Association of adenotonsillectomy with wheezing episodes in childhood: A secondary analysis of the Childhood Adenotonsillectomy Trial.

BACKGROUND: Observational studies suggest that asthma/wheezing improves after adenotonsillectomy (AT). However, there is a paucity of randomized clinical trial (RCT) specifically studying the effects of AT in asthma/wheezing. Therefore, we conducted a post-hoc analysis of the Childhood Adenotonsillectomy Trial (CHAT), the largest RCT of AT in children with obstructive sleep apnea (OSA) to test the hypothesis that AT would result in fewer wheezing episodes. METHODS: In the CHAT study, 464 children with OSA, aged 5-9 years, were randomized to early AT (n = 226) or watchful waiting with supportive care (WWSC) (n = 227). For this post-hoc analysis, children were categorized as having "any wheezing" versus "no wheezing" at baseline and at 7 months of follow-up. A multivariate analysis was conducted to evaluate the association between "any wheezing" at follow-up and treatment group after controlling for several potential confounders. RESULTS: Children in the "any wheezing" group were predominantly black, had more allergic rhinitis, eczema, second-hand smoke exposure, body mass index, apnea-hypopnea index (AHI), and had lower maternal education and family income than those in the "no wheezing group." In the AT arm, the prevalence of wheezing significantly decreased from baseline to follow-up (at 7 months of the intervention) (47% vs. 21.6%, p < 0.001); while in the WWSC arms did not change (45.2% vs. 43.1%, p = 0.67). In the multivariate analysis, second-hand smoke exposure, wheezing at baseline, and belong to WWSC arm (odds ratio: 3.65 [2.16-6.19]) increase the risk of wheezing at follow-up. CONCLUSION: This study demonstrated that AT decreased the risk of wheezing at 7 months of follow-up.

Fisiología respiratoria. Neumología de altura: saturación de oxígeno, edema pulmonar y pruebas de función pulmonar / Respiratory physiology - High -altitude pneumology: oxygen saturation, pulmonary edema and pulmonary function tests

En las alturas, sobre todo a 2500 metros sobre el nivel del mar, la cantidad absoluta de oxígeno va decreciendo y por lo tanto la cantidad disponible para el intercambio gaseoso disminuye, produciéndose una vasoconstricción hipóxica pulmonar (VHP). La VHP asociada a la hipoxia hipobárica de la altura produce un aumento de la presión pulmonar que es mayor en los lactantes y a mayores alturas. No hay valores únicos de saturación de oxígeno (SatO2) en la altura, porque ésta va disminuyendo según el mayor nivel de altura, aumenta con la edad, y la brecha entre la vigilia y sueño es grande (sobre todo en los primeros meses de vida). El 25% de los niños sanos que viven en altura tienen valores de SatO2 significativamente menores que el 75% restante. Los valores normales de los índices de apnea/hipopnea son distintos a los de nivel del mar. El edema pulmonar de las alturas es una patología frecuente, que se produce por un incremento desproporcionado en la VHP reflejando una hiperactividad del lecho vascular pulmonar ante la exposición aguda a la hipoxia hipobárica. Tiene cuatro fenotipos, es infrecuente en menores de 5 años y rara vez es mortal, la sospecha clínica y el manejo oportuno con oxigeno es la clave. Finalmente, en la altura los valores normales de la función pulmonar de la espirometría, oscilometría de impulso y capacidad de difusión son distintos que a nivel del mar.

At high altitude, especially > 2,500 meters above sea level, the absolute amount of oxygen decreases and therefore the amount available for gas exchange decreases, producing hypoxic pulmonary vasoconstriction (VHP). VHP associated with high-altitude hypobaric hypoxia produces an increase in pulmonary pressure that is greater in infants and at higher altitudes. There are no single values of oxygen saturation (SatO2) at altitude, because it decreases with the highest level of altitude, increases with age, and the gap between wakefulness and sleep is large (especially in the first months of life). Around 25% of healthy children living at altitude have SatO2 values significantly lower than the remaining 75%. The normal values of the apnea/hypopnea indices are different from those at sea level. High altitude pulmonary edema is a frequent pathology that is produced by a disproportionate increase in VHP reflecting hyperactivity of the pulmonary vascular bed in the face of acute exposure to hypobaric hypoxia, it has four phenotypes, it is uncommon in children under 5 years of age, and it is rarely fatal, the clinical suspicion and timely management with oxygen is the key. Finally, at high altitude, the normal values of lung function from spirometry, impulse oscillometry, and diffusing capacity are different from those at sea level.

