Relationship of serum antioxidants to asthma prevalence in youth

Dietary intake, antioxidants, minerals and vitamins in relation to childhood asthma: a Mendelian randomization study

Background

Currently, there is limited and inconsistent evidence regarding the risk association between daily dietary intake, antioxidants, minerals, and vitamins with Childhood Asthma (CA). Therefore, this study employs Mendelian Randomization (MR) methodology to systematically investigate the causal relationships between daily dietary intake, serum antioxidants, serum minerals, and the circulating levels of serum vitamins with CA.

Methods

This study selected factors related to daily dietary intake, including carbohydrates, proteins, fats, and sugars, as well as serum antioxidant levels (lycopene, uric acid, and β-carotene), minerals (calcium, copper, selenium, zinc, iron, phosphorus, and magnesium), and vitamins (vitamin A, vitamin B6, folate, vitamin B12, vitamin C, vitamin D, and vitamin E), using them as Instrumental Variables (IVs). Genetic data related to CA were obtained from the FinnGen and GWAS Catalog databases, with the primary analytical methods being Inverse Variance Weighting (IVW) and sensitivity analysis.

Results

Following MR analysis, it is observed that sugar intake (OR: 0.71, 95% CI: 0.55-0.91, P: 0.01) is inversely correlated with the risk of CA, while the intake of serum circulating magnesium levels (OR: 1.63, 95% CI: 1.06-2.53, P: 0.03), fats (OR: 1.44, 95% CI: 1.06-1.95, P: 0.02), and serum vitamin D levels (OR: 1.14, 95% CI: 1.04-1.25, P: 0.02) are positively associated with an increased risk of CA.

Conclusion

This study identified a causal relationship between the daily dietary intake of sugars and fats, as well as the magnesium and vitamin D levels in serum, and the occurrence of CA. However, further in-depth research is warranted to elucidate the specific mechanisms underlying these associations.

Relationship between serum iron and blood eosinophil counts in asthmatic adults: data from NHANES 2011-2018

Background

So far, quite a few studies have revealed that systemic iron levels are related to asthmatic inflammatory reactions. And most studies have focused on the correlation between systemic iron levels and asthma, with inconsistent findings. Yet, few studies have investigated the connection between serum iron and blood eosinophil counts. Hence, we have explored the connection between serum iron and blood eosinophil counts in asthmatics by utilizing data from NHANES.

Methods

A total of 2549 individuals were included in our study after screening NHANES participants from 2011 to 2018. The linear regression model and XGBoost model were used to discuss the potential connection. Linear or nonlinear association was further confirmed by the generalized additive model and the piecewise linear regression model. And we also performed stratified analyses to figure out specific populations.

Results

In the multivariable linear regression models, we discovered that serum iron levels were inversely related to blood eosinophil counts in asthmatic adults. Simultaneously, we found that for every unit increase in serum iron (umol/L), blood eosinophil counts reduced by 1.41/uL in model 3, which adjusted for all variables excluding the analyzed variables. Furthermore, the XGBoost model of machine learning was applied to assess the relative importance of chosen variables, and it was determined that vitamin C intake, age, vitamin B12 intake, iron intake, and serum iron were the five most important variables on blood eosinophil counts. And the generalized additive model and piecewise linear regression model further verify this linear and inverse association.

Conclusion

Our investigation discovered that the linear and inverse association of serum iron with blood eosinophil counts in asthmatic adults, indicating that serum iron might be related to changes in the immunological state of asthmatics. Our work offers some new thoughts for next research on asthma management and therapy. Ultimately, we hope that more individuals become aware of the role of iron in the onset, development, and treatment of asthma.

Dietary prevention strategies for childhood asthma

Asthma is the most common chronic disease in childhood and a rise in prevalence has been observed concomitantly with changing dietary habits in the Western world. This change has favored a more Westernized diet characterized by high intake of processed food and fat in contrast to a Mediterranean diet high in fruit, vegetable and fish intake. This has resulted in a decreased intake of several antioxidants and micronutrients including n-3 long-chained polyunsaturated fatty acids and vitamin D that are speculated to have anti-inflammatory effects and hold immunoregulatory properties. Several observational studies have investigated associations between dietary intake and wheeze and asthma but only few large well-conducted randomized controlled trials (RCTs) have been performed investigating the primary preventive effect of micronutrient supplementations. Currently, the recommendations from the Global Initiative for Asthma (GINA) for primary prevention of asthma in children do not include maternal dietary changes or supplementations during pregnancy, although the most recent report mentions both specific dietary patterns and micronutrients as potential protective supplementation regimes. This review will present the current literature and future research needs focusing on primary and secondary prevention of both early and late childhood asthma from dietary intake during pregnancy and early childhood to highlight potential preventive effects of specific dietary patterns and micronutrient supplements, which may facilitate the planning of future clinical trials in search of a preemptive strategy.

The Role of Vitamins in the Pathogenesis of Asthma

Vitamins play a crucial role in the proper functioning of organisms. Disturbances of their levels, seen as deficiency or excess, enhance the development of various diseases, including those of the cardiovascular, immune, or respiratory systems. The present paper aims to summarize the role of vitamins in one of the most common diseases of the respiratory system, asthma. This narrative review describes the influence of vitamins on asthma and its main symptoms such as bronchial hyperreactivity, airway inflammation, oxidative stress, and airway remodeling, as well as the correlation between vitamin intake and levels and the risk of asthma in both pre- and postnatal life.

Association between vitamin A and asthma: A meta-analysis with trial sequential analysis

Objective: To explore the association between vitamin A (vit A) status and risk of asthma. Methods: PubMed, Web of Science, Embase and the Cochrane Library were electronically searched to identify related studies that reported the association between vit A status and asthma. All databases were searched from inception to November 2022. Two reviewers independently screened literature, extracted data, and assessed risk bias of included studies. Meta-analysis was performed on R software Version 4.1.2 and STATA Version 12.0. Results: A total of 19 observational studies were included. A pooled analysis showed that the serum vit A concentrations in patients with asthma was lower than that in healthy controls (standard mean difference (SMD)= -2.479, 95% confidence interval (CI): -3.719, -.239, 95% prediction interval (PI): -7.510, 2.552), and relatively higher vit A intake in pregnancy was associated with an increased risk of asthma at age 7 years (risk ratio (RR)= 1.181, 95% CI: 1.048, 1.331). No significant correlation was observed between serum vit A levels or vit A intake and the risk of asthma. Conclusion: Our meta-analysis confirms that serum vit A levels are lower in patients with asthma than in healthy controls. Relatively higher vit A intake during pregnancy is associated with an increased risk of asthma at age 7 years. There is no significant correlation between vit A intake and asthma risk in children, nor between serum vit A levels and asthma risk. The effect of vit A may depend on age or developmental stage, diet and genetics. Therefore, further studies are needed to explore the association of vit A and asthma. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/CRD42022358930, identifier CRD42022358930.

