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Biomedical subjects

G Berglund

Publications and source records attributed to G Berglund.

At least 181 records · Page 10Linked to original sources
PubMed1989

Goals of antihypertensive therapy. Is there a point beyond which pressure reduction is dangerous?

It has been widely assumed that the preventive effect of antihypertensive treatment on cardiovascular events is increased as lower blood pressure (BP) is achieved. This assumption seemed logical in light of the well-known relationship between BP level and future cardiovascular events. Hypertension, however, develops over many years and is associated with both hypertrophic and atherosclerotic changes within the coronary and peripheral vessels. Antihypertensive drugs when instituted will bring down BP and often arterial blood flow within weeks. Coronary blood flow is limited to diastole. Theoretically then, very low diastolic BPs in coronary arteries with hypertrophic and/or atherosclerotic changes might precipitate a chain of events leading to a myocardial infarction and/or a lethal arrhythmia. Recently, results from several trials have been presented indicating a J-shaped relationship between achieved BP level and incidence of coronary heart disease. These trials are reviewed and problems in the interpretation of the findings such as biaz from varying risk at entry, varying follow-up time, and choice of statistical method, are discussed. Although, the burden of evidence strongly supports the hypothesis that low attained BPs are associated with an increased risk of a coronary heart disease event, problems in the interpretation of this evidence call for further analyses of the relationship within the large hypertension trials. Until such results are at hand caution should be to avoid decreasing BP below 85 mm Hg diastolic.

Antihypertensive Agents↗
PubMed1989

Radiological heart enlargement in treated hypertensive men: a comparative study of chest X-ray examination and M-mode echocardiography.

Twenty-five hypertensives with no history of myocardial infarction and with a radiologically determined heart enlargement were examined with M-mode echocardiography and compared with a normotensive control group (n = 41). All except two of the hypertensive patients were on a beta-blocker based antihypertensive treatment regime. The relative heart volume on X-ray was significantly larger in the hypertensives, 562 ml m-2 body surface area (BSA), compared to the normotensives, 408 ml m-2 BSA (P less than 0.001). Both left ventricular diameter (LVD) in end-diastole and end-systole and left arterial (LA) diameter were significantly larger in the hypertensives (56 vs. 51 mm, P less than 0.01; 35 vs. 31 mm, P less than 0.01; 46 vs. 42 mm, P less than 0.01, respectively) as was the LV mass (296 vs. 203 g, P less than 0.001). The end-systolic wall stress (ESWS) was significantly greater in the hypertensives. Despite these findings resting left ventricular fractional shortening was the same and showed a similar correlation with ESWS (r = 0.79 and r = 0.77, respectively) in both groups. Hence, left ventricular systolic performance was not impaired in the hypertensives compared to the normotensives. These results show that an enlarged cardiac silhouette on the chest X-ray in hypertensive subjects with beta-blocker based drug therapy must be interpreted with caution and must not, a priori, be judged as a sign of an impaired systolic cardiac function.

Adrenergic beta-Antagonists↗
PubMed1989

Atrial natriuretic peptide (ANP) in relation to blood pressure: a study in middle-aged men with normal and elevated blood pressure.

In order to investigate the potential role of atrial natriuretic peptide (ANP) in mild to moderate essential hypertension, a study was conducted in groups of normotensive and hypertensive middle-aged men born in 1926 and 1927. Venous plasma concentrations of immunoreactive ANP (irANP) were studied in relation to measurements of cardiac structure and function, urinary electrolytes as well as some cardiovascular hormones. Plasma irANP did not differ between normotensive controls (31 +/- 14 pmol l-1) and borderline or untreated hypertensive patients. However, irANP concentrations were slightly but significantly (P less than 0.05) lower in the borderline (26 +/- 8 pmol l-1) compared to the untreated established hypertensives (35 +/- 14 pmol l-1). No relationships were found between irANP and blood pressure, indices of left ventricular structure and function or hormone parameters in subgroups or the whole study group. Our data do not support the view that plasma irANP is increased in uncomplicated essential hypertension, since our groups of borderline or established hypertensive middle-aged men without major cardiac involvement did not differ in irANP concentrations compared to normotensive controls. Thus, during the development or in the early stages of essential hypertension, ANP secretion does not seem to be abnormal.

Antihypertensive Agents↗
PubMed1989

A population-based study of children with standard risk acute lymphoblastic leukemia in the five Nordic countries. A follow-up of 230 patients.

