Svendsen Tl

24-h ambulatory blood pressure in 352 normal Danish subjects, related to age and gender

UNLABELLED The study was conducted to determine age and sex stratified normal values for 24-h ambulatory blood pressure. A sample of 352 healthy subjects (all white) were randomly selected from the community register and stratified by sex and age groups in decades from 20 to 79 years of age. Persons with a history of hypertension, cerebral apoplexy, diabetes, myocardial or renal disease, and who were taking blood pressure-influencing medication were excluded. Ambulatory blood pressure was recorded over 24 h, with measurements taken every 15 min from 07:00 to 22:59, and every 30 min from 23:00 to 6:59. Systolic blood pressure increased only slightly with age and was significantly higher in men than in women. The diastolic blood pressure increased only slightly with age in both sexes until the 50 to 59 years age group and declined thereafter. The diastolic blood pressure was not different for the two sexes. Both systolic and diastolic blood pressure were approximately 15% lower during the night regardless of age or sex. Ambulatory blood pressure during the daytime was on an average of 5 mm Hg lower than office blood pressure, but the mean difference between the two measurements increased with age. The variability of the difference also increased with age. IN CONCLUSION Normal values for ambulatory blood pressure are presented in a randomly selected age- and gender-stratified population. Differences between office blood pressure and ambulatory blood pressure increased with age suggesting that the previously observed higher blood pressure seen in the elderly partly might be explained by a greater impact of white coat hypertension in older people.

Cardiovascular and adrenergic effects of cigarette smoking during immediate non-selective and selective beta adrenoceptor blockade in humans.

Abstract. The cardiovascular and adrenergic responses to cigarette smoking during acute selective and non‐selective beta adrenoceptor blockade were studied in seven young healthy volunteers in a double blind cross‐over fashion. Heart rate, arterial blood pressure, forearm blood flow and plasma levels of adrenaline and noradrenaline were determined before and during the terminal 5 min period of 15 min smoking test.

Adrenergic beta receptor blockade: Hemodynamic importance of intrinsic sympathomimetic activity at rest

Dose‐response curves for heart rate, cardiac output, arterial blood pressure, and pulmonary artery pressure were obtained in 37 patients with ischemic heart disease after intravenous administration of six increasing doses of propranolol, atenolol, practolol, pindolol, CPEP (1 ‐[2‐cyanophenoxy]‐3β‐[3‐phenylureido]‐ethylamino‐2‐propanol), and BMMP (1‐t‐butylamino‐3‐[2‐N‐methylcarbamoyl‐methoxyphenoxy]propan‐2‐ol‐hydrochloride). The doses were equipotent, as indicated by reduction in exercise‐induced tachycardia. The dose‐response curves for cardiac output and heart rate can be divided into three groups according to the degree of intrinsic sympathomimetic activity. One group without intrinsic sympathomimetic activity included propranolol and atenolol, which reduced cardiac output (about 26% to 28%) and heart rate (about 15% to 17%). A second group with moderate intrinsic sympathomimetic activity, represented by practolol and BMMP, induced less reduction in cardiac output (about 12% to 17%) and heart rate (about 7% to 10%). A third group with pronounced intrinsic sympathomimetic activity, represented by pindolol and CPEP, did not reduce cardiac output and heart rate. Mean systemic blood pressure was essentially unchanged even after the largest dose of any of the drugs. Mean pulmonary artery pressure rose after atenolol, propranolol, and BMMP but not after pindolol, CPEP, and practolol. Atenolol, BMMP, and practolol are beta‐1–selective drugs, it is concluded that the acute hemodynamic response to adrenergic beta receptor blocking drugs at rest is determined primarily by the degree of intrinsic sympathomimetic activity, whereas beta‐1 selectivity did not modify the central hemodynamic responses to beta adrenoceptor blockade.

Effect of labetalol on plasma noradrenaline and adrenaline in hypertensive man

SummaryInjection i. v. of labetalol, a new adrenergic alpha- and beta-blocking agent, decreased arterial blood pressure in 9 hypertensive subjects resting in the supine position, when standing and during supine exercise. Heart rate after labetalol was unchanged in the resting supine position, and it fell in the latter two conditions. Plasma noradrenaline concentration was higher after labetalol in all three experiments as compared to a control study. Plasma adrenaline after labetalol was increased only in the standing position, when the highest plasma noradrenaline concentrations were observed. Blood glucose concentration tended to increase after labetalol, but the difference was not statistically significant. The changes in plasma noradrenaline and blood glucose after labetalol mimic findings observed after alpha-adrenergic receptor blockade. The beta-adrenergic receptor blocking property of labetalol is responsible for the reduced heart rate and it is likely to contribute to the higher plasma noradrenaline concentration observed when standing and during supine exercise.

