Asthma and obesity in childhood: on the road ahead

Assessment of the Physical Activity of Children with Asthma Bronchiale

Physical activity is an especially important part of everyday life for children with chronic diseases. The aim of the study was to show whether asthma is a barrier to physical activity in our society. The correlations between the severity of the disease, body mass index, and physical activity were analyzed, and parents' opinions on whether children should participate in active sports were assessed. Physical activity of children with asthma was analyzed by questionnaires; 93 parents and their 93 children were involved in the survey. The age of children was 12.6 ± 3.5 years (mean ± SD), 69.9% were boys, 30.1% were girls. A total of 93.4% of the respondents participated in a physical education program and 56.5% also attended sporting activities on a regular basis. In terms of disease severity, 61.2% of the children had mild asthma, 37.6% moderate, and 1.2% severe, and 6.5% of the respondents also stated that their children's illness had been consistently or frequently limiting their performance concerning their school or home duties over the past four weeks. Of the parents surveyed, 12% felt that physical activity was not appropriate in the context of this disease. We concluded that fear of the consequences of physical activity depends largely on education, which should involve parents, teachers, and coaches.

Analysis of possible risk factors for the severity of paediatric obstructive sleep apnoea syndrome

PURPOSE

This study aimed to determine the effect of body mass index (BMI) percentile, asthma, sex, and age on the paediatric obstructive sleep apnoea (OSA) severity. Furthermore, to determine the possible predictive role of the BMI percentile and age in severe OSA.

METHODS

This retrospective study included 921 children aged 2-18 years diagnosed with OSA by polysomnography. Analysis of Covariance (ANCOVA), Spearman's correlation, Receiver Operating Characteristics (ROC) analyses were performed and area under the curve (AUC) was determined.

RESULTS

We observed a significant association between a higher BMI percentile and the severity of OSA (p < 0.001, ρ = 0.15). The correlation also was significant under (p = 0.007, ρ = 0.11) and over 7 (p = 0.0002, ρ = 0.23) years of age. There was no association between the severity of OSA and the presence of asthma (p = 0.9) or sex (p = 0.891), respectively. Age was significantly related to OSA severity (p = 0.01, ρ = 0.08). Although both the BMI percentile (0.59 AUC [0.54-0.65]) and age (0.58 AUC [0.52-0.63]) predicted severe OSA, according to the sensitivity and specificity values of the ROC curve, the association presents a slight clinical relevance.

CONCLUSIONS

OSA severity is determined by the BMI percentile and age in children; however, these factors are unsuitable for predicting severe OSA in clinical practice. Based on our results, obesity is also a significant risk factor for OSA in younger children. Our study highlights that older, overweight, and obese children have a higher risk for severe OSA.

Obesity and asthma

Obesity has been well recognized as an important comorbidity in patients with asthma, representing a unique phenotype and endotype. This association indicates a close relationship between metabolic and inflammatory dysregulation. However, the detailed organ-organ, cellular, and molecular interactions are not completely resolved. Because of that, the relationship between obesity and asthma remains unclear. In this article, clinical and epidemiological studies, as well as data from experimental animal work, are being summarized to provide a state of the art update on this important topic. Much more work is needed, particularly mechanistic, to fully understand the interaction between obesity and asthma and to develop novel preventive and therapeutic strategies.

Bidirectional Association Between Asthma and Obesity During Childhood and Adolescence: A Systematic Review and Meta-Analysis

