Determinants of arterial stiffness in an apparently healthy population over 60 years

Glycemia is associated with subclinical atherosclerosis through renal function in nondiabetic apparently healthy adults: a mediation analysis

The causative associations between glycemia and early alterations in renal and vascular function remain unclear. To examine the interplay among glycemia, renal function, and markers of subclinical atherosclerosis in apparently healthy subjects. Nondiabetic (30-60 years old) individuals (n = 205) without chronic kidney disease or cardiovascular disease were consecutively recruited from a cardiovascular prevention clinic. All subjects underwent arterial stiffness assessment by measuring the carotid-femoral pulse wave velocity (cfPWV). Glomerular filtration rate (GFR) was estimated by CKD-EPI equation. Study procedures were identical in the two visits (median follow-up 66 months). We employed structural equation modeling (SEM) analysis to investigate the directionality of associations. Baseline fasting plasma glucose (FPG) was independently and inversely associated with GFR (p = 0.008). GFR was significantly associated with cfPWV (p < 0.001) at baseline. By SEM analysis decreasing baseline GFR directly correlated with increasing cfPWV (p = 0.003) whereas FPG correlated with cfPWV indirectly through GFR (mediation) (P = 0.032). FPG did not mediate the effect of GFR on cfPWV (P = 0.768). SEM analysis of longitudinal data revealed bidirectional correlations between changes in FPG and GFR (P < 0.001). Alterations in GFR were directly related to changes in cfPWV (p < 0.001) whereas FPG only indirectly correlated with cfPWV through GFR changes (P = 0.002). In apparently healthy nondiabetic subjects, the association between baseline or longitudinal glycemia levels and arterial stiffening was indirect, consistently mediated by renal function status. These findings provide the first clinical evidence supporting the directionality between kidney function and glycemia in nondiabetic subjects leading to vascular dysfunction. In apparently healthy nondiabetic subjects, without cardiovascular disease or chronic kidney disease, the association between baseline or longitudinal glycemia levels and arterial stiffening was indirect, consistently mediated by renal function status.

The effect of aerobic exercise on pulse wave velocity in middle-aged and elderly people: A systematic review and meta-analysis of randomized controlled trials

A growing body of research examines the effect of aerobic exercise on pulse wave velocity (PWV) in middle-aged and elderly people, while findings of available studies were conflicting. The aim of this study was to explore the effect of aerobic exercise on PWV in middle-aged and elderly people. Searches were performed in PubMed, Web of Science, and EBSCO databases. Cochrane risk assessment tool was used to evaluate the methodological quality of the included literature. We included studies that satisfied the following criteria: (1) eligible studies should be randomized controlled trials (RCTs); (2) eligible studies should include both an intervention and a control group; (3) eligible studies should use the middle-aged or elderly people as subjects; and (4) eligible studies should use PWV as the outcome measure. From 972 search records initially identified, 11 studies with a total of 12 exercise groups (n = 245) and 11 control groups (n = 239) were eligible for meta-analysis. There was a significant effect of aerobic exercise on reducing PWV in middle-aged and elderly people [weighted mean difference (WMD), –0.75 (95% CI, –1.21 to –0.28), p = 0.002]. Specifically, a higher intensity [vigorous-intensity, –0.74 (–1.34 to –0.14), p = 0.02; moderate-intensity, –0.68 (–1.49 to 0.12), p = 0.10], a younger age [45 years ≤ age < 60 years, –0.57 (–0.78 to –0.37), p < 0.00001; age ≥ 60 years, –0.91 (–2.10 to 0.27), p = 0.13], a better health status [healthy, –1.19 (–2.06 to –0.31), p = 0.008; diseased, –0.32 (–0.64 to –0.01), p = 0.04], and a lower basal body mass index (BMI) [BMI < 25, –1.19 (–2.06 to –0.31), p = 0.008; 25 ≤ BMI < 30, –0.52 (–0.92 to –0.12), p = 0.01; BMI ≥ 30, –0.09 (–0.93 to 0.76), p = 0.84] were associatedwith larger reductions in PWV. Aerobic exercise, especially vigorous-intensity aerobic exercise, contributed to reducing PWV in middle-aged and elderly people. The effect of aerobic exercise on improving PWV was associated with characteristics of the participants. Specifically, a younger age, a better health status, and a lower basal BMI contributed to more significant reductions in PWV.

The endothelial glycocalyx in critical illness: A pediatric perspective

The vascular endothelium is the interface between circulating blood and end organs and thus has a critical role in preserving organ function. The endothelium is lined by a glycan-rich glycocalyx that uniquely contributes to endothelial function through its regulation of leukocyte and platelet interactions with the vessel wall, vascular permeability, coagulation, and vasoreactivity. Degradation of the endothelial glycocalyx can thus promote vascular dysfunction, inflammation propagation, and organ injury. The endothelial glycocalyx and its role in vascular pathophysiology has gained increasing attention over the last decade. While studies characterizing vascular glycocalyx injury and its downstream consequences in a host of adult human diseases and in animal models has burgeoned, studies evaluating glycocalyx damage in pediatric diseases are relatively few. As children have unique physiology that differs from adults, significant knowledge gaps remain in our understanding of the causes and effects of endothelial glycocalyx disintegrity in pediatric critical illness. In this narrative literature overview, we offer a unique perspective on the role of the endothelial glycocalyx in pediatric critical illness, drawing from adult and preclinical data in addition to pediatric clinical experience to elucidate how marked derangement of the endothelial surface layer may contribute to aberrant vascular biology in children. By calling attention to this nascent field, we hope to increase research efforts to address important knowledge gaps in pediatric vascular biology that may inform the development of novel therapeutic strategies.

