L-Citrulline supplementation attenuates aortic pulse pressure and wave reflection responses to cold stress in older adults

2022 ◽  
pp. 111685
Author(s):  
Salvador J. Jaime ◽  
Jessica Nagel ◽  
Arun Maharaj ◽  
Stephen M. Fischer ◽  
Elizabeth Schwab ◽  
...  
2020 ◽  
Vol 52 (7S) ◽  
pp. 232-232
Author(s):  
Salvador J. Jaime ◽  
Jessica Nagel ◽  
Elizabeth Schwab ◽  
Christopher Martinson ◽  
Kim Radtke ◽  
...  

Circulation ◽  
2016 ◽  
Vol 133 (suppl_1) ◽  
Author(s):  
Priya Palta ◽  
Jingkai Wei ◽  
Michelle Meyer ◽  
Melinda C Power ◽  
Jennifer A Deal ◽  
...  

Introduction: Small vessel disease is associated with decreased cognitive function, possibly differential by race. Age-related central arterial stiffening increases pulsatility resulting in hypoperfusion, microvascular damage and remodeling in the brain, potentially impairing cognition. We examined if arterial stiffness and pressure amplification are associated with lacunar infarcts and greater volumes of white matter hyperintensities (WMH) in a sample of Caucasian and African American (AA) older adults. Methods: We analyzed a cross-sectional sample of ARIC participants aged 67-90 years (n=1486) from visit 5 (2011-2013), with brain magnetic resonance imaging (MRI). The Omron VP-1000 Plus was used to measure aortic stiffness (carotid-femoral pulse wave velocity [cfPWV]) and pressure amplification measures (pulse pressure amplification [PPA], central pulse pressure [cPP], and estimated central systolic blood pressure [cSBP]). Aortic stiffness and pressure amplification were dichotomized at race-specific 25th percentile cut points. Brain MRI using 3D-1.5T equipment quantified the presence of lacunar infarcts and volumes of WMH following a standardized protocol. Logistic regression, adjusted for age, sex, education, ApoE4, heart rate, smoking and body mass index, was used to quantify the odds of lacunar infarcts in participants with high vs. low cfPWV, cPP, cSBP, and low vs. high PPA. Linear regression models, additionally adjusted for intracranial volume, estimated the difference in log-transformed volumes of WMH among participants with high vs. low cfPWV, cPP, cSBP, and low vs. high PPA. Probability sampling weights for an MRI were included to allow for generalizability to the full visit 5 cohort. Results: Among the 1486 participants with a brain MRI (mean age: 76, 41% male, 26% AA), measures of aortic stiffness and pressure amplification were associated with lacunar infarcts in Caucasians, but not in AAs. Caucasian participants with a high cfPWV had greater odds of lacunar infarcts (Odds Ratio [OR] =2.02, 95% confidence interval [CI]: 1.23, 2.20). Caucasians with high cSBP had higher odds of lacunar infarcts (OR=1.72, 95% CI: 1.10, 2.69). In Caucasians, high cfPWV was associated with a 21% (95% CI: 6, 38) greater volume of WMH as compared to a low cfPWV; high cSBP was associated with a 28% (95% CI: 14, 45) greater volume of WMH compared to a low cSBP. In AAs, high cfPWV was associated with a 32% (95% CI: 7, 62) greater volume of WMH as compared to low cfPWV. Cerebral microvascular imaging markers did not differ quantitatively with measures of PPA and cPP. Conclusions: Central arterial stiffening and pressure amplification are plausible microvascular contributors to cognitive aging, providing new information on modifiable pathways for previously observed associations between cardiovascular disease risk factors and the rates of cognitive decline and dementia among older adults.