Objective: Co-occurrence of pediatric asthma and obesity has been widely reported, yet the causal directions between these two disorders are still not well-understood. The objective of this meta-analysis is to explore whether there is a possibility of a bidirectional association for these two disorders in children and adolescents. Methods: PubMed, Embase, Web of Science, and CENTRAL databases were searched up to August 2020. Cohort studies reporting the associations of obesity with risk of physician-diagnosed asthma or physician-diagnosed asthma with risk of obesity in children and adolescents were eligible for the review. Results: A total of 3,091 records were identified from the four databases, with final inclusion of nine. Six studies reported the association between obesity and risk of asthma; three studies reported the association between asthma and risk of childhood obesity. As evaluated by the Newcastle-Ottawa quality assessment scale, all studies were assessed as high-quality studies. There was a statistically significant association between obesity and increased risk of physician-diagnosed asthma in children and adolescents. The pooled RR was 1.39 (95% CI: 1.28, 1.50; p < 0.001), with significant heterogeneity across studies (I ² = 81.7%; p _{heterogeneity} < 0.001). The pooled RR in boys was 1.53 (95% CI: 1.17, 1.99; p = 0.002), but such a significant association was not observed in girls (RR = 1.17, 95% CI: 0.79, 1.72; p = 0.434). For the association of asthma with risk of childhood obesity, the pooled RR was 1.47 (95%CI: 1.25, 1.72; p < 0.001) without statistical heterogeneity (I ² = 0%, p _{heterogeneity} = 0.652). Conclusion: There is a bidirectional association between obesity and asthma during childhood and adolescence, suggesting that childhood obesity drives an increase in the onset of asthma; meanwhile, childhood asthma may also increase risk of obesity for children and adolescents.

Association of body mass index and season with histamine skin reactivity in Chinese children with allergic rhinitis

BACKGROUND

To investigate the association between histamine skin reactivity and body mass index (BMI) and other clinical factors, 526 children (3-6 years old) who underwent a skin-prick test (SPT) to diagnose allergic rhinitis were enrolled.

METHODS

The SPT was carried out using 43 common allergens (commercial kit). The wheal size was analyzed. The associations between histamine reactivity and age, gender, BMI, atopy, parental smoking history, and testing season were examined.

RESULTS

Mean age was 4.6 ± 1.1 years. Among all 526 children, 202 (38.4%) had intermittent allergic rhinitis (IAR), 164 (32.1%) had IAR + persistent allergic rhinitis (PER), and 160 (30.4%) had PER. The size of the histamine skin wheal and maximum diameter for positive allergens showed significant seasonal differences (P = 0.001 and P = 0.02, respectively). Children with biparental allergy history had a higher BMI (P = 0.006). BMI (P < 0.001), summer testing (P = 0.001), and autumn testing (P < 0.001) were independently associated with the size of the histamine skin wheal. Only winter testing was independently associated with the maximal diameter for positive allergens (P = 0.002).

CONCLUSIONS

Higher histamine skin reactivity was associated with higher BMI and summer or autumn testing. Subject BMI and season should be considered for better interpretation of the SPT. The mechanisms underlying these associations require further study.

Association of body mass index and other factors with histamine skin reactivity in adults with allergic nasal symptoms

BACKGROUND

The skin-prick test is the most commonly used method to diagnose allergy. In addition, histamine skin reactivity is used as a positive control for the skin-prick test. However, there is individual variation in histamine skin reactivity. The factors that influence individual variation in histamine skin reactivity remain unknown.

OBJECTIVES

We aimed to investigate the factors associated with histamine skin reaction.

METHODS

Ninety-seven subjects who underwent a skin-prick test to diagnose allergic rhinitis were enrolled in this study. The skin-prick test was performed with six common allergens. The wheal size of the histamine skin reaction was analyzed; other variables included age, sex, body mass index (BMI), atopy, smoking history, and the testing season.

RESULTS

The wheal size in the histamine skin test was significantly associated with age and BMI. The association between histamine skin reactivity and BMI was also present in multivariate analysis, adjusted for age, sex, atopy, smoking history, and season.

CONCLUSION

Histamine skin reactivity increased with BMI (degree of obesity). This association should be considered for better interpretation of the skin-prick test. Further studies regarding the mechanism for this association are needed.

