Risk of stroke in male cigarette smokers

Perioperative primary stroke: is aspirin cessation to blame?

BACKGROUND

There are a number of reports in the literature of patients developing thrombotic events after stopping medically necessary antiplatelet and antithrombotic agents.

OBJECTIVE

The objective was to determine whether discontinuation of aspirin taken for primary prophylaxis contributes to the development of thrombotic complications in patients undergoing dermatologic surgery.

METHODS

A case is reported and the literature is reviewed.

RESULTS

We present the first reported case of a postoperative thrombotic event following dermatologic surgery in a patient withholding aspirin that was taken for primary prophylaxis.

CONCLUSION

We believe that the available data make it difficult to implicate aspirin discontinuation in the development of each thrombotic event, given the high baseline risk of thrombotic events in the Mohs surgery patient population and the low risk of developing such events when medications are withheld perioperatively.

Cigarette smoking as a risk factor for stroke death in Japan: NIPPON DATA80

BACKGROUND AND PURPOSE

Some previous Japanese cohort studies failed to show an association between smoking and stroke risk. Because such an association has been noted in other populations, this issue should be re-examined in a recent representative Japanese cohort with a higher total cholesterol level.

METHODS

A total of 9638 men and women aged 30 years and older without a history of cardiovascular disease (CVD) at baseline in 1980 were followed-up for 14 years.

RESULTS

We observed 203 stroke deaths (107 cerebral infarctions, 45 cerebral hemorrhages, and 51 others), 191 heart disease deaths, and 413 CVD deaths. The average serum total cholesterol level was approximately 4.91 mmol/L. Cox proportional hazard ratios were calculated adjusting for age, systolic blood pressure, and other conventional risk factors. The hazard ratios for men who smoked 1 to 20 cigarettes/day for all strokes, cerebral infarction, and cerebral hemorrhage were 1.60 (95% CI, 0.91 to 2.79), 2.97 (CI, 1.27 to 6.98), and 0.42 (CI, 0.16 to 1.09), respectively, and for those who smoked > or =21 cigarettes/day, they were 2.17 (CI, 1.09 to 4.30), 3.26 (CI, 1.11 to 9.56), and 0.68 (CI, 0.20 to 2.33), respectively. For women who smoked > or =21 cigarettes/day, the hazard ratio for all strokes was 3.91 (CI, 1.18 to 12.90). For CVD, all heart disease, and ischemic heart disease, the hazard risks of smoking were significant (1.49 to 4.25) for men but not significant for women.

CONCLUSIONS

Smoking in a cohort with moderate serum total cholesterol level was a potent risk factor for stroke, especially cerebral infarction, for both men and women, and for CVD and ischemic heart disease for men.

Influence of smoking on predictors of vascular disease

Beyond the already well-established strong causative relationship with cancer, smoking increases the risk for vascular disease. Smoking may act directly or adversely influence risk factors contributing to the development of vascular disease. Smoking causes endothelial dysfunction, dyslipidemia (decreased high-density lipoprotein cholesterol levels, hypertriglyceridemia and increased oxidation of low-density lipoprotein cholesterol) and platelet activation leading to a prothrombotic state. Smoking increases emerging risk factors (eg, fibrinogen, homocysteine, and high-sensitivity C-reactive protein) and increases insulin resistance and the risk of developing type 2 diabetes mellitus. The beneficial effects of statins and antioxidants (eg, vitamins C and E, beta-carotene) are counteracted by smoking. Smoking-induced alterations in growth factors, adhesion molecules, and even in genes can accelerate the progression of atherosclerosis. The aim of this review is to consider the adverse consequences of smoking on the factors predisposing to vascular disease and to emphasize the beneficial effects of smoking cessation.

Smoking and the risk of hemorrhagic stroke in men

BACKGROUND AND PURPOSE

Smoking is an established risk factor for ischemic stroke and subarachnoid hemorrhage (SAH), but the impact of smoking on intracerebral hemorrhage (ICH) is less clear.