Two hundred and thirty children with standard risk acute lymphoblastic leukemia (ALL) were diagnosed during a period of 3 years from July 1, 1981 to June 30, 1984 in the five Nordic countries. Criteria for standard risk ALL were age above 2.0 and below 10 years, WBC less than or equal to 20 x 10(9)/l, no evidence of CNS-involvement, mediastinal mass or T- or B-cell leukemia. The children were treated without prophylactic CNS irradiation, the majority (200 patients) according to two treatment programs. Follow-up of the entire group after a minimum of 30 months showed 64% of the children living in complete continuous remission with a probability of event-free survival of 0.60. The treatment results are not entirely satisfactory and intensification of therapy is required. A subgroup of patients with WBC between 10 and 20 x 10(9)/l and with adverse prognosis was identified, justifying a change of the present criteria for risk grouping.

Adolescent↗
PubMed1989

Beta-blockers and diuretics. The HAPPHY and MAPHY studies.

The question whether initial antihypertensive treatment with a beta-blocker prevents hypertensive complications better than initial treatment with a non-betablocker, mainly diuretic based treatment, has been studied in recent large-scale studies like the Medical Research Council (MRC) trial, the International Prospective Primary Prevention Study in Hypertension (IPPPSH), the Heart Attack Primary Prevention in Hypertension (HAPPHY) study and the Metoprolol Atherosclerosis Prevention in Hypertensives (MAPHY) study. The first three studies were unable to find a more beneficial effect of beta-blockers than of thiazide diuretics. The MAPHY study, however, found a lower total mortality, in the metoprolol treated group than in the diuretic treated. As the HAPPHY and MAPHY studies share a substantial part of patient-years and number of deaths, these diverging results have evoked confusion and debate. This paper presents the main results of both studies and discusses the possible reasons for the different outcome.

Adrenergic beta-Antagonists↗
PubMed1988

Cardiovascular and renal effects of long-term antihypertensive treatment.

To study whether restoration of a normal circulatory system could be achieved with antihypertensive treatment, 13 hypertensive men with structural cardiovascular changes and 37 normotensive control subjects were investigated by echocardiography, apexcardiography, plethysmography, inulin and p-amino-hippurate clearance, and determination of 24-hour urinary excretion of albumin, first at age 49 years and again seven years later. All men were untreated at the first investigation. Immediately thereafter, therapy with the cardioselective beta-adrenoceptor blocker metoprolol tartrate was initiated in the hypertensive men. Seven years of antihypertensive treatment resulted in (1) normalization of central and peripheral hemodynamic variables, (2) reversal of left ventricular hypertrophy in proportion to achieved blood pressure control, (3) normalization of systolic wall stress and a well-preserved systolic left ventricular function, (4) normalization of diastolic left ventricular function, and (5) normalization of increased microalbuminuria and a decrease in renal vascular resistance, with no change in glomerular filtration rate compared with control subjects. In conclusion, the findings strongly indicate that regression of cardiovascular structural changes can be achieved with long-term antihypertensive treatment.

Drug Therapy, Combination↗
PubMed1988

Primary prevention with metoprolol in patients with hypertension. Mortality results from the MAPHY study.

The present study of primary prevention in white men aged 40 to 64 years attempts to investigate whether a beta-blocker given as initial antihypertensive treatment would lower total mortality to a greater extent than thiazide diuretics. Patients were randomized to metoprolol (n = 1609, 8110 patient-years) or a thiazide diuretic (n = 1625, 8070 patient-years). The median follow-up time was 4.2 years. The mean dose of metoprolol was 174 mg/d, and of thiazide diuretics, 46 mg/d of hydrochlorothiazide or 4.4 mg/d of bendroflumethiazide. Identical control of blood pressure was achieved using a fixed therapeutic schedule. Total mortality was significantly lower for metoprolol than for thiazide diuretics because of fewer deaths from coronary heart disease and stroke. Total mortality was also significantly lower in smokers randomized to metoprolol. The benefit demonstrated in patients treated with metoprolol seems to have important implications for clinical practice.

Adult↗
PubMed1988

Different patterns of cellular sodium turnover in essential hypertension.

Erythrocyte sodium turnover was studied in 22 men aged 56 years who had been treated for hypertension for 7 years. Investigations were performed during treatment, and 1 and 4 weeks after withdrawal of therapy, and when hypertension had returned (blood pressure greater than or equal to 170/105 mmHg). Hypertension returned early in 11 patients (group A) and late in 11 patients (group B). There was no difference in blood pressure, therapy, body weight or peripheral resistance between the groups, but group A had a greater left ventricular mass. Intra-erythrocyte sodium was determined by flame photometry. Sodium influx and the rate constant of sodium efflux were calculated from uptake values of 22Na. In group B the return of hypertension was accompanied by a tendency for an increase in intra-erythrocyte sodium and a decrease in sodium efflux. In group A opposing changes were seen, so that significant differences occurred in sodium efflux and intra-erythrocyte sodium between the groups occurred at the reappearance of hypertension. The results are compatible with the appearance of a membrane abnormality in patients with a slow return of hypertension, whereas other mechanisms, e.g. increased sympathetic activity, may be associated with the more rapid rise in blood pressure in the other group.