The protective effect of butylated hydroxytoluene and 3-hydroxytyrosol on food allergy in mice

OBJECTIVE

To test the effect of two dietary antioxidants: butylated hydroxytoluene (BHT) and 3-hydroxytyrosol (3-HT) in experimental food allergy.

METHODS

BALB/c mice maintained on control diet or diet with BHT or 3-HT were sensitized with ovalbumin (OVA) or saline through transdermal exposure. Plasma OVA-specific IgE (OVA-IgE) and IgG1 (OVA-IgG1) antibody levels were determined using ELISA. Sensitized mice were challenged by oral gavage with OVA. Rectal temperature (RT) was measured before and after challenge. Mast cell degranulation was quantified by measuring the plasma levels of mouse mucosal mast cell protease-1 (mMCP-1). Flow cytometry was carried out to evaluate the percentage Th2 cells from the spleen.

RESULTS

Mice on either a 3-HT or BHT diet showed a significantly decreased IgE response to OVA sensitization and less severe anaphylaxis, as evidenced by a diminished drop in body temperature, attenuated clinical signs, a more rapid recovery and decreased mast cell degranulation (as determined by lower plasma mMCP-1 levels).

CONCLUSION

The present study indicates two dietary antioxidants: BHT and 3-HT may be protective against experimental food allergy. These results suggest 3-HT and BHT could potentially be useful for prevention of food allergy.

Serum cotinine cut-points for secondhand smoke exposure assessment in children under 5 years: A systemic review

Background

Serum cotinine has become the most widely used biomarker of secondhand smoke exposure (SHS) over time in all ages. The aim of this study was to review the serum cotinine cut-points used to classify children under 5 years as exposed to SHS.

Methods

A systematic review performed in the Pubmed (MEDLINE) and EMBASE databases up to April 2021 was conducted using as key words "serum cotinine", “tobacco smoke pollution” (MeSH), "secondhand smoke", "environmental tobacco smoke" and “tobacco smoke exposure”. Papers which assessed SHS exposure among children younger than 5 years old were included. The PRISMA 2020 guidelines were followed. Analysis was pre-registered in PROSPERO (registration number: CRD42021251263).

Results

247 articles were identified and 51 fulfilled inclusion criteria. The selected studies were published between 1985–2020. Most of them included adolescents and adults. Only three assessed postnatal exposure exclusively among children under 5 years. None of the selected studies proposed age-specific cut-points for children < 5 years old. Cut-point values to assess SHS exposure ranged from 0.015 to 100 ng/ml. The most commonly used cut-point was 0.05 ng/ml, derived from the assay limit of detection used by the National Health and Nutrition Examination Survey (NHANES).

Conclusions

No studies have calculated serum cotinine age-specific cut-points to ascertained SHS exposure among children under 5 years old. Children’s age-specific cut-points are warranted for health research and public health purposes aimed at accurately estimating the prevalence of SHS exposure and attributable burden of disease to such exposure, and at reinforcing 100% smoke-free policies worldwide, both in homes, private vehicles and public places.

Nutrition in Asthma

An emerging body of evidence suggests that diet plays an important role in both the development and management of asthma. The relationship between dietary intake and asthma risk has been explored in epidemiological studies, though intervention trials examining the effects of nutrient intake and dietary patterns on asthma management are scarce. Evidence for diets high in fruits and vegetables, antioxidants, omega-3 fatty acids and soluble fiber such as the Mediterranean diet is conflicting. However, some studies suggest that these diets may reduce the risk of asthma, particularly in young children, and could have positive effects on disease management. In contrast, a Westernized dietary pattern, high in saturated fatty acids, refined grains, and sugars may promote an inflammatory environment resulting in the onset of disease and worsening of asthma outcomes. This review will summarize the state of the evidence for the impact of whole dietary patterns, as well as individual nutrients on the prevalence and management of asthma.

Mineral Micronutrients in Asthma

Asthma represents one of the most common medical issues in the modern world. It is a chronic inflammatory disease characterized by persistent inflammation of the airways and disturbances in redox status, leading to hyperresponsiveness of bronchi and airway obstruction. Apart from classical risk factors such as air pollution, family history, allergies, or obesity, disturbances of the levels of micronutrients lead to impairments in the defense mechanisms of the affected organism against oxidative stress and proinflammatory stimuli. In the present review, the impact of micronutrients on the prevalence, severity, and possible risk factors of asthma is discussed. Although the influence of classical micronutrients such as selenium, copper, or zinc are well known, the effects of those such as iodine or manganese are only rarely mentioned. As a consequence, the aim of this paper is to demonstrate how disturbances in the levels of micronutrients and their supplementation might affect the course of asthma.

Serum selenium levels and asthma among seafood processing workers in Greenland

Selenium levels in the Inuit population of Greenland have been declining during the last decades. The association between Selenium and asthma has been investigated previously, but with conflicting results. The objective was to measure human serum Se (s-Se) in Greenlandic seafood processing workers, to compare with levels recorded in previous decades and to establish if s-Se is associated with asthma or lung function. Data, including questionnaire answers, spirometry, skin-prick test and s-Se from 324 seafood processing workers in Greenland were collected during 2016-2017. Mean s-Se values were compared by t-test and one-way ANOVA. Associations between s-Se and asthma, symptoms from the lower airways at work and lung function were assessed using linear regression. The mean s-Se was 96.2 µg/L. S-Se was higher among non-smokers and workers living in settlements. Workers with asthma did not have s-Se levels significantly different from those of non-asthmatics. We found a positive association between s-Se levels and FEV₁ values. Selenium levels appear to continue declining in Greenland, presumably because of a more Westernised lifestyle. The health effects of declining Selenium levels remain unclear. We did not establish an association between s-Se and asthma, but we did record a positive association between s-Se and FEV₁.

Lower circulating zinc and selenium levels are associated with an increased risk of asthma: evidence from a meta-analysis

OBJECTIVE

Previous studies evaluating the associations of circulating Zn and Se levels with asthma have produced inconsistent results. Therefore, we conducted a meta-analysis to summarize and quantitatively synthesize the evidence from observational research.

DESIGN

Meta-analysis.

