21 research outputs found
Micrometeorological and Soil Data for Calculating Evapotranspiration for Rainier Mesa, Nevada Test Site, Nevada 2002-05.
Micrometeorological and soil-moisture data were collected at two instrumented sites on Rainier Mesa at the Nevada Test Site, January 1, 2002/August 23, 2005. Data collected at each site include net radiation, air temperature, and relative humidity at two heights; wind speed and direction; subsurface soil heat flux; subsurface soil temperature; volumetric soil water; and matric water potential. These data were used to estimate 20-minute average and daily average evapotranspiration values. The data presented in this report are collected and calculated evapotranspiration rates
Newborn DNA-methylation, childhood lung function, and the risks of asthma and COPD across the life course
Rationale: We aimed to identify differentially methylated regions (DMRs) in cord blood DNA associated with childhood lung function, asthma and chronic obstructive pulmonary disease (COPD) across the life course.
Methods: We meta-analysed epigenome-wide data of 1688 children from five cohorts to identify cord blood DMRs and their annotated genes, in relation to forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity (FVC) ratio and forced expiratory flow at 75% of FVC at ages 7-13 years. Identified DMRs were explored for associations with childhood asthma, adult lung function and COPD, gene expression and involvement in biological processes.
Results: We identified 59 DMRs associated with childhood lung function, of which 18 were associated with childhood asthma and nine with COPD in adulthood. Genes annotated to the top 10 identified DMRs were HOXA5, PAOX, LINC00602, ABCA7, PER3, CLCA1, VENTX, NUDT12, PTPRN2 and TCL1A. Differential gene expression in blood was observed for 32 DMRs in childhood and 18 in adulthood. Genes related with 16 identified DMRs were associated with respiratory developmental or pathogenic pathways.
Interpretation: Our findings suggest that the epigenetic status of the newborn affects respiratory health and disease across the life course
Chronic obstructive pulmonary disease and related phenotypes: polygenic risk scores in population-based and case-control cohorts
Background Genetic factors influence chronic obstructive pulmonary disease (COPD) risk, but the individual variants
that have been identified have small effects. We hypothesised that a polygenic risk score using additional variants
would predict COPD and associated phenotypes.
Methods We constructed a polygenic risk score using a genome-wide association study of lung function (FEV1 and
FEV1/forced vital capacity [FVC]) from the UK Biobank and SpiroMeta. We tested this polygenic risk score in nine
cohorts of multiple ethnicities for an association with moderate-to-severe COPD (defined as FEV1/FVC <0·7 and FEV1
<80% of predicted). Associations were tested using logistic regression models, adjusting for age, sex, height, smoking
pack-years, and principal components of genetic ancestry. We assessed predictive performance of models by area
under the curve. In a subset of studies, we also studied quantitative and qualitative CT imaging phenotypes that
reflect parenchymal and airway pathology, and patterns of reduced lung growth.
Findings The polygenic risk score was associated with COPD in European (odds ratio [OR] per SD 1·81
[95% CI 1·74–1·88] and non-European (1·42 [1·34–1·51]) populations. Compared with the first decile, the tenth decile
of the polygenic risk score was associated with COPD, with an OR of 7·99 (6·56–9·72) in European ancestry and
4·83 (3·45–6·77) in non-European ancestry cohorts. The polygenic risk score was superior to previously described
genetic risk scores and, when combined with clinical risk factors (ie, age, sex, and smoking pack-years), showed
improved prediction for COPD compared with a model comprising clinical risk factors alone (AUC 0·80 [0·79–0·81]
vs 0·76 [0·75–0·76]). The polygenic risk score was associated with CT imaging phenotypes, including wall area
percent, quantitative and qualitative measures of emphysema, local histogram emphysema patterns, and destructive
emphysema subtypes. The polygenic risk score was associated with a reduced lung growth pattern.
