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Biomedical subjects

P O Wester

Publications and source records attributed to P O Wester.

At least 37 records · Page 2Linked to original sources
PubMed1993

Biological specimen bank for smelter workers.

The biological specimen bank was initiated by the department of Environmental Medicine and the department of Medicine at the University of Umeå in 1975. The aims of the bank are to collect information on trace elements in human organs. Special attention is focused on the influence of occupational exposure. Tissue samples are taken from deceased workers from a copper and lead smelter in northern Sweden. Control specimens have been collected from deceased normal individuals from four control areas. Lung, liver and kidney samples are collected with quartz instruments and stored in quartz ampoules to avoid contamination. Other samples, e.g. bone, brain, fat, hair, heart muscle, nails, skin and stomach are taken with common autopsy instruments and stored in acid-washed polyethene vessels. The samples are stored at -20 degrees C. The elements Sb, As, Cd, Cr, Co, La and Se are analyzed by neutron activation analysis, Pb and Zn by atomic absorption spectrophotometry. The findings over time can be related to a number of factors: normal values in tissues, airborne exposure and causes of death. Special attention is paid variation over time, reevaluation of threshold limit values and risk assessment.

Autopsy↗
PubMed1993

Effects of magnesium infusion on thrombolytic and non-thrombolytic treated patients with acute myocardial infarction.

UNLABELLED: A total of 109 consecutive patients were included in a double blind, randomized trial of the effect of intravenous magnesium sulfate in acute myocardial infarction. Of these 63% received intravenous fibrinolytic therapy. Twenty four-hour Holter monitoring of heart rhythm was performed during the initial hospital stay. A significant reduction in total cardiac mortality in hospital and during the 9 months follow-up was found in the magnesium treated non-thrombolytic group (P < 0.05). Within this subgroup development of heart failure was decreased (P < 0.01). No effect of magnesium infusion on ventricular arrhythmias was demonstrated, instead we found a greater proportion of patients with short runs of ventricular tachycardias in the magnesium treated non-thrombolytic group (P < 0.05), which may represent an increase in spontaneous reperfusion. CONCLUSION: these results indicates that magnesium infusion may have a beneficial effect on mortality in patients with acute myocardial infarction not receiving thrombolytic therapy, but opposes the view that the benefit is related to an antiarrhythmic effect. No additional effect of magnesium to ongoing fibrinolytic therapy could be demonstrated regarding mortality, reinfarction and heart failure.

Aged↗
PubMed1993

The dose-dependent reduction in blood pressure through administration of magnesium. A double blind placebo controlled cross-over study.

Seventeen patients with a diastolic blood pressure over 90 mm Hg were recruited from a running health screening program to participate in a double blind cross-over study of magnesium supplementation (15 mmol Mg2+/day (Emgesan, Kabi Pharmacia) for 3 weeks, followed by 30 mmol Mg2+/day for another 3 weeks, finishing with 40 mmol Mg2+/day for a final 3 weeks). A significant decrease in the mean systolic blood pressure was recorded from 154.0 +/- 10.7 mm Hg to 146.1 +/- 16.9 mm Hg (P = .031) while the mean diastolic blood pressure decreased from 100.2 +/- 4.2 mm Hg to 92.0 +/- 6.6 mm Hg (P = .0001).

Adult↗
PubMed1993

Changing social patterns of risk factors for cardiovascular disease in a Swedish community intervention programme.

Since 1985 a small-scale community-based cardiovascular disease (CVD) preventive programme has been in operation in an inland municipality, Norsjö, in Northern Sweden. The aim of this study was to assess the development of the relationship between social position and CVD risk factors in repeated cross-sectional surveys (1985-1990) among all men and women aged 30, 40, 50 and 60 years in the study area, using an age-stratified random sample from the Northern Sweden MONICA Study of 1986 and 1990 as reference population. These multiple cross-sectional surveys comprised a self-administered questionnaire and a health examination. Of the study population 95% (n = 1499) and 80% of those in the reference area (n = 3208) participated. Subjects were classified with regard to demographic, structural and social characteristics in relation to CVD risk factors and self-reported health status. Time trends in classical risk factor occurrence were assessed in terms of age- and sex- adjusted odds ratios using Mantel-Haenszel procedures. When simultaneously adjusting for several potential confounders we used a logistic regression analysis. Initially, more than half of the study population, both males and females, had and elevated (> or = 6.5 mmol/l) serum cholesterol level. After adjustments had been made for age and social factors it was found that the relative risk of hypercholesterolaemia dropped substantially and significantly among both sexes during the 6 years of CVD intervention in the study area. However, the probability of being a smoker was significantly reduced only in highly educated groups. Among other risk factors no single statistically significant change over time could be found. In the reference area there were no changes over time for the selected CVD risk factors. People in the study area had a less favourable perception of their health than those in the reference area. Social differences were found when perceived good health was measured, especially in variables indicating emotional and social support. When sex, age and social factors had been accounted for there was not clear change over the years in perceived good health.

