Publications
107 results found
Mueller A, Wouters EFM, Koul P, et al., 2024, Association between lung function and dyspnoea and its variation in the multinational Burden of Obstructive Lung Disease (BOLD) study, Pulmonology, ISSN: 2531-0429
Mak J, Feary J, Amaral AFS, et al., 2024, Occupational exposure to particulate matter and staff sickness absence on the London underground, Environment International, Vol: 185, ISSN: 0160-4120
The London Underground (LU) employs over 19,000 staff, some of whom are exposed to elevated concentrations of particulate matter (PM) within the network. This study quantified the occupational exposure of LU staff to subway PM and investigated the possible association with sickness absence (SA). A job exposure matrix to quantify subway PM2.5 staff exposure was developed by undertaking measurement campaigns across the LU network. The association between exposure and SA was evaluated using zero-inflated mixed-effects negative binomial models. Staff PM2.5 exposure varied by job grade and tasks undertaken. Drivers had the highest exposure over a work shift (mean: 261 µg/m3), but concentrations varied significantly by LU line and time the train spent subway. Office staff work in office buildings separate to the LU network and are unexposed to occupational subway PM2.5. They were found to have lower rates of all-cause and respiratory infection SA compared to non-office staff, those who work across the LU network and are occupational exposed to subway PM2.5. Train drivers on five out of eight lines showed higher rates of all-cause SA, but no dose-response relationship was seen. Only drivers from one line showed higher rates of SAs from respiratory infections (incidence rate ratio: 1.24, 95% confidence interval 1.10-1.39). Lower-grade customer service (CS) staff showed higher rates of all-cause and respiratory infection SA compared to higher grade CS staff. Doctor-certified chronic respiratory and cardiovascular SAs were associated with occupational PM2.5 exposure in CS staff and drivers. While some groups with higher occupational exposure to subway PM reported higher rates of SA, no evidence suggests that subway PM is the main contributing factor to SA. This is the largest subway study on health effects of occupational PM2.5 exposure and may have wider implications for subway workers, contributing to safer working environments.
Abozid H, Patel J, Burney P, et al., 2024, Prevalence of chronic cough, its risk factors and population attributable risk in the Burden of Obstructive Lung Disease (BOLD) study: a multinational cross-sectional study, EClinicalMedicine, Vol: 68, ISSN: 2589-5370
Background:Chronic cough is a common respiratory symptom with an impact on daily activities and quality of life. Global prevalence data are scarce and derive mainly from European and Asian countries and studies with outcomes other than chronic cough. In this study, we aimed to estimate the prevalence of chronic cough across a large number of study sites as well as to identify its main risk factors using a standardised protocol and definition.Methods:We analysed cross-sectional data from 33,983 adults (≥40 years), recruited between Jan 2, 2003 and Dec 26, 2016, in 41 sites (34 countries) from the Burden of Obstructive Lung Disease (BOLD) study. We estimated the prevalence of chronic cough for each site accounting for sampling design. To identify risk factors, we conducted multivariable logistic regression analysis within each site and then pooled estimates using random-effects meta-analysis. We also calculated the population attributable risk (PAR) associated with each of the identifed risk factors.Findings:The prevalence of chronic cough varied from 3% in India (rural Pune) to 24% in the United States of America (Lexington,KY). Chronic cough was more common among females, both current and passive smokers, those working in a dusty job, those with a history of tuberculosis, those who were obese, those with a low level of education and those with hypertension or airflow limitation. The most influential risk factors were current smoking and working in a dusty job.Interpretation:Our findings suggested that the prevalence of chronic cough varies widely across sites in different world regions. Cigarette smoking and exposure to dust in the workplace are its major risk factors.Funding:Wellcome Trust.
