Asthma In Infants Research Articles

Tidal Breathing Analysis as a Prognostic Index for Airway Obstruction Trajectory and Asthma in Preterm Infants.

An easy-to-implement and accurate lung function assessment tool for preterm infants is crucial to manage lifelong respiratory morbidities. We aimed to determine which pulmonary function parameters in preterm infants can predict the trajectory of airway obstruction and asthma development after 4years of age. We evaluated 52 preterm infants who had undergone both tidal breathing flow-volume loop (TBFVL) and multiple-breath washout (MBW) analyses in infancy and spirometry after the age of 4years. We evaluated the association between pulmonary function parameters in infancy and childhood and the pulmonary function trajectory until 13years of age and compared the changes in this trajectory according to pulmonary function parameters in infancy. Time to peak expiratory flow/expiratory time (TPEF/TE) in infancy was associated with FEV1, FEF25-75, and dysanapsis ratio in childhood and differed according to level of airway obstruction assessed by FEV1, FEV1/FVC, and FEF25-75, an asthma development. TPEF/TE was a significant predictive factor for airway obstruction and asthma after 4years of age, after adjusting for sex, extreme prematurity, duration of supplementary oxygen and mechanical ventilation, and recurrent wheezing during infancy. In premature infants with lower TPEF/TE, subsequent pulmonary function parameters remained low until 13years of age. In preterm infants, TPEF/TE could be useful to predict airway obstruction and asthma after 4years of age and even a lower pulmonary function trajectory until 13years of age. This information may help clinicians to provide lifelong care for pulmonary morbidity in children and adolescents born preterm.

Prognostic value of serum total IgE and FeNO levels in children with atopic constitution bronchiolitis

Bronchiolitis is a significant factor contributing to bronchial asthma in infants and young children. After treatment, recurrent wheezing symptoms often occur, especially in children with atopic constitution, who tend to have more severe conditions and poorer prognosis. Therefore, exploring the prognostic value of total serum immunoglobulin E (tIgE) and fractional exhaled nitric oxide (FeNO) levels in children with atopic constitution who suffer from bronchiolitis is of great significance. A total of 260 children with bronchiolitis admitted to our hospital from October 2020 to June 2022 were regarded as the research subjects with prospective study, according to whether the children had atopic constitution, they were grouped into non atopic constitution group (n = 156) and atopic constitution group (n = 104); after 6 months of treatment, children with atopic constitution were grouped into a good prognosis group (n = 58) and a poor prognosis group (n = 46) based on their prognosis; in addition, 260 healthy children who underwent physical examination and had clinical data consistent with those of children with bronchiolitis were regarded as the reference group. The serum tIgE and FeNO levels of each group were compared; multivariate Logistic regression was applied to analyze the prognostic factors of children with atopic constitution bronchiolitis; ROC curve was applied to analyze the predictive value of tIgE and FeNO levels after treatment for the prognosis of children with atopic constitution bronchiolitis. The tIgE levels in the control group, non-atopic group, and atopic group [(123.54 ± 29.62) IU/mL, (245.71 ± 30.59) IU/mL, (316.46 ± 31.78) IU/mL, respectively] increased sequentially, with statistically significant differences (F = 1766.954, P = 0.000). The FeNO levels in the control group, non-atopic group, and atopic group [(8.36 ± 3.57) ppb, (15.28 ± 3.69) ppb, (19.84 ± 3.58) ppb, respectively] also increased sequentially, with statistically significant differences (F = 765.622, P = 0.000). The tIgE, FeNO, proportion of patients with asthma family history, and proportion of patients with allergic family history in the poor prognosis group were obviously higher than those in the good prognosis group (P < 0.05). Multivariate Logistic regression analysis showed that family history of asthma, family history of allergies, tIgE, and FeNO were influencing factors for the prognosis of children with atopic bronchiolitis (P < 0.05). The AUC of the combination of tIgE and FeNO in predicting the prognosis of children with atopic constitutional bronchiolitis was 0.910, with a sensitivity of 78.26% and a specificity of 93.10%, which was superior to the independent prediction of tIgE and FeNO (Zcombined detection−tIgE = 2.442, Zcombined detection−FeNO = 3.080, P = 0.015, 0.002). The levels of tIgE and FeNO in children with atopic constitution bronchiolitis are obviously increased, and the combination of the two has high predictive value for the prognosis of atopic constitution bronchiolitis.

