Relationship of asthma and rhinoconjunctivitis with obesity, exercise and Mediterranean diet in Spanish schoolchildren

Obesity and Airway Dysanapsis in Children with and without Asthma

RATIONALE

For unclear reasons, obese children with asthma have higher morbidity and reduced response to inhaled corticosteroids.

OBJECTIVES

To assess whether childhood obesity is associated with airway dysanapsis (an incongruence between the growth of the lungs and the airways) and whether dysanapsis is associated with asthma morbidity.

METHODS

We examined the relationship between obesity and dysanapsis in six cohorts of children with and without asthma, as well as the relationship between dysanapsis and clinical outcomes in children with asthma. Adjusted odds ratios (ORs) were calculated for each cohort and in a combined analysis of all cohorts; longitudinal analyses were also performed for cohorts with available data. Hazard ratios (HRs) for clinical outcomes were calculated for children with asthma in the Childhood Asthma Management Program.

MEASUREMENTS AND MAIN RESULTS

Being overweight or obese was associated with dysanapsis in both the cross-sectional (OR, 1.95; 95% confidence interval [CI], 1.62-2.35 [for overweight/obese compared with normal weight children]) and the longitudinal (OR, 4.31; 95% CI, 2.99-6.22 [for children who were overweight/obese at all visits compared with normal weight children]) analyses. Dysanapsis was associated with greater lung volumes (FVC, vital capacity, and total lung capacity) and lesser flows (FEV1 and forced expiratory flow, midexpiratory phase), and with indicators of ventilation inhomogeneity and anisotropic lung and airway growth. Among overweight/obese children with asthma, dysanapsis was associated with severe disease exacerbations (HR, 1.95; 95% CI, 1.38-2.75) and use of systemic steroids (HR, 3.22; 95% CI, 2.02-5.14).

CONCLUSIONS

Obesity is associated with airway dysanapsis in children. Dysanapsis is associated with increased morbidity among obese children with asthma and may partly explain their reduced response to inhaled corticosteroids.

What Are the Effects of a Mediterranean Diet on Allergies and Asthma in Children?

This review updates the relationship between the adherence to Mediterranean diet (MedDiet) assessed by questionnaire and asthma, allergic rhinitis, or atopic eczema in childhood. It deals with the effect of MedDiet in children on asthma/wheeze, allergic rhinitis, and atopic dermatitis/eczema, and also with the effect of MedDiet consumption by the mother during pregnancy on the inception of asthma/wheeze and allergic diseases in the offspring. Adherence to MedDiet by children themselves seems to have a protective effect on asthma/wheezing symptoms after adjustment for confounders, although the effect is doubtful on lung function and bronchial hyperresponsiveness. By contrast, the vast majority of the studies showed no significant effect of MedDiet on preventing atopic eczema, rhinitis, or atopy. Finally, studies on adherence to MedDiet by the mother during pregnancy showed some protective effect on asthma/wheeze symptoms in the offspring only during the first year of life, but not afterward. Very few studies have shown a protective effect on wheezing, current sneeze, and atopy, and none on eczema. Randomized control trials on the effect of the adherence to MedDiet to prevent (by maternal consumption during pregnancy) or improve (by child consumption) the clinical control of asthma/wheezing, allergic rhinitis, or atopic dermatitis are needed.

Factors associated to recurrent wheezing in infants under one year of age in the province of Salamanca, Spain: Is intervention possible? A predictive model

OBJECTIVES

Wheezing is a very common problem in infants in the first months of life. The objective of this study is to identify risk factors that may be acted upon in order to modify the evolution of recurrent wheezing in the first months of life, and to develop a model based on certain factors associated to recurrent wheezing in nursing infants capable of predicting the probability of developing recurrent wheezing in the first year of life.

METHODS

The sample was drawn from a cross-sectional, multicentre, descriptive epidemiological study based on the general population. A total of 1164 children were studied, corresponding to a questionnaire response rate of 71%. The questionnaire of the Estudio Internacional de Sibilancias en Lactantes (EISL) was used. Multiple logistic regression analysis was used to estimate the probability of developing recurrent wheezing and to quantify the contribution of each individual variable in the presence of the rest.

RESULTS

Infants presenting eczema and attending nursery school, with a mother who has asthma, smoked during the third trimester of pregnancy, and did not consume a Mediterranean diet during pregnancy were found to have a probability of 79.7% of developing recurrent wheezing in the first year of life. In contrast, infants with none of these factors were seen to have a probability of only 4.1% of developing recurrent wheezing in the first year of life. These results in turn varied according to modifications in the risk or protective factors.

CONCLUSIONS

The mathematical model estimated the probability of developing recurrent wheezing in infants under one year of age in the province of Salamanca (Spain), according to the risk or protective factors associated to recurrent wheezing to which the infants are or have been exposed.

Effect of foods and Mediterranean diet during pregnancy and first years of life on wheezing, rhinitis and dermatitis in preschoolers

BACKGROUND

There is a conflictive position if some foods and Mediterranean diet (MedDiet) consumed by the mother during pregnancy and by the child during the first years of life can be protective for current wheezing, rhinitis and dermatitis at preschool age.

METHODS

Questionnaires of epidemiological factors and food intake by the mother during pregnancy and later by the child were filled in by parents in two surveys at two different time points (1.5 yrs and 4 yrs of life) in 1000 preschoolers.

RESULTS

The prevalences of current wheezing, rhinitis and dermatitis were 18.8%, 10.4%, and 17.2%, respectively. After multiple logistic analysis children who were low fruit consumers (never/occasionally) and high fast-food consumers (≥3 times/week) had a higher risk for current wheezing; while intermediate consumption of meat (1 or 2 times/week) and low of pasta by mothers in pregnancy were protected. For current rhinitis, low fruit consumer children were at higher risk; while those consuming meat <3 times/week were protected. For current dermatitis, high fast food consumption by mothers in pregnancy; and low or high consumption of fruit, and high of potatoes in children were associated to higher prevalence. Children consuming fast food >1 times/week were protected for dermatitis. MedDiet adherence by mother and child did not remain a protective factor for any outcome.

CONCLUSION

Low consumption of fruits and high of meat by the child, and high consumption of potatoes and pasta by the mother had a negative effect on wheezing, rhinitis or dermatitis; while fast food consumption was inconsistent.

Can geodata be used to determine the distribution of fast food outlets in relation to the prevalence and severity of asthma? A novel methodology

RESEARCH QUESTION

Can the distribution of fast food outlets be obtained and effectively used to identify if there is a relationship between the placement of these and the prevalence and severity of asthma, rhinoconjunctivitis and eczema (ARE) in children and adolescents?

METHOD

Fast food restaurant location data was obtained for seven countries. Data from the International Study of Asthma and Allergies in Childhood (ISAAC) was used from 53 centres in the same seven countries. Each ISAAC centre provided a detailed map of the study area. The location of restaurants and ISAAC centres were overlaid using the ArcMap software, and the number of restaurants within each ISAAC centre counted. Bivariate regression analysis was used to compare outlet density with ARE prevalence and severity.

RESULTS

The results from the analyses showed a positive (non-significant) trend on a regression plot between outlet density and ARE severity. This project has shown that it is practical to systematically obtain and map fast food outlets and compare their distribution worldwide with the prevalence and severity of diseases, in this case ARE. The devised methodology has proven to be an efficient way to obtain restaurant distribution data in a form that is manageable and suitable to compare with area based disease prevalences. This project has shown that a larger scale investigation is both feasible and warranted.

