176 research outputs found
Global distributions of age- and sex-related arterial stiffness: systematic review and meta-analysis of 167 studies with 509,743 participants
No full textBackground: Arterial stiffening is central to the vascular ageing process and a powerful predictor and cause of diverse vascular pathologies and mortality. We investigated age and sex trajectories, regional differences, and global reference values of arterial stiffness as assessed by pulse wave velocity (PWV).
Methods: Measurements of brachial-ankle or carotid-femoral PWV (baPWV or cfPWV) in generally healthy participants published in three electronic databases between database inception and August 24th, 2020 were included, either as individual participant-level or summary data received from collaborators (n = 248,196) or by extraction from published reports (n = 274,629). Quality was appraised using the Joanna Briggs Instrument. Variation in PWV was estimated using mixed-effects meta-regression and Generalized Additive Models for Location, Scale, and Shape.
Findings: The search yielded 8920 studies, and 167 studies with 509,743 participants from 34 countries were included. PWV depended on age, sex, and country. Global age-standardised means were 12.5 m/s (95% confidence interval: 12.1-12.8 m/s) for baPWV and 7.45 m/s (95% CI: 7.11-7.79 m/s) for cfPWV. Males had higher global levels than females of 0.77 m/s for baPWV (95% CI: 0.75-0.78 m/s) and 0.35 m/s for cfPWV (95% CI: 0.33-0.37 m/s), but sex differences in baPWV diminished with advancing age. Compared to Europe, baPWV was substantially higher in the Asian region (+1.83 m/s, P = 0.0014), whereas cfPWV was higher in the African region (+0.41 m/s, P < 0.0001) and differed more by country (highest in Poland, Russia, Iceland, France, and China; lowest in Spain, Belgium, Canada, Finland, and Argentina). High vs. other country income was associated with lower baPWV (-0.55 m/s, P = 0.048) and cfPWV (-0.41 m/s, P < 0.0001).
Interpretation: China and other Asian countries featured high PWV, which by known associations with central blood pressure and pulse pressure may partly explain higher Asian risk for intracerebral haemorrhage and small vessel stroke. Reference values provided may facilitate use of PWV as a marker of vascular ageing, for prediction of vascular risk and death, and for designing future therapeutic interventions.
Funding: This study was supported by the excellence initiative VASCage funded by the Austrian Research Promotion Agency, by the National Science Foundation of China, and the Science and Technology Planning Project of Hunan Province. Detailed funding information is provided as part of the Acknowledgments after the main text
Global distributions of age- and sex-related arterial stiffness: systematic review and meta-analysis of 167 studies with 509,743 participants
No full textBackground:
Arterial stiffening is central to the vascular ageing process and a powerful predictor and cause of diverse vascular pathologies and mortality. We investigated age and sex trajectories, regional differences, and global reference values of arterial stiffness as assessed by pulse wave velocity (PWV). //
Methods:
Measurements of brachial-ankle or carotid-femoral PWV (baPWV or cfPWV) in generally healthy participants published in three electronic databases between database inception and August 24th, 2020 were included, either as individual participant-level or summary data received from collaborators (n = 248,196) or by extraction from published reports (n = 274,629). Quality was appraised using the Joanna Briggs Instrument. Variation in PWV was estimated using mixed-effects meta-regression and Generalized Additive Models for Location, Scale, and Shape. //
Findings:
The search yielded 8920 studies, and 167 studies with 509,743 participants from 34 countries were included. PWV depended on age, sex, and country. Global age-standardised means were 12.5 m/s (95% confidence interval: 12.1–12.8 m/s) for baPWV and 7.45 m/s (95% CI: 7.11–7.79 m/s) for cfPWV. Males had higher global levels than females of 0.77 m/s for baPWV (95% CI: 0.75–0.78 m/s) and 0.35 m/s for cfPWV (95% CI: 0.33–0.37 m/s), but sex differences in baPWV diminished with advancing age. Compared to Europe, baPWV was substantially higher in the Asian region (+1.83 m/s, P = 0.0014), whereas cfPWV was higher in the African region (+0.41 m/s, P < 0.0001) and differed more by country (highest in Poland, Russia, Iceland, France, and China; lowest in Spain, Belgium, Canada, Finland, and Argentina). High vs. other country income was associated with lower baPWV (−0.55 m/s, P = 0.048) and cfPWV (−0.41 m/s, P < 0.0001). //
Interpretation:
China and other Asian countries featured high PWV, which by known associations with central blood pressure and pulse pressure may partly explain higher Asian risk for intracerebral haemorrhage and small vessel stroke. Reference values provided may facilitate use of PWV as a marker of vascular ageing, for prediction of vascular risk and death, and for designing future therapeutic interventions. //
Funding:
This study was supported by the excellence initiative VASCage funded by the Austrian Research Promotion Agency, by the National Science Foundation of China, and the Science and Technology Planning Project of Hunan Province. Detailed funding information is provided as part of the Acknowledgments after the main text
The anelastic structure and deep geology of the Derbyshire Dome from high frequency Rayleigh waves.