METHODS

Prospective cohort study among 22,022 US male physicians participating in the Physicians' Health Study. Incidence of stroke was measured by self-report and confirmed by medical record review. We used Cox proportional-hazards models to evaluate the association of smoking with risk of total hemorrhagic stroke, ICH, and SAH. We categorized smoking into 4 groups: never, past, or current smokers of <20 or of >or=20 cigarettes per day.

RESULTS

During 17.8 years of follow-up, 108 ICHs and 31 SAHs occurred. Never smokers and past smokers had equal rates of ICH and SAH. Current smokers of <20 cigarettes per day had multivariable-adjusted relative risks of 1.65 (95% CI, 0.61 to 4.50) for total hemorrhagic stroke, 1.60 (95% CI, 0.50 to 5.07) for ICH, and 1.75 (95% CI, 0.24 to 13.09) for SAH when compared with never smokers. Current smokers of >or=20 cigarettes had relative risks of 2.36 (95% CI, 1.38 to 4.02) for total hemorrhagic stroke, 2.06 (95% CI, 1.08 to 3.96) for ICH, and 3.22 (95% CI, 1.26 to 8.18) for SAH when compared with never smokers.

CONCLUSIONS

This prospective study suggests an increased risk of total hemorrhagic stroke, ICH, and SAH in current cigarette smokers with a graded increase in risk that depended on how many cigarettes were smoked. The effect of smoking on ICH is of about the same magnitude as the effect of smoking on ischemic stroke. Our results add to the multiple health benefits that can be accrued by abstaining from cigarette smoking.

Age-related changes in risk factor effects on the incidence of thromboembolic and hemorrhagic stroke

We examined the changes in risk factor effects on the incidence of thromboembolic and hemorrhagic stroke as they may occur with age. Findings were based on repeated risk factor measurements at four examinations over a 26-year period in 7589 men in the Honolulu Heart Program. After each examination, 6 years of follow-up were available to assess risk factor effects on the incidence of stroke over a broad range of ages (45-93 years). As compared with normotensive men, the risk of thromboembolic stroke in the presence of hypertension declined from a 7-fold excess in men aged 45 to 54 years to a 1.4-fold excess in men aged > or =75 (P<.001). Adverse effects of diabetes and atrial fibrillation seemed to be equally important across all ages, whereas a protective effect of physical activity increased with age. Except for men with atrial fibrillation, the incidence of thromboembolic stroke increased significantly with age regardless of risk factor status, including men with normal blood pressure (P<.001). Although hemorrhagic events were less common, positive relations with cigarette smoking seemed to strengthen with age, whereas those with hypertension tended to decline. Our findings suggest that strategies for the prevention of stroke may need to account for changes in risk factor effects as they occur with age. Control of diabetes and the encouragement of active lifestyles in the elderly seem to be especially important.

Impairment of nitric oxide synthase-dependent dilatation of cerebral arterioles during infusion of nicotine

The effects of nicotine on nitric oxide synthase (NOS)-dependent reactivity of cerebral arterioles remain uncertain. Our first goal was to examine whether infusion of nicotine alters NOS-dependent reactivity of cerebral arterioles. Our second goal was to examine the mechanisms that may account for the effects of nicotine on cerebral arterioles. We measured the diameter of pial arterioles to NOS-dependent (ADP and acetylcholine) and NOS-independent (nitroglycerin) agonists before and after the infusion of nicotine (2 microg x kg(-1) x min(-1) iv for 30 min, followed by a maintenance dose of 0.35 microg x kg(-1) x min(-1)). ADP- and acetylcholine-induced vasodilatation was impaired after the infusion of nicotine. In contrast, nicotine did not alter vasodilatation to nitroglycerin. Next, we examined whether the impaired responses of pial arterioles during infusion of nicotine may be related to oxygen radicals. We found that application of superoxide dismutase or tetrahydrobiopterin during infusion of nicotine could prevent impaired NOS-dependent vasodilatation. Thus acute exposure of cerebral vessels to nicotine specifically impairs NOS-dependent dilatation via the production of oxygen radicals possibly related to an alteration in the utilization of tetrahydrobiopterin.

