Wave Separation Research Articles

Hemodynamic Responses Following High Intensity Exercise In Long-covid-19 Patients With Brain Fog: Wave Separation Analysis

Hemodynamic Responses Following High Intensity Exercise In Long-covid-19 Patients With Brain Fog: Wave Separation Analysis

Relation of forward and backward traveling pressure waves with subclinical carotid artery wall remodeling and central pulse pressure.

Central pulse pressure (PP) is the sum of forward and backward traveling pressure waves that have been associated with cardiovascular disease (CVD) risk. However, previous studies have reported differential findings regarding the importance of the forward versus the backward wave for CVD risk. Therefore, we sought to determine the degree to which the forward and backward pressure waves are associated with subclinical carotid artery wall remodeling and central PP in healthy adults. Using applanation tonometry, carotid pressure waveforms were acquired in 308 healthy individuals (aged 45 ± 17 years, range 19-80 years, 61% women), from which the time integral of the forward (PfTI) and backward (PbTI) pressure waves were derived via pressure-only wave separation analysis. Common carotid artery intima-media thickness (cIMT), a biomarker of subclinical CVD risk, was derived via B-mode ultrasonography measured ∼2 cm from the carotid bulb. Both PfTI (r = 0.31, P < 0.001) and PbTI (r = 0.40, P < 0.001) were correlated with cIMT. However, further analysis revealed that PbTI mediated the relation between PfTI and cIMT (proportion mediated = 156%, P < 0.001). The association between PbTI and cIMT remained after adjusting for age, sex, body mass index, blood glucose, low-density lipoprotein cholesterol, heart rate, brachial systolic pressure, and aortic stiffness (B = 0.02, 95% confidence interval = 0.01, 2.77, P < 0.001). Both PfTI (r = -0.58, P < 0.001) and PbTI (r = -0.50, P < 0.001) were correlated with central PP, however, PfTI fully mediated the association between PbTI and central PP (proportion mediated = 124%, P < 0.001). Although PfTI is correlated with higher central PP, it is PbTI that is directly associated with carotid artery wall remodeling.NEW & NOTEWORTHY The present study contributes to the growing body of evidence highlighting the physiological and clinical insight provided by the pulsatile hemodynamic components of central artery pulse pressure. The notable findings of this study are: 1) The reflected (backward) pressure wave is associated with carotid intima-media thickness independent of traditional cardiovascular risk factors, including systolic blood pressure and aortic stiffness. 2) The incident (forward) pressure wave, and not the reflected pressure wave, is associated with greater central pulse pressure.

Large eddy simulation of supersonic flow in ducts with complex cross-sections

Large Eddy Simulation (LES) has been employed for the investigation of supersonic flow characteristics in five ducts with varying cross-sectional geometries. The numerical results reveal that flow channel configurations exert a considerable influence on the mainstream flow and the near-wall flow behavior. In contrast to straight ducts, square-to-circular and rectangular-to-circular ducts exhibit thicker boundary layers and a greater presence of vortex structures. Given the same inlet area, rectangular-to-circular ducts lead to higher flow drag force and total pressure loss than square-to-circular ducts. Characterized by the substantial flow separation and shock waves, the “S-shaped duct shows significant vertically-asymmetric characteristics.

Thermoregulation in Two Models of Trail Run Socks with Different Fabric Separation.

