Obstructive Lung Function Impairment Research Articles

Impact of lung function impairment after allogeneic hematopoietic stem cell transplantation

Late-onset noninfectious pulmonary complications (LONIPC) are a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). However, the clinical impact of lung function deterioration itself in long-term adult survivors of HSCT remains to be fully investigated. This retrospective, longitudinal study aimed to investigate pulmonary function following HSCT in terms of its change and the clinical significance of its decline. We examined 167 patients who survived for at least 2 years without relapse. The median follow-up period was 10.3 years. A linear mixed-effects model showed that the slope of pulmonary function tests values, including percent vital capacity (%VC), percent forced expiratory volume in one second (%FEV1), and FEV1/forced VC ratio (FEV1%), decreased over time. The cumulative incidence of newly obstructive and restrictive lung function impairment (LFI) at 10 years was 15.7% and 19.5%, respectively. Restrictive LFI was a significant, independent risk factor for overall survival (hazard ratio 7.11, P = 0.007) and non-relapse mortality (hazard ratio 12.19, P = 0.003). Our data demonstrated that lung function declined over time after HSCT and that the decline itself had a significant impact on survival regardless of LONIPC.

Impaired Lung Function and Lung Cancer Incidence: A Nationwide Population-Based Cohort Study.

Background: It is unclear whether the presence of minimal lung function impairment is an independent risk factor for the development of lung cancer in general populations. Methods: We conducted a population-based cohort study using nationally representative data from the Korean National Health and Nutrition Examination Survey and the Korean National Health Insurance Service. Results: Of 20,553 participants, 169 were diagnosed with lung cancer during follow-up (median, 6.5 years). Participants with obstructive lung function impairment had increased risk of lung cancer (aHR: 2.51; 95% CI: 1.729–3.629) compared with those with normal lung function. The lower was the quartile or decile of forced expiratory volume in one second (FEV1) or the FEV1/forced vital capacity (FVC) ratio, the significantly higher was the incidence rate of lung cancer (p for trend < 0.0001). With FEV1 values in the lowest quartile (Q4), the incidence of lung cancer was significantly increased regardless of FVC (FEV1 Q4 and FVC values in the higher three quartiles Q1–3: aHR 1.754; 95% CI 1.084–2.847, FEV1 Q4 and FVC Q4: aHR 1.889; 95% CI 1.331–2.681). Conclusion: Our findings suggest that minimal lung function impairment, as expressed by lower FEV1 or FEV1/FVC value, may be associated with increased risk of lung cancer

Impact of electronic cigarette ever use on lung function in adults aged 45–85: a cross-sectional analysis from the Canadian Longitudinal Study on Aging

ObjectiveTo describe the sociodemographic characteristics associated with e-cigarette ever use and to examine the impact of e-cigarette ever use on lung function impairment in an ageing population.DesignA cross-sectional analysis of...

Relationship between lung function impairment, hypertension, and major adverse cardiovascular events: A 10-year follow-up study.

Lung function impairment and hypertension, especially hypertension, are risk factors of major adverse cardiovascular events (MACEs). However, the relationships among lung function impairment, hypertension, and MACEs have not been well‐reported. We aimed to investigate the association between lung function and hypertension and MACEs. We studied 6769 people who were a representative sample of the general population in Jiangsu Province using the multi‐stage stratified cluster sampling method. The average age was 51.54 years. Cox proportional hazards models were used to analyze the relationships between the blood pressure status and various types of lung function impairment related to MACEs. Over a follow‐up of 10 years, 236 MACEs occurred. After adjusting for age, sex, BMI, smoking, drinking, education, physical activity, diabetes mellitus, dyslipidemia, creatine and use of antihypertensive drugs, hypertension [hazard ratio (HR) = 2.154, 95% confidence intervals (CI): 1.565–2.966], and restrictive lung function impairment (RLFI) (HR = 1.398, 95% CI: 1.021–1.879) were independently associated with MACEs. Individuals with hypertension and RFLI had the highest risk for MACEs (HR = 2.930, 95% CI: 1.734–4.953) and stroke (HR = 3.296, 95% CI: 1.862–5.832). Moreover, when combined with hypertension, obstructive lung function impairment (OLFI) (HR = 2.376, 95% CI: 1.391–4.056) and mixed lung function impairment (MLFI) (HR = 2.423, 95% CI: 1.203–4.882) were associated with MACEs. There is a synergistic effect of lung function impairment (especially RLFI) and hypertension on MACEs. Therefore, more attention should be paid to the incidence of MACEs in individuals with impaired lung function, especially those who have hypertension.

