Central wave reflection is associated with peripheral arterial resistance in addition to arterial stiffness in subjects without antihypertensive medication

Volume overload is a major characteristic in primary aldosteronism: a 3-year follow-up study

OBJECTIVES

We examined haemodynamics, focusing on volume balance and forward and backward wave amplitudes, before and after 2.8 years of targeted treatment of primary aldosteronism. Patients with essential hypertension and normotensive individuals were examined for comparison ( n  = 40 in each group).

METHODS

Recordings were performed using radial artery pulse wave analysis and whole-body impedance cardiography. Unilateral aldosteronism was treated with adrenalectomy ( n  = 20), bilateral aldosteronism with spironolactone-based medication ( n  = 20), and essential hypertension with standard antihypertensive agents.

RESULTS

Aortic SBP and DBP, forward and backward wave amplitudes, and systemic vascular resistance were equally elevated in primary aldosteronism and essential hypertension. All these haemodynamic variables were similarly reduced by the treatments. Primary aldosteronism presented with 1 litre (∼10%) extracellular water excess ( P  < 0.001) versus the other groups, and this excess was normalized by treatment. Initial pulse wave velocity (PWV) was similarly increased in primary aldosteronism and essential hypertension, but final values remained higher in primary aldosteronism ( P  < 0.001). In regression analyses, significant explanatory factors for treatment-induced forward wave amplitude reduction were decreased systemic vascular resistance ( β  = 0.380) and reduced extracellular water volume ( β  = 0.183). Explanatory factors for backward wave amplitude reduction were changes in forward wave amplitude ( β  = 0.599), heart rate ( β  = -0.427), and PWV ( β  = 0.252).

CONCLUSION

Compared with essential hypertension, the principal haemodynamic difference in primary aldosteronism was higher volume load. Volume excess elevated forward wave amplitude, which was subsequently reduced by targeted treatment of primary aldosteronism, along with normalization of volume load. We propose that incorporating extracellular water evaluation alongside routine diagnostics could enhance the identification and diagnosis of primary aldosteronism.

Arterial stiffness tested by pulse wave velocity and augmentation index for cardiovascular risk stratification in antiphospholipid syndrome

OBJECTIVES

Cardiovascular disease is a major cause of morbidity and mortality in Antiphospholipid syndrome (APS). Arterial stiffness (ArS) has emerged as a predictor of future cardiovascular events in the general population. We aimed to assess ArS in patients with thrombotic APS versus diabetes mellitus (DM) and healthy controls (HC) and identify predictors of increased ArS in APS.

METHODS

ArS was evaluated by carotid-femoral pulse wave velocity (cfPWV) and augmentation index normalized to 75 beats/min (AIx@75) using the SphygmoCor device. Participants also underwent carotid/femoral ultrasound for atherosclerotic plaque detection. We used linear regression to compare ArS measures among groups and assess ArS determinants in the APS group.

RESULTS

We included 110 patients with APS (70.9% female, mean age 45.4 years), 110 DM patients and 110 HC, all age/sex matched. After adjustment for age, sex, cardiovascular risk factors and plaque presence, APS patients exhibited similar cfPWV [β = -0.142 (95% CI -0.514, 0.230), p = 0.454] but increased AIx@75 [β = 4.525 (95% CI 1.372, 7.677), p = 0.005] compared with HC and lower cfPWV (p < 0.001) but similar AIx@75 (p = 0.193) versus DM patients. In the APS group, cfPWV was independently associated with age [β = 0.056 (95% CI 0.034, 0.078), p < 0.001], mean arterial pressure (MAP) [β = 0.070 (95% CI 0.043, 0.097), p < 0.001], atherosclerotic femoral plaques [β = 0.732 (95% CI 0.053, 1.411), p = 0.035] and anti-β2-glycoprotein I IgM positivity [β = 0.696 (95% CI 0.201, 1.191), p = 0.006]. AIx@75 was associated with age [β = 0.334 (95% CI 0.117, 0.551), p = 0.003], female sex [β = 7.447 (95% CI 2.312, 12.581), p = 0.005] and MAP [β = 0.425 (95% CI 0.187, 0.663), p = 0.001].

CONCLUSION

APS patients exhibit elevated AIx@75 vs HC and similar to DM patients, indicating enhanced arterial stiffening in APS. Given its prognostic value, ArS evaluation may help to improve cardiovascular risk stratification in APS.

Association Between Augmentation Index and Total Sleep Time in Night Shift Workers

Augmentation index and pulse wave velocity are markers of vascular compromise and independent predictors of cardiovascular risk and mortality. While the link between shift work and heightened cardiovascular risk is established, the intricate genesis of early cardiovascular outcomes in shift workers remains incompletely understood. However, there is evidence that sleep duration plays a role in this regard. Here we evaluate the association of total sleep time with pulse wave velocity, augmentation index, and central blood pressure in night shift workers. This study cross-sectionally evaluated the association of total sleep time evaluated by 10-day monitoring actigraphy with augmentation index, pulse wave velocity, and brachial and central blood pressure evaluated by oscillometry in nursing professionals, 63 shift workers (89% women; age = 45.0 ± 10.5 years), and 17 (100% women; age = 41.8 ± 15.6) day workers. There were no differences in the studied variables between shift workers and day workers. Results of correlation analysis demonstrated that pulse wave velocity, central systolic blood pressure, central diastolic blood pressure, brachial systolic blood pressure, and brachial diastolic blood pressure tended to have significant correlation with each other, while these measures did not have a significant relationship with augmentation index in both groups. However, results of adjusted restricted cubic spline analysis showed a U-shaped-curve association between total sleep time and augmentation index (p < 0.001 for trend) with a nadir at 300-360 min of total sleep time in shift workers. The present study showed that total sleep time, assessed by actigraphy, had a U-shaped association with augmentation index in shift workers, which indicated better characteristics of vascular functionality when sleep time was 5-6 h in the workers studied.

Differences in heart rate responses to upright posture are associated with variations in the high-frequency power of heart rate variability

High resting heart rate is a cardiovascular risk factor, but limited data exist on the underlying hemodynamics and reproducibility of supine-to-upright increase in heart rate. We recorded noninvasive hemodynamics in 574 volunteers [age, 44.9 yr; body mass index (BMI), 26.4 kg/m2; 49% male] during passive head-up tilt (HUT) using whole body impedance cardiography and radial artery tonometry. Heart rate regulation was evaluated using heart rate variability (HRV) analyses. Comparisons were made between quartiles of supine-to-upright heart rate changes, in which heart rate at rest ranged 62.6-64.8 beats/min (P = 0.285). The average upright increases in heart rate in the quartiles 1-4 were 4.7, 9.9, 13.5, and 21.0 beats/min, respectively (P < 0.0001). No differences were observed in the low-frequency power of HRV, whether in the supine or upright position, or in the high-frequency power of HRV in the supine position. Upright high-frequency power of HRV was highest in quartile 1 with lowest upright heart rate and lowest in quartile 4 with highest upright heart rate. Mean systolic blood pressure before and during HUT (126 vs. 108 mmHg) and the increase in systemic vascular resistance during HUT (650 vs. 173 dyn·s/cm5/m2) were highest in quartile 1 and lowest in quartile 4. The increases in heart rate during HUT on three separate occasions several weeks apart were highly reproducible (r = 0.682) among 215 participants. To conclude, supine-to-upright increase in heart rate is a reproducible phenotype with underlying differences in the modulation of cardiac parasympathetic tone and systemic vascular resistance. As heart rate at rest influences prognosis, future research should elucidate the prognostic significance of these phenotypic differences.NEW & NOTEWORTHY Subjects with similar supine heart rates are characterized by variable increases in heart rate during upright posture. Individual heart rate increases in response to upright posture are highly reproducible as hemodynamic phenotypes and present underlying differences in the modulation of cardiac parasympathetic tone and systemic vascular resistance. These results indicate that resting heart rate obtained in the supine position alone is not an optimal means of classifying people into groups with differences in cardiovascular function.

Blood Haemoglobin Concentration Is Directly and Independently Related with Pulse Wave Velocity, a Measure of Large Artery Stiffness

High haemoglobin level has been associated with metabolic syndrome, elevated blood pressure (BP), and increased mortality risk. In this cross-sectional study, we investigated the association of blood haemoglobin with haemodynamics in 743 subjects, using whole-body impedance cardiography and pulse wave analysis. The participants were allocated to sex-stratified haemoglobin tertiles with mean values 135, 144, and 154 g/L, respectively. The mean age was similar in all tertiles, while body mass index was higher in the highest versus the lowest haemoglobin tertile. The highest haemoglobin tertile had the highest erythrocyte and leukocyte counts, plasma C-reactive protein, uric acid, renin activity, and aldosterone. The lipid profile was less favourable and insulin sensitivity lower in the highest versus the lowest haemoglobin tertile. Aortic BP, cardiac output, and systemic vascular resistance were similar in all tertiles, while the pulse wave velocity (PWV) was higher in the highest versus the lowest haemoglobin tertile. In linear regression analysis, age (Beta 0.478), mean aortic BP (Beta 0.178), uric acid (Beta 0.150), heart rate (Beta 0.148), and aldosterone-to-renin ratio (Beta 0.123) had the strongest associations with PWV (p < 0.001 for all). Additionally, haemoglobin concentration was an explanatory factory for PWV (Beta 0.070, p = 0.028). To conclude, blood haemoglobin concentration had a small direct and independent association with a measure of large artery stiffness.

