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Biomedical subjects

P Omvik

Publications and source records attributed to P Omvik.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Losartan and the LIFE-study. Antihypertensive treatment with AT1-receptor antagonist].

The renin-angiotensin system, through the effects of angiotensin II, may be involved in the pathogenesis of essential hypertension and associated left ventricular hypertrophy. Treatment with angiotensin-converting enzyme inhibition (ACEI) lowers blood pressure and reduces left ventricular hypertrophy. ACEI, however, may not completely inhibit the production of angiotensin II and its effects, and adverse effects like cough and rise in creatinine have been associated with ACEI and reduced degradation of bradykinin. The first selective antagonist of the angiotensin II-1 (AT1) receptor, losartan, has recently been approved. The LIFE study has been started, in which 8,300 hypertensive patients with left ventricular hypertrophy in Scandinavia and the USA will be randomized to blinded treatment with either atenolol or losartan to compare the effects on cardiovascular morbidity and mortality over a period of five years.

Angiotensin I↗
PubMed1996

How smoking affects blood pressure.

The addictive effects of smoking are only partly known, but it is likely that hemodynamic effects of tobacco smoking may contribute to the habituation. It has since long been known that blood pressure and heart rate increase during smoking. These effects are specifically associated with nicotine while the other components of which more than a thousand have been isolated seem to be of minor importance. The rise in blood pressure is due both to an increase in cardiac output and total peripheral vascular resistance. The blood pressure rise appears immediately and occurs before any increase in circulating catecholamines. In hypertensive patients the blood pressure lowering effect of beta-blockers may be partly abolished by tobacco smoking whereas alpha-receptor blockers seem to maintain the antihypertensive efficacy in smokers. It is a paradox that while smoking acutely increases blood pressure, a slightly lower blood pressure level has been found among smokers than nonsmokers in larger epidemiological studies. Because blood pressure may increase after cessation of smoking, a smoke quitting program should not postpone initiation of antihypertensive treatment in patients otherwise in need of such treatment.

Adrenergic alpha-Antagonists↗
PubMed1996

Salt sensitivity in hypertensive type-1 diabetes mellitus.

UNLABELLED: As sodium retention has been proposed as a causal factor in the development of hypertension in diabetic patients, a high incidence of salt sensitivity has been suggested. To evaluate the influence of dietary sodium intake on blood pressure, casual and 24-h blood pressure was measured in 30 hypertensive type-1 diabetic patients aged 24-67 (mean 46) years while they were on habitual diet, after 6 days of low-sodium diet (50 mmol/day), and after 6 days of high-sodium diet (250 mmol/day). Nine patients (30%) who increased their 24-h mean blood pressure by more than 10% when going from low- to high-sodium intake were classified as salt sensitive; the others as salt resistant. The salt sensitive group had a significantly lower urinary excretion of dopamine at baseline, and a higher diuresis and a more pronounced decrease in 24-h blood pressure during salt depletion (all p < 0.01). Low-sodium diet reduced casual and 24-h blood pressure by 4% in the total study population compared with 9% in the salt sensitive group (p < 0.01). There was no difference in glomerular filtration rate, filtration fraction, proteinuria or urinary sodium excretion between the groups. CONCLUSIONS: Sodium restriction more effectively reduces blood pressure in the salt sensitive minority of hypertensive type-1 diabetic patients irrespective of renal function. The incidence of salt sensitivity is not increased in hypertensive type-1 diabetic patients compared with essential hypertensive patients.

Adult↗
PubMed1996

Unchanged 24 h ambulatory blood pressure during shjort-term salt restriction and salt repletion in normotensive volunteers.

BACKGROUND: The lack of significant correlation between sodium consumption and blood pressure in a population has tentatively been explained by individual differences in salt sensitivity. Previously we have shown that one-third of essential hypertensived patients respond to a salt load of 9 g daily for 5 days with an increase of 10% or more in 24 h ambulatory blood pressure. The present study was undertaken to examine the response to salt loading in healthy normotensive people. RESULTS:Only one out of 17 volunteers (6%) with a mean age of 24 years and mean ambulatory blood pressure of 136/70 mmHg had an increase in mean ambulatory blood pressure of at least 10% during salt loading. On average, blood pressure did not differ during periods of normal (150 mmol/24 h), low (120 mmol/24 h) or high (268 mmol/24 h) sodium excretion, respectively. CONCLUSION: Normotensive people tolerate short-term salt loading without significant changes in 24 h ambulatory blood pressure.

Journal Article↗
PubMed1995

Comparison of the angiotensin II antagonist losartan with the angiotensin converting enzyme inhibitor enalapril in patients with essential hypertension.

