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Biomedical subjects

E Lindenstrøm

Publications and source records attributed to E Lindenstrøm.

12 recordsLinked to original sources
PubMed1997

Is diastolic hypertension an independent risk factor for stroke in the presence of normal systolic blood pressure in the middle-aged and elderly?

In a prospective population-based study from the Copenhagen City Heart Study, the role of diastolic blood pressure as an independent risk factor of stroke, in the presence of normal systolic blood pressure, was assessed in 6,545 subjects aged 50 to 80 years. Follow-up was 12 years. Subjects were divided into various blood pressure categories according to both diastolic and systolic blood pressure. The risk of stroke was assessed using a multivariate Cox proportional hazards model, taking into account various cardiovascular risk factors (age, sex, smoking, diabetes mellitus, body mass index, and levels of serum cholesterol). After adjustment for risk factors, only subjects with elevated systolic blood pressure had a significantly increased risk of future stroke. The risk of stroke according to blood pressure categories further reflected increasing levels of pulse pressure, with the highest risk of stroke in subjects with the greatest pulse pressure. We conclude that systolic blood pressure is a better predictor of stroke than is diastolic blood pressure, and question whether diastolic blood pressure, in the presence of normal systolic blood pressure, is an independent risk factor for stroke in the middle-aged and elderly.

Age Factors↗
PubMed1995

Influence of systolic and diastolic blood pressure on stroke risk: a prospective observational study.

The purpose of this study was to estimate the influence of systolic (SBP) and diastolic blood pressure (DBP) on stroke risk. The Copenhagen City Heart Study is a prospective survey of 19,698 women and men who were invited to two cardiovascular examinations at 5-year intervals. Blood pressure was measured in participants once at each examination, together with other variables. Initial cases of stroke and transient ischemic attack were recorded from hospital records and death certificates from 1976 through 1988. When entered separately in the Cox regression model, both SBP and DBP had significant effects on stroke risk. In the lower 60% of the blood pressure distribution in the population, the relative risk of stroke was nearly constant, followed by a gradual increase in the upper 40% of blood pressure distribution. However, when SBP and DBP were entered simultaneously in the model, the effect of DBP vanished, while the pattern of the association between SBP and stroke risk remained unchanged. Persons on antihypertensive treatment had higher risk for stroke than non-treated persons with the same blood pressure, relative risk = 1.6 (95% confidence interval (CI) 1.2-2.2). The relative risk for the highest SBP levels, shared by nearly 3% of the population, was 4.0 (95% CI 2.2-7.3). The attributable risk of SBP in the upper 40% of SBP distribution, i.e., above the mean for each age and sex group, was 22%. Our results indicate that: 1) the association between blood pressure and stroke risk was not log-linear, and 2) SBP was a stronger stroke predictor than DBP.

Adult↗
PubMed1994

Influence of total cholesterol, high density lipoprotein cholesterol, and triglycerides on risk of cerebrovascular disease: the Copenhagen City Heart Study.

OBJECTIVE: To estimate the influence of plasma total cholesterol, high density lipoprotein cholesterol, and triglycerides on risk of cerebrovascular disease. DESIGN: The Copenhagen City Heart Study is a prospective observational survey with two cardiovascular examinations at five year intervals. Non-fasting plasma lipids were measured in participants once at each examination, along with other variables. The Cox regression model was used to establish the effect of the factors recorded on cerebrovascular events of mostly, but not exclusively, ischaemic origin. SUBJECTS: 19,698 women and men at least 20 years old, randomly selected after age stratification from an area of central Copenhagen. MAIN OUTCOME MEASURES: Initial cases of stroke and transient ischaemic attack recorded from hospital records and death certificates from 1976 through 1988. RESULTS: 660 non-haemorrhagic and 33 haemorrhagic events were recorded. Total cholesterol was positively associated with risk of non-haemorrhagic events, but only for levels > 8 mmol/l, corresponding to the upper 5% of the distribution in the study population. For lower plasma cholesterol values the relative risk remained nearly constant. Plasma triglyceride concentration was significantly, positively associated with risk of non-haemorrhagic events. The relative risk corresponding to an increase of 1 mmol/l was 1.12 (95% confidence interval 1.07 to 1.16). There was a negative, log linear association between high density lipoprotein cholesterol and risk of non-haemorrhagic events (0.53 (0.34 to 0.83)). There was no indication that the effects of plasma lipids were different in women and men. CONCLUSIONS: The pattern of the association between plasma cholesterol and risk of ischaemic cerebrovascular disease was not log linear, and the increased risk was confined to the upper 5% of the cholesterol distribution. Further studies should concentrate on the association between plasma cholesterol and verified haemorrhagic stroke.

