156 research outputs found

    Age at quitting smoking as a predictor of risk of cardiovascular disease incidence independent of smoking status, time since quitting and pack-years

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    BACKGROUND Risk prediction for CVD events has been shown to vary according to current smoking status, pack-years smoked over a lifetime, time since quitting and age at quitting. The latter two are closely and inversely related. It is not known whether the age at which one quits smoking is an additional important predictor of CVD events. The aim of this study was to determine whether the risk of CVD events varied according to age at quitting after taking into account current smoking status, lifetime pack-years smoked and time since quitting. FINDINGS We used the Cox proportional hazards model to evaluate the risk of developing a first CVD event for a cohort of participants in the Framingham Offspring Heart Study who attended the fourth examination between ages 30 and 74 years and were free of CVD. Those who quit before the median age of 37 years had a risk of CVD incidence similar to those who were never smokers. The incorporation of age at quitting in the smoking variable resulted in better prediction than the model which had a simple current smoker/non-smoker measure and the one that incorporated both time since quitting and pack-years. These models demonstrated good discrimination, calibration and global fit. The risk among those quitting more than 5 years prior to the baseline exam and those whose age at quitting was prior to 44 years was similar to the risk among never smokers. However, the risk among those quitting less than 5 years prior to the baseline exam and those who continued to smoke until 44 years of age (or beyond) was two and a half times higher than that of never smokers. CONCLUSIONS Age at quitting improves the prediction of risk of CVD incidence even after other smoking measures are taken into account. The clinical benefit of adding age at quitting to the model with other smoking measures may be greater than the associated costs. Thus, age at quitting should be considered in addition to smoking status, time since quitting and pack-years when counselling individuals about their cardiovascular risk.This research was supported by an NHMRC health services research grant (no. 465130), an NHMRC/NHF PhD scholarship and a Vichealth Fellowship

    Comparing trends in BMI and waist circumference

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    The nature of excess body weight may be changing over time to one of greater central adiposity. The aim of this study is to determine whether BMI and waist circumference (WC) are increasing proportionately among population subgroups and the range of bodyweight, and to examine the public health implications of the findings. Our data are from two cross-sectional surveys (the US National Health and Nutrition Examination Studies (NHANES) in 1988-1994 (NHANES III) and 2005-2006), from which we have used samples of 15,349 and 4,176 participants aged ≥20 years. Between 1988-1994 and 2005-2006 BMI increased by an average of 1.8kg/m2 and WC by 4.7cm (adjusted for sex, age, race-ethnicity, and education). The increase in WC was more than could be attributed simply to increases in BMI. This independent increase in WC (of on average, 0.9cm) was consistent across the different BMI categories, sexes, education levels, and race-ethnicity groups. It occurred in younger but not older age groups. Overall in each BMI category, the prevalence of low-risk WC decreased and the prevalence of increased-risk or substantially increased-risk WC increased. These results suggest that the adverse health consequences associated with obesity may be increasingly underestimated by trends in BMI alone. Since WC is closely linked to adverse cardiovascular outcomes, it is important to know the prevailing trends in both of these parameters

    Increased diastolic blood pressure is associated with MRI biomarkers of dementia-related brain pathology in normative ageing

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    Background hypertension is a risk for brain ageing, but the mechanisms underlying this effect remain unclear. Magnetic resonance imaging (MRI) detected biomarkers of brain ageing include white matter hyperintensities (WMHs), a marker of cerebrovascular disease, and hippocampal volume, a marker of Alzheimer’s disease pathology. Objective to examine relationships between blood pressure (BP) components and brain pathology in older adults. Subjects two hundred and twenty-seven members of the Aberdeen 1936 Birth Cohort between ages 64 and 68 years. Methods BP was assessed biennially between 64 and 68 years and brain MRI performed at 68 years. The risk factors of interest were diastolic and systolic BP and their visit-to-visit variability. Outcomes were WMH abundance and hippocampal volume. Regression models, controlling for confounding factors, examined their relationships. Results higher diastolic BP predicted increased WMH (β = 0.13, P = 0.044) and smaller hippocampi (β = −0.25, P = 0.006). In contrast, increased systolic BP predicted larger hippocampi (β = 0.22, P = 0.013). Variability of diastolic BP predicted lower hippocampal volume (β = −0.15, P = 0.033). These relationships were independent of confounding life-course risk factors. Anti-hypertensive medication did not modify these relationships, but was independently associated with increased WMH (β = 0.17, P = 0.011). Conclusion increased diastolic BP is associated with biomarkers of both cerebrovascular and Alzheimer’s diseases, whereas the role of systolic BP is less clear, with evidence for a protective effect on hippocampal volume. These differing relationships emphasise the importance of considering individual BP components with regard to brain ageing and pathology. Interventions targeting diastolic hypertension and its chronic variability may provide new strategies able to slow the accumulation of these harmful pathologies

    QUARC: Quantum Research Cubesat—A Constellation for Quantum Communication

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    Quantum key distribution (QKD) offers future proof security based on fundamental laws of physics. Long distance QKD spanning regions such as the United Kingdom (UK) may employ a constellation of satellites. Small satellites, CubeSats in particular, in low earth orbit (LEO) are a relatively low cost alternative to traditional, large platforms. They allow the deployment of a large number of spacecraft ensuring greater coverage and mitigating some of the risk associated with availability due to cloud cover. We present our mission analysis showing how a constellation of low cost 6U CubeSats can be used to form a secure communication backbone for ground based and metropolitan networks across the UK. We have estimated the monthly key rates at 43 sites across the UK incorporating local meteorological data, atmospheric channel modelling and orbital parameters. We have optimized the constellation topology for rapid revisit and thus low latency key distribution

    Nutritional B vitamin deficiency alters the expression of key proteins associated with vascular smooth muscle cell proliferation and migration in the aorta of atherosclerotic apolipoprotein E null mice.

