Global health impacts of ambient fine particulate pollution associated with climate variability

Air pollution is a key global environmental problem raising human health concern. It is essential to comprehensively assess the long-term characteristics of air pollution and the resultant health impacts. We first assessed the global trends of fine particulate matter (PM2.5) during 1980-2020 using a monthly global PM2.5 reanalysis dataset, and evaluated their association with three types of climate variability including El Niño-Southern Oscillation, Indian Ocean Dipole and North Atlantic Oscillation. We then estimated PM2.5-attributable premature deaths using integrated exposure-response functions. Results show a significant increasing trend of ambient PM2.5 during 1980-2020 due to increases in anthropogenic emissions. Ambient PM2.5 caused a total of ∼ 135 million premature deaths globally during the four decades. Occurrence of air pollution episodes was strongly associated with climate variability, which were associated with up to 14 % increase in annual global PM2.5-attributable premature deaths.

Defective monocyte-derived macrophage phagocytosis is associated with exacerbation frequency in COPD

BACKGROUND

Lower airway bacterial colonisation (LABC) in COPD patients is associated with increased exacerbation frequency and faster lung function decline. Defective macrophage phagocytosis in COPD drives inflammation, but how defective macrophage function contributes to exacerbations is not clear. This study investigated the association between macrophage phagocytosis and exacerbation frequency, LABC and clinical parameters.

METHODS

Monocyte-derived macrophages (MDM) were generated from 92 stable COPD patients, and at the onset of exacerbation in 39 patients. Macrophages were exposed to fluorescently labelled Haemophilus influenzae or Streptococcus pneumoniae for 4 h, then phagocytosis measured by fluorimetry and cytokine release by ELISA. Sputum bacterial colonisation was measured by PCR.

RESULTS

Phagocytosis of H. influenzae was negatively correlated with exacerbation frequency (r = 0.440, p < 0.01), and was significantly reduced in frequent vs. infrequent exacerbators (1.9 × 10³ RFU vs. 2.5 × 10³ RFU, p < 0.01). There was no correlation for S. pneumoniae. There was no association between phagocytosis of either bacteria with age, lung function, smoking history or treatment with inhaled corticosteroids, or long-acting bronchodilators. Phagocytosis was not altered during an exacerbation, or in the 2 weeks post-exacerbation. In response to phagocytosis, MDM from exacerbating patients showed increased release of CXCL-8 (p < 0.001) and TNFα (p < 0.01) compared to stable state.

CONCLUSION

Impaired COPD macrophage phagocytosis of H. influenzae, but not S. pneumoniae is associated with exacerbation frequency, resulting in pro-inflammatory macrophages that may contribute to disease progression. Targeting these frequent exacerbators with drugs that improve macrophage phagocytosis may prove beneficial.

Cost of Respiratory Syncytial Virus-Associated Acute Lower Respiratory Infection Management in Young Children at the Regional and Global Level: A Systematic Review and Meta-Analysis

Background

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory infection (ALRI) in young children aged &lt;5 years.

Methods

We aimed to identify the global inpatient and outpatient cost of management of RSV-ALRI in young children to assist health policy makers in making decisions related to resource allocation for interventions to reduce severe morbidity and mortality from RSV in this age group. We searched 3 electronic databases including Global Health, Medline, and EMBASE for studies reporting cost data on RSV management in children under 60 months from 2000 to 2017. Unpublished data on the management cost of RSV episodes were collected through collaboration with an international working group (RSV GEN) and claim databases.

Results

We identified 41 studies reporting data from year 1987 to 2017, mainly from Europe, North America, and Australia, covering the management of a total of 365 828 RSV disease episodes. The average cost per episode was €3452 (95% confidence interval [CI], 3265–3639) and €299 (95% CI, 295–303) for inpatient and outpatient management without follow-up, and it increased to €8591(95% CI, 8489–8692) and €2191 (95% CI, 2190–2192), respectively, with follow-up to 2 years after the initial event.

Conclusions

Known risk factors (early and late preterm birth, congenital heart disease, chronic lung disease, intensive care unit admission, and ventilator use) were associated with €4160 (95% CI, 3237–5082) increased cost of hospitalization. The global cost of inpatient and outpatient RSV ALRI management in young children in 2017 was estimated to be approximately €4.82 billion (95% CI, 3.47–7.93), 65% of these in developing countries and 55% of global costs accounted for by hospitalization. We have demonstrated that RSV imposed a substantial economic burden on health systems, governments, and the society.

