Predictors of stroke-associated mortality in the elderly

Social Determinants of Stroke Hospitalization and Mortality in United States' Counties

(1) Background: Stroke incidence and outcomes are influenced by socioeconomic status. There is a paucity of reported population-level studies regarding these determinants. The goal of this ecological analysis was to determine the county-level associations of social determinants of stroke hospitalization and death rates in the United States. (2) Methods: Publicly available data as of 9 April 2021, for the socioeconomic factors and outcomes, was extracted from the Centers for Disease Control and Prevention. The outcomes of interest were “all stroke hospitalization rates per 1000 Medicare beneficiaries” (SHR) and “all stroke death rates per 100,000 population” (SDR). We used a multivariate binomial generalized linear mixed model after converting the outcomes to binary based on their median values. (3) Results: A total of 3226 counties/county-equivalents of the states and territories in the US were analyzed. Heart disease prevalence (odds ratio, OR = 2.03, p < 0.001), blood pressure medication nonadherence (OR = 2.02, p < 0.001), age-adjusted obesity (OR = 1.24, p = 0.006), presence of hospitals with neurological services (OR = 1.9, p < 0.001), and female head of household (OR = 1.32, p = 0.021) were associated with high SHR while cost of care per capita for Medicare patients with heart disease (OR = 0.5, p < 0.01) and presence of hospitals (OR = 0.69, p < 0.025) were associated with low SHR. Median household income (OR = 0.6, p < 0.001) and park access (OR = 0.84, p = 0.016) were associated with low SDR while no college degree (OR = 1.21, p = 0.049) was associated with high SDR. (4) Conclusions: Several socioeconomic factors (e.g., education, income, female head of household) were found to be associated with stroke outcomes. Additional research is needed to investigate intermediate and potentially modifiable factors that can serve as targeted interventions.

Statin-Associated Side Effects

Hydroxy-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins are well tolerated, but associated with various statin-associated symptoms (SAS), including statin-associated muscle symptoms (SAMS), diabetes mellitus (DM), and central nervous system complaints. These are "statin-associated symptoms" because they are rare in clinical trials, making their causative relationship to statins unclear. SAS are, nevertheless, important because they prompt dose reduction or discontinuation of these life-saving mediations. SAMS is the most frequent SAS, and mild myalgia may affect 5% to 10% of statin users. Clinically important muscle symptoms, including rhabdomyolysis and statin-induced necrotizing autoimmune myopathy (SINAM), are rare. Antibodies against HMG-CoA reductase apparently provoke SINAM. Good evidence links statins to DM, but evidence linking statins to other SAS is largely anecdotal. Management of SAS requires making the possible diagnosis, altering or discontinuing the statin treatment, and using alternative lipid-lowering therapy.

Analysis of association between brain natriuretic peptide levels and blood pressure variability

The present study aimed to investigate the association between plasma brain natriuretic peptide (BNP) levels and systolic blood pressure (SBP) variability over a one-year period. Blood pressure was measured in 44 patients treated for hypertension (73±9 years old) at an outpatient clinic every one to two months over a one-year period. The standard deviation (SD) and the coefficient of variation (CV) were calculated to assess SBP variability. Mean SBP was also calculated over the year. Plasma BNP levels were measured at the end of the one-year period. BNP was found to correlate with mean SBP (r=0.599; P<0.001). However, BNP was not observed to be correlate with either the SD (r=0.219; P=0.153) or the CV (r=0.058; P=0.709) of the SBP. Multiple regression analysis revealed that only the mean values of SBP were independently associated with BNP (β=0.613; P<0.001). Thus, BNP was found to be correlated with mean SBP, but not SBP variability. In conclusion, plasma BNP levels may reflect the average SBP, but not SBP variability over the one-year period prior to the measurement of BNP in patients with hypertension.

Novel oral anticoagulants for stroke prevention in the geriatric population

Prior to the availability of several newer anticoagulant medications, there had been no new advances in anticoagulation management for stroke prevention since the advent of warfarin in the 1950s. The availability of the novel oral anticoagulants (NOACs) dabigatran, rivaroxaban,and apixaban represent improvements over warfarin in many respects, including the elimination of the need for therapeutic drug monitoring, fewer drug and food interactions,and favorable efficacy; however, these agents are not without risk. Specifically, the use of the NOACs in the geriatric population, who are more likely to have an increased risk of stroke due to atrial fibrillation and other medical comorbidities, is not without risk. The objective of this review is to update the clinician on the use of the NOACs in the geriatric population and introduce the controversies and risks surrounding these newer therapies.

Development and validation of a predicting model of all-cause mortality in patients with type 2 diabetes

OBJECTIVE

To develop and validate a parsimonious model for predicting short-term all-cause mortality in patients with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

Two cohorts of patients with T2DM were investigated. The Gargano Mortality Study (GMS, n = 679 patients) was the training set and the Foggia Mortality Study (FMS, n = 936 patients) represented the validation sample. GMS and FMS cohorts were prospectively followed up for 7.40 ± 2.15 and 4.51 ± 1.69 years, respectively, and all-cause mortality was registered. A new forward variable selection within a multivariate Cox regression was implemented. Starting from the empty model, each step selected the predictor that, once included into the multivariate Cox model, yielded the maximum continuous net reclassification improvement (cNRI). The selection procedure stopped when no further statistically significant cNRI increase was detected.

RESULTS

Nine variables (age, BMI, diastolic blood pressure, LDL cholesterol, triglycerides, HDL cholesterol, urine albumin-to-creatinine ratio, and antihypertensive and insulin therapy) were included in the final predictive model with a C statistic of 0.88 (95% CI 0.82-0.94) in the GMS and 0.82 (0.76-0.87) in the FMS. Finally, we used a recursive partition and amalgamation algorithm to identify patients at intermediate and high mortality risk (hazard ratio 7.0 and 24.4, respectively, as compared with those at low risk). A web-based risk calculator was also developed.

CONCLUSIONS

We developed and validated a parsimonious all-cause mortality equation in T2DM, providing also a user-friendly web-based risk calculator. Our model may help prioritize the use of available resources for targeting aggressive preventive and treatment strategies in a subset of very high-risk individuals.

Hemispheric differences in ischemic stroke: is left-hemisphere stroke more common?

