Cardio-ankle vascular index for predicting cardiovascular morbimortality and determinants for its progression in the prospective advanced approach to arterial stiffness (TRIPLE-A-Stiffness) study

BACKGROUND

The cardio-ankle vascular index (CAVI) measure of arterial stiffness is associated with prevalent cardiovascular risk factors, while its predictive value for cardiovascular events remains to be established. The aim was to determine associations of CAVI with cardiovascular morbimortality (primary outcome) and all-cause mortality (secondary outcome), and to establish the determinants of CAVI progression.

METHODS

TRIPLE-A-Stiffness, an international multicentre prospective longitudinal study, enrolled >2000 subjects ≥40 years old at 32 centres from 18 European countries. Of these, 1250 subjects (55% women) were followed for a median of 3.82 (2.81-4.69) years.

FINDINGS

Unadjusted cumulative incidence rates of outcomes according to CAVI stratification were higher in highest stratum (CAVI > 9). Cox regression with adjustment for age, sex, and cardiovascular risk factors revealed that CAVI was associated with increased cardiovascular morbimortality (HR 1.25 per 1 increase; 95% confidence interval, CI: 1.03-1.51) and all-cause mortality (HR 1.37 per 1 increase; 95% CI: 1.10-1.70) risk in subjects ≥60 years. In ROC analyses, CAVI optimal threshold was 9.25 (c-index 0.598; 0.542-0.654) and 8.30 (c-index 0.565; 0.512-0.618) in subjects ≥ or <60 years, respectively, to predict increased CV morbimortality. Finally, age, mean arterial blood pressure, anti-diabetic and lipid-lowering treatment were independent predictors of yearly CAVI progression adjusted for baseline CAVI.

INTERPRETATION

The present study identified additional value for CAVI to predict outcomes after adjustment for CV risk factors, in particular for subjects ≥60 years. CAVI progression may represent a modifiable risk factor by treatments.

FUNDING

International Society of Vascular Health (ISVH) and Fukuda Denshi, Japan.

Angiotensin-converting enzyme inhibitors and angiotensin-II-receptor antagonists modulate sodium handling based on endogenous lithium clearance

BACKGROUND

Numerous studies based on assessment of lithium clearance demonstrated higher sodium reabsorption in renal proximal tubules in individuals with hypertension, overweight, obesity, metabolic syndrome, or diabetes.

AIMS

We aimed to assess the influence of angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin-II-receptor antagonists (ARB) treatment on sodium handling.

METHODS

In a sample of 351Caucasian subjects without diuretic treatment with prevailing sodium consumption, we studied associations between renal sodium reabsorption in proximal (FPRNa) and distal (FDRNa) tubules assessed by endogenous lithium clearance and daily sodium intake measured by 24-hour excretion of sodium (UNaV), in the context of obesity and long-term treatment with ACE-I or ARB.

RESULTS

In the entire study population, we found a strong negative association between FPRNa and ACE-I/ARB treatment (b = -19.5; SE = 4.9; P <0.001). Subjects with FPRNa above the median value showed a significant adverse association between FPRNa and age (b = -0.06; SE = 0.02; P = 0.003), with no association with ACE-I/ARB treatment (P = 0.68). In contrast, in subjects with FPRNa below the median value, we found a strongly significant adverse relationship between FPRNa and ACE-I/ARB treatment (b = -30.4; SE = 8.60; P <0.001), with no association with age (P = 0.32).

CONCLUSIONS

ACE-I/ARB long-term treatment modulates FPRNa in the group with lower reabsorption, but not in that with higher than median value for the entire study population.

Cardiovascular risk factors as determinants of cerebral blood flow - a cross-sectional and 6-year follow-up study

