Pathway from central obesity to childhood asthma. Physical fitness and sedentary time are leading factors

Effect of stearoyl-coenzyme a desaturase 1 (SCD1) on the function of mast cells

Background: The prevalence of childhood asthma and obesity is increasing, while obesity increases the risk and severity of asthma. Lipid metabolism has been considered as an important factor in the pathogenesis of obesity-associated asthma. Stearoyl-CoA desaturase 1 (SCD1) is a rate-limiting enzyme that catalyzes the production of monounsaturated fatty acids (MUFA).Methods: In the present study, the microarray data retrieved from the Gene Expression Comprehensive Database (GEO) was analyzed to further clarify the impact of SCD1 on Mast cell activation related lipid mediators and the correlation between SCD1 and obesity asthma in the population.Results: SCD1 was highly expressed in IgE-activated bone marrow-derived mast cells (BMMCs). Meanwhile, SCD1 was also verified expressed highly in dinitrophenyl human serum albumin (DNP-HAS) stimulated RBL-2H3 cells. The expression of SCD1 was up-regulated in peripheral blood leukocytes of asthmatic children, and was positively correlated with skinfold thickness of upper arm, abdominal skinfold and body mass index (BMI). Inhibition of SCD1 expression significantly suppressed the degranulation, lipid mediator production, as well as the migration ability in DNP-HAS-stimulated RBL-2H3 cells.Conclusion: SCD1 is involved in obese-related asthma through regulating mast cells.

Enhancing microbial diversity as well as multi-organ health in hind-limb unloaded mice

During space travel, the gut microbiota is changed which can lead to health-related issues. Previously, we utilized the hind-limb unloaded (HU) mouse, which is an established ground-based in-vivo model of microgravity and observed altered gut microbiota. In this study, we evaluated the beneficial effects of novel bacterial conditioned media in HU mice to understand if they can offset the effects of unloading in the HU mouse model. We aimed to explore the influence of bacterial conditioned media on diversity and quantity of intestinal microbes in HU mice, and investigated the microarchitecture of mice retinas and kidneys to evaluate the potential systemic effects of bacterial conditioned media in HU mice. Four-month-old, male C57/Bl6 mice were separated into groups: including the ground-based control group, the HU group mice fed with vehicle as placebo (HU-placebo mice), and the HU group fed with bacterial conditioned media (HU-CP mice) and kept under controlled environmental conditions for three weeks. Next, mice were sacrificed; gut dissections were conducted, and metagenomic analysis of bacterial species was performed via DNA extraction and 16S rRNA analysis. The results revealed an HU-induced reduction in intestinal microbial diversity, and an increase in pathogenic bacteria dominated by Firmicutes (45%). In contrast, supplementation with bacterial conditioned media for three weeks led to a significant increase in gut microbial diversity with noticeable changes in the OTUs abundance in the HU mice. Additionally, HU-induced muscle weakness and structural abnormalities in the retina and kidney were partially prevented with bacterial conditioned media. Moreover, a greater diversity of several bacteria in the HU-CP was observed including, Bacteriodota, Firmicutes, Proteobacteria, Actionobacteriota, Verrucomicorbiota, Cyanobacteria, Gemmatimonadota, Acidobacteriota, Chloroflexi, Myxococcota, and others. Prospective research involving molecular mechanistic studies are needed to comprehend the systemic effects of bacterial metabolites conditioned media on experimental animal models under chronic stress.

Body composition modify the association between ambient particulate matter and lung function among asthma patients

The effect of ambient PM10 and PM2.5 on lung function modified by body muscle and adipose tissue is not fully understood at present. Our aims were to investigate the association between seasonal average air pollutants and lung function in asthmatic patients modified by body composition indicators. In this cross-sectional study, we recruited 914 doctor-diagnosed asthmatic patients, and performed interaction and stratified analysis using the median values of total body muscle (TBM), total body fat (TBF), and percentage body fat (PBF) as well as body mass index (BMI) =25 as the cutoff points of the high/low body composition groups. The adjusted R2 values of the developed LUR models of PM2.5 and PM10 were 91.4% and 90.5% and also verified by cross-validation, respectively. After adjusting for confounding factors, we found that TBM significantly modified the association between PM10 and lung function among asthma patients (interaction P value <0.05). In the low TBM group, seasonal average concentrations of PM10 estimated by the LUR model increased by 10 μg/m3, and negative associations with lung function indicators were observed. For obese patients with BMI>25 and high TBF, the increase in PM10 was associated with the decrease in lung function. The asthma patients with obesity and low total body muscle were more susceptible to adverse effects of PM10 on lung function.

The association of objectively measured sedentary time with asthma in US youth: A glimpse into the connection between obesity and asthma

BACKGROUND

Evidence suggests that asthma and obesity may share a common pathway, possibly through an increase in inflammation. Sedentary time is thought to promote both inflammation and obesity and previous studies have found a relationship between self-reported sedentary and asthma. However, the relationship between objectively measured sedentary time and asthma is not well described. We hypothesized that the association between asthma and sedentary time would not be present when physical activity was measured objectively, nor would objectively-measured sedentary time play an important role in the relationship between asthma and obesity.

OBJECTIVE

To determine if there is an association between asthma and objectively measured sedentary time in a large, nationally representative sample of the United States youth.

METHODS

Using the National Health and Nutrition Examination Survey 2003-2006, we assessed the relationship between asthma and sedentary time using objectively measured and self-reported measures of sedentary time, in 6-19 years-old subjects with available accelerometry data. We used multivariate logistic regression analysis to determine associations between the risk of asthma and sedentary time controlling for accelerometer wear time, gender, age, race/ethnicity, body mass index percentile, and moderate-to-vigorous physical activity (MVPA).

RESULTS

In this cohort, youth with asthma self-reported more time in sedentary behavior, specifically computer time, than those without asthma (p = 0.01). However, when sedentary time was measured objectively by accelerometry, sedentary time did not differ between youth with and without asthma (421 min [standard deviation 4.2] versus. 414 min [standard deviation 7.8] [p = 0.38]). Controlling for measures of activity, such as MVPA, or time spent in long versus short bouts of sedentary time did not modify our results.

CONCLUSIONS

Differences in sedentary time by self-report between those with and without asthma were not born out by examining sedentary time using objective measures. Further work is necessary to examine the complex interaction among inactivity, obesity, and asthma over time, specifically focusing on whether the type of sedentary activity (e.g., computer vs. television time) is important.

An updated prevalence of asthma, its phenotypes, and the identification of the potential asthma risk factors among young Chinese adults recruited in Singapore

Background

Asthma is a chronic inflammatory disease of the airway characterized by respiratory symptoms: wheezing, shortness of breath, coughing, and chest tightness. Globally, asthma affects over 300 million individuals and carries high morbidity and mortality burden. Previous studies have estimated the prevalence of asthma; however, prevalence estimates have been changing over time. Here, in a population of young Chinese adults from Singapore, we aimed to obtain an updated prevalence of asthma and its phenotypes, and identify potential associated risk factors.

Methods

The Singapore/Malaysia Cross-Sectional Genetics Epidemiology Study (SMCGES) is an ongoing study which uses established ISAAC guidelines to collect epidemiological data and information pertaining to allergic diseases such as asthma. Responses from young Chinese adults recruited in the National University of Singapore were analyzed.