Respiratory health effects of the fiberglass-reinforced plastic lamination process in the yacht-building industry.

Objectives:Fiberglass-reinforced plastics (FRP) manufacturing has been related to cases of severe airway obstruction and elevated risk of respiratory mortality. But the specific job content risk is not clear. This study evaluated the respiratory health effects of the FRP lamination process.Methods:A questionnaire was used to evaluate respiratory symptoms of workers in two yacht-building plants. Pre-shift (07:30–08:30 hours) and post-shift (17:00–18:00 hours) lung function was measured, while post-shift induced sputum was collected on the first day of the week. The participants were grouped into FRP laminators and non-laminators. Linear and logistic regression was used to investigate the effects of the lamination process on lung function.Results:Laminators had a higher prevalence of chronic cough, lower pre-shift forced expiratory volume in first second (FEV1) and FEV1/force vital capacity (FVC) (-3.3% and -1.5%), lower post-shift FVC and FEV1 (-3.6% and -4.9%), and larger post-shift reduction of FVC (-2.1%) compared to non-laminators. The laminators also had higher risk of early obstructive and overall (obstructive plus restrictive) lung function impairment, and post-shift reduction of FVC >10% [odds ratio (OR) 5.98, 4.98, and 3.87, respectively). They also had higher percentages of neutrophils and lymphocytes in the induced sputum.Conclusion:Laminators should undergo regular check-ups of respiratory symptoms and lung function. Further toxicologic studies are warranted to identify the specific causal agent in the FRP lamination process.

Transition from Restrictive to Obstructive Lung Function Impairment During Treatment and Follow-Up of Active Tuberculosis.

BackgroundPulmonary tuberculosis (PTB) is associated with many forms of chronic lung disease including the development of chronic airflow obstruction (AFO). However, the nature, evolution and mechanisms responsible for the AFO after PTB are poorly understood. The aim of this study was to examine the progression of changes in lung physiology in patients treated for PTB.MethodsImmunocompetent, previously healthy, adult patients receiving ambulatory treatment for a first episode of tuberculosis were prospectively followed up with serial lung physiology and quantitative computed tomography (CT) lung scans performed at diagnosis of tuberculosis, 2, 6, 12 and 18 months during and after the completion of treatment.ResultsForty-nine patients (median age 26 years; 37.2% males) were included, and 43 were studied. During treatment, lung volumes improved and CT fibrosis scores decreased, but features of AFO and gas trapping emerged, while reduced diffusing capacity (DLco) seen in a majority of patients persisted. Significant increases in total lung capacity (TLC) by plethysmography were seen in the year following treatment completion (median change 5.9% pred., P<0.01) and were driven by large increases in residual volume (RV) (median change +19%pred., P<0.01) but not inspiratory capacity (IC; P=0.41). The change in RV/TLC correlated with significant progression of radiological gas trapping after treatment (P=0.04) but not with emphysema scores. One year after completing treatment, 18.6% of patients had residual restriction (total lung capacity, TLC <80%pred), 16.3% had AFO, 32.6% had gas trapping (RV/TLC>45%), and 78.6% had reduced DLco.ConclusionSimple spirometry alone does not fully reveal the residual respiratory impairments resulting after a first episode of PTB. Changes in physiology evolve after treatment completion, and these findings when taken together, suggest emergence of gas trapping after treatment likely caused by progression of small airway pathology during the healing process.