A systematic review of the relationship between asthma, overweight, and the effects of physical activity in youth

PURPOSE

The association of asthma and overweight in youth is well studied. However, the temporal relationship between asthma and overweight, the strength of their association, and mediating factors involved in this relationship remain unclear. This review investigates the relationship between asthma and overweight in youth, while examining the role of physical activity as a mediator.

METHODS

A systematic review of literature was conducted using PubMed and Medline databases. Studies conducted among youth aged 0-18 years, published in English between 2000-2014 were included. The Strengthening the Reporting of Observational Studies in Epidemiology guidelines were consulted to evaluate quality of selected citations.

RESULTS

A comprehensive search yielded 143 studies in PubMed and 133 studies in Medline databases. Of these, 75 studies met the eligibility criteria. The review found varying hypotheses regarding the temporal relationship between asthma and overweight in youth; existing evidence supports the mediation of this association by decreased expenditure of energy due to reduced physical activity. Negative self-perception or parental perception of exercise ability due to asthma symptoms secondary to physical exertion was identified as a determinant of physical activity in asthmatic youth.

CONCLUSIONS

Physical activity likely mediates the relationship between asthma and overweight in youth. Temporality of this relationship remains unclear.

Pediatric Obesity-Related Asthma: The Role of Metabolic Dysregulation

The burden of obesity-related asthma among children, particularly among ethnic minorities, necessitates an improved understanding of the underlying disease mechanisms. Although obesity is an independent risk factor for asthma, not all obese children develop asthma. Several recent studies have elucidated mechanisms, including the role of diet, sedentary lifestyle, mechanical fat load, and adiposity-mediated inflammation that may underlie the obese asthma pathophysiology. Here, we review these recent studies and emerging scientific evidence that suggest metabolic dysregulation may play a role in pediatric obesity-related asthma. We also review the genetic and epigenetic factors that may underlie susceptibility to metabolic dysregulation and associated pulmonary morbidity among children. Lastly, we identify knowledge gaps that need further exploration to better define pathways that will allow development of primary preventive strategies for obesity-related asthma in children.

Exhaled nitric oxide in school children: Searching for the lost variability

OBJECTIVE

The factors - including asthma and rhinoconjunctivitis - which influence FeNO values in a general population of school children have been studied in order to know to what extent the variability of those values can be explained.

METHODS

FeNO was measured in a population of 240 school children aged 6-12 years by means of a Niox-Mino™ device in a standardised way. Parents filled in an ISAAC-validated questionnaire of symptoms and environmental factors. Diagnoses were checked against clinical records. Height and weight were measured. A multivariate regression analysis including all variables in the questionnaire was performed, which was followed by two Xi stepwise tests in order to build a predictive model which included the main variables influencing FeNO values.

RESULTS

Among the 240 children, 10 suffered from asthma, 16 from rhinoconjunctivitis and 15 from both conditions. FeNO values (GM±GSD) in children with rhinoconjunctivitis (19.61±1.20ppb), with asthma (18.62±1.32ppb), and with both conditions (17.62±1.19ppb) tended to be significantly higher than control children (11.42±1.04ppb), p=0.0016, p=0.08 and p=0.01, respectively. The different predictive models were able to explain only 20-27% of FeNO variability.

CONCLUSIONS

The proportion of FeNO inter-individual variability which can be explained by individual (including suffering from asthma or rhinoconjunctivitis), family, and environmental factors is very low (20-27%). This could have implications on the usefulness of FeNO as a diagnostic tool in asthma.

Association between dietary habits and asthma severity in children

OBJECTIVE

To investigate association between dietary habits and asthma severity in children.

DESIGN

Cross-sectional study.

SETTING

Two teaching hospitals in Brazil.

PARTICIPANTS

Cases (n=268) were children (3-12yr) with persistent asthma and age-matched controls (n=126) were those with intermittent asthma.

MAIN OUTCOME MEASURES

Dietary habits were determined based on food consumption in the past 12 months classified as frequent (≥3 times per week) or infrequent (never or <3 times per week).Nutritional status was classified into two categories according to WHO Child Growth Standards: obese: >2Z-score of BMI-for-age; non-obese: ≤2Z-score of BMI-for-age.

RESULTS

After adjusting for confounding factors, maternal smoking during pregnancy, preterm birth and obesity were significantly associated with persistent asthma, with adjusted ORs (95% CI) of 2.11 (1.08- 4.13), 2.61(1.07-6.35) and 2.89 (1.49-5.61), respectively. No significant association was observed between frequency of consumption of specific foods, food groups, or dietary pattern (pro- or contra-Mediterranean diet) and the severity of asthma.

CONCLUSIONS

This study did not find a significant association between dietary habits and asthma severity in children. Maternal smoking during pregnancy, preterm birth and obesity were independent factors associated with persistent asthma.

Children's Inter-Individual Variability and Asthma Development

Children of different ages vary in their response to environmental stressors due to their continuous development and changes in their bodies' anatomy, physiology, and biochemistry. Each age group of children has special biological features that distinguish their toxicokinetic and toxicodynamic characteristics from other age groups. The variability in responses extends to include children of the same age group. These intra- and inter-group differences in biological features explains the variability in responses to environmental exposures. Based on such differences in children's responses to exposures, adverse health outcomes and diseases develop differently in children. One of these diseases that are common in children is asthma. Asthma is a complex respiratory chronic disease that is multifactorial in origin. This paper discusses how variability in certain factors among children contributes to asthma occurrence or exacerbation, and links these factors to asthma in children of different ages. The importance of this review is to provide an insight on factors affecting asthma prevalence among children. These factors are usually overlooked in clinical or public health practice, which might significantly affect asthma management, and decrease the predictability of asthma detection measures. Therefore, keeping these factors into consideration can significantly improve asthma treatment and assist in asthma prevention amongst susceptible populations.

Association Between Adherence to the Mediterranean Diet and Asthma in Peruvian Children

PURPOSE

Adherence to a Mediterranean diet pattern may be associated with lower asthma prevalence in children. We sought to corroborate these findings in Peruvian children.

METHODS

This case-control study included children of ages 9-19 years living in Lima, Peru. A food frequency questionnaire (FFQ) was completed and diet pattern was analyzed using a modified Mediterranean diet score (MDS). Primary analysis investigated the relationship between MDS and asthma status. Maternal education, age, sex, and body mass index category were included in multivariate model. Secondary outcomes included asthma control, forced expiratory volume in 1 s (FEV1), allergic rhinitis, and atopic status.

RESULTS

287 participants with asthma and 96 controls without asthma completed a FFQ. Mean age was 13.5 years. According to the asthma control test (ACT), 86 % of those with asthma were controlled (score >19). MDS scores ranged 6-18 (median 15). In adjusted analysis, being above the median MDS scores was associated with decreased odds of asthma [OR = 0.55, 95 % CI (0.33, 0.92), p = 0.02]. Among children whose mothers completed secondary education, being above the median MDS significantly decreased the odds of asthma [OR = 0.31, 95 % CI (0.14, 0.71), p < 0.01], whereas among those whose mothers did not complete secondary education there was no protective effect [OR = 0.86, 95 % CI (0.43, 1.7), p = 0.66]. There was no association between MDS scores and asthma control, FEV1, allergic rhinitis, or atopic status.

CONCLUSION

Adherence to the Mediterranean diet was inversely associated with having asthma among children in Lima, Peru. This effect was strongest among children with better educated mothers.

Fast food consumption in pregnancy and subsequent asthma symptoms in young children

BACKGROUND

Recent cross-sectional studies suggested children's current fast food consumption to be related to frequency of asthma and allergies. Maternal prenatal diet has been suspected to contribute to children's asthma and atopic disease risks.

OBJECTIVES

We hypothesized that maternal fast food intake during pregnancy increases offspring's risk for asthmatic symptoms.