Adult↗
PubMed1993

The cost-effectiveness of treating hypertension in elderly people--an analysis of the Swedish Trial in Old Patients with Hypertension (STOP Hypertension).

OBJECTIVES: The aim of this study was to estimate the cost-effectiveness of antihypertensive treatment in elderly people based on the results of the Swedish Trial in Old Patients with Hypertension (STOP Hypertension). DESIGN: The STOP Hypertension study was a randomized trial comparing active antihypertensive treatment with a placebo. The risk of stroke, cardiovascular disease and total mortality was significantly reduced in the actively treated group compared to placebo. SETTING: One hundred and sixteen primary health care centres in Sweden. SUBJECTS: A total of 1627 hypertensive patients aged 70-84. No patient was lost to follow-up. INTERVENTIONS: Antihypertensive treatment with beta blockers and diuretics for a mean follow-up of 25 months. MAIN OUTCOME MEASURE: The cost-effectiveness ratio estimated as the net cost (the treatment cost minus saved costs of reduced cardiovascular morbidity) divided by the number of life-years gained (the increase in life expectancy from treatment). RESULTS: The cost per life-year gained was estimated as SEK 5000 for men and SEK 15,000 for women ($1 = SEK 6; 1 pound = SEK 10). The cost per life-year gained did not exceed SEK 100,000 in any of the sensitivity analyses. CONCLUSIONS: It is concluded that treatment of elderly hypertensive patients with beta blockers and/or diuretics is cost-effective according to the results of the STOP Hypertension study.

Aged↗
PubMed1993

STOP-Hypertension 2: a prospective intervention trial of "newer" versus "older" treatment alternatives in old patients with hypertension. Swedish Trial in Old Patients with Hypertension.

It is well established that hypertensive patients benefit from drug treatment of their disorder. In recent years three major out-come studies of antihypertensive treatment in elderly hypertensives have shown substantial benefits, i.e. a reduction in the risk of stroke and other cardiovascular mortality and morbidity. In all these studies beta-blockers and/or diuretics were used in comparison with placebo. Newer therapeutic alternatives have, however, at least theoretically, many advantages which could result in further improvements in prognosis. The initial Swedish Trial in Old Patients with Hypertension (STOP-Hypertension 1) was conducted in men and women aged 70-84 years. STOP-Hypertension 2 will evaluate the therapy used in STOP-Hypertension 1 against therapy based on either ACE-inhibitors (enalapril and lisinopril) or on calcium antagonists (isradipine and felodipine), using the PROBE design (Prospective, Randomised, Open, Blinded Endpoint evaluation). The primary aim will be to assess the effect on cardiovascular mortality. Statistical calculations indicate that 6,600 patients, followed for four years will be needed (2p < 0.05, power 90%) to obtain significance if there is a 25% difference between the new and the established therapy. Patients in primary health care (300 centres) will be included if their supine blood pressure is > or = 180/105 mmHg (and/or). Recruitment of patients started in September 1992 and so far more than 100 patients/week have been included.

Aged↗
PubMed1993

Swedish Trial in Old Patients with Hypertension (STOP-Hypertension) analyses performed up to 1992.