BACKGROUND AND PURPOSE

Understanding the mechanisms underlying stroke can aid the development of therapies and improve the final outcome. The purposes of this study were to establish whether there are characteristic mechanistic differences in the frequency, severity, functional outcome, and mortality between left- and right-hemisphere ischemic stroke and, given the velocity differences in the carotid circulation and direct branching of the left common carotid artery from the aorta, whether large-vessel ischemia (including cardioembolism) is more common in the territory of the left middle cerebral artery.

METHODS

Trial cohorts were combined into a data set of 476 samples. Using Trial of Org 10172 in Acute Stroke Treatment criteria, ischemic strokes in a total 317 patients were included in the analysis. Hemorrhagic stroke, stroke of undetermined etiology, cryptogenic stroke, and bilateral ischemic strokes were excluded. Laterality and vascular distribution were correlated with outcomes using a logistic regression model. The etiologies of the large-vessel strokes were atherosclerosis and cardioembolism.

RESULTS

The overall event frequency, mortality, National Institutes of Health Stroke Scale (NIHSS) score, Glasgow Coma Scale score, and rate of mechanical thrombectomy interventions differed significantly between the hemispheres. Left-hemispheric strokes (54%) were more common than right-hemispheric strokes (46%; p=0.0073), and had higher admission NIHSS scores (p=0.011), increased mortality (p=0.0339), and higher endovascular intervention rates (p≤0.0001). ischemic strokes were more frequent in the distribution of the left middle cerebral artery (122 vs. 97; p=0.0003) due to the higher incidence of large-vessel ischemic stroke in this area (p=0.0011).

CONCLUSIONS

Left-hemispheric ischemic strokes appear to be more frequent and often have a worse outcome than their right-hemispheric counterparts. The incidence of large-vessel ischemic strokes is higher in the left middle cerebral artery distribution, contributing to these hemispheric differences. The hemispheric differences exhibit a nonsignificant trend when strokes in the middle cerebral artery distribution are excluded from the analysis.

Genetic determinants of obesity and related vascular diseases

Obesity is one of the major risk factors of vascular diseases, and its prevalence is increasing worldwide. In the past decade, progress has been made in the understanding of genetic determinants of obesity and obesity-associated diseases. Genome-wide association studies identified a number of genetic variants associated with obesity. In addition to common variants, FTO and MC4R, new loci, such as TMEM18, KCTD15, GNPDA2, SH2B1, MTCH2, and NEGR1 have been detected. In the past years, abdominal obesity has been shown to be a more important vascular risk factor than the body mass index. In the context of vascular risk assessment, identification of genetic polymorphisms associated with accumulation of visceral fat is of special importance. Some polymorphisms associated with abdominal obesity, such as variants of gene encoding microsomal triglyceride transfer protein, have been already discovered. In this chapter, we provide a review of genetic determinants of obesity and discuss their role in obesity-related vascular diseases.

Visit-to-visit variability in blood pressure over a 1-year period is a marker of left ventricular diastolic dysfunction in treated hypertensive patients

Although visit-to-visit variability in systolic blood pressure (SBP) has recently been demonstrated to be a strong predictor of stroke, there are no data about relationships between SBP variability and cardiac damage in hypertensive patients. We compared relationships between visit-to-visit variability in SBP and left ventricular (LV) diastolic dysfunction with the relationships between the mean SBP value and cardiac parameters in treated patients. Forty treated hypertensive patients (69 ± 9 years of age) had their blood pressure measured at outpatient clinics every 1 or 2 months over a 1-year period. The standard deviation (s.d.) of SBP and the difference between the maximum and minimum SBPs during this year were calculated to assess visit-to-visit variability. The mean SBP during the year was also calculated. LV diastolic function was assessed by the ratio (E/A) of early (E) and late (A) diastolic transmitral flows, early diastolic mitral annular velocity (e') and the ratio (E/e') of E to e' using Doppler echocardiography. E/A only correlated with the s.d. of SBP (r=-0.327, P=0.040), whereas e' correlated with s.d. of SBP (r=-0.496, P=0.001) and maximum-minimum SBP difference (r=-0.490, P=0.001). E/e' correlated with s.d. of SBP (r=0.384, P=0.014), maximum-minimum SBP difference (r=0.410, P=0.009), and the mean value of SBP (r=0.349, P=0.028). Multiple regression analysis demonstrated only the maximum-minimum SBP difference independently associated with E/e' (β=0.410, P=0.009). Thus, the visit-to-visit variability of SBP showed better correlation with LV diastolic dysfunction than mean values of SBP. High visit-to-visit variability of SBP was associated with LV diastolic dysfunction and may constitute a high risk for diastolic heart failure in hypertensive patients.

Seasonal blood pressure variation and its relationship to environmental temperature in healthy elderly Japanese studied by home measurements

The purpose of the present study was to examine seasonal blood pressure variation and its relationship to environmental temperature in healthy elderly Japanese, as studied by home measurements. Fifteen healthy elderly Japanese (79.3 +/- 5.9 yrs) measured their blood pressure at home each morning for more than 25 times per month for 3 years. Monthly mean outdoor temperatures were obtained from the Takamatsu meteorological Observatory. The highest levels of systolic and diastolic blood pressure measured at home were observed in February (129 +/- 14 and 81 +/- 13 mmHg). The lowest levels of systolic and diastolic blood pressure measured at home were observed in August (117 +/- 11 and 73 +/- 10 mmHg). Likewise, the lowest and highest means of outdoor temperature were observed in February (5.0 degrees C) and August (29.2 degrees C), respectively. Hence, both systolic and diastolic blood pressure demonstrated a close inverse correlation with the means of outdoor temperature (r = -0.973, p < 0.001 and r = -0.985, p < 0.001, respectively). A 1 degree C decrease in the mean outdoor temperature was associated with rises of 0.43 mmHg in systolic blood pressure (SBP) and 0.29 mmHg in diastolic blood pressure (DBP). Seasonal variations in home blood pressure and outdoor temperature showed complete correspondence in healthy elderly Japanese, with the blood pressures being inversely related to the ambient temperature. These seasonal home blood pressure variations should be kept in mind when controlling blood pressure in elderly patients.

Predictors of stroke in the elderly

Hypertension, diabetes mellitus, coronary heart disease and cigarette smoking have repeatedly been identified as risk factors for stroke in young and middle-aged individuals. In order to find predicting factors for stroke in the elderly we assessed health characteristics in 55 stroke victims in the age range 65-75 years (mean 70.7 +/- 2.7) allocated to our stroke unit at Ostra University Hospital in Gothenburg. For comparison we used data from 2,009 individuals participating in the ongoing longitudinal population study "70-year-old people in Gothenburg, Sweden". Among the stroke victims we found a higher prevalence of hypertension (63.5% vs. 27.8%, p less than 0.001), diabetes mellitus (21.8% vs. 6.2%, p less than 0.001) and a history of previous myocardial infarction (12.7% vs. 4.8%, p less than 0.01), thus confirming previous findings. There was no difference with regard to smoking habits (32.7% vs. 27.5%, NS), which is at variance with findings in the young and middle-aged.