Trail running socks with the same fibers and design but with different separations of their three-dimensional waves could have different thermoregulatory effects. Therefore, the objective of this study was to evaluate the temperatures reflected on the sole of the foot after a mountain race with the use of two models of socks with different wave separations. In a sample of 34 subjects (twenty-seven men and seven women), the plantar temperature was analyzed with the thermal imaging camera Flir E60bx® (Flir systems, Wilsonville, OR, USA) before and after running 14 km in mountainous terrain at a hot temperature of 27 °C. Each group of 17 runners ran with a different model of separation between the waves of the tissue (2 mm versus 1 mm). After conducting the post-exercise thermographic analysis, a Likert-type survey was conducted to evaluate the physiological characteristics of both types of socks. There was a significant increase in temperature in all areas of interest (p < 0.001) after a 14 km running distance with the two models of socks. The hallux zone increased in temperature the most after the race, with temperatures of 8.19 ± 3.1 °C and 7.46 ± 2.1 °C for the AWC 2.2 and AWC 3, respectively. However, no significant differences in temperature increases were found in any of the areas analyzed between the two groups. Runners perceived significant differences in thermal sensation between AWC 2.2 socks with 4.41 ± 0.62 points and AWC 3 with 3.76 ± 1.03 points (p = 0.034). Both models had a similar thermoregulatory effect on the soles of the feet, so they can be used interchangeably in short-distance mountain races. The perceived sensation of increased thermal comfort does not correspond to the temperature data.

Superiority of a Representative MRI Flow Waveform over Doppler Ultrasound for Aortic Wave Reflection Assessment in Children and Adolescents With/Without a History of Heart Disease

Wave separation analysis (WSA) reveals the impact of forward- and backward-running waves on the arterial pressure pulse, but the calculations require a flow waveform. This study investigated (1) the variability of the ascending aortic flow waveform in children and adolescents with/without a childhood heart disease history (CHD); (2) the accuracy of WSA obtained with a representative flow waveform (RepFlow), compared with the triangulation method and published ultrasound-derived adult representative flow; (3) the impact of limitations in Doppler ultrasound on WSA; and (4) generalizability of results to adults with a history of CHD. Phase contrast MRI was performed in youth without (n = 45, Group 1, 10–19 years) and with CHD (n = 79, Group 2, 7–18 years), and adults with CHD history (n = 29, Group 3, 19–59 years). Segmented aortic cross-sectional area was used as a surrogate for the central pressure waveform in WSA. A subject-specific virtual Doppler ultrasound was performed on MRI data by extracting velocities from a sample volume. Time/amplitude-normalized ascending aortic flow waveforms were highly consistent amongst all groups. WSA with RepFlow therefore yielded errors < 10% in all groups for reflected wave magnitude and return time. Absolute errors were typically 1.5–3 times greater with other methods, including subject-specific (best-case/virtual) Doppler ultrasound, for which velocity profile skewing introduced waveform errors. Our data suggest that RepFlow is the optimal approach for pressure-only WSA in children and adolescents with/without CHD, as well as adults with CHD history, and may even be more accurate than subject-specific Doppler ultrasound in the ascending aorta.

DISTRIBUTION OF SEDIMENTS AT THE MAIN MOUTHS OF THE KILIA DENUBE DELTA AND THEIR SEDIMENTATION VALUE

Purpose: In the article the basic purpose is determination and analysis by distribution natural conformities of deltaic sediments after its movement across every arm, under impact of sea waves separation and influence of the coastal hydrogenetic factors. The noted peculiarities have important practical significance. Additionally, they explain the marine margin dynamics and sediment forming of deltaic types. Data &amp; Methods: This article is based on natural datum of sedimentary material sampling around of marine margin of the dynamical Danube delta, NW Coast of the Black Sea. The sampling was made in region from head of Zhebriyan bay in north side to Musura bay in south side during 2010–2020 period in different environment and synoptical conditions. Laboratory elaborations were made with representative instruments usage and mathematical methods of treatment. Samples of suspended and coarse drifts were elaborated and analyzed within conditions of different sides of marine margin of the Delta. Results: The general definitions of protruding deltas state that the delta cone of protrusion is composed of alluvial sediments. But in the studied delta, a significant place is occupied by coastal-marine facies of wave action. In addition, the newest river sedimentary material changes during the passage through deltaic watercourses (especially long ones). Therefore, on the delta coast within the marine wave field, sediments with a slightly changed composition appear. Therefore, several facies environments can be defined in the Danube delta: a) typically riverine; b) alluvial-delta; c) coastal sea with separated sediments; d) aeolian center of influence of the wind factor; e) typical marine on the outer strip of the sea. We recommend that all the mentioned features be taken into account during the analysis of the Danube’s flow sediments to the bottom of the Black Sea and the determination of sedimentation rates. The main paper outlines provisions of the lithodynamic model of delta-type sediments’ formation in the conditions of a generous influx of river sediments, a steep underwater slope, a non-tidal sea and strong wave action. Fractions of 0.1–0.01 mm dominate along the coastal edge, with integral Md = 0.048 mm, and the concentration of fractions &gt; 1.0 mm is sharply reduced. The content of CaСО3 is lower in comparison with sediments in Zhebriyansk Bay in the area of final dispersion of a strong alongshore flow of sand sediments. Within the studied deltaic natural system, the surrounding physical and geographical conditions actively influence the composition of delta sediments, create a sedimentary diversity of the facies network and tracts. The different composition of sediments leads to different density of the sediment layer, with different amounts of water content, mostly from 1% to 5%, different influence of river and sea factors. Accordingly, specific facies cells of the botanical and zoological substrate are formed in the areas of dominant influence of these factors. In the new parts of the delta, some cells settle first, others later, and the third – last in the life cycle. Therefore, in different areas, we meet the settlement of the primary territories of the delta by different plants and animals that are located in different parts of the warm period of the year.

