Boys with high body masses have an increased risk of developing asthma: findings from the National Longitudinal Survey of Youth (NLSY)

Obesity-related asthma in children and adolescents

There is substantial epidemiological and experimental evidence of an obesity-related asthma phenotype. Compared to children of healthy weight, children with obesity are at higher risk of asthma. Children with obesity who have asthma have greater severity and poorer control of their asthma symptoms, more frequent asthma exacerbations, and overall lower asthma-related quality of life than children with asthma who have a healthy weight. In this Review, we examine some of the latest evidence on the characteristics of this phenotype and its main underlying mechanisms, including genetics and genomics, changes in airway mechanics and lung function, sex hormone differences, alterations in immune responses, systemic and airway inflammation, metabolic dysregulation, and modifications in the microbiome. We also review current recommendations for the treatment of these children, including in the management of their asthma, and current evidence for weight loss interventions. We then discuss initial evidence for potential novel therapeutic approaches, such as dietary modifications and supplements, antidiabetic medications, and statins. Finally, we identify knowledge gaps and future directions to improve our understanding of asthma in children with obesity, and to improve outcomes in these susceptible children. We highlight important needs, such as designing paediatric-specific studies, implementing large multicentric trials with standardised interventions and outcomes, and including racial and ethnic groups along with other under-represented populations that are particularly affected by obesity and asthma.

Cytokines Profile and Lung Function in Children with Obesity and Asthma: A Case Control Study

The existence of common inflammatory biomarkers linking obesity and asthma in children has been hypothesized. Nevertheless, laboratory and clinical characteristics of children with obesity and asthma are still poorly defined. The primary aim of the present study is to investigate the lung function and the cytokine profile, in children with obesity and asthma. In this prospective, cross-sectional pilot study, pulmonary function tests, biochemical parameters, and serum cytokines levels were compared in three groups of 28 children each, matched for age and sex. Obese children showed normal forced spirometry values except an increased distal airway resistance in subjects with obesity and no asthma. Both groups including obese children showed higher leptin and IL-10 levels and lower adiponectin and TNF-alpha levels compared to children with no obesity and asthma. IL-33 and TGF-beta1 levels were higher in children with obesity and asthma vs. children with normal weight and asthma. Finally, IL-6 was undetectable in approximately 70% of obese children with no asthma, in 57% obese asthmatic children and in 100% of children with normal-weight and asthma. Children with obesity and asthma show the most striking cytokine profile, suggesting a pro-inflammatory role of fat mass in asthma development.

Asthma interactions between obesity and other risk factors

OBJECTIVE

To review and critically discuss published evidence on interactions between obesity and selected risk factors on asthma in children and adults, and to discuss potential future directions in this field.

DATA SOURCES

National Library of Medicine (via PubMed) STUDY SELECTION: A literature search was conducted for human studies on obesity and selected interactions (with sex, race and ethnicity, socioeconomic status, indoor and outdoor pollutants, depression, anxiety, and diet) on asthma. Studies that were published in English and contained a full text were considered for inclusion in this review.

RESULTS

Current evidence supports interactions between obesity and outdoor and indoor air pollutants (including second-hand smoke [SHS]) on enhancing asthma risk, although there are sparse data on the specific pollutants underlying such interactions. Limited evidence also suggests that obesity may modify the effects of depression or anxiety on asthma, whereas little is known about potential interactions between obesity and sex-hormone levels or dietary patterns.

CONCLUSION

Well-designed observational prospective studies (eg, for pollutants and sex hormones) and randomized clinical trials (eg, for the treatment of depression) should help establish the impact of modifying coexisting exposures to reduce the harmful effects of obesity on asthma. Such studies should be designed to have a sample size that is large enough to allow adequate testing of interactions between obesity and risk factors that are identified a priori and thus, well characterized, using objective measures and biomarkers (eg, urinary or serum cotinine for SHS, epigenetic marks of specific environmental exposures).

Association of Growth Trajectory Profiles with Asthma Development in Infants Hospitalized with Bronchiolitis

BACKGROUND

Little is known about the relationship of longitudinal growth trajectory in early life with asthma development, particularly in infants with bronchiolitis (a high-risk population).

OBJECTIVE

Among infants with bronchiolitis, we aimed to identify growth trajectory profiles and determine their longitudinal relationship with the risk for developing childhood asthma.

METHODS

A multicenter prospective study enrolled infants (aged <1 year) hospitalized for bronchiolitis. We identified growth trajectory profiles-derived from body mass index-for-age at ages 0, 6, 12, 15, 18, 24, and 36 months by using a longitudinal clustering method. We examined associations between growth trajectory profiles and asthma development by age 5 years.

RESULTS

The analytic cohort consists of 880 infants hospitalized for bronchiolitis (median age, 3 months). Overall, 26% developed asthma by age 5 years. The longitudinal clustering identified 5 distinct profiles: persistent low growth (27%), normative growth (33%), transient overweight (21%), late-onset overweight (16%), and persistent obesity (3%) profiles. In multivariable model, compared with children with a normative profile, those with a persistent obesity profile had significantly higher risks of developing asthma (24% vs 38%, odds ratio [OR]: 2.55, 95% confidence interval [CI]: 1.07-6.09, P = .03). Among children with a persistent obesity profile, those without allergic predisposition had significantly higher risks of asthma (OR: 3.02, 95% CI: 1.05-8.64, P = .04 in the nonparental allergic history group; OR: 3.18, 95% CI: 1.02-9.92, P = .047 in the non-IgE sensitization group), whereas those with allergic predisposition were not at increased risk.

CONCLUSIONS

This multicenter cohort study of infants with bronchiolitis demonstrated distinct growth trajectory profiles that have differential risks for developing asthma.

The modifiable biopsychosocial drivers of psychological distress for adolescents with asthma: Implications for Clinical Care

PURPOSE

Overwhelming distress exceeds the capacity of healthy coping strategies to feel better using healthy coping strategies alone, resulting in the use of unhealthy coping strategies. Unhealthy coping strategies may exacerbate asthma symptoms and asthma can contribute to overwhelming distress. This study aimed to review the modifiable drivers of overwhelming distress in adolescents with asthma.

METHODS

The biopsychosocial drivers of psychological distress for adolescents with asthma were explored within the domains of the modifiable biopsychosocial model of health and wellbeing.

RESULTS

Asthma in adolescents is associated with problems in the domains of environment, developmental outcomes, sense of belonging, health behaviours, coping, and treatment of illness.

