Risk factors for ischemic stroke: a case control analysis

Prevalence, contributing factors, and economic implications of strokes among older adults: a study of North-East India

Stroke is a significant cause of mortality and disability in India, with its economic impact on the rise. This study aims to investigate the prevalence and factors associated with stroke among the elderly population in seven north-eastern states of India and its economic consequences. Data from the initial phase of the Longitudinal Ageing Study in India (2017-2018) were utilized, and bivariate and multivariate analyses were done. Stroke prevalence (1.53%) was notable among both genders, with approximately 1% in females and 2.3% in males. Individuals with low physical activity, higher socio-economic status, and unemployment faced a higher risk of stroke. Females exhibited a 60% lower likelihood [AOR 0.40; (CI 0.250-0.627)] of stroke compared to males and hypertension was a significant risk factor. Stroke patients incur up to INR 50,000 of financial burden, with a considerable proportion facing disability in comprehension and speech. The economic burden of stroke-related hospitalization was significantly high, emphasizing the need for government-funded health insurance to cover stroke-related medications and reducing out-of-pocket expenses for patients seeking treatment in healthcare facilities. The study highlights the urgency for better schemes to address the growing threat of strokes in the north-eastern parts of India for comprehensively tackling this public health challenge.

Role of serum uric acid in ischemic stroke: A case-control study in Bangladesh

Introduction

Increased level of serum uric acid (SUA) is often considered a risk factor for ischemic stroke. This study was conducted to examine the association of SUA level with ischemic stroke and assessed gender-based differences, if any.

Methods

In this case-control study, neuroimaging-confirmed ischemic stroke patients were recruited as cases within three days of an incident from neurology in-patient department, and as controls, patients without stroke history were recruited from neurology out-patient department. Blood was collected from the respondents of both groups to assess SUA level, lipid profile and oral glucose tolerance test. Binary logistic regression was done for estimating the risks of ischemic stroke.

Results

A total of 338 participants were recruited, where 169 were cases and 169 were controls. Around 60 percent respondents of both case and control groups were male. Mean SUA levels for cases and controls were 6.03 (SD 1.84) mg/dl and 4.04 (SD 1.46) mg/dl, respectively. After adjustment for age, tobacco consumption status, diabetes, hypertension, coronary heart disease and dyslipidemia, elevated SUA level was found to be significantly associated with ischemic stroke only in females (OR = 1.49; 95% CI = 1.01–2.19; p<0.05). Overall, each unit increase in SUA level exhibits 25 percent increment in odds of having ischemic stroke (OR = 1.25; 95% CI = 1.02–1.5372; p<0.05).

Conclusion

This study concluded that elevated SUA level is significantly associated with the acute phase of an ischemic stroke and gender-specific analysis demonstrates this association only in females.

Review: Lipids and stroke

Stroke is the third leading cause of death in adults. Although vascular disease is the prime contributor to its pathogenesis, dyslipidaemia is not unambiguously established as a risk factor for stroke in the same way that it is for coronary artery disease. Non-statin treatments of dyslipidaemia have not been shown clearly to help in preventing stroke. However, large clinical trials of treatment with statins over a number of years have demonstrated that these drugs decrease ischaemic stroke rates in persons at risk. Whether this reflects the efficacy of statins in lowering low density lipoprotein-cholesterol (LDL-c) concentrations alone or whether additional mechanisms may apply is not clear.

Burden of Stroke: Indian Perspective

India will face an enormous socio-economic burden to meet the costs of stroke. Stroke prevention planning, reliable epidemiological infromation on pattern of disease and exposure to major risk factors and morbidity or mortality trends for CVD in defined populations is imperative. There is a great need to monitor these trends in a simple and reproducible way. The World Health Organization (WHO) STEPs program does this and is now being implemented in India through the Indian Collaborative Acute Stroke Study (ICASS). The initial data supports the high prevalence of vascular risk factors and the relatively young age of stroke cases in India. A number of stroke prevalence studies have been performed in recent years, further confirming the high burden of stroke in this country. Recognition of the trend in the burden of stroke in India is essential to assist target prevention and management strategies.