Arterial stiffness measurements in pregnancy as a predictive tool for hypertensive disorders of pregnancy and preeclampsia: Protocol for a systematic review and meta-analysis

Hypertensive disorders of pregnancy (HDPs) are a leading cause of maternal morbidity and mortality worldwide. Unfortunately, accurate early clinical screening methods for the development of these disorders are lacking. Arterial stiffness (AS) is an important hemodynamic indicator of vascular health that has shown promising results for the prediction of HDP onset. Past systematic reviews in the field have reported an increase in AS indices in women who develop HDPs and have highlighted the potential of AS measurements as a predictive tool early in pregnancy. The most recent systematic review, including papers up to 2015, assessed the differences in AS parameters between women with and without pregnancy complications. Since then, there has been a substantial influx of published research on the topic and a growing interest in the incorporation of AS measurements into clinical practice. Thus, we propose a systematic review and meta-analysis that is more inclusive to all HDP subsets and various hemodynamic indices of vascular health to provide a comprehensive overview of the current state of evidence. Specifically, we aim to evaluate these measures in women who develop HDPs compared to normotensive pregnancies to determine which measures are most associated with and/or can predict the development of HDPs. Major databases (Medline, Embase, The Cochrane Library, Web of Science, PubMed, and CINAHL), grey literature (Google Scholar) and clinical trials (clinicaltrials.gov) will be searched to identify studies that report AS and hemodynamic measurements in pregnant women with and without HDPs. No restrictions will be made on study type or year. Articles will be independently evaluated by three authors to determine eligibility based on inclusion and exclusion criteria. Methodological quality of included studies will be assessed. Pooled analyses will be conducted using a random-effects model. Publication bias and between-study heterogeneity will also be assessed. Sources of heterogeneity will be explored by sensitivity, subgroup, and/or meta-regression analyses. Results from this study will be shared through scientific conferences and publications in scientific journals. The analysis of potential AS and hemodynamic markers for HDP onset will help inform the development of screening guidelines and clinically relevant cut-off values of AS and hemodynamic markers for HDP risk, guiding future research. There are no applicable ethical considerations to the writing of this protocol.

Enabling Wearable Pulse Transit Time-Based Blood Pressure Estimation for Medically Underserved Areas and Health Equity: Comprehensive Evaluation Study

BACKGROUND

Noninvasive and cuffless approaches to monitor blood pressure (BP), in light of their convenience and accuracy, have paved the way toward remote screening and management of hypertension. However, existing noninvasive methodologies, which operate on mechanical, electrical, and optical sensing modalities, have not been thoroughly evaluated in demographically and racially diverse populations. Thus, the potential accuracy of these technologies in populations where they could have the greatest impact has not been sufficiently addressed. This presents challenges in clinical translation due to concerns about perpetuating existing health disparities.

OBJECTIVE

In this paper, we aim to present findings on the feasibility of a cuffless, wrist-worn, pulse transit time (PTT)-based device for monitoring BP in a diverse population.

METHODS

We recruited a diverse population through a collaborative effort with a nonprofit organization working with medically underserved areas in Georgia. We used our custom, multimodal, wrist-worn device to measure the PTT through seismocardiography, as the proximal timing reference, and photoplethysmography, as the distal timing reference. In addition, we created a novel data-driven beat-selection algorithm to reduce noise and improve the robustness of the method. We compared the wearable PTT measurements with those from a finger-cuff continuous BP device over the course of several perturbations used to modulate BP.

RESULTS

Our PTT-based wrist-worn device accurately monitored diastolic blood pressure (DBP) and mean arterial pressure (MAP) in a diverse population (N=44 participants) with a mean absolute difference of 2.90 mm Hg and 3.39 mm Hg for DBP and MAP, respectively, after calibration. Meanwhile, the mean absolute difference of our systolic BP estimation was 5.36 mm Hg, a grade B classification based on the Institute for Electronics and Electrical Engineers standard. We have further demonstrated the ability of our device to capture the commonly observed demographic differences in underlying arterial stiffness.

CONCLUSIONS

Accurate DBP and MAP estimation, along with grade B systolic BP estimation, using a convenient wearable device can empower users and facilitate remote BP monitoring in medically underserved areas, thus providing widespread hypertension screening and management for health equity.

Early Vascular Aging in Children With Type 1 Diabetes and Ambulatory Normotension

Background: Preliminary data suggest that target organ damage (TOD) and early vascular aging (EVA) may occur in children with normal blood pressure (BP). Objectives: To analyze TOD and EVA in normotensive (BP <95th percentile on ambulatory BP monitoring) type 1 diabetes children (T1D) in comparison to healthy controls (C). Subjects: 25 T1D aged 13.9 ± 2.6 years and 22 C aged 14.0 ± 3.4 years. Methods: We analyzed age- and height-related pulse wave velocity (PWV) Z-scores and expected PWV based on age, height, and mean arterial pressure (MAP). Expected vascular age based on measured PWV was calculated from pooled pediatric and adult PWV norms. Left ventricular mass index (LVMI), estimated glomerular filtration rate (eGFR), and urinary albumin/creatinine ratio (ACR) were obtained as markers of TOD. Results: T1D and C groups did not differ in anthropometry, ambulatory, LVMI, and ACR. However, median age- and height-related PWV Z-scores were higher in T1D compared to C (1.08 vs. 0.57, p = 0.006; 0.78 vs. 0.36, p = 0.02, respectively). Mean (±SD) difference between measured and expected PWV was 0.58 ± 0.57 in T1D vs. 0.22 ± 0.59 in C, p = 0.02. The mean (±SD) difference between chronological and expected vascular age was 7.53 ± 7.74 years in T1D vs. 2.78 ± 7.01 years in C, p = 0.04. Conclusion: Increased arterial stiffness and increased intraindividual differences between expected and measured PWV as well as between chronological and expected vascular age indicate that EVA may develop in T1D children even at normal ambulatory BP levels.