Antihypertensive Agents↗
PubMed1988

Renal function before and after withdrawal of long term antihypertensive treatment in primary hypertension.

Glomerular filtration rate (GFR) and renal plasma flow (inulin and para-aminohippurate clearance) were measured in a random sample of 17 normotensive and 20 untreated patients with primary hypertension. At the 7-year follow-up, 19 patients were on metoprolol (as the sole drug or in combination with either hydrochlorothiazide or hydralazine) and 1 patient was on hydrochlorothiazide. They were re-examined after withdrawal of treatment and return of hypertension. At the 7-year follow-up GFR was more reduced in the hypertensive (-17%) than in the normotensive group (-9%). The percentage decrease in renal blood flow was the same in both groups. No significant renal function changes appeared after withdrawal of treatment. In conclusion, there was a slightly greater deterioration in GFR in the hypertensive patients after long term treatment with metoprolol than can be explained by normal ageing.

Antihypertensive Agents↗
PubMed1988

Experiences from hypertension trials--effects on stroke and coronary heart disease.

This review summarises the results of major hypertension trials and addresses the major questions of whether stroke and coronary heart disease (CHD) can be prevented or postponed by blood pressure-lowering drug treatment. Several studies from the 1970s to the 1980s have shown beyond doubt that treatment of high blood pressure decreases the incidence of stroke. Most trials have used thiazide diuretics as active treatment; in one trial the beta-blocker propranolol, compared with placebo, was shown to lower stroke incidence. For thiazide diuretics the preventive effect has been shown for severe, moderate and mild hypertension. The situation regarding CHD is unclear. Early trials with thiazide diuretics showed a lower CHD mortality compared with placebo but no effect on total incidence of CHD events. Three trials during the early 1980s comparing thiazide diuretics and beta-blockers were not able to show a differential effect of the 2 types of drugs. Recently, however, a trial using the cardioselective beta-blocker metoprolol reported a significantly lower CHD mortality and total mortality compared with thiazide diuretics. Further analyses are needed before the question of whether beta-blockers are superior to thiazide diuretics in preventing CHD can be finally answered.

Antihypertensive Agents↗
PubMed1987

Cardiovascular morbidity in relation to change in blood pressure and serum cholesterol levels in treated hypertension. Results from the primary prevention trial in Göteborg, Sweden.

The relationship of cardiovascular disease (CVD) to the control of blood pressure (BP) and serum cholesterol levels was studied in 686 treated, middle-aged hypertensive men whose condition was followed up for 12 years. Both mean in-study BP (P less than .001) and serum cholesterol levels (P less than .001) were better predictors for CVD than the respective entry levels (both not significant) in multivariate analysis. Surprisingly, for mean in-study systolic and diastolic BP there seemed to be a level (approximately 150 and 85 mm Hg, respectively) below which further reduction of BP had no additional benefit from treatment. Analyses of CVD morbidity in relationship to changes in BP and serum cholesterol levels clearly showed that a combined reduction of both risk factors was necessary to achieve a substantial reduction in morbidity. These study findings indicate that (1) it may be unfavorable to reduce BP below a certain level in middle-aged hypertensive men; and (2) other risk factor interventions must be improved to improve the patient's prognosis.

Blood Pressure↗
PubMed1987

Beta-blockers versus diuretics in hypertensive men: main results from the HAPPHY trial.

Men aged 40-64 years with mild to moderate hypertension [diastolic blood pressure (DBP) 100-130 mmHg] were randomized to treatment with a diuretic (n = 3272) or a beta-blocker (n = 3297), with additional drugs if necessary, to determine whether a beta-blocker based treatment differs from thiazide diuretic based treatment with regard to the prevention of coronary heart disease (CHD) events and death. Patients with previous CHD, stroke or other serious diseases, or with contraindications to diuretics or beta-blockers were excluded. If normotension (DBP less than 95 mmHg) was not achieved by monotherapy, other antihypertensive drugs were added, but the two basic drugs were not crossed over. Patients were assessed at 6-monthly intervals. The mean follow-up for end-points was 45.1 months. Blood pressure (BP) side effects and end-points were recorded in a standardized manner. Entry characteristics and the BP reduction achieved were very similar in both treatment groups. All analyses were made on an intention-to-treat basis. The incidence of CHD did not differ between the two treatment groups. The incidence of fatal stroke tended to be lower in the beta-blocker treated group than in the diuretic treated group. Total mortality and the total number of end-points were similar in both groups. The percentage of patients withdrawn due to side effects was similar, whereas the number of reported symptoms, according to a questionnaire, was higher for patients on beta-blockers. The incidence of diabetes did not differ between the two groups. Subgroup analyses did not detect a difference in the effect of beta-blockers compared with diuretics in smokers as opposed to non-smokers, and beta-blockers also had the same effects as diuretics in the quartile with the highest predicted risk for CHD. Beta-blockers and thiazide diuretics were approximately equally well tolerated. The two drugs had a similar BP reducing effect although additional drugs had to be given more often in the diuretic group. Antihypertensive treatment based on a beta-blocker or on a thiazide diuretic could not be shown to affect the prevention of hypertensive complications, including CHD, to a different extent.