Fifty years of stroke researches in India

Currently, the stroke incidence in India is much higher than Western industrialized countries. Large vessel intracranial atherosclerosis is the commonest cause of ischemic stroke in India. The common risk factors, that is, hypertension, diabetes, smoking, and dyslipidemia are quite prevalent and inadequately controlled; mainly because of poor public awareness and inadequate infrastructure. Only a small number of ischemic stroke cases are able to have the benefit of thrombolytic therapy. Benefits from stem cell therapy in established stroke cases are under evaluation. Presently, prevention of stroke is the best option considering the Indian scenario through control and/or avoiding risk factors of stroke. Interventional studies are an important need for this scenario.

Risk factors of stroke in Western and Asian countries: a systematic review and meta-analysis of prospective cohort studies

Background

There has been an increasing trend in the incidence of stroke worldwide in recent years, and the number of studies focusing on the risk factors for stroke has also increased every year. To comprehensively evaluate the risk factors of stroke identified in prospective Western and Asian cohort studies.

Methods

Population-based cohort studies on stroke were searched in databases (PubMed, EMBASE, Web of Science, Google Scholar, etc.), and the library of the Third Military Medical University was manually searched for relevant information. A meta-analysis of Western and Asian studies on risk factors was performed. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to assess the final group of cohort studies.

Results

After screening, 22 prospective cohort studies were included in the analyses of this investigation. Two factors, smoking and alcohol consumption, showed statistically significant differences between Western and Asian populations, and the results were as follows (W/A): 2.05 (95% CI, 1.68 ~ 2.49)/1.27 (95% CI, 1.04 ~ 1.55) and 0.89 (95% CI, 0.76 ~ 1.04)/1.28 (95% CI, 1.07 ~ 1.53). The factor BMI = 18.5-21.9 kg/m² showed statistically significant differences only in Western populations, 0.96 (95% CI, 0.93 ~ 0.99); the factor SBP = 120-139 mm Hg showed statistically significant differences only in Asian populations, 2.29 (95% CI, 1.04 ~ 5.09).

Conclusions

The prevalences of risk factors affect the stroke morbidity in Western and Asian populations, which may be biased by race. The meta-analysis of population-based studies suggests that different preventive measures should be adopted for Western and Asian population groups that are at high risk for stroke.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-776) contains supplementary material, which is available to authorized users.

Serum lipids in patients with stroke--a cross-sectional case-control study

BACKGROUND

Vascular disease remains the prime contributor to the pathogenesis of stroke, but dyslipidemia has not been clearly established as a risk factor for stroke the same way it has been for coronary artery disease. There is no case-controlled study on the contribution of serum lipids to stroke in Nigerians. This study aimed at assessing the possibility of serum lipids as risk factor for stroke in Nigerian patients.

METHOD

The demography, blood pressure, fasting plasma glucose and fasting serum lipids of 87 consecutive patients with first-ever stroke managed at the University of Benin teaching hospital between January and December 2005 were analyzed and compared with those of age- and sex-matched controls.

RESULTS

Eighty-seven stroke patients (55 males and 32 females; mean age 61.25 +/- 14.77 years) were compared with age- and sex-matched controls. Ischemic stroke constituted 64.37%, while the rest had hemorrhagic stroke. There were no significant differences in the serum cholesterol, HDL-C and LDL-C levels of stroke patients and controls (p > 0.05), but the serum triglyceride level was higher among the stroke patients (p < 0.001) with a significant relative risk (RR = 1.77; p < 0.01).

CONCLUSION

In this cross-sectional case-control study, there is no significant difference in the serum lipids of Nigerian patients with stroke with the exception of serum triglyceride, which seems to confer significant stroke risk.

Risk factors for acute ischaemic stroke in young adults in South India

BACKGROUND

Stroke is a leading cause of death and disability in developing countries, afflicting individuals at a young age. The contribution of established vascular risk factors to ischaemic stroke in young adults has not been evaluated systematically in Indians.

METHODS

We conducted a case control study in 214 South Indian patients with first acute ischaemic stroke that occurred between the ages of 15 and 45 years, 99 age and sex matched hospital controls and 96 community controls. We compared the prevalence of the following risk factors: smoking, elevated blood pressure, high fasting blood glucose and abnormal lipids.

