Search

Background: It is challenging to diagnose asthma in preschool children. The asthma predictive index (API) has been used to predict asthma and decide whether to initiate treatment in preschool children. Purpose: This study aimed to investigate the association between questionnaire-based current asthma with API, pulmonary function, airway hyperreactivity (AHR), fractional expiratory nitric oxide (FeNO), and atopic sensitization in preschool children. Methods: We performed a population-based cross-sectional study in 916 preschool children aged 4–6 years. We defined current asthma as the presence of both physician-diagnosed asthma and at least one wheezing episode within the previous 12 months using a modified International Study of Asthma and Allergies in Childhood questionnaire. Clinical and laboratory parameters were compared between groups according to the presence of current asthma. Results: The prevalence of current asthma was 3.9% in the study population. Children with current asthma showed a higher rate of positive bronchodilator response and loose and stringent API scores than children without current asthma. The stringent API was associated with current asthma with 72.2% sensitivity and 82.0% specificity. The diagnostic accuracy of the stringent API for current asthma was 0.771. However, no intergroup differences in spirometry results, methacholine provocation test results, FeNO level, or atopic sensitization rate were observed. Conclusion: The questionnaire-based diagnosis of current asthma is associated with API, but not with spirometry, AHR, FeNO, or atopic sensitization in preschool children. [ABSTRACT FROM AUTHOR]

Background Relationship between recurrent wheeze and airway function and inflammation in preschool children is not fully known. Objective To investigate the relationship between recurrent wheeze and airway inflammation, lung function, airway hyper-reactivity (AHR) and atopy in preschool children. Design Observational study, comparing forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and midforced expiratory flow (FEF25%-75%), dose-response slope (DRS), exhaled nitric oxide (eNO) and atopic sensitisation between children with recurrent wheeze and those without. Setting Population-based, cross-sectional study in Seoul and the Gyeonggi province of Korea conducted as a government-funded programme to perform standardised measurement of the prevalence of allergic diseases, and related factors, in preschool children. Participants 900 children aged 4-6 years. Primary and secondary outcome measures eNO, FEV1/FVC, FEF25%-75%, DRS, atopic sensitisation and allergic diseases. Methods Children completed the modified International Study of Asthma and Allergies in Childhood questionnaire and underwent eNO assessments, spirometry, methacholine bronchial provocation tests and skin prick tests. Recurrent wheeze was defined as having a lifetime wheeze of more than three episodes, based on the questionnaire. The frequency of hospitalisation and emergency room visits was also obtained by means of the questionnaire. 'Current' wheeze was defined as having symptoms or treatments within the past 12 months. Results The prevalence of recurrent wheeze was 13.4%. Children with recurrent wheeze showed a higher prevalence of lifetime or current allergic rhinitis (p=0.01 and p=0.002, respectively) and lifetime atopic dermatitis (p=0.007). Children with recurrent wheeze showed lower FEV1/FVC (p=0.033) and FEF25%-75% (p=0.004), and higher eNO levels (p=0.013) than those without recurrent wheeze. However, the DRS, prevalence of atopic sensitisation and serum IgE levels were not significantly different between the two groups. Conclusions Recurrent wheeze in preschool children may be associated with airway inflammation and diminished airway function, but not with AHR or atopy. [ABSTRACT FROM AUTHOR]

Background: Treatment guidelines for asthma have been established based on asthma severity; there are limitations in the identification of underlying pathophysiology and prediction of prognosis in heterogeneous phenotypes of asthma. Although the complex interactions between environmental and genetic factors affect the development and progression of asthma, studies on asthma phenotypes considering environmental factors are limited. This study aimed to identify asthma phenotypes using latent class analysis including environmental factors in school-age children.Methods: We included 235 children (6-8 years) with parent-reported, physician-diagnosed asthma from the Children's HEalth and Environmental Research (CHEER) study, which is a 4-year prospective follow-up study with 2-year intervals. At every survey, pulmonary function tests, methacholine challenge tests and blood tests with questionnaire were conducted.Results: Four asthma phenotypes were identified. Cluster 1 (22% of children) was characterized by high prevalence of atopy and mild symptoms; subjects in cluster 2 (17%) consisted of less atopy and normal lung function, but intermittent troublesome; cluster 3 (29%) experienced late-onset atopic troublesome asthma with decreased lung function in combination with low socioeconomic status; and cluster 4 was associated with early-onset and less-atopic infrequent asthma.Conclusions: Late-onset, high atopy, and low socioeconomic status are associated with troublesome persistent asthma phenotype in school-age children. Environmental factors might be implicated in the clinical heterogeneity of asthma. Asthma phenotypes considering diverse factors might be more helpful in the identification of asthma pathogenesis and its prevention. [ABSTRACT FROM AUTHOR]

