Measure Of Wave Reflection Research Articles

Association of Arterial Stiffness With Mid- to Long-Term Home Blood Pressure Variability in the Electronic Framingham Heart Study: Cohort Study.

Short-term blood pressure variability (BPV) is associated with arterial stiffness in patients with hypertension. Few studies have examined associations between arterial stiffness and digital home BPV over a mid- to long-term time span, irrespective of underlying hypertension. This study aims to investigate if arterial stiffness traits were associated with subsequent mid- to long-term home BPV in the electronic Framingham Heart Study (eFHS). We hypothesized that higher arterial stiffness was associated with higher home BPV over up to 1-year follow-up. At a Framingham Heart Study research examination (2016-2019), participants underwent arterial tonometry to acquire measures of arterial stiffness (carotid-femoral pulse wave velocity [CFPWV]; forward pressure wave amplitude [FWA]) and wave reflection (reflection coefficient [RC]). Participants who agreed to enroll in eFHS were provided with a digital blood pressure (BP) cuff to measure home BP weekly over up to 1-year follow-up. Participants with less than 3 weeks of BP readings were excluded. Linear regression models were used to examine associations of arterial measures with average real variability (ARV) of week-to-week home systolic (SBP) and diastolic (DBP) BP adjusting for important covariates. We obtained ARV as an average of the absolute differences of consecutive home BP measurements. ARV considers not only the dispersion of the BP readings around the mean but also the order of BP readings. In addition, ARV is more sensitive to measurement-to-measurement BPV compared with traditional BPV measures. Among 857 eFHS participants (mean age 54, SD 9 years; 508/857, 59% women; mean SBP/DBP 119/76 mm Hg; 405/857, 47% hypertension), 1 SD increment in FWA was associated with 0.16 (95% CI 0.09-0.23) SD increments in ARV of home SBP and 0.08 (95% CI 0.01-0.15) SD increments in ARV of home DBP; 1 SD increment in RC was associated with 0.14 (95% CI 0.07-0.22) SD increments in ARV of home SBP and 0.11 (95% CI 0.04-0.19) SD increments in ARV of home DBP. After adjusting for important covariates, there was no significant association between CFPWV and ARV of home SBP, and similarly, no significant association existed between CFPWV and ARV of home DBP (P>.05). In eFHS, higher FWA and RC were associated with higher mid- to long-term ARV of week-to-week home SBP and DBP over 1-year follow-up in individuals across the BP spectrum. Our findings suggest that higher aortic stiffness and wave reflection are associated with higher week-to-week variation of BP in a home-based setting over a mid- to long-term time span.

Arterial Stiffness and Cardiorespiratory Fitness Impairment in the Community.

Background During exercise, a healthy arterial system facilitates increased blood flow and distributes it effectively to essential organs. Accordingly, we sought to understand how arterial stiffening might impair cardiorespiratory fitness in community-dwelling individuals. Methods and Results Arterial tonometry and maximum effort cardiopulmonary exercise testing were performed on Framingham Heart Study participants (N=2898, age 54±9 years, 53% women, body mass index 28.1±5.3 kg/m2). We related 5 arterial stiffness measures (carotid-femoral pulse wave velocity [CFPWV]: a measure of aortic wall stiffness; central pulse pressure, forward wave amplitude, characteristic impedance: measures of pressure pulsatility; and augmentation index: a measure of relative wave reflection) to multidimensional exercise responses using linear models adjusted for age, sex, resting heart rate, habitual physical activity, and clinical risk factors. Greater CFPWV, augmentation index, and characteristic impedance were associated with lower peak oxygen uptake (VO2; all P<0.0001). We observed consistency of associations of CFPWV with peak oxygen uptake across age, sex, and cardiovascular risk profile (interaction P>0.05). However, the CFPWV-peak oxygen uptake relation was attenuated in individuals with obesity (P=0.002 for obesity*CFPWV interaction). Higher CPFWV, augmentation index, and characteristic impedance were also related to cardiopulmonary exercise testing measures reflecting adverse O2 kinetics and lower stroke volume and peripheral O2 extraction but not to ventilatory efficiency, a prognostic measure of right ventricular-pulmonary vascular performance. Conclusions Our findings delineate relations of arterial stiffness and cardiorespiratory fitness in community-dwelling individuals. Future studies are warranted to evaluate whether the physiological measures implicated here may represent potential targets for improving cardiorespiratory fitness in the general population.

Composite wave-absorbing structure combining thin plasma and metasurface

In order to solve the thickness dependence of plasma absorption of electromagnetic waves and further reduce the backward radar scattering cross section (RCS) of the target, we designed a novel composite structure of a metasurface and plasma. A metasurface with three absorption peaks is designed by means of an equivalent circuit based on an electromagnetic resonance type metamaterial absorber. The reflection and absorption of the composite structure are numerically and experimentally verified. The finite integration method was used to simulate a composite structure of finite size to obtain the RCS. The experimental measurements of electromagnetic wave reflection were conducted by a vector network analyzer (Keysight N5234A) and horn antennas, etc. The research showed that the absorption capacity of this composite structure was substantially improved compared to either the plasma or the metasurface, and it is more convenient for application due to its low plasma thickness requirement and easy fabrication.