Results

Lifetime asthma prevalence rate was estimated at 19.1% (2049/10,736), while current asthma prevalence rate was estimated at 6.3% (679/10,736). For ever asthma, the most important risk factor was a parental history of asthma. Increased consumption of pulses (aOR: 0.822, 95% CI: 0.706-0.958) was associated with a lowered odds of ever asthma, but cereals (aOR: 1.256, 95% CI: 1.006-1.580), pasta (aOR: 1.265, 95% CI: 1.027-1.553), butter (aOR: 1.350, 95% CI: 1.113-1.632), and margarine (aOR: 1.343, 95% CI: 1.081-1.660) were associated with a higher risk of ever asthma. Increased television/computer usage was associated with a decreased risk of ever asthma (aOR: 0.448, 95% CI: 0.367-0.545). Conversely, genetic factors had a lower strength of effect on current asthma (parental history of asthma - OR: 1.465, 95% CI: 1.135-1.888) as compared to ever asthma. Only increased potato consumption was significantly associated with an increased risk of current asthma (most or all days per week vs never or only occasionally - aOR: 1.577, 95% CI: 1.145-2.180). Physical activity (aOR: 0.693, 95% CI: 0.542-0.885) was associated with a lower odds of asthma, while second-hand smoke exposure was associated with an increased risk for current asthma (aOR: 1.435, 95% CI: 1.001-2.047).

Conclusion

Overall, the prevalence of lifetime asthma and current asthma among young Chinese adults was 19.1% and 6.3%, higher than that of previous studies. Our results suggested a stronger association between genetic factors and ever asthma as compared to current asthma. Parental asthma was the most important intrinsic epidemiological factor for asthma manifestation, while various foods, physical activity levels, and television or computer usage were also significantly associated with asthma. Future studies should consider risk factors in conjunction with other accompanying variables given the potential interactions between them, to discern the effects of environment and lifestyle on asthma more distinctly.

Association of the consumption of common drinks with early puberty in both sexes

Background

We examined the effect of sugar-sweetened beverages (SSB) and common drink intake on pubertal development in both sexes.

Methods

Data were retrieved from Taiwan Children Health Study, which involved detailed pubertal stage assessments of 2,819 schoolchildren aged 11 years in 2011-2012. Drawings of secondary sexual characteristics and self-reported age at menarche or voice breaking were used to assess pubertal stages. Dietary intake was assessed using a detailed semi-quantitative food frequency questionnaire. Generalized estimating equation modeling was applied to obtain odds ratios (ORs) and 95% confidence intervals (CIs) to represent the effects of each drink on early pubertal development outcomes.

Results

In boys, an one cup/day increment of a SSB was associated with earlier voice breaking (β = -0.12; 95% CI = -0.20, -0.04), whereas consuming yogurt (≥2 cups/day) was a protective factor against early puberty (OR = 0.78; 95% CI = 0.73, 0.83). In girls, SSB consumption was associated with increased risk of early puberty in a dose-response manner, and a similar protective effect of yogurt consumption and fermented probiotic drink (≥2 cups/day) against early puberty was observed (OR = 0.96; 95% CI = 0.94, 0.99). Furthermore, the intake of both total sugar and added sugar within SSBs increased risk of early puberty in girls but not in boys.

Conclusions

Sugar-sweetened beverages were associated with early puberty, and probiotic drinks appeared to mitigate this link. These findings indicate that the gut-brain axis could play a crucial role in sexual maturation.

Mediators linking obesity to childhood asthma

BACKGROUND

Obesity and asthma are highly associated, but the mechanisms underlying the association remain unknown. We examined five mediators linking obesity with childhood asthma: (1) pulmonary function impairment, (2) airway inflammation, (3) physical fitness, (4) sleep-disordered breathing (SDB), and (5) early puberty.

METHODS

A Mendelian randomization (MR) study with mediation analysis of data obtained from 5965 children as part of the Taiwan Children Health Study. Observational analysis, MR two-stage least-squares method, and MR sensitivity analysis were carried out to investigate each causal pathway. Prospective cohort analyses were used to strengthen the findings.

RESULTS

The increased asthma risk associated with obesity was found to be mostly mediated through impaired pulmonary function, low physical fitness, and early puberty. In the MR analysis, body mass index was negatively associated with FEV1/FVC and physical fitness index (β = -2.17 and -0.71; 95% CI, -3.92 to -0.42 and -1.30 to -0.13, respectively) and positively associated with early puberty (OR, 1.09; 95% CI, 1.02-1.17). High FEV1/FVC and physical fitness index reduced asthma risk (OR, 0.98 and 0.93; 95% CI, 0.97-0.99 and 0.88-0.98, respectively), whereas SDB and early puberty increased the risk of asthma (OR, 1.03 and 1.22; 95% CI, 1.01-1.05 and 1.05-1.42, respectively). Temporal causality was strengthened in prospective cohort analyses. The three main mediators were low physical fitness, impaired pulmonary function, and early puberty, with mediation proportions of 73.76%, 61.63%, and 27.66%, respectively.

CONCLUSIONS

Interventions promoting physical fitness and pulmonary function might effectively reduce obesity-induced asthma risk.

Endotyping pediatric obesity-related asthma: Contribution of anthropometrics, metabolism, nutrients, and CD4+ lymphocytes to pulmonary function

BACKGROUND

Obesity-related complications including visceral fat, metabolic abnormalities, nutrient deficiencies, and immune perturbations are interdependent but have been individually associated with childhood asthma.

OBJECTIVE

We sought to endotype childhood obesity-related asthma by quantifying contributions of obesity-related complications to symptoms and pulmonary function.

METHODS

Multiomics analysis using Similarity Network Fusion followed by mediation analysis were performed to quantify prediction of obese asthma phenotype by different combinations of anthropometric, metabolic, nutrient, and TH-cell transcriptome and DNA methylome data sets.

RESULTS

Two clusters (n = 28 and 26) distinct in their anthropometric (neck and midarm circumference, waist to hip ratio [WHR], and body mass index [BMI] z score), metabolic, nutrient, and TH-cell transcriptome and DNA methylome footprint predicted 5 or more pulmonary function indices across 7 different data set combinations. Metabolic measures attenuated the association of neck, WHR, and BMI z score with FEV1/forced vital capacity (FVC) ratio and expiratory reserve volume (ERV), of neck, midarm, and BMI z score with functional residual capacity, but only of WHR with inspiratory capacity. Nutrient levels attenuated the association of neck, midarm circumference, and BMI z score with functional residual capacity, and of WHR with FEV1/FVC ratio, ERV, and inspiratory capacity. TH-cell transcriptome attenuated the association of all 4 anthropometric measures with FEV1/FVC ratio, but only of WHR with ERV and inspiratory capacity. The DNA methylome attenuated the association of all 4 anthropometric measures with FEV1/FVC ratio and ERV, but only of WHR with inspiratory capacity.

CONCLUSIONS

Anthropometric, metabolic, nutrient, and immune perturbations have individual but interdependent contributions to obese asthma phenotype, with the most consistent effect of WHR, highlighting the role of truncal adiposity in endotyping childhood obesity-related asthma.