SETTING

We searched PubMed, Web of Science and Scopus databases up to May 2019 for relevant available articles. Random-effects model was adopted to estimate the pooled standardized mean difference (SMD) with 95 % CI. Meta-regression analysis and 'leave-one-out' sensitivity analysis were used to assess heterogeneity.

PARTICIPANTS

The meta-analysis focused on general populations.

RESULTS

A total of twenty-six studies for Zn and forty studies for Se were included in the meta-analysis. The overall analyses identified that asthma patients had lower Zn (SMD = -0·40; 95 % CI -0·77, -0·03; I2 = 94·1 %) and Se (SMD = -0·32; 95 % CI -0·48, -0·17; I2 = 90·9 %) levels in serum or plasma compared with healthy controls. After removing the studies that contributed to the heterogeneity, the pooled SMD were -0·26 (95 % CI -0·40, -0·13; I2 = 37·42 %) for Zn and -0·06 (95 % CI -0·13, 0·02; I2 = 43·54 %) for Se.

CONCLUSIONS

Lower circulating Zn and Se levels might be associated with an increased risk of asthma.

Carotenoids, fatty acids and disease burden in obese minority adolescents with asthma

BACKGROUND

Paediatric obesity-related asthma causes high disease burden, is associated with metabolic abnormalities, has few therapeutic options, and disproportionately affects urban minority children. Although poor diet quality is linked to asthma, the association of nutritional status with disease burden among children with obesity-related asthma is not well understood.

OBJECTIVE

To quantify nutritional status, defined as concentrations of serum carotenoids and n-3 fatty acids, and its association with pulmonary function and metabolic markers among obese asthmatic children.

METHODS

We quantified serum carotenoids and fatty acids in a study cohort of 158 urban minority adolescents including 39 obese asthmatics, 39 healthy weight asthmatics, 38 obese controls and 42 healthy weight controls and compared between the groups. We correlated carotenoid and fatty acid levels with pulmonary function indices and with insulin resistance and dyslipidemia.

RESULTS

Mean total carotenoids were lowest in obese asthmatic children (0.41 μg/mL), lower than healthy weight asthmatics (0.52 μg/mL, P < 0.05) and healthy weight controls (0.60 μg/mL, P < 0.001). n-6/n-3 polyunsaturated fatty acid (PUFA) ratio also differed between the groups (P < 0.05). Total carotenoids positively correlated with per cent-predicted FEV₁ and inversely correlated with insulin resistance among obese asthmatics only. n-6/n-3 PUFA ratio inversely correlated with per cent-predicted FEV₁ in obese asthmatics.

CONCLUSIONS & CLINICAL RELEVANCE

Our findings suggest that carotenoids, which are lowest in obese asthmatic children, may have protective effects on metabolic health and pulmonary function among obese asthmatic children. Similarly, n-3 PUFA appear to be protective for pulmonary function.

Association between trace elements levels and asthma susceptibility

BACKGROUND

It is well-documented that the dysregulation of trace elements may be involved in the pathogenesis of asthma. However, the precise changes of trace elements levels in asthma cases remain elusive. We established whether trace elements levels were associated with asthma susceptibility by pooling case-control studies.

METHODS

34 studies were included. We extracted the standard mean differences (SMDs) and corresponding 95% confidence intervals (CIs). A pooled-analysis was performed.

RESULTS

No marked difference (95% CI: -1.437-0.218, p = 0.149) of Se level between asthma and controls. Significant difference (95% CI: 0.112-1.032, p = 0.015; 95% CI: 0.376-1.331, p < 10^-4) of Cu level between asthma and controls was noted among overall populations and Asians. No marked difference of Zn level between asthma and controls was observed among overall populations, Asians, Caucasians and Africans. Significant difference (95% CI: -0.567 to -0.238, p < 10^-4) of Mg level between asthma and controls was noted among Asians. Marked difference (95% CI: 0.258-2.864, p = 0.019; 95% CI: 0.270-3.282, p = 0.021) of Fe level between asthma and controls was noted among overall populations and Asians. Age had no impact on the pooled SMDs of Se, Cu, Zn, Mg and Fe between asthma and controls. Sensitivity analyses did not change the overall results. No publication bias was noted for overall populations.

CONCLUSIONS

Alterations of Cu, Mg and Fe levels may be a biomarker of asthma risk among specific populations. Further studies should be performed to clarify the strength of these elements in asthma.

Does vitamin E prevent asthma or wheeze in children: A systematic review and meta-analysis

Asthma is a heterogeneous disease with multiple phenotypes. Epidemiologic studies suggest a close relationship between vitamin E and the occurrence of asthma, wheezing and atopic conditions during childhood. Previous results on its effects have been conflicting. The aim of this meta-analysis was to critically examine the current evidence on the association of vitamin E with childhood asthma and wheezing. We searched electronic databases for observational studies in English-language journals published from 2000 to 2016. The initial search found 420 titles; nineteen studies were eligible according to the abstracts and details, which included reporting asthma or wheeze as an outcome. None of the articles included in this meta-analysis reported side effects of vitamin E supplementation during pregnancy. This meta-analysis found that vitamin E supplementation during pregnancy influenced the risk of asthma. To better understand the effectiveness and safety of vitamin E in children with asthma, large-scale, well-designed and randomized controlled trials are needed.

Serum carotenoid and tocopherol concentrations and risk of asthma in childhood: a nested case-control study

BACKGROUND

The antioxidant hypothesis regarding the risk of asthma in childhood has resulted in inconsistent findings. Some data indicate that the role of antioxidants in childhood asthma risk may have a critical time window of effect, but only a well-designed longitudinal cohort study can clarify this hypothesis.

OBJECTIVE

To study the longitudinal associations between serum carotenoid and tocopherol concentrations during the first 4 years of life and asthma risk by the age of 5 years.

METHODS

Based on a case-control design nested within a Finnish birth cohort, 146 asthma cases were matched to 270 controls on birth time, sex, genetic risk, and birth place. Non-fasting blood samples were collected at the ages of 1, 1.5, 2, 3, and 4 years and serum carotenoids and tocopherols were analysed. Parents reported the presence and age at start of persistent doctor-diagnosed asthma in the child at the age of 5 years. Data analyses were conducted using generalized estimating equations.

RESULTS

We did not find strong associations between serum carotenoids and tocopherols and the risk of asthma based on age-specific and longitudinal analyses. Both lower and higher quarters of α-carotene and γ-tocopherol increased the risk of asthma.