Predictors of cardiac and noncardiac mortality among 14,697 patients with coronary heart disease

The decrease in mortality from ischemic heart disease during the last 25 years may partly reflect improvement in diagnosis and treatment of patients with coronary heart disease. These patients, therefore, are experiencing morbidity and mortality due to other causes. The aim of our study was to describe the incidence and causes of cardiac mortality (CM) and noncardiac mortality (NCM) and to identify predictive factors. A cohort of 14,697 patients with coronary heart disease was merged with the Central Population Registry to identify mortality records from 1990 to 1996. Among the 1,839 deaths, 1,055 (57.4%) were cardiac, 626 (34.0%) were noncardiac, and 158 deaths (8.6%) were due to unknown causes as classified in the International Classification of Diseases-Ninth Edition (ICD). The 3 most significant predictors were age for a 10-year increment (odds ratios 1.75 and 2.25 for CM and NCM, respectively), chronic obstructive pulmonary disease (odds ratios 1.67 and 1.71), and current smoking (odds ratios 1.29 and 1.66). A history of cancer was a predictor of NCM, but not of CM, whereas peripheral vascular disease predicted CM but not NCM. As the number of predictive factors increased from none to >or=5, the risk of NCM gradually increased from 1.9% to 15.5%. Similar predictors expose subjects with coronary disease to CM and NCM, but smoking plays a more pronounced role in the prediction of NCM, whereas past myocardial infarction, lower levels of high-density lipoprotein cholesterol, and peripheral vascular disease are mainly associated with CM. Because of the similarity of antecedent predictors, treatment of risk factors among patients with coronary heart disease should prove valuable for the prevention of all-cause mortality.

Coronary atherosclerosis and somatic mutations: an overview of the contributive factors for oxidative DNA damage

Coronary artery disease (CAD) is a multifactorial process that appears to be caused by the interaction of environmental risk factors with multiple predisposing genes. Genetic research on CAD has traditionally focused on investigation aimed at identifying disease-susceptibility genes. Recent evidence suggests that somatically acquired DNA mutations may also contribute significantly to the pathogenesis of the disease, underlining the similarity between atherosclerotic and carcinogenic processes. The generation of oxidative stress has been emphasized as an important cause of DNA damage in atherosclerosis. This review highlights some of the major atherogenic risk factors as likely mediators in the oxidative modification of DNA. It also examines the hypothesis that an increase in oxidative stress may derive from "oxidatively" damaged mitochondria. Accordingly, further research in this field should be given high priority, since increased somatic DNA damage could be an important pathogenic factor and an additional prognostic predictor, as well as a potential target for therapeutic strategies in coronary artery disease.

Risk of hospitalized stroke in men enrolled in the Honolulu Heart Program and the Framingham Study: A comparison of incidence and risk factor effects

BACKGROUND AND PURPOSE

Risk of death due to stroke in Japan is more than double the risk in the United States. It remains unknown why some ethnic groups are more prone to stroke than others. Our purpose was to compare the 20-year incidence of hospitalized stroke between Japanese-American men in the Honolulu Heart Program and white men in the Framingham Study.

METHODS

This was a 20-year follow-up study beginning around 1965, a population-based study on the island of Oahu, Hawaii, and in Framingham, Mass. Participants were 7589 men in Honolulu and 1216 men in Framingham without prevalent coronary heart disease and stroke. Subjects were 45 to 68 years old when follow-up began. Main outcome measures were incident thromboembolic and hemorrhagic stroke.