Effect of β blockers on mortality after myocardial infarction in adults with COPD: population based cohort study of UK electronic healthcare records

OBJECTIVES

To investigate whether the use and timing of prescription of β blockers in patients with chronic obstructive pulmonary disease (COPD) having a first myocardial infarction was associated with survival and to identify factors related to their use.

DESIGN

Population based cohort study in England.

SETTING

UK national registry of myocardial infarction (Myocardial Ischaemia National Audit Project (MINAP)) linked to the General Practice Research Database (GPRD), 2003-11.

PARTICIPANTS

Patients with COPD with a first myocardial infarction in 1 January 2003 to 31 December 2008 as recorded in MINAP, who had no previous evidence of myocardial infarction in their GPRD or MINAP record. Data were provided by the Cardiovascular Disease Research using Linked Bespoke studies and Electronic Health Records (CALIBER) group at University College London.

MAIN OUTCOME MEASURE

Cox proportional hazards ratio for mortality after myocardial infarction in patients with COPD in those prescribed β blockers or not, corrected for covariates including age, sex, smoking status, drugs, comorbidities, type of myocardial infarction, and severity of infarct.

RESULTS

Among 1063 patients with COPD, treatment with β blockers started during the hospital admission for myocardial infarction was associated with substantial survival benefits (fully adjusted hazard ratio 0.50, 95% confidence interval 0.36 to 0.69; P<0.001; median follow-up time 2.9 years). Patients already taking a β blocker before their myocardial infarction also had a survival benefit (0.59, 0.44 to 0.79; P<0.001). Similar results were obtained with propensity scores as an alternative method to adjust for differences between those prescribed and not prescribed β blockers. With follow-up started from date of discharge from hospital, the effect size was slightly attenuated but there was a similar protective effect of treatment with β blockers started during hospital admission for myocardial infarction (0.64, 0.44 to 0.94; P=0.02).

CONCLUSIONS

The use of β blockers started either at the time of hospital admission for myocardial infarction or before a myocardial infarction is associated with improved survival after myocardial infarction in patients with COPD.

REGISTRATION

NCT01335672.

European union standards for tuberculosis care

The European Centre for Disease Prevention and Control (ECDC) and the European Respiratory Society (ERS) jointly developed European Union Standards for Tuberculosis Care (ESTC) aimed at providing European Union (EU)-tailored standards for the diagnosis, treatment and prevention of tuberculosis (TB). The International Standards for TB Care (ISTC) were developed in the global context and are not always adapted to the EU setting and practices. The majority of EU countries have the resources and capacity to implement higher standards to further secure quality TB diagnosis, treatment and prevention. On this basis, the ESTC were developed as standards specifically tailored to the EU setting. A panel of 30 international experts, led by a writing group and the ERS and ECDC, identified and developed the 21 ESTC in the areas of diagnosis, treatment, HIV and comorbid conditions, and public health and prevention. The ISTCs formed the basis for the 21 standards, upon which additional EU adaptations and supplements were developed. These patient-centred standards are targeted to clinicians and public health workers, providing an easy-to-use resource, guiding through all required activities to ensure optimal diagnosis, treatment and prevention of TB. These will support EU health programmes to identify and develop optimal procedures for TB care, control and elimination.

Defective macrophage phagocytosis of bacteria in COPD

Exacerbations of chronic obstructive pulmonary disease (COPD) are an increasing cause of hospitalisations and are associated with accelerated progression of airflow obstruction. Approximately half of COPD exacerbations are associated with bacteria and many patients have lower airways colonisation. This suggests that bacterial infection in COPD could be due to reduced pathogen removal. This study investigated whether bacterial clearance by macrophages is defective in COPD. Phagocytosis of fluorescently labelled polystyrene beads and Haemophillus influenzae and Streptococcus pneumoniae by alveolar macrophages and monocyte-derived macrophages (MDM) was assessed by fluorimetry and flow cytometry. Receptor expression was measured by flow cytometry. Alveolar macrophages and MDM phagocytosed polystyrene beads similarly. There was no difference in phagocytosis of beads by MDM from COPD patients compared with cells from smokers and nonsmokers. MDM from COPD patients showed reduced phagocytic responses to S. pneumoniae and H. influenzae compared with nonsmokers and smokers. This was not associated with alterations in cell surface receptor expression of toll-like receptor (TLR)2, TLR4, macrophage receptor with collagenous structure, cluster of differentiation (CD)163, CD36 or mannose receptor. Budesonide, formoterol or azithromycin did not suppress phagocytosis suggesting that reduced responses in COPD MDM were not due to medications. COPD macrophage innate responses are suppressed and may lead to bacterial colonisation and increased exacerbation frequency.