CONCLUSIONS

The current findings do not support the suggestion that the increased prevalence of asthma may be a consequence of decreased intake of antioxidant nutrients. Moreover, we did not confirm any critical time window of impact of antioxidants on asthma risk. Replication of these findings in similar longitudinal settings will strengthen this evidence base.

The pathophysiological role of mitochondrial oxidative stress in lung diseases

Mitochondria are critically involved in reactive oxygen species (ROS)-dependent lung diseases, such as lung fibrosis, asbestos, chronic airway diseases and lung cancer. Mitochondrial DNA (mtDNA) encodes mitochondrial proteins and is more sensitive to oxidants than nuclear DNA. Damage to mtDNA causes mitochondrial dysfunction, including electron transport chain impairment and mitochondrial membrane potential loss. Furthermore, damaged mtDNA also acts as a damage-associated molecular pattern (DAMP) that drives inflammatory and immune responses. In this review, crosstalk among alveolar epithelial cells, alveolar macrophages and mitochondria is examined. ROS-related transcription factors and downstream cell signaling pathways are also discussed. We conclude that targeting oxidative stress with antioxidant agents, such as thiol molecules, polyphenols and superoxide dismutase (SOD), and promoting mitochondrial biogenesis should be considered as novel strategies for treating lung diseases that currently have no effective treatment options.

Biomarkers of oxidative stress and antioxidants in severe asthma: A Prospective Case-Control Study

BACKGROUND

Bronchial airway inflammation is the hallmark of asthma, which may be driven by an imbalance between oxidative stress and antioxidant defenses. Antioxidants deficiency may play a role, but this has remained unconfirmed.

OBJECTIVE

To evaluate the oxidative stress burden and antioxidants defenses in patients with increasing asthma severity.

METHODS

This prospective case-control study compared fractional exhaled nitric oxide (FeNO), exhaled breath condensate nitrite/nitrate (EBC-NOx), spirometry, and serum vitamins and trace elements among patients with and without asthma.

RESULTS

Sixty participants were recruited (30 with severe asthma number; 23 women [76.7%]; mean age, 41.4 years; mean forced expiratory volume in 1 second [FEV₁], 2.2 L [72.2% predicted]; mean inhaled corticosteroid dosage, 2,540 μg/d; 18/30 [60%] receiving maintenance oral corticosteroids; 15 with mild asthma; all corticosteroids naïve; 9 women [60%]; mean age, 34.6 years; mean FEV₁, 3.48 L [100.5% predicted]; 15 healthy controls; 12 women [80%]; mean age, 37.6 years; and mean FEV₁, 3.53 L [111.7% predicted]). The mean FeNO levels increased significantly with increasing asthma severity (P = .01), but the EBC-NOx levels did not change significantly (P = .90). Paradoxically, vitamin A and vitamin E increased with increased disease severity, with vitamin E levels increasing significantly (P = .07 and P < .001, respectively). There was no significant difference between groups in the levels of copper (P = .37), zinc (P = .97), or selenium (P = .90).

CONCLUSION

FeNO but not EBC-NOx is increased significantly with asthma severity with no evidence of vitamins or trace elements deficiency in severe asthma. Impaired oxidative stress defenses in severe asthma may be driven by factors other than vitamins or trace elements deficiency.

Diet Hypotheses in Light of the Microbiota Revolution: New Perspectives

From an evolutionary standpoint, allergy has only recently emerged as a significant health problem. Various hypotheses were proposed to explain this, but they all indicated the importance of rapid lifestyle changes, which occurred in industrialized countries in the last few decades. In this review, we discuss evidence from epidemiological and experimental studies that indicate changes in dietary habits may have played an important role in this phenomenon. Based on the example of dietary fiber, we discuss molecular mechanisms behind this and point towards the importance of diet-induced changes in the microbiota. Finally, we reason that future studies unraveling mechanisms governing these changes, along with the development of better tools to manipulate microbiota composition in individuals will be crucial for the design of novel strategies to combat numerous inflammatory disorders, including atopic diseases.

Vitamin E and the risk of childhood asthma

INTRODUCTION

Asthma, a heterogeneous disease with multiple phenotypes, remains a significant health problem. Present treatments are not curative and prevention should be our ultimate goal. Vitamin E supplementation presents a potential easy and cheap preventive therapy but the results of studies are confusing and sometimes contradictory. Clarification is needed.

AREAS COVERED

Animal studies and research in pregnant women suggest enhanced lifetime resistance to asthma with appropriate fetal exposure to vitamin E. Vitamin E's preventive role is complex and includes functional variations of the different isoforms. Expert commentary: We review the most recent literature on the role of vitamin E isoforms on: lung inflammation, immune development, animal and clinical studies during pregnancy, and the potential influence of vitamin E isoforms on asthma development in offspring. We point out where data are seemingly contradictory, explain why this is so, and comment on where further clarifying research is needed and its future direction.

Modulación de la respuesta alérgica por los carotenoides de la dieta

<p>Los carotenoides son pigmentos isoprenoides que están presentes de manera natural y en altas concentraciones en la mayoría de alimentos vegetales —entre ellos, aguacate, papaya, tomate y zanahoria—, pero también encontrados como aditivos y colorantes en diversos productos cárnicos, aceites vegetales, salsas, aderezos, harinas, entre otros. En los últimos años, algunos estudios han descrito que los carotenoides de la dieta participan en varios procesos fisiopatológicos, incluyendo la respuesta inmune de tipo alérgico. Las tasas de prevalencia para este tipo de enfermedades han incrementado de manera alarmante durante las últimas cinco décadas en todo el mundo, a la vez que varios factores e hipótesis se han planteado tratando de explicar este fenómeno: uno de ellos es la hipótesis de la dieta, la cual plantea que la composición de varios micro y macronutrientes de la alimentación, así como los cambios en los patrones dietarios, influirían en tal problemática. Evidencia epidemiológica y básica experimental emergente señala que los carotenoides de la dieta participan en la regulación de la inflamación alérgica, y por ello se postulan como coadyuvantes en la terapia de tales padecimientos. En el presente artículo se revisará el estado del arte en relación a los efectos de los carotenoides de la dieta sobre la patología alérgica.</p>

Cyclic nitroxide radicals attenuate inflammation and Hyper-responsiveness in a mouse model of allergic asthma

