Primary prevention of asthma

Association of Obstructive Sleep Apnea with Asthma: A Meta-Analysis

This study evaluates the relationship between obstructive sleep apnea (OSA) and asthma. Literature search was carried out in several electronic databases and random effects meta-analyses were performed to obtain pooled estimates of the prevalence of OSA, OSA risk and sleep disordered breathing (SDB) in asthma patients and pooled odds ratios of the prevalence between asthma and non-asthma patients. In adult asthma patients, the prevalence [95% confidence interval] of OSA, OSA risk, and SDB was 49.50 [36.39, 62.60] %, 27.50 [19.31, 35.69] %, and 19.65 [14.84, 24.46] % respectively. The odds of having OSA, OS risk and SDB by the asthma patients were 2.64 [1.76, 3.52], 3.73 [2.90, 4.57] and 1.73 [1.11, 2.36] times higher (p < 0.00001 for all) in asthma than in non-asthma patients, respectively. Adult asthma patients with OSA had significantly higher BMI in comparison with asthma patients without OSA. This study reveals that the prevalence of OSA in asthma patients is considerably higher; even higher than OSA risk and SDB. Sleep studies should be performed in asthma patients with symptoms suggestive of OSA/OSA risk/SDB.

Sleep-disordered breathing and asthma: evidence from a large multicentric epidemiological study in China

Background

Previous studies have postulated that sleep-disordered breathing (SDB) may be associated with the occurrence and exacerbation of asthma. However, there was limited quantitative evidence on the topic. This study aimed at investigating the prevalence and predisposing factors of asthma, and quantifying the association between SDB and asthma among school-aged children in China. In addition, a comprehensive meta-analysis of the published evidences and our findings were further conducted.

Methods

To test the hypothesis, we conducted a multicentric cross-sectional study involving 22,478 children aged 5–12 years recruited from eight cities in China. Furthermore, a meta-analysis based on both previously published studies and our cross-sectional study was performed.

Results

The prevalence rate of SDB and asthma was 12.0% and 3.5% among our cross-sectional study sample. It was demonstrated that symptoms of SDB, such as habitual snoring (OR = 1.28, 95%CI: 1.01-1.62), and obstructive sleep apnea (OSA) (OR = 1.92, 95%CI: 1.34-2.76), were significantly associated with asthma, after adjusting for potential confounding factors. In the meta-analysis, SDB was correlated with the prevalence of asthma in both children (OR = 1.58, 95%CI: 1.35-1.80) and adults (OR = 1.55, 95%CI: 1.42-1.67).

Conclusions

Our results provide further evidence for the independent association between SDB and asthma. The clinical significance of our findings lies in the emphasis that children undergoing examination or treatment for asthma should be routinely screened for sleep problems. Further systematic study is required to illuminate the underlying mechanism.

Use of probiotics in pediatrics: rationale, mechanisms of action, and practical aspects

The use of probiotics (ingested microbes that can modify intestinal microbial populations in a way that benefit the host) has moved from concept to actual demonstration of specific benefits by specific microorganisms for specific populations. It is increasingly clear that these benefits to the host are mostly mediated by the profound effect that intestinal microflora (microbiota) have on gut barrier function and host immune response. Intestinal bacteria are more numerous than the human cells of the host that harbors them. Despite having many potential pathogens in this microflora, humans do not routinely get infected. It is no coincidence that gut-associated immune tissue constitutes approximately 80% of all immunologically active cells in the human host. The gut interacts with intestinal bacteria, both resident and ingested, to develop protective mechanisms (via improving gut barrier function and immune stimulation for defense) and appropriate, nonexaggerated responses (via immune modulation and immune tolerance) to support host health. The mechanisms of this interaction between host and bacteria are increasingly being unraveled and in great part explain the clinical benefits that have been reported with specific probiotic bacteria by enhancing host defense mechanisms (such as for treatment and prevention of viral diarrhea and reducing risk of necrotizing enterocolitis), mitigating antibiotic-associated diarrhea, and modulating host immune response (such as in allergic disease).

Ciclesonide: a novel inhaled corticosteroid

Inhaled corticosteroids (ICS) are a mainstay in the treatment of persistent asthma, a disease with increasing prevalence and cost implications worldwide. However, long-term use of currently available ICS is associated with local adverse effects that include hoarseness and oral candidiasis. In addition, systemic adverse effects including adrenal cortical suppression, osteoporosis, growth retardation, cataracts and glaucoma are also present. Ciclesonide is a novel ICS, which promises to provide airway anti-inflammatory efficacy that is comparable with that of the available ICS in addition to reducing the risk for local and systemic adverse events. Ciclesonide is an agent that is inactive until it reaches its target site, the lung, where it is converted to its active metabolite desisobutyryl-ciclesonide. In addition, other favourable pharmacokinetic and pharmacodynamic characteristics such as high protein binding, low oral bioavailability and rapid clearance contribute to the efficacy and improved systemic safety profile of ciclesonide.

