Association between menarche and increased bronchial hyper-responsiveness during puberty in female children and adolescents

STROBE: The relationship between asthma and early menarche in Korean adolescents

We explored the relationship between asthma and early menarche in a representative sample of Korean adolescents.Web-based self-reported data collected from 2006 to 2015 by the Korean Youth Risk Behavior Web-based Survey were used. Menarche status was divided into "early" (<12 years of age, n = 69,520) and "not early" (≥12 years of age, n = 234,065).Adolescent girls with early menarche exhibited a higher incidence of asthma (8.1% vs 7.4%, P < .001), more frequent school absences because of asthma (10.8% vs 8.7%), and more frequent ≤4-day stretches of school absence (4.6% vs 2.4%) compared with girls with "not early" menarche (all P < .001). Multivariate analysis performed after adjusting for multiple confounders revealed a 1.04-fold (95% confidence interval [CI] 1.00-1.07) greater likelihood of asthma in the early menarche than not early menarche group. In addition, the odds ratios for missing school due to asthma for 1 to 3 and ≥4 days per year in the early menarche group were 1.00 (95% CI 1.00-1.02) and 1.21 (95% CI 1.01-1.46), respectively.Adolescents with early menarche exhibited increased incidences of asthma and severe asthma.

Current Asthma Prevalence Using Methacholine Challenge Test in Korean Children from 2010 to 2014

BACKGROUND

Most epidemiological studies depend on the subjects' response to asthma symptom questionnaires. Questionnaire-based study for childhood asthma prevalence may overestimate the true prevalence. The aim of this study was to investigate the prevalence of "Current asthma" using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and methacholine challenge test in Korean children.

METHODS

Our survey on allergic disease included 4,791 children (age 7-12 years) from 2010 to 2014 in Korean elementary schools. Bronchial hyperresponsiveness (BHR) was defined as provocative concentration of methacholine causing a 20% fall in forced expiratory volume in one second (FEV1) (PC20) ≤ 16 mg/mL. "Current asthma symptoms" was defined as positive response to "Wheezing, current," "Treatment, current," or "Exercise, current." "Current asthma" was defined when the subjects with "Current asthma symptoms" showed BHR on the methacholine challenge test or had less than 70% of predicted FEV1 value.

RESULTS

The prevalence of "Wheezing, ever," "Wheezing, current," "Diagnosis, ever," "Treatment, current," "Exercise, current," and "Current asthma symptoms" was 19.6%, 6.9%, 10.0%, 3.3%, 3.5%, and 9.6%, respectively, in our cross-sectional study of Korean elementary school students. The prevalence of BHR in elementary school students was 14.5%. The prevalence of BHR in children with "Wheezing, ever," "Wheezing, current," "Diagnosis, ever," "Treatment, current," and "Exercise, current" was 22.3%, 30.5%, 22.4%, 28.8%, and 29.9%, respectively. BHR was 26.1% in those with "Current asthma symptoms." The prevalence of "Current asthma" was 2.7%.

CONCLUSIONS

Our large-scale study provides 2.7% prevalence of current asthma in Korean elementary school children. Since approximately one third of the children who have "Current asthma symptoms" present BHR, both subjective and objective methods are required to accurately predict asthma in subjects with asthma symptoms.

Sex-based differences in factors associated with bronchial hyperresponsiveness in adolescents with childhood asthma

BACKGROUND

Bronchial hyperresponsiveness (BHR), an important physiological feature of asthma, is a prognostic marker of childhood asthma.

PURPOSE

We aimed to investigate the factors associated with BHR in adolescents with childhood asthma.

METHODS

Two hundred and fifteen adolescents (≥13 years of age; 149 males, 66 females) who were diagnosed with asthma during childhood were enrolled, underwent methacholine challenge tests, and were divided into the BHR group (<25 mg/mL of provocation concentration causing a 20% fall in forced expiratory volume in 1 second [FEV1] [PC20], n=113) or non-BHR group (≥25 mg/mL of PC20, n=102). We examined longitudinal changes in BHR and the risk factors for its persistence in the 108 adolescents for whom baseline data, including methacholine PC20 at age 6 years, were available. Multivariate logistic regression analyses were performed to assess the factors associated with BHR in adolescents.

RESULTS

Mold sensitization (adjusted odds ratio [aOR], 5.569; P=0.005) and increased blood eosinophil count (aOR, 1.002; P=0.026) were independently associated with BHR in boys but not girls. The odds of BHR decreased by 32% with each 1-year increase in age in boys (aOR, 0.683; P=0.010) but not girls. A reduced FEV1/forced vital capacity ratio (<90%) was independently related with BHR in female patients only (aOR, 7.500; P=0.007). BHR decreased with age throughout childhood. A low methacholine PC20 at age 6 years was independently associated with persistent BHR throughout childhood in male and female patients, whereas early mold sensitization was a risk factor for persistent BHR in male patients only (aOR, 7.718; P=0.028).

