Overweight, Obesity, and Lung Function in Children and Adults-A Meta-analysis

Nonlinear relationship between visceral adiposity index and lung function: a population-based study

Background

As one of the critical indicators of obesity, the interaction between visceral fat content and lung disease is the focus of current research. However, the exact relationship between Visceral adipose index (VAI) and lung function is not fully understood. The purpose of this study was to evaluate the relationship between VAI and lung function,

Methods

Our study included all participants from the baseline survey population in Xinjiang in the Natural Population Cohort Study in Northwest China. A field survey was conducted in rural areas of Moyu County, Xinjiang, China, between 35 and 74 years old from June to December 2018. We collected standard questionnaires and completed physical examinations, visceral fat tests, and lung function measurements.

Results

The study included 2367 participants with a mean VAI of 10.35 ± 4.35, with males having a significantly higher VAI than females: 13.17 ± 3.91 vs. 7.58 ± 2.65. The piecewise linear spline models indicated a significant threshold effect between lung function and VAI in the general population and the males population, showing an inverted U-shaped curve. But there was no significant association between VAI and lung function in females. FEV1% predicted and FVC% predicted increased with the increase of VAI (β 0.76; 95% CI 0.30, 1.21) and (β 0.50; 95% CI 0.06, 0.94) in males with VAI ≤ 14, while FEV1% predicted and FVC% predicted decreased with the increase of VAI (β − 1.17; 95% CI − 1.90, − 0.45) and (β − 1.36; 95% CI − 2.08, − 0.64) in males with VAI ≥ 15.

Conclusions

The relationship between lung function and VAI in male participants showed an inverted U-shaped curve, with the turning point of VAI between 14 and 15. The association between visceral fat and lung function was more robust in males than in females.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01751-7.

Childhood Origins of Adult Lung Disease as Opportunities for Prevention

Prenatal and childhood exposures have been shown to impact lung development, lung function trajectory, and incidence and prevalence of respiratory disease. Early life may serve as a window of susceptibility to such exposures, with the potential to influence lifelong respiratory health. Risk factors encountered in early life with potentially durable impact on lung health include prematurity, respiratory viral illness, allergen sensitization and exposure, tobacco use and exposure, indoor and outdoor pollution, diet, and obesity. These exposures vary in the extent to which they are modifiable, and interventions aimed at reducing harmful exposures range from individual-level behavior modification to policy initiatives implemented to promote population health. For many exposures, including tobacco-related exposures, multilevel interventions are needed. Future research is needed to provide insight as to early-life interventions to promote optimal lung growth and prevent development of chronic respiratory disease. Clinicians should play an active role, assisting individual patients in avoiding known detrimental exposures including maternal smoking during pregnancy and initiation of active smoking. Clinicians can be empowered by evidence to support policies promoting reduction of population-level risk factors, such as restriction on electronic cigarette sales and legislation to uphold air quality standards, to encourage attainment of maximal lung function and reduce risk of chronic lung disease.

T2-"Low" Asthma: Overview and Management Strategies

Although the term "asthma" has been applied to all patients with airway lability and variable chest symptoms for centuries, phenotypes of asthma with distinct clinical and molecular features that may warrant different treatment approaches are well recognized. Patients with type 2 (T2)-"high" asthma are characterized by upregulation of T2 immune pathways (ie, IL-4 and IL-13 gene sets) and eosinophilic airway inflammation, whereas these features are absent in patients with T2-"low" asthma and may contribute to poor responsiveness to corticosteroid treatment. This review details definitions and clinical features of T2-"low" asthma, potential mechanisms and metabolic aspects, pediatric considerations, and potential treatment approaches. Priority research questions for T2-"low" asthma are also discussed.

The effect of low flow anesthesia on hemodynamic and peripheral oxygenation parameters in obesity surgery

Objectives:

To investigate the effects of low-flow anesthesia on hemodynamic parameters and recovery from anesthesia in obese individuals undergoing laparoscopic surgery.

Methods:

This randomized-controlled and prospective study included 44 obese patients who underwent laparoscopic sleeve gastrectomy operation. The patients were randomly allocated into 2 groups as low-flow and high-flow anesthesia. Further, the groups compared in terms of hemodynamic parameters, anesthesia recovery times, operation times, and arterial blood gas parameters.

Results:

The groups were similar with respect to demographic data. Heart rate, peripheral oxygen saturation, arterial blood pressure measurements, end-tidal, and CO₂, lactate levels measurements were similar in both groups during the entire procedure. There was also no statistically significant difference in terms of arterial blood gas parameters or anesthesia recovery periods.

Conclusion:

Low-flow anesthesia in laparoscopic obesity surgery seems to be safer compared to high-flow anesthesia in terms of the adequacy of tissue perfusion, depth of anesthesia, and postoperative recovery.

Small-Airway Function Variables in Spirometry, Fractional Exhaled Nitric Oxide, and Circulating Eosinophils Predicted Airway Hyperresponsiveness in Patients with Mild Asthma

Purpose

Patients with variable symptoms suggestive of asthma but with normal forced expiratory volume in 1 second (FEV₁) often fail to be diagnosed without a bronchial provocation test, but the test is expensive, time-consuming, risky, and not readily available in all clinical settings.

Patients and Methods

A cross-sectional study was performed in 692 patients with FEV₁≥80% predicted; normal neutrophils and chest high-resolution computed tomography; and recurrent dyspnea, cough, wheeze, and chest tightness.

Results

Compared with subjects negative for AHR (n=522), subjects positive for AHR (n=170) showed increased FENO values, peripheral eosinophils (EOS), and R5-R20; decreased FEV₁, FEV₁/Forced vital capacity (FVC), and forced expiratory flow (FEFs) (P≤.001 for all). Small-airway dysfunction was identified in 104 AHR⁺ patients (61.17%), and 132 AHR⁻ patients (25.29%) (P<0.001). The areas under the curve (AUCs) of variables used singly for an AHR diagnosis were lower than 0.77. Using joint models of FEF_50%, FEF_75%, or FEF_25%-75% with FENO increased the AUCs to 0.845, 0.824, and 0.844, respectively, significantly higher than univariate AUCs (P <0.001 for all). Patients who reported chest tightness (n=75) had lower FEFs than patients who did not (P<0.001 for all). In subjects with chest tightness, the combination of FEF_50% or FEF_25%-75% with EOS also increased the AUCs substantially, to 0.815 and 0.816, respectively (P <0.001 for all versus the univariate AUCs).

Conclusion

FENO combined with FEF_50% and FEF_25%-75% predict AHR in patients with normal FEV₁. FEF_25%-75%, FEF_50%, or FEF_25%-75% together with EOS also can potentially suggest asthma in patients with chest tightness.

Abnormal iron status is independently associated with reduced oscillometric lung function in schoolchildren

BACKGROUND

Associations between anemia and allergic diseases have been reported, but the relationship of iron deficiency with airway dysfunction in children remains unclear. We aimed to investigate the relationship between abnormal iron parameters and lung function in schoolchildren.

METHODS

Four hundred and forty-five children (10-12 years-old) from 11 elementary schools in were enrolled. The relationships of different iron parameters (hemoglobin, serum iron, transferrin saturation, and serum ferritin) with lung function evaluated by impulse oscillometry (airways resistance at 5 Hz [Rrs5], 10 Hz [Rrs10], and the difference of Rrs5 and Rrs20 Hz [Rrs5-20]), and with exhaled nitric oxide (FeNO) were evaluated after adjustment for confounders including height, sex, and body mass index z-score, and for additional covariates that could affect airway function.