Purpose: Adherence to treatment with inhaled corticosteroids (ICS) is a critical determinant of asthma control. The objective of this study was to assess factors that determine adherence to ICS therapy in children with asthma. Methods: Fifty-eight children with asthma, aged 5 to 16 years, used ICS with or without a spacer for 3 months. Adherence rates as measured from questionnaires and canisters, asthma symptom scores, and inhalation technique scores were assessed every 30 days. The degree of supervision by caregivers was assessed at day 30. Results: Adherence rates measured using canisters were lower at day 60 than at day 30 (P =0.044) and did not change thereafter (74.4%±17.4% at day 30, 66.5%±18.4% at day 60, and 67.4%±22.2% at day 90). Adherence rates at days 60 and 90 and during the total study period were significantly different when measured by using questionnaires versus canisters (P<0.001, P =0.022, and P =0.001, respectively). In the comparison of adherence rates repeatedly measured at days 30, 60, and 90 and adherence rates during the total study period among the 3 groups, adherence rates in the high-degree supervision group were significantly higher than those in the low-degree supervision group (82.0±16.0 vs. 66.1±14.5, 75.4±14.4 vs. 56.2±18.4, 75.0±18.3 vs. 55.0±19.7 [P =0.027]; 77.9±12.2 vs. 59.1± 11.4 [P =0.021]) after adjustment for sex and age. Conclusion: The level of caregiver supervision is an important factor affecting adherence to ICS therapy in children with asthma. Therefore, a high degree of supervision may be required to increase adherence to ICS therapy in children with asthma. [ABSTRACT FROM AUTHOR]

Background: Asthma is characterized by airway inflammation, and bronchial airways are particularly susceptible to oxidant-induced tissue damage.Objective: To investigate the effect of dietary antioxidant intake and environmental tobacco smoke (ETS) on the risk of childhood asthma according to genotypes susceptible to airway diseases.Methods: This cross-sectional study included 1124 elementary school children aged 7-12 years old. Asthma symptoms and smoking history were measured using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Intake of vitamin A (including retinol and β-carotene), C, and E was measured by a semi-quantitative food frequency questionnaire (FFQ). GSTP1 polymorphisms were genotyped from peripheral blood samples.Results: ETS was significantly associated with presence of asthma symptoms (adjusted odds ratio [aOR], 2.48; 95 % confidence interval [CI], 1.29-4.76) and diagnosis (aOR, 1.91; 95 % CI, 1.19-3.06). Dietary antioxidant intake was not associated with asthma symptoms, although ETS plus low vitamin A intake showed a significant positive association with asthma diagnosis (aOR, 2.23; 95 % CI, 1.10-4.54). Children with AA at nucleotide 1695 in GSTP1 who had been exposed to ETS and a low vitamin A intake have an increased risk of asthma diagnosis (aOR, 4.44; 95 % CI,1.58-12.52) compared with children who had not been exposed to the two risk factors. However, ETS exposure and low vitamin A intake did not significantly increase odds of asthma diagnosis in children with AG or GG genotypes.Conclusion: Low vitamin A intake and ETS exposure may increase oxidative stress and thereby risk for childhood asthma. These relationships may be modified by gene susceptibility alleles of GSTP1. [ABSTRACT FROM AUTHOR]