Associations of physical condition with lung function and asthma in adolescents from the general population

BACKGROUND

The relation of physical condition with respiratory outcomes in adolescents is unclear. We examined the hypothesis that adolescents with a lower physical condition represented by a lower cardiorespiratory fitness and physical activity, and a higher screen time have a lower lung function and higher risk of asthma.

METHODS

In a population-based prospective cohort study on 4854 children aged 13 years, we assessed cardiorespiratory fitness by using the peak work rate measured by the steep ramp test. Information on physical activity and screen time was obtained by self-reported questionnaires. Lung function was measured by spirometry and current asthma was assessed by a parental-reported questionnaire.

RESULTS

Taking sociodemographic, lifestyle, and growth-related confounders and multiple hypothesis testing into account, a 1 SD lower cardiorespiratory fitness was associated with a lower FEV₁ , FVC, and FEF₇₅ (Z-score difference (95% CI): -0.31 (-0.35, -0.28), -0.30 (-0.33, -0.26), -0.13 (-0.17, -0.10), respectively), and a higher risk of asthma (Odds Ratio (95% CI) 1.25 (1.06, 1.46)). A 1 SD higher screen time was associated with a lower FVC (Z-score difference (95% CI): -0.06 (-0.10, -0.03)). Physical activity and screen time were not related to asthma. Results did not materially change after additional adjustment for respiratory outcomes at an earlier age.

CONCLUSION

Adolescents with a lower cardiorespiratory fitness had a lower lung function and a higher risk of asthma. Those with a higher screen time had a lower FVC. Further studies are needed to explore the effect of improvements in physical condition on long-term respiratory outcomes.

Paucigranulocytic Asthma: Potential Pathogenetic Mechanisms, Clinical Features and Therapeutic Management

Asthma is a heterogeneous disease usually characterized by chronic airway inflammation, in which several phenotypes have been described, related to the age of onset, symptoms, inflammatory characteristics and treatment response. The identification of the inflammatory phenotype in asthma is very useful, since it allows for both the recognition of the asthmatic triggering factor as well as the optimization of treatment The paucigranulocytic phenotype of asthma (PGA) is characterized by sputum eosinophil levels <1−3% and sputum neutrophil levels < 60%. The precise characteristics and the pathobiology of PGA are not fully understood, and, in some cases, it seems to represent a previous eosinophilic phenotype with a good response to anti-inflammatory treatment. However, many patients with PGA remain uncontrolled and experience asthmatic symptoms and exacerbations, irrespective of the low grade of airway inflammation. This observation leads to the hypothesis that PGA might also be either a special phenotype driven by different kinds of cells, such as macrophages or mast cells, or a non-inflammatory phenotype with a low grade of eosinophilic inflammation. In this review, we aim to describe the special characteristics of PGA and the potential therapeutic interventions that could be offered to these patients.

High Insulin in Early Childhood Is Associated with Subsequent Asthma Risk Independent of Body Mass Index

BACKGROUND

Asthma and obesity are major, interconnected public health challenges that usually have their origins in childhood, and for which the relationship is strengthened among those with insulin resistance.

OBJECTIVE

To determine whether high insulin in early life confers increased longitudinal risk for asthma independent of body mass index.

METHODS

The study used data from the Tucson Children's Respiratory Study (TCRS) and the Avon Longitudinal Study of Parents and Children (ALSPAC). Nonfasting insulin was measured in TCRS participants at age 6 years and fasting insulin in ALSPAC participants at age 8 years. Physician-diagnosed active asthma was determined at baseline and at subsequent assessments up to age 36 years in TCRS and 17 years in ALSPAC.

RESULTS

In TCRS, high insulin (upper quartile) at age 6 years was associated with increased odds of having active asthma from ages 8 to 36 years compared with low insulin (odds ratio,1.98; 95% CI, 1.28-3.05; P = .002). Similarly, in ALSPAC, high insulin was associated with a significantly higher risk of active asthma from ages 11 to 17 years compared with low insulin (odds ratio, 1.59; 95% CI, 1.12-2.27; P = .009). These findings were independent of baseline body mass index in both cohorts, and were not related to other demographic and asthma risk factors nor other tested markers of systemic inflammation and metabolic syndrome.

CONCLUSIONS

In 2 separate birth cohorts, higher blood insulin level in early childhood was associated with increased risk of active asthma through adolescence and adulthood, independent of body mass index. High insulin indicates a novel mechanism for asthma development, which may be a target for intervention.

Investigating obesity-related risk factors for childhood asthma

BACKGROUND

We tested the hypothesis that multiple obesity-related risk factors (obesity, physical activity, cardiopulmonary physical fitness, sleep-disorder breathing (SDB), and sleep quality) are associated with childhood asthma using a Mendelian randomization (MR) design. Furthermore, we aim to investigate whether these risk factors were associated with incident asthma prospectively.

METHODS

In total, 7069 children aged 12 from the Taiwan Children Health Study were enrolled in the current study. Cross-sectional logistic regression, one-sample MR, summary-level MR sensitivity analyses, and prospective survival analyses were used to investigate each causal pathway.

RESULTS

In MR analysis, three of the five risk factors (obesity, SDB, and sleep quality) were associated with asthma, with the highest effect sizes per inter-quartile range (IQR) increase observed for sleep quality (odds ratio [OR] = 1.42; 95% confidence interval [CI]: 1.06 to 1.92) and the lowest for obesity (OR = 1.08; 95% CI: 1.00-1.16). In the prospective survival analysis, obesity showed the highest risk of incident asthma per IQR increase (hazard ratio [HR] = 1.28; 95% CI: 1.05 to 1.56), followed by SDB (HR = 1.18; 95% CI: 1.08 to 1.29) and sleep quality (HR = 1.10; 95% CI: 1.03 to 1.17).

CONCLUSION

Among the examined factors, the most plausible risk factors for asthma were obesity, SDB, and poor sleep quality. For the prevention of childhood asthma, relevant stakeholders should prioritize improving children's sleep quality and preventing obesity comorbidities such as SDB.

Risk factors of asthma in the Asian population: a systematic review and meta-analysis

Background and objective

An increasing trend of asthma prevalence was observed in Asia; however, contributions of environmental and host-related risk factors to the development of this disease remain uncertain. This study aimed to perform a systematic review and meta-analysis for asthma-associated risk factors reported in Asia.

Methods

We systematically searched three public databases (Web of Science, PubMed, and Scopus) in Feb 2021. We only included articles that reported environmental and host-related risk factors associated with asthma in the Asian population. Random-effect meta-analyses were conducted for frequently reported asthma-associated risk factors to provide an overall risk estimate of asthma development.