RESULTS

Total airway dysfunction represented by Rrs5 was reduced in participants with low serum iron level (aβ: -0.13, 95% CI: -0.23 to -0.03, p = 0.040) after adjustment for key confounders, but did not correlate with other iron profiles. Reduced oscillometric lung function recorded as Rrs5-20 was related with low serum iron and high serum ferritin, but the results were inconsistent after multiple comparisons. Associations were not observed with serum hemoglobin.

CONCLUSIONS

Decreased serum iron level was related with airway dysfunction represented as oscillomteric Rrs5. Our results suggest a relationship of reduced lung function with abnormal iron status in children.

Identification and treatment of T2-low asthma in the era of biologics

Currently, and based on the development of relevant biologic therapies, T2-high is the most well-defined endotype of asthma. Although much progress has been made in elucidating T2-high inflammation pathways, no specific clinically applicable biomarkers for T2-low asthma have been identified. The therapeutic approach of T2-low asthma is a problem urgently needing resolution, firstly because these patients have poor response to steroids, and secondly because they are not candidates for the newer targeted biologic agents. Thus, there is an unmet need for the identification of biomarkers that can help the diagnosis and endotyping of T2-low asthma. Ongoing investigation is focusing on neutrophilic airway inflammation mediators as therapeutic targets, including interleukin (IL)-8, IL-17, IL-1, IL-6, IL-23 and tumour necrosis factor-α; molecules that target restoration of corticosteroid sensitivity, mainly mitogen-activated protein kinase inhibitors, tyrosine kinase inhibitors and phosphatidylinositol 3-kinase inhibitors; phosphodiesterase (PDE)3 inhibitors that act as bronchodilators and PDE4 inhibitors that have an anti-inflammatory effect; and airway smooth muscle mass attenuation therapies, mainly for patients with paucigranulocytic inflammation. This article aims to review the evidence for noneosinophilic inflammation being a target for therapy in asthma; discuss current and potential future therapeutic approaches, such as novel molecules and biologic agents; and assess clinical trials of licensed drugs in the treatment of T2-low asthma.

Dramatic impact of morbid obesity on child lung development

OBJECTIVE

To assess the respiratory function and sleep characteristics of obese adults and children.

METHODS

All patients with non-syndromic, severe obesity (BMI ≥3 z-scores for children and ≥40.00kg/m² for adults), referred for pulmonary function tests at Lille University Hospital, were retrospectively included.

RESULTS

A total of 69 children (mean±SD BMI 36.8±6.7 and mean BMI z-score 4.7±1.0) and 70 adults were included (mean BMI 45.7±6.2). Metabolic syndrome was diagnosed in 13 children (26%) and 40 adults (80%). Reduced lung volumes were observed in 34 children (50.0%) and 16 adults (24.0%) and both the mean functional residual capacity (FRC) and the mean residual volume (RV) were lower in children than in adults (FRC: -1.7±2.1 z-score in children vs. -1.0±1.1 in adults, P=0.026; and RV: -0.8±1.2 z-score in children vs. -0.1±1.1 in adults, P=0.002). The prevalence of severe obstructive sleep apnea syndrome was greater in adults (40.7% vs. 18.8%, P=0.007). Children had a higher average oxygen saturation (median of 96.0% [91.0-98.0] vs. 93.0% [76.0-97.0] in adults, P<0.0001).

CONCLUSION

Obesity has consequences for lung volumes in children; however, a longitudinal study is needed to determine the impact on pulmonary expansion and growth.

Visceral Obesity, Metabolic Syndrome, and Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) represents an exemplar of obesity-associated carcinogenesis, with a progressive increase in EAC risk with increased body mass index. In this context, there is increased focus on visceral adipose tissue and associated metabolic dysfunction, including hypertension, diabetes mellitus and hyperlipidemia, or combinations of these in the metabolic syndrome. Visceral obesity (VO) may promote EAC via both directly impacting on gastro-esophageal reflux disease and Barrett's esophagus, as well as via reflux-independent effects, involving adipokines, growth factors, insulin resistance, and the microbiome. In this review these pathways are explored, including the impact of VO on the tumor microenvironment, and on cancer outcomes. The current evidence-based literature regarding the role of dietary, lifestyle, pharmacologic and surgical interventions to modulate the risk of EAC is explored.

Paediatric obesity-related asthma: Disease burden and effects on pulmonary physiology

The prevalence of asthma and obesity in children has been steadily increasing globally over the past several decades, with increased concern in low and middle income countries. In this review, we summarize the current literature on these two parallel epidemics and explore the relationship between paediatric obesity and asthma in the paediatric population. Finally, we focus on the current literature as it relates to underlying physiologic alterations and changes in pulmonary function for children with obesity and asthma.

Impact of obesity on pulmonary function: current understanding and knowledge gaps

PURPOSE OF REVIEW

Obesity is an increasing world-wide public health concern. Obesity both causes respiratory symptoms and contributes to many cardiorespiratory diseases. The effects of obesity on commonly used lung function tests are reviewed.

RECENT FINDINGS

The effects of obesity on lung function are attributed both to mechanical factors and to complex metabolic effects that contribute to a pro-inflammatory state. The effects of obesity on lung function correlate with BMI and correlate even better when the distribution of excess adipose tissue is taken into account, with central obesity associated with more prominent abnormalities. Obesity is associated with marked decreases in expiratory reserve volume and functional residual capacity. Total lung capacity, residual volume, and spirometry are less affected by obesity and are generally within the normal range except with severe obesity. Obesity decreases total respiratory system compliance primarily because of decreased lung compliance, with only mild effects on chest wall compliance. Obesity is associated with impaired gas transfer with decreases in oxygenation and varied but usually mild effects on diffusing capacity for carbon monoxide, while the carbon monoxide transfer coefficient is often increased.

SUMMARY

Obesity has significant effects on lung function. The relative contribution of the mechanical effects of obesity and the production of inflammatory cytokines by adipose tissue on lung function needs further study.

Contribution of comorbidities to obesity-related asthma in children

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

Weight loss in obese children with asthma - is it important?

Obesity is a significant public health problem worldwide, and it has been identified as an independent risk factor for asthma in both adults and children. Not only does obesity increase asthma risk, but it is also associated with decreased asthma-related quality of life, worsened symptoms and asthma control, increased frequency and severity of asthma exacerbations and reduced response to asthma medications. In this review we examine the epidemiology and implications of obesity in both children and adults with asthma, and how the obesogenic "western" diet contributes to asthma prevalence and progression. Finally, we summarise the current evidence on the impact of weight loss on asthma outcomes in both adults and children, highlighting the need for further research to be conducted in the paediatric population.

Childhood Obesity and Respiratory Diseases: Which Link?

Prevalence of childhood obesity is progressively increasing, reaching worldwide levels of 5.6% in girls and of 7.8% in boys. Several evidences showed that obesity is a major preventable risk factor and disease modifier of some respiratory conditions such as asthma and Obstructive Sleep Apnea Syndrome (OSAS). Co-occurrence of asthma and obesity may be due to common pathogenetic factors including exposure to air pollutants and tobacco smoking, Western diet, and low Vitamin D levels. Lung growth and dysanapsis phenomenon in asthmatic obese children play a role in impaired respiratory function which appears to be different than in adults. Genes involved in both asthma and obesity have been identified, though a gene-by-environment interaction has not been properly investigated yet. The identification of modifiable environmental factors influencing gene expression through epigenetic mechanisms may change the natural history of both diseases. Another important pediatric respiratory condition associated with obesity is Sleep-Disordered Breathing (SDB), especially Obstructive Sleep Apnea Syndrome (OSAS). OSAS and obesity are linked by a bidirectional causality, where the effects of one affect the other. The factors most involved in the association between OSAS and obesity are oxidative stress, systemic inflammation, and gut microbiota. In OSAS pathogenesis, obesity's role appears to be mainly due to mechanical factors leading to an increase of respiratory work at night-time. However, a causal link between obesity-related inflammatory state and OSAS pathogenesis still needs to be properly confirmed. To prevent obesity and its complications, family education and precocious lifestyle changes are critical. A healthy diet may lead to an improved quality of life in obese children suffering from respiratory diseases. The present review aimed to investigate the links between obesity, asthma and OSAS, focusing on the available evidence and looking for future research fields.

