal weight children with mild persistent asthma and to know the sociodemographic and clinical correlates of poor symptom control in them.

MATERIALS AND METHODS

Children aged 6 to 12 years with mild persistent asthma with BMI Z score for age and sex more than +1 Z score on WHO BMI Z score chart for age and sex formed the cases. Age- and sex-matched asthmatics with BMI Z score for age and sex between -2 Z and +1 Z score formed the controls. FEV1, FEV1/FVC were measured in both groups using Care Fusion Jaeger spirometer. Symptom control was assessed by ACT score. Statistical analysis was done using SPSS version 19 and Vassarstats.

RESULTS

The proportion of children with poor control was 19.1% in the overweight/obese group and 23.4% in the normal weight group. There was no significant correlation between BMI and symptom control as assessed by the ACT score. Overweight/obese children with good control showed a slightly lower FEV1/FVC ratio and higher median eosinophil count compared to children with normal weight. Gastroesophageal reflux and allergic rhinitis were more commonly seen in overweight/obese children. In the poor control group, FEV1, FEV1/FVC, and median eosinophil counts were not significantly different between overweight/obese and normal weight group but were less when compared to good control group.

CONCLUSION

The proportion of poor symptom control was not high in overweight/obese asthmatic children compared to normal weight asthmatic children. No significant risk factors for poor symptom control could be identified in our study for either of the groups.

Contribution of comorbidities to obesity-related asthma in children

Children with obesity are at increased risk for developing asthma that is difficult to control. A complicating factor to asthma management among these children is likely the commonplace co-morbidities that also result from obesity. We discuss three common obesity-related comorbidities which appear to complicate the effective management of asthma, including hypovitaminosis D, obstructive sleep apnea and gastro-esophageal reflux. Each conditions requires more research to understand their effects on asthma management.

Inflammation in Obesity-Related Complications in Children: The Protective Effect of Diet and Its Potential Role as a Therapeutic Agent

Obesity is a growing health problem in both children and adults, impairing physical and mental state and impacting health care system costs in both developed and developing countries. It is well-known that individuals with excessive weight gain frequently develop obesity-related complications, which are mainly known as Non-Communicable Diseases (NCDs), including cardiovascular disease, type 2 diabetes mellitus, metabolic syndrome, non-alcoholic fatty liver disease, hypertension, hyperlipidemia and many other risk factors proven to be associated with chronic inflammation, causing disability and reduced life expectancy. This review aims to present and discuss complications related to inflammation in pediatric obesity, the critical role of nutrition and diet in obesity-comorbidity prevention and treatment, and the impact of lifestyle. Appropriate early dietary intervention for the management of pediatric overweight and obesity is recommended for overall healthy growth and prevention of comorbidities in adulthood.

Weight Loss for Children and Adults with Obesity and Asthma. A Systematic Review of Randomized Controlled Trials

Background: Asthma and obesity are major public health problems, affecting hundreds of millions of people worldwide. Obesity is associated with increased asthma risk and severity, and lower asthma-related quality of life. Objective: In this systematic review, we aimed to evaluate whether weight loss in subjects with obesity and asthma leads to improvement in asthma-related outcomes. Data Sources and Extraction: We searched PubMed and Google Scholar for all studies in English published January 2000-December 2018. Studies were included if they were randomized, controlled clinical trials (RCTs) for overweight/obese children or adults with asthma, with sufficient data to assess outcomes and study quality. Non-randomized and non-controlled studies were excluded, as well as those in subjects without overweight/obesity, or with non-asthmatic controls. Synthesis: We identified four RCTs involving children (total n = 246) and six involving adults (n = 502). All interventions were designed for weight loss and varied from dietary restrictions to multifactorial interventions with exercise training and cognitive behavioral therapy; the duration of intervention ranged from 8 weeks to 18 months. All RCTs reported successful improvements in weight or body mass index (-0.14 standard deviation scores to -15.9% BMI reduction in children, 1.8%-14.5% weight loss in adults). RCTs generally reported improvements in asthma-related quality of life and, to some degree, asthma control. RCTs involving adults also reported improvements in lung function (FEV₁, FVC, TLC), while RCTs in children showed less consistent results. Conclusions: These findings suggest that weight loss in subjects with obesity and asthma may improve asthma outcomes. However, there was wide variability in populations studied, baseline and post-intervention assessments, follow-up length, outcome definition and reporting, and statistical approaches, which hindered the ability to compare studies, perform a pooled analysis, or assess generalizability. Primary Source of Funding: U.S. National Institutes of Health (NIH).

Onset of asthma-like symptoms in children with lower respiratory tract infections

Background

Asthma‐like symptoms (ALS) often occur among children with lower respiratory tract infections (LRTIs). We aimed to determine the potential risk factors for ALS onset in LRTIs children.

Methods

A total of 102 LRTIs with ALS and 474 without ALS were enrolled. The relative risk (RR) was used to test the influence of the clinical factors on the ALS risk. We compared the differences of birth data, wheezing history, disease severity, inflammatory markers, infectious pathogens, allergic markers, cardiac, liver, and kidney injury markers between LRTIs with and without ALS onset. Receiver operating curve (ROC) analysis was applied to determine the predictive value of various markers in the ALS risk in LRTIs. Multivariate logistic regression analysis was performed to evaluate the association between various clinical and laboratory parameters and ALS onset in LRTIs.

Results

The RRs of boys/girls ratio and wheezing history for ALS compared with non‐ALS was 1.263 and 2.850, respectively (P = .026, <10⁻⁴). There were significant differences of age, WBC, PLT, EOS, and CK between LRTIs with and without ALS onset (P = .004, .041, .006, .049, and .035). ROC analysis showed that significant associations between the parameters of age, WBC, and PLT and ALS risk among LRTIs were observed. Multivariate logistic regression analysis showed that the clinical and laboratory parameters were not independently associated with the risk of ALS onset among LRTIs.

Conclusions

Lower age, male, inflammation, and allergic state were risk factors for ALS onset in LRTIs. Comprehensive monitoring and evaluation of these factors may be helpful for ALS prevention.

Obesity and childhood asthma

PURPOSE OF REVIEW

Asthma is a common chronic disease of the airways characterized by recurrent respiratory symptoms, bronchoreactivity, and airway inflammation. The high toll on quality of life has led to sustained efforts to understand the factors leading to asthma inception and poor disease control. Obesity is another increasingly common pediatric disease, which appears to increase the risk for incident asthma and worsened disease severity. Currently, our understanding of how obesity affects asthma risk and affects its phenotypic characteristics remains incomplete. The current review describes our current understanding of the epidemiology, clinical characteristics, and management considerations of obesity-related asthma in children.

