Impact of obesity in asthma: evidence from a large prospective disease management study

Leptin, Obesity Parameters, and Atopy Among Children with Asthma

Leptin, as a major adipokine, positively correlates with the body's fat, while atopy is an important feature in the development of childhood asthma. We aimed to evaluate the relationship between leptin, parameters of obesity, and atopy in children with asthma. The study included 112 children (73 boys, 39 girls, mean age 11.1±2.4). 41 were overweight, 38 had asthma and a normal body mass index (BMI), and 33 were overweight asthmatics. Serum leptin levels, BMI, waist circumference (WC), and waist to hips ratio (WHR) were measured. Skin prick test (SPT)/CAP, total serum IgE, fractional exhaled nitric oxide (FeNO), and pulmonary function tests were performed. In asthmatic children, serum leptin median level was 9.2±16.2 ng/ml, in overweight children was 30.6±21.6 ng/ml, and in overweight asthmatics was 31.1±20.3 ng/ml with a significant difference between the groups (p=0.0374), yet with a significantly lower median level in the group of children with asthma compared to the overweight children: with asthma (p=0.00001) and without asthma (p=0.00001). In the three groups of patients, BMI and WC displayed a significant positive correlation with leptin (for BMI r=0.652 vs. r=0.530 vs. r=0.563, respectively and for WC r=0.508 vs. r=0.426 vs. r=0.527, respectively). No significant correlations of leptin within atopy parameters (Eo, IgE, SPT/CAP, FeNO) in all three analyzed groups (p>0.05) was detected. Conclusion: Atopy was not confirmed as an underlying mechanism of the association between asthma and being overweight. Leptin had a significant linear correlation as a parameter of central obesity with BMI and WC in all three groups, but not with WHR.

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.

School-Age Obese Asthmatic Children have Distinct Lung Function Measures From Lean Asthmatics and Obese Children

Background: The lung functions of children with obese asthma seem to be distinct from those of obese children or lean asthmatics.Aim: To measure baseline lung function, exercise-induced bronchoconstriction (EIB), and bronchial hyperreactivity (BHR) in school-age obese asthmatics (OA group) and to compare the data with obese children (O group), lean asthmatics (A group), and healthy controls (H group).Methods: One hundred seventy school-age children were enrolled in this prospective cross-sectional study. Baseline fractionated exhaled nitric oxide (FeNO), and baseline, post-exercise (post-E), and post-bronchodilation (post-BD) impulse oscillometry (IOS) and spirometry tests were performed. EIB and BHR were evaluated based on the difference (Δ) in post-E - baseline, and post-BD - baseline values.Results: The mean FeNO level was higher in the OA group than in the other groups (p = 0.002). Baseline zR5 and R5-20 were higher (p = 0.013 and p = 0.044), but zFEF25-75 was lower (p < 0.01), in the OA group. ΔPost-E - baseline zFEV1 was lower in the A group (p = 0.003) but was higher in the OA group (p = 0.014) than the other groups. ΔPost-BD - baseline zFEV1 was lower in the H group compared to the other three groups (p = 0.004), but no significant difference was observed among the O, A, and OA groups (p > 0.05).Conclusion: A higher airway inflammation (high FeNO), peripheral airway resistance (high zR5 and zR5-20) and a lower peripheral airway flow (low FEF25-75) were observed at baseline measurement in school-age obese asthmatics compared to lean asthmatics and obese children. Obese asthmatics had no EIB but exhibited a similar BHR to that of asthmatics.

Life course body mass index through childhood and young adulthood and risks of asthma and pulmonary function impairment

BACKGROUND

Adiposity is a key risk factor for asthma and impaired pulmonary function.

OBJECTIVES

We aimed to identify the critical period of life course adiposity for asthma in childhood and young adulthood, and to determine whether associations of adiposity and asthma vary across ages.

METHODS

Birth weight and body mass index (BMI) from birth to 17 years of age were assessed in 6130 children from the Taiwan Children Health Study. Logistic regression for asthma outcome and linear regression for pulmonary function outcome were used to investigate associations of adiposity with asthma. Seventeen BMI-related single-nucleotide polymorphisms were used to obtain genetic instrumental variables for adiposity to perform Mendelian randomization (MR) analysis.

RESULTS

Using both regression model and MR analyses, we confirmed that the critical period of adiposity in predicting childhood asthma would be before age 6 years. Further, we discovered that the sensitive period of adiposity gain related to young adulthood asthma was the prepubertal stage. Risks of asthma at age 17 per unit increase in z-score of the BMI increased from 0.94 (95% CI: 0.79-1.11) at birth, and became greater than 1.00 between age 11 and 12, then increased to 1.08 (95% CI: 0.95-1.22) at age 17. The associations of life course BMI with asthma and pulmonary function impairment at age 12 and with asthma at age 17 increased with age. The aforementioned association was most prominent among central obesity indicators.

CONCLUSIONS

To prevent asthma in childhood and young adulthood, we should aim at promoting healthy growth at the toddler period and prepubertal stage.

Associations between overweight and obesity and asthma outcomes in urban adolescents

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

Obesity is a risk factor for exercise-induced bronchospasm in asthmatic adolescents

INTRODUCTION

Exercise-induced bronchospasm (EIB) is common in young asthmatics and obesity is becoming an epidemic in this population. Both conditions can give rise to or worsen respiratory symptoms upon exercise and may interfere with recreational and sports activities.

OBJECTIVE

To investigate the association between obesity and the risk and severity of EIB in asthmatic children and adolescents.

METHODS

This study included data from asthmatic patients aged between 7 and 19 years undergoing treadmill running tests to evaluate EIB, defined as a reduction greater than or equal to 10% in forced expiratory volume in the first second (FEV₁ ) compared to baseline. Eutrophic, obese, and overweight individuals were categorized according to body mass index z-score (eutrophic, -0.5 < z ≤ 1; overweight, 1 < z < 2; and obese, z ≥ 2).

RESULTS

Of the 156 individuals studied (42% female), 58% were eutrophic, 22% overweight, and 19% obese. Seventy-three individuals (47%) presented with EIB, with higher risk among obese (OR, 2.86; 95% CI, 1.00-8.14; P = .05). Asthma severity was another independent risk factor for EIB (OR, 2.95; 95% CI, 1.36-6.42; P = .006). The number of patients in whom FEV₁ returned to baseline values (difference less than 10% from baseline) at the 13th minute after challenge was lower in obese individuals compared to eutrophic and overweight ones (P = .04). Baseline FEV₁ , gender, or age were not found to be risk factors for EIB in any of the groups.

CONCLUSION

Obese youngsters with asthma present a greater risk for EIB with slower recovery than their nonobese peers. Clinicians should be aware of this association, especially in those with more severe disease, for adequate recognition and treatment.

[Asthma and obesity: relationship and therapeutic implications in patients with asthma at the Department of Pneumology in Monastir, Tunisia]

Introduction

L’obésité et l’asthme sont deux maladies chroniques touchant des millions d’individus à travers le monde. La présence d’un lien de causalité est suggérée. L'objectif de notre travail est d'étudier le profil de l’asthmatique obèse et de déterminer la relation entre les différents paramètres de sévérité de l’asthme avec les grades de l’obésité.

