Post-bronchodilator Spirometry Research Articles

The Association between BMI and COPD: The Results of Two Population-based Studies in Guangzhou, China

Background and Objective: An association between chronic obstructive pulmonary disease (COPD) and low body mass index (BMI) has been well established in cross-sectional studies. However, there have been few cohort studies investigating this issue. We therefore aimed to address this gap. Methods: Two population-based studies, a cross-sectional study including 1818 subjects and a subsequent 4-year cohort study consisting of 759 individuals without COPD, were conducted in Guangzhou, China. Every subject was 40 years old or older at the time of recruitment and completed questionnaire interviews, anthropometric measurements and spirometry testing. As a follow-up, each subject underwent annual pre-bronchodilator spirometry testing. Subjects with a pre-bronchodilator FEV1/FVC <0.7 were required to undergo post-bronchodilator spirometry testing. Subjects with a post-bronchodilator FEV1/FVC <0.7 were diagnosed with COPD. Results: Compared to subjects with normal BMI (18.5 to 23.9 kg/m2), those with low BMI (<18.5 kg/m2) had a higher prevalence of COPD (21.1% vs. 7.5%), with an adjusted OR of 2.75 [95% confidence intervals (CI): 1.69 to 4.47]. Both low BMI and obese (≥28.0 kg/m2) subjects had lower FEV1 after adjustment. This association was further confirmed in the cohort study; non-COPD subjects with low BMI at baseline were more likely to develop COPD (RR = 2.88, 95% CI: 1.06 to 7.85), independent of smoking status and other confounders. Conclusions: Low BMI was not only a systemic consequence of COPD but also an important risk factor for the development of COPD, which raises the possibility that early intervention in subjects with low BMI may reduce the incidence of COPD.

Prevalência da doença pulmonar obstrutiva crónica em Lisboa, Portugal: estudo Burden of Obstructive Lung Disease

BackgroundThere is a great heterogeneity in the prevalence of Chronic Obstructive Pulmonary Disease (COPD) demonstrates a great heterogeneity across the world. The Burden of Obstructive Lung Disease (BOLD) initiative was started to measure the prevalence of COPD in a standardized way. We aimed to estimate the prevalence of COPD in Portuguese adults aged 40 years or older of a target population of 2,700 000 in the Lisbon region, in accordance with BOLD protocol. MethodsA stratified, multi-stage random sampling procedure was used which included 12 districts. The survey included a questionnaire with information on risk factors for COPD and reported respiratory disease and a post-bronchodilator spirometry performed at survey centres. ResultsFor the 710 participants with questionnaires and acceptable spirometry, the overall weighted prevalence of GOLD stage I+ COPD was 14.2% (95% C.I. 11.1, 18.1), and stage II+ was 7.3% (95% C.I. 4.7, 11.3). Unweighted prevalence was 20.2% (95% C.I.17.4, 23.3) for stage I+ and 9.5% (95% C.I. 7.6, 11.9) for stage II+. Prevalence of COPD in GOLD stage II+ increased with age and was higher in men. The prevalence of GOLD stage I+ COPD was 9.2% (95% C.I. 5.9, 14.0) in never smokers versus 27.4% (95% C.I. 18.5, 38.5) in those who had smoked >20 pack-years. The agreement between previous doctor diagnosis and spirometric diagnosis was low, with 86.8% of underdiagnosed individuals. ConclusionsThe 14.2% of COPD estimated prevalence indicates that COPD is a common disease in the Lisbon region. In addition, a large proportion of underdiagnosed disease was detected. The high prevalence of COPD with a high level of underdiagnosis, points to the need of raising awareness of COPD among health professionals, and requires more use of spirometry in the primary care setting.

Chronic obstructive pulmonary disease prevalence in Lisbon, Portugal: The burden of obstructive lung disease study

