Markers of impaired growth of pulmonary function in children and adolescents.

Our knowledge about the age-related growth of pulmonary function is incomplete. The purpose of this study was to describe the relation of various factors to the growth of pulmonary function in children and adolescents. A population sample comprising 408 children and adolescents (7-17 yr of age at enrollment) was reexamined after a 6-yr interval. Case history was obtained by interview and questionnaire. Pulmonary function, skin prick test reactivity to common allergens, and airway responsiveness (AR) were measured using standard techniques; airway hyperresponsiveness (AHR) was defined as a concentration of histamine causing a 20% decline in FEV1 < 8 mg/ml. The cross-sectional analyses of data from the two surveys showed that the presence of asthma (p < 0.02), atopy to house dust mite (HDM) (p = 0.03), and increasing degree of AR (p < 0.002) were associated with a lower level of FEV1 %pred. The longitudinal analysis revealed that asthma (p = 0.0001) and a lower level of FEV1 (p < 0.0001) at enrollment were associated with a lower level of FEV1 at follow-up. Further, an increase in the degree of AR (p = 0. 0001), new asthma (p = 0.0002), and new atopy to HDM (p = 0.03) also predicted a lower level of FEV1 at the end of the observation period. Confining the analysis to subjects without asthma and without evidence of AHR (n = 271) showed that both persistent (p = 0.04) and new (p = 0.03) atopy to HDM predicted a lower level of FEV1 at follow-up; compared with subjects with a negative skin reaction to HDM, those subjects who were sensitized to HDM had on average a 5%pred lower level of FEV1. The growth of FEV1 in children and adolescents appears to be impaired not only by symptomatic asthma but also by an increase in the degree of AR and atopy to HDM; sensitization to HDM appears to have a negative impact on the age-related growth in FEV1 even in nonasthmatic subjects without evidence of AHR.     

Indicators of asthma control among students in a rural,school-based asthma management program

Objective: The evaluation sought to determine if a comprehensive, school-based asthma management program in a small, rural school district helped students improve asthma control. Methods: To determine if students in the asthma program demonstrated better asthma control than students in a comparison school district, the evaluation team used a quasi-experimental, cross-sectional design and administered questionnaires assessing asthma control (which included FEV1 measurement) to 456 students with asthma in the intervention and comparison districts. Data were analyzed for differences in asthma control between students in the two districts. To determine if students in the intervention experienced increased asthma control between baseline and follow-up, the evaluation team used a one-group retrospective design. Program records for 323 students were analyzed for differences in percent of predicted forced expiratory volume in one second (FEV1) between baseline and follow-up. Results: Students with asthma in the intervention district exhibited significantly better asthma control than students with asthma in the comparison district. Percent of predicted FEV1 did not change significantly between baseline and follow-up for the intervention participants; however, post hoc analyses revealed students with poorly controlled asthma at baseline had significantly higher FEV1 scores at follow-up, and students with well-controlled asthma at baseline had significantly lower FEV1 scores at follow-up. Conclusions: Findings suggest that the comprehensive school-based program led to improvements in asthma control for students with poorly controlled asthma at baseline, and school-based programs need mechanisms for tracking students with initially well-controlled asthma to ensure they maintain control.     

Environmental tobacco smoke exposure during childhood is associated with increased prevalence of asthma in adults

OBJECTIVE: To examine if exposure to environmental tobacco smoke (ETS) during childhood has an impact on asthma prevalence in adults, and to identify the amount of nuisance from ETS and other lower airway irritants (LAWIs) in a city population. DESIGN: A postal survey. SETTING: The municipality of Orebro, Sweden. PARTICIPANTS: A total of 8,008 randomly selected inhabitants aged 15 to 69 years. MEASUREMENTS: Exposures, airway symptoms, and respiratory history were assessed using a questionnaire. RESULTS: The response rate was 84%. In never-smokers with childhood ETS exposure, the prevalence of physician-diagnosed asthma was 7.6% vs 5.9% in nonexposed subjects (p = 0.036). In never-smokers without a family history of asthma, the prevalence of physician-diagnosed asthma in subjects reporting childhood ETS exposure was 6.8% vs 3.8% in nonexposed subjects (p < 0.001). Subjects with childhood ETS exposure were more likely to start smoking in adulthood. The prevalence of ever-smokers was 54.5% vs 33.8% (p < 0.0001) in nonexposed subjects. ETS was the most commonly reported LAWI in the total sample (21%), followed by exercise in cold air (20%), dust (19%), exercise (16%), perfume (15%), cold air (12%), pollen (10%), and pets (8%). All LAWIs were more frequently reported by women. CONCLUSIONS: Childhood exposure to ETS is associated with an increased prevalence of asthma among adult never-smokers, especially in nonatopic subjects. Children exposed to ETS are also more likely to become smokers. ETS is as a major LAWI.     