Adrenergic beta-Antagonists↗
PubMed1987

Non-participants in a general population study of men, with special reference to social and alcoholic problems.

The bias introduced by non-participation in a study depends on the size and the composition of the non-participant group. Out of 10,000 men invited to a screening examination in a large primary prevention trial in Göteborg, Sweden, 25% did not come to the examination. The non-participants could be shown to be registered by the Board of Social Welfare for social problems and alcohol abuse to a greater extent than the participants in the study. The annual mortality among the non-participants was about twice that of the participants during the entire follow-up period of 11.8 years. The incidence of non-fatal myocardial infarction was not significantly higher in non-participants. Coronary death, on the other hand, was significantly more common among those not attending the examination (3.5 vs. 7.6%). Participants registered for alcoholic problems had coronary death rates approaching those of the non-participants. Sudden coronary death accounted for most of the excess coronary mortality. Most of the excess mortality in the non-participant group was from other causes than cardiovascular diseases and cancer but even so, about one third of the excess deaths could be attributed to coronary heart disease. Possible explanations of this excess coronary mortality include that non-participants may smoke more, more frequently have alcoholic problems and that non-participation may reflect an unwillingness to seek medical care even in the event of illness.

Aged↗
PubMed1987

Significant relationship between renin suppression and atrial natriuretic peptide (alpha-hANP) during volume loading in hypertensive men.

We have studied eight men with moderate hypertension to determine the atrial natriuretic peptide (alpha-hANP) response to acute volume expansion. Rapid infusion of 1,000 ml 0.9% saline (10-20 min) caused an increase in central venous pressure (4.7 +/- 1.6 cmH2O) while blood pressure and pulse pressure (arterial baroreceptor load) did not change. Stroke volume and heart rate were not affected by the volume load but plasma renin activity (PRA) was significantly suppressed (from 0.83 +/- 0.14 to 0.68 +/- 0.34 microgram AI I/ml-h; p less than 0.01). A significant hemodilution was also observed. Renal sodium excretion was significantly increased. Arterial alpha-hANP increased significantly from 21.1 +/- 6.1 to 30.5 +/- 4.0 pmol/l (p less than 0.02) during volume expansion. There was a significant correlation between corrected plasma volume increase (urine volume subtracted from the infused volume) and alpha-hANP plasma elevation (r = 0.78; p less than 0.05). There was also a significant negative correlation between changes alpha-hANP and PRA (r = -0.78, p less than 0.05). We conclude that only moderate volume loading in human hypertensives is a mechanism for increase in plasma alpha-hANP levels. The significant negative correlation between changes in alpha-hANP and PRA suggests that alpha-hANP may be the humoral factor at least partly responsible for suppression of renin in hypertensive man. Since increased fluid volume also affects sympathetic renal efferents as well as vasopressin secretion, our observed relationship between volume load and renin may well be related also to such mechanisms.

Adult↗
PubMed1987

Alcoholic intemperance, coronary heart disease and mortality in middle-aged Swedish men.

High alcohol consumption is one of the major risk indicators for premature death in middle-aged men. An indicator of alcohol abuse--registration with the social authorities for alcoholic problems--was used to evaluate the role of alcohol in relation to general and cause-specific mortality in a general population sample. Altogether 1,116 men (11%) out of a total population of 10,004 men were registered for alcoholic problems. Total mortality during 11.8 years' follow-up was 10.4% among the non-registered men, compared to 20.5% among men with occasional convictions for drunkenness and 29.6% among heavy abusers. Fatal cancer as a whole was not independently associated with alcohol abuse, but oropharyngeal and oesophageal cancers together were seven times more common in the alcohol-registered groups. Total coronary heart disease (CHD) was significantly and independently associated with alcohol abuse, but nearly all the excess CHD mortality among the alcohol-registered men could be attributed to sudden coronary death. Cases with definite recent myocardial infarction were not more common in the alcoholic population. A combined effect of coronary arteriosclerosis and heart muscle damage secondary to alcohol abuse is suggested. Other causes of death strongly associated with registration for alcohol abuse include pulmonary embolism, pneumonia and peptic ulcer, as well as death from liver cirrhosis and alcoholism. Of the excess mortality among alcohol-registered subjects, 20.1% could be attributed to CHD, 18.1% to violent death, 13.6% to alcoholism without another diagnosis and 11.1% to liver cirrhosis.

Alcohol Drinking↗