COVID-19 and Asthma Onset in Children.

Respiratory viral infections increase risk of asthma in infants and children. Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus can cause severe lung inflammation and prolonged respiratory symptoms. We sought to determine whether SARS-CoV-2 infection modified pediatric incident asthma risk. This retrospective cohort study examined children ages 1 to 16 within the Children's Hospital of Philadelphia Care Network who received polymerase chain reaction (PCR) testing for SARS-CoV-2 between March 1, 2020 and February 28, 2021. Multivariable Cox regression models assessed the hazard ratio of new asthma diagnosis between SARS-CoV-2 PCR positive and SARS-CoV-2 PCR negative groups within an 18-month observation window. Models were adjusted for demographic characteristics, socioeconomic variables, and atopic comorbidities. There were 27 423 subjects included in the study. In adjusted analyses, SARS-CoV-2 PCR positivity had no significant effect on the hazard of new asthma diagnosis (hazard ratio [HR]: 0.96; P = .79). Black race (HR: 1.49; P = .004), food allergies (HR: 1.26; P = .025), and allergic rhinitis (HR: 2.30; P < .001) significantly increased the hazard of new asthma diagnosis. Preterm birth (HR: 1.48; P = .005) and BMI (HR: 1.13; P < .001) significantly increased the hazard of new asthma diagnosis for children <5 years old. SARS-CoV-2 PCR positivity was not associated with new asthma diagnosis in children within the observation period, although known risk factors for pediatric asthma were confirmed. This study informs the prognosis and care of children with a history of SARS-CoV-2 infection.

Effects of COVID-19 pandemic–associated reduction in respiratory infections on infantile asthma development

BackgroundIt is speculated that the COVID-19 pandemic associated reduction in the prevalence of respiratory tract infections has influenced on the incidence of asthma in infants. ObjectivesWe investigated an association between the reduction in viral infections and the reduction in asthma in infants. MethodsThe subjects were infants born in the early stages of the COVID-19 pandemic in Japan, which began in February 2020. A questionnaire survey related to asthma and allergy was conducted at 18 months and 3 years old. These results were compared to those of age-matched infants during the non-pandemic period. ResultsThere were no epidemics of viral infectious diseases until the target child was 18 months old. At 18 months, the incidence of asthma/asthmatic bronchitis diagnosed by physicians in pandemic infants was significantly lower than that in non-pandemic infants. In 3-year-old infants, no marked difference was observed between non-pandemic infants and pandemic infants, except for an increase in RSV infection in pandemic infants. In a comparative study of the same infants at 18 months and 3 years old, an increased prevalence of asthma/asthmatic bronchitis was observed in pandemic infants. Furthermore, the incidence of asthma after RSV infection in pandemic infants was significantly lower than that in non-pandemic infants. ConclusionThe COVID-19 pandemic-associated reduction in respiratory tract infections may have reduced the incidence of asthma in infancy, and RSV infection after 18 months old had little effect on the onset of asthma. These results indicate the importance of preventing respiratory tract infections in early infancy.

The protective effects of Arctiin in asthma by attenuating airway inflammation and inhibiting p38/NF-κB signaling.

Asthma is a common chronic inflammatory disease of the airways, which affects millions of people worldwide. Arctiin, a bioactive molecule derived from the traditional Chinese Burdock, has not been previously reported for its effects on asthma in infants. In this study, an asthma model was established in mice by stimulation with ovalbumin (OVA). Bronchoalveolar lavage (BALF) was collected from OVA-challenged mice and the cells were counted. Lung tissue was harvested for hematoxylin-eosin (HE) staining and measurement of Wet/Dry weight ratios. The expressions of proteins were detected using enzyme-linked immunosorbent assay (ELISA) and Western blots. The superoxide dismutase (SOD) activity in lung tissue was measured using a commercial kit. We found that Arctiin had beneficial effects on asthma treatment. Firstly, it attenuated OVA-challenged lung pathological alterations. Secondly, it ameliorated pro-inflammatory response by reducing the number of inflammatory cells and mitigating the imbalance of Th1/Th2 factors in the bronchoalveolar lavage (BALF) of OVA-challenged mice. Importantly, Arctiin ameliorated OVA-induced lung tissue impairment and improved lung function. Additionally, we observed that oxidative stress (OS) in the pulmonary tissue of OVA-challenged mice was ameliorated by Arctiin. Mechanistically, Arctiin prevented OVA-induced activation of p38 and nuclear factor-κB (NF-κB). Based on these findings, we conclude that Arctiin might serve as a promising agent for the treatment of asthma.

