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L Thijs

Publications and source records attributed to L Thijs.

144 records · Page 8Linked to original sources
PubMed1991

An inventory of studies on ambulatory blood pressure in large groups of subjects.

We made an inventory of 19 studies that have been or are being undertaken to better characterize the distribution of ambulatory blood pressure in the population at large or in larger groups of individuals selected from the population. No study was without some degree of selection in the recruitment of its subjects, but none of the subjects was selected or excluded on the basis of ambulatory blood pressure. These studies could provide the data required to define more precise, age- and sex-specific, diagnostic criteria for ambulatory blood pressure measurement in day-to-day clinical practice.

Blood Pressure↗
PubMed1991

Age-related hypotensive effect of placebo and active treatment in patients older than 60 years. European Working Party on High Blood Pressure in the Elderly.

Elderly hypertensive patients were randomly assigned to active treatment (n = 365) or placebo (n = 377). The effects of treatment on blood pressure were calculated by subtracting pretreatment blood pressure from the blood pressure at 3 months. In the two treatment groups, the decrease in systolic and diastolic pressures was more pronounced in older patients. However, the slopes of blood pressure change with age were not significantly different in the two treatment groups: systolic, -0.47 and -0.37 mm Hg/year in the active-treated and placebo patients, respectively; diastolic, -0.26 and -0.15 mm Hg/year, respectively. Thus, proving that an observed age-related hypotensive effect is caused by a particular drug requires comparison with a control group on placebo.

Aged↗
PubMed1991

Ambulatory blood pressure monitoring in clinical trials.

Monitoring ambulatory blood pressure, instead of taking pressure readings in hospital, avoids the so-called white-coat effect and allows more readings to be obtained over a longer period of time. It improves the accuracy of the blood pressure estimate and increases the statistical power of therapeutic trials for hypertension. Subjects with white-coat or office hypertension can be detected by ambulatory blood pressure monitoring and excluded from clinical trials. In 23 studies, including a total of 3304 normotensive subjects, the 24-h ambulatory blood pressure averaged 118/72 mmHg; the daytime and night-time pressures were 123/76 mmHg and 106/64 mmHg, respectively. If the mean plus two standard deviation (s.d.) interval is considered the upper limit of normal, the meta-analysis suggested that hypertension may be suspected if the 24-h pressure exceeds 129/87 mmHg, or if the daytime or night-time pressures are higher than 146/91 mmHg or 127/79 mmHg, respectively. On balance, most studies suggest that placebo effects on blood pressure are not observed when blood pressure is measured with ambulatory recorders. If confirmed, this observation indicates that it is possible to simplify the design of trials in the field of hypertension. Ambulatory blood pressure readings should be obtained with properly validated monitors. If the recordings are of sufficient quality, editing does not increase the precision of the subsequent statistical analyses. The statistical analyses should account for diurnal rhythms, and subject and treatment effects.

Antihypertensive Agents↗
PubMed1990

Age-related effects of placebo and active treatment in patients beyond the age of 60 years: the need for a proper control group.

The age-related response to placebo and active antihypertensive treatment was evaluated in 742 elderly hypertensive patients who were followed in the double-blind placebo-controlled trial conducted by the European Working Party on High blood pressure in the Elderly (EWPHE). In the two treatment groups, the fall in systolic and diastolic blood pressures after 3 months was negatively correlated with age (P less than 0.02), indicating that the hypotensive effect of placebo and active treatment was more pronounced in older patients. Further comparison of the two treatment groups failed to demonstrate any statistical differences in the slopes of the hypotensive effect on age. These conclusions were not altered by cumulative adjustments for baseline blood pressure, pulse rate, serum creatinine and the presence of cardiovascular complications at entry. In conclusion, in the present study, a similar blood-pressure-lowering action which increased with age was observed on active and placebo treatment; thus, proof that an observed age-related hypotensive effect is caused by a particular drug requires comparison with a control group on placebo.

Aged↗
PubMed1990

Reference values for ambulatory blood pressure: a meta-analysis.

