98 research outputs found
Hyperreactivity of Salivary Alpha-Amylase to Acute Psychosocial Stress and Norepinephrine Infusion in Essential Hypertension
It is unknown whether the observed general physiological hyperreactivity to acute psychosocial stress in essential hypertension also extends to salivary alpha-amylase (sAA), a surrogate sympathetic nervous system marker. Here, we investigated sAA reactivity to acute psychosocial stress in essential hypertensive males (HT) as compared to normotensive controls (NT). To shed light on underlying mechanisms, we moreover tested for sAA reactivity following a standardized norepinephrine (NE) infusion. We hypothesized that both acute psychosocial stress and an NE infusion of similar duration would lead to greater sAA reactivity in HT than in NT. In the stress study, we examined sAA reactivity to 15 min of acute psychosocial stress induced by the Trier Social Stress Test (TSST) in 19 HT and 23 NT up to 40 min after stress. In the infusion study, 20 HT and 22 NT received a standardized NE infusion (5 Όg/mL/min) over 15 min mimicking NE release in reaction to acute psychosocial stress. HT exhibited greater sAA reactivity to the TSST as compared to NT (p = 0.049, ηp2 = 0.08, f = 0.29). In reaction to the standardized NE infusion, HT showed higher sAA reactivity as compared to NT (p = 0.033, ηp2 = 1.00, f = 0.33). Our findings suggest stress-induced sAA hyperreactivity in essential hypertension that seems to be at least in part mediated by a higher reactivity to a standardized amount of NE in HT. With respect to clinical implications, sAA stress reactivity may serve as a noninvasive marker indicative of early cardiovascular risk
Taking appreciation to heart: appreciation at work and cardiovascular risk in male employees.
INTRODUCTION
While perceived appreciation at work has been associated with self-reported health and wellbeing, studies considering biological health markers are lacking. In this study, we investigated whether appreciation at work would relate to coronary heart disease (CHD) risk as well as the specificity of this proposed association.
METHODS
Our study comprised a total of 103 male participants, including apparently healthy, medication-free, non-smoking men in the normotensive to hypertensive range (nâ=â70) as well as medicated hypertensive and CHD patients (nâ=â33). CHD risk was assessed by blood pressure [mean arterial pressure (MAP)], the diabetes marker glycated hemoglobin A1c (HbA1c), blood lipids [total cholesterol (TC)/high-density lipoprotein-cholesterol (HDL-C) ratio], coagulation activity (D-dimer and fibrinogen), and inflammation [interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP)]. Perceived appreciation at work, as well as potentially confounding psychological factors (social support, self-esteem, and work strain due to a lack of appreciation), were measured by self-report questionnaires.
RESULTS
We found higher appreciation at work to relate to lower overall composite CHD risk (p'sââ€â0.011) and, in particular, to lower MAP (p'sââ€â0.007) and lower blood lipids (p'sââ€â0.031) in medication-free participants as well as all participants. This overall association was independent of confounding factors, including related psychological factors (p'sââ€â0.049).
DISCUSSION
Our findings indicate that appreciation at work might be an independent health-promoting resource in terms of CHD risk. Implications include that encouraging appreciation at work may help reduce the development and progression of CHD
Acute Stress-Induced Blood Lipid Reactivity in Hypertensive and Normotensive Men and Prospective Associations with Future Cardiovascular Risk.
Hyperreactivity to stress may be one explanation for the increased risk of cardiovascular disease (CVD) in individuals with essential hypertension. We investigated blood lipid reactivity to the Montreal Imaging Stress Task (MIST), a psychosocial stressor, in hypertensive and normotensive men and tested for prospective associations with biological risk factors. Fifty-six otherwise healthy and medication-free hypertensive and normotensive men underwent the MIST. We repeatedly measured cortisol and blood lipid profiles (total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG)) immediately before and up to 1 h after stress. Lipid levels were corrected for stress hemoconcentration. Thirty-five participants completed follow-up assessment 2.9 ± 0.12 (SEM) years later. CVD risk was assessed by prospective changes in TC/HDL-C ratio, IL-6, D-dimer, and HbA1c from baseline to follow-up. The MIST induced significant changes in all parameters except TC (p-values †0.043). Compared with normotensives, hypertensives had higher TC/HDL-C-ratio and TG (p-values †0.049) stress responses. Blood lipid stress reactivity predicted future cardiovascular risk (p = 0.036) with increases in HbA1c (à = 0.34, p = 0.046), IL-6 (à = 0.31, p = 0.075), and D-dimer (à = 0.33, p = 0.050). Our results suggest that the greater blood lipid reactivity to psychosocial stress in hypertensives, the greater their future biological CVD risk. This points to lipid stress reactivity as a potential mechanism through which stress might increase CVD risk in essential hypertension
The SASI Model
The task of the SASI project was to identify the way transport infrastructure contributes to regional socio-economic development in different regional contexts. For this purpose an interactive computer simulation model for forecasting the impacts of transport infrastructure investments and transport system improvements of the trans-European transport networks on socio-economic activities in the regions of Europe was developed (see the other SASI reports in the SASI Home Page). This report describes the implementation of the SASI model, i.e. the application of empirical data to the model and the estimation of its parameters
Lower diurnal HPA-axis activity in male hypertensive and coronary heart disease patients predicts future CHD risk.
