Dietary patterns and asthma prevalence, incidence and control

Cardiorespiratory effects of indoor ozone exposure during sleep and the influencing factors: A prospective study among adults in China

Ambient ozone (O3) is recognized as a significant air pollutant with implications for cardiorespiratory health, yet the effects of indoor O3 exposure have received less consideration. Furthermore, while sleep occupies one-third of life, research on the health consequences of O3 exposure during this crucial period is scarce. This study aimed to investigate associations of indoor O3 during sleep with cardiorespiratory function and potential predisposing factors. A prospective study among 81 adults was conducted in Beijing, China. Repeated measurements of cardiorespiratory indices reflecting lung function, airway inflammation, cardiac autonomic function, blood pressure, systemic inflammation, platelet and glucose were performed on each subject. Real-time concentrations of indoor O3 during sleep were monitored. Associations of O3 with cardiorespiratory indices were evaluated using linear mixed-effect model. Effect modification by baseline lifestyles (diet, physical activity, sleep-related factors) and psychological status (stress and depression) were investigated through interaction analysis. The average indoor O3 concentration during sleep was 20.3 μg/m3, which was well below current Chinese indoor air quality standard of 160 μg/m3. O3 was associated with most respiratory indicators of decreased airway function except airway inflammation; whereas the cardiovascular effects were only manifested in autonomic dysfunction and not in others. An interquartile range increases in O3 at 6-h average was associated with changes of -3.60 % (95 % CI: -6.19 %, -0.93 %) and -9.60 % (95 % CI: -14.53 %, -4.39 %) in FVC and FEF25-75, respectively. Further, stronger effects were noted among participants with specific dietary patterns, poorer sleep and higher level of depression. This study provides the first general population-based evidence that low-level exposure to indoor O3 during sleep has greater effects on the respiratory system than on the cardiovascular system. Our findings identify the respiratory system as an important target for indoor O3 exposure, and particularly highlight the need for greater awareness of indoor air quality, especially during sleep.

The association of asthma and air pollution: Evidence from India

In the last two decades, air pollution has increased throughout India resulting in the deterioration of air quality. This paper estimates the prevalence of self-reported asthma in women aged 15-49 years and examines the link between outdoor air pollution and disease prevalence in India by combining satellite data on particulate matter (PM2.5) and the National Family Health Survey (NFHS-4), 2015-16. The results indicate that both indoor pollution as well as outdoor air pollution are important risk factors for asthma in women as both independently increase the probability of asthma among this group. Strategies around the prevention of asthma need to recognize the role of both indoor as well as outdoor air pollution. The other significant risk factors for asthma are smoking, second-hand smoking, type of diet and obesity.

Association between Butter, Margarine, and Olive Oil Intake and Asthma Symptoms among School Children: Result from a Large-Scale Cross-Sectional Study

Background

There are conflicting results about the association between dietary fat intake and asthma symptoms. Since few studies in the Middle East have been explored the relation between dietary fat consumption and risk of asthma, the present study was conducted to investigate the association between the consumption of butter, margarine, and olive oil and asthma risk in school children living in central Iran.

Method

In this cross-sectional study, out of 10,240 participants, asthma and its symptoms and dietary intake of butter, margarine, and olive oil of 7,667 children and adolescents were assessed using a validated International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. The relationship between fat subtypes and asthma was assessed using logistic regression.

Results

The prevalence of asthma confirmed by a doctor in the study population was 4.22%. An inverse association was found between butter and margarine consumption once or twice a week and odds of current asthma and wheezing in the past 12 months (OR = 0.52, 95% CI: 0.28-0.96; OR = 0.7, 95% CI: 0.55-0.88, respectively); however, those with higher consumption did not have a higher chance for developing wheezing or asthma.

Conclusion

We found that margarine and butter intake one or two times a week might have an inverse association with asthma and its symptoms among children. Prospective cohort studies are recommended to confirm these findings.

Association between the Consumption of Ultra-Processed Foods and Asthma in Adults from Ribeirão Preto, São Paulo, Brazil

BACKGROUND

Ultra-processed Food (UPF) consumption can play a role in the pathogenesis and progression of asthma. The aim of this study was to evaluate the association between the consumption of UPF and asthma.

METHODS

This cross-sectional study included 1857 adults aged 23-25 years from the Ribeirão Preto-SP birth cohort (1978/1979). The exposure variable was the consumption of UPF (expressed as their percentage contribution to energy intake-% total caloric value [%TCV] and their percentage contribution to the amount of food ingested-%grams), which was assessed with a food frequency questionnaire. Asthma was the outcome and was defined based on a positive methacholine challenge test and the presence of wheezing, chest tightness, or shortness of breath over the last 12 months. Poisson regression with robust variance was used to estimate the association between these variables. Unadjusted analyses and analyses adjusted for sex, age, household income, smoking, and physical activity level were performed.

RESULTS

The prevalence of asthma in the sample was 13.2%. The mean total consumption of UPF was 37.9 ± 11.2% TCV (corresponding to 35.1 ± 15.1% grams). There was no association between the consumption of UPF and asthma in adults.

CONCLUSION

This study provides no evidence for an association between the consumption of UPF and asthma in young adults.

Vitamin D and Omega-3 (Fatty Acid) Supplementation in Pregnancy for the Primary Prevention of Food Allergy in Children-Literature Review

During the last decades the prevalence of food allergy (FA), an adverse immune response to a specific food antigen, has risen, with negative effects on the quality of life (QoL) of many children and their families. The pathogenesis of FA is complex, involving both genetic and environmental factors. SPINK5, STAT6, HLA and FOXP3 are some of the genes that are reported to be implicated in FA development. Regarding environmental factors, particular interest has been focused on modification of the dietary habits of pregnant women for the primary prevention of FA. Specifically, Vitamin D and omega-3 (Ω-3) fatty acid supplementation during pregnancy may influence the development of FA in the offspring. Vitamin D is a hormone with various actions, including mediation of the immune system, reducing the production of inflammatory cytokines and promoting tolerance. Vitamin D deficiency in pregnancy suppresses T-regulatory cells in the fetus, and Vitamin D supplementation might protect against FA development. Dietary Ω-3 fatty acids are found mainly in fish and vegetable oils. They are beneficial for human health, playing a role in the immune system as anti-inflammatory agents, and providing cell membrane stabilization with inhibition of antigen presentation. It is documented that maternal supplementation with Ω-3 during pregnancy may protect from allergic sensitization in the children. The aim of this literature review was to explore the potential preventive role of maternal supplementation during pregnancy with Vitamin D and Ω-3 in the development of FA in the offspring. With the prevalence of FA rising, all the possible protective mechanisms and measures for FA prevention need to be explored, starting with those that can be modified.