RESULTS

Compared with community controls, stroke patients had a higher prevalence of smoking (multivariable adjusted odds ratio (OR) 7.77, 95% CI 1.93 to 31.27), higher systolic blood pressure (OR per SD increment of 1.88, 95% CI 1.01 to 3.49) and fasting blood glucose (OR per SD increment of 4.55, 95% CI 1.63 to 12.67), but lower high density lipoprotein (HDL) cholesterol (OR per SD increment of 0.17, 95% CI 0.09 to 0.30). Compared with hospital controls, stroke patients had a higher prevalence of smoking (OR 3.95, 95% CI 1.61 to 9.71) and lower HDL cholesterol (OR per SD increment 0.27, 95% CI 0.17 to 0.44). The presence of > or = 3 metabolic syndrome components was associated strongly with stroke (OR 4.76, 95% CI 1.93 to 11.76; OR 2.09, 95% CI 1.06 to 4.13) compared with community and hospital controls.

CONCLUSIONS

Key components of the metabolic syndrome and smoking are associated with ischaemic stroke in young South Indian adults. Our observations underscore the importance of targeting adolescents and young adults for screening and prevention to reduce the burden of ischaemic stroke in young adults.

Serum uric acid and long-term mortality from stroke, coronary heart disease and all causes

BACKGROUND

Increased serum uric acid (SUA) levels are linked to obesity, dyslipidemia, diabetes and hypertension. Whether SUA carries a risk for coronary heart disease (CHD) and stroke remains uncertain.

DESIGN

A prospective cohort study.

METHODS

Of an original cohort of middle-aged workers who were examined in 1963 and followed-up for 23 years, 9125 men, free of CHD at entry, are included in this study. Subjects were divided into quintiles according to baseline SUA levels. Hazard ratios (HR) for all-cause, CHD, and stroke mortality were estimated in SUA quintiles, with the third serving as a referent.

RESULTS

During follow-up, 2893 deaths were recorded, including 830 ascribed to CHD and 292 to stroke. The HR for all death [1.22, 95% confidence interval (CI) 1.09-1.37] and CHD (1.29, 95% CI 1.05-1.58) were increased in the upper SUA quintile. Fatal stroke showed a U-shaped relationship as both the upper (HR 1.48, 95% CI 1.02-2.17) and bottom (HR 1.43, 95% CI 0.99-2.08) quintiles were associated with a higher risk. Adjustment for confounders reduced the HR of the upper quintile for all outcomes, but did not attenuate the association of the bottom quintile with stroke (HR 1.52, 95% CI 1.04-2.23). When analysed separately by stroke type, the latter association seemed to be stronger for hemorrhagic (HR 3.27, 95% CI 1.14-9.33) than for ischemic stroke (HR 1.34, 95% CI 0.87-2.05).

CONCLUSION

In addition to findings supporting increased mortality among hyperuricemic subjects, we identified an association between low SUA levels and fatal stroke, which deserves further investigation.

Lipids and stroke: the opportunity of lipid-lowering treatment

Dyslipemia is a clear risk factor (RF) for ischemic heart disease and peripheral artery disease, but its relation with ischemic stroke (IS) is not so clear. HMG-CoA reductase inhibitor drugs or statins (simvastatin, atorvastatin, pravastatin) reduce the relative risk of IS by between 18 and 51% in patients with IHD, in patients with high vascular disease risk and in hypertensive patients with other RFs, acute coronary syndrome, and type 2 diabetes mellitus. According to the guidelines for use, statins are indicated in the majority of patients with IS since the risk is equivalent to that of IHD or high vascular disease risk. In view of the existing clinical evidence of benefit, it would not seem unreasonable to proceed with treatment of patients using statins while awaiting specific studies justifying their use. The non-lipid-lowering mechanisms of the statins and results of studies, such as the Heart Protection Study, provide evidence for widening the indications of statins beyond the prevention of dyslipemia, as a new therapeutic approach in the prevention of IS in patients with plasma levels of total cholesterol or low density lipoproteins currently considered within the normal distribution. The neuroprotective role, which these drugs may play in the acute phase of cerebral ischemia, remains to be clarified, but very recent evidence suggests that such patients may also benefit.

Plasma lipid profile and incident ischemic stroke: the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND PURPOSE

The role of circulating lipids and lipoproteins in the pathogenesis of ischemic stroke remains uncertain despite 3 decades of research. We examined this issue in a large population-based cohort.