OBJECTIVE: To evaluate the blood pressure lowering efficacy as well as tolerability and safety of the angiotensin II antagonist losartan compared with that of the angiotensin converting enzyme inhibitor enalapril in patients with mild-to-moderate essential hypertension. DESIGN AND METHODS: The study was a multicentre, double-blind, double-dummy, randomized, parallel study. Patients (n = 407) with diastolic blood pressure > or = 95 and < or = 120 mmHg at the end of a 2-week baseline placebo period were randomly allocated to receive either 50 mg losartan once a day or 20 mg enalapril once a day for 12 weeks. Blood pressure, clinical and laboratory safety, specific symptoms including coughing determined using a symptoms questionnaire and metabolic variables were examined at baseline and at weeks 6 and 12. RESULTS: Both losartan and enalapril decreased systolic and diastolic blood pressure from baseline at weeks 6 and 12. Blood pressure changes from baseline at trough (22-26 h after the dose) did not differ between the two groups in the per-protocol analysis. Response to treatment at trough was excellent or good (diastolic blood pressure < 90 mmHg or reduction in diastolic blood pressure of 10 mmHg) in 51 and 53% of the patients in the losartan and enalapril groups, respectively. Enalapril administration increased dry coughing symptoms whereas losartan did not. The incidence of dry coughing was 1.0 and 12.2% as a spontaneously reported discomfort at week 12 and 3.0 and 15.1% as a clinical adverse experience in the losartan and enalapril groups, respectively. The difference from baseline at week 12 in the incidence of dry coughing between the two groups was 14.9% as a specific symptom in the symptoms questionnaire. Losartan reduced serum uric acid concentration, whereas effects on other metabolic parameters did not differ between the groups. CONCLUSIONS: Losartan is an effective and well-tolerated antihypertensive drug showing similar blood-pressure-lowering efficacy to that of enalapril at trough. However, in contrast to enalapril, losartan does not increase the incidence of dry coughing. Thus, the angiotensin II antagonist losartan provides a promising new approach to treatment of hypertension.

Adult↗
PubMed1995

The Bergen Blood Pressure Study: prehypertensive changes in cardiac structure and function in offspring of hypertensive families.

Cardiac morphology and function were determined by echocardiography in normotensive offspring of 23 hypertensive and 22 normotensive families. The family histories of hypertension or normotension were based on 27 years' observation of parental blood pressure. Pulsed Doppler and M-mode echocardiography were performed in standard views. Out of the total 109 offspring, 94 participated in the present study (age (mean +/- SD) 36 +/- 7 years). Left ventricular posterior wall thickness was higher in offspring of hypertensive than normotensive families (10.1 +/- 1.7 vs. 9.3 +/- 1.5 mm; p < 0.05). Offspring of hypertensive families had lower transmitral early/late peak flow velocities (p < 0.001) and higher transmitral late peak flow velocities (p < 0.001) than offspring of normotensive families, but the differences between groups became inconsistent after adjustment for confounding variables (including left ventricular structural parameters). On the other hand, the family history of hypertension was consistently associated with increased transmitral early peak flow velocity and increased transmitral acceleration and deceleration slopes p < 0.05), a pattern suggesting increased left ventricular stiffness. Increased posterior wall thickness and diastolic functional changes may indicate cardiac hypertrophy and decreased left ventricular compliance and precede the development of hypertension in offspring of hypertensive families.

Adult↗
PubMed1995

Unchanged central hemodynamics after six months of moderate sodium restriction with or without potassium supplement in essential hypertension.

Sodium (Na) restriction and potassium (K) supplementation has been recommended as treatment of essential hypertension but the mechanism by which these may reduce blood pressure (BP) is unknown. We examined if moderately reduced Na intake, combined with a low-Na/high-K salt alternative (Pansalt: NaCl 57%, KCl 28%, MgSO4 12%) as substitute for standard table salt, induced clinically significant BP reduction in hypertensive patients and, if this therapy reduced total peripheral resistance. After a 2-month control period 40 patients aged 21-67 years with mean casual BP 156/103 mmHg were given a salt restricted diet (120 mmol Na/24 h) for 6 months. In addition, they were randomised in a double-blind manner to receive either Pansalt (P-group) or standard NaCl (S-group) as table salt in small amounts. Cardiac output was measured by dye dilution. Daily Na excretion was similarly reduced (20%) in both groups while K excretion was slightly increased in the P-group and reduced in the S-group (difference p < 0.05). No large changes occurred in 24-h ambulatory BP (by Accutracker II) or intraarterial pressure (through a brachial artery catheter) at rest or during exercise while casual BP was reduced (p < 0.05) 13/8 mmHg in the P-group and 8/5 mmHg in the S-group. While cardiac output was slightly reduced at rest and during 50W exercise in the P-group, no significant changes were seen in total peripheral resistance in either group. Thus, moderate reduction in Na intake, with or without addition of K, is not sufficient to induce significant long-term intraarterial or 24-h ambulatory BP changes in essential hypertension. Without BP changes invasively determined central hemodynamics remains remarkably stable over a 6-month period.

