Combined effect of ozone and household air pollution on COPD in people aged less than 50 years old.

OBJECTIVES: Air pollution has been suggested as an important risk factor for chronic obstructive pulmonary disease (COPD); however, evidence of interactive effects on COPD between different factors was sparse, especially for young adults. We aimed to assess the combined effects of ambient ozone (O3) and household air pollution on COPD in young individuals. METHODS: We conducted a population-based study of residents aged 15-50 years in the low-income and middle-income regions of western China. We used multivariable logistic regression models to examine the associations between long-term ozone exposure and COPD in young individuals. RESULTS: A total of 6537 young cases were identified among the participants, with a COPD prevalence rate of 7.8 (95% CI 7.2% to 8.5%), and most young COPD individuals were asymptomatic. Exposure to household air pollution was associated with COPD in young patients after adjustment for other confounding factors (OR 1.82, 95% CI 1.41 to 2.37). We also found positive associations of COPD with O3 per IQR increase of 20 ppb (OR 1.92, 95% CI 1.59 to 2.32). The individual effects of household air pollution and O3 were 1.68 (95% CI 1.18 to 2.46) and 1.55 (95% CI 0.99 to 2.43), respectively, while their joint effect was 3.28 (95% CI 2.35 to 4.69) with the relative excess risk due to interaction of 1.05 (95% CI 0.33 to 1.78). CONCLUSIONS: This study concludes that exposure to ambient O3 and household air pollution might be important risk factors for COPD among young adults, and simultaneous exposure to high levels of the two pollutants may intensify their individual effects.

Comparison of the lower limit of normal to the fixed ratio method for the diagnosis of airflow obstruction at high altitudes: a large cross-sectional survey of subjects living between 3000-4700 m above sea level.

BACKGROUND: There is no general agreement on the preferential use of a fixed ratio (FR) of forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 0.7 vs. the lower limit of normal (LLN) of FEV1/FVC to define airflow obstruction. Determining the impact of these different cut-off levels in people living at high altitudes has not been studied. We assessed the prevalence of airflow obstruction and its clinical characteristics in residents living at high altitude using a fixed ratio and the LLN of FEV1/FVC according to Global Lung Initiative 2012 (GLI) reference values. METHODS: Using a multistage stratified sampling method, 3702 participants (aged ≥ 15 years) living at an altitude of 3000-4700 m in Tibet were included. RESULTS: 11.4% and 7.7% of participants had airflow obstruction according to GLI-LLN and a fixed FEV1/FVC cut-off value, respectively. The participants in the FR-/LLN+ group were younger, predominantly female, more frequently exposed to household air pollution, and had a higher proportion of chronic obstructive pulmonary disease assessment test scores ≥ 10 than those in the FR-/LLN- group. They also had a significantly lower FEV1 and a higher frequency of small airway dysfunction. Compared with the participants of the FR+/LLN+ group, those in the FR-/LLN+ group showed no significant difference in the risk factors for airflow obstruction and respiratory symptoms, but had a lower prevalence of small airway dysfunction. CONCLUSIONS: Defining airflow obstruction according to LLN, instead of using an FR, identified younger individuals with more frequent clinical symptoms of airflow obstruction and small airway dysfunction.

Ambient particulate matter associates with asthma in high altitude region: A population-based study.

Background: Exposure to particulate matter (PM) has been a major public health threat, but the potentially differential effects on asthma of PM remain largely unknown in high altitude settings. We evaluated the effects of ambient PM on asthma in high altitude settings. Methods: The study recruited a representative sample from high altitude settings using a multistage stratified sampling procedure. Asthma was defined by a self-reported history of diagnosis by a physician or by wheezing symptoms in the preceding 12 months. The annual mean PM2.5 and PM10 concentrations were calculated for each grid cell at 1-km spatial resolution based on the geographical coordinates. Results: We analyzed data for participants (mean age 39.1 years, 51.4% female) and 183 (3.7%, 95% confidence interval (CI): 3.2-4.2) of the participants had asthma. Prevalence was higher in women (4.3%, 95% CI 3.5-5.1) than in men (3.1%, 2.4-3.8) and increasing with higher concentration of PM exposures. For an interquartile range (IQR) difference (8.77 µg/m3) in PM2.5 exposure, the adjusted odds ratio (OR) was 1.64 (95% CI 1.46-1.83, P < 0.001) for risk of asthma. For PM10, there was evidence for an association with risk of asthma (OR 2.34, 95% CI: 1.75-3.15, P < 0.001 per IQR of 43.26 µg/m3). Further analyses showed that household mold or damp exposure may aggravate PM exposure associated risks of asthma. Conclusions: This study identified that PM exposure could be a dominate environmental risk factor for asthma but largely unconsidered in the high-altitude areas. The association between PM exposure and asthma should be of interest for planners of national policies and encourage programs for prevention of asthma in residents living at high altitudes.