Postural changes in nasal and pulmonary resistance in subjects with asthma.

INTRODUCTION: Subjects with asthma frequently have nasal symptoms and complain of orthopnoea but airflow resistance is usually only assessed during oral breathing and while seated. METHOD: We have used a forced oscillation technique to measure total respiratory resistance (Rrs) at 6Hz during mouth breathing (Rrs,mo) and during nose breathing (Rrs,na) in the sitting and supine postures; resistance of the nasal airway (Rnaw) was estimated as Rrs,na--Rrs,mo. Forced oscillations were applied during normal tidal breathing and the mid-tidal lung volume (MTLV) was determined for each breathing route and posture. SUBJECTS: Three groups of subjects were studied: 10 normal subjects without lung or nasal disease (N; five males, mean age 33.5 [range 23-58] years, mean FEV1 105%pred, FEV1/VC 86%); seven subjects with asthma alone (A; four males, 40.3 [23-57] years, mean FEV1 66%pred, FEV1/VC 74%); 10 asthmatic subjects with nasal obstructive symptoms (AN; six males, 62.8 [38-80] years, mean FEV1 56%pred, FEV1/VC 75%). RESULTS: In all three groups of subjects, mean Rrs,mo and Rrs,na were higher in the supine than sitting posture. In normal subjects the increase in supine Rrs,mo was associated with a 0.6 liter fall in MTLV. In asthma supine Rrs,mo increased despite a much smaller fall in MTLV; supine increases in Rrs,na were particularly large in presence of nasal disease. DISCUSSION: Values of airflow resistance are 2-3 times higher in both normal and asthmatic subjects when breathing via the nose and supine than under normal laboratory conditions of oral breathing and seated.     

Prevalence of over-/misdiagnosis of asthma in patients referred to an allergy clinic

Objective: Increasing asthma incidence may be due to an overall increase in asthma awareness by physicians, potentially resulting in overdiagnosis. One of the unique features of asthma is bronchial hyperresponsiveness, which can be assessed by methacholine bronchial challenge (MBC). Overdiagnosis may result in over- or mistreatment. The aims of this study were to describe the prevalence of the over-/misdiagnosis of asthma and the use of anti-asthmatic drugs in patients with asthma-like symptoms who had not yet undergone a respiratory function assessment to confirm the diagnosis of asthma. Methods: This was a retrospective study analyzing all MBCs performed by our Outpatient Allergy Clinic in a two-year period to confirm/exclude the diagnosis of asthma in patients referred by general practitioners and complaining of asthma-like symptoms. Anti-asthmatic medications used by the patients until the MBC date were recorded. Results: 43.8% of the reviewed MBCs were positive and 37.4% of the patients with a positive MBC were previously taking anti-asthmatic drugs (568.8?±?76.4?mcg mean beclomethasone equivalents), compared to 51.2% of those patients with a negative MBC (464.8?±?57.8?mcg). No differences were found in the daily doses of inhaled corticosteroids or other anti-asthmatic drugs, or in the duration of treatment before the assessment of bronchial hyperresponsiveness. Conclusions: A sizeable percentage of subjects who reported physician-diagnosed asthma had a negative MBC. Nevertheless, a greater proportion of negative MBC patients were taking anti-asthmatic drugs compared to those with a confirmed diagnosis of asthma, illustrating that the overdiagnosis of asthma may lead to over- and mistreatment of respiratory symptoms.     

