Ethnic differences in spirometry measurements in China: Results from a large community‐based epidemiological study

Background and objective

No previous studies have examined differences in spirometry measurements among ethnic populations in China, and factors which may influence ethnic differences are unclear. Our study aimed to investigate whether forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) differ among Han Chinese and other ethnic minorities in China.

Methods

We recruited 7137 individuals aged 35–70 years from four areas of China inhabited by ethnic minority groups between 2007 and 2009. We conducted spirometry tests for all available participants, and compared FEV₁ and FVC among Uygur, Hui, Mongolian, Dai and Han Chinese ethnicities, using nonlinear multiplicative regression models.

Results

A total of 2005 healthy never‐smokers were enrolled in the analysis. For all ethnicities, spirometry values increased with height and decreased with age; FEV₁ and FVC were consistently higher in males than in females. Compared with Han Chinese, FEV₁ was 4.42% (95% CI: 2.11–6.78%) higher in Mongolians, 4.08% (95% CI: 1.33–6.76%) lower in Uygurs, 4.39% (95% CI: 1.33–7.35%) lower in Hui people and 4.72% (95% CI: 1.80–7.55%) lower in Dai people, after adjusted for potential confounders including height, age, sex and place of residence. We observed similar differences for FVC.

Conclusions

We detected significant differences in spirometry measurements among ethnic populations in China. Such differences cannot be fully explained by demographic, anthropometric or socioeconomic factors, but may also be attributed to genetic background as well as indoor and outdoor environmental exposures that need further investigation.

     

Baseline and post-bronchodilator interrupter resistance and spirometry in asthmatic children

In children unable to perform reliable spirometry, the interrupter resistance (R_int) technique for assessing respiratory resistance is easy to perform. However, few data are available on the possibility to use R_int as a surrogate for spirometry. We aimed at comparing R_int and spirometry at baseline and after bronchodilator administration in a large population of asthmatic children. We collected retrospectively R_int and spirometry results measured in 695 children [median age 7.8 (range 4.8–13.9) years] referred to our lab for routine assessment of asthma disease. Correlations between R_int and spirometry were studied using data expressed as z‐scores. Receiver operator characteristic curves for the baseline R_int value (z‐score) and the bronchodilator effect (percentage predicted value and z‐score) were generated to assess diagnostic performance. At baseline, the relationship between raw values of R_int and FEV₁ was not linear. Despite a highly significant inverse correlation between R_int and all of the spirometry indices (FEV₁, FVC, FEV₁/FVC, FEF_25–75%; P < 0.0001), R_int could detect baseline obstruction (FEV₁ z‐score ≤ ?2) with only 42% sensitivity and 95% specificity. Post‐bronchodilator changes in R_int and FEV₁ were inversely correlated (rhô = ?0.50, P < 0.0001), and R_int (≥35% predicted value decrease) detected FEV₁ reversibility (>12% baseline increase) with 70% sensitivity and 69% specificity (AUC = 0.79). R_int measurements fitted a one‐compartment model that explained the relationship between flows and airway resistance. We found that R_int had poor sensitivity to detect baseline obstruction, but fairly good sensitivity and specificity to detect reversibility. However, in order to implement asthma guidelines for children unable to produce reliable spirometry, bronchodilator response measured by R_int should be systematically studied and further assessed in conjunction with clinical outcomes. Pediatr Pulmonol. 2012. 47:987–993. © 2012 Wiley Periodicals, Inc.     

Spirometry in children aged 3 to 5 years: reliability of forced expiratory maneuvers.

The aim of this study was to evaluate the feasibility and reproducibility of forced expiratory maneuvers during standard spirometric evaluation in preschool children. Among 570 young children attending our laboratory, we retrospectively selected 355 patients (14% 3-4-year-olds, 48% 4-5-year-olds, and 38% 5-6-year-olds) who carried out spirometric tests for the first time. The indications for such tests were history of asthma (70%), followed by chronic cough (20%) and other miscellaneous conditions (10%). Eighty-eight, 175, and 92 children performed one, two, and three acceptable tests respectively. Forced expired volume in 1 sec (FEV(1)) and forced vital capacity (FVC) did not differ significantly between attempts in children performing either two or three attempts. Forced expiratory time (FET), i.e., the total time required for the forced expiratory maneuver, was 1.7 +/- 0.1 sec (mean +/- SEM), and was no greater than 1 sec in 21.3% of all tested children. Consequently, FEV(1) does not appear to be well-suited to this age group. Forced expiratory volume in 0.50 and 0.75 sec (FEV(0.5), FEV(0.75)) were thus measured in the group of children performing three attempts (n = 92), and there was no statistical difference between attempts. In 267 children performing two or three tests, the ATS criteria of reproducing FEV(1) and FVC within 相似文献   