Airflow obstruction and small airway dysfunction following pulmonary tuberculosis: a cross-sectional survey.

OBJECTIVES: Pulmonary function impairment and chronic respiratory symptoms after tuberculosis are relatively common in low-income and middle-income countries. We aimed to estimate the impact of post-tuberculosis (post-TB) on pulmonary function. METHODS: This large cross-sectional, population-based study included subjects aged 15 years or older with technically acceptable postbronchodilator spirometry measurements. Post-TB was diagnosed on the basis of radiological evidence and/or medical history. Airflow obstruction was defined as a postbronchodilator forced expiratory volume in 1 s/forced vital capacity ratio below the lower limit of normal of Global Lung Function Initiative (GLI) lung function equations. Small airway dysfunction was diagnosed if at least two of the following indicators were less than 65% of predicted: maximal mid-expiratory flow, forced expiratory flow (FEF) 50% or FEF 75%. RESULTS: In this population sample (N=8680, mean age: 40.1 years), 610 (7.0% (95% CI 6.5 to 7.6) participants were post-TB. Post-TB subjects had more frequent respiratory symptoms (46.8% vs 28.3%). Among post-TB subjects, 130 (21.3% (95% CI 18.1 to 24.8)) had airflow obstruction; OR of airflow obstruction was significantly associated with post-TB after adjustment for other confounding factors (OR 1.31, 95% CI 1.05 to 1.62). Post-TB was also associated with small airway dysfunction (OR 1.28, 95% CI1.07 to 1.53), which was present in 297 (48.9% (95% CI 33.9 to 53.0)) post-TB subjects. CONCLUSIONS: Our findings support existing knowledge that post-TB is positively associated with pulmonary function impairment and make for frequent respiratory symptoms. Post-TB should be considered as a potentially important cause of airflow obstruction and respiratory symptoms in patients originating from countries with a high burden of tuberculosis.

High-flow nasal oxygen reduces the incidence of hypoxia in sedated hysteroscopy for assisted reproduction.

Backgrounds and aims: Pain is the main reason for hysteroscopy failure. In day-surgical settings, hysteroscopy procedures are commonly performed with the patient under sedation. Hypoxia is the most common adverse event during sedation and can lead to severe adverse events. This study aimed to compare the incidence of hypoxia when using high-flow nasal oxygen (HFNO) with that when using regular nasal oxygen in patients undergoing hysteroscopy with sedation. Materials and methods: In this single-center, prospective, randomized, single-blinded study, 960 female patients undergoing elective diagnostic or operative hysteroscopy were randomly enrolled into the following two groups: the regular nasal group [O2 (3-6 L/min) covered by an HFNO] and the HFNO group [O2 (30-60 L/min)] from September 2021 to December 2021. All women were sedated with propofol (1.5 mg/kg) and remifentanil (1.5 µg/kg) in the operating room. The primary outcome was the incidence of hypoxia (75% ≤ SpO2 < 90%, < 60 s). Results: HFNO decreased the incidence of hypoxia (75% ≤ SpO2 < 90%, < 60 s), subclinical respiratory depression (90% ≤ SpO2 < 95%) and severe hypoxia (SpO2 < 75% for any duration or 75% ≤ SpO2 < 90% for ≥ 60 s) from 24.38 to 0.83%, from 11.25 to 1.46% and from 3.75 to 0%, respectively (P < 0.001). Conclusion: In procedures conducted to treat female infertility, HFNO can reduce hypoxia during hysteroscopy in patients sedated with propofol, and it can prevent the occurrence of subclinical respiratory depression and severe hypoxia.