RESPIRATORY SYMPTOMS AND LUNG FUNCTION AMONG ONLINE MOTORCYCLE TAXI DRIVERS

SESSION TITLE: Population-Wide Lung Health: Exposures and Risks SESSION TYPE: Original Investigations PRESENTED ON: 10/23/2019 10:45 AM - 11:45 AM PURPOSE: Online motorcycle taxi drivers have been heavily exposed to high concentration of hazardous air pollutants. It will cause harmful effects especially on the respiratory system. This study aimed to describe the respiratory symptoms and lung function among online motorcycle taxi drivers and risk factors that influence them. METHODS: A survey research design of 99 online motorcycle taxi drivers in Bekasi City was done. Lung function was measured using spirometer and predicted volume value from Pneumobile Project Indonesia. Risk factors and respiratory symptoms were collected using questionnaire. RESULTS: This study showed that 10,1% of subjects had restrictive lung function impairment and 5,1% had obstructive lung function impairment. Age had significant association with restrictive disorders (p= 0,006). The mean predicted forced vital capacity (FVC) was 3451 ml and the mean forced expiratory volume in one second (FEV1) was 2959 ml. There was a significant relationship between sex (p=0,001) and age (p=0,001) with the mean percent predicted forced vital capacity (%FVC). Age had significant association with the mean of percent predicted forced expiratory volume in one second (%FEV1) (p=0,039). However there were no significant relationship founded between sex, body mass index, safety equipment, history of smoking, duration of work, asthma history and previous tuberculosis disease with obstructive and restrictive lung function impairment. A proportion of respiratory symptoms among online motorcycle taxi drivers were cough (17,2%) and shortness of breath (6,1%). There were no significant relationship founded between respiratory symptoms and lung function result. CONCLUSIONS: This survey showed online motorcycle taxi drivers have respiratory symptoms and lung function impairment, however the causal relationship with the workplace environment is still unclear. Therefore, it will need further study to explore this findings. Moreover, education to the online motorcycle taxi drivers about the importance of using personal protective equipment will help them to protect respiratory systems from harmful gases. CLINICAL IMPLICATIONS: We report for the first time survey of online motorcycle taxi drivers in Indonesia which showed respiratory and impairment of lung function. Causal relationship with the workplace environment will be better explore with cohort study. Therefore, mask as personal protective equipment should be used in daily basis to protect them from air pollutants. DISCLOSURES: No relevant relationships by Triya Damayanti, source=Web Response No relevant relationships by Jaka Pradipta, source=Web Response no disclosure on file for Agus Susanto

Lung function and paper dust exposure among workers in a soft tissue paper mill

PurposeTo study respiratory effects of exposure to soft paper dust exposure, a relationship that is rarely studied.MethodsSoft tissue paper mill workers at a Swedish paper mill were investigated using a questionnaire and lung function and atopy screening. Spirometry without bronchodilation was performed with a dry wedge spirometer, and forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were obtained and expressed as percent predicted. Exposure to soft paper dust was assessed from historical stationary and personal measurements of total dust, in addition to historical information about the work, department, and production. The impact of high exposure to soft paper dust (> 5 mg/m3) vs. lower exposure ≤ 5 mg/m3, as well as cumulative exposure, was analyzed using multiple linear regression models. Multivariate models were adjusted for smoking, atopy, gender, and body mass index.ResultsOne hundred ninety-eight current workers (124 male and 74 female) were included. There were significant associations between both cumulative exposure and years of high exposure to soft paper dust and impaired lung function. Each year of high exposure to soft paper dust was associated with a 0.87% decrease in FEV1 [95% confidence interval (CI) − 1.39 to − 0.35] and decreased FVC (− 0.54%, 95% CI − 1.00 to − 0.08) compared to the lower exposed workers.ConclusionsThe present study shows that occupational exposure to soft paper dust (years exceeding 5 mg/m3 total dust) is associated with lung function impairment and increased prevalence of obstructive lung function impairment.

The association between glycemic control and lung function impairment in individuals with diabetes: the Saku study.