Abstract 14300: Arterial Stiffness is Associated With Intermediate-Term Home Blood Pressure Variability: The Electronic Framingham Heart Study

Introduction: Short-term blood pressure variability (BPV) is associated with arterial stiffness in patients with hypertension. Few studies examined associations between arterial stiffness and digital home BPV over an intermediate time span. Objective: We investigated if antecedent arterial stiffness was associated with home BPV among participants in the electronic Framingham Heart Study (eFHS). We hypothesize that higher arterial stiffness predicts higher intermediate-term home BPV over one-year follow-up. Methods: At an FHS research exam (2016-2019), participants underwent arterial tonometry to acquire mean arterial pressure (MAP) and measures of arterial stiffness (carotid femoral pulse wave velocity, CFPWV; forward pressure wave amplitude, FWA) and wave reflection (reflection coefficient, RC). Participants who agreed to enroll in eFHS were provided with a digital blood pressure (BP) cuff to measure home BP weekly. Participants with &lt; 3 weeks of BP readings were excluded. Linear regression models were used to examine associations of arterial measures with home average real variability (ARV) of systolic (SBP) and diastolic (DBP) BP adjusting for covariates. We obtained ARV as an average of the absolute differences of consecutive BP measurements. ARV considers not only the dispersion of the BP readings around the mean, but also the order of BP readings. We used p&lt;0.05 for significance. Results: Among 857 eFHS participants (mean age 54 years, 59% women, mean BP 119/76, 47% hypertension, mean ARV of DBP 5.50, mean ARV of SBP 8.61), higher FWA and RC were associated with higher ARV of SBP ( Table ). Higher CFPWV was associated with lower ARV of DBP ( Table ). Conclusion: In eFHS, higher FWA and RC were associated with higher intermediate-term home BPV of SBP while higher CFPWV was associated with blunted BPV of DBP. Our findings suggest that higher aortic stiffness and wave reflection may affect day-to-day modulation of blood pressure in a home-based setting.

Feasibility of waveform separation of central aortic pressure pulse based on lognormal flow wave approximation

Wave reflections affect the aortic pressure and flow waves and may yield effective indices for monitoring cardiovascular health and disease. More accurate measures of wave reflection are obtainable after separation of aortic pressure waveform into its forward and backwards components. This paper presents a novel method for waveform separation of aortic pressure using a single pressure pulse measurement together with a lognormal flow wave approximation. The separated forward and backward waves were used to calculate the wave reflection parameters including reflection amplitude (RM) and reflection index (RI), and derive the aortic pulse transit time (PTT). The feasibility of the proposed method was verified using the central aortic pressure estimated from a measured radial pressure pulse by an aortic pulse analyzer and aortic flow waveform (39 data sets). Wave separation analysis (WSA) was assessed using the pressure and approximated flow waveforms based on two methods respectively, the proposed lognormal flow wave and the existing triangular flow wave. The results were compared with that of the measured flow wave. In time domain, for RM, RI, and PTT, the relations between the values calculated from the estimated flow and that from the measured flows can be characterized accurately by the linear regression models with the following coefficients of determination: R2 = 0.87 (RM), 0.86 (RI), 0.79 (PTT) using the lognormal flow; R2 = 0.84 (RM), 0.83 (RI), 0.77 (PTT) using the triangular flow. Agreement between reference and approximated values was increased when the approximated flow waveform was obtained using lognormal approximation rather than triangular estimation. The lognormal flow wave, a more physiological waveform, for approximating the flow improved the results of WSA in both time and frequency domains.

Lower-body dynamic exercise reduces wave reflection in healthy young adults.