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

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

The clinical translation gap in child health exercise research: a call for disruptive innovation

In children, levels of play, physical activity, and fitness are key indicators of health and disease and closely tied to optimal growth and development. Cardiopulmonary exercise testing (CPET) provides clinicians with biomarkers of disease and effectiveness of therapy, and researchers with novel insights into fundamental biological mechanisms reflecting an integrated physiological response that is hidden when the child is at rest. Yet the growth of clinical trials utilizing CPET in pediatrics remains stunted despite the current emphasis on preventative medicine and the growing recognition that therapies used in children should be clinically tested in children. There exists a translational gap between basic discovery and clinical application in this essential component of child health. To address this gap, the NIH provided funding through the Clinical and Translational Science Award (CTSA) program to convene a panel of experts. This report summarizes our major findings and outlines next steps necessary to enhance child health exercise medicine translational research. We present specific plans to bolster data interoperability, improve child health CPET reference values, stimulate formal training in exercise medicine for child health care professionals, and outline innovative approaches through which exercise medicine can become more accessible and advance therapeutics across the broad spectrum of child health.

Sex differences in the relationship between asthma and overweight in Dutch children: a survey study

Objective

Obesity has been identified as a risk factor for asthma in children. However, in the Netherlands, the obesity prevalence is rising while the asthma prevalence in children is stabilising. The aim of this study is to clarify the association between asthma and Body Mass Index (BMI) in children and whether this association is influenced by sex.

Study Design

Parents of 39,316 children (6-16 years) in the south of the Netherlands were invited to complete an online questionnaire on respiratory symptoms, anthropometric variables and several potential confounding factors for asthma and obesity (including sex, birth weight and breastfeeding). Data was analysed by multivariable logistic regression models and an ordinal regression model.

Results

The response rate was 24% (n boys= 4,743, n girls= 4,529). The prevalence of asthma, overweight and obesity was 8%, 15% and 2% respectively. Body mass index - standard deviation Score (BMI-SDS) was related to current asthma (adjusted OR: 1.29; 95%CI: 1.14-1.45, p≤0.001). When stratified for sex, asthma and BMI-SDS were only related in girls (Girls: adjusted OR: 1.31; 95%CI: 1.13-1.51, p≤0.001. Boys: adjusted OR: 1.01; 95%CI: 0.91-1.14, p=0.72).

Conclusions

The positive association between BMI-SDS and asthma is only present in girls, not boys. Future studies into obesity and asthma should correct for sex in their analyses.

Timing of introduction of solid food and risk of allergic disease development: understanding the evidence

Strategies to prevent or reduce the risk of allergic diseases are needed. The time of exclusive breastfeeding and introduction of solid foods is a key factor that may influence the development of allergy. For this reason, the aim of this review was to examine the association between exposure to solid foods in the infant's diet and the development of allergic diseases in children. Classical prophylactic feeding guidelines recommended a delayed introduction of solids for the prevention of atopic diseases. Is it really true that a delayed introduction of solids (after the 4th or 6th month) is protective against the development of eczema, asthma, allergic rhinitis and food or inhalant sensitisation? In recent years, many authors have found that there is no statistically significant association between delayed introduction of solids and protection for the development of allergic diseases. Furthermore, late introduction of solid foods could be associated with increased risk of allergic sensitisation to foods, inhalant allergens and celiac disease in children. Tolerance may be driven by the contact of the mucosal immune system with the allergen at the right time of life; the protective effects seem to be enhanced by the practice of the breastfeeding at the same time when weaning is started. Therefore, recent guidelines propose a "window" approach for weaning practice starting at the 17th week and introducing almost all foods within the 27th week of life to reduce the risk of chronic diseases such as allergic ones and the celiac disease. Guidelines emphasize the role of breastfeeding during the weaning practice.

The relationship of serum triglycerides, serum HDL, and obesity to the risk of wheezing in 85,555 adults

BACKGROUND

Asthma has been linked to obesity and the presence of the metabolic syndrome.