Adult↗
PubMed1995

Evaluation and quality-of-life assessment of amlodipine and enalapril in patients with hypertension.

In this multicentre, double-blind trial in 461 patients with essential hypertension, amlodipine (5-10 mg once daily) and enalapril (10-40 mg once daily) were compared in terms of quality of life, efficacy and tolerability after 1 year of treatment (part 1). In part 2, 177 patients successfully treated with amlodipine in part 1 continued in an open evaluation of efficacy and safety of antihypertensive treatment with amlodipine for a further 2 years. In part 1, both drugs were similarly effective in lowering blood pressure (BP) (although significantly more enalapril patients required a diuretic) while maintaining quality of life. Apart from class-typical effects, such as oedema for calcium antagonists and cough for angiotensin-converting enzyme inhibitors, both drugs were equally well tolerated, with few adverse effects of clinical significance. Only a few patients (eight amlodipine (4%), nine enalapril (4%)) were withdrawn from the trial because of drug-related adverse events, demonstrating that the tolerability was good. Neutral to slightly beneficial effects were found in blood lipid concentrations after treatment with amlodipine. The BP reduction seen in the amlodipine patients after part 1 was maintained during part 2. Also, blood lipids and safety variables remained virtually constant. It is concluded that, at similar BP reduction, quality of life is equally well maintained on amlodipine and enalapril therapy. Thus, amlodipine compares favourably with enalapril as an effective and well-tolerated anti-hypertensive agent over the first year. Additionally, amlodipine patients evaluated over a 2-year extension maintained good BP control and the drug was well tolerated.

Adult↗
PubMed1995

The Bergen blood pressure study: offspring of two hypertensive parents have significantly higher blood pressures than offspring of one hypertensive and one normotensive parent.

OBJECTIVE: To study blood pressure and antihypertensive drug treatment in subjects with contrasting family histories of hypertension. SUBJECTS AND METHODS: We grouped 520 offspring examined in 1990 (mean +/- SD age 36 +/- 7 years) according to their parents' blood pressure screened in 1963-1964 as offspring of two normotensive (systolic/diastolic blood pressure < 135/70 mmHg) parents (group 1); offspring of one hypertensive (> or = 145/95 mmHg) and one normotensive (<135/70 mmHg) parent (group 2); and offspring of two hypertensive (> or = 140/90 mmHg) parents (group 3). Offspring blood pressure was measured with a conventional mercury sphygmomanometer by one observer. The mean of the last two of three seated measurements was used for analyses. Drug treatment was determined by interview. RESULTS: Mean +/- SD blood pressure was lowest in group 1 (121 +/- 12/72 +/- 10 mmHg), intermediate in group 2 (125 +/- 12/76 +/- 9 mmHg) and highest in group 3 (135 +/- 15/85 +/- 11 mmHg), P<0.01 for each. Of the subjects in groups 1, 2 and 3, 1.3, 2.4 and 11.7%, respectively, were taking antihypertensive drugs (P<0.01). CONCLUSIONS: Screening blood pressure in parents has implications for offspring blood pressure almost 30 years later. Offspring of hypertensive parents have higher blood pressure and are given antihypertensive drugs at higher rates than the offspring of normotensive parents. Also, substantial differences were seen between the offspring of one and of two hypertensive parents. Thus, risk associated with a family history of hypertension varies with the definition of the family history. To obtain maximum contrast in the predisposition to high blood pressure, comparative studies in offspring of hypertensive and normotensive families should be based on blood pressure data from both parents.

Adult↗
PubMed1994

Measurement of long-term hemodynamic changes and the use of 24-hour blood pressure monitoring to evaluate treatment.