What is the central question of this study? There is a paradoxical reduction in augmentation index during lower-body dynamic (LBD) exercise in the face of an increase in central pressure. To determine causality, the amplitudes of forward and backward pressure waves were assessed separately using wave separation analysis. What is the main finding and its importance? Reflection magnitude decreased during LBD exercise in healthy young adults and was attributable to an increased forward pressure wave amplitude and decreased backward pressure wave amplitude. This vasoactive response might limit the adverse effects of wave reflection during LBD exercise, optimizing ventricular-arterial interactions. Acute lower-body dynamic (LBD) exercise decreases surrogate measures of wave reflection, such as the augmentation index. However, the augmentation index is influenced by the combined effects of wave reflection timing, magnitude and other confounding factors external to wave reflection, which make it difficult to discern the origin of changes in surrogate measures. The relative contributions of forward (Pf) and backward (Pb) pressure wave amplitudes to central pressure can be determined by wave separation analysis. Reflection magnitude (RM=Pb/Pf) and the timing of apparent wave reflection return can also be determined. We tested the hypothesis that acute LBD exercise decreases RM and reflected wave transit time (RWTT). Applanation tonometry was used to record radial artery pressure waveforms in 25 adults (24 ± 4 years of age) at baseline and during light-, moderate- and vigorous-intensity exercise. Wave separation analysis was conducted offline using a personalized physiological flow wave to determine Pf, Pb, RM and RWTT. The RM decreased during all intensities of exercise compared with baseline (all P<0.001; baseline, 43 ± 5%; light, 33 ± 6%; moderate, 23 ± 7%; vigorous, 17 ± 5%). The reduction in RM was attributable to the combined effect of increased Pf and decreased Pb during exercise. The RWTT decreased during all intensities of exercise compared with baseline (all P<0.04; baseline, 156 ± 17ms; light, 144 ± 15ms; moderate, 129 ± 16ms; vigorous, 121 ± 17ms). Lastly, in a stepwise multilinear regression, Pf, but not Pb and RWTT, contributed to increased central pulse pressure during LBD exercise. These data show that wave reflection decreased and that central pulse pressure is most influenced by Pf during LBD exercise.

Acute Effect of Moderate-Intensity Aerobic Exercise on Arterial Stiffness in Fine Particulate Matter Environment: A Pilot Study

PURPOSE:This study aimed to examine the effect of one bout of moderate-intensity aerobic exercise on arterial stiffness under ambient fine particulate matter (PM2.5) exposure.METHODS: In a randomized crossover design, seven healthy young men performed 30 minutes of treadmill running at 70% of heart rate peak under high PM2.5 and low PM2.5 exposure. Arterial stiffness was assessed by measuring the carotid-femoral pulse wave velocity and augmentation index, a measure of pulse wave reflection before and after each exercise intervention.RESULTS: Regardless of the PM2.5 exposure, brachial systolic blood pressure and heart rate increased in response to one bout of moderate-intensity aerobic exercise (&lt;i&gt;p&lt;/i&gt;&lt;.05). However, the augmentation index adjusted at a heart rate of 75 beats/min, central diastolic blood pressure, central mean arterial pressure, and brachial diastolic blood pressure were increased after one bout of moderate-intensity aerobic exercise under the high PM2.5 condition (&lt;i&gt;p&lt;/i&gt;&lt;.05).CONCLUSIONS: Moderate-intensity aerobic exercise at the high PM2.5 level may result in acute negative arterial stiffness and blood pressure responses even in healthy young men.

Interpretation of Wave Reflections in the Umbilical Arterial Segment of the Feto-Placental Circulation: Computational Modeling of the Feto-Placental Arterial Tree.

Placental vascular abnormalities are associated with a host of pregnancy complications including placenta mediated fetal growth restriction (FGR). Umbilical arterial (UA) Doppler ultrasound velocity waveforms are widely used in the diagnosis of underlying placental vascular abnormalities in pregnancies with suspected FGR, which greatly helps to prevent stillbirth via ongoing fetal monitoring and timely delivery. However, the sensitivity of UA Doppler diagnosis diminishes late in gestation. Our goal was to present a generalized wave decomposition method to compute forward and reflected components from UA waveforms. A detailed anatomical based model was also developed to explain observed UA flow waveform and to explore how vascular properties affect the shape of flow wave components. Using data from a previous study of pregnant mice using high frequency ultrasound microscopy, we examined in utero Doppler and M-mode ultrasound measurements in 15 fetuses' UA. Following ultrasound, the placentas had been collected and perfused with contrast agent to obtain high-resolution 3D images of the feto-placental arteries. Model of these specimens indicates the significant role of terminal load impedance (capillary and/or veins) in creating positive or negative reflected flow waveforms. A negative flow reflected waveform is obtained when terminal impedance is elevated. This is consistent with the elongated and non-branching terminal villi that are proposed to cause the highly abnormal UA waveforms found in early-onset FGR. The significance of these findings for the diagnostic utility of UA Doppler in human pregnancy is that the identification and measurement of wave reflections may aid in discriminating between healthy and abnormal placental vasculature in pregnancies with suspected late-onset FGR.

