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Biomedical subjects

D A Duprez

Publications and source records attributed to D A Duprez.

At least 19 recordsLinked to original sources
PubMed2005

Relationship between C-reactive protein and arterial stiffness in an asymptomatic population.

Plasma concentration of high sensitive C-reactive protein (hsCRP) is used as a marker for inflammatory states and is directly correlated with the risk for coronary heart disease. Evidence concerning the role of inflammation in atheroma formation has been derived from several models of atherosclerosis. Inflammation should exert its adverse vascular effects by structural changes in the artery wall and consequently alterations in arterial elasticity, which could be detected already in asymptomatic early vascular disease. We hypothesized that CRP is related to large artery elasticity, but not to small artery elasticity in early vascular disease. Therefore, we examined the association between arterial stiffness of large and small arteries and inflammation in an asymptomatic population referred for primary prevention cardiovascular screening. Studies were performed in 391 subjects (age 21-82 years; 254 men, 137 women) who underwent screening at the Cardiovascular Disease Prevention Center. Large artery (C1) and small artery (C2) elasticity indices were obtained by the CVProfiler 2000 (HDI, Eagan, MN, USA). After overnight fasting, venous samples were taken for measurement of hsCRP, lipids, glucose. There was a significant inverse correlation between hsCRP (0.29 +/- 0.40 mg/dl) and C1 (16.7 +/- 5.8 ml/mmHg), r = -0.133, P = 0.01; there was no significant correlation between hsCRP and C2 (6.6 +/- 3.2 ml/mmHg). C2, but not hsCRP, was inversely correlated with age, abnormal lipids and glucose, whereas C1, but not hsCRP, was inversely correlated with age and systolic blood pressure (SBP). In multiple regression analysis, the relationship between hsCRP and C1 was not affected by age, body mass index, SBP, serum glucose or lipids. In conclusion, these findings support the hypothesis that hsCRP, a marker for acute and low-grade inflammation, is associated with large artery but not with small artery elasticity in asymptomatic individuals undergoing primary prevention cardiovascular screening.

Adult↗
PubMed2001

Relationship between periventricular or deep white matter lesions and arterial elasticity indices in very old people.

OBJECTIVE: To examine the relationship between the presence of cerebral white matter lesions and large and small artery elasticity indices in a population of healthy, very old subjects. METHODS: We studied 24 subjects (14 women, 10 men) with a mean age of 84+/-5 years, who were free from overt neurological, cardiovascular or psychiatric illness. We measured blood pressure and heart rate in supine and standing positions. Elasticity indices of the large arteries (C1) and small arteries (C2) were derived from radial artery pulse waves. Each subject had multi-slice spin-echo cerebral magnetic resonance imaging. The severity of white matter lesions was graded as 0, 1 or 2. RESULTS: Cerebral white matter lesions on magnetic resonance imaging were common in very old apparently healthy subjects: grade 0 (n=4, C1=2.68+/-1.80 ml/mmHg and C2=0.045+/-0.017 ml/mmHg), grade 1 (n=7, C1=2.13+/-0.36 ml/mmHg and C2=0.040+/-0.016 ml/mmHg) and grade 2 (n=13, C1=1.12+/-0.36 ml/mmHg and C2=0.018+/-0.003 ml/mmHg). There was no significant association between elasticity indices and blood pressure. CONCLUSION: In very old, apparently healthy subjects, both large and small artery elasticity indices were inversely related to the severity of cerebral white matter lesions on magnetic resonance imaging.

Aged↗
PubMed2001

A comparison between systolic and diastolic pulse contour analysis in the evaluation of arterial stiffness.

