Bronchial Asthma and Obesity in Childhood

Correlation of anthropometric index and cardiopulmonary exercise testing in children with pectus excavatum

BACKGROUND

Cardiopulmonary exercise testing (CPET) is a method used to evaluate functional impairment of patients with various diseases.

OBJECTIVE

The objective was to use CPET to estimate the usability of anthropometric index (AI) in patients with pectus excavatum (PE) as a marker of functional impairment caused by chest deformity.

METHODS

The study included 32 paediatric patients (28 males) with PE. Patients underwent CPET using a breath-by-breath exhaled gas analysis method and continuous monitoring of cardiac parameters.

RESULTS

In both groups, two (overall four) patients met criteria for cardiogenic limitation (low VO₂ and low O₂Pulse). Mean VO₂/WR was below two standard deviations (2SD) in patients with less severe PE; other observed parameters were within normal limits (Z-score ± 2 SD). The AI had no observed correlation with peak ventilation, VO₂peak and peak workload.

CONCLUSION

The obtained CPET data do not correlate well with the severity of chest deformity expressed with AI. There were similar physical activity limitations in both examined groups of patients and they did not depend on the severity of the deformity.

Inspiratory muscle function in asthmatic and healthy subjects: influence of age, nutrition and physical activity

OBJECTIVE

To compare inspiratory muscle function (strength and endurance) between asthmatics and healthy controls, and the influence of age, nutritional status and physical activity on them.

METHODS

This is a cross-sectional study. Asthmatic and healthy subjects, aged 6 to 18 years old, recruited from two public schools in Southern Brazil were included in the study. Asthmatic subjects were selected using the criteria presented by the International Study on Asthma and Allergies in Children and control subjects based on the absence of respiratory symptoms. Anthropometric data was measured, body mass index calculated and subjects classified as normal weight, overweight or obese. Physical activity levels, maximum inspiratory pressure (MIP) and inspiratory muscle endurance (IME) were also evaluated.

RESULTS

A total of 314 participants were included, separated into control group (181) and asthmatics (133), with a total mean age of 11 years. When both groups were compared, there were no significant differences in both MIP and IME. However, when groups were analyzed subdivided in children and adolescents, IME was significantly reduced (p = 0.003) in asthmatic adolescents. Indeed, when groups were also stratified considering the nutritional status, IME showed a reduction in asthmatic adolescents with overweight (p = 0.042) and obesity (p = 0.041) when compared to healthy controls. No effects of physical activity levels between groups were found.

CONCLUSIONS

Results demonstrate a reduction in the IME in asthmatic adolescents with overweight and obesity, indicating an association between asthma, nutritional status and respiratory muscle function.

SURGICAL AND NON-SURGICAL THERAPY OF OBSTRUCTIVE SLEEP APNEA SYNDROME IN CHILDREN

Interventions of paediatric obstructive sleep apnea syndrome are complex, varied and multidisciplinary. The goal of the treatment is to restore optimal breathing during the night and to relieve associated symptoms. Evidence suggests that the surgical intervention with removal of the tonsils and adenoids will lead to significant improvements in the most incomplicated cases, as recently reported from a meta-analysis. However, post-operative persistence of this syndrome in paediatric population is more frequent than expected, which supports the idea of the complexity of this syndrome. Adenotomy alone may not be sufficient in children with OSAS, because it does not address oropharyngeal obstruction secondary to tonsillar hyperplasia. Continuous positive airway pressure can effectively treat this syndrome in selected groups of children, improving both nocturnal and daytime symptoms, but poor adherence is a limiting factor. For this reason, CPAP is not recommended as first-line therapy for OSAS when adenotonsillectomy is an option. It is now being investigated the incorporation of nonsurgical approaches for milder forms and for residual OSAS after surgical intervention. Althought adeno-tonsillar hypertrophy is the most common for OSAS in children; obesity is emerging as an equally important etiological factor. Therefore an intensive weight reduction program and adequate sleep hygiene are also important lifestyle changes that may be very effective in mitigating the symptoms of this syndrome. Pharmacological therapy (leukotriene antagonists, topical nasal steroids) is usually use for mild forms of OSAS and in children with associated allergic diseases. Special orthodontic treatment and oropharyngeal exercises are a relatively new and promising alternative therapeutic modality used in selected groups of children with OSAS.

Obesity and asthma: a coincidence or a causal relationship? A systematic review

BACKGROUND AND AIM

Epidemiological data has established increasing adiposity as a risk factor for incident asthma. However, the mechanisms underlying the association between obesity and asthma are incompletely understood. In the present paper, we review current knowledge of possible mechanisms mediating the observed association between obesity and asthma.

METHODS

Systematic literature review.

RESULTS

Obesity and asthma share some etiological factors, such as a common genetic predisposition and effects of in utero conditions, and may also have common predisposing factors such as physical activity and diet. Obesity results in important changes in the mechanical properties of the respiratory system which could explain the occurrence of asthma. However, there are also plausible biological mechanisms whereby obesity could be expected to either cause or worsen asthma. These include co-morbidities such as gastro-oesophageal reflux, complications from sleep-disordered breathing, breathing at low lung volumes, chronic systemic inflammation, and endocrine factors, including adipokines and reproductive hormones. Obesity related asthma is in general not associated with eosinophilic airway inflammation, and adipokines are likely to play important roles in the inflammatory pathogenesis of asthma in obese individuals.

CONCLUSION

The association between obesity and asthma is not straightforward, and further knowledge is clearly needed, as understanding the underlying mechanisms may lead to new therapeutic options for this high-risk part of the asthma population.