The effects of stable cyclic nitroxide radicals have been extensively investigated both in vivo and in vitro demonstrating anti-inflammatory, radioprotective, anti-mutagenic, age-retardant, hypotensive, anti-cancer and anti-teratogenic activities. Yet, these stable radicals have not been evaluated in asthma and other airway inflammatory disorders. The present study investigated the effect of 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl (TPL) and 3-carbamoyl-proxyl (3-CP) in a mouse model of ovalbumin (OVA)-induced allergic asthma. Both 3-CP and TPL were non-toxic when administered either orally (1% w/w nitroxide-containing chow) or via intraperitoneal (IP) injection (∼300 mg/kg). Feeding the mice orally demonstrated that 3-CP was more effective than TPL in reducing inflammatory cell recruitment into the airway and in suppressing airway hyper-responsiveness (AHR) in OVA-challenged mice. To characterize the optimal time-window of intervention and mode of drug administration, 3-CP was given orally during allergen sensitization, during allergen challenge or during both sensitization and challenge stages, and via IP injection or intranasal instillation for 3 days during the challenge period. 3-CP given via all modes of delivery markedly inhibited OVA-induced airway inflammation, expression of cytokines, AHR and protein nitration of the lung tissue. Oral administration during the entire experiment was the most efficient delivery of 3-CP and was more effective than dexamethasone a potent corticosteroid used for asthma treatment. Under a similar administration regimen (IP injection before the OVA challenge), the effect of 3-CP was similar to that of dexamethasone and even greater on AHR and protein nitration. The protective effect of the nitroxides, which preferentially react with free radicals, in suppressing the increase of main asthmatic inflammatory markers substantiate the key role played by reactive oxygen and nitrogen species in the molecular mechanism of asthma. The present results demonstrate the therapeutic potential of nitroxides for the treatment of asthma.

Plasma Selenium Concentrations Are Sufficient and Associated with Protease Inhibitor Use in Treated HIV-Infected Adults

BACKGROUND

Selenium is an essential constituent of selenoproteins, which play a substantial role in antioxidant defense and inflammatory cascades. Selenium deficiency is associated with disease states characterized by inflammation, including cardiovascular disease (CVD). Although HIV infection has been associated with low selenium, the role of selenium status in HIV-related CVD is unclear.

OBJECTIVES

We sought to assess associations between plasma selenium and markers of inflammation, immune activation, and subclinical vascular disease in HIV-infected adults on contemporary antiretroviral therapy (ART) and to determine if statin therapy modifies selenium status.

METHODS

In the Stopping Atherosclerosis and Treating Unhealthy bone with RosuvastatiN trial, HIV-infected adults on stable ART were randomly assigned 1:1 to rosuvastatin or placebo. Plasma selenium concentrations were determined at entry, week 24, and week 48. Spearman correlation and linear regression analyses were used to assess relations between baseline selenium, HIV-related factors and markers of inflammation, immune activation, and subclinical vascular disease. Changes in selenium over 24 and 48 wk were compared between groups.

RESULTS

One hundred forty-seven HIV-infected adults were included. All participants were on ART. Median current CD4+ count was 613, and 76% had HIV-1 RNA ≤48 copies/mL (range: <20-600). Median plasma selenium concentration was 122 μg/L (range: 62-200). At baseline, higher selenium was associated with protease inhibitor (PI) use, lower body mass index, and a higher proportion of activated CD8+ T cells (CD8+CD38+human leukocyte antigen-DR+), but not markers of inflammation or subclinical vascular disease. Over 48 wk, selenium concentrations increased in the statin group (P < 0.01 within group), but the change did not differ between groups (+13.1 vs. +5.3 μg/L; P = 0.14 between groups).

CONCLUSIONS

Plasma selenium concentrations were within the normal range for the background population and were not associated with subclinical vascular disease in HIV-infected adults on contemporary ART. The association between current PI use and higher selenium may have implications for ART allocation, especially in resource-limited countries. Also, it appears that statin therapy may increase selenium concentrations; however, larger studies are necessary to confirm this finding. This trial was registered at clinicaltrials.gov as NCT01218802.

The association between paracetamol use and asthma: causation or coincidence?

A better understanding of the causation of asthma and allergic disorders could potentially lead to intervention strategies that reduce their prevalence and severity. One potential causative factor is the use of paracetamol. Most of the evidence for the link with asthma is from non-experimental studies of paracetamol exposure in utero, infancy, childhood and adult life; however, it has been difficult to rule out confounding and bias in the associations observed. The two randomized clinical trials of the effect of paracetamol in patients with asthma have been difficult to interpret, due to methodological issues. There have been no randomized controlled trials of paracetamol use and the development of asthma. Both asthma and paracetamol use are common, and so even if there is a relatively small effect of paracetamol exposure on the development of asthma or its severity, then such an effect would be of major public health significance. It is proposed that randomized controlled trials of the effect of paracetamol on the development of asthma and its severity are a high research priority.

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.

Effect of Retinoic Acid in a Mouse Model of Allergic Rhinitis

PURPOSE

All-trans retinoic acid (ATRA) modulates immune responses by affecting T cells. Several studies have revealed that allergic inflammation of the lower airways is negatively associated with the vitamin A concentration. However, the role of ATRA in allergic inflammation of the upper airways is unclear. We investigated the effects of ATRA in an allergic rhinitis mouse model.

METHODS

BALB/c mice except control groups (CON group) were sensitized with and challenged intra-nasally with Dermatophagoides farina (AR group). The ATRA groups were administered ATRA intraperitoneally. The steroid groups were administered steroid intranasally (ST group). Allergic symptoms and the average eosinophil number were counted. Cytokines and transcription factors were measured by Real-Time PCR and Western blotting. Der f-specific immunoglobulin E (IgE) was measured. Flow cytometry results of CD4⁺CD25⁺Foxp3⁺ T cells were analyzed.

RESULTS

The symptom scores were lower in the ATRA group than in the AR group and higher than in the CON group. The levels of IgE were lower in the ATRA group than in the AR group and higher than in the CON and ST groups. The levels of Foxp3, TGF-β, and IL-10 mRNA, as well as the percentage of CD4⁺CD25⁺Foxp3⁺ T cells, were higher in the ATRA group than in theAR group. In the ATRA group the levels of IFN-γ mRNA were higher, and the levels of GATA-3 and IL-4 mRNA, and ROR-γt were lower. In Western blotting analyses, the expression patterns of all factors, except Foxp3, showed similar to those of mRNA expression.

CONCLUSIONS

ATRA has anti-allergic effects in an allergic rhinitis model, and its underlying mechanisms mainly include the induction of regulatory T cells and the inhibition of Th2 responses.

New risk factors for adult-onset incident asthma. A nested case-control study of host antioxidant defense

RATIONALE

Host antioxidant defense, consisting of enzymatic antioxidant activity and nonenzymatic antioxidant micronutrients, is implicated in asthma pathogenesis. Studies of antioxidant defense and adult incident asthma have either used measures of antioxidants estimated from questionnaires or not considered enzymatic aspects of host defense.