Diet Quality and Exhaled Breath Condensate Markers in a Sample of School-Aged Children

Exhaled breath condensate (EBC) analysis is a recently developed, non-invasive method used to identify and quantify biomarkers, mainly those coming from the lower respiratory tract. It seems that diet can influence the airway's inflammation and change the exhaled breath composition. This study aimed to assess the association between diet quality intake and markers in EBC among school-aged children. A cross-sectional analysis included 150 children (48.3% females, aged 7-12 years, mean age: 8.7 ± 0.8 years) from 20 schools across Porto, Portugal. We assessed diet quality through the Healthy Eating Index (HEI)-2015, which was estimated based on a single 24 h food recall questionnaire. EBC samples were collected, and we assessed their ionic content (Na⁺, K⁺) and conductivity. The association between diet quality and Na⁺, K⁺, Na⁺/K⁺ ratio and conductivity was estimated using logistic regression models adjusted for potential confounders. After adjustment, a higher quality diet score increases the odds of higher conductivity values of the EBC (aOR = 1.04, 95%CI 1.00; 1.08). Our findings suggest that a higher diet quality in school-aged children is associated with higher conductivity levels of the EBC.

Dietary digestible carbohydrates are associated with higher prevalence of asthma in humans and with aggravated lung allergic inflammation in mice

BACKGROUND

Dietary carbohydrates and fats are intrinsically correlated within the habitual diet. We aimed to disentangle the associations of starch and sucrose from those of fat, in relation to allergic sensitization, asthma and rhinoconjuctivitis prevalence in humans, and to investigate underlying mechanisms using murine models.

METHODS

Epidemiological data from participants of two German birth cohorts (age 15) were used in logistic regression analyses testing cross-sectional associations of starch and sucrose (and their main dietary sources) with aeroallergen sensitization, asthma and rhinoconjunctivitis, adjusting for correlated fats (saturated, monounsaturated, omega-6 and omega-3 polyunsaturated) and other covariates. For mechanistic insights, murine models of aeroallergen-induced allergic airway inflammation (AAI) fed with a low-fat-high-sucrose or -high-starch versus a high-fat diet were used to characterize and quantify disease development. Metabolic and physiologic parameters were used to track outcomes of dietary interventions and cellular and molecular responses to monitor the development of AAI. Oxidative stress biomarkers were measured in murine sera or lung homogenates.

RESULTS

We demonstrate a direct association of dietary sucrose with asthma prevalence in males, while starch was associated with higher asthma prevalence in females. In mice, high-carbohydrate feeding, despite scant metabolic effects, aggravated AAI compared to high-fat in both sexes, as displayed by humoral response, mucus hypersecretion, lung inflammatory cell infiltration and T_H 2-T_H 17 profiles. Compared to high-fat, high-carbohydrate intake was associated with increased pulmonary oxidative stress, signals of metabolic switch to glycolysis and decreased systemic anti-oxidative capacity.

CONCLUSION

High consumption of digestible carbohydrates is associated with an increased prevalence of asthma in humans and aggravated lung allergic inflammation in mice, involving oxidative stress-related mechanisms.

The Burden of Carbohydrates in Health and Disease

Foods high in carbohydrates are an important part of a healthy diet, since they provide the body with glucose to support bodily functions and physical activity. However, the abusive consumption of refined, simple, and low-quality carbohydrates has a direct implication on the physical and mental pathophysiology. Then, carbohydrate consumption is postulated as a crucial factor in the development of the main Western diseases of the 21st century. We conducted this narrative critical review using MedLine (Pubmed), Cochrane (Wiley), Embase, and CinAhl databases with the MeSH-compliant keywords: carbohydrates and evolution, development, phylogenetic, GUT, microbiota, stress, metabolic health, consumption behaviors, metabolic disease, cardiovascular disease, mental disease, anxiety, depression, cancer, chronic kidney failure, allergies, and asthma in order to analyze the impact of carbohydrates on health. Evidence suggests that carbohydrates, especially fiber, are beneficial for the well-being and growth of gut microorganisms and consequently for the host in this symbiotic relationship, producing microbial alterations a negative effect on mental health and different organic systems. In addition, evidence suggests a negative impact of simple carbohydrates and refined carbohydrates on mood categories, including alertness and tiredness, reinforcing a vicious circle. Regarding physical health, sugar intake can affect the development and prognosis of metabolic disease, as an uncontrolled intake of refined carbohydrates puts individuals at risk of developing metabolic syndrome and subsequently developing metabolic disease.

The Role of Diet and Gut Microbiota in Regulating Gastrointestinal and Inflammatory Disease

Diet is an important lifestyle factor that is known to contribute in the development of human disease. It is well established that poor diet plays an active role in exacerbating metabolic diseases, such as obesity, diabetes and hypertension. Our understanding of how the immune system drives chronic inflammation and disease pathogenesis has evolved in recent years. However, the contribution of dietary factors to inflammatory conditions such as inflammatory bowel disease, multiple sclerosis and arthritis remain poorly defined. A western diet has been associated as pro-inflammatory, in contrast to traditional dietary patterns that are associated as being anti-inflammatory. This may be due to direct effects of nutrients on immune cell function. Diet may also affect the composition and function of gut microbiota, which consequently affects immunity. In animal models of inflammatory disease, diet may modulate inflammation in the gastrointestinal tract and in other peripheral sites. Despite limitations of animal models, there is now emerging evidence to show that anti-inflammatory effects of diet may translate to human gastrointestinal and inflammatory diseases. However, appropriately designed, larger clinical studies must be conducted to confirm the therapeutic benefit of dietary therapy.

Nutrition during Pregnancy and Lactation: Epigenetic Effects on Infants’ Immune System in Food Allergy

Food allergies are an increasing health problem worldwide. They are multifactorial diseases, in which the genome alone does not explain the development of the disease, but a genetic predisposition and various environmental factors contribute to their onset. Environmental factors, in particular nutritional factors, in the early stages of life are recognized as key elements in the etiology of food allergies. There is growing evidence advising that nutrition can affect the risk of developing food allergies through epigenetic mechanisms elicited by the nutritional factors themselves or by modulating the gut microbiota and its functional products. Gut microbiota and postbiotics can in turn influence the risk of food allergy development through epigenetic mechanisms. Epigenetic programming accounts not only for the short-term effects on the individual’s health status, but also for those observed in adulthood. The first thousand days of life represent an important window of susceptibility in which environmental factors, including nutritional ones, can influence the risk of developing allergies through epigenetic mechanisms. From this point of view, it represents an interesting window of opportunity and intervention. This review reports the main nutritional factors that in the early stages of life can influence immune oral tolerance through the modulation of epigenetic mechanisms.