Neighbourhood deprivation in childhood and adulthood and risk of arterial stiffness: the Cardiovascular Risk in Young Finns study

Purpose: Individual socioeconomic status is associated with increased arterial stiffness, but limited data are available on the relations of neighbourhood deprivation with this vascular measure. We prospectively examined whether neighbourhood deprivation in childhood and adulthood predicts arterial stiffness indicated by pulse wave velocity (PWV).Materials and methods: The study population comprised 1,761 participants aged 3-18 years at baseline (1980) from the longitudinal Cardiovascular Risk in Young Finns cohort study. PWV was measured in 2007 by whole-body impedance cardiography at ages 30-45 years. Cumulative lifetime neighbourhood deprivation was assessed using data from socioeconomic circumstances in participants' lifetime residential neighbourhoods, categorised as low versus high deprivation.Results: High deprivation in childhood and adulthood was associated with higher PWV in adulthood after adjustment for age, sex, and place of birth (mean difference = 0.57 m/s, 95%CI = 0.26-0.88, P for trend = 0.0004). This association was attenuated but remained statistically significant after further adjustment for childhood parental socioeconomic status and adulthood individual socioeconomic status (mean difference = 0.37 m/s, 95%CI = 0.05-0.70, P for trend 0.048). Also, low individual socioeconomic status in adulthood was associated with higher PWV when adjusted for age, sex, place of birth, parental socioeconomic status in childhood, and lifetime neighbourhood deprivation (mean difference = 0.54 m/s, 95%CI = 0.23-0.84, P for trend 0.0001).Conclusion: These findings suggest that lifetime neighbourhood deprivation and low adulthood socioeconomic status are independent risk factors for increased arterial stiffness in adulthood.

Unveiling the Silent Danger of Childhood Obesity: Non-Invasive Biomarkers Such as Carotid Intima-Media Thickness, Arterial Stiffness Surrogate Markers, and Blood Pressure Are Useful in Detecting Early Vascular Alterations in Obese Children

Obese children present a higher cardio-metabolic risk. Measuring vascular biomarkers that assess the evolution of arterial stiffness, subclinical atherosclerosis, and hypertension in such patients could be helpful in the long term. We studied 84 children, aged from 6 to 18 years: 50 obese subjects, versus 34 of normal weight. Clinical examination involved: BMI, waist circumference, waist-to-height ratio, and detection of the presence of acanthosis nigricans and irregular menstrual cycles (the latter in adolescent girls). The carotid intima-media thickness (CIMT) was measured with the Aixplorer MACH 30 echography device. The pulse wave velocity (PWV), augmentation index (AIx), and peripheral and central blood pressures (i.e., SBP, DBP, cSBP, cDBP, and cPP) were acquired through a Mobil-O-Graph device. Obese subjects underwent body composition analysis with a Tanita BC-418. Blood tests were: HOMA-IR, lipid panel, uric acid, and 25-OH vitamin D. All vascular biomarkers presented increased values in obese subjects versus controls. The following cut-off values were significant in detecting obesity: for PWV > 4.6 m/s, cSBP > 106 mmHg for the <12-year-olds, PWV > 4.5 m/s and cSBP > 115 mmHg for the 12-15-year-olds, and PWV > 5 m/s, cSBP > 123 mmHg for the >15-year-olds. AIx is higher in obese children, regardless of their insulin resistance status. Waist circumference and waist-to-height ratio correlate to all vascular parameters. HOMA-IR is an independent predictor for all vascular parameters except CIMT. Cut-off values for PWV of >4.8 m/s, SBP > 125 mmHg, and a cSBP > 117 mmHg predicted the presence of acanthosis nigricans. Obese girls with irregular menses displayed significantly higher PWV, SBP, and DPB. Elevated levels of uric acid, LDL-c, non-LDL-c, triglycerides, and transaminases, and low levels of HDL-c and 25-OH vitamin D correlated with higher arterial stiffness and CIMT values. We conclude that CIMT and the markers of arterial stiffness are useful in the early detection of vascular damage in obese children.

Low length-for-age Z-score within 1 month after birth predicts hyperdynamic circulation at the age of 21 years in rural Malawi

Low birth weight predisposes to the development of hypertension in middle- and high-income countries. We examined the relation of early life length-for-age score (Z-score) on cardiovascular function in young adults in Malawi, a low-income country. Capture of supine, seated, and standing brachial pulse waveforms (Mobil-O-Graph) were performed in 223 females and 152 males (mean age 21 years), and analyzed according to the length-for-age Z-score tertiles during the first month of life. Plasma LDL cholesterol in young adulthood was slightly lower in the lowest versus highest tertile. Otherwise, blood hemoglobin and plasma chemistry were similar in all tertiles. Irrespective of posture, blood pressure, forward and backward wave amplitudes, and pulse wave velocity were corresponding in all tertiles. In the three postures, the lowest tertile presented with 4.5% lower systemic vascular resistance than the highest tertile (p = 0.005), and 4.4% and 5.5% higher cardiac output than the middle and highest tertiles, respectively (p < 0.01). Left cardiac work was 6.8% and 6.9% higher in the lowest tertile than in the middle and highest tertiles, respectively (p < 0.01). To conclude, in a low-income environment, low length-for-age Z-score after birth predicted hyperdynamic circulation at 21 years of age without changes in blood pressure and metabolic variables.

The characteristics of elevated blood pressure in abdominal obesity correspond to primary hypertension: a cross-sectional study

BACKGROUND

Obesity-related hypertension and the associated metabolic abnormalities are considered as a distinct hypertensive phenotype. Here we examined how abdominal fat content, as judged by waist:height ratio, influenced blood pressure and hemodynamic profile in normotensive subjects and never-treated hypertensive patients.

METHODS

The 541 participants (20-72 years) underwent physical examination and laboratory analyses and were divided into age and sex-adjusted quartiles of waist:height ratio. Supine hemodynamics were recorded using whole-body impedance cardiography, combined with analyses of radial tonometric pulse wave form and heart rate variability.

RESULTS

Mean waist:height ratios in the quartiles were 0.46, 0.51, 0.55 and 0.62. Radial and aortic blood pressure, systemic vascular resistance, pulse wave velocity, markers of glucose and lipid metabolism, leptin levels and C-reactive protein were higher in quartile 4 when compared with quartiles 1 and 2 (p < 0.05 for all). Cardiac index was lower in quartile 4 versus quartile 1, while no differences were seen in heart rate variability, augmentation index, plasma renin activity, and aldosterone concentration between the quartiles. Linear regression analyses showed independent associations of abdominal obesity with higher aortic systolic and diastolic blood pressure, systemic vascular resistance, and pulse wave velocity (p < 0.05 for waist:height ratio in all regression models).

CONCLUSION

Higher waist:height ratio was associated with elevated blood pressure, systemic vascular resistance, and arterial stiffness, but not with alterations in cardiac sympathovagal modulation or activation of the circulating renin-angiotensin-aldosterone system. Although obesity-related elevation of blood pressure has distinct phenotypic features, these results suggest that its main characteristics correspond those of primary hypertension.

TRIAL REGISTRATION

ClinicalTrails.gov NCT01742702 (date of registration 5th December 2012).

Evaluating the Arterial Stiffness as a Useful Tool in the Management of Obese Children

Childhood obesity speeds up the development of arterial stiffness and progressively increases the values of arterial pressure. The purpose of this study is to investigate the value of using pulse wave analysis (PWA) to measure arterial stiffness as a sign of vascular wall impairment in obese children. The research was focused on 60 subjects: 33 obese and 27 normal-weight. Ages ranged from 6 to 18 years old. PWA includes parameters such as pulse wave velocity (PWV), augmentation index (AIx), peripheral and central blood pressure (SBP, DBP, cSBP, cDBP), heart rate, and central pulse pressure (cPP). The device used was a Mobil-O-Graph. Blood parameters were taken from the subject's medical history, not older than 6 months. A high BMI and a large waist circumference are linked to a high PWV. The levels of LDL-c, triglycerides (TG), non-HDL-c, TG/HDL-c ratio, and total cholesterol-HDL-c ratio significantly correlate to PWV, SBP, and cSBP. Alanine aminotransferase is a reliable predictor of PWV, AIx, SBP, DBP, and cDBP, while aspartate aminotransferase is a significant predictor of AIx, mean arterial pressure (MAP), cSBP, and cPP. 25-OH-Vitamin D negatively correlates with PWV, SBP, and MAP and significantly predicts the MAP. Cortisol and TSH levels are not significant to arterial stiffness in obese children without specific comorbidities and neither is fasting glucose in obese children without impaired glucose tolerance. We conclude that PWA contributes valuable data regarding patients' vascular health and should be considered a reliable tool in the management of obese children.