CONCLUSIONS

The relationship between asthma and psychological distress highlights the need for holistic treatment of asthma. Further research is needed to establish causation between variables and to investigate whether interventions that address either asthma symptoms or biopsychosocial drivers of distress can improve both factors.

Maternal and early childhood factors associated with asthma and obesity in children aged 6 to 7 years: a case control study

Objective

To determine the maternal and early childhood factors associated with asthma and obesity in children aged 6 to 7 years.

Methods

A case-control study conducted with children aged 6 to 7 years. Applications with questions about asthma symptoms in the last 12 months, maternal and childhood data in the first 2 years of life, and anthropometric data were collected. Children who presented asthma symptoms were considered as cases and those without asthma symptoms were considered as controls, later divided into two subgroups that were eutrophic or overweight/obesity. Logistic regression was performed to estimate the association between asthma symptoms (adequate weight and overweight/obesity) and gestational and personal factors, calculating odds ratio and 95% confidence interval (95%CI). Values of p<0.05 were considered significant.

Results

Two hundred and one children were evaluated, 25.4% had asthma symptoms, 37.2% of them were overweight/obesity. Waist circumference, triceps skinfold, and body mass index were higher in the group with overweight/obesity asthma symptoms compared to no asthma symptoms (p<0.05). Factors significantly associated with asthma and overweight/obesity symptoms included: the maternal history of asthma (odds ratio of 3.73; 95%CI: 1.10-12.6) and hypertension during pregnancy (odds ratio of 3.29; 95%CI: 1.08-9.94).

Conclusion

Maternal history of asthma and hypertension during pregnancy increased the chances of children, at 6 and 7 years of age, having symptoms of asthma and obesity.

Nutrition, Obesity and Asthma Inception in Children. The Role of Lung Function

Obesity is an important public health problem. WHO estimates that about 39 million children younger than 5 years of age are overweighted or obese. On the other hand, asthma is the most prevalent chronic disease in childhood, and thus, many children share those two conditions. In the present paper we review the epidemiology of children with asthma and obesity, as well as the consequences of being obese on the respiratory system. On the one hand obesity produces an underlying T-helper 2 (TH2) low inflammation state in which numerous cytokines, which could have an impact in the respiratory system play, a role. On the other hand, some respiratory changes have been described in obese children and, specially, the development of the so called “dysanapsis” (the disproportionate scaling of airway dimensions to lung volume) which seems to be common during the first stages of life, probably related to the early development of this condition. Finally, this review deals with the role of adipokines and insulin resistance in the inception and worsening of asthma in the obese child.

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.

BMI trajectory in childhood is associated with asthma incidence at young adulthood mediated by DNA methylation

PURPOSE

Body mass index (BMI) is associated with asthma but associations of BMI temporal patterns with asthma incidence are unclear. Previous studies suggest that DNA methylation (DNAm) is associated with asthma status and variation in DNAm is a consequence of BMI changes. This study assessed the direct and indirect (via DNAm) effects of BMI trajectories in childhood on asthma incidence at young adulthood.

METHODS

Data from the Isle of Wight (IoW) birth cohort were included in the analyses. Group-based trajectory modelling was applied to infer latent BMI trajectories from ages 1 to 10 years. An R package, ttscreening, was applied to identify differentially methylated CpGs at age 10 years associated with BMI trajectories, stratified for sex. Logistic regressions were used to further exclude CpGs with DNAm at age 10 years not associated with asthma incidence at 18 years. CpGs discovered via path analyses that mediated the association of BMI trajectories with asthma incidence in the IoW cohort were further tested in an independent cohort, the Avon Longitudinal Study of Children and Parents (ALSPAC).

RESULTS

Two BMI trajectories (high vs. normal) were identified. Of the 442,474 CpG sites, DNAm at 159 CpGs in males and 212 in females were potentially associated with BMI trajectories. Assessment of their association with asthma incidence identified 9 CpGs in males and 6 CpGs in females. DNAm at 4 of these 15 CpGs showed statistically significant mediation effects (p-value < 0.05). At two of the 4 CpGs (cg23632109 and cg10817500), DNAm completely mediated the association (i.e., only statistically significant indirect effects were identified). In the ALSPAC cohort, at all four CpGs, the same direction of mediating effects were observed as those found in the IoW cohort, although statistically insignificant.

CONCLUSION

The association of BMI trajectory in childhood with asthma incidence at young adulthood is possibly mediated by DNAm.

Leptin and Obesity: Role and Clinical Implication

The peptide hormone leptin regulates food intake, body mass, and reproductive function and plays a role in fetal growth, proinflammatory immune responses, angiogenesis and lipolysis. Leptin is a product of the obese (ob) gene and, following synthesis and secretion from fat cells in white adipose tissue, binds to and activates its cognate receptor, the leptin receptor (LEP-R). LEP-R distribution facilitates leptin's pleiotropic effects, playing a crucial role in regulating body mass via a negative feedback mechanism between adipose tissue and the hypothalamus. Leptin resistance is characterized by reduced satiety, over-consumption of nutrients, and increased total body mass. Often this leads to obesity, which reduces the effectiveness of using exogenous leptin as a therapeutic agent. Thus, combining leptin therapies with leptin sensitizers may help overcome such resistance and, consequently, obesity. This review examines recent data obtained from human and animal studies related to leptin, its role in obesity, and its usefulness in obesity treatment.

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.

The impact of obesity on immune function in pediatric asthma

PURPOSE OF REVIEW

Pediatric obese asthma is a complex disease that remains poorly understood. The increasing worldwide incidence of both asthma and obesity over the last few decades, their current high prevalence and the challenges in treating obese asthmatic patients all highlight the importance of a better understanding of the pathophysiological mechanisms in obese asthma. While it is well established that patients with obesity are at an increased risk of developing asthma, the mechanisms by which obesity drives the onset of asthma, and modifies existing asthma, remain unclear. Here, we will focus on mechanisms by which obesity alters immune function in asthma.

RECENT FINDINGS

Lung parenchyma has an altered structure in some pediatric obese asthmatics, known as dysanapsis. Central adiposity is linked to reduced pulmonary function and a better predictor of asthma risk in children than BMI. Obesity in young children is associated with an increased risk of developing asthma, as well as early puberty, and hormonal alterations are implicated in obese asthma. Obesity and asthma each yield immunometabolic dysregulation separately and we are learning more about alterations in these pathways in pediatric obese asthma and the potential impact of bariatric surgery on those processes.