State of the Art Compendium: Canadian Thoracic Society recommendations for the management of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common cause of disability and death in Canada. Moreover, morbidity and mortality from COPD continue to rise, and the economic burden is enormous. The main goal of the Canadian Thoracic Society's evidence-based guidelines is to optimize early diagnosis, prevention and management of COPD in Canada. The main message of the guidelines is that COPD is a preventable and treatable disease. Targeted spirometry is strongly recommended to expedite early diagnosis in smokers and former smokers who develop respiratory symptoms, and who are at risk for COPD. Smoking cessation remains the single most effective intervention to reduce the risk of COPD and to slow its progression. Education, especially self-management plans, are key interventions in COPD. Therapy should be escalated on an individual basis in accordance with the increasing severity of symptoms and disability. Long-acting anticholinergics and beta-2-agonist inhalers should be prescribed for patients who remain symptomatic despite short-acting bronchodilator therapy. Inhaled steroids should not be used as first line therapy in COPD, but have a role in preventing exacerbations in patients with more advanced disease who suffer recurrent exacerbations. Acute exacerbations of COPD cause significant morbidity and mortality and should be treated promptly with bronchodilators and a short course of oral steroids; antibiotics should be prescribed for purulent exacerbations. Patients with advanced COPD and respiratory failure require a comprehensive management plan that incorporates structured end-of-life care. Management strategies, consisting of combined modern pharmacotherapy and nonpharmacotherapeutic interventions (eg, pulmonary rehabilitation and exercise training) can effectively improve symptoms, activity levels and quality of life, even in patients with severe COPD.

Outcomes for COPD pharmacological trials: from lung function to biomarkers

The American Thoracic Society/European Respiratory Society jointly created a Task Force on "Outcomes for COPD pharmacological trials: from lung function to biomarkers" to inform the chronic obstructive pulmonary disease research community about the possible use and limitations of current outcomes and markers when evaluating the impact of a pharmacological therapy. Based on their review of the published literature, the following document has been prepared with individual sections that address specific outcomes and markers, and a final section that summarises their recommendations.

Relationship between depression and exacerbations in COPD

Chronic obstructive pulmonary disease is associated with exacerbations. Some patients are prone to frequent exacerbations and these individuals have a worse quality of life, greater limitation of their daily activity and faster disease progression than patients with less frequent exacerbations. A prospective study in a well-characterised cohort was performed and it was assessed whether depression, as determined by the Centre for Epidemiologic Studies Depression Scale, was related to exacerbation frequency, systemic inflammation and various social factors. The associations of any increase in depressive symptoms at exacerbation were also investigated. Frequent exacerbators had a significantly higher median (interquartile range) baseline depression score than infrequent exacerbators (17.0 (7.0-25.0) and 12.0 (6.0-18.0), respectively). Depressed patients spend significantly less time outdoors and had significantly worse quality of life as measured by the St George's Respiratory Questionnaire. Depression increased significantly in patients from baseline to exacerbation (12.5 (5.0-19.0) and 19.5 (12.0-28.0) respectively). The present study is the first to show a relationship between depression and exacerbation frequency in patients with chronic obstructive pulmonary disease. The finding that frequent exacerbators are more depressed than infrequent exacerbators is relevant, as exacerbation frequency is an important outcome measure in chronic obstructive pulmonary disease.

Strategies for improving outcomes of COPD exacerbations

COPD is uniquely situated as a chronic disease at the beginning of the 21st century; it is not only an established major cause of mortality and morbidity but is increasing in prevalence despite current medical interventions. In addition COPD is not a stable disease but its natural history is punctuated by periods of acute deterioration or exacerbations. Exacerbations generate considerable additional morbidity and mortality, and directly affect patients’ quality of life. However, despite significant advances in understanding and treating this disease, exacerbations continue to be the major cause of COPD-associated hospitalization, and provision for their management incurs considerable health care costs. This review will consider the current management of COPD exacerbations and how new clinical strategies may improve outcome of these important clinical events.

