Host and environmental predictors of exhaled breath temperature in the elderly

BACKGROUND: Exhaled breath temperature has been suggested as a new method to detect and monitor pathological processes in the respiratory system. The putative mechanism of this approach is based upon changes in the blood flow. So far potential factors that influence breath temperature have not been studied in the general population. METHODS: The exhaled breath temperature was measured in 151 healthy non-smoking elderly (aged: 60–80 years) at room temperature with the X-halo device with an accuracy of 0.03°C. We related exhaled breath temperature by use of regression models with potential predictors including: host factors (sex, age) and environmental factors (BMI, physical activity, and traffic indicators). RESULTS: Exhaled breath temperature was lower in women than in men and was inversely associated with age, physical activity. BMI and daily average ambient temperature were positively associated with exhaled breath temperature. Independent of the aforementioned covariates, exhaled breath temperature was significantly associated with several traffic indicators. Residential proximity to major road was inversely associated with exhaled breath temperature: doubling the distance to the nearest major intense road was observed a decrease of 0.17°C (95% CI: -0.33 to -0.01; p = 0.036). CONCLUSIONS: Exhaled breath temperature has been suggested as a noninvasive method for the evaluation of airway inflammation. We provide evidence that several factors known to be involved in proinflammatory conditions including BMI, physical activity and residential proximity to traffic affect exhaled breath temperature. In addition, we identified potential confounders that should be taken into account in clinical and epidemiological studies on exhaled breath temperature including sex, age, and ambient temperature

An epidemiological appraisal of the association between heart rate variability and particulate air pollution: a meta-analysis

Studies on the association between short-term exposure to ambient air pollution and heart rate variability (HRV) suggest that particulate matter (PM) exposure is associated with reductions in measures of HRV, but there is heterogeneity in the nature and magnitude of this association between studies. The authors performed a meta-analysis to determine how consistent this association is.status: publishe

Molecular responses in the telomere-mitochondrial axis of ageing in the elderly: a candidate gene approach

Experimental evidence shows that telomere shortening induces mitochondrial damage but so far studies in humans are scarce. Here, we investigated the association between leukocyte telomere length (LTL) and mitochondrial DNA (mtDNA) content in elderly and explored possible intermediate mechanisms by determining the gene expression profile of candidate genes in the telomere-mitochondrial axis of ageing. Among 166 non-smoking elderly, LTL, leukocyte mtDNA content and expression of candidate genes: sirtuin1 (SIRT1), tumor protein p53 (TP53), peroxisome proliferator-activated receptor -coactivator1 (PGC-1), peroxisome proliferator-activated receptor -coactivator1 (PGC-1), nuclear respiratory factor 1 (NRF1) and nuclear factor, erythroid 2 like 2 (NRF2), using a quantitave real time polymerase chain assay (qPCR). Statistical mediation analysis was used to study intermediate mechanisms of the telomere-mitochondrial axis of ageing. LTL correlated with leukocyte mtDNA content in our studied elderly (r = 0.23, p = 0.0047). SIRT1 gene expression correlated positively with LTL (r = 0.26, p = 0.0094) and leukocyte mtDNA content (r = 0.43, p < 0.0001). The other studied candidates showed significant correlations in the telomere-mitochondrial interactome but not independent from SIRT1. SIRT1 gene expression was estimated to mediate 40% of the positive association between LTL and leukocyte mtDNA content. The key finding of our study was that SIRT1 expression plays a pivotal role in the telomeremitochondrial interactome.publisher: Elsevier articletitle: Molecular responses in the telomere-mitochondrial axis of ageing in the elderly: A candidate gene approach journaltitle: Mechanisms of Ageing and Development articlelink: http://dx.doi.org/10.1016/j.mad.2015.02.003 content_type: article copyright: Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.status: publishe

Telomere length, cardiovascular risk and arteriosclerosis in human kidneys: an observational cohort study

Replicative senescence, associated with telomere shortening, plays an important role in aging and cardiovascular disease. The relation between telomere length, cardiovascular risk, and renal disease is unknown.status: publishe

Telomere length, cardiovascular risk and arteriosclerosis in human kidneys: an observational cohort study