Amaral A, Potts J, Knox-Brown B, et al., 2023, Cohort profile: Burden of Obstructive Lung Disease (BOLD) study, International Journal of Epidemiology, Vol: 52, Pages: e364-e373, ISSN: 0300-5771
Knox-Brown B, Potts J, Quintero Santofimio V, et al., 2023, Isolated small airways obstruction predicts future chronic airflow obstruction: A multinational longitudinal study, BMJ Open Respiratory Research, Vol: 10, ISSN: 2052-4439
Background Chronic airflow obstruction is a key characteristic of chronic obstructive pulmonary disease. We investigated whether isolated small airways obstruction is associated with chronic airflow obstruction later in life.Methods We used longitudinal data from 3957 participants of the multinational Burden of Obstructive Lung Disease study. We defined isolated small airways obstruction using the prebronchodilator mean forced expiratory flow rate between 25% and 75% of the forced vital capacity (FVC) (FEF25–75) if a result was less than the lower limit of normal (<LLN) in the presence of a normal forced expiratory volume in 1 s to FVC ratio (FEV1/FVC). We also used the forced expiratory volume in 3 s to FVC ratio (FEV3/FVC) to define small airways obstruction. We defined chronic airflow obstruction as post-bronchodilator FEV1/FVC<LLN. We performed mixed effects regression analyses to model the association between baseline isolated small airways obstruction and chronic airflow obstruction at follow-up. We assessed discriminative and predictive ability by calculating the area under the receiver operating curve (AUC) and Brier score. We replicated our analyses in 26 512 participants of the UK Biobank study.Results Median follow-up time was 8.3 years. Chronic airflow obstruction was more likely to develop in participants with isolated small airways obstruction at baseline (FEF25-75 less than the LLN, OR: 2.95, 95% CI 1.02 to 8.54; FEV3/FVC less than the LLN, OR: 1.94, 95% CI 1.05 to 3.62). FEF25-75 was better than the FEV3/FVC ratio to discriminate future chronic airflow obstruction (AUC: 0.764 vs 0.692). Results were similar among participants of the UK Biobank study.Conclusion Measurements of small airways obstruction can be used as early markers of future obstructive lung disease.
Lakoh S, Vamboi P, Ouedrago A, et al., 2023, High prevalence of TB multimorbidity among adults of a tertiary hospital in Sierra Leone: a cross-sectional study, BMC Research Notes, Vol: 16, ISSN: 1756-0500
Objective:Tuberculosis (TB) is a leading cause of death globally, with approximately 1.5 million deaths in 2020. TB often coexists with chronic communicable and non-communicable diseases, but data to determine the extent of comorbid diseases are limited. In this study, we aimed to assess the prevalence of TB multimorbidity and its risk factors in a tertiary hospital in Sierra Leone. This is a cross-sectional study of 240 adults with microbiologically-confirmed TB at Connaught Hospital in Freetown, between March and May 2022. Logistic regression analysis was used to identify factors associated with TB multimorbidity.Results:The mean age of the patients was 37 years. More than two-thirds were males and about the same number had two or more chronic diseases. The most common were hypertension (47.9%) and diabetes (24.2%). Patients under 35 years of age were less likely to have TB multimorbidity (< 25 years: adjusted OR 0.07, 95%CI 0.01–0.6; 25–34 years: adjusted OR 0.2, 95%CI 0.01–0.9). We report a high prevalence of comorbid diseases among TB patients in the largest treatment center in Sierra Leone, with hypertension and diabetes being the most common. These findings support the current call for addressing comorbid non-communicable diseases in TB patients through integrated care.
Ahmed R, Osman R, Nightingale R, et al., 2023, Prevalence and determinants of chronic respiratory diseases in adults in rural Sudan, International Journal of Tuberculosis and Lung Disease, Vol: 27, Pages: 841-849, ISSN: 1027-3719
BACKGROUND: Chronic respiratory diseases (CRDs) greatly contribute to worldwide mortality. Despite new data emerging from Africa, prevalence estimates and determinants of CRDs in rural settings are limited. This study sought to extend the existing research conducted in urban Sudan by conducting a rural comparison.METHODS: Participants aged ≥18 years (n = 1,850), living in rural Gezira State completed pre-and post-bronchodilator spirometry and a questionnaire. Prevalence of respiratory symptoms and spirometric abnormalities were reported. Regression analyses were used to identify risk factors for CRDs.RESULTS: Prevalence of chronic airflow obstruction (CAO) was 4.1% overall and 5.5% in those aged ≥40 years. Reversibility was seen in 6.4%. Low forced vital capacity (FVC) was seen in 58.5%, and at least one respiratory symptom was present in 40.7% of the participants. CAO was more common among people aged 60–69 years (OR 2.07, 95% CI 1.13–3.82) and less common among highly educated participants (OR 0.50, 95% CI 0.27–0.93). Being underweight was associated with lower FVC (OR 3.07, 95% CI 2.24–4.20).CONCLUSIONS: A substantial burden of CRD exists among adults in rural Sudan. Investment in CRD prevention and management strategies is needed.