Several methodologically independent measures of arterial stiffness derived from either the systolic or diastolic segments of the arterial pulse have been proposed. The exact nature of the large and small artery elasticity indices (C1 and C2, respectively) derived from diastolic pulse contour analysis remains largely unexplored, although C2 has controversially been termed to be "oscillatory" and "reflective." We investigated the relation between C2 and, respectively, a prototype of arterial reflectivity (ie, the augmentation index, AIx) and a covariate of arterial reflectivity (body height). A validated transfer function is used to transform a tonometrically obtained radial pressure wave into an ascending aortic pressure wave, from which AIx is derived using systolic pulse contour analysis. Diastolic pulse contour analysis using a modified Windkessel model is used to derive C1 and C2. One hundred subjects, who were free from atherothrombotic disease and 19 to 77 years of age, with a wide pressure range (97 to 186/52 to 104 mm Hg) were studied. Mean values of C1, C2, AIx, and body height were, respectively, 13.8+/-4.3 mL/mm Hgx10, 5.9+/-3.1 mL/mm Hgx100, 128.5+/-24.9%, and 169+/-9 cm. Coefficients of variation were 32.8% for C1, 33.3% for C2, and 6.7% for AIx. C2 was significantly and inversely correlated to AIx (r=-0.707, P<0.001). Both AIx and C2 were correlated to body height (r=-0.487, P<0.001, and r=0.514, P<0.001). In conclusion, the results of this study provide the first clinical evidence that validates a probable biophysical equivalent of the C2 element of a third-order, 4-element modified Windkessel model. We suggest that C2 is, at least in part, a measure of arterial wave reflectance. However, although short-term reproducibility of AIx is excellent, C2 showed markedly increased variability with the devices used.

Adult↗
PubMed2001

Small and large artery elasticity indices in peripheral arterial occlusive disease (PAOD).

In peripheral arterial occlusive disease (PAOD), arterial compliance of the central arteries has been reported to be reduced. It is, however, not clear whether, in PAOD, decreased arterial compliance is also accompanied by similar changes in the peripheral arteries. Therefore the aim of the study was to determine the large (C1) and small (C2) artery elasticity indices in PAOD and their relations to its well-accepted characteristics (ankle-brachial index, ABI; pulse pressure, PP; absolute claudication distance, ACD). A total of 43 patients with PAOD (mean age 68 +/- 9 years; ABI of the limiting leg 0.65 +/- 0.14; SBP (systolic blood pressure) 149 +/- 20 mmHg, and ACD 488 +/- 187 m) were enrolled as well as 16 control subjects of comparable age (69 +/- 4 years) and blood pressure (SBP 147 +/- 27 mmHg). All subjects underwent non-invasive pulse wave analysis in order to determine arterial compliance of the aorta and major side branches (C1) and of the distal circulation (C2), using a modified Windkessel model. In PAOD, both C1 (1.41 +/- 0.56 ml/mmHg) and C2 (0.023 +/- 0.012 ml/mmHg) were comparable to values in an age and blood pressure-matched control group (C1, 1.25 +/- 0.66 ml/mmHg; C2, 0.027 +/- 0.008 ml/mmHg). C1 was significantly correlated with ACD (r = 0.36, p = 0.02), PP (r = -0.33, p < 0.02) and only borderline with ABI (r = 0.28, p = 0.07). C2 was correlated with PP (r = -0.38, p < 0.01), ABI (r = 0.36, p < 0.02) but not with ACD. Large (C1) and small (C2) artery elasticity indices in PAOD were decreased but comparable to values in an elderly group with isolated systolic hypertension. Moreover, C1 and C2 correlated with markers (ABI and PP) of severity of vascular disease.

Aged↗
PubMed2001

Interchangeability of carotid and femoral intima-media thickness in risk stratification.