The aim of the present study was to perform a meta-analysis of published studies in an attempt to determine the mean and range of normal ambulatory blood pressure. Twenty-two studies, including a total of 2638 subjects, were reviewed. Most studies were compatible with a mean 24-h ambulatory pressure in the range of 115/70-120/75 mmHg, a mean daytime pressure of 120/75-125/80 mmHg and a mean night-time pressure of 105/60-110/65 mmHg. With weighting for the number of subjects included in the individual studies, the 24-h ambulatory pressure averaged 117/72 mmHg, the daytime pressure 122/77 mmHg and the night-time pressure 106/64 mmHg. The night:day pressure ratio averaged 0.87 for systolic and 0.83 for diastolic pressure, ranging from 0.79 to 0.92 and from 0.75 to 0.90, respectively, across the individual studies. With the mean +/- 2 standard deviation intervals in the various studies taken as normal, the range of normality averaged 97/57-137/87 mmHg over 24 h, 101/62-143/91 mmHg for the daytime pressure and 86/48-127/79 mmHg for the night-time pressure. Until the results of prospective studies on the relationship between ambulatory blood pressure and the incidence of cardiovascular morbidity and mortality become available, these estimates of normal ambulatory pressure could be applied as reference values in clinical practice.

Adolescent↗
PubMed1990

Evidence for a curvilinear relation between blood pressure and urinary sodium in men.

With the use of a linear model, the relation between urinary sodium and blood pressure has been reported to be positive, non-significant, or negative. The hypothesis that this relationship is more complex than linear was investigated in two different study populations, which were independently recruited and examined by different observers. In 1,071 men randomly selected from the general population and in an unrelated sample of 1,209 military men, systolic and diastolic blood pressure were correlated with urinary sodium following a model, which included both the linear and quadratic terms of urinary sodium. In both groups of men, these second order models, adjusted for age and body mass index, provided a better fit (P less than 0.05) than the relationships with only the linear term of urinary sodium. The quadratic models explained from 0.35 to 1.10% of the blood pressure variance. Third order models, which in addition included the cubic term of urinary sodium, did not further improve the correlations between systolic and diastolic blood pressure and urinary sodium in men. In 1,010 women drawn from the general population and in 499 military women, neither the first nor the second order correlations between systolic and diastolic blood pressure and urinary sodium were statistically significant. In conclusion, the present results, reproducible in two different study populations, suggest that a second order model is more appropriate than a simple linear correlation to describe the weak relationship between blood pressure and urinary sodium in men. However, recommendations for the prevention of hypertension must not be changed, until the present findings are confirmed by intervention studies.

Adolescent↗
PubMed1989

Isolated systolic blood pressure elevation in the elderly: mechanisms, risk, and the need for further studies.

Isolated systolic hypertension (ISH) is generally defined as a systolic pressure of 160 mm Hg or more, with a diastolic pressure cutoff point below 95 mm Hg in some studies and 90 mm Hg in others. Its prevalence and incidence vary from 3 to 30% depending on the definition applied, methodology of measurement, as well as the population and the age and sex of the patient. Mechanisms that could lead to the development of isolated systolic hypertension are discussed, especially the role of atherosclerosis. The risks of systolic hypertension on mortality and morbidity in the elderly are considered. The need for further studies to quantify the risk and the effect of treatment is emphasized. The Syst-Eur trial enters patients above the age of 60 years with a diastolic pressure below 95 mm Hg and a systolic of 160 mm Hg or more. The study is a double-blind, placebo-controlled trial and the main purpose is to examine the influence of ISH on morbidity, mortality, and general well-being. Investigation of blood pressure variation over 24 h and its relationship to morbidity and use for planning treatment will be incorporated. Other centers are invited to join in the enlarging project.

Adult↗
PubMed1989

Converting enzyme inhibitors in the treatment of elderly hypertensives.

Angiotensin-converting enzyme inhibitors are gaining acceptance as safe and effective agents for treatment of hypertension. Addressed in this review of the available literature are the questions whether they are effective in lowering blood pressure in the elderly, whether their effects are age-related, and what effects, if any, do they have on morbidity and mortality in geriatric hypertension.

Aged↗
PubMed1981

Clinical and experimental studies on electromechanical dissociation.

Electromechanical dissociation (EMD) is the most frequent cause of unsuccessful cardiac resuscitation in critically ill patients. In a clinical study of cardiac arrest, including 54 episodes in 50 fully monitored patients, 14 episodes of ventricular fibrillation were observed and seven were reversed. In the remaining 40 instances, 36 cases of EMD were initially observed. Four patients had asystole. None of the patients with EMD or asystole were successfully resuscitated. For objective study of EMD and its treatment, we developed an experimental model in which ventricular fibrillation was induced in mechanically ventilated dogs. EMD was predictably observed when, after an interval of 120 seconds, ventricular fibrillation was reversed with an external countershock. Neither metabolic acidosis nor metabolic alkalosis modified the incidence of EMD. A few dogs were pretreated with glucose-insulin-potassium or pharmacologic doses of methylprednisolone, but this did not clearly reduce the incidence of EMD. However, the onset of EMD was delayed when the body temperature of the animal was spontaneously reduced.