Regular physical activity: a major component of isolated systolic hypertension in the young

In the last few decades there has been much debate about the clinical significance of isolated systolic hypertension in youth (ISHY). Purpose of this article is to discuss the epidemiology and pathophysiology of ISHY focusing on the relationship between ISHY and aerobic exercise. There is evidence to suggest that regular physical activity produces favourable long-standing cardiovascular effects in young individuals including the improvement of arterial elasticity as measured from carotid-femoral pulse wave velocity and from small artery compliance. A recent ESH document recognises the heterogeneity of ISHY which may be associated with multiple factors that can interact to determine this BP phenotype. Several studies have shown that long-term training in aerobic sports is one main factor contributing to ISHY. In the athlete, the increased stroke volume secondary to low heart rate and the high arterial elasticity causes an increase in peripheral pulse pressure. This explains why ISHY is more common in physically trained than in sedentary individuals and is considered by some authors as a spurious hypertension. Recent results from the HARVEST study confirm the existence of an association between ISHY and endurance training. In that study the prevalence of ISHY was directly related to physical activity habits being 8.8% in the sedentary subjects and 25.7% in the athletes. Eligibility to competitive athletics of athletes with ISHY should be based on the results of 24-hour ambulatory BP monitoring and careful clinical assessment of all cardiovascular risk factors and target organ involvement in order to establish the global level of risk.

The Oscillometric Pulse Wave Analysis Is Useful in Evaluating the Arterial Stiffness of Obese Children with Relevant Cardiometabolic Risks

Early detection of all complications of childhood obesity is imperative in order to minimize effects. Obesity causes vascular disruptions, including early increased arterial stiffness and high blood pressure. This study’s aim is to assess the reliability of pulse wave analysis (PWA) in obese children and how additional risk factors influence the evaluated parameters. We analyzed 55 children aged 6–18 years old by measuring their pulse wave velocity (PWV), augmentation index (AIx), peripheral blood pressure (SBP, DBP), heart rate, central blood pressure (cSBP, cDBP) and central pulse pressure (cPP). We used the oscillometric IEM Mobil-O-Graph and performed a single-point brachial measurement. The subjects were divided into two groups: obese (n = 30) and normal-weight (n = 25) and were clinically and anamnestically assessed. BMI and waist circumference are significantly correlated to higher values for PWV, SBP, DBP, cSBP, and cDBP. Weight significantly predicts PWV, SBP, DBP and cPP. The risk factors that significantly influence the PWA and BP values are: a cardiometabolically risky pregnancy (higher PWV, AIx, SBP), active and passive smoking (higher PWV, SBP, cSBP, cDBP), sleep deprivation (higher PWV, SBP, cSBP) and sedentariness (higher PWV, AIx, peripheral and central BP). We conclude that obese children with specific additional cardiometabolic risk factors present increased arterial stiffness and higher blood pressure values.

Resting heart rate predicts cardiac autonomic modulation during passive head-up tilt in subjects without cardiovascular diseases

Background Resting heart rate (HR) and its variability (HRV) reflects the cardiac sympathovagal balance that is stimulated by head-up tilting. HRV is influenced by the level of HR, but how much HRV offers additional information about cardiac autonomic tone than HR alone remains unresolved. We examined the relation of resting HR with HRV during head-up tilt. Methods. Hemodynamics of 569 subjects without known cardiovascular diseases and medications with direct cardiovascular effects were recorded using whole-body impedance cardiography, radial pulse wave analysis, and electrocardiography-based HRV analysis during passive head-up tilt. Results. Higher low frequency to the high-frequency ratio (LF/HF) of HRV (reflecting sympathovagal balance) was associated with higher HR in supine (p < .05, both linear regression analysis and variance analysis comparing HR tertiles) and upright postures (p < .001, linear regression analysis). The association of HR with HRV during tilt-testing remained significant when the HR dependence of HRV was mathematically weakened by dividing the HRV power spectra with the fourth power of the average RR-interval. Conclusion. Higher resting HR is related to higher LF/HF both supine and upright, reflecting elevated sympathetic influence on cardiac autonomic modulation. Lower resting HR is associated with lower resting LF/HF, while the differences in LF/HF between the HR tertiles were minor during head-up tilt, suggesting a greater change in cardiac sympathovagal balance in response to upright posture in those with lowest resting HR. Altogether, resting HR well predicts HRV levels during head-up tilt.Trial registration: Clinicaltrialsregister.eu 2006-002065-39, first registered 5 May 2006. ClinicalTrials.gov NCT01742702, first registered 5 December 2012.

Heart Rate Recovery, Central Systolic Pressure, and Augmentation Index in Young Healthy Individuals

Purpose

Measuring heart rate recovery (HRR) holds valuable cardiovascular information and requires minimal technical skill and cost. Understanding the associations between HRR and more robust cardiovascular indicators, such as central systolic blood pressure (CSBP), can provide valuable cardiovascular information with less involvement. CSBP is a strong predictor of certain cardiovascular diseases. The study aims to examine the association between measures of HRR and CSBP and the augmentation index (AIx) in a group of young, healthy individuals and based on sex.

Participants and Methods

One-hundred and seven participants (men – 55, women – 52) were measured for HRR at one minute (HRR₁) and two minutes (HRR₂) after maximum oxygen consumption (VO_2max) testing, CSBP, and the AIx at a heart rate of 75 beats∙min⁻¹ (AIx@75).

Results

The Pearson correlation indicated no association between HRR₁, HRR₂, and CSBP in men and women combined: r = 0.06, P = 0.53; r = 0.05, P = 0.59, respectively, or based on sex: men = r = 0.01, P = 0.95; r = 0.04, P = 0.79, respectively, and women = r = −0.05, P = 0.75; r = −0.09, P = 0.52, respectively. However, there were associations between HRR₁ and AIx@75 in men and women combined: r = −0.37, P < 0.001, and based on sex: men = r = −0.31, P = 0.02, and women = r = −0.38, P < 0.01.

Conclusion

Measures of HRR were not associated with CSBP in a combined group of young men and women or based on sex. Most measures of HRR, especially those established by parasympathetic nervous activity, were associated with lower AIx@75. Though measures of HRR might be good indicators of cardiovascular disease, they might not be good indicators of CSBP in young, healthy individuals.

Central Pressure Waveform-Derived Indexes Obtained From Carotid and Radial Tonometry and Brachial Oscillometry in Healthy Subjects (2–84 Y): Age-, Height-, and Sex-Related Profiles and Analysis of Indexes Agreement

Aortic blood pressure (aoBP) waveform-derived indexes could provide valuable (prognostic) information over and above cardiovascular risk factors (CRFs). To obtain aoBP waveform-characteristics, several (i) techniques, (ii) recording sites, (iii) pressure-only waveform analysis mathematical approaches [e.g., pulse wave analysis (PWA), wave separation analysis (WSA)], and (iv) indexes [augmentation pressure and index (AP and AIx), forward (Pf) and backward (Pb) components of aoBP, reflection magnitude (RM), and reflection index (Rix)], were proposed. An accurate clinical use of these indexes requires knowing their physiological age-related profiles and the expected values for a specific subject. There are no works that have characterized waveform-derived indexes profiles in large populations considering: (i) as a continuous, data from different age stages (childhood, adolescence, and adulthood), (ii) complementary indexes, (iii) data obtained from different techniques and approaches, and (iv) analyzing potential sex- and body height (BH)-related differences. In addition, (v) there is a lack of normative data (reference intervals, RIs) for waveform-derived indexes.

Individual changes of central blood pressure in response to upright posture: different hemodynamic phenotypes

OBJECTIVES

Most studies about upright regulation of blood pressure have focused on orthostatic hypotension despite the diverse hemodynamic changes induced by orthostatic challenge. We investigated the effect of passive head-up tilt on aortic blood pressure.

METHODS

Noninvasive peripheral and central hemodynamics in 613 volunteers without cardiovascular morbidities or medications were examined using pulse wave analysis, whole-body impedance cardiography and heart rate variability analysis.

RESULTS

In all participants, mean aortic SBP decreased by -4 (-5 to -3) mmHg [mean (95% confidence intervals)] and DBP increased by 6 (5--6) mmHg in response to upright posture. When divided into tertiles according to the supine-to-upright change in aortic SBP, two tertiles presented with a decrease [-15 (-14 to -16) and -4 (-3 to -4) mmHg, respectively] whereas one tertile presented with an increase [+7 (7-- 8) mmHg] in aortic SBP. There were no major differences in demographic characteristics between the tertiles. In regression analysis, the strongest explanatory factors for upright changes in aortic SBP were the supine values of, and upright changes in systemic vascular resistance and cardiac output, and supine aortic SBP.

CONCLUSION

In participants without cardiovascular disease, the changes in central SBP during orthostatic challenge are not uniform. One-third presented with higher upright than supine aortic SBP with underlying differences in the regulation of systemic vascular resistance and cardiac output. These findings emphasize that resting blood pressure measurements give only limited information about the blood pressure status.

Plasma uric acid is related to large arterial stiffness but not to other hemodynamic variables: a study in 606 normotensive and never-medicated hypertensive subjects

Background

Elevated level of plasma uric acid (PUA) has been associated with cardiovascular disease, but whether uric acid is an independent risk factor or merely a marker remains controversial.