Muller A, Mraz T, Wouters EFM, et al., 2023, Prevalence of dyspnea in general adult populations: a systematic review and meta-analysis, Respiratory Medicine, Vol: 218, ISSN: 0954-6111
IntroductionDyspnea is a commonly described symptom in various chronic and acute conditions. Despite its frequency, relatively little is known about the prevalence and assessment of dyspnea in general populations. The aims of this review were: 1) to estimate the prevalence of dyspnea in general adult populations; 2) to identify associated factors; and 3) to identify used methods for dyspnea assessment.MethodsA systematic literature search was conducted using MEDLINE/PubMed, Embase, CINAHL and JAMA network. Records were screened by two independent reviewers and quality was assessed by using the Joanna Briggs Institute checklist for risk of bias in prevalence studies. Multi-level meta-analysis was performed to estimate pooled prevalence. The protocol was registered on PROSPERO (CRD42021275499).ResultsTwenty original articles, all from studies in high-income countries, met the criteria for inclusion. Overall, their quality was good. Pooled prevalence of dyspnea in general adult populations based on 11 studies was 10% (95% CI 7, 15), but heterogeneity across studies was high. The most frequently reported risk factors were increasing age, female sex, higher BMI and respiratory or cardiac disease. The MRC or the modified MRC scale was the most used tool to assess dyspnea in general populations.ConclusionsDyspnea is a common symptom in adults in high-income countries. However, the high heterogeneity across studies and the lack of data from low- and middle-income countries limit the generalizability of our findings. Therefore, more research is needed to unveil the prevalence of dyspnea and its main risk factors in general populations around the world.
Oosterwegel MJ, Ibi D, Portengen L, et al., 2023, Variability of the human serum metabolome over 3 months in the EXPOsOMICS Personal Exposure Monitoring study, Environmental Science and Technology (Washington), Vol: 57, Pages: 12752-12759, ISSN: 0013-936X
Liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) and untargeted metabolomics are increasingly used in exposome studies to study the interactions between nongenetic factors and the blood metabolome. To reliably and efficiently link detected compounds to exposures and health phenotypes in such studies, it is important to understand the variability in metabolome measures. We assessed the within- and between-subject variability of untargeted LC-HRMS measurements in 298 nonfasting human serum samples collected on two occasions from 157 subjects. Samples were collected ca. 107 (IQR: 34) days apart as part of the multicenter EXPOsOMICS Personal Exposure Monitoring study. In total, 4294 metabolic features were detected, and 184 unique compounds could be identified with high confidence. The median intraclass correlation coefficient (ICC) across all metabolic features was 0.51 (IQR: 0.29) and 0.64 (IQR: 0.25) for the 184 uniquely identified compounds. For this group, the median ICC marginally changed (0.63) when we included common confounders (age, sex, and body mass index) in the regression model. When grouping compounds by compound class, the ICC was largest among glycerophospholipids (median ICC 0.70) and steroids (0.67), and lowest for amino acids (0.61) and the O-acylcarnitine class (0.44). ICCs varied substantially within chemical classes. Our results suggest that the metabolome as measured with untargeted LC-HRMS is fairly stable (ICC > 0.5) over 100 days for more than half of the features monitored in our study, to reflect average levels across this time period. Variance across the metabolome will result in differential measurement error across the metabolome, which needs to be considered in the interpretation of metabolome results.
Patel J, Amaral A, Minelli C, et al., 2023, Chronic airflow obstruction attributable to poverty in the multinational Burden of Obstructive Lung Disease study, Thorax, Vol: 78, Pages: 942-945, ISSN: 0040-6376
Poverty is strongly associated with all-cause and chronic obstructive pulmonary disease (COPD) mortality. Less is known about the contribution of poverty to spirometrically defined chronic airflow obstruction (CAO) – a key characteristic of COPD. Using cross-sectional data from an asset-based questionnaire to define poverty in 21 sites of the Burden of Obstructive Lung Disease study, we estimated the risk of CAO attributable to poverty. Up to 6% of the population over 40 years had CAO attributable to poverty. Understanding the relationship between poverty and CAO might suggest ways to improve lung health, especially in low- and middle-income countries.