Though diabetes is a risk factor for lung function impairment, whether the glycemic control level affects lung function in individuals with diabetes remains unclear. The present study aimed to assess the association between glycemic control level and restrictive or obstructive lung function impairment in individuals with diabetes. This cross-sectional study included 1028 individuals with diabetes, aged 40-69years, who underwent a medical checkup between April 2008 and March 2014. Hemoglobin A1c (HbA1c) was categorized as < 6.9%, 7.0-7.9%, and ≥ 8.0%. Restrictive and obstructive lung function impairment was defined by a forced vital capacity (FVC) < 80% predicted and a forced expiratory volume in 1s to FVC ratio < 0.70. Of the participants, 8.7% and 6.3% were classified as having restrictive and obstructive lung function impairment, respectively. The multivariable-adjusted odds ratios and 95% confidence intervals for restrictive lung function impairment were 1.43 (0.84-2.42) in individuals with HbA1c 7.0-7.9%, and 2.42 (1.38-4.26) in individuals with HbA1c ≥ 8.0%, compared with those who had HbA1c < 6.9% (p for trend = 0.002). In contrast, glycemic control level was not associated with obstructive lung function impairment (p for trend = 0.749). Poor glycemic control was associated with restrictive lung function impairment in individuals with diabetes. Good glycemic control would be important to minimize restrictive lung function impairment in individuals with diabetes.

Lung function impairment is not associated with the severity of acute coronary syndrome but is associated with a shorter stay in the coronary care unit.

Previous population-based studies have suggested that lung function impairment (LFI) could be associated with an increase in the mortality of cardiovascular events. We evaluated the association between LFI and the severity and short-term prognosis of acute coronary syndrome (ACS). LFI was established through presence of a forced expiratory volume in one second (FEV1) and/or a forced vital capacity (FVC) less than 80% of predicted. Seventy-one LFI subjects (61.45±10.70 years, 83.10% males) and 247 non-LFI subjects (58.98±11.18 years, 80.57% males) with ACS were included. Subjects with LFI exhibited a higher prevalence of systemic hypertension (57.75% vs. 40.89%, P=0.02) and tobacco exposure (28.50±26.67 vs. 18.21±19.83 pack-years, P=0.007). No significant differences between groups were found regarding the severity of ACS (ejection fraction, Killip class, number of affected vessels, and peak plasma troponin). However, in comparison to non-LFI subjects, a significantly shorter length of stay in the coronary care unit (CCU) was observed in the LFI group (1.83±1.10 vs. 2.24±1.21 days, P=0.01) and this was even shorter in subjects with obstructive LFI (1.62±1.17 days, P=0.009). When considering obstructive sleep apnea (OSA), an interaction with length of stay was found, revealing that OSA subjects with obstructive LFI had the shortest length of stay in the CCU (0.60±0.89 days, P=0.05) also in comparison to non-LFI. This study indicates a possible association between LFI and a shorter length of stay in the CCU but does not show a significant association with ACS severity.

A prospective study of the impact of diabetes mellitus on restrictive and obstructive lung function impairment: The Saku study

BackgroundTo assess the impact of diabetes on restrictive and obstructive lung function impairment. MethodsThis 5-year prospective study included 7524 participants aged 40–69years without lung function impairment at baseline who underwent a comprehensive medical check-up between April 2008 and March 2009 at Saku Central Hospital. Diabetes was defined by fasting plasma glucose ≥7.0mmol/l (126mg/dl), HbA1c≥6.5% (48mmol/mol), or a history of diabetes, as determined by interviews conducted by the physicians. Restrictive and obstructive lung function impairment were defined as forced vital capacity (FVC) <80% predicted and forced expiratory volume in 1s (FEV1) to FVC ratio (FEV1/FVC) <0.70, respectively. Participants were screened until they developed restrictive or obstructive lung function impairment or until March 2014. ResultsDuring the follow-up period, 171 and 639 individuals developed restrictive and obstructive lung function impairment, respectively. Individuals with diabetes had a 1.6-fold higher risk of restrictive lung function impairment than those without diabetes after adjusting for sex, age, height, abdominal obesity, smoking status, exercise habits, systolic blood pressure, HDL-cholesterol, log-transformed high-sensitivity C-reactive protein, and baseline lung function [multivariable-adjusted HR and 95% CI; 1.57 (1.04–2.36)]. In contrast, individuals with diabetes did not have a significantly higher risk of obstructive lung function impairment [multivariable-adjusted HR and 95% CI; 0.93 (0.72–1.21)]. ConclusionDiabetes was associated with restrictive lung function impairment but not obstructive lung function impairment.