Méthodes

Il s'agit d'une étude rétrospective, monocentrique, analytique menée au Service de Pneumologie et d’Allergologie au CHU Fattouma Bourguiba de Monastir portant sur 450 asthmatiques, ayant un indice de masse corporelle (IMC) ≥ 30 kg/m² avec un recul d’au moins 6 mois.

Résultats

L’âge moyen au moment du diagnostic était de 45±12.8 ans. L’IMC moyen était de 34,8±4,2 kg/m². L’asthme était bien contrôlé chez 55,3% des patients. Des critères de sévérité étaient notés dans 37.4% des cas. Selon GINA 2016, 24,2% sont traités par le palier 4. Deux phénotypes de l’asthme associé à l’obésité étaient notés. Le premier phénotype (52,4%) était caractérisé par un asthme à début précoce, associé à une fréquence plus élevée d’allergie, et des manifestations d'atopie. Le deuxième (47,6 %) était caractérisé par un asthme à début tardif, fréquemment associé au sexe féminin et un taux plus élevé de comorbidités et d’hospitalisations. Les obèses de grade II et III avaient un déficit ventilatoire important (CVF: p = 0,002 et VEMS: p = 0,007).

Conclusion

L’obésité est l’un des facteurs clefs impliqués dans le mauvais contrôle de l’asthme. Sa prise en charge, qui n'est pas encore codifiée, doit être multidisciplinaire.

Overweight Proxies Are Associated with Atopic Asthma: A Matched Case-Control Study

BACKGROUND

Many studies have documented a link between overweight and asthma in children with contradictory results regarding the best way to measure overweight. Moreover, often, the dynamic development of atopy, overweight, and asthma is controlled for age dependency insufficiently.

OBJECTIVE

This study assesses and compares the associations of overweight measured as waist circumference, waist to height ratio (WHtR), neck circumference, and body mass index with the occurrence of asthma - best possibly controlling for age-dependencies of these parameters.

METHODS

From a sample of 2,511 children aged 6-17 years, we matched 157 children with asthma with 2 controls (n = 471) according to age and atopy status and performed conditional logistic regression analyses. We further investigated the role of known influencing factors of asthma occurrence.

RESULTS

In children with atopy, all overweight proxies were consistently positively associated with asthma. Statistical significance was reached for WHtR-SD score (OR 1.26, 95% CI 1.03-1.54, p = 0.025) and persisted when further covariates, such as birth weight or social status, were added to the model. Groups of atopic versus nonatopic participants do not differ in levels of interleukin-6 or high-sensitivity C-reactive protein.

CONCLUSION

In our cohort, overweight seems to carry a risk for asthma only if accompanied with atopy. We call for more strict age matching in pediatric cohort studies and longitudinal studies for a better understanding for causal links of overweight, atopy, and asthma.

Association between body mass index and asthma severity in Arab pediatric population: A retrospective study

Increased body mass index (BMI) has been associated with an increased prevalence of asthma in children, however the association between BMI status and asthma severity has been less well defined. The aim of this study was to describe the association between childhood obesity and asthma severity, frequency of hospital and emergency department visits as well as pattern of aeroallergen sensitization. A retrospective study was conducted at pediatric outpatient clinics in University Hospital Sharjah. All consecutive patients aged 6 years and above, with confirmed diagnosis of asthma visiting the outpatient pediatric clinics during 2018 were included in this study. Sources of information were the patient’s medical file, laboratory data, pharmacy data, as well as reports from the pediatric in charge. This study included 164 children with asthma. 63% of asthma patients were male. The vast majority of patients were from Arab ethnicities (n = 154, 94%), majority had mild asthmatic conditions (n = 133, 81%), and one-third were either overweight or obese (n = 52, 32%). Overweight or obese asthmatic children with BMI percentile of equal or more than 85% was associated with more asthma severity (odds ratio [OR]: 3.27, 95% confidence interval [CI]: 1.42–7.54; P = 0.005), as well as more frequent asthma related hospital visits (OR: 2.53, 95% CI: 1.22–5.26; P = 0.013). Overweight asthmatic children with BMI between the 85^th and 94th percentiles and obese asthmatic children with BMI equal to or greater than 95th percentile are associated with more severe asthma phenotype and more frequent hospital and emergency department visits.

Lung Function, Dietary Intake, and Weight Status in Children with Persistent Asthma from Low-Income, Urban Communities

OBJECTIVE

Asthma and obesity are prevalent chronic childhood diseases that commonly co-occur in youth from low-income, minority backgrounds. Diet is a known risk factor for obesity; however, its role in asthma/obesity comorbidity is not well established. This analysis examined the association between diet and lung function and effect modification by weight status.

METHODS

Lung function (FEV1 % predicted), anthropometric, and dietary data were collected from 95 children, ages 7-9 years old with persistent asthma, from low-income, urban communities in the United States. Associations between lung function, diet and weight status were examined using multivariable linear regression.

RESULTS

There were no significant differences in dietary intake between children with persistent asthma with and without obesity; however, >85% of participants did not meet recommendations for fruit, vegetable, and whole grain intake for their age and sex. Only intake of fruit (whole fruit and juice) was significantly associated with FEV1 % predicted (-3.36; 95% CI: -6.5 to -0.2).

CONCLUSIONS

Diet quality was poor in this sample, independent of weight status. More research is needed to understand the relationship between diet, lung function, and weight status, so that interventions can be developed to concurrently address obesity and weight.

The Association between Asthma and Obesity in Children - Inflammatory and Mechanical Factors

BACKGROUND:

Association of asthma and obesity has been demonstrated in numerous epidemiological studies. However, the underlying mechanisms of the association are not well understood. Both conditions are characterised by chronic tissue inflammation, which includes numerous different inflammatory markers, and possible atopy.

AIM:

The study aimed to investigate the association between asthma and obesity in children and assess several of potential underlying mechanisms, including the parameters of systemic inflammation (CRP, fibrinogen) and the mechanical effect of obesity on the respiratory system through parameters of lung function. An additional aim was to examine the role of atopy in overweight children with asthma and to investigate the type of respiratory inflammation.

MATERIAL AND METHODS:

This prospective study included 72 patients in the age group of 7-15 years, including 38 with high body mass index (BMI), 16 with asthma and normal BMI, and 18 with asthma and high BMI for sex and age. Non-specific inflammatory markers (fibrinogen, CRP), eosinophilia, and total serum IgE were investigated. The patients underwent a skin prick test (SPT) with standard inhalant allergen extracts, measurement of fractional exhaled nitric oxide Fe (NO), and an assessment of lung function.

RESULTS:

In overweight groups of children we determined significantly higher values (p < 0.001) of both acute inflammatory reactants, CRP and fibrinogen, with no difference between children with and without asthma. There was a significant increase in eosinophilia, total IgE, and positive SPT in the asthmatic groups compared to the group of non-asthmatic patients (p < 0.001 for the three parameters). Compared to the group composed of overweight patients without asthma, the asthmatic patients had higher NO values (p < 0.001). No significant difference in the lung function parameters was found between the three groups (p > 0.05).

CONCLUSION:

A positive association between asthma and obesity with inflammation as an underlying mechanism, eosinophilic one in asthmatic patients and non-eosinophilic one in overweight patients, was determined. It seems that the lung function parameters did not differ between asthmatic patients and overweight patients. No influence of atopy in the association between asthma and obesity was verified. Further analyses of specific inflammatory markers, for an in-depth evaluation of the mechanisms leading to the association of obesity and asthma, are warranted.