No full textThis work is an investigation of the anelastic structure of the Derbyshire Dome and adjacent areas from the analysis of high frequency, 0.6 - 4.2 Hz, fundamental mode Rayleigh waves observed from quarry blasts within the study area.
Seismic field experiments, designed and implemented to record Rayleigh waves accurately, are discussed together with the data preparation sequence. The effects of possible errors on timing and amplitude measurements are investigated and reduced.
Time domain measurements indicate the Carboniferous Limestone district of the Derbyshire Dome consists of smaller provinces the boundaries of which are marked by sudden changes in group velocity and co-incide with geological surface features. Similar provinces are not found in the adjacent Millstone Grit district. Approximate
estimates of group velocity are higher over the limestone than over the Millstone Grit district.
Transformation into the frequency domain facilitates the
determination of group arrival times and amplitude spectrum of each Rayleigh wave recorded. Least squares interstation analyses provide estimates of group slowness dispersion for the districts and component provinces and the Rayleigh wave specific attenuation factor, Qy-1(v), as a function of frequency for certain districts and provinces.
Group slowness which ranges from 0.33 - 1.1 s km 1,
increasing generally with frequency, is higher in the Millstone Grit district.
Qy-1 (v) ranges between 0.01'and 0.08 showing no marked correlation with surface lithology.
Models of shear wave velocity, ß(z), and intrinsic specific
11 attenuation factor for shear waves, Qßl(z), with depth, z, are obtained for the upper 1.5 km of the crust in each district and
province from the inversion of the observed dispersion and Q-1(v)Y data using linearised and Hedgehog techniques for ß(z) and similar methods for Qßl(z).
The deep geology of the area is inferred from the ß(z) models. The limestone district is divided by a major basement fault, to which surface features may be related. The Carboniferous Limestone of different provinces is underlain directly by Ordovician mudstones or Devonian sandstones. A sedimentary basin, of 1.5 km thickness,
displaying rhythmic sedimentation is postulated within the Millstone Grit district.