The airway hyperresponsiveness to methacholine may be predicted by impulse oscillometry and plethysmography in children with well-controlled asthma

Objective: Airway hyperresponsiveness (AHR) is a hallmark of asthma. Methacholine challenge test which is mostly used to confirm AHR is not routinely available. The aim of this study was to investigate the predictive values of fractional exhaled nitric oxide (FeNO), impulse oscillometry (IOS), and plethysmography for the assessment of AHR in children with well-controlled asthma. Methods: 60 children with controlled allergic asthma aged 6–18 years participated in the study. FeNO measurement, spirometry, IOS, and plethysmography were performed. Methacholine challenge test was done to assess AHR. PC20 and dose response slope (DRS) of methacholine was calculated. Results: Mild to severe AHR with PC20 < 4 mg/ml was confirmed in 31 (51.7%) patients. Baseline FeNO and total specific airway resistance (SRtot)%pred and residual volume (RV)%pred levels in plethysmography were significantly higher and FEV1%pred, FEV1/FVC%pred, MMEF%pred values were lower in the group with PC20 < 4 mg/ml. FeNO, SRtot%pred, and RV%pred levels were found to be positively correlated with DRS methacholine. The higher baseline FeNO, frequency dependence of resistance (R5–R20) in IOS and SRtot%pred in plethysmography were found to be significantly related to DRS methacholine in linear regression analysis (β: 1.35, p = 0.046, β: 4.58, p = 0.002, and β: 0.78, p = 0.035, respectively). The cut-off points for FeNO and SRtot% for differentiating asthmatic children with PC20 < 4 mg/ml from those with PC20 ≥ 4 mg/ml were 28 ppb (sensitivity: 67.7%, specificity: 72.4%, p < 0.001) and 294.9% (sensitivity: 35.5%, specificity: 96.6%, p = 0.013), respectively. Conclusion: IOS and plethysmography may serve as reliable and practical tools for prediction of mild to severe methacholine induced AHR in otherwise “seemingly well-controlled’’ asthma.     

Childhood asthma in Batumi,Georgia: Prevalence and environmental correlates

Objective: A relative lack of data for Eastern Europe and unknown epidemiology of childhood asthma in Batumi (Georgia) justified a study aimed at determining the prevalence of physician-diagnosed asthma and related respiratory conditions, a comparison of the prevalence of these conditions between urban and rural children, and identification of their environmental correlates. Methods: Subjects of the cross-sectional population-based study were 3238 urban and 2081 rural children aged 5–17 years whose respiratory status was assessed using the ISAAC questionnaire. Results: The overall prevalence of asthma was larger in rural children than in urban children (2.8% vs. 1.8%, respectively; p = 0.01). Spastic bronchitis occurred with similar frequency in urban (7.8%) and rural children (6.5%). Compared with urban children, rural subjects had dry cough at night (13.1 vs 8.2%, p < 0.001) and attacks of dyspnea (4.7 vs 2.4%, p < 0.001) more often. The prevalence of other symptoms did not differ significantly between urban and rural subjects. Results of multivariate analyses showed that both asthma and spastic bronchitis were associated (p < 0.05) with parental history of asthma, dampness in the house, and poor financial standing of the family. In addition, asthma was related to coal/wood-based heating whereas spastic bronchitis was associated with passive smoking and lower parental education. Conclusions: The findings show a low prevalence of ever-diagnosed asthma in the examined population. Nosological tradition and similar correlates of asthma and spastic bronchitis suggest that some cases of asthma might be included in the diagnostic category of spastic bronchitis.     

Self-reported physician-diagnosed asthma among Swedish adolescent,adult and former elite endurance athletes