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.

Potential Role of Omega-3 Polyunsaturated Fatty Acids in Pediatric Food Allergy

Polyunsaturated fatty acids (PUFAs) are involved both in immune system regulation and inflammation. In particular, within the PUFAs category, omega-3 (ω-3) may reduce inflammation, whereas omega-6 (ω-6) PUFAs are generally considered to have a proinflammatory effect. Recent evidence highlights an imbalance in the ω-3:ω-6 ratio with an increased intake of ω-6, as a consequence of the shift towards a westernized diet. In critical age groups such as infants, toddlers and young children, as well as pregnant and lactating women or fish allergic patients, ω-3 intake may be inadequate. This review aims to discuss the potential beneficial effects of PUFAs on pediatric food allergy prevention and treatment, both at prenatal and postnatal ages. Data from preclinical studies with PUFAs supplementation show encouraging effects in suppressing allergic response. Clinical studies results are still conflicting about the best timing and dosages of supplementation and which individuals are most likely to benefit; therefore, it is still not possible to draw firm conclusions. With regard to food-allergic children, it is still debated whether PUFAs could slow disease progression or not, since consistent data are lacking. In conclusion, more data on the effects of ω-3 PUFAs supplementation alone or in combination with other nutrients are warranted, both in the general and food allergic population.

LncRNA RP5-857K21.7 inhibits PDGF-BB-induced proliferation and migration of airway smooth muscle cells through the miR-508-3p/PI3K/AKT/mTOR axis

The continuous increase in the prevalence of asthma poses a threat to human health. Despites numerous researches, the understanding of asthma development still remain elusive, hindering the development of effective treatment. Here, we explored the role of lncRNA RP5-857K21.7 (RP5-857K21.7) in the development of asthma and its potential molecular mechanism of regulation. Airway smooth muscle cells (ASMCs) were isolated and cultured after which some of the cells were induced with PDGF-BB to build an asthma cell model, and then, qRT-PCR analysis was used to measure the expression level of RP5-857K21.7 in the cell model. Result shows that the RP5-857K21.7 is significantly downregulated in PDGF-BB-induced ASMCs cells. Through CCK-8, transwell, and flow cytometry assay, we examined the functional impact of RP5-857K21.7 on the proliferation, migration, and apoptosis of the ASMCs, respectively, and found that the overexpression of RP5-857K21.7 markedly inhibit PDGF-BB-induced ASMCs cell proliferation, migration and induce apoptosis. Bioinformatics analysis predicted that the RP5-857K21.7 could sponge miR-508-3p and result was validated through a dual-luciferase reporter assay, biotinylated RNA pull-down assay, and RIP-qRT-PCR analysis. Mechanistically, RP5-857K21.7 regulates the PI3K/AKT/mTOR pathway by endogenously sponging miR-508-3p to inhibit PDGF-BB-induced ASMCs cell proliferation, migration and induce apoptosis. The current research suggests that the RP5-857K21.7 and its associated molecular pathway (miR-508-3p/PI3K/AKT/mTOR axis) might be a useful therapeutic target for the treatment of asthma disease.

An Ultra-Processed Food Dietary Pattern Is Associated with Lower Diet Quality in Portuguese Adults and the Elderly: The UPPER Project

This study aimed to identify dietary patterns (DPs) and their associations with sociodemographic factors and diet quality in Portuguese adults and the elderly. Cross-sectional data were obtained from the National Food, Nutrition and Physical Activity Survey (2015-2016), with two non-consecutive dietary 24 h recalls. Food items were classified according to the NOVA system and its proportion (in grams) in the total daily diet was considered to identify DPs by latent class analysis, using age and sex as concomitant variables. Multinomial logistic and linear regressions were performed to test associations of DPs with sociodemographic characteristics and diet quality, respectively. Three DPs were identified: "Traditional" (higher vegetables, fish, olive oil, breads, beer and wine intake), "Unhealthy" (higher pasta, sugar-sweetened beverages, confectionery and sausages intake) and "Diet concerns" (lower intake of cereals, red meat, sugar-sweetened and alcoholic beverages). "Unhealthy" was associated with being younger and lower intake of dietary fiber and vitamins and the highest free sugars and ultra-processed foods (UPF). "Diet concerns" was associated with being female and a more favorable nutrient profile, but both DPs presented a higher contribution of UPF than the "Traditional" DP. These findings should be considered for the design of food-based interventions and public policies for these age groups in Portugal.

Understanding socio-economic inequalities in the prevalence of asthma in India: an evidence from national sample survey 2017-18

Background

Today, over 300 million people reside with asthma worldwide and India alone is home for 6% of children and 2% of adults suffering from this chronic disease. A common notion of disparity persists in terms of health outcomes across the poor and better-off section of the society. Thus, there is a need to explore socio-economic inequality in the contribution of various factors associated with asthma prevalence in India.

Methods

Data for the study were carved out from the 75th round of National Sample Survey (NSS), collected by the National Sample Survey Organization (NSSO) during 2017–18. The sample size for this study was 555,289 individuals, for which data was used for the analysis. Descriptive statistics were used to show the distribution of the study population. Further, bivariate and multivariate analysis was performed to identify the factors associated with Asthma prevalence. The concentration index was used to measure the inequality. Further, we used decomposition analysis to find the contribution of factors responsible for socio-economic status-related inequality in asthma prevalence.

Results

The prevalence of asthma was 2 per 1000 in the whole population; however, the prevalence differs by age groups in a significant manner. Age, sex, educational status, place of residence, cooking fuel, source of drinking water, household size and garbage disposal facility were significantly associated with asthma prevalence in India. It was found that asthma was more concentrated among individuals from higher socioeconomic status (concentration index: 0.15; p < 0.05). While exploring socio-economic inequality for asthma, richest wealth status (53.9%) was the most significant contributor in explaining the majority of the inequality followed by the urban place of residence (37.9%) and individual from age group 45–65 years (33.3%). Additionally, individual aged 65 years and above (27.9%) and household size less than four members (14.7%) contributed in explaining socio-economic inequality for asthma.