METHODS

Between 1987 and 1989, 14 175 middle-aged men and women, free of clinical cardiovascular disease, took part in the first examination of the Atherosclerosis Risk in Communities (ARIC) study cohort. Baseline measurements included plasma levels of LDL cholesterol, HDL cholesterol, apolipoprotein B, apolipoprotein A-1, and triglycerides and myriad risk factors for cardiovascular disease. The cohort was followed for cardiovascular disease end points.

RESULTS

Over an average follow-up of 10 years (142 704 person-years at risk), we documented clinical ischemic stroke in 305 participants (161 men and 144 women). After multivariable adjustment for stroke risk factors, categorical and spline regression analyses of the entire sample, as well as the sample of men alone, revealed weak and inconsistent associations between ischemic stroke and each of the 5 lipid factors. Among women, the most consistent findings were decreasing risk of ischemic stroke within the top half of the distribution of HDL cholesterol and increasing risk within the lower range of the triglyceride distribution.

CONCLUSIONS

The relation of circulating cholesterol to ischemic stroke does not resemble its well-known relation to coronary heart disease. Either the pathogenesis of a substantial proportion of ischemic strokes does not involve classic atherosclerotic mechanisms, or the effect of plasma lipids on atherogenesis is substantially different in the intracranial vascular bed.

Relation of lipid and lipoprotein(a) to ischaemic stroke

The relationship of lipids and Lp(a) to ischemic stroke hasn't been established yet. Our aim was to determine lipid profile and vascular risk factors in stroke patients and compare them with control subjects. Seventy-nine consecutive patients with ischemic stroke were analyzed by total cholesterol, HDL-C, LDL-C, triglyceride, Lp(a) and doppler ultrasonography and vascular risk factors were recorded. Thirty control subjects of same ages were compared with the patient group. Lp(a) and lipids were correlated with stroke subtype and carotid atherosclerosis. There was no statistical significance between patients and control subjects related to total cholesterol, triglyceride, HDL-C, LDL-C and Lp(a) (P>0.05). Atherotrombotic and lacunar strokes didn't show any difference correlated with lipids and Lp(a). Hypertension and diabetes mellitus were important risk factors with (OR=4.50, 95% CI=1.25-16.22) and (OR=4.43, 95% CI=1.79-10.93) respectively. These results were statistically significant (P<0.05). Total cholesterol (308.67+/-85.82) and Lp(a) (32.10+/-17.30) values showed statistical significance (P<0.05) in patients with marked stenosis when compared with patients of normal doppler ultrasonography. Hypertension and diabetes mellitus were found as independent risk factors for ischemic stroke. Lipids and Lp(a) were not independent for atherotrombotic and lacunar stroke. Lp(a) concentration and carotid atherosclerosis in ultrasonography were associated significantly.

Basis for primary prevention of stroke under a social health act

The probability of reducing the prevalence of stroke by control of risk factors has been calculated to be as high as 80%, particularly among patients with auricular fibrillation, based on randomized therapeutic trials. Because of the lack of education about stroke risk factor reduction among community physicians in Austria, the reduction of stroke prevalence has failed to reach such potential benefit. To achieve a basis for primary prevention of stroke identification of those at low, medium, and high vascular risk has been recommended. The present study has undertaken such goals by quantifying prevalence of vascular risk factors, as well as therapeutic interventions among the population of Graz, Austria, within the framework of our present socialized health system. Persons between the ages of 50 and 70 years comprise our cohort of 2,120 volunteers that have been randomized by our registry in Graz. All selected volunteers underwent stroke probability grading, including identification of potential of risk factors to be controlled or treated. By using 35 items in the screening protocol for risk factors for stroke, probability of stroke risk was evaluated. Minimal vascular risk was present in 686 volunteers; 595 were classified as mild vascular risk, 542 had medium risk, 326 were at high risk, and 71 were at maximum risk. Out of 1434 volunteers with increased vascular risk, 55% have not attempted lifestyle changes or any risk factor treatment. Of these, 30% with maximum vascular risk remain untreated. Existing risk factors have been controlled in 22% and remain untreated in 78%. Therefore, primary stroke prevention must be based on direct contact with volunteers in the age groups in which stroke onset is likely to occur and identifying and treating individuals with the highest stroke probability index.

Serum uric acid, diuretic treatment and risk of cardiovascular events in the Systolic Hypertension in the Elderly Program (SHEP)

OBJECTIVE

To assess longitudinally the association of serum uric acid and its change due to diuretic treatment with cardiovascular events in hypertensive patients.