Aged↗
PubMed1981

Use of methylprednisolone in patients following acute myocardial infarction. Hemodynamic and metabolic effects.

Hemodynamic and metabolic effects of methylprednisolone were investigated in a double-blind study of 28 patients with acute myocardial infarction (AMI), confirmed by unequivocal electrocardiographic and enzyme changes. Measurements were performed prior to and at 1.5, 3, 4, 4.5, 12 and 24 hours following infusion of methylprednisolone (13 patients) or placebo (15 patients). Although systemic vascular resistance decreased from 1,750 to 1,420 dynes . sec . cm-5 (p less than .001) and cardiac index increased from 2.77 to 3.10 L/min/m2 (p less than .02) between 0 and 4.5 hours, an abnormal increase in blood lactate was observed in 10 of the 13 patients following administration of methylprednisolone (3.0 vs 1.2 mM/L, p less than .001). Lactate elevation appeared one hour after infusion of methylprednisolone, was maximal at 12 hours, and persisted for more than 24 hours. There was no significant change in blood lactate in placebo treated patients. A transient but significant decrease in plasma volume was also observed following infusions of methylprednisolone. The elevation of blood lactate could not be explained by the reduction in plasma volume since the most striking increases in lactate were observed 12 hours following the initial infusion of methylprednisolone when the plasma volume was returning to the control value. No significant differences in other hemodynamic or metabolic parameters, infarct size or patient survival were observed between the two groups. We conclude that the hemodynamic benefits of glucocorticoids characterized by increased cardiac output and lowered systemic vascular resistance are counterbalanced by the potentially unfavorable conditions of lactate elevation and volume depletion.

Adult↗
PubMed1980

Effects of methylprednisolone on P50, 2,3 diphosphoglycerate and arteriovenous oxygen difference in acute myocardial infarction.

In a double-blind randomized study, 30 mg/kg of methylprednisolone sodium succinate (MPN) or 15 mg/kg of mannitol placebo (PL) were infused in 28 patients after acute myocardial infarction. Measurements were obtained immediately before and after for 24 hours after the initial infusion. The partial pressure of oxygen at 50% saturation of hemoglobin (P50) did not change significantly in vitro or in vivo after MPN, whereas 2,3 diphosphoglycerate (2,3 DPG) increased from 13.2 to 14.2 mumol/g Hb (p < 0.05) in the group receiving PL. The arteriovenous oxygen difference (Ca-VO2) remained constant after MPN or PL. The cardiac index (CI) increased after MPN (p < 0.02) associated with an increase in the oxygen consumption index (CI X A-V O2) from 146 to 170 ml/min/m2 (p < 0.05). These data show that MPN increases CI after acute myocardial infarction, but has no specific effects on P50, 2,3 DPG or Ca-VO2.

Adult↗
PubMedDate not supplied

Subgroup and per-protocol analysis of the randomized European Trial on Isolated Systolic Hypertension in the Elderly.