Conclusion

Due to the heterogeneous nature of asthma, associations between different socio-economic indicators and asthma can be complex and may point in different directions. Hence, considering the concentration of asthma prevalence in vulnerable populations and its long-term effect on general health, a comprehensive programme to tackle chronic respiratory diseases and asthma, in particular, is urgently needed.

Higher diversity of vegetable consumption is associated with less airway inflammation and prevalence of asthma in school-aged children

BACKGROUND

A diet rich in fruits and vegetables has been suggested to counteract the oxidative stress and inflammation that characterize asthma. We aimed to assess the association between vegetable and fruit diversity consumption and asthma and its related outcomes in school-aged children.

METHODS

Participants included 647 children (49% females, aged 7-12 years) recruited from 20 public schools across the city of Porto, in Portugal. Vegetable intake and fruit intake were ascertained using a single self-reported 24-hour recall questionnaire. A diversity score was built taking into account the different number of individual vegetables and fruits consumed and categorized into two groups based on the total reported median consumption, which was rounded to the nearest whole number (≤3 and >3, for vegetables; and ≤1 and >1, for fruits). A questionnaire was used to enquire about self-reported medical diagnosis of asthma and respiratory symptoms. Airway inflammation was assessed measuring exhaled fractional nitric oxide concentration (eNO) and was categorized into two groups (<35 and ≥35 ppb). The association between fruit and vegetable diversity and respiratory outcomes was examined using logistic regression models, adjusting for confounders.

RESULTS

A higher vegetable diversity consumption per day was negatively associated with having self-reported asthma (OR = 0.67; 95% CI 0.47, 0.95), while having a vegetable diversity consumption superior to 3 items per day was negatively associated with levels of eNO ≥ 35 ppb (OR = 0.38; 95% CI 0.16, 0.88) and breathing difficulties (OR = 0.39; 95% CI 0.16, 0.97).

CONCLUSION

Eating a greater variety of vegetables was associated with a lower chance of airway inflammation and prevalence of self-reported asthma in school children.

Asthma increased in young adults from 2008-2016 despite stable allergic rhinitis and reduced smoking

BACKGROUND

Studies have produced inconsistent results on prevalence trends in asthma and allergic rhinitis (AR). We surveyed young adults about asthma in 2008 and 2016 and examined the impact of gender, AR and smoking.

METHODS

Thirty-thousand randomly selected subjects aged 16-75 years in Western Sweden received postal questionnaires in 2008 and 50,000 in 2016. This study is based on responders aged 16-25 years, 2,143 in 2008 and 2,484 in 2016.

RESULTS

From 2008-2016 current asthma increased from 9.3% to 11.5% (p = 0.014) and was significant in males without AR (aOR 1.83, 95% CI 1.09-3.07) and male smokers (aOR 3.02, 95% CI 1.12-8.13). In both years the risk of current asthma was reduced by growing up on a farm (aOR 0.26, 95% CI 0.81-0.84 and aOR 0.47, 95% CI 0.23-0.996), independent of a family history of asthma or allergy. AR did not differ significantly from 2008-2016 (22.5% vs 24.4%, p = 0.144). Current smoking decreased from 20.3% to 15.2% (p<0.001), especially in females (23.5% to 16.2%, p<0.001). Female smokers started smoking later and smoked fewer cigarettes in 2016 than 2008. In 2016, 4.8% of the cohort reported using electronic cigarettes. Of those, 60.7% also smoked tobacco and more than two-thirds who used both (67.2%) were heavy smokers.

CONCLUSION

Current asthma increased in respondents aged 16-25 from 2008-2016, mainly among males without AR and male smokers. Current AR levelled off in this young population, while current smoking decreased among females.

Consumption of ultra-processed products and wheezing respiratory diseases in children: The SENDO project

INTRODUCTION

The consumption of ultra-processed products (UP) is associated with many diseases in the adult, such as arterial hypertension, diabetes, or asthma.

OBJECTIVE

To determine whether the consumption of UP in children is associated with wheezing respiratory diseases (asthma or bronchitis/recurrent wheezing).

MATERIAL AND METHODS

A cross-sectional study was conducted within the Follow-up of the Child for Optimal Development (SENDO) project (an open, multidisciplinary and multiple outcome study of Spanish children). The consumption of UP was calculated using semi-quantitative questionnaires on the frequency of food consumption. The foods were grouped according to the NOVA classification, and the daily consumption was estimated along with the percentage of Kilocalories from the UP. The exposure was grouped into "high" and "low" from the median consumption. Odds Ratios and 95% confidence intervals were calculated for wheezing respiratory diseases associated with the high consumption UP, using low consumption as a reference. Crude and multi-adjusted estimators were calculated, and mixed regression models were used to take into account the correlation between siblings.

RESULTS

In the 513 children studied (51.8% males, mean age 5.2 years), the mean consumption of UP was 446.76 g/day, representing 39.9% of the total calories ingested. A high consumption of UP was associated with an increase of 87% in the prevalence of wheezing respiratory diseases (OR: 1.87, 95% CI: 1.01-3.45). It was found that a higher consumption of UP multiplied by 2.12 (95% CI: 1.10-4.05) the prevalence of bronchitis/recurrent wheezing.

CONCLUSIONS

The results of this study show a direct relationship between UP consumption and the prevalence of wheezing diseases in children.

The Infant Microbiome and Its Impact on Development of Food Allergy

The prevalence of food allergy (FA) has been increasing over the past few decades; recent statistics suggest that FA has an impact on up to 10% of the population and 8% of children. Although the pathogenesis of FA is unclear, studies suggest gut microbiome plays a role in the development of FA. The gut microbiome is influenced by infant feeding method, infant diet, and maternal diet during lactation. Breastfeeding, Mediterranean diet, and probiotics are associated with commensal gut microbiota that protect against FA. This area of research is essential to discovering potential preventive methods or therapeutic targets against FA.

[Consumption of ultra-processed products and wheezing respiratory diseases in children: The SENDO project]

INTRODUCTION

The consumption of ultra-processed products (UP) is associated with many diseases in the adult, such as arterial hypertension, diabetes, or asthma.

OBJECTIVE

To determine whether the consumption of UP in children is associated with wheezing respiratory diseases (asthma or bronchitis/recurrent wheezing).