Retinal vascular image analysis as a potential screening tool for cerebrovascular disease: a rationale based on homology between cerebral and retinal microvasculatures

The retinal and cerebral microvasculatures share many morphological and physiological properties. Assessment of the cerebral microvasculature requires highly specialized and expensive techniques. The potential for using non-invasive clinical assessment of the retinal microvasculature as a marker of the state of the cerebrovasculature offers clear advantages, owing to the ease with which the retinal vasculature can be directly visualized in vivo and photographed due to its essential two-dimensional nature. The use of retinal digital image analysis is becoming increasingly common, and offers new techniques to analyse different aspects of retinal vascular topography, including retinal vascular widths, geometrical attributes at vessel bifurcations and vessel tracking. Being predominantly automated and objective, these techniques offer an exciting opportunity to study the potential to identify retinal microvascular abnormalities as markers of cerebrovascular pathology. In this review, we describe the anatomical and physiological homology between the retinal and cerebral microvasculatures. We review the evidence that retinal microvascular changes occur in cerebrovascular disease and review current retinal image analysis tools that may allow us to use different aspects of the retinal microvasculature as potential markers for the state of the cerebral microvasculature.

Correlation of MR lumbar spine bone marrow perfusion with bone mineral density in female subjects

PURPOSE

To prospectively assess lumbar spine bone marrow perfusion at dynamic magnetic resonance (MR) imaging and correlate perfusion with bone mineral density (BMD) in female subjects.

MATERIALS AND METHODS

BMD measurement and dynamic MR imaging of the lumbar spine were performed in 69 female subjects (mean age +/- standard deviation, 57 years +/- 11). Subjects were stratified into premenopausal (n = 19) and postmenopausal (n = 50) groups, with the latter group including both women who were (n = 13) and women who were not (n = 37) receiving hormone replacement therapy. BMD (in grams per square centimeter) was measured with dual energy absorptiometry in the lumbar spine. Peak enhancement ratio, measured with time-signal intensity curves calculated from dynamic MR image data, represented bone marrow perfusion. Peak enhancement ratio was compared with age and BMD by using linear regression analysis and Pearson correlation.

RESULTS

A significant positive correlation was found for BMD with peak enhancement ratio of lumbar vertebrae among all subjects (n = 69, r = 0.63, P <.001), all postmenopausal women (n = 50, r = 0.50, P <.001), and postmenopausal women without hormone replacement therapy (n = 37, r = 0.61, P <.001). However, the correlation between BMD and peak enhancement ratio was not significant (P >.05) in premenopausal women (n = 19) or postmenopausal women receiving hormone therapy (n = 13). Both BMD and peak enhancement ratio were inversely correlated with age (P <.001, Pearson correlation). Pearson partial correlation coefficient for peak enhancement ratio and mean in all subjects, with control for inverse correlation with age, was significant (r = 0.63, P <.001).

CONCLUSION

Significant correlation was found between the peak enhancement ratio of vertebral bone marrow and BMD in postmenopausal female subjects. This result may suggest a vascular component in the pathogenesis of osteoporosis.

Smoking habits and attitudes of age concern volunteers

As the population is ageing, health promotion is becoming increasingly important to prevent disease and disability. Cigarette smoking is strongly associated with excess mortality and smoking cessation even after the age of 65 years, improves health and lowers mortality. The voluntary sector is an under-utilised resource for health promotion to older people. Age Concern Cymru is the leading voluntary organisation in Wales involved in promoting 'healthy ageing'. The aim of this study was to determine the smoking habits and attitudes of older Age Concern volunteers. A questionnaire enquiring about smoking habits and attitudes was circulated to all volunteers aged 65 years and over attending age concern meetings in Wales between July and September 1999. Of 375 respondents (93% response rate) 16% were current-smokers, 58% ex-smokers and 26% life-long non-smokers. A significantly greater proportion of women were non-smokers. Significantly more ex-smokers (90%) and non-smokers (93%) compared with current-smokers (72%) believed that smoking causes heart disease (P<0.002). More ex-smokers (91%) and non-smokers (94%) than current-smokers (80%) believed smoking causes lung cancer (P<0.05). In conclusion, the majority of volunteers are currently non-smokers. Over 90% of ex-smokers and non-smokers believed in the deleterious effects of smoking on health. These volunteers could be utilised for smoking-cessation campaigns.

Prevalence of coronary artery disease, ischemic stroke, and symptomatic peripheral arterial disease and of associated risk factors in older men and women with and without diabetes mellitus

The authors performed a retrospective analysis of the prevalence of coronary artery disease, ischemic stroke, and symptomatic peripheral arterial disease and of associated risk factors in 99 men (mean age 79±8 years) with diabetes mellitus vs. 368 men (mean age 81±8 years) without diabetes mellitus, and in 260 women (mean age 80±8 years) with diabetes mellitus vs. 1184 women (mean age 81±8 years) without diabetes mellitus. All patients were seen in an academic outpatient geriatrics practice. Diabetic men had a higher prevalence of coronary artery disease, ischemic stroke, and symptomatic peripheral arterial disease (p<0.0001); a higher prevalence of smoking (p=0.023), hypertension (p<0.0001), and obesity (p=0.0007); higher levels of serum total and low density lipoprotein cholesterol (p<0.0001) and triglycerides (p=0.003); and lower levels of serum high density lipoprotein cholesterol (p=0.0001) than men without diabetes mellitus. Diabetic women had a higher prevalence of coronary artery disease, ischemic stroke, and symptomatic peripheral arterial disease (p<0.0001); a higher prevalence of hypertension and obesity (p<0.0001); higher levels of serum total and low density lipoprotein cholesterol (p=0.0001) and triglycerides (p=0.005); and lower levels of serum high density lipoprotein cholesterol (p=0.0001) than women without diabetes mellitus. (c) 2000 by CHF, Inc.