Purpose: The parameters of cerebral blood flow are modulated by many factors. The aim of the study was to prospectively assess the relationship between the number of the established cardiovascular risk factors and hemodynamic parameters of cerebral blood flow.Material and methods: The study was cross-sectional baseline and 6-year follow-up data analysis. We analyzed data regarding cardiovascular risk factors, medications use, and ultrasonographically (transcranial Doppler) obtained mean cerebral blood flow velocity (mCBFV), pulsatility (PI), resistance (RI) indexes of middle cerebral artery.Results: After 6.0 ± 0.6 years of follow-up, there was increase in systolic (p = .047), and decrease in diastolic (p = .005) blood pressure, resulting in greater pulse pressure (p < .001). Although intima-media thickness increased during follow-up (p = .019), PI, RI and mCBFV did not differ between baseline and follow-up. In the cohort without follow-up (n = 112), we observed strong association between number of studied cardiovascular risk factors and lower mCBFV, and higher PI and RI (all p < .001), in the cohort with 6 year follow-up (n = 53), we confirmed similar association for mCBFV and PI (p = .002) at baseline, and mCBFV (p = .024) after follow-up. During follow-up, more patients were treated with vasoactive medications (p < .05). Also the median (interquartile range) of total number of taken drugs at follow-up 2 (1-3) was greater than at baseline 1 (0-2), (p < .001). The addition of vasoactive medications during follow-up was associated with increase of the mCBFV (0.012 ± 0.02 m/s, p = .013).Conclusion: The parameters of the cerebral blood flow are adversely influenced by accretion of cardiovascular risk factors, both at baseline and after 6 years of follow-up. The addition of a vasoactive medication during follow-up is associated with an increase of the mCBFV, a possibly beneficial effect.

Insulin Resistance and Renal Sodium Handling Influence Arterial Stiffness in Hypertensive Patients with Prevailing Sodium Intake

BACKGROUND

Insulin resistance and renal tubular sodium handling influence arterial structure and function and play an essential role in salt-sensitive forms of hypertension.

METHODS

In a population with prevailing sodium consumption, we assessed the relationship between cardiovascular phenotypes (peripheral and central blood pressures, elastic properties of large arteries, the left ventricular structure) and sodium handling parameters (daily urinary sodium excretion, fractional urinary lithium excretion in proximal-FELi and distal tubules), as a function of insulin sensitivity-measured by homeostasis model assessment-insulin resistance (HOMA-IR), leptin-to-adiponectin (L/A) ratio, and homeostasis model assessment-adiponectin (HOMA-AD).

RESULTS

In patients with FELi below the median value (corresponding to the group with increased proximal sodium reabsorption) and higher insulin resistance as measured by HOMA-IR, pulse wave augmentation indexes were significantly higher-AIxP (99.4% vs. 86.2%; P = 0.007), AIxC1 (159.4% vs. 144.2%; P = 0.04), and AIxC2 (36.1% vs. 28.3%; P = 0.02), than in patients with lower insulin resistance. The same trend was observed in relation to L/A ratio-AIxP (98.7% vs. 87.1%; P = 0.005), AIxC1 (158.6% vs. 144.5%; P = 0.02), and AIxC2 (35.6% vs. 28.5%; P = 0.01) and HOMA-AD-AIxP (99.7% vs. 83.8%; P = 0.001), AIxC1 (160.5% vs. 140.3%; P = 0.007), and AIxC2 (36.6% vs. 26.3%; P = 0.003). Such relationships were not observed in patients with FELi above the median value.

CONCLUSIONS

In the hypertensive population with prevailing sodium intake, insulin resistance and increased sodium reabsorption in proximal tubules may affect arterial wall function.

Osteoprotegerin and osteoprotegerin/TRAIL ratio are associated with cardiovascular dysfunction and mortality among patients with renal failure

PURPOSE

The high prevalence of cardiovascular morbidity and mortality among patients with chronic kidney disease (CKD) is observed especially in those undergoing dialysis. Osteoprotegerin (OPG) and its ligands, receptor activator of nuclear factor kappa-B ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) have been associated with cardiovascular complications. Our aim was to study their role as cardiovascular risk factors in stage 5 CKD patients.

PATIENTS AND METHODS

OPG, RANKL and TRAIL concentrations were measured in 69 hemodialyzed CKD patients and 35 healthy volunteers. In CKD patients, cardiovascular dysfunction was assessed with aortic pulse wave velocity (AoPWV), carotid artery intima-media thickness (CCA-IMT), coronary artery calcium score (CACS) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) serum concentrations. Cardiovascular and overall mortality data were collected during a 7-years follow-up.