RECENT FINDINGS

The epidemiologic relationship between obesity in children and incident asthma remains confusing despite numerous longitudinal cohort studies, and appears to be influenced by early life exposures, patterns of somatic growth and underlying familial risks of allergic disease. Children with comorbid obesity and asthma demonstrate diverse phenotypic characteristics which are still becoming clear.

SUMMARY

Like any child with asthma, a child with comorbid obesity requires an individualized approach adhering to current best-practice guidelines and an understanding of how obesity and asthma may interact.

Bariatric surgery: a potential cure for asthma?

Asthma incidence and severity are increased in obese populations. Systematic reviews have shown benefit from weight-loss interventions on asthma outcomes, but the role of bariatric surgery is still unclear. In this review, cohorts of obese asthmatic patients undergoing bariatric surgery were examined regarding different asthma outcomes. The available data on patients who were followed up showed improvements in asthma control, exacerbation risk, asthma-related hospitalisation, medication use and airway hyperresponsiveness, with some patients not requiring further treatment for asthma. Follow-up duration was variable, being mostly of 1 year, with some studies reporting long-term outcomes after 5 years. The studies reviewed had many limitations, including small numbers of patients, lack of control arm in some studies and lack of standardisation of asthma diagnosis, classification and outcome measures, in addition to possible reporting bias. Data on small numbers of patients also show the possibility of benefit exclusively in nonallergic asthma. Larger, more stringent clinical trials are needed before recommending bariatric surgery for treatment of asthma.

The etiologic origins for chronic obstructive pulmonary disease

COPD, characterized by long-term poorly irreversible airway limitation and persistent respiratory symptoms, has resulted in enormous challenges to human health worldwide, with increasing rates of prevalence, death, and disability. Although its origin was thought to be in the interactions of genetic with environmental factors, the effects of environmental factors on the disease during different life stages remain little known. Without clear mechanisms and radical cure for it, early screening and prevention of COPD seem to be important. In this review, we will discuss the etiologic origins for poor lung function and COPD caused by specific adverse effects during corresponding life stages, as well as try to find new insights and potential prevention strategies for this disease.

Obesity and severe asthma

Obesity is an important global health issue for both children and adults. Obesity increases the prevalence and incidence of asthma and also increases the risk for severe asthma. Here we describe the features of severe asthma phenotypes for which obesity is a defining characteristic, including steroid resistance, airway inflammation, and co-morbidities. We also review current concepts regarding the mechanistic basis for the impact of obesity in severe asthma, including possible roles for vitamin D deficiency, systemic inflammation, and the microbiome. Finally, we describe data indicating a role for diet, weight loss, and exercise in the treatment of severe asthma with obesity. Better understanding of the mechanistic basis for the role of obesity in severe asthma could lead to new therapeutic options for this population.

Asthma over the Adult Life Course: Gender and Hormonal Influences

Asthma is a common disorder that affects genders differently across the life span. Earlier in life, it is more common in boys. At puberty, asthma becomes more common and often more severe in girls and women. The effect of sex hormones on asthma incidence and its severity is difficult to differentiate from other asthma severity risk factors, such as racial background, socioeconomic factors, obesity, atopy, environmental exposure, and, in particular, lung aging. Recognizing gender-associated and age-associated differences is important to understanding the pathobiology of asthma and to providing effective education and personalized care for patients with asthma across the life course.

Children with Obesity and Asthma: Which Are the Best Options for Their Management?

Obesity and asthma are complex disorders related to gene-environment interactions and various lifestyle factors. At present, they represent two of the most significant paediatric health problems worldwide, particularly in industrialized nations. The aim of this narrative review is to evaluate possible therapeutic strategies to manage asthma in children with overweight/obesity. PubMed was used to search for all of the studies published from January 2008 to June 2018 using the following key words: “asthma” and “overweight” or “obesity” or “obese” and “children” or “paediatric”. The literature review showed that growing evidence underlines the existence of an “obese asthma” phenotype characterised by difficult-to-control asthma with additional symptoms, worse control, more frequent and severe exacerbations, reduced response to inhaled corticosteroids, and lower quality of life than other phenotypes. Currently, therapeutic strategies centred on prevention are suggested and the development of resources to assist families with weight loss strategies seems useful for effective weight control and optimal asthma management. Studies on vitamin D supplementation and further knowledge are needed to better define the best therapeutic options to manage asthma in children with overweight/obesity and to reduce the onset and severity of this chronic respiratory disease through the design of a multifactorial intervention.

Obesity and asthma

Obesity is a vast public health problem and both a major risk factor and disease modifier for asthma in children and adults. Obese subjects have increased asthma risk, and obese asthmatic patients have more symptoms, more frequent and severe exacerbations, reduced response to several asthma medications, and decreased quality of life. Obese asthma is a complex syndrome, including different phenotypes of disease that are just beginning to be understood. We examine the epidemiology and characteristics of this syndrome in children and adults, as well as the changes in lung function seen in each age group. We then discuss the better recognized factors and mechanisms involved in disease pathogenesis, focusing particularly on diet and nutrients, the microbiome, inflammatory and metabolic dysregulation, and the genetics/genomics of obese asthma. Finally, we describe current evidence on the effect of weight loss and mention some important future directions for research in the field.

Adiposity and Asthma in a Nationwide Study of Children and Adults in the United States

RATIONALE

Although obesity has been associated with asthma, body mass index is suboptimal to fully characterize adiposity.

OBJECTIVES

We examined the relation between adiposity and asthma in a large sample of the U.S. population, using indices defined by dual-energy X-ray absorptiometry.

METHODS

We analyzed data from 8,886 children (aged 8-19 yr) and 12,795 adults (aged 20-69 yr) from the 2001 to 2006 National Health and Nutrition Examination Survey. In addition to body mass index, percent body fat, waist circumference, and waist-to-height ratio, dual-energy X-ray absorptiometry was used to calculate whole-body and local adiposity indices: fat mass index; total, trunk, and legs percent fat; and trunk-to-total fat mass ratio, legs-to-total fat mass ratio, and trunk-to-legs fat mass ratios. Logistic regression was used for the analysis of adiposity measures and asthma.