BACKGROUND: Carotid intima-media thickness (c-IMT) is an intermediate phenotype not only for the local but also the global arteriosclerotic status, a concept which has been validated by its ability to act as a marker for future cardiovascular and cerebrovascular events. Whether the association between c-IMT and risk factors, distant atherosclerotic disease and prognosis are the sole prerogative of the carotid artery, or whether these findings can be extrapolated to other arterial sites is less well studied. In view of the concept of vascular heterogeneity, we measured the IMT in a muscular, lower extremity artery, the common femoral (f-IMT), and in elastic upper extremity artery, the common carotid, in apparently healthy individuals and explored the relationship with risk factors and the individuals 10-year cardiovascular (CV) risk, calculated using the Framingham systolic blood pressure equation. METHODS: A population of 156 apparently healthy normotensive Caucasian volunteers between 18 and 65 years was studied (mean age 43+/-13 years; 68 men, 88 women; mean arterial blood pressure 126 +/- 15/70 +/- 10 mmHg). The c-IMT and f-IMT were measured using a 10 MHz vascular linear array transducer at the far walls 1 to 2 centimetres proximal to the right common carotid and right common femoral artery bifurcations, respectively. Risk factors were assessed and the 10-year cardiovascular risk was calculated using the Framingham systolic blood pressure equation. RESULTS: The median c-IMT was 0.52 mm (interquartile range 0.45-0.62 mm) and f-INT was 0.52 mm (0.39-0.67). Both parameters were significantly correlated (r = 0.363; p < 0.01) and both were significantly correlated to the calculated 10-year CV risk (r = 0.579; p < 0.01 and r = 0.574; p < 0.01 for the carotid and c-IMT and f-IMT, respectively). Median risk was low: 2.11% (0.27-5.50). Although measures of agreement were higher for the f-IMT versus risk (0.47) than for the c-IMT versus risk (0.30), the former showed a significantly wider scatter with increasing age and with quartiles of CV risk. The c-IMT and f-IMT do not share determinant risk factors to the same extent and with only 20% of mutual variance explained, cannot be regarded as interchangeable. CONCLUSIONS: Although the c-IMT and f-IMT are significantly intercorrelated and correlate to the calculated 10-year CV risk, they are not interchangeable. While the f-IMT is less suited as a continuous variable for risk stratification in a low-risk population, our data suggest its possible use as a dichotomised risk marker.

Adolescent↗
PubMed2000

Inverse relation between aldosterone and venous capacitance in chronically treated congestive heart failure.

The purpose of this study was to examine if there is a relation between the aldosterone escape phenomenon and venous capacitance of the upper and lower limbs in patients with long-term congestive heart failure (CHF) receiving chronic treatment with angiotensin-converting enzyme (ACE) inhibitors. The study group consisted of 16 subjects with ischemic CHF in New York Heart Association functional class II (age 59 +/-2 years, ejection fraction 24+/-4%), stabilized under a constant drug regimen comprising furosemide, captopril 50 mg 3 times daily, and digoxin for at least 3 months. Thirteen apparently healthy volunteers, aged 50+/-4 years acted as controls. Forearm and calf venous capacitances were measured simultaneously by venous occlusion plethysmography using mercury-in-silastic strain gauges. The equilibration technique was used to derive venous capacitance from the recorded pressure-volume curves. Active renin, angiotensin II, and aldosterone levels were determined on venous blood samples obtained in the supine position. Angiotensin II (p<0.05) and aldosterone (p<0.01) were statistically significantly higher in patients with CHF under long-term ACE inhibition than in controls (aldosterone escape phenomenon). In CHF, forearm venous capacitance was 2.19+/-0.18 ml/100 ml; calf venous capacitance was 2.83+/-0.27 ml/100 ml. Aldosterone significantly and inversely correlated with venous capacitance in both upper (r = -0.586; p = 0.017) and lower (r = -0.625; p = 0.01) limbs. No correlations were found between forearm or calf venous capacitance and renin or angiotensin II. In patients with heart failure chronically treated with diuretics and full ACE inhibition, venous capacitance is inversely correlated with aldosterone through the mechanism of aldosterone escape, creating the potential for further deterioration of the CHF process.

Aldosterone↗
PubMed2000

Relationship between arterial elasticity indices and carotid artery intima-media thickness.