Objective: Asthma is common among elite endurance athletes. Since the first published Swedish studies in 1993, awareness of “skiers' asthma” has increased. The current prevalence of asthma among Swedish skiers is unknown. This paper aims to present the design of a 5-year prospective annual questionnaire study on asthma among Swedish current and former elite endurance athletes, the first cross-sectional results on prevalence, age of onset, and predictors of self-reported physician-diagnosed asthma in the study population. Methods: An annual postal questionnaire is sent to Swedish elite skiers and orienteers during 2011–2015. In 2013, former Swedish Olympic skiers were similarly invited. We present cross-sectional data obtained in 2011 from the adolescents and adults and in 2013 from former skiers. A total of 491 athletes were invited. The results are presented by age, sex and sport. Chi-square test was used for group comparisons. Predictors of asthma were identified using logistic regression. Results: Response rate was 82%. Among athletes aged 15–19, 29% of the skiers (38% of the female skiers), and 17% of the orienteers reported asthma (p?=?0.071). Among the athletes aged 20–34, 35% of the skiers and 16% of the orienteers reported asthma (p?=?0.029). Among the former skiers aged 40–94, 22% reported asthma. Among the active athletes, the onset of asthma was in early adolescence. Logistic regression found increasing age, female sex, allergy, family history of allergy/asthma and being skier predictors of self-reported physician-diagnosed asthma. Conclusions: The prevalence of physician-diagnosed asthma is high among Swedish endurance athletes, especially female adolescent skiers.     

The leaky lung test: a pilot study using inhaled mannitol to measure airway barrier function in asthma

Objective: Airway epithelial barrier dysfunction is emerging as an important feature of asthma pathogenesis, but this is difficult to measure in individual subjects. We aimed to develop a noninvasive way to measure airway permeability in asthma. Methods: Healthy controls and subjects with mild asthma inhaled dry powder mannitol in a dose-escalating manner on two separate occasions, stopping at 155?mg or 315?mg. Serum mannitol levels were measured at baseline and then 30, 90, and 150?min after mannitol inhalation. Mannitol absorption was compared with measurements of airflow obstruction (FEV1) and airway inflammation (FeNO). Results: Serum mannitol levels increased in a time- and dose-dependent manner in both healthy control and subjects with asthma. There were no significant differences in mannitol absorption when comparing healthy controls and subjects with asthma. Mannitol absorption did not correlate with markers of airway obstruction or inflammation. Conclusions: Measuring serum concentrations of mannitol after inhalation challenge can potentially provide insights into airway barrier function in asthma.     

Role of serum cortisol levels in children with asthma

Decreased serum cortisol levels have been proposed to contribute to nocturnal airway obstruction. We investigated whether endogenous cortisol levels are lower, and also whether the 24-h cortisol variation is greater, in children with asthma than in control subjects and assessed the relationship between serum cortisol and nocturnal airflow limitation in children with asthma. Cortisol and FEV(1) were measured every 4 h over 24 h; blood eosinophils, airway responsiveness to methacholine and adenosine 5'-monophosphate (AMP) were measured at 0400 and 1600. Children with asthma had lower cortisol levels than did control subjects; at midnight the difference was significant. Subjects with nocturnal asthma (24-h FEV(1) variation > or =15%) had significantly lower cortisol levels than did control subjects at 0000, 0800, and 1200. A higher mean 24-h cortisol level in subjects with asthma was associated with a significantly higher FEV(1) as a percentage of the predicted value (FEV(1) %pred) at 0400, 0800, and 2000, yet not in control subjects. Higher 24-h cortisol variation was associated with lower FEV(1) %pred at all time points in both control subjects and subjects with nonnocturnal asthma. There was no significant association between the level or variation of cortisol and PD(20) methacholine (provocative dose of methacholine causing a 20% fall in FEV(1)), PD(20) AMP, or eosinophils. Our data suggest that lower cortisol levels contribute to both overall lower levels of FEV(1) especially at night. This may be due to a lack of suppression of airway inflammation.     

Postural Changes in Nasal and Pulmonary Resistance in Subjects with Asthma

Introduction. Subjects with asthma frequently have nasal symptoms and complain of orthopnoea but airflow resistance is usually only assessed during oral breathing and while seated. Method. We have used a forced oscillation technique to measure total respiratory resistance (Rrs) at 6Hz during mouth breathing (Rrs,mo) and during nose breathing (Rrs,na) in the sitting and supine postures; resistance of the nasal airway (Rnaw) was estimated as Rrs,na ? Rrs,mo. Forced oscillations were applied during normal tidal breathing and the mid‐tidal lung volume (MTLV) was determined for each breathing route and posture. Subjects. Three groups of subjects were studied: 10 normal subjects without lung or nasal disease (N; five males, mean age 33.5 [range 23–58] years, mean FEV₁ 105%pred, FEV₁/VC 86%); seven subjects with asthma alone (A; four males, 40.3 [23–57] years, mean FEV₁ 66%pred, FEV₁/VC 74%); 10 asthmatic subjects with nasal obstructive symptoms (AN; six males, 62.8 [38–80] years, mean FEV₁ 56%pred, FEV₁/VC 75%). Results. In all three groups of subjects, mean Rrs,mo and Rrs,na were higher in the supine than sitting posture. In normal subjects the increase in supine Rrs,mo was associated with a 0.6 liter fall in MTLV. In asthma supine Rrs,mo increased despite a much smaller fall in MTLV; supine increases in Rrs,na were particularly large in presence of nasal disease. Discussion. Values of airflow resistance are 2–3 times higher in both normal and asthmatic subjects when breathing via the nose and supine than under normal laboratory conditions of oral breathing and seated.     