SERUM LIPID PROFILE AND ARTERIAL STIFFNESS IN NON-DIPPERS

Background. A non-dipping blood pressure profile (NDP) is associated with increased arterial stiffness and other cardiovascular target organ damage. Serum lipid profiles have been shown to be important determinants of arterial stiffness. Objective. The aim of the research was to assess serum lipid profiles and arterial stiffness in non-dippers. Methods. This cross-sectional study was conducted involving 796 (288 males and 508 females) participants of black African origin. A twenty-four-hour ambulatory BP monitoring was done using a Spacelabs 90207 (Spacelabs Inc., Redmond, Washington, USA) monitor. Carotid-Femoral pulse wave velocity measurements were performed using a high fidelity SPC-301 micromanometer (Millar instruments Inc., Houston, TX). Results. Of the 288 males, 140 were classified as non-dippers. Of the 508 females, 273 were classified as non-dippers. In the general population, males had higher triglycerides when compared with females 1.46±0.96 vs 1.13±1.02, p<0.0001. Additionally, dipper males had higher serum TRGL when compared with dipper females 1.32±0.98 vs 1.06±0.58, p = 0.0012. Non-dipper males also had higher serum TRGL when compared with non-dipper females 1.61±2.05 vs 1.19±1.14, p=0.0078. Serum HDLc was lower in the non-dipper male group when compared to the non-dipper female group (p=0.008). In both male and female groups, non-dippers had higher CFPWV when compared with dippers; 7.53±3.60 vs 5.74±2.47, p<0.0001 and 6.64±2.52 vs 5.98±2.23, p=0.0021 respectively. However, non-dipper males had significantly higher CFPWV when compared with non-dipper females (7.53±3.60 vs 6.64±2.52, p=0.0031). Conclusions. Therapies targeting a reduction of serum triglycerides levels might be beneficial in improving arterial compliance with or without the presence of non-dipping.

Whole Milk and Full-Fat Dairy Products and Hypertensive Risks

Lifestyle modifications in the form of diet and exercise are generally a first-line approach to reduce hypertensive risk and overall cardiovascular disease (CVD) risk. Accumulating research evidence has revealed that consumption of non- and low-fat dairy products incorporated into the routine diet is an effective means to reduce elevated blood pressure and improve vascular functions. However, the idea of incorporating whole-fat or full-fat dairy products in the normal routine diet as a strategy to reduce CVD risk has been met with controversy. The aim of this review is to review both sides of the argument surrounding saturated fat intake and CVD risk from the standpoint of dairy intake. Throughout the review, we examined observational studies on relationships between CVD risk and dairy consumption, dietary intervention studies using non-fat and whole-fat dairy, and mechanistic studies investigating physiological mechanisms of saturated fat intake that may help to explain increases in cardiovascular disease risk. Currently available data have demonstrated that whole-fat dairy is unlikely to augment hypertensive risk when added to the normal routine diet but may negatively impact CVD risk. In conclusion, whole-fat dairy may not be a recommended alternative to non- or low-fat dairy products as a means to reduce hypertensive or overall CVD risk.

Carotid Artery Stiffness in Metabolic Syndrome: Sex Differences

INTRODUCTION

The effect of metabolic syndrome (MS) on carotid stiffness (CS) in the context of gender is under research.

OBJECTIVE

We examined the relationship between the MS and CS in men (M) and women (W) and investigated if the impact of cardiovascular risk factors on CS is modulated by gender.

PATIENTS AND METHODS

The study included 419 subjects (mean age 54.3 years): 215 (51%) with MS (109 W and 106 M) and 204 (49%) without MS (98 W and 106 M). Carotid intima-media thickness (IMT) and CS parameters (beta stiffness index (beta), Peterson's elastic modulus (Ep), arterial compliance (AC) and one-point pulse wave velocity (PWV-beta)) were measured with the echo-tracking (eT) system.

RESULTS

ANCOVA demonstrated that MS was associated with elevated CS indices (p = 0.003 for beta and 0.025 for PWV-beta), although further sex-specific analysis revealed that this relationship was significant only in W (p = 0.021 for beta). Age was associated with CS in both M and W, pulse pressure (PP) and body mass index turned out to be determinants of CS solely in W, while the effect of mean arterial pressure (MAP) and heart rate was more pronounced in M. MANOVA performed in subjects with MS revealed that age and diabetes mellitus type 2 were determinants of CS in both sexes, diastolic blood pressure and MAP - solely in M and systolic blood pressure, PP and waist circumference - solely in W (the relationship between the waist circumference and AC was paradoxical).

CONCLUSION

The relationship between MS and CS is stronger in W than in M. In subjects with MS, various components of arterial pressure exert different sex-specific effects on CS - with the impact of the pulsative component of arterial pressure (PP) observed in W and the impact of the steady component (MAP) observed in M.

The effect of sex and menopause on carotid intima-media thickness and pulse wave velocity in morbid obesity

BACKGROUND

Women are relatively protected from cardiovascular disease compared with men. Since morbid obesity is an independent risk factor for cardiovascular disease, the current study investigated whether the association between sex and cardiovascular risk factors and outcomes can be demonstrated in subjects suffering from morbid obesity.

MATERIALS AND METHODS

Two hundred subjects enrolled in a study on cardiovascular risk factors in morbid obesity underwent extensive laboratory screening, carotid intima-media thickness (cIMT) and pulse wave velocity (PWV) measurements. Gender differences were analysed using univariate and multivariable linear regression models. In addition, the effect of menopause on cIMT and PWV was analysed. Results of these models were reported as B coefficients with 95% confidence intervals.

RESULTS

The group consisted of 52 men and 148 women, with a mean age of 41 (±11.8) years and a mean body mass index (BMI) of 42.7 (±5.2) kg/m² . Both, cIMT and PWV were significantly higher in men than in women, although the difference in cIMT disappeared after adjustment for covariables such as waist circumference, age, high-density lipoprotein cholesterol and mean arterial pressure. PWV was associated with sex after adjustments for covariables in morbidly obese patients. Postmenopausal women had significantly increased cIMT and PWV when compared with premenopausal women.