RESULTS

OPG plasma concentrations were higher in CKD patients comparing to controls. Total soluble RANKL was lower and OPG/RANKL ratio higher in patients. Soluble TRAIL concentrations did not differ between the groups and OPG/TRAIL ratio was higher in CKD patients. OPG and OPG/TRAIL positively predicted long-term mortality (all-cause and cardiovascular) in CKD patients. OPG positively correlated with AoPWV, CCA-IMT and NT-proBNP whereas OPG/TRAIL with AoPWV and NT-proBNP. Described relationships were independent of classical and non-classical cardiovascular risk factors, with exception of age.

CONCLUSIONS

Our study confirmed the role of OPG as a biomarker of cardiovascular dysfunction and a predictor of mortality in stage 5 CKD. OPG/TRAIL ratio can be proposed as a predictor of cardiovascular dysfunction and mortality.

Blood pressure, arterial stiffness and endogenous lithium clearance in relation to AGTR1 A1166C and AGTR2 G1675A gene polymorphisms

Introduction:

Although recently a matter of epidemiologic controversy, sodium overload and its interaction with genetic factors predispose to hypertension and related target organ complications.

Methods:

In 131 (66 male) treated hypertensives, we measured peripheral and central arterial pressures and pulse wave augmentation indexes (AIx_P, AIx_C1, AIx_C2), pulse wave velocity (PWV), daily urinary sodium excretion and did genetic studies of AGTR1 A1166C and AGTR2 G1675A polymorphisms. Proximal (FE_Li) and distal (FDR_Na) sodium reabsorption measurements were performed using endogenous lithium clearance.

Results:

In men, we found interaction between FDR_Na and AGTR2 G1675A polymorphism with respect to AIx_C1 (p_INT=0.01), AIx_C2 (p_INT=0.05) and AIx_P (p_INT=0.006). Arterial stiffness increased with higher sodium reabsorption in the distal tubule, in the presence of AGTR2 G allele with the opposite tendency in A allele carriers. In the subgroup with FDR_Na below median, as compared to those with FDR_Na above median, the AIx_C1 (139.6±3.8 vs 159.1±5.7%; p=0.009), AIx_C2 (26.3±1.8 vs 33.3±1.7%; p=0.016) and AIx_P (83.4±2.5 vs 96.5±2.6%; p<0.0001) were lower, in the G allele carrying men and GG homozygous women.

Conclusions:

The relation between sodium reabsorption in the distal tubule and the development of arterial stiffness depends on the AGTR2 G1675A polymorphism in blood pressure independent fashion.

Does sodium intake affect the relationship between blood pressure and vascular damage?

INTRODUCTION

Although the differences between central and peripheral blood pressure (BP) values have been known for decades, the consequences of decision making based on peripheral rather than central BP have only recently been recognized. Recently, a U-shaped relation between sodium intake and cardiovascular risk has been suggested.

OBJECTIVES

The aim of the study was to evaluate the relationship between intima-media thickness (IMT) and central and peripheral BP as well as the effect of 24-hour urinary sodium excretion on this relationship.

PATIENTS AND METHODS

The study included 182 subjects (mean age, 37.3 ±14.0 years, 92 men and 90 women) who were members of families randomly selected from one of the gminas (administrative regions) in southern Poland. In all patients, peripheral and central BP (using applanation tonometry), IMT, and 24-hour sodium excretion were measured.

RESULTS

Hypertension was observed in 44.5% of the participants. The mean urinary sodium excretion was 243 ±81 mmol/d. IMT was significantly more correlated with central pulse pressure (PP) compared with peripheral PP (r = 0.54 vs r = 0.27; P <0.01). After multivariate adjustments, IMT remained significantly related to central systolic BP and central and peripheral PP. When the study group was divided according to the tertiles of sodium excretion, central PP was related to IMT only in the second and third tertiles. When the study group was divided according to sex and sex-specific median values of sodium excretion, IMT was associated with central PP only in subjects with sodium excretion exceeding the median values (both in men and women).

CONCLUSIONS

IMT is more correlated with central than with peripheral BP. The association between IMT and central PP may be modulated by sodium intake. This hypothesis should be tested in larger studies.

Association of red blood cell distribution width, inflammation markers and morphological as well as rheological erythrocyte parameters with target organ damage in hypertension

OBJECTIVES

To assess the relationships of red blood cell distribution width (RDW), mean corpuscular hemoglobin concentration (MCHC) and erythrocyte deformability with pathological changes of selected target organs, and with inflammation markers interleukin-6 (IL-6) and fibrinogen, in a group of newly diagnosed, never-treated and otherwise healthy hypertensive patients.

