PURPOSE: It is becoming generally recognized that wheezing in early childhood is a heterogeneous condition and does not always develop into asthma. This study aimed to determine characteristics of wheezing phenotypes in early childhood and investigate their relation to asthma. METHODS: Two hundreds and sixty 6-8 year old children with past or present wheezeing were enrolled, and their history of wheezing was examined through medical records. Forty-three age- matched children who had never suffered from wheezing served as controls. Each subject underwent methacholine bronchial challenge and skin prick tests with airbone allergens. RESULTS: Forced expiratory volume in 1 second(FEV1) % predicted value was significantly lower in early-onset persistent wheezers(EP group) and late-onset wheezers(LW group) than in non-wheezers (NW group)(P<0.01, P<0.05, respectively). EP and LW groups demonstrated enhanced bronchial hyperresponsiveness(BHR), compared with early-onset transient wheezers(ET group) and NW group(all P<0.001). But there was no significant difference between the ET and NW groups. Atopy was significantly more prevalent in EP and LW groups than ET and NW groups, and serum IgE levels also showed similar figures(all P<0.001). CONCLUSION: Persistent wheezing with early childhood onset and late-onset wheezing are associated with high levels of atopy and BHR. It suggests that these two wheezing phenotypes are more closely related to asthma than transient wheezing phenotype.
Allergens ; Asthma ; Child* ; Forced Expiratory Volume ; Humans ; Immunoglobulin E ; Medical Records ; Methacholine Chloride ; Phenotype ; Respiratory Sounds* ; Skin

PURPOSE: This study was undertaken to compare blood eosinophilic inflammatory markers between the acute period and clinical remission in children with upper respiratory infection (URI) -induced wheezing, and to assess the effects of atopy and age on these changes. METHODS: In 77 children with URI-induced wheezing, blood eosinophil count and serum eosinophil cationic protein (ECP) were measured during the acute wheezing phase and clinical remission period. The data were analyzed in the subgroups divided by atopy and age, respectively. RESULTS: Blood eosinophil count was significantly lower during acute period (181.6/microliter, 67.3-490.0) than that during clinical remission period (261.8/microliter, 120.7-567.7, P=0.001), and this significant eosinopenic response was found in non-atopic children (n=36) [92.2 (41.3-206.0) /microliter vs 204.5 (106.6-392.2) /microliter, P< 0.001], but not in atopic children (n=41). A significantly higher level of serum ECP was observed during acute period (15.1 microgram/L, 7.2-31.6) than during clinical remission (13.0 microgram/L, 6.6-25.7, P=0.05), and this difference was significant only in atopic children[24.2 (15.3-38.1) microgram/L vs 16.2 (8.3-31.6) microgram/L, P< 0.001]. A significant fall in blood eosinophil count during acute period was found only in children < or=4 years (n=37), while a significant rise in serum ECP was detected only in children > 4 years (n=40). However, these differences a due to dissimilar distribution of atopy in the two age groups. CONCLUSION: Our results showed different eosinophil responses to infection in non-atopic and atopic children with URI-induced wheezing. It appears that the blunted eosinopenic response in atopic children may be associated with the predominant Th2-like response to infection.
Child* ; Eosinophil Cationic Protein ; Eosinophils* ; Humans ; Respiratory Sounds*

Background: Subclinical thyroid disease is characterized by abnormal thyroid stimulating hormone (TSH) levels with normal free thyroxine (T4) levels. This study aimed to verify the association between subclinical hypothyroidism and depression measured using the Patient Health Questionnaire-9 (PHQ-9) score in the Korean population. Methods: This cross-sectional study included 1,786 adults aged ≥19 years with normal free T4 levels and serum TSH levels ≥0.45 mIU/L who had participated in the Korea National Health and Nutrition Examination Survey (KNHANES) 2014. The PHQ-9 was first introduced in the KNHANES to detect depression (PHQ score of ≥10). Serum TSH level of 0.45–4.49 mIU/L was defined as the reference range. The association between subclinical hypothyroidism and depression according to gender and age was evaluated using the binary logistic regression analysis after adjusting for age, education, and body mass index. Results: There was no association between subclinical hypothyroidism and depression according to gender. The odds ratio for depression was 2.498 (95% confidence interval [CI], 0.905–6.895; P=0.077) in men and 0.727 (95% CI, 0.352–1.503; P=0.390) in women. Additionally, there was no association between subclinical hypothyroidism and depression according to age. Conclusion These results suggest that subclinical hypothyroidism was not associated with depression in Korean adults.