SUMMARY

The recent progress in clarifying the connections between childhood obesity and asthma and their combined impacts on immune function moves us closer to the goals of improved understanding of the pathophysiological mechanisms underpinning obese asthma and improved therapeutic target selection. However, this common inflammatory disease remains understudied, especially in children, and much remains to be learned.

A systematic review of asthma case definitions in 67 birth cohort studies

BACKGROUND

Birth cohort studies are a valuable source of information about potential risk factors for childhood asthma. To better understand similarities and variations in findings between birth cohort studies, the methodologies used to measure asthma require consideration.

OBJECTIVE

To review and appraise the definitions of "asthma" used in birth cohort studies.

METHODS

A literature search, conducted in December 2017 in the MEDLINE database and birth cohort repositories, identified 1721 citations published since 1990. Information extracted included: study name, year of publication, sample size, sample age, prevalence of asthma (%), study region, source of information about asthma, measured outcome, and asthma case definition. A meta-analysis evaluated whether asthma prevalence in cohorts from Europe and North America varied by the studies' definition of asthma and by their data sources.

RESULTS

The final review included 67 birth cohorts, of which 48 (72%) were from Europe, 14 (21%) from North America, 3 (5%) from Oceania, 1 (1%) from Asia and 1 (1%) from South America. We identified three measured outcomes: "asthma ever", "current asthma", and "asthma" without further specification. Definitions of "asthma ever" were primarily based upon an affirmative parental response to the question whether the child had ever been diagnosed with asthma by a physician. The most frequently used definition of "current asthma" was "asthma ever" and either asthma symptoms or asthma medications in the last 12 months. This definition of "current asthma" was used in 16 cohorts. There was no statistically significant difference in the pooled asthma prevalence in European and North American cohorts that used questionnaire alone versus other data sources to classify asthma.

CONCLUSION

There is substantial heterogeneity in childhood asthma definitions in birth cohort studies. Standardisation of asthma case definitions will improve the comparability and utility of future cohort studies and enable meta-analyses.

Prevalence and risk factors of asthma among school going children in urban area of North India

Introduction

Bronchial asthma is a chronic respiratory illness of global importance. Recent reports depict the increasing prevalence of this disorder in urban areas.

Methods

An observational study was designed with a sample size of 1163 children from grade 4 to grade 12, involving 8 randomly selected schools in 2015-2016. Modified International Study of Asthma and Allergy in Childhood [ISAAC] questionnaire in local language [Hindi version] was used for data collection. The data of assessed risk factors were collected and analysed.

Results

Prevalence of asthma in the studied population was 2.8%. Multivariate analysis revealed a significant association of risk of asthma with use of firewood kitchener for cooking, keeping pet animals at home, high body mass index (BMI), absence of ventilator measures like chimney and aero-vent. Logistic regression analysis revealed use of firewood kitchener for cooking (odds ratio (OR) = 4.9, 95% confidence interval (CI) = 2.93-11.3), absence of smoke outlet (OR 2.8, 95% CI 1.3-5.8) and keeping pet animals (OR 3.2, CI 1.6-6.8) at home were observed to be significantly associated with asthma.

Conclusion

Prevalence of asthma in our cohort was significantly lesser than that of developed world. Household smoke was the most conspicuous risk factor contributory to childhood asthma in this part of world.

Nutritional modulation of leptin expression and leptin action in obesity and obesity-associated complications

In obesity, an elevated accumulation and dysregulation of adipose tissue, due to an imbalance between energy intake and energy expenditure, usually coexists with the loss of responsiveness to leptin in central nervous system, and subsequently with hyperleptinemia. Leptin, a peptide hormone mainly produced by white adipose tissue, regulates energy homeostasis by stimulating energy expenditure and inhibiting food intake. Human obesity is characterized by increased plasma leptin levels, which have been related with different obesity-associated complications, such as chronic inflammatory state (risk factor for diabetes, cardiovascular and autoimmune diseases), as well as infertility and different types of cancer. Besides, leptin is also produced by placenta, and high leptin levels during pregnancy may be related with some pathological conditions such as gestational diabetes. This review focuses on the current insights and emerging concepts on potentially valuable nutrients and food components that may modulate leptin metabolism. Notably, several dietary food components, such as phenols, peptides, and vitamins, are able to decrease inflammation and improve leptin sensitivity by up- or down-regulation of leptin signaling molecules. On the other hand, some food components, such as saturated fatty acids may worsen chronic inflammation increasing the risk for pathological complications. Future research into nutritional mechanisms that restore leptin metabolism and signals of energy homeostasis may inspire new treatment options for obesity-related disorders.

Effects of Obesity and Asthma on Lung Function and Airway Dysanapsis in Adults and Children

Obesity increases the risk of developing asthma in children and adults. Obesity is associated with different effects on lung function in children and adults. In adults, obesity has been associated with reduced lung function resulting from a relatively small effect on forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC), with the FEV₁/FVC ratio remaining unchanged or mildly increased (restrictive pattern). In contrast, in children, obesity is associated with normal or higher FEV₁ and FVC but a lower FEV₁/FVC ratio (obstructive pattern). This anomaly has recently been associated with a phenomenon known as dysanapsis which results from a disproportionate growth between lung parenchyma size and airway calibre. The mechanisms that promote disproportionate lung parenchyma growth compared with airways in obese children remain to be elucidated. Obesity and dysanapsis in asthma patients might contribute to asthma morbidity by increasing airway obstruction, airway hyper-reactivity and airway inflammation. Obesity and dysanapsis in asthma patients are associated with increased medication use, more emergency department visits, hospitalizations and systemic corticosteroid burst than patients with normal weight. Dysanapsis may explain the reduced response to asthma medications in obese children. Weight loss results in a significant improvement in lung function, airway reactivity and asthma control. Whether these improvements are associated with the changes in the dysanaptic alteration is as yet unclear.

Role of Leptin in Inflammation and Vice Versa

Inflammation is an essential immune response for the maintenance of tissue homeostasis. In a general sense, acute and chronic inflammation are different types of adaptive response that are called into action when other homeostatic mechanisms are insufficient. Although considerable progress has been made in understanding the cellular and molecular events that are involved in the acute inflammatory response to infection and tissue injury, the causes and mechanisms of systemic chronic inflammation are much less known. The pathogenic capacity of this type of inflammation is puzzling and represents a common link of the multifactorial diseases, such as cardiovascular diseases and type 2 diabetes. In recent years, interest has been raised by the discovery of novel mediators of inflammation, such as microRNAs and adipokines, with different effects on target tissues. In the present review, we discuss the data emerged from research of leptin in obesity as an inflammatory mediator sustaining multifactorial diseases and how this knowledge could be instrumental in the design of leptin-based manipulation strategies to help restoration of abnormal immune responses. On the other direction, chronic inflammation, either from autoimmune or infectious diseases, or impaired microbiota (dysbiosis) may impair the leptin response inducing resistance to the weight control, and therefore it may be a cause of obesity. Thus, we are reviewing the published data regarding the role of leptin in inflammation, and the other way around, the role of inflammation on the development of leptin resistance and obesity.