Fluid saturation conditions are inferred from the Qß1(2)
models. On comparison with previous laboratory work values of Q1-ß which exhibit a possible frequency dependence imply partial saturation of the upper layers of the limestone district whilst field estimates of Qß-1 not exhibiting any frequency dependence imply the Millstone Grit district to be fully saturated at all levels. Two mechanisms of dissipation based on the petrographic character of the
rock and fluid flow are believed to operate jointly
Die arterielle Steifigkeit wird bei Hämodialyse-Patienten von oxidativem Stress, Inflammation und Calcium-Phosphat Metabolismus beeinflusst
No full textDie progressive Einschränkung der Nierenfunktion führt zu einer vermehrten Versteifung der Gefäße (Arteriosklerose), unabhängig von und zusätzlich zur Atherosklerose, die eine erhöhte kardiovaskuläre Komplikationsrate zur Folge haben kann. Das durch die Urämie veränderte metabolische Milieu führt zu einem erhöhten oxidativen Stress, damit assoziert zu einer beträchtlichen inflammatorischen Belastung sowie zu einer gestörten Calcium-Phosphat-Homöostase, Konstellation die für vaskulären Veränderungen verantwortlich ist. Ein in klinischen Studien etablierter Surrogatparameter der arteriellen Gefäßsteifigkeit ist die Pulswellengeschwindigkeit (PWV). Ziel dieser Studie war, weitere Einblicke in den Pathomechanismus der beschleunigten Arteriosklerose von Hämodialyse-Patienten zu gewinnen, insbesondere dabei die Relation zwischen der PWV und Marker für oxidativen Stress, Prokoagulation und Inflammation sowie des Calcium-Phosphat-Produktes zu überprüfen. Wir haben eine Querschnittsstudie mit 53 stabilen Patienten, 30 Männer und 20 Frauen, im Alter von 59 ± 16 Jahren, an Hämodialyse seit 68 ± 48 Monaten, durchgeführt. Die Carotis-Radialis PWV wurde mithilfe eines semiautomatischen Gerätes, Complior SP (Artech Medical, France) gemessen. Die Advanced glycosylation end-products (AGE) und Advanced oxidation protein products (AOPP) wurden mittels schon beschriebener Methoden bestimmt. Das hochsensitive CRP wurde mittels ELISA gemessen, während für die anderen biochemischen Parameter, Fibrinogen, Albumin, Calcium, Phosphat, Cholesterol und Trigylzeride Routine-Methoden verwendet wurden. Die statistischen Berechnungen wurden mittels SPSS (Statistical Package of Social Science, 12.0, 2003) durchgeführt. Die Korrelationen zwischen PWV (abhängige Variable) und mehreren unabhängigen Variablen wurden mittels multipler Regressionsanalyse bestimmt. Dabei wurde der Einfluß traditioneller kardiovaskulärer Risikofaktoren und der Medikation der Patienten auf die abhängige Variable, PWV, berücksichtigt. Die Pulswellengeschwindigkeit korrelierte signifikant mit CRP (p=0.003), LDLCholesterin (p<0.001), Triglyzeride (p<0.001), AGE (p=0.002), Calcium (p<0.001), Phosphat (p=0.001), and Fibrinogen (p=0.020). Zwischen PWV und Dauer der Dialysebehandlung (Monate) wurde eine interessante quadratische Beziehung beobachtet. Die multiple Regressionsanalyse zeigte eine negative Korrelatin zwischen AOPP und PWV (p=0.001). Wir konnten keine signifikante Korrelation zwischen der PWV und dem Alter, dem systolischen Blutdruck oder der Herzfrequenz nachweisen. Von der Gruppe der konventionellen kardiovaskulären Risikofaktoren wurde in dieser Studie eine positive Korrelation ausschließlich zwischen dem LDL-Cholesterinspiegel und der PWV belegt. Wir konnten in dieser Querschnittserfassung zeigen, dass bei Hämodialyse-Patienten die anhand der PWV abgeschätzte arterielle Steifigkeit positiv und signifikant mit Surrogatparametern der Inflammation, Prokoagulation (Fibrinogen) und mit dem Phosphatspiegel korreliert. Die vaskuläre Architektur scheint synergistisch durch die für die Urämie charakteristische Konstellation – erhöhte inflammatorische und prokoagulatorische Aktivität und gestörter Knochenstoffwechsel – , modelliert zu werden.End-stage renal disease has been denominated a vasculopathic state, owing to the accelerated arterial stiffening, which occurs in addition to and independent of atherosclerosis and bears an increased