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Biomedical subjects

P O Wester

Publications and source records attributed to P O Wester.

At least 19 recordsLinked to original sources
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↗
PubMed1988

Multielemental assay of tissues of deceased smelter workers and controls.

Concentrations of 23 elements in lung, liver and kidney from deceased smelter workers are compared with those from rural and urban controls. The analyses were made by neutron activation analysis and atomic absorption spectrophotometry. Significantly higher levels of antimony, arsenic, cadmium, chromium, cobalt, lanthanum, lead and selenium were found in the smelter workers lungs (n = 85) compared with the rural controls (n = 15). Significantly higher concentrations of antimony, arsenic and lead were observed among all smelter workers compared with urban controls (n = 10). The highest increase, about 11-fold, was found for antimony in smelter workers compared with non-exposed controls. A six-fold increase was noted for arsenic. Workers who died from lung cancer (n = 7) had the lowest lung selenium content relative to concentrations of other metals, both compared with other disease categories among the workers (GI-cancer, other cancers, cardiovascular diseases, cerebrovascular diseases, other causes) and with the two control groups. The low lung selenium concentrations may have influenced the development of lung cancer. The highest lung tissue levels of cadmium were found in the lung cancer group. Smokers and ex-smokers were over-represented in this group and tobacco is a known cadmium source. The highest, or one of the highest, lung values for some of the other metals (antimony, arsenic, cadmium, lanthanum and lead) were observed in one or several of the lung cancer cases. Metal concentrations in liver (metabolism) and kidney (excretion) reflect the systemic distribution. The highest cadmium levels in the liver and the lowest selenium content in the kidney were found among the lung cancer cases. A multifactorial genesis for the development of lung cancer is concluded from this study, which visualizes the need for systematic health surveillance and follow-ups both in active and retired workers.

Aged↗
PubMed1988

Effects of triamterene on serum and skeletal muscle electrolytes in diuretic-treated patients.

The effects on plasma and skeletal muscle electrolytes of the combination of triamterene 37.5 mg and hydrochlorothiazide 25 mg daily were studied in 19 patients on prior long-term (greater than 1 year) diuretic therapy for arterial hypertension and/or congestive heart failure. A further 20 patients fulfilling the same admission criteria were used as controls. Blood samples and skeletal muscle biopsies were taken before the study and after 6 months on therapy. The diuretic-treated group had a significant increase in skeletal muscle potassium and magnesium after 6 months on therapy as compared to the controls. Thus, the combination of triamterene and hydrochlorothiazide appeared effective in preserving the cellular content of potassium and magnesium on a long-term basis in the type of patient studied.

Aged↗
PubMed1988

Effects of peroral magnesium on plasma and skeletal muscle electrolytes in patients on long-term diuretic therapy.

Twenty patients on long-term diuretic therapy for arterial hypertension and/or congestive heart failure were given a supplementary dose of 15 mmol magnesium aspartate hydrochloride per day for 6 months. Nineteen patients, fulfilling the same admission criteria as the treatment group, served as controls. The addition of magnesium aspartate hydrochloride resulted in a significant rise of the cellular potassium and magnesium content and in a significant decrease of both systolic and diastolic blood pressure. It is concluded that supplementation with magnesium aspartate hydrochloride may effectively prevent the diuretic induced disturbances of electrolyte balance.

Administration, Oral↗
PubMed1988

Blood pressure does not predict mortality in the elderly.

The purpose of our study was to estimate the extent to which casual blood pressure measurements can predict mortality in elderly people in a defined population. A random sample of subjects born between 1890 and 1914 was extracted and their medical records were studied. Their earliest blood pressure record was chosen, provided the patient was at least 60 years old at the time of measurement. The population consisted of 961 patients (49.8% women), 560 of whom died between 1968 and 1987. Their mean age was 70.1 years and the total number of person-years involved was 8625. The mortality risk was estimated as a function of sex, present age, systolic (SBP) and diastolic (DBP) blood pressures, by a version of the Cox regression model. On the basis of close confidence intervals we conclude that blood pressure in the elderly is a very weak predictor of mortality.

Aged↗
PubMed1988

Diagnostic criteria and quality control of the registration of stroke events in the MONICA project.

Stroke events are being registered in 27 of the MONICA collaborating centres. Coding of test cases has shown the greatest discrepancies in coding of the type of stroke (different pathoanatomical diagnoses) and of the diagnostic category (whether a definite stroke has occurred or not), 23% and 14% discrepancies respectively. A check for completeness of stroke registration at the Northern Sweden MONICA Center showed that more than 91% of the events were retrieved by routine registration procedures. Measures to reduce the discrepancies in coding between centres and to check for completeness of data are suggested. In many centres, the number of stroke events below 65 years of age is too small to permit meaningful analyses. By including also stroke events in the 65-74 year age range, the number of fatal events in the Northern Sweden MONICA area increased by 195% and non-fatal events by 149%. Many other MONICA centres have also extended their upper age limit for the registration of stroke events, thus improving the preconditions for statistical evaluations of the long-term changes in stroke incidence.

Age Factors↗
PubMed1988

Amiloride prevents thiazide-induced intracellular potassium and magnesium losses.

To study the effect of a combination of amiloride, 5 mg, and hydrochlorothiazide, 50 mg (Moduretic), on plasma and skeletal muscle electrolytes in patients on long-term diuretic therapy (greater than 1 year) for arterial hypertension and/or congestive heart failure, 58 patients were recruited. Fifty-five patients completed the study, 27 controls and 28 in the treatment group. The Moduretic group demonstrated a significant increase in skeletal muscle potassium and magnesium values and a significant decrease in systolic blood pressure after 6 months on therapy. There was no significant change in these parameters in the control group. It is concluded that this combination of amiloride and hydrochlorothiazide is capable of preserving the internal and external balance of potassium and magnesium on a long-term basis in the patient categories studied.

Aged↗
PubMed1988

Cardiovascular risk factors in the Northern Sweden MONICA Study.

In the WHO MONICA Study, determinants and trends in cardiovascular disease are monitored during a 10-year period in 40 centers in 27 countries. The Northern Sweden MONICA Center is located furthest to the north of all participating centers. In this report, baseline data on cardiovascular risk factors are presented. In the first population screening, 1,625 of 2,000 (81%) invited individuals participated. Diastolic blood pressure greater than or equal to 90 mmHg was recorded in 19% and 9% were on drug treatment for hypertension. Median cholesterol level was 6.10 mmol/l and the frequency of hypercholesterolemia was high. A body mass index of greater than or equal to 30, indicating severe obesity, was observed in 9%, a lower proportion than in most other European populations. Among men, the total proportion of tobacco consumers was 49%, including 22% snuffers. Of the women, 31% were tobacco consumers, very few being snuffers. Women had, in general, a more favorable cardiovascular risk factor profile up to the age of 45. Thereafter, the two genders were similar. By international comparisons, the population in northern Sweden is characterized by high serum cholesterol levels, intermediate blood pressure levels, a relatively low prevalence of severe obesity and a high consumption of smokeless tobacco.

Adult↗