BACKGROUND
Coronary heart disease (CHD) and its major risk factor hypertension have both been associated with altered activity of the hypothalamus-pituitary-adrenal (HPA)-axis but the biological mechanisms underlying prospective associations with adverse disease outcomes are unclear. We investigated diurnal HPA-axis activity in CHD-patients, hypertensive (HT) and healthy normotensive men (NT) and tested for prospective associations with biological CHD risk factors.
METHODS
Eighty-three male CHD-patients, 54 HT and 54 NT men repeatedly measured salivary cortisol over two consecutive days. Prospective CHD risk was assessed by changes between baseline and follow-up in the prothrombotic factors D-dimer and fibrinogen, the pro-inflammatory measures interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and acute phase protein C-reactive protein (CRP), as well as blood lipids in terms of total cholesterol (tChol)/high-density-lipoprotein cholesterol (HDL)-ratio. We aggregated coagulation and inflammatory measures to respective indices.
RESULTS
The groups differed in repeated daytime cortisol (dayCort) secretion (p=.005,η2 p=.03,f=0.18) and cortisol awakening response (CAR) (p=.006,η2 p=.03,f=0.18), with similarly lower overall dayCort and CAR in CHD-patients and HT, as compared to NT. The groups differed further in cortisol at awakening (p=.015,η2 p=.04,f=0.20) with highest levels in HT (pÂŽsâ€.050), and in diurnal slope between waking and evening cortisol (p=.033,η2 p=.04,f=0.20) with steepest slopes in HT (pÂŽsâ€.039), although in part not independent of confounders. Lower aggregated dayCort and CAR in terms of area-under-the-curve (AUC) independently predicted increases in future overall CHD risk (AUCdayCort: p=.021,η2 p=.10,f=0.33;AUCCAR: p=.028,η2 p=.09,f=0.31) 3.00 ± 0.06(SEM) years later, with risk prediction most pronounced in fibrinogen (AUCdayCort: p=.017,ÎR 2= 0.12;AUCCAR: p=.082).
CONCLUSION
We found evidence for an HPA-axis hypoactivity in CHD and HT with lower diurnal HPA-axis activity predicting increases in cardiovascular risk as evidenced by increases in circulating levels of biomarkers of atherothrombotic risk. Down-regulation of basal HPA-axis activity may contribute to the pathogenesis of atherosclerosis and thrombosis in CHD via effects on coagulation
Multi-material laser powder bed fusion additive manufacturing of concentrated wound stator teeth
Additive manufacturing using Powder Bed Fusion by Laser Beam (PBF-LB) enables products with high design freedom. In addition, the ability to process more than one material in all three spatial directions makes it possible to produce highly functional components in one single process. This article investigates whether multi-material manufacturing using PBF-LB is suitable for producing coils for electric motors, which are designed with integrated cooling channels to increase the power density. For this purpose, the copper alloy CuCr1Zr for the coils and the stainless steel 1.4404 (316L) for the core are processed simultaneously. The component designs were verified using 2D and 3D finite element analysis and then manufactured in a multi-material PBF-LB process. While good electrical conductivity of the copper alloy was achieved by heat treatment, it was found that thermal distortion caused deviations from the nominal geometry. The measurement of the electrical properties showed that this distortion leads to short-circuit currents within the coils and the teeth. On this basis, ideas for solutions were developed, with the help of which the functionality of the coils can be ensured or the power density can also be increased. In addition to adapting the design of the component, this includes processing additional or other materials, such as soft magnetic composites
Circulating miRNAs in bone health and disease
microRNAs have evolved as important regulators of multiple biological pathways essential for bone homeostasis, and microRNA research has furthered our understanding of the mechanisms underlying bone health and disease. This knowledge, together with the finding that active or passive release of microRNAs from cells into the extracellular space enables minimal-invasive detection in biofluids (circulating miRNAs), motivated researchers to explore microRNAs as biomarkers in several pathologic conditions, including bone diseases. Thus, exploratory studies in cohorts representing different types of bone diseases have been performed. In this review, we first summarize important molecular basics of microRNA function and release and provide recommendations for best (pre-)analytical practices and documentation standards for circulating microRNA research required for generating high quality data and ensuring reproducibility of results. Secondly, we review how the genesis of bone-derived circulating microRNAs via release from osteoblasts and osteoclasts could contribute to the communication between these cells. Lastly, we summarize evidence from clinical research studies that have investigated the clinical utility of microRNAs as biomarkers in musculoskeletal disorders. While previous reviews have mainly focused on diagnosis of primary osteoporosis, we have also included studies exploring the utility of circulating microRNAs in monitoring anti-osteoporotic treatment and for diagnosis of other types of bone diseases, such as diabetic osteopathy, bone degradation in inflammatory diseases, and monogenetic bone diseases.Peer reviewe
Alpha-Adrenergic Mechanisms in the Cardiovascular Hyperreactivity to Norepinephrine-Infusion in Essential Hypertension.