METHODS

The study group consisted of 101 adults divided into three sub-groups: 37 diagnosed arterial hypertension, 29 with hypercholesterolemia, and 35 healthy. The individuals with hypertension or hypercholesterolemia were otherwise healthy and were not on any therapy prior to entering the study. For each individual, data were obtained on: systolic and diastolic blood pressure (SBP, DBP), pulse wave velocity (PWV), carotid intima media thickness (IMT), left ventricle geometry, blood morphology, lipids profile, fibrinogen, CRP, IL-6 and red blood cell deformability index (DI).

RESULTS

In the group of hypertensives, the multivariate regression analysis showed significant relationship of RDW with PWV, IL6 and fibrinogen. Also, RDW was found to be correlated with MCHC and DI, and MCHC was significantly related to IMT and IL-6.

CONCLUSIONS

A hypothesis has been formulated that the development of target organ damage in hypertension is accompanied by the increasing impairment of erythropoiesis. This process may be mediated by inflammation.

Comprehensive geriatric evaluation in former Siberian deportees with posttraumatic stress disorder

OBJECTIVES

Posttraumatic stress disorder (PTSD) develops after exposure to particularly traumatic events. Its severity depends on the nature and intensity of the stressor and the susceptibility of the exposed person. The aim of our study was to assess the relationship between PTSD resulting from deportation to Siberia in the patients' childhood and cognitive, emotional, and physical decline in advanced age.

METHODS

Eighty patients with PTSD with a history of deportation to Siberia and 70 subjects without PTSD were diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; severity of the symptoms included in the criteria was also assessed. In all patients, a standardized interview (including demographic data and comprehensive geriatric assessment tools such as the Mini-Mental State Examination, Geriatric Depression Scale, activities of daily living, and instrumental activities of daily living) was performed.

RESULTS

In analyses with the comparison group, patients with PTSD had a higher frequency of cognitive deficits (7.1% versus 22.5%), depression (31.4% versus 88.8%) and physical disability in activities of daily living (0% versus 21.3%), and instrumental activities of daily living (40.0% versus 88.8%). Moreover, increasing severity of PTSD was associated with significant deterioration in cognitive function, severity of depression, and the deterioration of basic and complex activities of daily living.

CONCLUSIONS

Higher frequency of cognitive function deficits, depression, and physical disability was found in the group of former deportees compared with the group of individuals without history of such a traumatic experience.

Fractal dimensions of skin microcirculation flow in subjects with familial predisposition or newly diagnosed hypertension

BACKGROUND

Fractal analysis has been shown to be capable of characterizing irregular time series generated in non-linear systems. Fluctuations in skin flow signals have a fractal nature, but to date there has been no analysis of subjects with hypertension. The aim of this study is to assess the fractal dimensions of skin microcirculation flows in subjects with a familial predisposition or newly diagnosed hypertension.

METHODS

A four-minutes rest flow (RF), minimal flow (BZ) during three-minutes ischemia and eight-minutes heat flow (HF) were recorded (using laser Doppler flowmetry) in patients with untreated hypertension, and in normotensives with no [NT(-)] or with a familial predisposition to hypertension [NT(+)]. Average one-minute surface areas under the curve of flow records and box dimensions (D) were calculated. Anova Kruskall-Wallis, c2 statistic and multivariate reverse regression analysis were used for calculation.

RESULTS

We studied 70 people (average age 36.1 ± 10.3 years, 39 men). Hypertensives (n = 31) had significantly higher values of both clinical blood pressure and 24-hour ambulatory blood pressure, body mass index, glucose, triglycerides and insulin than the NT(-), (n = 17) and NT(+), (n = 22) groups. Mean values of flows and surface area under the curve of RF, BZ, HF records, D RF and D HF were comparable in studied groups, but D BZ differed (1.13 ± ± 0.05 vs 1.15 ± 0.05 vs 1.11 ± 0.05, respectively; p = 0.04). A family history of hypertension, insulin level and variability of 24-hour diastolic blood pressure were significant predictors of D BZ lower values in the multiple regression model.