A longitudinal analysis of arterial stiffness and wave reflection in preeclampsia: Identification of changepoints

PurposePreeclampsia (PrE) is a leading complication of pregnancy characterized by vascular dysfunction. Characterizing the longitudinal changes in vascular function prior to PrE onset is critical to the identification of optimal timepoints for vascular assessment and the development of effective early screening strategies. MethodsIn this prospective longitudinal study of women with singleton high-risk pregnancies, arterial stiffness and wave reflection parameters were assessed using applanation tonometry at 10–13 weeks' gestation and repeated every 4 weeks throughout pregnancy. Changepoints in carotid-femoral pulse wave velocity (cfPWV), carotid-radial PWV (crPWV), augmentation index (AIx), time to wave reflection (T1R), pulse pressure amplification (PPA), and subendocardial viability ratio (SEVR) were compared between women who did and did not subsequently develop PrE. ResultsA changepoint in cfPWV and crPWV was detected at 14–17 weeks' gestation. cfPWV then increased in women who went on to develop PrE but decreased in women who did not; a 1.2 m/s difference in cfPWV between the groups was observed at 22–25 weeks' gestation. Conversely, crPWV converged in the two groups from a baseline difference of 1.05 m/s (95% credible interval: 0.37, 1.72). Women who subsequently developed PrE demonstrated an increase in AIx at 18–21 weeks' gestation that was not seen in women who did not develop PrE until 30–33 weeks. No differences in T1R, PPA, or SEVR were observed between the groups. ConclusionsAltered vascular adaptations were detected using measures of arterial stiffness and wave reflection in the early second trimester of pregnant women who developed PrE compared to those who did not. These findings demonstrate the potential clinical utility of arterial stiffness and wave reflection parameters as an early screening tool for PrE, which can be used to inform clinical management of high-risk pregnancies.

Wave reflections in the umbilical artery measured by Doppler ultrasound as a novel predictor of placental pathology.

BackgroundThe umbilical artery (UA) Doppler pulsatility index is used clinically to detect elevated feto-placental vascular resistance. However, this metric is confounded by variation in fetal cardiac function and is only moderately predictive of placental pathology. Our group developed a novel ultrasound methodology that measures wave reflections in the UA, thereby isolating a component of the Doppler signal that is specific to the placenta. The present study examined whether wave reflections in the UA are predictive of placental vascular pathology.MethodsStandard clinical Doppler ultrasound of the UAs was performed in 241 pregnant women. Of these, 40 women met narrowly defined preset criteria for the control group, 36 had maternal vascular malperfusion (MVM) and 16 had fetal vascular malperfusion (FVM). Using a computational procedure, the Doppler waveforms were decomposed into a pair of forward and backward propagating waves.FindingsCompared to controls, wave reflections were significantly elevated in women with either MVM (p<0.0001) or FVM pathology (p = 0.02). In contrast, the umbilical and uterine artery pulsatility indices were only elevated in the MVM group (p<0.0001) and there were no differences between women with FVM and the controls.InterpretationThe measurement of wave reflections in the UA, combined with standard clinical ultrasound parameters, has the potential to improve the diagnostic performance of UA Doppler to detect placental vascular pathology. Identifying women with FVM pathology is particularly challenging prenatally and future investigations will determine if women at risk of this specific placental disease could benefit from this novel diagnostic technique.

Vascular Responses to High-Intensity Battling Rope Exercise between the Sexes.

The purpose of the study was to assess high-intensity battling rope exercise (HI-BRE) on hemodynamics, pulse wave reflection and arterial stiffness during recovery and between sexes. Twenty-three young, healthy resistance-trained individuals (men: n = 13; women: n = 10) were assessed for all measures at Rest, as well as 10-, 30-, and 60-minutes following HI-BRE. A one-way repeated measures ANOVA was used to analyze the effects of HI-BRE across time (Rest, 10, 30, and 60-minutes) on all dependent variables. Significant main effects were analyzed using paired t-tests with a Sidak correction factor. Significance was accepted a priori at p 0.05. There were significant reductions in hemodynamic measures of diastolic blood pressure (BP) in women, but not men following HI-BRE at 30 minutes. Further, measures of pulse wave reflection, specifically those of the augmentation index (AIx) and wasted left ventricular energy (ΔEw), were significantly increased in both men and women for 60 minutes, but changes were significantly attenuated in women suggesting less ventricular work. There were also significant increases in arterial stiffness in regard to the aorta and common carotid artery that were fully recovered by 30 and 60 minutes, respectively with no differences between men and women. Thus, the primary findings of this study suggest that measures of hemodynamics and pulse wave reflection are collectively altered for at least 60 minutes following HI-BRE, with women having attenuated responses compared to men.

ARTERIAL STIFFNESS AND WAVE REFLECTIONS IN PATIENTS WITH SERONEGATIVE SPONDYLOARTHROPATHIES TREATED WITH TUMOR NECROSIS ALPHA BLOCKERS

