Pulse wave velocity as a marker of arteriosclerosis and its comorbidities in Chinese patients

Association Between Kidney Disease Index and Decline in Cognitive Function with Mediation by Arterial Stiffness in Asians with Type 2 Diabetes

Background

Decline in renal function impairs systemic clearance of amyloid-β which characterizes Alzheimer's disease while albuminuria is associated with blood-brain barrier disruption due to endothelial damage. Arterial stiffness adversely affects the brain with high pulsatile flow damaging cerebral micro-vessels.

Objective

To examine association between a novel kidney disease index (KDI), which is a composite index of estimated glomerular filtration (eGFR) and urinary albumin-to-creatinine ratio (uACR), and cognitive function with potential mediation by arterial stiffness.

Methods

This was a longitudinal multi-center study of participants with type 2 diabetes (T2D) aged 45 years and above. We assessed cognitive function with Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Pulse wave velocity (PWV), an index of arterial stiffness, was measured using applanation tonometry method. KDI was calculated as geometric mean of 1/eGFR and natural logarithmically-transformed (ln)(ACR*100).

Results

There were 1,303 participants with mean age 61.3±8.0 years. LnKDI was associated with lower baseline RBANS total score with adjusted coefficient -2.83 (95% CI -4.30 to -1.35; p < 0.001). 590 participants were followed over up to 8.6 years. LnKDI was associated with lower follow-up RBANS score in total, immediate memory, visuo-spatial/construction and attention domains with corresponding adjusted coefficients -2.35 (95% CI -4.50 to -0.20; p = 0.032), -2.93 (95% CI -5.84 to -0.02; p = 0.049), -3.26 (95% CI -6.25 to -0.27; p = 0.033) and -4.88 (95% CI -7.95 to -1.82; p = 0.002). PWV accounted for 19.5% of association between and follow-up RBANS total score.

Conclusions

KDI was associated with lower cognitive function globally, and in immediate memory, visuo-spatial/construction and attention domains. Arterial stiffness mediated the association between KDI and cognitive decline in patients with T2D.

Polyvinyl Alcohol Phantoms With Heterogeneous Plaques: Estimation of Pulse Wave Velocity at the Stenotic Region Using Pulse Wave Imaging

OBJECTIVE

Plaque characterization is essential for stroke prevention. In the study reported herein, we describe a heterogeneous phantom manufacturing technique with varying plaque compositions of different stiffness using polyvinyl alcohol (PVA) to emulate stenotic arteries and evaluated the use of pulse wave imaging (PWI) to assess plaque stiffness by comparing derived pulse wave velocities, with the goal of assessing plaque vulnerability and identifying high-risk patients for stroke.

METHODS

Five stenotic phantoms (50% stenosis) were fabricated by pouring PVA solutions into 3-D-printed molds. Two of the phantoms had heterogeneous plaque compositions of soft (E0 = 13 kPa) and intermediate (E0 = 40 kPa) materials and of stiff (E0 = 54 kPa) and intermediate materials. Ultrasound sequences were acquired as the arterial phantoms were connected to a pulsating pump, and PWI was performed on the ultrasound acquisition using normalized cross-correlation to track the pulse-induced phantom wall distension propagations. Pulse wave velocities were estimated by fitting a linear regression line between the arrival time of the peak acceleration of the wall distension waveform and the corresponding location.

RESULTS

Arterial phantoms with heterogeneous plaque stiffness were successfully fabricated. Pulse wave velocities of 2.06, 2.21, 2.49, 2.67 and 3.31 m/s were found in the phantom experiments using PWI for homogeneous soft plaque, the heterogeneous soft and intermediate plaque, homogeneous intermediate plaque, the heterogeneous stiff and intermediate plaque and homogeneous stiff plaque, respectively.

CONCLUSION

A novel arterial phantom building technique was reported with varying heterogenous plaque compositions of different stiffness. The feasibility of using PWI to evaluate plaque stiffness in stenotic arteries was determined and found that PWI can distinguish between plaques of distinct stiffness and composition.