Hannemann J, Thorarinnsdottir EH, Amaral A, et al., 2023, Biomarkers of the L-arginine / dimethylarginine / nitric oxide pathway in people with chronic airflow obstruction and obstructive sleep apnoea, Journal of Clinical Medicine, Vol: 12, ISSN: 2077-0383
Background: Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea (OSA) are common chronic diseases that are associated with chronic and intermittent hypoxemia, respectively. Patients affected by the overlap of COPD and OSA have a particularly unfavourable prognosis. The L-arginine/nitric oxide (NO) pathway plays an important role in regulating pulmonary vascular function. Asymmetric (ADMA) and symmetric dimethylarginine (SDMA) interfere with NO production. Methods: We analysed the serum concentrations of ADMA, SDMA, L-arginine, L-citrulline, and L-ornithine in a large sample of the Icelandic general population together with chronic airflow obstruction (CAO), a key physiological marker of COPD that was assessed by post-bronchodilator spirometry (FEV1/FVC < LLN). OSA risk was determined by the multivariable apnoea prediction (MAP) index. Results: 713 individuals were analysed, of whom 78 (10.9%) showed CAO and 215 (30%) had MAP > 0.5. SDMA was significantly higher in individuals with CAO (0.518 [0.461–0.616] vs. 0.494 [0.441–0.565] µmol/L; p = 0.005), but ADMA was not. However, ADMA was significantly associated with decreasing FEV1 percent predicted among those with CAO (p = 0.002). ADMA was 0.50 (0.44–0.56) µmol/L in MAP ≤ 0.5 versus 0.52 (0.46–0.58) µmol/L in MAP > 0.5 (p = 0.008). SDMA was 0.49 (0.44–0.56) µmol/L versus 0.51 (0.46–0.60) µmol/L, respectively (p = 0.004). The highest values for ADMA and SDMA were observed in individuals with overlap of CAO and MAP > 0.5, which was accompanied by lower L-citrulline levels. Conclusions: The plasma concentrations of ADMA and SDMA are elevated in COPD patients with concomitant intermittent hypoxaemia. This may account for impaired pulmonary NO production, enhanced pulmonary vasoconstriction, and disease progression.
Markevych I, Zhao T, Fuertes E, et al., 2023, Residential greenspace and lung function decline over 20 years in a prospective cohort: the ECRHS study, Environment International, Vol: 178, Pages: 1-10, ISSN: 0160-4120
BackgroundThe few studies that have examined associations between greenspace and lung function in adulthood have yielded conflicting results and none have examined whether the rate of lung function decline is affected.ObjectiveWe explored the association between residential greenspace and change in lung function over 20 years in 5559 adults from 22 centers in 11 countries participating in the population-based, international European Community Respiratory Health Survey.MethodsForced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were measured by spirometry when participants were approximately 35 (1990–1994), 44 (1999–2003), and 55 (2010–2014) years old. Greenness was assessed as the mean Normalized Difference Vegetation Index (NDVI) in 500 m, 300 m, and 100 m circular buffers around the residential addresses at the time of lung function measurement. Green spaces were defined as the presence of agricultural, natural, or urban green spaces in a circular 300 m buffer. Associations of these greenspace parameters with the rate of lung function change were assessed using adjusted linear mixed effects regression models with random intercepts for subjects nested within centers. Sensitivity analyses considered air pollution exposures.ResultsA 0.2-increase (average interquartile range) in NDVI in the 500 m buffer was consistently associated with a faster decline in FVC (−1.25 mL/year [95% confidence interval: −2.18 to −0.33]). These associations were especially pronounced in females and those living in areas with low PM10 levels. We found no consistent associations with FEV1 and the FEV1/FVC ratio. Residing near forests or urban green spaces was associated with a faster decline in FEV1, while agricultural land and forests were related to a greater decline in FVC.ConclusionsMore residential greenspace was not associated with better lung function in middle-aged European adults. Instead, we observed slight but consistent declin
Burney P, Knox-Brown B, Amaral A, 2023, Addressing the origins and health effects of small lungs – Authors' reply, The Lancet Respiratory Medicine, Vol: 11, Pages: e74-e74, ISSN: 2213-2600
Knox-Brown B, Sylvester K, Amaral A, 2023, The association of cardiorespiratory fitness with spirometric small airways obstruction, ERJ Open Research, Vol: 9, Pages: 1-4, ISSN: 2312-0541
Knox-Brown B, Patel J, Potts J, et al., 2023, The association of spirometric small airways obstruction with respiratory symptoms, cardiometabolic diseases, and quality of life: Results from the Burden of Obstructive Lung Disease (BOLD) study, Respiratory Research, Vol: 24, ISSN: 1465-9921