Cost-utility analysis of prenatal supplementation with long-chain n-3 fatty acids to reduce the incidence of wheezing and asthma in neonates

Introduction Recent evidence indicates that Maternal Supplementation with Long-Chain n-3 Fatty Acids During Pregnancy Substantially Mitigates Offspring’s Asthma. Adding information regarding its cost-utility will undoubtedly allow its adoption, or not, in clinical practice guidelines. This research aimed to determine the cost-utility of LCPUFA supplementation in the third trimester of pregnancy to reduce the risk of wheezing and asthma in infants in Colombia. Methods A Markov model was formulated to estimate the cost and quality-adjusted life-years (QALYs) attributed to individuals with severe asthma in Colombia, with a time horizon of five years and a cycle length of two weeks. Probabilistic sensitivity analysis and a value of information (VOI) analysis were conducted to evaluate the uncertainties in the case base. Cost-utility was assessed at a willingness-to-pay (WTP) value of US$5180. All costs were adjusted to 2021 with a 5% annual discounting rate for cost and QALYs. Results The mean incremental cost of LCPUFA supplementation versus no supplementation was US-43.65. The mean incremental benefit of LCPUFA supplementation versus no supplementation was 0.074 QALY. The incremental cost-utility ratio was estimated at US$590.68 per QALY. The outcomes derived from our primary analysis remained robust when subjected to variations in all underlying assumptions and parameter values. Conclusion Supplementation strategy supplementation with long-chain n-3 fatty acids during pregnancy is cost-effective in reducing the risk of developing asthma during childhood in Colombia.

Air pollution after acute bronchiolitis is a risk factor for preschool asthma: a nested case-control study

BackgroundAcute bronchiolitis and air pollution are both risk factor of pediatric asthma. This study aimed to assess subsequent exposure to air pollutants related to the inception of preschool asthma in infants with acute bronchiolitis. This study aimed to assess subsequent exposure to air pollutants related to the inception of preschool asthma in infants with acute bronchiolitis.MethodsA nested case-control retrospective study was performed at the Kaohsiung Medical University Hospital systems between 2009 and 2019. The average concentration of PM10, PM2.5, SO2, NO, NO2, and NOX was collected for three, six, and twelve months after the first infected episode. Adjusted regression models were employed to evaluate the association between asthma and air pollution exposure after bronchiolitis.ResultsTwo thousand six hundred thirty-seven children with acute bronchiolitis were included. Exposure to PM10, PM2.5, SO2, NO, NO2, and NOX in the three, six, and twelve months following an episode of bronchiolitis was found to significantly increase the risk of preschool asthma in infants with a history of bronchiolitis.(OR, 95%CI: PM10 = 1.517-1.559, 1.354–1.744; PM2.5 = 2.510-2.603, 2.148–3.061; SO2 = 1.970-2.040, 1.724–2.342; ; NO = 1.915-1.950, 1.647–2.272; NO2 = 1.915-1.950, 1.647–2.272; NOX = 1.752-1.970, 1.508–2.252) In a sensitive analysis of hospitalized infants, only PM10, PM2.5, SO2, and NO were found to have significant effects during all time periods. (OR, 95%CI: PM10 = 1.613-1.650, 1.240–2.140; PM2.5 = 2.208-2.286, 1.568–3.061; SO2 = 1.679-1.622, 1.197–2.292; NO = 1.525-1.557, 1.094–2.181)ConclusionThe presence of ambient PM10, PM2.5, SO2 and NO in the three, six, and twelve months following an episode of acute bronchiolitis has been linked to the development of preschool asthma in infants with a history of acute bronchiolitis.

The protective associations of breastfeeding with infant overweight and asthma are not dependent on maternal FUT2 secretor status.