Association between greenhouse working exposure and bronchial asthma: A pilot, cross-sectional survey of 5,420 greenhouse farmers from northeast China

Long-term exposure to greenhouse environments exposes greenhouse workers to inhalation of antigens that can cause respiratory diseases. This study was conducted to investigate the prevalence and potential risk factors for bronchial asthma among the Chinese greenhouse workers based on questionnaire and spirometry data. This was an observational cross-sectional study, performed via stratified-cluster-random sampling. It was conducted in Liaoning Province from the northeast of People's Republic of China, using a population-based sample of 5,880 workers at 835 plastic film greenhouses. All subjects were interviewed using a standardized questionnaire and underwent pulmonary function tests. Multiple logistic regression analysis was conducted to assess associations between self-reported factors of greenhouse worker exposure and bronchial asthma and to identify potential risk factors for this disease. A total of 5,420 questionnaires were completed. The overall prevalence of asthma in greenhouse workers was 19.2% (1040/5420). Multiple logistic regression analysis revealed that the use of multiple pesticides (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.03-1.49), bad odors in the greenhouse (OR = 1.26, 95% CI = 1.07-1.49), and report of the onset of cough when entering the greenhouse (OR = 1.25, 95% CI = 1.09-1.44) were associated with the development of asthma. In contrast, a higher body mass index (BMI >18.5 kg/m^2, OR = 0.93, 95% CI = 0.90-0.95), planting flowers (OR = 0.92, 95% CI = 0.87-0.98), open sidewall to outside (natural ventilation) for at least 30 min per event (OR = 0.82, 95% CI = 0.69-0.96), living in greenhouse (OR = 0.85, 95% CI = 0.73-0.99), and experiencing cough before 14 years old (OR = 0.61, 95% CI = 0.43-0.84) were protective factors to the presentation of asthma among greenhouse workers. Our results suggest that asthma is a major public health problem among Chinese greenhouse workers and more attention should be devoted to preventive measures and management of this disease.

Barriers to daily life physical activities for Brazilian children with asthma: a cross-sectional study

BackgroundObjective: To identify barriers to daily life physical activities (DLPA) and to evaluate physical activity levels for children with asthma and without asthma.Method: This is a cross-sectional study that enrolled 130 children with asthma and 54 non-asthma, from 7 to 12 years old. All of the children in both groups used an accelerometer for 6 consecutive days to assess DLPA and completed a questionnaire to evaluate barriers to physical activity. Accelerometer was used to measure each child's total number of steps, as well as the number of steps and the time spent in moderate-to-vigorous physical activity (MVPA). The barrier questionnaire to DLPA included 11 questions, divided into three domains: personal, social and environmental.Results: The most commonly described barrier to DLPA in the asthma and non-asthma groups was an unsafe environment (23.6% vs 28.5%, respectively). The asthma group reported having asthma (19%) and lack of parental encouragement (17.3%) as being other important barriers to DLPA. It was also observed that the asthma and non-asthma groups presented similar values for the total number of steps (13,379 ± 3,837 vs 14,055 ± 3,914, respectively, p > 0.05), number of steps in MVPA (5,654 ± 1,988 vs. 6,025 ± 2,058, p > 0.05), and time spent in MVPA (46 ± 16 min vs. 50.8 ± 14.7 min, p > 0.05).Conclusions: An unsafe environment is the main barrier to physical activity for Brazilian children. Moreover, a lack of parental encouragement and having asthma were considered to be barriers to physical activity. And lastly, children have similar levels of physical activity whether they have asthma or do not have asthma.

Obesity Trends among Asthma Patients in the United States: A Population-based Study

Background:

Obesity is strongly associated with worse asthma control and poorer quality of life. The current obesity epidemic has reached historically high levels, with an estimated prevalence rate of 37% in the general United States (US) population. However, less is known about trends in the prevalence of obesity among individuals with asthma or which sociodemographic groups are at higher risk for increased weight.

Methods:

The study was conducted with data from the Behavioral Risk Factor Surveillance System (BRFSS) study, a nationally representative probability-based sample of the US population. We included participants ≥18 years of age who were interviewed between 1999 and 2016. Using stratified weighting, we estimated the annual prevalence of participants with, and without a diagnosis of asthma, classified according to their body mass index (BMI), into: normal weight (18.5–25 kg/m²), overweight (25–30 kg/m²), or obese (>30 kg/m²). We calculated the annual odds of obesity among participants with vs. without asthma to assess if trends among individuals with asthma followed those of the general US population. Nominal regression analysis assessed the association between age, sex, race/ethnicity, and income with prevalence of obesity among participants with asthma.

Results:

Among the 543,574 BRSFF participants with asthma, the prevalence of overweight and obesity changed from 34.3% and 24.7% in 1999 to 28.8% and 41.1% in 2016, respectively. The odds ratio (OR) of obesity in patients with asthma compared to the general population without asthma, increased during the same period from 1.39 (95% confidence interval [CI]: 1.36–1.36) in 1999 to 1.75 (95% CI: 1.75–1.76) in 2016. Adjusted analysis showed that older (OR: 2.32, 95% CI: 2.32–2.33), Black (OR: 1.61, 95% CI: 1.61–1.61) and Hispanic (OR: 1.29, 95%. CI: 1.28–1.29) participants with asthma had higher rates of obesity.

Conclusions:

There has been a substantial increase in the prevalence of obesity among individuals with asthma in the last two decades, beyond what could be explained by general population trends. These results suggest that obesity is an increasing determinant of asthma morbidity and should be particularly targeted in minorities with asthma.

Association Between Obesity and Acute Severity Among Patients Hospitalized for Asthma Exacerbation

BACKGROUND

Although studies have demonstrated relations between obesity and incident asthma, little is known about the association of obesity with acute severity in adults hospitalized for asthma exacerbation.

OBJECTIVES

To investigate the association of obesity with acute severity of asthma exacerbation.

METHODS

This is a retrospective cohort study using population-based data of 8 geographically diverse US states from 2010 through 2013. We included adults (age 18-54 years) hospitalized for asthma exacerbation. The outcome measures were markers of acute severity-use of mechanical ventilation (defined by noninvasive positive pressure ventilation and/or invasive mechanical ventilation) and hospital length of stay. To determine the association of obesity with each outcome, we fit multivariable models adjusting for patient-level confounders (eg, age, sex, race/ethnicity, primary insurance, quartiles for household income, residential status, and comorbidities) and potential patient clustering within hospitals.

RESULTS

Among the 72,086 patients hospitalized for asthma exacerbation, 24% were obese. Obesity was associated with a significantly higher risk of any mechanical ventilation use (8.3% vs 5.0%; adjusted odds ratio [OR], 1.77; 95% CI, 1.63-1.92; P < .001) driven by the higher risk of noninvasive positive pressure ventilation use (7.2% vs 3.4%; adjusted OR, 2.14; 95% CI, 1.96-2.35; P < .001). Likewise, obese patients were more likely to have a hospital length of stay of 3 or more days compared with nonobese patients (59.4% vs 46.5%; adjusted OR, 1.37; 95% CI, 1.32-1.43; P < .001). These findings were consistent with stratifications by age, sex, and race/ethnicity.

CONCLUSIONS

In this population-based study of adults hospitalized for asthma exacerbation, obesity was associated with higher acute severity.