Objective: The seronegative spondyloarthropathies (SpA) are a group of rheumatic disorders characterized by oligoarticular arthritis, enthesitis and axial involvement. Cardiovascular manifestations play a pivotal role in determining the excess mortality in SpA, owing to the linkage between systemic inflammation and accelerated atherogenesis. Arterial stiffness measured as carotid-femoral pulse-wave velocity (PWV) and wave reflections are validated markers of cardiovascular disease. Anti-inflammatory therapy with anti-tumor necrosis factor-α (TNFα) agents may have a role in reducing arterial stiffening in some disease models but data in patients with SpA are inconclusive. Design and method: Twenty-three patients with a short duration and high disease activity SpA (8 males, 15 females, mean age 53.9 ± 11.5 years) and without overt cardiovascular disease were enrolled. PWV and augmentation index (AIx, as a measure of wave reflections) were measured by a validated arterial tonometer (PulsePen, DiaTecne, Milan). Patients were compared with 23 controls matched for age, gender, blood pressure and heart rate. Arterial tonometry was repeated in 10 patients after 16 weeks of treatment with an anti-TNFα agent (Adalimumab, in 9 patients; Certolizumab, in 1 patient). Results: Of the patients enrolled, 14 had ankylosing spondylitis, 8 psoriatic SpA, 1 Crohn's disease-associated SpA. The median duration of the disease from diagnosis was 2 years (2–11 years). In the comparison with matched controls, no significant differences in PWV or AIx were found (PWV: SpA 8.9 ± 2.0 m/s, controls 9.2 ± 3.8m/s, p = 0.80; AIx: SpA 18.3 ± 14.7, controls 19.5 ± 12.0, P = 0.77). During the 16-weeks follow-up of patients treated with anti-TNFα therapy, despite significant improvement in disease activity parameters (ASDAS-CRP: 2.75 ± 0.8 to 1.67 ± 0.4, P &lt; 0.01; BASDAI: 5.05 ± 1.9 to 3,0 ± 1.2, P 0.05), no significant change was found in the hemodynamic parameters (PWV: 8.5 ± 1.8 to 9.7 ± 3.5 m/s, p = 0.11; AIx 16.6 ± 15.5 to 13.7 ± 10.0, p = 0.47). Conclusions: In patients with a short duration SpA, arterial stiffness and wave reflections are not significantly impaired. Anti-TNFα agents have no effects on arterial stiffness parameters in the short term, despite control of clinical and inflammatory burden. Forthcoming studies should explore the cardiovascular effects of novel therapeutics opportunities (anti-IL12/23 and anti-IL17) in patients with SpA.

PULSE WAVE REFLECTION AND GENDER DIFFERENCE IN OBESE INDIVIDUALS

Objective: Although obesity is considered a cardiovascular risk factor due to its association with metabolic syndrome, recent studies in obese subjects with heart failure have shown that they have reduced adverse outcomes compared to non-obese individuals. This is consistent with the “obesity paradox”. However, body mass index (BMI) conventionally used to classify obesity, does not distinguish body shape or body fat distribution. This study aimed to explore the association between BMI and/or central obesity parameters and measures of arterial hemodynamics to assess the effect of obesity on function of large arteries. Design and method: Data was obtained from 832 normal individuals and stable patients with regular heart rate attending an outpatient health assessment clinic at Ruijin North Hospital, Shanghai. Subjects were divided into 3 groups according to their Body Mass Index (BMI &lt; 24 normal, 24–28 overweight, &gt; 28 obese; Chinese classification). Radial arterial waveforms and carotid-femoral pulse wave velocity (cfPWV) (SphygmoCor, AtCor Medical, Sydney) were measured with subjects recumbent, and calibrated to brachial cuff systolic (BSP) and diastolic pressure (BDP). Results: Central augmentation pressure (CAP), augmentation index (CAIx, a measure of wave reflection) and pressure amplification were lowest in the obese group (p &lt; 0.001). BSP, CSP and cfPWV were highest in the overweight group, but only in females (p &lt; 0.05). In males, CAP, CAIx and pressure amplification were significantly less as BMI increased (p &lt; 0.05). In both sexes, central obesity measure of weight-to-height ratio (WHtR) was significantly different between BMI classes (p &lt; 0.05). WHtR may be more appropriately correlated with hemodynamic parameters despite remaining differences between sexes (p &lt; 0.05). Conclusions: Obesity in humans is associated with changes in the arterial pressure waveforms that are opposite of those usually described in aging and aortic stiffening. Differences are more obvious in males than females, and features of the “obesity paradox” are apparent when obesity is defined by BMI class only. Further study is warranted to investigate differences of associations between males and females, and effect of central obesity in males and females.

Clinical Associations of Vascular Stiffness, Microvascular Dysfunction, and Prevalent Cardiovascular Disease in a Black Cohort: The Jackson Heart Study.

