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J Staessen

Publications and source records attributed to J Staessen.

At least 73 records · Page 4Linked to original sources
PubMed1992

The diurnal blood pressure profile. A population study.

This population study included 399 subjects, of whom 370 (93%) showed a significant diurnal blood pressure (BP) rhythm. The nocturnal BP fall was normally distributed and averaged 16 +/- 9 mm Hg systolic and 14 +/- 7 mm Hg diastolic (mean +/- SD). The amplitude of the diurnal BP curve followed a positively skewed distribution, with a mean of 16 +/- 5 mm Hg for systolic BP and 14 +/- 4 mm Hg for diastolic BP. The daily BP maximum occurred at 15:54 +/- 4:47 for systolic BP and at 15:11 +/- 4:20 for diastolic BP. Thirty-four subjects were reexamined after a median interval of 350 days. The test for the presence of a significant diurnal rhythm was discordant in only two subjects. Repeatability (twice the standard deviation of the differences between paired recordings expressed as a percentage of the mean) varied from 11 to 25% for the 24 h, daytime, and overnight BP, and from 76 to 138% for the parameters describing the diurnal BP rhythm. In nine subjects with an initial night/day ratio of mean BP less than 0.78, the nighttime BP was significantly increased at the repeat examination, whereas the opposite tendency was observed in nine subjects with an initial ratio greater than 0.87. In conclusion, the distribution of the nocturnal BP fall is unimodal. The reproducibility of the ambulatory BP is satisfactory for the level of BP and for the presence of a diurnal BP rhythm, but not for the parameters of the diurnal BP curve. Thus, one 24 h recording is insufficient to fully characterize an individual's diurnal BP profile.

Adult↗
PubMed1992

Erythrocyte membrane lipids and cationic transport systems in men.

OBJECTIVE: The relationship between erythrocyte membrane and plasma lipids and various transmembrane erythrocyte cationic fluxes was examined in 53 normal men. DESIGN: Different measurements of erythrocyte transport systems were obtained: Na(+)-Li+ countertransport activity; Na+, K+ cotransport activity; Na+, K(+)-ATPase pump activity and the ground membrane permeability for Na+ and K+ as well as the intra-erythrocyte Na+, K+ and Mg2+ concentrations. Plasma cholesterol, triglycerides, phospholipids, free fatty acids, low- and high-density lipoprotein cholesterol levels and the erythrocyte membrane contents of cholesterol, phospholipids and free fatty acids were obtained from fasting subjects. RESULTS: In single regression analysis the erythrocyte Na(+)-Li+ countertransport and Na+, K+ cotransport activities were negatively related to the erythrocyte membrane cholesterol, phospholipids and free fatty acids contents. The Na+, K(+)-ATPase pump activity as assessed by the ouabain-sensitive Na+ efflux was also inversely related to the membrane cholesterol and phospholipids contents. In multiple regression analysis the red blood cell Na(+)-Li+ countertransport activity was independently and negatively related to the membrane cholesterol and free fatty acids contents. CONCLUSION: Our data show that an elevated level of erythrocyte membrane lipids in normal men is accompanied by lower Na(+)-Li+ countertransport, Na+, K+ cotransport and Na+, K(+)-ATPase pump activities.

Adult↗
PubMed1992

Syst-Eur--a multicenter trial on the treatment of isolated systolic hypertension in the elderly: first interim report.

Syst-Eur is a multicenter placebo-controlled outcome trial designed by the European Working Party on High Blood Pressure in the Elderly to investigate the effect of antihypertensive treatment on the incidence of stroke in elderly patients with isolated systolic hypertension (ISH). Eligible patients must be at least 60 years old and have a systolic blood pressure averaging 160-219 mm Hg with a diastolic blood pressure less than 95 mm Hg. The present paper is an interim report on the first 316 patients randomized into this trial. The placebo (n = 170) and active treatment (n = 146) groups were similar at randomization with respect to age (73 +/- 8 years; mean +/- SD), sitting blood pressure (178 +/- 12 mm Hg systolic; 85 +/- 7 mm Hg diastolic), percentage of men (34%), and percentage of patients with cardiovascular complications (29%). After randomization blood pressure fell more (p less than 0.001) in patients on active treatment than in those in the placebo group (19 +/- 20 mm Hg systolic; 6 +/- 10 mm Hg diastolic vs. 7 +/- 19 and 1 +/- 10 mm Hg for sitting blood pressure). This first interim report on the Syst-Eur trial demonstrates that a multinational trial in elderly patients with ISH is feasible and that a significant blood pressure difference between the two treatment groups can be achieved and maintained. New centers are being recruited in order to randomize a total of 3,000 patients.