Reduced COVID-19 morbidity and mortality in hemodialysis patients across the various Omicron sublineages-A retrospective analysis.

Hemodialysis (HD) patients are a COVID-19 high risk population due to comorbidities and impaired immune response. Vaccines, advent of effective treatment and the emergence of novel variants have fundamentally changed the pandemic. We aimed to assess temporal changes of COVID-19 in HD patients of our catchment area, and risk factors for severe and fatal course. We retrospectively collected data from 274 patients admitted to the Medical University Graz, Austria for HD between 1st of May 2020 and 31st of August 2022. We analyzed clinical and demographic data between different COVID-19 waves and assessed factors associated with hospitalization, ICU admission and mortality by logistic regression. To further evaluate the dialysis at-risk population, we collected demographic and vaccination data between August 2021 and August 2022. Time of infection and SARS-CoV-2 sequencing data allowed for distinction of five separate waves of infection with different impact on the dialysis population: While in the initial four waves frequencies of hospitalization, necessity of critical care and mortality were around 60%, 10% and 20%, respectively. These events became rare during the large fifth wave, when Omicron had become the dominant variant. Although only 16.9% had to be hospitalized, this resulted in 29 hospital admissions, due to the high prevalence of COVID-19 during the Omicron era. Furthermore, we observed similar clinical outcomes with BA.4/5 as with BA.1/BA.2 Omicron sublineages. The proportion of previously infected increased simultaneously with the number of vaccination doses in our dialysis population. Vaccination at time of positivity and infection with an Omicron variant conferred protection against hospitalization and mortality in univariate analysis, but only infection with an Omicron variant remained a robust predictor for these outcomes in multivariable analysis. While a fourth of our at-risk population became infected during the Omicron wave, mortality was almost non-existent. Several concomitant factors have contributed to the decrease of COVID-19 severity in HD patients. This trend appears to be continued with BA.4/5, which was equally mild as BA.1 and BA.2 in our well vaccinated dialysis population.

Dynamical Drivers of the Exceptional Warmth over Siberia during the Spring of 2020

