Decreased pulmonary diffusing capacity of divers over a 6-year period

Non-smoking, male, professional firemen divers (n = 15) underwent two pulmonary function tests (PFT) separated by 6 years. Measured data were compared to European Coal Steel Community recommended reference values to permit cross-sectional and then longitudinal study. Higher vital capacity (VC; P < 0.01) and forced expiratory volume in 1 s (FEV₁; P < 0.05), and lower maximal mid-expiratory flow (MMEF) coefficient with VC (MMEF/VC; P < 0.05) were observed in both PFT. Diver's pulmonary diffusing capacity (DL_CO) and the coefficient with alveolar volume (DL_CO/V _A) showed significantly (P < 0.001) different evolution profiles than those expected from predicted values. In divers, DL_CO and DL_CO/V _A decreased from 104.0% to 91.4% and from 106.4% to 91.5% of predicted values respectively. Changes in DL_CO and DL_CO/V _A correlated positively with the initial measurement of DL_CO (r = 0.67, P < 0.01) and DL_CO/V _A (r = 0.74, P < 0.01) respectively, whereas no correlation between changes in pulmonary gas transfer function and age or diving history parameters was found. Thus, it is suggested from our observations that hyperbaric atmosphere exposure increases the effects of aging on pulmonary diffusing capacity and that pulmonary gas transfer function should be regularly tested in professional and recreational divers. Accepted: 22 February 1997     

慢性阻塞性肺疾病患者中血清亲环素A、趋化因子CX3CL1表达水平及临床意义

摘要 目的：探讨慢性阻塞性肺疾病（COPD）患者中血清亲环素A（CyPA）、趋化因子CX3CL1以及其他炎性指标的表达水平及其临床意义。方法：选取2019年1月-2021年6月本院收治的COPD患者120例作为研究对象,其中68例患者为急性加重期组,52例患者为稳定期组;另选取体检健康者45例作为对照组。收集所有受试者的临床资料,检测其血清中CyPA、CX3CL1、C反应蛋白（CRP）、白细胞介素-6（IL-6）以及基质金属蛋白酶-9（MMP-9）水平,比较3组患者各参数的差异,并与肺功能进行相关性分析,比较急性加重期患者治疗前后各指标的差异。结果：急性加重期组患者的血清 CyPA、CX3CL1、CRP、IL-6、MMP-9水平均明显高于稳定期组和对照组患者,稳定期组患者的血清 CyPA、CX3CL1、CRP、IL-6、MMP-9水平均明显高于对照组患者（均P＜0.05）;而急性加重期组患者的第1s用力呼气量（FEV₁）、用力肺活量（FVC）、第1s用力呼气量（FEV₁）与用力肺活量（FVC）的比值（FEV₁%）、最大呼气峰流速（PEF）以及最大呼气中期流速（MMEF）明显低于稳定期组和对照组患者,稳定期组患者的FEV₁、FVC、FEV₁/FVC、PEF、MMEF明显低于对照组患者（均P＜0.05）。COPD患者的血清CyPA、CX3CL1、CRP、IL-6、MMP-9水平与FEV₁、FVC、FEV₁/FVC、PEF、MMEF呈负相关（P<0.05）。与治疗前相比较,急性加重期组患者在治疗后血清CyPA、CX3CL1、CRP、IL-6、MMP-9水平明显下降,而FEV₁、FVC、FEV₁/FVC、PEF、MMEF明显上升（均P＜0.05）。结论：COPD患者的血清CyPA、CX3CL1、CRP、IL-6、MMP-9水平可在一定程度上预测患者的严重程度,同时也可以作为急性加重期治疗后效果的评价指标。     

Effect of intensive swimming training on lung volumes, airway resistances and on the maximal expiratory flow-volume relationship in prepubertal girls