Recognizing Risks and Optimizing Perioperative Care to Reduce Respiratory Complications in the Pediatric Patient

There have been significant advancements in the safe delivery of anesthesia as well as improvements in surgical technique; however, the perioperative period can still be high risk for the pediatric patient. Perioperative respiratory complications (PRCs) are some of the most common critical events that can occur in pediatric surgical patients and they can lead to increased length of hospitalization, worsened patient outcomes, and higher hospital and postoperative costs. It is important to determine the various factors that put pediatric patients at increased risk of PRCs. This will allow for more detailed and accurate informed consent, optimized perioperative management strategy, improved allocation of clinical resources, and, hopefully, better patient experience. There are only a few risk prediction models/scoring tools developed for and validated in the pediatric patient population, but they have been useful in helping identify the key factors associated with a high likelihood of developing PRCs. Some of these factors are patient factors, while others are procedure-related factors. Some of these factors may be modified such that the patient’s clinical status is optimized preoperatively to decrease the risk of PRCs occurring perioperatively. Fore knowledge of the factors that are not able to be modified can help guide allocation of perioperative clinical resources such that the negative impact of these non-modifiable factors is buffered. Additional training in pediatric anesthesia or focused expertise in pediatric airway management, vascular access and management of massive hemorrhage should be considered for the perioperative management of the less than 3 age group. Intraoperative ventilation strategy plays a key role in determining respiratory outcomes for both adult and pediatric surgical patients. Key components of lung protective mechanical ventilation strategy such as low tidal volume and moderate PEEP used in the management of acute respiratory distress syndrome (ARDS) in pediatric intensive care units have been adopted in pediatric operating rooms. Adequate post-operative analgesia that balances pain control with appropriate mental status and respiratory drive is important in reducing PRCs.

The Dynamic Relationship Between Asthma and Obesity in Schoolchildren

Asthma and obesity are among the most prevalent chronic health conditions in children. Although there has been compelling evidence of co-occurrence of asthma and obesity, it is uncertain whether asthma contributes to the development of obesity or obesity contributes to the onset of asthma or both. In this study, we used a joint transition modeling approach with cross-lagged structure to understand how asthma and obesity influence each other dynamically over time. Subjects for this study included 5,193 kindergarten and first-grade students enrolled from 13 communities in 2002-2003 in the Southern California Children's Health Study, with up to 10 years of follow-up. We found that nonobese children with diagnosed asthma at a study visit were at 37% higher odds of becoming obese by the next annual visit compared with children without asthma (odds ratio = 1.38; 95% credible interval: 1.12, 1.71). However, the presence of obesity at the current visit was not statistically significantly associated with asthma onset in the next visit (odds ratio = 1.25; 95% credible interval: 0.94, 1.62). In conclusion, childhood asthma appears to drive an increase in the onset of obesity among schoolchildren, while the onset of obesity does not necessarily imply the future onset of asthma, at least in the short term.

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.

Association between overweight or obesity and the risk for childhood asthma and wheeze: An updated meta-analysis on 18 articles and 73 252 children

BACKGROUND

Overweight or obesity is increasingly recognized as a possible risk factor for childhood asthma.

OBJECTIVES

We aimed to meta-analyse the association between overweight or obesity and the risk for childhood asthma and wheeze and meanwhile explore potential causes of between-study heterogeneity.

METHODS

Literature search, study selection, and data extraction were performed independently and in duplicate. Data were analysed by STATA software.

RESULTS

Eighteen articles and 73 252 children were analysed. In overall analyses, there was a significant association between overweight or obesity and the risk for childhood asthma (odds ratio [OR] = 1.30; 95% confidence interval [CI], 1.23-1.39; P < 0.001) and wheeze (OR = 1.90; 95% CI, 1.38-2.63; P < 0.001), with none/marginal publication bias as revealed by the Egger test (P = 0.938/0.038), respectively. Subgroup analyses showed that children with obesity (OR = 1.40; 95% CI, 1.29-1.52) were more likely to have asthma than children with overweight (OR = 1.22; 95% CI, 1.14-1.31), and in children with overweight or obesity, girls (OR = 1.34; 95% CI, 1.16-1.56) were more likely to have asthma than boys (OR = 1.27; 95% CI, 1.15-1.40).

CONCLUSIONS

Our findings indicate that overweight or obesity is a significant risk factor for childhood asthma and wheeze and in children with overweight or obesity, the risk is more evident in girls than in boys.

Severe obesity in children as an independent risk factor for perioperative respiratory adverse events during anaesthesia for minor non-airway surgery, a retrospective observational study

Purpose:

The purpose of this article is to quantify grades of obesity and their independent effects on perioperative adverse events in children having ambulatory minor non-airway surgery.

Methods:

After obtaining ethics committee approval, we selected every tenth child aged 2 to 16 years who was identified as having been a day case between January 2012 and December 2014. Weight groups were defined based on age- and gender-specific body mass index (BMI) cutoff points. A sample size of 1102 was calculated to demonstrate a three-fold increase in the primary outcome measure, perioperative respiratory-airway adverse events, among obese children, with a power of 80% and an alpha error of 5%. Chi-squared and Fisher exact tests were used to compare proportions, and independent sample t tests were used to compare means.

Results:

Severely obese children had a significantly higher incidence of perioperative respiratory-airway adverse events when compared to normal-weight children despite no difference in respiratory and other comorbidity. Obese children had higher prevalence of overall medical comorbidities and obstructive sleep apnoea when compared to normal-weight children and there was no significant difference in the incidence of perioperative respiratory-airway adverse events and other outcome measures between obese and normal-weight children.

Conclusions and recommendations:

Severely obese children have a higher risk of perioperative respiratory-airway adverse events even during minor non-airway surgery despite absence of medical comorbidities. We recommend the use of age- and sex- specific BMI cutoffs or BMI percentile charts to identify children who are severely obese to anticipate and prevent major respiratory adverse events.