2016 ◽  
Vol 121 (3) ◽  
pp. 771-780 ◽  
Author(s):  
Isabella Tan ◽  
Hosen Kiat ◽  
Edward Barin ◽  
Mark Butlin ◽  
Alberto P. Avolio

Studies investigating the relationship between heart rate (HR) and arterial stiffness or wave reflections have commonly induced HR changes through in situ cardiac pacing. Although pacing produces consistent HR changes, hemodynamics can be different with different pacing modalities. Whether the differences affect the HR relationship with arterial stiffness or wave reflections is unknown. In the present study, 48 subjects [mean age, 78 ± 10 (SD), 9 women] with in situ cardiac pacemakers were paced at 60, 70, 80, 90, and 100 beats per min under atrial, atrioventricular, or ventricular pacing. At each paced HR, brachial cuff-based pulse wave analysis was used to determine central hemodynamic parameters, including ejection duration (ED) and augmentation index (AIx). Wave separation analysis was used to determine wave reflection magnitude (RM) and reflection index (RI). Arterial stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV). Pacing modality was found to have significant effects on the HR relationship with ED ( P = 0.01), central aortic pulse pressure ( P = 0.01), augmentation pressure ( P < 0.0001), and magnitudes of both forward and reflected waves ( P = 0.05 and P = 0.003, respectively), but not cfPWV ( P = 0.57) or AIx ( P = 0.38). However, at a fixed HR, significant differences in pulse pressure amplification ( P < 0.001), AIx ( P < 0.0001), RM ( P = 0.03), and RI ( P = 0.03) were observed with different pacing modalities. These results demonstrate that although the HR relationships with arterial stiffness and systolic loading as measured by cfPWV and AIx were unaffected by pacing modality, it should still be taken into account for studies in which mixed pacing modalities are present, in particular, for wave reflection studies.


2002 ◽  
Vol 103 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Denis CHEMLA ◽  
Jean-Louis HÉBERT ◽  
Eduardo APTECAR ◽  
Jean-Xavier MAZOIT ◽  
Karen ZAMANI ◽  
...  

Mean arterial pressure (MAP) is estimated at the brachial artery level by adding a fraction of pulse pressure (form factor; = 0.33) to diastolic pressure. We tested the hypothesis that a fixed form factor can also be used at the aortic root level. We recorded systolic aortic pressure (SAP) and diastolic aortic pressure (DAP), and we calculated aortic pulse pressure (PP) and the time-averaged MAP in the aorta of resting adults (n = 73; age 43±14 years). Wave reflection was quantified using the augmentation index. The aortic form factor (range 0.35-0.53) decreased with age, MAP, PP and augmentation index (each P<0.001). The mean form factor value (0.45) gave a reasonable estimation of MAP (MAP = DAP+0.45PP; bias = 0±2mmHg), and the bias increased with MAP (P<0.001). An alternative formula (MAP = DAP+PP/3+5mmHg) gave a more precise estimation (bias = 0±1mmHg), and the bias was not related to MAP. This latter formula was consistent with the previously reported mean pulse wave amplification of 15mmHg, and with unchanged MAP and diastolic pressure from aorta to periphery. Multiple linear regression showed that 99% of the variability of MAP was explained by the combined influence of DAP and SAP, thus confirming major pressure redundancy. Results were obtained irrespective of whether the marked differences in heart period and extent of wave reflection between subjects were taken into account. In conclusion, the aortic form factor was strongly influenced by age, aortic pressure and wave reflection. An empirical formula (MAP = DAP+PP/3+5mmHg) that is consistent with mechanical principles in the arterial system gave a more precise estimate of MAP in the aorta of resting humans. Only two distinct pressure-powered functions were carried out in the (SAP, DAP, MAP, PP) four-pressure set.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
O S Pavlova ◽  
T L Denisevich ◽  
M I Belskaya ◽  
E V Shafranovskaya ◽  
S E Ogurtsova ◽  
...  