Pulse wave imaging of a stenotic artery model with plaque constituents of different stiffnesses: Experimental demonstration in phantoms and fluid-structure interaction simulation

Vulnerable plaques associated with softer components may rupture, releasing thrombotic emboli to smaller vessels in the brain, thus causing an ischemic stroke. Pulse Wave Imaging (PWI) is an ultrasound-based method that allows for pulse wave visualization while the regional pulse wave velocity (PWV) is mapped along the arterial wall to infer the underlying wall compliance. One potential application of PWI is the non-invasive estimation of plaque's mechanical properties for investigating its vulnerability. In this study, the accuracy of PWV estimation in stenotic vessels was investigated by computational simulation and PWI in validation phantoms to evaluate this modality for assessing future stroke risk. Polyvinyl alcohol (PVA) phantoms with plaque constituents of different stiffnesses were designed and constructed to emulate stenotic arteries in the experiment, and the novel fabrication process was described. Finite-element fluid-structure interaction simulations were performed in a stenotic phantom model that matched the geometry and parameters of the experiment in phantoms. The peak distension acceleration of the phantom wall was tracked to estimate PWV. PWVs of 2.57 ms-1, 3.41 ms-1, and 4.48 ms-1 were respectively obtained in the soft, intermediate, and stiff plaque material in phantoms during the experiment using PWI. PWVs of 2.10 ms-1, 3.33 ms-1, and 4.02 ms-1 were respectively found in the soft, intermediate, and stiff plaque material in the computational simulation. These results demonstrate that PWI can effectively distinguish the mechanical properties of plaque in phantoms as compared to computational simulation.

Factors Associated with Variability in Pulse Wave Transit Time Using Pulse Oximetry: A Retrospective Study

Pulse wave transit time (PWTT) is the time difference between the occurrence of an R-wave on an electrocardiogram and the detection of pulsatile signals on a pulse oximeter, which reflects changes in blood pressure (BP) corresponding to the vessel wall compliance. However, the factors affecting PWTT variability have not been determined. Thus, we investigated the BP changes associated with variations in PWTT and identified the clinical characteristics associated with these variations. Data related to 605 cases of dental procedures performed under intravenous conscious sedation from April 2020 to November 2021 were collected, and 485 cases were enrolled. Heart rate, systolic blood pressure before and after local anesthesia (LA) administration, and crest and trough PWTT waves during LA administration were recorded. Thereafter, PWTT variability was calculated; cases were divided into two groups: large PWTT variability (LPV, n = 357) and small PWTT variability (SPV, n = 128). The index of large PWTT variability could not detect changes in BP. Logistic regression analysis revealed that factors, such as LA use, age, hypertension, and dental treatment phobia were associated with PWTT variability. The use of epinephrine more than 36.25 µg in each LA resulted in PWTT variability of more than 15 ms.

Subclinical Atherosclerosis Could Increase the Risk of Hearing Impairment in Males: A Community-Based Cross-Sectional Survey of the Kailuan Study

Objective

The relationship between subclinical atherosclerosis and hearing impairment (HI) has not been widely considered. Brachial ankle pulse wave velocity (baPWV) is a good indicator of muscular artery elasticity and could be a feasible method to screen for subclinical atherosclerosis. Our study aimed to elucidate the relationship between baPWV and HI.

Methods

This cross-sectional study was based on the Kailuan cohort. All participants completed a standardized questionnaire and underwent physical examinations and laboratory assessments at recruitment. Since 2010, some participants received additional baPWV testing during follow-up visits, and some who were exposed to occupational hazards such as noise received a pure-tone average hearing threshold (PTA) test after 2014. Male subjects with a complete physical examination, baPWV, and PTA data were recruited for this study. HI was defined as PTA > 25 dB. Multivariate linear and multivariate logistic regression analyses were used to evaluate the relationship between baPWV and PTA or HI.