BackgroundMeasures of vascular dysfunction are related to adverse cardiovascular disease (CVD) outcomes in non‐Hispanic, White populations; however, data from Black individuals are limited. We aimed to investigate the associations between novel hemodynamic measures and prevalent CVD in a sample of Black individuals.Methods and ResultsAmong older Black participants of the Jackson Heart Study, we assessed noninvasive vascular hemodynamic measures using arterial tonometry and Doppler ultrasound. We assessed 5 measures of aortic stiffness and wave reflection (carotid‐femoral pulse wave velocity, pulse wave velocity ratio, forward pressure wave amplitude, central pulse pressure, and augmentation index), and 2 measures of microvascular function (baseline and hyperemic brachial flow velocity). Using multivariable logistic regression models, we examined the relations between vascular hemodynamic measures and prevalent CVD. In models adjusted for traditional CVD risk factors, higher carotid‐femoral pulse wave velocity (odds ratio [OR],1.25; 95% CI, 1.01–1.55; P=0.04), lower augmentation index (OR, 0.84; 95% CI, 0.70–0.99; P=0.05), and lower hyperemic brachial flow velocity (OR, 0.77; 95% CI, 0.65–0.90; P=0.001) were associated with higher odds of CVD. After further adjustment for hypertension treatment, lower augmentation index (OR, 0.84; 95% CI, 0.70–0.99; P=0.04) and hyperemic brachial flow velocity (OR, 0.79; 95% CI, 0.67–0.94; P=0.006), but not carotid‐femoral pulse wave velocity (OR, 1.23; 95% CI, 0.99–1.051; P=0.06), were associated with higher odds of CVD.ConclusionsIn a sample of older Black individuals, more severe microvascular damage and aortic stiffness were associated with prevalent CVD. Further research on hemodynamic mechanisms that contribute to cardiovascular risk among older Black individuals is merited.

Sex Difference On Arterial Stiffness And Measures Of Pulse Wave Reflection Response To Weight Machines

PURPOSE: To evaluate sex-specific responses to acute bout of machine weight resistance exercise on arterial stiffness and measures of pulse wave reflection. METHODS: Resistance-trained men (n=21; Mean±SD: Age: 23±3yrs) and women (n=20: Age: 22±3yrs) volunteered to participate in the study. Arterial stiffness, measured via pulse wave velocity, and measures of pulse wave reflection, were evaluated at rest, and 10 minutes following an acute bout of weight machine exercise composed of 3 sets of 10 reps at 75% 1RM on the chest press, leg press, lat pulldown, leg flexion and leg extension. Two minutes of rest was given between sets and exercises. A 2x2x2 ANOVA was used to analyze the effects of sex (men, women) across condition (acute resistance exercise, control) and time (rest, recovery (Rec)). RESULTS: There were no significant three-way interactions for any variable, as well as no sex specific responses. Acute resistance exercise had no effect on arterial stiffness (p=0.07), or augmentation pressure (p=0.16). A significant condition by time interaction (p=0.001) was noted for [email protected] ([email protected]: Men: Rest: 7.0±8.1%; Rec: 19.4±9.2%; Women: Rest: 11.0±16.0%; Rec: 14.0±6.0%) such that it was increased in response to the acute resistance exercise, but not the control. A significant (p=0.0001) condition by time effect was also noted for the subendocardial viability ratio (SEVR: Men: Rest: 141.0±24.0%; Rec: 82.1±38.0%; Women: Rest: 136.0±13.4%; Rec: 91.3±28.0%) in that the acute resistance exercise reduced SEVR during recovery, but not the control. There was also a significant (p=0.007) main effect of time for myocardial workload (Ew: Men: Rest: 809.0±639.2dynes s/cm2; Rec: 984.0±896.0dynes s/cm2; Women: Rest: 985.0±965.0dynes s/cm2; Rec: 364.0±540.0dynes s/cm2) in that it was reduced during recovery from the acute resistance exercise compared to rest, as well as the control. CONCLUSIONS: These data suggest that weight machines may not significantly alter arterial stiffness or measures of pulse wave reflection differently between the sexes. However, an acute bout of resistance exercises consisting of weight machines may reduce function of the left ventricle for at least 10 minutes.

Sex Differences On Measures Of Pulse Wave Reflection Response To Heavy Battle Rope Exercise