CONCLUSION

Sex differences in PWV persist in subjects suffering from morbid obesity. However, no difference was found in cIMT between morbidly obese men and women after adjustment for classic cardiovascular risk factors. Premenopausal morbidly obese women are protected for cardiovascular disease when compared with postmenopausal morbidly obese women.

Unreliable Estimation of Aortic Pulse Wave Velocity Provided by the Mobil-O-Graph Algorithm-Based System in Marfan Syndrome

Background Several devices have been proposed to assess arterial stiffness in clinical daily use over the past few years, by estimating aortic pulse wave velocity (PWV) from a single measurement of brachial oscillometric blood pressure, using patented algorithms. It is uncertain if these systems are able to provide additional elements, beyond the contribution carried by age and blood pressure levels, in the definition of early vascular damage expressed by the stiffening of the arterial wall. Methods and Results The aim of our study was to compare the estimated algorithm-based PWV values, provided by the Mobil-O-Graph system, with the standard noninvasive assessment of aortic PWV in patients with Marfan syndrome (ie, in subjects characterized by premature aortic stiffening and low blood pressure values). Aortic stiffness was simultaneously evaluated by carotid-femoral PWV with a validated arterial tonometer and estimated with an arm cuff-based ambulatory blood pressure monitoring Mobil-O-Graph device on 103 patients with Marfan syndrome (50 men; mean± SD age, 38±15 years). Aortic PWV, estimated by the Mobil-O-Graph, was significantly ( P<0.0001) lower (mean± SD, 6.1±1.3 m/s) than carotid-femoral PWV provided by arterial tonometry (mean± SD , 8.8±3.1 m/s). The average of differences between PWV values provided by the 2 methods (±1.96×SD) was -2.7±5.7 m/s. Conclusions The Mobil-O-Graph provides PWV values related to an ideal subject for a given age and blood pressure, but it is not able to evaluate early vascular aging expressed by high PWV in the individual patient. This is well shown in patients with Marfan syndrome.

LDL cholesterol is associated with systemic vascular resistance and wave reflection in subjects naive to cardiovascular drugs

BACKGROUND AND AIM

Low density lipoprotein cholesterol (LDL-C) is a primary risk factor for atherosclerosis, but it is also associated with elevated blood pressure (BP) and future development of hypertension. We examined the relationship between LDL-C and haemodynamic variables in normotensive and never-treated hypertensive subjects.

METHODS

We recruited 615 volunteers (19-72 years) without lipid-lowering and BP-lowering medication. Supine haemodynamics were recorded using continuous radial pulse wave analysis, whole-body impedance cardiography, and single channel electrocardiogram. The haemodynamic relations of LDL-C were examined using linear regression analyses with age, sex, body mass index (BMI) (or height and weight as appropriate), smoking status, alcohol use, and plasma C-reactive protein, sodium, uric acid, high density lipoprotein cholesterol (HDL-C), triglycerides, estimated glomerular filtration rate, and quantitative insulin sensitivity check index as the other included variables.

RESULTS

The mean (SD) characteristics of the subjects were: age 45 (12) years, BMI 27 (4) kg/m², office BP 141/89 (21/13) mmHg, creatinine 74 (14) µmol/l, total cholesterol 5.2 (1.0), LDL-C 3.1 (0.6), triglycerides 1.2 (0.8), and HDL-C 1.6 (0.4) mmol/l. LDL-C was an independent explanatory factor for aortic systolic and diastolic BP, augmentation index, pulse wave velocity (PWV), and systemic vascular resistance index (p < 0.05 for all). When central BP was included in the model for PWV, LDL-C was no longer an explanatory factor for PWV.

CONCLUSIONS

LDL-C is independently associated with BP via systemic vascular resistance and wave reflection. These results suggest that LDL-C may play a role in the pathogenesis of primary hypertension.

Gender-related differences in the progression of carotid stiffness with age and in the influence of risk factors on carotid stiffness

Background

In recent years, there has been growing interest in the impact of gender-related factors on the function and structure of the arterial tree. The aim of our study was to identify gender-specific differences in the progression of carotid stiffness parameters with age and in the impact of risk factors on carotid stiffness.

Subjects and methods

The study group included 256 subjects (mean age: 54.7 years): 134 women (52%) and 122 men (48%) with cardiovascular risk factors: hypertension, type 2 diabetes mellitus, dyslipidemia, smoking, and obesity. Local parameters of carotid stiffness: β stiffness index (β), Peterson’s elastic modulus (Ep), pulse wave velocity β (PWV-β) and arterial compliance (AC) were determined with ultrasound echo-tracking software application.

Results

Women were characterized by lower AC than men (women: 0.57 mm²/kPa vs men: 0.69 mm²/kPa, p < 0.001) and the subanalysis in three age groups revealed that the difference in AC value between genders became significant over the age of 45 years. Although no significant difference in the value of β, Ep and PWV-β were found between genders in the whole study group, women <45 years were characterized by lower values of β and Ep than their men counterparts (β: women: 5.4 vs men: 6.6, p = 0.002; Ep: women: 72 kPa vs men: 84 kPa, p = 0.015). Among analyzed risk factors, the significant determinants of carotid stiffness were age, blood pressure components (pulse pressure and mean arterial pressure), type 2 diabetes mellitus and heart rate. The relationship between carotid stiffness and pulse pressure was observed only in women and between carotid stiffness and heart rate – only in men.

Conclusion

There are gender-related differences in the progression of carotid stiffness parameters with age and in the influence of risk factors on carotid stiffness.

Increased arterial stiffness - similar findings in patients with inflammatory bowel disease without prior hypertension or diabetes and in patients with well-controlled hypertension

PURPOSE

Chronic inflammatory diseases are related with earlier onset of atherosclerosis. We hypothesized that inflammatory bowel disease patients with chronic, systemic inflammation have an increased arterial stiffness associated with the disease duration. Also, we wanted to compare arterial stiffness markers between inflammatory bowel disease and well-controlled hypertension patients.