METHODS

We conducted a population-based study of 1201 mother/child pairs in Los Angeles, California. Detailed information about prenatal fast food intake and other dietary, lifestyle/environmental factors, and pregnancy was collected shortly after birth; further data were retrieved from birth certificates. Using the International Study of Asthma and Allergies in Childhood core questions, asthma and rhinitis symptoms were assessed, and doctor's diagnoses were recorded in offspring 3.5 years after birth. Poisson regression with robust error variance using a log link function was used to estimate relative risks (RRs). Models were adjusted using covariates or propensity scores.

RESULTS

Maternal prenatal fast food consumption related to increased relative risks of their children for severe, and current asthma symptoms (wheeze last 12 months combined with doctor's diagnosis) in a dose-dependent manner: 'once a month': RR: 0.99 (95% CI: 0.36, 2.75), 'once a week': 1.26 (0.47, 3.34); '3-4 days a week': 2.17 (0.77, 6.12); and 'every day' 4.46 (1.36 14.6) compared to 'never', adjusting for potential confounders (p for trend = 0.0025). There was also suggestion of increased risks for rhinitis symptoms.

CONCLUSIONS

These findings suggest that in utero exposure to frequent fast food through maternal diet may be a risk factor for asthmatic symptoms in young children.

Antioxidant foods consumption and childhood asthma and other allergic diseases: The Greek cohorts of the ISAAC II survey

BACKGROUND

Antioxidant intake changes have been implicated with the increase in asthma and allergies outcomes, but no clear association has been revealed. In this cross sectional study, the overall effect of antioxidants on asthma and allergic diseases was studied.

METHODS

Data from the cohorts of the phase II ISAAC survey (2023 children 9-10 years old) in two metropolitan Greek cities were analysed. Using a semi-quantitative food frequency questionnaire, an Antioxidant Eating Index (AEI, range 0-6) was created with the pro-antioxidant (vegetables, fruits, fresh juice, fish) and the non-antioxidant (meat, burgers) food intake and was evaluated with allergic diseases. Higher values of the score suggest closer to an "antioxidant" and lesser to a "saturated fatty" diet.

RESULTS

Prevalence of lifetime and current asthma, current rhinitis and sensitisation were higher in Thessaloniki compared to Athens. The AEI score of the entire cohort was 4.2 ± 1.2 (median 4.0) and was higher in Athens compared to Thessaloniki (4.3 ± 1.2 vs. 4.0 ± 1.2, p=0.001) and in girls than boys (4.3 ± 1.1 vs. 4.0 ± 1.2, p=0.001). AEI was inversely associated with lifetime asthma (OR: 0.87, 95%CI 0.77, 0.99) in either cities independently of other cofounders such as family history, sensitisation, exercise, house smoking, breast feeding, pet or dampness in houses. No association with other allergic disease or sensitisation was detected.

CONCLUSION

Antioxidant foods seem to be a non-pharmacological, protective dietary pattern for asthma development in children irrespectively of atopy or heredity; AEI was a rough indicator and the role of antioxidants in allergic diseases is still under consideration.

Adherence to a Mediterranean-like dietary pattern in children from eight European countries. The IDEFICS study

BACKGROUND

Despite documented benefits of a Mediterranean-like dietary pattern, there is a lack of knowledge about how children from different European countries compare with each other in relation to the adherence to this pattern. In response to this need, we calculated the Mediterranean diet score (MDS) in 2-9-year-old children from the Identification and prevention of dietary- and lifestyle-induced health effects in children and infants (IDEFICS) eight-country study.

SUBJECTS AND METHODS

Using 24 h dietary recall data obtained during the IDEFICS study (n=7940), an MDS score was calculated based on the age- and sex-specific population median intakes of six food groups (vegetables and legumes, fruit and nuts, cereal grains and potatoes, meat products and dairy products) and the ratio of unsaturated to saturated fats. For fish and seafood, which was consumed by 10% of the population, one point was given to consumers. The percentages of children with high MDS levels (>3) were calculated and stratified by sex, age and by having at least one migrant parent or both native parents. Demographic (sex and age) and socioeconomic characteristics (parental education and income) of children showing high (>3) vs low (⩽3) MDS levels were examined.

RESULTS

The highest prevalence of children with MDS>3 was found among the Italian pre-school boys (55.9%) and the lowest among the Spanish school-aged girls (26.0%). Higher adherence to a Mediterranean-like dietary pattern was not associated with living in a Mediterranean country or in a highly educated or high-income family, although with some exceptions. Differences in adherence between boys and girls or age groups varied between countries without any general pattern.

CONCLUSIONS

With the exception of Italian pre-schoolers, similar adherence levels to a Mediterranean-like dietary pattern have been observed among European children.

Urban-rural differences in asthma prevalence among young adolescents: The role of behavioural and environmental factors

BACKGROUND

Asthma prevalence has been reported to be lower in rural areas compared to urban areas, although this has been inconsistent. This study aims to identify the influence of urban-rural residence on asthma prevalence in adolescents in the Republic of Macedonia and to investigate characteristics that may explain observed associations.

METHODS

Following International Study of Asthma and Allergies in Childhood protocol, a national sample of Macedonian urban and rural dwelling adolescents (12-16 years) was recruited in 2006. Self-completed questionnaires were used to collect data on wheeze and asthma as well as personal, environmental and dietary characteristics. Following descriptive and multiple logistic regression analyses, a mediation analysis approach was performed to help explain observed associations.

RESULTS

A lower prevalence of current wheeze and ever-diagnosed asthma was observed in rural compared to urban dwelling adolescents (4.9% vs. 7.2% and 1.2% vs. 1.9%, respectively). After adjustment for potential confounders, the associations, although still protective, were not statistically significant (wheeze: OR=0.74, 95%CI=0.46-1.21; asthma: OR=0.97, 95%CI=0.38-2.46). The associations between urban-rural status with current wheeze and asthma were mediated by region of the country (wheeze 9%; asthma 19%) and by diet (>5% change for both wheeze and asthma). Having a dog resulted in a strengthening of the association between urban-rural status and current wheeze by 11.9%.

CONCLUSIONS

The prevalence of asthma and wheeze was lower in rural dwelling Macedonian adolescents and the association was mediated by the region of the country with diet likely to be part of the reason for this mediating effect.

Dietary habits and prevalence of allergic rhinitis in 6 to 7-year-old schoolchildren in Turkey

BACKGROUND

The prevalence of allergic rhinitis and other allergies has risen worldwide. Dietary habits are considered to be among the potential risk factors. The aim of this study was to evaluate the prevalence of allergic rhinitis and its relationship with dietary habits and other risk factors among 6 to 7-year-old Turkish schoolchildren.

METHODS

In this cross-sectional study, a total of 11483 children aged 6-7 years were surveyed. The prevalence of symptoms of allergic rhinitis was assessed using the ISAAC protocol. Dietary information was collected using a food frequency questionnaire.

RESULTS

Of them, 9875 (50.7% M 49.3% F) questionnaires were appropriately completed. The prevalence rates of lifetime rhinitis, current rhinitis, current rhinoconjunctivitis and physician-diagnosed allergic rhinitis, were 44.3%, 29.2%, 8.5% and 8.1%, respectively. Consumption of rice, and cereals ≥3 times per week showed protective effect on physician-diagnosed allergic rhinitis (aOR = 0.53, 95% CI = 0.32-0.87 and aOR = 0.58, 95% CI = 0.36-0.92). Eating pasta, and chocolates ≥3 times per week showed protective effect on current rhinoconjunctivitis (aOR = 0.45, 95% CI = 0.25-0.79 and aOR = 0.50, 95% CI = 0.29-0.86). Eating lollipops, candies and animal fats ≥3 times per week was positively associated with current rhinoconjunctivitis (aOR = 1.47, 95% CI = 1.00-2.17 and aOR = 2.25, 95% CI = 1.11-4.56). Protective effect of the Mediterranean diet was not significant.