Can asthma be well controlled with NAEPP guideline care in morbidly obese children? The Breathmobile

BACKGROUND

Obesity is thought to be associated with poor asthma control, increased health resource utilization, and reduced responsiveness to inhaled corticosteroids.

OBJECTIVE

Based on previous experience, our hypothesis was that by improved access to comprehensive guideline care, outcomes in normal weight would be comparable in obese children with asthma.

METHODS

This was a retrospective cohort study of predominately Hispanic children (3-18 years of age) in underserved areas of Orange County, California, who enrolled in the Breathmobile Program from 2003 to 2012. Outcomes were examined by using Cox regression and generalized estimating equations analyses, adjusted for potential confounding factors.

RESULTS

Clinical outcomes in more than 1,200 children followed up for a mean of 6 visits (standard deviation [SD] = 2.2) across 403 days (SD = 112) were improved, on average, regardless of body mass index (BMI). Morbidly obese (MOB) patients were able to achieve significant reductions of approximately 60% or more in report of emergency department (ED) visits, hospitalizations, school absenteeism, usual exercise limitations, and exacerbations to levels that were comparable those of normal weight (NW) patients. The importance of close follow-up, particularly for the MOB patient, was evidenced by achieving 80% cumulative probability of well controlled asthma by visit 3, similar to patients in lower BMI risk groups with good adherence, when the visit interval did not exceed 90 days. These outcomes were achieved across all BMI groups with similar mean step of therapy, adjusted for severity (P < .001).

CONCLUSION

Access to effective community-based care where trust, education, and continuity of care consistent with National Asthma Education and Prevention Program (NAEPP) guidelines is possible, as demonstrated by the Breathmobile Program, can provide an opportunity for children with asthma in all BMI categories to achieve well-controlled disease.

The impact of maternal smoking during pregnancy on childhood asthma: adjusted for exposure misclassification; results from the National Health and Nutrition Examination Survey, 2011-2012

PURPOSE

We sought to examine the association between childhood asthma and self-reported maternal smoking during pregnancy (MSDP) after adjusting for a range of exposure misclassification scenarios using a Bayesian approach that incorporated exposure misclassification probability estimates from the literature.

METHODS

Self-reported MSDP and asthma data were extracted from National Health and Nutrition Examination Survey 2011-2012. The association between self-reported MSDP and asthma was adjusted for exposure misclassification using a Bayesian bias model approach.

RESULTS

We included 3074 subjects who were 1-15 years of age, including 492 asthma cases. The mean (SD) of age of the participants was 8.5 (4.1) and 7.1 (4.2) years and the number (percentage) of female was 205 (42%) and 1314 (51%) among asthmatic and nonasthmatic groups, respectively. The odds ratio (OR) for the association between self-reported MSDP and asthma in logistic regression adjusted for confounders was 1.28 (95% confidence interval: 0.92, 1.77). In a Bayesian analysis that adjusted for exposure misclassification using external data, we found different ORs between MSDP and asthma by applying different priors (posterior ORs 0.90 [95% credible interval {CRI}: 0.47, 1.60] to 3.05 [95% CRI: 1.73, 5.53] in differential and 1.22 [CRI 95%: 0.62, 2.25] to 1.60 CRI: 1.18, 2.19) in nondifferential misclassification settings.

CONCLUSIONS

Given the assumptions and the accuracy of the bias model, the estimated effect of MSDP on asthma after adjusting for misclassification was strengthened in many scenarios.

Clinical characterization of children with resistant airflow obstruction, a multicenter study

OBJECTIVE

To characterize a cohort of children with airflow limitation resistant to bronchodilator (BD) therapy.

METHODS

Pulmonary function tests performed in children 6-17 years of age at 15 centers in a clinical research consortium were screened for resistant airflow limitation, defined as a post-BD FEV₁ and/or an FEV₁/FVC less than the lower limits of normal. Demographic and clinical data were analyzed for associations with pulmonary function.

RESULTS

582 children were identified. Median age was 13 years (IQR: 11, 16), 60% were males; 62% were Caucasian, 28% were African-American; 19% were obese; 32% were born prematurely and 21% exposed to second hand smoke. Pulmonary diagnoses included asthma (93%), prior significant pneumonia (28%), and bronchiectasis (5%). 65% reported allergic rhinitis, and 11% chronic sinusitis. Subjects without a history of asthma had significantly lower post-BD FEV₁% predicted (p = 0.008). Subjects without allergic rhinitis had lower post-BD FEV₁% predicted (p = 0.003). Children with allergic rhinitis, male sex, obesity and Black race had better pulmonary function post-BD. There was lower pulmonary function in children after age 11 years without a history of allergic rhinitis, as compared to those with a history of allergic rhinitis.

CONCLUSIONS

The most prevalent diagnosis in children with BD-resistant airflow limitation is asthma. Allergic rhinitis and premature birth are common co-morbidities. Children without a history of asthma, as well as those with asthma but no allergic rhinitis, had lower pulmonary function. Children with BD-resistant airflow limitation may represent a sub-group of children with persistent obstruction and high risk for life-long airway disease.

At-risk children with asthma (ARC): a systematic review

Introduction

Asthma attacks are responsible for considerable morbidity and may be fatal. We aimed to identify and weight risk factors for asthma attacks in children (5–12 years) in order to inform and prioritise care.

Methods

We systematically searched six databases (May 2016; updated with forward citations January 2017) with no language/date restrictions. Two reviewers independently selected studies for inclusion, assessed study quality and extracted data. Heterogeneity precluded meta-analysis. Weighting was undertaken by an Expert Panel who independently assessed each variable for degree of risk and confidence in the assessment (based on study quality and size, effect sizes, biological plausibility and consistency of results) and then achieved consensus by discussion. Assessments were finally presented, discussed and agreed at a multidisciplinary workshop.

Results

From 16 109 records, we included 68 papers (28 cohort; 4 case-control; 36 cross-sectional studies). Previous asthma attacks were associated with greatly increased risk of attack (ORs between 2.0 and 4.1). Persistent symptoms (ORs between 1.4 and 7.8) and poor access to care (ORs between 1.2 and 2.3) were associated with moderately/greatly increased risk. A moderately increased risk was associated with suboptimal drug regimen, comorbid atopic/allergic disease, African-American ethnicity (USA), poverty and vitamin D deficiency. Environmental tobacco smoke exposure, younger age, obesity and low parental education were associated with slightly increased risk.

Discussion

Assessment of the clinical and demographic features identified in this review may help clinicians to focus risk reduction management on the high-risk child. Population level factors may be used by health service planners and policymakers to target healthcare initiatives.

Trial registration number

CRD42016037464.

Overweight/obesity status in preschool children associates with worse asthma but robust improvement on inhaled corticosteroids

BACKGROUND

Overweight/obesity (OW) is linked to worse asthma and poorer inhaled corticosteroid (ICS) response in older children and adults.

OBJECTIVE

We sought to describe the relationships between OW and asthma severity and response to ICS in preschool children.

METHODS

This post hoc study of 3 large multicenter trials involving 2- to 5-year-old children compared annualized asthma symptom days and exacerbations among normal weight (NW) (body mass index: 10th-84th percentiles) versus OW (body mass index: ≥85th percentile) participants. Participants had been randomized to daily ICS, intermittent ICS, or daily placebo. Simple and multivariable linear regression was used to compare body mass index groups.