The aim of the present study was to analyse the effect of 1 year of intensive swimming training on lung volumes, airway resistance and on the flow-volume relationship in prepubertal girls. Five girls [9.3 (0.5) years old] performing vigorous swimming training for 12 h a week were compared with a control group of 11 girls [9.3 (0.5) years old] who participated in various sport activities for 2 h per week. Static lung volumes, maximal expiratory flows (MEF) at 75, 50 and 25% of vital capacity, 1-s forced expiratory volume (FEV_1.0) and airway resistance (R _aw) were measured by means of conventional body plethysmograph techniques. Prior to the training period there were no significant differences between the two groups for any of the parameters studied. Moreover, for both groups, all parameters were within the normal range for children of the corresponding age. After 1 year of training, vital capacity (VC), total lung capacity (TLC) and functional residual capacity (FRC) were larger (P<0.05) in the girl swimmers than in the control group, while physical development in terms of height and weight was similar. FEV_1.0 (P<0.01), MEF₂₅, MEF₅₀ (P<0.05) and MEF₇₅ as well as the ratio MEF₅₀ / TLC (P<0.05) had increased in the girl swimmers but were unchanged in the control group. R _aw tended to be lower in the girl swimmers and higher in the control group. The results indicate that intensive swimming training prepuberty enhances static and dynamic lung volumes and improves the conductive properties of both the large and the small airways. As to the causative mechanism, it can be speculated that at prepuberty intensive swimming training promotes isotropic lung growth by harmonizing the development of the airways and of alveolar lung spaces. Accepted: 5 March 1997     

Pulmonary function and incident bronchitis and asthma in children: a community-based prospective cohort study

Background

Previous studies revealed that reduction of airway caliber in infancy might increase the risks for wheezing and asthma. However, the evidence for the predictive effects of pulmonary function on respiratory health in children was still inconsistent.

Methods

We conducted a population-based prospective cohort study among children in 14 Taiwanese communities. There were 3,160 children completed pulmonary function tests in 2007 and follow-up questionnaire in 2009. Poisson regression models were performed to estimate the effect of pulmonary function on the development of bronchitis and asthma.

Results

After adjustment for potential confounders, pulmonary function indices consistently showed protective effects on respiratory diseases in children. The incidence rate ratios of bronchitis and asthma were 0.86 (95% CI 0.79–0.95) and 0.91 (95% CI 0.82–0.99) for forced expiratory volume in 1 second (FEV₁). Similar adverse effects of maximal mid-expiratory flow (MMEF) were also observed on bronchitis (RR = 0.73, 95% CI 0.67–0.81) and asthma (RR = 0.85, 95% CI 0.77–0.93). We found significant decreasing trends in categorized FEV₁ (p for trend = 0.02) and categories of MMEF (p for trend = 0.01) for incident bronchitis. Significant modification effects of traffic-related air pollution were noted for FEV₁ and MMEF on bronchitis and also for MMEF on asthma.

Conclusions

Children with high pulmonary function would have lower risks on the development of bronchitis and asthma. The protective effect of high pulmonary function would be modified by traffic-related air pollution exposure.     

Bronchial response to breathing dry gas at 3.7 MPa ambient pressure

In diving, pulmonary mechanical function is limited by the increased density of the gas breathed. Breathing cold and dry gas may cause an additional increase in airways resistance. We have measured forced vital capacity, forced expired volume in 1 s (FEV₁) and forced midexpiratory flow rate (FEF_25%–75%) before and after breathing dry or humid gas at 29–32°C during a standardized exercise intensity on a cycle ergometer at an ambient pressure of 3.7 MPa. The atmosphere was a helium and oxygen mixture with a density of 6.8 kg · m^–3. Six professional saturation divers aged 26–37 years participated in the study. There were no significant differences in convective respiratory heat loss between the exposures. The mean evaporative heat loss was 67 W (range 59–89) breathing dry gas and 37 W (range 32–43) breathing humid gas, corresponding to water losses of 1.7 g · min^–1 (range 1.5–2.2) and 0.9 g · min^–1 (range 0.8–1.1), respectively. There was a significant reduction in FEV₁ of 4.6 (SD 3.6)% (P<0.05), and in FEF_25%–75% of 5.8 (SD 4.7)% (P<0.05) after breathing dry gas. There were no changes after breathing humid gas. By warming and humidifying the gas breathed in deep saturation diving bronchoconstriction may be prevented.     