OBJECTIVE

To explore which components of the metabolic syndrome that were associated with wheezing, a main symptom of asthma. Further, to explore whether these associations were different in individuals with and without rhinitis symptoms.

METHODS

We used data from the Ibermutuamur Cardiovascular Risk Assessment Plan (ICARIA) including 85,555 Spanish workers (median age = 34, range = 16-75 years) with assessments of self reported wheezing and rhinitis symptoms. Fasting blood samples were analysed for serum triglyceride (s-TG), HDL (s-HDL) and glucose; blood pressure, waist circumference (WC) and body mass index (BMI) were measured.

RESULTS

In mutually adjusted analyses including all components of the metabolic syndrome and possible confounders, elevated WC (or BMI), elevated s-TG and low s-HDL were significantly associated with wheezing. Odds ratio (OR) with confidence interval (CI) were: elevated WC = 1.54 (1.46-1.62), elevated s-TG = 1.24 (1.18-1.30), low s-HDL = 1.17 (1.12-1.22). These associations were stronger in individuals without than in those with rhinitis symptoms, OR's (CI's) were WC = without rhinitis 1.70 (1.57-1.85) vs. with rhinitis 1.47 (1.37-1.58). Elevated s-TG = without rhinitis 1.36 (1.26-1.46) vs. with rhinitis 1.21 (1.13-1.29). Low s-HDL = without rhinitis 1.24 (1.15-1.34) vs. with rhinitis 1.11 (1.04-1.18).

CONCLUSIONS

High s-TG and low s-HDL were associated with wheezing after adjustment for adiposity. This may substantiate elevated s-TG and lowered s-HDL as markers or inducers of inflammation associated disease. The study supports the notion that these biochemical markers have differential effects on different types of wheezing.

Asthma in children and adolescents: a comprehensive approach to diagnosis and management

Asthma is a chronic disease that has a significant impact on quality of life and is particularly important in children and adolescents, in part due to the higher incidence of allergies in children. The incidence of asthma has increased dramatically during this time period, with the highest increases in the urban areas of developed countries. It seems that the incidence in developing countries may follow this trend as well. While our knowledge of the pathophysiology of asthma and the available of newer, safer medication have both improved, the mortality of the disease has undergone an overall increase in the past 30 years. Asthma treatment goals in children include decreasing mortality and improving quality of life. Specific treatment goals include but are not limited to decreasing inflammation, improving lung function, decreasing clinical symptoms, reducing hospital stays and emergency department visits, reducing work or school absences, and reducing the need for rescue medications. Non-pharmacological management strategies include allergen avoidance, environmental evaluation for allergens and irritants, patient education, allergy testing, regular monitoring of lung function, and the use of asthma management plans, asthma control tests, peak flow meters, and asthma diaries. Achieving asthma treatment goals reduces direct and indirect costs of asthma and is economically cost-effective. Treatment in children presents unique challenges in diagnosis and management. Challenges in diagnosis include consideration of other diseases such as viral respiratory illnesses or vocal cord dysfunction. Challenges in management include evaluation of the child’s ability to use inhalers and peak flow meters and the management of exercise-induced asthma.

Clinical application of exhaled nitric oxide measurement in pediatric lung diseases

Fractional exhaled nitric oxide (FeNO) is a non invasive method for assessing the inflammatory status of children with airway disease. Different ways to measure FeNO levels are currently available. The possibility of measuring FeNO levels in an office setting even in young children, and the commercial availability of portable devices, support the routine use of FeNO determination in the daily pediatric practice. Although many confounding factors may affect its measurement, FeNO is now widely used in the management of children with asthma, and seems to provide significantly higher diagnostic accuracy than lung function or bronchial challenge tests. The role of FeNO in airway infection (e.g. viral bronchiolitis and common acquired pneumonia), in bronchiectasis, or in cases with diffuse lung disease is less clear. This review focuses on the most recent advances and the current clinical applications of FeNO measurement in pediatric lung disease.

