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L Thijs

Publications and source records attributed to L Thijs.

At least 127 records · Page 7Linked to original sources
PubMed1992

Treatment of the older hypertensive: paradigms, practices, and proofs.

Recent outcome trials in patients above age 60 with systolo-diastolic hypertension are reviewed. The meta-analysis suggests that antihypertensive drug therapy can decrease cardiovascular and coronary mortality in selected patients. Based on these studies it is suggested that antihypertensive drug therapy is indicated in patients between age 60 and 75 when the diastolic pressure remains above 95 mmHg after repeated measurements. A target for systolic b.p. is not definitely established but a pressure of 150 mmHg may serve as a temporary proposal. Whether uncomplicated isolated systolic hypertension in symptomless patients should be treated is still under investigation.

Aged↗
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

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

Ambulatory blood pressure monitoring in elderly patients with isolated systolic hypertension.

OBJECTIVES: This study compared clinic and ambulatory blood pressure measurement and the reproducibility of these measurements in older patients with isolated systolic hypertension (ISH). PATIENTS: Eighty-seven patients aged greater than or equal to 60 years with ISH on clinic measurement were followed in the placebo run-in phase of the Syst-Eur trial. METHODS: Clinic blood pressure was defined as the mean of two blood pressure readings on each of three clinic visits (six readings in total). Ambulatory blood pressure was measured over 24 h using non-invasive ambulatory blood pressure monitors. RESULTS: Daytime ambulatory systolic pressure was, on average, 21 mmHg lower than the clinic blood pressure, whereas diastolic pressure was, on average, similar with both techniques of measurement. In the 42 patients who had repeat measurements, clinic blood pressure levels nad the amplitude of the diurnal blood pressure profile (fitted by Fourier analysis) were equally reproducible. However, both were less reproducible than ambulatory blood pressure levels. The repeatability coefficients, expressed as per cent of near maximum variation (four times the standard deviation of a given measurement), were 52% and 45% for the clinic systolic and diastolic pressures, 56% and 42% for the amplitude of the diurnal profile, and 29% and 26% for mean 24-h pressures. CONCLUSIONS: In older patients with ISH, clinic and ambulatory systolic blood pressure measurements may differ largely: the prognostic significance of this difference remains to be elucidated. Furthermore, in these patients the level of pressure is more reproducible by daytime ambulatory blood pressure measurement than by clinic measurement.

Aged↗
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

Mean and range of the ambulatory pressure in normotensive subjects from a meta-analysis of 23 studies.

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-hour BP in the range of 115 to 120/70 to 75 mm Hg, a mean daytime BP of 120 to 125/75 to 80 mm Hg, and a mean nighttime BP of 105 to 110/60 to 65 mm Hg. With weighting for the number of subjects included in the individual studies, the 24-hour BP averaged 118/72 mm Hg, the daytime BP 123/76 mm Hg, and the nighttime BP 106/64 mm Hg. 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 mm Hg for the 24-hour BP, 101 to 146/61 to 91 mm Hg for the daytime BP, and 86 to 127/48 to 79 mm Hg for the nighttime 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

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

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

Pulse rate and sodium intake interact to determine blood pressure. A population study.

It has been suggested that certain factors need to be present for the pressor effect of sodium to become apparent. The present population study investigated whether pulse rate (PR) and salt intake interact to determine blood pressure (BP). Twenty-four hour urinary sodium (UNaV) was used as a measure of salt intake. A random population sample, including 2081 subjects with a minimum age of 18 years, was stratified on tertiles of PR. In subjects with a slow PR(less than 68 beats/min) and in those with a fast PR (greater than 78 beats/min), a significant curvilinear relationship between BP and UNaV was found, while in subjects with an intermediate PR the BP-UNaV correlation was not significant. There was also a significant interaction between PR and UNaV, indicating that when UNaV increased from 160 to 300 mmol/24 h, systolic/diastolic BP rose by 2/1 mm Hg in the fast PR third, but declined by 1/1 mm Hg in the slow PR third. These divergent trends could not be explained by smoking habits or alcohol consumption and were still present after cumulative adjustment for other important correlates of BP, ie, gender, age, body weight, urinary potassium, and contraceptive pill intake in women. In conclusion, the present data suggest that in subjects with a pulse rate greater than 78 beats/min a high salt intake may be associated with blood pressure elevation, whereas the opposite tendency is observed in individuals with a pulse rate less than 68 beats/min.

Adolescent↗
PubMed1991

The effect of antihypertensive treatment on electrocardiogram voltages in the EWPHE trial.

