Maximal Mid-expiratory Flow Research Articles

Association of Neutrophil to Lymphocyte Ratio With Pulmonary Function in a 30-Year Longitudinal Study of US Veterans

Chronic obstructive pulmonary disease (COPD) is a critical public health burden. The neutrophil to lymphocyte ratio (NLR), an inflammation biomarker, has been associated with COPD morbidity and mortality; however, its associations with lung function decline and COPD development are poorly understood. To explore the associations of NLR with lung function decline and COPD risks. This longitudinal cohort study included white male veterans in the US with more than 30 years of follow-up to investigate the associations of NLR with lung function, COPD, and hypomethylation of cg05575921, the top DNA methylation marker of lung function changes in response to tobacco smoking. This study included 7466 visits from 1549 participants, each examined up to 13 times between 1982 and 2018. A subgroup of 1411 participants without COPD at baseline were selected to analyze the association of NLR with incident COPD. Data were analyzed from September 2019 to January 2020. The primary exposure was NLR, which was estimated using automated whole blood cell counts based on a blood sample collected at each visit. The methylation level of cg05575921 was measured in blood DNA from a subgroup of 1228 visits. The outcomes of interest were lung function, measured as forced respiratory volume in the first second (FEV1) in liters, forced vital capacity (FVC) in liters, percentage of FVC exhaled in the first second (FEV1/FVC), and maximal midexpiratory flow rate (MMEF) in liters per minute and COPD status, defined as meeting the Global Initiative for Chronic Obstructive Lung Diseases stage II (or higher) criteria. Both outcomes were measured as each visit. Among 1549 included men (mean [SD] age, 68.3 [9.3] years) with 7466 visits from 1982 to 2018, a 1-unit increase in NLR was associated with statistically significant mean (SE) decreases of 0.021 (0.004) L in FEV1, 0.016 (0.005) L in FVC, 0.290% (0.005) L in FVC, 0.290% (0.065%) in FEV1/FVC, and 3.65 (0.916) L/min MMEF. Changes in NLR up to approximately 10 years were associated with corresponding longitudinal changes in lung function. Furthermore, this increase in NLR was associated with 9% higher odds of COPD (odds ratio, 1.09 [95% CI, 1.03-1.15]) for all visits and 27% higher risk of incident COPD (odds ratio, 1.07 [95% CI, 1.07-1.51]) for participants without COPD at baseline. Additionally, a 1-unit increase in NLR was associated with a mean (SE) decrease of 0.0048 (0.0021 in cg05575921 hypomethylation, which may mediate the adverse association of NLR-related inflammation on lung function. These findings suggest that NLR may be a clinically relevant biomarker associated with high risk of lung function impairment and COPD alone or in combination with DNA methylation profiles.

Prevalence and risk factors of small airway dysfunction, and association with smoking, in China: findings from a national cross-sectional study

Small airway dysfunction is a common but neglected respiratory abnormality. Little is known about its prevalence, risk factors, and prognostic factors in China or anywhere else in the world. We aimed to estimate the prevalence of small airway dysfunction using spirometry before and after bronchodilation, both overall and in specific population subgroups; assess its association with a range of lifestyle and environmental factors (particularly smoking); and estimate the burden of small airway dysfunction in China. From June, 2012, to May, 2015, the nationally representative China Pulmonary Health study invited 57 779 adults to participate using a multistage stratified sampling method from ten provinces (or equivalent), and 50 479 patients with valid lung function testing results were included in the analysis. We diagnosed small airway dysfunction on the basis of at least two of the following three indicators of lung function being less than 65% of predicted: maximal mid-expiratory flow, forced expiratory flow (FEF) 50%, and FEF 75%. Small airway dysfunction was further categorised into pre-small airway dysfunction (defined as having normal FEV1 and FEV1/forced vital capacity [FVC] ratio before bronchodilator inhalation), and post-small airway dysfunction (defined as having normal FEV1 and FEV1/FVC ratio both before and after bronchodilator inhalation). Logistic regression yielded adjusted odds ratios (ORs) for small airway dysfunction associated with smoking and other lifestyle and environmental factors. We further estimated the total number of cases of small airway dysfunction in China by applying present study findings to national census data. Overall the prevalence of small airway dysfunction was 43·5% (95% CI 40·7-46·3), pre-small airway dysfunction was 25·5% (23·6-27·5), and post-small airway dysfunction was 11·3% (10·3-12·5). After multifactor regression analysis, the risk of small airway dysfunction was significantly associated with age, gender, urbanisation, education level, cigarette smoking, passive smoking, biomass use, exposure to high particulate matter with a diameter less than 2·5 μm (PM2·5) concentrations, history of chronic cough during childhood, history of childhood pneumonia or bronchitis, parental history of respiratory diseases, and increase of body-mass index (BMI) by 5 kg/m2. The ORs for small airway dysfunction and pre-small airway dysfunction were similar, whereas larger effect sizes were generally seen for post-small airway dysfunction than for either small airway dysfunction or pre-small airway dysfunction. For post-small airway dysfunction, cigarette smoking, exposure to PM2·5, and increase of BMI by 5 kg/m2 were significantly associated with increased risk, among preventable risk factors. There was also a dose-response association between cigarette smoking and post-small airway dysfunction among men, but not among women. We estimate that, in 2015, 426 (95% CI 411-468) million adults had small airway dysfunction, 253 (238-278) million had pre-small airway dysfunction, and 111 (104-126) million had post-small airway dysfunction in China. In China, spirometry-defined small airway dysfunction is highly prevalent, with cigarette smoking being a major modifiable risk factor, along with PM2·5 exposure and increase of BMI by 5 kg/m2. Our findings emphasise the urgent need to develop and implement effective primary and secondary prevention strategies to reduce the burden of this condition in the general population. Ministry of Science and Technology of China; National Natural Science Foundation of China; National Health Commission of China.

