RESUMEN
BACKGROUND: Observational studies suggest that total testosterone (TT) and sex hormone-binding globulin (SHBG) may have beneficial effects on lung function, but these findings might be spurious due to confounding and reverse causation. We addressed these limitations by using multivariable Mendelian randomisation (MVMR) to investigate the independent causal effects of TT and SHBG on lung function. METHODS: We first identified genetic instruments by performing genome-wide association analyses of TT and SHBG in the large UK Biobank, separately in males and females. We then assessed the independent effects of TT and SHBG on forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC using one-sample MVMR. We addressed pleiotropy, which could bias MVMR, using several methods that account for it. We performed subgroup MVMR analyses by obesity, physical activity and menopausal status, and assessed associations between TT and SHBG with lung function decline. Finally, we compared the MVMR results with those of observational analyses in the UK Biobank. FINDINGS: In the MVMR analyses, there was evidence of pleiotropy, but results were consistent when accounting for it. We found a strong beneficial effect of TT on FVC and FEV1 in both males and females, but a moderate detrimental effect of SHBG on FEV1 and FEV1/FVC in males only. Subgroup analyses suggested stronger effects of TT among obese and older males. The observational analyses, in line with previous studies, agreed with MRMV for TT, but not for SHBG. INTERPRETATION: These findings suggest that testosterone improves lung function in males and females, while SHBG has an opposite independent effect in males.
Asunto(s)
Estudio de Asociación del Genoma Completo , Análisis de la Aleatorización Mendeliana , Globulina de Unión a Hormona Sexual , Testosterona , Humanos , Masculino , Globulina de Unión a Hormona Sexual/análisis , Globulina de Unión a Hormona Sexual/metabolismo , Femenino , Testosterona/sangre , Capacidad Vital , Volumen Espiratorio Forzado , Persona de Mediana Edad , Reino Unido , Pulmón/fisiopatología , Pruebas de Función Respiratoria , Anciano , ObesidadRESUMEN
BACKGROUND: A usual interstitial pneumonia (UIP) pattern of lung injury is a key feature of idiopathic pulmonary fibrosis (IPF) and is also observed in up to 40% of individuals with rheumatoid arthritis (RA)-associated interstitial lung disease (RA-ILD). The RA-UIP phenotype could result from either a causal relationship of RA on UIP or vice versa, or from a simple co-occurrence of RA and IPF due to shared demographic, genetic or environmental risk factors. METHODS: We used two-sample bidirectional Mendelian randomisation (MR) to test the hypothesis of a causal effect of RA on UIP and of UIP on RA, using variants from genome-wide association studies (GWAS) of RA (separately for seropositive (18 019 cases and 991 604 controls) and seronegative (8515 cases and 1 015 471 controls) RA) and of IPF (4125 cases and 20 464 controls) as genetic instruments. Sensitivity analyses were conducted to assess the robustness of the results to violations of the MR assumptions. FINDINGS: IPF showed a significant causal effect on seropositive RA, with developing IPF increasing the risk of seropositive RA (OR=1.06, 95% CI: 1.04 to 1.08, p<0.001) which was robust under all models. For the MR in the other direction, seropositive RA showed a significant protective effect on IPF (OR=0.93; 95% CI: 0.87 to 0.99; p=0.032), but the effect was not significant when sensitivity analyses were applied. This was likely because of bias due to exclusion of patients with RA from among the cases in the IPF GWAS, or possibly because our genetic instruments did not fully capture the effect of the complex human leucocyte antigen region, the strongest RA genetic risk factor. INTERPRETATION: Our findings support the hypothesis that RA-UIP may be due to a cause-effect relationship between UIP and RA, rather than due to a coincidental occurrence of IPF in patients with RA. The significant causal effect of IPF on seropositive RA suggests that pathomechanisms involved in the development of UIP may promote RA, and this may help inform future guidelines on screening for ILD in patients with RA.