Alpha-1 Antitrypsin PiMZ Genotype Is Associated with Chronic Obstructive Pulmonary Disease in Two Racial Groups.

Alpha-1 antitrypsin deficiency, caused primarily by homozygosity for the Z allele of the SERPINA1 gene, is a well-established genetic cause of chronic obstructive pulmonary disease (COPD). Whether the heterozygous PiMZ genotype for alpha-1 antitrypsin confers increased risk for COPD has been debated. We analyzed 8,271 subjects in the Genetic Epidemiology of COPD (COPDGene) Study, hypothesizing that PiMZ would independently associate with COPD and COPD-related phenotypes. The COPDGene Study comprises a multiethnic, cross-sectional, observational cohort of non-Hispanic white and African American current and former smokers with at least 10 pack-years of smoking who were enrolled for detailed clinical and genetic studies of COPD and COPD-related traits. We performed multivariate logistic regression analysis for moderate to severe COPD and assessed Pi genotype with other relevant covariates in models stratified by race. We analyzed quantitative characteristics on the basis of volumetric computed tomography with generalized linear models controlling for genotype, scanner type, and similar covariates. White PiMZ COPDGene subjects had significantly lower lung function, FEV1 percent predicted (68 ± 28 vs. 75 ± 27; P = 0.0005), and FEV1/FVC ratio (0.59 ± 0.18 vs. 0.63 ± 0.17; P = 0.0008), as well as more radiographic emphysema (P = 0.001), than subjects without alpha-1 antitrypsin Z risk alleles. Similarly, African American PiMZ subjects had lower lung function, FEV1 percent predicted (65 ± 33 vs. 84 ± 25; P = 0.009) and FEV1/FVC (0.61 ± 0.21 vs. 0.71 ± 0.15; P = 0.03). In the COPDGene Study, we demonstrate that PiMZ heterozygous individuals who smoke are at increased risk for COPD and obstructive lung function impairment compared with Z-allele noncarriers, regardless of race. Although severe alpha-1 antitrypsin deficiency is uncommon in African Americans, our study adds further support for initial targeted detection of all subjects with COPD for alpha-1 antitrypsin deficiency, including African Americans. Clinical trial registered with www.clinicaltrials.gov (NCT00608784).

Prevalence of airflow obstruction in patients with stable systolic heart failure

BackgroundChronic obstructive pulmonary disease (COPD) is an important differential diagnosis in heart failure (HF). However, routine use of spirometry in outpatient HF clinics is not implemented. The aim of the present study was to determine the prevalence of both airflow obstruction and non obstructive lung function impairment in patients with HF and to examine the effect of optimal medical treatment for HF on lung function parameters.MethodsConsecutive patients with HF (ejection fraction (EF) < 45%) and New York Heart Association (NYHA) functional class II-IV at 10 different outpatient heart failure clinics were examined with spirometry at their first visit and after optimal medical treatment for HF was achieved. airflow obstruction was classified and graded according to the GOLD 2011 revision.ResultsBaseline spirometry was performed in 593 included patients and 71 (12%) had a clinical diagnosis of COPD. Mean age was 69 ± 11 years and mean EF was 30 ± 9%. Thirty-two % of the patients were active smokers and 53% were previous smokers. Mean FEV1 and FVC was 77.9 ± 1.7% and 85.4 ± 1.5% of predicted respectively. Obstructive pattern was observed in 233 (39%) of the patients. Of these, 53 patients (9%) had mild disease (GOLD I) and 180 (30%) patients had moderate to very severe disease (GOLD II-IV). No difference in spirometric variables was observed following up titration of medication.ConclusionIn stable patients with HF airflow obstruction is frequent and severely underdiagnosed. Spirometry should be considered in all patients with HF in order to improve diagnosis and treatment for concomitant pulmonary disease.