Background:Spirometric small airways obstruction (SAO) is common in the general population. Whether spirometric SAO is associated with respiratory symptoms, cardiometabolic diseases, and quality of life (QoL) is unknown.Methods:Using data from the Burden of Obstructive Lung Disease study (N = 21,594), we defined spirometric SAO as the mean forced expiratory flow rate between 25 and 75% of the FVC (FEF25-75) less than the lower limit of normal (LLN) or the forced expiratory volume in 3 s to FVC ratio (FEV3/FVC) less than the LLN. We analysed data on respiratory symptoms, cardiometabolic diseases, and QoL collected using standardised questionnaires. We assessed the associations with spirometric SAO using multivariable regression models, and pooled site estimates using random effects meta-analysis. We conducted identical analyses for isolated spirometric SAO (i.e. with FEV1/FVC ≥ LLN).Results:Almost a fifth of the participants had spirometric SAO (19% for FEF25-75; 17% for FEV3/FVC). Using FEF25-75, spirometric SAO was associated with dyspnoea (OR = 2.16, 95% CI 1.77–2.70), chronic cough (OR = 2.56, 95% CI 2.08–3.15), chronic phlegm (OR = 2.29, 95% CI 1.77–4.05), wheeze (OR = 2.87, 95% CI 2.50–3.40) and cardiovascular disease (OR = 1.30, 95% CI 1.11–1.52), but not hypertension or diabetes. Spirometric SAO was associated with worse physical and mental QoL. These associations were similar for FEV3/FVC. Isolated spirometric SAO (10% for FEF25-75; 6% for FEV3/FVC), was also associated with respiratory symptoms and cardiovascular disease.Conclusion:Spirometric SAO is associated with respiratory symptoms, cardiovascular disease, and QoL. Consideration should be given to the measurement of FEF25-75 and FEV3/FVC, in addition to traditional spirometry parameters.
Feary J, Quintero Santofimio V, Potts J, et al., 2023, Occupational exposures and small airways obstruction in the UK Biobank Cohort, ERJ Open Research, Vol: 9, Pages: 1-9, ISSN: 2312-0541
Background Small airways obstruction (SAO) is a key feature of both Chronic Obstructive Pulmonary Disease and asthma, which have been associated with workplace exposures. Whether SAO, which may occur early in the development of obstructive lung disease and without symptoms, also associates with occupational exposures is unknown.Methods Using UK Biobank data, we derived measurements of SAO from the 65,145 participants with high quality spirometry and lifetime occupational histories. The ALOHA+ Job Exposure Matrix was used to assign lifetime occupational exposures to each participant. The association between SAO and lifetime occupational exposures was evaluated using a logistic regression model adjusted for potential confounders. A second logistic regression model was run to also account for potential co-exposures.Results SAO was present in varying proportions of the population depending on definition used: 5.6% (FEF25–75<LLN)and 21.4% (FEV3/FEV6<LLN). After adjustment for confounders and co-exposures, people in the highest category of exposure to pesticides were significantly more likely to have SAO (FEV3/FEV6<LLN: OR 1.24, 95%CI 1.06–1.44). The association between pesticides and SAO showed an exposure-response pattern. SAO was also less likely among people in the highest exposure categories of aromatic solvents (FEV3/FEV6<LLN: OR 0.85, 95%CI 0.73–0.99) and metals (FEV3/FEV6<LLN: OR 0.77, 95%CI 0.62–0.94).Conclusion Our findings suggest that occupational exposure to pesticides play a role in the SAO. However, further work is needed to determine causality, and identify the specific component(s) responsible and the underlying mechanisms involved.
Burney P, Knox-Brown B, Amaral A, 2023, Small lung syndrome: the need to re-classify chronic lung disease, The Lancet Respiratory Medicine, Vol: 11, Pages: 405-406, ISSN: 2213-2600
Ratanachina J, Amaral A, De Matteis S, et al., 2023, Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study, European Respiratory Journal, Vol: 60, Pages: 1-16, ISSN: 0903-1936
Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study.We analysed cross-sectional data from 28,823 adults (≥40years) in 34 countries. Eleven occupations were considered and grouped by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, FEV1/FVC and FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income (GNI).Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20years were more likely to have chronic cough (OR=1.52, 95%CI 1.19-1.94), wheeze (OR=1.37, 95%CI 1.16-1.63), and dyspnoea (OR=1.83, 95%CI 1.53-2.20), but not lower FVC (β=0.02L, 95%CI -0.02L to 0.06L) or lower FEV1/FVC (β=0.04%, 95%CI -0.49% to 0.58%). Some findings differed by sex and GNI. In summary, at a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they associate with more respiratory symptoms. As not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.