RESULTS

Among children, general adiposity was significantly associated with asthma, with no major differences by sex. Results were driven by nonatopic children, in whom trunk-predominant (central) adiposity (assessed by waist circumference, waist-to-height ratio, trunk-to-total fat mass ratio, and trunk-to-legs fat mass ratio) was also associated with asthma. There were no significant associations among atopic children. Among adults, all adiposity indices were associated with asthma, with central adiposity significant only among women. The results in adults were driven by atopy, especially in women.

CONCLUSIONS

Adiposity measured by dual-energy X-ray absorptiometry provides similar information to that obtained by using anthropometric indices among children of both sexes and among adult men. However, dual-energy X-ray absorptiometry provides additional information in adult women, in whom dual-energy X-ray absorptiometry-measured central adiposity is significantly associated with asthma, particularly atopic asthma.

A review of obesity and asthma across the life span

OBJECTIVE

This literature review aims to compare obese-asthmatic adults and children, and to characterize differences and similarities between the two subgroups from epidemiological, demographical, phenotypical, and physiological perspectives.

METHODS

Literature search was conducted using Pubmed database with "obesity," "asthma," "epidemiology," "cluster analysis," "demography," "mechanics," and ''FeNO'' as search terms.

METHODS

Articles investigating epidemiological, demographic, phenotypical variation, and mechanical aspects of breathing specifically in obese asthmatics were identified. The studies were then divided according to age: children (<18 years of age) and adults (>18 years of age).

RESULTS

Increase in asthma incidence and prevalence is observed in both obese-asthmatic children and adults. Asthma prevalence is greater in adult females regardless of ethnic background, and in men of African American and Hispanic ethnicities. Degree of weight gain and early onset of menarche appears to directly affect asthma severity in adolescent girls and females. Airway hyperresponsiveness and fractional exhaled nitric oxide do not have any positive correlation with high BMI in obese-asthmatic children and adults. Obesity also alters lung mechanics in asthmatics, but the impact is different for children and adults likely due to differential effect of obesity on central and peripheral airway.

CONCLUSION

Existing literature suggests both similarities and differences in obese-asthmatic children and adults. The most pertinent differences are related to gender, ethnicity, and lung functions.

Association of exercise-induced wheeze and other asthma symptoms with emergency department visits and hospitalizations in a large cohort of urban adolescents

OBJECTIVE

Exercise-induced wheeze (EIW) has been found to be associated with asthma-related urgent care in school-aged children. Despite asthma's high prevalence and morbidity among adolescents, this association has not been examined in adolescents. We tested the association of EIW and other asthma symptoms to asthma-related ED visits and hospitalizations in urban adolescents with probable asthma. We hypothesized that EIW would be associated with urgent care.

METHODS

In this cross-sectional study 30,467 high school students (mean age = 16.0) from 49 NYC schools completed two brief validated measures, one assessing probable asthma and the other the frequency of six asthma symptoms over the past year. Adolescents also reported if in the past year they had an asthma-related ED visit or hospitalization. Analyses presented here included students with probable asthma (n = 9149). Using logistic regression, we modeled each asthma symptom as a function of ED visits and hospitalizations adjusting for sex, age, race/ethnicity and asthma severity. Multivariable models included all symptoms to account for the potential interaction between symptoms.

RESULTS

Among adolescents with probable asthma, EIW was associated with ED visits and hospitalizations. In multivariable models wheeze without a cold, chest tightness, night wakening, but not EIW, were significantly associated with both ED visits and hospitalizations.

CONCLUSIONS

Unlike findings with younger children, EIW does not appear to be associated with ED visits and hospitalizations among urban adolescents with probable asthma. Instead, symptoms, such as chest tightness and night wakening, appear to be important at identifying adolescents at risk for asthma-related urgent care.

Relationships between self-reported asthma and pulmonary function and various measures of obesity

OBJECTIVE

We explore the association with self-reported asthma and pulmonary function based on spirometry measurements using different measures to determine obesity because body mass index (BMI) is limited in not differentiating fat and muscle mass.

METHODS

A multi-year cross-sectional study using Korean National Health and Nutrition Examination Survey data was conducted between July 2008 and May 2011. A total of 9409 subjects were included in the final analysis.

RESULTS

Obesity was associated with self-reported asthma and pulmonary function limitations mainly in adult women aged between 40 and 65 years and elderly men aged 65 or older. The association was stronger when the measurement of obesity was based on body fat percentage or waist-to-height ratio (WHtR), compared to BMI. There was a higher self-reported asthma risk among obese women according to the WHtR [odds ratio (OR) = 1.817, 95% CI: (1.208, 2.735)]. There was an increased risk of pulmonary function limitation with abdominal obesity [OR 1.418, 95% CI (1.020, 1.972)], weight-to-height ratio [OR 1.467, 95% CI (1.058, 2.034)], and obesity with regard to body fat percentage [OR 1.753, 95% CI (1.251, 2.457)] in adult women. In elderly men, obesity based on body fat percentage was associated with an increased risk of pulmonary function limitation [OR 1.93, 95% CI (1.098, 3.388)].

CONCLUSIONS

Measures other than BMI should be examined when investigating the effect of obesity on self-reported asthma and pulmonary function limitation.

Comparative Clinical, Physiological, and Inflammatory Characteristics of Elderly Subjects With or Without Asthma and Young Subjects With Asthma

BACKGROUND

Asthma seems to present in the elderly as a specific phenotype that remains to be further described. In this prospective observational study, we aimed to assess the multidimensional aspects of asthma in the elderly.

METHODS

In young (18 to 35 years old) subjects with mild to moderate asthma and elderly subjects (aged ≥60 years) either with or without mild to moderate asthma, we compared asthma control, health care and medication use, lung function, markers of airway and systemic inflammation, and adherence to therapy.

RESULTS

Fifty subjects were recruited in each group. Elderly people with asthma showed more marked airway obstruction compared with young people with asthma and elderly people without asthma. They also had poorer asthma control, mainly associated with a lower FEV₁, compared with young people with asthma, although airway responsiveness, health care use, prescribed doses of inhaled corticosteroids, and adherence to treatment were similar in both groups. Elderly subjects had an increase in some markers of systemic inflammation and bronchial epithelial dysfunction compared with young people with asthma. Blood eosinophils were higher in both asthma groups, particularly in elderly people with asthma. Sputum neutrophils were increased in both groups of elderly subjects and sputum eosinophils were increased in elderly people with asthma compared with the other two groups.

CONCLUSIONS

Asthma in the elderly presents as a specific phenotype associated with increased airway obstruction and mixed airway inflammation in addition to signs of systemic inflammation.