Methods

We investigated in a cross-sectional setting the association of PUA with hemodynamics in 606 normotensive and never-medicated hypertensive subjects (295 men, 311 women, age range 19–73 years) without cardiovascular disease or gout. In all except 15 individuals, PUA was within the normal range. Supine hemodynamics were recorded using whole-body impedance cardiography and radial tonometric pulse wave analysis.

Results

The mean concentrations of PUA in age, sex and body mass index adjusted quartiles were 234, 278, 314, and 373 µmol/l, respectively. The highest PUA quartile presented with higher aortic to popliteal pulse wave velocity (PWV) than the lowest quartile (8.7 vs. 8.2 m/s, p = 0.026) in analyses additionally adjusted for plasma concentrations of C-reactive protein, low density lipoprotein cholesterol, triglycerides, and mean aortic blood pressure. No differences in radial and aortic blood pressure, wave reflections, heart rate, cardiac output, and systemic vascular resistance were observed between the quartiles. In linear regression analysis, PUA was an independent explanatory factor for PWV (β = 0.168, p < 0.001, R² of the model 0.591), but not for systolic or diastolic blood pressure. When the regression analysis was performed separately for men and women, PUA was an independent predictor of PWV in both sexes.

Conclusions

PUA concentration was independently and directly associated with large arterial stiffness in individuals without cardiovascular disease and PUA levels predominantly within the normal range. Trial registration ClinicalTrials.gov NCT01742702.

Insulin stimulation reduces aortic wave reflection in adults with metabolic syndrome

Adults with metabolic syndrome (MetS) have increased fasting arterial stiffness and altered central hemodynamics that contribute, partly, to increased cardiovascular disease (CVD) risk. Although insulin affects aortic wave reflections in healthy adults, the effects in individuals with MetS are unclear. We hypothesized that insulin stimulation would reduce measures of pressure waveforms and hemodynamics in people with MetS. Thirty-five adults with obesity (27 women; 54.2 ± 6.0 yr; 37.1 ± 4.8 kg/m²) were selected for MetS (ATP III criteria) following an overnight fast. Pulse wave analysis was assessed using applanation tonometry before and after a 2-h euglycemic-hyperinsulinemic clamp (90 mg/dL, 40 mU/m²/min). Deconvolution analysis was used to decompose the aortic waveform [augmentation index corrected to heart rate of 75 beats/min (AIx@75); augmentation pressure (AP)] into backward and forward pressure components. Aerobic fitness (V̇o_2max), body composition (DXA), and blood biochemistries were also assessed. Insulin significantly reduced augmentation index (AIx@75, 28.0 ± 9.6 vs. 23.0 ± 9.9%, P < 0.01), augmentation pressure (14.8 ± 6.4 vs. 12.0 ± 5.7 mmHg, P < 0.01), pulse pressure amplification (1.26 ± 0.01 vs. 0.03 ± 0.01, P = 0.01), and inflammation [high-sensitivity C-reactive protein (hsCRP): P = 0.02; matrix metallopeptidase 7 (MMP-7): P = 0.03] compared to fasting. In subgroup analyses to understand HTN influence, there were no insulin stimulation differences on any outcome. V̇o_2max, visceral fat, and blood potassium correlated with fasting AIx@75 (r = -0.39, P = 0.02; r = 0.41, P = 0.03; r = -0.53, P = 0.002). Potassium levels were also associated with insulin-mediated reductions in AP (r = 0.52, P = 0.002). Our results suggest insulin stimulation improves indices of aortic reflection in adults with MetS.NEW & NOTEWORTHY This study is one of the first to investigate the effects of insulin on central and peripheral hemodynamics in adults with metabolic syndrome. We provide evidence that insulin infusion reduces aortic wave reflection, potentially through a reduction in inflammation and/or via a potassium-mediated vascular response.

Associations between left ventricular function, vascular function and measures of cerebral small vessel disease: a cross-sectional magnetic resonance imaging study of the UK Biobank

OBJECTIVES

Impaired cardiovascular function has been associated with cognitive deterioration; however, to what extent cardiovascular dysfunction plays a role in structural cerebral changes remains unclear. We studied whether vascular and left ventricular (LV) functions are associated with measures of cerebral small vessel disease (cSVD) in the middle-aged general population.

METHODS

In this cross-sectional analysis of the UK Biobank, 4366 participants (54% female, mean age 61 years) underwent magnetic resonance imaging to assess LV function (ejection fraction [EF] and cardiac index [CI]) and cSVD measures (total brain volume, grey and white matter volumes, hippocampal volume and white matter hyperintensities [WMH]). Augmentation index (AIx) was used as a measure of arterial stiffness. Linear and non-linear associations were evaluated using cardiovascular function measures as determinants and cSVD measures as outcomes.

RESULTS

EF was non-linearly associated with total brain volume and grey matter volume, with the largest brain volume for an EF between 55 and 60% (both p < 0.001). EF showed a negative linear association with WMH (- 0.23% [- 0.44; - 0.02], p = 0.03), yet no associations were found with white matter or hippocampal volume. CI showed a positive linear association with white matter (β 3194 mm³ [760; 5627], p = 0.01) and hippocampal volume (β 72.5 mm³ [23.0; 122.0], p = 0.004). No associations were found for CI with total brain volume, grey matter volume or WMH. No significant associations were found between AIx and cSVD measures.

CONCLUSIONS

This study provides novel insights into the complex associations between the heart and the brain, which could potentially guide early interventions aimed at improving cardiovascular function and the prevention of cSVD.

KEY POINTS

• Ejection fraction is non-linearly and cardiac index is linearly associated with MRI-derived measures of cerebral small vessel disease. • No associations were found for arterial stiffness with cSVD measures.

Parathyroid hormone may play a role in the pathophysiology of primary hypertension

Parathyroid hormone has been related with the risk of hypertension, but the matter remains controversial. We examined the association of parathyroid hormone with central blood pressure and its determinants in 622 normotensive or never-treated hypertensive subjects aged 19-72 years without diabetes, cardiovascular or renal disease, or cardiovascular medications. The methods were whole-body impedance cardiography and analyses of pulse wave and heart rate variability. Cardiovascular function was examined in sex-specific tertiles of plasma parathyroid hormone (mean concentrations 3.0, 4.3 and 6.5 pmol/L, respectively) during head-up tilt. Explanatory factors for haemodynamics were further investigated using linear regression analyses. Mean age was 45.0 (s.d. 11.7) years, BMI 26.8 (4.4) kg/m2, seated office blood pressure 141/90 (21/12) mmHg, and 309 subjects (49.7%) were male. Only five participants had elevated plasma parathyroid hormone and calcium concentrations. Highest tertile of parathyroid hormone presented with higher supine and upright aortic diastolic blood pressure (P < 0.01) and augmentation index (P < 0.01), and higher upright systemic vascular resistance (P < 0.05) than the lowest tertile. The tertiles did not present with differences in pulse wave velocity, cardiac output, or measures of heart rate variability. In linear regression analyses, parathyroid hormone was an independent explanatory factor for aortic systolic (P = 0.005) and diastolic (P = 0.002) blood pressure, augmentation index (P = 0.002), and systemic vascular resistance (P = 0.031). To conclude, parathyroid hormone was directly related to central blood pressure, wave reflection, and systemic vascular resistance in subjects without cardiovascular comorbidities and medications. Thus, parathyroid hormone may play a role in the pathophysiology of primary hypertension.

Primary aldosteronism: Higher volume load, cardiac output and arterial stiffness than in essential hypertension

BACKGROUND

The diagnostics of primary aldosteronism (PA) are usually carried out in patients taking antihypertensive medications. We compared haemodynamics between medicated PA, medicated essential hypertension (EH), never-medicated EH and normotensive controls (n = 130 in all groups).

METHODS

The hypertensive groups were matched for age (53 years), sex (84 male/46 female) and body mass index (BMI) (30 kg m^-2 ); normotensive controls had similar sex distribution (age 48 years, BMI 27 kg m^-2 ). Haemodynamics were recorded using whole-body impedance cardiography and radial pulse wave analysis, and the results were adjusted as appropriate. Radial blood pressure recordings were calibrated by brachial blood pressure measurements from the contralateral arm.

RESULTS

Radial and aortic systolic and diastolic blood pressure was similar in PA and never-medicated EH, and higher than in medicated EH and normotensive controls (P ≤ 0.001 for all comparisons). Extracellular water balance was ~ 4% higher in PA than in all other groups (P < 0.05 for all), whilst cardiac output was ~ 8% higher in PA than in medicated EH (P = 0.012). Systemic vascular resistance and augmentation index were similarly increased in PA and both EH groups when compared with controls. Pulse wave velocity was higher in PA and never-medicated EH than in medicated EH and normotensive controls (P ≤ 0.033 for all comparisons).

CONCLUSIONS

Medicated PA patients presented with corresponding systemic vascular resistance and wave reflection, but higher extracellular water volume, cardiac output and arterial stiffness than medicated EH patients. Whether the systematic evaluation of these features would benefit the clinical diagnostics of PA remains to be studied in future.