CONCLUSIONS

Frequent consumption of cereals, rice, pasta and chocolates may have beneficial effect on symptoms of rhinoconjunctivitis. Although dietary habits may affect the prevalence of symptoms of current rhinoconjunctivitis, the Mediterranean diet alone may not be protective against rhinoconjunctivitis.

Risk factors affecting asthma prevalence in adolescents living in Istanbul, Turkey

BACKGROUND

Asthma is one of the most important diseases of childhood. The aim of this study was to evaluate the prevalence of asthma symptoms and risk factors affecting asthma.

METHODS

In a cross-sectional study design, 9991 children, aged 13-14 years in 61 primary schools in 32 districts of Istanbul were evaluated. Asthma prevalence among the children was assessed using the ISAAC protocol.

RESULTS

In our study, a total of 10,894 questionnaires were distributed to 13-14 years old children, and of these 9991 questionnaires were suitable for analysis with an overall response rate of 91.7%. The rates of wheeze ever, wheezing in last 12 months and lifetime doctor diagnosed asthma prevalence were 17.4%, 9.0%, and 11.8%, respectively. There were 4746 boys (47.9%) and 5166 girls (52.1%) with M/F ratio of 0.92. Atopic family history, fewer than three siblings living at home, tonsillectomy or adenoidectomy history, consumption of fermented foods, mixed pickles, margarine and meat were found to be associated with an increased asthma risk. Use of paracetamol in the last 12 months, consumption of fruit and animal fats acted as a protective factor against asthma. The Mediterranean-style diet was not associated with the prevalence of asthma.

CONCLUSIONS

Lifetime doctor diagnosed asthma prevalence was found to be 11.8% in 13-14 year olds. History of tonsillectomy and/or adenoidectomy and consumption of fermented foods, mixed pickles, margarine and meat may increase the symptoms of asthma. Usage of paracetamol and consumption of animal fats may be investigated as a protective factor against asthma.

Body mass index change and atopic diseases are not always associated in children and adolescents

BACKGROUND

Several studies have suggested an association between the increasing prevalence of allergic diseases and dietary factors.

OBJECTIVE

To prospectively explore the association between changes in body mass index (BMI) and symptoms of asthma, rhinitis, rhinoconjunctivitis, and atopic dermatitis to find out whether an increase in BMI increases the risk of developing atopic diseases in adolescence.

METHODS

Comprehensive questionnaires and anthropometric measurements were applied in a random subsample of the International Study of Asthma and Allergies in Childhood phase II (1995-1996, 9 to 11 years of age) in Germany. Of these participants, 1,794 could be followed up in 2002 to 2003 in the Study on Occupational Allergy Risks (16 to 18 years of age). The associations between changes of BMI from baseline to follow-up and incident and persistent respiratory diseases and atopic dermatitis were assessed.

RESULTS

In logistic regression analyses, weight change in either direction was not statistically significantly associated with the incidence or persistence of any of the diseases of interest except for rhinitis. An increase in BMI was linked to an increased risk of incident rhinitis (odds ratio 1.9, 95% confidence interval 1.2-2.9).

CONCLUSION

These results indicate a nonsignificant trend between increased body weight and risk of atopic diseases. Aside from limitations owing to a small subgroup of obese participants and questionnaire-based asthma diagnosis, reasons might be related to an interaction between BMI and hormonal influences, age, and duration and severity of overweight. The results underline that BMI does not necessarily play a decisive role in the course of atopic diseases in all populations.

Dietary pattern and asthma: a systematic review and meta-analysis

Background

The literature on the relationship between diet and asthma has largely focused on individual nutrients, with conflicting results. People consume a combination of foods from various groups that form a dietary pattern. Studying the role of dietary patterns in asthma is an emerging area of research. The purpose of this study was to systematically review dietary patterns and asthma outcomes in adults and children, to review maternal diet and child asthma, and to conduct a meta-analysis on the association between asthma prevalence and dietary patterns in adults.

Methods

We searched Medline, Scopus, and ISI Web of Knowledge up to January 2014. Two researchers independently reviewed studies meeting the inclusion criteria using the American Dietetic Association quality criteria. A linear mixed model was used to derive the pooled effect size (95% confidence interval) for each of three dietary pattern categories (healthy, unhealthy, and neutral).

Results

Thirty-one studies were identified (16 cross-sectional, one case-control, 13 cohort, and one randomized controlled trial), including 12 in adults, 13 in children, five in pregnant woman–child pairs, and one in both children and pregnant woman–child pairs. Six of the 12 adult studies reported significant associations between dietary patterns and asthma outcomes (eg, ever asthma and forced expiratory volume in one second). Seven of ten studies examining the Mediterranean diet showed protective effects on child asthma and/or wheeze. Four of the six studies in mother-child pairs showed that maternal dietary patterns during pregnancy were not associated with child asthma or wheeze. The meta-analysis including six adult studies, the primary outcome of which was the prevalence of current or ever asthma, showed no association with healthy, unhealthy, or neutral dietary patterns.

Conclusion

The evidence suggests no association of dietary patterns with asthma prevalence in adults or of maternal diet with child asthma or wheeze. The Mediterranean diet in children may prevent asthma or wheeze, but randomized controlled trials are lacking.

Fruit and vegetable intake and risk of wheezing and asthma: a systematic review and meta-analysis

Major bibliographic databases were searched for studies examining the relationship between fruit and vegetable consumption and the risk of wheezing and asthma. Random-effects models were used to pool study results. Subgroup analyses were conducted by fruit and vegetable categories, study design, and age group. Twelve cohorts, 4 population-based case-control studies, and 26 cross-sectional studies published between January 1990 and July 2013 were identified. For the meta-analysis of adults and children, the relative risk (RR) and confidence intervals (CI) when comparing the highest intake group with the lowest intake group were 0.78 (95%CI, 0.70-0.87) for fruit and 0.86 (95%CI, 0.75-0.98) for vegetables. High intake of fruit and vegetables (RR = 0.76; 95%CI, 0.68-0.86 and RR = 0.83; 95%CI, 0.72-0.96) reduced the risk of childhood wheezing. Total intake of fruit and vegetables had a negative association with risk of asthma in adults and children (RR = 0.54; 95%CI, 0.41-0.69). Consuming fruit and vegetables during pregnancy had no association with the risk of asthma in offspring. High intake of fruit and vegetables may reduce the risk of asthma and wheezing in adults and children.

Adherence to the Mediterranean diet in Italian school children (The ZOOM8 Study)

The adherence to the Mediterranean diet (MD) of 1740 Italian 8-9-year-olds was evaluated using the KIDMED index and a descriptive analysis of it by socio-demographic and lifestyle factors was performed. Only 5.0% of the children resulted "high" adherers of MD (62.2% "average" and 32.8% "poor"). This scarce adherence was due to a low consumption of fruit, vegetables, legumes, dairy products and a high intake of commercially baked goods for breakfast and sweets. Hindrances to fruit, vegetables and pulses consumption were reported for one-third of the sample. The adherence rates did not differ significantly with BMI and gender. Adherence improved with: having lunch at school; liking lunch at school; breakfast with family; no free access to food; availability of fruit and pulses; liking vegetables; higher maternal education; lower child screen time; population size of place of residence. The results show it is important to improve family food habits and dietary knowledge.