Oral health and reduction in respiratory capacity in a cohort of community-dwelling elderly people: a population-based 5-year follow-up study

Objectives: Several anaerobic bacteria originating in periodontal pockets have been isolated from infected lungs and pharyngeal microflora. Increased bacterial load in lungs is known to be a risk factor for decline in forced expiratory volume during the first second. The aim was to evaluate both cross‐sectionally and longitudinally the association between oral health status and forced expiratory volume during the first second (FEV₁) in older residents of the city of Jyväskylä, Finland. Design: Cross‐sectional and prospective cohort study over a 5‐year follow‐up. Setting: Research laboratory of the University of Jyväskylä. Participants: In 1990 dental status and FEV₁ were examined in 203 80‐year‐old people, of whom 88 survivors were retested 5 years later. Main outcome measures: Primary: dental status and FEV₁. Secondary: existence of pulmonary diseases, height, handgrip strength, smoking, and length of education. Results: Participants were regrouped into three categories according to their baseline oral health status. At baseline, men with complete prostheses had the lowest FEV₁. Five years later the greatest reduction in FEV₁ was seen in subjects with poor periodontal status or complete prostheses (?9.4%) while those with healthy periodontal status showed no reduction in FEV₁ values (+1.0%, p = 0.006). Conclusions: Periodontal infections and complete prostheses may be reservoirs for pathogens which may be harmful and partly explain the observed reduction in FEV₁ during ageing.     

Synergistic Impaired Effect between Smoking and Manganese Dust Exposure on Pulmonary Ventilation Function in Guangxi Manganese-Exposed Workers Healthy Cohort (GXMEWHC)

PurposeThe aims of this study were to investigate the effects of manganese (Mn) dust exposure on lung functions and evaluate the potential synergistic effect between smoking and Mn dust exposure among refinery workers.MethodsA retrospective study including 1658 workers in a ferromanganese refinery was conducted, with subjects who were from the Guangxi manganese-exposed workers healthy cohort (GXMEWHC). Based on the Mn manganese cumulative exposure index (Mn-CEI), all subjects were divided into the low exposure group (n = 682) and the high exposure group (n = 976). A pulmonary function test was performed using an electronic spirometer, including the values and percentages of FVC, FEV₁, FEV₁/FVC, MMEF, PEFR, MVV, respectively.ResultsNo significant effect of Mn dust exposure on the pulmonary function was found in the female workers (all p>0.05). However, there was an obvious decrease in the male workers in the high exposure group compared with those in the low exposure group (FVC -60 ml, FEV₁ -120 ml, MMEF -260 ml/s, MVV -5.06 L, all p<0.05). In the high exposure group, the reduction in FVC% predicted, MMEF and MMEF% predicted was 1.0%, 210 mL/s, and 4.9%, respectively. In particular, among the exposed subjects smokers had a statistically significant decrease in lung function compared with non-smokers and the reduction in FVC% predicted, MMEF and MMEF% predicted was 1.0%, 210 mL/s, and 4.9%, respectively (p<0.05). Partial correlation analysis showed that there was also negative correlation between Mn-CEI and decreased changes in MMEF (r = -0.159, p = 0.018) and also MMEF% predicted (r = -0.163, p = 0.015).ConclusionsMn dust can impair the pulmonary ventilation function of male workers but not females, and individual smoking habits and manganese exposure had a synergistic effect on the lung function decrease.     

Fungal content of air samples from some asthmatic childrens’ homes in Mexico City

Fungal particles can be considered a potential risk factor in children causing asthma, rhinitis, and allergy. However, a direct relationship between mold exposure and respiratory symptoms is difficult to establish, particularly if volumetric results are not well documented, as is often the case in Mexico. In order to assess mold exposure in some asthmatic childrens’ homes, eight asthmatic children were selected. For each child, lung function was measured by spirometry and the flow expiratory volume drop in the first second (FEV₁) as well as the CVF were estimated at 5, 10 and 15 min, after a running period on a treadmill. Exercise induced asthma (EIA) was defined as a FEV₁ drop <10% or FEV₁/CVF drop >10%. Atopy was estimated by skin testing of allergen extracts. Each room was volumetrically sampled using Burkard Personal samplers, every week for a month and with different degrees of activity. Fungal composition was mostly dominated by allergenic molds, spores smaller than 10 μm and non-seasonal molds. Concentrations ranged from 0 to 2087 CFU/m³ and 102 553–29 522 200 spores/m³, being significantly higher in indoor air, but the differences between rooms or weeks were not significant, either for CFUs (P>0.27) or for total particles (P>0.80). In general, mold counts were dominated byPenicillium spp. andCladosporium spp. especiallyP. aurantiogriseum andC. cladosporioides. We observed that the median concentration values were in general higher for children with exercise induced asthma (EIA). But the differences were significant only for EIA and degree, of asthma particularly for total (P=0.038), mycotoxin producers (P<0.009), seasonal molds (P<0.006) andPenicillium spp. (P=0.012). Total spore counts showed the highest median values in children without EIA, moderate asthma degree and no atopy. Significant differences were found for almost all spore, type groupings when comparing the presence of EIA (P<0.05) or asthma degree categories (P<0.030), but no differences were observed for atopy (P>0.21). We conclude that respiratory symptoms as described by EIA, asthma severity and atopy may give a good correlation with fungal concentrations and especially comparisons based on their physical and chemical properties.     