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Artritis Reumatoide , Estudio de Asociación del Genoma Completo , Fibrosis Pulmonar Idiopática , Análisis de la Aleatorización Mendeliana , Humanos , Artritis Reumatoide/genética , Artritis Reumatoide/complicaciones , Fibrosis Pulmonar Idiopática/genética , Factores de Riesgo , Masculino , Femenino , Predisposición Genética a la EnfermedadRESUMEN
BACKGROUND: We determined the effectiveness of an intervention to reduce cotton dust-related respiratory symptoms and improve lung function of textile workers. METHODS: We undertook a cluster randomised controlled trial at 38 textile mills in Karachi, Pakistan. The intervention comprised: training in occupational health for workers and managers, formation of workplace committees to promote a health and safety plan that included wet mopping and safe disposal of cotton dust, provision of simple face masks, and further publicity about the risks from cotton dust. Participating mills were randomised following baseline data collection. The impact of the intervention was measured through surveys at 3, 12 and 18â months using questionnaires, spirometry and dust measurements. The primary outcomes were 1) changes in prevalence of a composite respiratory symptom variable, 2) changes in post-bronchodilator percentage predicted forced expiratory volume in 1â s (FEV1) and 3) changes in cotton dust levels. These were assessed using two-level mixed effects linear and logistic regression. RESULTS: Of 2031 participants recruited at baseline, 807 (40%) were available at the third follow-up. At that point, workers in the intervention arm were more likely to report an improvement in respiratory symptoms (OR 1.58, 95% CI 1.06-2.36) and lung function (FEV1 % pred: ß 1.31%, 95% CI 0.04-2.57%). Personal dust levels decreased, more so in intervention mills, although we did not observe this in adjusted models due to the small number of samples. CONCLUSION: We found the intervention to be effective in improving the respiratory health of textile workers and recommend scaling-up of such simple and feasible interventions in low- and middle-income countries.
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Enfermedades Pulmonares , Exposición Profesional , Humanos , Polvo , Exposición Profesional/prevención & control , Textiles , Volumen Espiratorio ForzadoRESUMEN
BACKGROUND: Previous studies have reported an association between warm temperature and asthma hospitalisation. They have reported different sex-related and age-related vulnerabilities; nevertheless, little is known about how this effect has changed over time and how it varies in space. This study aims to evaluate the association between asthma hospitalisation and warm temperature and investigate vulnerabilities by age, sex, time and space. METHODS: We retrieved individual-level data on summer asthma hospitalisation at high temporal (daily) and spatial (postcodes) resolutions during 2002-2019 in England from the NHS Digital. Daily mean temperature at 1 km×1 km resolution was retrieved from the UK Met Office. We focused on lag 0-3 days. We employed a case-crossover study design and fitted Bayesian hierarchical Poisson models accounting for possible confounders (rainfall, relative humidity, wind speed and national holidays). RESULTS: After accounting for confounding, we found an increase of 1.11% (95% credible interval: 0.88% to 1.34%) in the asthma hospitalisation risk for every 1°C increase in the ambient summer temperature. The effect was highest for males aged 16-64 (2.10%, 1.59% to 2.61%) and during the early years of our analysis. We also found evidence of a decreasing linear trend of the effect over time. Populations in Yorkshire and the Humber and East and West Midlands were the most vulnerable. CONCLUSION: This study provides evidence of an association between warm temperature and hospital admission for asthma. The effect has decreased over time with potential explanations including temporal differences in patterns of heat exposure, adaptive mechanisms, asthma management, lifestyle, comorbidities and occupation.
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Asma , Calor , Humanos , Masculino , Asma/epidemiología , Teorema de Bayes , Estudios Cruzados , Inglaterra/epidemiología , HospitalizaciónRESUMEN
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-income and middle-income countries.