Hemodynamic studies at rest as well as during exercise are useful for profiling the hemodynamic derangements in essential hypertension and for evaluating the changes produced by antihypertensive therapy. Modern, lightweight, 24-hour ambulatory blood pressure monitoring devices can provide useful information in understanding circadian variation of blood pressure, and also in evaluating blood pressure control over 24 hours. We have studied in > 400 patients the hemodynamic profiles of most of the commonly used antihypertensive agents. Results from our study of amlodipine, a novel calcium antagonist, are presented as an example. Nineteen patients with mild-to-moderate essential hypertension underwent invasive hemodynamic studies while at rest, supine, and sitting, and during 50, 100, and 150 W bicycle exercise in the sitting position. Systolic, diastolic, and mean arterial blood pressure decreased 16% (p < 0.01) at rest and during exercise, and total peripheral resistance was reduced 18%. Blood pressure during the daytime and during sleep was reduced approximately 16%. The reductions in systolic and diastolic pressures were similar. There were no significant changes in heart rate or cardiac output. Amlodipine was well tolerated. Two patients developed ankle edema, which disappeared when the dose was reduced, and in 1 patient the drug was withdrawn because of nondrug-related side effects.

Adult↗
PubMed1994

The Bergen Blood Pressure Study: inappropriately low levels of circulating atrial natriuretic peptide in offspring of hypertensive families.

Plasma atrial natriuretic peptide (ANP), plasma and 24-h urine catecholamines, plasma renin activity (PRA), and serum aldosterone were studied in offspring of hypertensive and normotensive families [n = 82; age 37 +/- 7 years (mean +/- SD)]. Despite higher age, higher blood pressure, and higher urine excretion of catecholamines--all of which are factors associated with increased ANP levels--the mean basal plasma ANP concentration tended to be lower in offspring of hypertensive than normotensive families. The same pattern was found in all age-tertiles, and the between-group difference was statistically significant in subjects aged 34-39 years (p < 0.01). Also, the family history of hypertension was associated with low ANP levels after covariate adjustment (p < 0.05). The 24-h urine excretion of epinephrine and norepinephrine tended to be higher in offspring of hypertensive than normotensive families while the morning venous plasma levels were similar. The ratio between venous plasma ANP and norepinephrine was lower in offspring of hypertensive than normotensive families (p < 0.05). PRA, serum aldosterone level, and 24-h urine excretion of dopamine did not differ significantly between groups. Inappropriately low basal plasma ANP concentrations and low plasma ANP/norepinephrine ratios may be related to the development of essential hypertension in offspring of hypertensive families.

Adult↗
PubMed1994

Salt sensitive essential hypertension evaluated by 24 hour ambulatory blood pressure.

Thirty men with essential hypertension were examined at three different levels of sodium intake, containing 135, 44 and 290 mmol sodium per day, respectively. Ten patients who increased their 24 hour mean ambulatory blood pressure 10% or more when going from low to high sodium intake were defined as salt sensitive, the others as salt resistant. The casual and 24 hour ambulatory blood pressure measurements defined partly different patients as salt sensitive. In multiple regression analysis, salt sensitivity was associated with an increase in diuresis during low sodium intake, demonstrating a dissociation between water and sodium excretion during salt depletion in the salt sensitive group. The change 24 hour ambulatory blood pressure during salt repletion was positively correlated to the increase in the atrial natriuretic peptide (p < 0.01), and inversely correlated to the plasma concentration of atrial natriuretic peptide after salt depletion (p < 0.01). No difference in plasma norepinephrine, renin, aldosterone, plasma volume, blood volume or 24 hour sodium excretion was found between salt sensitive and salt resistant subjects. We conclude that salt sensitivity is difficult to describe as an entity, but seems to be associated with lower levels of atrial natriuretic peptide and a different response to salt depletion.

Adult↗
PubMed1994

The relationships between casual and ambulatory blood pressure measurements and central hemodynamics in essential human hypertension.

OBJECTIVE: To determine the association between ambulatory blood pressure (ABP) and central hemodynamics in hypertensive patients and between the area under the 24-h blood pressure curve and the hemodynamic indexes. PATIENT POPULATION: Forty untreated essential hypertensive patients (28 previously untreated, 12 withdrawn from therapy for > 12 weeks). METHODS: Patients underwent casual and 24-h ABP monitoring and invasive measurements of central hemodynamics. Central measures of ABP included 24-h mean, awake, and sleep values guided by activity journals. The ABP data were modeled by Fourier series and the ability of the smoothed and unsmoothed data to predict hemodynamics was compared. Individual blood pressure curves were analyzed by calculating the area under the curve using different threshold awake and sleep values to test the correlations between this form of blood pressure load and hemodynamics. RESULTS: Hemodynamic measures were not predicted by casual blood pressure but were related to ABP. Total peripheral resistance was strongly predicted by the area under the diastolic blood pressure (DBP) curve using an awake threshold of 90 mmHg and a sleep threshold of 80 mmHg (r = 0.56, P < 0.001). Data smoothing using Fourier transformation did not alter any correlations between ABP and hemodynamics. Exercise stroke index, an indicator of cardiac function impaired in early hypertensive heart disease, was also best predicted by area under the DBP curve using the same thresholds as above (r = -0.56, P < 0.001). CONCLUSIONS: These data imply that integrated areas under the ABP curve are related to hemodynamic hypertensive indexes and could be used to assess the extent of hypertensive burden in clinical trials.