RESULTS

Framingham men had a 40% excess of thromboembolic stroke compared with Honolulu men after adjustment for age and other risk factors (62/1000 versus 45/1000, respectively, P<0.001), whereas incidence of hemorrhagic stroke was nearly identical (14.8/1000). In both cohorts, each stroke type was consistently elevated in the presence of hypertension and cigarette smoking. Diabetes and body mass index increased the risk of thromboembolic stroke in both samples, and diabetes increased the risk of hemorrhagic events in Framingham. Alcohol intake and low total cholesterol were associated with hemorrhagic events in Honolulu but not in Framingham. Despite occasional differences in risk factor effects, none were significantly different between cohorts.

CONCLUSIONS

The incidence of thromboembolic stroke requiring hospitalization is markedly less in Honolulu than in Framingham. The difference in stroke incidence rates observed cannot be explained by the traditional risk factors. Further studies are needed to identify factors that protect Japanese-American men in Honolulu from stroke.

Ankle-brachial blood pressure in elderly men and the risk of stroke: the Honolulu Heart Program

Although low ankle/brachial blood pressure index (ABI) is a marker of generalized atherosclerosis in the elderly, it has not been identified as a risk factor for stroke. The purpose of this report is to examine the relation between ABI and stroke in elderly men. ABI was measured from 1991 to 1993 in 2767 men aged 71 to 93 years in the Honolulu Heart Program without a history of stroke and coronary heart disease. Subjects were followed for 3 to 6 years for fatal and nonfatal thromboembolic and hemorrhagic stroke. During follow-up, there were 91 strokes. There was an age-adjusted 2-fold excess in men with an ABI < 0.9 (6.0%) versus men with an ABI > or = 0.9 (2.9%, P < 0.01). Thromboembolic events occurred in 4.6% of men with an ABI < 0.9 and in 2.0% in those with an ABI > or = 0.9 (P < 0.01). Hemorrhagic stroke was also more frequent in men with a low ABI (< 0.9) versus a higher ABI (1.9 vs. 0.8%, respectively). After adjusting for other factors, the risk of total and thromboembolic strokes increased with declining ABI (P = 0.019 and P = 0.004, respectively). The relation between ABI and stroke was similar and statistically significant in the presence and absence of diabetes and hypertension (P < 0.05). Findings suggest that ABI is inversely related to the incidence of stroke. Simple measurement of ABI in an outpatient setting could be an important tool for assessing the risk of stroke in the elderly.

Attributable risk of common and rare determinants of subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Smoking, hypertension, alcohol consumption, autosomal dominant polycystic kidney disease (ADPKD), and positive family history for subarachnoid hemorrhage (SAH) are well-known risk factors for SAH. For effective prevention, knowledge about the contribution of these risk factors to the overall occurrence of SAH in the general population is pivotal. We therefore investigated the population attributable risks of the risk factors for SAH.

METHODS

We retrieved the relative risk and prevalence of established risk factors for SAH from the literature and calculated the population attributable risks of these risk factors.

RESULTS

Drinking alcohol 100 to 299 g/wk accounted for 11% of the cases of SAH, drinking alcohol >/=300 g/wk accounted for 21%, and smoking accounted for 20%. An additional 17% of the cases could be attributed to hypertension, 11% to a positive family history for SAH, and 0.3% to ADPKD.

CONCLUSIONS

Screening and preventive treatment of patients with familial preponderance of SAH alone will cause a modest reduction of the incidence of SAH in the general population. Further reduction can be achieved by reducing the prevalence of the modifiable risk factors alcohol consumption, smoking, and hypertension.

Primary stroke prevention

Stroke is one of the leading causes of death and disability worldwide. Although important advances in therapeutic approaches have been made, treatment is still far from satisfactory. Thus, major efforts should be made on stroke prevention. We present evidence-based recommendations for primary stroke prevention. Changes to modifiable risk factors, the role of drugs and surgery are discussed. New markers may help identification of subjects at high risk.