DESIGN

Cohort study in a randomized trial.

SETTING

Cohort of hypertensive patients.

PARTICIPANTS

A total of 4327 men and women, aged > or = 60 years, with isolated systolic hypertension, randomized to placebo or chlorthalidone, with the addition of atenolol or reserpine if needed, were observed for 5 years.

MAIN OUTCOME MEASURES

Major cardiovascular events, coronary events, stroke and all-cause mortality.

RESULTS

Cardiovascular event rates for quartiles of baseline serum uric acid were: I, 32.7 per 1000 person-years; II, 34.5 per 1000 person-years; III, 38.1 per 1000 person-years; and IV, 41.4 per 1000 person-years (P for trend = 0.02). The adjusted hazard ratio (HR), of cardiovascular events for the highest quartile of serum uric acid versus the lowest quartile was 1.32 (95% CI, 1.03-1.69). The benefit of active treatment was not affected by baseline serum uric acid. After randomization, an increase of serum uric acid < 0.06 mmol/l (median change) in the active treatment group was associated with a HR of 0.58 (0.37-0.92) for coronary events compared with those with a serum uric acid increase > or = 0.06 mmol/l. This difference was not explained by blood pressure effects. Those with a serum uric acid increase > or = 0.06 mmol/l in the active treatment group had a similar risk of coronary events as the placebo group.

CONCLUSIONS

Serum uric acid independently predicts cardiovascular events in older persons with isolated systolic hypertension. Monitoring serum uric acid change during diuretic treatment may help to identify patients who will most benefit from treatment.

HDL-Cholesterol, total cholesterol, and the risk of stroke in middle-aged British men

BACKGROUND AND PURPOSE

The purpose of this study was to examine the relation between serum HDL cholesterol and total cholesterol and risk of stroke.

METHODS

We carried out a prospective study in 7735 men, 40 to 59 years of age, drawn from 1 group practice in each of 24 British towns. Men with history of stroke were excluded (n=52).

RESULTS

During the mean follow-up period of 16.8 years, there were 343 stroke cases (fatal and nonfatal) in the 7683 men with no history of stroke. Higher levels of HDL cholesterol were associated with a significant decrease in risk of stroke even after adjustment for potential confounders (top fifth versus lowest fifth: adjusted relative risk=0.68, 95% CI 0.46 to 0.99). The inverse relation was seen only for nonfatal strokes (adjusted relative risk=0.59, 95% CI 0.39 to 0.90; top fifth versus lowest fifth). Total cholesterol showed no graded association with fatal strokes, but men with levels > or =8.1 mmol/L (top 5% of the distribution) showed increased risk of nonfatal stroke, although this was not statistically significant after adjustment (adjusted RR=1.46, 95% CI 0.91 to 2.32). The beneficial effects of elevated HDL cholesterol on nonfatal stroke were seen in both smokers and nonsmokers and were more evident in men with hypertension than in normotensives. In hypertensive men, elevated HDL cholesterol (top fifth) was associated with a significant 50% reduction in risk of nonfatal strokes compared with men in the lowest fifth.

CONCLUSIONS

Higher levels of HDL cholesterol were associated with a significant decrease in risk of nonfatal stroke. In contrast, elevated total cholesterol showed a weak positive association with nonfatal strokes. The marked inverse association between HDL cholesterol and stroke seen in hypertensives emphasizes the importance of those modifiable risk factors for stroke known to lower the concentrations of HDL cholesterol.

Serum lipids in young patients with ischaemic stroke: a case-control study

OBJECTIVES

The relation between serum lipids and ischaemic stroke remains controversial. Studies of lipid related risk factors in cerebrovascular disease have varied greatly in their findings and also in their definition of the cerebrovascular end points. Serum lipids are thought to interact with the pathogenesis of stroke through an atherosclerosis mechanism. Stroke in young patients have been shown to be related to non-atherosclerotic causes most of the time. The aim was to determine the serum lipid profile and the vascular risk factors for ischaemic stroke in a series of patients under 45 with an ischaemic stroke and to compare them with a series of controls of the same age.

METHODS

Ninety four consecutive patients with ischaemic stroke were compared with 111 controls of the same age recruited from a regional electoral list. Vascular risk factors were recorded and serum lipid profile was determined in all of them.