Pulmonary function and high-resolution computed tomography in outdoor rock drillers exposed to crystalline silica

ObjectivesChronic obstructive pulmonary disease and silicosis are associated with exposure to crystalline silica. We determined the exposure to respirable crystalline silica and estimated exposure–response relationships between cumulative exposure and pulmonary...

Biomarkers of aging and lung function in the normative aging study.

Elderly individuals who are never smokers but have the same height and chronological age can have substantial differences in lung function. The underlying biological mechanisms are unclear. To evaluate the associations of different biomarkers of aging (BoA) and lung function, we performed a repeated-measures analysis in the Normative Aging Study using linear mixed-effect models. We generated GrimAgeAccel, PhenoAgeAccel, extrinsic and intrinsic epigenetic age acceleration using a publically available online calculator. We calculated Zhang’s DNAmRiskScore based on 10 CpGs. We measured telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN) using quantitative real-time polymerase chain reaction. A pulmonary function test was performed measuring forced expiratory volume in 1 second / forced vital capacity (FEV1/FVC), FEV1, and maximum mid-expiratory flow (MMEF). Epigenetic-based BoA were associated with lower lung function. For example, a one-year increase in GrimAgeAccel was associated with a 13.64 mL [95% confidence interval (CI), 5.11 to 22.16] decline in FEV1; a 0.2 increase in Zhang’s DNAmRiskScore was associated with a 0.009 L/s (0.005 to 0.013) reduction in MMEF. No association was found between TL/mtDNA-CN and lung function. Overall, this paper shows that epigenetics might be a potential mechanism underlying pulmonary dysfunction in the elderly.

Pattern of Pulmonary Dysfunctions in Craniovertebral Junction Anomaly and Its Persistence after Rigid Occipitocervical Fixation

Abstract Introduction Despite a significant advancement in operative techniques of occipitocervical fixation, there is a poor postoperative patient outcome. This can be attributed to restrictive lung pattern in craniovertebral junction anomalies (CVJAs) patients resulting from repeated trauma to cervicomedullary junction by the pincer action of the bony anomalies and compression of the brainstem. We evaluate the changes in pulmonary function tests (PFTs) following rigid occipitocervical fixation in CVJA. Methods PFTs of 20 CVJA patients were measured pre and postoperatively using spirometry. Measurements included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), maximum forced mid-expiratory flow rate (FEF25–75%), and ratio of FEV1 and FVC (FEV1%). The parameters were compared with the predicted normal values based on their age and sex. PFTs were repeated on the seventh postoperative day. McCormick grading was used to assess neurological function. Results The values of PFTs in the preoperative period were significantly lower than predicted normal values. The mean values of FVC, FEV1, FEF25–75% were 72, 68, and 71% of their mean predicted values, with FEV1% in the range of 70 to 95% with a mean of 81.4%. Postoperatively there was further significant reduction in the mean values of FVC, FEV1, FEF25–75%, and FEV1% compared with the preoperative values. There was neurological improvement in McCormick grades of patients postoperatively (from grade III and IV to grade II). Conclusion A significant restrictive lung disease is present in patients of CVJA, even though not clinically apparent, and it persists in the early postoperative period. However, a long-term follow-up is required to assess whether pulmonary function parameters improve subsequently.

Spirometric traits show quantile-dependent heritability, which may contribute to their gene-environment interactions with smoking and pollution.