Results

Of 4030 records obtained from public databases, 289 articles were selected for review. The most frequently reported asthma-associated risk factor was the family history of allergy-related conditions. The random-effect asthma risk estimates (pooled odds ratio, OR) were 4.66 (95% confidence interval (CI): 3.73–5.82) for the family history of asthma, 3.50 (95% CI: 2.62–4.67) for the family history of atopy, 3.57 (95% CI: 3.03–4.22) for the family history of any allergic diseases, 1.96 (95% CI: 1.47–2.61) for the family history of allergic rhinitis, and 2.75 (95% CI: 1.12–6.76) for the family history of atopic dermatitis. For housing-related factors, including the presence of mold, mold spots, mold odor, cockroach, water damage, and incense burning, the random-effect pooled OR ranged from 1.43 to 1.73. Other risk factors with significant pooled OR for asthma development included male gender (1.30, 95% CI: 1.23–1.38), cigarette smoke exposure (1.44, 95% CI: 1.30–1.60), cigarette smoking (1.66, 95% CI: 1.44–1.90), body mass index (BMI)–related parameters (pooled OR ranged from 1.06 to 2.02), various types of air pollution (NO₂, PM10, and O₃; pooled OR ranged from 1.03 to 1.22), and pre- and perinatal factors (low birth weight, preterm birth, and cesarean section; pooled OR ranged from 1.14 to 1.32).

Conclusions

The family history of asthma was the most frequently reported risk factor for asthma development in Asia with the highest risk estimate for asthma development. This suggests a major role of the genetic component in asthma pathogenesis. Further study on asthma genetics is required to improve the current understanding of asthma etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40101-021-00273-x.

Treatment approaches for the patient with T2 low asthma

OBJECTIVE

To identify treatment approaches that can be used in the management of patients with asthma who lack significant type 2 inflammation, also called T2 low asthma.

DATA SOURCES

Recent expert guideline updates on the management of asthma, recent journal articles and review articles, and foundational journal articles are referenced.

STUDY SELECTIONS

This review cites clinical cohort studies of highly characterized patients with asthma, clinical interventional trials of high impact, mechanistic studies relevant to T2 low asthma, and emerging work in this area.

RESULTS

T2 low asthma accounts for approximately one-third to one-half of individuals with asthma. Characteristics of participants with T2 low asthma include higher body mass index, cigarette smoking/smoke exposure, relative lack of responsiveness to steroids, less bronchodilator reversibility, and often the presence of neutrophilic inflammation. Multiple available interventions target these characteristics, including standard inhalers, azithromycin, and lifestyle interventions of weight loss and smoking cessation.

CONCLUSION

Treatment of T2 low asthma should involve currently available approaches and will benefit from improved definition and understanding of disease pathobiology.

Asthma, Allergic Rhinitis, and Atopic Dermatitis Incidence in Korean Adolescents before and after COVID-19

With changes in personal habits (masks and handwashing) during the COVID-19 outbreak, the study analyzed the reporting of physician-diagnosed cases (incidence) of allergic diseases (asthma, allergic rhinitis, and atopic dermatitis) using the data for years 2019 and 2020 from the Korean adolescent risk behavior web-based survey (KYRBWS-15 and 16). Altogether, 92,659 adolescents (48,443 in 2019 and 44,216 in 2020) were enrolled. The crude and adjusted odd ratios (ORs) were calculated for each disease in 2020 compared to that in 2019 using multiple logistic regression. Subgroup analyses were performed according to sex and economic status. The incidence of asthma decreased from 1.5% in 2019 to 1.0% 2020 (p < 0.001). The incidence of allergic rhinitis in 2019 and 2020 was 19.5% and 16.3%, respectively (p < 0.001). Compared with 2019, the adjusted OR (aOR) in 2020 was 0.68 (95% CI = 0.66–0.77, p value < 0.001) for asthma and 0.82 (95% CI = 0.78–0.85, p < 0.001) for allergic rhinitis. In contrast, there was no statistically significant difference between the incidence of atopic dermatitis in 2019 and that in 2020 (6.4%, vs. 6.4%, p > 0.05, respectively). Subgroup analyses results were consistent. In conclusion, there was decrease in the incidence of asthma and allergic rhinitis but not in that of atopic dermatitis from 2019 to 2020.

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.

The Role of Nutritional Factors in Asthma: Challenges and Opportunities for Epidemiological Research

The prevalence of asthma has nearly doubled over the last decades. Twentieth century changes in environmental and lifestyle factors, including changes in dietary habits, physical activity and the obesity epidemic, have been suggested to play a role in the increase of asthma prevalence and uncontrolled asthma worldwide. A large body of evidence has suggested that obesity is a likely risk factor for asthma, but mechanisms are still unclear. Regarding diet and physical activity, the literature remains inconclusive. Although the investigation of nutritional factors as a whole (i.e., the “diet, physical activity and body composition” triad) is highly relevant in terms of understanding underlying mechanisms, as well as designing effective public health interventions, their combined effects across the life course has not received a lot of attention. In this review, we discuss the state of the art regarding the role of nutritional factors in asthma, for each window of exposure. We focus on the methodological and conceptual challenges encountered in the investigation of the complex time-dependent interrelations between nutritional factors and asthma and its control, and their interaction with other determinants of asthma. Lastly, we provide guidance on how to address these challenges, as well as suggestions for future research.

Associations between sleep duration, lung function, FeNO and blood eosinophils among current asthmatics (NHANES 2007-12)

Short sleep duration potentially affects the risk of developing asthma and asthmatic exacerbation. Our aim is to determine the associations between sleep duration with asthmatic phenotypes, fraction of exhaled NO (FeNO), blood eosinophils, and lung function among current asthmatics. A total of 558 individuals from the National Health and Nutrition Examination Survey during 2007-2012 were included in this study. Self-reported sleep duration was divided into three groups: short (⩽6 h), healthy (7-8 h) and long (⩾9 h). By using a multivariate generalized additive model with binomial or Poisson regression, the abovementioned associations were evaluated after adjustment for potential confounders. Our study population included 284 short sleepers, 240 healthy sleepers and 34 long sleepers. In multivariate binomial regression analysis, we found that short sleep duration was associated with increased risk of asthma with central obesity (adjusted OR = 0.58, 95%CI: 0.33-0.99, P = 0.047) compared with healthy sleep duration. Multivariate Poisson regression analyses revealed a significant increase in FeNO (adjusted OR = 1.19, 95%CI: 1.14-1.26, P < 0.01) and reduction of blood eosinophil percentage (adjusted OR = 0.86, 95%CI: 0.77-0.96, P < 0.01) in the healthy sleep duration group compared with the short sleep duration group. The individuals with healthy and long sleep duration harbored better lung function than those with short sleep duration, with the exception of FEV1/FVC. Our study suggested that short sleepers potentially increase the risk of asthma with central obesity and lung function impairment than healthy sleepers among current asthmatics. We also observed that short sleep duration is associated with a significant reduction of FeNO and increase of blood eosinophil percentage.

Moving more: physical activity and its positive effects on long term conditions in children and young people

While the benefits of regular participation in physical activity in children and young people are clear, misconceptions have developed about the possible negative effects and potential complications of exercise on long-term conditions such as epilepsy, asthma and diabetes. Over the last decade evidence has emerged supporting the positive impact that physical activity has on long-term conditions. Previous concerns were raised about the risks of hypoglycaemia in children with type 1 diabetes mellitus (T1DM) thus limiting participation in sports. Importantly, physical activity improves the metabolic profile, bone mineral density, cardiorespiratory fitness and insulin sensitivity while lowering mortality risk in children with T1DM. Children with asthma were prevented from doing exercise due to concerns about precipitating an acute asthmatic episode. To the contrary, physical activity interventions have consistently shown an increase in cardiovascular fitness, physical capacity, asthma-free days and quality of life in childhood asthmatics. Children with epilepsy are often excluded from sports due to concerns relating to increased seizure frequency, yet evidence suggests that this is not the case. The evidence supporting physical activity in childhood survivors of cancer is growing but still primarily confined to patients with acute lymphoblastic leukaemia. Participation in sports and physical activity also reduces mental health problems developing in adolescence. While further research is required to investigate benefits of physical activity on specific aspects of long-term conditions in children, in general this group should be advised to increase participation in sports and exercise as a means of improving long-term physical and mental health.