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Enfermedad Pulmonar Obstructiva Crónica , Humanos , Estudios Transversales , Factores de Riesgo , Capacidad Vital , Volumen Espiratorio Forzado , Espirometría , Pulmón , PobrezaRESUMEN
BACKGROUND: Observational studies suggest asthma is a risk factor for coronary heart disease (CHD) and sex modifies the risk, but they may suffer from methodological limitations. To overcome these, we applied a "triangulation approach", where different methodologies, with different potential biases, were leveraged to enhance confidence in findings. METHODS: First, we conducted an observational study using UK medical records to match asthma patients 1:1, by age, sex and general practitioner (GP) practice, to the general population. We measured the association between asthma and incident CHD (myocardial infarction: hospitalisation/death) by applying minimal sufficient adjustment: model 1, smoking, body mass index, oral corticosteroids, atopy and deprivation; model 2, additionally adjusting for healthcare behaviour (GP consultation frequency). Second, we conducted a Mendelian randomisation (MR) study using data from the UK Biobank, Trans-National Asthma Genetic Consortium (TAGC) and Coronary Artery Disease Genome-wide Replication and Meta-analysis consortium (CARDIoGRAM). Using 64 asthma single nucleotide polymorphisms, the effect of asthma on CHD was estimated with inverse variance-weighted meta-analysis and methods that adjust for pleiotropy. RESULTS: In our observational study (n=1 522 910), we found asthma was associated with 6% increased risk of CHD (model 1: HR 1.06, 95% CI 1.01-1.13); after accounting for healthcare behaviour, we found no association (model 2: HR 0.99, 95% CI 0.94-1.05). Asthma severity did not modify the association, but sex did (females: HR 1.11, 95% CI 1.01-1.21; males: HR 0.91, 95% CI 0.84-0.98). Our MR study (n=589 875) found no association between asthma and CHD (OR 1.01, 95% CI 0.98-1.04) and no modification by sex. CONCLUSIONS: Our findings suggest that asthma is not a risk factor for CHD. Previous studies may have suffered from detection bias or residual confounding.
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Asma , Enfermedad de la Arteria Coronaria , Infarto del Miocardio , Femenino , Humanos , Masculino , Análisis de Varianza , Asma/complicaciones , Asma/epidemiología , Asma/genética , Estudio de Asociación del Genoma Completo , Infarto del Miocardio/epidemiología , Polimorfismo de Nucleótido Simple , Factores de Riesgo , Análisis de la Aleatorización MendelianaRESUMEN
BACKGROUND: Gastro-oesophageal reflux disease (GORD) is associated with idiopathic pulmonary fibrosis (IPF) in observational studies. It is not known if this association arises because GORD causes IPF or because IPF causes GORD, or because of confounding by factors, such as smoking, associated with both GORD and IPF. We used bidirectional Mendelian randomisation (MR), where genetic variants are used as instrumental variables to address issues of confounding and reverse causation, to examine how, if at all, GORD and IPF are causally related. METHODS: A bidirectional two-sample MR was performed to estimate the causal effect of GORD on IPF risk and of IPF on GORD risk, using genetic data from the largest GORD (78 707 cases and 288 734 controls) and IPF (4125 cases and 20 464 controls) genome-wide association meta-analyses currently available. RESULTS: GORD increased the risk of IPF, with an OR of 1.6 (95% CI 1.04-2.49; p=0.032). There was no evidence of a causal effect of IPF on the risk of GORD, with an OR of 0.999 (95% CI 0.997-1.000; p=0.245). CONCLUSIONS: We found that GORD increases the risk of IPF, but found no evidence that IPF increases the risk of GORD. GORD should be considered in future studies of IPF risk and interest in it as a potential therapeutic target should be renewed. The mechanisms underlying the effect of GORD on IPF should also be investigated.
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Reflujo Gastroesofágico , Fibrosis Pulmonar Idiopática , Humanos , Reflujo Gastroesofágico/complicaciones , Reflujo Gastroesofágico/genética , Reflujo Gastroesofágico/tratamiento farmacológico , Estudio de Asociación del Genoma Completo , Fibrosis Pulmonar Idiopática/genética , Fibrosis Pulmonar Idiopática/complicacionesRESUMEN
BACKGROUND: Asbestos has been hypothesised as the cause of the recent global increase in the incidence of 'idiopathic' pulmonary fibrosis (IPF). Establishing this has important diagnostic and therapeutic implications. The association between occupational asbestos exposure and IPF, and interaction with a common (minor allele frequency of 9% in European populations) genetic variant associated with IPF, MUC5B rs35705950, is unknown. METHODS: Multicentre, incident case-control study. Cases (n=494) were men diagnosed with IPF at 21 UK hospitals. Controls (n=466) were age-matched men who attended a hospital clinic in the same period. Asbestos exposure was assessed at interview using a validated job exposure matrix and a source-receptor model. The primary outcome was the association between asbestos exposure and IPF, estimated using logistic regression adjusted for age, smoking and centre. Interaction with MUC5B rs35705950 was investigated using a genetic dominant model. RESULTS: 327 (66%) cases and 293 (63%) controls ever had a high or medium asbestos exposure risk job; 8% of both cases and controls had cumulative exposure estimates ≥25 fibre ml⻹ years. Occupational asbestos exposure was not associated with IPF, adjusted OR 1.1 (95% CI 0.8 to 1.4; p=0.6) and there was no gene-environment interaction (p=0.3). Ever smoking was associated with IPF, OR 1.4 (95% CI 1 to 1.9; p=0.04) and interacted with occupational asbestos exposure, OR 1.9 (95% CI 1 to 3.6; p=0.04). In a further non-specified analysis, when stratifying for genotype there was significant interaction between smoking and work in an exposed job (p<0.01) for carriers of the minor allele of MUC5B rs35705950. CONCLUSION: Occupational asbestos exposure alone, or through interaction with MUC5B rs35705950 genotype, was not associated with IPF. Exposure to asbestos and smoking interact to increase IPF risk in carriers of a common genetic variant, the minor allele of MUC5B rs35705950. TRIAL REGISTRATION NUMBER: NCT03211507.