OBJECTIVES

We conducted the first study designed and powered to investigate the association of antioxidant defenses on adult incident asthma.

METHODS

In a nested case-control study, we followed Shanghai women (aged 40-70 years) without prevalent asthma at baseline, over 8 years. Subjects with incident asthma were ascertained prospectively by gold standard testing of symptomatic women and matched to two asymptomatic control subjects.

MEASUREMENTS AND MAIN RESULTS

Baseline urinary F2-isoprostanes, plasma concentrations of antioxidant micronutrients (tocopherols, xanthines, carotenes, and lycopene), and antioxidant enzyme activity (platelet-activating factor acetylhydrolase [PAF-AH] and superoxide dismutase) were measured from samples collected before disease onset. Among 65,372 women, 150 (0.24%) developed asthma. F2-isoprostane levels before asthma onset were not different between cases and control subjects. Doubling of α-tocopherol concentrations and PAF-AH activity was associated with 50 and 37% decreased risk of incident asthma (α-tocopherol: adjusted odds ratio = 0.52; 95% confidence interval, 0.32-0.84; PAF-AH: adjusted odds ratio = 0.63; 95% confidence interval, 0.42-0.93).

CONCLUSIONS

In this prospective study, α-tocopherol, within normal reference ranges, and PAF-AH enzymatic activity were associated with decreased asthma development. These modifiable risk factors may be an effective strategy to test for primary asthma prevention.

Risk and protective factors for the development of childhood asthma

Childhood asthma prevalence worldwide has been increasing markedly over several decades. Various theories have been proposed to account for this alarming trend. The disease has a broad spectrum of potential determinants ranging from genetics to lifestyle and environmental factors. Epidemiological observations have demonstrated that several important lifestyle and environmental factors including obesity, urban living, dietary patterns such as food low in antioxidants and fast food, non-breastfeeding, gut flora imbalance, cigarette smoking, air pollution, and viral infection are associated with asthma exacerbations in children. However, only environmental tobacco smoke has been associated with the development of asthma. Despite epidemiological studies indicating that many other factors are probably associated with the development of asthma, the relationships are not considered causal due to the inadequate evidence and inconsistent results from recent studies. This may highlight that sufficient data and exact mechanisms of causality are still in need of further study.

Relationships between Plasma Micronutrients, Serum IgE, and Skin Test Reactivity and Asthma among School Children in Rural Southwest Nigeria

Objective. Increasing prevalence of asthma has been attributed to changes in lifestyle and environmental exposures. We conducted a case-control study to investigate the relationship between serum micronutrients and asthma in rural school children in Nigeria. Methods. We administered questionnaires to 1,562 children to identify children with asthma. Serum concentration levels of 12 micronutrients were determined in asthma cases (N = 37) and controls (N = 30). Allergy skin prick test and spirometry were also performed. Results. Plasma levels of the following micronutrients were significantly different between cases and controls: calcium (7.48 ± 2.16 versus 8.29 ± 1.62 mg/dL; P = 0.04), manganese (44.1 ± 11.5 versus 49.3 ± 7.9 mg/L; P = 0.01), selenium (76.1 ± 14.9 versus 63.3 ± 26.8 μg/L; P = 0.02), and albumin (3.45 ± 0.90 versus 3.91 ± 0.99 g/dL; P = 0.04). Plasma concentrations of iron and selenium were positively correlated with lung function, r = 0.43 (P < 0.05 in each case) while manganese serum concentration was negatively correlated with asthma (r = −0.44; P < 0.05). Conclusions. Children with asthma had reduced levels of plasma manganese, calcium, and albumin but raised level of selenium. The protective or risk effects of these micronutrients on asthma warrant further investigation.

Effects of antioxidant supplements and nutrients on patients with asthma and allergies

Asthma and allergic diseases have become a worldwide public health concern because of their increased prevalence. Despite decades of research on risk factors, the causes of these disorders are poorly understood. They are thought to develop through complex interactions between genetic and environmental factors. Because pulmonary and systemic oxidative stress increase inflammatory responses relevant to asthma and allergy, dietary or vitamin supplementation with antioxidants (a broad and varied category) has been proposed as an approach to reducing asthma incidence or morbidity. Meta-analyses of observational epidemiologic studies of variable methodological quality suggest associations of relatively low dietary intake of antioxidants and higher asthma and allergy prevalence. However, there have been few longitudinal studies of maternal or child dietary or vitamin/supplement antioxidant intake and asthma/allergy development. Moreover, there are no clinical trial data to support the use of dietary antioxidants or supplements to prevent asthma or allergy. A few small clinical trials suggest that specific antioxidants from diet or vitamin supplements might improve asthma control or lung function in asthmatic children or adults. Studies suggest that responses to antioxidants might be modified by life stage, genetic susceptibility, and environmental sources of oxidative stress. Large trials of antioxidant vitamin supplementation to prevent cancer suggest an increase in overall mortality with antioxidant vitamin supplementation, at least in populations with sufficient dietary antioxidant intake. This cautionary experience suggests that future trials to assess whether antioxidants reduce asthma incidence or improve asthma control should focus on supplementation of dietary sources of antioxidants. The potential benefits and risks of trials of vitamin supplements might be considered in special situations in which vulnerable populations have marked deficiency in dietary antioxidants, poor access to dietary antioxidants, and high exposure to environmental sources of oxidants.

Allergic diseases: the price of civilisational progress

Atopic disorders are a major global health problem. The prevalence of asthma, allergic rhinitis and atopic dermatitis has been increasing over the last four decades, both in the industrialized and developing countries. It seems to be related to changes in the social structure, increasing industrialization, pollution and dietary changes. Many hypotheses link the allergy epidemic to stringent hygiene, dominance of a westernized lifestyle and an accelerated pace of life. Dietary antioxidants, lipids, sodium, vitamin D seem also to be implicated. We endeavour to review the most relevant theories with a special emphasis on the hygiene, antioxidative, lipid and air pollution hypotheses. It is however important to note that none of them explains all the aspects of unprecedented rise in the prevalence of allergic disorders. A complex interplay between host's immune response, invading pathogens, diversity of environmental factors and genetic background seems to be of a particular importance. Current allergy epidemic is multifactorial and basic and epidemiologic studies are warranted to further our understanding of this phenomenon.