Milk consumption does not lead to mucus production or occurrence of asthma

There is a belief among some members of the public that the consumption of milk and dairy products increases the production of mucus in the respiratory system. Therefore, some who believe in this effect renounce drinking milk. According to Australian studies, subjects perceived some parameters of mucus production to change after consumption of milk and soy-based beverages, but these effects were not specific to cows' milk because the soy-based milk drink with similar sensory characteristics produced the same changes. In individuals inoculated with the common cold virus, milk intake was not associated with increased nasal secretions, symptoms of cough, nose symptoms or congestion. Nevertheless, individuals who believe in the mucus and milk theory report more respiratory symptoms after drinking milk. In some types of alternative medicine, people with bronchial asthma, a chronic inflammatory disease of the lower respiratory tract, are advised not to eat so-called mucus-forming foods, especially all kinds of dairy products. According to different investigations the consumption of milk does not seem to exacerbate the symptoms of asthma and a relationship between milk consumption and the occurrence of asthma cannot be established. However, there are a few cases documented in which people with a cow's milk allergy presented with asthma-like symptoms.

Association of asthma-related symptoms with snoring and apnea and effect on health-related quality of life

OBJECTIVES

This study aimed to investigate the association of asthma-related symptoms with snoring and apnea, and to assess their effects on health-related quality of life (HRQL).

DESIGN

Population-based cross-sectional study.

SUBJECTS AND METHODS

A total of 10,224 parents and grandparents of students from 14 randomly selected primary schools in city center were asked to answer questionnaires sent by their children. All subjects were questioned for asthma-related symptoms, sleep-related disorders (snoring and apnea), and for HRQL using the Respiratory Questionnaire, Sleep and Health Questionnaire, and Short Form-12 (SF-12) Health Survey, respectively.

RESULTS

The overall response rate to questionnaires was 97.7%, and all analysis was performed on 7,469 subjects (3,920 women and 3,549 men) who provided sufficient responses to questions. There were 2,713 subjects who reported asthma-related symptoms. The snoring and the observed apnea were more prevalent in subjects with asthma-related symptoms (54.0% vs 41.4%; odds ratio [OR], 1.7; 95% confidence interval [CI], 1.5 to 1.8; p < 0.001) than those without asthma-related symptoms (16.7% vs 7.0%; OR, 2.7; 95% CI, 2.3 to 3.1; p < 0.001), respectively. Asthma-related symptoms were found to be associated with snoring (OR, 1.5; 95% CI, 1.3 to 1.6; p < 0.001) and observed apnea (OR, 2.2; 95% CI, 1.8 to 2.5; p < 0.001) after adjusting for gender, age, body mass index, income, education, and smoking. Also, HRQL was found to be adversely affected by asthma-related symptoms, snoring, and observed apnea (beta = - 0.26, p < 0.001; beta = - 0.07, p < 0.001; and beta = - 0.08, p < 0.001, respectively, for SF-12 overall score) after adjusting for other confounding factors.

CONCLUSION

Present data suggest that there is a link between the sleep-related breathing disorders and asthma-related symptoms. Moreover, the presence of snoring and observed apnea in individuals with asthma-related symptoms causes further impairment in HRQL. The effects on HRQL of coexistence of these three disorders should be supported by clinical studies.

Allergen avoidance as primary prevention: con

There has been a dramatic increase in the prevalence of atopic diseases, such as atopic dermatitis, food allergy, allergic rhinitis, and allergic asthma. Because environmental factors such as early allergen exposure to nutritional and inhalant allergens have been suspected as potential environmental factors favoring the development of allergic diseases and asthma, primary prevention studies have begun to investigate the effect on sensitization and wheezing. Designs of the studies are different and, therefore, are not completely comparable. Although no clear primary prevention study is available for pets, mite allergen avoidance during infancy can achieve a reduction of specific sensitization and, in some studies, can also produce a slight effect on respiratory symptoms.