Aged↗
PubMed1992

Comparison of the effect of celiprolol and nifedipine on blood pressure and plasma lipids.

During a double-blind, randomized study in hypertensive patients, changes in blood pressure (BP) and in plasma lipid and lipoprotein levels during treatment with celiprolol were compared with those occurring during nifedipine treatment. Fifty-three patients (28 men and 25 women) with mild-to-moderate hypertension, aged 20-64 years, were studied. After a 1-month placebo run-in period, patients were randomly assigned to receive either nifedipine (40 mg daily) or celiprolol (200 mg daily) each time using a double dummy technique. After 6 weeks, dosages of each drug could be doubled. Both drugs caused similar reductions in blood pressure but after 12 weeks treatment, the percentage of decrease in diastolic BP (DBP) was more pronounced (p less than 0.01) in the nifedipine group (-18%) than in the celiprolol group (-12%). After 6 weeks, there were no differences in plasma lipids between the two treatment groups. However, the changes after 12 weeks treatment were different (p less than 0.05) between the groups, leading to lower levels of plasma esterified cholesterol, low-density lipoprotein (LDL) cholesterol and apoprotein AI, AII, and B in the celiprolol group. Plasma lecithin cholesterol acyltransferase activity (LCAT) was not modified, suggesting that reverse cholesterol transport was not affected by the drugs. In both treatment groups, a significant positive relationship was observed between changes in LDL cholesterol and apoprotein B. As compared with nifedipine, celiprolol after 12-week therapy had a rather favorable plasma lipid profile. The clinical relevance of such findings, in terms of prevention of cardiovascular complications, has yet to be established.

Acyltransferases↗
PubMed1992

Determinants of serum zinc in a random population sample of four Belgian towns with different degrees of environmental exposure to cadmium.

This report investigated the distribution of serum zinc and the factors determining serum zinc concentration in a large random population sample. The 1977 participants (959 men and 1018 women), 20-80 years old, constituted a stratified random sample of the population of four Belgian districts, representing two areas with low and two with high environmental exposure to cadmium. For each exposure level, a rural and an urban area were selected. The serum concentration of zinc, frequently used as an index for zinc status in human subjects, was higher in men (13.1 mumole/L, range 6.5-23.0 mumole/L) than in women (12.6 mumole/L, range 6.3-23.2 mumole/L). In men, 20% of the variance of serum zinc was explained by age (linear and squared term, R = 0.29), diurnal variation (r = 0.29), and total cholesterol (r = 0.16). After adjustment for these covariates, a negative relationship was observed between serum zinc and both blood (r = -0.10) and urinary cadmium (r = -0.14). In women, 11% of the variance could be explained by age (linear and squared term, R = 0.15), diurnal variation in serum zinc (r = 0.27), creatinine clearance (r = -0.11), log gamma-glutamyltranspeptidase (r = 0.08), cholesterol (r = 0.07), contraceptive pill intake (r = -0.07), and log serum ferritin (r = 0.06). Before and after adjustment for significant covariates, serum zinc was, on average, lowest in the two districts where the body burden of cadmium, as assessed by urinary cadmium excretion, was highest. These results were not altered when subjects exposed to heavy metals at work were excluded from analysis.

Adult↗
PubMed1992

Factors influencing the cadmium body burden in a population study.

The cadmium body burden, as estimated from 24-h urinary cadmium (Cd-U), was determined in 1523 non-occupationally exposed subjects living in five areas of Belgium. It increased with age until 55-65 years in both sexes and thereafter decreased slightly. It was higher in smokers but was inversely associated with alcohol consumption and social class. In men only, it was also positively correlated with body mass index. After the menopause, women showed a significant increase in 24-h Cd-U independently of the other factors. In addition, the cadmium body burden was independently associated with place of residence in both sexes. Highest levels of Cd-U were found in subjects living in an area with soils heavily polluted by cadmium.

Adolescent↗
PubMed1992

Effects of cadmium exposure on the cardiovascular system and on calcium metabolism: results of a cross-sectional population study.