Exploring the obesity-asthma link: do all types of adiposity increase the risk of asthma?

BACKGROUND

Obesity and risk of asthma are linked. Different distributions of adiposity, such as visceral, subcutaneous or ectopic adiposity, may affect asthma risk differently.

OBJECTIVE

To explore the association of different adiposity types with self-reported asthma, bronchial inflammation and lung function, accounting for possible effect modifiers, such as atopy and gender.

METHODS

In a general population sample of 3471 persons aged 19-72, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured by ultrasound, and fat percentage by bio-impedance. Body mass index, waist circumference, waist-to-hip ratio (WHR), bronchial inflammation as fractional expiratory nitric oxide (FeNO), lung function [FEV(1) and forced vital capacity (FVC)], and atopy (specific IgE) were measured.

RESULTS

All adiposity measures were associated with a higher risk of asthma. The risk estimates (odds ratios, OR, with 95% confidence interval, CI) of current asthma were of similar magnitude for all six adiposity measures ranging between 1.17, CI = 0.98-1.40 (SAT) and 1.51, CI = 1.17-1.95 (WHR). The adiposity-asthma associations were significantly stronger in non-atopics than in atopics. In non-atopics the risk estimates of current asthma ranged between 1.35 CI = 1.08-1.72 and 1.82 CI = 1.34-2.46 for SAT and WHR respectively. Consistent results were obtained using dichothomized adiposity measures (obese vs. non-obsese). The FVC and FEV(1) decreased significantly with increasing adiposity in both atopics and non-atopics, e.g. FVC decreased between 36 mL (CI = 10, 62 mL) and 155 mL (CI = 124, 186 mL) for one unit (standard error) increase of SAT and VAT respectively. Adiposity measures were not associated with atopy and not consistently associated with FeNO levels.

CONCLUSIONS AND CLINICAL RELEVANCE

The effect of adiposity on asthma was mainly seen in non-atopics and did not appear to depend on the distribution of adiposity as reflected by the adiposity measures used in the present study. Increasing adiposity was associated with lower lung function independent of atopic status.

Review on the impact of pregnancy and obesity on influenza virus infection

A myriad of risk factors have been linked to an increase in the severity of the pandemic H1N1 2009 influenza A virus [A(H1N1)pdm09] including pregnancy and obesity where death rates can be elevated as compared to the general population. The goal of this review is to provide an overview of the influence of pregnancy and obesity on the reported cases of A(H1N1)pdm09 virus infection and of how the concurrent presence of these factors may have an exacerbating effect on infection outcome. Also, the hypothesized immunologic mechanisms that contribute to A(H1N1)pdm09 virus severity during pregnant or obese states are outlined. Identifying the mechanisms underlying the increased disease severity in these populations may result in improved therapeutic approaches and future pandemic preparedness.

Obesity and pulmonary disease: unanswered questions

Obesity is associated with risk of pulmonary disease, and adversely affects lung function. The parallel increase in obesity and asthma suggests the two conditions are linked; indeed, they can worsen each other. Obesity and inadequate asthma control are associated with poor quality of life, and place a high economic burden on public health. Although the obesity-lung interaction is a major issue for basic research and clinical studies, various questions remain unanswered. Do intrauterine and early life factors impact on the development of obesity and lung disease? If so, can this be prevented? Asthma is generally more severe in obese subjects, but is adiposity a driver of a new asthma phenotype that features greater morbidity and mortality, worse control and decreased response to medications? Obese individuals have small lung volumes, hence their airway calibre is reduced and airway resistance is increased. What puzzles physicians is whether peripheral airways undergo remodelling, which would increase bronchoconstriction. Obese asthmatics respond suboptimally to anti-inflammatory treatment, which raises the question: 'what drug for what patient?' Life expectancy is decreased in obesity and in chronic pulmonary disorders, but does obesity protect against or trigger chronic obstructive pulmonary disease? The time has come to find answers to these questions.