Breastfeeding supplies infant gut bacteria with human milk oligosaccharides (HMOs) as a nutrient source. HMO profiles are influenced by the FUT2 gene, which encodes an enzyme affecting the fucosylation of milk sugars. 20 to 40% of individuals have a "non-secretor" polymorphism that inactivates the FUT2 gene, resulting in variable HMO proportions in milk. This has engendered a concerning, yet unfounded, perception that non-secretor milk is "inferior." To address this untested hypothesis, we re-analyzed two datasets in which we previously showed that breastfeeding was protective against early life asthma and excessive infant weight gain in the Canadian CHILD Cohort Study. Using stratified regression models, we found that the protective association of exclusive breastfeeding and infant asthma was not modified by maternal secretor status (secretors aOR: 0.53, 95% CI 0.31 to 0.92; non-secretors aOR: 0.36, 95% CI 0.12 to 1.04; p for interaction = 0.50, N = 2086 children). Similarly, the association of breastfeeding with lower infant BMI and weight gain velocity did not vary by maternal secretor status (infant BMI: secretors aβ -0.47, 95% CI -0.66 to -0.29; non-secretors aβ -0.46, 95% CI -0.78 to -0.13; p for interaction = 0.60; N = 1971 infants). Our results indicate that secretor and non-secretor mothers can equally promote infant growth and respiratory health through breastfeeding. These findings run contrary to the idea that non-secretor milk is an inferior food source, and instead reify the importance of breastfeeding for all infants. The results of this study can inform feeding recommendations that are applicable to all infants, regardless of maternal secretor status.

Prevalence of asthma in preterm and associated risk factors based on prescription data from the Korean National Health Insurance database

We retrospectively analyzed National Health Insurance claims data (January 2002–December 2018) to determine the asthma prevalence and risk factors among preterm infants born in Korea. Patients with asthma were defined as those with a history of asthma medication prescriptions at least twice per year with International Classification of Diseases, Tenth Edition codes J45 and J46. We enrolled 99,139 preterm infants. The prevalence of asthma among preterm and term infants was 32.7% and 26.9%, 21.2% and 19.1%, 6.7% and 5.9%, 2.0%, and 1.6%, and 2.4% and 1.6% at 2, 5, 10, 15, and 16 years of age, respectively. The relative risk (RR) of asthma in preterm infants was 1.1-fold that in female preterm infants. The RR of asthma medication prescriptions for infants with extreme prematurity was 1.92-fold that of infants with moderate/late pre-term status. Among preterm with bronchopulmonary dysplasia (BPD) and respiratory distress syndrome (RDS) without comorbidities, the RRs for the number of asthma medication prescriptions were 1.34 and 1.06, respectively. This study revealed a higher prevalence of asthma among preterm infants than that in term infants. Male sex, extreme prematurity, BPD, and RDS were identified as risk factors for asthma medication prescriptions in preterm infants.

Prevalence of asthma in premature infants using data from 2002–2018 Korea national health insurance claims data

Prevalence of asthma in premature infants using data from 2002–2018 Korea national health insurance claims data

Maternal heated tobacco product use during pregnancy and allergy in offspring.

Little is known about the association between maternal use of heated tobacco products (HTPs) during pregnancy and the onset of allergy among offspring. This study aimed to determine whether maternal HTP smoking is associated with allergy in their offspring and to evaluate the potential dose-response association. In this web-based, cross-sectional survey conducted in July and August 2021 in Japan, we investigated 5688 pairs of postpartum women and infants (<3 years). Clinical diagnoses of infant asthma, rhinitis, conjunctivitis, or atopic dermatitis were reported. Using multilevel Poisson regression, we estimated the prevalence ratios (PRs) and 95% confidence intervals (CIs) of allergy in infants with HTP smoking categories cross-classified by pregnancy periods, and adjusted for potential covariates including maternal cigarette smoking and partner's smoking status. Non-smokers served as the reference group. In total, 2.4% women smoked HTPs during pregnancy. Allergy occurred in 7.8% of the infants. The prevalence of allergy increased among the offspring of current HTP smokers during pregnancy at 15.2% (PR=1.98, 95% CI 1.28-3.05); this association was the most pronounced during the first trimester but attenuated before pregnancy and postpartum. Dose-response associations were observed, for example a one-unit increase in daily maternal HTP use during pregnancy was associated with a 5% increase in allergy onset. Sub-group analyses excluding cigarette smokers during pregnancy and sensitivity analyses using the International Study of Asthma and Allergies in Childhood questionnaire showed a similar pattern. Maternal HTP smoking during pregnancy is associated with allergy in the offspring.