Effects of dietary habits and risk factors on allergic rhinitis prevalence among Turkish adolescents

BACKGROUND

Allergic rhinitis (AR) is a global health problem affecting many people from childhood to adulthood. The aim of this study was to evaluate the prevalence of AR and related symptoms, and to assess the risk factors, dietary habits and the Mediterranean diet affecting AR.

METHODS

In a cross-sectional study design, 9991 children, aged 13-14 years in 61 primary schools in 32 districts of Istanbul were evaluated. The prevalence of AR symptoms among the children was evaluated using the ISAAC protocol.

RESULTS

In our study, total of 10,984 questionnaires were distributed to 13-14yr-old schoolchildren to 61 schools in 32 district of Istanbul and 9991 questionnaires were suitable for analysis with an overall response of 91.7%. The rates of lifetime rhinitis, rhinitis in last 12 months and lifetime doctor diagnosed AR prevalence were 53.5%, 38.3% and 4.5%, respectively. The variation among districts in the prevalence of doctor diagnosed AR was very high. The highest prevalence was about 10 times higher than in the district with the lowest prevalence (range: 1.4-14.5) of Istanbul. A family history of atopy, mother with a university degree, presence of cat at home during last 12 months and adenoidectomy were significant for increased doctor diagnosed AR risk. Additionally, although fish and other sea foods, fermented drinks made from millets and various seeds, animal fats and butter were independent risk factors for doctor diagnosed AR, fish oil and hamburger were protective foods for doctor diagnosed AR. The MD was not associated with the prevalence of doctor diagnosed AR.

CONCLUSIONS

This study shows that that there are wide variations for the prevalence of AR related symptoms in 13-14yr-old schoolchildren among districts of Istanbul in Turkey. Socio-economical, environmental factors, some dietary habits, but not Mediterranean diet may affect the prevalence of AR.

DASH for asthma: a pilot study of the DASH diet in not-well-controlled adult asthma

This pilot study aims to provide effect size confidence intervals, clinical trial and intervention feasibility data, and procedural materials for a full-scale randomized controlled trial that will determine the efficacy of Dietary Approaches to Stop Hypertension (DASH) as adjunct therapy to standard care for adults with uncontrolled asthma. The DASH diet encompasses foods (e.g., fresh fruit, vegetables, and nuts) and antioxidant nutrients (e.g., vitamins A, C, E, and zinc) with potential benefits for persons with asthma, but it is unknown whether the whole diet is beneficial. Participants (n = 90) will be randomized to receive usual care alone or combined with a DASH intervention consisting of 8 group and 3 individual sessions during the first 3 months, followed by at least monthly phone consultations for another 3 months. Follow-up assessments will occur at 3 and 6 months. The primary outcome measure is the 7-item Juniper Asthma Control Questionnaire, a validated composite measure of daytime and nocturnal symptoms, activity limitations, rescue medication use, and percentage predicted forced expiratory volume in 1 second. We will explore changes in inflammatory markers important to asthma pathophysiology (e.g., fractional exhaled nitric oxide) and their potential to mediate the intervention effect on disease control. We will also conduct pre-specified subgroup analyses by genotype (e.g., polymorphisms on the glutathione S transferase gene) and phenotype (e.g., atopy, obesity). By evaluating a dietary pattern approach to improving asthma control, this study could advance the evidence base for refining clinical guidelines and public health recommendations regarding the role of dietary modifications in asthma management.

Investigating the effectiveness of the Mediterranean diet in pregnant women for the primary prevention of asthma and allergy in high-risk infants: protocol for a pilot randomised controlled trial

BACKGROUND

Over recent decades there has been a substantial increase in asthma and allergic disease especially in children. Given the high prevalence, and the associated high disease burden and costs, there is a need to identify effective strategies for the primary prevention of asthma and allergy. A recent systematic review of the literature found strong supportive epidemiological evidence for a protective role of the Mediterranean diet, which now needs to be confirmed through formal experimental studies. This pilot trial in pregnant women aims to establish recruitment, retention and acceptability of a dietary intervention, and to assess the likely impact of the intervention on adherence to a Mediterranean diet during pregnancy.

METHODS/DESIGN

This study was a pilot, two-arm, randomised controlled trial in a sample population of pregnant women at high risk of having a child who will develop asthma or allergic disease.

DISCUSSION

The work ultimately aims to contribute to improving health outcomes through seeking to reduce the incidence of asthma and allergic problems. This pilot trial will prove invaluable in informing the subsequent planned large-scale, parallel group, randomised controlled trial.

Influence of Mediterranean diet on asthma in children: a systematic review and meta-analysis

BACKGROUND

There is epidemiological evidence that Mediterranean diet exposure is associated with lower asthma prevalence in children. We aimed to summarize the available data and to know whether the Mediterranean setting modifies this association.

METHODS

The literature search, up to May 2012, was on epidemiological studies in the general population of children assessing whether adherence to Mediterranean diet (measured as a score) was associated with the prevalence of 'current wheeze'; 'current severe wheeze'; or 'asthma ever'. Odds ratios (OR) of the eight included studies compared the highest tertile of the score with the lowest. Random-effects meta-analyses for the whole group of studies and stratified by Mediterranean setting (centers <100 Km from the Mediterranean coast) were performed. Differences between strata were assessed using the Q test.

RESULTS

For 'current wheeze', there was a negative significant association with the highest tertile of Mediterranean diet score (OR 0.85, 95% CI 0.75-0.98; p = 0.02), driven by Mediterranean centers (0.79, 0.66-0.94, p = 0.009), although the difference with the non-Mediterranean centers (0.91, 0.78-1.05, p = 0.18) was not significant. The results for 'current severe wheeze' were as follows: 0.82, 0.55-1.22, p = 0.330 (all); 0.66, 0.48-0.90, p = 0.008 (Mediterranean); and 0.99, 0.79-1.25, p = 0.95 (non-Mediterranean); with the difference between regions being significant. For 'asthma ever', the associations were as follows: 0.86, 0.78-0.95, p = 0.004 (all); 0.86, 0.74-1.01, p = 0.06 (Mediterranean); 0.86, 0.75-0.98; p = 0.027 (non-Mediterranean); with the difference between regions being negligible.

CONCLUSIONS

Adherence to the Mediterranean diet tended to be associated with lower occurrence of the three respiratory outcomes. For current and current severe wheeze, the association was mainly driven by the results in Mediterranean populations.

Mediterranean diet adherence during pregnancy and risk of wheeze and eczema in the first year of life: INMA (Spain) and RHEA (Greece) mother-child cohort studies

Maternal diet during pregnancy might influence the development of childhood allergic disorders. The aim of the present study was to evaluate the impact of Mediterranean diet (MD) adherence during pregnancy on wheeze and eczema in the first year of life in two population-based mother-child cohorts in Spain and Greece. We studied 1771 mother-newborn pairs from the Spanish multi-centre 'INMA' (INfancia y Medio Ambiente) study (Gipuzkoa, Sabadell and Valencia) and 745 pairs from the 'RHEA' study in Crete, Greece. The symptoms of wheeze and eczema were based on the criteria of the International Study of Asthma and Allergies in Childhood. Maternal diet during pregnancy was assessed by FFQ and MD adherence was evaluated through an a priori score. Multivariate log-binomial regression models were used to adjust for several confounders in each cohort and summary estimates were obtained by a meta-analysis. MD adherence was not associated with the risk of wheeze and eczema in any cohort, and similar results were identified in the meta-analysis approach. High meat intake (relative risk (RR) 1·22, 95 % CI 1·00, 1·49) and 'processed' meat intake (RR 1·18, 95 % CI 1·02, 1·37) during pregnancy were associated with an increased risk of wheeze in the first year of life, while a high intake of dairy products was significantly associated with a decreased risk of infantile wheeze (RR 0·83, 95 % CI 0·72, 0·96). The results of the present study show that high meat intake during pregnancy may increase the risk of wheeze in the first year of life, while a high intake of dairy products may decrease it.