BackgroundThere is a great heterogeneity in the prevalence of Chronic Obstructive Pulmonary Disease (COPD) across the world. The Burden of Obstructive Lung Disease (BOLD) initiative was started to measure the prevalence of COPD in a standardized way. We aimed to estimate the prevalence of COPD in Portuguese adults aged 40 years or older of a target population of 2,700,000 in the Lisbon region, in accordance with BOLD protocol. MethodsA stratified, multi-stage random sampling procedure was used which included 12 districts. The survey included a questionnaire with information on risk factors for COPD and reported respiratory disease and a post-bronchodilator spirometry performed at survey centres. ResultsFor the 710 participants with questionnaires and acceptable spirometry, the overall weighted prevalence of GOLD stage I+ COPD was 14.2% (95% C.I. 11.1, 18.1), and stage II+ was 7.3% (95% C.I. 4.7, 11.3). Unweighted prevalence was 20.2% (95% C.I.17.4, 23.3) for stage I+ and 9.5% (95% C.I. 7.6, 11.9) for stage II+. Prevalence of COPD in GOLD stage II+ increased with age and was higher in men. The prevalence of GOLD stage I+ COPD was 9.2% (95% C.I. 5.9, 14.0) in never smokers versus 27.4% (95% C.I. 18.5, 38.5) in those who had smoked ≥20 pack-years. The agreement between previous doctor diagnosis and spirometric diagnosis was low, with 86.8% of underdiagnosed individuals. ConclusionsThe 14.2% of COPD estimated prevalence indicates that COPD is a common disease in the Lisbon region. In addition, a large proportion of underdiagnosed disease was detected. The high prevalence of COPD with a high level of underdiagnosis, points to the need of raising awareness of COPD among health professionals, and requires more use of spirometry in the primary care setting.

Diagnostic score for COPD: Validation of the DS-COPD in clinical settings

Abstract Background Diagnosing Chronic Obstructive Pulmonary Disease (COPD) without spirometry is difficult; we had developed previously a scale (DS-COPD) in an epidemiological setting. It allowed diagnosing COPD confidently when scored high, and excluded confidently when low. Aim To validate the DS-COPD in clinical setting through a case-control study, and to evaluate the cost saving by its use. Methods In two tertiary care hospitals, we calculated the DS-COPD scale in suspected COPD and controls; COPD was predicted in the study sample and in symptomatic individuals. COPD status was confirmed by post-bronchodilator spirometry. Results From the ROC curve, the Area Under Curve was 0.945. The Positive Predictive Value was 79% if DS-COPD was >17 and the Negative Predictive Value was 83% if DS-COPD was Conclusions We were able to validate a scale (DS-COPD) for COPD diagnosis in clinical setting. It would be valuable in primary care settings, where spirometry may not be available and in clinical settings before availability of spirometry results. Future prospective studies are still needed to confirm its value.

Evaluation of Interpretation Strategies and Substantial Bronchodilator Response in Pediatric Patients With Normal Baseline Spirometry

Controversy exists regarding the best method to interpret pediatric spirometry. There is also controversy regarding the benefit of performing post-bronchodilator spirometry after normal baseline spirometry. This study compares the use of lower limit of normal (LLN) against percent of predicted (PP) in the interpretation of spirometry. We also investigate the occurrence of a substantial bronchodilator response for patients who received post-bronchodilator spirometry. Spirometric tests performed in the pediatric clinic at San Antonio Military Medical Center were retrospectively reviewed. Results of spirometry were compared using LLN and PP for interpretation. Abnormal spirometry was defined as a low FEV1 or low FEV1/FVC, indicating evidence of airway obstruction. The presence of a substantial bronchodilator response was recorded and the results were analyzed. Of 242 tests, 212 normal and 30 abnormal tests were reported using the LLN interpretation strategy. Using the PP interpretation strategy, there was a significant difference in the number of normal (183) and abnormal (59) tests, when compared to the LLN (P < .001). No significant difference between LLN versus PP interpretation strategies was noted in the number of baseline tests, normal or abnormal, that demonstrated a substantial response to bronchodilator. Of the subjects with normal baseline spirometry, 10% (PP) and 12% (LLN) had a substantial bronchodilator response. An abnormal baseline spirometry was more likely to have a substantial response to bronchodilator, compared to normal baseline spirometry (P < .001). The use of LLN for interpretation is more likely to report a test as normal, when compared to the PP interpretation strategy. Although a substantial bronchodilator response is more likely to occur following abnormal baseline spirometry, 10-12% of subjects with normal baseline spirometry showed a substantial bronchodilator response. This suggests that normal baseline spirometry may miss reversible airway obstruction, which is a hallmark of asthma.