Results

Among 11,141 subjects, the age range was 18–65 years, with mean age of 43.3 ± 8.9 years, the average PTA was 20.54 ± 10.40 dB, and the detection rate of HI was 1,821/11,141 (16.3%). Subjects were divided into four subgroups according to baPWV quartile. As the baPWV quartile increased, age, systolic blood pressure, diastolic blood pressure, body mass index, total cholesterol, high-density-lipoprotein cholesterol, fasting blood glucose, PTA, and proportions of subjects reporting smoking, alcohol consumption, hypertension, and diabetes increased significantly (p < 0.05 for trend). The odds of HI were higher in the fourth quartile group [adjusted odds ratio (aOR): 1.33, 95% CI: 1.10–1.62] than in the first quartile group. For every 100 m/s increase in baPWV, the PTA increased by 13 dB (95% CI: 4–23). When we divided the subjects into young (5,478 subjects; age range 22–44 years; mean age 35.6 ± 5.5 years) or non-young subgroups (5,663 subjects; age range 45–65 years; mean age 50.7 ± 3.7 years) based on a cut-off age of 45 years, the aOR of the fourth quartile group increased to 2.65 (95% CI: 1.68–4.19), and the PTA increment increased to 18 dB (95% CI: 10–27) for every 100 m/s increase in baPWV in the young subgroup. However, this relationship became statistically insignificant in the non-young subgroup.

Conclusion

Our study revealed the quantitative relationship between baPWV and HI in the Kailuan cohort subjects, although the results are not universally consistent in different populations.

Frequency Characteristics of Pulse Wave Sensor Using MEMS Piezoresistive Cantilever Element

Wearable sensor devices with minimal discomfort to the wearer have been widely developed to realize continuous measurements of vital signs (body temperature, blood pressure, respiration rate, and pulse wave) in many applications across various fields, such as healthcare and sports. Among them, microelectromechanical systems (MEMS)-based differential pressure sensors have garnered attention as a tool for measuring pulse waves with weak skin tightening. Using a MEMS-based piezoresistive cantilever with an air chamber as the pressure change sensor enables highly sensitive pulse-wave measurements to be achieved. Furthermore, the initial static pressure when attaching the sensor to the skin is physically excluded because of air leakage around the cantilever, which serves as a high-pass filter. However, if the frequency characteristics of this mechanical high-pass filter are not appropriately designed, then the essential information of the pulse-wave measurement may not be reflected. In this study, the frequency characteristics of a sensor structure is derived theoretically based on the air leakage rate and chamber size. Subsequently, a pulse wave sensor with a MEMS piezoresistive cantilever element, two air chambers, and a skin-contacted membrane is designed and fabricated. The developed sensor is 30 mm in diameter and 8 mm in thickness and realizes high-pass filter characteristics of 0.7 Hz. Finally, pulse wave measurement at the neck of a participant is demonstrated using the developed sensor. It is confirmed that the measured pulse wave contains signals in the designed frequency band.

Mask-Type Sensor for Pulse Wave and Respiration Measurements and Eye Blink Detection

This paper reports on a mask-type sensor for simultaneous pulse wave and respiration measurements and eye blink detection that uses only one sensing element. In the proposed sensor, a flexible air bag-shaped chamber whose inner pressure change can be measured by a microelectromechanical system-based piezoresistive cantilever was used as the sensing element. The air bag-shaped chamber is fabricated by wrapping a sponge pad with plastic film and polyimide tape. The polyimide tape has a hole to which the substrate with the piezoresistive cantilever adheres. By attaching the sensor device to a mask where it contacts the nose of the subject, the sensor can detect the pulses and eye blinks of the subject by detecting the vibration and displacement of the nose skin caused by these physiological parameters. Moreover, the respiration of the subject causes pressure changes in the space between the mask and the face of the subject as well as slight vibrations of the mask. Therefore, information about the respiration of the subject can be extracted from the sensor signal using either the low-frequency component (<1 Hz) or the high-frequency component (>100 Hz). This paper describes the sensor fabrication and provides demonstrations of the pulse wave and respiration measurements as well as eye blink detection using the fabricated sensor.