Genome-Wide Joint Meta-Analysis of SNP and SNP-by-Smoking Interaction Identifies Novel Loci for Pulmonary Function

Genome-wide association studies have identified numerous genetic loci for spirometic measures of pulmonary function, forced expiratory volume in one second (FEV₁), and its ratio to forced vital capacity (FEV₁/FVC). Given that cigarette smoking adversely affects pulmonary function, we conducted genome-wide joint meta-analyses (JMA) of single nucleotide polymorphism (SNP) and SNP-by-smoking (ever-smoking or pack-years) associations on FEV₁ and FEV₁/FVC across 19 studies (total N = 50,047). We identified three novel loci not previously associated with pulmonary function. SNPs in or near DNER (smallest P _JMA =5.00×10⁻¹¹), HLA-DQB1 and HLA-DQA2 (smallest P _JMA =4.35×10⁻⁹), and KCNJ2 and SOX9 (smallest P _JMA =1.28×10⁻⁸) were associated with FEV₁/FVC or FEV₁ in meta-analysis models including SNP main effects, smoking main effects, and SNP-by-smoking (ever-smoking or pack-years) interaction. The HLA region has been widely implicated for autoimmune and lung phenotypes, unlike the other novel loci, which have not been widely implicated. We evaluated DNER, KCNJ2, and SOX9 and found them to be expressed in human lung tissue. DNER and SOX9 further showed evidence of differential expression in human airway epithelium in smokers compared to non-smokers. Our findings demonstrated that joint testing of SNP and SNP-by-environment interaction identified novel loci associated with complex traits that are missed when considering only the genetic main effects.     

Effects of ultrasonic nebulization on pulmonary mechanics and blood gases in obstructive disease

Administration of ultrasonically nebulized mist to 17 patients with obstructive lung disease resulted in a temporary deterioration of mechanical lung function with decreases in vital capacity (VC), forced expired volume in one second expressed as a percentage of VC (FEV₁%), and compliance and with increased inspiratory and expiratory airway resistance. Despite hyperventilation there was an associated decrease in arterial oxygen tension. Although concomitant administration of a bronchodilator afforded protection against the bronchospastic reaction, blood gas derangements were still provoked.     

Obesity Is Associated With Altered Lung Function Independently of Physical Activity and Fitness

Measures of obesity, especially central adiposity, have been associated with reduced lung function. However, previous studies may have been affected by confounding by physical activity and fitness. This study aimed to examine the relationship among body fatness, fat distribution, and lung function, adjusted for physical activity energy expenditure (PAEE) and aerobic fitness (VO₂max), in a cohort of British white adults with a family history of type 2 diabetes. A total of 320 adults (mean age 40.4 ± 6.0 years) attended for anthropometric and VO₂max testing, and had ambulatory heart rate monitoring for 4 days to determine PAEE. Spirometry was used to measure forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC). The tests were repeated 12 months later, and a cross‐sectional analysis using linear regression with repeated measures was performed. Measures of obesity (BMI, waist circumference (WC), fat mass (FM), body fat percentage (BF%)) were associated with lower lung function in men and women (P < 0.01), while waist‐to‐hip ratio (WHR) was associated with lower lung function in men only (P < 0.001). Associations remained after adjusting for age, smoking status, height, PAEE, and VO₂max. The estimated difference in mean FEV₁ and FVC per unit increase in the exposure measures were consistently stronger in men compared to women (P for interaction <0.001). Obesity is inversely associated with lung function in adults, but central fat distribution appears to have a stronger relationship with respiratory mechanics in men than in women. These associations were independent of the degree of physical activity and aerobic fitness in this cohort.     