Obesity is Associated with Poor Covid-19 Outcomes: A Systematic Review and Meta-Analysis

Our aim was to assess the association between obesity and the risk of unfavourable outcomes (composite of severe disease and mortality) in inpatients with COVID-19. We conducted a systematic search of databases between December 2019 and 28th June 2020. Studies were included if they reported or allowed estimation of an odds ratio (OR) for unfavourable outcome in obese compared to non-obese patients hospitalised for COVID-19. Twenty cohort studies of 28 355 hospitalised patients with COVID-19 infection were included. Meta-analysis estimated a pooled OR of 2.02 (1.41-2.89, p<0.001) for an unfavourable outcome in obese versus non-obese patients when adjusted for age, sex and co-morbidities. When unadjusted for confounders, the OR for unfavourable outcomes was 1.25 (CI 1.07-1.45, p=0.005). An increased adjusted OR was also seen for death (OR 1.51; CI 1.13-2.21, p=0.006) and severe illness (OR 2.26; CI 1.47-3.48, p<0.001). Compared to a normal BMI, the risk of an unfavourable outcome was increased even in overweight patients, with severe obesity having an escalated risk.Obesity is independently associated with an unfavourable outcome of COVID-19 illness, with obese patients having twice the risk of a composite outcome of severe disease or mortality, and a 50% increased risk of death.

Choice of biologics in asthma endotypes

PURPOSE OF REVIEW

The aim of this study was to highlight the phenotypes and endotypes of asthma as a tool for selection of the Food and Drug Administration approved biologic therapies.

RECENT FINDINGS

An evolving concept of asthma has led to the identification of distinct phenotypes and endotypes in this disease. Asthma endotypes are defined as the biological mechanism and are often categorized as T2-high and T2-low based on the influence of T helper type 2 (T2) cells and type 2 cytokines, including interleukin (IL)-4, IL-5, IL-9 and IL-13. Biomarkers such as peripheral blood absolute eosinophil count, total IgE, specific IgE and fractional exhaled nitric oxide may be used as indicators of asthma endotypes and help predict response to biologic therapies. There are currently five biologic therapies approved as a treatment option for T2-high asthma: omalizumab, benralizumab, mepolizumab, reslizumab and dupilumab.

SUMMARY

Here, we explore the current understandings of asthma endotypes and review their associated phenotypes. We provide practical and evidence-based guidance for clinicians considering a biologic for asthma add-on maintenance therapy.

Particulate matter inhalation and the exacerbation of cardiopulmonary toxicity due to metabolic disease

Particulate matter is a significant public health issue in the United States and globally. Inhalation of particulate matter is associated with a number of systemic and organ-specific adverse health outcomes, with the pulmonary and cardiovascular systems being particularly vulnerable. Certain subpopulations are well-recognized as being more susceptible to inhalation exposures, such as the elderly and those with pre-existing respiratory disease. Metabolic syndrome is becoming increasingly prevalent in our society and has known adverse effects on the heart, lungs, and vascular systems. The limited evaluations of individuals with metabolic syndromehave demonstrated that theymay compose a sensitive subpopulation to particulate exposures. However, the toxicological mechanisms responsible for this increased vulnerability are not fully understood. This review evaluates the currently available literature regarding how the response of an individual's pulmonary and cardiovascular systems is influenced by metabolic syndrome and metabolic syndrome-associated conditions such as hypertension, dyslipidemia, and diabetes. Further, we will discuss potential therapeutic agents and targets for the alleviation and treatment of particulate-matter induced metabolic illness. The information reviewed here may contribute to the understanding of metabolic illness as a risk factor for particulate matter exposure and further the development of therapeutic approaches to treat vulnerable subpopulations, such as those with metabolic diseases.

Atopy and pulmonary function among healthy-weight and overweight/obese children with asthma

INTRODUCTION

Epidemiologic studies have found low/absence of atopy in obese asthmatic children, but the association or lack thereof of atopy with disease morbidity, including pulmonary function, in obese asthma is not well understood. We sought to define the association of atopy with pulmonary function in overweight/obese minority children with asthma.

METHODS

In a retrospective chart review of 200 predominantly minority children evaluated at an academic Pediatric Asthma Center over 5 years, we compared the prevalence of atopy, defined as ≥ 1 positive skin prick test or serum-specific immunoglobulin E quantification to environmental allergens, and its association with pulmonary function in overweight/obese (body mass index [BMI] > 85th percentile) (n = 99) to healthy-weight children (BMI, 5th-85th percentile for age) (n = 101).

RESULTS

In a cohort comprised of 47.5% Hispanics and 39.5% African Americans, 81% of overweight/obese and 74% of healthy-weight children were atopic. While atopic healthy-weight children had lower percent-predicted forced expiratory volume in the first second (FEV₁ ) (93 ± 13.6 vs 107% ± 33.2%, P = .03) and lower percent-predicted forced vital capacity (FVC) (93% ± 12.2% vs 104% ± 16.1%, P = .01) as compared to nonatopic children, atopy was not associated with FEV₁ (P = .7) or FVC (P = .17) in overweight/obese children. Adjusting for demographic and clinical variables, atopy was found to be an independent predictor of FEV₁ and FVC in healthy-weight (β = -2.4, P = .07 and β = -1.7, P = .04, respectively) but not in overweight/obese children (β = .6, P = .5 and β = .8, P = .3).

CONCLUSIONS

Atopy is associated with lower lung function in healthy-weight asthmatics but not in overweight/obese asthmatics, supporting the role of nonallergic mechanisms in disease burden in pediatric obesity-related asthma.

Pulmonary function tests in type 2 diabetes: a meta-analysis

OBJECTIVES

The aim of this study was to determine the association between type 2 diabetes (T2D) and pulmonary function tests.

METHODS

After conducting an exhaustive literature search, we performed a meta-analysis. We employed the inverse variance method with a random-effects model to calculate the effect estimate as the mean difference (MD) and 95% confidence interval (CI). We calculated the heterogeneity with the I2 statistic and performed a meta-regression analysis by sex, body mass index (BMI), smoking and geographical region. We also conducted a sensitivity analysis according to the studies' publication date, size of the T2D group and the study quality, excluding the study with the greatest weight in the effect.

RESULTS

The meta-analysis included 66 studies (one longitudinal, two case-control and 63 cross-sectional), with 11 134 patients with T2D and 48 377 control participants. The pooled MD (95% CI) for the predicted percentage of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), forced expiratory flow at 25-75% of FVC, peak expiratory flow, and diffusing capacity of the lung for carbon monoxide were -7.15 (95% CI -8.27, -6.03; p<0.001), -9.21 (95% CI -11.15, -7.26; p<0.001), -9.89 (95% CI -14.42, -5.36; p<0.001), -9.79 (95% CI -13.42, -6.15; p<0.001) and -7.13 (95% CI -10.62, -3.64; p<0.001), respectively. There was no difference in the ratio of FEV1/FVC (95% CI -0.27; -1.63, 1.08; p=0.69). In all cases, there was considerable heterogeneity. The meta-regression analysis showed that between studies heterogeneity was not explained by patient sex, BMI, smoking or geographical region. The findings were consistent in the sensitivity analysis.

CONCLUSIONS

T2D is associated with impaired pulmonary function, independently of sex, smoking, BMI and geographical region. Longitudinal studies are needed to investigate outcomes for patients with T2D and impaired pulmonary function.