Abstract Much of Siberia experienced exceptional warmth during the spring of 2020, which followed an unusually warm winter over the same region. Here, we investigate the drivers of the spring warmth from the perspective of atmospheric dynamics and remote influences, focusing on monthly-time-scale features of the event. We find that the warm anomalies were associated with separate quasi-stationary Rossby wave trains emanating from the North Atlantic in April and May. The wave trains are shown to be extreme manifestations of the dominant modes of spring subseasonal meridional wind variability over the Northern Hemisphere. Using a large ensemble of simulations from NASA’s GEOS atmospheric model, in which the model is constrained to remain close to observations over selected regions, we further elucidate the remote drivers of the unusual spring temperatures in Siberia. In both April and May, the wave trains were likely forced from an upstream region including eastern North America and the western North Atlantic. Analysis with a stationary wave model shows that transient vorticity flux forcing over and downwind of the North Atlantic, which is strongly related to storm activity caused by internal variability, is key to generating the wave trains, suggesting limited subseasonal predictability of the Rossby waves and hence the exceptional Siberian warmth. Our observational and model analyses also suggest that anomalous tropical atmospheric heating contributed to the unusual warmth in Siberia through a teleconnection involving upper-troposphere dynamics and the mean meridional circulation. This tropical–extratropical teleconnection offers a possible physical mechanism by which anthropogenic climate change influenced the extreme Siberian warmth.

Numerical study of microdevice with surface acoustic waves for separation of gas mixtures

Recently, it was shown that traveling surface acoustic waves (SAWs) can affect gas flow in microchannels. The effect of SAWs was studied in free-molecular flow regime, and it was shown that SAWs can induce separation of gas mixtures. In the present work, this effect is studied for denser flow regimes, which are more interesting from a practical point of view. The problem is studied numerically using own modification of the direct simulation Monte Carlo method on the example of a neon–argon mixture. The main finding is that SAWs still enhance separation of gas mixtures outflowing into vacuum through a microchannel under all studied rates of gas rarefaction up to Kn≈0.1. Another important practical result is that effect is present for wave speeds typical for existing SAWs (≈1000 m/s) and in a wide range of SAW amplitude to channel height ratios. Influence of other practical aspects, such as channel length, masses of species, and available magnitudes of material surface speed, are also briefly discussed.

Numerical Simulation of Flow Field Over a Sharp-Tipped Double Cone at High Speed

The flowfield over a sharp-tipped double cone axisymmetric configuration is carried out by solving time dependent axisymmetric laminar compressible Navier-Stokes equations for freestream Mach number range of 2.0 - 6.0. The fluid dynamics equations are discretized in spatial coordinates using integral formulation in conjunction with finite volume method which reduces the governing equations to semi-discretized ordinary differential equations. Temporal integration is performed employing multistage Runge-Kutta time-stepping scheme. A local time step is used to achieve steady-state solution. The numerical computation is carried out on a mono-block with structured grids. The flowfield features over the sharp-tipped double cone configuration such as conical shock wave, separation region, separation and reattachment shock wave and bow shock wave in the cone region, expansion fan, and recirculation flow in the base region are well captured at Mach number 3 and 6 which are identical to the Edney VI type shock interaction. The velocity vector, Mach contours plots and variations of surface pressure coefficient along the sharp-tipped double cone configuration are analyzed at various Mach numbers. The fore-body aerodynamic drag is calculated employing computed pressure distribution. The paper presents the influence of the freestream Mach number on the flows with shock interactions over the sharp-tipped double cone geometry.

Swash flows generated by a train of solitary waves on a planar slope

Six consecutive solitary waves with identical wave height and separation time are generated to study the flow structures during the uprush–downwash interactions in the swash zone. Using particle image velocimetry, the cross-shore velocity fields are captured. Two different wave conditions are examined with different wave-height-to-water-depth ratios, i.e.$H_o/h=0.11$and 0.22. The uprush–downwash interaction reaches quasi-steady state from the third solitary wave for both cases. For the former case, a weak non-stationary hydraulic jump appears during the downwash flow for all the six consecutive waves. The weak hydraulic jump evolves into a momentarily ‘stationary’ broken bore when the next wave arrives. For the latter case, the larger wave height generates stronger wave breaking. No non-stationary hydraulic jump is observed as the duration of downwash flow is relatively short. The flow reverses to the onshore direction before the downwash Froude number reaches the hydraulic jump condition. The temporal and spatial evolution of turbulence structure at the quasi-steady state is quantified using the spatial spectral analysis, the integral length scale and turbulence eddy viscosity. The results suggest that the large-scale energy generated during the uprush–downwash interaction modified the slope of the turbulence energy spatial spectrum in the inertial subrange from$-$5/3 to$-$1 in the larger length scale region, indicating the energy cascade depends not only on the dissipation rate, but also on the turbulent kinetic energy from the large-scale turbulence structure because of the large-scale energy injection in the inertial subrange.