The aim of study was to describe Mycoplasma pneumoniae epidemics in a hospital-based population. Special attention was paid to the relationship between antibody titer to M. pneumoniae and sex, age, and atopy. During the eight 6-month periods between January 2000 and December 2003, serum samples were obtained from 1,319 Korean children who presented with respiratory symptoms, and were examined for antibodies to M. pneumoniae using the indirect particle agglutination test. Geometric mean antibody titers peaked in the second half of 2000 and then decreased gradually, a second peak occurred in the second half of 2003. Likewise, the frequency of high antibody titers (>or=1:640) also peaked during these two periods. Antibody titers in children aged 0-3 yr were lower than in older children during both peak periods and for 2 yr after the first peak. Sex and atopy had no effect on antibody titers. During the years 2000-2003, geometric mean antibody titers and the frequencies of high antibody titers varied with time. These changes suggest a cyclic pattern of M. pneumoniae infection, with two epidemic peaks separated by 3 yr.
Adolescent ; Age Distribution ; Antibodies, Bacterial/*blood ; Child ; Child, Preschool ; Disease Outbreaks/statistics & numerical data ; Female ; Humans ; Infant ; Infant, Newborn ; Korea/epidemiology ; Male ; Mycoplasma pneumoniae/*immunology ; Pneumonia, Mycoplasma/*blood/epidemiology/immunology ; Research Support, Non-U.S. Gov't ; Sex Distribution ; Time Factors

The aim of this study was to investigate the possible adverse effects of Asian dust events on respiratory health in asthmatic children. Fifty-two children with mild asthma were studied for eight consecutive weeks in the spring of 2004 (March 8 to May 2). During the study period, five Asian dust days were identified; we included a lag period of two days following each of the events. Subjects recorded their respiratory symptom diaries and peak expiratory flow (PEF) twice daily during the study period; and they underwent methacholine bronchial challenge tests. The subjects reported a significantly higher frequency of respiratory symptoms during the Asian dust days than during the control days. They showed significantly more reduced morning and evening PEF values, and more increased PEF variability (10.1%+/-3.5% vs. 5.5%+/-2.2%) during the Asian dust days than during the control days. Methacholine PC20 was not significantly different between before and after the study period (geometric mean: 2.82 mg/mL vs. 3.16 mg/mL). These results suggest that the short-term Asian dust events might be associated with increased acute respiratory symptoms and changes in PEF outcomes. However, there might be little long-term influence on airway hyperresponsiveness in children with mild asthma.
Adolescent ; Asthma/*physiopathology ; Bronchial Hyperreactivity/physiopathology ; Child ; *Dust ; Female ; Humans ; Male ; Methacholine Chloride/diagnostic use ; *Peak Expiratory Flow Rate ; Respiration Disorders/*etiology/physiopathology

PURPOSE: This study aimed to determine the efficacy and usefulness of chest auscultation and oxygen saturation measurement in the assessment of bronchial hyperresponsiveness to inhaled methacholine in pre-school wheezing children. METHODS: One hundred and four children with histories of wheezing underwent bronchial challenges with nebulized methacholine using chest auscultation and oxygen saturation measurement. The challenge was considered positive when PCW(provocation concentration at wheezing), PCSat(provocation concentration at 5% fall of oxygen saturation), or PCRR(provocation concentration at 50% increase in respiratory rate), was detected below 8 mg/mL of methacholine concentration. Patients were grouped according to their history of wheezing in the previous year:Group 1(children who had no episode, n=45), Group 2(children who wheezed one or two times, n=18), and Group 3(children who wheezed more than three times, n=41). Thirty-three children with no history of wheezing served as normal controls. RESULTS: The geometric means of PCW and PCSat of Group 2 and Group 3 were significantly lower than that of the control group(P<0.0001). There were decreasing tendencies of the geometric means of PCW and PCSat in the order of Group 1, Group 2, and Group 3. The PCRR of Group 3 was significantly lower than the other groups. The proportions of positive responses tend to increase in the order of control group, Group 1, Group 2, and Group 3(P<0.0001). CONCLUSION: We propose that chest auscultation and oxygen saturation measurement for the assessment of bronchial hyperresponsiveness to methacholine in pre-school children are effective and useful for diagnosis of asthma.
Asthma ; Auscultation* ; Child* ; Diagnosis ; Humans ; Methacholine Chloride ; Oxygen* ; Respiratory Rate ; Respiratory Sounds* ; Thorax*

PURPOSE: Bronchial hyperresponsiveness (BHR) is considered a hallmark of asthma. Increased levels of eosinophil cationic protein (ECP) have been identified in serum of asthma patients. Several studies have examined the relationship between serum ECP and bronchial responsiveness, expressed as methacholine PC20 in asthmatic patients, with conflicting results. The aims of this study were to examine the relationship between serum ECP and deltaFVC, another index of bronchial responsiveness, which reflects increased maximal airway response. METHODS: Six to 8-year-old children with asthma (n=109) underwent methacholine bronchoprovocation testing. The PC20 dose of methacholine and deltaFVC were calculated for each individual from the methacholine dose response curves. Serum ECP levels and blood total eosinophil counts were also measured. RESULTS: Serum ECP correlated with deltaFVC (r=0.217, P=0.023), as well as PC20 (r=-0.208, P=0.030). However, blood eosinophil counts failed to show any correlations with deltaFVC (r=0.085, P=0.378) or PC20 (r=-0.148, P=0.125). deltaFVC did not correlate with PC20 (r=-0.079, P=0.417). CONCLUSION: Blood eosinophil activation is associated with both components of BHR including increased sensitivity and increased maximal response in 6-8 year old children with asthma.
Asthma* ; Child* ; Eosinophil Cationic Protein* ; Eosinophils ; Humans ; Methacholine Chloride