The effect of obesity, weight gain, and weight loss on asthma inception and control

PURPOSE OF REVIEW

There is ample and growing evidence that obesity increases the risk of asthma and morbidity from asthma. Here, we review recent clinical evidence supporting a causal link between obesity and asthma, and the mechanisms that may lead to 'obese asthma'.

RECENT FINDINGS

Although in some children obesity and asthma simply co-occur, those with 'obese asthma' have increased asthma severity, lower quality of life, and reduced medication response. Underlying mechanistic pathways may include anatomical changes of the airways such as obstruction and dysanapsis, systemic inflammation, production of adipokines, impaired glucose-insulin metabolism, altered nutrient levels, genetic and epigenetic changes, and alterations in the airway and/or gut microbiome. A few small studies have shown that weight loss interventions may lead to improvements in asthma outcomes, but thus far research on therapeutic interventions for these children has been limited.

SUMMARY

Obesity increases the risk of asthma - and worsens asthma severity or control - via multiple mechanisms. 'Obese asthma' is a complex, multifactorial phenotype in children. Obesity and its complications must be managed as part of the treatment of asthma in obese children.

[Effect of obesity on pulmonary function in asthmatic children of different age groups]

OBJECTIVE

To study the effect of obesity on pulmonary function in newly diagnosed asthmatic children of different age groups.

METHODS

Two hundred and ninety-four children with newly diagnosed asthma were classified into preschool-age (<6 years) and school-age (6 to 12.5 years) groups. They were then classified into obese, overweight, and normal-weight subgroups based on their body mass index (BMI). All the children underwent pulmonary function tests, including large airway function tests [forced vital capacity (FVC%) and forced expiratory volume in one second (FEV1%)] and small airway function tests [maximal expiratory flow at 25% of vital capacity (MEF25%), maximal expiratory flow at 50% of vital capacity (MEF50%), and maximal expiratory flow at 75% of vital capacity (MEF75%)].

RESULTS

The school-age group showed lower FEV1%, MEF25%, and MEF50% than the preschool-age group (P<0.05) after adjustment for sex and BMI. The normal-weight children in the school-age group had lower FEV1%, MEF25%, and MEF50% compared with their counterparts in the preschool-age group (P<0.05). The overweight children in the school-age group showed lower FVC% and MEF50% than those in the preschool-age group. However, all the pulmonary function parameters showed no significant differences between the obese children in the preschool-age and school-age groups. In the preschool-age group, FVC%, FEV1%, and MEF75% of the obese children were lower than those of the normal-weight children. In the school-age group, only FVC% and FEV1% showed differences between the obese and normal-weight children (P<0.05).

CONCLUSIONS

The effect of obesity on the pulmonary function varies with age in children with asthma, and the effect is more obvious in those of preschool age.

Asthma in adolescence: Is there any news?

Asthma is a chronic disease that has a significant impact quality of life, which is particularly important in adolescence. We will discuss aspects of epidemiology, the clinical spectrum, diagnostics, and management of asthma in adolescence. In particular, we will highlight the psychological implications of having asthma during this developmental period. Data published in the past 10 years, since we last reviewed the subject, will be the main focus of this paper. The care of the teenager with asthma should take into account the rapid physical, emotional, cognitive, and social changes that occur during normal adolescence. The diagnostic process may be more difficult since teenagers tend to deny their illness. Thus, both under-diagnosis and under-assessment of asthma severity may lead to under-treatment and potentially avoidable morbidity and even mortality. Conversely, teenagers may be often misdiagnosed as having asthma or their asthma severity may be overestimated leading to inappropriate and sometimes excessive treatment. Educational programs, environmental avoidance measures, proper use of medications along with a skilled approach, and a caring attitude of health providers are all very important for successful management. Pediatr Pulmonol. 2017;52:129-138. © 2016 Wiley Periodicals, Inc.

Sex Differences in the Relationship between Fitness and Obesity on Risk for Asthma in Adolescents

OBJECTIVE

To evaluate the relationship of fitness and obesity on asthma risk in adolescent girls and boys.

STUDY DESIGN

A cross-sectional assessment of participants 12-19 years of age was conducted by the use of data from the 1999-2004 National Health and Nutrition Examination Survey. Participants completed cardiorespiratory fitness testing, body composition measurements, and respiratory questionnaires.

RESULTS

A total of 4828 participants were included. Overweight/obesity was associated with increased odds of history of asthma (aOR 1.63, 95% CI 1.16-2.30), current asthma (aOR 1.73, 95% CI 1.13, 2.64), and wheezing (aOR 1.40, 95% CI 1.03-1.91) in girls. Overweight/obesity also was associated with increased odds of asthma attacks (aOR 2.67, 95% CI 1.56-4.65) and wheezing related to exercise (aOR 1.60, 95% CI 1.07-2.38) in girls. High fitness was associated with lower odds of asthma-related visits to the emergency department (aOR 0.24, 95% CI 0.07-0.89), wheezing-related medical visits (aOR 0.31, 95% CI 0.13-0.75), wheezing-related missed days (aOR 0.14, 95% CI 0.06-0.33), and wheezing related to exercise (aOR 0.43, 95% CI 0.24-0.76) in boys.

CONCLUSION

Overweight/obesity is associated with increased asthma prevalence and morbidity in girls but not in boys, independent of fitness. High fitness is associated with decreased rates of asthma morbidity in boys but not in girls, independent of weight status. Obesity and fitness may each influence asthma onset and severity in different ways for girls compared with boys.

Associations between asthma, overweight and physical activity in children: a cross-sectional study

Background

Asthma and obesity are highly prevalent in children, and are interrelated resulting in a difficult-to-treat asthma-obesity phenotype. The exact underlying mechanisms of this phenotype remain unclear, but decreased physical activity (PA) could be an important lifestyle factor. We hypothesize that both asthma and overweight/obesity decrease PA levels and interact on PA levels in asthmatic children with overweight/obesity.

Methods

School-aged children (n = 122) were divided in 4 groups (healthy control, asthma, overweight/obesity and asthma, and overweight/obesity). Children were asked to perform lung function tests and wear an activity monitor for 7 days. PA was determined by: step count, active time, screen time, time spent in organized sports and active transport forms. We used multiple linear regression techniques to investigate whether asthma, body mass index-standard deviation score (BMI-SDS), or the interaction term asthma x BMI-SDS were associated with PA. Additionally, we tested if asthma features (including lung function and medication) were related to PA levels in asthmatic children.