Effect of Respiration Training-Assisted Western Medicine Therapy on Activity Tolerance, Pulmonary Function, and Quality of Life of Chronic Obstructive Pulmonary Disease Patients in the Stable Phase.

Objective: To explore the effect of respiration training-assisted western medicine therapy on activity tolerance, pulmonary function, and quality of life (QOL) of chronic obstructive pulmonary disease (COPD) patients in the stable phase. Methods: The medical data of 90 COPD patients in the stable phase treated in the respiratory medicine of our hospital (November 2020-November 2021) were chosen for the retrospective analysis, and the patients were split into group A (n = 45, respiration training-assisted western medicine therapy) and group B (n = 45, western medicine therapy) according to the clinical reception order, so as to record and compare the activity tolerance, lung function, and QOL between the groups after intervention. Results: Compared with group B after intervention, group A showed greatly longer mean 6-min walking distance, significantly lower St. George's Respiratory Questionnaire (SGRQ) score, significantly higher specific airway conductance (sGAW) and level values of various lung function indicators, and significantly lower level values of airway resistance (RAW) and specific airway resistance (sRAW) (p all<0.001); the total effective rate was significantly higher in group A (p < 0.05). Conclusion: Respiration training-assisted western medicine therapy is a dependable way to improve the activity tolerance of COPD patients in the stable phase, and such strategy largely improves patients' lung function and QOL. Deeper studies will be helpful to establish a preferable solution for such patients.

Staem5: A novel computational approachfor accurate prediction of m5C site.

5-Methylcytosine (m5C) is an important post-transcriptional modification that has been extensively found in multiple types of RNAs. Many studies have shown that m5C plays vital roles in many biological functions, such as RNA structure stability and metabolism. Computational approaches act as an efficient way to identify m5C sites from high-throughput RNA sequence data and help interpret the functional mechanism of this important modification. This study proposed a novel species-specific computational approach, Staem5, to accurately predict RNA m5C sites in Mus musculus and Arabidopsis thaliana. Staem5 was developed by employing feature fusion tactics to leverage informatic sequence profiles, and a stacking ensemble learning framework combined five popular machine learning algorithms. Extensive benchmarking tests demonstrated that Staem5 outperformed state-of-the-art approaches in both cross-validation and independent tests. We provide the source code of Staem5, which is publicly available at https://github.com/Cxd-626/Staem5.git.

Solid Fuel Exposure and Chronic Obstructive Pulmonary Disease in Never-Smokers.

Background: Chronic obstructive pulmonary disease (COPD) is a public health challenge globally. The burden of COPD is high in never-smokers but little is known about its causes. We aimed to find the prevalence and correlates of COPD in never-smokers, with a special focus on solid fuel exposure. Methods: We conducted a cross-sectional study in Western China. COPD was defined by FEV1/FVC < lower limits of normal (LLN). Descriptive statistics and multivariable logistic regression were used for analyses. Results: Six thousand two hundred and seventy one patients were enrolled between June 2015 and August 2016. The prevalence of COPD in never-smokers was 15.0% (95% confidence interval 14.1-15.9). The common independent predictors of COPD in never-smokers included age ≥60 years, exposure to solid fuel, living in a rural area and a history of tuberculosis. Participants with solid fuel exposure were 69% more likely to have COPD (adjusted odds ratio 1.69, 95% CI 1.41-2.04) than those without such exposure. In addition, we found a positive association between small airway dysfunction and solid fuel exposure (OR 1.35, 95% CI 1.18-1.53). Conclusions: This study confirmed the substantial burden of COPD among never-smokers and also defined the risk factors for COPD in never-smokers. Furthermore, we found a positive association between solid fuel exposure and COPD or small airway dysfunction.

Prevalence and Risk Factors for COPD at High Altitude: A Large Cross-Sectional Survey of Subjects Living Between 2,100-4,700 m Above Sea Level.