Hypertension is increasingly common with advancing age and a risk factor for all kinds of cardiovascular complications. Moreover, cardiovascular disease is a major cause of morbidity and mortality in the elderly. The Swedish Trial in Old Patients with Hypertension (STOP-Hypertension) was set up by the Swedish Hypertension Society to investigate the value of antihypertensive treatment in the elderly. In this placebo controlled randomised prospective study 1,627 men and women aged 70-84 years with a supine blood pressure > or = 180/105 mmHg (and/or) but not isolated systolic hypertension participated. Three beta-blockers and one diuretic were used as blood pressure lowering agents and the average follow-up in the study was 25 months (3,390 patient-years). Administration of active antihypertensive therapy, reduced supine blood pressure from 195/102 mmHg to 167/87 mmHg at longest follow-up in comparison with placebo. A majority of the patients needed combined treatment to reach the goal blood pressure (160/95 mmHg). Associated with a fall in blood pressure were significant reductions in all cardiovascular primary endpoints (-40%, p = 0.0031), in fatal and non-fatal stroke (-47%, p = 0.0081) and in total mortality (-43%, p = 0.0079). In addition to the substantial effects on primary endpoints active treatment also showed clinically relevant effects on secondary endpoints (e.g. heart failure). The impact on cardiovascular morbidity and mortality with antihypertensive treatment in this elderly cohort was greater than previously seen in middle-aged hypertensive patients, with maintained tolerability and a favourable cost-effectiveness ratio. Finally, women benefited from treatment at least as much as men.

Adrenergic beta-Antagonists↗
PubMed1992

Tobacco and myocardial infarction: is snuff less dangerous than cigarettes?

OBJECTIVE: To estimate the risk of myocardial infarction in snuff users, cigarette smokers, and non-tobacco users in northern Sweden, where using snuff is traditional. DESIGN: Case-control study. SETTING: Northern Sweden. SUBJECTS: All 35-64 year old men who had had a first myocardial infarction and a population based sample of 35-64 year old men who had not had an infarction in the same geographical area. MAIN OUTCOME MEASURE: Tobacco consumption (regular snuff dipping, regular cigarette smoking, non-tobacco use) and risk of acute myocardial infarction. RESULTS: 59 of 585 (10%) patients who had a first myocardial infarction and 87 of 589 (15%) randomly selected men without myocardial infarction were non-smokers who used snuff daily. The age adjusted odds ratio for myocardial infarction was 0.89 (95% confidence interval 0.62 to 1.29) for exposure to snuff and 1.87 (1.40 to 2.48) for cigarette smoking compared with non-tobacco users, showing an increased risk in smokers but not in snuff dippers. Regular cigarette smokers had a significantly higher risk of myocardial infarction than regular snuff dippers (age adjusted odds ratio 2.09; 1.39 to 3.15). Smoking, but not snuff dipping, predicted myocardial infarction in a multiple logistic regression model that included age and level of education. CONCLUSIONS: In middle aged men snuff dipping is associated with a lower risk of myocardial infarction than cigarette smoking.

Adult↗
PubMed1992

Electrolyte balance in heart failure and the role for magnesium ions.

It is well established that clinically significant changes in a number of electrolytes occur in patients with congestive heart failure (CHF). Magnesium ions are an essential requirement for many enzyme systems, and evidence is rapidly emerging that magnesium deficiency is a major risk factor for survival of CHF patients. In animal experiments, magnesium has been shown to be involved in several steps of the atherosclerotic process and, although in humans the situation is somewhat more complex, magnesium ions play an extremely important role in CHF and various cardiac arrhythmias. A number of drugs commonly used to treat CHF can significantly affect not only cellular magnesium ion homeostasis, but potassium as well. These include mercurial, thiazide, and loop diuretics. It has also been reported that hypomagnesemia is common in digitalis intoxication. In contrast, a number of agents have been shown to have either a magnesium-conserving effect (potassium-sparing diuretics) or not to affect magnesium ion balance (angiotensin-converting enzyme inhibitors). The clinical consequences of magnesium deficiency include the development of various cardiac arrhythmias, all of which respond well to magnesium treatment. Thus, it is more than apparent that magnesium ion homeostasis is of major importance in CHF. Future studies should address the complex role of magnesium ions in electrolyte imbalance, particularly in relation to heart failure.

Animals↗
PubMed1992

The ICOH and IUPAC international programme for establishing reference values of metals.

In cooperation with the ICOH Scientific Committee on the Toxicology of metals and IUPAC Commission on Toxicology, we have developed evaluation criteria for derivation of reference values for metal concentrations in human tissues and fluids. In a first attempt to illustrate how these criteria may be used, tentative reference values for mercury in human blood were derived. For persons who do not eat fish, a mean value of 10 mumol/1 (2 micrograms/1) was suggested. It was pointed out, however, that this value was based on information that did not meet the desired quality requirements, which, unfortunately were not met by any of the published reports.