This paper summarizes the findings of the Cadmibel Study, a cross-sectional population study of the health effects of cadmium, but only with respect to the cardiovascular system and calcium metabolism. The study disproved the hypothesis that exposure to cadmium would lead to an increase in blood pressure and in the prevalence of hypertension and other cardiovascular diseases. On the other hand, there was a positive relationship between urinary cadmium (Cd-U) and both serum alkaline phosphatase activity and urinary excretion of calcium. The regression coefficients obtained after adjustment for significant co-variates indicated that, when Cd-U increased two-fold, serum alkaline phosphatase and urinary calcium rose by 4% and 0.25 mmol/24 h, respectively. These findings suggest that calcium metabolism is gradually affected as cadmium accumulates in the body. The morbidity associated with the latter phenomenon is still unknown, and requires further investigation, preferably in a longitudinal prospective population study, in which the incidence of morbid events would be monitored in relation to the cadmium body burden.

Adult↗
PubMed1992

Trials in elderly patients with isolated systolic hypertension.

The hypothesis that antihypertensive drugs should be prescribed to elderly patients with isolated systolic hypertension is being addressed in at least 3 trials: the Systolic Hypertension in the Elderly Program (SHEP) in the United States, a trial in China, and the Syst-Eur study in Europe. The SHEP trial has recently reported its final morbidity and mortality results. This article summarizes the protocol of the European study. To be eligible for the Syst-Eur trial, patients must be at least 60 years old and have a systolic blood pressure averaging 160-219 mmHg with a diastolic pressure less than 95 mmHg. Patients must give their informed consent and be free of major cardiovascular and non-cardiovascular diseases at entry. The patients are randomized into active treatment or placebo. Active treatment consists of nitrendipine (10-40 mg/d), combined with enalapril (5-20 mg/d) and hydrochlorothiazide (12.5-25 mg/d), as necessary. The control group received matching placebos. The drugs (or matching placebos) are stepwise titrated and combined in order to reduce systolic blood pressure by 20 mmHg at least to a level below 150 mmHg. Morbidity and mortality are monitored to enable an intention-to-treat and per protocol comparison of the outcome in the two treatment groups.

Aged↗
PubMed1992

Mean and range of the ambulatory pressure in normotensive subjects.

To perform a meta-analysis of published reports in an attempt to determine the mean and range of normal ambulatory blood pressure (BP), 23 studies including a total of 3,476 normal subjects were reviewed. Most studies were compatible with a mean 24-h BP in the range of 115-120/70-75 mmHg, a mean day time BP of 120-125/75-80 mmHg, and a mean night time BP of 105 to 110/60 to 65 mmHg. With weighting for the number of subjects included in the individual studies, the 24-h BP averaged 118/72 mmHg, the day time BP 123/76 mmHg, and the night time BP 106/64 mmHg. The night/day pressure ratio averaged 0.87 for systolic and 0.83 for diastolic BP, with ranges across the individual studies from 0.79 to 0.92 and from 0.75 to 0.90, respectively. If the mean +/- 2 standard deviation interval in the various studies was considered normal, the range of normality was on average 97 to 139/57 to 87 mmHg for the 24-h BP, 101 to 146/61 to 91 mmHg for the day time BP, and 86 to 127/48 to 79 mmHg for the night time BP. Until the results of prospective studies on the relation between the ambulatory BP and the incidence of cardiovascular morbidity and mortality become available, the aforementioned intervals, which summarize the experience of 23 investigators, could serve as a temporary reference for clinical practice.

Adolescent↗
PubMed1991

Blood pressure, the prevalence of cardiovascular diseases, and exposure to cadmium: a population study.

In a population study conducted from 1985 to 1989 in Belgium, the authors investigated whether exposure to cadmium is associated with blood pressure elevation and with an increased prevalence of cardiovascular diseases. The participants, aged 20-88 years, constituted a random sample of the households living in two low exposure areas (n = 803) and two high exposure areas (n = 1,283). For each exposure level, a rural and an urban district were selected. The cadmium levels in blood (8.5 vs. 11.0 nmol/liter) and urine (7.2 vs. 8.7 nmol/24 hours) were significantly (p less than 0.001) raised in the two high exposure areas compared with the two low exposure areas (p less than 0.001). Systolic pressure was similar in both rural areas, but in the urban area with high exposure systolic pressure was 5 mmHg (p less than 0.001) higher than in the control town. Diastolic pressure was similar in the four districts and the same was true for the prevalence of hypertension and of other cardiovascular diseases. Adjustment of systolic pressure for blood and urinary cadmium did not remove the difference in systolic pressure between both urban areas, suggesting that it was not related to the cadmium burden on the environment. Further analyses in individual subjects showed that neither blood pressure nor the presence of cardiovascular diseases were significantly and positively correlated with blood and urinary cadmium. Thus, the present population study did not confirm the hypothesis that increased exposure of the population to cadmium is associated with blood pressure elevation and with a higher prevalence of cardiovascular diseases.

