Search PubMed⌕ Search

Biomedical subjects

P W de Leeuw

Publications and source records attributed to P W de Leeuw.

At least 19 recordsLinked to original sources
PubMed2006

[The use of angiotensin converting enzyme (ACE) inhibitors during pregnancy clearly increases the risk of congenital malformations].

Recently, an important study was published concerning the possible teratogenic effects of angiotensin converting enzyme (ACE) inhibitors. Non-diabetic women who had used an ACE inhibitor during the first trimester of pregnancy had a significantly greater chance of giving birth to an infant with congenital malformations than women who had used no or other antihypertensive agents. The excess risk remained even after adjusting for several potential confounders. The results indicate that ACE inhibitors should not be prescribed to women who are likely to become pregnant during the course of treatment.

Abnormalities, Drug-Induced↗
PubMed2006

Ambulatory blood pressure, asymptomatic cerebrovascular damage and cognitive function in essential hypertension.

Prolonged exposure to elevated blood pressure (BP) can lead to both structural (white matter lesions (WML) or infarctions) and functional changes in the brain. We studied in previously diagnosed essential hypertensive individuals if diurnal BP variation and ambulatory BP (ABP) profile (daytime, night time and 24-h BP averages) were related to evidence of WML, the presence of 'silent' infarcts, and cognitive performance. A group of 86 patients (mean age 57.4+/-10 years, range 40-80) were first screened for hypertension-related organ damage and underwent 24-h ABP monitoring, magnetic resonance imaging (MRI) of the brain, and a comprehensive neurocognitive assessment. Age and ABP profile were related to more periventricular, but not subcortical, WML and to presence of lacunar infarctions on MRI. After correction for demographical group differences, no association was found between night time dipping of BP on the one hand and both WML load and cognitive parameters (verbal memory, sensorimotor speed, cognitive flexibility) on the other. The presence of lacunar infarctions, however, predicted lower performance on verbal memory. Furthermore, daytime and 24-h pulse pressure averages were associated with pWML, whereas systolic BP and mean arterial pressure (MAP) for daytime, night-time and 24-h periods were higher in patients with lacunar infarctions. Notwithstanding the large variability of WML in this sample, the evidence of a connection between diurnal BP variation and early target organ damage in the brain was not convincing. However, the ABP profile may be predictive of cerebral lesion type.

Adult↗
PubMed2006

Selective endothelin B receptor blockade does not influence BNP-induced natriuresis in man.

Brain natriuretic peptide (BNP) and endothelin-1 (ET-1) both exhibit natriuretic activity within the human kidney. Furthermore, they both act partly through activation of the endothelial nitric oxide pathway. Since ET-1 may cause vasodilation and natriuresis via stimulation of the ET-B receptor, the aim of the present study was to investigate whether renal ET-B receptors participate in the renal actions of BNP. In this placebo-controlled, crossover study, we infused BNP (4 pmol/kg/min) or placebo (i.v.) for 1 h, with or without co-infusion of the ET-B receptor antagonist BQ-788 (50 nmol/min) for 15 min on 4 separate days, in 10 healthy subjects (mean age 54+/-6 years.). During infusion, we measured effective renal plasma flow (ERPF), and glomerular filtration rate (GFR) using PAH/inulin clearance. Cardiac output was measured before and after infusion, using echocardiography. Blood pressure and heart rate (HR) were monitored as well. Urine and plasma samples were taken every hour to measure diuresis, natriuresis, cyclic 3',5' guanosine monophosphate, and ET-1 levels. BNP with or without ET-B receptor blockade increased natriuresis and diuresis. In addition, BNP alone increased GFR and filtered load, without changing ERPF. BQ-788 infusion did not affect renal hemodynamics or natriuresis. Neither BNP nor BQ-788 altered cardiac output, blood pressure, and heart rate. In conclusion, the present study shows that selective ET-B receptor blockade has no effect on the BNP-induced natriuresis and glomerular filtration rate.

Cross-Over Studies↗
PubMed2005

C-reactive protein, atherosclerosis and kidney function in hypertensive patients.