Animals↗
PubMed1992

Antihypertensive efficacy and side effects of three beta-blockers and a diuretic in elderly hypertensives: a report from the STOP-Hypertension study.

OBJECTIVE: To compare the blood pressure-lowering efficacy, the frequency of side effects and changes in laboratory values of three beta-blockers and a potassium-sparing diuretic combination in elderly hypertensive patients. DESIGN: The Swedish Trial in Old Patients with Hypertension (STOP-Hypertension) was a prospective, randomized, double-blind, multicentre trial comparing active antihypertensive treatment with placebo in patients aged 70-84 years. METHODS: The study group consisted of 1627 elderly hypertensive patients (mean +/- SD age 75.7 +/- 3.7 years; 37% males, 63% females). Supine and standing blood pressure, heart rate and side effects were recorded at each visit. Blood was drawn for routine analysis. The mean length of follow-up was 25 months (range 6-65). No patient was lost to follow-up. RESULTS: After 2-months' single-drug therapy, all four active drugs were found to be equally effective in reducing diastolic blood pressure (DBP). However, there were differences in their efficacy in reducing systolic blood pressure (SBP); the diuretic was significantly more effective than the beta-receptor blockers. The results of a series of multiple linear regression analyses showed that the observed differences in effect on SBP could not be explained by the different effects of the drugs on heart rate. More than two-thirds of the patients were given supplementary treatment, most of them already by the 2-month visit, after which there was no significant difference in blood pressure among the treatment regimens. The changes in laboratory values and in the prevalence of symptoms were minor for all four regimens. CONCLUSION: Metoprolol (controlled release), atenolol, pindolol and the combination hydrochlorothiazide + amiloride were equally effective as single drugs in reducing DBP. There were differences in their efficacy in reducing SBP, the diuretic being more effective than the beta-blockers. After addition of supplementary treatment (beta-blocker to diuretic, or vice versa) there were no significant differences in blood pressure reduction among the groups. The changes in laboratory values and in the prevalence of symptoms were minor for all active treatment regimens. Thus, the satisfactory effect on cardiovascular morbidity and mortality was not impaired by low tolerability of the drugs.

Aged↗
PubMed1992

The stroke preventive effect in elderly hypertensives cannot fully be explained by the reduction in office blood pressure--insights from the Swedish Trial in Old Patients with Hypertension (STOP-Hypertension).

OBJECTIVE: To study whether the cardiovascular preventive effect of antihypertensive therapy can be explained solely by the reduction in office blood pressure, and to what extent the risk of stroke and cardiac events is associated with in-study diastolic blood pressure (DBP) and systolic blood pressure (SBP). DESIGN: The Swedish Trial in Old Patients with Hypertension (STOP-Hypertension) was a prospective, randomized, double-blind, multicentre trial comparing active antihypertensive treatment with placebo in patients aged 70-84 years. The study group comprised 1,627 elderly patients (mean blood pressure 195/102 mm Hg; mean age 75.7, SD 3.7; 63% females). The average follow-up was 25 months (range 6-65 months). No patient was lost to follow-up. METHOD: We applied a Poisson model taking current age, sex, treatment, DBP and SBP into account for all patients in the study. The constants of the model were estimated by the maximum likelihood method. RESULTS: The risk of stroke was significantly lower (42%, p = 0.0402) for a patient on active therapy than for a patient on placebo having the same blood pressure level, age, and sex. There was a corresponding, non-significant, reduction in cardiac events of 21%. In the whole study group the risk of stroke increased by 3% per mmHg (p = 0.0247) with increasing diastolic blood pressure for a given systolic pressure. The corresponding value for cardiac events was 2% per mmHg (p = 0.0376). CONCLUSION: In STOP-Hypertension we found a substantial risk reduction in stroke in actively treated patients, which was not solely explained by the blood pressure reduction obtained by treatment with beta-blockers and a potassium-sparing diuretic combination.