Obesity-associated asthma in childhood

Obesity and bronchial asthma are very common diseases in children and adolescents, associated with a considerable burden of disease, reduced quality of life and comorbidities. Obesity is a significant risk factor for bronchial asthma. On the one hand, obesity leads to changes in the mechanics and function of the lungs and chest. On the other hand, obesity-associated inflammatory processes with increased production of leptin and cytokines may trigger bronchial inflammation with the appearance of asthmatic symptoms. The diseases are also linked by genetic factors. Physical activity and weight reduction have a significant benefit. Pharmacotherapy must be based on the pattern of inflammation. This article summarizes the current state of the literature on the association of asthma and obesity and presents current and possible future treatment options.

Advances in understanding and reducing the burden of severe asthma in children

Severe asthma in children is rare, accounting for only a small proportion of childhood asthma. After addressing modifiable factors such as adherence to treatment, comorbidities, and adverse exposures, children whose disease is not well controlled on high doses of medication form a heterogeneous group of severe asthma phenotypes. Over the past decade, considerable advances have been made in understanding the pathophysiology of severe therapy-resistant asthma in children. However, asthma attacks and hospital admissions are frequent and mortality is still unacceptably high. Strategies to modify the natural history of asthma, prevent severe exacerbations, and prevent lung function decline are needed. Mechanistic studies have led to the development of several biologics targeting type 2 inflammation. This growing pipeline has the potential to reduce the burden of severe asthma; however, detailed assessment and characterisation of each child with seemingly severe asthma is necessary so that the most effective and appropriate management strategy can be implemented. Risk stratification, remote monitoring, and the integration of multiple data sources could help to tailor management for the individual child with severe asthma.

Prevalence and temporal trends of presarcopenia metrics and related body composition measurements from the 1999 to 2006 NHANES

OBJECTIVE

To evaluate the prevalence and temporal trends of presarcopenia and related body composition measurements.

DESIGN

Cross-sectional study.

SETTING

National Health and Nutrition Examination Survey (NHANES) 1999-2006.

METHODS

Presarcopenia was defined according to the guidelines from the European Working Group on Sarcopenia. Logistic or linear regression models were used to evaluate the linear trend of the prevalence of presarcopenia, obesity and related body composition measurements.

PARTICIPANTS

A total of 29 947 participants aged 18-90 years from five waves of the NHANES were included in the analysis.

OUTCOME MEASURES

Presarcopenia was sex-specifically defined as having a skeletal mass index ≤7.26 kg/m² in men and ≤5.5 kg/m² in women. Body composition measurements, including total body fat percentage, total body fat mass, total lean body mass, appendicular skeletal muscle mass and bone mineral density, were obtained by dual-energy X-ray absorptiometry.

RESULTS

The overall prevalence of presarcopenia ranged from 16.4% in 1999-2000 to 14.8% in 2005-2006 (p for trend=0.78). Presarcopenia was stable in both males (p for trend=0.36) and females (p for trend=0.20). The presarcopenia prevalence was significantly elevated among the age group of 18-39 years old (from 11.3% to 14.1%, p for trend=0.04) and among non-Hispanic blacks (p for trend <0.001). Adults aged ≥80 years old had the highest prevalence.

CONCLUSIONS

The prevalence of presarcopenia increased among young individuals over time. Non-Hispanic blacks also demonstrated an increasing trend in the prevalence over time.

Association between Body Mass Index Status and Childhood Asthma Control

Background: The association between body mass index (BMI) status and childhood asthma control is not well understood. The aim of this study was to explore the association between BMI status and childhood asthma control. Methods: Two hundred forty-two children, aged 6-11 years, with asthma were included. The outcome variables were asthma control levels assessed by the Chinese version of the childhood asthma control test (C-ACT), asthma-related hospitalizations or emergency department (ED) visits in the past 12 months, and forced expiratory volume in 1 second (FEV₁) as a percentage of the predicted value. The associations between BMI status (underweight, overweight, or obese, relative to normal weight) and the three outcome variables were estimated by ordinal logistic regression, binary logistic regression, and multiple linear regression analyses. Results: No significant association was found between BMI status and asthma control levels assessed by C-ACT, and between BMI status and asthma-related hospitalizations or ED visits in the past 12 months, after adjustment for age, sex, father's education level, mother's education level, per capita family monthly income, medical insurance, passive smoking, allergic rhinitis, course of disease, and medication compliance. A significant association between underweight and FEV₁ as a percentage of the predicted value was found after adjustment for the above covariates. However, no significant association between overweight or obese and FEV₁ as a percentage of the predicted value was found. Conclusions: This study shows that BMI status may not be associated with childhood asthma control. Given the inconsistency in current evidence, more studies are needed in the future to investigate this association.

Low fitness and increased sedentary time are associated with worse asthma-The National Youth Fitness Survey

BACKGROUND

Asthma is the most common chronic illness in children and is independently impacted by obesity and by fitness. The National Youth Fitness Survey collected data on aerobic fitness, body composition, and health outcomes in children 6 to 11 years old. The goal of this study is to test hypotheses regarding relationships between asthma, aerobic fitness, and sedentary time in this uniquely studied cohort of young children.

METHODS

A total of 665 children (6-11 years old; 49% male) were included in analyses. We explored relationships between asthma outcomes and aerobic fitness (measured by endurance time), self-reported sedentary time, and body mass index categories. Fitness was categorized as unfit (lowest 25% of endurance times) or fit. Multivariate logistic regression models were created for asthma outcomes and adjusted for race, age, sex, poverty status, and overweight/obesity.

RESULTS

Among the participants, 17.9% had a previous history of asthma and 11.4% had current asthma. Additionally, 37.3% of participants were overweight or obese. Low fitness was significantly associated with increased odds of past asthma, current asthma, asthma attacks, wheeze with exercise, and wheeze with activity limitations in multivariate models. Increased sedentary time was significantly associated with increased odds of previous asthma, current asthma, asthma attacks, and wheeze with activity limitations.

CONCLUSION

Decreased aerobic fitness and increased sedentary time were associated with worse asthma outcomes in this group of children (6-11 years old). This data suggest that fitness and sedentary time, both modifiable factors, each have an independent effect on asthma and should be included in assessments and management of asthma health.

Early pubertal maturation and risk of childhood asthma: A Mendelian randomization and longitudinal study

BACKGROUND

Studies on early puberty and incident asthma have reported inconsistent results and are mainly performed in females. In this longitudinal study, we investigated the causal relationship between pubertal maturation and asthma through Mendelian randomization (MR) and explored the joint effect of overweightness and early pubertal maturation on asthma.