Obesity and asthma: an association modified by age

BACKGROUND

Some studies indicate some causal relationship between obesity and asthma, while others show inconsistent results. Our objective was to evaluate the prevalence of asthma according to obesity in children.

METHODS

A cross-sectional study, following the ISAAC study methodology, was conducted on two randomly selected groups consisting of 6-7 year-old children (n=7485) and 13-14 year-old adolescents (n=8496). The asthma symptoms and potential risk factors were determined from the questionnaire. Overweight and obesity were defined based on the body mass index. Multiple logistic regression was used to obtain adjusted prevalence odds ratios (OR) and 95% confidence intervals.

RESULTS

Obesity was associated with an increase in wheezing ever (OR: 1.35) and exercise-induced asthma (OR: 1.62) in the 6-7 year-old group. No significant relationship was observed in the adolescent population.

CONCLUSION

Obesity was associated with a higher prevalence of asthma in young children, but not in adolescents.

Impact of parental smoking on childhood asthma

OBJECTIVE

To evaluate the exposure to environmental tobacco smoke (ETS) of the childhood population in this community and its relationship with asthma symptoms.

METHODS

A cross-sectional study was conducted using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire on children and adolescents in this community. The symptoms "wheezing ever", "current asthma", "severe asthma", and "exercise-induced asthma" were defined by this questionnaire. Parental smoking was classified into four mutually exclusive categories: 1) no parent smokes; 2) only the mother smokes; 3) only the father smokes; and 4) both parents smoke. The odds ratio of the prevalence of asthma symptoms according to ETS exposure was calculated using logistic regression.

RESULTS

A total of 10,314 children and 10,453 adolescents were included. Over 51% of the children and adolescents were exposed to ETS at home. ETS is associated with a higher prevalence of asthma symptoms, particularly if the mother or both parents smoke.

CONCLUSION

The prevalence of ETS is still high in this community, although there has been a decreasing tendency in the last 15 years. ETS is associated with higher prevalence of asthma.

Nutrition and asthma

Over the past four decades, the prevalence of asthma has markedly increased in Westernized countries and countries transitioning to this lifestyle. It has been hypothesized that these increases are a consequence of changing environmental and/or behavioral factors. The modification of dietary habits (ie, decreased intake of fruits/vegetables and increased intake of "Westernized" processed foods) and a decrease in sun exposure have led to decreased intake of antioxidant vitamins and fatty acids and to decreased circulating levels of vitamin D, and have been proposed to explain the rise in asthma prevalence. This article summarizes the main findings on foods and nutrients connected to asthma based on several exhaustive recent reviews on the topic, and examines the evidence for an effect of dietary patterns on asthma. Overall, findings underscore the importance of conducting prospective studies and clinical trials to better understand the role of diet in the etiology of asthma.

Truck traffic related air pollution associated with asthma symptoms in young boys: a cross-sectional study

OBJECTIVES

The aim of this study was to evaluate the influence of intensity of truck traffic on asthma symptomatology, and its relationship with age and gender.

STUDY DESIGN

A cross-sectional study was conducted on children and adolescents from Galicia (North-West Spain).

METHODS

Following the methodology of the International Study of Asthma and Allergies in Childhood (ISAAC): children from schools randomly selected, answered a self-administered questionnaire included questions on asthma symptoms and some risk factors. The association between self-reported truck traffic on the street of residence and symptoms of asthma were investigated by logistic regression adjusted for body mass index, maternal education and parental smoking.

RESULTS

Almost 40% of children in Galicia are exposed to the frequent and constant passing of heavy goods vehicles. The odds of 6-7 year-old boys having severe or exercise induced asthma is tripled when they live in streets with the constant passing of heavy goods vehicles, compared with those living in streets where these vehicles never pass. In adolescents and 6-7 year-old girls, no relationship was observed between truck traffic and asthma symptoms.

CONCLUSIONS

The results of this study appear to support a distinct effect of truck traffic on asthma symptoms depending on the age and sex of the exposed population, being more harmful for young males.

Asthma in Mexican school-age children is not associated with passive smoking or obesity

Background

Asthma has increased in various regions of the world. The factors associated with the growth in prevalence are still to be determined.

Objective

To evaluate the degree of association of the prevalence of asthma with passive smoking and obesity in school-children in western Mexico.

Methods

A population-based cross-section analytic study. A stratified random sample of 740 primary school pupils of between 6 and 12 years of age was chosen. Asthma, passive smoking and a background of allergic diseases were identified by means of a standardized questionnaire filled out by the parents of the participants. Obesity was identified by means of the body mass index. Proportional sections of population were estimated and the degree of association between asthma (dependent variable) and the independent variables was evaluated by means of multivariate logistic regression.

Results

The following factors of prevalence were found: asthma 8.1%; obesity 19.9%; background of smoking in the father 6.7% and in the mother 13.3%. There was no significant association to be found with asthma in either passive smoking where one of the parents smoked (p = 0.39) or in obesity (p = 0.09). On the other hand, the background of allergic diseases in the mother showed statistically significant association with asthma in the boys (odds ratio = 3.5, 95% confidence interval 1.4 to 8.59), but not in the girls.

Conclusion

With the exception of the maternal background of allergy, neither obesity nor passive smoking are factors associated with asthma in Mexican children.

Environmental exposures and respiratory outcomes in children

Asthma is a complex condition where genetic and environmental interactions occur at critical periods in development. The focus of this review was the role of environmental exposures on asthma causation. Selected studies published in 2010 and 2011 were reviewed to illustrate the challenge in relating environmental exposure(s) on asthma causation and also to focus on some exposures currently thought to be important to asthma pathogenesis. Challenges in understanding how environmental exposures may translate into asthma causation are summarised. Inhaled and ingested exposures are described, including microbial products, swimming pools, diet and antenatal tobacco exposure. A final synthesis summarises what is currently understood about childhood asthma causation and what advice might be given to parents and governments interested in reducing asthma risk.

Influence of mediterranean diet on asthma symptoms, lung function, and systemic inflammation: a randomized controlled trial

OBJECTIVE

The rapidly increasing prevalence of asthma in developed countries suggests an environmental cause. The benefits of Mediterranean diet (MD) in cardiovascular disease have been tentatively attributed to its anti-inflammatory properties. Asthma is an inflammatory disease and MD is associated with reduced asthma risk in epidemiological studies, but there are no reported interventional studies of MD in asthma.

METHODS

In this 12-week open-label randomized trial, 38 adults with symptomatic asthma were allocated to high-intervention (HI), low-intervention (LI), and control groups. The first two groups were encouraged to adopt an MD and received multiple consultation sessions with a nutritionist, written advice, and vouchers for the purchase of appropriate foods. Food frequency questionnaires, asthma control questionnaires, asthma-related quality of life questionnaires (AQLQs), and spirometry were completed at the beginning and at the end of the study.

RESULTS

The MDt score increased in the HI group (p < .001), indicating successful alteration of dietary behavior. Statistically, nonsignificant improvements were seen in spirometry and several AQLQ subdomains in the two intervention groups. No changes were seen in the asthma control or in inflammatory markers.

CONCLUSIONS

The trial intervention has successfully altered the dietary behavior among adults with asthma. Small but consistent improvements were seen in quality of life and spirometry among the intervention group. The use of the MD to treat asthma is feasible and warrants evaluation in a larger study, powered to examine clinical endpoints.