How changes in nutrition have influenced the development of allergic diseases in childhood

The increasing prevalence of allergic diseases in childhood in the last decades could be linked to concomitant dietary changes, especially with the modified and lower consumption of fruit, vegetables and minerals. The consumption of these foods by pregnant women and children in the first years of life seems to be associated with a reduced risk of asthma and related symptoms. Foods that can prevent the development of wheezing through their antioxidant effects contain vitamin C and selenium; blood levels of these elements correlate negatively with the risk of wheezing. Intake of vitamin E during pregnancy also appears to be correlated with a reduced risk of wheezing for the unborn child. Similarly, low intake of zinc and carotenoids by pregnant women is associated with an increased risk of wheezing and asthma in childhood. Fiber also has anti-inflammatory properties and protective effects against allergic diseases such as atopic dermatitis and asthma. The consumption of fat influences the development of the airways. Populations in Western countries have increased their consumption of n-6 PUFAs and, in parallel, reduced n-3 PUFAs. This has led to decreased production of PGE2, which is believed to have a protective effect against inflammation of the airways. Conflicting hypotheses also concern vitamin D; both an excess and a deficiency of vitamin D, in fact, have been associated with an increased risk of asthma. Further studies on the role of these substances are necessary before any conclusions can be drawn on a clinical level.

The Pediatric Asthmatic

The incidence of allergies and asthma in the Western world has been increasing over the past 30 years. However, more recent data suggests that over the past 5–10 years, the overall global trends of asthma incidence have begun to stabilize (1). Urbanization and industrialization has contributed to the increase in developed countries, but the reasons for this are still unclear. Asthma is estimated to be responsible for 1 in every 250 deaths worldwide. Many of these deaths are preventable, and specific issues have been identified that may contribute to this high mortality rate. Factors that contribute to high ­mortality and morbidity include slow access to care and medications, inadequate environmental control of allergens and irritants, dietary changes, genetic variations, cultural barriers, lack of education amongst patients and providers, insufficient resources, and improper use of health care dollars.

Weight gain in infancy and post-bronchiolitis wheezing

AIM

Low birth weight, high birth weight and excessive weight gain after birth may be risk factors for asthma in childhood, but their associations with wheezing in early childhood are poorly studied. The aim of the study was to evaluate birth weight, weight gain in early infancy and overweight in infancy assessed by weight for length (WFL) as risk factors for wheezing after hospitalization for bronchiolitis in early infancy.

METHODS

In all, 127 full-term infants hospitalized for bronchiolitis at age <6 months have been followed up until the mean age of 1.5 years. The weights and lengths of the infants were measured on admission to hospital and at the control visit. Birth weights were obtained from the hospital records.

RESULTS

Both occurrence and recurrence of post-bronchiolitis wheezing were associated with birth weight >4000 g and the recurrence of post-bronchiolitis wheezing with WFL >110% at age 1.5 years. The associations were robust to adjustments with gender and allergy. Higher weight gain from birth to hospitalization at age <6 months was associated with wheezing in the subgroup of children with birth weight >4000 g.

CONCLUSION

High birth weight and the development of overweight may be associated with post-bronchiolitis wheezing in infancy.

Overweight does not increase asthma risk but may decrease allergy risk at school age after infantile bronchiolitis

AIM

Increasing evidence suggests that overweight children are at increased risk of asthma. The association between weight gain and allergy is more complex. The aim was to evaluate the association between overweight or obesity and asthma, allergy, bronchial reactivity or atopic sensitization at school age in children with bronchiolitis in infancy.

SUBJECTS AND METHODS

Eighty-one children hospitalized for bronchiolitis at <24 months of age attended control visits at 7.2 and 12.3 years of ages. The visits consisted of medical examinations, weight and height measurements, body mass index (BMI) calculations, skin prick tests and exercise challenge tests. BMI >1.3 SD from age- and gender-specific references meant overweight and BMI >2.0 SD obesity.