METHODS

We used data from the Taiwan Children Health Study with longitudinal follow-ups of 2991 children aged 11-17 years. Six puberty-related single-nucleotide polymorphisms (combined into a weighted allelic score) were used to yield genetic instrumental variables for early puberty. Early pubertal maturation was defined as reaching a certain pubertal stage earlier than the median age for that stage. Incident asthma cases were calculated by excluding children with a history of asthma prior to that age.

RESULTS

The results of MR analysis revealed that early pubertal maturation was associated with active asthma (OR = 1.18; 95% CI: 1.08-1.28); this effect was significant in male children. Early pubertal maturation significantly increased the risk of incident asthma outcomes at 12 and 17 years of age in both sexes (hazard ratio = 2.15; 95% CI: 1.21-3.84). Taking non-overweight and non-early puberty children as the reference group, we observed a synergistic effect of overweightness and early pubertal maturation on asthma risk (OR = 1.08; 95% CI: 1.04-1.11) in children of both sexes.

CONCLUSIONS

Early screening and intervention for obesity are recommended to prevent future early pubertal onset and asthma occurrence.

Association between Depressive Symptoms and Food Insecurity among Indonesian Adults: Results from the 2007-2014 Indonesia Family Life Survey

BACKGROUND

Depressive symptoms and food insecurity are two of the public health concerns in developing countries. Food insecurity is linked to several chronic diseases, while little is known about the association between food insecurity and depressive symptoms among adults. A person with limited or uncertain availability or access to nutritionally sufficient, socially relevant, and safe foods is defined as a food-insecure person.

MATERIALS AND METHODS

Data were obtained from 8613 adults who participated in the Indonesia Family Life Survey (IFLS) in 2007 and 2014. The 10 items of the food frequency questionnaire (FFQ) were used in food consumption score analysis to assess food insecurity based on the concept of the World Food Program (WFP). Depressive symptoms were assessed using 10 items of the self-reported Center for Epidemiologic Studies Depression (CES-D) questionnaire. A linear and multiple logistic regression model with a generalized estimating equation was used to test the hypothesis while accounting for the health behaviors and sociodemographic characteristics.

RESULTS

Food consumption score was negatively associated with CES-D 10 score (β-coefficients: -9.71 × 10-3 to -1.06 × 10-2; 95% CIs: -7.46 × 10-3 to -1.26 × 10-2). The borderline and poor food consumption group was positively associated with the depressive symptoms, both in the unadjusted and adjusted models (exponentiated β-coefficients: 1.13 to 1.18; 95% CIs: 1.06 to 1.28). Conclusions: Depressive symptoms were positively significantly associated with food insecurity. Thus, health professionals must be aware of the issue, and should consider health and nutrition programs for adults at risk of food insecurity.

Assessing causality between childhood adiposity and early puberty: A bidirectional Mendelian randomization and longitudinal study

AIMS

Obesity and early puberty have been reported to be mutually causative. We investigated the causal relationship between adiposity and early puberty by performing bidirectional Mendelian randomization (MR) and longitudinal data analyses.

METHODS

We used information from the Taiwan Children Health Study (3109 adolescents aged 11-12 years) with 17 body mass index (BMI)- and 10 puberty-related single-nucleotide polymorphisms (SNPs) to produce genetic instrumental variables (IVs). The two-stage least squares (2SLS) method, MR sensitivity analysis, and survival analysis were used to explore and confirm causality.

RESULTS

Regression estimates from IVs revealed that significantly increased association of BMI with early puberty was noted (coefficients: 0.13, 0.10, and 0.09; 95% CI: 0.07-0.19, 0.02-0.19, and 0.02-0.16 for all participants, male adolescents, and female adolescents, respectively). Genetic IVs for puberty were not associated with BMI. MR sensitivity and two-sample MR analyses produced similar results. Longitudinal analysis results revealed that prepubertal overweight and obesity could predict early onset of puberty. However, after excluding children with a history of overweight and obesity at the age of 7-12 years, early puberty was not found to trigger new-onset of overweight and obesity at the age of 18 years in either sex.

CONCLUSIONS

Higher adiposity may lead to early puberty. However, the causal effects of early puberty on adiposity accumulation were not supported by our data. Targeted interventions to reduce childhood obesity are strongly recommended to prevent obesity-related comorbidities, as well as early puberty onset.

Asthma, exercise and metabolic dysregulation in paediatrics

Asthma is the most frequent chronic disease in childhood. Chest tightness, cough, wheezing and dyspnoea during or after exercise may be unique manifestations of asthma in up to 90% of subjects. Physical activity may be reduced by uncontrolled asthma symptoms and parental beliefs, impairing physical fitness of asthmatic children. Clinicians working in the field of allergy are aware of evidence supporting the benefits of physical activity for patients with asthma. Treatment of asthma is required in order to obtain its control and to avoid any limitation in sports and active play participation. As exercise performance in children with controlled asthma is not different from that of healthy controls, any exercise limitation cannot be accepted. Overweight and obesity may interfere with asthma and exercise, leading to dyspnoea symptoms. Evidences on the effect of insulin resistance on airway smooth muscle and on bronchial hyperactivity are presented. CONCLUSION: Exercise is part of the strategy to obtain the best control of asthma in childhood, but we have to optimise the asthma control therapy before starting exercise programming. Furthermore, it is crucial to give best attention on the effects of obesity and insulin resistance, because they could in turn influence patients' symptoms.

Association between abdominal obesity and asthma: a meta-analysis

Background

Studies evaluating the association between abdominal obesity and asthma yielded conflict results. Whether abdominal obesity is positively associated with asthma remains unclear.

Objective

To quantitatively determine the association between abdominal obesity and asthma.

Methods

Databases including PubMed, Web of Science, China National Knowledge Infrastructure, China Biology Medicine disc, Chinese Scientific and Technological Journal Database and Wanfang Data were searched up to February 2018 to collect all relevant studies. Reference lists of related articles were also checked. After study selection and data extraction, meta-analysis was conducted to calculate the pooled odds ratio (OR) and corresponding 95% confidence interval (CI). Subgroup analyses by study design and age groups of participants were further performed. Publication bias was assessed via Begg’s rank correlation and Egger’s linear regression methods.

Results

A total of 13 studies were included in the final meta-analysis, including 2 case–control studies, 6 cohort studies, and 5 cross-sectional studies. Our meta-analysis observed a positive association between abdominal obesity and asthma (OR = 1.47, 95% CI 1.35–1.59). No evidence of heterogeneity (I² = 10.7%) or publication bias (Begg’s test P = 0.200, Egger’s test P = 0.146) was found. Subgroup analyses by study design and age groups of participants obtained consistently positive results across subgroups. Moreover, our meta-analysis observed similar results when considering this association separately in males and females (Males: OR = 1.37, 95% CI 1.18–1.58; Females: OR = 1.39, 95% CI 1.22–1.58). In addition, the association between abdominal overweight and asthma was further explored in this meta-analysis and the pooled OR and 95% CI was 1.13 (1.03, 1.24), indicating that there is a dose–response relationship between abdominal weight status and asthma.

Conclusions

Our meta-analysis shows a positive association between abdominal obesity and asthma. Moreover, this association is similar in males and females. In addition, our meta-analysis indicates that there is a dose–response relationship between abdominal weight status and asthma. Therefore, addressing abdominal obesity issue is of great importance. More studies are needed in the future to clarify the association between abdominal obesity and asthma.