Elevated exhaled leukotriene B4 in the small airway compartment in children with asthma

BackgroundInflammatory processes in the asthmatic lung involve the large and small airway and alveolar sites. Leukotriene B4 (LTB4) is an important disease marker, but its role in inflammation of the small airways in asthma has not been established yet. ObjectiveTo distinguish between large and small airway or alveolar LTB4 concentrations in children with asthma using the new technique of fractionated exhaled breath condensate sampling. MethodsSixty-eight children (9–17 years old, 33 children with asthma and 35 controls) underwent fractional exhaled nitric oxide (FeNO) measurements, lung function testing, and collection of fractionated exhaled breath condensate using a capnograph-based approach. The LTB4 concentrations in the small airway or alveolar and large airway fractions were correlated to disease status, lung function impairment, and clinical parameters. ResultsChildren with asthma had significantly higher LTB4 concentrations in the small airway or alveolar fraction than controls (5.58 pg/mL; 95% interquartile range [IQR], 2.0–11.77 pg/mL; vs 2.0 pg/mL; 95% IQR, 2.0–6.2 pg/mL; P = .003). No difference was found between the groups in the large airway fraction. Children with obstructive lung function impairment (forced expiratory volume in 1 second z score <−1.65) had increased small airway or alveolar LTB4 concentrations compared with children without impairment (2.0 pg/mL; 95% IQR, 2.0–9.21 pg/mL; vs 18.32 pg/mL; 95% IQR, 3.7–23.02 pg/mL; P = .04). Children with asthma but without pathologic obstructive lung function still had higher LTB4 concentrations than controls (5.57 pg/mL; 95% IQR, 2.00–10.60 pg/mL; vs 2.00 pg/mL; 95% IQR, 2.00–6.20 pg/mL; P = .01). ConclusionLTB4 is detectable and elevated in the small airway or alveolar fraction of exhaled breath condensate in pediatric asthma. Because of the possibility of detecting elevated levels in patients without lung function impairment in controlled disease, it may be used as a noninvasive marker of small airways disease; however, future long-term studies are needed.

Subjects with COPD and productive cough have an increased risk for exacerbations and death

Chronic bronchitis is related to worse general health status, exacerbations and mortality among subjects with COPD. Also less longstanding cough and phlegm may be related to worse prognosis in COPD but this has rarely been evaluated in population-based studies. To evaluate the relationship between productive cough, exacerbations and mortality among subjects with and without COPD. All subjects with COPD (n = 993) were identified together with sex- and age matched reference subjects without obstructive lung function impairment from four population-based cohorts in 2002-04. Baseline spirometry and structured interview including data on exacerbations last 12 months were used in this study (n = 1986) together with mortality data collected until February 2012. Productive cough was more common in COPD than non-COPD (42.8 vs. 23.5%, p < 0.001), more common in men than women, but associated to exacerbations in both sexes. COPD-subjects with productive cough had the highest risk for exacerbations in both sexes and they had a significantly increased risk for death (HR 1.48, 95% CI 1.13-1.94) also when adjusted for sex, age, BMI, smoking habits and heart disease. Productive cough was common and increased the risk for exacerbations in both sexes, in both COPD and non-COPD. COPD-subjects with productive cough had the highest risk for exacerbations and a significantly higher risk for death also after adjustment for common risk factors.