RESULTS

Within the group not treated with a daily controller, OW children had more asthma symptom days (90.7 vs 53.2, P = .020) and exacerbations (1.4 vs 0.8, P = .009) thanNW children did. Within the ICS-treated groups, OW and NW children had similar asthma symptom days (daily ICS: 47.2 vs 44.0 days, P = .44; short-term ICS: 61.8 vs 52.9 days, P = .46; as-needed ICS: 53.3 vs 47.3 days, P = .53), and similar exacerbations (daily ICS: 0.6 vs 0.8, P = .10; short-term ICS: 1.1 vs 0.8 days, P = .25; as-needed ICS: 1.0 vs 1.1, P = .72). Compared with placebo, daily ICS in OW led to fewer annualized asthma symptom days (90.7 vs 41.2, P = .004) and exacerbations (1.4 vs 0.6, P = .006), while similar protective ICS effects were less apparent among NW.

CONCLUSIONS

In preschool children off controller therapy, OW is associated with greater asthma impairment and exacerbations. However, unlike older asthmatic patients, OW preschool children do not demonstrate reduced responsiveness to ICS therapy.

Diet and Asthma: Is It Time to Adapt Our Message?

Asthma is a chronic respiratory disorder which is associated with airway inflammation. Environmental factors, in association with genetic susceptibility, play a critical role in asthma pathophysiology. Inhaled allergens, smoke exposure, indoor and outdoor air pollution are common triggers of asthma symptoms. Although the role of diet has clearly established mechanisms in diseases such as cardiovascular disease, type 2 diabetes, and cancer, it is not commonly identified as a causal factor in asthma. However, some dietary patterns, such as the Western diet, which includes a high intake of refined grains, processed and red meats, and desserts, have pro-inflammatory effects. On the contrary, the Mediterranean diet, with high intake of fruits and vegetables has anti-inflammatory properties. The influence of food on asthma outcomes is of growing interest, but dietary habits of asthma patients are not commonly investigated in clinical practice. In this review, we focus on the impact of diet on asthma risk and asthma control. We also detail the influence of diet on obese patients with asthma.

The weighty issue of obesity in paediatric respiratory medicine

Some have observed that developed world is fat and getting fatter. This is even extending into the developing world, and it is important to appreciate that the consequences of childhood obesity last into adulthood and are associated with premature death. From the paediatric respiratory perspective, the deposition of excess adipose tissue in the thoraco-abdominal region begins early in life and is believed to alter diaphragm mobility and chest wall expansion, reduce lung compliance, and result in a rapid shallow breathing pattern with an increased work of breathing and reduction in maximum ventilatory capacity. This results in respiratory symptoms of exertional dyspnoea related to deconditioning which may present as exercise limitation, leading to confusion with common lung diseases such as asthma. The manifestations of the increasingly prevalent problems of overweight and obesity in young people and their interaction with common conditions of asthma and obstructive sleep apnoea will be discussed.

Contribution of weight status to asthma prevalence racial disparities, 2-19 year olds, 1988-2014

PURPOSE

Racial disparities in childhood asthma prevalence increased after the 1990s. Obesity, which also varies by race/ethnicity, is an asthma risk factor but its contribution to asthma prevalence disparities is unknown.

METHODS

We analyzed nationally representative National Health Examination and Nutrition Survey data for 2-19 year olds with logistic regression and decomposition analyses to assess the contributions of weight status to racial disparities in asthma prevalence, controlling for sex, age, and income status.

RESULTS

From 1988-1994 to 2011-2014, asthma prevalence increased more among non-Hispanic black (NHB) (8.4% to 18.0%) than non-Hispanic white (NHW) youth (7.2% to 10.3%). Logistic regression showed that obesity was an asthma risk factor for all groups but that a three-way "weight status-race/ethnicity-time" interaction was not significant. That is, weight status did not modify the race/ethnicity association with asthma over time. In decomposition analyses, weight status had a small contribution to NHB/NHW asthma prevalence disparities but most of the disparity remained unexplained by weight status or other asthma risk factors (sex, age and income status).

CONCLUSIONS

NHB youth had a greater asthma prevalence increase from 1988-1994 to 2011-2014 than NHW youth. Most of the racial disparity in asthma prevalence remained unexplained after considering weight status and other characteristics.

Obese asthmatic patients have decreased surfactant protein A levels: Mechanisms and implications

BACKGROUND

Eosinophils are prominent in some patients with asthma and are increased in the submucosa in a subgroup of obese patients with asthma (OAs). Surfactant protein A (SP-A) modulates host responses to infectious and environmental insults.

OBJECTIVE

We sought to determine whether SP-A levels are altered in OAs compared with a control group and to determine the implications of these alterations in SP-A levels in asthmatic patients.

METHODS

Bronchoalveolar lavage fluid from 23 lean, 12 overweight, and 20 obese subjects were examined for SP-A. Mouse tracheal epithelial cells grown at an air-liquid interface were used for mechanistic studies. SP-A^-/- mice were challenged in allergen models, and exogenous SP-A therapy was given after the last challenge. Eosinophils were visualized and quantitated in lung parenchyma by means of immunostaining.

RESULTS

Significantly less SP-A (P = .002) was detected in samples from OAs compared with those from control subjects. A univariable regression model found SP-A levels were significantly negatively correlated with body mass index (r = -0.33, P = .014), whereas multivariable modeling demonstrated that the correlation depended both on asthma status (P = .017) and the interaction of asthma and body mass index (P = .008). Addition of exogenous TNF-α to mouse tracheal epithelial cells was sufficient to attenuate SP-A and eotaxin secretion. Allergen-challenged SP-A^-/- mice that received SP-A therapy had significantly less tissue eosinophilia compared with mice receiving vehicle.

CONCLUSIONS

SP-A functions as an important mediator in resolving tissue and lavage fluid eosinophilia in allergic mouse models. Decreased levels of SP-A in OAs, which could be due to increased local TNF-α levels, might lead to impaired eosinophil resolution and could contribute to the eosinophilic asthma phenotype.

Lifestyle Risk Factors for Weight Gain in Children with and without Asthma

A higher proportion of children with asthma are overweight and obese compared to children without asthma; however, it is unknown whether asthmatic children are at increased risk of weight gain due to modifiable lifestyle factors. Thus, the aim of this cross-sectional study was to compare weight-gain risk factors (sleep, appetite, diet, activity) in an opportunistic sample of children with and without asthma. Non-obese children with (n = 17; age 10.7 (2.4) years) and without asthma (n = 17; age 10.8 (2.3) years), referred for overnight polysomnography, underwent measurement of lung function, plasma appetite hormones, dietary intake and food cravings, activity, and daytime sleepiness. Sleep latency (56.6 (25.5) vs. 40.9 (16.9) min, p = 0.042) and plasma triglycerides (1.0 (0.8, 1.2) vs. 0.7 (0.7, 0.8) mmol/L, p = 0.013) were significantly greater in asthmatic versus non-asthmatic children. No group difference was observed in appetite hormones, dietary intake, or activity levels (p > 0.05). Sleep duration paralleled overall diet quality (r = 0.36, p = 0.04), whilst daytime sleepiness paralleled plasma lipids (r = 0.61, p =0.001) and sedentary time (r = 0.39, p = 0.02). Disturbances in sleep quality and plasma triglycerides were evident in non-obese asthmatic children referred for polysomnography, versus non-asthmatic children. Observed associations between diet quality, sedentary behavior, and metabolic and sleep-related outcomes warrant further investigation, particularly the long-term health implications.