Aldosterone-to-renin ratio is related to arterial stiffness when the screening criteria of primary aldosteronism are not met

Aldosterone-to-renin ratio (ARR) is a screening tool for primary aldosteronism (PA), but the significance of ARR when the PA criteria are not met remains largely unknown. In this cross-sectional study we investigated the association of ARR with haemodynamic variables in 545 normotensive and never-medicated hypertensive subjects (267 men, 278 women, age range 19-72 years) without suspicion of PA. Supine haemodynamic data was recorded using whole-body impedance cardiography and radial tonometric pulse wave analysis. In sex-adjusted quartiles of ARR, determined as serum aldosterone to plasma renin activity ratio, the mean values were 282, 504, 744 and 1467 pmol/µg of angiotensin I/h, respectively. The only difference in haemodynamic variables between the ARR quartiles was higher pulse wave velocity (PWV) in the highest quartile versus other quartiles (p = 0.004), while no differences in blood pressure (BP), heart rate, wave reflections, cardiac output or systemic vascular resistance were observed between the quartiles. In linear regression analysis with stepwise elimination, ARR was an independent explanatory factor for PWV (β = 0.146, p < 0.001, R2 of the model 0.634). In conclusion, ARR was directly and independently associated with large arterial stiffness in individuals without clinical suspicion of PA. Therefore, ARR could serve as a clinical marker of cardiovascular risk.Trial registration: ClinicalTrails.gov: NCT01742702.

Arterial Stiffness Predicts Mortality in Individuals With Type 1 Diabetes

OBJECTIVE

Type 1 diabetes is accompanied by a significant burden of cardiovascular disease (CVD), which is poorly explained by traditional risk factors. We therefore aimed to explore whether arterial stiffness estimated by the augmentation index (AIx) predicts mortality in individuals with type 1 diabetes.

RESEARCH DESIGN AND METHODS

After baseline examination comprising pulse wave analysis by applanation tonometry alongside assessment of traditional cardiovascular risk factors, 906 individuals with type 1 diabetes from the Finnish Diabetic Nephropathy (FinnDiane) Study were followed up for a median of 8.2 years (interquartile range 5.7-9.7). Associations between baseline hemodynamics, including AIx, and all-cause mortality as well as a composite of cardiovascular and/or diabetes-related mortality were investigated using multivariable Cox regression models.

RESULTS

The 67 individuals who died during follow-up had higher baseline AIx (median 28% [interquartile range 21-33] vs. 19% [9-27]; P < 0.001) compared with those alive. This association was independent of conventional risk factors (age, sex, BMI, HbA_1c, estimated glomerular filtration rate [eGFR], and previous CVD event) in Cox regression analysis (standardized hazard ratio 1.71 [95% CI 1.10-2.65]; P = 0.017) and sustained in a subanalysis of individuals with chronic kidney disease. Similarly, higher AIx was associated with the composite secondary end point of cardiovascular and diabetes-related death (N = 53) after adjustments for sex, BMI, eGFR, previous CVD event, and height (standardized hazard ratio 2.30 [1.38-3.83]; P = 0.001).

CONCLUSIONS

AIx predicts all-cause mortality as well as a composite cardiovascular and/or diabetes-related cause of death in individuals with type 1 diabetes, independent of established cardiovascular risk factors.

Evaluation of Vascular Reactivity of Maternal Vascular Adaptations of Pregnancy With Quantitative MRI: Pilot Study

BACKGROUND

Abnormal maternal vascular function during pregnancy stemming from systemic endothelial dysfunction (EDF) has a central role in the pathophysiology of preeclampsia (PE).

PURPOSE

To utilize quantitative MRI to investigate changes in physiological measures of vascular reactivity during normal pregnancy, and to explore EDF associated with preeclampsia.

STUDY TYPE

Prospective.

POPULATION

Healthy pregnant (HP) (n = 14, mean GA = 26 ± 7 weeks) and nonpregnant women (NP; n = 14); newly postpartum (PP <48 hours) women with severe PE (PP-PE; n = 4) and normotensive pregnancy (PP-HP; n = 5).

FIELD STRENGTH/SEQUENCE

1.5T/3T. RF spoiled multiecho gradient-recalled echo, 1D phase-contrast MRI, time-of-flight.

ASSESSMENT

The micro- and macrovascular function (vasodilatory capacity of arterioles and conduit arteries, respectively) of the femoral vascular bed was evaluated with MRI-based venous oximetry, arterial velocimetry, and luminal flow-mediated dilation quantification, during cuff-induced reactive hyperemia. Aortic arch pulse-wave velocity (aPWV) was quantified to assess arterial stiffness using an ungated 1D technique.

STATISTICAL TESTS

Two-tailed unpaired t-tests were performed to address our two, primary a priori comparisons, HP vs. NP, and PP-PE vs. PP-HP. Given the pilot nature of this study, adjustments for multiple comparisons were not performed.

RESULTS

In HP, microvascular function was attenuated compared to NP by a significant increase in the washout time (10 ± 2 vs. 8 ± 2 sec; P < 0.05) and reduced upslope (2.1 ± 0.5 vs. 3.2 ± 0.8%HbO₂ /s; P < 0.05), time of forward flow (28 ± 5 vs. 33 ± 6 sec, P < 0.05), and hyperemic index (11 ± 3 vs. 16 ± 4 cm/s² ; P < 0.05), but luminal flow-mediated dilatation (FMD_L )was comparable between HP and NP. PP-PE exhibited significant vascular dysfunction compared to PP-HP, as evidenced by differences in upslope (2.2 ± 0.6 vs. 1.3 ± 0.2%HbO₂ /s, P < 0.05), overshoot (16 ± 5 vs. 7 ± 3%HbO₂ , P < 0.05), time of forward flow (28 ± 6 vs. 15 ± 7 s, P < 0.05), and aPWV (7 ± 1 vs. 8 ± 1 m/s, P < 0.05).

DATA CONCLUSION

Attenuated vascular reactivity during pregnancy suggests that the systemic vasodilatory state partially depletes nitric oxide bioavailability. Preliminary data support the potential for MRI to identify vascular dysfunction in vivo that underlies PE. Level of Evidence 2 Technical Efficacy Stage 1 J. MAGN. RESON. IMAGING 2021;53:447-455.

Maternal arterial stiffness in hypertensive pregnancies with and without small-for-gestational-age neonate

OBJECTIVE

Pregnancies complicated by pre-eclampsia with a small-for-gestational-age (SGA) neonate have poorer maternal hemodynamic function compared to those with hypertensive disorders of pregnancy (HDP) and an appropriately grown neonate. Arterial stiffness is a recognized prognostic marker of cardiovascular disease in the general population. The aim of this study was to compare maternal arterial stiffness between hypertensive pregnancies with, and those without, a SGA neonate and normotensive control pregnancies.

METHODS

This was a prospective cohort study of pregnancies complicated by pre-eclampsia or gestational hypertension and healthy normotensive control pregnancies, presenting to a tertiary referral hospital between January 2012 and May 2018. Maternal arterial stiffness was assessed by aortic pulse-wave velocity (PWV) and aortic augmentation index (AIx), which were recorded using a non-invasive device (Arteriograph®). Maternal and hemodynamic factors were adjusted for using linear regression analysis. Pregnancies with HDP were divided into those that delivered a SGA (birth weight < 10^th percentile) neonate (HDP + SGA group) and those that delivered an appropriately grown neonate (HDP-only group). Comparisons between groups were carried out using the Mann-Whitney U-test for continuous variables and the chi-square (or Fisher's exact) test for categorical variables.

RESULTS

Included in the analysis were 69 patients with HDP who delivered a SGA neonate, 129 with HDP who delivered a normally grown neonate and 220 healthy controls. Maternal age, weight, height and heart rate were associated significantly with brachial and aortic AIx. Maternal weight, height, mean arterial pressure, heart rate and gestational age were significant predictors of aortic PWV. Adjusted aortic AIx was significantly higher in both the HDP + SGA and HDP-only groups, compared with in controls (12.5% and 10.0% vs 7.6%; both P < 0.01), and was significantly different between the two HDP groups (P = 0.002). Adjusted PWV was significantly higher in the HDP-only group compared with in controls and the HDP + SGA group (7.7 m/s vs 7.1 m/s and 7.1 m/s; both P < 0.001). Conversely, unadjusted PWV was not significantly different between the two HDP groups (P = 0.414).

CONCLUSIONS

Pregnancies complicated by HDP with, and those without, a SGA neonate have significantly higher aortic AIx compared with uncomplicated normotensive pregnancies. Aortic AIx was highest in those pregnancies complicated by HDP with a SGA neonate, reflecting a progression in severity of arterial stiffness abnormality with a worsening clinical picture. These findings most likely reflect systemic reduced vascular compliance and increased systemic vascular resistance in pregnancy complicated by HDP. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Leukocyte telomere length is inversely associated with arterial wave reflection in 566 normotensive and never-treated hypertensive subjects

Telomeres are short segments in chromosome ends, the length of which is reduced during cell lifecycles. We examined the association of mean leukocyte telomere length (LTL) and short telomere proportion (STP) with hemodynamic variables in normotensive and never-treated hypertensive volunteers (n=566, 19-72 years). STP and mean LTL were determined using Southern blotting, and supine hemodynamics recorded using continuous tonometric pulse wave analysis and whole-body impedance cardiography. The analyses were adjusted for age, body mass index (BMI), alcohol use, smoking, plasma chemistry, and estimated glomerular filtration rate (eGFR). In univariate analyses, mean LTL and STP both correlated with age, BMI, eGFR, aortic blood pressure, augmentation index, and pulse wave velocity (p<0.05 for all). Mean LTL also correlated with systemic vascular resistance (p<0.05). In linear regression analyses of all hemodynamic variables, mean LTL was only an independent explanatory factor for augmentation index (Beta -0.006, p=0.032), while STP was not an explanatory factor for any of the hemodynamic variables, in contrast to age, BMI and several cardiovascular risk factors. To conclude, augmentation index was predominantly related with chronological aging, but also with mean LTL, suggesting that this variable of central wave reflection is a modest marker of vascular biological aging.