Medical therapeutics for pulmonary arterial hypertension: from basic science and clinical trial design to evidence-based medicine

Pulmonary arterial hypertension is a severe disease with poor prognosis, caused by obliteration of the pulmonary vasculature as a result of pulmonary-vascular remodeling, active vasoconstriction and in situ thrombosis. Left untreated, pulmonary arterial hypertension results in right-ventricular failure and death. There has been dramatic progress in the treatment of pulmonary arterial hypertension during recent years. A remarkable number of randomized-controlled trials with agents known to target specific abnormalities present in pulmonary arterial hypertension have been completed. Most commonly, therapeutic efficacy was judged by the ability of the drug under study to improve exercise capacity and to decrease the rate of severe complications. Completed clinical trials have mainly evaluated patients with relatively advanced disease. Despite these advances, responses to therapy in pulmonary arterial hypertension are not uniformly favorable and frequently incomplete. In addition, the methods of delivery and the adverse effect profile of the currently available pulmonary arterial hypertension-specific drugs create further management difficulties. Based on newly identified pathobiologic abnormalities in the pulmonary vasculature, future studies are likely to focus on the discovery of new therapeutic targets. Clinical trial design will continue to evolve in an attempt to enable inclusion of patients with less advanced disease and evaluation of treatment combinations or comparisons of the currently approved drugs.

Serum vitamin E concentrations at 1 year and risk of atopy, atopic dermatitis, wheezing, and asthma in childhood: the PASTURE study

BACKGROUND

Prospective studies investigating the role of serum vitamin E concentrations during early life in the development of childhood allergies and asthma are limited.

OBJECTIVE

To study the associations between serum vitamin E concentrations at first year of life and longitudinal development of atopy, atopic dermatitis, wheeze, and asthma up to 6 years of age.

METHODS

The setting was the PASTURE study, a multicenter prospective birth cohort study in five European rural settings. Children of 1133 mothers recruited during pregnancy were followed from birth with measurement of serum vitamin E levels at year 1 and repeated assessments of serum immunoglobulin E antibodies (year 1, 4.5, 6), atopic dermatitis, wheezing symptoms, and asthma (year 1, 1.5, 2, 3, 4, 5, 6).

RESULTS

At 6 years of age, 66% and 82% of the original 1133 subjects underwent blood test for IgE and answered the questionnaire, respectively. We did not observe any statistically significant associations between serum vitamin E concentrations at year 1 and the endpoints, but borderline inverse associations between alpha tocopherol and wheezing without cold (OR 0.45, 95% CI 0.19-1.09) and any wheezing symptom (OR 0.52, 95% CI 0.27-1.02).

CONCLUSIONS

Serum vitamin E concentrations at year 1 were not associated with allergies or asthma by 6 years of age. While further prospective studies with repeated assessments of vitamin E during early life may clarify its putative role in the development of the diseases, it is also possible that the antioxidant hypothesis in the development of allergies and asthma does not hold.

Diet and allergic diseases among population aged 0 to 18 years: myth or reality?

Allergic diseases are an important health problem. However, epidemiological studies concerning childhood diet-related allergic diseases are scarce. This review examines published articles dealing with diet, dietary patterns and nutrition in relation with allergic diseases among population aged 0 to 18 years. Studies and trials were identified using MEDLINE/PubMed and Cochrane Database of Systematic Reviews and were limited to those published in English or French from 1992 until 2012. This manuscript also reviews the evidence for maternal diet during pregnancy and diet during early childhood and their association with childhood atopic diseases, taking into account the methodology used to evaluate dietary patterns. The evidence reviewed is derived from large epidemiological studies exploring the effects of different food categories on asthma, atopic dermatitis, and allergic rhinitis in children. Overall, maternal diet during pregnancy and a childhood diet rich in antioxidants and omega-3 fatty acids are considered as healthy diets that could be protective for allergic diseases in childhood.

Diet and asthma: vitamins and methyl donors

Diet changes can partly explain the high burden of asthma in industrialised nations. Findings from experimental studies have stimulated many observational studies of the association between vitamins (A, C, D, and E) or nutrients acting as methyl donors (folate, vitamin B12, and choline) and asthma. However, observational studies are susceptible to several sources of bias; well conducted randomised controlled trials (RCTs) are the gold standard to establish whether diet has an effect on asthma. Evidence from observational studies and a few RCTs strongly justifies ongoing and future RCTs in three areas: vitamin D for the prevention or treatment of asthma, choline supplementation as adjuvant treatment for asthma, and vitamin E to prevent the detrimental effects of air pollution in patients with asthma. At present, insufficient evidence exists to recommend supplementation with any vitamin or nutrient acting as a methyl donor to prevent or treat asthma.

Selenium status in a group of schoolchildren from the region of Madrid, Spain

BACKGROUND

To assess the selenium status of a group of schoolchildren from the Region of Madrid, Spain.

METHODS

Study subjects comprised 483 children (216 boys and 267 girls) aged between 8 and 13 years. Selenium intake was determined using a 3-day food record. The foods consumed were transformed into energy and nutrients, and the selenium intake was compared with that recommended. Serum selenium levels were also recorded.

RESULTS

Mean (SD) selenium intake [91.0 (25.2) μg day(-1) ] was above the recommended level in 99.4% of subjects; the main dietary sources were cereals, meats, fish and milk products. The serum selenium concentration [mean (SD) 71.1 (14.4) μg L(-1) ], however, was <60 μg L(-1) in 13.9% of subjects, and <45 μg L(-1) in 5.6%. The serum selenium concentration correlated with the selenium intake (r = 0.169; P < 0.05). Children with a serum selenium concentration of <75 μg L(-1) had significantly smaller selenium intakes than those with a serum concentration of ≥75 μg L(-1) .

CONCLUSIONS

Although selenium intake was generally above that recommended, the serum selenium concentration of the children could be improved. This could be achieved by increasing the relative consumption of cereals and other selenium rich foods such as fish.

Molecular mechanisms of reactive oxygen species-related pulmonary inflammation and asthma

Asthma is a highly relevant disorder that can be induced by many environmental factors such as allergens and pollutants. One of the most critical pathological symptoms of asthma is airway inflammation. In order to identify a cause of respiratory inflammation, we thoroughly examine the unique role of reactive oxygen species (ROS). Evidence supports that the inhalation of aggravating compounds such as allergens can promote the increased generation of ROS. Accordingly, ROS have a proven role in the cellular signaling cascades of many respiratory diseases that cause respiratory inflammation, including asthma. Although there is no known cure for asthma, current treatments effectively lessen the inflammation symptom. Based on the investigations of asthma pathogenesis and the mechanism of ROS formation, we have identified several novel anti-inflammatory therapeutic treatments, shedding light on a fundamental understanding for the cure of this disorder. In this review, we will outline the pathogenesis of asthma and its relationship to ROS, oxidative stress, and pulmonary inflammation.