Cardiorespiratory Fitness in Childhood and Adolescence Affects Future Cardiovascular Risk Factors: A Systematic Review of Longitudinal Studies

BACKGROUND

Although cardiorespiratory fitness (CRF) in childhood and adolescence may be linked to future cardiovascular health, there is currently limited evidence for a longitudinal association.

OBJECTIVES

To provide a systematic review on the prospective association between CRF in childhood and adolescence and cardiovascular disease (CVD) risk factors at least 2 years later.

METHODS

Using a systematic search of Medline, Embase, and SPORTDiscus, relevant articles were identified by the following criteria: generally healthy children and adolescents between 3 and 18 years of age with CRF assessed at baseline, and a follow-up period of ≥ 2 years. The outcome measures were CVD risk factors. We appraised quality of the included articles with STROBE and QUIPS checklists.

RESULTS

After screening 7524 titles and abstracts, we included 38 articles, assessing 44,169 children and adolescents followed up for a median of 6 years. Eleven articles were of high quality. There was considerable heterogeneity in methodology, measurement of CRF, and outcomes, which hampered meta-analysis. In approximately half of the included articles higher CRF in childhood and adolescence was associated with lower body mass index (BMI), waist circumference, body fatness and lower prevalence of metabolic syndrome in later life. No associations between CRF in childhood and adolescence and future waist-to-hip ratio, blood pressure, lipid profile, and glucose homeostasis were observed.

CONCLUSION

Although about half of the included articles reported inverse associations between CRF in childhood and adolescence and future BMI, body fatness, and metabolic syndrome, evidence for other CVD risk factors was unconvincing. Many articles did not account for important confounding factors such as adiposity. Recommendations for future research include standardizing the measurement of CRF, i.e. by reporting VO_2max, using standardized outcome assessments, and performing individual patient data meta-analyses.

Causal relationships between adiposity and childhood asthma: bi-directional Mendelian Randomization analysis

BACKGROUND/OBJECTIVES

Obesity and asthma are common chronic diseases and have been reported to be mutually causative. We investigated the causal direction of the relationship between adiposity and asthma using genetic markers as instrumental variables (IVs) in bi-directional Mendelian randomization (MR) analysis.

SUBJECTS/METHODS

We used data from the Taiwan Children Health Study with 24 body mass index (BMI)-single-nucleotide polymorphisms (SNPs, combined into a weighted allelic score) and 16 asthma-SNPs (combined into two weighted allelic scores, separately for asthma inflammatory and antioxidative genes) to yield genetic IVs for adiposity and asthma, respectively.

RESULTS

The weighted allele score for BMI was strongly associated with adiposity (p = 2 × 10^-16) and active asthma (p = 0.03). The two-stage least square regression risk ratio (RR) for the effect of BMI on asthma was 1.04 (95% confidence interval: 1.00-1.07, p = 0.03). Although the weighted asthma genetic scores were significantly associated with asthma (p = 8.4 × 10^-3), no association was seen for genetically instrumented asthma with BMI using MR. Central obesity was the most accurate predictor of asthma. Adiposity showed higher causal effects on asthma in boys and children with non-atopic asthma. Sensitivity analysis for MR revealed no directional genetic pleiotropy effects. The causal effect RRs of BMI on asthma were 1.04, 1.08, and 1.03 for inverse-variance weighted, MR-Egger regression (slope), and weighted median methods, respectively, all in accordance with the MR estimates.

CONCLUSIONS

High adiposity may lead to asthma, whereas the effects of asthma on adiposity accumulation are likely to be small.

The microbiome of professional athletes differs from that of more sedentary subjects in composition and particularly at the functional metabolic level

OBJECTIVE

It is evident that the gut microbiota and factors that influence its composition and activity effect human metabolic, immunological and developmental processes. We previously reported that extreme physical activity with associated dietary adaptations, such as that pursued by professional athletes, is associated with changes in faecal microbial diversity and composition relative to that of individuals with a more sedentary lifestyle. Here we address the impact of these factors on the functionality/metabolic activity of the microbiota which reveals even greater separation between exercise and a more sedentary state.

DESIGN

Metabolic phenotyping and functional metagenomic analysis of the gut microbiome of professional international rugby union players (n=40) and controls (n=46) was carried out and results were correlated with lifestyle parameters and clinical measurements (eg, dietary habit and serum creatine kinase, respectively).

RESULTS

Athletes had relative increases in pathways (eg, amino acid and antibiotic biosynthesis and carbohydrate metabolism) and faecal metabolites (eg, microbial produced short-chain fatty acids (SCFAs) acetate, propionate and butyrate) associated with enhanced muscle turnover (fitness) and overall health when compared with control groups.

CONCLUSIONS

Differences in faecal microbiota between athletes and sedentary controls show even greater separation at the metagenomic and metabolomic than at compositional levels and provide added insight into the diet-exercise-gut microbiota paradigm.

Time-Dependent Associations Between Body Composition, Physical Activity, and Current Asthma in Women: A Marginal Structural Modeling Analysis

The role of obesity in adult asthma is well-known and has been partly attributed to a confounding role of physical inactivity. However, the interrelationships between obesity, physical activity, and asthma have been incompletely addressed, probably because their time-dependent and bidirectional nature represents a methodologically challenging research question. We aimed to estimate the independent causal effects of body mass index (BMI; weight (kg)/height (m)2) and physical activity on current asthma using marginal structural models (MSMs). MSMs were applied to 15,353 adult women from a 2011 case-control study of asthma (Asthma-E3N) nested within the French E3N study (Etude Epidémiologique auprès de Femmes de la Mutuelle Générale de l'Education Nationale). Three time periods (1997-2000-2002, 2000-2002-2005, and 2002-2005-2011) were defined, where exposures (BMI and physical activity) were measured at time t, outcome (current asthma) was measured at time t + 1, and covariates were measured at time t - 1 or at baseline. A strong significant and positive dose-response relationship between BMI and current asthma was observed (odds ratios were 0.90 (95% confidence interval (CI): 0.79, 1.03), 1.29 (95% CI: 1.17, 1.42), and 1.87 (95% CI: 1.60, 2.18) for the BMI groups <20.0, 25.0-29.9, and ≥30.0, respectively, versus the normal-weight group (BMI 20.0-24.9)). We found no association between physical activity and current asthma. Our results suggest an independent causal deleterious effect of overweight and obesity on current asthma, whereas no independent causal effect of physical activity was found.

Effects of a 3-month recreative exercise applied to individuals with intellectual disability on their electromyogram (EMG) variations and balance performance

Objective: The objective of the present study was to determine how 3-month recreative exercises affect the balance performance of individuals with intellectual disability (ID) and to evaluate the electromyogram (EMG) changes following exercises. Methods: Eleven individuals (M=14.18, S.D=1.94) with mild intellectual disability (MID) who attend the school for children with ID and to the vocational school were included in the study. In the study, the subjects were applied a recreative exercise program (60 min/3 days/12 weeks) and their balance, EMG, and aerobic and anaerobic performances were evaluated by means of the pretest-posttest model. Results: When the EMG values in our study were examined, differences were found in terms of EMG₃-VL muscle variable (P=0.075/2=0.038), EMG₃-RF muscle variable (P=0.080/2=0.040), and EMG₅-RF muscle variable (P=0.066/2=0.033). The exercise program decreased the EMG values significantly. When the balance scores were evaluated, significant differences were found in terms of the variables of Balance 2 (after 30 s) (P=0.077/2=0.039) and Balance 3 (after 3 min) (P=0.084/2=0.042). The exercise program significantly decreased the balance values. Conclusion: Consequently, it was determined that 3-month recreative exercises applied to individuals with ID lowered the EMG and Balance values during and after the exercise. In this context, it is thought that the people working with the children with MID need to consider the parameters constituting the balance in a detailed way in their exercise practices and to include activities improving their balance skills into their programs, and that recreative exercises can also provide contribution in this term.