cardiovascular risk. The altered metabolic milieu in uraemia leads to an increased oxidative stress, heightened inflammatory burden, and an abnormal calcium-phosphate metabolism, which are thought to be responsible for the vascular changes. The pulse wave velocity (PWV) is a widely employed surrogate parameter of arteriosclerosis. The purpose of this study was to gain more insight into the pathogenesis of arterial stiffness, by investigating the influence of markers of oxidative stress, procoagulation, and inflammation, and of the calcium-phosphate product on the PWV. We conducted a cross-sectional study in 53 stable patients aged 59 ± 16 years, who had been on haemodialysis for at least 4 months (68 ± 48). Carotid-radial PWV was measured using a semi-automated device, Complior SP (Artech Medical, France). Advanced glycosylation end-products (AGE) and advanced oxidation protein products (AOPP), were quantified according to previously described methods. High sensitive CRP was measured using ELISA, whereas the other biochemical parameters, i.e. fibrinogen, albumin, calcium, phosphate, cholesterol, and triglycerides, were determined using routine methods. For statistical calculations we employed SPSS (Statistical Package of Social Science, 12.0, 2003). The correlations between PWV, as the dependent variable, and many dependent variables were assessed by means of multiple regression analysis, in which we controlled for the influence of the traditional cardiovascular risk factors and some of the patients’ medication (calcium-channel blockers and statins). PWV was found to be significantly correlated to serum CRP (p=0.003), LDLcholesterol (p<0.001), triglycerides (p<0.001), AGE (p=0.002), calcium (p<0.001), phosphate (p=0.001), and fibrinogen (p=0.020). Between PWV and dialysis duration (months) an interesting quadratic relationship (p=0.058) was noted. Against expectation, regression analysis showed a negative correlation between AOPP and PWV (p=0.001). We failed to confirm the correlation between PWV and age, systolic blood pressure, or heart rate. Among traditional cardiovascular risk factors only LDL-cholesterol was positively correlated to PWV. In this cross-sectional analysis we could put forward that PWV correlates positively and significantly with fibrinogen, CRP, AGEs, calcium, phosphate, and LDL-cholesterol in haemodialysis patients. It seems procoagulatory and proinflammatory pathways, oxidative stress, and the calcium-phosphate product exert a synergistic effect on disturbances of vascular architecture in ESRD patients
Effect of 12-month intervention with low-dose atorvastatin on pulse wave velocity in subjects with type 2 diabetes and dyslipidaemia
No full textCardiovascular disease is the leading cause of morbidity and mortality in subjects with type 2 diabetes mellitus. Increased aortic stiffness, assessed with the carotid–femoral pulse wave velocity, is an independent risk factor for cardiovascular disease. Statins reduce effectively cardiovascular disease and mortality in high-risk patients. The aim of this prospective non-randomized, observational study was to examine the impact of treatment with either 10 mg atorvastatin plus diet or diet alone on carotid–femoral pulse wave velocity in subjects with type 2 diabetes mellitus and dyslipidaemia. A total of 79 subjects with type 2 diabetes mellitus and dyslipidaemia were included; 46 subjects were treated with atorvastatin 10 mg daily plus diet and 33 were managed by diet alone for 12 months. Carotid–femoral pulse wave velocity and carotid–radial pulse wave velocity were measured using applanation tonometry. In the atorvastatin-treated group, carotid–femoral pulse wave velocity reduced significantly during the study and there was a trend for reduction in the carotid–radial pulse wave velocity. Total cholesterol, low-density lipoprotein cholesterol, triglycerides and C-reactive protein were reduced only in the atorvastatin-treated participants. No significant changes were found in body mass index, blood pressure, heart rate, diabetes control and high-density lipoprotein cholesterol in either study group. Treatment with low-dose atorvastatin for 12 months improves carotid–femoral pulse wave velocity in subjects with type 2 diabetes mellitus and dyslipidaemia. © The Author(s) 2018