Haemodynamic effects of atenolol, pindolol and propranolol during adrenaline infusion in man.

SummaryIn a double blind, cross over study the haemodynamic effects of an i.v. infusion of adrenaline during concomitant administration of atenolol, pindolol, propranolol or placebo were examined in 7 healthy volunteers.During coadministration with placebo, adrenaline caused an increase in systolic blood pressure (SBP) of 26 mm Hg and a decrease in diastolic blood pressure (DBP) of 20 mm Hg. Heart rate (HR) and stroke volume (SV) were increased by about 20–30%. Total peripheral resistance (TPR) fell significantly. When the subjects were pretreated with atenolol, the adrenaline increased SBP by 16 mm Hg, the DBP did not change, HR and SV increased by 19 and 30%, and TPR fell.During concomitant administration of the non-selective betablocker pindolol, which has strong intrinsic sympathomimetic activity (ISA), adrenaline increased SBP by 11 mm Hg and DBP by 17 mm Hg. This pure pressor response led to a significant reduction in HR and SV and an increase in TPR, probably mediated through the baroreceptors. The haemodynamic response to adrenaline during coadministration of propranolol was very similar to that seen after pindolol. It is concluded that a beta1-selective blocker interferes very little with the haemodynamic response to adrenaline, whereas it is changed to a pure pressor response during coadministration of a non-selective betablockers. ISA did not significantly modify the pressor response.

Retinol-binding protein and transferrin in urine: New markers of renal function in essential hypertension and white coat hypertension?*

We studied the 24 h urinary excretion of albumin, transferrin, immunoglobulin G, and retinol-binding protein in individuals with essential hypertension, white coat hypertension, and normotension. In 56 individuals, we measured the 24 h ambulatory blood pressure (AMBP). The individuals could be divided into three groups: 26 hypertensives, 14 white coat hypertensives, and 16 normotensives. Daytime AMBP values were (median values with range in parentheses, mm Hg): hypertensives 158/105 (198 to 121/95 to 120), white coat hypertensives 141/83 (161 to 129/72 to 90), and normotensives 123/75 (148 to 102/63 to 86). We determined with immunochemical methods the 24 h urinary excretions of albumin, transferrin, and immunoglobulin G, all markers of glomerular dysfunction, and retinol-binding protein, a marker of impaired proximal tubular function. We found a significantly higher excretion of albumin and transferrin in hypertensives (P < .0000/P < .0001) and in white coat hypertensives (P < .003/P < .02) compared to normotensives. Out of 26 hypertensives, seven had microalbuminuria (> or = 30 to < 300 mg albumin/ 24 h). Two cases of microalbuminuria were found among the 14 white coat hypertensives. Immunoglobulin G excretion was not significantly increased in any of the hypertensive groups. Retinol-binding protein excretion was significantly higher in hypertensive patients (P < .007), whereas no elevation was observed in persons with white coat hypertension. In hypertensives, a significant correlation was found between urinary excretion of albumin and transferrin and office blood pressure and systolic AMBP. There was no significant correlation between the urinary excretions of IgG and retinol-binding protein and blood pressures in any of the three groups. Our findings indicate that patients with white coat hypertension, like hypertensives, have a selective type of glomerular dysfunction. However, proximal tubular dysfunction was seen only in hypertensives. Urinary excretions of albumin, transferrin, and retinol-binding protein may be useful as markers of glomerular and tubular dysfunction in essential hypertension.

Immediate central hemodynamic effects of five different beta-adrenoceptor-blocking agents, acebutolol, atenolol, pindolol, practolol, and propranolol, in patients with ischemic heart disease

The hemodynamic effects of acebutolol were studied in six patients with ischemic heart disease. The changes in heart rate, cardiac output, and arterial blood pressure were determined after intravenous administration of six increasing doses of acebutolol to a cumulative dose of 0.64 mg/kg. After the sixth dose of acebutolol, cardiac output and heart rate were reduced 15% and 8%, respectively. Pulmonary artery pressure was increased by 4 mm Hg. Arterial blood pressure was not changed significantly. The effects of graded doses of acebutolol on heart rate and cardiac output were compared with earlier obtained results after atenolol (0.19 mg/kg), pindolol (0.025 mg/kg), practolol (0.64 mg/kg), and propranolol (0.19 mg/kg). The effects of increasing doses of acebutolol and practolol were very similar and significantly different from the effects of the other three drugs in spite having been administered at equipotent doses. The hemodynamic effects of acebutolol support the hypothesis that the hemodynamic response to beta-adrenoceptor antagonist drugs at rest is determined primarily by the degree of intrinsic sympathomimetic activity, whereas beta-1 selectivity does not modify the central hemodynamic response.