Asunto(s)
Amianto , Fibrosis Pulmonar Idiopática , Exposición Profesional , Masculino , Humanos , Femenino , Estudios de Casos y Controles , Fibrosis Pulmonar Idiopática/etiología , Fibrosis Pulmonar Idiopática/genética , Genotipo , Exposición Profesional/efectos adversos , Amianto/efectos adversosRESUMEN
BACKGROUND: There is emerging evidence suggesting a link between ambient heat exposure and chronic obstructive pulmonary disease (COPD) hospitalisations. Individual and contextual characteristics can affect population vulnerabilities to COPD hospitalisation due to heat exposure. This study quantifies the effect of ambient heat on COPD hospitalisations and examines population vulnerabilities by age, sex and contextual characteristics. METHODS: Individual data on COPD hospitalisation at high geographical resolution (postcodes) during 2007-2018 in England was retrieved from the small area health statistics unit. Maximum temperature at 1 km ×1 km resolution was available from the UK Met Office. We employed a case-crossover study design and fitted Bayesian conditional Poisson regression models. We adjusted for relative humidity and national holidays, and examined effect modification by age, sex, green space, average temperature, deprivation and urbanicity. RESULTS: After accounting for confounding, we found 1.47% (95% Credible Interval (CrI) 1.19% to 1.73%) increase in the hospitalisation risk for every 1°C increase in temperatures above 23.2°C (lags 0-2 days). We reported weak evidence of an effect modification by sex and age. We found a strong spatial determinant of the COPD hospitalisation risk due to heat exposure, which was alleviated when we accounted for contextual characteristics. 1851 (95% CrI 1 576 to 2 079) COPD hospitalisations were associated with temperatures above 23.2°C annually. CONCLUSION: Our study suggests that resources should be allocated to support the public health systems, for instance, through developing or expanding heat-health alerts, to challenge the increasing future heat-related COPD hospitalisation burden.
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Calor , Enfermedad Pulmonar Obstructiva Crónica , Teorema de Bayes , Estudios Cruzados , Hospitalización , Humanos , Enfermedad Pulmonar Obstructiva Crónica/epidemiologíaRESUMEN
Rationale: The Global Burden of Disease program identified smoking and ambient and household air pollution as the main drivers of death and disability from chronic obstructive pulmonary disease (COPD). Objectives: To estimate the attributable risk of chronic airflow obstruction (CAO), a quantifiable characteristic of COPD, due to several risk factors. Methods: The Burden of Obstructive Lung Disease study is a cross-sectional study of adults, aged ≥40, in a globally distributed sample of 41 urban and rural sites. Based on data from 28,459 participants, we estimated the prevalence of CAO, defined as a postbronchodilator FEV1-to-FVC ratio less than the lower limit of normal, and the relative risks associated with different risk factors. Local relative risks were estimated using a Bayesian hierarchical model borrowing information from across sites. From these relative risks and the prevalence of risk factors, we estimated local population attributable risks. Measurements and Main Results: The mean prevalence of CAO was 11.2% in men and 8.6% in women. The mean population attributable risk for smoking was 5.1% in men and 2.2% in women. The next most influential risk factors were poor education levels, working in a dusty job for ≥10 years, low body mass index, and a history of tuberculosis. The risk of CAO attributable to the different risk factors varied across sites. Conclusions: Although smoking remains the most important risk factor for CAO, in some areas, poor education, low body mass index, and passive smoking are of greater importance. Dusty occupations and tuberculosis are important risk factors at some sites.