Interpretation A risk score comprised of genetic variants can identify a small subset of individuals at markedly
increased risk for moderate-to-severe COPD, emphysema subtyp
Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD
Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p 10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10−392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In conclusion, given the frequency of highly significant local pQTLs, the large amount of variance potentially explained by pQTL, and the differences observed between pQTLs and eQTLs SNPs, we recommend that protein biomarker-disease association studies take into account the potential effect of common local SNPs and that pQTLs be integrated along with eQTLs to uncover disease mechanisms. Large-scale blood biomarker studies would also benefit from close attention to the ABO blood group
Non-emphysematous chronic obstructive pulmonary disease is associated with diabetes mellitus
Background: Chronic obstructive pulmonary disease (COPD) has been classically divided into blue bloaters and pink puffers. The utility of these clinical subtypes is unclear. However, the broader distinction between airway-predominant and emphysema-predominant COPD may be clinically relevant. The objective was to define clinical features of emphysema-predominant and non-emphysematous COPD patients. Methods: Current and former smokers from the Genetic Epidemiology of COPD Study (COPDGene) had chest computed tomography (CT) scans with quantitative image analysis. Emphysema-predominant COPD was defined by low attenuation area at -950 Hounsfield Units (LAA-950) ≥10%. Non-emphysematous COPD was defined by airflow obstruction with minimal to no emphysema (LAA-950 < 5%). Results: Out of 4197 COPD subjects, 1687 were classified as emphysema-predominant and 1817 as non-emphysematous; 693 had LAA-950 between 5-10% and were not categorized. Subjects with emphysema-predominant COPD were older (65.6 vs 60.6 years, p < 0.0001) with more severe COPD based on airflow obstruction (FEV1 44.5 vs 68.4%, p < 0.0001), greater exercise limitation (6-minute walk distance 1138 vs 1331 ft, p < 0.0001) and reduced quality of life (St. George's Respiratory Questionnaire score 43 vs 31, p < 0.0001). Self-reported diabetes was more frequent in non-emphysematous COPD (OR 2.13, p < 0.001), which was also confirmed using a strict definition of diabetes based on medication use. The association between diabetes and non-emphysematous COPD was replicated in the ECLIPSE study. Conclusions: Non-emphysematous COPD, defined by airflow obstruction with a paucity of emphysema on chest CT scan, is associated with an increased risk of diabetes. COPD patients without emphysema may warrant closer monitoring for diabetes, hypertension, and hyperlipidemia and vice versa
Estimated ground-water discharge by evapotranspiration from Death Valley, California, 1997-2001 /
Shipping list no.: 2004-0061-P.Includes bibliographical references (p. 26-27).Mode of access: Internet
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Lobar Emphysema Distribution Is Associated With 5-Year Radiological Disease Progression
BackgroundEmphysema has considerable variability in its regional distribution. Craniocaudal emphysema distribution is an important predictor of the response to lung volume reduction. However, there is little consensus regarding how to define upper lobe-predominant and lower lobe-predominant emphysema subtypes. Consequently, the clinical and genetic associations with these subtypes are poorly characterized.MethodsWe sought to identify subgroups characterized by upper-lobe or lower-lobe emphysema predominance and comparable amounts of total emphysema by analyzing data from 9,210 smokers without alpha-1-antitrypsin deficiency in the Genetic Epidemiology of COPD (COPDGene) cohort. CT densitometric emphysema was measured in each lung lobe. Random forest clustering was applied to lobar emphysema variables after regressing out the effects of total emphysema. Clusters were tested for association with clinical and imaging outcomes at baseline and at 5-year follow-up. Their associations with genetic variants were also compared.ResultsThree clusters were identified: minimal emphysema (n = 1,312), upper lobe-predominant emphysema (n = 905), and lower lobe-predominant emphysema (n = 796). Despite a similar amount of total emphysema, the lower-lobe group had more severe airflow obstruction at baseline and higher rates of metabolic syndrome compared with subjects with upper-lobe predominance. The group with upper-lobe predominance had greater 5-year progression of emphysema, gas trapping, and dyspnea. Differential associations with known COPD genetic risk variants were noted.ConclusionsSubgroups of smokers defined by upper-lobe or lower-lobe emphysema predominance exhibit different functional and radiological disease progression rates, and the upper-lobe predominant subtype shows evidence of association with known COPD genetic risk variants. These subgroups may be useful in the development of personalized treatments for COPD