Impaired glucose metabolism and bronchial hyperresponsiveness in obese prepubertal asthmatic children

INTRODUCTION

The prevalence of asthma and obesity has risen in parallel over the last decades, but the exact mechanisms linking these two diseases still remain unclear. The aim of the present study was to investigate the associations between bronchial hyperresponsiveness (BHR), impaired glucose metabolism, obesity, and asthma in prepubertal children.

METHODS

A total of 71 prepubertal children were included in the study and divided in four groups according to the presence of asthma and their Body Mass Index (BMI): Group 1-Healthy Controls (HC), Group 2-Non Obese Asthmatics (NOA), Group 3-Obese Non Asthmatics (ONA), Group 4-Obese Asthmatics (OA) Αll children underwent spirometry and bronchial hyperresponsiveness testing by using the cumulative Provoking Dose of mannitol (PD_15, primary study variable); homeostasis model assessment-estimated insulin resistance (HOMA-IR) index was calculated in order to evaluate insulin resistance. Obese children also underwent an oral glucose tolerance testing (OGTT).

RESULTS

A statistically significant difference in bronchial hyperreactivity (mean ± SD) was detected in the group of obese asthmatic children who had lower values ​​of PD₁₅ , (174.16 ± 126.42) as compared to normal weight asthmatic children (453.93 ± 110.27), (P < 0.001). Moreover, obese asthmatic children with confirmed insulin resistance (HOMA-IR ≥2.5), had significantly lower PD₁₅ values (89.05 ± 42.75) as ​​compared to those with HOMA-IR <2.5 (259.27 ± 125.75), (P = 0.006). Finally, obese asthmatic children with impaired OGTT had likewise significantly lower PD₁₅ (81.02 ± 42.16) measurements as compared to children with normal OGTT (267.3 ± 112.62), (P = 0.001).

CONCLUSION

Our findings suggest that obesity per se does not correlate to airway hyperreactivity unless it is accompanied by glucose intolerance and insulin resistance. Pediatr Pulmonol. 2017;52:160-166. © 2016 Wiley Periodicals, Inc.

Lack of Recognition, Diagnosis, and Treatment of Overweight/Obesity in Children Hospitalized for Asthma

OBJECTIVES

Information is lacking regarding recognition and treatment of overweight and obesity in children hospitalized for asthma. The study objectives were to determine the current practice of recognition, diagnosis, and treatment of overweight and obesity for children hospitalized for asthma and to describe demographic, asthma, and weight characteristics for these patients.

METHODS

A retrospective record review was conducted for children admitted to the hospital with asthma in 2012. Charts were reviewed for evidence of recognition, diagnosis, and treatment of overweight and obesity. Subjects were classified into age-adjusted Centers for Disease Control and Prevention weight categories based on BMI percentile and chronic asthma severity categories according to National Asthma Education and Prevention Program guidelines.

RESULTS

A total of 510 subjects aged 3 to 17 years were studied. Obesity was present in 19.6% and overweight in 13.3% of subjects. BMI percentile was recorded in only 3.3% of all charts, in only 11% of subjects with obesity, and in 0% of subjects with overweight. BMI percentile was documented more often in subjects with severe obesity (P = .013) and with moderate to severe persistent asthma (P = .035). Only 9 of 168 subjects who were overweight or obese (5.6%) were given a discharge diagnosis indicating overweight or obesity, and 14 (8.3%) received treatment. Chronic asthma severity differed by BMI weight category (P < .001), with a significant relationship between obesity status and chronic asthma severity in older subjects (P = .033). There were no differences in severity of acute episodes based on weight group.

CONCLUSIONS

Overweight and obesity were underrecognized, underdiagnosed, and undertreated in children hospitalized for asthma.

Burden of Obesity on Pediatric Inpatients with Acute Asthma Exacerbation in the United States

BACKGROUND

Obesity and asthma are common health problems in the United States.

OBJECTIVE

The objective of this study was to evaluate the clinical and economic burdens of obesity on hospitalized children with acute asthma exacerbation in 2012.

METHODS

Hospital discharge records of patients aged 2 to 18 years with a diagnosis of asthma were obtained from the 2012 Kids' Inpatient Database, wherein the data were compiled by the Agency for Healthcare Research and Quality. The discharge records were weighted to estimate the number of hospitalizations because of asthma exacerbations in the United States. To classify whether the patient was obese or not, we used the International Classification of Diseases, Ninth Revision, Clinical Modification code 278.0x. We compared the odds of using noninvasive or invasive mechanical ventilation, mean total charges for inpatient service, and length of hospital stay between obese and nonobese patients.

RESULTS

A total of 74,338 patient discharges were extracted. Of these, 3,494 discharges were excluded because of chronic medical conditions. Using discharge weight variables, we estimated a total of 100,157 hospitalizations with asthma exacerbations among children aged between 2 and 18 years in 2012. Obesity was significantly associated with higher odds of using mechanical ventilation (odds ratio 1.59, 95% CI 1.28-1.99), higher mean total hospital charges (adjusted difference: $1588, 95% CI $802-$2529), and longer mean length of hospital stay (0.24 days, 95% CI 0.17-0.32 days) compared with nonobesity.

CONCLUSIONS

These findings suggest that obesity is a significant risk factor of severe asthma exacerbation that requires mechanical ventilation, and obesity is an economically complicating factor.

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.

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

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

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.

Relationship Between Functional Exercise Capacity and Lung Functions in Obese Chidren

OBJECTIVE

Cardiovascular, respiratory and musculoskeletal system disorders which may affect the functional exercise capacity are common in obese patients. We aimed to investigate the functional exercise capacity and its relationship with functional pulmonary capacity in obese children.

METHODS

A total of 74 obese and 36 healthy children as a control group were enrolled in the study. Pulmonary functions and functional exercise capacity were measured by spirometry and six-minute walk test (6 MWT), respectively.

RESULTS

The distances covered during the 6 MWT in obese and control groups were 570.9 ± 67.5 and 607.8 ± 72.5 meters, respectively (p=0.010). In spirometric pulmonary function tests (PFTs), forced expiratory volume in 1 sec (FEV1) and forced mid-expiratory flows (25-75) were lower in the obese group (p=0.048 and p=0.047, respectively), whereas forced vital capacity (FVC), the FEV1/FVC ratio and peak expiratory flow were not statistically different between the obese and control groups. Multiple regression analysis revealed that among all parameters of anthropometric measures and PFTs, only body mass index standard deviation score (BMI-SDS) was the independent factor influencing 6 MWT.

CONCLUSION

Functional exercise and lung capacities of obese children were diminished as compared to those of non-obese children. The most important factor influencing functional exercise capacity was BMI-SDS.

Obesity and asthma: current knowledge and future needs

PURPOSE OF REVIEW

Obesity has significant impact on asthma incidence and manifestations. The purpose of the review is to discuss recent observations regarding the association between obesity and asthma focusing on underlying mechanisms, clinical presentation, response to therapy and effect of weight reduction.