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Enfermedad Pulmonar Obstructiva Crónica , Adulto , Teorema de Bayes , Estudios Transversales , Femenino , Volumen Espiratorio Forzado , Humanos , Masculino , Prevalencia , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Factores de Riesgo , Fumar/efectos adversos , Fumar/epidemiología , EspirometríaRESUMEN
BACKGROUND: Distinguishing between mortality attributed to respiratory causes and other causes among people with asthma, COPD, and asthma-COPD overlap (ACO) is important. This study used electronic health records in England to estimate excess risk of death from respiratory-related causes after accounting for other causes of death. METHODS: We used linked Clinical Practice Research Datalink (CPRD) primary care and Office for National Statistics mortality data to identify adults with asthma and COPD from 2005 to 2015. Causes of death were ascertained using death certificates. Hazard ratios (HR) and excess risk of death were estimated using Fine-Gray competing risk models and adjusting for age, sex, smoking status, body mass index and socioeconomic status. RESULTS: 65,021 people with asthma and 45,649 with COPD in the CPRD dataset were frequency matched 5:1 with people without the disease on age, sex and general practice. Only 14 in 100,000 people with asthma are predicted to experience a respiratory-related death up to 10 years post-diagnosis, whereas in COPD this is 98 in 100,000. Asthma is associated with an 0.01% excess incidence of respiratory related mortality whereas COPD is associated with an 0.07% excess. Among people with asthma-COPD overlap (N = 22,145) we observed an increased risk of respiratory-related death compared to those with asthma alone (HR = 1.30; 95% CI 1.21-1.40) but not COPD alone (HR = 0.89; 95% CI 0.83-0.94). CONCLUSIONS: Asthma and COPD are associated with an increased risk of respiratory-related death after accounting for other causes; however, diagnosis of COPD carries a much higher probability. ACO is associated with a lower risk compared to COPD alone but higher risk compared to asthma alone.
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Asma/complicaciones , Asma/mortalidad , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/mortalidad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Causas de Muerte , Estudios de Cohortes , Inglaterra/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Respiratorias/mortalidad , Medición de Riesgo , Factores de Riesgo , Adulto JovenRESUMEN
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.
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Contaminantes Atmosféricos , Contaminación del Aire , Enfermedad Pulmonar Obstructiva Crónica , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/análisis , Contaminación del Aire/estadística & datos numéricos , Polvo , Exposición a Riesgos Ambientales/análisis , Exposición a Riesgos Ambientales/estadística & datos numéricos , Femenino , Humanos , Masculino , Material Particulado/análisis , Material Particulado/toxicidad , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Enfermedad Pulmonar Obstructiva Crónica/etiologíaRESUMEN
Rationale: Poor lung health in adult life may occur partly through suboptimal growth and development, as suggested by epidemiological evidence pointing to early life risk factors.Objectives: To systematically investigate the effects of lung development genes on adult lung function.Methods: Using UK Biobank data, we tested the association of 391 genes known to influence lung development with FVC and FEV1/FVC. We split the dataset into two random subsets of 207,616 and 138,411 individuals, using the larger subset to select the most promising signals and the smaller subset for replication.Measurements and Main Results: We identified 55 genes, of which 36 (16 for FVC, 19 for FEV1/FVC, and one for both) had not been identified in the largest, most recent genome-wide study of lung function. Most of these 36 signals were intronic variants; expression data from blood and lung tissue showed that the majority affect the expression of the genes they lie within. Further testing of 34 of these 36 signals in the CHARGE and SpiroMeta consortia showed that 16 replicated after Bonferroni correction and another 12 replicated at nominal significance level. Of the 55 genes, 53 fell into four biological categories whose function is to regulate organ size and cell integrity (growth factors; transcriptional regulators; cell-to-cell adhesion; extracellular matrix), suggesting that these specific processes are important for adult lung health.Conclusions: Our study demonstrates the importance of lung development genes in regulating adult lung function and influencing both restrictive and obstructive patterns. Further investigation of these developmental pathways could lead to druggable targets.