MATERIALS AND METHODS

A total of 89 inflammatory bowel disease patients (60 patients with Crohn's disease and 29 patients with ulcerative colitis, age range 20-64 years) without history of arterial hypertension or diabetes were enrolled and age matched with a control group of patients (73 patients, age range 25-69 years, 41 (56.1%) males) with known history of well-controlled arterial hypertension. We have used a noninvasive device that simultaneously measures brachial blood pressure and estimates PWV and AIx in inflammatory bowel disease and hypertension groups of patients.

RESULTS

Patients with pathological PWV values were significantly older, had significantly longer duration of inflammatory bowel disease, higher values of serum cholesterol and HDL-cholesterol, and higher AIx (17.4% vs. 9.8%) (all p < .05). Higher PWV was associated with age and duration of inflammatory bowel disease in the linear regression model. PWV values were higher in hypertensive patients in the first two age quartiles while interestingly, in the last two quartiles, PWV was lower than in inflammatory bowel disease group of patients.

CONCLUSIONS

Chronic subclinical inflammation is responsible for dyslipidemia and accelerated atherosclerosis which consequently alterates arterial elasticity. Inflammatory bowel disease and its duration should also be considered a risk factor for subclinical organ damage, as well as hypertension.

Comparison of pulse wave velocity and pulse pressure amplification in association with target organ damage in community-dwelling elderly: The Northern Shanghai Study

This study aimed to investigate the discrepancy between pulse wave velocity (PWV) and pulse pressure amplification (PPA) in association with hypertensive target organ damage (TOD) in the elderly. From June 2014 to August 2015, 1599 participants aged >65 years old from communities located in northern Shanghai were recruited. Carotid-femoral pulse wave velocity (cfPWV), peripheral blood pressure (BP), central BP and other TOD indicators, including the ratio of the early ventricular filling velocity (E) to the peak velocity of the tissue Doppler velocity of septal mitral annulus (E/Ea), left ventricular mass index (LVMI), carotid intima-medium thickness (CIMT), estimated glomerular filtration rate (eGFR), and urinary albumin-creatinine ratio (ACR), were determined for each participant. PPA was defined as the peripheral-to-central pulse pressure ratio. In multivariable linear regression analysis, cfPWV was significantly associated with CIMT (β = 12.83 ± 4.28 μm per SD; P = 0.003) and eGFR (β = -1.85 ± 0.69 ml/min/1.73 m² per SD; P = 0.007), whereas PPA was significantly associated with E/Ea (β = -0.25 ± 0.10 per SD; P = 0.01) and LVMI (β = -3.00 ± 0.78 g/m² per SD; P < 0.001). Similarly, in multivariable logistic regression analysis, cfPWV was significantly associated with arterial plaque (odds ratio [OR], 1.21 [95% confidence interval [CI], 1.05-1.39]; P = 0.007), peripheral artery disease (OR, 1.22 [95% CI, 1.06-1.42]; P = 0.007), chronic kidney diseases (OR, 1.24 [95% CI, 1.01-1.54]; P = 0.04) and microalbuminuria (OR, 1.21 [95% CI, 1.07-1.37]; P = 0.002), while PPA was tightly associated with left ventricular hypertrophy (OR, 0.85 [95% CI, 0.72-0.99]; P = 0.04) and diastolic dysfunction (OR, 0.78 [95% CI, 0.64-0.96]; P = 0.02). In conclusion, cfPWV is a vessel-related and renal-related biomarker, while PPA is a cardiac-related biomarker in community-based elderly.

Does obesity attenuate the beneficial cardiovascular effects of cardiorespiratory fitness?

BACKGROUND AND AIMS

Higher cardiorespiratory fitness is associated with lower pulse wave velocity and arterial stiffness in normal weight individuals, and this has not been examined in obese individuals. It is unclear whether an altered body composition acts as a modifier of the association between cardiorespiratory fitness and arterial stiffness. We examined the association between peak oxygen uptake and brachial-ankle pulse wave velocity and analysed whether body composition attenuates this association in obese middle-aged individuals.

METHODS

Bio-impedance analysis-derived body composition assessment in 212 healthy and sedentary either overweight or obese individuals was followed by measurement of brachial-ankle pulse wave velocity and spiroergometric peak oxygen uptake. Multivariate analysis was performed to analyse the association between peak oxygen uptake and brachial-ankle pulse wave velocity and to assess the moderating effect of several body composition-related interaction terms (BMI, total body mass, body fat mass, waist circumference, waist-to-height ratio) on this association.

RESULTS

Peak oxygen uptake was inversely associated with brachial-ankle pulse wave velocity (β = -0.059, 95% CI = -0.099; -0.018, p = 0.005). Testing for the impact of different body composition-related interaction terms on this association showed no significance, 95% CI lateralized towards positivity.

CONCLUSIONS

This study shows an inverse association between cardiorespiratory fitness and arterial stiffness in middle-aged obese individuals. We also found a tendency towards an attenuating impact of an obese body composition on this association. Physical fitness seems to be a stronger modulator of cardiovascular risk than body composition but the success of training efforts may be compromised by obesity.

Relation of Central Arterial Stiffness to Incident Heart Failure in the Community

BACKGROUND

Arterial stiffness, pressure pulsatility, and wave reflection are associated with cardiovascular disease. Left ventricular function is coupled to proximal aortic properties, but the association of central aortic stiffness and hemodynamics with incident clinical heart failure (HF) is not well described.