Background“Quantile-dependent expressivity” refers to a genetic effect that is dependent upon whether the phenotype (e.g., spirometric data) is high or low relative to its population distribution. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and the FEV1/FVC ratio are moderately heritable spirometric traits. The aim of the analyses is to test whether their heritability (h2) is constant over all quantiles of their distribution.MethodsQuantile regression was applied to the mean age, sex, height and smoking-adjusted spirometric data over multiple visits in 9,993 offspring-parent pairs and 1,930 sibships from the Framingham Heart Study to obtain robust estimates of offspring-parent (βOP), offspring-midparent (βOM), and full-sib regression slopes (βFS). Nonparametric significance levels were obtained from 1,000 bootstrap samples. βOPs were used as simple indicators of quantile-specific heritability (i.e., h2 = 2βOP/(1+rspouse), where rspouse was the correlation between spouses).ResultsβOP ± standard error (SE) decreased by 0.0009 ± 0.0003 (P = 0.003) with every one-percent increment in the population distribution of FEV1/FVC, i.e., βOP ± SE were: 0.182 ± 0.031, 0.152 ± 0.015; 0.136 ± 0.011; 0.121 ± 0.013; and 0.099 ± 0.013 at the 10th, 25th, 50th, 75th, and 90th percentiles of the FEV1/FVC distribution, respectively. These correspond to h2 ± SEs of 0.350 ± 0.060 at the 10th, 0.292 ± 0.029 at the 25th, 0.262 ± 0.020 at the 50th, 0.234 ± 0.025 at the 75th, and 0.191 ± 0.025 at the 90th percentiles of the FEV1/FVC ratio. Maximum mid-expiratory flow (MMEF) h2 ± SEs increased 0.0025 ± 0.0007 (P = 0.0004) with every one-percent increment in its distribution, i.e.: 0.467 ± 0.046, 0.467 ± 0.033, 0.554 ± 0.038, 0.615 ± 0.042, and 0.675 ± 0.060 at the 10th, 25th, 50th, 75th, and 90th percentiles of its distribution. This was due to forced expiratory flow at 75% of FVC (FEF75%), whose quantile-specific h2 increased an average of 0.0042 ± 0.0008 for every one-percent increment in its distribution. It is speculated that previously reported gene-environment interactions may be partially attributable to quantile-specific h2, i.e., greater heritability in individuals with lower FEV1/FVC due to smoking or airborne particles exposure vs. nonsmoking, unexposed individuals.ConclusionHeritabilities of FEV1/FVC, MMEF, and FEF75% from quantile-regression of offspring-parent and sibling spirometric data suggest their quantile-dependent expressivity.

Does fine particulate matter (PM2.5) affect the benefits of habitual physical activity on lung function in adults: a longitudinal cohort study

BackgroundPhysical activity (PA) increases a person’s inhalation of air pollutants due to greater ventilation, possibly leading to larger adverse health effects. This study aims to investigate the combined effects of long-term exposure to fine particulate matter (PM2.5) and habitual PA on lung function in adults.MethodsThis was a longitudinal cohort study that included 278,065 Taiwan residents with an age of 20 years old or above who joined a standard medical screening programme between 2001 and 2014. Each participant received at least one medical examination (including spirometric, blood, and urinary tests and a standard self-administered questionnaire survey) during the study period. We estimated the 2-year average PM2.5 concentrations at each participant’s address using a new physical model based on observational data. Information on the participants’ PA was collected using the standard self-administrated questionnaire. Generalised linear mixed models were used to investigate the combined effects of PM2.5 and PA on pulmonary function. We also performed stratified analyses by different levels of PM2.5 exposure and habitual PA.ResultsEach 10 MET-h increase in PA was associated with a higher level of 0.20%, 0.16%, and 0.19% in forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and maximum mid-expiratory flow (MMEF), respectively, after adjusting for PM2.5 exposure and a wide range of covariates including age, sex education, body mass index, lifestyles, and health conditions. Each 10 μg/m3 increase in PM2.5 was associated with a lower FVC, FEV1, and MMEF (2.43%, 2.78% and 3.10%, respectively). Negative interactions were observed, and PM2.5 exposure was associated with a greater reduction in lung function among the participants with higher PA levels.ConclusionsWe found significant negative interaction effects between long-term exposure to PM2.5 and habitual PA, suggesting that the increased intake of PM2.5 due to PA may attenuate the benefits of habitual PA on lung function. However, the PA benefits generally remained stable at different stratum of PM2.5 in the stratified analyses, and habitual PA may still be recommended to people residing in relatively polluted regions.

Effects of the Use of Air Purifier on Indoor Environment and Respiratory System among Healthy Adults.