CONCLUSIONS

Subjects with a familial predisposition to hypertension reveal altered homeodynamics of microvascular flow, with diminished chaotic ischemic flow.

Neurogenic and myogenic resting skin blood flowmotion in subjects with masked hypertension

The aim of our study was to investigate, whether masked hypertension (MH) and sustained hypertension (HT) are associated with alteration of resting skin blood flow and flowmotion. Subjects recruited to the study were assigned to three groups according to the results of blood pressure (BP) measurements. Resting blood flow (RF) and an index of cutaneous vascular conductance (CVC), were measured by Laser Doppler Flowmetry (LDF). Total power of the studied interval and five subintervals related to: endothelium, sympathetic, myogenic, respiration and heart activity, were analyzed. Serum glucose, sodium level, lipid profile, as well as insulin, endothelin and norepinephrine levels were measured. The study population consisted of 82 persons: 29 NT, 17 MH and 36 HT. There were no differences between the study groups with respect to age and gender, but they significantly differed with respect to body mass index (p=0.04) and waist circumference (p=0.02), triglyceride levels (p=0.04; highest in HT group), norepinephrine levels (p=0.01; highest in MH group). RF as well as CVC RF were similar in NT, MH and HT groups. Power spectrum of sympathetic origin was significantly different in the study groups (p=0.03), with highest values in MH group. Moreover, the subjects with MH revealed increased power spectrum of myogenic activity, both absolute (p=0.05) and relative (p=0.08). Daytime systolic BP was the most consistent predictor of sympathetic and myogenic origin of elevated skin blood flowmotion in multiple regression models. Our findings suggest that subjects with MH revealed altered microcirculation with elevated resting flowmotion of sympathetic and myogenic origin.

Patient's education in arterial hypertension

Non-compliance is an important factor in lack of appropriate control of blood pressure. Education of hypertensive patients on about consequences of hypertension and benefits of antihypertensive therapy has been reported to improve the results of the management of hypertension. The aim of this article is to present main factors influencing patients' compliance with antihypertensive treatment and the role of educational interventions in the process of therapy.

Arterial stiffness is increased in hypertensive centenarians

BACKGROUND

The aim of our study was to assess the relationship between blood pressure and arterial stiffness in Polish centenarians.

MATERIALS AND METHODS

We examined 59 centenarians with the mean age of 101.3 years. Peripheral blood pressure was estimated upon mean value of three measurements and arterial stiffness by pulse wave analysis (PWA). Pressure waveforms were recorded from the radial artery and the waveform data were then processed by SphygmoCor to produce the estimated aortic pressure waveform. All subjects were divided into the three subgroups: normotensives (< 140/ 90 mmHg), systolic hypertensives (ISH, SBP > or = 140 and DBP < 90 mmHg) and systolo-diastolic hypertensives (> or = 140/90 or treated).

RESULTS

The mean values of peripheral BP for the entire group were: 149.5/76.8 mmHg for SBPP/DBPP and 136.1/ 77.8 mmHg for central SBPC/DBPC, respectively. The mean value of pulse pressures were: 72.7/58.4 mmHg for peripheral (PPP)/central (PPc). Arterial stiffness indices calculated from PWA were: 96.6%, 33.2% and 32.2% for peripheral (AIxP), central (AIxC) and central normalized for heart rate (AIxC75) augmentation indexes, respectively. The PPc was the lowest in the normotensive group (40.1 mmHg) when compared both with the ISH group (71.1 mmHg) and the systolo-diastolic group (58.1 mmHg). The lowest arterial stiffness indices (AIxp, AIxC75) calculated from PWA were found in the normotensive group: 85.4% and 28.5%, comparing with 96.1% and 33.7% in the ISH group and 104.8% and 32.9% for the systolo-diastolic group.

CONCLUSIONS

In centenarians, similarly to younger subjects, those with hypertension present with arterial stiffness.

Pulse wave velocity in patients with coronary artery disease or type 2 diabetes mellitus

OBJECTIVE

To check whether the presence of coronary artery disease (CAD) or type 2 diabetes mellitus (DM) has a differentiating effect on arterial stiffness assessed with pulse wave velocity (PWV)--a simple, reproducible and clinically feasible measure of arterial stiffening.