PURPOSE: To determine if there are sex-specific responses to heavy battle rope exercise (HRE) on measures of pulse wave reflection. METHODS: Twenty-seven resistance-trained individuals (Men: n=14, Mean±SD: Age: 23 ± 3 yrs; Women: n=13, Age: 22 ± 2yrs) participated. All measurements were collected at Rest, and 15 (Rec1), 30 (Rec2), and 60 (Rec3) minutes following HRE. Augmentation index (AIx), augmentation index at 75bpm ([email protected]), wasted left ventricle energy (EW), and subendocardial viability ratio (SEVR) were recorded via applanation tonometry. HRE utilized six 15-second exercise bouts using a double wave pattern (180bpm), with 30-second seated recovery. Two-way repeated measures ANOVAs were used to determine sex differences across time. RESULTS: There were significant sex by time interactions for AIx (p = 0.003), [email protected] (p = 0.029), and EW (p ≤ 0.001). AIx for men was augmented compared to women during Rec1, Rec2, and Rec3 (Men= Rest: 9.4 ± 9.6 %, Rec1: 31.4 ± 13.1 %, Rec2: 18.3 ± 12.4 %, Rec3: 18.6 ± 8.3 %; Women= Rest: 10.5 ± 10.8 %, Rec1: 21.1 ± 10.6 %, Rec2: 12.6 ± 7.3 %, Rec3: 7.1 ± 5.7 %). [email protected] for men was augmented during Rec1, Rec2 and Rec3 compared to women (Men= Rest: 0.4 ± 7.6 %, Rec1: 33.6 ± 12.4 %, Rec2: 20.1 ± 13.3 %, Rec3:15.8 ± 9.9 %; Women= Rest: 16.8 ± 39.5 %, Rec1: 33.6 ± 12.4 %, Rec2: 20.1 ± 13.3 %, Rec3: 15.8 ± 9.9 %). EW for men was augmented compared to women during Rec1, Rec2, and Rec3 (Men= Rest: 305.4 ± 219.6 dynes/sec/cm-2, Rec1: 2153.5 ± 866.7 dynes/sec/cm-2, Rec2: 1235.3 ± 779.5 dynes/sec/cm-2, Rec3: 1212.0 ± 593.7 dynes/sec/cm-2; Women= Rest: 258.4 ± 248.2 dynes/sec/cm-2, Rec1: 1257.3 ± 656.7 dynes/sec/cm-2, Rec2: 706.1 ± 688.9 dynes/sec/cm-2, Rec3: 331.9 ± 287.2 dynes/sec/cm-2). Compared to Rest, AIx, [email protected], and EW for men was significantly greater during Rec3, while Rec3 for women returned to Rest. SEVR had a significant main effect of time (p ≤ 0.001), in that Rest was augmented compared to Rec1, Rec2, and Rec3 for both sexes (Men= Rest: 159.4 ± 26.0 % , Rec1: 92.3 ± 14.2 %, Rec2: 103.9 ± 27.6 %, Rec3: 127.6 ± 22.4 %; Women= Rest: 142.4 ± 25.3 %, Rec1: 83.2 ± 15.5 %, Rec2: 109.0 ± 21.3 %, Rec3: 129.3 ± 22.0 %). CONCLUSION: These data suggest sex differences in pulse wave velocity after HRE. There was a greater decrement of left ventricular function in men up to 60 minutes, and women recovered faster following HRE.

P0957DISABILITY OF DIALYSIS PATIENTS AND CONDITION OF THEIR BLOOD VESSELS

Abstract Background and Aims Epidemiological data indicate constant increase of mean age among hemodialysis patients. These population have high burden of comorbid conditions, including cardiovascular (CV) diseases, which lead to disability and the need for continuous care. The aim of the study was to analyze the problems of disability in hemodialysis patients in the context of cardiovascular complication and vascular condition. Method In this cross-sectional study 129 patients (mean age 64.5 y, 54 females, with mean dialysis vintage 61 months) were enrolled from 3 satellite dialysis centers (inclusion criteria: age ≥18 y, dialysis vintage≥3 months). Demographic and comorbidity data were collected from medical records and during interview. The degree of disability (Bartel scale), 10-year cardiovascular risk (QRISK®3 online calculator), degree of imbalance (questionnaire - Falls Efficacy Scale – International (FES-I)) were assessed. In addition, ambulatory measurements of hemodynamic parameters with Mobil-O-Graph monitor (IEM, Stolberg,Germany), which records oscillometric arm blood pressure (SBP and DBP), central systolic (cSBP) and diastolic (cDBP), pulse pressure (pPP), ejection fraktion - (EF), cardiac output - (CO) and pulse waves. It calculates augmentation index (AIx@75) as measure of wave reflections, and pulse wave velocity (PWV) as measure of arterial stiffness. Results The most common causes of renal failure in the study group were ischemic - 35%, and diabetic nephropathy 26% (Fig. 1). Only 8 out of 129 pts. (6.2%) were professionally active, 40 (31%) received disability pension and 81 (62.8%) retirement. 25 (19%) used a wheelchair for transport and 21 (16%) used crutch. More than half (51%) were independent in everyday activities reaching 80-100 points on the Bartel scale, however only 14% were fully independent (100 points). Minimally dependent (60-79 points) constituted 27% (35 pts) of all patients, partially dependent (40-59 points) - 10% (13 pts), highly dependent (20-39 points) - 7% (9 pts) and fully dependent (&amp;lt;20 points) 5% (6 pts). The most common causes of disability were heart problems, including heart failure in 20.9%, lower limb ischemia, diabetic foot and amputation in 13.1% and cerebrovascular event in 10.8% followed by weakness associated with dialysis and degenerative joints disease (Fig. 2). Less disable group (80-100 points on the Bartel scale) showed significantly lower PWV, lower QRISK®3 and FES I index compared to the non self-reliant group (Fig 3). The degree of disability according to Bartel scale negatively correlated with age, PWV, QRISK®3 and FES I index (Fig 4). Conclusion Our results indicate that half of the population of hemodialysis patients show some degree of functional dependence. The group of patients with higher degree of disability are older and characterize of the more advanced changes in the arteries, higher risk of the CV incidents and increase risk of fall.