Reliability of FEV1/FEV6 to Diagnose Airflow Obstruction Compared with FEV1/FVC: The PLATINO Longitudinal Study

QUESTION

A 6-second spirometry test is easier than full exhalations. We compared the reliability of the ratio of the Forced expiratory volume in 1 second/Forced expiratory volume in 6 seconds (FEV₁/FEV₆) to the ratio of the FEV₁/Forced vital capacity (FEV₁/FVC) for the detection of airway obstruction.

METHODS

The PLATINO population-based survey in individuals aged 40 years and over designed to estimate the prevalence of post-Bronchodilator airway obstruction repeated for the same study participants after 5–9 years in three Latin-American cities.

RESULTS

Using the FEV₁/FVC<Lower limit of normal (LLN) index, COPD prevalence apparently changed from 9.8 to 13.2% in Montevideo, from 9.7 to 6.0% in São Paulo and from 8.5 to 6.6% in Santiago, despite only slight declines in smoking prevalence (from 30.8% to 24.3%). These changes were associated with differences in Forced expiratory time (FET) between the two surveys. In contrast, by using the FEV₁/FEV₆ to define airway obstruction, the changes in prevalence were smaller: 9.7 to 10.6% in Montevideo, 8.6 to 9.0% in São Paulo, and 7.5 to 7.9% in Santiago. Changes in the prevalence of COPD with criteria based on FEV₁/FVC correlated strongly with changes in the FET of the tests (R² 0.92) unlike the prevalence based on a low FEV₁/FEV₆ (R² = 0.40).

CONCLUSION

The FEV₁/FEV₆ is a more reliable index than FEV₁/FVC because FVC varies with the duration of the forced exhalation. Reporting FET and FEV₁/FEV₆<LLN helps to understand differences in prevalence of COPD obtained from FEV₁/FVC-derived indices.     

慢性阻塞性肺疾病急性加重期患者血清SAA水平与肺功能、炎性因子的相关性及其诊断价值分析

目的:探讨慢性阻塞性肺疾病急性加重期(AECOPD)患者血清淀粉样蛋白A(SAA)水平与肺功能及炎性因子的相关性,并分析其诊断价值。方法:选取2013年6月-2018年6月中国人民解放军第970医院收治的204例慢性阻塞性肺疾病(COPD)患者作为研究对象,其中COPD稳定期患者132例作为COPD稳定组,AECOPD患者72例作为AECOPD组。另选取同期于中国人民解放军第970医院进行健康体检的50例健康体检者作为健康组。比较三组受试者血清SAA水平、白细胞介素-8(IL-8)、白细胞介素-6(IL-6)、C反应蛋白(CRP)、降钙素原(PCT)水平及肺功能,采用Pearson相关性分析AECOPD患者血清SAA水平与肺功能及炎性因子的相关性,并分析SAA对AECOPD的诊断价值。结果:AECOPD组患者血清SAA、PCT、CRP、IL-6、IL-8水平较COPD稳定组及健康组升高(P0.05),COPD稳定组患者血清SAA、IL-6、IL-8、PCT、CRP水平均高于健康组,差异有统计学意义(P0.05);AECOPD组患者第一秒用力呼气容积(FEV1)、用力肺活量(FVC)、第一秒用力呼吸容积占用力肺活量的百分比(FEV1/FVC%)、第一秒用力呼气容积占预计值百分比(FEV1%)低于COPD稳定组及健康组,差异有统计学意义(P0.05),COPD稳定组患者FEV1、FVC、FEV1/FVC%、FEV1%低于健康组,差异有统计学意义(P0.05)。Pearson相关性分析显示,AECOPD患者血清SAA水平与IL-8、IL-6、CRP、PCT呈正相关,与FEV1%、FEV1/FVC%、FEV1、FVC呈负相关(P0.05)。受试者工作特征(ROC)曲线结果显示,SAA对AECOPD诊断的敏感度为80.85%,特异度为80.07%,曲线下面积为0.832。结论:AECOPD患者血清SAA水平明显升高,其与患者肺功能及炎症因子存在相关性,具有较高的诊断价值,可用于AECOPD患者病情的评估。     

Lysophosphatidic acid and apolipoprotein A1 predict increased risk of developing World Trade Center-lung injury: a nested case-control study

Abstract

Rationale: Metabolic syndrome, inflammatory and vascular injury markers measured in serum after World Trade Center (WTC) exposures predict abnormal FEV₁. We hypothesized that elevated LPA levels predict FEV₁?<?LLN.