Knox-Brown B, Patel J, Potts J, et al., 2023, Small airways obstruction and its risk factors in the Burden of Obstructive Lung Disease (BOLD) study: a multinational cross-sectional study, The Lancet Global Health, Vol: 11, Pages: e69-e82, ISSN: 2214-109X
Ahmed R, Osman N, Noory B, et al., 2022, Prevalence and determinants of chronic respiratory diseases in adults in Khartoum State, Sudan, International Journal of Tuberculosis and Lung Disease, ISSN: 1027-3719
Background:Chronic respiratory diseases are considered a significant cause of morbidity and mortality worldwide, although data from Africa are limited. This study aimed to determine the prevalence and determinants of chronic respiratory diseases in Khartoum, Sudan.Methods:Data was collected from 516 participants, aged ≥ 40, who had completed a questionnaire and undertook pre- and post-bronchodilator spirometry testing. Trained field workers conducted questionnaires and spirometry. Survey-weighted prevalence of respiratory symptoms and spirometric abnormalities were estimated. Regression analysis models were used to identify risk factors for chronic lung diseases.Results:Using the NHANESIII reference equations, the prevalence of Chronic Airflow Obstruction (CAO) was 10%. The main risk factor was older age 60-69 years (Odds ratio 3.16, 95% Confidence Interval 1.20 – 8.31). Lower education, high body mass index and a history of tuberculosis were also identified as significant risk factors. The prevalence of a low forced vital capacity (FVC) using NHANES III was 62.7% [SE 2.2] and 11.3% [SE 1.4] using locally derived values.Conclusion:The prevalence of spirometric abnormality mainly (low FVC); was high suggesting that chronic respiratory disease is of substantial public health importance in urban Sudan. Strategies for the prevention and control of these problems are needed.
Knox-Brown B, Amaral AF, Burney P, 2022, Concerns about PRISm., Lancet Respir Med, Vol: 10, Pages: e51-e52
Moitra S, Carsin A-E, Abramson M, et al., 2022, Long-term effect of asthma on the development of obesity among adults: an international cohort study, ECRHS, Thorax, ISSN: 0040-6376
Nafees AA, Muneer MZ, De Matteis S, et al., 2022, Impact of using different predictive equations on the prevalence of chronic byssinosis in textile workers in Pakistan, Occupational and Environmental Medicine, Vol: 79, Pages: 242-244, ISSN: 1351-0711
<jats:sec><jats:title>Objective</jats:title><jats:p>Byssinosis remains a significant problem among textile workers in low/middle-income countries. Here we share our experience of using different prediction equations for assessing ‘chronic’ byssinosis according to the standard WHO classification using measurements of forced expiratory volume in 1 s (FEV<jats:sub>1</jats:sub>).</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We enrolled 1910 workers in a randomised controlled trial of an intervention to improve the health of textile workers in Pakistan. We included in analyses the 1724 (90%) men who performed pre-bronchodilator spirometry tests of acceptable quality. We compared four different equations for deriving lung function percentage predicted values among those with symptoms-based byssinosis: the third US National Health and Nutrition Examination Survey (NHANES-III, with ‘North Indian and Pakistani’ conversion factor); the Global Lung Function Initiative (GLI, ‘other or mixed ethnicities’); a recent equation derived from survey of a western Indian population; and one based on an older and smaller survey of Karachi residents.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>58 men (3.4%) had symptoms-based byssinosis according to WHO criteria. Of these, the proportions with a reduced FEV<jats:sub>1</jats:sub> (<80% predicted) identified using NHANES and GLI; Indian and Pakistani reference equations were 40%, 41%, 14% and 12%, respectively. Much of this variation was eliminated when we substituted FEV<jats:sub>1</jats:sub>/forced vital capacity (FVC) ratio (<lower limit of normality) as a measure of airway obstruction.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>Accurate measures
Knox-Brown B, Mulhern O, Feary J, et al., 2022, Spirometry parameters used to define small airways obstruction in population-based studies: systematic review., Respir Res, Vol: 23
BACKGROUND: The assessment of small airways obstruction (SAO) using spirometry is practiced in population-based studies. However, it is not clear what are the most used parameters and cut-offs to define abnormal results. METHODS: We searched three databases (Medline, Web of Science, Google Scholar) for population-based studies, published by 1 May 2021, that used spirometry parameters to identify SAO and/or provided criteria for defining SAO. We systematically reviewed these studies and summarised evidence to determine the most widely used spirometry parameter and criteria for defining SAO. In addition, we extracted prevalence estimates and identified associated risk factors. To estimate a pooled prevalence of SAO, we conducted a meta-analysis and explored heterogeneity across studies using meta regression. RESULTS: Twenty-five studies used spirometry to identify SAO. The most widely utilised parameter (15 studies) was FEF25-75, either alone or in combination with other measurements. Ten studies provided criteria for the definition of SAO, of which percent predicted cut-offs were the most common (5 studies). However, there was no agreement on which cut-off value to use. Prevalence of SAO ranged from 7.5% to 45.9%. As a result of high heterogeneity across studies (I2 = 99.3%), explained by choice of spirometry parameter and WHO region, we do not present a pooled prevalence estimate. CONCLUSION: There is a lack of consensus regarding the best spirometry parameter or defining criteria for identification of SAO. The value of continuing to measure SAO using spirometry is unclear without further research using large longitudinal data. PROSPERO registration number CRD42021250206.