Air purifiers have become popular among ordinary families. However, it remains controversial whether indoor air purification improves the respiratory health of healthy adults. A randomized crossover intervention study was conducted with 32 healthy individuals. The subjects were categorized into two groups. One group continuously used true air purifiers, and the other followed with sham air purifiers for 4 weeks. Following this first intervention, all the subjects underwent a 4-week washout period and continued with the second 4-week intervention with the alternate air purifiers. We collected fine particulate matter (PM) ≤ 2.5 µm in aerodynamic diameter (PM2.5), coarse particulate matter between 2.5 and 10 µm in aerodynamic diameter (PM10–2.5) and ozone (O3). The subjects’ pulmonary function and fractional exhaled nitric oxide (FeNO) were measured during the study period. The indoor PM2.5 concentrations decreased by 11% with the true air purifiers compared to those with sham air purifiers. However, this decrease was not significant (p = 0.08). The air purification did not significantly improve the pulmonary function of the study subjects. In contrast, an increase in the indoor PM10–2.5 and O3 concentration led to a significant decrease in the forced expiratory volume in one second (FEV1.0)/forced vital capacity (FVC) and maximal mid-expiratory flow (MMEF), respectively. In conclusion, air purification slightly improved the indoor PM2.5 concentrations in ordinary homes but had no demonstrable impact on improving health.

Effects of cigarette smoking and biomass fuel on lung function and respiratory symptoms in middle-aged adults and the elderly in Guangdong province, China: A cross-sectional study.

We sought to investigate the association between active cigarette smoking (ex- and current smokers) with or without exposure to biomass fuels and respiratory symptoms/lung function in middle-aged adults and the elderly. In the chronic obstructive pulmonary disease surveillance conducted in six cities of Guangdong province, China, we surveyed 1986 residents aged 40-93years. We recorded respiratory symptoms, smoking status, use of biomass fuel, and other covariates by using a structured questionnaire. All models were adjusted for second-hand smoking. Active smoking with or without exposure to biomass fuels was significantly associated with wheezing, chronic cough, and phlegm (all P<.05). Active smoking alone with or without exposure to biomass fuels was associated with 2.5% and 0.6% reduction in the mean forced vital capacity predicted, 6.8% and 4.2% reduction in the mean forced expiratory volume in one second predicted, and 9.0% and 4.7% reduction in the mean maximal mid-expiratory flow predicted compared with the exposure to neither smoking nor biomass fuels, respectively. However, exposure to biomass fuel alone was associated with neither greater lung function impairment nor respiratory symptoms except for chronic cough. Efforts should be made to protect home owners and their family from adverse effects of indoor air pollution.

Respiratory muscle training in stroke patients with respiratory muscle weakness, dysphagia, and dysarthria - a prospective randomized trial.

Objective:To examine the efficacy of combined inspiratory and expiratory respiratory muscle training (RMT) with respect to the swallowing function, pulmonary function, functional performance, and dysarthria in patients with stroke.Design:Prospective, randomized controlled trial.Setting:Tertiary hospital.Participants:The trial included 21 subjects (12 men, 9 women) aged 35 to 80 years presenting with 6 months history of unilateral stroke, respiratory muscle weakness (≥70% predicted maximal inspiratory pressure (MIP) and/or ≤70% maximal expiratory pressure (MEP)), dysphagia, or dysarthria. These subjects were randomly assigned to the control (n = 10, rehabilitation) and experimental (n = 11, rehabilitation with RMT) groups.Intervention:Inspiratory RMT starting from 30% to 60% of MIP and expiratory RMT starting from 15% to 75% of MEP for 5 days/week for 6 weeks.Main outcome measures:MIP, MEP, pulmonary function, peak cough flow, perception of dyspnea, Fatigue Assessment Scale, Modified Rankin Scale, Brunnstrom stage, Barthel index, Functional Oral Intake Scale (FOIS), and parameters of voice analysis.Results:Significant differences were observed between both groups in terms of MIP, forced vital capacity (FVC), and forced expiratory volume per second (FEV1) of the percentage predicted. Significant difference was found with respect to the change in fatigue, shimmer percent, amplitude perturbation quotient, and voice turbulence index (VTI) according to the acoustic analysis in the RMT group. The FEV1/FVC ratio was negatively correlated with jitter percent, relative average perturbation, pitch perturbation quotient, and VTI; the maximum mid-expiratory flow (MMEF) and MMEF% were also negatively correlated with VTI. Significant differences among participants of the same group were observed while comparing the Brunnstrom stage before and after training of the affected limbs and the Barthel scale and FOIS scores in both the groups.Conclusions:Altogether, 6-week combined inspiratory and expiratory RMT is feasible as adjuvant therapy for stroke patients to improve fatigue level, respiratory muscle strength, lung volume, respiratory flow, and dysarthria.Clinical trial registration number (Clinical Trial Identifier): NCT03491111.