Sex differences in arterial wave reflection and the role of exogenous and endogenous sex hormones: results of the Berlin Aging Study II.

Arterial stiffness is tightly linked to hypertension. Sex differences in hypertension and arterial stiffness have already been established, yet the role of sex hormones is not precisely defined. This study examined age and sex differences of arterial wave reflection and associations with endogenous and exogenous sex hormones in women. Pulse wave analysis was performed with an oscillometric device in 590 male and 400 female participants of the Berlin Aging Study II. Participants have been recruited from two age-strata, 22-35 years and 60-82 years. Data on exposures and potential confounders, including medication, have been collected at baseline visit. Aumentation index (AIx) and pulse wave velocity increased with age. Mean AIx was higher in women than in men. Multivariable regression analysis showed a positive association between use of oral contraceptive pills (OCPs) and AIx controlling for confounders (age, BMI, current smoking, central blood pressure), with a significantly higher mean AIx in OCP-users compared with nonusers (mean group difference: 4.41; 95% confidence interval 1.61-7.22). Per quartile decrease in estradiol level AIx increased by 1.72 (95% confidence interval 0.43-3.00). In OCP users endogenous estradiol was largely suppressed. The findings suggest important sex differences in measures of arterial wave reflection, with a higher mean AIx observed in women compared with men. OCPs may promote the development of hypertension by increasing AIx. Suppressed endogenous estradiol levels may be responsible for this increased wave reflection due to increased vasotonus of the small and medium arteries.

Antioxidant cocktail following a high-sodium meal does not affect vascular function in young, healthy adult humans: a randomized controlled crossover trial

Chronic high sodium intake is a risk factor for cardiovascular disease as it impairs vascular function through an increase in oxidative stress. The objective of this study was to investigate the acute effects of a high-sodium meal (HSM) and antioxidant (AO) cocktail on vascular function. We hypothesized that a HSM would impair endothelial function, and increase arterial stiffness and wave reflection, while ingestion of the AO cocktail would mitigate this response. Healthy adults ingested either an AO cocktail (vitamin C, E, alpha-lipoic acid) or placebo (PLA) followed by a HSM (1500 mg) in a randomized crossover blinded design. Blood pressure (BP), endothelial function (flow-mediated dilation; FMD) and measures of arterial stiffness (pulse wave velocity; PWV) and wave reflection (augmentation index; AIx) were made at baseline and 30, 60, 90, and 120 min after meal consumption. Forty-one participants (20M/21W; 24 ± 1 years; BMI 23.4 ± 0.4 kg/m2) completed the study. Mean BP increased at 120 min relative to 60 min (60 min: 79 ± 1; 120 min: 81 ± 1 mmHg; time effect P = .01) but was not different between treatments (treatment × time interaction P = .32). AIx decreased from baseline (time effect P < .001) but was not different between treatments (treatment × time interaction P = .31). PWV (treatment × time interaction, P = .91) and FMD (treatment × time interaction P = .65) were also not different between treatments. In conclusion, a HSM does not acutely impair vascular function suggesting young healthy adults can withstand the acute impact of sodium on the vasculature and therefore, the AO cocktail is not necessary to mitigate the response.

The effects of repeated binge drinking on arterial stiffness and urinary norepinephrine levels in young adults.

The aim of this study was to investigate the effect of repeated binge drinking and moderate alcohol consumption in young adults on arterial stiffness and sympathetic activity. We enrolled 49 healthy young adults, free of cardiovascular diseases (25 men; age: 23.5 ± 0.4 years; BMI: 23.4 ± 0.4 kg/m; mean ± S.E). Individuals included were those with a history of repeated binge drinking (>2 years duration; n = 20), drank at moderate levels (MODs, >5 years duration; n = 16) and abstained from alcohol (last 2-3 years; n = 13). Arterial stiffness was assessed using carotid to femoral pulse wave velocity (cfPWV) and sympathetic activity was assessed using 24-h urinary norepinephrine levels. Also measured was aortic SBP and augmentation index (AIx), a measure of wave reflection. Binge drinkers and MODs had higher cfPWV than alcohol abstainers (0.6 and 0.5 m/s, respectively; P ≤ 0.04). In addition, binge drinkers had higher urinary norepinephrine levels than MODs and alcohol abstainers (P < 0.05). Higher cfPWV were correlated with higher norepinephrine levels (r = 0.35. P = 0.02). Aortic SBP (P = 0.2) and AIx (P = 0.96) were similar among binge drinkers, MODs and alcohol abstainers. Our findings suggest that repeated exposure to alcohol, regardless of drinking pattern, may increase aortic arterial stiffness in healthy young adults. In addition, sympathetic activation, reflected by increased 24-h urinary norepinephrine levels, may contribute to alcohol-induced arterial stiffening in young adults.