FEV1 To Forced Vital Capacity Research Articles

Preliminary study to explore gene-PM2.5 interactive effects on respiratory system in traffic policemen.

Traffic-related particulate matter (PM) is one of the major sources of air pollution in metropolitan areas. This study is to observe the interactive effects of gene and fine particles (particles smaller than 2.5 μm - PM2.5) on the respiratory system and explore the mechanisms linking PM2.5 and pulmonary injury. The participants include 110 traffic policemen and 101 common populations in Shanghai, China. Continuous 24 h individual-level PM2.5 is detected and the pulmonary function, high-sensitivity C-reactive protein (hs-CRP), Clara cell protein 16 (CC16) and the polymorphism in CXCL3, NME7 and C5 genes are determined. The multiple linear regression method is used to analyze the association between PM2.5 and health effects. Meanwhile, the interactive effects of gene and PM2.5 on lung function are analyzed. The individual PM2.5 exposure for traffic policemen was higher than that in the common population whereas the forced expiratory volume in 1 s (FEV1), the ratio of FEV1 to forced vital capacity (FEV1/FVC) and lymphocytes are lower. In contrast, the hs-CRP level is higher. In the adjusted analysis, PM2.5 exposure was associated with the decrease in lymphocytes and the increase in hs-CRP. The allele frequencies for NME7 and C5 have significant differences between FEV1/FVC ≤ 70% and FEV1/FVC > 70% participants. The results didn't find the interaction effects of gene and PM2.5 on FEV1/FVC in all the 3 genes. The results indicated that traffic exposure to high levels of PM2.5 was associated with systemic inflammatory response and respiratory injury. Traffic policemen represent a high risk group suffering from the respiratory injury.

Differences in spirometry values between U.S. children 6-11 years and adolescents 12-19 years with current asthma, 2007-2010.

National Asthma Education and Prevention Program (NAEPP) guidelines recommend that periodic spirometry be performed in youth with asthma. NAEPP uses different spirometry criteria to define uncontrolled asthma for children (6-11 years) and adolescents (12+ years). To describe differences in spirometry between U.S. children and adolescents with current asthma. We examined cross-sectional spirometry data from 453 U.S. youth with current asthma age 6-19 years from the 2007-2010 National Health and Nutrition Examination Surveys. The main outcomes were percentage predicted forced expiratory volume at 1 sec (FEV1%) ≤80 and the ratio of FEV1 to forced vital capacity (FEV1/FVC) ≤0.80. We also examined the prevalence of youth with spirometry values consistent with uncontrolled asthma, using NAEPP age-specific criteria, defined for children aged 6-11 years as FEV1% ≤80 or FEV1/FVC ≤0.80, and for adolescents aged 12-19 years as FEV1% ≤80. Children 6-11 years and adolescents 12-19 years did not differ in prevalence of FEV1% ≤80 (10.1% vs. 9.0%) or FEV1/FVC ≤0.80 (30.6% vs. 29.8%). However, based on the NAEPP age-specific criteria, 33.0% of children 6-11 years and 9.0% of adolescents 12-19 years had spirometry values consistent with uncontrolled asthma (P < 0.001). Children 6-11 years and adolescents 12-19 years with current asthma did not differ in the percentage with FEV1% ≤80 or FEV1/FVC ≤0.80. However, the percent of children and adolescents with spirometry values consistent with uncontrolled asthma did differ. The difference appears to stem mainly from the different spirometry criteria for the two age groups.

Airflow obstruction and left ventricular filling pressure in suspected chronic obstructive pulmonary disease

Left ventricular (LV) filling impairment is present in patients with chronic obstructive pulmonary disease (COPD). Airflow obstruction is related to reduced LV end-diastolic volume, stroke volume, and cardiac output. The ratio of peak early diastolic filling velocity of the mitral inflow to peak early diastolic velocity of the mitral annulus (E/e′), an echocardiographic parameter, can be applied as a surrogate marker of LV filling pressures. Forty-seven individuals with suspected COPD underwent pulmonary function tests and echocardiography. The ratio of forced expiratory volume in 1s to forced vital capacity (FEV1/FVC) and the E/e′ ratio were determined. Multivariate linear regression analysis showed that the FEV1/FVC ratio (β=0.01; 95% confidence interval, 0.001–0.019; p=0.036) independently predicted the log transformed E/e′ ratio. An increase of FEV1/FVC ratio (in percentage) by 1 unit was associated with an increase of the E/e′ ratio multiplied by 1.01. Airflow obstruction inversely predicts LV filling pressure in suspected COPD cases.