Asthma in the Americas: An Update: A Joint Perspective from the Brazilian Thoracic Society, Canadian Thoracic Society, Latin American Thoracic Society, and American Thoracic Society.

Asthma affects a large number of people living in the Americas, a vast and diverse geographic region comprising 35 nations in the Caribbean and North, Central, and South America. The marked variability in the prevalence, morbidity, and mortality from asthma across and within nations in the Americas offers a unique opportunity to improve our understanding of the risk factors and management of asthma phenotypes and endotypes in children and adults. Moreover, a better assessment of the causes and treatment of asthma in less economically developed regions in the Americas would help diagnose and treat individuals migrating from those areas to Canada and the United States. In this focused review, we first assess the epidemiology of asthma, review known and potential risk factors, and examine commonalities and differences in asthma management across the Americas. We then discuss future directions in research and health policies to improve the prevention, diagnosis, and management of pediatric and adult asthma in the Americas, including standardized and periodic assessment of asthma burden across the region; large-scale longitudinal studies including omics and comprehensive environmental data on racially and ethnically diverse populations; and dissemination and implementation of guidelines for asthma management across the spectrum of disease severity. New initiatives should recognize differences in socioeconomic development and health care systems across the region while paying particular attention to novel or more impactful risk factors for asthma in the Americas, including indoor pollutants such as biomass fuel, tobacco use, infectious agents and the microbiome, and psychosocial stressor and chronic stress.

Maternal Obesity Is Associated With Higher Cord Blood Adipokines in Offspring Most Notably in Females.

BACKGROUND: Deleterious long-term effects in the offspring from women with pregravid obesity have been described; however, the evidence supporting early metabolic and inflammatory markers in the offspring at birth and gender differences are conflicting. OBJECTIVE: The present study aimed to compare cord blood adipokines and cytokines concentrations and anthropometric characteristics of the offspring of women with maternal obesity (MO) and normal-weight mothers (NWM). Also, maternal and neonatal variables on the association of maternal body mass index (BMI) with cord blood adipokines were evaluated. METHODS: A cross-sectional analysis of a subsample of mother-child dyads participating in a cohort study (n = 221) was assessed. Anthropometrics, cord blood adipokines (leptin and adiponectin) and cytokines (interleukin [IL]-1ß, IL-4, IL-10, IL-12 p40, IL-12p70, IL-13, and tumor necrosis factor α) concentrations in the offspring of normal-weight women (BMI >18.5 and <24.9 kg/m2) and women with pregravid obesity (BMI > 30 kg/m2) without comorbidities was performed. RESULTS: Offspring from mothers with obesity had higher birth weight, a higher proportion of large for gestational age, higher ponderal index, and heavier placentae than offspring from normal-weight mothers (P < 0.05). Within the offspring from women with obesity, males had significantly higher weight, length, the proportion of large-for-gestational-age newborns, higher weight for length ratio. Males had more efficient placentas than females (P < 0.05). Higher adiponectin and leptin in both sexes and higher leptin in female offspring of mothers with obesity after adjusting for birth size (P < 0.05) were found. Higher IL-12p40 in the offspring of women with MO with no other differences in other cytokines among groups were evidenced. CONCLUSIONS: Maternal obesity associates with a higher concentration of adiponectin and leptin in their offspring at birth. There is a relevant effect on anthropometrics in male offspring and on leptin in female newborn. Further studies need to evaluate the extension of these effects in postnatal life. TRAIL IDENTIFICATION NUMBER: NCT02903134.

Solar radiation, air pollution, and bronchiolitis hospitalizations in Chile: An ecological study.