Adult↗
PubMed1994

Comparison of probability of stroke between the Copenhagen City Heart Study and the Framingham Study.

BACKGROUND AND PURPOSE: We wished to test the validity of a stroke probability point system from the Framingham Study for a sample of the population of Copenhagen, Denmark. In the Framingham cohort, the regression model of Cox established the effect on stroke of the following factors: age, systolic blood pressure, the use of antihypertensive therapy, diabetes mellitus, cigarette smoking, prior cardiovascular disease, atrial fibrillation, and left ventricular hypertrophy. Derived from this model, stroke probabilities were computed for each sex based on a point system. The authors claimed that a physician can use this system for individual stroke prediction. METHODS: The Copenhagen City Heart Study is a prospective survey of 19,698 women and men aged 20 years or older invited to two cardiovascular examinations at 5-year intervals. The baseline examination included 3015 men and 3501 women aged 55 to 84 years; 474 stroke events occurred during 10 years of follow-up. In both cohorts initial cases of stroke and transient ischemic attack recorded during 10 years of follow-up were used. We used the statistical model from the Framingham Study to establish a corresponding stroke probability point system using data from the Copenhagen City Heart Study population. We then compared the effects of the relevant risk factors, their combinations, and the corresponding stroke probabilities. We also assessed stroke events during 10 years of follow-up in several subgroups of the Copenhagen population with different combinations of risk factors. RESULTS: For the Copenhagen City Heart Study population some of the risk factors (diabetes mellitus, cigarette smoking, atrial fibrillation, and left ventricular hypertrophy) had regression coefficients different from those of the Framingham Study population. Consequently, the probability of stroke for persons presenting these risk factors and their combinations varied between the two studies. For some other risk factors (age, blood pressure, and cardiovascular disease), no major differences were found. The recorded frequency of stroke events in subgroups of the Copenhagen population was compatible with the estimated probability intervals of stroke from the Copenhagen City Heart Study and with those from the Framingham Study, but these intervals were very large. CONCLUSIONS: The majority of risk factors for stroke identified by the Framingham Study also had a significant effect in the Copenhagen City Heart Study population. The differences found could be due partly to different definitions of these factors used by the two studies. Although estimated stroke probabilities based on point systems from the Copenhagen City Heart Study and the Framingham Study were similar, the points scored in the two systems did not always correspond to the same combination of risk factors. Such systems can be used for estimating stroke probability in a given population, provided that the statistical confidence limits are known and the definitions of risk factors are compatible. However, because of the large statistical uncertainty, a prognostic index should not be applied for individual prediction unless it is used as an indicator of high relative risk associated with the simultaneous presence of several risk factors.

Adult↗
PubMed1993

Risk factors for stroke in Copenhagen, Denmark. I. Basic demographic and social factors.

The Copenhagen City Heart Study is a prospective study based on a randomly selected sample of an urban population of, initially, 19,698 participants followed since 1976. Risk factor analysis was based on the initial examination of 13,000 persons > or = 35 years old without previous stroke who responded to the first invitation. In the period 1976-1988, 696 initial cases were identified: 584 strokes, 106 transient ischemic attacks and 6 retinal-artery occlusions. We used the regression model of Cox based on a hierarchic system of risk factors that indicated the way they influence each other. This method distinguishes independent risk factors and estimates their causal influences on the risk of stroke. Among the basic variables analyzed in this paper, significant effects were found for age, sex, length of school education and income. There was a tendency for living alone to be a risk factor as opposed to living with someone, while no influence could be demonstrated for family history of stroke.

Adult↗
PubMed1993

Risk factors for stroke in Copenhagen, Denmark. II. Life-style factors.