Association of antioxidants with allergic rhinitis in children from seoul

Purpose

The prevalence of allergic diseases has risen over the last few decades. Many factors, including environmental factors such as those related to diet, have been considered. Among dietary factors, intake of antioxidant-related nutrients has been associated with the risk of allergic disease. We investigated the association of antioxidant nutritional status with allergic rhinitis (AR) in Korean schoolchildren aged 6-12 years.

Methods

Subjects were 4,554 children in Seoul, Korea. The risk of allergic disease was measured using the Korean version of the International Study of Asthma and Allergies in Childhood, and dietary intake was measured by a semi-quantitative food frequency questionnaire. Intake of vitamins A (including retinol and β-carotene), C, and E was used in the analysis.

Results

Vitamin C intake was negatively associated with an increased risk of current symptoms (adjusted odds ratio, 0.886; 95% confidence interval, 0.806-0.973). There was no association between AR and intake of vitamin A, retinol, β-carotene, or vitamin E. Total serum IgE level and sensitization to allergen did not differ according to nutrient intake.

Conclusions

The group of children with increased vitamin C consumption had fewer AR symptoms, despite the lack of a difference in total serum IgE level or allergen sensitization. These findings suggest that nutrient intake, especially that of vitamin C, influences AR symptoms.

Confounding and effect modification in studies of diet and childhood asthma and allergies

OBJECTIVE

To propose a comprehensive set of confounders and effect modifiers that should be considered in epidemiologic investigations.

METHODS

Two reviewers independently critiqued studies included in a recent systematic review and extracted data on the confounders and effect modifiers that were considered and the approaches used to justify inclusion.

RESULTS

Of the 62 studies reviewed, 20 were cohort, 16 case-control, 25 cross-sectional studies, and one ecologic study. All cohort, cross-sectional, and ecologic studies had some adjustment for confounding or consideration of effect modification, but this was only the case for 7/16 (44%) case-control studies. Of the 53 studies that considered confounding or effect modification, 39/53 (74%) gave no justification for the inclusion of the variables considered. Studies that justified the inclusion of the variables did so based on empirical evidence (n = 10), conceptual justification (n = 7), or a combination of the two (n = 3). Confounding was handled mainly by using regression modeling, but some case-control studies utilized matching and anova. Ten studies handled effect modification by stratification, eight tested for interaction, and five used both strategies.

CONCLUSIONS

We have found substantial shortcomings in the handling of confounding and effect modification in studies of diet and development of childhood asthma/allergies. Selection of variables should be based on conceptual considerations and empirical evidence. Using this approach, we have proposed a comprehensive set of confounders and effect modifiers that need to be considered in future studies.

Glutathione redox control of asthma: from molecular mechanisms to therapeutic opportunities

Asthma is a chronic inflammatory disorder of the airways associated with airway hyper-responsiveness and airflow limitation in response to specific triggers. Whereas inflammation is important for tissue regeneration and wound healing, the profound and sustained inflammatory response associated with asthma may result in airway remodeling that involves smooth muscle hypertrophy, epithelial goblet-cell hyperplasia, and permanent deposition of airway extracellular matrix proteins. Although the specific mechanisms responsible for asthma are still being unraveled, free radicals such as reactive oxygen species and reactive nitrogen species are important mediators of airway tissue damage that are increased in subjects with asthma. There is also a growing body of literature implicating disturbances in oxidation/reduction (redox) reactions and impaired antioxidant defenses as a risk factor for asthma development and asthma severity. Ultimately, these redox-related perturbations result in a vicious cycle of airway inflammation and injury that is not always amenable to current asthma therapy, particularly in cases of severe asthma. This review will discuss disruptions of redox signaling and control in asthma with a focus on the thiol, glutathione, and reduced (thiol) form (GSH). First, GSH synthesis, GSH distribution, and GSH function and homeostasis are discussed. We then review the literature related to GSH redox balance in health and asthma, with an emphasis on human studies. Finally, therapeutic opportunities to restore the GSH redox balance in subjects with asthma are discussed.

Exposure to paracetamol and asthma symptoms

BACKGROUND

Paracetamol is one of the factors that have been associated with the observed increase in asthma prevalence in the last few years. The influence of environmental or genetic factors in this disease may be different in some countries than in others. The purpose of this study was to analyse the relationship between the paracetamol consumption and asthma prevalence in our community.

METHODS

A cross-sectional study was conducted on more than 20,000 children and adolescents in Galicia, Spain. The International Study of Asthma and Allergies in Childhood methodology was used to collect the information on asthma symptoms in children, paracetamol consumption, body mass index (BMI), pets in the home, education level of the mother and parental asthma and smoking habits. The influence of paracetamol consumption on the prevalence of asthma symptoms was calculated using logistic regression, adjusted for the other parameters included in the study.

RESULTS

After adjusting for gender, BMI, having a cat or dog, maternal education, parental asthma and smoking, in 6- to 7-year-old children, the consumption of paracetamol during the first year of life is associated with asthma [odds ratio (OR) 2.04 (1.79-2.31) for wheezing at some time]. Paracetamol consumption in the previous year leads to a significant increase in the probability of wheezing at some time [OR 3.32 (2.51-4.41)] in young children and adolescents [OR 2.12 (1.68-2.67)].

CONCLUSIONS

Paracetamol consumption is associated with a significant increase in asthma symptoms. The effect is greater the more often the drug is taken.

Dietary intake of α-linolenic acid and low ratio of n-6:n-3 PUFA are associated with decreased exhaled NO and improved asthma control

As recently described, adherence to the Mediterranean diet is associated with improved asthma control. However, evidence of how specific nutrients such as fatty acids and antioxidants may affect this relationship remains largely unknown. We aimed to examine the association between dietary intake of fatty acids and antioxidants and asthma control. A cross-sectional study was developed in 174 asthmatics, mean age of 40 (SD 15) years. Dietary intake was obtained by a FFQ, and nutritional content was calculated using Food Processor Plus™ software (ESHA Research, Inc., Salem, OR, USA). Good asthma control was defined by the combination of forced expiratory volume during the first second, exhaled NO (eNO) and Asthma Control Questionnaire (ACQ) score (control: forced expiratory volume in the first second ≥80 %; eNO ≤35 ppb; ACQ <1·0, scale 0-6 score). Multiple linear and logistic regression models were performed to analyse the associations between nutrients and asthma outcomes, adjusting for confounders. A high n-6:n-3 PUFA ratio predicted high eNO, whereas high intakes of n-3 PUFA, a-linolenic acid (ALA) and SFA were associated with low eNO. Odds for controlled asthma improved along with an increased intake of n-3 PUFA (OR 0·14, 95% CI 0·04, 0·45; P for trend=0·001), SFA (OR 0·36, 95% CI 0·13, 0·97; P for trend=0·047) and ALA (OR 0·18, 95% CI 0·06, 0·58; P for trend=0·005). A high n-6:n-3 PUFA ratio increased the odds for uncontrolled asthma (OR 3·69, 95% CI 1·37, 9·94; P for trend=0·009), after adjusting for energy intake, sex, age, education and use of inhaled corticosteroids. Higher intakes of n-3 PUFA, ALA and SFA were associated with good asthma control, while the risk for uncontrolled asthma increased with a higher n-6:n-3 PUFA ratio. The present results introduce a protective effect of ALA in asthma control, independent of marine n-3 fatty acids, and provide a rationale to dietary intervention studies in asthma.