MATERIAL AND METHODS

A cross-sectional study was conducted within the Follow-up of the Child for Optimal Development ?SENDO? project (an open, multidisciplinary and multiple outcome study of Spanish children). The consumption of UP was calculated using semi-quantitative questionnaires on the frequency of food consumption. The foods were grouped according the NOVA classification, and the daily consumption was estimated along with the percentage of kilocalories from the UP. The exposure was grouped into "high" and "low" from the median consumption. Odds ratios and 95% confidence intervals were calculated for wheezing respiratory diseases associated with the high consumption UP, using low consumption as a reference. Crude and multi-adjusted estimators were calculated, and mixed regression models were used to take into account the correlation between siblings.

RESULTS

In the 513 children studied (51.8% males, mean age 5.2 years), the mean consumption of UP was 446.76g/day, representing 39.9% of the total calories ingested. A high consumption of UP was associated with an increase of 87% in the prevalence of wheezing respiratory diseases (OR 1.87; 95% CI 1.01-3.45). It was found that a higher consumption of UP multiplied by 2.12 (95% CI 1.10-4.05) the prevalence of bronchitis/recurrent wheezing.

CONCLUSIONS

The results of this study show a direct relationship between UP consumption and the prevalence of wheezing diseases in children.

The inflammatory potential of diet impacts the association between air pollution and childhood asthma

BACKGROUND

Inhalation of fine particulate matter (PM) can cause systematic inflammation and oxidative stress, which may further aggravate the development and progression of asthma. Although nutritional intake of fatty acids and antioxidants may attenuate some effects of fine PM, the role of the inflammatory potential of diet has not been addressed. Therefore, we aimed to investigate possible modulatory effects of dietary inflammatory potential on the association between indoor air pollution and childhood asthma-related outcomes.

METHODS

In a sample of 501 children (48.1% females, aged 7-12 years) from 20 public schools located in Porto, Portugal, we evaluated airway reversibility, exhaled nitric oxide levels, atopy, and current respiratory symptoms. Dietary inflammatory index was calculated based on information collected through a reported 24-hour recall questionnaire, and participants were categorized as having an anti-inflammatory or pro-inflammatory diet. Concentrations of indoor PM2.5 and PM10 were measured to assess indoor air quality. Generalized linear mixed models were used to investigate the proportion of effects explained by the exposure to PM2.5 and PM10.

RESULTS

After adjustment, the exposure effect of PM2.5 and PM10 levels on children with asthma was higher for those having a pro-inflammatory diet (OR = 1.44, 95% CI: 1.01-2.21; and OR = 1.29, 95% CI: 1.03-1.68, respectively) compared to those having an anti-inflammatory diet.

CONCLUSION

These findings suggest that the quality of diet might affect the association between indoor pollution and asthma in children, highlighting the relevance of children's diet as a potential protective factor to pollutant exposure in childhood asthma.

Higher Omega-3 Index Is Associated with Better Asthma Control and Lower Medication Dose: A Cross-Sectional Study

Asthma is a chronic inflammatory airway disease, associated with systemic inflammation. Omega-3 polyunsaturated fatty acids (n-3 PUFA) have established anti-inflammatory effects, thus having potential as an adjunct therapy in asthma. This study aimed to compare erythrocyte n-3 PUFA in adults with (n = 255) and without (n = 137) asthma and determine the relationship between erythrocyte n-3 PUFA and clinical asthma outcomes. Subjects had blood collected, lung function measured and Juniper Asthma Control Questionnaire (ACQ) score calculated. Fatty acids were measured in erythrocyte membranes by gas chromatography, and the omega-3 index (O3I) was calculated (% eicosapentaenoic acid + % docosahexaenoic acid). O3I was similar in subjects with and without asthma (p = 0.089). A higher O3I was observed in subjects with controlled or partially controlled asthma (ACQ < 1.5) compared to subjects with uncontrolled asthma (ACQ ≥ 1.5) (6.0% (5.4–7.2) versus 5.6% (4.6–6.4) p = 0.033). Subjects with a high O3I (≥8%) had a lower maintenance dose of inhaled corticosteroids (ICS) compared to those with a low O3I (<8%) (1000 μg (400–1000) versus 1000 μg (500–2000) p = 0.019). This study demonstrates that a higher O3I is associated with better asthma control and with lower ICS dose, suggesting that a higher erythrocyte n-3 PUFA level may have a role in asthma management.

Dietary Acid Load: A Novel Nutritional Target in Overweight/Obese Children with Asthma?

Obesity has been repeatedly linked to asthma, and several potential mechanisms have been proposed in the etiologies of the obese-asthma phenotype. Considering that lungs play an important role in systemic pH and acid–base regulation, are a key organ in asthma development, and that nutritional inadequacy of several nutrients and high dietary acid load can affect airway inflammation and reactivity, we aimed to test the hypothesis that dietary acid load may be associated with asthma in children. Data on 699 children (52% females), aged 7–12 years, were analyzed. Anthropometric measurements were performed to assess body mass index. Dietary acid load was calculated using potential renal acid load (PRAL) equations from a 24 h dietary recall administrated to children. Adjusted PRAL for total energy intake was applied with the use of the residual method. Lung function and airway reversibility were assessed with spirometry. Asthma was defined by a positive bronchodilation or self-reported medical diagnosis with reported symptoms (wheezing, dyspnea, or dry cough) in the past 12 months. After adjustment for energy intake, sex, age, parent’s education level, and physical activity, positive and significant associations were found between asthma and PRAL [odds ratio (OR) = 1.953, 95% CI = 1.024, 3.730) in overweight/obese children. Our findings suggest that dietary acid load might be a possible mechanism in overweight/obese-asthma phenotype development.

Association between Soft Drink Consumption and Asthma among Qatari Adults

We aimed to examine the association between soft drink consumption and asthma and lung function among Qatari adults. In the cross-sectional study, we used data from 986 Qatari participants aged 20 years and above attending the Qatar Biobank Study. Usual consumption of soft drink was assessed using a food frequency questionnaire. Lung function was measured by spirometry and asthma was based on self-report. The associations between soft drink consumption and asthma and lung function were assessed using multivariable logistic and linear regression, respectively. In total, 65 participants out of 986 (6.6%) reported having asthma. A clear dose-response relationship between soft drink consumption and asthma was found. High soft drink consumers (≥7 times/week) were 2.60 (95% CI 1.20–5.63) times more likely to have asthma as compared to non-consumers. The association was partly mediated by BMI and inflammation. Diet soft drink consumption was positively associated with asthma (OR 1.12 (95% CI 1.02–1.23)) but not with lung function. Regular soft drink consumption was inversely associated with FEV1, but not with FVC. In conclusion, soft drink consumption is positively associated with asthma in Qatari adults. The association is partly mediated by obesity and inflammation. Limiting soft drink consumption should be taken into consideration for asthma prevention.