Previous studies have shown a relationship between coronary or carotid atherosclerosis and C-reactive protein (CRP) concentrations. In the present investigation, we evaluated the relationship between high-sensitivity CRP (hsCRP) concentrations and the presence of atherosclerotic lesions in the renal arteries and/or abdominal aorta. In 95 hypertensive patients who underwent intra-arterial DSA on suspicion of renovascular disease, blood was sampled during the procedure for measurement of hsCRP. The presence of atherosclerotic lesions was assessed at the level of the renal arteries and the abdominal aorta. Haemodynamically significant renal artery stenosis was diagnosed when 50% or more stenosis was observed. Patients with fibromuscular disease (n = 8) or incomplete data (n = 4) were excluded from analysis. The results revealed that the median hsCRP concentrations were significantly higher among the 57 patients with atherosclerosis of the aorta and/or renal arteries compared to those in the 26 patients without any angiographic lesions (4.6 vs 1.7 mg/l; P < 0.005). Moreover, in patients with renal artery stenosis, levels of hsCRP were higher when the degree of stenosis exceeded 50%. However, the association between hsCRP and the presence of atherosclerosis appeared to be confounded by serum creatinine, creatinine clearance, age and gender. In the whole group a significant inverse relationship was found between creatinine clearance and hsCRP (P < 0.05). In conclusion, hsCRP concentrations are related to atherosclerotic lesions in the renal arteries and the abdominal aorta. While this supports the view that atherosclerotic renal artery stenosis is part of a systemic inflammatory vascular disease, increased concentrations of CRP may also coincide with decreased renal function.

Adult↗
PubMed2005

Regional differences in cardiovascular risk factor profile cannot fully explain differences in cardiovascular morbidity in the Netherlands: a comparison of two urban areas.

BACKGROUND: Our objective was to investigate whether a region in the south of the Netherlands (Heerlen/Kerkrade) had a high burden of cardiovascular disease in comparison with a nearby region (Maastricht) and the average Dutch population, respectively. We also wanted to determine if there are interregional differences in cardiovascular risk factor profile. DESIGN: Cross-sectional study. METHODS: Data from a nationwide registry (CBS) were used to analyse cardiovascular mortality in the two regions and the average in the Netherlands. Data from a primary care morbidity registration network (RNH) were used to compare cardiovascular morbidity and cardiovascular risk factors in both regions. A standardisation procedure was carried out for age and sex. Data were analysed using logistic regression analyses. RESULTS: The overall cardiovascular mortality rate was higher in the Heerlen/Kerkrade region (7.8 per thousand) compared with Maastricht (6.1 per thousand, OR=1.3, 95% CI 1.2-1.5) and the average in the Netherlands (5.7 per thousand). Similarly, most cardiovascular morbidity rates for Heerlen/Kerkrade were more elevated compared with the RNH overall and with Maastricht. Prevalence rates of risk factors such as diabetes mellitus (7.2%, OR=1.5, 95% CI 1.3-1.7) and overweight (10.8%, OR= 2.0, 95% CI 1.8-2.2) were significantly higher in the Heerlen/Kerkrade region compared with Maastricht. There were no differences with regard to hypertension (15.2%, OR=1.0, 95% CI 0.9-1.1). CONCLUSION: Heerlen/Kerkrade is indeed a region with a high burden of cardiovascular disease. Differences in morbidity between Heerlen/Kerkrade and Maastricht cannot be fully explained by differences in cardiovascular risk factor profile.

Adult↗
PubMed2004

[Recently published European and American guidelines for the diagnosis and treatment of hypertension].

The European Society of Hypertension in conjunction with the European Society of Cardiology has published new guidelines on the management of hypertension. At about the same time, the Joint National Committee in the United States updated the American hypertension guidelines. Both guidelines agree on a number of issues, such as the importance of systolic blood pressure, the necessity to take into account additional risk factors and the growing emphasis on combination treatment. As far as pharmacotherapy is concerned, however, there are major differences between the guidelines. Whereas the European report permits a choice from among several classes of drugs for initial treatment, the American guidelines still consider diuretics to be the first choice.

Antihypertensive Agents↗
PubMed2003

[Treating hypertension is more important than the choice of agent; results from the largest clinical trial until now].