A medical nutrition therapy primer for childhood asthma: current and emerging perspectives

Asthma is the most common chronic disease in children. Prevalence has increased in the past 2 decades and has reached a plateau of approximately 9% of children in the United States, affecting about 6.7 million children. The increased prevalence of childhood asthma has paralleled the increased prevalence in childhood obesity. Changes in diet have also been implicated in the increased prevalence of asthma, among other risk factors. The main symptoms of asthma (ie, wheezing, coughing, and chest tightness) require medical evaluation and monitoring. The cornerstone of asthma management is medication therapy, frequently consisting of inhaled bronchodilators and corticosteroids and, when needed, therapy of corticosteroids by mouth. As part of the multidisciplinary management of this chronic disease, nutrition assessment and follow-up in childhood asthma is necessary to identify and address relevant nutrition-related problems. These problems can involve food-medication interactions, obesity, gastroesophageal reflux disease, food allergies, and other issues; therefore, individualized medical nutrition therapy is warranted. Finally, counseling to achieve a healthy balanced diet is recommended for overall health and weight management. A recent but small number of descriptive investigations agree that adherence to a Mediterranean dietary pattern can be associated with a decreased risk of current asthma symptoms in children. Although this evidence is promising, food interventions are required to substantiate an evidence-based foundation for medical nutrition therapy in childhood asthma. At this time, there is no known health risk if a Mediterranean diet is adopted.

Use of dietary indexes among children in developed countries

In this article, we review studies that have used dietary indexes to assess different aspects of diet in relation to health outcomes and sociodemographic factors in childhood populations of developed countries. Eighty-four papers published from 1980 to mid-2010 including 90 unique dietary indexes were reviewed. Seventy-two indexes were developed (or have been adapted) specifically for childhood populations; 38 of these were used to assess diet-disease associations, mostly of diet and obesity. In the majority of these studies, small inverse associations between dietary indexes and obesity indexes were shown. Children who were younger, female, and from high-income families had better dietary quality scores. Forty-nine indexes (of 90) were compared with other aspects of dietary intakes or behaviors, with correlations ranging from very low to modest (∼r = 0.05-0.50). Only 2 validation studies compared an index with nutritional biomarkers, and correlations were quite weak for most plasma nutrients (P < 0.10). Overall, a large number of indexes have been created and used, but the majority of studies are descriptive. Fewer analytic studies on index-health associations have been performed, and most analyses insufficiently adjusted for confounders. Thus, prospective and intervention research in diverse populations is needed to further test these tools. In conclusion, indexes are potentially useful methods for dietary assessment, because they offer valuable information on overall dietary patterns in children. However, understanding the advantages and limitations when applying them in research and public health settings is important, and more research is needed to further develop their utility.

Adherence to the Mediterranean type of diet is associated with lower prevalence of asthma symptoms, among 10-12 years old children: the PANACEA study

Epidemiological studies have shown several associations between asthma symptoms and dietary factors. The aim of this work was to evaluate the relationship between adherence to the Mediterranean diet and childhood asthma. A cross-sectional analysis was performed on 700 children (323 boys), 10-12 yr old, selected from 18 schools located in Athens greater area. Children and their parents completed questionnaires, which evaluated, among others, dietary habits. Asthma was defined according to ISAAC II criteria. Adherence to the Mediterranean diet was evaluated using the KIDMED score (theoretical range 0-12). Higher KIDMED score corresponds to greater adherence to the Mediterranean diet. Greater adherence to the Mediterranean diet was inversely associated with ever had wheeze (p = 0.001), exercise wheeze (p = 0.004), ever had diagnosed asthma (p = 0.002) and with any asthma symptoms (p < 0.001). One-unit increase in the KIDMED score was associated with 14% lower likelihood of having asthma symptoms (odds ratio = 0.86, 95% confidence interval 0.75-0.98), after adjusting for various confounders. No significant associations were found between asthma symptoms and consumption of fruits (p = 0.25), vegetables (p = 0.97), legumes (p = 0.76), cereals (p = 0.71), dairy (p = 0.61), salty snacks (p = 0.53), or margarine/butter (p = 0.42) consumption, while increased fish and meat intake was associated with less asthma symptoms (p = 0.04 and p = 0.01, respectively). Our findings suggest an inverse relationship between level of adherence to the Mediterranean diet and prevalence of asthma in school-aged children.

Salty-snack eating, television or video-game viewing, and asthma symptoms among 10- to 12-year-old children: the PANACEA study

BACKGROUND

Salty-snack consumption, as well as the amount of time children spend watching television or playing video games, have been implicated in the development of asthma; however, results are still conflicting.

OBJECTIVE

The aim of this work was to evaluate the association of salty-snack eating and television/video-game viewing with childhood asthma symptoms.

DESIGN

Cross-sectional study.

SETTINGS

Seven hundred children (323 male), 10 to 12 years old, from 18 schools located in the greater area of Athens were enrolled. Children and their parents completed questionnaires, which evaluated, among other things, dietary habits. Adherence to the Mediterranean diet was evaluated using the KIDMED (Mediterranean Diet Quality Index for Children and Adolescents) score.

STATISTICAL ANALYSIS

The association of children's characteristics with asthma symptoms was performed by calculating the odds ratios and corresponding 95% confidence intervals.

RESULTS

Overall lifetime prevalence of asthma symptoms was 23.7% (27.6% boys, 20.4% girls; P=0.03). Forty-eight percent of children reported salty-snack consumption (≥ 1 times/week). Salty-snack consumption was positively associated with the hours of television/video-game viewing (P=0.04) and inversely with the KIDMED score (P=0.02). Consumption of salty snacks (>3 times/week vs never/rare) was associated with a 4.8-times higher likelihood of having asthma symptoms (95% confidence interval: 1.50 to 15.8), irrespective of potential confounders. The associations of salty-snack eating and asthma symptoms were more prominent in children who watched television or played video games >2 hours/day. In addition, adherence to the Mediterranean diet was inversely associated with the likelihood of asthma symptoms.

CONCLUSIONS

Unhealthy lifestyle behaviors, such as salty-snack eating and television/video-game viewing were strongly associated with the presence of asthma symptoms. Future interventions and public health messages should be focused on changing these behaviors from the early stages of life.

Nutrients and foods for the primary prevention of asthma and allergy: systematic review and meta-analysis

BACKGROUND

Epidemiologic studies suggest that deficiencies of the nutrients selenium; zinc; vitamins A, C, D, and E; and low fruit and vegetable intake may be associated with the development of asthma and allergic disorders.

OBJECTIVES

To investigate the evidence that nutrient and food intake modifies the risk of children developing allergy.

METHODS

We systematically searched 11 databases. Studies were critically appraised, and meta-analyses were undertaken.

RESULTS

We identified 62 eligible reports. There were no randomized controlled trials. Studies used cohort (n = 21), case-control (n = 15), or cross-sectional (n = 26) designs. All studies were judged to be at moderate to substantial risk of bias. Meta-analysis revealed that serum vitamin A was lower in children with asthma compared with controls (odds ratio [OR], 0.25; 95% CI, 0.10-0.40). Meta-analyses also showed that high maternal dietary vitamin D and E intakes during pregnancy were protective for the development of wheezing outcomes (OR, 0.56, 95% CI, 0.42-0.73; and OR, 0.68, 95% CI, 0.52-0.88, respectively). Adherence to a Mediterranean diet was protective for persistent wheeze (OR, 0.22; 95% CI, 0.08-0.58) and atopy (OR, 0.55; 95% CI, 0.31-0.97). Seventeen of 22 fruit and vegetable studies reported beneficial associations with asthma and allergic outcomes. Results were not supportive for other allergic outcomes for these vitamins or nutrients, or for any outcomes in relation to vitamin C and selenium.

CONCLUSION

The available epidemiologic evidence is weak but nonetheless supportive with respect to vitamins A, D, and E; zinc; fruits and vegetables; and a Mediterranean diet for the prevention of asthma. Experimental studies of these exposures are now warranted.