Results

Asthma, BMI-SDS and the interaction between asthma x BMI-SDS were not related to any of the PA variables (p ≥ 0.05). None of the asthma features could predict PA levels (p ≥ 0.05). Less than 1 in 5 children reached the recommended daily step count guidelines of 12,000 steps/day.

Conclusion

We found no significant associations between asthma, overweight and PA levels in school-aged children in this study. However, as PA levels were worryingly low, effective PA promotion in school-aged children is necessary.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3600-1) contains supplementary material, which is available to authorized users.

Childhood obesity in relation to poor asthma control and exacerbation: a meta-analysis

To estimate the association between obesity and poor asthma control or risk of exacerbations in asthmatic children and adolescents, and to assess whether these associations are different by sex.

A meta-analysis was performed on unpublished data from three North-European paediatric asthma cohorts (BREATHE, PACMAN (Pharmacogenetics of Asthma medication in Children: Medication with Anti-inflammatory effects) and PAGES (Pediatric Asthma Gene Environment Study)) and 11 previously published studies (cross-sectional and longitudinal studies). Outcomes were poor asthma control (based on asthma symptoms) and exacerbations rates (asthma-related visits to the emergency department, asthma-related hospitalisations or use of oral corticosteroids). Overall pooled estimates of the odds ratios were obtained using fixed- or random-effects models.

In a meta-analysis of 46 070 asthmatic children and adolescents, obese children (body mass index ≥95th percentile) compared with non-obese peers had a small but significant increased risk of asthma exacerbations (OR 1.17, 95% CI 1.03–1.34; I2: 54.7%). However, there was no statistically significant association between obesity and poor asthma control (n=4973, OR 1.23, 95% CI 0.99–1.53; I2: 0.0%). After stratification for sex, the differences in odds ratios for girls and boys were similar, yet no longer statistically significant.

In asthmatic children, obesity is associated with a minor increased risk of asthma exacerbations but not with poor asthma control. Sex does not appear to modify this risk.

Association between obesity and asthma - epidemiology, pathophysiology and clinical profile

Obesity is a risk factor for asthma, and obese asthmatics have lower disease control and increased symptom severity. Several putative links have been proposed, including genetics, mechanical restriction of the chest and the intake of corticosteroids. The most consistent evidence, however, comes from studies of cytokines produced by the adipose tissue called adipokines. Adipokine imbalance is associated with both proinflammatory status and asthma. Although reverse causation has been proposed, it is now acknowledged that obesity precedes asthma symptoms. Nevertheless, prenatal origins of both conditions complicate the search for causality. There is a confirmed role of neuro-immune cross-talk mediating obesity-induced asthma, with leptin playing a key role in these processes. Obesity-induced asthma is now considered a distinct asthma phenotype. In fact, it is one of the most important determinants of asthma phenotypes. Two main subphenotypes have been distinguished. The first phenotype, which affects adult women, is characterised by later onset and is more likely to be non-atopic. The childhood obesity-induced asthma phenotype is characterised by primary and predominantly atopic asthma. In obesity-induced asthma, the immune responses are shifted towards T helper (Th) 1 polarisation rather than the typical atopic Th2 immunological profile. Moreover, obese asthmatics might respond differently to environmental triggers. The high cost of treatment of obesity-related asthma, and the burden it causes for the patients and their families call for urgent intervention. Phenotype-specific approaches seem to be crucial for the success of prevention and treatment.

Adiposity influences airway wall thickness and the asthma phenotype of HIV-associated obstructive lung disease: a cross-sectional study

Background

Airflow obstruction, which encompasses several phenotypes, is common among HIV-infected individuals. Obesity and adipose-related inflammation are associated with both COPD (fixed airflow obstruction) and asthma (reversible airflow obstruction) in HIV-uninfected persons, but the relationship to airway inflammation and airflow obstruction in HIV-infected persons is unknown. The objective of this study was to determine if adiposity and adipose-associated inflammation are associated with airway obstruction phenotypes in HIV-infected persons.

Methods

We performed a cross-sectional analysis of 121 HIV-infected individuals assessed with pulmonary function testing, chest CT scans for measures of airway wall thickness (wall area percent [WA%]) and adipose tissue volumes (mediastinal and subcutaneous), as well as HIV- and adipose-related inflammatory markers. Participants were defined as COPD phenotype (post-bronchodilator FEV₁/FVC < lower limit of normal) or asthma phenotype (doctor-diagnosed asthma or bronchodilator response). Pearson correlation coefficients were calculated between adipose measurements, WA%, and pulmonary function. Multivariable logistic and linear regression models were used to determine associations of airflow obstruction and airway remodeling (WA%) with adipose measurements and participant characteristics.

Results

Twenty-three (19 %) participants were classified as the COPD phenotype and 33 (27 %) were classified as the asthma phenotype. Body mass index (BMI) was similar between those with and without COPD, but higher in those with asthma compared to those without (mean [SD] 30.7 kg/m² [8.1] vs. 26.5 kg/m² [5.3], p = 0.008). WA% correlated with greater BMI (r = 0.55, p < 0.001) and volume of adipose tissue (subcutaneous, r = 0.40; p < 0.001; mediastinal, r = 0.25; p = 0.005). Multivariable regression found the COPD phenotype associated with greater age and pack-years smoking; the asthma phenotype with younger age, female gender, smoking history, and lower adiponectin levels; and greater WA% with greater BMI, younger age, higher soluble CD163, and higher CD4 counts.

Conclusions

Adiposity and adipose-related inflammation are associated with an asthma phenotype, but not a COPD phenotype, of obstructive lung disease in HIV-infected persons. Airway wall thickness is associated with adiposity and inflammation. Adipose-related inflammation may play a role in HIV-associated asthma.

Impact of Obesity on Clinical Outcomes in Urban Children Hospitalized for Status Asthmaticus

BACKGROUND AND OBJECTIVE

The prevalence of both childhood asthma and obesity remain at historically high levels and disproportionately affect urban children. Asthma is a common and costly cause for pediatric hospitalization. Our objective was to determine the effect of obesity on outcomes among urban children hospitalized with status asthmaticus.

METHODS

A retrospective cohort study was performed by using billing system data and chart review to evaluate urban children admitted for asthma. Demographics, asthma severity, reported comorbidities, and outcomes were assessed. Obesity was defined by BMI percentile (lean<85%, overweight 85%-95%, obese≥95%). Outcomes were length of stay, hospitalization charges, ICU stay, repeat admissions, and subsequent emergency department (ED) visits. Bivariate analysis assessed for differences between overweight/obese and lean children. Multivariable regression assessed the relationship between overweight status and primary outcomes while controlling for other variables. Post hoc age-stratified analysis was also performed.