Risk factors for ischemic stroke in older persons in an academic hospital based geriatrics practice

We performed a retrospective analysis of charts investigating risk factors for ischemic stroke in 467 men (mean age 80±8 years) and 1444 women (mean age 81±8 years) seen in an academic geriatrics practice. Ischemic stroke was present in 126 of 467 men (27%) and in 296 of 1444 women (20%) (p=0.003). Stepwise logistic regression analysis showed that significant independent risk factors for ischemic stroke were age (p=0.005 in men and 0.010 in women, odds ratio=1.04 in men and 1.03 in women); cigarette smoking (p=0.006, odds ratio=1.7 in women); hypertension (p<0.001 in men and women, odds ratio=4.6 in men and 3.9 in women); diabetes mellitus (p=0.018 in men and <0.001 in women, odds ratio=1.9 in men and 2.0 in women); serum low-density lipoprotein cholesterol (p<0.001 in men and women, odds ratio=1.02 in men and 1.01 in women); and serum high-density lipoprotein cholesterol (p<0.001, odds ratio=0.97 in women). Significant independent risk factors for ischemic stroke in both sexes were: age, hypertension, diabetes mellitus, and serum low-density cholesterol; and in older women: cigarette smoking and serum high-density lipoprotein cholesterol (inverse association). (c) 2000 by CHF, Inc.

Risk factors for new atherothrombotic brain infarction in older Hispanic men and women

BACKGROUND

We report the prevalence and incidence of atherothrombotic brain infarction (ABI) in older Hispanic men and women in a long-term health care facility.

METHODS

The prevalence and incidence of ABI and the association of risk factors with new ABI were investigated in 201 Hispanic men, mean age 79 +/- 8 years, and in 302 Hispanic women, mean age 80 +/- 9 years, in a long-term health care facility. Mean follow-up was 42 +/- 20 months in men and 47 +/- 26 months in women.

RESULTS

The prevalence of prior ABI was 33% in Hispanic men and 30% in Hispanic women. The incidence of new ABI was 24% in Hispanic men and 23% in Hispanic women. Significant independent risk factors for new ABI were age (risk ratio = 1.09 in men and 1.08 in women for each increase of 1 year of age), current cigarette smoking (risk ratio = 2.8 in men and 2.7 in women), hypertension (risk ratio = 2.8 in men), diabetes mellitus (risk ratio = 3.5 in men and 5.0 in women), prior ABI (risk ratio = 5.6 in men and 5.5 in women), serum total cholesterol (risk ratio = 1.03 in men and 1.01 in women for each 1 mg/dl increase), and serum high-density lipoprotein (HDL) cholesterol (risk ratio = 1.06 in men and 1.06 in women for each 1 mg/dl decrease).

CONCLUSIONS

Significant independent risk factors for new ABI were age, current cigarette smoking, diabetes mellitus, prior ABI, serum total cholesterol, and serum HDL cholesterol (inverse association) in older Hispanic men and women and hypertension in older Hispanic men.

Retinal microvascular abnormalities and their relationship with hypertension, cardiovascular disease, and mortality

Retinal microvascular abnormalities, such as generalized and focal arteriolar narrowing, arteriovenous nicking and retinopathy, reflect cumulative vascular damage from hypertension, aging, and other processes. Epidemiological studies indicate that these abnormalities can be observed in 2-15% of the nondiabetic general population and are strongly and consistently associated with elevated blood pressure. Generalized arteriolar narrowing and arteriovenous nicking also appear to be irreversible long-term markers of hypertension, related not only to current but past blood pressure levels as well. There are data supporting an association between retinal microvascular abnormalities and stroke, but there is no convincing evidence of an independent or direct association with atherosclerosis, ischemic heart disease, or cardiovascular mortality. New computer-related imaging methods are currently being developed to detect the presence and severity of retinal arteriolar narrowing and other microvascular characteristics. When reliably quantified, retinal microvascular abnormalities may be useful as risk indicators for cerebrovascular diseases.

Risk factors for new atherothrombotic brain infarction in older African-American men and women

Independent risk factors for new atherothrombotic brain infarction (ABI) in older African-American men were hypertension (risk ratio 4.381), diabetes mellitus (risk ratio 2.872), and previous ABI (risk ratio 1.904). Independent risk factors for new coronary events in older African-American women were cigarette smoking (risk ratio 2.754), hypertension (risk ratio 5.914), diabetes mellitus (risk ratio 3.464), serum total cholesterol (risk ratio 1.008), serum high-density lipoprotein cholesterol (inverse association) (risk ratio 0.958), age (risk ratio 1.026), and previous ABI (risk ratio 2.601).

Prospective association of smoking and alcohol use with cognitive function in an elderly cohort

Cross-sectional studies of the associations of alcohol and tobacco use with cognitive function do not take into account behavior change after memory loss or differential survival. This prospective study examines the association of cigarette smoking and alcohol consumption at baseline with risk of poor cognitive function 13-18 years later. Between 1973 and 1975, 1469 relatively well-educated, noninstitutionalized men and women from Rancho Bernardo, California, answered standardized questions about smoking and alcohol consumption. Between 1988 and 1991, 511 of these men and women completed five standardized cognitive function tests. At baseline, 20.4% of the men and 23.0% of the women were cigarette smokers. Smoking was associated with increased mortality in men but not in women. In surviving male participants, cognitive function test scores did not significantly differ by baseline smoking status. Among female participants, smoking was associated with categorically defined poorer function on two of five tests. At baseline, 16% of the men and 29% of the women were nondrinkers. Drinking more than two drinks per day was associated with decreased mortality in both sexes. Among women, increasing consumption of alcohol predicted a significant decline in the long-term recall and savings scores of the visual reproduction test. Moderate drinking, approximately two drinks per day, predicted categorically defined poor performance on the Buschke long-term recall task in women. Alcohol consumption was not associated with cognitive function in men. Overall, the observed associations were weak, and no clear pattern was observed. Although there were some gender differences in observed associations and a survivor effect cannot be excluded, data from these healthy, educated, noninstitutionalized people offer no compelling evidence that social drinking or cigarette smoking causes or prevents impaired cognitive function in old age. The large number of comparisons and inconsistent results suggest that the few statistically significant findings may be spurious. Additional long-term prospective studies are needed to determine the generalizability of these findings to individuals in less healthy or less well-educated cohorts.

Seasonal variation of blood pressure in maintenance hemodialysis

CONTEXT

Seasonal variation in arterial blood pressure has been reported in studies with hypertensive and normotensive subjects. However, the influence of seasonal change on blood pressure of hemodialysis patients has not been reported.

OBJECTIVE

To investigate the seasonal variation of blood pressure in Brazil, a tropical country, in patients on hemodialysis.