Auto-adaptive positive airway pressure improves lung function and arterial stiffness parameters in patients with severe obstructive sleep apnea syndrome over a 1 year follow-up

OBJECTIVE

Auto-adaptive positive airway pressure (APAP) is an emerging therapeutic modality for obstructive sleep apnea (OSA) patients. However, their associated physiological effects have not been well-defined. Therefore, we aimed to investigate the impact of a 1 year APAP treatment on lung function and arterial stiffness parameters.

APPROACH

This study enrolled male patients with newly diagnosed severe OSA who have undergone APAP treatment. A total of 35 patients completed a 1 year follow up. Blood pressure, arterial stiffness (PWV, cAIx, pAIx, cSBP), and lung function readings (FEV₁, FVC, FEV₁/FVC, PEF) were obtained basally and after 1, 3, 6, and 12 months of treatment.

MAIN RESULTS

A gradual increase in FEV₁ has been observed over the follow-up (2.92 ± 0.88 versus 3.07 ± 0.92 versus 3.18 ± 0.93 versus 3.28 ± 0.93 versus 3.41 ± 0.97 L), while PWV showed a gradual decrease over the follow-up (9.72 ± 1.64 versus 9.32 ± 1.73 versus 8.89 ± 1.65 versus 8.53 ± 1.61 versus 8.46 ± 1.60 m s^-1), as measured by absolute values. Linear mixed effects model analysis revealed a statistically significantly higher FEV₁ values (coefficient of 0.11, 0.20, and 0.33 for 3rd month, 6th month, and 12th month, respectively, P < 0.001) and lower PWV values (coefficient of -0.69, -0.63, and -0.34 for 3rd month, 6th month, and 12th month, respectively, P < 0.001), after the initiation of APAP treatment.

SIGNIFICANCE

We conclude that APAP treatment improves main lung function and arterial stiffness parameters in male patients with severe OSA over a 1 year follow-up.

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.

Association between obesity and lung function changes by sex and age in adults with asthma

OBJECTIVE

The lung function changes presenting before and after asthma treatment in obese people remain largely unknown. This study aimed to investigate the association between obesity and lung function changes before and after treatment in adults with asthma.

METHODS

We enrolled 937 newly diagnosed asthma patients from Cohort for Reality and Evolution of Adult Asthma in Korea cohort in 2015-2017, who performed follow-up spirometry after three months of asthma treatment. The percentage changes (Δ) between the spirometry results before and after treatment were calculated. Patients were categorized into four body mass index (BMI) groups; underweight (<18.5), normal (18.5-22.9), overweight (23.0-24.9), and obese (≥25.0). Association between percent change of pulmonary function and BMI was analyzed according to sex and/or age (< 45 yrs, 45-65 yrs, ≥ 65 yrs), which were statistically corrected for age, sex, smoking status, and medication history.

RESULTS

There was no consistent correlation between BMI and each lung function parameter. However, there were significant differences between BMI and ΔFEV₁/FVC before and after 3 months of controller treatment. The obese asthmatics showed significantly lower ΔFEV₁/FVC (6.0 ± 13.5%) than the underweight (12.6 ± 21.4%, P = 0.044) or normal weight (9.1 ± 14.6%, P = 0.031). Middle-aged women had higher BMI (24.11 ± 3.60 vs. 22.39 ± 3.52) and lower ΔFEV₁/FVC (5.7 ± 11.9% vs. 8.9 ± 14.3%, P = 0.012) than young women.

CONCLUSIONS

Obesity is negatively correlated with the ΔFEV₁/FVC before and after controller treatment. Sex and age differentially contribute to lung function changes in response to asthma medications in adult asthmatics, showing a significant decrease in the ΔFEV₁/FVC in middle-aged women.

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.

Effect of Body Mass Index on Lung Function in Chinese Patients with Chronic Obstructive Pulmonary Disease: A Multicenter Cross-Sectional Study

Objective

The aim of this study was to explain “obesity paradox” in chronic obstructive pulmonary disease (COPD) by evaluating the effect of body mass index (BMI) on lung function in Chinese patients with COPD.

Methods

A total of 1644 patients diagnosed with COPD were recruited from four Chinese tertiary hospitals and were divided into four groups including underweight, normal weight, overweight and obese according to BMI classification standard. The medical data of these patients were collected and used for the multiple linear regression analyses.

Results

After adjustment for age, sex, educational level, economic status, smoking status, alcohol consumption, duration of COPD history, events of acute exacerbation in previous year, hypertension, diabetes mellitus, cardiovascular disease, cerebrovascular disease and osteoporosis, BMI had a curvilinear correlation with the forced expiratory volume in the first second (FEV₁) in patients with Global Initiative for Obstructive Lung Disease (GOLD) 1–2 grade (first-order coefficient β, 0.09; 95% CI, 0.03–0.16; second-order coefficient β, −0.002; 95% CI, −0.003–-0.001; P<0.01). However, BMI had a positive correlation with FEV₁ in patients with GOLD 3–4 grade (β, 0.01; 95% CI, 0.008–0.017; P<0.01) when BMI was used as a quantitative variable. When BMI was used as a qualitative variable, only FEV₁ in overweight group with GOLD 1–2 grade was significantly higher than that of normal weight group (P<0.01). Interestingly, both overweight and obese groups had higher FEV₁ in GOLD 3–4 grade compared with normal weight group (β, 0.06; 95% CI, 0.02–0.11; β, 0.11; 95% CI, 0.04–0.18; P<0.01). The effect of BMI on predicted percentage of FEV₁ (FEV₁%) was similar to that of FEV₁ in different GOLD grades.

Conclusion

Obesity only had a protective effect on lung function in COPD patients with GOLD 3–4 grade rather than GOLD 1–2 grade.

Trial Registry

ClinicalTrials.gov, No.: NCT 03182309, URL: www.clinicaltrials.gov.

Associations between overweight and obesity and asthma outcomes in urban adolescents

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

Metabolic Syndrome and Incident Asthma in Chinese Adults: An Open Cohort Study

BACKGROUND

Although metabolic syndrome is awell-known risk factor for many non-communicable diseases, its contribution to asthma remains controversial.

OBJECTIVE

The aim of this study was to explore the associations of metabolic syndrome and its components with incident asthma in Chinese adults.

METHODS

We conducted an open cohort study of participants who were asthma-free at baseline (n=42,304) in the Shandong multi-center health check-up longitudinal study from 2004 to 2015. Participants aged ≥20 years and had regular physical examination (once ayear) more than three times during follow-up.

RESULTS

Ninety subjects (38 women and 52 men) developed incident asthma over 12 years of follow-up. Our study suggested that metabolic syndrome itself was not significantly associated with incident asthma in either women or men (P>0.050). Interestingly, we found that overweight and/or obesity was arisk factor for incident asthma among women but not men in the Cox proportional hazards model after adjusting covariates (adjusted incidence rate ratio (IRR)= 2.940, 95% confidence interval (CI): 1.467-5.894, P=0.002). The result was consistent with the Poisson regression model (hazard ratio (HR)= 2.241, 95% CI: 1.135-4.988, P=0.026). After stratifying according to overweight and/or obesity, we found that female subjects with overweight and obesity were associated with the occurrence of incident asthma (P<0.050). However, we did not find this result among men.

CONCLUSION

Metabolic syndrome was not significantly associated with incident asthma in both women and men; however, overweight and/or obesity was shown to be asignificant risk factor for incident asthma but only in women, not in men.

Bidirectional relationship between diabetes and pulmonary function: a systematic review and meta-analysis

AIM

Evidence of the lungs being a target organ of diabetes-related pathophysiology is increasing, and decreased pulmonary function increases the risk of diabetes after adjusting for demographic and metabolic factors. This systematic review and meta-analysis evaluates the bidirectional relationship between diabetes and pulmonary function.