RESULTS

The study included 333 subjects; 38% were overweight/obese. Overweight/obese children admitted with asthma were more likely than lean children to have subsequent ED visits (odds ratio 1.6, 95% confidence interval 1.0-2.6). When stratified by age, overweight/obese preschool-age children (<5 years) were >2 times as likely to have repeat ED visits than lean preschool-age children (odds ratio 2.3, 95% confidence interval 1.0-5.6). There were no differences in the other outcomes between overweight/obese and lean individuals within the entire cohort or within other age groups.

Atopy, but not obesity is associated with asthma severity among children with persistent asthma

BACKGROUND AND OBJECTIVE

Obesity is associated with an increased risk of asthma in children. Atopic sensitization is a major risk factor for asthma including severe asthma in children. It is unclear if obesity is associated with worse asthma control or severity in children and how its effects compare to atopy. We sought to examine relationships of weight status and atopy to asthma control and severity among a population of predominantly low income, minority children and adolescents with persistent asthma.

METHODS

A cross-sectional analysis of 832 children and adolescents, age range 5-17 years, with persistent asthma was performed. Clinical assessments included asthma questionnaires of symptoms, asthma severity score, health care utilization and medication treatment step, lung function testing, and skin prick testing as well as measures of adiposity. Data were collected between December 2010 and August 2014 from Johns Hopkins Hospital in Baltimore, MD and Children's Hospital of Boston, MA.

RESULTS

Obesity was not associated with worse asthma control or severity in this group of predominantly low income, minority children and adolescents with persistent asthma. However, a greater degree of atopy was associated with lower lung function, higher asthma severity score, and higher medication treatment step.

CONCLUSION

Atopy may be a more important risk factor for asthma severity than obesity among low-income minority children and adolescents with persistent asthma living in Northeastern cities in the United States.

Health Issues in Hispanic/Latino Youth

This review focuses on obesity, asthma and mental health functioning as salient health issues affecting Hispanic youth. Burden of these conditions and consequences for adult health are also discussed. Hispanic youth are affected by obesity at an early age; the prevalence of obesity among Hispanic children 6-11 years old is twice as high as the prevalence for non-Hispanic White children of the same age, but among 2-5 years old is 4 times higher. Asthma disproportionally affects certain Hispanic groups, notably children of Puerto Rican ancestry, and the comorbidity of asthma and obesity is an emerging health issue. Another area of concern is the scant data on mental health functioning among Hispanic youth. Research on Hispanic youth mental health have reported high rates of depressive symptomatology and high rates of alcohol use among Hispanic adolescents but despite these findings, they have inadequate access to mental health services. This review highlights the need for better data to gain a better understanding of the health status of Hispanic youth and help develop preventive programs that addresses the need of this population. Improving access to health services, in particular mental health services, is also a crucial aspect.

[An analysis of skin prick test reactivity to dust mite in overweight and normal weight children with allergic asthma before and after specific immunotherapy]

OBJECTIVE

To study the skin prick test (SPT) reactivity to house dust mite allergens in overweight and normal weight children with allergic asthma before and after standard subcutaneous specific immunotherapy.

METHODS

Two hundred and fifteen children with allergic asthma who had positive SPT responses to Dermatophagoides pteronyssinus (DP) and Dermatophagoides farinae (DF) were enrolled. According to the weight index, they were classified into overweight (n=63) and normal weight groups (n=152). Skin indices (SI) to DP and DF were compared between the two groups at 6 months and 1 year after standard subcutaneous specific immunotherapy.

RESULTS

The overweight group had a significantly larger histamine wheal diameter than the normal weight group after controlling the variation in testing time (P<0.05). After controlling the variation in weights, there were significant differences in the SIs to DP and DF before specific immunotherapy and at 6 months and 1 year after specific immunotherapy. At 6 months and 1 year after specific immunotherapy, the SIs to DP and DF were significantly reduced in both groups (P<0.05), and the overweight group had greater decreases in the SIs to DP and DF than the normal weight group.

CONCLUSIONS

The overweight children with allergic asthma have stronger responses to histamine than the normal weight patients. Specific immunotherapy can reduce the reactivity to dust mite allergens in children with allergic asthma. Within one year after specific immunotherapy, the overweight children with allergic asthma have a significantly greater decrease in the reactivity to dust mite allergens than the normal weight patients.

Gastro-oesophageal reflux and worse asthma control in obese children: a case of symptom misattribution?

BACKGROUND

Obese children for unknown reasons report greater asthma symptoms. Asthma and obesity both independently associate with gastro-oesophageal reflux symptoms (GORS). Determining if obesity affects the link between GORS and asthma will help elucidate the obese-asthma phenotype.

OBJECTIVE

Extend our previous work to determine the degree of associations between the GORS and asthma phenotype.

METHODS

We conducted a cross-sectional study of lean (20%-65% body mass index, BMI) and obese (≥95% BMI) children aged 10-17 years old with persistent, early-onset asthma. Participants contributed demographics, GORS and asthma questionnaires and lung function data. We determined associations between weight status, GORS and asthma outcomes using multivariable linear and logistic regression. Findings were replicated in a second well-characterised cohort of asthmatic children.

RESULTS

Obese children had seven times higher odds of reporting multiple GORS (OR=7.7, 95% CI 1.9 to 31.0, interaction p value=.004). Asthma symptoms were closely associated with GORS scores in obese patients (r=0.815, p<0.0001) but not in leans (r=0.291, p=0.200; interaction p value=0.003). Higher GORS scores associated with higher FEV1-per cent predicted (p=0.003), lower airway resistance (R10, p=0.025), improved airway reactance (X10, p=0.005) but significantly worse asthma control (Asthma Control Questionnaire, p=0.007). A significant but weaker association between GORS and asthma symptoms was seen in leans compared with obese in the replicate cohort.

CONCLUSION

GORS are more likely to associate with asthma symptoms in obese children. Better lung function among children reporting gastro-oesophageal reflux and asthma symptoms suggests that misattribution of GORS to asthma may be a contributing mechanism to excess asthma symptoms in obese children.