Comparison of FEV(3), FEV(6), FEV(1)/FEV(3) and FEV(1)/FEV(6) with usual spirometric indices

Background and objective: Pulmonary function tests play an important role in the management of pulmonary diseases. One of the tests that are widely used is spirometry. Performing an acceptable spirometry manoeuvre according to the standards set by the American Thoracic Society/European Respiratory Society is difficult. The aim of this study was to compare forced expiratory volume in 3 s (FEV₃) and forced expiratory volume in 6 s (FEV₆) with forced vital capacity (FVC), and forced expiratory volume in 1 s FEV₁/FEV₃ and FEV₁/FEV₆ with FEV₁/FVC, in order to substitute the usual spirometric manoeuvres with manoeuvres that are easier to perform. Methods: In a cross‐sectional study, spirometry was performed for 588 subjects who were referred for occupational health evaluations. The accuracy of FEV₃, FEV₆, FEV₁/FEV₃ and FEV₁/FEV₆ was compared with that of FVC and FEV₁/FVC. Chi‐square tests and kappa tests were used to analyse the data. Results: Individuals with normal (n = 297) and abnormal spirometry (n = 291) were evaluated. The sensitivity, specificity, positive predictive value and negative predictive value of FEV₁/FEV₆, as compared with that of FEV₁/FVC for detecting obstruction, were 93.56, 99.32, 98.95 and 96.09, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of FEV₆, as compared with that of FVC for detecting restriction, were 96.68, 98.65, 96.68 and 98.65, respectively. Conclusions: FEV₆ and FEV₁/FEV₆ can be used as surrogates for FVC and FEV₁/FVC, respectively, and these parameters showed acceptable sensitivity, specificity, positive predictive value and negative predictive value for occupational health evaluations.     

Assessment of a low-cost home monitoring spirometer for children

Electronic devices are now available to measure and store lung function parameters in the home. Before adopting a device for clinical or research use, it is important to validate it in the target patient group. The aim of this study was to assess a low-cost, portable, logging spirometer, the VM Plus (VM), against a standard laboratory Jaeger spirometer (JS) for use in children with respiratory disease. Seventy children with stable asthma or cystic fibrosis performed spirometry on the two devices, and results for peak expiratory flow (PEF) and forced expiratory volume in 1 sec (FEV(1)) were compared. Comparison was made both using the two devices separately (separate method) and with the devices connected in series (series method). Reproducibility of the VM measurements was also assessed. Correlation between measurements was close (R values: separate, PEF, 0.91; FEV(1), 0.94; series, PEF, 0.97, FEV(1), 0.99), but PEF readings on the VM Plus were substantially higher than with the JS (mean difference: separate, 54.8 L/min; series, 28.2 L/min). This reflects well-reported differences in PEF measurements between the Mini-Wright PEF meter, on which the VM Plus spirometer is based, and conventional spirometers. Limits of agreement (series method) were: PEF, -13.2 to +69.6 L/min; FEV(1), -0.03 to +0.19 L. Reproducibility of VM Plus measurements was acceptable: coefficient of variation for PEF was 4%; for FEV(1), 4.3%; coefficient of reproducibility for PEF, 39 L/min; for FEV(1), 0.26 L. The VM Plus provides reasonably accurate, reproducible measurements of PEF and FEV(1), but intrinsic bias, particularly in PEF measurement, needs to be taken into account. Its potential to document longitudinal changes in lung function in children with respiratory disease at home merits further study.     