During the past few years, several randomised trials have compared the effects of older blood-pressure lowering drugs (diuretics, beta-blockers) with those of newer ones (angiotensin converting enzyme (ACE) inhibitors, calcium entry blockers) on the long-term prognosis. In general, no significant differences were found between these regimes. Recently, the ALLHAT trial, which was the largest hypertension trial ever and in which over 40,000 patients with hypertension participated, was completed. The initial treatment consisted of either the diuretic chlorthalidone, the calcium entry blocker amlodipine, the ACE inhibitor lisinopril, or the alpha-blocker doxazosin. The latter arm was prematurely discontinued because of a higher incidence of the secondary endpoint heart failure and stroke. Based on an intention-to-treat analysis, the other types of treatment proved to be equivalent in terms of the primary endpoint, a composite of fatal coronary heart disease and non-fatal myocardial infarction. Although the investigators conclude that ALLHAT suggests that thiazide diuretics should be first choice in the treatment of hypertension, there are several caveats that tend to lessen the strength of this conclusion.

Adrenergic beta-Antagonists↗
PubMed2003

Home versus Office blood pressure MEasurements: Reduction of Unnecessary treatment Study: rationale and study design of the HOMERUS trial.

The Home versus Office MEasurements, Reduction of Unnecessary treatment Study (HOMERUS) is a multicentre prospective study, primarily designed to examine in subjects with mild to moderate hypertension whether treatment decisions based on home blood pressure measurements can lead to reduction in the use of antihypertensive drugs and the associated costs, compared to office blood pressure measurements. After inclusion, 360 patients are randomized to two groups. In one group, antihypertensive therapy is based on blood pressure measured in the outpatient clinic: the office pressure (OP) group. In the other group, antihypertensive therapy is based on home blood pressure measurements: the self-pressure (SP) group. All readings, both in OP and in SP, are obtained with the same validated oscillometric device, the Omron 705 CP. Treatment decisions are taken by an independent physician at the coordinating centre, who is unaware whether the patient belongs to the SP or OP group. Following a standardized treatment schedule, blood pressure is targeted at 120-139 mmHg for systolic and 80-89 mmHg for diastolic pressure. Patients are followed for 1 year. At the start and at the end of the study, ambulatory blood pressure measurements are obtained as a reference. Microalbuminuria and echocardiography are assessed to evaluate the possible development of target organ damage. It is expected that, at the end of the trial, patients in both groups will have the same blood pressure, at the expense of more medication in the OP group. Therefore, a cost-minimization analysis will be performed first. If short-term effects appear not to be comparable for OP and SP, a cost-effectiveness analysis will be performed to assess the value of the SP strategy in comparison to standard practice. In addition, medication compliance is recorded within random subgroups of the SP and OP groups by means of Medication Event Monitoring System (MEMS) V TrackCaps.

Algorithms↗
PubMed2003

Fluid homeostasis in chronic obstructive lung disease.

Chronic obstructive pulmonary disease (COPD) often leads to massive oedema and the development of what is usually called cor pulmonale. The mechanisms by which patients with COPD retain salt and water are not completely understood. Several abnormalities have been found including reduced renal blood flow with relatively preserved glomerular filtration rate and elevated levels of renin, aldosterone, arginine vasopressin and atrial natriuretic peptide. Generally, these abnormalities worsen with the severity of COPD and are most marked during the oedematous phases. Cardiac output is remarkably normal, suggesting that "cor pulmonale" is not primarily a cardiac disorder but rather a condition of volume overload due to activation of sodium-retaining mechanisms. The stimulus for this activation could be underfilling of the arterial system (reduced effective circulating volume) secondary to a fall in total peripheral vascular resistance. The latter is caused by hypercapnia-induced dilation of the precapillary sphincters. Apparently, the massive sodium retention by the kidney is not able to restore the circulating volume and a vicious cycle ensues ultimately leading to a clinical picture which resembles right-sided heart failure. Predictably, only blockade of the effects of carbon dioxide at the level of the precapillary sphincters would be able to halt this process.

Edema↗
PubMed2003

Who should be taking the blood pressure?