The time window of pet ownership exposure modifies the relationship of Environmental Tobacco Smoke with lung function: A large population-based cohort study

There is a large body of evidence linking Environmental Tobacco Smoke (ETS) exposure with impaired lung function. However, it is not known whether exposure to pets modifies this relationship. To investigate if pet ownership changes the association between ETS exposure and lung function, a population-based sample of 7326 children, 7-14 years old, were randomly recruited from 24 districts in northeast China. Lung function including forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), peak expiratory flow (PEF), and maximal mid-expiratory flow (MMEF) was measured by spirometry, while pet ownership time periods and ETS exposure were collected by questionnaire. Two-level regression analysis was done, with covariates controlled for. The results showed pet exposure in certain early lifetime windows modified the associations of ETS exposure on decreased lung function in children. Among children exposed to current ETS, those exposed to pets in utero had greater reductions in lung function (for instance: OR for reduced FVC (<85% predicted)=10.86; 95% CI: 3.80-30.97) than those not exposed to pets in utero (OR=2.32; 95% CI: 1.76-3.05) (pinteraction=0.005). While, children exposed to current pet ownership reduced the lung function impairment induced by ETS exposure during the first 2 years of life and/or ETS exposure during pregnancy, especially for FVC impairment. For instance, OR (95%CI) for reduced FVC (<85% predicted) was 0.81 (0.56, 1.18) and 1.42 (1.15, 1.74), respectively, for children with or without current pet ownership exposed to ETS during the first 2 years of life (pinteraction=0.010). Furthermore, pet type or number of pets did not significantly modify associations between ETS exposure and lung function. In conclusion, the timing of pet ownership modified associations between ETS exposure and lung function, pet ownership in utero and during the first 2 years of life significantly worsened the adverse impacts of passive smoking on lung function.

Association of plasma roundabout 4 concentration with pulmonary ventilation function decline in COPD patients

Objective: To investigate the association of plasma roundabout 4 concentration with pulmonary ventilation function decline in chronic obstructive pulmonary disease (COPD) patients. Methods: To get the effective data, the study was conducted in the outpatient department of West China Hospital from September 2017 to September 2018. The subjects meeting the inclusion and exclusion criteria were continuously included. Among them, the COPD group (75 cases) was from the respiratory outpatient department, and the healthy control group (57 cases) was from the health examination center at the same time. Data of basic demographic characteristics, clinical characteristics, pulmonary ventilation function parameters and blood samples were collected. The concentrations of roundabout 4, C reactive protein (CRP), interleukin (IL)-6, IL-8, IL-1b and tumor necrosis factor (TNF)-α in plasma were detected, and the differences among groups were compared, the correlation between plasma roundabout 4 and pulmonary ventilation function parameters and inflammatory factors was analyzed. The diagnostic efficiency of roundabout 4 to COPD was analyzed according to receiver operating characteristic (ROC) curve. Results: The plasma concentration of roundabout 4 in COPD group was significantly higher than that in healthy control group [(41.3±14.2) vs (27.7±13.3) ng/L; P<0.001], the sensitivity and specificity of roundabout 4 in the diagnosis of COPD were 0.827 and 0.702 respectively. Correlation analysis showed that the plasma concentration of roundabout 4 was negatively correlated with lung function parameters forced expiratory volume in one second/forced vital capacity (FEV(1)/FVC), the first second forced expiratory volume as a percentage of the estimated value (FEV(1)%pred), forced exhalation of 50% and 25% lung capacity (MEF50, MEF25) and maximal mid-expiratory flow (MMEF) (r=-0.399, -0.321, -0.439, -0.363, -0.458; all P<0.001), positively correlated with CRP (adjusted r=0.311, P<0.001). Conclusion: The increased concentration of roundabout 4 in plasma leads to the decline of pulmonary ventilation function in COPD patients.

Long-Term Clinical Sequelae and Immunological Features of COVID-19 Survivors: A Cross-Sectional Study in Wuhan, China