OBJECTIVE: To evaluate trends and geographic distribution of infant bronchiolitis hospitalizations in Chile, a country with large variation in solar radiation (SR) and high rates of urban air pollution. METHODS: We performed a nationwide ecological study of bronchiolitis hospitalizations from 2001 to 2014. We investigated the associations of regional SR (a proxy of vitamin D status) and regional fine particulate matter (PM2.5) air pollution with bronchiolitis hospitalizations. We also evaluated the role of sociodemographic factors, including regional poverty, education, indigenous population, and rurality rates. RESULTS: During the study period, 119 479 infants were hospitalized for bronchiolitis in Chile; 59% were boys. The mean bronchiolitis hospitalization rate increased from 29 to 41 per 1000 infants per year (P = .02). There was an inverse correlation between regional SR and incidence of hospital admissions for bronchiolitis (r = -0.52, P = .049), accounting for 27% of these hospitalizations. There was also a significant direct correlation between regional ambient PM2.5 and bronchiolitis hospitalizations (R = 0.68, P = .006), accounting for 42% of the variation in admission rate. High firewood and/or coal residential use for heating, high regional poverty, lower years of education, and high rurality rates were also significantly correlated with bronchiolitis hospitalization rates. None of the environmental or sociodemographic factors evaluated were correlated with regional case fatality rates or length of stay at the hospital. CONCLUSIONS: This ecological study revealed significant associations between regional SR, air pollution, and sociodemographic factors with infant bronchiolitis hospitalizations in Chile, suggesting that these factors play a major role in the incidence and severity of respiratory infections in early childhood.

The impact of asthma and its treatment on growth: an evidence-based review / O impacto da asma e seu tratamento no crescimento: revisão baseada em evidências

Abstract Objectives: To assess the impact of asthma and its treatment (inhaled corticosteroids and other control medications) on growth. Data sources: The authors searched PubMed (up to August 24, 2018) and screened the reference lists of retrieved articles. Systematic reviews and meta-analysis were selected. If there was no such article, the authors selected either randomized clinical trials or observational studies. Data synthesis: A total of 37 articles were included in this review. The findings from 21 studies suggest that asthma per se, especially more severe and/or uncontrolled cases, can transitorily impair child's growth. Two Cochrane reviews of randomized clinical trials showed a small mean reduction in linear growth (-0.91 cm/year for beclomethasone, -0.59 cm/year for budesonide, and -0.39 cm/year for fluticasone) in the first year of treatment with inhaled corticosteroids in prepubertal children with persistent asthma. The effects were likely to be molecule- and dose-dependent. A recent review showed that most of "real-life" observational studies had not found significant effects of inhaled corticosteroids on growth in asthmatic children. Fifteen studies showed that the maintenance systemic corticosteroids could cause a dose-dependent growth suppression in children with severe asthma, but other controllers (cromones, montelukast, salmeterol, and theophylline) had no significant adverse effects no growth. Conclusions: Severe and/or uncontrolled asthma can transitorily impair child's growth. Regular use of inhaled corticosteroids may cause a small reduction in linear growth in children with asthma, but the well-established benefits of inhaled corticosteroids in controlling asthma outweigh the potential adverse effects on growth. Use of the minimally effective dose of inhaled corticosteroids and regular monitoring of child's height during inhaled corticosteroids therapy are recommended.