Aim of Study: Four hundred million people live at high altitude worldwide. Prevalence and risk factors for COPD in these populations are poorly documented. We examined the prevalence and risk factors for COPD in residents living at an altitude of 2,100-4,700 m. Methods: We performed a cross-sectional survey in Xinjiang and Tibet autonomous region. A multistage stratified sampling procedure was used to select a representative population aged 15 years or older from eight high altitude regions. All participants underwent pre- and post-bronchodilator measurement of forced expiratory volumes. COPD was diagnosed according to 2019 Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. Results: Between June, 2015 and August 2016, 4,967 subjects were included. Median age was 38.0 years (range: 15-91 years; inter-quartile range: 28-49 years); 51.4% participants were female. Overall prevalence of spirometry-defined COPD was 8.2% (95% CI 7.4-8.9%): 9.3% in male (95% CI 8.2-10.4%), and 7.1% in female (95% CI 6.1-8.2%). By multivariable logistic regression analysis, COPD was significantly associated with being aged ≥40 years (odds ratio: 2.25 [95% CI 1.72-2.95], P < 0.0001), exposure to household air pollution (OR: 1.34 [95% CI 1.01-1.79], P = 0.043), and a history of tuberculosis (OR: 1.79 [95% CI 1.23-2.61], P = 0.030), while living at a higher altitude (OR: 0.45 [95% CI 0.33-0.61], P < 0.0001) and having a higher educational level (OR: 0.64 [95% CI 0.43-0.95], P = 0.025) were associated with a lower prevalence of COPD. Conclusions: Our results show that the spirometry-defined COPD is a considerable health problem for residents living at high altitudes and COPD prevalence was inversely correlated with altitude. Preventing exposure to household air pollution and reducing the incidence of tuberculosis should be public health priorities for high altitude residents.

[A preliminary study of the distribution and the characteristics of nonspecific pulmonary function].

OBJECTIVE: To investigate the manifestations, pulmonary function test (PFT) characteristics and imaging features of patients with nonspecific pulmonary function (NSPF). METHODS: All the data from the same PFT apparatus in Beijing Hospital were collected from January 2003 to December 2012. NSPF was defined as normal FEV1/FVC and TLC, but decreased FEV1 or FVC or both. Patients with complete clinical data from January 2012 to June 2012 were enrolled into this analysis. The NSPF group was compared with the normal group, the obstructive group, the restrictive group and the mixed group. RESULTS: There were totally 14 771 cases of PFT on this apparatus during 10 year period, and those with NSPF were 2759 (18.68%). From January 2012 to June 2012, 341 patients were enrolled into this study with a sex ratio of 1.37:1, and an average age of 66±12 years. Compared with the normal group, the NSPF group had a significantly higher rate of small airway abnormalities and elevated RV/TLC. Multiple logistic regression analysis showed that statistical differences were found in TLC%pred (OR=0.668, P<0.01, 95%CI 0.563-0.791), FEF25-75%pred (OR=0.963, P<0.01, 95%CI 0.939-0.988), RV%pred (OR=1.144, P<0.01, 95%CI 1.075-1.217), and RV/TLC (OR=1.31, P<0.01, 95%CI 1.15-1.492). Compared with the obstructive group, the NSPF group had a significantly lower rate of small airway abnormalities. Multiple logistic regression analysis showed that female gender(OR=15.283, P<0.001, 95%CI 3.526-66.248), TLC%pred (OR=0.961, P=0.02, 95%CI 0.928-0.994), and FEF50%%pred (OR=1.189, P<0.001, 95%CI 1.103-1.281) were significantly different between the 2 groups. Respiratory symptoms were more common in the NSPF group. Airway diseases were diagnosed in more cases of the NSPF group when compared to the normal group, but in fewer cases when compared to the obstructive group. Clinical manifestations and imaging features of the NSPF cases were not specific. CONCLUSIONS: NSPF is a common clinical condition which mainly affects the small airway function with some degree of restrictive dysfunction. NSPF has limited predictive value for diagnosis because the manifestations and imaging features are not specific.