Verification and intercomparison of global ocean Eulerian near-surface currents

The OceanPredict task team for Intercomparison and Validation (IV-TT) has established the CLASS4 data standard for routine forecast verification against selected reference observing platforms. The set of CLASS4 reference data has been recently extended to include near-surface currents derived from the trajectories of drifting buoys drogued at 15 m. We have applied these data to the Ocean Model, Analysis and Prediction System (OceanMAPS) at the Australian Bureau of Meteorology (ABoM) for verification and inter-comparison with Mercator Océan International ocean forecast system (MOi), the operational models of the Met Office, UK: Forecast Ocean Assimilation Model (FOAM) and Coupled Atmosphere-Land-Ocean-Ice Data Assimilation (CPLDA) systems, and the Global Ice Ocean Prediction System (GDPS-GIOPS) at the Canadian Centre for Meteorological and Environmental Prediction (CCMEP). The aims for this verification analysis are to extend the routine monitoring of the operational system; to assess the OceanMAPS skill against other models; and to inform our stakeholders of the OceanMAPS performance.We have evaluated the impacts of adding Stokes drift and tidal currents from separate global wave and global tide models to the model currents on the verification of currents. Including Stokes drift leads to significant improvements in representation and the metrics for model skill while inclusion of tides has no significant impact on the global statistics. Zonal currents have a stronger signal than the meridional currents as indicated by their high correlation with observations, and lower errors. This indicates zonal currents on average are more predictable and persistent than the meridional currents, resulting in improved representation in the models.Overall, MOi, and the new version of OceanMAPS (4.0i), and FOAM show marginally better performance against the observations relative to other models. Although there are significant differences in the configurations of the eight models under evaluation, all the models are shown to be remarkably statistically equivalent with consistent spatial and temporal patterns indicating the main differences are attributable to unrepresented processes. We therefore conclude that there is significant scope to further improve the representation of the modelled currents with the observations.

‘What a waste of time’: An examination of cybersecurity legitimacy

AbstractManagers who oversee cybersecurity policies commonly rely on managerial encouragement (e.g., rewards) and employee characteristics (e.g., attitude) to drive compliant behaviour. However, whereas some cybersecurity initiatives are perceived as reasonable by employees, others are viewed as a ‘waste of time’. This research introduces employee judgements of cybersecurity legitimacy as a new angle for understanding employee compliance with cybersecurity policies over time. Drawing on theory from the organisational legitimacy and cybersecurity literature, we conduct a three‐wave survey of 529 employees and find that, for each separate wave, negative legitimacy judgements mediate the relationship between management support and compliance, as well as between cybersecurity inconvenience and compliance. Our results provide support for cybersecurity legitimacy as an important influence on employee compliance with cybersecurity initiatives. This is significant because it highlights to managers the importance of not simply expecting compliant employee behaviour to follow from the introduction of cybersecurity initiatives, but that employees need to be convinced that the initiatives are fair and reasonable. Interestingly, we did not find sufficient support for our expectation that the increased likelihood of a cybersecurity incident will moderate the legitimacy‐policy compliance relationship. This result suggests that the legitimacy perceptions of employees are unyielding to differences in the risk characteristics of the cybersecurity incidents facing organisations.

Introducing the Mapping Attitudes, Perceptions and Support (MAPS) dataset on the Colombian peace process

This article introduces the Mapping Attitudes, Perceptions and Support (MAPS) dataset, which provides rich survey data from more than 12,000 respondents in Colombia. Our panel survey – carried out in two separate waves in 2019 and 2021 – is representative at the level of each ‘Program for Development with a Territorial Focus’ (PDET, for its acronym in Spanish), the most war-affected regions and those targeted for peace agreement implementation. We describe the sample and compare support for the peace agreement in MAPS to other recent surveys in Colombia, showing how MAPS reveals regional variation obscured in nationally representative surveys. Regression analyses illustrate how the panel data allow us to explore how and why people’s perceptions of the agreement shift over time. The MAPS data will enable scholars to gain insights into the microfoundations of peacebuilding over time and across space.