Like mother, like child: The maternal microbiome impacts offspring asthma

The link between the maternal microbiome and offspring allergy is poorly defined. McCauley and colleagues now demonstrate that heritable bacteria are associated with infant asthma susceptibility and induce immunosuppression of allergic inflammation, suggesting significant implications for asthma-preventative interventions1.

Expression and significance of TGF-β1 in infant asthma model

This article aimed to study the expression and role of TGF-β1 in young rat asthma. The experimental method in this paper is to replicate the asthma model by aerosolization of egg protein. The young rats with asthma were sacrificed after 2, 4 and 8 weeks. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the mRNA of TGF-β1 and α-SMA. The expression level was detected by the immunohistochemical staining method to detect the protein expression of TGF-β1, α-SMA, Smad3, Smad4 and Smad7 in bronchopulmonary tissues. At the same time, the image analysis method was used to measure the airway morphological parameters of young rats. The experimental results showed that the expression of TGF-β1 in the lung tissue of young rats in the asthma group was increased after two weeks of the challenge. Compared with the control group, the difference was significant (P<0.05); the expression of TGF-β1, α-SMA and mRNA in the 4-week group was significantly higher, compared with the control group and the 2-week challenge group, the difference was significant (P<0.05). Therefore, the change of asthma airway remodeling is a dynamic process. The TGF-β1 pathway presents a dynamic process in the airway remodeling model of young asthmatic rats. Among them, TGF-β1 induces the division and proliferation of airway fibroblasts and promotes fibroblasts. The cells transform into myofibroblasts and increase the synthesis of fibronectin and collagen, suggesting that it plays an important role in asthma inflammation and pulmonary fibrosis.

Prenatal and Postnatal Exposure to Ambient Air Pollution and Preschool Asthma in Neonatal Jaundice Infants.

PurposeBoth air pollutant exposure and neonatal jaundice (NJ) have known effects on childhood asthma, but a higher total serum bilirubin (TSB) level has been associated with lung protection. This study aimed to assess whether prenatal/postnatal exposure to ambient air pollutants is related to the development of asthma in infants with NJ.Patients and MethodsA nested case–control retrospective study was performed using the data of infants with NJ in the Kaohsiung Medical University Hospital Research Database. Data on average ambient air pollution concentrations within six months, the first year and second year after birth, and in the first, second and third prenatal trimesters were collected. NJ was defined as TSB levels ≥ 2 mg/dl with the diagnosis less than one-month-old. Asthma was defined as a diagnosis with medication use. We constructed conditional logistic regression models to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs).ResultsExposure to NO and SO2 at all six time points in the study was significantly associated with an increased risk of preschool asthma in infants with NJ. The overall peak OR (95% CI) of SO2, PM2.5, PM10, NO, NO2, and NOX were 1.277 (1.129–1.444), 1.057 (1.023–1.092), 1.035 (1.011–1.059), 1.272 (1.111–1.455), 1.168 (1.083–1.259) and 1.104 (1.051–1.161), respectively. Fetuses in the first and second trimester were most vulnerable to ambient air pollutant exposure such as SO2 PM2.5, NO, NO2 and NOX during the prenatal period. Exposure to all six ambient air pollutants during the first and second years after birth significantly affected preschool asthma in NJ infants.ConclusionIn different time windows, prenatal and postnatal exposure to SO2, PM2.5, PM10, NO, NO2, and NOX were associated with preschool asthma in NJ infants. The relatively high impact of NO and SO2 exposure in infants with NJ requires further studies and prevention measures.

The effect of phthalates exposure during pregnancy on asthma in infants aged 0 to 36months: a birth cohort study.