RECENT FINDINGS

Clinical and epidemiological studies indicate that obese patients with asthma may represent a unique phenotype, which is more difficult to control, less responsive to asthma medications and by that may have higher healthcare utilization. A number of common comorbidities have been linked to both obesity and asthma, and may, therefore, contribute to the obese-asthma phenotype. Furthermore, recently published studies indicate that even a modest weight reduction can improve clinical manifestations and outcome of asthma.

SUMMARY

Compared with normal-weight patients, obese and overweight patients with asthma have poorer asthma control and respond less to corticosteroid therapy. Future studies focusing on the mechanism underlying both obesity and asthma including the obese-asthma phenotype are required to better characterize the link between the conditions and target the management of this patient group.

Chronic disease management programmes for adults with asthma

BACKGROUND

The burden of asthma on patients and healthcare systems is substantial. Interventions have been developed to overcome difficulties in asthma management. These include chronic disease management programmes, which are more than simple patient education, encompassing a set of coherent interventions that centre on the patients' needs, encouraging the co-ordination and integration of health services provided by a variety of healthcare professionals, and emphasising patient self-management as well as patient education.

OBJECTIVES

To evaluate the effectiveness of chronic disease management programmes for adults with asthma.

SEARCH METHODS

Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register, MEDLINE (MEDLINE In-Process and Other Non-Indexed Citations), EMBASE, CINAHL, and PsycINFO were searched up to June 2014. We also handsearched selected journals from 2000 to 2012 and scanned reference lists of relevant reviews.

SELECTION CRITERIA

We included individual or cluster-randomised controlled trials, non-randomised controlled trials, and controlled before-after studies comparing chronic disease management programmes with usual care in adults over 16 years of age with a diagnosis of asthma. The chronic disease management programmes had to satisfy at least the following five criteria: an organisational component targeting patients; an organisational component targeting healthcare professionals or the healthcare system, or both; patient education or self-management support, or both; active involvement of two or more healthcare professionals in patient care; a minimum duration of three months.

DATA COLLECTION AND ANALYSIS

After an initial screen of the titles, two review authors working independently assessed the studies for eligibility and study quality; they also extracted the data. We contacted authors to obtain missing information and additional data, where necessary. We pooled results using the random-effects model and reported the pooled mean or standardised mean differences (SMDs).

MAIN RESULTS

A total of 20 studies including 81,746 patients (median 129.5) were included in this review, with a follow-up ranging from 3 to more than 12 months. Patients' mean age was 42.5 years, 60% were female, and their asthma was mostly rated as moderate to severe. Overall the studies were of moderate to low methodological quality, because of limitations in their design and the wide confidence intervals for certain results.Compared with usual care, chronic disease management programmes resulted in improvements in asthma-specific quality of life (SMD 0.22, 95% confidence interval (CI) 0.08 to 0.37), asthma severity scores (SMD 0.18, 95% CI 0.05 to 0.30), and lung function tests (SMD 0.19, 95% CI 0.09 to 0.30). The data for improvement in self-efficacy scores were inconclusive (SMD 0.51, 95% CI -0.08 to 1.11). Results on hospitalisations and emergency department or unscheduled visits could not be combined in a meta-analysis because the data were too heterogeneous; results from the individual studies were inconclusive overall. Only a few studies reported results on asthma exacerbations, days off work or school, use of an action plan, and patient satisfaction. Meta-analyses could not be performed for these outcomes.

AUTHORS' CONCLUSIONS

There is moderate to low quality evidence that chronic disease management programmes for adults with asthma can improve asthma-specific quality of life, asthma severity, and lung function tests. Overall, these results provide encouraging evidence of the potential effectiveness of these programmes in adults with asthma when compared with usual care. However, the optimal composition of asthma chronic disease management programmes and their added value, compared with education or self-management alone that is usually offered to patients with asthma, need further investigation.

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.

Piecewise Mixed Effects Model to Compare the Weight-gain Patter ns Before and After Diagnosis of Asthma in Children Younger than 5 Years

Asthma and obesity are two significant public health problems that both originate in early childhood and have shared risk factors and manifestations. Studies suggest a strong association between asthma development and subsequent accelerated weight gain. Children are diagnosed with asthma in early childhood and are often exposed to factors associated with rapid weight gain. This article intends to demonstrate an innovative application of the piecewise mixed effects model to characterize the difference in the temporal rate of change in BMIz, the standardized scores of body mass index and weight-for-length that measure weight status, before and after asthma diagnosis in children younger than 5 years. The data consist of unique sequences from 1194 children's clinic visits during the first 5 years of life. We used a knot at the time of diagnosis and detected a differential weight-gain pattern before and after asthma diagnosis. The pre- and post-asthma-diagnosis weight-gain patterns further differ by sex and race-ethnicity. After asthma diagnosis, female children showed a higher increase in the rate of change in BMIz than males. Non-Hispanic African Americans and Hispanics had higher post-diagnosis rates of change in BMIz than Caucasians. The differential weight-gain patterns between male and female children were mainly contributed by Caucasian children. These findings could have important implications in the clinical care of children after asthma diagnosis.

Effects of dietary induced weight loss on exercise-induced bronchoconstriction in overweight and obese children

RATIONALE

Previous studies showed that obesity in asthmatic children is associated with more severe exercise-induced bronchoconstriction (EIB), compared with non-obese asthmatic children. This study investigates the effect of weight loss on EIB in overweight and obese asthmatic children.

METHODS

In this intervention study, children aged 8-18 years with EIB and moderate to severe overweight, followed a diet based on healthy daily intake for 6 weeks. Before and after the diet period they underwent an exercise challenge test in cold air. Primary outcome was change in exercise-induced fall in FEV1 and relation between weight loss and EIB. Secondary outcomes were changes in recovery of FEV1 ("area under the curve"; AUC), fraction of exhaled nitric oxide (FeNO) and scores of the Pediatric Asthma Quality of Life Questionnaire (PAQLQ) and Asthma Control Questionnaire (ACQ).

RESULTS

Twenty children completed the study. After the diet period, weight, and body mass index (BMI) were significantly reduced (changes respectively -2.6% and -1.5 kg/m(2), P < 0.01). There was a significant improvement of the percentage exercise-induced fall in FEV1 (30.6% vs. 21.8%, P < 0.01), AUC and PAQLQ score. The reduction in BMI z-score was significantly related to the reduction in the percentage exercise-induced fall in FEV1 in children that lost weight (r = 0.53, P = 0.03). There were no changes in FeNO and ACQ.

CONCLUSIONS

Dietary induced weight loss in overweight and obese asthmatic children leads to significant reduction in severity of EIB and improvement of the quality of life. The reduction in BMI z-score is significantly related to the improvement of EIB.

Asthma and insulin resistance in obese children and adolescents

BACKGROUND

Obese children and adolescents have an increased risk for asthma. A few studies have evaluated the association of insulin resistance and asthma in obese pediatric populations. We examined whether there was a relationship between high degrees of insulin resistance and the presence of asthma in obese children and adolescents.

METHODS

A total of 153 patients aged 4-15 years with at or above the 95th percentile BMI for age were prospectively recruited. Assessments included diagnosis of asthma, skin prick test reactivity to common environmental aeroallergens, and HOMA estimated insulin resistance, with the median (2.22) used as a cutoff value to categorize insulin resistance.