European Stroke Initiative (EUSI) recommendations for stroke management. The European Stroke Initiative Writing Committee

The European Stroke Initiative (EUSI) is the common body of stroke-related activities within the European Federation of Neurological Societies (EFNS), the European Neurological Society (ENS) and the European Stroke Council (ESC). The Executive committee of the EUSI has authorized the writing committee of the EUSI to create recommendations for stroke management covering all areas of stroke treatment. The recommendations are listed according to levels of evidence pre-specified and modified according to several proposals in the literature. The recommendations have been approved by the executive committees of the EUSI, the ESC, the EFNS and the ENS. They are called recommendations rather than guidelines in order to underline the large amount of individual decision making due to the fact that for many important questions, no data of high evidence level is available. The EUSI plans to review and update the recommendations on a regular basis.

Incidence and risk factors for subtypes of cerebral infarction in a general population: the Hisayama study

BACKGROUND AND PURPOSE

We estimated the incidence of first-ever cerebral infarction in regard to its subtypes and analyzed their risk factors separately in a community-based prospective cohort study in Japan.

METHODS

Stroke-free subjects (n=1621) aged >/=40 years were followed up for 32 years from 1961. During this period, 298 cerebral infarctions occurred and were divided into 167 lacunar, 62 atherothrombotic, 56 cardioembolic, and 13 undetermined subtypes of infarction on the basis of clinical information including brain imaging and autopsy findings.

RESULTS

The age-adjusted incidence of lacunar infarction (3.8 per 1000 person-years for men and 2.0 for women) was higher than that of atherothrombotic infarction (1.2, 0. 7) and cardioembolic infarction (1.3, 0.5) in both sexes. Time-dependent Cox's proportional hazard analysis revealed systolic blood pressure as well as age to be independent risk factors for all subtypes of cerebral infarction except for cardioembolic infarction in men. Additionally, ST depression on ECG, glucose intolerance, and smoking in men and left ventricular hypertrophy on ECG and body mass index in women remained significant risk factors for lacunar infarction. ST depression was also significantly related to events of atherothrombotic infarction in women. The risk of atrial fibrillation for cardioembolic infarction was outstandingly high in both sexes, and left ventricular hypertrophy and lower total cholesterol were additional risk factors for cardioembolic infarction in women.

CONCLUSIONS

In this Japanese population, lacunar infarction was the most common subtype of cerebral infarction and had a greater variety of risk factors, including not only hypertension but also ECG abnormalities, diabetes, obesity, and smoking, than did atherothrombotic infarction or cardioembolic infarction.

Transient Ischemic Attack and Secondary Stroke

Transient ischemic attack (TIA) is a clinical syndrome that has been shown to be a major risk factor for stroke. Patients with transient neurologic deficits of sudden onset that last less than 24 hours require prompt medical and neurologic evaluation for identifiable stroke risk factors. The appropriate treatment depends on the cardio- or neurovascular lesion that caused the TIA. Based on this evaluation, the optimal stroke prevention regimen in a person with TIA will vary from surgical repair of a stenotic carotid artery to daily aspirin use.

Genetic determinants of arterial thrombosis

This chapter describes examples of genetic variation involved in the function or regulation of a number of haemostatic proteins involved in the thrombotic process. In each case, the data suggest associations between genotype and disease and, particularly in the case of fibrinogen, PAI-1, Factor VII and Factor XIII, there is interaction between genotype and environment in determination of the relevant plasma level, providing a possible explanation for the differential response of individuals to their environment.