METHODS

MEDLINE, Embase, The Cochrane Library and Web of Science databases were searched, and all studies describing this bidirectional relationship were identified. Two reviewers independently extracted study characteristics and assessed the risk of bias.

RESULTS

A total of 93 studies were included in the meta-analysis. The pooled weighted mean difference (WMD) between diabetes patients and non-diabetic participants for forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) were -5.65% and -5.91%, respectively, of predicted values. Diabetes-related microvascular complications and poor glycaemic control were associated with poorer pulmonary function in those with diabetes. In addition, diabetes was associated with a restrictive spirometry pattern (RSP) in both cross-sectional studies [odds ratio (OR): 2.88, 95% confidence interval (CI): 2.18-3.81, I² = 0.0%] and prospective cohort studies [hazard ratio (HR): 1.57, 95% CI: 1.04-2.36]. In five longitudinal studies, the conclusions were inconsistent as to whether or not diabetes accelerates pulmonary function decline. However, every 10% decrease in baseline predicted FVC value was associated with a 13% higher risk of incident diabetes (HR: 1.13, 95% CI: 1.09-1.17, I² = 0.0%).

CONCLUSION

There is a bidirectional relationship between diabetes and pulmonary function. However, further investigations into whether dynamic changes in glycaemic levels before and shortly after diabetes onset mediate the deleterious effects on pulmonary function, or vice versa, are now required.

The Association between Body Mass Index and Physical Fitness of Normal Weight/Overweight/Obese University Students

This study aimed to apply longitudinal data (in four waves) to examine relationships between body mass index (BMI), flexibility, muscular endurance, and explosive power, and employed a random-intercept panel model (RIPM) to divide the variations of different waves into between- and within-person variations. Furthermore, a multi-group model test was conducted to explore whether an interaction effect existed between sex and these relationships. The data were collected from a university in Taiwan between August 2009 and July 2010, and 3863 freshman and junior students were recruited. Results showed that the between- and within-person relationships between BMI and explosive power, and between BMI and muscular endurance, were negative (independent of sex). The negative between- and within-person associations between BMI and muscular endurance were both invariant with respect to sex. The negative between-person associations between BMI and explosive power were not equivalent for both sexes, yet the within-person associations between BMI and explosive power were equivalent for both sexes. The between-person associations between BMI and flexibility were positive for both sexes, but the within-person associations of these two variables were negative for both sexes. The invariance test confirmed that the positive associations of between-person BMI and between-person flexibility were invariant for both sexes, yet the negative associations of within-person BMI and within-person flexibility were not equivalent for both sexes. Between-and within-person correlations among explosive power, muscular endurance, and flexibility were significantly positive. Only the auto-regressions of BMI and muscular endurance were significant and equivalent for both sexes.

Factors influencing the length of stay after mediastinal tumor resection in the setting of an enhanced recovery after surgery (ERAS)-TUBELESS protocol

Background

Prolonged length of stay after surgery is considered to increase cost and hospital-acquired complications. Therefore, we aimed to identify the risk factors that were associated with an increased length of stay after mediastinal tumor resection in the setting of an enhanced recovery after surgery (ERAS)-TUBELESS protocol.

Methods

This prospective cohort study collected data on consecutive patients undergoing video-assisted thoracoscopic surgery (VATS) resection for mediastinal tumor between December 2015 and November 2018 at a single center in China. All patients followed the ERAS-TUBELESS protocol. A length of stay after VATS tumor resection (LOS) greater than 3 days was considered an increased LOS. Univariable and multivariable logistic regression models were used to identify potential factors associated with increased LOS. Factors were divided into patient-related risk factors and procedure-related risk factors.

Results

A total of 204 patients were included, of which 85 (41.67%) patients had a LOS of more than 3 days. The median LOS for the entire cohort was 3 days. All the patient-related risk factors had no significantly associated with a prolonged LOS. Procedure-related risk factors that were significantly associated with a prolonged LOS were surgeon, operation time, intraoperative blood loss, drainage tube, analgesic drugs, and complications. Anesthesia with spontaneous ventilation was correlated with early discharge (LOS ≤1 day).

Conclusions

In the setting of an ERAS-TUBELESS protocol, the main drivers of LOS were procedure-related factors. Anesthesia with spontaneous ventilation was associated with early discharge (LOS ≤1 day) and thus promoted thoracic day surgery.

Role of DNA methylation in the association of lung function with body mass index: a two-step epigenetic Mendelian randomisation study

BACKGROUND

Low lung function has been associated with increased body mass index (BMI). The aim of this study was to investigate whether the effect of BMI on lung function is mediated by DNA methylation.

METHODS

We used individual data from 285,495 participants in four population-based cohorts: the European Community Respiratory Health Survey, the Northern Finland Birth Cohort 1966, the Swiss Study on Air Pollution and Lung Disease in Adults, and the UK Biobank. We carried out Mendelian randomisation (MR) analyses in two steps using a two-sample approach with SNPs as instrumental variables (IVs) in each step. In step 1 MR, we estimated the causal effect of BMI on peripheral blood DNA methylation (measured at genome-wide level) using 95 BMI-associated SNPs as IVs. In step 2 MR, we estimated the causal effect of DNA methylation on FEV1, FVC, and FEV1/FVC using two SNPs acting as methQTLs occurring close (in cis) to CpGs identified in the first step. These analyses were conducted after exclusion of weak IVs (F statistic < 10) and MR estimates were derived using the Wald ratio, with standard error from the delta method. Individuals whose data were used in step 1 were not included in step 2.

RESULTS

In step 1, we found that BMI might have a small causal effect on DNA methylation levels (less than 1% change in methylation per 1 kg/m2 increase in BMI) at two CpGs (cg09046979 and cg12580248). In step 2, we found no evidence of a causal effect of DNA methylation at cg09046979 on lung function. We could not estimate the causal effect of DNA methylation at cg12580248 on lung function as we could not find publicly available data on the association of this CpG with SNPs.

CONCLUSIONS

To our knowledge, this is the first paper to report the use of a two-step MR approach to assess the role of DNA methylation in mediating the effect of a non-genetic factor on lung function. Our findings do not support a mediating effect of DNA methylation in the association of lung function with BMI.

Association between air pollution and lung development in schoolchildren in China

Background

China has been facing nationwide air pollution at unprecedented high levels primarily from fossil–fuel combustion in the past decade. However, few studies have been conducted on the adverse effect of severe air pollution on lung development in school-age children.

Methods

Using wellness check and air pollution data from 2014 to 2017, we conducted a retrospective analysis of lung development in 21 616 school-age children from Shijiazhuang and Qingdao from North China with severe vs mild air pollution. Linear mixed effects model was performed to assess the effect of air pollution on forced vital capacity (FVC) growth.

Results

Exposure to severe air pollution was associated with a dramatic reduction in annual FVC growth rate (−71.3 mL,  p< 0.001). In addition, every 10 μg/m³ increase in annual PM_2.5 level was associated with a reduction of annual FVC growth by 12.2 mL ( p< 0.001). Sex discrepancy (boys vs girls) in FVC growth was greater in Qingdao (35.4 mL/year, 95% CI: 26.0 to 44.7) than in Shijiazhuang (19.8 mL/year, 95% CI: 9.3 to 30.3) (p for interaction=0.063). Exposure to indoor coal- or wood-burning stove heating (−79.4 mL,  p< 0.001) and secondhand smoke at home (−59.3 mL,  p= 0.003) were inversely associated with FVC growth.

Conclusion

Our study raised serious alarm over the threat of severe air pollution to lung development in school-age children. Sex discrepancy in lung development was reduced dramatically in heavily polluted area.