COPD in Helsinki, Finland: socioeconomic status based on occupation has an important impact on prevalence

Chronic obstructive pulmonary disease (COPD) is globally a major, but often undiagnosed, cause of morbidity and mortality. The aims of this study were to assess the prevalence of COPD in Helsinki, Finland, with international diagnostic criteria and to analyse risk factors including socioeconomic status, and disease severity. A general population sample of 628 adults (368 women) completed flow-volume spirometry with bronchodilation test and a structured interview. Post-bronchodilation spirometry was assessed both using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria and relative to the fifth percentile of the reference value (lower limit of normal, LLN). According to GOLD criteria, 37 (5.9%), and by using the LLN criteria, 43 subjects (6.8%) had airway obstruction consistent with COPD. Using the GOLD criteria, four subjects or 0.6% of the population had severe, 3.0% moderate, and 2.2% mild COPD. Of those with post-bronchodilator obstruction, 49% had no previous diagnosis of obstructive airways disease and did not use medication for any respiratory disease. The prevalence of undiagnosed COPD defined by GOLD was 2.9% (LLN 3.3%). In addition to age, smoking history, and prior history of asthma, socioeconomic status based on occupation was significantly related to COPD in the population. Manual workers in industry (GOLD 10.0%, LLN 11.7%) and non-manual assistant employees (10.2%, 10.2%) had a significantly higher prevalence of COPD than professionals (2.8%, 2.3%). Although smoking is the main modifiable risk factor for COPD, the disease was significantly related to manual workers and non-manual assistant employees, i.e. socioeconomic groups reflecting occupation.

Changed terms for drug payment influenced GPs’ diagnoses and prescribing practice for inhaled corticosteroids

Background: Inhaled glucocorticosteroids (ICS) are first-line anti-inflammatory treatment in asthma, but not in chronic obstructive pulmonary disease (COPD). To restrict ICS use in COPD to cases of severe disease, new terms for reimbursement of drug costs were introduced in Norway in 2006, requiring a diagnosis of COPD to be verified by spirometry.Objectives: To describe how GPs’ diagnoses and treatment of patients who used ICS before 2006 changed after a reassessment of the patients that included spirometry.Methods: From the shared electronic patient record system in one group practice, patients ≥ 50 years prescribed ICS (including in combination with long-acting beta2-agonists) during the previous year were identified and invited to a tailored consultation including spirometry to assure the quality of diagnosis and treatment. GPs’ diagnoses and ICS prescribing patterns after this reassessment were recorded, retrospectively.Results: Of 164 patients identified, 112 were included. Post-bronchodilator spirometry showed airflow limitation indicating COPD in 55 patients. Of the 57 remaining patients, five had a positive reversibility test. The number of patients diagnosed with asthma increased (from 25 to 62) after the reassessment. A diagnosis of COPD was also more frequently used, whereas fewer patients had other pulmonary diagnoses. ICS was discontinued in 31 patients; 20 with mild to moderate COPD and 11 with normal spirometry.Conclusion: Altered reimbursement terms for ICS changed GPs’ diagnostic practice in a way that made the diagnoses better fit with the treatment given, but over-diagnosis of asthma could not be excluded. Spirometry was useful for identifying ICS overuse.

Is spirometry properly used to diagnose COPD? Results from the BOLD study in Salzburg, Austria: a population-based analytical study.

Background:Current guidelines recommend spirometry to confirm a diagnosis of chronic obstructive pulmonary disease (COPD).Aims:To investigate whether a self-reported diagnosis of COPD is associated with prior spirometry and whether a correct diagnosis of COPD is more likely when spirometry was performed.Methods:We used data from the population-based Austrian Burden of Obstructive Lung Disease (BOLD) study. Participants were aged >40 years and completed post-bronchodilator spirometry. Reported COPD diagnosis and reported prior lung function test were based on questionnaire. Persistent airflow limitation was defined as post-bronchodilator forced expiratory volume in one second/forced vital capacity ratio <0.7, corresponding with COPD Global initiative for chronic Obstructive Lung Disease (GOLD) grade I+, and GOLD grade II+ was also investigated. A correct diagnosis of COPD was defined as a reported physician's diagnosis of COPD and the presence of persistent airflow limitation.Results:68 (5.4%) of 1,258 participants reported a prior physician's diagnosis of COPD. Of these, only 17 (25.0%) reported a lung function test within the past 12 months and 46 (67.6%) at any time in the past. The likelihood for a correct COPD GOLD grade I+ diagnosis was similar among subjects reporting a lung function test during the last 12 months (likelihood ratio 2.07, 95% CI 0.89 to 5.50) and those not reporting a lung function during the last 12 months (likelihood ratio 2.78, 95% CI 1.58 to 4.87). Similar likelihood ratios were seen when GOLD grade II+ was investigated and when lung function was reported at any time in the past.Conclusions:One-third of subjects with a reported diagnosis of COPD never had a lung function test. When spirometry was reported, this did not increase the likelihood of a correct COPD diagnosis.