Functional and structural changes of the arterial wall appear to serve as early hallmarks of the hypertensive disease process. Structural vascular changes can be studied by the determination of the intima-media wall thickness (IMT) at the carotid artery. The elastic behavior of the proximal and distal parts of the arterial tree can be assessed from noninvasively recorded radial artery waveforms. The aim of the study was to compare large (proximal, C1) and small (distal, C2) artery elasticity indices in two age-matched study groups with high- and low-normal blood pressure (BP) and to assess the relation between elasticity indices and IMT. A total number of 22 subjects with high-normal BP (40 +/- 2 years; BP, 147 +/- 2.5/84 +/- 1.5 mm Hg) and 22 matched controls with low-normal BP (40 +/- 2 years; BP, 123 +/- 1.9/69 +/- 1.5 mm Hg) were enrolled. The IMT was echographically determined at the common carotid artery by the leading-edge technique. Large artery (C1) and small artery (C2) elasticity indices were calculated from a third-order, four-element model of the arterial circulation. In the group with high-normal BP large and small artery elasticity indices were significantly decreased versus controls with low-normal BP (C1: 1.63 +/- 0.08 v 1.99 +/- 0.09 mL/mm Hg, P < .01; C2: 0.059 +/- 0.005 v 0.076 +/- 0.007 mL/ mm Hg, P < .05) and IMT increased significantly (0.607 +/- 0.039 v 0.516 +/- 0.027 mm, P < .05). Moreover, there was an inverse relationship between IMT and small artery elasticity index (r = -0.60, P = .004). In subjects with a high-normal BP there is already a change in the IMT of the carotid artery versus normotension. The IMT is related to the small artery elasticity index (C2).

Adult↗
PubMed2000

A non-invasive cardiovascular index for the quantification of arterial load.

OBJECTIVE: Our aim is to quantify steady and pulsatile components of arterial load in a concise and sensitive way by means of a new non-invasive cardiovascular index (NICI). METHODS AND RESULTS: NICI is based on non-invasively measured pressure (sphygmomanometer), stroke volume index and cardiac index (Doppler echocardiography and ECG) and yields a numerical value (in mm Hg). It expresses the difference between the actual arterial load and reference loading conditions as determined in a control group (29 M/35 F, age 34 +/- 13 yr.) of healthy subjects, with blood pressure 116/61 mm Hg (systolic/diastolic), stroke volume index (SVI) 34 +/- 18 ml.m-2 and cardiac index (CI) 2.1 +/- 0.5 l.min-1.m-2. NICI was calculated in the control group and in 23 borderline hypertensive subjects (10 M/13 F, age 65 +/- 12 yr.) with blood pressure 156/79 mm Hg, SVI 36 +/- 10 ml.m-2 and CI 2.4 +/- 0.6 l.min-1.m-2. NICI was higher in borderline hypertensives (33 +/- 51 vs. 0 +/- 34 mm Hg; P < 0.001) and was strongly correlated with total peripheral resistance index (r = 0.89; P < 0.001) and with the ratio of SVI and pulse pressure (r = -0.89; P < 0.001), expressing the combined effect of both known determinants of cardiac load. NICI was also correlated with effective arterial elastance index (r = 0.89; P < 0.001). CONCLUSIONS: NICI quantifies, within a logical biomechanical framework, the arterial load as seen by the ejecting ventricle. It combines steady and pulsatile components of arterial load and has a single control value of zero mm Hg.

Adult↗
PubMed1998

Long- and short-term blood pressure and RR-interval variability and psychosomatic distress in chronic fatigue syndrome.

1. Chronic low blood pressure has been associated with fatigue and low mood. However, in the chronic fatigue syndrome (CFS) the blood pressure (BP) and heart rate profile and their variabilities have not been characterized as yet. 2. We performed office and 24 h ambulatory BP recordings in 38 subjects (age, 34.8 +/- 8.0 years) who fulfilled the Holmes criteria for CFS and in 38 healthy control subjects (age 35.6 +/- 10.5 years), as well as short-term beat-to-beat BP and RR-interval recordings for 10 min in supine and standing position, and calculated spectral indices. 3. In CFS office (123 +/- 19/70 +/- 12 mmHg) as well as 24-h, day- and night-time blood pressure values (116 +/- 11.1/71 +/- 11.1, 121 +/- 9.2/77 +/- 8.0 and 110 +/- 10.5/65 +/- 9.2 mmHg respectively) were within reference limits. 4. Heart rate was consistently higher (P < 0.01) in CFS patients, based on both office (77 +/- 12 compared with 68 +/- 12 beats min-1) and 24 h ambulatory recordings (77 +/- 12 compared with 67 +/- 15 beats min-1). 5. In supine position, spectral indices of BP variability (total, low-frequency and high-frequency variances) were all significantly (P < 0.01) lower in CFS. In standing position the differences disappeared. Analysis of RR-interval variability could not detect major alterations in autonomic function in CFS.