Asthma is Different in Women

Gender differences in asthma incidence, prevalence and severity have been reported worldwide. After puberty, asthma becomes more prevalent and severe in women, and is highest in women with early menarche or with multiple gestations, suggesting a role for sex hormones in asthma genesis. However, the impact of sex hormones on the pathophysiology of asthma is confounded by and difficult to differentiate from age, obesity, atopy, and other gender associated environmental exposures. There are also gender discrepancies in the perception of asthma symptoms. Understanding gender differences in asthma is important to provide effective education and personalized management plans for asthmatics across the lifecourse.

Asthma in the older adult: presentation, considerations and clinical management

Asthma affects older adults to the same extent as children and adolescents. However, one is led to imagine that asthma prevalence decreases with aging and becomes a rare entity in the elderly. From a clinical perspective, this misconception has nontrivial consequences in that the recognition of the disease is delayed and the treatment postponed. The overall management of asthma in the elderly population is also complicated by specific features that the disease develops in the most advanced ages, and by the difficulties that the physician encounters when approaching the older asthmatic subjects. The current review article aims at describing the specific clinical presentations of asthma in the elderly and highlights the gaps and pitfalls in the diagnostic and therapeutic approaches. Relevant issues with regard to the clinical management of asthma in the elderly are also discussed.

An elevated body mass index increases lung volume but reduces airflow in Italian schoolchildren

Background

Asthma and obesity are important and growing health issues worldwide. Obesity is considered a risk factor for asthma, due to the induction of changes in airway mechanics and altered airway inflammation.

Methods

We cross-sectionally investigated the effect of increased weight on pulmonary function in a large population sample of healthy children, aged 10–17 yrs living in Palermo, Italy. Explanatory effect of weight on lung function variables were evaluated by multiple linear regression models, taking into account height, gender, and age-class.

Results

Among the 2,393 subjects, FVC and FEV₁ were positively correlated to weight. Multiple regression models showed that the weight beta coefficient for FEV₁ was significantly lower with respect to that for FVC (0.005 and 0.009 l/kg, respectively), indicating a different magnitude in explanatory effect of weight on FVC and FEV₁. Both FEV₁/FVC and FEF_25–75%/FVC ratios were negatively correlated to weight, while FEF_25–75% was not significantly correlated. Similar results were obtained also when 807 symptomatic subjects were introduced in the model through a sensitivity analysis.

Conclusion

In healthy children, the disproportionate increase of FEV₁ and FVC with weight produces airflow decrease and consequently apparent poorer lung function independently from respiratory disease status.

Prospective Study on the Relationship of Obesity to Asthma Impairment and Risk

BACKGROUND

Although studies consistently show an association between obesity and increased asthma incidence, the role of obesity in asthma control is less clear.

OBJECTIVE

The objective of this study was to evaluate the association between baseline body mass index (BMI) and measures of subsequent asthma control in a large real-world cohort of adults with persistent asthma.

METHODS

In Kaiser Permanente Southern California (KPSC), a large managed care organization, we identified adults with persistent asthma in 2006, continuous health plan enrollment in 2007 and 2008, and a BMI measurement in 2006 or 2007. Each patient's last BMI measure in 2006 or 2007 was categorized into a BMI group: normal (<25 kg/m(2)), overweight (25-29.9 kg/m(2)), or obese (≥30 kg/m(2)). Asthma control outcomes in 2008 included asthma hospitalizations or emergency department visits (EDHO), oral corticosteroid dispensings linked to an asthma encounter (OCS), and dispensing of ≥7 short-acting beta-agonist canisters (SABA7). Multivariable analyses were conducted to assess the relationships of BMI categories with the risk of the asthma control outcomes after controlling for potential confounders.

RESULTS

In the 10,233 eligible adults-after adjusting for potential demographic, comorbidity, and prior utilization confounders-we found an increased relative risk (RR) of EDHO in overweight and obese (RR 1.40, 95% CI 1.10-1.78) individuals. Only obesity was associated in adjusted analyses with a significant increased relative risk of SABA7 (RR 1.27, 95% CI 1.15-1.40).

CONCLUSIONS

Elevated BMI, particularly obesity, is associated with subsequent poor asthma control, especially in the risk domain (exacerbations). These findings further support the importance of facilitating weight loss in overweight and obese adults with asthma.

Excess weight in preschool children with a history of severe bronchiolitis is associated with asthma

BACKGROUND

The relationship between excess weight gain and asthma in childhood remains inadequately defined. The aim of this study was to evaluate, as part of a prospective post-bronchiolitis follow-up, whether there is a link between earlier or current overweight or obesity and asthma or asthma symptoms at 5-7 years of age.

METHODS

In all, 151 former bronchiolitis patients were followed-up until the mean age of 6.45 years. At the control visit, the weights and heights were measured, and the asthma symptoms and medications for asthma were recorded. The weight status was expressed as body mass index (BMI) z-scores (zBMI).

RESULTS

There were 10 obese and 31 overweight (zBMI over national references) children. In adjusted analyses, presence of current asthma at 6-7 years of age (aOR 3.05, 95% CI 1.02-9.93) differed between overweight and normal weight children. Further, asthma ever, asthma at age 4-5 years, asthma at age 5-6 years, use of bronchodilators ever and use of ICSs during the last 12 months were more common in currently overweight than in normal weight children. Obesity was associated only with current asthma and asthma ever. Instead, there were no significant associations between birth weight, excess weight gain in infancy, or overweight at age 1.5 years, and later asthma, asthma symptoms or use of asthma medication.

CONCLUSION

Asthma was more common in currently overweight than in normal weight former bronchiolitis patients at preschool age and early school age.

Overweight children report qualitatively distinct asthma symptoms: analysis of validated symptom measures

BACKGROUND

Past studies of asthma in overweight/obese children have been inconsistent. The reason overweight/obese children commonly report worse asthma control remains unclear.

OBJECTIVE

To determine qualitative differences in symptoms between lean and overweight/obese children with early-onset, atopic asthma.

METHODS

We conducted a cross-sectional analytic study of lean (20% to 65% body mass index) and overweight/obese (≥85% body mass index) 10- to 17-year-old children with persistent, early-onset asthma. Participants completed 2 to 3 visits to provide a complete history, qualitative and quantitative asthma symptom characterization, and lung function testing. We determined associations between weight status and symptoms using multivariable linear and logistic regression methods.