DESIGN

Prospective, cohort study.

SETTING

Dialysis unit of a tertiary medical center (a teaching hospital of the University of São Paulo School of Medicine, São Paulo).

PATIENTS

Sixteen patients with chronic renal failure undergoing hemodialysis.

OUTCOMES

Blood pressure, body weight, and ambient temperature were evaluated during 6 hemodialysis sessions carried out on 13 days during the four seasons.

RESULTS

The diastolic blood pressure was lower in summer than in fall and winter (95 +/- 8 vs 107 +/- 10 and 101 +/- 10 mmHg, respectively; p < 0.05). The same was observed with mean blood pressure (116 +/- 8 vs 130 +/- 11 and 124 +/- 9 mmHg, respectively; p < 0.01). On the other hand, the ambient temperature was higher in summer than in fall and winter (23.0 +/- 1.6 vs 19.5 +/- 3.0 and 15.8 +/- 1.9 degrees C, respectively; p < 0.01).

CONCLUSIONS

We concluded that for patients with chronic renal failure the blood pressure has a seasonal variation with higher pressures in fall and winter than in summer. Thus, further studies are needed to elucidate the impact of this observation on the adjustment of antihypertensive treatment and on morbidity and mortality in maintenance dialysis patients.

Development of a health risk appraisal for the elderly (HRA-E)

The purpose of this project is to develop a health risk appraisal for the elderly (HRA-E) and test its application in both medical and nonmedical settings. The HRA-E system consists of a questionnaire and software for computer-generation of personalized reports to participants, 55 years and older, and their physicians. Items in the questionnaire cover a comprehensive range of content domains relevant to health promotion in the elderly. The goal of the HRA-E system is to prevent functional decline. Samples of eligible subjects from the American Association of Retired Persons (AARP), a group practice, and a senior center were extended invitations to participate. Those responding affirmatively to the invitation were given a questionnaire and evaluation form. Each person who returned the questionnaire received his or her personal report and a second evaluation form. Four months after receiving their reports, respondents were questioned about behavior changes during the interim. Preliminary findings, based on 1895 respondents, indicate that nearly all participants found the questionnaire easy to complete and were pleased with its overall length. In addition, most participants read their reports, and many planned to take action, based on report recommendations. In the next phase of this project, the intent is to refine the questionnaire, extend the intervention protocols for longitudinal application, and evaluate its impact on health-related behaviors, medical care utilization, and functional decline.

Epidemiology of stroke

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Risk factors for new atherothrombotic brain infarction in 664 older men and 1,488 older women

The relation between obesity and new ABI is also unclear. The Framingham Study found that relative weight was not a risk factor for new ABI in older men but was a weak risk factor for new ABI in older women. Barrett-Connor and Khaw found no association between body mass index and new ABI in older men or women. The present study showed that obesity was not a risk factor for new ABI in older men. Obesity was a risk factor for new ABI in older women by univariate analysis but not by multivariate analysis. However, because obesity is associated with other risk factors for ABI and new coronary events, we would try to lower weight in obese older men and women.

Vitamin C and risk of death from stroke and coronary heart disease in cohort of elderly people

OBJECTIVES

To determine whether vitamin C status, as measured by dietary intake and plasma ascorbic acid concentration, is related to mortality from stroke and coronary heart disease in people aged 65 and over.

DESIGN

A 20 year follow up study of a cohort of randomly selected elderly people living in the community who had taken part in the 1973-4 Department of Health and Social Security nutritional survey and for whom dietary and other data had been recorded.

SETTING

Eight areas in Britain (five in England, two in Scotland, and one in Wales).

SUBJECTS

730 men and women who had completed a seven day dietary record and who had no history or symptoms of stroke, cerebral arteriosclerosis, or coronary heart disease when examined by a geriatrician in 1973-4.

RESULTS

Mortality from stroke was highest in those with the lowest vitamin C status. Those in the highest third of the distribution of vitamin C intake had a relative risk of 0.5 (95% confidence interval 0.3 to 0.8) compared with those in the lowest third, after adjustment for age, sex, and established cardiovascular risk factors. The relation between vitamin C intake and stroke was independent of social class and other dietary variables. A similar gradient in risk was present for plasma ascorbic acid concentrations. No association was found between vitamin C status and risk of death from coronary heart disease.

CONCLUSION

In elderly people vitamin C concentration, whether measured by dietary intake or plasma concentration of ascorbic acid, is strongly related to subsequent risk of death from stroke but not from coronary heart disease.

Body fat and stroke: unmasking the hazards of overweight and obesity

STUDY OBJECTIVE

It has been frequently noted that overweight and obesity have a stronger relationship to hypertension and diabetes mellitus than to the risk of stroke. The reason for this observation has not been clear. This study aimed to examine the lifelong relation between body fat and stroke to shed light on why the public health risks of overweight and obesity have tended to be obscured in previous epidemiological studies.

DESIGN

Case-control study.

SETTING

Eleven general practices in west Birmingham.

PARTICIPANTS

Altogether 125 men and women who had just had their first stroke and were aged 35-74 years and 198 controls frequency matched for age and sex were recruited over 24 months during 1988-90.

MAIN RESULTS

Those in both the thinnest and fattest quartiles of subscapular skinfold thickness were at increased risk of stroke compared with those in the middle quartiles (age adjusted odds ratios 2.12 (95% confidence interval (CI) 1.2, 3.9) and 2.08 (1.1, 3.8) respectively). When lifelong maximum reported body mass index was assessed the hazards of obesity but not leanness were seen (odds ratio for the highest versus the lowest quartile were--age adjusted, 1.54 (0.8, 3.0) and multiple risk factor adjusted, 2.25 (1.1, 4.5). This lifelong pattern of risk seemed to be established early, the odds ratios for the highest versus the lowest quartile of reported body mass index aged 21 years were--age adjusted, 2.18 (1.1, 4.4) and multiple risk factor adjusted 2.13 (1.1, 4.2). The risks of both maximum reported body mass index and reported body mass index aged 21 years were more clear in those who had never smoked cigarettes (test for trend in odds ratio, p = 0.009 and p = 0.02 respectively).

CONCLUSIONS

Potentially important risks of excessive body fat for stroke can be obscured by both a history of cigarette smoking and thinness associated with deteriorating health. The results seem to explain why excess body fat has previously been consistently related to hypertension and diabetes mellitus but less consistently to stroke. Avoiding overweight and obesity during adult life offers protection against stroke.