Adult↗
PubMed1998

Inverse relationship between aldosterone and large artery compliance in chronically treated heart failure patients.

AIMS: The purpose of this study was to examine, in chronically treated heart failure patients vs control subjects, the influence of neurohumoral activation and aldosterone escape on arterial elastic behaviour, assessed by non-invasive mathematical lumped-parameter modelling of the compliance of the arterial system. METHODS AND RESULTS: Radial arterial pulse waves were recorded non-invasively for 30 s with an arterial tonometer sensor array in 13 chronic heart failure patients (mean age, 59 +/- 2.5 years) in New York Heart Association class II. The patients had been taking digoxin, furosemide, captopril and aspirin for more than 3 months. Thirteen healthy subjects (mean age, 50 +/- 4.0 years) acted as controls. Compliance of the proximal (aorta and major branches, C1) and distal parts (C2) of the circulation were derived from a third order four-element modified Windkessel model which can reproduce arterial pressure waveforms, including both exponential and oscillatory sections. Active renin, angiotensin II and aldosterone levels were determined on venous blood samples in the supine position and after 30 min active standing. There was decreased proximal (C1, 1.51 +/- 0.11 ml x mmHg(-1), P<0.01) and distal (C2, 0.050 +/- 0.011 ml x mmHg(-1)) arterial compliance in the chronic heart failure patients vs controls (C1, 1.71 +/- 0.16 ml x mmHg(-1); C2, 0.054 +/- 0.006 ml x mmHg(-1)). The chronic heart failure patients were characterized by an aldosterone escape phenomenon which was inversely correlated with the proximal arterial compliance in both supine (r= - 0.795, P=0.002) and standing (r= - 0.628, P=0.029) positions. CONCLUSIONS: In chronically treated heart failure patients with full angiotensin-converting enzyme-inhibition and diuretics, there is decreased compliance of the aorta and its major branches, which is inversely correlated with the aldosterone escape phenomenon.

Aldosterone↗
PubMed1998

Calcium antagonists, is there a real concern about safety?

Calcium antagonists are widely used in the treatment of arterial hypertension and, or in ischemic heart disease. During the last 3 years, controversial articles and editorials have been published concerning the potential risk of calcium antagonists in regard to mortality, cancer and haemorrhage. The information has been mainly derived from case-control studies. The major concern about such observational studies of treatment outcome is the large potential for systematic error to affect the results. However, overviews of controlled trials with calcium antagonists do not provide clear evidence of an effect of calcium antagonists on mortality, risk of cancer and risk of bleeding.

Bias↗
PubMed1996

Genetic polymorphisms and erythrocyte sodium-lithium countertransport in essential hypertension.

Erythrocyte sodium-lithium countertransport (SLC) activity is elevated in essential arterial hypertension. With the growing attention to the genetic substrate of disturbed biochemical tests associated with essential arterial hypertension, we were particularly interested in the involvement of key genes for the regulation of SLC, possibly related to the pathophysiology of essential arterial hypertension. Consequently, the aim of the present study was to investigate SLC and its determining factors in essential hypertension. The influence of haptoglobin (Hp)-polymorphism, insertion/deletion polymorphism of angiotensin converting enzyme (ACE-I/D) and MNS blood group system on the regulation of SLC was studied. SLC activity was studied in a cross-sectional case-control study including 90 Caucasians: 60 patients with essential arterial hypertension who had been treated for at least 1 year and 30 normotensive controls. In essential hypertension, the SLC activity is significantly higher (P = 0.00005) than in controls. In normotensive patients, no differences in SLC are observed for the different polymorphisms studied. However, in the hypertensive group, SLC activity is higher (P = 0.003) in Hp 2-1 phenotype and independent of ACE-I/D genotyping and MNS blood group polymorphism. Multifactor analysis of variance in essential hypertension reveals significant (P = 0.001) differences in SLC activity for the presence or absence of Hp 2-1 phenotype and for body weight (P = 0.0003). Multivariate regression analysis shows the same parameters to be independent determining factors of SLC in essential arterial hypertension. No relation is found between SLC activity and target organ damage which includes coronary artery disease, peripheral arterial occlusive disease, left ventricular hypertrophy and cerebrovascular accident. We conclude that erythrocyte SLC activity is elevated despite pressure-lowering therapy. In essential arterial hypertension, individuals of Hp 2-1 phenotype show higher SLC activity than patients of other Hp-types, suggesting genetic heterogeneity of essential arterial hypertension. The presence or absence of Hp 2-1 phenotype is an independent determining factor of SLC activity whereas body weight codetermines SLC activity in essential hypertension.