PURPOSE: This study aimed to evaluate the validity of chest auscultation and oxygen saturation measurement in the assessment of bronchial hyperreactivity to inhaled methacholine in preschool children who were thought to be asthmatic clinically. METHODS: Seventy-two children with a history of more than three wheezing episodes in the previous year were considered the asthma group and underwent methacholine bronchial challenges. Provocation concentration at wheezing (PCw), at 5% fall of oxygen saturation (PCSat), and at 50% increase in respiratory rate (PCRR) were determined in each subject. One hundred and eighteen children who have had less than two wheezing episodes in their life served as control group. RESULTS: The geometric means of PCw, PCSat, and PCRR of asthma group were significantly lower than those of the control group. The optimal cut-off level for PCw was 8 mg/mL, giving a sensitivity of 63% and a specificity of 78%. Corresponding values for PCSat and PCRR were 8 mg/mL (72%, 67%) and 16 mg/mL (49%, 86%), respectively. The area under the receiver operating characteristic (ROC) curve for PCw, PCSat, and PCRR were 0.80, 0.88, and 0.70 respectively. The discriminative capacity of PCSat as judged by ROC curve analysis exceed those of PCw and PCRR. CONCLUSION: These findings provide support for the use of chest auscultation and oxygen saturation measurement as a tool in the assessment of bronchial hyperreactivity. The cut-off level of 8 mg/mL for PCSat, owing to its highest discriminative capacity, may be useful for the diagnosis of asthma in preschool children.
Asthma ; Auscultation* ; Bronchial Hyperreactivity* ; Bronchial Provocation Tests ; Child ; Child, Preschool* ; Diagnosis ; Humans ; Methacholine Chloride ; Oxygen* ; Respiratory Rate ; Respiratory Sounds* ; ROC Curve ; Sensitivity and Specificity ; Thorax*

PURPOSE: The identification of risk factors for bronchial hyperresponsiveness (BHR) is important in furthering the understanding of the cause of asthma. BHR is known to be related to atopy. We investigated the relations of BHR to sensitization to the five allergen groups in children aged 6-8 years. METHODS: Four hundred and seven 6-8 year old children with acute or chronic respiratory symptoms were enrolled. Each subject underwent methacholine bronchial challenge and skin-prick tests with airbone allergens. BHR was defined as PC20< or =8 mg/mL methacholine. Multiple logistic regression analysis was performed to study the independent relationship between BHR and sensitization to individual allergen group. RESULTS: The significant associations between BHR and skin-test response were against house dust mites (odds ratio=1.64, 95% confidence interval=1.02-2.65) and pollen (3.47, 1.18- 10.17) in total subjects, all after adjustment by sex, age, FEV1/FVC, total IgE, and a positive response to any of the other four allergen groups measured. In subjects with asthma, the significant association between BHR and positive skin-test response was observed only for house dust mites (2.53, 1.11-5.77). CONCLUSION: BHR was found to be related to atopy against house dust mite and pollen in subjects with respiratory symptoms, and against only house dust mites in subjects with asthma. These findings suggest atopy, especially against house dust mites, is an important risk factor for bronchial hyperresponsiveness in this age group.
Allergens ; Asthma ; Child* ; Humans ; Immunoglobulin E ; Logistic Models ; Methacholine Chloride ; Pollen ; Pyroglyphidae ; Risk Factors

PURPOSE: This study was designed to estimate the prevalence of Mycoplasma pneumoniae infection during an epidemic period by means of examining the antibody conversion rate and to investigate the association of the antibody conversion with age, initial antibody titer, and atopy. METHODS: We chose 191 children whose antibody titer to M. pneumoniae was negative, 1:40, or 1:80 during the first half of 2003. After the second half of 2003 when the M. pneumoniae epidemic occurred, follow-up collection of sera was performed during the first half of 2004. M. pneumoniae antibody titer was measured by Serodia-Myco II particle agglutination test. RESULTS: Of 191 children, antibody conversion was detected in 83 children(43.5 percent). No significant difference was found between the conversion and non-conversion group with respect to age, sex and atopy. Dividing the subjects into four groups by age, results on the antibody conversion rate revealed no significant differences between the groups. Assessed by initial antibody titer, a diminished trend of conversion rate was observed in children with 1:80 titer but the difference was not significant. There was no significant difference in the antibody conversion rate between atopic and non-atopic children. CONCLUSION: Based on the antibody conversion rate in this study, the prevalence of M. pneumoniae infection during an epidemic period was estimated to be 43.5 percent. This high infection rate suggests that during an epidemic, we should bear in mind M. pneumoniae as an important etiologic agent for respiratory infection in children.
Agglutination Tests ; Child ; Follow-Up Studies ; Humans ; Mycoplasma pneumoniae* ; Mycoplasma* ; Pneumonia ; Pneumonia, Mycoplasma* ; Prevalence