Associations of ultra-processed food and drink products with asthma and wheezing among Brazilian adolescents

BACKGROUND

Although both consumptions of ultra-processed products and asthma are common during adolescence, the epidemiological evidence in regarding their association is unclear. We investigated the associations of ultra-processed products consumption with asthma and wheezing in a representative sample of Brazilian adolescents.

METHODS

We used data from a representative sample of 109 104 Brazilian adolescents enrolled in the National Survey of School Health, 2012. The consumption of ultra-processed products was based on the weekly consumption (0-2, 3-4, ≥5 d/wk) of sweet biscuits, salty biscuits, ultra-processed meats, sweets/candies, soft drinks, and packaged snacks over the previous 7 days. We also calculated an ultra-processed consumption score by adding partial scores corresponding to weekly frequency intake of each ultra-processed product. The ultra-processed consumption score ranged from 0 to 42, the higher score, the higher the intake of these products. The presence of wheezing in the previous 12 months and asthma at any time in the past was self-reported.

RESULTS

The adjusted odds ratios of asthma comparing the extreme categories ranged from 1.08 (95% CI 1.03-1.13) for sweets/candies to 1.30 (1.21-1.40) for ultra-processed meats. Similar magnitude of associations was found for wheezing outcome. The ultra-processed consumption score was positively associated with the presence of asthma and wheezing in a dose-response manner. The adjusted OR of asthma and wheezing comparing highest to lowest quintile of ultra-processed consumption score was 1.27 (95% CI 1.15-1.41) and 1.42 (1.35-1.50), respectively.

CONCLUSIONS

The consumption of ultra-processed products was positively associated with the presence of asthma and wheezing in adolescents.

Impact of Dietary Cholesterol on the Pathophysiology of Infectious and Autoimmune Disease

Cellular cholesterol metabolism, lipid raft formation, and lipoprotein interactions contribute to the regulation of immune-mediated inflammation and response to pathogens. Lipid pathways have been implicated in the pathogenesis of bacterial and viral infections, whereas altered lipid metabolism may contribute to immune dysfunction in autoimmune diseases, such as systemic lupus erythematosus, multiple sclerosis, and rheumatoid arthritis. Interestingly, dietary cholesterol may exert protective or detrimental effects on risk, progression, and treatment of different infectious and autoimmune diseases, although current findings suggest that these effects are variable across populations and different diseases. Research evaluating the effects of dietary cholesterol, often provided by eggs or as a component of Western-style diets, demonstrates that cholesterol-rich dietary patterns affect markers of immune inflammation and cellular cholesterol metabolism, while additionally modulating lipoprotein profiles and functional properties of HDL. Further, cholesterol-rich diets appear to differentially impact immunomodulatory lipid pathways across human populations of variable metabolic status, suggesting that these complex mechanisms may underlie the relationship between dietary cholesterol and immunity. Given the Dietary Guidelines for Americans 2015⁻2020 revision to no longer include limitations on dietary cholesterol, evaluation of dietary cholesterol recommendations beyond the context of cardiovascular disease risk is particularly timely. This review provides a comprehensive and comparative analysis of significant and controversial studies on the role of dietary cholesterol and lipid metabolism in the pathophysiology of infectious disease and autoimmune disorders, highlighting the need for further investigation in this developing area of research.

Body Mass Index Categories and Attained Height in Portuguese Adults

OBJECTIVE

To analyze the associations between height and BMI categories in a Portuguese representative sample.

METHODS

This is a cross-sectional study with a representative sample of 32,644 Portuguese adults (52.4% females). Sociodemographic and lifestyle characteristics were obtained along with self-reported height and weight. We performed generalized linear models to assess the differences in attained height across BMI categories; analyses were adjusted for age, gender, education, family income per month, proxy reporting information, dietary patterns, and smoking.

RESULTS

BMI categories included underweight and normal weight (46.4%), overweight (37.6%), obese class I and II (15.2%), and obese class III (0.8%). Adults with normal weight had a significantly higher height (females +7 cm and males +5 cm) when compared to obese class III. As BMI categories increased, height decreased. In females and males, after adjusting for confounders, estimates of attained height decreased when compared to the unadjusted model (β = -0.049, 95% CI = -0.050; -0.049 and β = -0.030, 95% CI = -0.031; -0.029, respectively), although they remained still significant.

CONCLUSION

Our results suggest a significant difference in attained height between BMI categories. Future intervention programs aiming at preventing overweight and obesity should monitor sociodemographic, health and environmental conditions that affect attained height potential.

Fruit intake reduces the onset of respiratory allergic symptoms in schoolchildren

BACKGROUND

Previous studies have shown that dietary pattern is associated with allergy prevention.

METHODS

We conducted a prospective cohort study on all primary schools in Omihachiman City, Shiga Prefecture, Japan. Questionnaires regarding allergic symptoms and diet were distributed to the parents of all 759 7-year-old schoolchildren for 4 consecutive years, from 2011 to 2014. Specific immunoglobulin E to inhalant allergens was measured at 10 years of age. Participants were then categorized as low, medium, or high intake during the study period for four food groups (fruits, vegetables, fish, and beans). Logistic regression analysis was performed to estimate odds ratios and 95% confidence intervals.

RESULTS

A total of 520 children (68.5%) whose parents responded to the questionnaires all 4 years were included in the analysis. The prevalence of asthma, rhinitis, and any allergic symptoms at age 10 was significantly decreased with increases in fruit intake. In addition, the onset of any allergic symptoms during the study period was significantly decreased with increases in fruit intake (33.3%, 28.3%, and 14.3% in children with low, medium, and high fruit intake, respectively; P for trend =.01). The sensitization rate to ragweed at age 10 was significantly decreased with increases in fruit intake (P for trend =.046). No significant effect was observed for the other three food groups, except for the association between fish intake and new-onset asthma symptoms.

CONCLUSIONS

These findings suggest that higher intake of fruit can help prevent respiratory allergic symptoms in schoolchildren.