Cigarette smoking and periodontitis: methodology to assess the strength of evidence in support of a causal association

Identification of the cause of the development and progression of periodontitis has received extensive attention, with notable advances over the past decade in clinical, microbiological, immunological, biochemical, and behavioral knowledge. However, it is still largely unknown which factors lead to the conversion of non-destructive forms of periodontal disease into destructive forms and disease progression. Chronic adult periodontitis is believed to be influenced by an interaction of host defense and environmental factors. Although these variables have been studied extensively, no study has employed randomized controlled prospective human or randomized controlled community intervention designs, methodologies necessary to prove a variable to be a cause of periodontitis. Owing to the absence of literature employing rigorous experimental design, this article assesses systematically observational, cross-sectional and longitudinal studies to examine the potential causal association between cigarette smoking and periodontitis. The methodology of Sir Bradford Hill's criteria for causation was used as the framework. Results suggest that cigarette smoking is causally associated with periodontitis. That is, cigarette smoking is consistently associated with an increased prevalence/severity of periodontitis and is suspected on theoretical grounds of playing a causal role. Hill's criteria provide a useful methodology to better understand the pathogenesis of periodontal diseases and may be applied to study the pathogenesis of other dental diseases as well.

Age-associated alteration of blood thiol-group-related antioxidants in smokers

Total blood glutathione and nonglutathione free sulfhydryl compounds, glutathione peroxidase, and glutathione S-transferase in erythrocytes and plasma and also lipid peroxides in plasma were investigated in 48 male smokers and 42 male nonsmokers. We found that the level of total blood glutathione was significantly increased in young smokers (age <40) but no such change was noted in aging smokers (age>/=40). The activities of glutathione peroxidase and glutathione S-transferase in plasma were significantly decreased in young smokers and the plasma levels of these two enzymes and nonglutathione free sulfhydryl compounds were more drastically decreased in aging smokers. The average concentration of plasma lipid peroxides of the aging smokers (2.76+/-0.46 nmol/ml) was significantly higher than that of the aging nonsmokers (2.32+/-0. 41nmol/ml, P=0.049). On the other hand, the level of total blood glutathione was negatively correlated with the level of plasma lipid peroxides (r=-0.305, P=0.002) and was positively correlated with the smoking index (r=0.307, P=0.019) of all the study subjects under age control. These results indicate that the activities of glutathione peroxidase and glutathione S-transferase declined to a great extent under smoking-mediated oxidative stress in the blood of both young and aging smokers. Moreover, the compensatory generation of total blood glutathione may effectively prevent plasma lipids from peroxidation in young smokers, although the activities of glutathione peroxidase and glutathione S-transferase in plasma were decreased. By contrast, total blood glutathione was inadequate for such protection in the aging smokers. We suggest that supplementation of thiol-group-related agents may be considered for the prevention or alleviation of oxidative stress in aging smokers, whose capability and capacity for the disposal of smoking-mediated free radicals and reactive oxygen species are compromised.

Characteristics of stroke in Hofuf, Saudi Arabia

BACKGROUND

Stroke is a common neurological disorder that is encountered in most hospitals in both developed and developing countries. This two-year study was designed to show the characteristics of the problem at the King Fahad Hospital, Hofuf, Saudi Arabia.

PATIENTS AND METHOD

This was a prospective study of all Saudi stroke patients admitted to the medical wards in the study period. All patients were assessed individually by one of the two available neurologists. Data was collected on pre-designed protocol, and analysis was performed using tables and figures, and EpiInfo A(R) computer software.

RESULTS

The 329 Saudi patients studied fulfilled the criteria for stroke. The male:female ratio of the patients was 1:1, and their ages ranged between 42 and 92 years (mean 62.8+/-11.1) for males, and between 20 and 100 years (mean 59.6+/-15.4) for females. The relative frequencies of stroke subtypes were ischemic infarcts (79%), of which 46% were lacunar infarcts, intracerebral hemorrhage (18.8%), and subarachnoid hemorrhage (2.2%). The most common risk factor was concomitant hypertension with diabetes mellitus (40.4%), hypertension alone (24.9%), diabetes alone (11.6%), atrial fibrillation (5.8%), other cardiac factors (5.5%), transient ischemic attack (TIA) and prior stroke (2.1% each), and smoking (1.8%). No risk factor was detected in 5.8% of the patients. The overall in-hospital mortality was 10.0%, with a significant male preponderance.