Symptom perception and functional morbidity across a 1-year follow-up in pediatric asthma

The purpose of this study was to examine the association between asthma symptom perception measured during a 5-6 week baseline and functional morbidity measured prospectively across a 1-year follow-up. Symptom perception was measured by comparing subjective ratings with peak expiratory flow rate (PEFR) and forced expiratory volume in one second (FEV(1)). We hypothesized that accurate symptom perception (ASP) would be associated with less functional morbidity. Participants consisted of 198 children with asthma ages 7-17 recruited from three sites. The children used a programmable electronic spirometer in the home setting to guess their PEFR prior to exhalation. Each "subjective" guess was classified as being in an ASP, dangerous symptom perception (DSP; underestimation of symptoms), or symptom magnification (SM; overestimation) zone based upon the corresponding measurement of PEFR or FEV(1). An index of functional morbidity was collected by parent report at baseline and across 1-year follow-up. A greater proportion of ASP blows and a lower proportion of DSP blows based on PEFR predicted less functional morbidity reported at baseline, independent of asthma severity and race/ethnicity. A greater proportion of ASP blows (using PEFR and FEV(1)) and a lower proportion of SM blows (using FEV(1)) predicted less functional morbidity across 1-year follow-up. Symptom perception was not associated with emergency department visits for asthma at baseline or across follow-up. In comparison to PEFR, FEV(1) more frequently detected a decline in pulmonary function that children did not report. Symptom perception measured in naturalistic settings was associated with functional morbidity at baseline and prospectively across 1-year follow-up. Support was found for including multiple measures of pulmonary function in the assessment of asthma symptom perception.     

Evaluation of daily home spirometry for school children with asthma: new insights

Home spirometers are useful for monitoring asthma therapy and for research, but the validity of maneuvers in children is in question. We evaluated the quality of PEF, FEV(1), and FVC data obtained from 67 children with persistent asthma who self-administered spirometry at home using the hand-held ndd EasyOne Frontline Spirometer with full expiratory curve data, electronic measurements of maneuver quality, and on-screen incentives. Half were studied in 2003 in one region, and half in 2004 in another region of Southern California. Subjects were followed at home weekly over 2 months and daily over 10 consecutive days. We retained completed spirometry sessions (9,916) consisting of three of six best maneuvers in the morning, afternoon, and evening. Percent compliance, software assessed repeatability and acceptability modified from American Thoracic Society criteria, and visually assessed quality of maneuvers, were compared across daily and weekly follow-up, study regions, and subject characteristics. Compliance was higher for daily (>90%) than for weekly follow-up (>84%), but not significantly different, and was consistent across subject characteristics. The number with two reproducible and acceptable maneuvers was significantly lower in the first than second region for daily (70 vs. 90%) and weekly follow-up (66 vs. 87%). Of 22,926 software accepted maneuvers, 1,944 (8.5%) were visually rejected (variable effort, cough, glottic closure). Maneuver quality was significantly lower for subjects age 9-12 versus 13-18 years, for subjects not taking anti-inflammatory medications, and for subjects with <80% predicted FEV(1). Longitudinal data collection is possible in children with asthma by employing repeated home training and follow-up, and using spirometers with built in quality assurance and incentive software. Region, age, and multiple indicators of persistent asthma, predict ability to perform reliable and accurate lung function maneuvers.     

Wheezes and desert breezes: when asthma and valley fever collide

Objective: To evaluate interactive effects of pulmonary coccidioidomycosis and asthma.

Methods: We identified three groups of 33 age- and sex-matched patients: Group 1 (both asthma and coccidioidomycosis), Group 2 (asthma only), and Group 3 (pulmonary coccidioidomycosis only). Predetermined end points included: rate of disseminated coccidioidomycosis, duration of symptoms and antifungal therapy, hospitalization, death, and escalation of asthma therapies.

Results: Baseline characteristics were similar across groups. Group 1 patients had worsening asthma outcomes (except forced expiratory volume in 1?s) with coccidioidomycosis. They required more asthma medications (median, 2.0 vs 0.0; p?<?0.001), more corticosteroids (mean [SD], 0.9 [4.2] vs 0.3 [0.6]; p?<?0.001), and more healthcare visits (mean [SD], 0.2 [0.4] vs 0.1 [0.3]; p?=?0.03). Groups 1 and 3 had no differences in coccidioidal end points, including rates of dissemination (1 vs 0; p?>?0.99), symptom duration (mean, 15.2 vs 23.6 weeks; p?=?0.24), antifungal treatment (n?=?21 [63.6%] vs n?=?24 [72.7%]; p?=?0.60), and treatment duration (median, 26.5 vs 11 weeks; p?=?0.09). Ten patients in Group 1 versus none in Group 3 required systemic corticosteroids for coccidioidomycosis (p?<?0.001).