RESULTS

Current or previous overweight or obesity did not increase the risk of asthma, allergy, bronchial reactivity or atopic sensitization at 7.2 or 12.3 years of age. Previous and current obesity decreased the risk of atopic dermatitis, and current overweight and obesity decreased the risk of sensitization to outdoor allergens at 12.3 years of age.

CONCLUSION

Previous or current overweight does not increase asthma or allergy risk but current obesity may decrease allergy risk at school age after bronchiolitis in infancy.

A cross-sectional study assessing the relationship between BMI, asthma, atopy, and eNO among schoolchildren

BACKGROUND

Increased body weight may influence airway inflammatory mechanisms.

OBJECTIVE

To assess whether overweight-obesity (OW-O), evaluated as increased body mass index, is associated either with exhaled nitric oxide (eNO), a marker of airway inflammation, or with allergic sensitization in a large sample of children and adolescents.

METHODS

A cross-sectional, epidemiological study was performed on a population sample of schoolchildren evaluating 708 subjects (age 10-16 years; BMI 13-39 kg/m(2)) by respiratory health questionnaire, skin prick tests, spirometry, and eNO measure.

RESULTS

Prevalence rates were: OW-O 16.4%, asthma ever (A) 11.9%, and rhinoconjunctivitis (RC) 14.8%. Asthma ever and allergic sensitization were significantly more frequent among OW-O (21.0 and 51.6%) than in non-OW-O (10.2 and 37.0%, respectively). The forced expiratory volume in 1 second (FEV(1))/forced vital capacity (FVC) ratio was not significantly different between OW-O and non-OW-O. Exhaled NO (median and interquartile range) was 15.3 (11.2-23.1) ppb in the overall sample, 20.3 (12.9-35.8) ppb among allergic subjects, and 13.9 (10.6-18.3) ppb among nonallergic subjects (P<.0001). No significant difference between OW-O and non OW-O subjects was found in eNO levels. Similarly, OW-O subjects with A or RC did not show significantly higher eNO levels than non-OW-O. In a logistic regression model, presence of allergic sensitization, A, and RC, and not OW-O, were significant predictors of increased eNO.

CONCLUSIONS

In children, OW-O was not associated with increased eNO levels, but it was an independent risk factor for asthma and allergic sensitization.

Asthma and Sleep

Asthma significantly affects quality of sleep. Asthma physiology follows a diurnal pattern with peak flow at its lowest during early morning hours. The type and timing of release of inflammatory mediators also varies during the day and nighttime. Nocturnal symptoms are common in poorly controlled asthma. Hence, these nighttime symptoms play a significant role in the assessment of asthmatic patients as demonstrated in validated asthma control and quality of life questionnaires. Comorbid conditions may include allergic rhinitis, obesity, obstructive sleep apnea, and gastroesophageal reflux, all of which may worsen asthma symptoms, especially during sleep. In addition, exposure to greater loads of allergens in susceptible individuals during sleep is a significant problem and must be addressed to break the cycle of poor asthma control. Thus, asthma education for better symptom control should address these particular issues surrounding sleep.

Obesity duration is associated to pulmonary function impairment in obese subjects