METHODS AND RESULTS

The mean age of 101 participants was 63.5 +/- 19.7 years. Fifty-one % of them had CAD, 31.0% had DM and 52.5% were hypertensive subjects. The aortic PWV ranged from 3.40 to 27.50 m/s, with an average of 1.73 +/- 4.69 m/s. PWV was significantly higher (P < 0.01) in both CAD and DM positive groups as compared with CAD and DM negatives, respectively. After adjustment for established co-variables, patients with CAD had significantly higher PWV when compared to CAD negatives (13.0 vs. 10.5 m/s, P < 0.01). After adjustment, DM did not seem to affect PWV.

CONCLUSIONS

CAD patients had higher values of PWV when compared to those without the disease. DM, a metabolic equivalent of arterial damage, after adjustment for possible confounders, did not seem to contribute per se to arterial stiffening. The presence of high PWV values in that group of patients should be viewed as an indicator of established widespread atherosclerosis possibly affecting the coronary arteries.

Arterial characteristics in normotensive offspring of parents with or without a history of hypertension

BACKGROUND

In this study we compared the arterial characteristics and blood pressure (BP) of normotensive offspring of two normotensive parents (OFF/NT) and normotensive offspring who had at least one hypertensive parent (OFF/HT).

METHODS

A total of 174 OFF/HT (17 to 40 years of age) and 59 OFF/NT (16 to 34 years) were recruited in Cracow, Poland (n = 138) and Pilsen, Czech Republic (n = 95). Peripheral pulse pressure (PPp) was determined from conventional and 24-h ambulatory BP. A SphygmoCor device was used to measure the central (CAIx) and peripheral (PAIx) systolic augmentation indexes, central pulse pressure (PPc), and the aortic pulse wave velocity (PWV). In multivariate analyses family clusters and significant covariates were accounted for.

RESULTS

The OFF/HT had higher (.14 < P < .0007) conventional BP and PPp on conventional BP measurement (121/75 v 114/71 mm Hg and 46 v 42 mm Hg) as well as on 24-h ambulatory monitoring (118/70 v 114/67 mm Hg and 48 v 47 mm Hg). OFF/HT, compared with OFF/NT, also had higher (.05 < P < .0008) PPc (28 v 26 mm Hg), PAIx (54.7% v 44.9%), CAIx (108.8% v 99.8%), and PWV (7.4 v 6.6 m/sec). However, complex adjustment including mean arterial pressure and age removed the differences between the offspring in the PAIx, CAIx, and PWV.

CONCLUSIONS

Large-artery properties are altered in OFF/HT compared with OFF/NT. The findings from this cross-sectional study suggest that the alterations in arterial function in subjects with a family history of hypertension are determined mainly by an increased BP and age-related hemodynamic changes.

Sodium excretion as a modulator of genetic associations with cardiovascular phenotypes in the European Project on Genes in Hypertension

Hypertension is a chronic age-related disorder, affecting nearly 20% of all adult Europeans. This disease entails debilitating cardiovascular complications and is the leading cause for drug prescriptions in Europeans older than 50 years. Intensive research over the past two decades has so far failed to identify common genetic polymorphisms with a major impact on blood pressure or associated cardiovascular phenotypes, suggesting that multiple genes each with a minor impact, along with gene-gene and gene-environment interactions, play a role. The European Project on Genes in Hypertension (EPOGH) is a large-scale, family-based study in which participants from seven different populations were phenotyped and genotyped according to standardized procedures. This review article summarizes the initial 5-year findings and puts these observations into perspective against other published studies. The EPOGH demonstrated that phenotype-genotype relations strongly depend on host factors such as gender and lifestyle, in particular salt intake as reflected by the 24-h urinary excretion of sodium. The EPOGH therefore highlights the concept that phenotype-genotype relations can only be studied within a defined ecogenetic context.