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Biología Evolutiva , Predisposición Genética a la Enfermedad , Crecimiento y Desarrollo/genética , Pulmón/crecimiento & desarrollo , Fenómenos Fisiológicos Respiratorios/genética , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Pruebas de Función Respiratoria , Factores de Riesgo , Reino UnidoRESUMEN
BACKGROUND: Post-traumatic cerebral infarction (PTCI) is common after traumatic brain injury (TBI). It is unclear what the occurrence of a PTCI is, how it impacts the long-term outcome, and whether it adds incremental prognostic value to established outcome predictors. METHODS: This was a prospective multicenter cohort study of moderate and severe TBI patients. The primary objective was to evaluate if PTCI was an independent risk factor for the 6-month outcome assessed with the Glasgow Outcome Scale (GOS). We also assessed the PTCI occurrence and if it adds incremental value to the International Mission for Prognosis and Clinical Trial design in TBI (IMPACT) core and extended models. RESULTS: We enrolled 143 patients, of whom 47 (32.9%) developed a PTCI. In the multiple ordered logistic regression, PTCI was retained in both the core and extended IMPACT models as an independent predictor of the GOS. The predictive performances increased significantly when PTCI was added to the IMPACT core model (AUC = 0.73, 95% C.I. 0.66-0.82; increased to AUC = 0.79, 95% CI 0.71-0.83, p = 0.0007) and extended model (AUC = 0.74, 95% C.I. 0.65-0.81 increased to AUC = 0.80, 95% C.I. 0.69-0.85; p = 0.00008). Patients with PTCI showed higher ICU mortality and 6-month mortality, whereas hospital mortality did not differ between the two groups. CONCLUSIONS: PTCI is a common complication in patients suffering from a moderate or severe TBI and is an independent risk factor for long-term disability. The addition of PTCI to the IMPACT core and extended predictive models significantly increased their performance in predicting the GOS. TRIAL REGISTRATION: The present study was registered in ClinicalTrial.gov with the ID number NCT02430324.
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Lesiones Traumáticas del Encéfalo/complicaciones , Infarto Cerebral/etiología , Evaluación de Resultado en la Atención de Salud/normas , Adulto , Área Bajo la Curva , Lesiones Traumáticas del Encéfalo/epidemiología , Infarto Cerebral/epidemiología , Estudios de Cohortes , Femenino , Escala de Consecuencias de Glasgow/estadística & datos numéricos , Humanos , Italia/epidemiología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Estudios Prospectivos , Curva ROC , Estadísticas no ParamétricasRESUMEN
BACKGROUND: Low lung function has been associated with increased body mass index (BMI). The aim of this study was to investigate whether the effect of BMI on lung function is mediated by DNA methylation. METHODS: We used individual data from 285,495 participants in four population-based cohorts: the European Community Respiratory Health Survey, the Northern Finland Birth Cohort 1966, the Swiss Study on Air Pollution and Lung Disease in Adults, and the UK Biobank. We carried out Mendelian randomisation (MR) analyses in two steps using a two-sample approach with SNPs as instrumental variables (IVs) in each step. In step 1 MR, we estimated the causal effect of BMI on peripheral blood DNA methylation (measured at genome-wide level) using 95 BMI-associated SNPs as IVs. In step 2 MR, we estimated the causal effect of DNA methylation on FEV1, FVC, and FEV1/FVC using two SNPs acting as methQTLs occurring close (in cis) to CpGs identified in the first step. These analyses were conducted after exclusion of weak IVs (F statistic < 10) and MR estimates were derived using the Wald ratio, with standard error from the delta method. Individuals whose data were used in step 1 were not included in step 2. RESULTS: In step 1, we found that BMI might have a small causal effect on DNA methylation levels (less than 1% change in methylation per 1 kg/m2 increase in BMI) at two CpGs (cg09046979 and cg12580248). In step 2, we found no evidence of a causal effect of DNA methylation at cg09046979 on lung function. We could not estimate the causal effect of DNA methylation at cg12580248 on lung function as we could not find publicly available data on the association of this CpG with SNPs. CONCLUSIONS: To our knowledge, this is the first paper to report the use of a two-step MR approach to assess the role of DNA methylation in mediating the effect of a non-genetic factor on lung function. Our findings do not support a mediating effect of DNA methylation in the association of lung function with BMI.