METHODS AND RESULTS

Framingham Study participants without clinical HF (n=2539, mean age 64 years, 56% women) underwent applanation tonometry to measure carotid-femoral pulse wave velocity (CFPWV), central pulse pressure, forward wave amplitude, and augmentation index. CFPWV was inverse-transformed to reduce heteroscedasticity and multiplied by -1 to restore effect direction (iCFPWV). Over 10.1 (range 0.04-12.9) years, 170 HF events developed. In multivariable-adjusted analyses, iCFPWV was associated with incident HF in a continuous, graded fashion (hazards ratio [HR] per SD unit [SDU] 1.29, 95% confidence interval [CI] 1.02-1.64, P=0.037). iCFPWV was associated with HF with reduced ejection fraction (HR=1.69/SDU, 95% CI 1.19-2.42, P=0.0037) in age- and sex-adjusted models, which was attenuated in multivariable-adjusted models (P=0.065). Central pulse pressure and forward wave amplitude were associated with HF in age- and sex-adjusted models (per SDU, HR=1.20, 95% CI 1.06-1.37, P=0.006, and HR=1.15, 95% CI 1.01-1.31, P=0.036, respectively), but not in multivariable-adjusted models (both P≥0.28). Augmentation index was not associated with HF risk (P≥0.19 in all models).

CONCLUSIONS

In our prospective investigation of a large community-based sample of middle-aged to elderly individuals, greater aortic stiffness (reflected by higher iCFPWV) was associated with increased risk of HF. Future studies may investigate the impact of modifying aortic stiffness in reducing the community burden of HF.

Elderly Algerian women lose their sex-advantage in terms of arterial stiffness and cardiovascular profile

OBJECTIVES

Several studies have shown lower carotid-femoral pulse wave velocity (cfPWV) levels in women compared to men, a difference that could partially explain the increased longevity in women. However, these studies have been performed in industrial countries while few data are available in emerging populations. We studied arterial stiffness, as evaluated by cfPWV, in elderly Algerian men and women.

METHODS

cfPWV was studied in 321 Algerian men (81.2 ± 5.3 years) and women (81.1 ± 4.4 years). An age-matched and sex-matched cohort of European individuals (n = 321) was used as a control group.

RESULTS

Comparatively to men, Algerian women exhibited higher BMI and heart rate (HR), higher prevalence of hypertension, and were more frequently treated for hypertension. cfPWV was not different between Algerian men (14.8 ± 3.3 m/s) and women (14.9 ± 3.4 m/s). By contrast, in Europeans, women had lower cfPWV (12.7 ± 2.7 m/s) than men (14.0 ± 3.3 m/s; P <0.001). Comparatively to European women, Algerian women had a higher cfPWV (P <0.01). In both ethnic groups, multivariate analyses revealed that age, mean blood pressure (BP), HR, and diabetes were positively associated with cfPWV, whereas female sex was associated with lower cfPWV only in Europeans.

CONCLUSION

Elderly Algerian women exhibit arterial stiffness similar to men, whereas European women display lower arterial stiffness than men. This loss of 'arterial sex advantage' in Algerians may be explained by higher BP, HR, and a worse metabolic profile in Algerian women. Interventions in emerging populations, especially in women, should be a priority in order to address these risk factors by acting on current lifestyle.

Seeking a blood pressure-independent measure of vascular properties

Pulse wave velocity (PWV) and pulse pressure (PP) are blood pressure (BP)-dependent surrogates for vascular stiffness. Considering that there are no clinically useful markers for arterial stiffness that are BP-independent, our objective was to identify novel indices of arterial stiffness and compare them with previously described markers. PWV and PP were measured in young and old male Fisher rats and in young and old male spontaneously hypertensive rats (SHR) over a wide range of BPs. The BP dependence of these and several other indices of vascular stiffness were evaluated. An index incorporating PWV and PP was also constructed. Both PWV and PP increase in a non-linear manner with rising BP for both strains of animals (Fisher and SHRs). Age markedly changes the relationship between PWV or PP and BP. The previously described Ambulatory Arterial Stiffness Index (AASI) was able to differentiate between young and old vasculature, whereas the Cardio-Ankle Vascular Index (CAVI) did not reliably differentiate between the two. The novel Arterial Stiffness Index (ASI) differentiated stiffer from more compliant vasculature. Considering the limitations of the currently available indices of arterial stiffness, we propose a novel index of intrinsic arterial stiffness, the ASI, which is robust over a range of BPs and allows one to distinguish between compliant and stiff vasculature in both Fisher rats and SHRs. Further studies are necessary to validate this index in other settings.

Neural control of the circulation: how sex and age differences interact in humans

The autonomic nervous system is a key regulator of the cardiovascular system. In this review, we focus on how sex and aging influence autonomic regulation of blood pressure in humans in an effort to understand general issues related to the cardiovascular system as a whole. Younger women generally have lower blood pressure and sympathetic activity than younger men. However, both sexes show marked interindividual variability across age groups with significant overlap seen. Additionally, while men across the lifespan show a clear relationship between markers of whole body sympathetic activity and vascular resistance, such a relationship is not seen in young women. In this context, the ability of the sympathetic nerves to evoke vasoconstriction is lower in young women likely as a result of concurrent β2-mediated vasodilation that offsets α-adrenergic vasoconstriction. These differences reflect both central sympatho-inhibitory effects of estrogen and also its influence on peripheral vasodilation at the level of the vascular smooth muscle and endothelium. By contrast postmenopausal women show a clear relationship between markers of whole body sympathetic traffic and vascular resistance, and sympathetic activity rises progressively in both sexes with aging. These major findings in humans are discussed in the context of differences in population-based trends in blood pressure and orthostatic intolerance. The many areas where there is little sex-specific data on how the autonomic nervous system participates in the regulation of the human cardiovascular system are highlighted.