Abstract Introduction Telomere length and telomerase are biomarkers of aging and cardiovascular diseases. Arterial stiffness is associated with vascular age and higher risk of cardiovascular diseases. Decreased reparative cell's potential may cause vascular ageing and predispose to the progression of hypertension. Objective To determine association leukocyte telomerase concentration (TC) and relative telomere length (RTL) with arterial stiffness in hypertensive patients. Material and methods The study included 120 people (70 patients with uncomplicated arterial hypertension (AH) and 50 normotensive individuals). Mean age of hypertensives was 54.8±9.3 and of normotensives was 50.2±9.73 years. Dietary habits, smoking, level of physical activity, body mass index, waist circumference, presence of obesity, blood pressure (BP) level, family history of cardiovascular deseases, depressive episodes and psychological stress according the international questionnaires, glucose; cholesterol, angiotensin II, renin and aldosteron in blood were assessed in the participants. Aortic BP, aortic pulse pressure, augmentation index (AIx), AIx adjusted for heart rate 75 beats per minute (Aix@HR75), pulse wave velocity (PWV) were determined by the applanation tonometry. RTL of peripheral blood leukocytes was performed by real-time PCR. The leukocyte TC was measured using the enzyme immunoassay. Results There were no differences between patients with AH and normotensives in both leukocyte TC (4.9 (4.0; 8.0) versus 6.2 (4.1; 9.4), p=0.281) and RTL (0.94 (0.86; 1.0) versus 0.96 (0.83; 1.0), p=0.978). In hypertensive and normotensive groups the mean systolic aortic BP were 130.6±17,7 and 109.9±11.7 mmHg (p&lt;0.001), aortic pulse pressure – 41.5±9,7 and 33.6±10,4 mmHg (p&lt;0.001), Aix@HR75 – 16.0 (7.0; 28.0) and 27.0 (13.0; 35.0)% (p=0.004), PWV –7.9±1.4 and 8.1±1,7 m/s (p=0.409) respectively. In patients with AH the mean leukocyte TC was lower with an increased Aix@75 (&gt;25%) in contrast to the group of patients with normal Aix@75 (4.45 (3.9; 7.8) versus 7.97 (4.6; 10.0) ng/ml; p=0.043). Based on the multivariate logistic regression analysis independent factors influencing on the Aix@75 were leukocyte TC &lt;5 ng/ml with the family history of AH (OR=1.9, 95% CI: 1.1–3.4; p=0.036), the degree of AH combined with decreased salt sensitivity (OR=3.1; 95% CI: 1.3–7.5; p=0.010) and age (OR=1.2; 95% CI: 1.1–1.2; p=0.001). Conclusions Decrease of the leukocyte telomerase concentration associated with the raise of augmentation index in patient with uncomplicated AH. As a parameter of central wave reflection the augmentation index may considered as an early sign of biological and vascular aging in hypertension. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The state program of scientific research “Fundamental and applied sciences for medicine”


2021 ◽  
Author(s):  
Jonna Nilsson ◽  
Maria Ekblom ◽  
Olga Tarassova ◽  
Martin Lövdén

This project concerns new analyses based on pre-existing data from a randomized controlled multicomponent intervention study combining physical exercise and cognitive training in healthy older adults. The project tests the predictive role of cardiorespiratory fitness, physical activity and pulse pressure for learning in a working memory training context, in combination with physical exercise and in isolation. Specifically, two learning outcomes are considered: change in trained working memory tasks from before to after the intervention period (pre-post change) and day-by-day change in n-back performance during the intervention period (up to 32 timepoints). The results did not support a predictive role of cardiorespiratory fitness, physical activity or pulse pressure for learning in this particular study context. Please note that this document is intended solely as a report of the results pertaining to the registered hypotheses on Open Science Framework (https://osf.io/h5npm), simply to ensure transparency also of the null findings. As such, this document is not intended for formal peer-review or publication. If you are interested in the results, please do not hesitate to contact the author of this document ([email protected]).


2020 ◽  
Vol 16 (S4) ◽  
Author(s):  
Alexandra J. Weigand ◽  
Daniel A. Nation ◽  
Lisa Delano‐Wood ◽  
Katherine J. Bangen ◽  
Doug R. Galasko ◽  
...  
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