Resumo Objetivos: Avaliar o impacto da asma e seu tratamento (corticosteroides inalados e outros medicamentos de controle) no crescimento. Fontes de dados: Uma busca foi feita no PubMed (até 24 de agosto de 2018) e foram triadas as listas de referência dos artigos recuperados. Revisões sistemáticas e metanálises foram selecionadas. Se não houvesse tal artigo, ensaios clínicos randomizados ou estudos observacionais eram selecionados. Síntese dos dados: Trinta e sete artigos foram incluídos nesta revisão. Os achados de 21 estudos sugerem que a asma por si só, especialmente os casos mais graves e/ou descontrolados, podem prejudicar o crescimento da criança. Duas revisões Cochrane de ensaios clínicos randomizados mostraram uma pequena redução média no crescimento linear (−0,91 cm/ano para beclometasona, −0,59 cm/ano para budesonida e −0,39 cm/ano para fluticasona) no primeiro ano de tratamento com corticosteroides inalados em crianças pré-púberes com asma persistente. Os efeitos pareciam ter efeito dose- e molécula-dependente. Uma revisão recente mostrou que a maioria dos estudos observacionais da "vida real" não encontrou efeitos significativos dos corticosteroides inalados no crescimento de crianças asmáticas. Quinze estudos mostraram que a manutenção de corticosteroides sistêmicos poderia causar uma supressão do crescimento dose-dependente em crianças com asma grave, mas outros controladores (cromonas, montelucaste, salmeterol e teofilina) não tiveram efeitos adversos significativos no crescimento. Conclusões: A asma grave e/ou descontrolada pode prejudicar o crescimento da criança. O uso regular de corticosteroides inalados pode causar uma pequena redução no crescimento linear em crianças com asma, mas os benefícios bem estabelecidos dos corticosteroides inalados no controle da asma superam os potenciais efeitos adversos no crescimento. Recomenda-se o uso de doses minimamente eficazes de corticosteroides inalados e o monitoramento regular da altura da criança durante a terapia com corticosteroides inalados.

The relationship between inflammation and remodeling in childhood asthma: A systematic review.

OBJECTIVES: We aimed to perform a systematic review of all studies with direct measurements of both airway inflammation and remodeling in the subgroup of children with repeated wheezing and/or persistent asthma severe enough to warrant bronchoscopy, to address whether airway inflammation precedes remodeling or is a parallel process, and also to assess the impact of remodeling on lung function. METHODS: Four databases were searched up to June 2017. Two independent reviewers screened the literature and extracted relevant data. RESULTS: We found 526 references, and 39 studies (2390 children under 18 years old) were included. Airway inflammation (eosinophilic/neutrophilic) and remodeling were not present in wheezers at a mean age of 12 months, but in older pre-school children (mean 2.5 years), remodeling (mainly increased reticular basement membrane [RBM] thickness and increased area of airway smooth muscle) and also airway eosinophilia was reported. This was worse in school-age children. RBM thickness was similar in atopic and non-atopic preschool wheezers. Airway remodeling was correlated with lung function in seven studies, with FeNO in three, and with HRCT-scan in one. Eosinophilic inflammation was not seen in patients without remodeling. There were no invasive longitudinal or intervention studies. CONCLUSION: The relationship between inflammation and remodeling in children cannot be determined. Failure to demonstrate eosinophilic inflammation in the absence of remodeling is contrary to the hypothesis that inflammation causes these changes. We need reliable, non-invasive markers of remodeling in particular if this is to be addressed.

Automated chart review utilizing natural language processing algorithm for asthma predictive index.

BACKGROUND: Thus far, no algorithms have been developed to automatically extract patients who meet Asthma Predictive Index (API) criteria from the Electronic health records (EHR) yet. Our objective is to develop and validate a natural language processing (NLP) algorithm to identify patients that meet API criteria. METHODS: This is a cross-sectional study nested in a birth cohort study in Olmsted County, MN. Asthma status ascertained by manual chart review based on API criteria served as gold standard. NLP-API was developed on a training cohort (n = 87) and validated on a test cohort (n = 427). Criterion validity was measured by sensitivity, specificity, positive predictive value and negative predictive value of the NLP algorithm against manual chart review for asthma status. Construct validity was determined by associations of asthma status defined by NLP-API with known risk factors for asthma. RESULTS: Among the eligible 427 subjects of the test cohort, 48% were males and 74% were White. Median age was 5.3 years (interquartile range 3.6-6.8). 35 (8%) had a history of asthma by NLP-API vs. 36 (8%) by abstractor with 31 by both approaches. NLP-API predicted asthma status with sensitivity 86%, specificity 98%, positive predictive value 88%, negative predictive value 98%. Asthma status by both NLP and manual chart review were significantly associated with the known asthma risk factors, such as history of allergic rhinitis, eczema, family history of asthma, and maternal history of smoking during pregnancy (p value < 0.05). Maternal smoking [odds ratio: 4.4, 95% confidence interval 1.8-10.7] was associated with asthma status determined by NLP-API and abstractor, and the effect sizes were similar between the reviews with 4.4 vs 4.2 respectively. CONCLUSION: NLP-API was able to ascertain asthma status in children mining from EHR and has a potential to enhance asthma care and research through population management and large-scale studies when identifying children who meet API criteria.