A Dynamic Bronchial Airway Gene Expression Signature of Chronic Obstructive Pulmonary Disease and Lung Function Impairment

Molecular phenotyping of chronic obstructive pulmonary disease (COPD) has been impeded in part by the difficulty in obtaining lung tissue samples from individuals with impaired lung function. We sought to determine whether COPD-associated processes are reflected in gene expression profiles of bronchial airway epithelial cells obtained by bronchoscopy. Gene expression profiling of bronchial brushings obtained from 238 current and former smokers with and without COPD was performed using Affymetrix Human Gene 1.0 ST Arrays. We identified 98 genes whose expression levels were associated with COPD status, FEV1% predicted, and FEV1/FVC. In silico analysis identified activating transcription factor 4 (ATF4) as a potential transcriptional regulator of genes with COPD-associated airway expression, and ATF4 overexpression in airway epithelial cells in vitro recapitulates COPD-associated gene expression changes. Genes with COPD-associated expression in the bronchial airway epithelium had similarly altered expression profiles in prior studies performed on small-airway epithelium and lung parenchyma, suggesting that transcriptomic alterations in the bronchial airway epithelium reflect molecular events found at more distal sites of disease activity. Many of the airway COPD-associated gene expression changes revert toward baseline after therapy with the inhaled corticosteroid fluticasone in independent cohorts. Our findings demonstrate a molecular field of injury throughout the bronchial airway of active and former smokers with COPD that may be driven in part by ATF4 and is modifiable with therapy. Bronchial airway epithelium may ultimately serve as a relatively accessible tissue in which to measure biomarkers of disease activity for guiding clinical management of COPD.

Is an Individual Prediction of Maximal Work Rate by 6-Minute Walk Distance and Further Measurements Reliable in Male Patients with Different Lung Diseases?

Background: In patients with chronic lung diseases, the work rate for endurance training is calculated by the maximal work rate (W_max). Because the assessment bears side effects, a prediction by easier accessible tests would be of practical use. Objective: We addressed the reliability of predicting W_max on the basis of the 6-min walk distance (6MWD) test and a set of further parameters in patients with different lung diseases. Methods: Baseline data of a longitudinal study including 6MWD, W_max, peripheral muscle force, lung function, fat-free mass and dyspnea (Modified Medical Research Council score) of 255 men with occupational lung diseases (104 asthma, 69 asbestosis, 42 silicosis, 40 chronic obstructive pulmonary disease) were evaluated. Results: 6MWD correlated with W_max (r = 0.51, p < 0.05). The product of 6MWD and body weight, in particular fat-free mass, led to an improvement in the correlation of W_max with 6MWD. Muscle force, lung function and Modified Medical Research Council score correlated moderately but significantly with W_max (p < 0.05 each). The maximum correlation gained by including 6MWD and further parameters in the prediction equations was r = 0.76 in patients with obstructive lung function impairment and r = 0.61 in asbestosis patients. The residual standard deviations of W_max predicted by the calculated equations ranged between 20 and 28 W, and the 95% prediction intervals of W_max ranged between ±47 and ±65 W. Conclusions: A reliable prediction of individual W_max by 6MWD or related measures and therefore a replacement by other tests is not possible. Nevertheless, it may be useful for the comparison of average values in epidemiological and clinical studies.

Lung function in asbestos-exposed workers, a systematic review and meta-analysis.

BackgroundA continuing controversy exists about whether, asbestos exposure is associated with significant lung function impairments when major radiological abnormalities are lacking. We conducted a systematic review and meta-analysis in order to assess whether asbestos exposure is related to impairment of lung function parameters independently of the radiological findings.MethodsMEDLINE was searched from its inception up to April 2010. We included studies that assessed lung function parameters in asbestos exposed workers and stratified subjects according to radiological findings. Estimates of VC, FEV1 and FEV1/VC with their dispersion measures were extracted and pooled.ResultsOur meta-analysis with data from 9,921 workers exposed to asbestos demonstrates a statistically significant reduction in VC, FEV1 and FEV1/VC, even in those workers without radiological changes. Less severe lung function impairments are detected if the diagnoses are based on (high resolution) computed tomography rather than the less sensitive X-ray images. The degree of lung function impairment was partly related to the proportion of smokers included in the studies.ConclusionsAsbestos exposure is related to restrictive and obstructive lung function impairment. Even in the absence of radiological evidence of parenchymal or pleural diseases there is a trend for functional impairment.