Comorbid Obesity and Depressive Symptoms in Childhood Asthma: A Harmful Synergy

BACKGROUND

Overweight/obesity (OV/OB) and depression have each been separately associated with worsened childhood asthma severity and control. Pathways by which these factors may jointly affect childhood asthma have not been elucidated.

OBJECTIVE

To examine the interrelationship of OV/OB and depressive symptoms with childhood asthma and explore associated psychobiologic pathways. The present study investigated whether comorbid OV/OB and depressive symptoms are associated with impaired baseline lung function and increased airway resistance during emotional stress, and to assess whether such effects may be mediated by autonomic nervous system (ANS) dysregulation, specifically through predominance of vagal over sympathetic reactivity (vagal bias).

METHODS

A total of 250 children with asthma, aged 7 to 17, were assessed for OV/OB using body mass index, depressive symptoms using the Children's Depression Inventory (CDI), and asthma severity using National Asthma Education and Prevention Program Expert Panel Report 3 criteria. Baseline pulmonary function (forced expiratory volume in 1 second [FEV₁]) was assessed. The film "E.T. the Extra-Terrestrial" was used in a laboratory paradigm to evoke emotional stress/arousal. Airway resistance (R_int) was measured before and after the film to determine changes in airway function. ANS reactivity was assessed by measuring parasympathetic/vagal and sympathetic reactivity throughout the film.

RESULTS

In OV/OB children with asthma, depressive symptoms predicted lower baseline FEV₁ (β = -0.67, standard error [SE] = 0.24, P = .008), CDI predicted vagal bias under emotion stress/arousal (β = 0.27, SE = 0.09, P = .009), and vagal bias predicted increased R_int (β = 3.55, SE = 1.54, P = .023).

CONCLUSION

This study is the first to link OV/OB and depressive symptoms in their relationship to childhood asthma. In OV/OB children with asthma, depression may potentiate airway compromise, mediated by vagal bias. Use of antidepressant and anticholinergic therapies should be studied in this subgroup of patients.

Association between adiposity measures and COPD risk in Chinese adults

Bodyweight and fat distribution may be related to COPD risk. Limited prospective evidence linked COPD to abdominal adiposity. We investigated the association of body mass index (BMI) and measures of abdominal adiposity with COPD risk in a prospective cohort study.The China Kadoorie Biobank recruited participants aged 30-79 years from 10 areas across China. Anthropometric indexes were objectively measured at the baseline survey during 2004-2008. After exclusion of participants with prevalent COPD and major chronic diseases, 452 259 participants were included and followed-up until the end of 2016. We used Cox models to estimate adjusted hazard ratios relating adiposity to risk of COPD hospitalisation or death.Over an average of 10.1 years of follow-up, 10 739 COPD hospitalisation events and deaths were reported. Compared with subjects with normal BMI (18.5-<24.0 kg·m-2), underweight (BMI <18.5 kg·m-2) individuals had increased risk of COPD, with adjusted hazard ratio 1.78 (95% CI 1.66-1.89). Overweight (BMI 24.0-<28.0 kg·m-2) and obesity (BMI ≥28.0 kg·m-2) were not associated with an increased risk after adjustment for waist circumference. A higher waist circumference (≥85 cm for males and ≥80 cm for females) was positively associated with COPD risk after adjustment for BMI. Additionally, waist-to-hip ratio and waist-to-height ratio were positively related to COPD risk.Abdominal adiposity and underweight were risk factors for COPD in Chinese adults. Both BMI and measures of abdominal adiposity should be considered in the prevention of COPD.

Respiratory Muscle Training Improves Functional Outcomes and Reduces Fatigue in Patients with Myasthenia Gravis: A Single-Center Hospital-Based Prospective Study

Background

Myasthenia gravis (MG) is an immune-mediated disorder characterized by muscle fatigue and fluctuating weakness. Impairment in respiratory strength and endurance has been described in patients with generalized MG. We tested the hypothesis that respiratory muscle training (RMT) can improve functional outcomes and reduce fatigue in patients with MG.

Methods

Eighteen patients with mild to moderate MG participated in this study. The training group underwent home-based RMT three times a week for 12 weeks. Sixteen patients with MG without RMT were enrolled as a disease control group. Lung function, autonomic testing, Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF), and functional outcome measurement by using quantitative myasthenia gravis (QMG) score and myasthenia gravis composite (MGC) scale were measured before and after the 12-week RMT.

Results

The 12-week RMT significantly increased forced vital capacity (FVC) from 77.9 ± 12.6% to 83.8 ± 17.7% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (

Conclusion

The home-based RMT is an effective pulmonary function training for MG patients. The RMT can not only improve short-term outcomes but also reduce fatigue in patients with mild to moderate generalized MG.

Joint effect of polycyclic aromatic hydrocarbons and phthalates exposure on telomere length and lung function

Exposure to polycyclic aromatic hydrocarbons and phthalates are linked to lung function decline and altered relative telomere length (RTL) accompanying with oxidative stress and inflammatory events in human body. However, limited data are available about impacts of co-exposure of PAHs and phthalates on lung function and RTL. We conducted a pilot study with repeated measures during the winter of 2014 and summer of 2015 in Wuhan city, China. Participants took part in the measures of lung function, RTL, urinary monohydroxylated-PAHs (OH-PAHs) and phthalate metabolites over three consecutive days in each season. Linear mixed-effect (LME) models and Bayesian kernel machine regression (BKMR) were used to analyze the relations of OH-PAHs or phthalate metabolites with lung function or RTL. LME models showed the negative associations of 3-day average of hydroxyphenanthrene (2 + 3-, 4-OHPhe) or 1-hydroxypyrene with FEV1, 3-day average of 2 + 3-OHPhe with FVC. BKMR models revealed the negative relation of eight OH-PAHs with FEV1, FVC or RTL; nine phthalate metabolites may counteract an overall effect of eight OH-PAHs on FEV1, FVC or RTL. The findings indicated that urinary phthalate metabolites may counteract the negative association of urinary OH-PAHs on FEV1 or FVC, which may be partially linked to shorter RTL regarding biological aging.

Lung Function Decline in Farm and Nonfarm Rural Residents of Saskatchewan

OBJECTIVE

This study aims to assess the annual changes in lung function among farm and nonfarm adult residences in rural Saskatchewan, Canada.

METHODS

Data from the Saskatchewan Rural Health Study survey (2010 to 2014) among 724 adults were used.

RESULTS

For forced expiratory volume in 1 second (FEV1) measurements, estimates of annual decline (in milliliters) were highest in older age male (65+ years) (Mean, SD) (-42.63, 21.16); and among old heavy smokers (-57.79, 24.30). Estimates of annual decline in forced vital capacity (FVC) were highest in current smokers without the use of natural gas (-25.78, 14.78) and among old heavy smokers (-33.88, 20.28). Living on a farm is associated with decreased FEV1 and FVC, but not statistically significant by sex and age.

CONCLUSIONS

A complex mix of personal and contextual factors may affect these estimates.

Pediatric obesity-related asthma: A prototype of pediatric severe non-T2 asthma

Childhood obesity contributes to many diseases, including asthma. There is literature to suggest that asthma developing as a consequence of obesity has a nonallergic or non-T2 phenotype. In this review, obesity-related asthma is utilized as a prototype of non-T2 asthma in children to discuss several nonallergic mechanisms that underlie childhood asthma. Obesity-related asthma is associated with systemic T helper (Th)1 polarization occurring with monocyte activation. These immune responses are mediated by insulin resistance and dyslipidemia, metabolic abnormalities associated with obesity, that are themselves associated with pulmonary function deficits in obese asthmatics. As in other multifactorial diseases, there is both a genetic and an environmental contribution to pediatric obesity-related asthma. In addition to genetic susceptibility, differential DNA methylation is associated with non-T2 immune responses in pediatric obesity-related asthma. Initial investigations into the biology of non-T2 immune responses have identified the upregulation of genes in the CDC42 pathway. CDC42 is a RhoGTPase that plays a key role in Th cell physiology, including preferential naïve Th cell differentiation to Th1 cells, and cytokine production and exocytosis. Although these novel pathways are promising findings to direct targeted therapy development for obesity-related asthma to address the disease burden, there is evidence to suggest that dietary interventions, including diet modification, rather than caloric restriction alone, decrease disease burden. Adoption of a diet rich in micronutrients, including carotenoids and 25-OH cholecalciferol, a vitamin D metabolite, may be beneficial since these are positively correlated with pulmonary function indices, while being protective against metabolic abnormalities associated with the obese asthma phenotype.