Rapid adiposity growth increases risks of new-onset asthma and airway inflammation in children

BACKGROUND/OBJECTIVES

We aim to (1) examine the influence of long-term adiposity status/short-term adiposity changes on asthma with high or low fractional exhaled nitric oxide (Fe_NO), and (2) to determine the differences in long-term adiposity status/short-term adiposity changes on atopy, airway inflammation and pulmonary function.

SUBJECTS/METHODS

We recruited 2450 fourth- to sixth-grade children from the nationwide Taiwan Children Health Study. Data regarding various adiposity indicators, atopic status, pulmonary function tests and asthma outcomes were collected annually. New-onset asthma was stratified by airway inflammation status using Fe_NO. The generalized estimating equation was used for analyzing longitudinal relationships between long-term adiposity status/short-term adiposity changes and new-onset asthma. Individual adiposity growth slopes were obtained using a hierarchical linear model to establish the relationships between short-term adiposity changes and asthma among children with high airway inflammation.

RESULTS

We found long-term adiposity status predicted childhood asthma with low Fe_NO, whereas short-term adiposity changes may increase risks of childhood asthma with high Fe_NO. Long-term adiposity status reduced pulmonary function, whereas short-term adiposity increase were associated with atopic diseases and airway inflammation.

CONCLUSIONS

Obesity-induced asthma could be mediated by high or low airway inflammation, depending on the velocity of increase in adiposity. Rapid adiposity growth may increase risks of childhood asthma and airway inflammation.

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.

Asthma

Asthma is one of the most frequent chronic respiratory diseases worldwide, with an increase in its prevalence in the last decade. Ongoing studies continue to search for better diagnostic tools and advanced treatment options in an effort to decrease the morbidity and mortality associated with it. Unfortunately, many asthmatic patients still suffer from poorly controlled asthma, which may lead to life-threatening situations. This article reviews the basics of asthma and highlights the current guidelines in making accurate diagnosis and initiating therapeutic plan.

Severe Asthma in Children: Lessons Learned and Future Directions

Severe asthma in children is a complicated and heterogeneous disorder that is extremely challenging to treat. Although most children with asthma derive clinical benefit from daily administration of low-to-medium-dose inhaled corticosteroid (ICS) therapy, a small subset of children with "severe" or "refractory" asthma require high doses of ICS and even systemic corticosteroids to maintain symptom control. These children with severe asthma are at increased risk for adverse outcomes including medication-related side effects and recurrent and life-threatening exacerbations that significantly impair quality of life. This review highlights findings on severe asthma in school-age children (age 6-17 years) from the National Heart, Lung and Blood Institute's Severe Asthma Research Program (SARP) over a 10-year period, between 2001 and 2011. Although SARP has advanced knowledge of the unique clinical, biological, and molecular attributes of severe asthma in children, considerable gaps remain for which additional studies are needed.

Associations between allergic diseases and attention deficit hyperactivity/oppositional defiant disorders in children

BACKGROUND

We aim to investigate the detailed associations between allergic diseases with attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) among children.

METHODS

Clinical information from 2,896 children enrolled in the Taiwan Children Health Study was obtained for analyses. Allergic diseases, including atopic dermatitis, asthma, and allergic rhinitis, have been evaluated based on the questions adjusted from International Study of Asthma and Allergies in Childhood. The Swanson, Nolan, and Pelham questionnaire was used to assess symptoms of ADHD and ODD. Symptoms of depression, stress, and poor sleep quality were evaluated as the interactive risk factors.

RESULTS

Children having symptoms of allergic diseases within the past 1 y were associated with having all dimensions of symptoms of ADHD and ODD. Children with ever having a physician-diagnosed atopic dermatitis were associated with inattentive and hyperactive-impulsive symptoms of ADHD. Ever diagnosed asthma was associated with ADHD and ODD. Ever diagnosed allergic rhinitis was associated with inattentive and combined symptoms of ADHD and ODD.

CONCLUSION

Children with allergic diseases, such as atopic dermatitis, asthma, and allergic rhinitis, were associated with exhibiting ADHD and ODD.

A systematic review of early life factors which adversely affect subsequent lung function

It has been known for many years that multiple early life factors can adversely affect lung function and future respiratory health. This is the first systematic review to attempt to analyse all these factors simultaneously. We adhered to strict a priori criteria for inclusion and exclusion of studies. The initial search yielded 29,351 citations of which 208 articles were reviewed in full and 25 were included in the review. This included 6 birth cohorts and 19 longitudinal population studies. The 25 studies reported the effect of 74 childhood factors (on their own or in combinations with other factors) on subsequent lung function reported as percent predicted forced expiration in one second (FEV₁). The childhood factors that were associated with a significant reduction in future FEV₁ could be grouped as: early infection, bronchial hyper-reactivity (BHR) / airway lability, a diagnosis of asthma, wheeze, family history of atopy or asthma, respiratory symptoms and prematurity / low birth weight. A complete mathematical model will only be possible if the raw data from all previous studies is made available. This highlights the need for increased cooperation between researchers and the need for international consensus about the outcome measures for future longitudinal studies.

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.

An evidence-update on the prospective relationship between childhood sedentary behaviour and biomedical health indicators: a systematic review and meta-analysis

Evidence for adverse health effects of excessive sedentary behaviour in children is predominantly based on cross-sectional studies, measuring TV viewing as proxy for sedentary behaviour. This systematic review and meta-analysis summarizes the evidence on the prospective relationship between childhood sedentary behaviour and biomedical health indicators, overall and stratified by type of sedentary behaviour (TV viewing, computer use/games, screen time and objective sedentary time). PubMed, EMBASE, PsycINFO and Cochrane were systematically searched till January 2015. Methodological quality of all included studies was scored, and a best evidence synthesis was applied. We included 109 studies of which 19 were of high quality. We found moderate-to-strong evidence for a relationship of overall sedentary time with some anthropometrics (overweight/obesity, weight-for-height), one cardiometabolic biomarker (HDL-cholesterol) and some fitness indicators (fitness, being unfit). For other health indicators, we found no convincing evidence because of inconsistent or non-significant findings. The evidence varied by type of sedentary behaviour. The meta-analysis indicated that each additional baseline hour of TV viewing (β = 0.01, 95%CI = [-0.002; 0.02]) or computer use (β = 0.00, 95%CI = [-0.004; 0.01]) per day was not significantly related with BMI at follow-up. We conclude that the evidence for a prospective relationship between childhood sedentary behaviour and biomedical health is in general unconvincing.

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

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