Obesity is associated with pulmonary function disturbances. We hypothesized that lung function decreases with increasing duration of obesity. We evaluated pulmonary function tests (PFTs) in 188 nonsmoking subjects with primary obesity (aged 8-76 years; 36% with systemic hypertension). Duration of obesity was assessed by questionnaire in adults, and by height and weight growth patterns in children. Asthma and/or other allergic diseases were investigated by standardized questionnaires. BMI and BMI-standard deviation scores (SDS) were 38.7 and 2.4 kg/m(2), respectively. Forty-six percent of patients were atopic. Among subjects with ever asthma (33%), 20 had current asthma (11% of the total). Forced vital capacity (FVC), forced expiratory volume in 1 s, total lung capacity (TLC), and functional residual capacity (FRC) were 103, 104, 95, and 76% predicted, respectively. Mean duration of obesity was 8.3 years. Compared with subjects who had been obese for ≤5 years, patients who had been obese for >15 years had significantly lower values on PFTs (P < 0.05). In subjects with systemic hypertension, PFTs were lower than in patients without hypertension (P < 0.01). Duration of obesity was significantly related to all PFTs (P ≤ 0.001). In a multiple regression analysis where duration and severity of obesity, hypertension, atopy, asthma, and family history of atopic diseases were independent variables, duration of obesity was a predictor of lower PFTs (P < 0.01). Of the remaining variables, only hypertension contributed to lower lung volumes. In obese individuals, lung function was significantly lower in subjects with greater years of obesity. Fat loss programs should be encouraged to prevent late pulmonary function impairment.

Update on pediatric sleep-disordered breathing

Pediatric sleep-disordered breathing (SDB) includes an increasingly recognized, highly prevalent, yet still underdiagnosed spectrum of respiratory disorders, the most common and clinically significant of which is obstructive sleep apnea. SDB is linked with significant end-organ dysfunction across various systems, particularly with cardiovascular, neurocognitive, and metabolic consequences. This review summarizes recent advances in understanding of pediatric SDB and discusses the challenges inherent in diagnosing and treating children with SDB.

Fetal and early postnatal life roots of asthma

The origins of asthma might be traced back to events occurring during fetal life. Reduced lung development has been shown to be a risk factor both for viral induced wheeze and allergic asthma. The evidence for a causal relationship between exposure to environmental tobacco smoke, chemical domestic products for cleaning, outdoor pollutants, and reduction in lung function is quite strong. Reduced maternal intake of vitamin E, vitamin D, and zinc, or increased use of paracetamol during pregnancy is associated with increased wheezing outcomes in children. The odds ratio for asthma onset is also increased in infants born from mothers with oligohydramnios, chorioamnionitis, hypertension, preeclampsia, diabetes and exposed to stressful events. The risk of developing allergic asthma is increased if the child is exposed in the first months of life to synthetic bedding and is enhanced by allergen exposure and an inadequate barrier function of the skin. In conclusion, several lines of evidence support the concept of fetal programming and very early life events in the development of the different phenotypes of asthma. Since some environmental triggers can be easily avoided and some protective factors can be easily implemented all efforts should be made to prevent intrauterine insults and early sensitization.

Early childhood weight status in relation to asthma development in high-risk children

BACKGROUND

Obesity has been proposed to be a risk factor for the development of childhood asthma.

OBJECTIVE

We sought to examine weight status from birth to age 5 years in relation to the occurrence of asthma at ages 6 and 8 years.

METHODS

Two hundred eighty-five full-term high-risk newborns with at least 1 asthmatic/atopic parent enrolled in the Childhood Origin of Asthma project were studied from birth to age 8 years. Overweight was defined by weight-for-length percentiles of greater than the 85th percentile before the age of 2 years and a body mass index percentile of greater than the 85th percentile at ages 2 to 5 years.

RESULTS

No significant concurrent association was found between overweight status and wheezing/asthma occurrence at each year of age. In contrast, longitudinal analyses revealed complex relationships between being overweight and asthma. Being overweight at age 1 year was associated with a decreased risk of asthma at age 6 (odds ratio [OR], 0.32; P = .02) and 8 (OR, 0.35; P = .04) years, as well as better lung function. However, being overweight beyond infancy was not associated with asthma occurrence. In fact, only children who were overweight at age 5 years but not at age 1 year had an increased risk of asthma at age 6 years (OR, 5.78; P = .05).

CONCLUSION

In children genetically at high risk of asthma, being overweight at age 1 year was associated with a decreased risk of asthma and better lung function at ages 6 and 8 years. However, being overweight beyond infancy did not have any protective effect and even could confer a higher risk for asthma.