This cohort study sought to investigate the effects of phthalates exposure during pregnancy on offspring asthma and its association with placental stress and inflammatory factor mRNA expression levels. A total of 3474 pregnant women from the China Ma'anshan birth cohort participated in this study. Seven phthalate metabolites were detected in urine samples during pregnancy by solid phase extraction-high-performance liquid chromatography tandem mass spectrometry. Placenta stress and inflammation mRNA expression were assessed by real-time quantitative polymerase chain reaction (RT-qPCR). Early pregnancy may be the critical period when phthalates exposure increases the risk of asthma in infants and young children, and there is a certain gender difference in the risk of asthma in infants and young children. Moreover, through the placenta stress and inflammatory factor associated with infant asthma found anti-inflammatory factor of interleukin-10 (IL-10) mRNA expression will reduce the risk of 36-month-old male infant asthma. The expression of interleukin-4(IL-4) and macrophage (M2) biomarker cluster of differentiation 206(CD206) mRNA reduced the risk of asthma in 18-month-old female infants. Placental stress and inflammatory response were analyzed using mediating effects. Tumor necrosis factor-α (TNFα) showed a complete mediating effect between mono-benzyl phthalate (MBzP) exposure in early pregnancy and asthma in 12-month-old males, and IL-10 also showed a complete mediating effect between mono-n-butyl phthalate (MBP) exposure in early and late pregnancy and asthma in 36-month-old males. In summary, exposure to phthalates during pregnancy may contribute to the development of asthma in infants, which may be associated with placental stress and inflammation.

Prevalence of infantile wheezing and eczema in a metropolitan city in Japan: A complete census survey.

Infantile wheezing and eczema are associated with the subsequent onset of asthma and other atopic diseases. However, there are no large population-based surveys on infantile allergic symptoms in Japan. The objective of the study was to determine the prevalence of wheezing and asthma in infants in Nagoya, Japan. This population-based cross-sectional study was performed in the metropolitan city of Nagoya, Japan. We surveyed parents to ascertain the prevalence of wheezing and eczema in infants who attended group health checkups at 3, 18, and 36 months of age. Their parents completed modified questionnaires from the International Study of Asthma and Allergies in Childhood. More than 90% of the approximately 40,000 children in each study group living in the target area were included in the survey. The prevalence of wheezing was 8%, 17%, and 13% at 3, 18, and 36 months, respectively, and was characterized by birth season. The prevalence of eczema was 24%, 30%, and 31%, at 3, 18, and 36 months, respectively. Participants born in autumn and winter had a higher incidence of eczema in each age group. Three-quarters of the children had a parental history of allergic conditions. Parental allergic diseases and male gender are risk factors for wheezing and eczema in children. This survey had a high response rate and covered almost the entire population of the target age groups in a large city. We believe that the results of this study, therefore, provide a much higher level of confidence regarding the prevalence of allergies in infants in Japan than that in previous studies with limited cohorts.

Do Probiotics in Pregnancy Reduce Allergies and Asthma in Infancy and Childhood? A Systematic Review.

The maternal immune system is very important in the development of the foetal immune system. Probiotics have been shown to help regulate immune responses. Therefore, it is possible that the administration of probiotics to pregnant women could influence the development of the foetal immune system, reducing the likelihood of infants and children developing an allergic condition. The aim of this research was to conduct a systematic review to determine whether administering probiotics to pregnant women can reduce the incidence of allergic disease in their children. Medline, CINAHL and Embase databases were searched for randomised controlled trials (RCTs) that compared supplementation of probiotics to pregnant women to a placebo control and recorded the presentation of allergic conditions in their children. Data extracted from the study reports included their characteristics and findings. Study quality and risk of bias were assessed. From a total of 850 articles identified in the search, 6 were eligible for inclusion in this review. Two studies found no effect of maternal probiotics on the outcomes measured, two studies found that the incidence of eczema or atopic dermatitis (AD) was reduced by maternal probiotics, one study found no effect on the overall incidence of atopic sensitisation, but a reduction in a subgroup of children at high hereditary risk of allergic disease, and one study found no effect in an intention to treat analysis, but a reduction in AD in complete case analysis. The results of these studies are inconsistent but demonstrate that probiotics may have the potential to reduce infant allergies when administered prenatally, particularly in children at high risk of allergy development. There is a need for further larger-scale studies to be performed in order to provide a more definitive answer. Such studies should focus on at-risk groups.

Diagnosis and management of asthma in infants and preschoolers.