CONCLUSION

This study demonstrated that stroke is a common neurological condition in the Al-Hassa region of the Kingdom. The male:female ratio was dissimilar from that observed in other parts of Saudi Arabia. The study also showed that hypertension with diabetes constituted a potent risk factor. Sickle cell anemia was not found to be a risk factor. The case fatality was low and both the incidence and mortality showed seasonal preference. We believe that there is a need to establish a Stroke Register at the King Fahad Hospital at Hofuf for the Al-Hassa region.

Hyperinsulinemia and the risk of stroke in healthy middle-aged men: the 22-year follow-up results of the Helsinki Policemen Study

BACKGROUND AND PURPOSE

Several studies have shown that hyperinsulinemia is associated with the risk of coronary heart disease, but information on the association of hyperinsulinemia with the risk of stroke is limited. We investigated the association of hyperinsulinemia with the risk of stroke during a 22-year follow-up of the Helsinki Policemen Study population.

METHODS

The study was based on a cohort of 970 men aged 34 to 64 years who were free of cerebrovascular disease, other cardiovascular disease, or diabetes. Risk factor measurements at baseline examination included an oral glucose tolerance test with blood glucose and plasma insulin measurements at 0, 1, and 2 hours. Area under the insulin response curve during oral glucose tolerance test was used as a composite variable reflecting plasma insulin levels.

RESULTS

During the 22-year follow-up, 70 men had a fatal or nonfatal stroke. Hyperinsulinemia (highest area under the insulin response curve quintile compared with the combined 4 lower quintiles) was associated with the risk of stroke (age-adjusted hazard ratio, 2.12; 95% CI, 1.28 to 3.49), but not independently of other risk factors (multiple-adjusted hazard ratio, 1.54; 95% CI, 0.90 to 2.62), which was mainly due to the impact of obesity, particularly upper body obesity, with subscapular skinfold thickness used as an index. Of other risk factors, upper body obesity, blood pressure, and smoking were independent predictors of the risk of stroke.

CONCLUSIONS

Hyperinsulinemia was associated with the risk of stroke in Helsinki policemen during the 22-year follow-up, but not independently of other risk factors, particularly upper body obesity.

Vascular damage from smoking: disease mechanisms at the arterial wall

The products of tobacco combustion are absorbed into the systemic circulation. Absorbed nicotine stimulates the release of catecholamines, whilst other products (perhaps including nicotine) injure the arterial endothelium and promote atherogenesis. Free radicals and aromatic compounds diminish the endothelial synthesis of nitric oxide, causing impaired endothelium-dependent relaxation of arteries, the earliest clinical sign of endothelial dysfunction. Smoking alters the shear forces and rheology at the endothelial surface and these changes enhance the effects of products of tobacco combustion to upregulate leucocyte adhesion molecules on the endothelial surface. The increased oxidation of low density lipoprotein (LDL) in smokers has synergistic effects to promote monocyte adhesion and monocyte migration into the subintimal space. Continued stimulation of intimal cells by oxidized LDL leads to the development of atherosclerosis. Many of these effects are ameliorated by high concentrations of vitamin C. Smoking also potentiates thrombosis at the dysfunctional endothelium by increasing the concentration of plasma fibrinogen and altering the activity of platelets. All these proatherogenic effects of smoking to injure the endothelium also are observed, albeit to lesser extent, in passive smokers.

Coffee consumption in hypertensive men in older middle-age and the risk of stroke: the Honolulu Heart Program

OBJECTIVE

To examine the association between coffee consumption and the development of stroke in men at high risk for cardiovascular disease.

METHODS

Coffee intake was observed from 1965 to 1968 in a cohort of men enrolled in the Honolulu Heart Program with follow-up for incident stroke over a 25-year period. Subjects were 499 hypertensive men (having systolic or diastolic blood pressures at or above 140 and 90 mm Hg, respectively) in older middle-age (55 to 68 years) when follow-up began. Past and current cigarette smokers were excluded from follow-up.