RESULTS

Multivariate analyses showed that low HDL cholesterol, male sex, smoking, hypertension, and oral contraceptives were risk factors for intracerebral arterial occlusion.

CONCLUSION

Low HDL cholesterol was the only serum lipid index to be associated to an increased risk of stroke in this population. Low HDL cholesterol must be considered in the care management of young patients regardless of the detectable presence of atherosclerosis.

Stroke prevention: hypertension, diabetes, tobacco, and lipids

This article reviews the most recent epidemiologic evidence supporting topics such as hypertension, diabetes, tobacco, and lipids as risks for stroke. Where available, American Stroke Association (ASA) and National Stroke Association (NSA) consensus statement guidelines for the treatment of these risk factors are given.

LDL receptor mutations and ApoB mutations are not risk factors for ischemic cerebrovascular disease of the young, but lipids and lipoproteins are

BACKGROUND

The genetic background for ischemic cerebrovascular disease of the young and the role of lipids and lipoproteins as risk factors are not clear.

METHODS

We determined five LDL receptor mutations (Trp23Stop, Trp66Gly, Trp556Ser, 313+1G --> A, 1846-1G --> A) and three apolipoprotein B mutations (Arg3500Gln, Arg3500Trp, Arg3531Cys), and other risk factors for ischemic cerebrovascular disease in 80 patients (36 women, 44 men) with onset of disease before the age of 50 years compared with 3366 individuals from a general population sample within the same age range.

RESULTS

None of the patients were carriers of mutations in the LDL receptor (Trp23Stop, Trp66Gly, Trp556Ser, 313+1G --> A, 1846 - 1G --> A) or the apolipoprotein B gene (Arg3500Gln, Arg3500Trp, Arg3531Cys) associated with hypercholesterolemia. However, on univariate analysis as well as on logistic regression analysis allowing for age and gender, plasma cholesterol (OR 1.4; P < 0.0005), HDL-cholesterol (OR 0.4; P < 0.005), diabetes (OR 5.8; P < 0.0001), and hypertension (OR 3.9; P < 0.001) were significant predictors of ischemic cerebrovascular disease.

CONCLUSIONS

The five most common LDL receptor mutations in Danish patients with familial hypercholesterolemia and three mutations in the apolipoprotein B gene did not predispose to ischemic cerebrovascular disease of the young. However, cholesterol and HDL-cholesterol are important risk factors for ischemic cerebrovascular disease of the young in the present study. The elevation in cholesterol could in some patients be due to rare LDL receptor mutations not tested for, and could in other patients be multifactorial in origin.

Ultrasound and lipoproteins as predictors of lipid-rich, rupture-prone plaques in the carotid artery

The aim of this review is to summarize present knowledge of the ultrasonic detection and determinants of carotid atherosclerosis with lipid-rich cores and to review the evidence that these measures of plaque type may predict cerebral events. With the use of high-resolution ultrasound B-mode imaging, carotid plaques evaluated as only weakly reflecting the ultrasound beam (echolucent) have been associated with a higher risk of neurological events than are plaques reflecting the ultrasound signal strongly (echorich). Histologically, these echolucent plaques have a higher content of lipid and hemorrhage than do echorich plaques, which contain more calcification and fibrous tissue. Findings in the coronary arteries indicate that a lipid-rich plaque with a thin, fibrous cap is more vulnerable, is more prone to rupture, and cause symptoms compared with fibrous plaques. A search for determinants in the blood for these vulnerable plaques suggests that low density lipoprotein (LDL) cholesterol is the best lipid predictor for the extent of atherosclerosis, whereas triglyceride-rich lipoproteins in particular seem to predict an echolucent plaque. Lowering of LDL cholesterol and triglyceride-rich lipoproteins in plasma is associated with reduced progression of coronary atherosclerosis and coronary events. LDL cholesterol reduction is also associated with a reduced stroke rate. These improvements in the prognosis are thought to be the result of a reduction in the lipid content of the plaques, making them more stable and resistant to rupture rather than an actual reduction in plaque volume and degree of stenosis. In conclusion, it appears that ultrasound B-mode imaging as well as lipoproteins presumably may predict dangerous and rupture-prone, lipid-rich plaques in the carotid arteries, thereby being potential diagnostic tools in the prevention of neurological events.