Regional anaesthesia for caesarean section in severe preeclampsia: spinal anaesthesia is the preferred choice
No full textPart of the Portfolio Thesis by Geoffrey H. Sharwood-Smith: The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts, available at http://hdl.handle.net/10023/1815Standard textbooks advocate epidural rather than spinal anaesthesia for caesarean section in severe preeclampsia. The basis for this recommendation is the theoretical risk of severe hypotension but no published scientific studies have been identified to support this assertion. We therefore designed a prospective study to compare spinal versus epidural anaesthesia in severely pre-eclamptic patients requiring hypotensive therapy. Following ethics committee approval, 28 women with preeclampsia requiring hypotensive medication who were scheduled for urgent (not emergency) or elective caesarean section consented to receive epidural or spinal anaesthesia by random assignment. Seven patients were excluded due to protocol violations. Four of these were in the epidural group of which two were excluded due to inadequate analgesia. No spinal patient was excluded because of inadequate analgesia. Mean ephedrine dosage was 5.2 mg (range 0–24 mg) in the spinal group and 6.3 mg (range 0–27 mg) in the epidural group. Six of the 11 patients in the spinal group required no ephedrine as did five of 10 in the epidural group. One patient in the spinal group suffered from mild intraoperative pain. By contrast in the epidural group three patients had mild pain and four others had pain severe enough to warrant intraoperative analgesia. There were no differences in neonatal outcomes. These findings support recent studies suggesting the safety and efficacy of spinal anaesthesia in this group of patients.Publisher PD
Estimated pulse wave velocity improves risk stratification for all-cause mortality in patients with COVID-19
No full text\ua9 2021, The Author(s). Accurate risk stratification in COVID-19 patients consists a major clinical need to guide therapeutic strategies. We sought to evaluate the prognostic role of estimated pulse wave velocity (ePWV), a marker of arterial stiffness which reflects overall arterial integrity and aging, in risk stratification of hospitalized patients with COVID-19. This retrospective, longitudinal cohort study, analyzed a total population of 1671 subjects consisting of 737 hospitalized COVID-19 patients consecutively recruited from two tertiary centers (Newcastle cohort: n = 471 and Pisa cohort: n = 266) and a non-COVID control cohort (n = 934). Arterial stiffness was calculated using validated formulae for ePWV. ePWV progressively increased across the control group, COVID-19 survivors and deceased patients (adjusted mean increase per group 1.89 m/s, P < 0.001). Using a machine learning approach, ePWV provided incremental prognostic value and improved reclassification for mortality over the core model including age, sex and comorbidities [AUC (core model + ePWV vs. core model) = 0.864 vs. 0.755]. ePWV provided similar prognostic value when pulse pressure or hs-Troponin were added to the core model or over its components including age and mean blood pressure (p < 0.05 for all). The optimal prognostic ePWV value was 13.0 m/s. ePWV conferred additive discrimination (AUC: 0.817 versus 0.779, P < 0.001) and reclassification value (NRI = 0.381, P < 0.001) over the 4C Mortality score, a validated score for predicting mortality in COVID-19 and the Charlson comorbidity index. We suggest that calculation of ePWV, a readily applicable estimation of arterial stiffness, may serve as an additional clinical tool to refine risk stratification of hospitalized patients with COVID-19 beyond established risk factors and scores
Local versus global aortic pulse wave velocity in early atherosclerosis: An animal study in ApoE-/--mice using ultrahigh field MRI.