The objective of the present work was to identify independent life-style factors for stroke and to estimate their causal contribution. The study is based on a random sample of the Copenhagen population selected in 1976 and stratified by age. The present analysis includes 12,961 subjects examined initially, aged 35 or over and without a previous cerebrovascular event, for whom information about life-style factors was recorded between 1976 and 1978. The outcome was the first-in-life stroke or transient ischemic attack during 12 years of follow-up. The events were ascertained at a second examination 5 years later and from hospital records and death certificates through 1988. Cox's regression model was used to estimate the effect on stroke risk of the factors recorded. In the period 1976-1988, 693 initial events were recorded in eligible responders. Among the life-style factors analyzed, a significant, independent effect was found for cigarette smoking, daily consumption of sleeping pills or tranquilizers and body mass index (BMI). There was a tendency for daily alcohol intake to be associated with lower risk, this could not be demonstrated for physical activity at leisure time. Among smokers, stroke risk was influenced by the number of cigarettes smoked, and daily alcohol intake was associated with a significantly lower risk. The effect of smoking decreased with age. BMI in smokers still had a significant effect on stroke risk but neither daily consumption of tranquilizers, nor physical inactivity at leisure time had a significant influence.

Adult↗
PubMed1993

Lifestyle factors and risk of cerebrovascular disease in women. The Copenhagen City Heart Study.

BACKGROUND AND PURPOSE: The purpose of the present analysis was to determine how lifestyle influences the risk of cerebrovascular disease in women participating in the Copenhagen City Heart Study. METHODS: A random sample of a white, lower and middle-class, urban population selected in 1976 was invited to two cardiovascular examinations at 5-year intervals. The present analysis was based on 7060 women invited to an initial examination from 1976 through 1978, aged 35 years or more, and without previous stroke or transient ischemic attack. At the initial examination, potential risk factors were recorded. The 265 first cases of stroke and transient ischemic attack were ascertained at a second examination 5 years later and through hospital records and death certificates through 1988. The Cox regression model was used to estimate the influence of the factors recorded on the risk of cerebrovascular disease. RESULTS: The relative risks of cigarette smoking and lack of physical activity were 1.4 and 1.45; 95% confidence limits, 1.02 to 1.94 and 1.01 to 2.08, respectively). The relative risk of daily consumption of tranquilizers was 1.25 (95% confidence limits, 0.96 to 1.62). No significant influence was found for number of cigarettes, body mass index, or alcohol intake. In postmenopausal women, there was a statistically significant interaction (P < .041) between smoking and hormone replacement therapy. Smokers receiving this therapy had a 28% lower risk of cerebrovascular disease than smokers not receiving it. CONCLUSIONS: The statistically significant and equally potent effects on the risk of cerebrovascular disease were found for cigarette smoking and lack of physical activity. The risk associated with smoking seemed to be influenced by hormonal replacement therapy.

Adult↗
PubMed1992

Stroke incidence in Copenhagen, 1976-1988.

BACKGROUND AND PURPOSE: Temporal trends in stroke incidence in Denmark have not been previously reported. The Copenhagen City Heart Study is a prospective study based on a randomly selected sample of an urban population of, initially, 19,698 participants followed since 1976. Over a period of 12 years, we studied three important aspects of stroke incidence in 848 identified cases: temporal trends, dependence on age and sex, and comparison of responders and nonresponders. METHODS: The participants were invited to two health examinations at 5-year intervals. The participants who attended at least one of the two examinations are termed responders and those who attended none nonresponders. The cases of first-ever stroke were collected from responders, the National Patient Register, and the National Register of Deaths and were verified by study of hospital records and death certificates. RESULTS: For responders aged 35-64 years and greater than or equal to 65 years, there were no significant changes in the weighted rates in four consecutive 3-year periods. There was a tendency toward decreasing rates among younger women, but not in older women or men. The age- and sex-adjusted rates per 1,000 (based on the Danish population in 1982) in responders in the entire 12-year follow-up period were 1.61 in women, 2.67 in men, and 2.14 in both sexes combined. Stroke incidence rates increased exponentially with age in both sexes, with rates in men generally twice those in women, even in the greater than or equal to 75 years of age group. Age-adjusted rates were higher in nonresponders than in responders. For women, this ratio was 1.7; for men, 1.1. CONCLUSIONS: The stroke incidence in Copenhagen is relatively high and has shown no decreasing tendency over the period 1976-1988.

Adult↗