Aims
Essential hypertension (EHT) is characterized by cardiovascular hyperreactivity to stress but underlying mechanism are not fully understood. Here, we investigated the role of α-adrenergic receptors (α-AR) in the cardiovascular reactivity to a norepinephrine (NE)-stress reactivity-mimicking NE-infusion in essential hypertensive individuals (HT) as compared to normotensive individuals (NT).
Methods
24 male HT and 24 male NT participated in three experimental trials on three separate days with a 1-min infusion followed by a 15-min infusion. Trials varied in infusion-substances: placebo saline (Sal)-infusions (trial-1:Sal+Sal), NE-infusion without (trial-2:Sal+NE) or with non-selective α-AR blockade by phentolamine (PHE) (trial-3:PHE+NE). NE-infusion dosage (5”g/ml/min) and duration were chosen to mimic duration and physiological effects of NE-release in reaction to established stress induction protocols. We repeatedly measured systolic (SBP) and diastolic blood pressure (DBP) as well as heart rate before, during, and after infusions.
Results
SBP and DBP reactivity to the three infusion-trials differed between HT and NT (p'sâ€.014). HT exhibited greater BP reactivity to NE-infusion alone compared to NT (trial-2-vs-trial-1: p'sâ€.033). Group differences in DBP reactivity to NE disappeared with prior PHE blockade (trial-3: p=.26), while SBP reactivity differences remained (trial-3: p=.016). Heart rate reactivity to infusion-trials did not differ between HT and NT (p=.73).
Conclusion
Our findings suggest a mediating role of α-AR in DBP hyperreactivity to NE-infusion in EHT. However, in SBP hyperreactivity to NE-infusion in EHT, the functioning of α-AR seems impaired suggesting that the SBP hyperreactivity in hypertension is not mediated by α-AR
Measuring Political Commitment in Statistical Models for Evidence-based Agenda Setting in Nonmotorized Traffic
When investigating national and international transport policies of the last decade, an ever increasing
emphasis on promoting non-motorized transport modes such as walking or cycling can be identified, aiming
at reaching multiple political targets (eg. reducing pollution, increasing health or lowering land
consumption). However, despite substantial financial efforts being put into infrastructural or awarenessraising
activities, achieving the desired modal shift towards active mobility remains a challenge. This is
frequently due to unclear cause and effect patterns between active mode shares and their determinants, which
in turn leads to uncoordinated or highly fragmented initiatives that impede target-oriented planning.
An internationally adopted approach to overcome this problem is applying aggregated statistical models that
explain modal choice involving multiple regression techniques and hypothetical covariates. Still, general
critique against these models points out that important intangible soft factors such as attitudinal
characteristics of the local population or mind-sets and political commitment of decision makers are not duly
reflected. Also, for Austria there is currently no systematic holistic approach to explain spatial variance in
active travel shares on the scale of municipalities.
Hence the main objective of our research is to design a comprehensive macroscopic model-based approach
for the quantitative explanation of modal split shares in active travel modes in Austria. In our approach we
attach great importance to the inclusion of soft factors in order to contribute novel findings on the dynamics
behind active travel. The research outcomes will aid decision makers and planners in their question where
and more specifically, how to effectively invest into active mobility by revealing key soft factors and
intangible determinants of active travel mode shares alongside a broad range of more known, traditional
factors. Based on this evidence-based decision support approach it is possible to simulate impacts of actions
when aiming at locally promoting active travel modes
Sympathetic nervous system responses to acute psychosocial stress in male physicians with clinical burnout
Background: Occupational burnout has been associated with an increased risk of cardiovascular disease, with sympathetic nervous system (SNS) dysfunction as one explanation. This study examined the effects of burnout on responses of SNS activity measures to acute psychosocial stress in male physicians, a population at risk for burnout.
Methods: Study participants were 60 male physicians, 30 with clinical burnout, assessed with the Maslach Burnout Inventory, and 30 without burnout (controls). All participants underwent the 15-min Trier Social Stress Test. Heart rate, blood pressure, salivary alpha-amylase, and plasma levels of epinephrine (EPI) and norepinephrine were assessed pre-stress, immediately post-stress, and 15 min and 45 min post-stress.
Results: Physicians with burnout and controls differed in EPI changes over time, controlling for age, job stress and anxiety symptoms (F (3,147) = 5.18, p = .002 for 'Time by Group' interaction; η2p = .096). Burnout was associated with a smaller increase in EPI from pre-stress to immediately post-stress (r(54) = -.40, p = .004). The emotional exhaustion dimension of burnout was a significant driver of this effect. The area under the curve with respect to increase in EPI was also smaller in the burnout group (F (1,49) = 6.06, p = .017, η2p = .110). Group differences were not significant for the other SNS activity measures.
Conclusions: Burnout may be linked to dysfunction of the sympathoadrenal medullary (SAM) system, when exposed to acute psychosocial stress. In keeping with the allostatic load concept, an insufficient SAM stress response in burnout could potentially contribute to cardiovascular disease
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