Diagnosis of Chronic Obstructive Pulmonary Disease, simpler is better Complexity and simplicity

From a clinical and even scientific point of view, an appropriate and timing diagnosis is pivotal in patientswith chronic diseases, not only for estimating the real prevalence of the illness. Indeed, the ability to discriminate patients from normal individuals is an important step in the view of assessing the stage of the disease, to eventually describe its prognosis, and to define the earliest and most appropriate pharmacological or non-pharmacological therapies for each single patient. The acronym COPD (Chronic Obstructive Pulmonary Disease) identifies a respiratory disease with a persistent enhanced local (Fig. 1) and systemic inflammatory pattern associated to a slowly progressive reduction of bronchial airflow, with only partial or no reversibility to bronchodilating medications at lung function testing (post-bronchodilator spirometry) [1].

Asthma diagnosis and treatment – 1016. Is atopy in people aged 40 and over related to fixed airflow obstruction?

Background: The Tucson and Normative Ageing studies showed atopy was not related to airflow obstruction in later life, when known asthmatics were excluded. However these studies were based on pre-bronchodilator spirometry. Aim: To examine independent associations between atopy and post-bronchodilator airflow obstruction in people aged 40 years and over. Methods: We used data from the BOLD-Australia study. Persons aged 40 years and over were randomly selected from the electoral roll, either directly or via a two stage sampling procedure, in centres based in four Australian States. Spirometry was performed before and after administration of salbutamol 200 μg, according to a standardised protocol with careful attention to quality control. Subjects with post-bronchodilator FEV1/FVC ratio < 0.7 were classified as GOLD stage 1 or higher. Subjects who also had FEV1 12% of pre-bronchodilator value and > 200 ml were classified as reversible. Atopy was assessed by skin prick tests (SPTs) to house dust mites (D. pteronyssinus and D. farinae), cat, dog, cockroach, Alternaria, Aspergillus, rye grass and mixed grass pollens. Subjects with any allergen SPT ≥ 4 mm were classified as atopic. Results: Post-bronchodilator spirometry and SPT data were available for 2,767 subjects (51.4% female, 12.1% aged ≥ 75). The prevalence of GOLD stage 1 or higher was 15.9%, the prevalence of GOLD stage 2 or higher was 6.8%, and 4.7% had bronchodilator reversibility. One in nine subjects selfreported current asthma and 50.5% had ever been smokers. The prevalence of atopy in this population was 42.7%. The associations between atopy and airflow obstruction did not differ by self-reported asthma or smoking status (all interactions p > 0.2). However atopy was associated with GOLD stage 2 after adjustment for sex, self-reported current asthma and smoking status (OR=1.56, 95%CI 1.13-2.17). As expected, atopy was related to the presence of bronchodilator reversibility (OR=1.89, 95%CI 1.32-2.72). Conclusions: The apparent association of atopy with fixed airflow obstruction using post-bronchodilator spirometry in people aged 40 years and over may be due to clinical heterogeneity.

Chronic Obstructive Pulmonary Disease (COPD) is associated with pulmonary artery stiffness - the MESA COPD study

Background This study seeks to evaluate indices of pulmonary artery (PA) stiffness in patients with COPD and compare with normal controls. We hypothesize that patients with COPD would have increased pulmonary artery stiffness. To test this we determine the pulmonary artery area change (distensibility in %) by cardiac MRI and relate the distensibility to a wide range of severity of COPD. Methods The MESA COPD Study recruited 290 patients (135 patients of various COPD severity and 155 controls) from four field centers in the US, age 50-79 years with ≥10 pack-years of smoking, all free of clinical cardiovascular disease. COPD was defined on post-bronchodilator spirometry by GOLD criteria (FEV1/FVC 80% = mild, 50-80%=moderate, <50%=severe). All participants underwent full-lung CTs. Percent emphysema was defined as the percentage of total voxels within the lung field that fell below -910 Hounsfield units. MRI studies were performed using 1.5T scanners. To measure ventricular function, the entire heart was imaged in short-axis orientation using a retrospectively gated steady-state free precession sequence. Phase-contrast images of the pulmonary arteries were obtained using a segmented fast gradient echo sequence with free breathing and analyzed quantitatively using dedicated software (FLOW, Medis). Distensibility of the pulmonary vessels (in %) are measured by the following formula, 100×(maximum PA area-minimum PA area)/minimum PA area. The base model (model 1) was adjusted for age, gender, height, weight, race/ethnicity and cohort of selection, given relationships of COPD severity to the pulmonary distensibility. We then additionally adjusted for smoking status, pack-years, diabetes mellitus, hypertension, oxygen saturation, LDL, HDL and statin use (model 2).