Aged↗
PubMed1991

Morbidity and mortality in the Swedish Trial in Old Patients with Hypertension (STOP-Hypertension)

Although the benefits of antihypertensive treatment in "young" elderly (under 70 years) hypertensive patients are well established, the value of treatment in older patients (70-84 years) is less clear. The Swedish Trial in Old Patients with Hypertension (STOP-Hypertension) was a prospective, randomised, double-blind, intervention study set up to compare the effects of active antihypertensive therapy (three beta-blockers and one diuretic) and placebo on the frequency of fatal and non-fatal stroke and myocardial infarction and other cardiovascular death in hypertensive Swedish men and women aged 70-84 years. We recruited 1627 patients at 116 health centres throughout Sweden, who were willing to participate, and who met the entry criteria of three separate recordings during a 1-month placebo run-in period of systolic blood pressure between 180 and 230 mm Hg with a diastolic pressure of at least 90 mm Hg, or a diastolic pressure between 105 and 120 mm Hg irrespective of the systolic pressure. The total duration of the study was 65 months and the average time in the study was 25 months. 812 patients were randomly allocated active treatment and 815 placebo. The mean difference in supine blood pressure between the active treatment and placebo groups at the last follow-up before an endpoint, death, or study termination was 19.5/8.1 mm Hg. Compared with placebo, active treatment significantly reduced the number of primary endpoints (94 vs 58; p = 0.0031) and stroke morbidity and mortality (53 vs 29; p = 0.0081). Although we did not set out to study an effect on total mortality, we also noted a significantly reduced number of deaths in the active treatment group (63 vs 36; p = 0.0079). The benefits of treatment were discernible up to age 84 years. We conclude that antihypertensive treatment in hypertensive men and women aged 70-84 confers highly significant and clinically relevant reductions in cardiovascular morbidity and mortality as well as in total mortality.

Adrenergic beta-Antagonists↗
PubMed1991

Key learnings from the STOP-Hypertension study: an update on the progress of the ongoing Swedish study of antihypertensive treatment in the elderly.

The Swedish Trial in Old Patients with Hypertension (STOP-Hypertension) is an ongoing multicenter, randomized, double-blind study of antihypertensive treatment (beta-blockers or diuretics) compared to placebo in hypertensive men and women aged 70-84 years. The main trial, which is now in progress, is being carried out at approximately 120 primary health care centers in Sweden, the aim being to recruit 2000 patients, who will be studied for an average period of 3 years. The main study was preceded by a 1-year pilot study in 31 centers. Almost 5000 patients were screened in the pilot study, 55% of whom were labelled hypertensive, i.e., their recumbent blood pressure was greater than or equal to 180/105 mmHg or they were already receiving antihypertensive therapy. After 1 year, 89 patients (1.9%) had been randomized to double-blind treatment and 66 patients (1.4%) were in the run-in/washout period, whereas the remainder had not been included in the trial. The most common reason for not being included as a failure to reach the inclusion blood pressure criteria (greater than or equal to 180 mmHg systolic and/or greater than or equal to 105 mmHg diastolic) following withdrawal of previous antihypertensive medication. In the main trial, recruitment of new centers and new patients has improved gradually and by April 1989 approximately 900 patients had been randomized to double-blind treatment. In an analysis of 961 elderly patients (mean age 70.1 years), the relation between systolic and diastolic blood pressure and mortality was not significant.

Aged↗
PubMed1991

A review of normal concentrations of mercury in human blood.

The present survey is a critical review and quality grading of 98 publications in the international scientific literature presenting mercury concentrations in human whole blood, blood cells and plasma of individuals who have not been occupationally exposed to mercury ("normal values"). Most of the papers reviewed were published after 1976 and were found in the Medline database. Additional information has been obtained in response to requests addressed to scientists with high reputation from different parts of the world working in the field of trace element analysis. The evaluation system includes separate grade scales for sampling and chemical analysis. In no case were the requirements justifying the highest Grade 1 i.e. superior quality, fulfilled. Most reports suffered from various degrees of a lack of information concerning description of individuals, diet, experimental design or analytical and statistical treatment. Nineteen papers were rejected because of insufficient information or obvious erroneous sampling or analytical treatment (Part I). The influence on blood mercury level of various non-occupational exposures, particularly fish consumption, but also medication with mercury-containing drugs, presence of amalgam restorations, etc., has been surveyed. The levels have been systematized according to such parameters. The evaluated and systematized data have been stored in a PC database "Tracy", which includes information about concentrations of total, inorganic or organic mercury in whole blood, blood cells or plasma. Mercury in maternal-cord blood is also included. One hundred and thirty-two data sets from 79 reports were included in the database (Part II). Because of the shortcomings of the available information, only tentative reference values for mercury in whole blood, blood cells and plasma were established (Part III). There is an obvious need for additional high-quality data.

Humans↗