The Andean Latin-American burden of diabetes attributable to high body mass index: A comparative risk assessment

BACKGROUND

Body mass index (BMI) has increased in Latin-America, but the implications for the diabetes burden have not been quantified. We estimated the proportion and absolute number of diabetes cases attributable to high BMI in Bolivia, Ecuador and Peru (Andean Latin-America), with estimation of region-level indicators in Peru.

METHODS

We estimated the population attributable fraction (PAF) of BMI on diabetes (regardless of type 1 or 2) from 1980 to 2014, including the number of cases attributable to overweight (BMI 25-<30), class I (30-<35), class II (BMI 35-<40) and class III (BMI ≥ 40) obesity. We used age- and sex-specific prevalence estimates of diabetes and BMI categories (NCD-RisC and Peru's DHS survey) combined with relative risks from population-based cohorts in Peru.

FINDINGS

Across Andean Latin-America in 2014, there were 1,258,313 diabetes cases attributable to high BMI: 209,855 in Bolivia, 367,440 in Ecuador and 681,018 in Peru. Between 1980 and 2010, the absolute proportion of diabetes cases attributable to class I obesity increased the most (from 12.9% to 27.2%) across the region. The second greatest increase was for class II obesity (from 3.6% to 16.5%). There was heterogeneity in the fraction of diabetes cases attributable to high BMI by region in Peru, as coastal regions had the largest fractions, and so did high-income regions.

INTERPRETATION

Over one million diabetes cases are attributable to high BMI in Andean Latin-America. Public health efforts should focus on implementing population-based interventions to reduce high BMI and to develop focused interventions targeted at those at highest risk of diabetes.

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.

Obesity and adult asthma: diagnostic and management challenges

PURPOSE OF REVIEW

Despite advances in our understanding of the obese asthma phenotype, heterogeneity and large gaps in knowledge have hindered significant advances in directed interventions.

RECENT FINDINGS

Obesity is associated with poorer asthma-related outcomes and increased risk of progression to severe asthma. Obese asthma is associated with variability in the expression of inflammatory markers, lung function impairments, and response to conventional and biologic therapies. In addition, traditional asthma biomarkers are not as reliable in obese patients. Several mechanistic pathways that uniquely impact asthma in obesity have been identified. Pathways involving innate lymphoid cells (ILC) type 2 (ILC-2) cells, surfactant protein-A, cell division control protein (CDC)42, interleukin (IL)-6, IL-17, and IL-33 are likely causal inflammatory pathways. Obesity also confounds lung function parameters making accurate diagnosis more challenging. As such, personalized asthma therapies directed towards obese asthma endotypes remain elusive.

SUMMARY

Obesity confounds traditional asthma biomarkers and lung function measurements, thus defining obese asthma endotypes remains challenging. Novel pathways are being identified and hold promise for future targeted therapies. However, we are in dire need of updated guidelines regarding asthma diagnosis in obese patients and the development of biomarkers that more accurately identify specific endotypes.

Interactions between ambient air pollution and obesity on lung function in children: The Seven Northeastern Chinese Cities (SNEC) Study

Children are vulnerable to air pollution-induced lung function deficits, and the prevalence of obesity has been increasing in children. To evaluate the joint effects of long-term PM₁ (particulate matter with an aerodynamic diameter ≤ 1.0 μm) exposure and obesity on children's lung function, a cross-sectional sample of 6740 children (aged 7-14 years) was enrolled across seven northeastern Chinese cities from 2012 to 2013. Weight and lung function, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), peak expiratory flow (PEF), and maximal mid-expiratory flow (MMEF), were measured according to standardized protocols. Average PM₁, PM_2.5, PM₁₀ and nitrogen dioxide (NO₂) exposure levels were estimated using a spatiotemporal model, and sulphur dioxide (SO₂) and ozone (O₃) exposure were estimated using data from municipal air monitoring stations. Two-level logistic regression and general linear models were used to analyze the joint effects of body mass index (BMI) and air pollutants. The results showed that long-term air pollution exposure was associated with lung function impairment and there were significant interactions with BMI. Associations were stronger among obese and overweight than normal weight participants (the adjusted odds ratios (95% confidence intervals) for PM₁ and lung function impairments in three increasing BMI categories were 1.50 (1.07-2.11) to 2.55 (1.59-4.07) for FVC < 85% predicted, 1.44 (1.03-2.01) to 2.51 (1.53-4.11) for FEV₁ < 85% predicted, 1.34 (0.97-1.84) to 2.04 (1.24-3.35) for PEF < 75% predicted, and 1.34 (1.01-1.78) to 1.93 (1.26-2.95) for MMEF < 75% predicted). Consistent results were detected in linear regression models for PM₁, PM_2.5 and SO₂ on FVC and FEV₁ impairments (P_Interaction < 0.05). These modification effects were stronger among females and older participants. These results can provide policy makers with more comprehensive information for to develop strategies for preventing air pollution induced children's lung function deficits among children.

Obesity and disease severity magnify disturbed microbiome-immune interactions in asthma patients

In order to improve targeted therapeutic approaches for asthma patients, insights into the molecular mechanisms that differentially contribute to disease phenotypes, such as obese asthmatics or severe asthmatics, are required. Here we report immunological and microbiome alterations in obese asthmatics (n = 50, mean age = 45), non-obese asthmatics (n = 53, mean age = 40), obese non-asthmatics (n = 51, mean age = 44) and their healthy counterparts (n = 48, mean age = 39). Obesity is associated with elevated proinflammatory signatures, which are enhanced in the presence of asthma. Similarly, obesity or asthma induced changes in the composition of the microbiota, while an additive effect is observed in obese asthma patients. Asthma disease severity is negatively correlated with fecal Akkermansia muciniphila levels. Administration of A. muciniphila to murine models significantly reduces airway hyper-reactivity and airway inflammation. Changes in immunological processes and microbiota composition are accentuated in obese asthma patients due to the additive effects of both disease states, while A. muciniphila may play a non-redundant role in patients with a severe asthma phenotype.

Obesity survival paradox in pneumonia supported with extracorporeal membrane oxygenation: Analysis of the national registry

PURPOSE

To investigate whether the obesity survival paradox, where obesity is associated with improved survival, exists for pneumonia supported with extracorporeal membrane oxygenation (ECMO).

MATERIALS AND METHODS

Between January 2014 and December 2015, 223 patients with acute respiratory failure who underwent ECMO in 11 hospitals in South Korea were enrolled retrospectively, and data relating to pneumonia cases were analyzed. Patients were divided into groups according to their pre-treatment body mass index (BMI): obese (BMI ≥ 25 kg/m²) and non-obese (BMI < 25 kg/m²). The BMI cut-off was adopted from the World Health Organization for Asian populations.