Assessment of fracture risk and its application to screening for postmenopausal osteoporosis: synopsis of a WHO report. WHO Study Group

The criteria required for an effective screening strategy for osteoporosis are largely met in Caucasian women. The disease is common and readily diagnosed by the measurement of bone mineral with single- or dual-energy absorptiometry. Such measurements have high specificity but lower sensitivity, so that the value of the technique is greater for those identified as being at higher risk. Against this background there is little evidence that osteoporosis can usefully be tackled by a public health policy to influence risk factors such as smoking, exercise and nutrition. This suggests that it is appropriate to consider targetting of treatment with agents affecting bone metabolism to susceptible individuals. Since the main benefits of the use of hormone replacement therapy (HRT) are probably on cardiovascular morbidity, the major role for selective screening is to direct non-HRT interventions. An appropriate time to consider screening and intervention is at the menopause, but screening at later ages is also worthy of consideration. Since the cost of screening is low and that of bone-active drugs is high, the selective use of screening techniques will improve the cost-benefit ratio of intervention.

Age and cerebral infarction: a postmortem study of 77 cases of cerebral infarcts in the middle cerebral artery territory

Adverse effect of age on ischemic stroke short-term mortality was reported in some studies and attributed either to more frequent extracerebral causes of death or to an increased severity of ischemia in the aged brain. Relationship between age, size of infarcts, and causes of death were studied in 77 consecutive patients who died from infarction in the middle cerebral artery territory. Area of infarcts was assessed by planimetry, and results were expressed as an index of infarcted area. No significant relationship was found between age and the size of infarcts, the cause of death, or the interval from stroke to death. These results do not support the hypothesis of an increased severity of ischemia in the aged brain.

Association between low bone density and stroke in elderly women. The study of osteoporotic fractures

BACKGROUND AND PURPOSE

To determine whether women with low bone mineral density are at increased risk of stroke, the present study was conducted.

METHODS

We studied 4024 ambulatory women aged 65 years or older participating in the prospective Study of Osteoporotic Fractures. Bone mineral density was measured at baseline using single photon absorptiometry; strokes were ascertained using a computerized Medicare data base and death certificates.

RESULTS

During a mean of 1.98 years of follow-up, 83 women suffered first strokes (five fatal). Osteopenia was associated with an increased stroke risk: Each SD decrease in bone mineral density at the calcaneus (0.09 g/cm2) was associated with a 1.31-fold increase in stroke (95% confidence interval, 1.03-1.65), adjusted for age, follow-up time, and several potential confounders, including diabetes, systolic blood pressure, use of alcohol, cigarettes or postmenopausal estrogens, cognitive ability, grip strength, and functional ability. The observed relation between bone density and stroke was strongest for intracerebral hemorrhages and occlusions.

CONCLUSIONS

Most likely, low bone density does not cause stroke; some other process probably results in both osteopenia and cerebrovascular disease.

Maintenance of functioning in the elderly

Dramatic declines in age-specific mortality have led to large increases in the number of older people in the United States and other industrialized populations. While increased survival time is to be desired, it is important to consider the functional ability of those who survive to older ages, and whether preventive activities can lead to higher levels of functioning. Using data from the Alameda County Study, results indicating that incident chronic diseases are associated with poorer levels of physical functioning are presented. Many of the behavioral, social, and demographic risk factors that are associated with risk of chronic disease and mortality in this cohort are also associated with poorer physical functioning. Thus, interventions that reduce or delay the development of chronic diseases in the elderly may also result in higher levels of physical functioning. These same risk factors also modify the impact of chronic disease on functioning. Therefore, interventions that reduce risk factors for chronic disease may increase levels of functioning in those who survive with or without disease.

Lifestyle factors and risk of cerebral infarction

BACKGROUND AND PURPOSE

We evaluated the impact of lifestyle factors on the risk of ischemic stroke.

METHODS

We used a nested case-control design. The cases comprised 163 persons (median age 69 years) admitted to a stroke unit and diagnosed with acute cerebral infarction. All cases had earlier participated in the North Trøndelag Health Survey. The controls comprised 567 participants from the North Trøndelag Health Survey, matched by sex and year of birth.

RESULTS

Raised systolic (p less than 0.001) and diastolic (p = 0.02) blood pressure, antihypertensive treatment (p less than 0.001), previous myocardial infarction (p less than 0.001), prior stroke (p = 0.002), diabetes (p less than 0.001), and former daily smoking (p = 0.02) were identified as significant risk factors by univariate conditional logistic regression. No difference in risk was detected at different levels of alcohol consumption, salt intake, physical activity, or body mass index. Current smokers had virtually the same risk as nonsmokers. No association was found between stroke and the number of cigarettes smoked per day or the number of years of smoking. Multivariate conditional logistic regression identified diabetes (p = 0.002), raised systolic blood pressure (p less than 0.001), and former daily smoking (p = 0.01) as significant and independent risk factors. Previous myocardial infarction (p = 0.07), previous stroke (p = 0.1), and current daily smoking (p = 0.1) were of marginal significance.

CONCLUSIONS

The established medical risk factors for stroke are confirmed. With the possible exception of smoking, we have not identified any lifestyle factor with a significant impact on the risk of ischemic stroke.

Prevalence of extracranial carotid artery disease detectable by echo-Doppler in an elderly population

BACKGROUND AND PURPOSE

Little information is available on extracranial carotid artery disease in free-living elderly individuals. We sought to evaluate the prevalence of carotid lesions in the elderly.

METHODS

Using echo-Doppler, we assessed the prevalence of possible atherosclerotic lesions in the internal carotid arteries (n = 478) and the external and common carotid arteries (n = 956) of 239 subjects 65-94 years of age living in retirement homes in Seattle, Wash.

RESULTS

We found that 152 (31.8%) internal carotid arteries were affected by nonstenosing plaque and 37 arteries (7.7%) had stenosis or occlusion. In addition, 193 (20.2%) external or common carotid arteries showed nonstenosing plaques. There were 128 subjects (53.6%) with internal carotid disease, 106 (44.3%) with evidence of external or common carotid disease, and 75 (31.4%) affected by disease in all three sites. There were 80 subjects (33.5%) with no ultrasound evidence of carotid disease. We found that the presence and severity of carotid disease increased between the decades 65-74 and 75-84. We also demonstrated a positive association between systolic blood pressure and ultrasound evidence of carotid disease that was independent of age.