Differences between preschoolers with asthma and allergies in urban and rural environments.

OBJECTIVE: Previous studies have provided conflicting results about how living in a rural or urban environment influences schoolchildren with asthma and allergic diseases in different ways. The aim of the present study was to evaluate if recurrent wheezing preschoolers from rural or urban areas differ in asthma, allergic diseases, and atopy. METHODS: A cross-sectional-study in Rafaela, Argentina, on 143 preschoolers with recurrent wheezing from rural and urban settings was performed (2010-2012). Diagnosis of asthma (by positive asthma predictive index [API]), allergic diseases (rhinitis, dermatitis), and atopy (by skin prick test [SPT], peripheral blood eosinophils, and serum total IgE) were assessed. RESULTS: Preschoolers from rural settings had significantly higher prevalence of vaginal delivery, longer breastfeeding, earlier onset of wheezing, more parental smoking, siblings, shared a bedroom, and more exposure to chemicals used in plant fumigation or farm animals, and unpasteurized milk consumption, in comparison to preschoolers living in urban setting. In contrast, preschoolers from urban areas had significantly higher prevalence of parental history of allergy, positive skin prick test, and positive API. After multivariate analysis adjusting for covariates, maternal smoking [odds ratio (OR) = 3.44] and positive SPT (OR = 5.57) significantly increase the risk of asthma diagnosis (positive API); in contrast, living in rural setting (OR = 0.04), and having more siblings (OR = 0.51) decrease their risk. CONCLUSIONS: Recurrent wheezing preschoolers from rural areas had a significant inverse odds of being diagnosed with asthma (type-2 inflammation) when compared to those from urban areas. Exposure to farm animals and consumption of unpasteurized milk might have a role.

IL-10 expression in macrophages from neonates born from obese mothers is suppressed by IL-4 and LPS/INFγ.

Obese women offspring have a higher risk of developing chronic diseases associated with an altered immune function. We aim to determine, in neonatal monocyte-derived macrophages, whether maternal obesity is associated with an altered expression and DNA methylation of pro- and anti-inflammatory genes, along with a higher pro-inflammatory response. Cord blood from newborns of obese (Ob) and lean (control) women were obtained at delivery. Monocytes were isolated and differentiated into macrophages, in which M1 (LPS/IFNγ) and M2 (IL-4) polarization were assayed. The mRNA levels for TNFα, IL-1ß, IL-12A, IL-12B, IL-10, and IL-4R were quantified by qPCR and the DNA methylation of candidate genes determined by pyrosequencing. RESULTS: Ob-monocytes had decreased levels of mRNA for pro-inflammatory cytokines IL-1ß, IL-10, and IL-12B compared with controls. Conversely, Ob-macrophages showed increased levels of mRNA for TNFα, IL-4R, and IL-10 compared with controls. M1 response was comparable between both groups, characterized by an important induction of TNFα and IL-1ß. In response to an M2 stimulus, control macrophages showed a decreased expression of inflammatory mediators while Ob-macrophages had an additional suppression of the anti-inflammatory mediator IL-10. Changes in IL-1ß (monocytes) and IL-10 (macrophages) in Ob-monocytes were paralleled by changes in their promoter DNA methylation in fetal monocytes. These results suggest that monocyte-derived macrophages from obese newborns show a basal anti-inflammatory phenotype with an unbalanced response to M1 and M2 polarization stimuli. The presence of changes in DNA methylation of key inflammatory genes in neonatal monocytes suggests an intrauterine programing of immune function by maternal obesity.

[Epigenetics and obesity]. / Epigenética y obesidad.