Adult↗
PubMed1994

The Bergen Blood Pressure Study. Estimated prevalence of postural hypotension is influenced by the alerting reaction to blood pressure measurement.

The prevalence of postural hypotension, defined as a > or = 20 mmHg decline in SBP from the sitting to the standing position, was studied in 430 subjects aged 67.2 +/- 6.8 years (mean +/- SD). Before the subjects assumed the upright position, three sitting measurements were performed. The difference between the first sitting and standing recording revealed a postural hypotension prevalence of 18.9%. However, when the mean of the two last sitting recordings was used as baseline, only 4.9% of the subjects experienced a > or = 20 mmHg drop in SBP on standing. It is well documented that the alerting reaction to conventional sphygmomanometry causes the BP to rise and that BP decreases spontaneously with repeated measurements. When postural hypotension is based on the difference between the first sitting and the standing recording, the change in BP is not caused by the change in posture alone but reflects the effect of repeated measurements and the regression-towards-the-mean-phenomenon as well. Consequently, the prevalence of postural hypotension is overestimated. Repeated baseline recordings are encouraged in the assessment of postural hypotension.

Aged↗
PubMed1994

A long-term, double-blind, comparative study on quality of life during treatment with amlodipine or enalapril in mild or moderate hypertensive patients: a multicentre study.

The efficacy, tolerability and impact on quality of life of amlodipine and enalapril were compared in a multicentre, double-blind, general practice study in 461 mild and moderate hypertensives over a 50-week active treatment period. Amlodipine (5-10 mg, once daily) and enalapril (10-40 mg, once daily) were found to be similarly effective in lowering blood pressure while not adversely affecting quality-of-life parameters. However, 20% of the enalapril group compared with 11% of the amlodipine group required the addition of hydrochlorothiazide for blood pressure control (P < 0.01). Diastolic blood pressure was normalised or reduced by 10 mmHg in 204 (90%) patients on amlodipine and in 190 (85%) patients on enalapril. Side-effects were, in general, mild or of little clinical significance. The major side-effects recorded were class-typical of ACE inhibitors and calcium antagonists, namely cough (enalapril) and oedema (amlodipine), respectively. Tolerability was very good, with only 17 patients (8 amlodipine, 4%; 9 enalapril, 4%) being withdrawn from the study due to side-effects definitely related to treatment. Amlodipine monotherapy produced a slightly beneficial effect on blood lipid concentration, and both drugs reduced the calculated 10-year risk of coronary heart disease. It was concluded that the calcium antagonist amlodipine compared favourably with the ACE inhibitor enalapril in terms of antihypertensive efficacy, tolerability and impact on quality of life.

Adult↗
PubMed1993

[Does antihypertensive treatment with amlodipine or enalapril affect quality of life? A multicenter study in general practice].

In this multicentre trial in general practice the effect of one year of therapy with amlodipine or enalapril on quality of life and blood pressure was studied in 461 hypertensive patients. Quality of life was evaluated by means of a questionnaire administered on five occasions during the study. A total of 125 questions were distributed between psychological general well-being, own perception of health, social relations, sexual and cognitive functioning, and a combined index for frequency and intensity of symptoms. Both drugs were equally effective in reducing blood pressure, from 162/106 to 142/91 mm Hg, and had the same effect on quality of life. Neither of the drugs reduced quality of life, and in some of the variables a slight improvement (2-5%) was observed. The two compounds were tolerated equally well. Apart from class-typical effects (coughing for enalapril and edema for amlodipine) no clinically significant side effects were experienced.

Adult↗
PubMed1993

[How much is the decrease in blood pressure shown by repeated measurements during the same examination?].

The recommendations for blood pressure determination by sphygmomanometer encourage repeated measurements. In 430 subjects aged 56-87 years, three recordings were obtained at one minute intervals. On average, the blood pressure decreased 10/3 mm Hg from the first to the third recording (p < 0.001). The decrease was more pronounced in hypertensives (12/4 mmHg) than in normotensives (7/2 mm Hg) (p < 0.01), but was little influenced by sex, age, or body mass. A change of 10/3 mm Hg is relevant with respect to the risk of cardiovascular disease, diagnosis of hypertension, and antihypertensive therapy. Also, repeated measurements may reduce the number of falsely positive hypertensives, and is recommended as the standard procedure in conventional blood pressure determination.

Aged↗