COPD AWARENESS SURVEY: DO BELGIAN PULMONARY PHYSICIANS COMPLY WITH THE GOLD GUIDELINES 2010?

Chronic Obstructive Pulmonary Disease (COPD) is underestimated, underdiagnosed and often undertreated in the general population. A survey of 17 structured questions, delivered to all Belgian pulmonary physicians (PPs) (116 responses), evaluated diagnosis and treatment strategies in accordance with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines 2010 and assessed opinions about the importance of diurnal variation of COPD symptoms. All COPD diagnoses (37% new cases) were spirometry confirmed. Main diagnostic parameters were symptoms (99%), external risk factors (99%), clinical examination (97%), exacerbations (96%) and patient mobility (96%). FEV1 (forced expiratory volume in 1s) (97%) or FEV1/FVC (ratio of FEV1 to forced vital capacity) (93%) were used most to assess diagnosis and severity. The 3 most important therapeutic objectives were symptom relief, preventing exacerbations, and improving quality of life; if these were not reached, the preferred strategy (60% of PPs) was adding another medication. Treatment strategies varied with COPD stage: short-acting β2-agonists (90%) and short-acting anti-cholinergics (59%) were used for GOLD I disease, whereas for higher stages long-acting β2-agonists (36-48%) and long-acting anti-cholinergics (79%) were given with inhaled corticosteroids (21-67%). Symptoms were perceived to vary throughout the day, affecting quality of life (97%) and mobility (89%). In particular, respiratory symptoms were more severe in the morning (51-92%), leading PPs to adapt treatment (69%). This survey demonstrated that management of COPD by PPs in Belgium is generally in line with the GOLD guidelines 2010 and that they perceive morning symptoms as being frequent and having an impact on patient’s life.

COPD in chronic heart failure: Less common than previously thought?

BackgroundUsing a fixed ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) < 0.70 instead of the lower limit of normal (LLN) to define chronic obstructive pulmonary disease (COPD) may lead to overdiagnosis of COPD in elderly patients with heart failure (HF) and consequently unnecessary treatment with possible adverse health effects. ObjectiveThe aim of this study was to determine COPD prevalence in patients with chronic HF according to two definitions of airflow obstruction. MethodsSpirometry was performed in 187 outpatients with stable chronic HF without pulmonary congestion who had a left ventricular ejection fraction <40% (mean age 69 ± 10 years, 78% men). COPD diagnosis was confirmed 3 months after standard treatment with tiotropium in newly diagnosed COPD patients. ResultsCOPD prevalence varied substantially between 19.8% (LLN-COPD) and 32.1% (GOLD-COPD). Twenty-three of 60 patients (38.3%) with GOLD-COPD were potentially misclassified as having COPD (FEV1/FVC < 0.7 but > LLN). In contrast to patients with LLN-COPD, potentially misclassified patients did not differ significantly from those without COPD regarding respiratory symptoms and risk factors for COPD. ConclusionsOne fifth, rather than one third, of the patients with chronic HF had concomitant COPD using the LLN instead of the fixed ratio. LLN may identify clinically more important COPD than a fixed ratio of 0.7.

Genetic variation in antioxidant enzymes and rate of decline in lung function

The oxidant/antioxidant balance in the lung is hypothesized to play an important role in chronic obstructive pulmonary disease (COPD). Deficits in antioxidant defenses due to variation in genes encoding antioxidant enzymes may cause accelerated lung function decline and increase disease risk. This study explored the association between genetic variation in a network of antioxidant enzymes and rate of decline in lung function phenotypes, including forced expiratory volume in the first second (FEV1) and the ratio of FEV1 to forced vital capacity (FEV1/FVC). 287 SNPs in 56 genes (MAF ≥ 1%) were analyzed using mixed effects models in 1,487 European American participants in the Health, Aging, and Body Composition study. The 7 top hits (nominal p&lt;0.02, range 0.007 to 0.017) for FEV1 were in 4 genes: mGST3, GSTA4, GPX1, and GPX2. The rs6904771 locus in GSTA4 was associated with a 12 ml/yr steeper rate of decline in FEV1 per T allele. Markers in two genes (GCLC, GSTO2) were associated (nominal p&lt;0.02) with the ratio of FEV1/FVC. mGST3, GPX1, and GPX2 have not been previously identified in human studies of lung outcomes, but agree with prior animal studies, and all 6 genes have known functional relevance to lung outcomes. In summary, genetic variants in antioxidant enzymes are associated with rate of decline in lung function. These pathways should be further investigated for possible antioxidant approaches to prevent and/or treat COPD. The project was supported by RC1 AG035835, R01 HL74104, R01 HL071022, genotyping services were provided by the Johns Hopkins University under N01‐HV‐48195 from the NHLBI, and NIA contracts N01‐AG‐6‐2101, N01‐AG‐2103, and N01‐AG‐6‐2106.