Diet, Lung Function, and Asthma Exacerbations in Puerto Rican Children

Changes in dietary patterns may partly explain the epidemic of asthma in industrialized countries. The objective of this study was to examine the relationship between dietary patterns and lung function and asthma exacerbations in Puerto Rican children. This is a case-control study of 678 Puerto Rican children (ages 6-14 years) in San Juan (Puerto Rico). All participants completed a respiratory health questionnaire and a 75-item food frequency questionnaire. Food items were aggregated into 7 groups: fruits, vegetables, grains, protein, dairy, fats, and sweets. Logistic regression was used to evaluate consumption frequency of each group and asthma. Based on the results, a dietary score was created [range from -2 (unhealthy diet: high consumption of dairy and sweets, low consumption of vegetables and grains) to 2 (healthy diet: high consumption of vegetables and grains and low consumption of dairy and sweet)]. Multivariable linear or logistic regression was used to assess the relationship between dietary score and lung function or asthma exacerbations. After adjustment for covariates, a healthier diet (each 1-point increment in dietary score) was associated with significantly higher %predicted forced expiratory volume in the first second (FEV₁) and %predicted forced vital capacity (FVC) in control subjects. Dietary pattern alone was not associated with asthma exacerbations, but children with an unhealthy diet and vitamin D insufficiency (plasma 25(OH)D <30 ng/mL) had higher odds of ≥1 severe asthma exacerbation [odds ratio (OR) = 3.4, 95% confidence interval (CI) = 1.5-7.5] or ≥1 hospitalization due to asthma (OR = 3.9, 95% CI = 1.6-9.8, OR = 3.4, 95% CI = 1.5-7.5) than children who ate a healthy diet and were vitamin D sufficient. A healthy diet, with frequent consumption of vegetables and grains and low consumption of dairy products and sweets, was associated with higher lung function (as measured by FEV₁ and FVC). Vitamin D insufficiency, together with an unhealthy diet, may have detrimental effects on asthma exacerbations in children.

Paeoniflorin inhibits PDGF‑BB‑induced human airway smooth muscle cell growth and migration

Abnormal proliferation and migration of airway smooth muscle cells (ASMCs) is important in the progression of asthma. Paeoniflorin (PF), one of the major active ingredients of Paeonia lactiflora, has been reported to exhibit anti‑asthmatic effects. However, the effects of PF in the regulation of platelet‑derived growth factor (PDGF)‑BB‑induced ASMC proliferation and migration remain unknown. The present study was designed to investigate the effects of PF on human ASMCs and the underlying mechanism. The results demonstrated that PF treatment significantly reduced the numbers of live ASMC cells and their PDGF‑BB‑induced migration. PF treatment also suppressed PDGF‑BB‑induced α‑smooth muscle actin expression in ASMCs. Furthermore, pretreatment with PF reduced PDGF‑BB‑induced phosphorylation of phosphoinositide 3‑kinase (PI3K) and AKT serine/threonine kinase 1 (Akt) in ASMCs. In conclusion, the present study demonstrated for the first time that PF inhibited ASMC growth and migration induced by PDGF‑BB, and that this effect may be partly due to inhibition of the PI3K/Akt signaling pathway. The results provide novel information regarding the role of PF as a potential therapeutic agent for the treatment of asthma.

Correlation of types of food and asthma diagnosis in childhood: A case-control study

Objective: Studies concerning asthma in Lebanon investigated environmental and personal factors but none of them took into account the effect of nutritional habits. Our objective is to assess the effect of nutritional habits on asthma and allergies in Lebanese children aged 3-16 years old. Methods: This is a case-control study, conducted between December 2015 and April 2016. The Food Frequency Questionnaire was composed of 16 semi-quantitative questions covering different food categories. Results: This study included 1,276 children (976 healthy and 300 asthmatic children). Eating dairy products less than twice a week, 3-6 times per week and daily were significantly and inversely associated with asthma, as compared to never eating dairy products (p = 0.02, ORa = 0.285, CI 0.099-0.821; p < 0.001, ORa = 0.140, CI 0.052-0.378 and p < 0.001, ORa = 0.161, CI 0.061-0.422), whereas eating red meat daily compared to never was associated with asthma significantly (p = 0.037, ORa = 2.051, CI 1.046-4.024). Eating nuts less than twice weekly as compared to never was significantly and inversely associated with asthma (p = 0.035, ORa = 0.597, CI 0.369-0.965). The age categories 7-10 and 11-13 years were significantly associated with asthma as compared to the 3-6 years category (p < 0.001, ORa = 3.359, CI 1.869-6.038 and p = 0.008, ORa = 2.191, CI 1.228-3.909, respectively), while male gender was significantly more prone to asthma (p = 0.014, ORa = 0.686, CI 0.507-0.926). Conclusions: Knowing the correlation between nutritional habits and asthma is important to promote healthy eating. Educational programs for parents about healthy food and breastfeeding encouragement is warranted.

Is fruit and vegetable intake associated with asthma or chronic rhino-sinusitis in European adults? Results from the Global Allergy and Asthma Network of Excellence (GA2LEN) Survey

Background

Fruits and vegetables are rich in compounds with proposed antioxidant, anti-allergic and anti-inflammatory properties, which could contribute to reduce the prevalence of asthma and allergic diseases.

Objective

We investigated the association between asthma, and chronic rhino-sinusitis (CRS) with intake of fruits and vegetables in European adults.

Methods

A stratified random sample was drawn from the Global Allergy and Asthma Network of Excellence (GA²LEN) screening survey, in which 55,000 adults aged 15–75 answered a questionnaire on respiratory symptoms. Asthma score (derived from self-reported asthma symptoms) and CRS were the outcomes of interest. Dietary intake of 22 subgroups of fruits and vegetables was ascertained using the internationally validated GA²LEN Food Frequency Questionnaire. Adjusted associations were examined with negative binomial and multiple regressions. Simes procedure was used to control for multiple testing.

Results

A total of 3206 individuals had valid data on asthma and dietary exposures of interest. 22.8% reported having at least 1 asthma symptom (asthma score ≥1), whilst 19.5% had CRS. After adjustment for potential confounders, asthma score was negatively associated with intake of dried fruits (β-coefficient −2.34; 95% confidence interval [CI] −4.09, −0.59), whilst CRS was statistically negatively associated with total intake of fruits (OR 0.73; 95% CI 0.55, 0.97). Conversely, a positive association was observed between asthma score and alliums vegetables (adjusted β-coefficient 0.23; 95% CI 0.06, 0.40). None of these associations remained statistically significant after controlling for multiple testing.