Adult↗
PubMed1991

Relation of cardiac output at rest and during exercise to age in essential hypertension.

It has been suggested that the decline of cardiac output with age is due to increased prevalence of disease, particularly occult coronary artery disease. Therefore, the relation of cardiac output (direct oxygen Fick method) to age was analyzed in 110 sixteen- to 64-year-old men with World Health Organization stage I or II essential hypertension at the time of the hemodynamic study, who were alive and free of cardiovascular complications 7 years later. At supine and seated rest, during upright bicycle exercise at 50 W and and at peak work load, cardiac output was inversely (p less than 0.01) related to age. These relations were independent of weight and mean intraarterial pressure. Stroke volume decreased with advancing age at supine rest, but not at rest and during exercise in the seated position. Heart rate was not affected by age in the supine position, but was slower in older patients during upright rest and at peak exercise. In conclusion, in patients with essential hypertension who remained free of cardiovascular complications for 7 years, cardiac output was independently and inversely related to age at various levels of activity. These findings suggest that occult cardiovascular disease does not explain the decline in cardiac output with age in patients with essential hypertension.

Adolescent↗
PubMed1991

Review of the major hypertension trials in the elderly.

The different intervention trials in elderly hypertensives are compatible with the hypothesis that hypotensive drug treatment can decrease cardiovascular mortality mainly by decreasing cerebrovascular mortality. A decrease in the fatal and nonfatal cardiovascular event rate is mainly due to a decrease in cerebrovascular events. It is not established whether hypotensive drug treatment is advisable in symptomless patients with isolated systolic hypertension and in patients with uncomplicated hypertension above age 80. A sudden reduction in blood pressure should be avoided, but whether a progressive reduction of systolic blood pressure below 140 mmHg and of diastolic blood pressure below 85 mmHg is dangerous or advantageous remains to be established.

Aged↗
PubMed1991

Hormonal effects of the diuretic xipamide in healthy men.

The effect of xipamide on plasma alpha-atrial natriuretic peptide and the renin-aldosterone-kallikrein system have been studied in 12 healthy men, using a double-blind cross-over design. After a run-in period on placebo of 1 week, the subjects were treated with either placebo (n = 6) or xipamide 20 mg once daily (n = 6) for 16 weeks and were then switched to the alternative medication for another 16 weeks. The plasma concentration of alpha-atrial natriuretic peptide fell after 1 week of xipamide administration and increased during prolonged xipamide administration but remained reduced. The changes in plasma alpha-ANP observed after 1 week of xipamide were negatively correlated with the changes in hematocrit and hemoglobin. Plasma renin activity (PRA), aldosterone concentration (PAC), and urinary excretion of aldosterone and kallikrein increased after 1 week of xipamide administration, levelled off during the second and fourth weeks, but remained elevated during further prolonged xipamide administration for 16 weeks. The xipamide-induced changes in PRA and PAC were positively correlated with the changes in the hematocrit and hemoglobin. The changes in plasma renin, aldosterone, and alpha-atrial natriuretic peptide during xipamide administration may be related to diuretic-induced volume contraction.

Adult↗
PubMed1991

Is prevention of vascular dementia possible? The Syst-Eur Vascular Dementia Project.