Amaral A, 2022, Prevalence of chronic airflow obstruction in sub-Saharan Africa, International Journal of Tuberculosis and Lung Disease, Vol: 26, Pages: 181-182, ISSN: 1027-3719
Kulbacka-Ortiz K, Triest FJJ, Franssen FME, et al., 2022, Restricted spirometry and cardiometabolic comorbidities: results from the international population based BOLD study., Respir Res, Vol: 23
BACKGROUND: Whether restricted spirometry, i.e. low Forced Vital Capacity (FVC), predicts chronic cardiometabolic disease is not definitely known. In this international population-based study, we assessed the relationship between restricted spirometry and cardiometabolic comorbidities. METHODS: A total of 23,623 subjects (47.5% males, 19.0% current smokers, age: 55.1 ± 10.8 years) from five continents (33 sites in 29 countries) participating in the Burden of Obstructive Lung Disease (BOLD) study were included. Restricted spirometry was defined as post-bronchodilator FVC < 5th percentile of reference values. Self-reports of physician-diagnosed cardiovascular disease (CVD; heart disease or stroke), hypertension, and diabetes were obtained through questionnaires. RESULTS: Overall 31.7% of participants had restricted spirometry. However, prevalence of restricted spirometry varied approximately ten-fold, and was lowest (8.5%) in Vancouver (Canada) and highest in Sri Lanka (81.3%). Crude odds ratios for the association with restricted spirometry were 1.60 (95% CI 1.37-1.86) for CVD, 1.53 (95% CI 1.40-1.66) for hypertension, and 1.98 (95% CI 1.71-2.29) for diabetes. After adjustment for age, sex, education, Body Mass Index (BMI) and smoking, the odds ratios were 1.54 (95% CI 1.33-1.79) for CVD, 1.50 (95% CI 1.39-1.63) for hypertension, and 1.86 (95% CI 1.59-2.17) for diabetes. CONCLUSION: In this population-based, international, multi-site study, restricted spirometry associates with cardiometabolic diseases. The magnitude of these associations appears unattenuated when cardiometabolic risk factors are taken into account.