Adult↗
PubMed1996

Angina in the elderly.

Coronary artery disease (CAD) remains the most common cause of heart disease in the elderly, in whom it exhibits some unique features. It is more likely to be diffuse and severe and left main coronary artery stenosis and triple-vessel disease are more prevalent. Diagnosis is less dependent on the presence of chest pain since other symptoms may present as an anginal equivalent in such patients. The ECG of elderly patients often shows abnormalities that are not specific for myocardial ischaemia. In such patients, and in those who are unable to perform sufficient exercise to increase the heart rate to > or = 85% of predicted maximal heart rate for age and sex, radionuclide or pharmacological stress testing may be used. When the diagnosis of CAD remains questionable, coronary arteriography should be considered. Physical examination and basic laboratory screening should be used to identify conditions which exacerbate myocardial ischaemia and will, therefore, affect treatment. The initial approach to treatment should include risk factor modification and initiation of an anti-ischaemic pharmacological regimen. The usual anti-anginal medications are as efficacious in the elderly as in the young; however, attention must be paid to altered pharmacodynamics and pharmacokinetics. When symptoms are poorly controlled by medical therapy or when multivessel or left main coronary artery stenosis is identified, myocardial revascularization should be considered. In elderly patients with symptomatic angina or unstable angina symptoms, uncontrolled by medical therapy, percutaneous transluminal coronary angiography may be a reasonable alternative to surgical revascularization.

Age Factors↗
PubMed1996

Influence of the arterial blood pressure and nonhemodynamic factors on regional arterial wall properties in moderate essential hypertension.

Structural and functional abnormalities may occur at the left ventricle and in different large arteries in essential hypertension. Noninvasive high resolution pulsed doppler echo-tracking technique allows calculation of regional arterial wall properties, which might be determined by either hemodynamic or non-hemodynamic factors. Therefore we aimed to study regional arterial wall properties in three different vascular territories and examined whether hemodynamic and non-hemodynamic parameters were significantly associated to a specific vascular territory. In 30 patients (mean age 47 +/- 2 years) with newly diagnosed and untreated essential arterial hypertension, arterial wall properties were determined at the carotid (common, external and internal), femoral, and brachial artery using a noninvasive ultrasound wall movement detector system. The study parameters were arterial diameter, relative diameter change, arterial distensibility (DC) and cross-sectional compliance (CC) coefficient. On the day of the experiments office blood pressure (BP) was measured as well as an ambulatory 24 h BP profile performed on an outpatient basis. Blood samples were taken on the day of the vascular examination for the determination of plasma renin activity (PRA), aldosterone, intact (1-84) parathyroid hormone (PTH), insulin and plasma noradrenaline and adrenaline. Among the studied vascular territories, only DC and CC of the common carotid artery were significantly (P < 0.01) correlated with office and ambulatory systolic BP. Intact PTH was significantly correlated with the diameter (r = 0.61, P = 0.005) and DC (r = -0.53, P = 0.01) of the internal carotid artery. Noradrenaline was inversely correlated with DC of the femoral artery (r = - 0.55, P < 0.01). All correlations remained significant after adjustment for age and body mass index as confounding variables. In conclusion, in mild to moderate arterial essential hypertension there is a heterogeneity of vascular wall properties and their relationship to BP and humoral factors between brachial, femoral and carotid (common, external and internal) arteries. Our findings might renew interest in the old concept of the 'circulatory paradox'.

Adult↗
PubMed1995

Renin-angiotensin-aldosterone system, RR interval, and blood pressure variability during postural changes in borderline arterial hypertension.