A discriminant function model as an alternative method to spirometry for COPD screening in primary care settings in China.

COPD is often underdiagnosed in a primary care setting where the spirometry is unavailable. This study was aimed to develop a simple, economical and applicable model for COPD screening in those settings. First we established a discriminant function model based on Bayes' Rule by stepwise discriminant analysis, using the data from 243 COPD patients and 112 non-COPD subjects from our COPD survey in urban and rural communities and local primary care settings in Guangdong Province, China. We then used this model to discriminate COPD in additional 150 subjects (50 non-COPD and 100 COPD ones) who had been recruited by the same methods as used to have established the model. All participants completed pre- and post-bronchodilator spirometry and questionnaires. COPD was diagnosed according to the Global Initiative for Chronic Obstructive Lung Disease criteria. The sensitivity and specificity of the discriminant function model was assessed. THE ESTABLISHED DISCRIMINANT FUNCTION MODEL INCLUDED NINE VARIABLES: age, gender, smoking index, body mass index, occupational exposure, living environment, wheezing, cough and dyspnoea. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, accuracy and error rate of the function model to discriminate COPD were 89.00%, 82.00%, 4.94, 0.13, 86.66% and 13.34%, respectively. The accuracy and Kappa value of the function model to predict COPD stages were 70% and 0.61 (95% CI, 0.50 to 0.71). This discriminant function model may be used for COPD screening in primary care settings in China as an alternative option instead of spirometry.

Can spirometric norms be set using pre- or post- bronchodilator test results in older people?

BackgroundChronic Obstructive Pulmonary Disease (COPD) is defined by post-bronchodilator spirometry. Data on “normal values” come predominantly from pre-bronchodilator spirometry. The effects of this on diagnosis are unknown.MethodsLower limits of normal (LLN) were estimated from “normal” participants in the Burden of Obstructive Lung Disease (BOLD) programme. Values separately derived using pre- and post-bronchodilator spirometry were compared. Sensitivity and specificity of criteria derived from pre-bronchodilator spirometry and pre-bronchodilator spirometry adjusted by a constant were assessed in the remaining population. The “gold standard” was the LLN for the post-bronchodilator spirometry in the “normal population”. For FEV1/FVC, sensitivity and specificity of criteria were also assessed when a fixed value of < 70% was used rather than LLN.ResultsOf 6,600 participants with full data, 1,354 were defined as “normal”. Mean differences between pre- and post- bronchodilator measurements were small and the Bland-Altman plots showed no association between difference and mean value. Compared with using the gold standard, however, tests using pre-bronchodilator spirometry had a sensitivity and specificity of detecting a low FEV1 of 78.4% and 100%, a low FVC of 99.8% and 99.1% and a low FEV1/FVC ratio of 65% and 100%. Adjusting this by a constant improved the sensitivity without substantially altering the specificity for FEV1 (99%, 99.8%), FVC (97.4%, 99.9%) and FEV1/FVC (98.7%, 99.5%).ConclusionsUsing pre-bronchodilator spirometry to derive norms for lung function reduces sensitivity compared to a post-bronchodilator gold standard. Adjustment of these values by a constant can improve validity of the test.