Conclusions: Active pulmonary coccidioidomycosis significantly worsens asthma outcomes. Asthma (or its treatment) does not worsen coccidioidal outcomes, despite increasing the likelihood of treatment with systemic corticosteroids.     

Therapeutic methods repeatability of response to hypertonic saline aerosol in children with mild to severe asthma

Non-isotonic aerosols are being used more commonly to perform bronchial provocation tests. In contrast to histamine and methacholine challenge tests they appear to have higher specificity and a higher predictive value. The aim of the present study was to assess the reproducibility of the response to challenge with 4.5% hypertonic saline administered via an ultrasonic nebulizer in children with mild to severe asthma. Seventeen children with asthma aged 10 to 14 years completed two or three challenge tests at the same time of day within a 10 day period. Of these 17 children 9 had mild, 4 moderate, and 4 severe asthma. Children inhaled 4.5% hypertonic NaCl from an ultrasonic nebulizer with an output of 1.9 to 2.5 mL/min (Timeter) using the protocol developed by Anderson with modifications. A fall in forced expiratory volume in 1 second (FEV₁) from baseline of 15% or more was considered a positive response and PD₁₅, was calculated. In 16/17 subjects a greater than 15% fall in FEV₁ occurred consistently on all study days. One subject with moderate asthma had a less than 15% fall in FEV₁ on both study days. The coefficient of repeatability for PD₁₅ was 1.8. This equals 0.85 of a doubling dose difference between the two or three measurements of PD₁₅. The cumulative time of aerosol inhalation causing a fall in FEV₁ 2 15%) (PT₁₅) showed a coefficient of repeatability of 1.59, similar to 0.67 doubling dose difference. The PD₁₅ and PT₁₅ were highly significantly correlated. The 4.5% NaCl challenge test yields good reproducibility in children with mild to severe asthma under laboratory conditions. Pediatr Pulmonol. 1994;18:330–336 © Wiley-Liss, Inc.     

Effect of Desloratadine on Patients with Allergic Rhinitis and Exercise-Induced Bronchoconstriction: A Placebo Controlled Study

Background. Exercise induced broncho-constriction (EIB) is a significant problem in asthmatic patients. The link between allergic rhinitis and asthma is now well established. Patients with allergic rhinitis may have EIB. Objective. This study compared the effects of desloratadine and placebo on EIB in a group of patients with allergic rhinitis and EIB. Methods. This was a double blind placebo controlled, randomized, crossover study. Exercise challenge tests were performed before and after 7 days of treatment with either 5 mg desloratadine or placebo. Patients then underwent a washout period for 7 days and were crossed over to receive either 5mg desloratadine or placebo. The exercise challenge tests were repeated. Results. Desloratadine had no effect on the reduction in percentage fall in FEV₁, the AUC (0–60 min) and the time to recovery. Conclusions. Desloratadine has no effect in attenuating the broncho-constriction caused by exercise in patients with allergic rhinitis and exercise induced broncho-constriction. Clinical implications. Patients with allergic rhinitis and exercise induced broncho-constriction must be treated with either a ß₂-agonist or LRTA for relief or prophylaxis of their EIB. Capsule Summary. Desloratadine does not have an effect on exercise induced bronchoconstriction. Patients with allergic rhinitis with exercise induced bronchoconstriction who are on desloratadine will still require treatment with ß₂ agonist or leukotriene receptor antagonist for their symptoms.     