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    Low B vitamin status is linked with human vascular disease. We employed a proteomic and biochemical approach to determine whether nutritional folate deficiency and/or hyperhomocysteinemia altered metabolic processes linked with atherosclerosis in ApoE null mice. Animals were fed either a control fat (C; 4 % w/w lard) or a high-fat [HF; 21 % w/w lard and cholesterol (0/15 % w/w)] diet with different B vitamin compositions for 16 weeks. Aorta tissue was prepared and global protein expression, B vitamin, homocysteine and lipoprotein status measured. Changes in the expression of aorta proteins were detected in response to multiple B vitamin deficiency combined with a high-fat diet (P < 0.05) and were strongly linked with lipoprotein concentrations measured directly in the aorta adventitia (P < 0.001). Pathway analysis revealed treatment effects in the aorta-related primarily to cytoskeletal organisation, smooth muscle cell adhesion and invasiveness (e.g., fibrinogen, moesin, transgelin, vimentin). Combined B vitamin deficiency induced striking quantitative changes in the expression of aorta proteins in atherosclerotic ApoE null mice. Deregulated expression of these proteins is associated with human atherosclerosis. Cellular pathways altered by B vitamin status included cytoskeletal organisation, cell differentiation and migration, oxidative stress and chronic inflammation. These findings provide new insight into the molecular mechanisms through which B vitamin deficiency may accelerate atherosclerosis

    Optimising medication data collection in a large-scale clinical trial

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    © 2019 Lockery et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Objective: Pharmaceuticals play an important role in clinical care. However, in community-based research, medication data are commonly collected as unstructured free-text, which is prohibitively expensive to code for large-scale studies. The ASPirin in Reducing Events in the Elderly (ASPREE) study developed a two-pronged framework to collect structured medication data for 19,114 individuals. ASPREE provides an opportunity to determine whether medication data can be cost-effectively collected and coded, en masse from the community using this framework. Methods: The ASPREE framework of type-to-search box with automated coding and linked free text entry was compared to traditional method of free-text only collection and post hoc coding. Reported medications were classified according to their method of collection and analysed by Anatomical Therapeutic Chemical (ATC) group. Relative cost of collecting medications was determined by calculating the time required for database set up and medication coding. Results Overall, 122,910 participant structured medication reports were entered using the type-tosearch box and 5,983 were entered as free-text. Free-text data contributed 211 unique medications not present in the type-to-search box. Spelling errors and unnecessary provision of additional information were among the top reasons why medications were reported as freetext. The cost per medication using the ASPREE method was approximately USD 0.03comparedwithUSD0.03 compared with USD 0.20 per medication for the traditional method. Conclusion Implementation of this two-pronged framework is a cost-effective alternative to free-text only data collection in community-based research. Higher initial set-up costs of this combined method are justified by long term cost effectiveness and the scientific potential for analysis and discovery gained through collection of detailed, structured medication data

    The CATERPILLER protein Monarch-1 is an antagonist of toll-like receptor-, tumor necrosis factor α-, and Mycobacterium tuberculosis-induced pro-inflammatory signals

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    The CATERPILLER (CLR, also NOD and NLR) proteins share structural similarities with the nucleotide binding domain (NBD)-leucine-rich repeat (LRR) superfamily of plant disease-resistance (R) proteins and are emerging as important immune regulators in animals. CLR proteins contain NBD-LRR motifs and are linked to a limited number of distinct N-terminal domains including transactivation, CARD (caspase activation and recruitment), and pyrin domains (PyD). The CLR gene, Monarch-1/Pypaf7, is expressed by resting primary myeloid/monocytic cells, and its expression in these cells is reduced by Toll-like receptor (TLR) agonists tumor necrosis factor (TNF) α and Mycobacterium tuberculosis. Monarch-1 reduces NFκB activation by TLR-signaling molecules MyD88, IRAK-1 (type I interleukin-1 receptor-associated protein kinase), and TRAF6 (TNF receptor (TNFR)-associated factor) as well as TNFR signaling molecules TRAF2 and RIP1 but not the downstream NFκB subunit p65. This indicates that Monarch-1 is a negative regulator of both TLR and TNFR pathways. Reducing Monarch-1 expression with small interference RNA in myeloid/monocytic cells caused a dramatic increase in NFκB activation and cytokine expression in response to TLR2/TLR4 agonists, TNFα, or M. tuberculosis infection, suggesting that Monarch-1 is a negative regulator of inflammation. Because Monarch-1 is the first CLR protein that interferes with both TLR2 and TLR4 activation, the mechanism of this interference is significant. We find that Monarch-1 associates with IRAK-1 but not MyD88, resulting in the blockage of IRAK-1 hyperphosphorylation. Mutants containing the NBD-LRR or PyD-NBD also blocked IRAK-1 activation. This is the first example of a CLR protein that antagonizes inflammatory responses initiated by TLR agonists via interference with IRAK-1 activation
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