Interactive effects of adiposity and insulin resistance on the impaired lung function in asthmatic adults: cross-sectional analysis of NHANES data

BACKGROUND

Obesity is considered a risk factor for both asthma and insulin resistance in adults. Insulin resistance (IR) also influences pulmonary function in the non-obese population.

AIM

To investigate the modifying effect of insulin resistance on the predictive role of anthropometric measures in the estimation of impaired lung function among asthmatic adults.

SUBJECTS AND METHODS

A cross-sectional study of 1276 adults extracted from the NHANES 2009-2012 database was performed. Adjusted multiple linear regression was conducted to analyse the contributory role of obesity and IR in predicting lung function among asthmatic adults.

RESULTS

BMI, waist circumference (WC) and waist-to-height ratio (WHtR) showed significantly negative correlations with FVC (r=-0.24, -0.18, -0.39, respectively; p < 0.001), FEV1(r=-0.24, -0.21, -0.40, respectively; p < 0.001) and FEF 25-75% (r=-0.15, -0.18, -0.27, respectively; p < 0.001). Even after adjustment for the covariates (age, gender, smoking history and standing height), BMI and HOMA-IR had significant relationships with FVC (β= -10.3; p < 0.01 and β= -16.0; p < 0.05) and FEV1 (β= -8.7; p < 0.01 and β= -11.7; p < 0.05). BMI could significantly predict the decreased FVC (β= -13.7; p < 0.01) and FEV1 (β= -10.7; p < 0.01) only in the insulin resistant asthmatics.

CONCLUSION

WHtR and IR predict impaired lung function in overweight/obese asthmatic adults independently. IR also modifies the association between excessive adiposity and respiratory function in asthmatic adults.

Asthma and obesity in the Middle East region: An overview

This paper aims to cover the current status of asthma and obesity in the Middle East, as well as to introduce the various studies tying the two diseases; further expanding on the proposed mechanisms. Finally, the paper covers recent literature related to sphingolipids and its role in asthma, followed by recommendations and future directions. In preparation of this paper, we searched PubMed and Google Scholar, with no restrictions, using the following terms; asthma, obesity, Middle East, sphingolipids. We also used the reference list of retrieved articles to further expand on the pool of articles that were used for this review.

Being Overweight or Obese and the Development of Asthma

OBJECTIVES

Adult obesity is linked to asthma cases and is estimated to lead to 250 000 new cases yearly. Similar incidence and attributable risk (AR) estimates have not been developed for children. We sought to describe the relationship between overweight and obesity and incident asthma in childhood and quantify AR statistics in the United States for overweight and obesity on pediatric asthma.

METHODS

The PEDSnet clinical data research network was used to conduct a retrospective cohort study (January 2009-December 2015) to compare asthma incidence among overweight and/or obese versus healthy weight 2- to 17-year-old children. Asthma incidence was defined as ≥2 encounters with a diagnosis of asthma and ≥1 asthma controller prescription. Stricter diagnostic criteria involved confirmation by spirometry. We used multivariable Poisson regression analyses to estimate incident asthma rates and risk ratios and accepted formulas for ARs.

RESULTS

Data from 507 496 children and 19 581 972 encounters were included. The mean participant observation period was 4 years. The adjusted risk for incident asthma was increased among children who were overweight (relative risk [RR]: 1.17; 95% confidence interval [CI]: 1.10-1.25) and obese (RR: 1.26; 95% CI: 1.18-1.34). The adjusted risk for spirometry-confirmed asthma was increased among children with obesity (RR: 1.29; 95% CI: 1.16-1.42). An estimated 23% to 27% of new asthma cases in children with obesity is directly attributable to obesity. In the absence of overweight and obesity, 10% of all cases of asthma would be avoided.

CONCLUSIONS

Obesity is a major preventable risk factor for pediatric asthma.

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.

Clinic and Home-Based Behavioral Intervention for Obesity in Preschoolers: A Randomized Trial

OBJECTIVE

To test the hypotheses that an innovative skills-based behavioral family clinic and home-based intervention (LAUNCH) would reduce body mass index z score (BMIz) compared with motivational interviewing and to standard care in preschool-aged children with obesity.

STUDY DESIGN

Randomized controlled trial with children between the ages of 2 and 5 years above the 95^th percentile for body mass index for age and sex recruited from 27 pediatrician offices across 10 recruitment cycles between March 12, 2012 and June 8, 2015. Children were randomized to LAUNCH (an 18-session clinic and home-based behavioral intervention), motivational interviewing (delivered at the same frequency as LAUNCH), or standard care (no formal intervention). Weight and height were measured by assessors blinded to participant assignment. The primary outcome, BMIz at month 6 after adjusting for baseline BMIz, was tested separately comparing LAUNCH with motivational interviewing and LAUNCH with standard care using regression-based analysis of covariance models.

RESULTS

A total of 151 of the 167 children randomized met intent-to-treat criteria and 92% completed the study. Children were 76% White and 57% female, with an average age of 55 months and BMI percentile of 98.57, with no demographic differences between the groups. LAUNCH participants demonstrated a significantly greater decrease in BMIz (mean = -0.32, SD = ±0.33) compared with motivational interviewing (mean = -0.05, SD = ±0.27), P < .001, ω² = 0.74 and compared with standard care (mean = -0.13, SD = ±0.31), P < .004, ω² = 0.75.

CONCLUSIONS

In preschool-age children, an intensive 6-month behavioral skills-based intervention is necessary to reduce obesity.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01546727.

Overweight adolescents and asthma: Revealing motivations and challenges with adolescent-provider communication

OBJECTIVE

Among teens with asthma, challenges of disease management may be greater in those with a body mass index (BMI) >85th percentile compared to youth within the parameters for normal weight-for-age. This mixed-methods study assessed teens' awareness of the link between weight and asthma management, and perspectives on how medical providers might open a discussion about managing weight.

METHOD

Teens aged 13-18, having BMI >85 percentile and chronic asthma, identified using health system databases and a staff email message board, were invited to complete a semi-structured, in-depth phone interview. Interviews were audio taped, transcribed, and qualitatively analyzed, using the Framework Method. Responses were summarized and themes identified. Descriptive summaries were generated for a 16-item survey of weight conversation starters.

RESULTS

Of 35 teens interviewed, 24 (69%) were girls, 11 (31%) boys, 20 (63%) African-American. All teens reported having "the weight conversation" with their doctors, and preferred that parents be present. Half knew from their doctor about the link between being overweight and asthma, others knew from personal experience. Nearly all expressed the importance of providers initiating a weight management conversation. Most preferred conversation starters that recognized challenges and included parents' participation in weight management; least liked referred to "carrying around too much weight."