Lay Evaluations of Restraints and Prohibitions During the 1st, 2nd, and 4th Wave of the COVID-19 Pandemic in Lithuania

The article analyzes how, during the separate waves (the 1st, 2nd, and the 4th) of the coronavirus pandemic, participants of a study (overall n = 1356) assessed the government-imposed restrictions, prohibitions, liabilities and penalties for non-compliance with said restrictions, the perceived fairness of the behavior of other people during the pandemic, and the changes of their assessments during the coronavirus pandemic. Obtained evidence suggests that during the Covid-19 pandemic (from the 1st to the 4th wave) the participants of the study assessed the non-compliance with restrictions and prohibitions more and more forgivingly.

On singular value decomposition for split quaternion matrices and applications in split quaternionic mechanics

In the theoretical studies and numerical computations of split quaternionic quantum mechanics, the singular value decomposition theorem of split quaternion matrices plays an essential role. In general the problem of singular value decomposition over split quaternion algebra has hitherto remained tangential for split quaternion matrices. In this paper, by means of a real representation matrix of a split quaternion matrix, the singular value decomposition of split quaternion matrices is studied, the singular value decomposition theorem and the corresponding algorithm for split quaternion matrices are given. Finally, three applications for solving the split quaternion least squares problem and the wave separation problem are given based on the singular value decomposition over split quaternion algebra.

High-fidelity aeroelastic transonic analysis using higher-order structural models

A novel computational approach for static aeroelastic analysis of metal and composite wings in transonic flows is proposed. Static aeroelastic analysis is often performed coupling beam/plate structural formulations with low-fidelity inviscid and irrotational aerodynamics. When high subsonic, transonic or supersonic regimes are met, low-fidelity aerodynamics is unable to accurately describe flow separation, viscous phenomena, and/or shock waves, unless suitable corrections are considered. This work combines the use of a variable-order kinematics structural model with Computational Fluid Dynamics (CFD), with the aim of developing a flexible computational aeroelastic framework. In particular, the structural model is based on the Carrera Unified Formulation and Equivalent Plate Modelling, whose governing equations are then solved through the Finite Element Method. The CFD analysis is performed using the high-fidelity open-source software SU2. The fluid–structure interaction is captured resorting to an energetic approach based on the Moving Least Squares patch technique. The generality and flexibility of the developed tool is demonstrated considering: the structural analysis of a wing exhibiting taper ratio, sweep angle, spars and ribs; the aeroelastic static analysis of a transonic AGARD 445.6 wing; and a prototype aeroelastic tailoring study on a composite wing. Comparison with available literature results confirms the robustness of the approach.

Aerodynamic performance of a characteristic airfoil at low-Reynolds number and transonic flow under Mars sand-containing environment

The propeller tip of an unmanned aerial vehicle on Mars operates at a low-Reynolds number (Re = 1–5 × 104) and transonic velocity range (Ma = 0.7–1.2). Generally, this implies flow separation and shock waves in the flow field. Furthermore, the impact of Martian atmospheric sand particles significantly affects the aerodynamic performance, and numerical simulations of this issue have received increasing attention recently. Aimed at a characteristic airfoil, the study of a low-Reynolds number transonic flow and the influence of sand-containing flow on airfoil aerodynamic performance were analyzed in this study. The discrete phase model was adopted to simulate the two-phase flow considering Re = 8100–56 800 and Ma = 0.2–1.4. The results indicate that, compared with the atmospheric environment on Earth, the low-pressure atmosphere on Mars can delay the generation of the surface shock wave of the airfoil as well as alter the shock wave structure, significantly increasing the lift-to-drag ratio at high subsonic velocities (Ma = 0.6–0.8). Moreover, due to the weak compressive wave generated at the separation position, the low-pressure atmosphere weakens the strength of the trailing-edge oblique shock wave and reduces the drag when Ma = 0.9–1.4. Compared with a sand-free environment, sand-containing flow can affect the separation and transition positions of laminar separation bubbles, in addition to alter the shock wave structure. At different Mach numbers, the lift and drag of the airfoil first increased and then decreased as the sand particles flowed in the horizontal direction during the entire process of particles entering and exiting the airfoil flow field.