Current evidence supports the notion that exposure to various environmental conditions in early life may induce permanent changes in the epigenome that persist throughout the life-course. This article focuses on early changes associated with obesity in adult life. A review is presented on the factors that induce changes in whole genome (DNA) methylation in early life that are associated with adult onset obesity and related disorders. In contrast, reversal of epigenetic changes associated with weight loss in obese subjects has not been demonstrated. This contrasts with well-established associations found between obesity related DNA methylation patterns at birth and adult onset obesity and diabetes. Epigenetic markers may serve to screen indivuals at risk for obesity and assess the effects of interventions in early life that may delay or prevent obesity in early life. This might contribute to lower the obesity-related burden of death and disability at the population level. The available evidence indicates that epigenetic marks are in fact modifiable, based on modifications in the intrauterine environment and changes in food intake, physical activity and dietary patterns patterns during pregnancy and early years of adult life. This offers the opportunity to intervene before conception, during pregnancy, infancy, childhood, and also in later life. There must be documentation on the best preventive actions in terms of diet and physical activity that will modify or revert the adverse epigenetic markers, thus preventing obesity and diabetes in suceptible individuals and populations.

Epigenética y obesidad / Epigenetics and obesity

La evidencia indica que la exposición a diversas condiciones ambientales en etapas tempranas de la vida puede inducir alteraciones persistentes en el epigenoma. Los estudios epigenómicos en sujetos obesos han permitido evaluar el papel de los mecanismos epigenéticos en el origen y desarrollo de la obesidad. La presente revisión aborda estudios que dan cuenta de la asociación entre la obesidad y metilación global del genoma (ADN), analizando el potencial impacto de intervenciones previas y posteriores al nacimiento que afectan la metilación del ADN y la obesidad en etapas más avanzadas de la vida. Estudios realizados principalmente en leucocitos, han logrado identificar sitios del ADN diferencialmente metilados asociados con obesidad. Estudios hasta la fecha no han demostrado que dichos cambios en metilación sean revertidos luego de bajar de peso. Esto contrasta con resultados iniciales en este campo, que sugieren que existirían marcadores epigenéticos presentes desde el nacimiento que permitirían definir el riesgo de obesidad durante el curso de la vida. La evidencia actual sugiere que algunas marcas epigenéticas son modificables, basándonos en la exposición en la vida intrauterina y también por los hábitos dietarios y de actividad fisica durante las etapas del crecimiento y en la adultez. Esto sugiere que existe la oportunidad de intervenir durante la gestación o en la vida posnatal temprana, que modificaría los perfiles epigenéticos desfavorables e idealmente contribuiría a prevenir la obesidad en los sujetos o poblaciones susceptibles.

Current evidence supports the notion that exposure to various environmental conditions in early life may induce permanent changes in the epigenome that persist throughout the life-course. This article focuses on early changes associated with obesity in adult life. A review is presented on the factors that induce changes in whole genome (DNA) methylation in early life that are associated with adult onset obesity and related disorders. In contrast, reversal of epigenetic changes associated with weight loss in obese subjects has not been demonstrated. This contrasts with well-established associations found between obesity related DNA methylation patterns at birth and adult onset obesity and diabetes. Epigenetic markers may serve to screen indivuals at risk for obesity and assess the effects of interventions in early life that may delay or prevent obesity in early life. This might contribute to lower the obesity-related burden of death and disability at the population level. The available evidence indicates that epigenetic marks are in fact modifiable, based on modifications in the intrauterine environment and changes in food intake, physical activity and dietary patterns patterns during pregnancy and early years of adult life. This offers the opportunity to intervene before conception, during pregnancy, infancy, childhood, and also in later life. There must be documentation on the best preventive actions in terms of diet and physical activity that will modify or revert the adverse epigenetic markers, thus preventing obesity and diabetes in suceptible individuals and populations.

Down's syndrome is a risk factor for severe lower respiratory tract infection due to respiratory syncytial virus.