Conclusion and clinical relevance

There was no consistent evidence for an association of asthma or CRS with fruit and vegetable intake in this representative sample of European adults.

Soda consumption and hospital admissions among Californian adults with asthma

INTRODUCTION

Asthma prevalence has been increasing consistently since 1995 in California. Recent studies have found that consuming soda and sugar-containing drinks may pose a risk for asthma. Research that examines the relationship between soda intake and asthma among adult asthmatics is limited.

OBJECTIVE

This study investigated the relationship between sugar-sweetened soda consumption and asthma hospitalization among adult asthmatics in California.

METHODS

This cross-sectional study was based on the 2011-2012 California Health Interview Survey (CHIS) data and included 3,784 adults who were diagnosed with asthma by a doctor and who currently reported either that they still had asthma, or that they had suffered from an asthma attack in the last 12 months. The analysis was survey weighted. The exposure variable was soda intake measured as the number of times soda was consumed in the last week. The health outcome measure was overnight hospital admission due to asthma. Logistic regression was used to examine the association between soda consumption and overnight hospital admission after adjusting for age, education, sex, race/ethnicity, weight status, smoking status, and self-rated health.

RESULTS

Adults with asthma who drank soda three or more times per week reported higher odds of overnight hospitalization (adjusted odds ratio = 2.77, 95% CI: 1.51-5.10, p = 0.001).

CONCLUSIONS

Our findings suggest that efforts designed to limit soda consumption would benefit asthma suffers by reducing hospital admissions. This, however, needs further research to confirm a direct causal association.

Obesity increases the prevalence and the incidence of asthma and worsens asthma severity

BACKGROUND & AIMS

We aimed to explore the association between obesity and asthma prevalence, incidence and severity.

METHODS

The study included 32,644 adults, 52.6% female, from a representative sample of the 4th Portuguese National Health Survey. The following asthma definitions were used: ever asthma (ever medical doctor asthma diagnosis), current asthma (asthma within the last 12 months), current persistent asthma (required asthma medication within the last 12 months), current severe asthma (attending an emergency department because of asthma within the last 12 months), and incident asthma (asthma diagnosis within the last 12 months). Body mass index was calculated based on self-reported weight and height and categorised according to WHO classification. Logistic regression models adjusted for confounders were performed.

RESULTS

Prevalence of ever asthma was 5.3%, current asthma 3.5%, current persistent asthma 3.0%, current severe asthma 1.4%, and incident asthma 0.2%. Prevalence of obesity was 16%, overweight 37.6%, normal weight 44.6% and underweight 0.2%. Being overweight, obesity class I and II, and obesity class III were associated with an OR (95% CI) with ever asthma 1.22 (1.21-1.24), 1.39 (1.36-1.41), 3.24 (3.08-3.40) respectively; current asthma 1.16 (1.14-1.18), 1.86 (1.82-1.90), 4.73 (4.49-4.98) respectively; current persistent asthma 1.08 (1.06-1.10), 2.06 (2.01-2.10), 5.24 (4.96-5.53), and current severe asthma 1.36 (1.32-1.40), 1.50 (1.45-1.55) and 3.70 (3.46-3.95), respectively. Considering the incidence of asthma, obesity more than quadrupled the odds (OR = 4.46, 95% CI 4.30, 4.62).

CONCLUSION

Obesity is associated in a dose dependent way with an increase of prevalent and incident asthma, and it seems to increase the odds of a more persistent and severe asthma phenotype independently of socio-demographic determinants, physical activity, and dietary patterns. Our results provide rational for future lifestyle intervention studies for weight reduction in the obesity-asthma phenotype.

Dietary n-3 long chain polyunsaturated fatty acids in allergy prevention and asthma treatment

The rise in non-communicable diseases, such as allergies, in westernized countries links to changes in lifestyle and diet. N-3 long chain polyunsaturated fatty acids (LCPUFA) present in marine oils facilitate a favorable milieu for immune maturation and may contribute to allergy prevention. N-3 LCPUFA can suppress innate and adaptive immune activation and induce epigenetic changes. Murine studies convincingly show protective effects of fish oil, a source of n-3 LCPUFA, in food allergy and asthma models. Observational studies in human indicate that high dietary intake of n-3 LCPUFA and low intake of n-6 PUFA may protect against the development of allergic disease early in life. High n-6 PUFA intake is also associated with an increased asthma risk while n-3 LCPUFA may be protective and reduce symptoms. The quality of the marine oil used has impact on efficacy of allergy prevention and several observations link in particular n-3 LCPUFA DHA to allergy suppression. Randomized controlled trials indicate that optimal timing, duration and dosage of n-3 LC-PUFA is required to exert an allergy protective effect. Supplementation during early pregnancy and lactation has shown promising results regarding allergy prevention. However these findings should be confirmed in a larger cohort. Although clinical trials in asthma patients reveal no consistent clinical benefits of n-3 LCPUFA supplementation on lung function, it can suppress airway inflammation. Future food-pharma approaches may reveal whether adjunct therapy with dietary n-3 LCPUFA can improve allergy prevention or immunotherapy via support of allergen specific oral tolerance induction or contribute to the efficacy of drug therapy for asthma patients.

Air Pollutants, Climate, and the Prevalence of Pediatric Asthma in Urban Areas of China

Background. Prevalence of childhood asthma varies significantly among regions, while its reasons are not clear yet with only a few studies reporting relevant causes for this variation. Objective. To investigate the potential role of city-average levels of air pollutants and climatic factors in order to distinguish differences in asthma prevalence in China and explain their reasons. Methods. Data pertaining to 10,777 asthmatic patients were obtained from the third nationwide survey of childhood asthma in China's urban areas. Annual mean concentrations of air pollutants and other climatic factors were obtained for the same period from several government departments. Data analysis was implemented with descriptive statistics, Pearson correlation coefficient, and multiple regression analysis. Results. Pearson correlation analysis showed that the situation of childhood asthma was strongly linked with SO2, relative humidity, and hours of sunshine (p < 0.05). Multiple regression analysis indicated that, among the predictor variables in the final step, SO2 was found to be the most powerful predictor variable amongst all (β = -19.572, p < 0.05). Furthermore, results had shown that hours of sunshine (β = -0.014, p < 0.05) was a significant component summary predictor variable. Conclusion. The findings of this study do not suggest that air pollutants or climate, at least in terms of children, plays a major role in explaining regional differences in asthma prevalence in China.