Methods: Nested case-control study of WTC-exposed firefighters. Cases had FEV₁?<?LLN. Controls derived from the baseline cohort. Demographics, pulmonary function, serum lipids, LPA and ApoA1 were measured.

Results: LPA and ApoA1 levels were higher in cases than controls and predictive of case status. LPA increased the odds by 13% while ApoA1 increased the odds by 29% of an FEV₁?<?LLN in a multivariable model.

Conclusions: Elevated LPA and ApoA1 are predictive of a significantly increased risk of developing an FEV₁?<?LLN.     

Prognostic Value of the Six-Second Spirometry in Patients with Chronic Obstructive Pulmonary Disease: A Cohort Study

BackgroundThe six-second spirometry has been proposed as an alternative to diagnose airflow limitation, although its prognostic value in patients with chronic obstructive pulmonary disease (COPD) remains unknown. The purpose of this study was to determine the prognostic value of the postbronchodilator forced expiratory volume in 1 second (FEV₁)/forced expiratory volume in 6 seconds (FEV₆) ratio and FEV₆ in COPD patients.ConclusionsIn a general COPD outpatient population, airflow obstruction assessed by the FEV₁/FEV₆ is an independent risk factor for both death and hospitalization.     

Gene promoter methylation is associated with lung function in the elderly: The normative aging study

Lung function is a strong predictor of mortality. While inflammatory markers have been associated with lung function decrease, pathways are still poorly understood and epigenetic changes may participate in lung function decline mechanisms. We studied the cross-sectional association between DNA methylation in nine inflammatory genes and lung function in a cohort of 756 elderly men living in the metropolitan area of Boston. Participants donated a blood sample for DNA methylation analysis and underwent spirometry at each visit every 3 to 5 y from 1999–2006. We used separate multivariate mixed effects regression models to study the association between each lung function measurement and DNA methylation within each gene. Decreased CRAT, F3 and TLR2 methylation was significantly associated with lower lung function. One interquartile range (IQR) decrease in DNA methylation was associated with lower forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁), respectively by 2.94% (p < 10^?4) and 2.47% (p < 10^?3) for F3, and by 2.10% (p < 10^?2) and 2.42% (p < 10^?3) for TLR2. Decreased IFNγ and IL6 methylation was significantly associated with better lung function. One IQR decrease in DNA methylation was associated with higher FEV₁ by 1.75% (p = 0.02) and 1.67% (p = 0.05) for IFNγ and IL6, respectively. These data demonstrate that DNA methylation may be part of the biological processes underlying the lung function decline and that IFNγ and IL6 may have ambivalent roles through activation of negative feedback.     

CT Air Trapping Is Independently Associated with Lung Function Reduction over Time

Purpose

We aimed to study the association between lung function decline and quantitative computed tomography (CT) air trapping.

Materials and Methods

Current and former heavy smokers in a lung cancer screening trial underwent volumetric low-dose CT in inspiration and expiration. Spirometry was obtained at baseline and after 3 years. The expiratory to inspiratory ratio of mean lung density (E/I-ratio_MLD) was used to quantify air trapping. CT emphysema was defined as voxels in inspiratory CT below −950 Hounsfield Unit. Linear mixed modeling was used to determine the association between CT air trapping and lung function.

Results

We included 985 subjects with a mean age of 61.3 years. Independent of CT emphysema, CT air trapping was significantly associated with a reduction in forced expiratory volume in one second (FEV₁) and the ratio of FEV₁ over the forced vital capacity (FEV₁/FVC); FEV₁ declines with 33 mL per percent increase in CT air trapping, while FEV₁/FVC declines 0.58% per percent increase (both p<0.001). CT air trapping further elicits accelerated loss of FEV₁/FVC (additional 0.24% reduction per percent increase; p = 0.014).

Conclusion

In a lung cancer screening cohort, quantitatively assessed air trapping on low-dose CT is independently associated with reduced lung function and accelerated decline of FEV₁/FVC.     