Postloading insulinemia is independently associated with arterial stiffness in young Japanese persons

Associations of arterial stiffness with glucose, insulin, and proinsulin dynamics during the oral glucose tolerance test (OGTT) remain under debate. The aim of this study was to investigate whether plasma glucose (PG), insulin, and proinsulin (Pro) contribute to arterial stiffness, measured by pulse wave velocity (PWV), in young Japanese persons. PG, immunoreactive insulin (IRI), and Pro levels were determined in 1193 young Japanese subjects (<40 years of age) with normal glucose tolerance or nondiabetic hyperglycemia before and at 30, 60, and 120 min during a 75-g OGTT. Participants were divided into two groups according to the median PWV. Background factors, PG, IRI, and Pro levels during the OGTT, and insulin sensitivity (SI) indices in each group were compared. Several multiple regression analysis models were used to evaluate factors contributing to PWV. All IRI and Pro levels before and after glucose loading and the area under the curve (AUC) values for IRI and Pro increased with higher PWV. 1/HOMA-IR and ISI-Matsuda as measures of SI decreased with higher PWV. The IRI AUC and Pro level before glucose loading (Pro0) were independently associated with PWV, in addition to male sex, heart rate, and mean blood pressure. The IRI AUC had a stronger relationship with PWV than Pro0. The IRI AUC had an independent relationship with PWV, whereas both SI indices did not. Postloading insulinemia, but not reduced SI, was independently associated with arterial stiffness in young Japanese persons.

Monitoring of vital bio-signs by analysis of speckle patterns in a fabric-integrated multimode optical fiber sensor

Continuous noninvasive measurement of vital bio-signs, such as cardiovascular parameters, is an important tool in evaluation of the patient's physiological condition and health monitoring. Based on new enabling technologies, continuous monitoring of heart and respiration rate, pulse wave velocity and blood pressure have been investigated, advanced and reflected in numerous papers published in recent years. In this paper, we introduce a new technique for noninvasive sensing of vital bio-signs based on a multimode optical fiber sensor that can be integrated into a fabric. The sensor consists of a laser, optical fiber, video camera and computer. Its operation is based on tracking of point-wise intensity variations on speckle patterns caused by interference of the light modes within the fiber subjected to deformation. The paper contains theoretical analysis and experimental validation of the proposed scheme. The main goal is to advance a simple low-cost sensor embedded in a cloth fabric to track changes in the cardiovascular condition of the wearer.

Arterial Function in Healthy Pregnant Women vs. Non-Pregnant Women-A 10-Year Study

INTRODUCTION

Maternal age for the first pregnancy is increasing and so, the prevalence of cardiovascular risk factors in pregnancy is also increasing. Heart disease is the main reason for maternal death during pregnancy in developed countries. Arterial stiffness is an independent risk factor for atherosclerosis and a predictor of cardiovascular morbidity and mortality. The most widespread parameters for detecting subclinical atherosclerosis are augmentation index (AIx) and pulse wave velocity (PWV). The objective of this prospective study was to assess the differences between arterial function in pregnant vs. non-pregnant women of the same age, and its changes throughout the gestation period.

MATERIALS AND METHODS

Between 2010-2019, 887 patients were enrolled into 2 groups: pregnant (N1 = 471) and non-pregnant (N2 = 416). Data about their anthropometric characteristics, arterial function (for group 1 in all three trimesters and 6 weeks post-partum), smoking status and physical activity were collected.

RESULTS

There were statistically significant differences (p < α, α = 0.05) between the two groups regarding the body mass index, brachial AIx, systolic, diastolic and central blood pressure, and pulse pressure values. In the first group, there was a decrease of both brachial AIx and PWV in the second and third trimester, followed by a post-partum increase; better outcomes were noticed in physically active women.