AIM: Previous studies have suggested that Down's syndrome is an independent risk factor for severe respiratory infection due to respiratory syncytial virus (RSV). We compared the clinical characteristics of children with and without Down's syndrome hospitalised due to RSV. METHODS: This retrospective cohort study compared data from hospitalisations due to RSV lower respiratory tract infections (LRTI) in children under 14 years of age with (n = 58) and without (n = 58) Down's syndrome. RESULTS: The Down's group had longer hospital stays than the controls of six versus four days (p < 0.0001), even after adjusting for age, weeks of gestation at birth, presence of asthma, bronchopulmonary dysplasia, haemodynamically significant and nonsignificant congenital heart disease. This difference increased when only children under one year of age were analysed to 11 versus five days (p < 0.0001). Children with Down's syndrome were more likely to be admitted to intensive care unit (43.1% versus 22.4%, p = 0.017), need noninvasive mechanical ventilation (36.2% versus 13.7%, p = 0.005) and be prescribed antibiotics and steroids. CONCLUSION: Children with Down's syndrome hospitalised due to RSV LRTI had longer hospital stays and worse clinical courses than controls, highlighting the need for RSV prophylaxis for children with Down's syndrome, especially under one year of age.

Risk and Protective Factors for Childhood Asthma: What Is the Evidence?

To summarize the principal findings on risk and protective factors for childhood asthma, we retrieved systematic reviews on these topics in children (aged 1 to 18 years), up to January 2016, through MEDLINE, EMBASE, CINAHL, SCOPUS, and CDSR. A total of 227 studies were searched from databases. Among those, 41 systematic reviews (SRs) were included: 9 focused on prenatal factors, 5 on perinatal factors, and 27 on postnatal factors. Of these 41 SRs, 83% had good methodological quality, as determined by the Assess Systematic Reviews tool. After reviewing all evidence, parental asthma, prenatal environmental tobacco smoke, and prematurity (particularly very preterm birth) are well-established risk factors for childhood asthma. Current findings do suggest mild-to-moderate causal effects of certain modifiable behaviors or exposures during pregnancy (maternal weight gain or obesity, maternal use of antibiotics or paracetamol, and maternal stress), the perinatal period (birth by Caesarean delivery), or postnatal life (severe respiratory syncytial virus infection, overweight or obesity, indoor exposure to mold or fungi, and outdoor air pollution) on childhood asthma, but this suggestive evidence must be confirmed in interventional studies or (if interventions are not feasible) well-designed prospective studies.

Sleep-disordered breathing in children with asthma: a systematic review on the impact of treatment.

BACKGROUND: The objective was to perform a systematic review in order to describe the relationship between asthma and sleep-disordered breathing (SDB) in children, especially regarding the impact of treatment and management. METHODS: We performed an electronic search in MEDLINE, EMBASE, and LILACS database. Study inclusion criteria were the following: 1) studies that examined the relationship between asthma/wheezing and SDB/obstructive sleep apnea (OSA); and 2) studies conducted in children <18 years of age. Primary outcomes were the prevalence of asthma and SDB, the tests used for diagnosis, and the influence of their treatment and management. RESULTS: One thousand and twenty studies were identified, among which 32 were selected (n=143,343 children; 51% males; age [mean ± standard deviation] 8.4±2.5 years). Most studies (n=26) diagnosed SDB using questionnaires or clinical history. Nine studies performed a sleep study for diagnosing OSA. The diagnosis of asthma was based on clinical history (n=16), previous medical diagnosis (n=4), questionnaires (n=12), and spirometry (n=5). Children with asthma were more likely to develop habitual snoring and OSA, and children with SDB were more likely to develop asthma. Moreover, asthma was associated with more severe OSA, and the presence of SDB was associated with severe asthma. Treatment of SDB with adenotonsillectomy was associated with significant asthma improvement. CONCLUSION: The relationship between asthma and SDB appears to be bidirectional, and adenotonsillectomy appears to improve asthma control. Future trials on how asthma treatment could impact on SDB are needed.

[Epigenetics in allergic diseases and asthma]. / Epigenética en enfermedades alérgicas y asma.

Allergic diseases and asthma are the result of complex interactions between genetic predisposition and environmental factors. Asthma is one of the most prevalent chronic disease among children. In this article we review some environmental factors like: allergen exposition, tobacco, bacteria, microbial components, diet, obesity and stress, which influences during intrauterine and infancy life in the epigenetic regulation of asthma and allergic diseases. The review has been done in three models: in-vitro, animal and human.