Increased systolic ambulatory blood pressure and microalbuminuria in treated and non‐treated hypertensive smokers

Objective: The primary aim of the present study was to evaluate the impact of smoking status on both clinic and ambulatory blood pressure (BP) and heart rate (HR) by using 24‐h ambulatory BP monitoring in treated and non‐treated hypertensive smokers and non‐smokers. A secondary aim was to evaluate the interrelations between BP, smoking status and microalbuminuria. Design: Five hundred and eighty treated and non‐treated hypertensive smokers and non‐smokers were consecutively recruited. The patients were divided into groups of non‐smokers (n = 414) and smokers (n = 166). We were able to match 115 smokers with 230 non‐smokers with regard to clinic BP, gender and age. Methods: Microalbuminuria (albumin/creatinine ratio on morning spot urine sample), sitting clinic BP (mercury sphygmomanometry) and ambulatory BP (A&D TM 2421) were measured. Results: In the matched group we found a significant difference in ambulatory systolic and diastolic daytime BP between smokers and non‐smokers (146.5 ± 15.0/90.6 ± 9.7 mmHg vs 142.3 ± 12.6/89.0 ± 9.0 mmHg). The smokers had significantly higher log albumin/creatinine ratio (0.51 ± 0.93 vs 0.19 ± 0.87). These results were found to be valid for treated as well as untreated patients. In both the matched and unmatched groups, the smokers had significantly higher HR. Conclusion: The higher daytime BP and HR as well as microalbuminuria in smokers may contribute to their increased cardiovascular risk. Furthermore, the higher ambulatory BP in smokers implicates that these patients tend to be underdiagnosed and undertreated if only clinic BP is used.

Isolated systolic hypertension in an elderly Danish population. Prevalence and daytime ambulatory blood pressure

Isolated systolic hypertension (ISH) is a major risk factor for cardiovascular complications. Nevertheless, data on the prevalence in a representative population do not seem to be available. The prevalence of ISH and the white coat effect was thus studied in a cross‐sectional survey of 2806 inhabitants aged 70–80 years. In untreated subjects, the prevalence of ISH was 17.4% (95% CI 14.9–20.2) in women and 13.5% (95% CI 11.3–15.9) in men using clinic blood pressure at first visit. The prevalence increased significantly with age. The prevalence was reduced to 10.4% when using the average of all‐visits clinic blood pressures. By a simulation model, it was demonstrated that his reduction mainly resulted from a regression towards the mean. Average all‐visits clinic blood pressure was 172.6 ±10.4/81.1±6.0 mmHg. Less than one‐third of those with all‐visit ISH had sustained ISH. Identifying subjects with sustained ISH requires measurements in more than three visits.

Haemodynamic Effects and Kinetics of Concomitant Intravenous Disopyramide and Atenolol in Patients with Ischaemic Heart Disease

SummaryThe haemodynamic effects of concomitant intravenous administration of disopyramide (Norpace) and atenolol (Tenormin) were studied in a cross-over trial in 7 patients with ischaemic heart disease. Following 150 mg disopyramide i.v. the cardiac index (CI) and stroke volume index (SVI) decreased by 14% and 26%, respectively and the heart rate (HR) and preejection period index (PEPI) increased by 13% and 19%, respectively. A decrease in CI of 14% and HR of 21%, respectively were noted after intravenous administration of 7.5 mg atenolol; PEPI increased by 10% whereas SVI remained unchanged. The cardiac Index (CI) fell by 33% following the administration of both drugs. The effect on CI of the two drugs was additive. The effect of disopyramide and atenolol on HR, SVI and PEPI was not significantly modified by coadministration of the other drug. No change in blood pressure was observed after disopyramide or atenolol. A correlation (ρ) of 0.540 and 0.387 was observed between the change in PEPI and the log free and total serum concentrations of disopyramide, respectively. Combined intravenous use of the two drugs in patients with incipient or overt heart failure is not recommended, unless it is due to the arrhythmia to be treated.