Association of airway responsiveness with asthma and persistent wheeze in a Chinese population

STUDY OBJECTIVES: Data from a cross-sectional study were analyzed to examine the association of increased airway responsiveness with physician-diagnosed asthma and persistent wheeze. DESIGN: Two methods for calculating the provocative dose that decreases the airflow rate by 20% (PD(20)) were used as indexes for increased airway responsiveness: (1) a 20% drop in FEV(1) calculated from baseline FEV(1) (PD(20)b), and (2) a 20% drop in FEV(1) from FEV(1) measurements after inhalation of saline solution (PD(20)s). Both PD(20)b and PD(20)s were measured through induction by varying doses of methacholine. SETTING: Anqing, Anhui Province, China. PARTICIPANTS: Study subjects were 8 to 74 years of age and were classified into four groups: children (< 15 years old), young adults (15 to 29 years old), adults (30 to 44 years old), and older adults (> or 5 years old). INTERVENTIONS: The differences in estimated odds ratios of airway hyperresponsiveness with asthma and wheeze, sensitivity and specificity, and coefficients of variation were compared between PD(20)b and PD(20)s. The sample for analysis consisted of 10,284 subjects from 2,663 nuclear families with complete data on wheeze, asthma, and major potential confounding factors. MEASUREMENTS AND RESULTS: The prevalence of asthma in this sample was lowest in subjects with no demonstrable PD(20) and had a reverse dose-response relationship with PD(20) across all age groups. Using the receiver operating characteristic, the sensitivity and specificity of the PD(20)s or PD(20)b were found to be almost identical. A similar trend was found for persistent wheeze, although the estimated odds ratios for persistent wheeze appeared slightly smaller than those for physician-diagnosed asthma. CONCLUSIONS: This study demonstrates a dose-response relationship between increased airway responsiveness and asthma and wheeze in this Chinese population. PD(20)s or PD(20)b yielded virtually indistinguishable results, which indicated that either of the two tests could serve as an index of airway hyperresponsiveness.     

Prevalence,risk factors and underdiagnosis of asthma and wheezing in adults 40 years and older: A population-based study

Objective: There are differences in the prevalence and risk factors of asthma around the world. The epidemiological situation of adults 40 years and older is not well established. Our aim was to determine the prevalence, underdiagnosis and risk factors of asthma and wheezing in adults in Colombia. Methods: A cross-sectional, population-based study including 5539 subjects from 40 to 93 years selected by a probabilistic sampling technique in five cities was conducted. Measurements: respiratory symptoms and risk factors questionnaire and spirometry. Definitions: (a) Wheezing: Affirmative answer to the question “have you ever had two or more attacks of “wheezes” causing you to feel short of breath?” (b) Asthma: Wheezing definition and FEV₁/FVC post-bronchodilator?≥?70%. (c) Underdiagnosis: Asthma definition without a physician-diagnosis. Logistic regression was used for exploring risk factors. Results: Prevalence of asthma was 9.0% (95% CI: 8.3-9.8) and wheezing 11.9% (95% CI: 11.0-12.8). Asthma underdiagnosis was 69.9% and increased to 79.0% in subjects 64 years or older. The risk factors related to asthma and/or wheezing were: living in Bogota or Medellin, female gender, first degree relative with asthma, respiratory disease before 16 years of age, obesity, no education, indoor wood smoke exposure and occupational exposure to dust particles, gases or fumes. Conclusion: We described the epidemiologic situation of asthma in adults 40 years and older in Colombia. In addition to some recognized risk factors, our data supports the association of indoor wood smoke and occupational exposures with asthma and wheezing. Underdiagnosis of asthma in adults was high, particularly in older subjects.     