CONCLUSION

Our study revealed sex-specific differences in the factors associated with BHR in adolescents with childhood asthma. Our findings suggest the risk factors that might affect asthma transition from childhood to adolescence and adulthood.

TNF-α (rs1800629) polymorphism modifies the effect of sensitization to house dust mite on asthma and bronchial hyperresponsiveness in children

Asthma is a complex disease, with various genetic and environmental factors implicated in its development. Sensitization to the house dust mite (HDM) is closely linked with the development of respiratory allergies, including asthma. However, some children sensitized to HDM do not complain of any symptoms of respiratory allergies, even though HDM is correlated with an increased risk for developing asthma, suggesting the involvement of other factors. Tumor necrosis factor (TNF)-α is associated with the pathophysiologies of asthma in combination with its genetic polymorphism. The aim of the present study was to elucidate the associations between sensitization to HDM, polymorphism of TNF-α rs1800629, and asthma/bronchial hyperresponsiveness (BHR). Our results revealed that sensitization to HDM is associated with asthma diagnosis in lifetime, current asthma, and BHR in Korean children. Furthermore, the genetic polymorphism of TNF-a rs1800629 was found to modify and interact with these associations. This study suggests that prevention strategies for childhood asthma need to be targeted according to genetic susceptibility.

Prenatal mold exposure is associated with development of atopic dermatitis in infants through allergic inflammation

OBJECTIVE

Mold exposure in early life may be associated with development of atopic dermatitis; however, studies of this link are inconclusive and evidence for the underlying mechanism(s) is lacking. This study identified the association between the time of mold exposure and development of atopic dermatitis and investigated the underlying mechanisms.

METHOD

The association between atopic dermatitis and mold exposure was examined in the Cohort for Childhood Origin of Asthma and Allergic Diseases birth cohort study (n=1446). Atopic dermatitis was diagnosed at 1 year of age by pediatric allergists. Exposure to mold was assessed by questionnaire. The Illumina MiSeq platform was used to examine the environmental mycobiome in 20 randomly selected healthy infants and 20 infants with atopic dermatitis at 36 weeks of gestation.

RESULTS

Prenatal, but not postnatal, mold exposure was significantly associated with atopic dermatitis (adjusted odds ratio, 1.36; 95% confidence interval, 1.01-1.83). Levels of total serum IgE at 1 year of age were higher in infants with atopic dermatitis exposed to mold during pregnancy than in healthy infants not exposed to mold during pregnancy (p=0.021). The relative abundance of uncultured Ascomycota was higher in infants with atopic dermatitis than in healthy infants. The relative abundance of uncultured Ascomycota correlated with total serum IgE levels at 1 year of age (r=0.613, p<0.001).

CONCLUSION

Indoor mold exposure during the fetal period is associated with development of atopic dermatitis via IgE-mediated allergic inflammation. Avoidance of mold exposure during this critical period might prevent the development of atopic dermatitis.

Clinical phenotypes of bronchial hyperresponsiveness in school-aged children

BACKGROUND

Bronchial hyperresponsiveness (BHR), one of the key features of asthma, has a diverse natural course in school-aged children, but studies on BHR phenotypes are lacking.

OBJECTIVE

To classify BHR phenotypes according to onset age and persistence in children and investigate the characteristics and factors associated with each phenotype in a longitudinal study.

METHODS

This study analyzed 1,305 elementary school children from the Children's Health and Environmental Research (CHEER) study, a 4-year, prospective, follow-up study with 2-year intervals starting at a mean age of 7years. Total serum IgE levels and blood eosinophil counts were measured, and allergy workup, including methacholine challenge tests with the International Study of Asthma and Allergies in Childhood questionnaire, was performed at each survey.

RESULTS

The 4 BHR phenotypes were classified as non-BHR (n = 942 [72.2%]), early-onset transient BHR (n = 201 [15.4%]), late-onset BHR (n = 87 [6.7%]), and early-onset persistent BHR (n = 75 [5.7%]). Early-onset persistent BHR is characterized by an increased eosinophil count, total serum IgE level, sensitization rate, decreased lung function, and increased risk of newly diagnosed asthma during follow-up (adjusted odds ratio, 3.89; 95% confidence interval, 1.70-8.88). The 2 early-onset phenotypes were associated with peripheral airway dysfunction. The late-onset BHR phenotype was related to increased risks of allergic rhinitis symptoms at baseline and later sensitization against inhalant allergens.

CONCLUSION

The early-onset persistent BHR phenotype in school-aged children is associated with high atopic burden and increased risk of newly diagnosed asthma, whereas the late-onset BHR phenotype related with later sensitization and allergic rhinitis symptoms. Diverse BHR phenotypes in children have specific characteristics that require targeted follow-ups.