Vascular dementia (VD) is the second most common cause of dementia in the elderly after Alzheimer's disease (AD). Prevalence estimates from community surveys indicate that, on average, 5% of persons over 65 and 15 to 20% of people over 80 suffer from "severe dementia". Clinico-pathological studies have shown that AD accounts for 50 to 60% of the cases and VD for about 10 to 20%; 20% of the patients have both disorders. The incidence rate of VD ranges from 7 per 1,000 person-years in normal volunteers to 16 per 1,000 person-years in subjects with risk factors for strokes, particularly high blood pressure. The only effective therapeutic approach to VD is the prevention of strokes, mainly through the treatment of hypertension; however, none of the therapeutic trials has included VD prevention as one of its treatment goals. Syst-Eur Study is a European placebo controlled trial which aims to determine whether morbidity and mortality are changed when elderly patients (60 years and over) with isolated systolic hypertension are treated. In this trial, the incidence of VD will be carefully recorded during the five year follow-up of the expected 3,000 patients. The present side project to the Syst-Eur trial will specifically address the following questions: does antihypertensive treatment reduce the incidence of VD?, and how do the cognitive functions of elderly patients change when treated with active or placebo treatment? The protocol is based on the administration of the MMS (Folstein) once a year to all patients. If the MMS score is 23 or less, a set of criteria will be used to establish the diagnosis of vascular dementia. A pilot study has demonstrated the feasibility of the trial. The main study is in progress.

Aged↗
PubMed1991

Mortality and treated blood pressure in patients of the European Working Party on High Blood Pressure in the Elderly.

Elderly hypertensive patients were randomly assigned to treatment with diuretics and methyldopa (n = 352) or placebo (n = 339), and divided into three groups, each according to their blood pressures, after nine months of treatment. Subsequently, 65 placebo patients and 56 treated patients died. A U-shaped relation was seen in treated patients between mortality and systolic blood pressure, and in placebo patients between mortality and diastolic blood pressure. Whereas in treated patients, the highest mortality was seen in patients with the lowest diastolic pressure, the lowest mortality was seen in the group with the highest diastolic pressure. The increased mortality in treated patients with the lowest blood pressure may not be drug-induced, but an expression of deterioration in general health, as indicated by the decreases in body weight and hemoglobin levels found in patients with the lowest blood pressures in previous analyses of these data.

Adult↗
PubMed1991

Isolated systolic hypertension in the elderly: an epidemiologic review.

Isolated systolic hypertension (ISH) is usually defined as a systolic blood pressure greater than or equal to 160 mm Hg and diastolic blood pressure less than 90 or 95 mm Hg. Systolic blood pressure has been found to increase with age in most populations studied and thus the prevalence of ISH can be expected to increase with age. ISH is more prevalent in elderly women than in elderly men. Estimates of the prevalence of ISH vary according to its definition and the number of blood pressure measurements. There is evidence that the prevalence of ISH is decreasing. Results of a survey of the prevalence of ISH in 11 countries are presented; the estimates among men aged 60 to 69 years ranged from 1% in Israel to 24% in Norway. Only a prospective standardized survey conducted in several countries will reveal the true prevalence of ISH.

Adult↗
PubMed1991

Does environmental exposure to cadmium represent a health risk? Conclusions from the Cadmibel study.

Cadmium is a very dispersive pollutant which has progressively accumulated in the environment mainly in the areas where nonferrous smelters have been in operation. An important toxicological feature of cadmium is its exceptionally long biological half-life in the human body. For the general population mainly exposed to cadmium by the diet and smoking, the kidney is the main target organ. Some studies have also suggested that cadmium might play a role in the pathogenesis of hypertension. A cross-sectional study (called Cadmibel) was undertaken to assess whether environmental pollution by cadmium in Belgium might represent a health risk. This paper does not present the detailed results of this study which are published elsewhere but simply report its main conclusions. A total number of 2327 subjects (stratified according to age and sex) was randomly sampled in two urban (Liège and Charleroi) and two rural (Hechtel-Eksel and Noorderkempen) areas, with different environmental pollution by cadmium. After allowing for the various factors known to influence cadmium accumulation, it was estimated that the cadmium body burden of the residents of the most polluted district (Noorderkempen) was 50 to 85% higher than in the less polluted areas. No statistical association was found between environmental exposure to cadmium and blood pressure elevation or the prevalence of cardiovascular diseases. However, the study has shown that the environmental exposure of the general population to cadmium may induce slight renal tubular dysfunction and may probably also affect cadmium homeostasis. The probability of tubular dysfunction (as assessed by sensitive tests) is about 10% when cadmium in urine reaches 2 micrograms/day. The morbidity associated with the changes in the renal proximal tubule and the calcium metabolism observed when the body burden of cadmium exceeds this value remains to be assessed.

Adult↗