Objectives: To describe the clinical sequelae and immunological features of COVID-19 survivors who have been discharged from the hospital for 5-8 months. Methods: This study is a cross-sectional study of confirmed COVID-19 patients aged ≥18 years who were discharged from hospitals in Wuhan from January to April 2020. The demographics, clinical features, and laboratory findings of the participants were collected from medical records in the hospital. The participants from the study completed an investigation of clinical sequelae, blood tests, a pulmonary function examination and an unarmed rehabilitation evaluation at Hubei Provincial Hospital of Traditional Chinese & Western Medicine. A group of volunteers who were free of COVID-19 and lived in Wuhan during the outbreak were recruited as the comparison group.Results: The average age of the 574 COVID-19 survivors was 57.7±11.4 years, and 348 (60.6%) survivors were female. The average number of days from the onset of symptoms was 241.79±16.16. The average number of days from discharge was 194.3±14.4. Clinical sequelae were common, including general symptoms (n=321, 55.9%), respiratory symptoms (n=265, 46.2%), digestive symptoms (n=84, 14.6%), nervous symptoms (n=75,13.1%) and psychosocial symptoms (n=201, 35%). A total of 190 (33.7%) survivors reported reduced exercise capacity. Through the results of pulmonary function examination, anomalies were noted in carbon monoxide diffusion capacity (DLCO)% in 110 cases (32.4%), maximal mid-expiratory flow (MMEF)% in 105 cases (30.7%), forced expired flow at 50% of forced vital capacity (FEF 50 )% in 128 cases (37.4%), and forced expired flow at 75% of forced vital capacity (FEF 75 )% in 240 cases (70.2%). The counts of T lymphocyte, CD4+ T lymphocyte counts, CD8+ T lymphocyte counts, B lymphocyte and NK cell in the survival group was significantly lower than that in the comparison group(all P +T lymphocyte counts had dropped, 231 (40.2%) whose CD8+ T lymphocyte counts had dropped, 119 (20.7%) whose B lymphocyte counts had dropped, and 54 (9.4%) whose NK cell counts had dropped. But there were no statistically significant differences in the incidence of lymphocyte subsets reduction between severe and nonsevere groups (all P > 0.05). The T lymphocyte counts, CD4+ T lymphocyte counts and CD8+ T lymphocyte counts of the patients before discharge were significantly higher than those in the early stage of admission (P Conclusion: Even after 5 to 8 months of discharge, many survivors still have clinical sequelae, and some of them have impaired immune function. Therefore, the long-term rehabilitation of COVID-19 survivors remains a concern.Funding Statement: This study was funded by the National Key R&D Plan of China (2020YFC0841600), Guangdong Provincial Key Laboratory of Research on Emergency in TCM (2017B030314176), R&D plan in key areas of Guangdong Province (2020B1111300005), and National Administration of Traditional Chinese Medicine (2020ZYLCYJ05-11).Declaration of Interests: The authors declare that they have no competing interests.Ethics Approval Statement: This study was approved by the ethical committees of Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China (GPHCM; No. BF2020-205-01). All participants signed informed consent forms.

Early Peritoneal Dialysis Ameliorates Blast Lung Injury by Alleviating Pulmonary Edema and Inflammation.

Blast lung injury is a high-energy trauma with high mortality for explosion victims. A treatment for blast lung injury is still lacking. The aim of this study was to observe the efficacy and mechanism of peritoneal dialysis combined with glucocorticoids (GC) in the treatment of blast lung injury in rats. Rats were randomly divided into five groups: control, sham, GC, peritoneal dialysis (dialysis for short), and dialysis + GC groups. All rats were injured by a biological shock tube-I. The lung water levels in the dialysis group and dialysis + GC group were significantly lower than that in the control group at 6 and 24 h after blast injury. The oxygenation index, forced vital capacity, maximum midexpiratory flow, and functional residual capacity of rats in the dialysis and dialysis + GC groups were significantly higher than those in the control group. The serum levels of interleukin (IL)-1β, IL-6, tumor necrosis factor- α, monocyte chemoattractant protein-1, C-reactive protein, and IL-10 in the dialysis and dialysis + GC groups were significantly lower than those in the control group. Genome-wide mRNA microarray results showed that the aquaporin 1 level in the lung tissue of the dialysis group was 6.67 times higher than that in the control group. Early peritoneal dialysis can attenuate pulmonary edema and inflammation, and protect acute lung injury after blast injury.

Effect of lung protective ventilation on perioperative pulmonary infection in elderly patients with mild to moderate COPD under general anesthesia