Given the variability of blood pressure, it is often difficult to make a diagnosis of hypertension or to evaluate the effect of treatment on the basis of single blood pressure readings in the office. To obtain multiple measurements one can either turn to ambulatory blood pressure monitoring or have the patient take his or her own pressure. Both approaches require the availability of reliable, validated devices. Currently, only some instruments which measure blood pressure oscillometrically at the upper arm can be recommended for self-measurements. Studies are in progress to assess the prognostic significance of self-measured blood pressure data.

Automation↗
PubMed2002

['Survival of the fittest': effect of regular physical exercise on health and life expectancy].

According to the 'Australian burden of disease study', physical inactivity appears to be a leading risk factor in the population at large, accounting for no less than 6.7% of the total loss of disability-adjusted life years. In women it is even the most important risk factor. Regular physical mobility and exercise can reduce this negative influence. The effects are: improvement of cardiovascular fitness, prevention of coronary events, and the reduction of excess mortality. The mortality risk may be reduced by 47% by physical activity, depending on the energy expenditure. Especially the studies of the last two years have so convincingly proven a robust effect of daily physical exercise that on this point permissiveness is no longer acceptable in the advice to the population at large.

Cardiovascular Diseases↗
PubMed2002

Prognostic value of blood pressure in acute stroke.

Manipulation of blood pressure (BP) in acute stroke may improve outcome. Despite various studies, data on the prognostic significance of early BP in stroke remain unclear. Therefore, we studied the relationship between various BP variables in the acute phase of stroke and functional outcome at 3 months. Blood pressures were collected by reviewing BP records of 817 patients who were admitted to our stroke unit between 1987 and 1992. Besides the first systolic and diastolic admission BP (SBP and DBP), we also used the mean of the daytime as well as the night-time systolic and diastolic BP values. Finally, we studied the relationship between the decrease in BP between day 0 and 4 and outcome. As dependent outcome variable we used the Rankin handicap score at 3 months dichotomized in a score >3 (poor outcome) vs a score 3 (good outcome). A total of 430 patients were admitted within 24 h following stroke onset. There was no significant relationship between the systolic and diastolic BP and the outcome at 3 months. Only night-time systolic BP 165 mm Hg (odds ratio (OR) 2.8; 95% CI 1.1-6.8), night-time diastolic BP 60 mm Hg (OR 8.1; 95% CI 1.1-58.3), and a decrease in daytime diastolic BP between day 0 and 4 of 10 mm Hg (OR 3.0; 95% CI 1.1-7.9) showed a significant relationship with poor outcome. Our findings suggest that admission BP values may not reliably reflect any impact of BP on stroke outcome. They also suggest a potential differential effect of BP manipulation: increasing or decreasing BP may be beneficial for patients with BP extremes in one direction, but detrimental for those with BP values in the opposite direction.

Adult↗
PubMed2002

Renovascular disease in patients with hypertension: detection with duplex ultrasound.

The aim of this study was to evaluate the accuracy of duplex ultrasound for the diagnosis of renovascular disease in a cohort of hypertensive patients. In 78 patients suspected of renovascular hypertension on clinical grounds duplex ultrasound examination of the renal arteries was performed. Renal angiography was used as the standard of reference. Duplex ultrasound was inconclusive in 11 kidneys (7%). None of the supernumerary renal arteries was detected with duplex ultrasound. The overall prevalence of significant renovascular disease (> or =50% stenosis) was 20%. Based on the combination of parameters at thresholds commonly applied in current literature: ie PSV(max) >180 cm/sec and RAR >3.5 the overall sensitivity of duplex ultrasound for detection of haemodynamically significant renovascular disease was 50.0% with a specificity of 91.3% (PPV: 87.9%; NPV: 59.1). Lowering the thresholds for both parameters improved the test results at the cost of a significant increase of false positive examinations. In a population of hypertensive patients clinically suspected of renovascular hypertension, only limited results for duplex ultrasound could be acquired in the detection of renovascular disease. This result, in combination with the wide range of sensitivities and specificities published in international literature and the relatively large number of incomplete examinations does not support the general application of duplex ultrasound as a screening procedure for detection and assessment of renovascular disease.

Adult↗
PubMed2002

Short-term cortisol infusion in the brachial artery, with and without inhibiting 11 beta-hydroxysteroid dehydrogenase, does not alter forearm vascular resistance in normotensive and hypertensive subjects.