CONCLUSIONS

The prevalence of extracranial artery disease in an apparently healthy population was high, although stenoses in most instances were not severe. We conclude that noninvasive ultrasound methods identify a relatively small fraction of individuals (5% of the total) at high risk for stroke or transient ischemic attack. Echo-Doppler might be used to monitor further disease progression and to evaluate the efficacy of different therapeutic or preventive interventions.

Elderly subjects aged 70 years and above have different risk factors for ischemic and hemorrhagic strokes compared to younger subjects

OBJECTIVE

To compare risk factors for ischemic and hemorrhagic strokes in subjects aged 70 years and above with those in younger subjects.

DESIGN

Case control study, with controls matched for age and sex in 5-year age groups.

SETTING

A general district hospital in Hong Kong with a catchment population of over 1 million.

PATIENTS

All patients admitted consecutively over a 6-month period. Classification of stroke was by neurological examination and CT scan, or autopsy if death occurred before CT scanning could be performed.

EXCLUSION CRITERIA

onset of ictus greater than 48 hours before admission, those with previous stroke, subarachnoid hemorrhage, or embolic stroke from rheumatic heart disease, and those with liver, renal, biliary, or thyroid diseases. For ischemic strokes, 78 pairs less than 70 years and 121 pairs greater than or equal to 70 years were recruited. For hemorrhagic strokes, the numbers were 40 and 39, respectively.

RESULTS

For ischemic strokes, atrial fibrillation and the presence of ischemic heart disease were risk factors only for those aged 70 years and above, while smoking and left ventricular hypertrophy were risk factors only for those below 70 years. Hypertension and glucose intolerance were risk factors for both age groups, although the effect of glucose intolerance was less marked in the older group. No marked difference in serum lipids and lipoproteins as risk factors was observed between the two age groups. Hypertension was the only demonstrable risk factor for hemorrhagic stroke in the younger, but not in the older, group.

CONCLUSION

Risk factors for ischemic and hemorrhagic strokes are different in elderly compared with younger subjects, with the possibility that certain risk factors for ischemic strokes, in contrast to those for hemorrhagic strokes, may be modifiable even in subjects aged 70 years or above.

Fibrinogen and lipid concentrations as risk factors for transient ischaemic attacks and minor ischaemic strokes

OBJECTIVES

To determine whether fibrinogen and lipid concentrations are risk factors for ischaemic stroke.

DESIGN

Case-control study with a population based comparison within the overall study.

SETTING

Oxfordshire community stroke project and a neurology clinic.

SUBJECTS

105 patients who had a transient ischaemic attack or minor ischaemic stroke and 352 randomly chosen controls matched for age and sex from the same general practitioners as the incident cases. 52 controls were ineligible or refused interview. 104 cases and 241 controls gave blood samples for analysis.

MAIN OUTCOME MEASURES

Response to structured questionnaire, height, weight, blood pressure, and serum concentrations of fibrinogen and lipids.

RESULTS

Adjusted for other variables, odds ratios of ischaemic stroke were 1.78 (95% confidence interval 0.91 to 3.48; p = 0.09) [corrected] for fibrinogen concentrations greater than 3.6 g/l; 1.73 (0.90 to 3.29; p = 0.09) [corrected] for total cholesterol concentrations greater than 6.0 mmol/l; 1.34 (0.69 to 2.61; p greater than 0.4) for low density lipoprotein cholesterol concentrations greater than 3.5 mmol/l; and 0.32 (0.15 to 0.69; p = 0.002) for high density lipoprotein cholesterol concentration greater than 1.2 mmol/l. Similar results emerged comparing only community derived cases with transient ischaemic attacks and controls. The effects of fibrinogen, total cholesterol, and high density lipoprotein cholesterol were significant in a test of trend after adjusting for all other variables in the study (chi 2 = 4.14, p less than 0.05; chi 2 = 4.31, p less than 0.05, and chi 2 = 12.15, p greater than 0.001, respectively). History of ischaemic heart disease and hypertension were the only other variables that showed significance, though both lost significance after adjustment (2.06, p = 0.08 and 1.53, p = 0.2, respectively).

CONCLUSIONS

Fibrinogen and lipids are important risk factors for ischaemic stroke. The pattern of changes mirrors that found in ischaemic heart disease.

Non-trauma mortality in elderly women with low bone mineral density. Study of Osteoporotic Fractures Research Group

9704 ambulatory women aged 65 years or older were prospectively studied to determine whether low bone mineral density (osteopenia) was associated with mortality. Bone mineral density was measured at entry to the study by single-photon absorptiometry. 299 women died during a mean of 2.8 years' follow-up. Osteopenia was associated with increased non-trauma mortality, probably because it is a marker for several other adverse factors. Each standard deviation decrease in proximal radius bone mineral density (0.104 g/cm2) was associated with a 1.19-fold increase in mortality (95% confidence interval 1.04-1.36), adjusted for age and duration of follow-up. Diminished bone mineral density at the proximal radius was strongly associated with deaths from stroke (relative risk = 1.74; 95% CI 1.12-2.70), an association that was not confounded by history of previous stroke, hypertension, postmenopausal use of oestrogen, thiazide diuretic treatment, diabetes mellitus, and smoking. Most deaths in women with low bone mineral density are unrelated to the occurrence of fractures-an observation that should be taken into account when estimating the need for and cost-effectiveness of bone-density screening and fracture prevention programmes.

Overweight and stroke in the Whitehall study

STUDY OBJECTIVE

The aim was to examine the risk of increasing overweight for death from stroke.

DESIGN

This was a prospective cohort study, in which the main outcome measure was the mortality ratio for stroke with increasing body mass index.

SETTING

Civil service departments, Whitehall, London.

SUBJECTS

Participants were 17,753 men aged 40 to 64 years.

MEASUREMENTS AND MAIN RESULTS

208 stroke deaths were recorded. Men aged 40 to 54 in the most overweight quintile of body mass index had a mortality ratio of 2.01 (95% confidence interval 0.9 to 4.7) compared to the thinnest quintile. The mortality ratio was 1.19 (95% CI 0.7 to 2.0) in men aged 55 to 64. The increase in risk was more apparent in non-smokers: age adjusted mortality ratio 2.58 (95% CI 1.2 to 5.7). When smoking status and overweight were considered in combination a gradient of the age adjusted mortality ratio was observed, from 1.0 in thinner/non-smokers up to 3.15 in fatter/current smokers. On the assumption that smoking and obesity cause strokes, an estimated 60% of strokes could be prevented if these two easily identifiable risk factors could be avoided.