CONCLUSIONS

Most teens responded favorably to initiating weight loss if it impacted asthma management, valued their provider addressing weight and family participation in weight management efforts. Adolescents' views enhance program development fostering more effective communication targeting weight improvement within the overall asthma management plan.

The influence of gender and atopy in the relationship between obesity and asthma in childhood

BACKGROUND

The objective of the study was to examine the relationship between asthma and overweight-obesity in Spanish children and adolescents and to determine whether this relationship was affected by gender and atopy.

METHODS

The study involves 8607 Spanish children and adolescents from the International Study of Asthma and Allergies in Childhood phase III. Unconditional logistic regression was used to obtain adjusted odds ratios (OR) and 95% confidence intervals (95% CI) for the association between asthma symptoms and overweight-obesity in the two groups. Afterwards, it was stratified by sex and rhinoconjunctivitis.

RESULTS

The prevalence of overweight and obesity in 6-7-year-old children was 18.6% and 5.2% respectively and in 13-14 year-old teenagers was 11.4% and 1.1% respectively. Only the obese children, not the overweight children, of the 6-7 year old group had a higher risk of any asthma symptoms (wheezing ever: OR 1.68 [1.15-2.47], asthma ever: OR 2.29 [1.43-3.68], current asthma 2.56 [1.54-4.28], severe asthma 3.18 [1.50-6.73], exercise-induced asthma 2.71 [1.45-5.05]). The obese girls had an increased risk of suffering any asthma symptoms (wheezing ever: OR 1.73 [1.05-2.91], asthma ever: OR 3.12 [1.67-5.82], current asthma 3.20 [1.65-6.19], severe asthma 4.83[1.94-12.04], exercise-induced asthma 3.68 [1.67-8.08]). The obese children without rhinoconjunctivitis had a higher risk of asthma symptoms.

CONCLUSIONS

Obesity and asthma symptoms were associated in 6-7 year-old children but not in 13-14 year-old teenagers. The association was stronger in non-atopic children and obese girls.

Is impaired glucose metabolism the missing piece in the obesity-asthma puzzle?

Obesity is a major risk factor for several conditions including atherosclerotic disease, metabolic syndrome, and upper airway dysfunction. However, the purported link between obesity and asthma has remained more difficult to define, in part due to limitations in past epidemiologic studies and the inherent challenge in accurately defining asthma in children. It is possible that obesity leads to asthma only in the presence of a mediating variable such as an obesity-related conditions such as esophageal reflux or insulin resistance. The article by Karampatakis and colleagues in this week's edition of the journal is important because it addresses the hypothesis that altered glucose metabolism/insulin resistance associates with bronchial hyperresponsiveness (BHR), a central and objectively measured marker of asthma. They studied pre-pubertal children with and without asthma with a range of body mass indices and found for the first time in pre-pubertal asthmatic children that both insulin resistance and impaired glucose tolerance were more closely related to BHR than was obesity. Their work opens the way for directed mechanistic study of the effects of impaired glucose metabolism on airway development during childhood and airway responsiveness, and for the study of insulin sensitizing therapies in children to prevent lower airway disease. Pediatr Pulmonol. 2017;52:147-150. © 2016 Wiley Periodicals, Inc.

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.

Growth trajectories and asthma/rhinitis in children: a longitudinal study in Taiwan

Studies have reported the effect of body weight in early childhood on asthma. However, the effect of growth patterns during school age on asthma and rhinitis has yet to be explored. We sought to investigate whether various growth patterns predict incident asthma and rhinitis.We conducted a nationwide longitudinal study (Taiwan Children Health Study) in 14 Taiwanese communities. Body mass index (BMI) z-scores of 4422 children aged 6-11 years were collected annually and distinct growth trajectory classes were identified using a latent generalised mixture model. Pulmonary function and exhaled nitric oxide fraction (F_eNO) levels were also measured. Whether different growth trajectory classes predict incident asthma and rhinitis at age 12, 15 and 18 years was determined using a discrete time hazard model.Four growth trajectory classes were identified. Persistently overweight children exhibited significantly increased risks of asthma and rhinitis at age 12 years. Furthermore, being persistently overweight had a long-term effect on incident asthma (hazard ratio 2.47, 95% CI 1.18-5.12) and rhinitis (hazard ratio 1.44, 95% CI 1.12-1.84) in adolescence and early adulthood. Children in high BMI classes exhibited significantly lower pulmonary functions compared with normal growth children. F_eNO levels were lower in children in the high BMI classes and higher in children showing declining obesity compared with normal growth children.Persistently overweight children exhibited incident asthma and rhinitis in adolescence and early adulthood.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

A systematic review of the relationship between asthma, overweight, and the effects of physical activity in youth

PURPOSE

The association of asthma and overweight in youth is well studied. However, the temporal relationship between asthma and overweight, the strength of their association, and mediating factors involved in this relationship remain unclear. This review investigates the relationship between asthma and overweight in youth, while examining the role of physical activity as a mediator.

METHODS

A systematic review of literature was conducted using PubMed and Medline databases. Studies conducted among youth aged 0-18 years, published in English between 2000-2014 were included. The Strengthening the Reporting of Observational Studies in Epidemiology guidelines were consulted to evaluate quality of selected citations.

RESULTS

A comprehensive search yielded 143 studies in PubMed and 133 studies in Medline databases. Of these, 75 studies met the eligibility criteria. The review found varying hypotheses regarding the temporal relationship between asthma and overweight in youth; existing evidence supports the mediation of this association by decreased expenditure of energy due to reduced physical activity. Negative self-perception or parental perception of exercise ability due to asthma symptoms secondary to physical exertion was identified as a determinant of physical activity in asthmatic youth.

CONCLUSIONS

Physical activity likely mediates the relationship between asthma and overweight in youth. Temporality of this relationship remains unclear.