ObjectiveThe research aims to explore the effects of different ventilation time on postoperative pulmonary infection in elderly patients with the mild and moderate chronic pulmonary obstructive disease (COPD), so as to provide evidence for reducing postoperative pulmonary infection complications in patients with COPD. Methods120 elderly patients with mild and moderate COPD were selected as the research objects. First, the general information of patients with COPD before surgery and the difference between healthy population and lung forced expiratory volume in 1s (FEV1), forced vital capacity (FVC), FEV1/FVC and maximum midexpiratory flow (MMEF) functional indexes were analyzed and detected. Patients with COPD were operated on with single lung ventilation and general anesthesia. Patients with mild and moderate COPD were divided into two groups according to lung ventilation time (ventilation time 1.0–2.0h group, ventilation time >2.0h group). The inflammatory factors of IL-6, IL-21, TNF-α, and CXCL13 as well as inflammatory indicators of polycaprolactam (PCT), C-reactive protein (CRP) and white blood cell (WBC) in serum of all patients were detected after the operation. The probability of pulmonary infection after COPD was diagnosed and analyzed. Finally, the regression analysis of postoperative pulmonary infection in COPD patients was analyzed. Results(1) The results showed that the smoking rate of mild and COPD patients was significantly higher than that of healthy people (P<0.05). (2) The lung function indexes of the mild and moderate groups were significantly lower than those of the control group (P<0.01), while the lung function indexes of the moderate group were significantly lower than those of the mild group (P<0.05). (3) All the inflammatory indicators of moderate COPD patients were significantly higher than those of mild COPD patients (P<0.05). (4) All inflammation-related indicators in patients with mild and moderate COPD with ventilation time of >2.0h were significantly higher than those in the 1.0–2.0h group (P<0.05). (5) The probability of postoperative pulmonary infection in moderate patients was significantly higher than that in mild patients (P<0.01). The probability of postoperative pulmonary infection in >2.0h group was significantly higher than that in the 1.0–2.0h group (P<0.01). (6) Multivariate Logistic regression analysis results showed that lung function, duration of lung ventilation and smoking were independent risk factors for postoperative pulmonary infection in COPD patients. ConclusionIt is important to detect pulmonary function before surgery, maintain single lung ventilation protection for no more than 2.0h during surgery, and quit smoking to improve pulmonary infection in patients with COPD after surgery. In addition, the incidence of postoperative pulmonary infection in patients with moderate COPD was higher than that in patients with mild COPD, suggesting that early treatment in patients with COPD was also of great significance in reducing the incidence of postoperative pulmonary infection.

Mediterranean diet during pregnancy and childhood respiratory and atopic outcomes: birth cohort study.

Evidence for associations between Mediterranean diet during pregnancy and childhood asthma, allergy and related outcomes is conflicting. Few cohorts have followed children to school age, and none have considered lung function.In the Avon Longitudinal Study of Parents and Children, we analysed associations between maternal Mediterranean diet score during pregnancy (estimated by a food frequency questionnaire, using an a priori defined score adapted to pregnant women; score ranging from 0 (low adherence) to 7 (high adherence)) and current doctor-diagnosed asthma, wheeze, eczema, hay fever, atopy and lung function in 8907 children at 7–9 years. Interaction between maternal Mediterranean diet and maternal smoking in pregnancy was investigated.The maternal Mediterranean diet score was not associated with asthma or other allergic outcomes. Weak positive associations were found between maternal Mediterranean diet score and childhood maximal mid-expiratory flow (forced expiratory flow at 25–75% of forced vital capacity (FEF25–75%)) after controlling for confounders. Higher Mediterranean diet scores were associated with increased FEF25–75% z-scores adjusted for age, height and sex (β 0.06, 95% CI 0.01–0.12; p=0.03, comparing a score of 4–7 versus a score of 0–3). Stratifying associations by maternal smoking during pregnancy showed that associations with FEF25–75% were only seen in children of never-/passive-smoking mothers, but no evidence for a statistically significant interaction was found.Results suggest adherence to a Mediterranean diet during pregnancy may be associated with increased small airway function in childhood, but we found no evidence for a reduced risk of asthma or other allergic outcomes.

Diagnostic value of FeNO and MMEF for predicting cough variant asthma in chronic cough patients with or without allergic rhinitis

Objective To evaluate the diagnostic value of fractional exhaled nitric oxide (FeNO) and maximum mid-expiratory flow (MMEF) for differentiating cough variant asthma (CVA) from chronic cough in patients with or without allergic rhinitis. Methods In total, 328 patients with chronic cough who underwent spirometry and FeNO testing were consecutively included in the retrospective analysis. Patients were divided into the CVA (n = 125) or NCVA (n = 203) groups according to the diagnostic criteria of CVA. Receiver operating characteristic (ROC) curves were established to assess the diagnostic efficiency and optimal cutoff points of FeNO and MMEF for the prediction of CVA. Results The optimal cutoff values of FeNO and MMEF to discriminate CVA from chronic cough were 24.5 ppb (AUC, 0.765; sensitivity, 69.60%; specificity 72.91%; PPV, 61.27%; NPV, 79.57%) and 66.2% (AUC, 0.771; sensitivity, 67.20%; specificity 78.33%; PPV, 65.63%; NPV, 79.50%). The optimal cutoff values of combining FeNO with MMEF to discriminate CVA from chronic cough were >22 ppb for FeNO and <62.6% for MMEF (AUC, 0.877). In patients with and without allergic rhinitis, the optimal cutoff point of FeNO to discriminate CVA from chronic cough was 24.5 ppb (AUC, 0.820) and 33.5 ppb (AUC, 0.707), respectively. Conclusions FeNO and MMEF might have greater value as negative parameters for differentiating CVA from chronic cough. Combining FeNO and MMEF provided a significantly better prediction than either alone. The diagnostic accuracy of FeNO for predicting CVA in chronic cough patients with allergic rhinitis was higher than in chronic cough patients without allergic rhinitis.