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Índice de Masa Corporal , Metilación de ADN , Pulmón/fisiología , Análisis de la Aleatorización Mendeliana/métodos , Anciano , Islas de CpG , Estudios Transversales , Femenino , Finlandia , Volumen Espiratorio Forzado , Estudio de Asociación del Genoma Completo , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
In observational studies, early menopause is associated with lower forced vital capacity (FVC) and a higher risk of spirometric restriction, but not airflow obstruction. It is, however, unclear if this association is causal. We therefore used a Mendelian randomisation (MR) approach, which is not affected by classical confounding, to assess the effect of age at natural menopause on lung function.We included 94â742 naturally post-menopausal women from the UK Biobank and performed MR analyses on the effect of age at menopause on forced expiratory volume in 1â
s (FEV1), FVC, FEV1/FVC, spirometric restriction (FVCAsunto(s)
Pulmón/fisiopatología
, Menopausia Prematura/genética
, Anciano
, Femenino
, Volumen Espiratorio Forzado
, Humanos
, Análisis de la Aleatorización Mendeliana
, Menopausia/genética
, Persona de Mediana Edad
, Polimorfismo de Nucleótido Simple
, Factores Protectores
, Enfermedad Pulmonar Obstructiva Crónica/epidemiología
, Enfermedad Pulmonar Obstructiva Crónica/fisiopatología
, Capacidad Vital
RESUMEN
BACKGROUND: There is uncertainty about the clinical usefulness of currently available asthma predictive tools. Validation of predictive tools in different populations and clinical settings is an essential requirement for the assessment of their predictive performance, reproducibility and generalizability. We aimed to critically appraise asthma predictive tools which have been validated in external studies. METHODS: We searched MEDLINE and EMBASE (1946-2017) for all available childhood asthma prediction models and focused on externally validated predictive tools alongside the studies in which they were originally developed. We excluded non-English and non-original studies. PROSPERO registration number is CRD42016035727. RESULTS: From 946 screened papers, eight were included in the review. Statistical approaches for creation of prediction tools included chi-square tests, logistic regression models and the least absolute shrinkage and selection operator. Predictive models were developed and validated in general and high-risk populations. Only three prediction tools were externally validated: the Asthma Predictive Index, the PIAMA and the Leicester asthma prediction tool. A variety of predictors has been tested, but no studies examined the same combination. There was heterogeneity in definition of the primary outcome among development and validation studies, and no objective measurements were used for asthma diagnosis. The performance of tools varied at different ages of outcome assessment. We observed a discrepancy between the development and validation studies in the tools' predictive performance in terms of sensitivity and positive predictive values. CONCLUSIONS: Validated asthma predictive tools, reviewed in this paper, provided poor predictive accuracy with performance variation in sensitivity and positive predictive value.
Asunto(s)
Asma/diagnóstico , Toma de Decisiones Clínicas/métodos , Niño , Manejo de la Enfermedad , Humanos , Funciones de Verosimilitud , Modelos Estadísticos , Evaluación del Resultado de la Atención al Paciente , Pronóstico , Sesgo de Publicación , Reproducibilidad de los Resultados , Factores de Riesgo , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Asthma, a heterogeneous disease with variable age of onset, results from the interplay between genetic and environmental factors. Early-life tobacco smoke (ELTS) exposure is a major asthma risk factor. Only a few genetic loci have been reported to interact with ELTS exposure in asthma. OBJECTIVE: Our aim was to identify new loci interacting with ELTS exposure on time-to-asthma onset (TAO) in childhood. METHODS: We conducted genome-wide interaction analyses of ELTS exposure on time-to-asthma onset in childhood in five European-ancestry studies (totalling 8273 subjects) using Cox proportional-hazard model. The results of all five genome-wide analyses were meta-analysed. RESULTS: The 13q21 locus showed genome-wide significant interaction with ELTS exposure (P = 4.3 × 10-8 for rs7334050 within KLHL1 with consistent results across the five studies). Suggestive interactions (P < 5 × 10-6 ) were found at three other loci: 20p12 (rs13037508 within MACROD2; P = 4.9 × 10-7 ), 14q22 (rs7493885 near NIN; P = 2.9 × 10-6 ) and 2p22 (rs232542 near CYP1B1; P = 4.1 × 10-6 ). Functional annotations and the literature showed that the lead SNPs at these four loci influence DNA methylation in the blood and are located nearby CpG sites reported to be associated with exposure to tobacco smoke components, which strongly support our findings. CONCLUSIONS AND CLINICAL RELEVANCE: We identified novel candidate genes interacting with ELTS exposure on time-to-asthma onset in childhood. These genes have plausible biological relevance related to tobacco smoke exposure. Further epigenetic and functional studies are needed to confirm these findings and to shed light on the underlying mechanisms.