The relationship between serum adipocytokines and Graves' ophthalmopathy: A hospital-based study

Adipocytokines are thought to be associated with inflammatory disorders and autoimmune diseases. However, limited information is available on the relationship between serum adipocytokine levels, Graves' disease (GD), and Graves' ophthalmopathy (GO). The present study examined the relationship between serum adipocytokine levels and GD and GO. A total of 80 patients with GD participated in this study. The medical records of patients were reviewed retrospectively. GO activity was assessed using the clinical activity score (CAS). GO severity was assessed by the modified NOSPECS classification and included soft tissue involvement, proptosis, and extraocular muscle involvement. Serum adiponectin, leptin, resistin, and retinol-binding protein 4 (RBP-4) levels were measured using commercially available enzyme-linked immunosorbent assays. The prevalence of GO was 36.3%. Serum adiponectin, leptin, and resistin levels were significantly higher in patients with GO than in those without GO. The CAS was positively correlated with serum adiponectin and leptin levels. The total eye score was positively correlated with serum adiponectin, leptin, resistin, and RBP-4 levels. A multivariate analysis revealed that serum leptin and resistin levels were associated with the presence of GO after adjusting for clinical factors. Free thyroxine was negatively correlated with serum leptin level. These results suggest that adipocytokines, such as leptin and resistin, may play a role in inflammatory and autoimmune processes of GD and GO. Future studies with larger numbers of patients are required to establish relationships between serum adipocytokines levels and GO and ascertain the role of adipocytokines in GD and GO.

Obesity, Asthma, and Exercise in Child and Adolescent Health

Obesity increases the risk of asthma throughout life but the underlying mechanisms linking these all too common threats to child health are poorly understood. Acute bouts of exercise, aerobic fitness, and levels of physical activity clearly play a role in the pathogenesis and/or management of both childhood obesity and asthma. Moreover, both obesity and physical inactivity are associated with asthma symptomatology and response to therapy (a particularly challenging feature of obesity-related asthma). In this article, we review current understandings of the link between physical activity, aerobic fitness and the asthma-obesity link in children and adolescents (e.g., the impact of chronic low-grade inflammation, lung mechanics, and direct effects of metabolic health on the lung). Gaps in our knowledge regarding the physiological mechanisms linking asthma, obesity and exercise are often compounded by imprecise estimations of adiposity and challenges of assessing aerobic fitness in children. Addressing these gaps could lead to practical interventions and clinical approaches that could mitigate the profound health care crisis of the increasing comorbidity of asthma, physical inactivity, and obesity in children.

Fetal Growth, Obesity, and Atopic Disorders in Adolescence: a Retrospective Birth Cohort Study

BACKGROUND

Developmental status at birth and subsequent obesity have been implicated in the development of childhood atopic dermatitis (AD) and allergic rhinitis (AR).

METHODS

The current study analysed the cohort data of 74 688 junior high school students from a national retrospective birth cohort study in Taiwan. A random 10% sample was selected from singleton livebirths with complete data on the analytical variables of interest. Atopic disorders, including AD and AR, were assessed by questionnaires (International Study of Asthma and Allergies in Childhood). Logistic regression analyses were applied with adjustments for related risk factors.

RESULTS

Among subjects mainly 13-15 years of age, the estimated prevalence was 7.6% for AD and 22.4% for AR. While the role of fetal growth in allergic disorders was less evident, the risk of developing AD and AR were both influenced by a combination of fetal growth status and adolescent body mass index (BMI). Compared with those with normal fetal growth and school-aged BMI, the risk of developing AD increased 64% among adolescents with both restricted fetal growth and high BMI (odds ratio 1.64, 95% confidence interval 1.37, 1.97). The risk for this combination was higher than that for either restricted fetal growth or high BMI alone. Nevertheless, the overall interaction between BMI and fetal growth status on atopic disorders did not reach statistical significance.

CONCLUSIONS

Excessive weight gain could be an important risk factor related to developing atopic dermatitis and allergic rhinitis during adolescence, especially among infants born small for gestational age.

Genetic approach identifies distinct asthma pathways in overweight vs normal weight children

The pathogenesis of asthma in the context of excess body weight may be distinct from asthma that develops in normal weight children. The study's objective was to explore the biology of asthma in the context of obesity and normal weight status using genetic methodologies. Associations between asthma and SNPs in 49 genes were assessed, as well as, interactions between SNPs and overweight status in child participants of the Greater Cincinnati Pediatric Clinic Repository. Asthma was significantly associated with weight (OR = 1.38; P = 0.037). The number of genes and the magnitude of their associations with asthma were notably greater when considering overweight children alone vs normal weight and overweight children together. When considering weight, distinct sets of asthma-associated genes were observed, many times with opposing effects. We demonstrated that the underlying heterogeneity of asthma is likely due in part to distinct pathogenetic pathways that depend on preceding/comorbid overweight and/or allergy. It is therefore important to consider both obesity and asthma when conducting studies of 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.

Metabolic origins of childhood asthma

Childhood obesity and incidence of asthma are increasing globally. The parallel increase of the two suggests that obesity and asthma may be related and that abnormalities in the lipid and/or glucose metabolism may contribute to the pathogenesis of asthma. The clinical presentation of obese asthma is distinct from other asthma phenotypes and depending on age of onset of symptoms. Asthma in obese people tends to be more severe, not typically associated with allergy, and less responsive to standard anti-inflammatory therapy, including corticosteroids. Obesity and obesity-related comorbidities may lead to asthma via a number of mechanisms including changes in lung mechanics, the nitric oxide metabolism, and by causing inflammation. Furthermore, evidence suggests that nutrition during pregnancy contributes to intrauterine immune and metabolic programming in the offspring, which may have major influences on predisposition to cardiovascular, metabolic, and allergic diseases, including asthma, later in life. This review will highlight some suggested mechanistic links between obesity and diabetes with asthma.

Health-related quality of life and asthma among United States adolescents

OBJECTIVE

To examine the direction and the magnitude of associations between asthma and health-related quality of life (HRQoL) in a population-based sample of US adolescents.

STUDY DESIGN

We obtained data from the 2001-2010 cross-sectional National Health and Nutrition Examination Survey. We used multinomial logistic regression and negative binomial regression to estimate corresponding percentages, prevalence ratios (PRs), and predicted days of 4 domains of HRQoL by 3 asthma status categories: never having asthma, having asthma without symptoms, and having asthma with symptoms.

RESULTS

Compared with those who never had asthma, adolescents with asthma with symptoms of dry cough or wheezing reported significantly worse self-rated health (13.58% [95% CI, 10.32%-17.67%] vs 7.54% [95% CI, 6.50%-8.72%] for fair or poor health), significantly impaired physical health (PR = 1.34, P = .004; adjusted physically unhealthy days, 2.7 days vs 2 days), and impaired mental health (PR = 1.26, P = .025). Among adolescents having asthma with symptoms, those who currently smoked reported 1 more physically unhealthy day and 2.4 more mentally unhealthy days than those who did not smoke and did not have asthma. Those reporting limited physical functioning reported 2 more physically unhealthy days and 1.5 more mentally unhealthy days than those who did not report limited functioning.