RESULTS

In total, 84 patients had pneumonia: obese group, 26; non-obese group, 58 (mean BMI, 27.8 vs. 21.4, p < 0.001). Pre-ECMO parameters and rescue therapy did not differ between the groups. The rate of successful weaning from ECMO was not different between the groups (76.9% vs. 72.4%, p = 0.753), but survival-to-discharge (73.1% vs. 36.2%, p = 0.002) and 6-month survival (69.2% vs. 36.2%, p = 0.005) rates were higher in the obese group. After adjusting for age and the pre-treatment PaO₂/FiO₂ ratio, low BMI was significantly associated with 6-month mortality (odds ratio 3.28, 95% confidence interval: 1.06-11.03, p = 0.044).

CONCLUSIONS

An obesity survival paradox exists in pneumonia supported with ECMO.

Lung function, obesity and physical fitness in young children: The EXAMIN YOUTH study

OBJECTIVE

The prevalence of obesity and physical inactivity in children are increasing globally. The study aimed to investigate the association of obesity and cardiorespiratory fitness (CRF) with patterns of lung function in young children.

METHODS

In this cross-sectional study, lung function, body mass index (BMI), blood pressure (BP) and CRF (shuttle run stages) were measured in an unselected cohort of 1246 children aged 7.2 ± 0.4 years. All parameters and lung function, such as the ratio of forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC), were assessed by standardized procedures for children. Statistical models were applied for systematic adjustment of potential confounders.

RESULTS

Obese children had significantly higher FEV1 (Coef. (95% CI) (1.57 (1.50; 1.64) L) and FVC (1.75 (1.67; 1.83) L) compared to normal weight children (1.38 (1.37; 1.40) L; (1.53 (1.51; 1.54) L, respectively). However, with each unit increase of BMI, FEV1/FVC decreased (-0.003 (-0.005; -0.001)) due to a disproportional increase in FVC compared to FEV1. Per stage increase of CRF, FEV1 (0.017 (0.008; 0.025) L) and FVC increased (0.022 (0.012; 0.031) L)). In obese children, higher CRF was independently associated with higher FEV1/FVC (0.03 (0.5E-4; 0.06)) due to a higher increase of FEV1 over FVC with increasing fitness.

CONCLUSIONS

The decrease of FEV1/FVC with increasing BMI suggests that childhood obesity is associated with an imbalance of ventilation and airway flow. In children with obesity, higher CRF is associated with an improved FEV1/FVC ratio. Physical exercise programs may have the potential to improve patterns of lung function in children with obesity.

Metabolic syndrome and lung function in Korean children and adolescents: A cross-sectional study

This study aimed to investigate whether obesity and metabolic syndrome (MetS) are associated with pulmonary function in Korean children and adolescents. Data from the 2009–2011 Korea National Health and Nutrition Examination Survey which is cross-sectional, nationwide, and representative survey were used. Adjusted regression analysis was performed to evaluate the association of obesity and MetS with lung function in children and adolescents. A total of 763 children and adolescents aged 10–18 years were evaluated. We found no significant difference in FEV₁% predicted, FVC% predicted, and FEV₁/FVC ratio among the obesity groups. Subjects with MetS showed a significantly lower FEV₁ predicted (91.54 ± 0.74% vs 94.64 ± 0.73%, P = 0.004), lower FVC% predicted (91.86 ± 0.63% vs 95.20 ± 0.63%, P < 0.001), and lower FEV₁/FVC ratio (76.76 ± 0.43% vs 80.13 ± 0.43%, P < 0.001) than those without MetS. Elevated waist circumference (WC), systolic blood pressure, fasting glucose, and lower high-density lipoprotein cholesterol (HDL-C) were independently associated with lower FEV₁/FVC ratio (all P < 0.05, respectively). Among MetS components, increased WC was the most important factor influencing lower FEV₁/FVC ratio. In conclusion, lung function in MetS patients was significantly lower, and the MetS component was independently associated.

Association between soft drinks consumption and asthma: a systematic review and meta-analysis

OBJECTIVES

To carry out meta-analysis and systematic review on the association between soft drinks consumption and asthma prevalence among adults and children.

DESIGN

Systematic review and meta-analysis of observational research.

DATA SOURCES

Medline, Scopus, ISI Web of Science and the Cochrane Library were searched up to December 2018.

ELIGIBILITY CRITERIA

We included observational studies investigating the association between soft drinks consumption (including maternal consumption during pregnancy) and asthma or wheeze.

DATA EXTRACTION AND SYNTHESIS

Data were extracted by one author and reviewed independently by two other authors. The most adjusted estimate from each original study was used in the meta-analysis. Meta-analysis was conducted using random-effects model. The quality of studies was assessed using the Newcastle-Ottawa scale and heterogeneity was evaluated using I² statistic.

RESULTS

Of 725 publications originally identified, 19 were included in this systematic review, including 3 cohort studies and 16 cross-sectional studies. Ten articles reported on children up to 18 years, 5 articles on adults (>18 years) and 2 articles on prenatal exposure. In total, 468 836 participants were included, with more than 50 000 asthma cases. Soft drinks consumption was associated with significantly increased odds of asthma in both adults (OR=1.37; 95% CI, 1.23 to 1.52) and children (OR=1.14; 95% CI, 1.06 to 1.21). Prenatal exposure had marginally statistically significant association (OR=1.11; 95% CI, 1.00 to 1.23) with asthma in children. In subgroup analysis for childhood exposure, the association persists for sugar-sweetened soft drinks but not for carbonated drinks.

CONCLUSION

Our findings show a positive association between soft drinks consumption and asthma prevalence, mostly from cross-sectional studies. Therefore, more longitudinal research is required to establish causality.

[Obesity in childhood: What are the respiratory risks?]

In childhood and adolescence overweight is defined as a body mass index (BMI) above the 97th percentile for age and sex, according to the curves established by the International Obesity Task Force (IOTF). In France, it is estimated that 25 % of children under 18 years old are overweight. Overweight and obesity in this population are multifactorial, with an important influence of genetic factors, modulated by pre and post-natal (maternal smoking), societal and psychological determinants. The impact of obesity on respiratory function in children is mostly characterized by a decreased FEV1/FCV. Moreover, several studies have shown an association between asthma and overweight/obesity, with a pejorative impact of BMI on asthma control. However, asthma is still poorly characterized in this population, and the determinants of bronchial obstruction seem to differ from non-obese children, with less eosinophilic inflammation. Obstructive sleep apnea syndrome (OSAS) is a frequent complication of obesity, affecting up to 80% of obese children and adolescents. It has a specific polysomnographic definition in children. Symptoms are similar to adult OSAS, but with cognitive and neurobehavioral alterations often more important in adolescents. The treatment consists in ENT surgery when indicated (with systematic post-operative polysomnography), and nocturnal continuous positive airway pressure (CPAP). The obesity-hypoventilation syndrome (OHS) has the same definition in children as in adults and affects up to 20% of obese patients. Treatment consists in nocturnal ventilation using bilevel positive airway pressure (BiPAP). Finally, in some extreme cases, bariatric surgery can be performed. The indication should be discussed in a specialised paediatric reference centre.

Weight Status and Respiratory Health in Asthmatic Children

In this study,we explored the effect of adiposity as measured by BMI on lung function in 72 asthmatic school children (5-12 years) using baseline data from the Mediterranean diet enriched with fatty fish intervention study. Bronchial function was assessed using spirometry and fractional exhaled nitric oxide (FeNO). BMI categories were classified as normal and overweight/obese based on International Obesity Task Force cut-offs. Weak correlations were observed between BMI and FVC (p = 0.013) and FEV₁ (p = 0.026). Median FeNO was lower in the overweight/obese as compared to normal weight group (p = 0.027). Linear regression showed an increment in FEF_25-75% in the overweight/obese group as compared to normal weight after controlling for confounders namely age, height, sex, regular physical activity, medication and KIDMED score (p = 0.043; β = 11.65 units, 95% CI 0.36-22.94), although with no effect on FeNO. In conclusion, the findings of this study suggest that excess body weight could impact pulmonary dynamics in childhood asthma.