Functional Performance in Chronic Obstructive Pulmonary Disease Declines with Time

it is well known that people with chronic obstructive pulmonary disease experience declines in functional performance, but little is known about the rate of decline. The purposes of this research were to describe the rate of decline in functional performance and to examine the contribution of disease severity, body composition, symptoms, and functional capacity. Functional performance was defined as the activities that people choose to engage in on a day-to-day basis. people (n = 108) with chronic obstructive pulmonary disease were enrolled and followed yearly for 3 yr with self-reported functional performance (Functional Performance Inventory), spirometry, lung volumes, diffusion capacity, body composition (dual-energy x-ray absorptiometry), dyspnea and fatigue (Chronic Respiratory Disease Questionnaire), and functional capacity (6-min walk distance (6MWD), isokinetic strength of knee flexors and extensors, handgrip strength, and maximal inspiratory pressure). A total of 88 subjects completed a (mean ± SD) of 2.7 ± 0.9 yr of follow-up. significant negative slopes were observed for functional performance (P = 0.001), spirometry (the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), P < 0.0001), diffusion capacity (P < 0.0001), and muscle strength (P < 0.0001)). The slopes for dyspnea, fatigue, and functional capacity were not significantly different from zero, but there was a wide individual variation. Hierarchical regression demonstrated that 31% of the variance in the slope of functional performance was accounted for by the hierarchical model, and the primary predictors were the slopes of the FEV1/FVC, 6MWD, and muscle strength (knee flexors/extensor and handgrip). subjects experienced a slow decline in functional performance, associated with declines in functional capacity and increases in body fat. Symptoms were relatively stable and not associated with declines in functional performance.

Defining chronic obstructive pulmonary disease in older persons

To develop a more age-appropriate spirometric definition of chronic obstructive pulmonary disease (COPD) among older persons. Using data from the Third National Health and Nutrition Examination Survey (NHANES III), we developed a two-part spirometric definition of COPD in older persons, aged 65-80 years, that 1) determines a cut-point for the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) based on mortality risk; and 2) among persons below this critical FEV1/FVC threshold, determines cut-points for the FEV1, expressed as a standardized residual percentile (SR-tile) and based on the prevalence of respiratory symptoms and mortality risk. Measurements included spirometry, health questionnaires, and mortality (National Death Index). There were 2480 older participants with a mean age of 71.7 years; 1372 (55.4%) had a smoking history, 1097 (44.2%) had respiratory symptoms and, over the course of 12-years, 868 (35.0%) had died. Among participants with an FEV1/FVC<.70 and FEV1<5th SR-tile, representing 7.7% of the cohort, the risk of death was doubled (adjusted hazard ratio, 2.01; 95% confidence interval [CI], 1.60-2.54). Among participants with an FEV1/FVC<.70 and FEV1<10th SR-tile, representing 13.4% of the cohort, the prevalence of respiratory symptoms was elevated (adjusted odds ratio, 2.44; CI, 1.79-3.33). In a large, nationally representative sample of community-living older persons, defining COPD based on an FEV1/FVC<.70, with FEV1 cut-points at the 10th and 5th SR-tiles, identifies individuals with an increased prevalence of respiratory symptoms and an increased risk of death, respectively.

Respiratory evaluation of patients on continuous ambulatory peritoneal dialysis prior to renal transplantation