Obstructive lung disease in acute medical patients

OBJECTIVES

To determine the proportion of adult medical patients who have chronic obstructive pulmonary disease (COPD), using the Global initiative for Chronic Obstructive Lung Disease guidelines (GOLD), and its relation to vascular disease.

METHODS

This is a prospective cross-sectional study of adult patients admitted to acute medical wards. Interviewer administered questionnaire, anthropometric and spirometric measurements were done.

RESULTS

Spirometry was performed in 720 acute admissions [Mean (SD) age 50.0 (18.9) years, FEV1: 1.98 L (0.83), FEV1/FVC%: 75.1 (11.9)%; males 332 (46.1%), smokers 318 (44%); 43.2% had vascular disease]. Sixty-seven per cent of patients (480) had no airway disease including 35 (4.5%) with chronic cough and sputum with normal spirometry; 89 (12.4%) had asthma and 151 (20.9%) had COPD. Patients with COPD were significantly older [60.3 (16.6) years] than non-COPD patients [47.3 (18.5) years], p < 0.001 and had a greater number of pack years of smoking. A greater percentage of patients with COPD had vascular disease (52%) than the non-COPD patients (40.1%), p = 0.017). Multivariate analysis with vascular disease as outcome variable revealed relationships with older age (p < 0.001) and Indo-Trinidadian ethnicity (p = 0.015), but not with gender (p = 0.321) and smoking (p = 0.442). FEV1% as well as FEV1 showed a significant inverse relationship with vascular disease (p < 0.05).

CONCLUSIONS

The prevalence of COPD using GOLD guidelines in acute hospital admissions is 20.9%; 11.7% of admissions have chronic sputum or cough with normal spirometry. Vascular disease is more prevalent in those with COPD. Patients admitted to acute medical care with vascular disease may also have COPD.

Effect of tiotropium on sputum and serum inflammatory markers and exacerbations in COPD

Chronic obstructive pulmonary disease (COPD) patients experiencing frequent exacerbations demonstrate increased stable-state airway inflammation. Tiotropium has been shown to reduce exacerbation frequency, but its effect on airway inflammation is unknown. The aim of the present study was to investigate the effect of tiotropium on sputum inflammatory markers and exacerbation frequency. Patients (n = 142) were randomised to receive tiotropium or placebo in addition to their usual medication for 1 yr. Sputum and serum cytokines were assayed by ELISA and exacerbation frequency calculated using a symptom-based diary. There was no difference in the area under the curve for sputum interleukin (IL)-6 or myeloperoxidase between the groups, but sputum IL-8 level was increased in the tiotropium arm. There was no difference between start and end of study in serum IL-6 or C-reactive protein level. Tiotropium was associated with a 52% reduction in exacerbation frequency (1.17 versus 2.46 exacerbations.yr(-1)). Of patients on tiotropium, 43% experienced at least one exacerbation, compared with 64% on placebo. The total number of exacerbation days was reduced compared with placebo (17.3 versus 34.5 days). Tiotropium reduces exacerbation frequency in chronic obstructive pulmonary disease, but this effect does not appear to be due to a reduction in airway or systemic inflammation.

Chronic obstructive pulmonary disease exacerbation and risk of pulmonary embolism

Pulmonary embolism is not a common feature in patients with chronic obstructive pulmonary disease with uncomplicated exacerbations

Inflammatory changes, recovery and recurrence at COPD exacerbation

Chronic obstructive pulmonary disease (COPD) exacerbations are associated with increased airway and systemic inflammation, though relationships between exacerbation recovery, recurrent exacerbation and inflammation have not been previously reported. In the present study, inflammatory changes at COPD exacerbations were related to clinical nonrecovery and recurrent exacerbations within 50 days. Serum interleukin (IL)-6, C-reactive protein (CRP), sputum IL-6 and IL-8 were measured in 73 COPD patients when stable, at exacerbation and at 7, 14 and 35 days post-exacerbation. In 23% of patients, symptoms did not recover to baseline by day 35. These patients had persistently higher levels of serum CRP during the recovery period. A total of 22% of the patients who had recurrent exacerbations within 50 days had significantly higher levels of serum CRP at day 14, compared with those without recurrences: 8.8 mg.L(-1) versus 3.4 mg.L(-1). Frequent exacerbators had a smaller reduction in systemic inflammation between exacerbation onset and day 35 compared with infrequent exacerbators. Nonrecovery of symptoms at chronic obstructive pulmonary disease exacerbation is associated with persistently heightened systemic inflammation. The time course of systemic inflammation following exacerbation is different between frequent and infrequent exacerbators. A high serum C-reactive protein concentration 14 days after an index exacerbation may be used as a predictor of recurrent exacerbations within 50 days.