The Interplay between the Effects of Lifetime Asthma, Smoking, and Atopy on Fixed Airflow Obstruction in Middle Age

The contribution by asthma to the development of fixed airflow obstruction (AO) and the nature of its effect combined with active smoking and atopy remain unclear. To investigate the prevalence and relative influence of lifetime asthma, active smoking, and atopy on fixed AO in middle age. The population-based Tasmanian Longitudinal Health Study cohort born in 1961 (n = 8,583) and studied with prebronchodilator spirometry in 1968 was retraced (n = 7,312) and resurveyed (n = 5,729 responses) from 2002 to 2005. A sample enriched for asthma and chronic bronchitis underwent a further questionnaire, pre- and post-bronchodilator spirometry (n = 1,389), skin prick testing, lung volumes, and diffusing capacity measurements. Prevalence estimates were reweighted for sampling fractions. Multiple linear and logistic regression were used to assess the relevant associations. Main effects and interactions between lifetime asthma, active smoking, and atopy as they relate to fixed AO were measured. The prevalence of fixed AO was 6.0% (95% confidence interval [CI], 4.5-7.5%). Its association with early-onset current clinical asthma was equivalent to a 33 pack-year history of smoking (odds ratio, 3.7; 95% CI, 1.5-9.3; P = 0.005), compared with a 24 pack-year history for late-onset current clinical asthma (odds ratio, 2.6; 95% CI, 1.03-6.5; P = 0.042). An interaction (multiplicative effect) was present between asthma and active smoking as it relates to the ratio of post-bronchodilator FEV(1)/FVC, but only among those with atopic sensitization. Active smoking and current clinical asthma both contribute substantially to fixed AO in middle age, especially among those with atopy. The interaction between these factors provides another compelling reason for atopic individuals with current asthma who smoke to quit.

Care of patients with a diagnosis of chronic obstructive pulmonary disease: a cluster randomised controlled trial

To evaluate a partnership model of care for patients with a diagnosis of chronic obstructive pulmonary disease (COPD). Cluster randomised controlled trial with blinded outcome assessment of 44 general practices in south-western Sydney comprising 451 people with a diagnosis of COPD, conducted between 2006 and 2009. Participants from intervention group practices were visited at their home by a registered nurse with specific training in COPD care who worked with the general practitioner, the patient and other health professionals to develop and implement an individualised care plan based on best-practice guidelines. Participants from control group practices received usual care. The primary outcome was disease-related quality of life measured using the St George's Respiratory Questionnaire (SGRQ) at 12-month follow-up. Other outcomes were overall quality of life, lung function, smoking status, immunisation status, patient knowledge of COPD, and health service use. Of the 451 participants, 257 (57.8%) were confirmed as having COPD on post-bronchodilator spirometry. Follow-up was completed for 330 patients (73.2%). At 12 months, there was no statistically significant difference in the mean SGRQ scores between intervention and control groups (38.7 v 37.6; difference, 1.1; 95% CI, - 1.53-3.74; P = 0.41) or in measures of quality of life, lung function and smoking status. Compared with the control group, in the intervention group, attendance at pulmonary rehabilitation was more frequent (31.1% v 9.6%; OR, 5.16; 95% CI, 2.40-11.10; P = 0.002) and the mean COPD knowledge score was higher (10.5 v 9.8; difference, 0.70; CI, 0.10-1.21; P = 0.02). The nurse-GP partnership intervention did not have an impact on disease-related quality of life at 12-month follow-up. However, there was evidence of improved quality of care, in particular, in attendance at pulmonary rehabilitation and patient knowledge of COPD. Australian Clinical Trials Registry ACTRN012606000304538.

673 Pre and Post Bronchodilator Airway Resistance Values in Children with Asthma Using Airflow Perturbation Device (Apd)

BackgroundAsthma is the most common chronic disease of childhood and pulmonary function testing plays an important role in assessment and management of children with asthma. Pre and post bronchodilator spirometry...

Longitudinal Changes in Patient-reported Dyspnea in Patients with COPD

Background: Although guidelines recommend monitoring symptoms in patients with chronic obstructive pulmonary disease (COPD), there is limited information on the longitudinal changes in patient-reported dyspnea (PRD) related to activities of daily living. The hypothesis was that PRD scores on the modified Medical Research Council (mMRC) scale, the self-administered computerized (SAC) transition dyspnea index (TDI), and the University of California San Diego Shortness of Breath questionnaire (UCSD SOBQ) would demonstrate progression over two years. Methods: Observational cohort study of symptomatic patients with stable COPD evaluated every 6 months for 2 years. Patients rated the impact of activities of daily living on dyspnea using three patient-reported instruments presented in random order, and then performed post-bronchodilator (pBD) spirometry. Results: Seventy patients (37 female/33 male; age: 66 ± 9 years; and pBD forced expiratory volume in one second [(FEV1): 51 ± 16% predicted] participated. Using fixed effects regression modeling, there was significant worsening in the PRD scores with the SAC TDI (–0.9 ± 2.7; p = 0.03) and UCSD SOBQ (+5.7 ± 18.3; p = 0.001), but not with the mMRC scale (p = 0.52). Both pBD FEV1 (p = 0.19) and pBD forced vital capacity (p = 0.65) were unchanged. Conclusions: Multidimensional instruments (SAC TDI and UCSD SOBQ) demonstrated the frequently observed decline in PRD experienced by patients with COPD. The progression in PRD occurred despite stable lung function. Monitoring PRD provides unique clinical information and should be considered along with measuring lung function to assess patient status over time.