Wielscher M, Amaral AFS, van der Plaat D, et al., 2021, Genetic correlation and causal relationships between cardio-metabolic traits and lung function impairment, Genome Medicine, Vol: 13
<jats:title>Abstract</jats:title><jats:sec> <jats:title>Background</jats:title> <jats:p>Associations of low lung function with features of poor cardio-metabolic health have been reported. It is, however, unclear whether these co-morbidities reflect causal associations, shared genetic heritability or are confounded by environmental factors.</jats:p> </jats:sec><jats:sec> <jats:title>Methods</jats:title> <jats:p>We performed three analyses: (1) cardio-metabolic health to lung function association tests in Northern Finland Birth cohort 1966, (2) cross-trait linkage disequilibrium score regression (LDSC) to compare genetic backgrounds and (3) Mendelian randomisation (MR) analysis to assess the causal effect of cardio-metabolic traits and disease on lung function, and vice versa (bidirectional MR). Genetic associations were obtained from the UK Biobank data or published large-scale genome-wide association studies (<jats:italic>N</jats:italic> > 82,000).</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>We observed a negative genetic correlation between lung function and cardio-metabolic traits and diseases. In Mendelian Randomisation analysis (MR), we found associations between type 2 diabetes (T2D) instruments and forced vital capacity (FVC) as well as FEV1/FVC. Body mass index (BMI) instruments were associated to all lung function traits and C-reactive protein (CRP) instruments to FVC. These genetic associations provide evidence for a causal effect of cardio-metabolic traits on lung function. Multivariable MR suggested independence of these causal effects from other tested cardio-metabolic traits and diseases. Analysis of lung function specific SNPs revealed a potential causal effect of FEV1/FVC on blood pres
Amaral A, Burney P, Patel J, et al., 2021, Chronic airflow obstruction and ambient particulate air pollution, Thorax, Vol: 76, Pages: 1236-1241, ISSN: 0040-6376
Smoking is the most well-established cause of chronic airflow obstruction (CAO) but particulate air pollution and poverty have also been implicated. We regressed sex-specific prevalence of CAO from 41 Burden of Obstructive Lung Disease study sites against smoking prevalence from the same study, the gross national income per capita and the local annual mean level of ambient particulate matter (PM2.5) using negative binomial regression. The prevalence of CAO was not independently associated with PM2.5 but was strongly associated with smoking and was also associated with poverty. Strengthening tobacco control and improved understanding of the link between CAO and poverty should be prioritised.
Knox-Brown B, Mulhern O, Amaral A, 2021, Spirometry parameters used to define small airways obstruction in population-based studies: Systematic review protocol, BMJ Open, Vol: 11, ISSN: 2044-6055
Introduction: In recent years, there has been increasing interest in the use of spirometry for the assessment of small airways obstruction (SAO) driven by the idea that these changes occur prior to development of established obstructive lung disease. Maximal mid-expiratory and distal flow rates have been widely used despite a lack of agreement regarding parameter selection or definition of an abnormal result. We aim to provide evidence from population-based studies, describing the different parameters, definitions of normal range and the resulting impact on prevalence estimates for SAO. Summarising this evidence is important to inform development of future studies in this area.Methods and analysis: A systematic review of population-based studies will be conducted. MEDLINE, Web of Science and Google Scholar will be searched from database inception to May 2021. Primary outcomes will include the spirometry parameter used to define SAO, and the definition of an abnormal result. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be followed for study selection. Study methods will be assessed using the Newcastle-Ottawa scale and the Grading of Recommendations Assessment, Development and Evaluation working group methodology. Narrative synthesis will be conducted for all included studies. Meta-analysis will also be conducted for prevalence estimates and associated risk factors where data quality and availability allow. Random effects models will be used to conduct the meta-analysis and I2 statistics will be used to assess heterogeneity across studies. Where appropriate subgroup analysis will be conducted to explore heterogeneity.Ethics and dissemination: There is no requirement for ethical approval for this project. Findings will be disseminated via peer-reviewed publications and other formats, for example, conferences, congresses or symposia.
Migliori GB, Marx FM, Ambrosino N, et al., 2021, Clinical standards for the assessment, management, and rehabilitation of post-TB lung disease, International Journal of Tuberculosis and Lung Disease, Vol: 25, Pages: 797-813, ISSN: 1027-3719
BACKGROUND: Increasing evidence suggests that post-TB lung disease (PTLD) causes significant morbidity and mortality. The aim of these clinical standards is to provide guidance on the assessment and management of PTLD and the implementation of pulmonary rehabilitation (PR).METHODS: A panel of global experts in the field of TB care and PR was identified; 62 participated in a Delphi process. A 5-point Likert scale was used to score the initial ideas for standards and after several rounds of revision the document was approved (with 100% agreement).RESULTS: Five clinical standards were defined: Standard 1, to assess patients at the end of TB treatment for PTLD (with adaptation for children and specific settings/situations); Standard 2, to identify patients with PTLD for PR; Standard 3, tailoring the PR programme to patient needs and the local setting; Standard 4, to evaluate the effectiveness of PR; and Standard 5, to conduct education and counselling. Standard 6 addresses public health aspects of PTLD and outcomes due to PR.CONCLUSION: This is the first consensus-based set of Clinical Standards for PTLD. Our aim is to improve patient care and quality of life by guiding clinicians, programme managers and public health officers in planning and implementing adequate measures to assess and manage PTLD.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.