Asunto(s)
Asma/genética , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple , Contaminación por Humo de Tabaco/efectos adversos , Niño , Citocromo P-450 CYP1B1/genética , Proteínas del Citoesqueleto/genética , Enzimas Reparadoras del ADN/genética , Femenino , Estudio de Asociación del Genoma Completo , Humanos , Hidrolasas/genética , Masculino , Proteínas de Microfilamentos/genética , Proteínas Nucleares/genéticaRESUMEN
OBJECTIVES: We aimed to investigate whether there has been a geographic shift in the distribution of mesothelioma deaths in Great Britain given the decline of shipbuilding and progressive exposure regulation. METHODS: We calculated age-adjusted mesothelioma mortality rates and estimated rate ratios for areas with and without a dockyard. We compared spatial autocorrelation statistics (Moran's I) for age-adjusted rates at local authority district level for 2002-2008 and 2009-2015. We measured the mean distance of the deceased's postcode to the nearest dockyard at district level and calculated the association of average distance to dockyard and district mesothelioma mortality using simple linear regression for men, for 2002-2008 and 2009-2015. RESULTS: District age-adjusted male mortality rates fell during 2002-2015 for 80 of 348 districts (23%), rose for 267 (77%) and were unchanged for one district; having one or more dockyards in a district was associated with rates falling (OR=2.43, 95% CI 1.22 to 4.82, p=0.02). The mortality rate ratio for men in districts with a dockyard, compared with those without a dockyard was 1.41 (95% CI 1.35 to 1.48, p<0.05) for 2002-2008 and 1.18 (95% CI 1.13 to 1.23, p<0.05) for 2009-2015. Spatial autocorrelation (measured by Moran's I) decreased from 0.317 (95% CI 0.316 to 0.319, p=0.001) to 0.312 (95% CI 0.310 to 0.314, p=0.001) for men and the coefficient of the association between distance to dockyard and district level age-adjusted male mortality (per million population) from -0.16 (95% CI -0.21 to -0.10, p<0.01) to -0.13 (95% CI -0.18 to -0.07, p<0.01) for men, when comparing 2002-2008 with 2009-2015. CONCLUSION: For most districts age-adjusted mesothelioma mortality rates increased through 2002-2015 but the relative contribution from districts with a dockyard fell. Dockyards remain strongly spatially associated with mesothelioma mortality but the strength of this association appears to be falling and mesothelioma deaths are becoming more dispersed.
Asunto(s)
Neoplasias Pulmonares/mortalidad , Mesotelioma/mortalidad , Enfermedades Profesionales/mortalidad , Navíos , Anciano , Femenino , Humanos , Masculino , Mesotelioma Maligno , Reino Unido/epidemiologíaRESUMEN
Rationale: Puberty may influence lung function, but the precise role of pubertal height growth in lung development is unclear.Objectives: To examine associations of timing of puberty and peak velocity of pubertal height growth with lung function in adolescence and early adulthood.Methods: Longitudinal analyses of repeat height measurements from age 5 to 20 years for a British birth cohort with 4,772 males and 4,849 females were conducted to characterize height growth trajectories and to derive pubertal age and peak height velocity using the validated SITAR (SuperImposition by Translation and Rotation) model. Association of these estimates with prebronchodilator and post-bronchodilator spirometry measures: FEV1; FVC; FEV1/FVC; FEF25-75% at age 15 and 24 years were investigated using multivariable regression models adjusted for lung function at age 8 years, height and age at time of outcome measurements, and potential confounders.Measurements and Main Results: Later pubertal age and greater peak velocity were associated with higher FEV1 and FVC at 24 years in both sexes. A 1-year increase in pubertal age was associated with a 263-ml higher FVC (95% confidence interval [CI], 167-360 ml) for males (n = 567) and 100-ml (95% CI, 50-150 ml) higher FVC for females (n = 990). A 1-cm/yr increase in peak velocity was associated with 145-ml (95% CI, 56-234 ml) and 50-ml (95% CI, 2-99 ml) increases in FVC for males and females, respectively. No associations were found with FEV1/FVC.Conclusions: Later onset and greater peak velocity of height growth in puberty are associated with increased FEV1 and FVC in young adults but there was no evidence of dysanapsis of pubertal lung growth.