Reference Values in White Europeans for the Arterial Pulse Wave Recorded by Means of the SphygmoCor Device

Measurement of blood pressure together with applanation tonometry at the radial artery allows the reproducible assessment of various indexes of arterial stiffness, including the peripheral (PPp) and central pulse pressures (PPc) and the peripheral (Alp) and central augmentation indexes (Alc). We defined preliminary diagnostic thresholds, using the distributional characteristics of these hemodynamic measurements in a reference population. We randomly recruited 870 subjects from 3 European populations. PPp was the average difference between systolic and diastolic blood pressure measured five times at one home visit. For measurement of PPc, Alp and Alc, we used the SphygmoCor device. We selected subjects without hypertension, diabetes, dyslipidemia in need of medical treatment or previous or concomitant cardiovascular disease. The study population included 228 men and 306 women (mean age 34.9 years). All hemodynamic measurements were curvilinearly related to age, and Alp and Alc were lower in men than in women. In men at age 40, the upper 95% prediction bands of the relations of the hemodynamic measurements with age approximated 60 mmHg for PPp, 40 mmHg for PPc, 90% for Alp, and 30% for Alc. For PPc, Alp and Alc, these thresholds must be adjusted for age, leading to lower and higher thresholds at younger and older age, respectively. In addition, in women of any age, the Alp and Alc thresholds must be increased by 10% and 7%, respectively. Pending validation in prospective outcome studies, distributional characteristics of arterial stiffness indexes in a reference population can be used to generate operational thresholds for use in clinical practice.

The relationship between pulse wave velocity and indexes of collagen synthesis in hypertensive patients, according to the level of systolic blood pressure

Vascular stiffening, a process responsible for the development of isolated systolic hypertension, depends on dysregulation of collagen-elastine production and arrangement, yet it is not known whether the effect is uniform throughout wide blood pressure (BP) range. To check whether arterial stiffness is similarly related to increased fibrotic remodelling, in patients with systolic blood pressure (SBP) above and below 160 mmHg. Consecutive peri- and postmenopausal female outpatients treated for hypertension and free from other disorders interfering with fibrotic processes, had their BP, pulse wave velocity (PWV), and collagen (N-terminal procollagen type III propeptide (PIIINP); C-terminal procollagen type I propeptide-(PICP)) measured. The average age of 100 women was 71.8+/-10.5 years, BP was 145/83+/-25/15 mmHg, pulse pressure 63+/-17 mmHg, and mean blood pressure (MBP) 104+/-17 mmHg. PWV was 12.9+/-3.6 m/s and was significantly higher among 30 patients with SBP of > or =160 mmHg. PIIINP averaged 4.6+/-1.6 ng/ml and PICP 142.2+/-47.0 ng/ml. In the low SBP (<160 mmHg) group there was no relationship between PWV and collagen concentrations. However, in the > or =160 mmHg group there was significant correlation between PWV and PIIINP concentration. The relationship held significant after adjustment for age, and BP components. Our result can help explaining the results of recent intervention trials where older patients tended to benefit more from potentially antifibrotic drugs (ACE-I), whereas those with compliant arteries tend to benefit from diuretics.

Epistatic interaction between α- and γ-adducin influences peripheral and central pulse pressures in white Europeans

BACKGROUND

Adducin is a membrane skeleton protein consisting of alpha- and beta- or alpha- and gamma-subunits. Mutations in alpha- and beta-adducin are associated with hypertension. In the European Project on Genes in Hypertension, we investigated whether polymorphisms in the genes encoding alpha-adducin (Gly460Trp), beta-adducin (C1797T) and gamma-adducin (A386G), alone or in combination, affected pulse pressure (PP), an index of vascular stiffness.

METHODS

We measured peripheral and central PP by conventional sphygmomanometry and applanation tonometry, respectively. We randomly recruited 642 subjects (162 nuclear families and 70 unrelated individuals) from three European populations. In multivariate analyses, we used generalized estimating equations and the quantitative transmission disequilibrium test.

RESULTS

Peripheral and central PP averaged 46.1 and 32.6 mmHg, respectively. Among carriers of the alpha-adducin Trp allele, peripheral and central PP were 5.8 and 4.7 mmHg higher in gamma-adducin GG homozygotes than in their AA counterparts, due to an increase in systolic pressure. gamma-Adducin GG homozygosity was associated with lower urinary Na/K ratio among alpha-adducin Trp allele carriers and with higher urinary aldosterone excretion among alpha-adducin GlyGly homozygotes. Sensitivity analyses in founders and offspring separately, and tests based on the transmission of the gamma-adducin G allele across families, confirmed the interaction between the alpha- and gamma-adducin genes.

CONCLUSIONS

In alpha-adducin Trp allele carriers, peripheral and central PP increased with the gamma-adducin G allele. This epistatic interaction is physiologically consistent with the heterodimeric structure of the protein and its influence on transmembranous sodium transport.