不同性别及年龄哮喘儿童大气道与小气道指标间相关性研究

目的探讨不同性别及年龄哮喘儿童肺功能第一秒最大呼气量(FEV1)及最大呼气流速峰值(PEF)与小气道各项指标间的相关性。方法选择14岁以下缓解期患儿200例,测定肺功能。结果大气道指标FEV1、FVC、PEF异常率分别为49.50%、56.50%、85.50%,测量水平分别为(1.05±0.35)L、(0.96±0.24)L、(2.40±0.81)L/S,小气道指标MEF25、MEF50、MEF75异常率分别为51.50%、46.00%、40.00%,检测水平分别为(0.60±0.81)L/S、(1.22±0.32)L/S、(2.02±0.68)L/S,PEF异常率高于FEV1、FVC(P0.05),MEF25异常率高于MEF75(P0.05),检测水平高于MEF50、MEF75(P0.05);男性及女性患儿大气道指标中均以PEF异常率最高,分别达到85.71%、85.14%,小气道指标中均以MEF25异常率最高,分别达到53.17%、48.65%,大气道指标FEV1、FVC、PEF及小气道指标MEF25、MEF50、MEF75异常率及水平在不同性别之间比较无统计学差异性(P0.05);3-5岁、6-9岁、10-14岁患儿大气道指标中均以PEF异常率最高,分别达到83.33%、90.63%、85.29%,小气道指标中均以MEF25异常率最高,分别达到52.94%、43.75%、61.76%,大气道指标FEV1、FVC、PEF及小气道指标MEF25、MEF50、MEF75异常率及水平在不同年龄段患儿之间比较无统计学差异性(P0.05);Spearman相关性分析结果显示男性、女性哮喘患儿PEF、FEV1与MEF25、MEF50、MEF75间均具有正相关性(P0.05),各年龄段患儿PEF、FEV1与MEF25、MEF50、MEF75间均具有正相关性(P0.05)。结论不同性别、不同年龄段的哮喘患儿大气道指标FEV1及PEF与小气道指标MEF25、MEF50、MEF75之间变化具有正相关性,大气道与小气道指标的变化与年龄及性别无关。     

Exploring the relationship between forced maximal flow at functional residual capacity and parameters of forced expiration from raised lung volume in healthy infants

The raised volume rapid thoraco-abdominal compression technique (RVRTC) is being increasingly used to assess airway function in infants, but as yet no consensus exists regarding the equipment, methods, or analysis of recorded data. The aim of this study was to explore the relationship between maximal flow at functional residual capacity (V'(maxFRC)) and parameters derived from raised lung volumes, and to address analytical aspects of the latter technique in an attempt to assist with future standardization initiatives. Forced vital capacity (FVC) from lung volume raised to 3 kPa, timed forced expiratory volumes (FEV(t)), and forced expiratory flow parameters at different percentages of expired FVC (FEF(%)) were measured in 98 healthy infants (1-69 weeks of age). V'(maxFRC) using the tidal rapid thoraco-abdominal compression (RTC) technique was also measured. The within-subject relationships and within-subject variability of the various parameters were assessed.Duration of forced expiration was < 0.5 sec in 5 infants, meaning that FEV(0.3) and FEV(0.4) were the only timed volume parameters that could be calculated in all infants during the first months of life, and even when it could be calculated, FEV(0.5) approached FVC in many of these infants. It is recommended that FEV(0.4) be routinely reported in infants less than 3 months of age. Contrary to previous reports, within subject variability of V'(maxFRC) was less than that of FEF(75) (mean CV = 6.3% and 8.9%, respectively).A more standardized protocol when analyzing data from the RVRTC would facilitate comparisons of results between centers in the future.     

A prospective cohort study of pulmonary function during pregnancy in women with and without asthma

Background and objective: Pregnancy alters the severity of asthma unpredictably. Uncertainty still exists about longitudinal changes in pulmonary function during pregnancy in both healthy and asthmatic women. This study aimed to compare pulmonary function changes during pregnancy in healthy and asthmatic women and to determine the relationship between pulmonary function and asthma-related quality of life during pregnancy. A secondary aim was to investigate the application of forced expiratory volume in 6?s (FEV₆) for monitoring asthma during pregnancy. Methods: Pregnant women with (n?=?20) and without asthma (n?=?20) had pulmonary function tests at 8–20, 21–28 and 29–40 weeks gestation. Those with asthma also completed the Asthma Control Questionnaire (ACQ) and mini Asthma Quality of Life Questionnaire (mAQLQ) at each visit. Results: Pulmonary function declined in both groups at follow-up #1 (more markedly in those with asthma) but then improved at follow-up #2 (more markedly in those with asthma). In those with asthma, ACQ scores increased, while mAQLQ scores declined at follow-up #1; whilst at follow-up #2 these changes were in the opposite direction. FEV₆ and forced vital capacity (FVC) were highly correlated (r?=?0.88, p?<?0.01) in asthmatics. Conclusions: Pulmonary function changes during second and third trimesters were more pronounced in asthmatics than in healthy women. FEV₆ monitoring may assist pregnant women and their health professionals in optimizing asthma management. The changes in pulmonary function in women with asthma were not significantly associated with changes in asthma control or asthma-related quality of life.