Left ventricular ejection time, not heart rate, is an independent correlate of aortic pulse wave velocity

Several studies showed a positive association between heart rate and pulse wave velocity, a sensitive marker of arterial stiffness. However, no study involving a large population has specifically addressed the dependence of pulse wave velocity on different components of the cardiac cycle. The aim of this study was to explore in subjects of different age the link between pulse wave velocity with heart period (the reciprocal of heart rate) and the temporal components of the cardiac cycle such as left ventricular ejection time and diastolic time. Carotid-femoral pulse wave velocity was assessed in 3,020 untreated subjects (1,107 men). Heart period, left ventricular ejection time, diastolic time, and early-systolic dP/dt were determined by carotid pulse wave analysis with high-fidelity applanation tonometry. An inverse association was found between pulse wave velocity and left ventricular ejection time at all ages (<25 years, r(2) = 0.043; 25-44 years, r(2) = 0.103; 45-64 years, r(2) = 0.079; 65-84 years, r(2) = 0.044; ≥ 85 years, r(2) = 0.022; P < 0.0001 for all). A significant (P < 0.0001) negative but always weaker correlation between pulse wave velocity and heart period was also found, with the exception of the youngest subjects (P = 0.20). A significant positive correlation was also found between pulse wave velocity and dP/dt (P < 0.0001). With multiple stepwise regression analysis, left ventricular ejection time and dP/dt remained the only determinant of pulse wave velocity at all ages, whereas the contribution of heart period no longer became significant. Our data demonstrate that pulse wave velocity is more closely related to left ventricular systolic function than to heart period. This may have methodological and pathophysiological implications.

Sex-specific effect of matrix metalloproteinase-9 functional promoter polymorphism on carotid artery stiffness

BACKGROUND AND PURPOSE

Large artery stiffness is considered to be a marker for cardiovascular disease. Serum matrix metalloproteinase-9 (MMP-9) level has been found to correlate with arterial stiffness and predict cardiovascular risk. This study was aimed to investigate the relationship between the MMP-9 genotypes and artery stiffness, and to examine whether the genetic effect is sex specific.

METHODS

Three carotid stiffness modalities were assessed in 1218 (704 females) stroke- and myocardial infarction-free volunteers aged 21-86 years old. The genotypes of MMP-9 promoter polymorphism (-1562C/T) were determined using the polymerase chain reaction-restriction fragment length polymorphism method. Analysis was conducted to test for the overall and sex specific effect using multivariate regression model.

RESULTS

T allele carriers (CT and TT) had stiffer arteries than CC homozygotes after adjusting for age and sex (p = 0.013, 0.028, and 0.017 for Ep, β, and PWV, respectively). Further sex-stratified analysis showed that the significant association only existed in women. Women with the T allele had significantly stiffer arteries than CC homozygotes after adjusting for age (p = 0.003, 0.018, and 0.006 for Ep, β, and PWV, respectively), and this association remained significant after adjusting for known covariates. When menopausal status was further considered, all three carotid stiffness modalities were significantly different between T allele carriers and CC homozygotes in menopausal but not in pre-menopausal women.

CONCLUSIONS

This study indicates that individuals carrying the -1562T allele are predisposed to stiffer arteries, especially among menopausal women. Women with the T allele should be considered at high risk for cardiovascular disease.

Factors associated with brachial-ankle pulse wave velocity in the general population

The present study investigated factors that modify or affect arterial stiffness as assessed by brachial-ankle pulse wave velocity (baPWV) in the general population. Subjects had previously participated in a physical checkup program (n=911), and baPWV and urinary albumin and sodium excretion were also measured. Urine albumin was expressed as the ratio of urine albumin to urine creatinine. Individual salt intake was assessed by estimating 24-h urinary salt excretion and expressed as the ratio of estimated salt intake to body weight. The mean blood pressure and baPWV were 127.1±15.2/77.0±9.5 mm Hg and 15.9±3.3 m s(-1), respectively. Univariate analysis demonstrated that baPWV correlated with various factors including age, blood pressure, electrocardiogram voltage (SV(1)+RV(5)), urine albumin and salt intake. Multivariate regression analysis revealed that electrocardiogram voltage (P<0.001), systolic blood pressure (P<0.0001), urine albumin (P<0.001) and salt intake (P<0.001), independently correlated with baPWV after adjustment for other possible factors. Similar results were obtained for participants not taking any medication. These results suggest that the baPWV value is independently associated with individual salt intake and cardiac and renal damage, and could be a useful procedure for identifying individuals with concealed risk of cardiovascular disease.

Ethnic differences in carotid artery diameter and stiffness: the Northern Manhattan Study

OBJECTIVE

Race/ethnic differences in carotid arterial function and structure exist among those with cerebrovascular disease, but whether differences persist among healthy populations is unknown. Our objective was to investigate differences in carotid artery diameter and stiffness between race/ethnic groups, and examine whether these race/ethnic differences were age-dependent.

METHODS

Carotid diameters were assessed by B-mode ultrasound among 1536 participants from the Northern Manhattan Study (NOMAS), and carotid stiffness metrics were calculated. We used multivariable linear regression models to determine the relationship between race/ethnicity and both carotid arterial stiffness and carotid diastolic diameter.

RESULTS

Mean participant age was 70 ± 9 years (Hispanics = 68 ± 8, blacks = 72 ± 9, and whites = 74 ± 9, p < 0.0001). Mean DDIAM was 6.2 ± 1.0mm (Hispanics = 6.2 ± 0.9 mm, blacks = 6.3 ± 1.0 mm, and whites = 6.3 ± 1.0 mm, p < 0.005) and mean STIFF was 8.7 ± 6.3 (Hispanics = 8.5 ± 5.7, blacks = 9.2 ± 6.2 and whites = 8.9 ± 6.9, p < 0.02). In a model that adjusted for sociodemographics and vascular risk factors including hypertension, diabetes, dislipidemia, renal function, physical acticity and a history of known coronary artery diseases; age was positively associated with greater DDIAM in Hispanics (p < 0.0001) but not among blacks or whites. Older age was associated with greater stiffness among Hispanics (p < 0.0001) and blacks (p < 0.003), but not among whites.

CONCLUSIONS

We found race/ethnic differences in the association between age and arterial stiffness and diameter, including age-dependent arterial dilation observed in Hispanics that was not observed among blacks or whites.