Background: Exposure to perinatal anxiety affects disease susceptibility in offspring but studies on the association between perinatal anxiety and gene polymorphisms are lacking. This study aimed to elucidate the interaction between perinatal anxiety and polymorphisms in antioxidant defense and innate immunity genes on the development of respiratory tract infections (RTIs) during early infancy. Methods: Trait anxiety levels in 440 women were assessed by the State-Trait Anxiety Inventory during late gestation. The occurrence of RTIs, including bronchiolitis, during the first year of life was assessed by parent-reported doctor diagnosis. Polymorphisms in glutathione S-transferase P-1 (GSTP1, rs1695) and CD14 (rs2569190) were genotyped using the TaqMan assay. Copy number variations of GSTT1 were measured by real-time polymerase chain reaction. Results: Exposure to high levels of perinatal anxiety increased the risk of bronchiolitis in the first year of life (adjusted odds ratio [aOR], 1.30; 95% confidence interval [CI]: 1.00–1.80), in particular among children with the AG + GG genotype of GSTP1 or the GSTT1 null genotype (aOR 3.36 and 2.79). In infants with the TC + CC genotype of CD14, high levels of perinatal anxiety were associated with an increased risk of upper RTI, lower RTI, and bronchiolitis (aOR 2.51, 4.60, and 4.31, respectively). Conclusions: Perinatal maternal anxiety levels affect the occurrence of bronchiolitis in offspring. The effect of perinatal anxiety on the occurrence of bronchiolitis during infancy was influenced by genetic polymorphisms in antioxidant defense and innate immunity genes. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies suggest that the concentration of 25-hydroxyvitamin D [25(OH)D] in cord blood may show an inverse association with respiratory tract infections (RTI) during childhood. The aim of the present study was to examine the influence of 25(OH)D concentrations in cord blood on infant RTI in a Korean birth cohort. Methods: The levels of 25(OH)D in cord blood obtained from 525 Korean newborns in the prospective COhort for Childhood Origin of Asthma and allergic diseases were examined. The primary outcome variable of interest was the prevalence of RTI at 6-month follow-up, as diagnosed by pediatricians and pediatric allergy and pulmonology specialists. RTI included acute nasopharyngitis, rhinosinusitis, otitis media, croup, tracheobronchitis, bronchiolitis, and pneumonia. Results: The median concentration of 25(OH)D in cord blood was 32.0 nmol/L (interquartile range, 21.4 to 53.2). One hundred and eighty neonates (34.3%) showed 25(OH)D concentrations less than 25.0 nmol/L, 292 (55.6%) showed 25(OH)D concentrations of 25.0-74.9 nmol/L, and 53 (10.1%) showed concentrations of ⩾75.0 nmol/L. Adjusting for the season of birth, multivitamin intake during pregnancy, and exposure to passive smoking during pregnancy, 25(OH)D concentrations showed an inverse association with the risk of acquiring acute nasopharyngitis by 6 months of age (P for trend= 0.0004). Conclusion: The results show that 89.9% of healthy newborns in Korea are born with vitamin D insufficiency or deficiency (55.6% and 34.3%, respectively). Cord blood vitamin D insufficiency or deficiency in healthy neonates is associated with an increased risk of acute nasopharyngitis by 6 months of age. More time spent outdoors and more intensified vitamin D supplementation for pregnant women may be needed to prevent the onset of acute nasopharyngitis in infants. [ABSTRACT FROM AUTHOR]

A complex interplay between genetic and environmental factors partially contributes to the development of allergic diseases by affecting development during prenatal and early life. To explain the dramatic increase in the prevalence of allergic diseases, the hygiene hypothesis proposed that early exposure to infection prevented allergic diseases. The hygiene hypothesis has changed to the microbial hypothesis, in which exposure to microbes is closely linked to the development of the early immune system and allergic diseases. The intestinal flora may contribute to allergic disease through its substantial effect on mucosal immunity. Based on findings that exposure to microbial flora early in life can change the Th1/Th2 balance, thus favoring a Th1 cell response, probiotics may be beneficial in preventing allergic diseases. However, evidence from clinical and basic research to prove the efficacy of probiotics in preventing allergy is lacking. To date, studies have yielded inconsistent findings on the usefulness of probiotics in allergic diseases. It is difficult to demonstrate an exact effect of probiotics on asthma, allergic rhinitis, and food allergy because of study limitations, such as different first supplementation period, duration, different strains, short follow-up period, and host factors. However, many studies have demonstrated a significant clinical improvement in atopic dermatitis with the use of probiotics. An accurate understanding of the development of human immunity, intestinal barrier function, intestinal microbiota, and systemic immunity is required to comprehend the effects of probiotics on allergic diseases [ABSTRACT FROM AUTHOR]