Systemic Arterial Stiffness in New Diagnosed Idiopathic Pulmonary Arterial Hypertension Patients

Objective

We suggested: 1) patients with idiopathic pulmonary hypertension (IPAH) have active factors which could damage not only the pulmonary but systemic arteries too as in arterial hypertensive patients; 2) if these changes were present, they might correlate with other parameters influencing on the prognosis. This study is the first attempt to use cardio-ankle vascular index (CAVI) for the evaluation of systemic arterial stiffness in patients with IPAH.

Methods

A total of 112 patients were included in the study: group 1 consisted of 45 patients with new diagnosed IPAH, group 2 included 32 patients with arterial hypertension, and in the control group were 35 healthy persons adjusted by age. Right heart catheterization, ECG, a 6-minute walk test (6MWT), echocardiography, blood pressure (BP) measurement and ambulatory BP monitoring, pulse wave elastic artery stiffness (PWVe; segment carotid-femoral arteries) and muscular artery stiffness (PWVm; segment carotid-radial arteries), CAVI, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) level were provided. The Spearman correlation, a linear regression and multivariable binary logistic analysis were performed to indicate the predictors associated with PWV and CAVI.

Results

The groups were adjusted for principal characteristics influenced on arterial stiffness. IPAH patients had significantly (P<0.001 for all) shorter 6MWT distance and higher Borg dyspnea score than the patients with arterial hypertension (systolic/diastolic BP = 146.1±10.7/94.2±9.8 mmHg) and the control group = 330.2±14.6 vs 523.8±35.3 and 560.9±30.2 m respectively and 6.2±1.8 vs 1.2±2.1 and 0.9±2.8 points. The PWVm and PWVe were the highest in hypertensive patients (10.3±1.5 and 11.42±1.70 m/s). The control group and IPAH did not have significant differences in aorta BP, but PWVm/PWVe values were significantly (P<0.003/0.008) higher in IPAH patients than in the control group (8.1±1.9/8.49±1.92 vs 6.63±1.34/7.29±0.87 m/s). The CAVIs on both sides were significantly lower in the healthy subjects (5.91±0.99/5.98±0.87 right/left side). Patients with IPAH did not differ from the arterial hypertension patients by CAVIs in comparison with the control group (7.40±1.32/7.22±1.32 vs 7.19±0.78/7.2±1.1 PWVe) did not correlate with any parameters except uric acid. PWVm correlated with uric acid (r=0.58, P<0.001), NT-proBNP (r=0.33, P=0.03) and male gender (r=0.37, P=0.013) at Spearman analysis, but not at multifactorial linear regression analysis. The CAVI correlated with age and parameters characterized functional capacity (6MWT distance) and right ventricle function (NT-proBNP, TAPSE) at Spearman analysis and with age and TAPSE at multifactorial linear regression analysis. At binary logistic regression analysis CAVI > 8.0 at right and/or left side had a correlation with age, 6MWT distance, TAPSE, but an independent correlation was only with age (β=1.104, P=0.008, CI 1.026–1.189) and TAPSE (β=0.66, P=0.016, CI 0.474–0.925).

Conclusion

In spite of equal and at normal range BP level, the age-adjusted patients with IPAH had significantly stiffer arteries than the healthy persons and they were comparable with the arterial hypertensive patients. Arterial stiffness evaluated by CAVI correlated with age and TAPSE in IPAH patients. Based on our results it is impossible to conclude the pathogenesis of arterial stiffening in IPAH patients, but the discovered changes and correlations suggest new directions for further studies, including pathogenesis and prognosis researches.

Childhood Obesity: Does it Have Any Effect on Young Arteries?

Prevalence of overweight (OW) and obesity (O) in children and adolescents has been increased in the past three decades. Increased arterial stiffness measuring by aortic pulse wave velocity (PWV_ao) might be detected in OW/O children and adolescents. The aim of our study was to compare the arterial function parameters (AFPs), such as PWV_ao; aortic augmentation index (Aix_ao); aortic systolic blood pressure (SBP_ao) and brachial systolic blood pressure (SBP_brach) measured simultaneously in O/OW patients and healthy subjects. In our study 6,816 subjects (3,668 boys) aged 3-18 years were recruited and categorized by their body mass index (BMI) into normal weight (N), OW and O groups regarding their age and sex. AFPs were measured by a non-invasive, occlusive-oscillometric device. 19.9% (n = 1,356) of the population were OW/O, 911 (516 boys) were OW and 445 (272 boys) were O. After accounting for the effect of covariates, PWV_ao did not differ significantly between N (5.9 ± 0.8 m/s) and OW patients (5.9 ± 0.8 m/s); and N (6.0 ± 0.7 m/s) and O patients (6.0 ± 0.8 m/s). Aix_ao was significantly lower in OW (9.3 ± 7.4% vs. 7.6 ± 7.0%, p < 0.00001) and in O patients (9.7 ± 8.1% vs. 6.6 ± 7.2%, p < 0.00001) compared to controls. No significant difference was found regarding SBP_ao values between controls and OW and O groups (N = 110.7 ± 12.4 mmHg vs. OW = 110.3 ± 11.9 mmHg; N = 115.6 ± 14.0 mmHg vs. O = 114.3 ± 12.8 mmHg). According to our results we may conclude that the unchanged PWV_ao in O/OW subjects might be due to the compensatory decrease in Aix_ao, referring to enhanced vasodilatory status in the studied population.

Changes in hemodynamics associated with metabolic syndrome are more pronounced in women than in men

The increase in cardiovascular risk associated with metabolic syndrome (MS) seems higher in women than in men. We examined hemodynamics during head-up tilt in 252 men and 250 women without atherosclerosis, diabetes, or antihypertensive medication, mean age 48 years, using whole-body impedance cardiography and radial pulse wave analysis. MS was defined according to Alberti et al. 2009. Men and women with MS presented with corresponding elevations of systolic and diastolic blood pressure (10-14%, p ≤ 0.001) versus controls. Supine pulse wave velocity (16-17%, p < 0.001) and systemic vascular resistance (7-9%, p ≤ 0.026), and upright cardiac output (6-11%, p ≤ 0.008) were higher in both MS groups than controls. Elevation of supine aortic characteristic impedance was higher in women than in men with MS (16% vs. 8%, p = 0.026), and in contrast to men, no upright impedance reduction was observed in women. When upright, women but not men with MS showed faster return of reflected pressure wave (p = 0.036), and smaller decrease in left cardiac work (p = 0.035) versus controls. The faster upright return of reflected pressure, lower upright decrease in left cardiac work, and higher elevation of aortic characteristic impedance may contribute to the greater increase in MS-related cardiovascular risk in women than in men.

Plasma total calcium concentration is associated with blood pressure and systemic vascular resistance in normotensive and never-treated hypertensive subjects

Purpose: The underlying causes of primary hypertension are not fully understood. Evidence on the relation of plasma calcium concentration with blood pressure (BP) is inconsistent and relies largely on studies utilizing office BP measurements in populations using cardiovascular drugs. In many studies adjustment for confounders was not optimal. In this cross-sectional study we examined the association of plasma total calcium concentration with the haemodynamic determinants of blood pressure.Subjects and methods: Supine haemodynamics were recorded using pulse wave analysis, whole-body impedance cardiography, and heart rate variability analysis in 618 normotensive or never-treated hypertensive subjects (aged 19-72 years) without diabetes, cardiovascular or renal disease, or cardiovascular medications. Linear regression analysis was used to investigate factors associated with haemodynamic variables.Results: Mean age was 45.0 years, body mass index 26.8 kg/m², seated office BP 141/89 mmHg, and 307 subjects (49.7%) were male. Mean values of routine blood and plasma chemistry analyses were within the reference limits of the tests except for low-density lipoprotein cholesterol (3.05 mmol/l). In the laboratory, mean supine radial BP was 131/75 mmHg, and both systolic and diastolic BP correlated directly with plasma total calcium concentration (r = 0.25 and r = 0.22, respectively, p < 0.001 for both). In regression analysis plasma total calcium concentration was an independent explanatory variable for radial and aortic systolic and diastolic BP, and systemic vascular resistance, but not for cardiac output, pulse wave velocity, or any of the heart rate variability parameters.Conclusion: Plasma total calcium concentration was directly associated with systolic and diastolic BP and systemic vascular resistance in normotensive or never-treated hypertensive subjects without comorbidities and cardiovascular medications. Higher plasma calcium concentration potentially plays a role in primary hypertension via an effect on vascular resistance.