Long-term effects of antihypertensive treatment on various electrocardiogram (ECG) voltages and the association between ECG findings at randomization and subsequent mortality were evaluated in the double-blind, placebo-controlled trial of elderly hypertensive patients, conducted by the European Working Party on High Blood Pressure in the Elderly (EWPHE). Patients were treated with a combination of hydrochlorothiazide and triamterene or matching placebo; methyldopa or placebo was added if blood pressures remained high. RaVL and SV1 + RV5 at randomization were related to systolic blood pressure (SBP) and RaVL was also related to diastolic blood pressure (DBP), after adjustment for age, gender, and body mass index (BMI). When adjusted for age and body mass index, the decreases in RaVL and SV1 + RV5 were not correlated with the changes in SBP after 1 year of active treatment but the decreases in SV1 + RV5 were positively related to the fall in DBP. After 4 years of active treatment, the fall in SBP was associated with decreases in RaVL and in SV1 + RV5, after adjustment for age and changes in BMI.

Aged↗
PubMed1991

Prognostic significance of exercise versus resting blood pressure in hypertensive men.

The outcome of 143 male hypertensive patients, investigated in the period 1972-1982, was ascertained in 1989 to determine if brachial artery pressure measured during a progressive graded exercise test on the bicycle ergometer is a better predictor of mortality and cardiovascular events than pressure at rest. During the total follow-up time of 1,573 patient years, 27 patients suffered at least one fatal or nonfatal cardiovascular event and 13 patients died. Using the Cox regression model, the age-adjusted relative hazard rates of systolic pressure at supine rest, at 50 W, at peak work load, and at 50% of peak exercise capacity were significant for total mortality (p less than or equal to 0.01) and for cardiovascular events (p less than or equal to 0.03). Pressure during exercise, however, did not significantly (p = 0.11-0.97) predict the outcome of the patients when age and pressure at rest were taken into account. The results were similar for diastolic pressure. In conclusion, intra-arterial pressures at rest and during submaximal and peak exercise significantly predict mortality and the incidence of cardiovascular events in hypertensive men, independent of age. However, there is no additional prognostic precision of the exercise pressures when age and the rest pressure are taken into account.

Adolescent↗
PubMed1991

Treatment of isolated systolic hypertension in the elderly.

Isolated systolic hypertension affects between 10 and 20% of the elderly population and carries a substantial risk of cardiovascular complications. As no prospective, randomized trials have produced scientific evidence of a treatment benefit in elderly patients with isolated systolic hypertension, opinion on when and how to treat this condition differs among expert committees as well as among individual doctors. This article reviews the present treatment policies in patients with isolated systolic hypertension. It describes the ongoing intervention studies that have been designed to examine the hypothesis that antihypertensive treatment confers a benefit to elderly patients with isolated systolic hypertension in terms of a reduced morbidity and mortality. The Syst-Eur trial, which was recently initiated by the European Working Party on High Blood Pressure in the Elderly, is described in greater detail.

Aged↗
PubMed1991

Reference values for the ambulatory blood pressure and the blood pressure measured at home: a population study.

In order to determine reference values for the ambulatory blood pressure, a population sample of 328 subjects, aged 20-81 years, who reported themselves to be in good health, was investigated. The ambulatory blood pressure was recorded over 24 h, taking measurements at 20 min intervals from 8 am to 10 pm, and at 45 min intervals from 10 pm to 8 am. Blood pressure was also measured by trained observers on each of two separate home visits (5 readings per visit). The ambulatory blood pressure in the 328 subjects averaged 118/71 mmHg over 24 h, 124/76 mmHg during the day (10 am-8 pm), and 108/62 mmHg at night (0 am-6 am). Blood pressure measured by an observer at the occasion of the second home visit was 4/5 mmHg lower (P less than 0.001) than the daytime ambulatory blood pressure. The 95th centiles for the daytime ambulatory pressures were 144/95 mmHg in 85 men below age 50; 154/90 mmHg in 74 men aged greater than or equal to 50 years; 132/85 mmHg in 96 women below age 50; and 151/91 mmHg in 73 women aged greater than or equal to 50 years. The 95th centiles for the nighttime pressures in these four sex-age groups were 124/79, 140/83, 121/70, and 132/72 mmHg, respectively.

Adult↗
PubMed1991

Methods for describing the diurnal blood pressure curve.

Ambulatory blood pressure recordings supply information on the blood pressure variation during habitual daily activities and sleep. Whether the circadian blood pressure curve is modulated by an endogenous clock or whether the diurnal fluctuations in blood pressure are mainly or exclusively determined by the pattern of activity remains disputed. Whatever the underlying mechanism, most experts agree that it still remains to be ascertained whether the blood pressure profile can help in unraveling the pathophysiology of hypertension and determining a subject's cardiovascular risk. The methods for parametrizing the diurnal blood pressure curve in individual subjects, summarized in this article, may provide summary statistics for larger groups of individuals or for the population at large.

Activities of Daily Living↗