BACKGROUND: Vascular tone is increased in primary hypertension, and glucocorticoids affect vascular tone. Local cortisol availability is modulated by activity of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD). As this activity may be decreased in patients with primary hypertension, vascular sensitivity to cortisol may be increased in these patients. We studied the acute effect of cortisol on forearm vascular resistance (FVR) by infusing cortisol directly into the brachial artery, both with and without inhibition of 11 beta-HSD, in normotensive and hypertensive subjects. DESIGN: Twenty normotensive volunteers and 20 patients with primary hypertension participated in the study. After a 10-min infusion of vehicle (glucose 5%), cortisol was infused into the brachial artery in three stepwise increasing doses (3.5, 10.5 and 35 microg per 100 mL of forearm volume), each for 10 min. Next, the participants received placebo or 500 mg glycyrrhetinic acid (GA) orally, and 150 min later the same infusion schedule was repeated. Forearm vascular resistance was measured during the last 5 min of the infused vehicle and of each dose. Arterial and forearm venous plasma samples for measurement of cortisol and cortisone were taken at the end of the infusions of glucose 5% and the highest cortisol dose. RESULTS: In both normotensive and hypertensive subjects, neither the infusion of cortisol nor the administration of GA changed FVR. Also 2 h after the cortisol infusion there remained no change in FVR in both the normotensive and hypertensive groups who received placebo. Following the infusion of the highest cortisol dose, total plasma cortisone levels in the venous plasma were decreased compared with levels in the arterial plasma (36 +/- 3 and 49 +/- 4 nmol L-1, respectively, P < 0.05). The protein-bound venous cortisone was 37.1 +/- 4.8 nmol L-1 during the vehicle compared with 23.9 +/- 3.7 nmol L-1 during the cortisol infusion (P < 0.01), whereas the free cortisone level was not altered by the cortisol infusion. CONCLUSIONS: In both normotensive and hypertensive subjects, high-dose cortisol infusion both with and without 11 beta-HSD inhibition did not change FVR either immediately or after 2 h. We could not demonstrate in vivo 11 beta-HSD activity in the forearm vascular tissues. When binding of cortisone to CBG is changed, e.g. during cortisol infusion, arterio-venous changes in cortisone cannot reliably be used to assess (alterations in) local 11 beta-HSD activity.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed2001

Diagnostic tests for renal artery stenosis in patients suspected of having renovascular hypertension: a meta-analysis.

PURPOSE: To summarize and compare the validity of computed tomography angiography, magnetic resonance angiography, ultrasonography, captopril renal scintigraphy, and the captopril test for diagnosis of renal artery stenosis in patients suspected of having renovascular hypertension. DATA SOURCES: For each diagnostic modality, published studies were identified by MEDLINE literature searches. STUDY SELECTION: Original studies were selected if they met the following criteria: 1) suspicion of renovascular hypertension was the indication for the test; 2) intra-arterial x-ray angiography was used as the gold standard; 3) a cutoff point for a positive test result was explicitly defined; and 4) absolute numbers of true-positive, false-negative, true-negative, and false-positive results were available or could be derived from the presented data. DATA EXTRACTION: A standard form was used to extract relevant data. DATA SYNTHESIS: Data on the accuracy of the different diagnostic methods were analyzed and compared by constructing summary receiver-operating characteristic (ROC) curves and by computing areas under the summary ROC curves. RESULTS: Although accuracy varied greatly for all diagnostic modalities, summary ROC curves found that computed tomography angiography and gadolinium-enhanced, three-dimensional magnetic resonance angiography performed significantly better than the other diagnostic tests. CONCLUSIONS: Computed tomography angiography and gadolinium-enhanced three-dimensional magnetic resonance angiography seem to be preferred in patients referred for evaluation of renovascular hypertension. However, because few studies of these tests have been published, further research is recommended.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2001

Prevention of ventilator-associated pneumonia by oral decontamination: a prospective, randomized, double-blind, placebo-controlled study.