Replicative senescence, associated with telomere shortening, plays an important role in aging and cardiovascular disease. The relation between telomere length, cardiovascular risk, and renal disease is unknown.status: publishe

Placental DNA hypomethylation in association with particulate air pollution in early life

BACKGROUND: There is evidence that altered DNA methylation is an important epigenetic mechanism in prenatal programming and that developmental periods are sensitive to environmental stressors. We hypothesized that exposure to fine particles (PM2.5) during pregnancy could influence DNA methylation patterns of the placenta. METHODS: In the ENVIRONAGE birth cohort, levels of 5'-methyl-deoxycytidine (5-mdC) and deoxycytidine (dC) were quantified in placental DNA from 240 newborns. Multiple regression models were used to study placental global DNA methylation and in utero exposure to PM2.5 over various time windows during pregnancy. RESULTS: PM2.5 exposure during pregnancy averaged (25th-75th percentile) 17.4 (15.4-19.3) mug/m3. Placental global DNA methylation was inversely associated with PM2.5 exposures during whole pregnancy and relatively decreased by 2.19% (95% confidence interval (CI): -3.65, -0.73%, p = 0.004) for each 5 mug/m3 increase in exposure to PM2.5. In a multi-lag model in which all three trimester exposures were fitted as independent variables in the same regression model, only exposure to PM2.5 during trimester 1 was significantly associated with lower global DNA methylation (-2.13% per 5 mug/m3 increase, 95% CI: -3.71, -0.54%, p = 0.009). When we analyzed shorter time windows of exposure within trimester 1, we observed a lower placental DNA methylation at birth during all implantation stages but exposure during the implantation range (6-21d) was strongest associated (-1.08% per 5 mug/m3 increase, 95% CI: -1.80, -0.36%, p = 0.004). CONCLUSIONS: We observed a lower degree of placental global DNA methylation in association with exposure to particulate air pollution in early pregnancy, including the critical stages of implantation. Future studies should elucidate genome-wide and gene-specific methylation patterns in placental tissue that could link particulate exposure during in utero life and early epigenetic modulations.status: publishe

Host and environmental predictors of exhaled breath temperature in the elderly

Exhaled breath temperature has been suggested as a new method to detect and monitor pathological processes in the respiratory system. The putative mechanism of this approach is based upon changes in the blood flow. So far potential factors that influence breath temperature have not been studied in the general population.status: publishe

Placental Mitochondrial DNA Content and Particulate Air Pollution during in Utero Life

Background: Studies emphasize the importance of particulate matter (PM) in the formation of reactive oxygen species and inflammation. We hypothesized that these processes can influence mitochondrial function of the placenta and fetus.Objective: We investigated the influence of PM10 exposure during pregnancy on the mitochondrial DNA content (mtDNA content) of the placenta and umbilical cord blood.Methods: DNA was extracted from placental tissue (n = 174) and umbilical cord leukocytes (n = 176). Relative mtDNA copy numbers (i.e., mtDNA content) were determined by real-time polymerase chain reaction. Multiple regression models were used to link mtDNA content and in utero exposure to PM10 over various time windows during pregnancy.Results: In multivariate-adjusted analysis, a 10-µg/m³ increase in PM10 exposure during the last month of pregnancy was associated with a 16.1% decrease [95% confidence interval (CI): -25.2, -6.0%, p = 0.003] in placental mtDNA content. The corresponding effect size for average PM10 exposure during the third trimester was 17.4% (95% CI: -31.8, -0.1%, p = 0.05). Furthermore, we found that each doubling in residential distance to major roads was associated with an increase in placental mtDNA content of 4.0% (95% CI: 0.4, 7.8%, p = 0.03). No association was found between cord blood mtDNA content and PM10 exposure.Conclusions: Prenatal PM10 exposure was associated with placental mitochondrial alterations, which may both reflect and intensify oxidative stress production. The potential health consequences of decreased placental mtDNA content in early life must be further elucidated.status: publishe

Blood Pressure and Same-Day Exposure to Air Pollution at School: Associations with Nano-Sized to Coarse PM in Children

Ultrafine particles (UFP) may contribute to the cardiovascular effects of particulate air pollution, partly because of their relatively efficient alveolar deposition. In this study, we assessed associations between blood pressure and short-term exposure to air pollution in a population of school children.status: publishe