BACKGROUND: In 1989, the European Working Party on High Blood Pressure in the Elderly started the double-blind, placebo-controlled, Systolic Hypertension in Europe Trial to test the hypothesis that antihypertensive drug treatment would reduce the incidence of fatal and nonfatal stroke in older patients with isolated systolic hypertension. This report addresses whether the benefit of antihypertensive treatment varied according to sex, previous cardiovascular complications, age, initial blood pressure (BP), and smoking or drinking habits in an intention-to-treat analysis and explores whether the morbidity and mortality results were consistent in a per-protocol analysis. METHODS: After stratification for center, sex, and cardiovascular complications, 4695 patients 60 years of age or older with a systolic BP of 160 to 219 mm Hg and diastolic BP less than 95 mm Hg were randomized. Active treatment consisted of nitrendipine (10-40 mg/d), with the possible addition of enalapril maleate (5-20 mg/d) and/or hydrochlorothiazide (12.5-25 mg/d), titrated or combined to reduce the sitting systolic BP by at least 20 mm Hg, to below 150 mm Hg. In the control group, matching placebo tablets were employed similarly. RESULTS: In the intention-to-treat analysis, male sex, previous cardiovascular complications, older age, higher systolic BP, and smoking at randomization were positively and independently correlated with cardiovascular risk. Furthermore, for total (P = .009) and cardiovascular (P = .09) mortality, the benefit of antihypertensive drug treatment weakened with advancing age; for total mortality (P = .05), the benefit increased with higher systolic BP at entry, while for fatal and nonfatal stroke (P = .01), it was most evident in nonsmokers (92.5% of all patients). In the perprotocol analysis, active treatment reduced total mortality by 24% (P = .05), reduced all fatal and nonfatal cardiovascular end points by 32% (P<.001), reduced all strokes by 44% (P = .004), reduced nonfatal strokes by 48% (P = .005), and reduced all cardiac end points, including sudden death, by 26% (P = .05). CONCLUSIONS: In elderly patients with isolated systolic hypertension, stepwise antihypertensive drug treatment, starting with the dihydropyridine calcium channel blocker nitrendipine, improves prognosis. The per-protocol analysis suggested that treating 1000 patients for 5 years would prevent 24 deaths, 54 major cardiovascular end points, 29 strokes, or 25 cardiac end points. The effects of antihypertensive drug treatment on total and cardiovascular mortality may be attenuated in very old patients.

Aged↗
PubMedDate not supplied

Ambulatory blood pressure of adults in Novosibirsk, Russia: interim report on a population study.

OBJECTIVE: To describe the distributions of the ambulatory blood pressure in a sample drawn from the Siberian population. METHODS: In the European Project On Genes in Hypertension (EPOGH), a random population sample of 162 persons (72 men and 90 women) was investigated in Novosibirsk, Russia. Mean age (+/-SD) was 40.6+/-15.3 years. Validated oscillometric 90207 SpaceLabs monitors were programmed to obtain ambulatory blood pressure readings at intervals of 15min from 0800h to 2200h and at 30min intervals from 2200h to 0800h. Daytime and nighttime were defined using short fixed-clock time intervals, which ranged from 1000h to 2000h and from midnight to 0600h, respectively. RESULTS: In the 162 participants, of whom 54 were hypertensive, 24-h clocktime day and clocktime night blood pressures averaged 120/73, 126/79 and 110/60mmHg, respectively. Compared with daytime values, blood pressures at the clinic were 5.7/1.1mmHg lower in 108 normotensive people, but 17.0/13.1mmHg higher in 54 hypertensive patients. In the normotensive subgroup, the 95th percentiles of the 24-h clocktime day and clocktime night blood pressures were 128/81, 136/86 and 118/72mmHg, respectively. CONCLUSION: In comparison with other population surveys, the present interim report on the EPOGH study produced consistent results with respect to the distributions of the ambulatory measurements both in normotensive subjects and in the overall study population.

Adolescent↗
PubMedDate not supplied

[Syst-Eur study: analysis of the benefits of nitrendipine in hypertensive type 2 diabetics].

OBJECTIVE: To demonstrate that nitrendipine reduces the morbimortality of elderly type 2 diabetic patients with isolated systolic hypertension. METHODOLOGY: New analyses of the 547 type 2 diabetics patients with isolated systolic hypertension (160 < PAS < 219: PAD < 95 mmHg), included in the international Syst-Eur trial, with an average follow-up of 2 years. Type 2 diabetes is defined according to the 1998 WHO guidelines: a fasting glycemia level, > or = 126 mg/dl and a post-prandial glycemia > or = 200 mg/dl. RESULTS: Nitrendipine as a first line treatment provides better protection against fatal and no fatal cardiovascular events compared with placebo. The risk reduction of cardiovascular mortality is 70% (IC 95%: -89/-18; p = 0.01), 61% (IC 95%: -79/-29; p = 0.001) for fatal and non fatal cardiovascular events, 65% (IC 95%: -86/-10; p = 0.02) for fatal and non fatal stroke and 61% (IC 95%: -83/-11; p = 0.02) for fatal and non fatal cardiac events. Therefore, nitrendipine as a first line treatment, reduces significantly cardiovascular events, strokes and cardiac events (p = 0.02; p = 0.007; p = 0.009; p = 0.04, respectively) in the diabetic group versus the no diabetic group, with a big trend (p = 0.07) for total mortality. Nitrendipine was well tolerated by this population. CONCLUSION: These results demonstrate the benefits of nitrendipine as a first line treatment in type 2 diabetic hypertensive patients.

Antihypertensive Agents↗