COPD exacerbations .1: Epidemiology

The epidemiology of exacerbations of chronic obstructive pulmonary disease (COPD) is reviewed with particular reference to the definition, frequency, time course, natural history and seasonality, and their relationship with decline in lung function, disease severity and mortality. The importance of distinguishing between recurrent and relapsed exacerbations is discussed.

MMP-9, TIMP-1 and inflammatory cells in sputum from COPD patients during exacerbation

Background

Irreversible airflow obstruction in Chronic Obstructive Pulmonary Disease (COPD) is thought to result from airway remodelling associated with aberrant inflammation. Patients who experience frequent episodes of acute deterioration in symptoms and lung function, termed exacerbations, experience a faster decline in their lung function, and thus over time greater disease severity However the mechanisms by which these episodes may contribute to decreased lung function are poorly understood.

This study has prospectively examined changes in sputum levels of inflammatory cells, MMP-9 and TIMP-1 during exacerbations comparing with paired samples taken prior to exacerbation.

Methods

Nineteen COPD patients ((median, [IQR]) age 69 [63 to 74], forced expiratory volume in one second (FEV1) 1.0 [0.9 to1.2], FEV1% predicted 37.6 [27.3 to 46.2]) provided sputa at exacerbation. Of these, 12 were paired with a samples collected when the patient was stable, a median 4 months [2 to 8 months] beforehand.

Results

MMP-9 levels increased from 10.5 μg/g [1.2 to 21.1] prior to exacerbation to 17.1 μg/g [9.3 to 48.7] during exacerbation (P < 0.01). TIMP-1 levels decreased from 3.5 μg/g [0.6 to 7.8] to 1.5 μg/g [0.3 to 4.9] (P = 0.16). MMP-9/TIMP-1 Molar ratio significantly increased from 0.6 [0.2 to 1.1] to 3.6 [2.0 to 25.3] (P < 0.05). Neutrophil, eosinophil and lymphocyte counts all showed significant increase during exacerbation compared to before (P < 0.05). Macrophage numbers remained level. MMP-9 levels during exacerbation showed highly significant correlation with both neutrophil and lymphocyte counts (Rho = 0.7, P < 0.01).

Conclusion

During exacerbation, increased inflammatory burden coincides with an imbalance of the proteinase MMP-9 and its cognate inhibitor TIMP-1. This may suggest a pathway connecting frequent exacerbations with lung function decline.

Effects of exacerbations and seasonality on exhaled nitric oxide in COPD

Exhaled nitric oxide (eNO) appears to be associated with airway inflammation seen in chronic obstructive pulmonary disease (COPD). The present authors studied the effects of exacerbation, season, temperature and pollution on eNO. eNO was measured seasonally and at exacerbations in 79 outpatients suffering from COPD (mean forced expiratory volume in one second=42%). The effects of exacerbation symptoms, physiological and environmental parameters were analysed. Stable eNO levels were correlated positively with arterial oxygen tension. Median levels were found to be lower in smokers (5.3 ppb) than in ex- or nonsmokers (6.8 ppb). Levels were higher during October to December (6.9 ppb) than in April to June (4.6 ppb). Levels were also higher during 68 exacerbations in 38 patients (7.4 ppb) than in stable conditions (5.4 ppb), independent of the effects of smoking. The rise in eNO was greater in exacerbations that were associated with colds, a sore throat or dyspnoea combined with a cold. In conclusion, exhaled nitric oxide levels were higher in colder weather and in the autumn, perhaps related to the increased prevalence of viral infection at this time of year. The levels were lower in more severe chronic obstructive pulmonary disease. Exhaled nitric oxide levels were raised at the onset of exacerbation, particularly in the presence of a cold.