Liquorice ingestion attenuates vasodilatation via exogenous nitric oxide donor but not via β2-adrenoceptor stimulation

We examined the effect of liquorice ingestion on haemodynamic responses to exogenous nitric oxide donor (nitroglycerin) and β2-adrenoceptor agonist (salbutamol), and 11β-hydroxysteroid dehydrogenase activity, in 21 volunteers and 21 reference subjects. Haemodynamic data was captured before and after sublingual nitroglycerin (0.25 mg) and inhaled salbutamol (400 μg) during orthostatic challenge utilising radial pulse wave analysis and whole-body impedance cardiography. The recordings were performed at baseline and following two weeks of liquorice intake (290-370 mg/d glycyrrhizin). Urinary cortisone and cortisol metabolites were examined. Liquorice intake elevated aortic systolic and diastolic blood pressure and systemic vascular resistance when compared with the reference group. Following research drug administration the liquorice-induced increase in systemic vascular resistance was observed in the presence of nitroglycerin (p<0.05) but no longer in the presence of salbutamol. Liquorice ingestion decreased cardiac chronotropic response to upright posture (p = 0.032) in unadjusted analysis, but when adjusted for age and sex the difference in the upright change in heart rate was no longer significant. The urinary cortisone to cortisol metabolite ratio decreased from 0.70 to 0.31 (p<0.001) after liquorice intake indicating significant inhibition of the 11β-hydroxysteroid dehydrogenase type 2. In the reference group the haemodynamic variables remained virtually unchanged. These results suggest that liquorice exposure impaired vasodilatation in vivo that was induced by exogenous nitric oxide donor but not that induced by β2-adrenoceptor stimulation. Trial registration: EU Clinical Trials Register 2006-002065-39 ClinicalTrials.gov NCT01742702.

Isolated systolic hypertension in the young: a position paper endorsed by the European Society of Hypertension

: Whether isolated systolic hypertension in the young (ISHY) implies a worse outcome and needs antihypertensive treatment is still a matter for dispute. ISHY is thought to have different mechanisms than systolic hypertension in the elderly. However, findings from previous studies have provided inconsistent results. From the analysis of the literature, two main lines of research and conceptualization have emerged. Simultaneous assessment of peripheral and central blood pressure led to the identification of a condition called pseudo or spurious hypertension, which was considered an innocent condition. However, an increase in pulse wave velocity has been found by some authors in about 20% of the individuals with ISHY. In addition, obesity and metabolic disturbances have often been documented to be associated with ISHY both in children and young adults. The first aspect to consider whenever evaluating a person with ISHY is the possible presence of white-coat hypertension, which has been frequently found in this condition. In addition, assessment of central blood pressure is useful for identifying ISHY patients whose central blood pressure is normal. ISHY is infrequently mentioned in the guidelines on diagnosis and treatment of hypertension. According to the 2013 European Guidelines on the management of hypertension, people with ISHY should be followed carefully, modifying risk factors by lifestyle changes and avoiding antihypertensive drugs. Only future clinical trials will elucidate if a benefit can be achieved with pharmacological treatment in some subgroups of ISHY patients with associated risk factors and/or high central blood pressure.

Arterial stiffness and peripheral vascular resistance in offspring of hypertensive parents: influence of sex and other confounders

AIM

Established essential hypertension is associated with increased arterial stiffness and peripheral resistance, but the extent of vascular changes in persons genetically predisposed for essential hypertension is uncertain.

METHODS

Participants from the Danish Hypertension Prevention Project (DHyPP) (both parents hypertensive) (n = 95, 41 ± 1 years, 53% men) were compared with available spouses (n = 45, 41 ± 1 years) using measurements of ambulatory blood pressure (BP), left ventricular mass index (LVMI), pulse wave velocity, central BP and augmentation index (AIx) in addition to forearm resting and minimal resistance [forearm resting vascular resistance (Rrest) and forearm minimal vascular resistance (Rmin)].

RESULTS

DHyPP patients with participating spouses had higher 24-h mean BP (94 ± 1 vs. 88 ± 1 mmHg, P < 0.01), LVMI (94 ± 3 vs. 80 ± 2 g/m, P < 0.01), central SBP (121 ± 2 vs. 111 ± 2 mmHg, P < 0.01) and AIx (16.0 ± 1.2 vs. 10.5 ± 1.7%, P < 0.01), but similar carotid-femoral pulse wave velocity (7.5 ± 0.2 vs. 7.1 ± 0.2 m/s), Rrest (53 ± 3 vs. 51 ± 3 mmHg/ml/min/100 ml) and log Rmin (0.58 ± 0.02 vs. 0.55 ± 0.02 mmHg/ml/min/100 ml) when compared with spouses. Using multiple linear regression analysis (adjusting for sex, age, BMI, creatinine clearance and 24-h BP, heart rate and sodium excretion) AIx and LVMI remained elevated in DHyPP patients [4.2% (0.7; 7.7), P = 0.02 and 6.3 g/m (0.7; 11.9), P = 0.03]. For the entire DHyPP cohort AIx, Rrest and Rmin were higher in women than men (P < 0.01), and the same was true for AIx and Rmin among spouses (P < 0.05). Furthermore, AIx was linearly associated with Rrest and Rmin.

CONCLUSION

Young to middle-aged individuals genetically predisposed for essential hypertension display increased AIx and LVMI, although vascular stiffness and peripheral resistance are still normal.

Adverse influence of bisoprolol on central blood pressure in the upright position: a double-blind placebo-controlled cross-over study

Treatment with beta-blockers is characterized by inferior reduction of central versus peripheral blood pressure. We examined changes in blood pressure, cardiac function, and vascular resistance after 3 weeks of bisoprolol treatment (5 mg/day) during passive head-up tilt in 16 never-treated Caucasian males with grade I–II primary hypertension. A double-blind, randomized, placebo-controlled cross-over design was applied, and hemodynamics were recorded using continuous tonometric pulse wave analysis and whole-body impedance cardiography. Bisoprolol decreased blood pressure in the aorta (~8/10 mmHg, p ≤ 0.032) and radial artery (~10/9 mmHg, p ≤ 0.037), but upright aortic systolic blood pressure was not significantly reduced (p = 0.085). Bisoprolol reduced heart rate and left cardiac work, and increased subendocardial viability index in supine and upright positions (p ≤ 0.044 for all). Bisoprolol increased stroke volume in the supine (~11 ml, p = 0.02) but not in the upright position, while only upright (~1 l/min, p = 0.007) but not supine cardiac output was reduced. Upright elevation in systemic vascular resistance was increased 2.7-fold (p = 0.002), while upright pulse pressure amplification was decreased by ~20% (p = 0.002) after bisoprolol. Aortic augmentation index, augmentation pressure, and pulse pressure were not changed in the supine position but were increased in the upright position (from 9% to 17%, 3–6 mmHg, and 30–34 mmHg, respectively, p ≤ 0.016 for all). In conclusion, although bisoprolol treatment reduced peripheral blood pressure, central systolic blood pressure in the upright position was not decreased. Importantly, the harmful influences of bisoprolol on central pulse pressure and pressure wave reflection were manifested in the upright position.

Atherogenic index of plasma is related to arterial stiffness but not to blood pressure in normotensive and never-treated hypertensive subjects

BACKGROUND AND AIMS

Atherogenic index of plasma (AIP), defined as the logarithm of triglycerides to high-density lipoprotein cholesterol (HDL-C) ratio, is a strong predictor of future cardiovascular disease. Our aim was to examine the association of AIP with haemodynamic variables in normotensive and never-treated hypertensive subjects in a cross-sectional study.

METHODS

Supine haemodynamics in 615 subjects without antihypertensive and lipid-lowering medications were examined using whole-body impedance cardiography and radial pulse wave analysis. Linear regression analysis was applied to investigate the association of AIP with haemodynamic variables and age, sex, body mass index (BMI), smoking status, alcohol consumption, plasma C-reactive protein, electrolytes, uric acid, low density lipoprotein cholesterol (LDL-C), estimated glomerular filtration rate, and quantitative insulin sensitivity check index.

RESULTS

The demographics and laboratory values of the study population were (mean ± 95% confidence interval): age 44.9 ± 1.0 years, BMI 26.8 ± 0.4 kg/m², office blood pressure 140.6 ± 1.6/89.4 ± 1.0 mmHg, total cholesterol 5.2 ± 0.08, LDL-C 3.1 ± 0.08, triglycerides 1.2 ± 0.08, HDL-C 1.6 ± 0.04 mmol/l, and AIP -0.15 ± 0.02. Age (standardized coefficient Beta 0.508, p < .001) and aortic systolic blood pressure (Beta 0.239, p < .001) presented with the strongest associations with pulse wave velocity. However, AIP was also associated with pulse wave velocity (Beta 0.145, p < .001). AIP was not related with aortic or radial blood pressure, cardiac output, systemic vascular resistance, or augmentation index.