RESULTS

There were 56 (36.6%) asthmatic and 97 (63.4%) non-asthmatic patients. HOMA values were significantly associated with positive skin tests (p = 0.008) and allergic asthma diagnosis (p = 0.016). Baseline insulin value was significantly associated with the risk of presenting asthma with positive skin testing (odds ratio 1.084, p = 0.037). Differences in age, BMI, and waist circumference were found between the groups of HOMA-IR <2.22 and ≥2.22. Waist circumference (WC) was significantly associated with FVC (p = 0.0001) and FEV1 (p < 0.0003); the greater the WC, the lower FVC and FEV1 values.

CONCLUSIONS

Insulin resistance is a risk for allergic asthma in obese children and adolescents. Waist circumference was related to CVF and FEV1 impairment.

Childhood obesity and risk of allergy or asthma

The simultaneous increment in the prevalence of obesity and allergic diseases suggests a possible link between them. This review focuses on the consequences of obesity on allergic diseases, especially asthma in children and adolescents, and evaluates the available evidence on the possible mechanisms. Obesity is related more strongly to nonatopic than atopic asthma, suggesting non-eosinophilic inflammation and Th1 polarization. Among other allergic diseases, the association is more consistent with eczema compared to allergic rhinitis/rhinoconjunctivitis. The mechanisms of asthma in obese individuals could involve mechanical effects of obesity on lung function, adipokines-mediated inflammation, shared factors (diet, genetics, sedentary lifestyle) and comorbidities.

Obesity and asthma: association or epiphenomenon?

OBJECTIVE

To relate obesity and asthma by comparing gender, age, initial classification of asthma, clinical control, basal forced expiratory volume in one second (FEV1) and forced expiratory flow between 25 and 75% (FEF25-75%) with rates of body mass index (BMI) in asthmatic adolescents.

METHODS

Cross-sectional study involving 120 asthmatics patients (1.9 male: 1 female) with a mean age of 14.1 years (9 to 20.1 years of age), classified according to asthma severity and control, and evaluated by spirometry using their basal FEV1 and FEF25-75%. The data were described by frequency, mean and standard deviation or median and range and analyzed by ANOVA, unpaired t test, Fischer's exact test, Kruskal-Wallis and Pearson's correlation, considering significant p<0.05.

RESULTS

There was no difference between gender in relation to the initial classification and the level of asthma control; 91.7% (100 cases) received initial classification as persistent and 106 cases (88.3%) were partially or totally controlled. There was no statistical difference between controlled patients and the others in relation to BMI. No significant correlations were found between zBMI and FEV1 and between zBMI and FEF25-75%, analyzing all patients and only patients with overweight or obese.

CONCLUSIONS

In this study, no significant correlation was found between overweight/obesity and asthma using clinical, anthropometric and spirometric parameters.

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.

Obesity and its effects on pediatric supracondylar humeral fractures

BACKGROUND

This study evaluates the effects of childhood obesity on fracture complexity and associated injuries in pediatric supracondylar humeral fractures.

METHODS

A billing query identified all patients who were two to eleven years of age and had undergone operative treatment for extension-type supracondylar humeral fractures over a 12.5-year period. Records were reviewed for demographic data, body mass index percentile, and injury data. Complex fractures were defined as type-3 supracondylar humeral fractures, supracondylar humeral fractures with intercondylar extension, or supracondylar humeral fractures with ipsilateral upper-extremity fractures. Logistic regression analyses were used to test relationships among body mass index subgroups, fracture complexity, elbow motion, preoperative and postoperative neurovascular status, and complications.

RESULTS

Three hundred and fifty-four patients met our inclusion criteria. Forty-one children were underweight (BMI in the <5th percentile), 182 were normal weight (BMI in the 5th to 85th percentile), sixty-three were overweight (BMI in the >85th to 95th percentile), and sixty-eight were obese (BMI in the >95th percentile). There were 149 patients, eleven of whom were obese, with isolated type-2 fractures and 205 patients, fifty-seven of whom were obese, with complex fractures. Thirty-two patients had preoperative nerve palsies and twenty-eight patients had postoperative nerve palsies. Using logistic regression, obesity was associated with complex fractures (odds ratio, 9.19 [95% confidence interval, 4.25 to 19.92]; p < 0.001), preoperative nerve palsies (odds ratio, 2.69 [95% confidence interval, 1.15 to 6.29]; p = 0.02), postoperative nerve palsies (odds ratio, 7.69 [95% confidence interval, 2.66 to 22.31]; p < 0.001), and postoperative complications (odds ratio, 4.03 [95% confidence interval, 1.72 to 9.46]; p < 0.001). Additionally, obese patients were more likely to sustain complex fractures from a fall on an outstretched hand than normal-weight patients (odds ratio, 13.00 [95% confidence interval, 3.44 to 49.19]; p < 0.001).

CONCLUSIONS

Obesity is associated with more complex supracondylar humeral fractures, preoperative and postoperative nerve palsies, and postoperative complications. To our knowledge, this study is the first to assess the implications of obesity on supracondylar humeral fracture complexity and associated injuries and it validates public health efforts in combating childhood obesity.

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.

Diet-induced weight loss in obese children with asthma: a randomized controlled trial

BACKGROUND

Obesity is highly prevalent in asthmatic children and associated with worse clinical outcomes. Energy restriction to induce weight loss in asthmatic children has not been investigated in a randomized controlled trial (RCT).

OBJECTIVE

To assess if (1) weight loss can be achieved in obese asthmatic children using a dietary intervention; and (2) changes in asthma outcomes occur following diet-induced weight loss.

METHODS

In a 10-week pilot RCT, obese asthmatic children, aged 8-17 years, were randomized to a wait-list control (WLC) (n = 15) or dietary-intervention group (DIG) (n = 13). Lung function, Asthma Control Questionnaire (ACQ) score, and sputum and systemic inflammation were assessed at baseline and post-intervention. (Australian New Zealand Clinical Trials Registry: ACTRN12610000955011).

RESULTS

Body mass index (BMI) z-score reduced significantly in the DIG vs. the WLC (-0.2 [-0.4, -0.1] vs. 0.0 [-0.1, 0.0], P = 0.014). Expiratory reserve volume (ERV) increased significantly within the DIG, but not compared to the WLC (0.7 [0.0, 1.0] L vs. 0.3 [0.0, 0.8] L, P = 0.355). ACQ improved significantly in the DIG, compared to the WLC (-0.4 [-0.7, 0.0] vs. 0.1 [0.0, 0.6], P = 0.004). Airway and systemic inflammation did not change within the DIG. In comparison, C-Reactive Protein (CRP) increased significantly in the WLC (-0.4 [-0.5, 0.4] vs. 0.7 [-0.1, 1.9], P = 0.037). Change (∆) in BMI z-score correlated with ∆CRP (r = 0.47, P = 0.012) and ∆exhaled nitric oxide (eNO) (r = 0.46, P = 0.034), and ∆ACQ was associated with ∆CRP (r = 0.43, P = 0.029).

CONCLUSION AND CLINICAL RELEVANCE

Dietary intervention can induce acute weight loss in obese asthmatic children with subsequent improvements in static lung function and asthma control. Systemic and airway inflammation did not change following weight loss. However, changes in BMI z-score were associated with changes in airway and systemic inflammation and this requires further investigation in a larger RCT. This is the first weight loss RCT conducted in obese asthmatic children. Diet-induced weight loss can achieve significant improvements in clinical outcomes for obese children with asthma.