CONCLUSION

Adolescents with asthma and symptoms reported worse HRQoL compared with those with asthma not reporting symptoms and those without asthma. Those who smoked or reported limited physical functioning reported worse physical and mental HRQoL. Reducing symptoms, quitting smoking, and improving physical functioning may improve HRQoL among adolescents with asthma.

Childhood body mass index and wheezing disorders: a systematic review and meta-analysis

BACKGROUND

It has been claimed that overweight/obesity, childhood asthma and wheezing disorders are associated, although the results of observational studies have remained inconsistent. We conducted a systematic review and meta-analysis to investigate this.

METHODS

An online search of published papers linking childhood asthma and wheezing with overweight/obesity up to May 2014 using EMBASE and MEDLINE medical research databases was carried out. Summary odds ratios (OR) were estimated using random-effects models. Subgroup meta-analyses were performed to assess the robustness of risk associations and between-study heterogeneity.

RESULTS

A total of 38 studies comprising 1,411,335 participants were included in our meta-analysis. The summary ORs of underweight (<5th percentile), overweight (>85th to <95th percentile) and obesity (≥ 95 th percentile) were 0.85 (95% CI: 0.75 to 0.97; p = 0.02), 1.23 (95% CI: 1.17 to 1.29; p < 0.001) and 1.46 (95% CI: 1.36 to 1.57, p < 0.001), respectively. Heterogeneity was significant and substantial in all three weight categories, and not accounted for by pre-defined study characteristics.

CONCLUSION

Our results suggest that underweight is associated with a reduced risk of childhood asthma, and overweight and obesity are associated with an increased risk of childhood asthma. Although our findings assert that overweight/obesity and childhood asthma are associated, the causal pathway and temporal aspects of this relationship remain unanswered and deserve further epidemiological investigation.

Peak weight and height velocity to age 36 months and asthma development: the Norwegian Mother and Child Cohort Study

Background

The immediate postnatal period is the period of the fastest growth in the entire life span and a critical period for lung development. Therefore, it is interesting to examine the association between growth during this period and childhood respiratory disorders.

Methods

We examined the association of peak weight and height velocity to age 36 months with maternal report of current asthma at 36 months (n = 50,311), recurrent lower respiratory tract infections (LRTIs) by 36 months (n = 47,905) and current asthma at 7 years (n = 24,827) in the Norwegian Mother and Child Cohort Study. Peak weight and height velocity was calculated using the Reed1 model through multilevel mixed-effects linear regression. Multivariable log-binomial regression was used to calculate adjusted relative risks (adj.RR) and 95% confidence intervals (CI). We also conducted a sibling pair analysis using conditional logistic regression.

Results

Peak weight velocity was positively associated with current asthma at 36 months [adj.RR 1.22 (95%CI: 1.18, 1.26) per standard deviation (SD) increase], recurrent LRTIs by 36 months [adj.RR 1.14 (1.10, 1.19) per SD increase] and current asthma at 7 years [adj.RR 1.13 (95%CI: 1.07, 1.19) per SD increase]. Peak height velocity was not associated with any of the respiratory disorders. The positive association of peak weight velocity and asthma at 36 months remained in the sibling pair analysis.

Conclusions

Higher peak weight velocity, achieved during the immediate postnatal period, increased the risk of respiratory disorders. This might be explained by an influence on neonatal lung development, shared genetic/epigenetic mechanisms and/or environmental factors.

Obesity and asthma: pathophysiology and implications for diagnosis and management in primary care

The effects of obesity on asthma diagnosis, control, and exacerbation severity are increasingly recognized; however, the underlying pathophysiology of this association is poorly understood. Mainstream clinical practice has yet to adopt aggressive management of obesity as a modifiable risk factor in asthma care, as is the case with a risk factor like tobacco or allergen exposure. This review summarizes existing data that support the pathophysiologic mechanisms underlying the association between obesity and asthma, as well as the current and future state of treatment for the obese patient with asthma. Our review suggests that evidence of chronic inflammatory response linking obesity and asthma indicates a need to address obesity during asthma management, possibly using patient-centered approaches such as shared decision making. There is a need for research to better understand the mechanisms of asthma in the obese patient and to develop new therapies specifically targeted to this unique patient population.

Body mass index and the incidence of asthma in children

PURPOSE OF REVIEW

When evaluating the causal link between obesity and the development of asthma in children, prospective cohort studies are essential. The results of the most recently published birth cohort studies from Sweden, Germany, Brazil, Belarus, and California, USA, as well as from a joint analysis of eight European birth cohorts of the Global Allergy and Asthma European Network are evaluated. Moreover, the results of two meta-analyses are presented.

RECENT FINDINGS

Most recent prospective cohort studies found a dose-response association between overweight or obesity and asthma. The evidence of effect modification by sex, ethnicity, and age was inconsistent. Both meta-analyses also showed that overweight children were at an increased risk of incident asthma compared with nonoverweight children and that the relationship was further elevated for obesity.

SUMMARY

Prospective cohort studies and two recently published meta-analyses found an association between overweight (and especially obesity) and asthma in the appropriate temporal sequence and in a dose-response manner. Children with a pronounced weight gain slope in early life were particularly at risk for asthma within the first 6 years of life. The gain in BMI over time during infancy may be an even more important predictor for asthma in childhood than excess weight at any specific 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.

Changes in parent motivation predicts changes in body mass index z-score (zBMI) and dietary intake among preschoolers enrolled in a family-based obesity intervention

OBJECTIVES

To examine whether changes in parent motivation over the course of a pediatric obesity intervention are significantly associated with long-term changes in treatment outcomes. 

METHODS

 Study hypotheses were tested with a secondary data analysis of a randomized controlled trial (N = 42). Study analyses tested whether baseline to posttreatment change in total score for a self-report parent motivation measure (Parent Motivation Inventory [PMI]) was significantly associated with baseline to 6-month follow-up changes in body mass index z-score (zBMI), dietary variables, and physical activity. 

RESULTS

 Increases in PMI were significantly associated with decreased zBMI, decreased consumption of sugar-sweetened beverages and sweets, and increased consumption of artificially sweetened beverages. 

CONCLUSIONS

 Given that increases in parent motivation were associated with some treatment benefits, future research should evaluate the impact of directly assessing and targeting parent motivation on weight outcomes for preschoolers participating in a weight management program.

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.