Effect of incentive spirometer exercise on pulmonary functions in children with spastic cerebral palsy

BackgroundSpastic cerebral palsy (CP) patients have lower pulmonary functions than normal healthy individuals as they usually have decreased chest wall mobility, deviation of optimal chest wall structure, and weak respiratory muscles.PurposeThe aim was to study the effect of incentive spirometer exercise (ISE) on spirometry pulmonary function in children with spastic CP.Materials and methodsFifty spastic CP patients were randomly divided into two groups: the study group consisted of 30 patients and the control group consisted of 20 patients. Both groups were following and doing physiotherapy in the National Institute of Neuromotor System, the study group added incentive spirometer exercise to their physiotherapy program. We assessed forced expiratory volume at first second (FEV1%), the forced vital capacity (FVC %), FEV1/ FVC ratio, and maximal mid-expiratory flow before and after 4 weeks of exercise and lastly after another 4 weeks of exercise.ResultsThe authors found significant improvements in FEV1%, FVC %, and maximal mid-expiratory flow in the study group, but not in the control group.ConclusionThe authors support the use of ISE for improving pulmonary functions in children with spastic CP.

Long-Term Exposure to Ambient Fine Particulate Matter () and Lung Function in Children, Adolescents, and Young Adults: A Longitudinal Cohort Study.

Background:The association between long-term exposure to ambient fine particulate matter with aerodynamic diameter () and lung function in young people remains uncertain, particularly in Asia, where air pollution is generally a serious problem.Objectives:This study investigated the association between long-term exposure to ambient and lung function in Taiwanese children, adolescents, and young adults.Methods:This study comprised 24,544 participants 6–24 years of age, with 33,506 medical observations made between 2000 and 2014. We used a spatiotemporal model to estimate concentrations at participants’ addresses. Spirometry parameters, i.e., forced vital capacity (FVC), forced expiratory volume in 1 s (), and maximum midexpiratory flow (MMEF), were determined. A generalized linear mixed model was used to examine the associations between long-term exposure to ambient and lung function. The odds ratios (ORs) of poor lung function were also calculated after adjusting for a range of covariates.Results:Every increase in the 2-y average concentration was associated with decreases of 2.22% [95% confidence interval (CI): , ], 2.94 (95% CI: , ), and 2.79% (95% CI: , ) in the FVC, , and MMEF, respectively. Furthermore, it was associated with a 20% increase in the prevalence of poor lung function (OR: 1.20; 95% CI: 1.12, 1.29).Conclusions:Two-year ambient concentrations were inversely associated with lung function and positively associated with the prevalence of poor lung function in children, adolescents, and young adults in Taiwan. https://doi.org/10.1289/EHP5220

Reference value for expiratory time constant calculated from the maximal expiratory flow-volume curve

BackgroundThe expiratory time constant (RCEXP), which is defined as the product of airway resistance and lung compliance, enable us to assess the mechanical properties of the respiratory system in mechanically ventilated patients. Although RCEXP could also be applied to spontaneously breathing patients, little is known about RCEXP calculated from the maximal expiratory flow-volume (MEFV) curve. The aim of our study was to determine the reference value for RCEXP, as well as to investigate the association between RCEXP and other respiratory function parameters, including the forced expiratory volume in 1 s (FEV1)/ forced vital capacity (FVC) ratio, maximal mid-expiratory flow rate (MMF), maximal expiratory flow at 50 and 25% of FVC (MEF50 and MEF25, respectively), ratio of MEF50 to MEF25 (MEF50/MEF25).MethodsSpirometric parameters were extracted from the records of patients aged 15 years or older who underwent pulmonary function testing as a routine preoperative examination before non-cardiac surgery at the University of Tokyo Hospital. RCEXP was calculated in each patient from the slope of the descending limb of the MEFV curve using two points corresponding to MEF50 and MEF25. Airway obstruction was defined as an FEV1/FVC and FEV1 below the statistically lower limit of normal.ResultsWe retrospectively analyzed 777 spirometry records, and 62 patients were deemed to have airway obstruction according to Japanese spirometric reference values. The cut-off value for RCEXP was 0.601 s with an area under the receiver operating characteristic curve of 0.934 (95% confidence interval = 0.898–0.970). RCEXP was strongly associated with FEV1/FVC, and was moderately associated with MMF and MEF50. However, RCEXP was less associated with MEF25 and MEF50/MEF25.ConclusionsOur findings suggest that an RCEXP of longer than approximately 0.6 s can be linked to the presence of airway obstruction. Application of the concept of RCEXP to spontaneously breathing subjects was feasible, using our simple calculation method.