[Wheezing in infants and toddlers: new insights]

Wheezing in infants and toddlers is a common symptom, and these patients are difficult to approach--both diagnostically and therapeutically. Congenital conditions causing wheezing disorders should not be missed and--not all wheezy bronchitis is or will become asthma. Results from longitudinal studies indicate that the term "asthma" includes different phenotypes: so-called transient early wheezing, non atopic wheezing and atopic wheezing (asthma). Transient early wheezing is generally accepted to define recurrent wheezing in non-atopic babies or toddlers and tends to disappear by the age of 3. The primary risk factor is reduced pulmonary function since birth. The most common cause for non-atopic wheezing is viral infection, most frequently caused by respiratory syncytial virus. Infection with respiratory syncytial virus is a risk factor for ongoing wheeze during childhood but resolves in most children by the age of 13. Asthma can start at any age and is determined by a more chronic condition, provoked by a number of triggers in addition to viruses, frequently associated with a family history of atopy, early allergic sensitization and concomitant atopic dermatitis. Only asthma seems to be a progressive disease; and there is evidence from long-term studies that if anti-inflammatory interventions are started late, it might be too late to alter the natural course of the disease with its decline in pulmonary function. On the other hand, there is no evidence that small children with non-atopic wheezy bronchitis would benefit from long-term therapy with anti-inflammatory treatment; in this group a therapeutic trial with bronchodilators is sufficient. The diagnostic and therapeutic challenges of diagnosing asthma in this age group are considerable and require a comprehensive approach.

Strategies for preventing wheezing and asthma in small children

OBJECTIVE

To assess the effects of living in agreement with allergy preventive guidelines on wheezing and asthma at 2 years of age.

DESIGN

Prospective birth cohort study (BAMSE). Questionnaires on heredity and environmental factors were answered when the child was 2 months, and detailed questionnaires on symptoms at 1 and 2 years of age.

PARTICIPANTS

4089 children, born during 1994-1996.

SETTING

Child Health Centres in central and north-western parts of Stockholm, Sweden.

MAIN OUTCOME MEASURES

Wheezing and asthma up to the age of 2.

RESULTS

The effects of preventive guidelines regarding breastfeeding, maternal tobacco smoke and home dampness on wheezing and asthma were assessed in multiple logistic regression models. The cumulative incidence of recurrent wheezing at 2 years of age was 12.6% and of asthma 6.8% among those with a lifestyle in agreement with all guidelines and 24.1 and 17.9%, respectively, in families exposed to at least two of the three risk factors. Among children with no heredity, family lifestyle according to the guidelines gave a twofold reduction of asthma (5.3 vs. 10.5%), while the group with heredity had a threefold reduction (9.1 vs. 27.3%). The attributable fraction for asthma associated with the guidelines was 23% in total and 33% among those with heredity.

CONCLUSION

In this observational study, family lifestyle according to preventive guidelines is associated with an important reduction of recurrent wheezing and asthma at 2 years of age, especially among children with allergic heredity. A follow-up will determine whether there still a risk reduction of both symptoms and disease.

Geographical variations of asthma and asthma symptoms among schoolchildren aged 5 to 8 years and 12 to 15 years in Palestine: the International Study of Asthma and Allergies in Childhood (ISAAC)

BACKGROUND

Many studies demonstrated the existence of geographic differences, within and between countries, in the prevalence of asthma, rhinitis, and eczema. However, in Palestine, there are no comprehensive Palestinian data to compare with those from other regional and international centers.

OBJECTIVE

To describe the prevalence of asthma and asthma symptoms in schoolchildren in two districts (Ramallah and North Gaza) in Palestine.

METHODS

After a two-stage stratified systematic sampling, approximately 14,500 schoolchildren, from the first and second grades of elementary school (ages 5 to 8 years) and eighth and ninth school grades (ages 12 to 15 years), were invited to participate in a survey using International Study of Asthma and Allergies in Childhood phase III questionnaires and protocols.

RESULTS

In general, younger children were reported to have a higher 12-month wheezing prevalence rate than older children (9.6 and 7.2%, respectively), and more physician-diagnosed asthma (8.4 and 5.9%, respectively). However, nocturnal cough and exercise-related wheezing were higher in the older age group compared with younger children. Younger children living in North Gaza district showed slightly higher prevalence rates for asthma and asthma symptoms, but older children had higher rates in Ramallah district. After adjustment using logistic regression analysis, male sex, living in inland areas, and younger age were shown to predict 12-month wheezing and physician-diagnosed asthma.

CONCLUSIONS

Palestinian children have asthma symptoms rates that are similar to several countries in the Mediterranean region such as Spain and Turkey, but still lower than other Middle East countries such as Saudi Arabia and Israel.

Preventive measures and their effects. Results from cohort studies

The prevalence of asthma and atopic diseases continues to rise. Genetic factors alone cannot explain this rapid rise and the immunological mechanisms involved are insufficiently explained to allow direct intervention on a population-wide scale. Long-term observational birth cohort studies have provided data on which primary prevention studies are based. This review discusses the "who", "how", "when" and "what" of primary prevention and the experiences to date in prospective intervention cohort studies.