CONCLUSIONS

Arterial function modifies during pregnancy and these alterations differ according to the trimester of gestation. Further research is needed to establish the cut-off values for this category. Pregnant women can have better outcomes through physical activity.

MEMS-Based Pulse Wave Sensor Utilizing a Piezoresistive Cantilever

This paper reports on a microelectromechanical systems (MEMS)-based sensor for pulse wave measurement. The sensor consists of an air chamber with a thin membrane and a 300-nm thick piezoresistive cantilever placed inside the chamber. When the membrane of the chamber is in contact with the skin above a vessel of a subject, the pulse wave of the subject causes the membrane to deform, leading to a change in the chamber pressure. This pressure change results in bending of the cantilever and change in the resistance of the cantilever, hence the pulse wave of the subject can be measured by monitoring the resistance of the cantilever. In this paper, we report the sensor design and fabrication, and demonstrate the measurement of the pulse wave using the fabricated sensor. Finally, measurement of the pulse wave velocity (PWV) is demonstrated by simultaneously measuring pulse waves at two points using the two fabricated sensor devices. Furthermore, the effect of breath holding on PWV is investigated. We showed that the proposed sensor can be used to continuously measure the PWV for each pulse, which indicates the possibility of using the sensor for continuous blood pressure measurement.

Relationship between sum of the four limbs' pulse pressure and brachial-ankle pulse wave velocity and atherosclerosis risk factors in Chinese adults

The aim of the present study was to analyze the relationship between the sum of the four limbs' pulse pressure (Sum-PP) and brachial-ankle pulse wave velocity (baPWV) and atherosclerosis risk factors and evaluate the feasibility of Sum-PP in diagnosing atherosclerosis systemically. For the purpose, a cross-sectional study was conducted on the basis of medical information of 20748 adults who had a health examination in our hospital. Both Sum-PP and baPWV exhibited significant variations among different human populations grouped by gender, smoking, drinking, and age. Interestingly, Sum-PP had similar varying tendency with baPWV in different populations. And further study in different populations showed that Sum-PP was significantly positively related to baPWV. We also investigated the relationship between Sum-PP, baPWV, and cardiovascular risk factors, respectively. We found that both Sum-PP and baPWV had significant positive correlation with atherosclerosis risk factors while both of them were negatively related to HDL-c. In addition, there was a significant close correlation between Sum-PP and baPWV in the whole population (r = 0.4616, P < 0.0001). Thus, Sum-PP is closely related to baPWV and is of important value for clinical diagnosis of atherosclerosis.

Correlation between serum lactadherin and pulse wave velocity and cardiovascular risk factors in elderly patients with type 2 diabetes mellitus

AIMS

This study was carried out with the purpose of investigating the association between serum lactadherin, monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNFα) and carotid-femoral pulse wave velocity (PWV) in elderly patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 105 subjects including 27 T2DM patients without vascular complications (DM), 28 T2DM patients with vascular complications (DC), 25 elderly healthy volunteers (older) and 25 younger healthy volunteers (younger) were recruited into the study. Carotid-femoral PWV was measured using an automatic device. Serum lactadherin, MCP-1 and TNFα were determined by enzyme linked immunosorbent assay.

RESULTS

PWV and lactadherin, MCP-1 and TNFα were significantly higher in DM and DC groups than those of older and younger groups. PWV and lactadherin were higher in older group than those of younger group. Moreover, lactadherin was significantly correlated with MCP-1, TNFα, PWV, HbA1c and 2 h postprandial blood glucose (P2hBG) (P<0.05). In multivariate regression analysis, the independent determinants of lactadherin were HbA1c, P2hBG and age (P<0.05).

CONCLUSIONS

These findings underscore that lactadherin is correlated with poor blood glucose control and diabetic vascular complications.