Pulmonary function tests (PFTs) and cardiopulmonary exercise tests (CPETs) are important in predicting preoperative pulmonary complications and mortality rate in potentially renal transplant recipients. There is no adequate clinical research aimed at learning the effect of empty and full status of the peritoneal cavity on PFTs and CPET for estimating decide PFTs and CPET timing in preoperative evaluation. The aim of this study was to investigate whether PFT and CPET results are altered in patients on continuous ambulatory peritoneal dialysis (CAPD) according to the presence of dialysis solution in the abdomen. 22 subjects were included (12 male, 10 female, mean age 29.64 +/- 8.29 years, CAPD duration, 37.35 +/- 7.15 months). Data were collected from each patient when the peritoneal cavity was filled with solution (full status) and again when the cavity had been drained (empty status). Forced expiratory volume in 1 s (FEV1), ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), total lung capacity (TLC), and residual volume (RV) were calculated. Peak oxygen uptake (peak VO2) and exercise duration were determined by cardiopulmonary exercise testing. When the peritoneal cavity was empty, mean (+/- SD) values for the parameters tested were % predicted FEV1: 85 +/- 17%, %FEV1/FVC: 84 +/- 8%, % predicted TLC: 98 +/- 17%, % predicted RV: 108 +/- 25%, % predicted DLCO: 90 +/- 14%, peak VO2: 43 +/- 11 ml/kg/min, test duration: 6.8 +/- 1.6 min. When the peritoneal cavity was full, mean (+/- SD) values were % predicted FEV1: 86 +/- 17%, %FEV1/FVC: 83 +/- 7%, % predicted TLC: 91 +/- 14%, % predicted RV: 95 +/- 22%, % predicted DLCO: 87 +/- 16%, peak VO2: 42 +/- 8 ml/kg/min, test duration 6.5 +/- 1.7 min. % predicted FEV1, %FEV1/FVC, % predicted DLCO and peak VO2 were not statistically significant between the mean values at empty status versus those at full status (p < 0.05 for all). There were significant decreases between the mean values for % predicted TLC and % predicted RV at full status versus empty status (p < 0.002 for TLC, p < 0.001 for RV). No statistically significant correlation was found between PFTs and % change ratio of dialysate. FEV1, %FEV1/FVC, % predicted DLCO and CPET test results do not differ according to abdomen status in CAPD patients suggesting that the timing of PFT maneuver does not affect preoperative transplantation evaluation. Therefore, when evaluating the results of these tests prior to transplantation period, the presence of dialysis solution in the abdomen may be ignored.

Accelerated obstructive pulmonary disease in HIV infected patients with bronchiectasis

Human immunodeficiency virus (HIV) infection has been associated with a wide spectrum of pulmonary disease. We report three HIV-seropositive patients with rapidly worsening airway obstruction associated with bronchiectasis. All subjects (age range 33-39 yrs) were cigarette smokers. Two had previously used intravenous drugs. The CD4 lymphocyte count ranged 40-250 cells x mm(-3). All individuals had complained of increasing dyspnoea for 3-6 months. Within 1 yr, they all developed severe airway obstruction with a decrease in both forced expiratory volume in one second (FEV1) and ratio of FEV1 to forced vital capacity (FEV1/FVC) to less than 60% of predicted value, and a decrease in mean forced expiratory flow at 25-75% of the forced vital capacity (FEF25-75) to less than 35% of predicted value. Computed tomography of the chest disclosed bilateral dilated and thickened bronchi. No classical causes of genetic or acquired bronchiectasis were identified in our patients. Recurrent bacterial bronchitis occurred in the follow-up period of the three patients. In conclusion, unusually rapid airway obstruction associated with bronchiectasis should be added to the wide spectrum of respiratory complications of human immunodeficiency virus infection.

Maximum Inspiratory Muscle Endurance Capacity during Resistive Loading in Chronic Obstructive Pulmonary Disease

In 10 patients with stable severe chronic obstructive pulmonary disease (COPD) we evaluated the relationship between the degree of airway obstruction and hyperinflation, and the maximum inspiratory muscle endurance capacity during added inspiratory resistive loading. We measured the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) and airway resistance (Raw) as indices of airway obstruction, and the ratio of functional residual capacity to total lung capacity (FRC/TLC) as an index of hyperinflation. The mean resting transdiaphragmatic pressure to its maximum (Pdi/Pdimax), the tension time index of the diaphragm, and the maximum transdiaphragmatic pressure (Pdimax) were also determined. Following 15 min of resting breathing, the patients breathed through added inspiratory resistances which were progressively increased every 3 min until exhaustion. Maximum endurance capacity (ECmax) was defined as the product of the esophageal pressure - time integral and frequency at the maximum load sustainable for 3 min. ECmax correlated significantly with Raw (r = -0.67, p less than 0.04). The addition of FRC/TLC to the analysis resulted in a significant increase in the correlation coefficient (r = 0.86, p less than 0.01). ECmax did not correlate with FEV1/FVC. Both resting Pdi/Pdimax and Pdimax independently influenced ECmax. In addition, Pdimax correlated significantly with FRC/TLC, and resting Pdi/Pdimax with Raw. We conclude that in stable patients with severe COPD, both airway obstruction and hyperinflation affect maximum inspiratory muscle endurance capacity during inspiratory resistive loading.