No full textIncreased aortic stiffness is known to be associated with atherosclerosis and has a predictive value for cardiovascular events. This study aims to investigate the local distribution of early arterial stiffening due to initial atherosclerotic lesions. Therefore, global and local pulse wave velocity (PWV) were measured in ApoE-/- and wild type (WT) mice using ultrahigh field MRI. For quantification of global aortic stiffness, a new multi-point transit-time (TT) method was implemented and validated to determine the global PWV in the murine aorta. Local aortic stiffness was measured by assessing the local PWV in the upper abdominal aorta, using the flow/area (QA) method. Significant differences between age matched ApoE-/- and WT mice were determined for global and local PWV measurements (global PWV: ApoE-/-: 2.7±0.2m/s vs WT: 2.1±0.2m/s, P<0.03; local PWV: ApoE-/-: 2.9±0.2m/s vs WT: 2.2±0.2m/s, P<0.03). Within the WT mouse group, the global PWV correlated well with the local PWV in the upper abdominal aorta (R2 = 0.75, P<0.01), implying a widely uniform arterial elasticity. In ApoE-/- animals, however, no significant correlation between individual local and global PWV was present (R2 = 0.07, P = 0.53), implying a heterogeneous distribution of vascular stiffening in early atherosclerosis. The assessment of global PWV using the new multi-point TT measurement technique was validated against a pressure wire measurement in a vessel phantom and showed excellent agreement. The experimental results demonstrate that vascular stiffening caused by early atherosclerosis is unequally distributed over the length of large vessels. This finding implies that assessing heterogeneity of arterial stiffness by multiple local measurements of PWV might be more sensitive than global PWV to identify early atherosclerotic lesions
Quasistatic component generation of group velocity mismatched guided waves in tubular structures for microdamage localization
No full textQuasistatic component (QSC) of guided wave (GW) has relatively low attenuation due to low frequency and high sensitivity to microdamage. The group velocity matching between primary GW and its QSC or higher harmonics usually facilitates the measurement of nonlinear signals due to cumulative effect of amplitude, but it restricts the determination of microdamage location. While group velocity mismatch is general for most of the wave mode pairs in nonlinear GW testing, this study presents a novel method for identifying the location of early stage microdamage using QSC generation of ultrasonic GW propagation in tubular structures under group velocity mismatching condition. A three-dimensional finite element (FE) model is developed to provide insights into the generation and propagation characteristics of the QSC induced by both global material weak nonlinearity and simulated local microdamage in metallic pipes. The FE analysis verifies the L(0,1) mode of the QSC generated from propagations of different fundamental wave modes. The generation efficiency and cumulation feature of the QSC pulse are obtained and discussed. By exploiting the group velocity mismatching condition, a microdamage localization method is proposed based on the L(0,1)-QSC mode pair, which requires one-way excitation of only one primary wave. Experiments are conducted using early corrosion aluminum specimens to investigate the QSC pulse signals and verify the proposed method. The FE and experimental results demonstrate the fundamental properties of QSC generation by GWs in isotropic metallic hollow cylindrical structures. The feasibility of the proposed microdamage localization method is validated experimentally for promising industrial applications
Higher carotid-radial pulse wave velocity is associated with non-melancholic depressive symptoms in men : findings from Helsinki Birth Cohort Study
No full textBackground: Depression and cardiovascular disease (CVD) are major causes of global disease burden that are interrelated through mostly unknown mechanisms. We studied the relationship of melancholic and non-melancholic depressive symptoms with arterial stiffness, an important underlying mechanism of CVD.
Methods: The Helsinki Birth Cohort Study recruited 683 previously extensively phenotyped subjects for this sub-study. Cross-sectional data along with responses regarding depressive symptoms were obtained for each participant. For evaluation of depressive symptoms, the Beck Depression Inventory (BDI)and subscales were used to measure melancholic and non-melancholic depressive symptoms. Arterial stiffness was assessed as pulse wave velocity (PWV) that was measured between the carotid and radial artery, and carotid and femoral artery.
Results: Of the participants, 532 scored <10 on the BDI and were classified as not having depressive symptoms. Of the 151 participants that scored ≥10 on the BDI, 122 were classified as having non-melancholic depressive symptoms and 29 as having melancholic depressive symptoms. Men had higher carotid-radial PWV (crPWV) values than women (p < .001). A positive relationship between BDI scores and crPWV (p < .001) was found in men. We also found higher crPWV in men with non-melancholic depressive symptoms compared to all others. No such differences were found in women.
Discussion: Arterial stiffness has a relationship with depressive symptoms and subtypes of depressive symptoms, at least in men. There is a significant relationship between higher PWV and non-melancholic depressive symptoms in men. Due to the intricate nature of the disease causality or directionality is impossible to infer solely based on this study. Further studies into the subtypes of depressive symptoms may be of benefit to understanding depression.KEY MESSAGESIt is known that arterial stiffness contributes to cardiovascular disease, and is associated with depression.Higher Beck Depression Inventory scores are associated with higher carotid-radial pulse wave velocity in men.Non-melancholic depressive symptoms are associated with higher carotid-radial pulse wave velocity in men.peerReviewe
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