Evolution of arterial stiffness after kidney transplantation

BACKGROUND

Increased arterial stiffness (AS) is a major determinant of cardiovascular complications in end-stage renal disease (ESRD) patients. Little is known about AS evolution after kidney transplantation. The aim of the study was to characterize the evolution of AS after kidney transplantation in a population of ESRD patients, in comparison to those remaining in dialysis.

METHODS

Eighty-eight patients (age between 35 and 65) were recruited from the waiting list for kidney transplantation of the University Hospital of Nancy. Two vascular evaluations were performed at a 1-year interval. During this interval, 39 patients were transplanted and 49 remained in dialysis.

RESULTS

At inclusion, median pulse-wave velocity (PWV) was similar in transplanted patients and transplantation-pending patients, respectively, 9.2 (7.9-11.9) and 9.8 (7.7-12.1) m/s. No difference between the two groups was found at the 1-year interval. Median of time after transplantation was 6.3 (3.8-10.1) months. Median of blood pressure (MBP) decreased only in the transplanted patients [99 (93-112) versus 96 (90-101) mmHg, P < 0.01] Multivariate analysis showed that PWV changes depend on changes in MBP and baseline PWV.

CONCLUSION

Although no difference in the 1-year PWV evolution was found, the low MBP value in transplanted patients allow to expect a better long-term evolution of AS and a better cardiovascular prognosis after kidney transplantation than in transplantation-pending patients.

Use of cardio-ankle vascular index in chronic dialysis patients

BACKGROUND

Arterial stiffness is an independent predictor of all-cause and cardiovascular mortality, particularly in patients with chronic kidney disease and end-stage renal disease (ESRD). The objective of this study was to determine the risk factors for de novo arterial stiffness in long-term dialysis patients.

MATERIALS AND METHODS

A total of 59 dialysis patients without initial arterial stiffness were studied for 1 year. Cardio-ankle vascular index (CAVI) was measured and a CAVI value ≥ 9 at the end of 1 year was defined as de novo arterial stiffness. The initial baseline characteristics and laboratory parameters and final laboratory parameters after 1 year were analysed.

RESULTS

Dialysis patients with de novo arterial stiffness were significantly older than dialysis patients without de novo arterial stiffness. Initial serum phosphorus and calcium × phosphorus product of dialysis patients with de novo arterial stiffness were significantly greater than those of dialysis patients without de novo arterial stiffness. The haematocrit of dialysis patients with de novo arterial stiffness was significantly lower than that of dialysis patients without de novo arterial stiffness. Multivariate logistic regression analysis showed that age and initial serum phosphorus were independent risk factors for de novo arterial stiffness in dialysis patients.

CONCLUSION

After 1-year follow-up, de novo arterial stiffness in dialysis patients as determined by CAVI was significantly associated with age and initial serum phosphorus.

Differing effects of aging on central and peripheral blood pressures and pulse wave velocity: a direct intraarterial study

OBJECTIVES

There have been a few noninvasive studies showing the effect of aging on blood pressure (BP) and pulse wave velocity (PWV) in different arterial segments. The aim of this study was to evaluate the effect of aging on arterial hemodynamics in central and peripheral arteries using an invasive method.

METHODS

We observed 175 individuals undergoing coronary angiography. SBP and DBP were measured by pressure wave at the radial artery, abdominal aorta, and aortic arch. Aortic arch-abdominal aorta PWV (aoPWV) and aortic arch-radial artery PWV (arPWV) were also assessed by the foot-to-foot velocity method using a fluid-filled system.

RESULTS

SBP and pulse pressure were significantly positively correlated and DBP was significantly negatively correlated with age through the arterial tree in a multivariate analysis after adjusting for sex, coronary artery disease, diabetes, dyslipidemia, smoking status, and the use of antihypertensive agents. Pulse pressure, SBP, and DBP were significantly associated with age (ranked in order of association strength) at all studied arterial segments. Each central BP showed a consistently higher correlation with age than radial BP. aoPWV and arPWV were also significantly correlated with age, and this relationship was much stronger for aoPWV (r = 0.474, P < 0.001) than for arPWV (r = 0.224, P = 0.003).

CONCLUSION

The present invasive study suggests that aging has a greater effect on central rather than peripheral arterial hemodynamics. The central pulse pressure was the predominant BP affected by aging, which could be caused by the stronger relationship of aging with central arterial stiffness.

Reference values of aortic pulse wave velocity in the elderly

BACKGROUND

Increased aortic pulse wave velocity (AoPWV) is an independent predictor of cardiovascular morbidity and mortality. There are, however, no generally accepted limits for defining the normal or reference values. The aim of the present study was to define reference values for AoPWV.

PATIENTS AND METHODS

AoPWV was assessed using applanation tonometry (PulsePen device) in a community living ambulatory population of 455 individuals aged 60-75 years. AoPWV was studied in a group of 206 individuals without hypertension or diabetes, called the 'reference-values group' (RVG), and in a group of 249 individuals with hypertension or diabetes, called the hypertension-diabetes group (HDG). The 95th percentile of the samples was used to determine the upper limit of AoPWV reference values.

RESULTS

Mean AoPWV was 8.7+/-2.3 m/s in the RVG and 10.2+/-2.5 m/s in the hypertension-diabetes group (P<0.0001). In the RVG, median AoPWV in the three age subgroups was 8.0 m/s (7.6-8.5) in the 60-64-, 8.0 m/s (7.5-9.0) in the 65-69- and 9.0 m/s (7.9-9.5) in the 70-75-year-old group (NS among groups). In the entire RVG, the upper bounds of the 75th and the 95th percentile of the sample's AoPWV were 10 and 13 m/s, respectively, with no difference between sexes.

CONCLUSION

In elderly individuals of 60-75 years, an AoPWV value below 10 m/s, measured with the PulsePen device, can be considered as a normal value. Values of 10-13 m/s can be considered as 'high normal' or 'borderline', whereas an AoPWV above 13 m/s is frankly elevated. This study provides, for the first time in the elderly, reference values of AoPWV.