CONCLUSIONS

AIP is directly and independently associated with arterial stiffness, a variable strongly related to cardiovascular risk. This supports more widespread use of AIP in standard clinical cardiovascular disease risk evaluation.

Seasonal variation of novel arterial stiffness indexes in Japanese hypertensive patients

Background and Objective: Seasonal variation of blood pressure (BP) is well known, and a relationship between increases in BP and the incidence of cardiovascular accidents (CVAs) in the winter has been reported. Parameters of arterial stiffness may exhibit seasonal variation; however, available data are currently limited. Novel arterial stiffness indexes, namely the arterial velocity pulse index (AVI) and arterial pressure-volume index (API), can be determined through usual maneuver for BP measurement during the regular examination in the outpatient clinic.The present study assessed the seasonal variation of AVI and API in 59 hypertensive patients undergoing stable treatment and regularly visiting our outpatient clinic over a period of 30 months. Methods: BP, pulse rate (PR), AVI, and API were measured using the AVE-1500 (Pasesa) in the sitting position. Six time frames of assessment were established. All measurements (average: 17.9 measurements per person) were sorted using these six time frames, and their averages were used for analysis. Results: Significant seasonal variations in PR (P < 0.001) and AVI (P < 0.001), along with weak variation in systolic BP (SBP) (P = 0.047) and marginal variation in API (P = 0.055), were confirmed by repeated analysis of variance. SBP, API, and PR were decreased, whereas AVI was increased in the summer. Coefficient variations were SBP 5.1%, PR 4.9%, AVI 12.6%, and API 10.6%. Conclusion: AVI was associated with reflected wave like as augmentation index. Thus, a high AVI may suggest increased central wave reflection. Although the significance of seasonal variation of AVI remains unknown, AVI may influence seasonal variations in the incidence of CVA.

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.

Effect of present versus previous smoking on non-invasive haemodynamics

We examined cardiovascular function in 637 volunteers (19-72 years) without antihypertensive medication in never smokers (n = 365), present smokers (n = 81) and previous smokers (n = 191, median abstinence 10 years). Haemodynamics during passive head-up tilt were recorded using whole-body impedance cardiography and radial pulse wave analysis. Results were adjusted for age, sex, body mass index, LDL cholesterol and alcohol use. Systolic and diastolic blood pressure, heart rate, and pulse wave velocity were not different between the groups. Supine aortic reflection times did not differ, while upright values were shorter in present versus previous smokers (p = 0.04). Heart rate adjusted augmentation index was increased in the supine position in present smokers versus controls (p = 0.045), and in present (p < 0.001) and previous (p = 0.031) smokers versus controls in the upright position. Supine and upright cardiac output was higher (p ≤ 0.016) and systemic vascular resistance lower (p ≤ 0.001) in present versus previous smokers. In spite of the long abstinence, in the upright position previous smokers had lower cardiac output (p = 0.032) and higher systemic vascular resistance (p = 0.014) than never smokers. In the absence of differences in blood pressure and arterial stiffness, present smokers presented with hyperdynamic circulation and enhanced wave reflection compared with previous smokers.

Salbutamol-induced Decrease in Augmentation Index is Related to the Parallel Increase in Heart Rate

The change in augmentation index following salbutamol inhalation has been applied to evaluate endothelial function. We examined the contribution of salbutamol-induced increase in heart rate to the observed decrease in augmentation index. Haemodynamics were recorded using whole-body impedance cardiography and continuous pulse wave analysis from tonometric radial blood pressure. All subjects (n = 335, mean age 46, body mass index 26, 48% men) were without medications with cardiovascular influences. The effects of salbutamol inhalation (0.4 mg) versus the endothelium-independent agent nitroglycerin resoriblet (0.25 mg) were examined during passive head-up tilt, as the haemodynamic influences of these compounds depend on body position. Salbutamol decreased augmentation index by ~3-4% units in supine and upright positions. Although salbutamol moderately increased cardiac index (+4.5%) and decreased systemic vascular resistance (-8.5%), the significant haemodynamic explanatory factors for decreased augmentation index in multivariate analysis were increased supine heart rate, and increased upright heart rate and decreased ejection duration (p < 0.001 for all, r²  = 0.36-0.37). Sublingual nitroglycerin decreased supine and upright augmentation index by ~15% units and ~23% units, respectively. The haemodynamic explanatory factors for these changes in multivariate analysis were increased heart rate, reduced ejection duration and reduced systemic vascular resistance (p ≤ 0.021 for all, r²  = 0.22-0.34). In conclusion, the lowering influence of salbutamol on augmentation index may be largely explained by increased heart rate, suggesting that this effect may not predominantly reflect endothelial function.

Positive correlation of the serum angiopoietin-like protein 3 levels with the aortic augmentation index in patients with coronary artery disease

Purpose

Angiopoietin-like protein 3 (ANGPTL3) plays an important role in lipid metabolism and angiogenesis and is elevated in familial hypercholesterolemia, metabolic syndrome, and insulin resistance. This study aims to evaluate the relationship between the fasting serum ANGPTL3 levels and the aortic augmentation index (AIx) in patients with coronary artery disease (CAD).

Materials and methods

Fasting blood samples were obtained from 100 patients with CAD. The AIx was measured using a validated tonometry system (SphygmoCor). The serum ANGPTL3 levels were assessed using a commercial enzyme-linked immunosorbent assay kit.

Results

The aortic AIx values were higher in female patients with CAD (P=0.003) than those in male patients with CAD. The univariate linear analysis of the aortic AIx values reveals that the height (r=−0.363; P<0.001) and body weight (r=−0.350; P<0.001) were negatively correlated, whereas the age (r=0.202; P=0.044) and logarithmically transformed ANGPTL3 (log-ANGPTL3, r=0.357; P<0.001) were positively correlated with the aortic AIx values in patients with CAD. The multivariate forward stepwise linear regression analysis of the factors significantly associated with the aortic AIx revealed that the height (β=−0.269; adjusted R² change=0.123; P=0.007) and serum log-ANGPTL3 level (β=0.259; adjusted R² change=0.051; P=0.010) were independent predictors of the aortic AIx values in patients with CAD.

Conclusion

The fasting serum ANGPTL3 level positively correlated with the aortic AIx values among patients with CAD.

Voluntary liquorice ingestion increases blood pressure via increased volume load, elevated peripheral arterial resistance, and decreased aortic compliance

We investigated the haemodynamic effects of two-week liquorice exposure (glycyrrhizin dose 290-370 mg/day) in 22 healthy volunteers during orthostatic challenge. Haemodynamics were recorded during passive 10-minute head-up tilt using radial pulse wave analysis, whole-body impedance cardiography, and spectral analysis of heart rate variability. Thirty age-matched healthy subjects served as controls. Liquorice ingestion elevated radial systolic (p < 0.001) and diastolic (p = 0.018) blood pressure and systemic vascular resistance (p = 0.037). During orthostatic challenge, heart rate increased less after the liquorice versus control diet (p = 0.003) and low frequency power of heart rate variability decreased within the liquorice group (p = 0.034). Liquorice intake increased central pulse pressure (p < 0.001) and augmentation index (p = 0.002) supine and upright, but in the upright position the elevation of augmentation index was accentuated (p = 0.007). Liquorice diet also increased extracellular fluid volume (p = 0.024) and aortic to popliteal pulse wave velocity (p = 0.027), and aortic characteristic impedance in the upright position (p = 0.002). To conclude, in addition to increased extracellular fluid volume and large arterial stiffness, two weeks of liquorice ingestion elevated systemic vascular resistance and augmentation index. Measurements performed at rest may underestimate the haemodynamic effects of liquorice ingestion, as enhanced central wave reflection and reduced chronotropic response were especially observed in the upright position.

Influence of Child and Adult Elevated Blood Pressure on Adult Arterial Stiffness: The Cardiovascular Risk in Young Finns Study

Elevated blood pressure (BP) in childhood has been associated with increased adult arterial stiffness, the independent predictor of cardiovascular and all-cause mortality. The favorable BP change from childhood to adulthood and the risk of high adult arterial stiffness has not been reported. We examined the effect of child and adult BP on pulse wave velocity (PWV) assessed in adulthood among 1540 white adults followed-up for 27 years since baseline (1980, aged 6-18 years). Childhood elevated BP was defined according to the tables from the National High Blood Pressure Education Program. In adulthood, BP was classified as elevated if systolic BP ≥120 mm Hg, diastolic BP ≥80 mm Hg, or self-reported use of antihypertensive medications. PWV was measured in 2007 by whole-body impedance cardiography, and high PWV was defined as values at or above the age-, sex-, and heart rate-specific 80th percentile. Individuals with persistently elevated BP and individuals with normal child but elevated adult BP had increased risk of high adult PWV (relative risk [95% confidence interval], 3.18 [2.22-4.55] and 2.64 [1.79-3.88], respectively) in comparison with individuals with normal (both child and adult) BP. In contrast, individuals with elevated BP in childhood but not in adulthood did not have significantly increased risk of high PWV (relative risk [95% confidence interval], 1.26[0.80-1.99]). The results were consistent when different definitions for child and adult elevated BP were applied. These findings highlight the importance of BP control in the primary prevention of cardiovascular diseases.