Sputum eosinophilia, airway hyperresponsiveness and airway narrowing in young adults with former asthma.

Background: 30-80% of outgrown asthma subjects develop symptoms again later in life. We investigated inflammation and function of lower airway in adolescents with former asthma. Methods: 326 never-smoking young adults (mean age 24.0 years) were interviewed with special emphasis on history of asthma. Diagnosis of asthma was based on GINA guidelines. Former asthma subjects consisted of ones with a history of physician-diagnosed childhood asthma, who had been free of asthma symptoms without the use of medication for at least 10 years prior to the study. Provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 second (FEV(1))(PC(20)) and eosinophil percentage in induced sputum were measured. Results: 31 subjects were former asthma subjects (FBA), 11 subjects were current asthma subjects (CBA) and 284 subjects had no history of asthma (non-BA). PC(20) and FEV(1)/FVC ratio were significantly lower in the FBA group than in the non-BA group (P < 0.01). Maximal mid-expiratory flow (MMF) was significantly lower in the FBA group than in the non-BA group (P < 0.05). Sputum eosinophil percentage was significantly increased in the FBA group compared with the non-BA group (P < 0.01). PC(20) was significantly lower in the CBA group than in the FBA and non-BA groups (P < 0.01). FEV(1), FEV(1)/FVC ratio and MMF were significantly lower in the CBA group than in the FBA group (P < 0.05, P < 0.05 and P < 0.05, respectively) and the non-BA group (P < 0.01, P < 0.01 and P < 0.05, respectively). Sputum eosinophils were significantly higher in the CBA group than in the FBA and non-BA groups (P < 0.01). Conclusions: This study shows that subjects with long-term outgrown asthma continue to have airway eosinophilic inflammation, airway hyperresponsiveness and airway narrowing.     

Asthma in American Indian adults: the Strong Heart Study

BACKGROUND: Despite growing recognition that asthma is an important cause of morbidity among American Indians, there has been no systematic study of this disease in older adults who are likely to be at high risk of complications related to asthma. Characterization of the impact of asthma among American Indian adults is necessary in order to design appropriate clinical and preventive measures. METHODS: A sample of participants in the third examination of the Strong Heart Study, a multicenter, population-based, prospective study of cardiovascular disease in American Indians, completed a standardized respiratory questionnaire, performed spirometry, and underwent allergen skin testing. Participants were > or = 50 years old. RESULTS: Of 3,197 participants in the third examination, 6.3% had physician-diagnosed asthma and 4.3% had probable asthma. Women had a higher prevalence of physician-diagnosed asthma than men (8.2% vs 3.2%). Of the 435 participants reported in the asthma substudy, morbidity related to asthma was high: among those with physician-diagnosed asthma: 97% reported trouble breathing and 52% had severe persistent disease. The mean FEV(1) in those with physician-diagnosed asthma was 61.3% of predicted, and 67.2% reported a history of emergency department visits and/or hospitalizations in the last year, yet only 3% were receiving regular inhaled corticosteroids. CONCLUSIONS: The prevalence of asthma among older American Indians residing in three separate geographic areas of the United States was similar to rates in other ethnic groups. Asthma was associated with low lung function, significant morbidity and health-care utilization, yet medications for pulmonary disease were underutilized by this population.     

Seroepidemiological comparison of Helicobacter pylori infection rates in Shanghai urban districts in 1990 and 2001