Capacidade aeróbica em crianças e adolescentes com asma intermitente e persistente leve no período intercrises

To assess children and adolescents diagnosed with mild intermittent or mild persistent asthma, in terms of their aerobic capacity between attacks. We included 33 children and adolescents recently diagnosed with asthma (mild intermittent or mild persistent) and 36 healthy children and adolescents. Those with asthma were evaluated between attacks. All participants underwent clinical evaluation; assessment of baseline physical activity level; pre- and post-bronchodilator spirometry; and a maximal exercise test, including determination of maximal voluntary ventilation, maximal oxygen uptake, respiratory quotient, maximal minute ventilation, ventilatory equivalent, ventilatory reserve, maximal HR, SpO2, and serum lactate. No significant differences were found among the groups (intermittent asthma, persistent asthma, and control) regarding anthropometric or spirometric variables. There were no significant differences among the groups regarding the variables studied during the maximal exercise test. A diagnosis of mild intermittent/persistent asthma has no effect on the aerobic capacity of children and adolescents between asthma attacks.

Methylated Genes in Sputum Among Older Smokers With Asthma

The epigenetic basis for human asthma is not well studied, particularly among older adults. This study investigated the methylation profiles in sputum DNA among older adults with asthma, using a population of smokers. This was a cross-sectional study using the Lovelace Smokers Cohort, a population of former and current smokers aged ≥ 40 years in New Mexico. One hundred eighty-four smokers with asthma were compared with 511 smoker control subjects with a similar smoking history, after carefully excluding those with COPD. Environmental exposures were assessed by a standard questionnaire. Postbronchodilator spirometry was performed. Induced sputum was analyzed for the methylation prevalence of 12 selected asthma-related genes using nested methylation-specific polymerase chain reaction assay. Asthma was associated with a greater number of methylated genes and, specifically, with methylated protocadherin-20 gene in sputum DNA compared with control subjects with a similar smoking history. These associations remained significant after adjustment for covariates as well as Bonferroni correction. A synergistic interaction was noted between two methylated genes (protocadherin-20 and paired box protein transcription factor-5α) in sputum DNA on the odds for asthma (P = .009). Interestingly, the epigenetic-asthma associations were not explained by the environmental factors studied. Further, methylated genes in sputum DNA, including the protocadherin-20 gene, identified a symptomatically more severe asthma phenotype in a subgroup analysis. Asthma is associated with methylation of selected genes, such as protocadherin-20 gene, in sputum DNA. If future studies establish causality, novel demethylating interventions to prevent and treat asthma among older smokers may be possible.

Risk factors associated with asthma phenotypes in dental healthcare workers.

Exposure in the dental environment can increase the risk of respiratory disease in dental healthcare workers (HCWs). This study investigated the prevalence of asthma phenotypes in dental HCWs and associated risk factors. A cross-sectional study of 454 dental HCWs in five dental institutions in South Africa was conducted. A self-administered questionnaire elicited the health and employment history of subjects. Sera was analyzed for atopic status and latex sensitization. Pre- and post-bronchodilator spirometry was performed. The prevalence of atopic asthma was 6.9%, non-atopic asthma 5.9% and work-exacerbated asthma (WEA) 4.0%. Atopy and work-related ocular-nasal symptoms were strong predictors of WEA (OR: 3.4; 95% CI: 1.07-10.8; OR: 6.7, 95% CI: 2.4-19.1), respectively. Regular use of personal protective equipment (PPE) was associated with a protective affect (OR: 0.23, 95% CI: 0.1-0.7) among non-atopic asthmatics, while glove use and respiratory protection was protective among atopic asthmatics (OR: 0.39, 95% CI: 0.17-0.89). Identification of risk factors associated with specific asthma phenotypes in dental HCWs can be used to focus preventive strategies for asthmatics.