Asthma is one of the most common chronic disease affecting children, and it often starts in infancy and preschool years. In previous birth cohorts, frequent wheezing in early life was associated with the development of asthma in later childhood and reduced lung function persisting into adulthood. Preschool wheezing is considered an umbrella term for distinctive diseases with different clinical features (phenotypes), each of which may be related to different underlying pathophysiologic mechanisms (endotypes). The classification of phenotypes of early wheezing is needed to identify children at high risk for developing asthma later who might benefit from early intervention. However, diagnosis of asthma in infants and preschoolers is particularly difficult because objective lung function tests cannot be performed and definitive biomarkers are lacking. Moreover, management of early asthma is challenging because of its different phenotypic presentations. Many prediction models and asthma guidelines have been developed to provide useful information for physicians to assess young children with recurrent wheezing and manage them appropriately. Many recent studies have investigated the application of personalized medicine for early asthma by identifying specific phenotypes and biomarkers. Further researches, including genetic and molecular studies, are needed to establish a clear definition of asthma and develop more targeted therapeutic approaches in this age group.

Predictors of pearl vitamin D3 consumption in pregnant women: application of the theory of planned behaviour

This study aimed at determining the applicability planned-behaviour theory to predict the consumption of pearl vitamin D3 (1000 IU) among pregnant women in Iran in 2020. The participants of the present study were 200 pregnant women who were selected through random cluster sampling. In addition, data collection was done through the use of questionnaire and the proceeding analyses including correlation and linear regression were conducted using SPSS (version 20) (SPSS Inc., Chicago, IL) statistical software package. The findings showed that all three structure attitudes (r = 0.69, p<.001), subjective norms (r = 0.58, p<.001) and perceived behavioural control (PBC) (r = 0.52, p<.001) had significant correlations with consumption. Among the variables entered into the regression model, attitude, subjective norms and PBC were able to predict a total of 65% of pearl vitamin D3 (1000 IU) consumption variance among participants (F = 60.75, R = 0.66, R 2=0.65). According to the findings, TPB and its constructs were used to predict pearl vitamin D3 consumption in pregnant women in Iran. This outcome indicates that efforts to promote behavioural intentions through targeting subjective norms, attitude and PBC may promote pearl vitamin D3 consumption. Impact Statement What is already known on this subject? The results of this study showed predictors of pearl vitamin D3 consumption in pregnant women based on the theory of planned behaviour (TPB). Women receive adequate and proper knowledge, along with a positive attitude towards taking pearl vitamin D3, and feel that taking pearl vitamin D3 is at their discretion in terms of environmental factors (facilities and barriers), increases intend to use pearl vitamin D3. What do the results of this study add? The results of this study also showed that the amount of pearl vitamin D3 intake during pregnancy increased by pregnant women and decreased risk of foetal growth retardation, low birth weight, decreased risk of respiratory infections in infants, decreased asthma and eczema in infants. What are the implications of these findings for clinical practice and/or further research? The study showed the importance of the role of education based on TPB in consumption promoting pearl vitamin D3.

Infant feeding practices and asthma in children aged 6 months to 5 years using a propensity score approach

We examined the association between exclusive breastfeeding, early introduction of feeding formula, early weaning, and asthma in children aged six months to five years in a sample of non-institutionalized US children using a propensity score approach. Our study used data from the National Survey of Children's Health (2012-2018) of 3,820 children with physician-diagnosed asthma aged 6 months to 5 years. Propensity score matching (PSM) was applied to control selection bias with age, sex, race, birth weight, Federal Poverty Level, parent's education, and parent smoking history used as covariates in PSM. The total number in the matched sample was 6,904 (3,452 non-asthmatics; 3,452 asthmatics). Matched and unmatched samples were analysed using the χ2 test and multiple logistic regression. Exclusive breastfeeding was protective against asthma in the pre-matching (AOR 0.72; 95% CI: 0.54-0.97; p = 0.03) and post-matching (AOR 0.66; 95% CI: 0.55-0.81; p < 0.001) samples. Formula feeding before 6 months was associated with asthma in unmatched (AOR 1.38; 95% CI: 1.15-1.66; p < 0.001) and matched (AOR 1.31; 95% CI: 1.16-1.47; p < 0.001) sample. Early weaning before 6 months was associated with asthma in unmatched (AOR 1.62; 95% CI: 1.35-1.54; p < 0.001) and matched sample (AOR 1.37; 95% CI: 1.23-1.54; p < 0.001). Public health systems should continue to recommend the implementation of the World Health Organization exclusive breastfeeding guideline in developed countries. Asthma interventions in children under two years should continue to emphasize exclusive breastfeeding to reduce the incidence of infant asthma.