Combined Analysis of EPHX1, GSTP1, GSTM1 and GSTT1 Gene Polymorphisms in Relation to Chronic Obstructive Pulmonary Disease Risk and Lung Function Impairment

Smoking is considered as the major causal factor of chronic obstructive pulmonary disease (COPD). Nevertheless, a minority of chronic heavy cigarette smokers develops COPD. This suggests important contribution of other factors such as genetic predisposing. Our objective was to investigate combined role of EPHX1, GSTP1, M1 and T1 gene polymorphisms in COPD risk, its phenotypes and lung function impairment. Prevalence of EPHX1, GSTP1, M1 and T1 gene polymorphisms were assessed in 234 COPD patients and 182 healthy controls from Tunisia. Genotypes of EPHX1 (Tyr113His; His139Arg) and GSTP1 (Ile105Val; Ala114Val) polymorphisms were performed by PCR-RFLP, while the deletion in GSTM1 and GSTT1 genes was determined using multiplex PCR. Analysis of combinations showed a significant association of 113His/His EPHX1/null-GSTM1 (OR = 4.07) and null-GSTM1/105Val/Val GSTP1 (OR = 3.56) genotypes with increased risk of COPD (respectively P=0.0094 and P=0.0153). The null-GSTM1/ null-GSTT1, 105Val/Val GSTP1/null GSTT1, 113His/His EPHX1/null-GSTM1 and null-GSTM1/105Val/Val GSTP1 genotypes were related to emphysema (respectively P = 0.01; P = 0.009; P = 0.008 and P = 0.001). Combination of 113His/His EPHX1/null-GSTM1 genotypes showed a significant association with the decrease of ΔFEV1 in patients (P = 0.028).In conclusion, our results suggest combined EPHX1, GSTP1, GSTM1 and GSTT1 genetic polymorphisms may play a significant role in the development of COPD, emphysema and decline of the lung function.

Combined analysis of EPHX1, GSTP1, GSTM1 and GSTT1 gene polymorphisms in relation to chronic obstructive pulmonary disease risk and lung function impairment.

Smoking is considered as the major causal factor of chronic obstructive pulmonary disease (COPD). Nevertheless, a minority of chronic heavy cigarette smokers develops COPD. This suggests important contribution of other factors such as genetic predisposing. Our objective was to investigate combined role of EPHX1, GSTP1, M1 and T1 gene polymorphisms in COPD risk, its phenotypes and lung function impairment. Prevalence of EPHX1, GSTP1, M1 and T1 gene polymorphisms were assessed in 234 COPD patients and 182 healthy controls from Tunisia. Genotypes of EPHX1 (Tyr113His; His139Arg) and GSTP1 (Ile105Val; Ala114Val) polymorphisms were performed by PCR-RFLP, while the deletion in GSTM1 and GSTT1 genes was determined using multiplex PCR. Analysis of combinations showed a significant association of 113His/His EPHX1/null-GSTM1 (OR = 4.07) and null-GSTM1/105Val/Val GSTP1 (OR = 3.56) genotypes with increased risk of COPD (respectively P=0.0094 and P=0.0153). The null-GSTM1/ null-GSTT1, 105Val/Val GSTP1/null GSTT1, 113His/His EPHX1/null-GSTM1 and null-GSTM1/105Val/Val GSTP1 genotypes were related to emphysema (respectively P = 0.01; P = 0.009; P = 0.008 and P = 0.001). Combination of 113His/His EPHX1/null-GSTM1 genotypes showed a significant association with the decrease of ΔFEV1 in patients (P = 0.028).In conclusion, our results suggest combined EPHX1, GSTP1, GSTM1 and GSTT1 genetic polymorphisms may play a significant role in the development of COPD, emphysema and decline of the lung function.