This study aimed to examine the changes in RR interval and blood pressure (BP) variability and humoral factors during postural changes in borderline arterial hypertension. Twenty-nine patients (44 +/- 3 year; BP, 145 +/- 3/84 +/- 3 mm Hg) with borderline hypertension and a control group of 38 subjects (35 +/- 2 year; BP, 123 +/- 3/70 +/- 2 mm Hg) underwent power spectrum analysis of RR interval and BP (low frequency (LF), 0.05 to 0.15 Hz; high frequency (HF), 0.15 to 0.40 Hz) in the supine and standing positions. Concentrations of plasma renin activity, angiotensin II, and aldosterone in supine and standing positions had been determined in the hypertensive group. Borderline hypertensives are characterized by higher oscillations of systolic and diastolic BP, but not of RR interval in the supine position versus the control group. Low frequency and HF components of systolic and diastolic BP expressed as absolute data are also significantly higher in borderline hypertensives. Moreover, standing tended to increase the LF/HF ratio of both RR interval and BP variability compared to controls. The standing position was able to further activate the LF but not the HF component of BP variability. In borderline hypertension renin release during postural changes correlated well with the decrease in the power of the HF vagal component of RR interval variability (r = -0.70, P < .001) and with the increase of the LF component of diastolic blood pressure variability (r = 0.43, P = .03). In conclusion, our results indicate that in borderline arterial hypertension, LF and HF oscillations of BP are already significantly increased at rest.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Refractory hypertension is associated with the haptoglobin 2-2 phenotype.

BACKGROUND: Many cases of refractory hypertension cannot be attributed to specific identifiable factors. Haptoglobin polymorphism has been suggested as a candidate genetic marker in essential hypertension. The aim of this study was to investigate the distribution of haptoglobin types in patients with refractory hypertension. METHODS: Haptoglobin polymorphism was studied in 383 patients with non-refractory and 62 patients with refractory hypertension. Haptoglobin was typed using starch gel electrophoresis of haemoglobin-supplemented serum. RESULTS: In the group of patients with refractory hypertension, the relative allele frequency of haptoglobin 1 (0.266) was lower than in the group with non-refractory hypertension (0.385: P < or = 0.05). The relative frequency of haptoglobin 2-2 was 39% in the non-refractory compared with 56% in the refractory group (P < or = 0.05). In the latter group, the relative frequency of haptoglobin 2-2 was highest (75%) in patients requiring medication with four classes of drug. CONCLUSION: Hypertension patients with the haptoglobin 2-2 phenotype are at higher risk of developing refractory hypertension than those with other haptoglobin phenotypes.

Alleles↗
PubMed1993

Influence of arterial blood pressure and aldosterone on left ventricular hypertrophy in moderate essential hypertension.

In a group of 36 untreated patients with mild-to-moderate essential hypertension (office systolic blood pressure [SBP] 160 +/- 3.4 mm Hg, office diastolic blood pressure [DBP], 102 +/- 1.5 mm Hg), 24-hour ambulatory blood pressure monitoring, and determination of left ventricular (LV) mass index according to the formula of Devereux were performed. After an overnight fast, blood samples were taken for the determination of serum aldosterone levels and plasma renin activity. Urinary catecholamine concentrations were assayed from 24-hour urine collections. Left ventricular mass index (143.7 +/- 8 g/m2) did not correlate significantly with either office SBP or office DBP. The correlation of LV mass index with mean 24-hour SBP (145 +/- 3 mm Hg) was statistically significant: r = 0.395, p = 0.026. However, the best correlation was obtained with mean 24-hour DBP (90 +/- 3 mm Hg) with r = 0.499 (p = 0.004). Urinary catecholamine levels did not correlate with LV mass index. In addition, LV mass index correlated significantly with plasma renin activity (r = 0.346, p = 0.050) and serum aldosterone levels (r = 0.559, p = 0.0009). There was a strongly significant correlation between LV mass index and serum aldosterone levels even after adjustment for mean 24-hour SBP (r = 0.496, p = 0.005) and DBP (r = 0.514, p = 0.004). These results demonstrate that ambulatory blood pressure determinations but not office blood pressure parameters correlate well with left ventricular hypertrophy in essential hypertension. Nonhemodynamic factors are important determinants of left ventricular mass as well.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