BACKGROUND: The incidence of diseases related to Helicobacter pylori infection, such as gastric cancer, has been decreasing in developed countries and areas where the economy is rapidly developing. This is also the situation in Shanghai, the largest city in China. However, the prevalent trend of Helicobacter pylori infection in Shanghai is unknown. OBJECTIVE: To investigate changes in the sero‐prevalence rate of Helicobacter pylori infection in Shanghai residents between 1990 and 2001. METHODS: We tested serum H. pylori immuno­globulin G antibodies in 1557 blood samples from healthy residents of the Shanghai urban area in 2001 using the ELISA method. The sero‐prevalence rate of H. pylori infection in 2001 was compared with that in 1990. RESULTS: In the Shanghai urban area the overall sero‐prevalence rate of H. pylori infection in 2001 was 58.3%, higher than that in 1990 (40.5%, P = 0.001). No significant differences in sero‐prevalence rates were found in subjects aged 1?9, 10?19 and 20?29 years between 1990 and 2001 (19.8, 42.7, 52.4 vs 27.4, 39.6, and 41.4; P = 0.683, 0.707 and 0.068, respectively). In subjects older than 30 years, a significantly higher prevalence rate of H. pylori infection was observed in 2001 than in 1990 (P < 0.05). CONCLUSION: The prevalence of H. pylori infection in urban Shanghai residents in 2001 was greater than that found in 1990.     

Prevalence of bronchial hyperresponsiveness and asthma in the adult population in Thailand

OBJECTIVES: We conducted a nationwide cross-sectional survey of respiratory health in adults aged 20 to 44 years during 2001 to 2002 to determine the prevalence of bronchial hyperresponsiveness (BHR) and asthma in the adult Thai population. DESIGN: Subjects were selected by a multistage stratified random sampling. The stratification was done on geographic area, age group, and sex. Subjects were interviewed with questionnaires and underwent spirometric testing. Methacholine challenge tests were performed on all subjects without contraindication to determine BHR defined as the provocative concentration of methacholine producing a 20% fall in FEV(1) < or = 8 mg/mL. Definite asthma was defined as BHR present with any asthma symptom within the past 12 months or demonstrated reversible airflow obstruction. Current diagnosed asthma was defined as previous physician-diagnosed asthma and any asthma symptom within the past 12 months or currently receiving asthma medication. RESULTS: The study population was from 20 provinces of five geographic regions of Thailand and included 1,882 women and 1,572 men. The prevalence of BHR was 3.31% (95% confidence interval [CI], 2.68 to 3.94). However, if subjects with positive reversibility test results were included, the prevalence increased to 3.98% (95% CI, 3.30 to 4.67). The prevalence of definite asthma was 2.91% (95% CI, 2.32 to 3.50), whereas the prevalence of current diagnosed asthma by the questionnaire interview was 2.15% (95% CI, 1.66 to 2.63). The kappa index of the agreement between both definitions of asthma was 0.40, indicating poor to fair agreement. CONCLUSION: The prevalence of BHR and asthma in the adult Thai population is relatively low as compared with western countries.     

哮喘-慢性阻塞性肺疾病重叠综合征患者呼出气冷凝集液中TNF-α、IL-8、IL-10的检测水平及意义

目的检测哮喘-慢性阻塞性肺疾病重叠综合征(ACOS)患者呼出气冷凝集液(EBC)中肿瘤坏死因子α(TNF-α)、白细胞介素8(IL-8)、IL-10水平,并分析其与该疾病的关系.方法选取2016年2月至2019年3月成都市第三人民医院收治的ACOS患者105例,单纯哮喘患者109例(哮喘组),单纯COPD患者104例(COPD组),另选取同期体检的正常人100例(健康对照组).酶联免疫吸附法检测EBC中TNF-α、IL-8、IL-10水平,自动血液仪检测外周血嗜酸粒细胞比例,利用肺功能仪检测所有受试者第1秒用力呼气容积(FEV1)、用力肺活量(FVC).结果ACOS组、哮喘组、COPD组患者血清IgE水平、外周血嗜酸粒细胞显著高于健康对照组(t=13.594、23.188、3.595;20.886、26.966、20.036,P值均<0.05).ACOS组EBC中TNF-α、IL-8水平显著高于COPD组、哮喘组、健康对照组(t=11.999、13.157、26.807;6.961、7.741、32.496,P值均<0.05),IL-10水平、FEV1%pred显著低于哮喘组、COPD组、健康对照组(t=7.566、9.568、40.129;t=11.539、14.339、28.837,P值均<0.05),FEV1/FVC值显著低于健康对照组(t=16.756,P<0.05);COPD组、哮喘组EBC中TNF-α水平、IL-8水平显著高于健康对照组(t=14.892、14.057;25.544、25.146,P值均<0.05),IL-10水平、FEV1%pred、FEV1/FVC值显著低于健康对照组(t=32.562、31.045;t=17.372、14.939;13.752、16.341,P值均<0.05);哮喘组和COPD组TNF-α、IL-8、IL-10水平、FEV1%pred、FEV1/FVC值比较差异无统计学意义(t=1.015、0.697、1.909、2.658、2.457,P值均>0.05).Pearson检验结果显示,ACOS患者EBC中TNF-α、IL-8水平与FEV1%pred、FEV1/FVC呈负相关(r=-0.463、-0.504;-0.447、-0.476,P值均<0.05);IL-10水平与FEV1%pred、FEV1/FVC呈正相关(r=0.429、0.474,P值均<0.05);Logistic回归分析结果显示,血清IgE水平升高、EBC中TNF-α、IL-8水平升高是ACOS的危险因素(P<0.05),EBC中IL-10水平升高是ACOS的保护因素(P<0.05).结论EBC中TNF-α、IL-8、IL-10水平可能具有潜在的鉴别ACOS生物标志价值.     