FEV1 Is a Better Predictor of Mortality than FVC: The PLATINO Cohort Study

Objective

To determine whether the presence of chronic obstructive lung disease (COPD) and reduction of lung function parameters were predictors of mortality in a cohort.

Materials/Patients and Methods

Population based cohorts were followed in Montevideo, Santiago and Sao Paulo during 5, 6 and 9 years, respectively. Outcomes included all-cause, cardiovascular, respiratory and cancer mortality; exposures were COPD, forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC). Cox regression was used for analyses. Sensitivity, specificity, positive and negative predictive values, receiver operator characteristics curves and Youden''s index were calculated.

Results

Main causes of death were cardiovascular, respiratory and cancer. Baseline COPD was associated with overall mortality (HR = 1.43 for FEV₁/FVC<LLN; 2.01 for GOLD 2-4; 1.46 for GOLD 1-4; 1.50 for FEV₁/FEV₆ <LLN). For cardiovascular mortality, significant associations were found with GOLD 2-4 (HR = 2.68) and with GOLD 1-4 (HR = 1.78) for both genders together (not among women). Low FEV₁ was risk for overall and respiratory mortality (both genders combined). FVC was not associated with overall mortality. For most COPD criteria sensitivity was low and specificity high. The area under the curve for FEV₁ was greater than for FVC for overall and cardiovascular mortality.

Answer to the Question

COPD and low FEV₁ are important predictors for overall and cardiovascular mortality in Latin America.     

Assessment of Upper Airways Obstruction

An indication of obstruction to the upper airways (trachea and larynx) may be obtained by calculating the ratio of the forced expired volume in one second to the peak expiratory flow rate (FEV₁/PEFR). This index was found to be usually less than 10 in normal subjects (mean 7·3), and in patients with asthma (mean 6·9), chronic bronchitis (mean 7·7), or interstitial lung disease (mean 6·3). A study of simulated upper airways obstruction showed that this index rises as the obstruction becomes more severe. All of 18 patients with proved upper airways obstruction had FEV₁/PEFR indices greater than 10 (mean 14·0). This test can be carried out with forced expiratory manoeuvres only, and it does not require the use of complicated equipment. An FEV₁/PEFR ratio greater than 10, when upper airways obstruction is suspected, indicates that significant obstruction may be present. High values suggest that the obstruction may be severe, and that further investigations are indicated.     

沙丁胺醇、布地奈德不同雾化吸入联合头孢哌酮钠舒巴坦钠对AECOPD患者血气指标和肺功能的影响

目的:探讨沙丁胺醇、布地奈德不同雾化吸入联合头孢哌酮钠舒巴坦钠对慢性阻塞性肺疾病急性加重期(AECOPD)患者血气指标和肺功能的影响。方法:选取本院2015年1月至2018年10月期间收治的210例AECOPD住院患者作为研究对象,随机分为对照组(头孢哌酮钠舒巴坦钠治疗)、持续雾化组(沙丁胺醇、布地奈德持续雾化治疗+头孢哌酮钠舒巴坦钠)、先后雾化组(先给予沙丁胺醇雾化、后给予布地奈德雾化治疗+头孢哌酮钠舒巴坦钠),每组各70例,对比三组的临床疗效、血气指标、肺功能及不良反应。结果:先后雾化组总有效率为91.43%,高于持续雾化组的78.57%及对照组的67.14%(P0.05)。先后雾化组患者治疗5天后氧分压(PaO_2)、氧饱和度(SaO_2)高于持续雾化组及对照组,且持续雾化组高于对照组(P0.05);先后雾化组患者治疗5天后二氧化碳分压(PaCO_2)低于持续雾化组及对照组,且持续雾化组低于对照组(P0.05)。先后雾化组患者第一秒用力呼气容积(FEV_1)、用力肺活量(FVC)、第一秒用力呼吸容积占用力肺活量的百分比(FEV_1/FVC%)、第一秒用力呼气容积占预计值百分比(FEV_1%)高于持续雾化组及对照组,且持续雾化组高于对照组(P0.05)。三组不良反应总发生率比较无统计学差异(P0.05)。结论:沙丁胺醇、布地奈德先后雾化吸入联合头孢哌酮钠舒巴坦钠治疗AECOPD患者疗效确切,可提高患者肺功能,改善血气相关指标。