Nutritional supplements and plasma antioxidants in childhood asthma

OBJECTIVE

This study investigated the relationship of plasma antioxidants to airway inflammation and systemic oxidative stress in children suffering from atopic asthma with consideration of the intake of nutritional supplements.

SUBJECTS AND RESEARCH METHODS

A total of 35 asthmatic children (AG) and 21 healthy controls (CG) participated in this study. Plasma levels of vitamins A and E, β-carotene, coenzyme Q10 and malondialdehyde (MDA) were analyzed with high-performance liquid chromatography (HPLC); the total antioxidant capacity (TAC) was measured photometrically, and selenium was determined by atomic absorption spectroscopy (AAS). The volume of fractionated exhaled nitric oxide (FeNO) was measured with the NIOX nitric oxide monitoring system.

RESULTS

The plasma antioxidants vitamins A and E, selenium, and coenzyme Q10 but not β-carotene were significantly (p < 0.05) lower in asthmatics than in controls. Further, asthmatic children had significantly reduced plasma concentrations of TAC (p < 0.01), significantly enhanced levels of MDA (p < 0.001), and exhaled a significantly (p < 0.001) higher mean volume of FENO than healthy children. Regular intake of supplements had a significant positive influence on plasma vitamin E (p < 0.01), selenium (p < 0.01), TAC (p < 0.05), MDA (p < 0.01), and FENO (p < 0.01) in asthmatics but not in controls. Additionally, significant negative associations of vitamin E and MDA (AG: p < 0.01; CG: p < 0.05), and vitamin E and FENO (AG: p < 0.05; CG: p > 0.05) were identified.

CONCLUSION

These results indicate that nutritional supplements beneficially modulate plasma antioxidants and thus might have a positive influence on systemic redox balance and subsequently, pulmonary inflammation in asthmatic children.

Non-pro-vitamin A and pro-vitamin A carotenoids in atopy development

Carotenoids are important derivatives of the human diet and occur in high concentrations in the human organism. Various carotenoids are also present in human breast milk and are transferred to breast-fed children. The alternative to breastfeeding is supplementation with an infant milk formula, but these formulas contain only a limited variety of carotenoids. Our question is: 'What is the function of various carotenoids in human nutrition with a special emphasis on child development and the development of atopy?' In this review, the mechanisms of action of the most important non-pro-vitamin A and pro-vitamin A carotenoids: α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene and retinoids are discussed. In summary, the combination of carotenoids, especially lycopene, seems to be of great importance, and exclusive usage of β-carotene in infant formula may yield in an increased atopy prevalence mediated in various target organs like the skin, lungs and immune competent cells. We conclude that the determination of novel bioactive metabolites of various carotenoids, at various stages in different organs during atopy development, might be the key to understanding the potential importance of carotenoids on atopy development.

Lipid profiles in children with and without asthma: interaction of asthma and obesity on hyperlipidemia

AIMS

The joint effect of obesity and asthma on hyperlipidemia has never been explored. We aim to examine (1) the association of dyslipidemia and asthma, (2) the interaction effect of asthma and obesity on hyperlipidemia, and (3) whether a gender difference existed in the above relationships.

METHODS

Between 2009 and 2010, 10- to 15-year-old children were recruited from 7 schools and 2 hospitals in Northern Taiwan. The population consisted of 237 asthmatic children and 225 non-asthmatic controls, and was further divided into four groups: non-obese controls, obese controls, non-obese asthmatics, and obese asthmatics. Measurements included anthropometric measures and blood samples for analysis of metabolic factors. The Cook's criteria were used to define childhood metabolic syndrome. General linear models were used to analyze how lipid profiles were associated with obesity and asthma.

RESULTS

Total cholesterol and low density lipoprotein cholesterol levels increased progressively in the group order obese asthmatics>non-obese asthmatics>obese controls>non-obese controls. In boys, low density lipoprotein cholesterol levels were significantly higher in obese asthmatics compared to obese non-asthmatics, with a mean difference of 6.2 mmol/L in the general linear model. We also discovered a significant interactive effect of obesity and asthma on hyperlipidemia in boys (p for interaction=0.03).

CONCLUSIONS

Asthma was associated with higher low density lipoprotein cholesterol levels and this association was amplified in overweight and obese subjects. A gender difference was observed in the joint effect of obesity and asthma on hyperlipidemia.

Role of selenium and zinc in the pathogenesis of food allergy in infants and young children

INTRODUCTION

Selenium and zinc are indispensable microelements for normal functioning and development of the human body. They are cofactors of many enzymes of the antioxidative barrier (selenium - glutathione peroxidase; zinc - superoxide dismutase). The aim of the study was to evaluate the importance of selenium and zinc in the pathogenesis of food allergy in small children.

MATERIAL AND METHODS

The study was performed in 134 children with food allergy, aged 1 to 36 months. The control group was composed of 36 children at the same age, without clinical symptoms of food intolerance. Each child had estimated serum levels of zinc and selenium. Furthermore, the authors evaluated activity of glutathione peroxidase (GSH-Px) in erythrocyte lysates and serum. Tests were performed twice, before and after 6-month administration of elimination diet.

RESULTS

The obtained results showed that children with food allergy had significantly lower concentrations of selenium, zinc and examined enzymes in comparison to children from the control group. Concentration of selenium and zinc as well as activity of examined enzymes increased after application of eliminative diet.

CONCLUSIONS

In children with allergy decreased concentrations of selenium and zinc, and lower values of glutathione peroxidase and superoxide dismutase which increased after elimination diet were affirmed. These observations suggest their role in pathogenesis of food allergy. Conducted observations indicate the need to monitor trace elements content in the diet in children with food allergy. The results showed that children with food allergy had a weakened antioxidative barrier.

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.

The interplay between diet and emerging allergy: what can we learn from Indigenous Australians?

The pathophysiology of atopic diseases, including asthma and allergy, is the result of complex gene-environment interactions. Since European colonization the Indigenous population of Australia has undergone significant changes with respect to their lifestyle as hunter-gatherers. These changes have had a detrimental effect on Aboriginal health, in part due to immunological modification. This review provides a comparative look at both the traditional Aboriginal/Indigenous diet and modern Western diets, examines some common allergies increasingly reported in contemporary Indigenous populations, and reviews concepts such the effect of vitamin deficiencies and changes in gut microbiota on immune function.

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.