Increased Prevalence of Self-Reported Asthma Among Korean Adults: An Analysis of KNHANES I and IV Data

Background

Asthma is one of the most common chronic conditions. Knowing the longitudinal trends of prevalence is important in developing health service planning and in assessing the impact of the disease. However, there have been no studies that examined current asthma prevalence trends in Korea through the analysis of nationwide surveys.

Methods

Data were acquired from patients aged 20–59 years who participated in the First Korean National Health and Nutritional Examination Surveys (KNHANES), which was conducted in 1998, and in the second year of the Fourth KNHANES, which was conducted in 2008. To estimate the prevalence of asthma with age and gender standardization, we used data from the Population and Housing Census, which was conducted by Statistics Korea in 2005.

Results

The prevalence of physician-diagnosed asthma increased from 1998 to 2008 (1998: 0.7 %, 2008: 2.0 %). The prevalence of asthma medication usage also increased from 1998 to 2008 (1998: 0.3 %, 2008: 0.7 %); however, the prevalence of wheezing decreased between 1998 and 2008 (1998: 13.7 %, 2008: 6.3 %). A similar trend was observed after estimating the prevalence of asthma with age and gender standardization. Allergic rhinitis might be the reason for the increased prevalence of physician-diagnosed asthma, while the observed decrease in wheezing may be related to the decrease in smoking or the increase in the use of asthma medication.

Conclusions

The present study showed that the prevalence of both self-reported physician-diagnosed asthma and asthma medication usage increased from 1998 to 2008 in Korea, despite a possible changing pattern of diagnosing asthma.     

Effects of bronchoscopy on lung function in asthmatics

Background: To better understand the changes in pulmonary physiology related to asthma severity following bronchoscopy, we performed scheduled pre- and post-procedure spirometry on subjects undergoing bronchoscopy in our research program. Methods: Control subjects and asthma subjects were recruited for bronchoscopy. On the day of bronchoscopy, subjects underwent spirometry pre-bronchoscopy and then up to three sets within 2 hour following the completion of bronchoscopy. A subset of patients had a second bronchoscopy after 2 weeks of treatment with oral prednisolone (40mg daily). Results: A total of 92 subjects had at least one bronchoscopy (12 control subjects, 56 nonsevere asthma (NSA), 24 severe asthma (SA)). The SA and NSA groups had similar decreases in forced expiratory volume in 1 second (FEV1) (?20±13% vs.?19±16%, p = 0.92) and forced vital capacity (FVC) (?20±12% vs.?20±14%, p = 0.80), but no change in FEV1/FVC ratio. The control and NSA group had more rapid recovery of both FEV1 and FVC by 2 hour compared to the SA group (p = 0.01). In the subset of 36 subjects (22 NSA, 14 SA) who underwent a second bronchoscopy following the administration of oral prednisolone for 14 days, steroids resulted in more rapid recovery of lung function (p < 0.04). Conclusion: Following bronchoscopy the lung function of NSA subjects recovered more quickly than SA subjects. Treatment with oral corticosteroids was associated with a quicker recovery of FEV1 which suggests an inflammatory mechanism for these changes in lung compliance.