RESULTS

Overweight/obese and lean asthmatic children displayed similar lung function. Despite lower fraction of exhaled nitric oxide (30.0 vs 62.6 ppb; P = .037) and reduced methacholine responsiveness (PC20FEV1 1.87 vs 0.45 mg/mL; P < .012), overweight/obese children reported more than thrice frequent rescue treatments (3.7 vs 1.1 treatments/wk; P = .0002) than did lean children. Weight status affected the child's primary symptom reported with loss of asthma control (Fisher exact test; P = .003); overweight/obese children more often reported shortness of breath (odds ratio = 11.8; 95% CI, 1.41-98.7) and less often reported cough (odds ratio = 0.26; 95% CI, 0.08-0.82). Gastroesophageal reflux scores were higher in overweight/obese children (9.6 vs 23.2; P = .003) and appear to mediate overweight/obesity-related asthma symptoms.

CONCLUSIONS

Overweight/obese children with early-onset asthma display poorer asthma control and a distinct pattern of symptoms. Greater shortness of breath and β-agonist use appears to be partially mediated via esophageal reflux symptoms. Overweight children with asthma may falsely attribute exertional dyspnea and esophageal reflux to asthma, leading to excess rescue medication use.

Macrophage activation, age and sex effects of immunometabolism in obese asthma

Obese asthma is characterised by infiltration of adipose tissue by activated macrophages and mast cells. The aim of this study was to examine the age and sex effects of immunometabolism in obese asthma. Obese and non-obese asthmatic children and adults underwent spirometry, body composition assessment by dual energy X-ray absorptiometry and measurement of serum soluble CD163 (sCD163), tryptase, C-reactive protein (CRP) and other adipocytokines. Plasma CRP (p<0.01) and leptin (p<0.01) were elevated in obese asthmatic adults, and sCD163 (p=0.003) was elevated in obese asthmatic children. We observed significantly higher sCD163 in obese female children compared to obese female adults and male children, and higher CRP in obese female adults compared to obese male children and adults. Serum tryptase concentrations were not significantly different across age groups. sCD163 positively correlated with the proportion of android fat in obese female children (r=0.70, p=0.003) and obese female adults (r=0.65, p=0.003). In obese female children, sCD163 was inversely associated with forced expiratory volume in 1 s % predicted (r=-0.55, p=0.02) and was positively associated with the Asthma Control Questionnaire (r=0.57, p=0.02). Obese children with asthma have sex-specific macrophage activation, which may contribute to worse asthma control and lung function. The heterogeneous systemic inflammatory profile across age and sex suggests the existence of sub-phenotypes in obese asthma at the molecular level.

Body mass index change and atopic diseases are not always associated in children and adolescents

BACKGROUND

Several studies have suggested an association between the increasing prevalence of allergic diseases and dietary factors.

OBJECTIVE

To prospectively explore the association between changes in body mass index (BMI) and symptoms of asthma, rhinitis, rhinoconjunctivitis, and atopic dermatitis to find out whether an increase in BMI increases the risk of developing atopic diseases in adolescence.

METHODS

Comprehensive questionnaires and anthropometric measurements were applied in a random subsample of the International Study of Asthma and Allergies in Childhood phase II (1995-1996, 9 to 11 years of age) in Germany. Of these participants, 1,794 could be followed up in 2002 to 2003 in the Study on Occupational Allergy Risks (16 to 18 years of age). The associations between changes of BMI from baseline to follow-up and incident and persistent respiratory diseases and atopic dermatitis were assessed.

RESULTS

In logistic regression analyses, weight change in either direction was not statistically significantly associated with the incidence or persistence of any of the diseases of interest except for rhinitis. An increase in BMI was linked to an increased risk of incident rhinitis (odds ratio 1.9, 95% confidence interval 1.2-2.9).

CONCLUSION

These results indicate a nonsignificant trend between increased body weight and risk of atopic diseases. Aside from limitations owing to a small subgroup of obese participants and questionnaire-based asthma diagnosis, reasons might be related to an interaction between BMI and hormonal influences, age, and duration and severity of overweight. The results underline that BMI does not necessarily play a decisive role in the course of atopic diseases in all populations.

Obesity and asthma in children: current and future therapeutic options

With the childhood prevalence of obesity and asthma increasing, it is important for pediatric professionals to appreciate that obesity modifies the diagnosis and management of asthma. These disease modifications present challenges to clinical management, including decreased responsiveness to controller therapy and decreased quality of life compared with normal-weight asthmatic children. While consensus guidelines do not currently suggest specific changes in asthma management for obese patients, management of some patients may be improved with consideration of the latest evidence. This article briefly summarizes what is known regarding the complex relationship between obesity and asthma in children, and discusses practical issues associated with the diagnosis and effective clinical management of asthma in obese children. On average, obese patients with asthma do not respond as well to inhaled corticosteroid therapy. Management approaches including weight loss and routine exercise are safe, and may improve important asthma outcomes. Asthma providers should learn to facilitate weight loss for their obese patients. In addition, pharmacologic interventions for weight loss in obese asthma, though not currently recommended, may soon be considered.

Poor asthma control in obese children may be overestimated because of enhanced perception of dyspnea

BACKGROUND

Although studies in adults have shown a non-TH2 obese asthma phenotype, whether a similar phenotype exists in children is unclear.

OBJECTIVE

We hypothesized that asthmatic children with obesity, defined as a body mass index above the 95th percentile for age and sex, would have poorer asthma control as well as decreased quality of life, increased health care utilization, and decreased pulmonary function measures as a function of increased TH1 versus TH2 polarization.

METHODS

This study involved a post hoc analysis of cross sectional data from 269 children 6 to 17 years of age enrolled in the National Heart, Lung, and Blood Institute Severe Asthma Research Program. Children answered questionnaires and underwent spirometry, plethysmography, exhaled nitric oxide determination, and venipuncture for TH1/TH2 cytokine determination. Asthma control was defined according to national asthma treatment guidelines that are based on prespecified thresholds for lung function and symptom frequency.

RESULTS

Fifty-eight children (22%) were overweight and 67(25%) were obese. Obese children did not have poorer asthma control but were more likely to report nonspecific symptoms such as dyspnea and nocturnal awakenings. Obese children did have decreased asthma-related quality of life and increased health care utilization, but this was not associated with airflow limitation. Instead, obese children had decreased functional residual capacity. A unique pattern of TH1 or TH2 polarization was not observed.

CONCLUSIONS

Poor asthma control in obese children with asthma may be overestimated because of enhanced perception of nonspecific symptoms such as dyspnea that results from altered mechanical properties of the chest wall. Careful assessment of physiologic as well as symptom-based measures is needed in the evaluation of obese children with respiratory symptoms.