CONCLUSIONS

The risks of overweight for death from stroke were more apparent in younger subjects and non-smokers. A substantial proportion of stroke deaths occurring under the age of 80 years would probably be prevented if cigarette smoking and overweight could be avoided.

Obesity, hypertension and stroke

Central fat distribution may be more closely associated with stroke risk than relative weight or body mass index, although both are associated with hypertension. Some of this association may reflect the fact that central obesity reflects adult weight gain, which may be more relevant to stroke risk than weight in old age. Three attributes associated with central obesity, hypertension and stroke risk deserve further exploration as a possible explanatory variables for the central obesity-stroke risk association. They are cigarette smoking, heavy alcohol intake and diabetes. Prevention of smoking and excess alcohol intake would be consistent with general public health guidelines and might be more relevant to stroke prevention than caloric reduction and management of general overweight.

Meta-analysis of relation between cigarette smoking and stroke

There is a lack of consensus among studies on the possible risks of stroke from cigarette smoking; because of this a meta-analysis was conducted. All published data on the association were sought and the relative risk for each study obtained whenever possible. The pooled relative risks were calculated by using estimates of the precision of the individual relative risks to weight their contribution to the meta-analysis. Thirty two separate studies were analysed. The overall relative risk of stroke associated with cigarette smoking was 1.5 (95% confidence interval 1.4 to 1.6). Considerable differences were seen in relative risks among the subtypes: cerebral infarction 1.9, cerebral haemorrhage 0.7, and subarachnoid haemorrhage 2.9. An effect of age on the relative risk was also noted; less than 55 years 2.9, 55-74 years 1.8, and greater than or equal to 75 years 1.1. A dose response between the number of cigarettes smoked and relative risk was noted, and there was a small increased risk in women compared with men. Ex-smokers under the age of 75 seemed to retain an appreciably increased risk of stroke (1.5); for all ages the relative risk in ex-smokers was 1.2. The meta-analysis provides strong evidence of an excess risk of stroke among cigarette smokers. Stroke should therefore be added to the list of diseases related to smoking.

Individual variation in susceptibility to extracranial carotid atherosclerosis

Risk factors for coronary disease were assessed and noninvasive methods were used to quantitate the extent of extracranial carotid atherosclerosis in 382 patients free of cerebrovascular symptoms. The ages of the participants ranged from 27 to 80 years. There were 183 men and 199 women, 30 black and 352 white persons. All patients had heart disease symptoms and were hospitalized for coronary angiography. Correlation of risk factors with extent of extracranial carotid atherosclerosis in this series of patients undergoing coronary angiography uncovered individual variability in relationships between risk factors and carotid atherosclerosis that depended on coronary status. Risk factors for carotid atherosclerosis in patients with and without coronary disease differed. Age and hypertension were independently related to carotid atherosclerosis in patients with, as well as those without, coronary disease. However, other risk factors were related to carotid atherosclerosis in only one group or the other. Risk factors correlated strongly with carotid atherosclerosis in patients with coronary disease (r2 = 0.41) but poorly in those with no coronary disease (r2 = 0.21). Certain risk factors (age, pack years of smoking, left ventricular hypertrophy) related differently to the extent of carotid atherosclerosis in patients with, than in those without, coronary disease. Clarification of the role of coronary status in the carotid atherosclerosis response to risk factors may partly explain the results of certain population-based studies that have related race, gender, and other risk factors to carotid atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk factors for extracranial carotid artery atherosclerosis

We related risk factors, cardiovascular symptoms, and coronary status to the extent of extracranial carotid atherosclerosis as measured by B-mode ultrasonography in 376 volunteers hospitalized for elective coronary angiography. In a first analysis, we correlated risk factors and cardiovascular symptoms with carotid atherosclerosis. Univariate analysis showed that relations between many continuous risk factors and carotid atherosclerosis were graded and consistent for men and women. Multivariate analysis identified 6 significant variables (age, hypertension, pack-years smoked, and inversely, plasma concentrations of high density lipoprotein cholesterol and uric acid, and Framingham Type A score) that together accounted for 35% of the variability in extent of carotid atherosclerosis. In a second multivariate analysis, addition of coronary status (presence or absence of coronary stenosis as evaluated by coronary angiography) to the roster of candidate independent variables produced a new equation that accounted for an additional 5% of the variability in carotid atherosclerosis extent. Although much of the variability in extent of carotid atherosclerosis remains unexplained, these data define an association between coronary and carotid atherosclerosis that depends partly on shared exposure of both arteries to the same risk factors. They are also consistent with the concept that as yet undiscovered risk factors and/or genetic (e.g., arterial wall) factors common to both arterial beds also contribute to the relation between coronary and carotid atherosclerosis in human beings.

Mortality among the elderly in the Alameda County Study: behavioral and demographic risk factors

We studied the association between behavioral and demographic risk factors and 17-year mortality in members of the Alameda County (California) Study who were 60-94 years of age at baseline. In this age group, increased risk of death is associated with being male, smoking, having little leisure-time physical activity, deviating from moderate weight relative to height, and not regularly eating breakfast. These increased risks were independent of age, race, socioeconomic position (SEP), other behavioral risk factors, and baseline physical health status. Further examination of the group aged 70 or more revealed the same patterns of heightened risk.

Dietary potassium and stroke-associated mortality. A 12-year prospective population study

Hypertension is the most important known risk factor for stroke. Clinical, experimental, and epidemiologic evidence suggests that a high dietary intake of potassium is associated with lower blood pressure. In hypertensive rats, a high intake of potassium is reported to protect against stroke, even though blood pressure is not affected. We examined the relation between the 24-hour dietary potassium intake at base line and subsequent stroke-associated mortality in a population-based cohort of 859 men and women (aged 50 to 79 years) in Southern California. After 12 years, 24 stroke-associated deaths had occurred. The relative risks of stroke-associated mortality in the lowest tertile of potassium intake, as compared with that in the top two tertiles combined, were 2.6 (P = 0.16) in men and 4.8 (P = 0.01) in women. In multivariate analyses, a 10-mmol increase in daily potassium intake was associated with a 40 percent reduction in the risk of stroke-associated mortality (P less than 0.001). This effect was independent of other dietary variables, including the intake of calories, fat, protein, fiber, calcium, magnesium, and alcohol. The effect was also apparently independent of known cardiovascular risk factors, including age, sex, blood pressure, blood cholesterol level, obesity, fasting blood glucose level, and cigarette smoking. These findings support the hypothesis that a high intake of potassium from food sources may protect against stroke-associated death.