The risk of hospitalization for ischemic stroke among older adults

OBJECTIVES

The purpose of this study was to identify risk factors for stroke and to estimate their relative importance in a large, nationally representative sample of very old men and women.

METHODS

The study was designed as a secondary analysis of the Longitudinal Study on Aging. Baseline (1984) in-person interview data were linked to Medicare hospitalization records for 1984 to 1991. Participants were 6,071 noninstitutionalized adults 70 years old or older at baseline. Hospitalization for ischemic stroke was defined as having one or more episodes with a primary discharge diagnosis containing ICD-9-CM codes of 433.0-434.9, 436, and 437.0-437.1. Multivariable proportional hazards regression was used to estimate the risks associated with previously identified epidemiologic factors.

RESULTS

Five hundred and three persons (8.3%) had at least one primary discharge diagnosis of ischemic stroke. In descending order of importance-based on the partial r statistics associated with their adjusted hazards ratios (AHRs), the salient risk factors were having a previous history of stroke (AHR = 2.86), age (AHR = 1.04 per year), diabetes (AHR = 1.78), male gender (AHR = 1.42), lower body limitations (AHR = 1.09 per limitation), arthritis (AHR = 0.74), hypertension (AHR = 1.29), and poverty (AHR = 1.33).

CONCLUSION

Patients presenting with the high risk factors identified in this study should be considered for further evaluation and monitoring. Current protocols for the therapeutic management of these higher risk patients should be considered, and compliance should be encouraged.

Risk factors for ischemic stroke in a Russian community: a population-based case-control study

BACKGROUND AND PURPOSE

This study was conducted to determine the risk factors for ischemic stroke in a defined Russian population.

METHODS

Our data are based on a population-based case-control study of 237 patients with first-ever ischemic stroke and 237 age- and sex-matched controls. Logistic regression methods for matched pairs were used to estimate the relative risk for the variables studied.

RESULTS

In a multivariate analysis, hypertension, left ventricular hypertrophy on electrocardiography, ischemic heart disease, mitral valve disease, current cigarette smoking, and high body mass index were significant and independent risk factors for ischemic stroke in this Russian community.

CONCLUSIONS

The significant risk factors for ischemic stroke in Novosibirsk are similar to those from other populations and cohorts. This study, the first of stroke risk factors in Russia, has implications for clinical practice and the planning of stroke prevention in the population.

Parental history of cardiovascular disease and risk of stroke. A prospective follow-up of 14371 middle-aged men and women in Finland

BACKGROUND AND PURPOSE

Studies on risk factors for stroke have been less intensive than those for coronary disease. Only a few studies have addressed the question of the role of heredity in the occurrence of stroke. We analyzed whether a positive parental history of cardiovascular disease predicts the risk of stroke independently from other risk factors and whether the role of parental history varies by age and stroke subtypes.

METHODS

This study was a prospective follow-up of 14371 middle-aged men and women. A positive parental history of cardiovascular disease was defined as either stroke or coronary disease before the age of 60 years. The end point of the follow-up was an incident case of stroke. Multivariate analyses were performed with the Cox proportional hazards model.

RESULTS

The risk ratio of stroke after multifactorial adjustment (age, smoking, blood pressure, cholesterol, diabetes, and education) associated with a positive parental history of stroke was 1.89 (P = .004) in men and 1.80 (P = .007) in women. The association between parental history of stroke and the risk of stroke was stronger among subjects aged 25 to 49 years than among older subjects. Parental history of coronary disease was not associated with the risk of stroke in men, but in women it had a borderline significant association with the risk of ischemic stroke.

CONCLUSIONS

A positive parental history of stroke predicted the risk of stroke independently from the other risk factors.

Low serum cholesterol and the risk of cerebral haemorrhage

In addressing the potential for any hazards associated with lowering serum cholesterol, a recent meta-analysis by Law and colleagues (Br Med J 1994;308:373) concluded that that there was no evidence that a low or reduced serum cholesterol concentration increases mortality from any cause other than haemorrhagic stroke. In this review, the evidence for this unexpected association will be addressed, and possible mechanisms discussed. Overall implications of the phenomenon, particularly for the hypertensive patient, will be addressed in the context of the anticipated consequences of lipid-lowering therapy for all stroke, haemorrhagic and non-haemorrhagic, as well as ischaemic heart disease (IHD).