UNLABELLED: Colonization of the intestinal tract has been assumed to be important in the pathogenesis of ventilator-associated pneumonia (VAP), but relative impacts of oropharyngeal, gastric, or intestinal colonization have not been elucidated. Our aim was to prevent VAP by modulation of oropharyngeal colonization, without influencing gastric and intestinal colonization and without systemic prophylaxis. In a prospective, randomized, placebo-controlled, double-blind study, 87 patients received topical antimicrobial prophylaxis (gentamicin/ colistin/vancomycin 2% in Orabase, every 6 h) in the oropharynx and 139 patients, divided over two control groups, received placebo (78 patients were studied in the presence of patients receiving topical prophylaxis [control group A] and 61 patients were studied in an intensive care unit where no topical prophylaxis was used [control group B]). Baseline characteristics were comparable in all three groups. Topical prophylaxis eradicated colonization present on admission in oropharynx (75% in study group versus 0% in control group A [p < 0.00001] and 9% in control group B patients [p < 0.00001]) and in trachea (52% versus 22% in A [p = 0.03] and 7% in B [p = 0.004]). Moreover, topical prophylaxis prevented acquired oropharyngeal colonization (10% versus 59% in A [p < 0.00001] and 63% in B [p < 0.00001]). Colonization rates in stomach and intestine were not affected. Incidences of VAP were 10% in study patients, 31% in Group A, and 23% in Group B patients (p = 0.001 and p = 0.04, respectively). This was not associated with shorter durations of ventilation or ICU stay or better survival. Oropharyngeal colonization is of paramount importance in the pathogenesis of VAP, and a targeted approach to prevent colonization at this site is a very effective method of infection prevention. KEYWORDS: cross infection, prevention and control; respiration, artificial, adverse effects; antibiotics, administration and dosage infection control methods; pneumonia, etiology, prevention and control; intubation, intratracheal, adverse effects

Administration, Topical↗
PubMed2001

Non-pregnant circulatory volume status predicts subsequent pregnancy outcome in normotensive thrombophilic formerly preeclamptic women.

BACKGROUND: Preeclampsia seems to be superimposed upon a preexisting hemodynamic, hemostatic, autoimmune or metabolic disorder. We tested the hypothesis that in normotensive thrombophilic formerly preeclamptic subjects, the non-pregnant circulatory volume status predicts the development of subsequent hypertensive pregnancy and/or fetal growth restriction. METHODS: In 250 non-diabetic formerly preeclamptic women and 15 normal parous controls, we measured and calculated the following variables at least 5 months postpartum at day 5 (+/-2) of the menstrual cycle: mean arterial pressure, body mass index, plasma volume and the clotting function. In the subsequent pregnancy we determined, birth weight, birth-weight centile and the incidence of preterm birth, fetal growth restriction, pregnancy-induced hypertension, preeclampsia and HELLP-syndrome. We only included in the final analysis normotensive subjects with a thrombophilic phenotype at the time of the pre-pregnant screening, who had a subsequent singleton pregnancy, ongoing beyond 16 weeks gestation within 1 year after pre-pregnant evaluation. As a consequence, 23 formerly preeclamptic women and 12 controls were eligible for final analysis. The thrombophilic formerly preeclamptic participants received aspirin in combination with low-molecular-weight heparin throughout pregnancy. If thrombophilia was diagnosed on the basis of hyperhomocysteinemia, the treatment consisted of aspirin, pyridoxine and folic acid, instead. RESULTS: Among 250 formerly preeclamptic 131/250 (52%) had a normotensive thrombophilic phenotype. Only 23 (18%) of these 131 participants had an ongoing pregnancy within 1 year. They were allocated to subgroup THROMB. None of the controls had hypertension or thrombophilia. In contrast, 12/15 (80%) controls had an ongoing pregnancy within a year. The observations in the THROMB subgroup were compared with those in the control group. None of the baseline demographic and blood pressure variables differed between THROMB and controls. With respect to pregnancy outcome, the incidence of the following pregnancy complications were observed in THROMB subjects: preterm birth: 9%, pregnancy-induced hypertension: 44%, preeclampsia: 13%, HELLP-syndrome: 13%, and fetal growth restriction: 30%. A low non-pregnant plasma volume was found to predispose for hypertensive complications in a subsequent pregnancy. CONCLUSION: Pre-pregnant plasma volume in normotensive thrombophilic formerly preeclamptic women have predictive value with respect to hypertensive complications in the subsequent pregnancy.

Aspirin↗