Prevalence, Risk Factors and Cutoff Values for Bronchial Hyperresponsiveness to Provocholine in 7-Year-Old Children

Background

A US Food and Drug Administration (FDA)-approved drug methacholine chloride (Provocholine^®) was recently introduced to Korea where it is now widely used in clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine in 7-year-old children.

Methods

Six hundred and thirty-three children from the Panel Study on Korean Children who visited 16 regional hospitals were evaluated. Skin prick tests, spirometry and bronchial provocation tests for Provocholine as well as a detailed history and physical examinations were performed. The bronchial provocation test was reliably performed on 559 of these children.

Results

The prevalence of ever-diagnosed asthma via medical records was 7.7%, and that of current asthma (wheezy episode in the last 12 months + diagnosed asthma by physicians) was 3.2%. The prevalence of BHR to Provocholine was 17.2% and 25.8%, respectively, for a PC20 < 8 and < 16 mg/mL. The risk factors for BHR (PC20 < 16 mg/mL) were atopic dermatitis diagnosis and current dog ownership, whereas those for current asthma were allergy rhinitis diagnosis, a history of bronchiolitis before the age of 3, recent use of analgesics/antipyretics and maternal history of asthma. The BHR prevalence trend showed an increase along with the increased immunoglobulin E (IgE) quartile. The cutoff value of PC20 for the diagnosis of current asthma in children at age 7 was 5.8 mg/mL (sensitivity: 47.1%, specificity: 87.4%).

Conclusions

BHR to Provocholine (PC20 < 8 mg/mL) was observed in 17.2% of 7-year-olds children from the general population and the cutoff value of PC20 for the diagnosis of current asthma was 5.8 mg/mL in this age group. The risk factors for BHR and current asthma showed discrepancies suggesting different underlying mechanisms. Bronchial provocation testing with Provocholine will be a useful clinical tool in the future.

Baseline Features of the Severe Asthma Research Program (SARP III) Cohort: Differences with Age

BACKGROUND

The effect of age on asthma severity is poorly understood.

OBJECTIVES

The objective of this study was to compare the baseline features of severe and nonsevere asthma in the Severe Asthma Research Program (SARP) III cohort, and examine in cross section the effects of age on those features.

METHODS

SARP III is a National Institutes of Health/National Heart Lung Blood Institute multisite 3-year cohort study conducted to investigate mechanisms of severe asthma. The sample included 188 children (111 severe, 77 nonsevere) and 526 adults (313 severe, 213 nonsevere) characterized for demographic features, symptoms, health care utilization, lung function, and inflammatory markers compared by age and severity.

RESULTS

Compared with children with nonsevere asthma, children with severe asthma had more symptoms and more historical exacerbations, but no difference in body weight, post-bronchodilator lung function, or inflammatory markers. After childhood, and increasing with age, the cohort had a higher proportion of women, less allergen sensitization, and overall fewer blood eosinophils. Enrollment of participants with severe asthma was highest in middle-aged adults, who were older, more obese, with greater airflow limitation and higher blood eosinophils, but less allergen sensitization than adults with nonsevere asthma.

CONCLUSIONS

The phenotypic features of asthma differ by severity and with advancing age. With advancing age, patients with severe asthma are more obese, have greater airflow limitation, less allergen sensitization, and variable type 2 inflammation. Novel mechanisms besides type 2 inflammatory pathways may inform the severe asthma phenotype with advancing age.

The impact of parity and age at first and last childbirth on the prevalence of delayed-onset asthma in women: The Korean National Health and Nutrition Examination Survey

OBJECT

Asthma is a chronic inflammatory airway disease. The aim of this study was to investigate the relationships between asthma and reproductive factors, including age at first childbirth and parity, in a representative sample of Korean women.

MAIN OUTCOME MEASURES

We analyzed data from the Korean National Health and Nutrition Examination Survey (2010-2012). A total of 7837 adults who completed a questionnaire and examination were evaluated. The presence of asthma was based on the Health Interview Survey. Reproductive factors were estimated by trained interviewers using participant recall.

RESULTS

The women with asthma were significantly older than those without asthma. BMI, hypertension, education level, income level, occupation, alcohol consumption, and age at menarche and first birth were significantly associated with the diagnosis of asthma. Higher parity was positively associated with later-onset asthma. In addition, women who were younger at first birth had a greater prevalence of later-onset asthma. After controlling for confounders, being aged under 20 at first birth was significantly associated with an asthma diagnosis compared with women aged 25-29 at first birth (OR [95% CI]: 1.81 [1.14-2.89]).

CONCLUSIONS

Although higher parity was associated with asthma in women, its significance disappeared after adjustment. These results warrant future studies to explore the mechanisms responsible for the association between reproductive factors and asthma.