Epigenética en enfermedades alérgicas y asma / Epigenetics in allergic diseases and asthma

Las enfermedades alérgicas y el asma son el resultado de complejas interacciones entre la predisposición genética y factores ambientales. El asma es una de las enfermedades crónicas más prevalentes en niños. En este artículo se revisan algunos factores ambientales como la exposición a alérgenos, tabaco, bacterias, componentes microbianos, dieta, obesidad y estrés, que intervienen durante la vida intrauterina y la infancia en la regulación epigenética de las enfermedades alérgicas y el asma. La revisión se realiza en tres tipos de modelos: in-vitro, animales y humanos.

Allergic diseases and asthma are the result of complex interactions between genetic predisposition and environmental factors. Asthma is one of the most prevalent chronic disease among children. In this article we review some environmental factors like: allergen exposition, tobacco, bacteria, microbial components, diet, obesity and stress, which influences during intrauterine and infancy life in the epigenetic regulation of asthma and allergic diseases. The review has been done in three models: in-vitro, animal and human.

[General concepts of epigenetics: Projections in paediatrics]. / Conceptos generales de epigenética: proyecciones en pediatría.

Current evidence supports the notion that alterations in intrauterine growth and during the first years of life have a substantial effect on the risk for the development of chronic disease, which in some cases is even higher than those due to genetic factors. The persistence and reproducibility of the phenotypes associated with altered early development suggest the participation of mechanisms that would record environmental cues, generating a cellular reprogramming (i.e., epigenetic mechanisms). This review is an introduction to a series of five articles focused on the participation of epigenetic mechanisms in the development of highly prevalent chronic diseases (i.e., cardiovascular, metabolic, asthma/allergies and cancer) and their origins in the foetal and neonatal period. This series of articles aims to show the state of the art in this research area and present the upcoming clues and challenges, in which paediatricians have a prominent role, developing strategies for the prevention, early detection and follow-up.

Conceptos generales de epigenética: proyecciones en pediatría / General concepts of epigenetics: projections in paediatrics

La asociación entre factores ambientales presentes durante el desarrollo embrionario/fetal y enfermedades que puedan presentarse durante la vida representa un campo de creciente interés. En este contexto la evidencia actual apoya fuertemente que alteraciones en el crecimiento intrauterino y durante los primeros años de vida presentan una fuerte influencia en el riesgo de padecer enfermedades crónicas que en muchos casos pudiera ser mayor que la carga genética del paciente. La persistencia y reproducibilidad de los fenotipos asociados a alteraciones en el desarrollo temprano sugieren la participación de mecanismos moleculares que registran dichas modificaciones (i.e. mecanismos epigenéticos) generando una «reprogramación¼ celular y fisiológica. Esta revisión es la introducción a una serie de 5 artículos en torno a la participación de los mecanismos epigenéticos en el desarrollo de enfermedades crónicas (i.e. cardiovasculares, metabólicas, asma/alergias y cáncer) y su relación con el origen de dichas enfermedades en etapas tempranas del desarrollo. El objetivo de esta serie es mostrar el estado actual de esta área de la investigación y presentar los desafíos e interrogantes futuros en los cuales la pediatría tiene un papel preponderante, desarrollando estrategias para la prevención, detección precoz y seguimiento.

Current evidence supports the notion that alterations in intrauterine growth and during the first years of life have a substantial effect on the risk for the development of chronic disease, which in some cases is even higher than those due to genetic factors. The persistence and reproducibility of the phenotypes associated with altered early development suggest the participation of mechanisms that would record environmental cues, generating a cellular reprogramming (i.e. epigenetic mechanisms). This review is an introduction to a series of five articles focused on the participation of epigenetic mechanisms in the development of highly prevalent chronic diseases (i.e. cardiovascular, metabolic, asthma/allergies and cancer) and their origins in the foetal and neonatal period. This series of articles aims to show the state of the art in this research area and present the upcoming clues and challenges, in which paediatricians have a prominent role, developing strategies for the prevention, early detection and follow-up.