Transmission loss measurement of recycled granular material using wave decomposition by impulse response extraction based on deconvolution

A simplified method for measuring transmission loss with a single fixed microphone inside an impedance tube is proposed. The separation of the incident wave from the reflected wave is achieved by deconvolving the loudspeaker driver voltage signal with the microphone signal to extract the impulse response. Random noise and a sinusoidal sweep signal were used as excitation signals for extraction of the impulse response, and two deconvolution methods were employed: linear deconvolution based on the adaptive LMS algorithm and simple spectral division. To avoid the overlap of incident and reflected pulses, a long impedance tube was used. Using a long impedance tube eliminates the need for an anechoic tube termination and the need to calibrate microphones. It is found that a reflective tube termination provides more accurate results compared to an approximately anechoic termination. The approximately anechoic termination shortens the available time window of the reflected pulse because it reflects some of the low-frequency sound. The standard deviation of the results and the dynamic range of the proposed method were determined experimentally. The applicability of the new method was tested on samples of unconsolidated granular material recycled from construction sites. The measured transmission losses of the different granular fractions were compared with a theoretical model for transmission losses at low frequencies. Samples consisting of smaller granule fractions were found to have surprisingly high transmission loss values. The design of the extended vertical impedance tube in combination with the proposed method is cost effective, speeds up the measurement procedure and provides reliable results.

1784-PUB: Empagliflozin (EMPA) Enhances Vascular Insulin Sensitivity and Lowers Plasma ICAM in Subjects with Type 2 Diabetes (T2D)

Background: The mechanism(s) by which sodium-glucose cotransporter 2 inhibitor (SGLT2i) use improves cardiovascular and renal outcomes in T2D are not well-defined. We hypothesized that EMPA would increase vascular insulin sensitivity and decrease endothelial cell (EC) stress markers in T2D. Study Design: Ten 18-60 years-old persons with T2D, 6.5 &amp;lt; a1c 3 months, were studied. we measured vascular stiffness (pulse wave separation analysis), ec function (flow-mediated dilation (fmd)), and stress biomarkers (elisa) before after a 2-hour, 1 mu min kg euglycemic clamp at 0 12 weeks treatment with 10 mg empa daily. results: not wk 0, but wks, insulin decreased forward backward arterial pressures from 28±3 to 20±2 24±3 13±1 mmhg, respectively, (p&amp;lt;0.02, each) improved the fmd response (p="0.02)," indicating function. peripheral systolic diastolic unchanged by week declined (p&amp;lt;0.03, treatment. lowered baseline post-insulin plasma icam-1 (p&amp;lt;0.002, increased vcam-1 (p&amp;lt;0.0005). infusion pecam-1 (p&amp;lt;0.03) vasoconstrictor endothelin-1 (p&amp;lt;0.01) comparably or without e-selectin s100a8 9 did change significantly either empa. decrease suggests that inflammation. insulin’s action lower appeared independent of empa, may contribute empa’s beneficial actions. Interpretation: EMPA for 12 weeks enhanced insulin’s action to: 1) diminish arterial stiffness, 2) enhance EC function including biomarker release, and 3) lower blood pressure. Improved vascular insulin sensitivity may contribute to the improved CVD outcomes seen with SGLTi treatment. Disclosure T.Nguyen: None. L.Jahn: None. L.Hartline: None. K.W.Aylor: None. E.Barrett: None. Funding National Institutes of Health (R01HL142250)