Association of peripheral and central arterial wave reflections with the CYP11B2 ???344C allele and sodium excretion

OBJECTIVE

Angiotensin II and aldosterone, generated by the angiotensin-converting enzyme (ACE) and aldosterone synthase (CYP11B2), respectively, not only regulate sodium and water homeostasis, but also influence vascular remodeling in response to high blood pressure. In the European Project on Genes in Hypertension (EPOGH), we therefore investigated whether the ACE I/D and CYP11B2 C-344T polymorphisms influence early arterial wave reflections, a measure of vascular stiffness.

METHODS

We measured the peripheral and central augmentation index of systolic blood pressure by applanation tonometry at the level of the radial artery in 622 subjects (160 families and 64 unrelated individuals) randomly recruited from three European populations, whose average urinary sodium excretion ranged from 196 to 245 mmol/day. In multivariate analyses, with sodium excretion analyzed as a continuous variable, we explored the phenotype-genotype associations by means of generalized estimating equations and the quantitative transmission disequilibrium test.

RESULTS

The peripheral and central augmentation indexes were significantly higher in CYP11B2 -344C allele carriers than in -344T homozygotes. In offspring, early wave reflections increased with the transmission of the -344C allele. This effect of the CYP11B2 polymorphism occurred in subjects with a higher than median urinary sodium excretion (210 mmol/day). The ACE I/D polymorphism did not influence augmentation of systolic blood pressure.

CONCLUSIONS

The CYP11B2 C-344T polymorphism affects arterial stiffness. However, sodium intake seems to modulate this genetic effect.

[Mechanisms of large artery remodeling]

Degenerative changes of elastin, increase of collagen fibres, proliferation of muscle cells and impairment in endothelium function occurs in the vessel wall with ageing, in hypertensive and others diseases. Early changes are potentially reversible. Atherosclerosis is a late stage of pathologies occurring in the arterial wall in response to various factors. The present paper describes current knowledge on mechanisms of arterial wall remodelling. The authors define basic indices of arterial compliance and describe several physiological and pathological factors which occur play the main role in process of arterial wall remodelling. A chapter is devoted to the effects of increased arterial stiffness on heart pathology and clinical implications of measuring these parameters.

[Pulse wave analysis: from the basic sciences to clinical applications]

Assessment of the pulse character is one of the earliest recorded medical skills, but objective recordings of pulse waveform emerged only in the nineteenth century. This technique fell into disuse with the advent of the sphygmomanometer, but interest has recently been rekindled with the introduction of computer technology and high fidelity applanation tonometry. Sphygmocardiography is a non-invasive and accurate technology which utilizes tonometric analysis of the radial or carotid artery pulse wave and measurement of peripheral arterial blood pressure to derive a central arterial pulse wave, central arterial blood pressure and related indices. In clinical studies pulse wave analysis is a highly reproducible method and easy to apply. This measure provides important information about arterial stiffness and heart-vascular interactions. This technique may provides better cardiovascular risk assessment associated with increased arterial stiffness and allow treatment to be targeted to those most in need.

[Laser doppler flowmetry--repeatability of the method]

The aim of the study was to evaluate the repeatability of flow microcirculation measurements by laser doppler flowmetry (Periflix, firm Perimed, Sweden). Measurements of right forearm skin perfusion were performed twice in 3-4 day intervals in 40 healthy subject aged 39.5 +/- 18.3. Two independent investigators analysed the results. Pearson correlation and analysis ac. Bland and Altman (Lancet 1986, 1, 307-310) were performed during comparing results obtained in the same studied persons and by the investigators. There was a high correlation between the compared results performed on the same subjects within a few days interval, especially between the results for post-occlusive congestion reaction in basic temperature (r = 0.64-0.72) and the results for congestion reaction at a temperature of 44 degrees C (r = 0.5-0.56). High correlation values (r = 0.8-0.95) were also observed when comparing both investigators' evaluations. Repeatability evaluation using Bland and Altman analysis was poorer, especially for values observed in resting conditions and for some values observed after stimulation with both investigators (2.5-10% of results were out of interval: mean +/- 2SD). The results show good repeatability of microcirculation flow measurements, especially under stimulation.