RESULTS

In the course of follow-up, 76 men developed a stroke. After age-adjustment, risk of thromboembolic stroke increased significantly with increases in coffee consumption (P = 0.002). No relationships were observed with hemorrhagic stroke. When adjusted for other factors, the risk of thromboembolic stroke was more than doubled for men who consumed three cups of coffee per day as compared to nondrinkers of coffee (RR = 2.1; 95% CI = 1.2-3.7).

CONCLUSIONS

Although in need of further confirmation, consumption of coffee appears to be positively associated with an increased risk of thromboembolic stroke in hypertensive men in older middle-age. Findings suggest that it may be prudent to advise older middle-aged men with hypertension who consume large amounts of coffee to consider reducing their coffee intake.

Cigarette smoking as a determinant of high-grade carotid artery stenosis in Hispanic, black, and white patients with stroke or transient ischemic attack

BACKGROUND AND PURPOSE

We sought to investigate the association of cigarette smoking with high-grade carotid artery stenosis in Hispanic, black, and white patients with cerebral ischemia in two independent samples.

METHODS

Prospectively collected data from the Northern Manhattan Stroke Study (NOMASS) (n=431) and the Berlin Cerebral Ischemia Databank (BCID) (n=483) were used separately for a cross-sectional study estimating the association between cigarette smoking and high-grade carotid stenosis (defined as a luminal narrowing of > or =60%, diagnosed by duplex and/or Doppler ultrasound). In both studies, cerebral ischemia patients with normal sonographic findings or nonstenosing plaques of their carotid arteries served as a comparison group. Multivariate logistic regression models were used for statistical tests to determine the association between smoking and the dependent variable for high-grade carotid stenosis. Age, sex, hypertension, diabetes, hypercholesterolemia, and race/ethnicity were considered potential confounders. Further analyses of the NOMASS data estimated the effect of the amount of cigarette use and the impact of race/ethnicity.

RESULTS

High-grade carotid stenoses were found in 14% of the NOMASS and in 21% of the Berlin patients. In Berlin the entire sample was white, whereas in New York only 19% of the cohort were white. In both samples, smoking was independently associated with severe carotid stenosis (NOMASS: odds ratio [OR], 1.5; 95% confidence interval [CI], 1.1 to 2.0; BCID: OR, 3.9; 95% CI, 2.4 to 6.4). Patients smoking 20 pack-years or more showed a significant association (OR, 2.0; 95% CI, 1.1 to 3.9), whereas no significant effect was found for lower amounts of cigarette use. In NOMASS, white smokers displayed a significant (OR, 3.2; 95% CI, 1.1 to 8.9) association with high-grade carotid stenosis, the association for black smokers was less strong, and no association was found among Hispanics.

CONCLUSIONS

Smoking is an independent determinant of severe carotid artery stenosis in patients with focal cerebral ischemia. The association differs by race/ethnicity, with the greatest effect observed among whites.

Increased oxygen extraction fraction is associated with prior ischemic events in patients with carotid occlusion

BACKGROUND AND PURPOSE

The purpose of our study was to investigate the relationship between misery perfusion (increased oxygen extraction fraction, OEF) and baseline risk factors in patients with carotid occlusion.

METHODS

One-hundred seventeen patients with atherosclerotic carotid occlusion were studied prospectively by clinical evaluation, laboratory testing, and positron emission tomography (PET). PET measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), and OEF were made on enrollment in the study. Increased ipsilateral OEF was identified by comparison with 18 normal control subjects. Twenty-five baseline clinical, epidemiological, and arteriographic risk factors were assessed on study entry. Student t tests, chi(2) tests, and Fisher exact tests with Bonferroni correction were used to assess statistical significance (P<.05).

RESULTS

Of 117 patients, 44 had increased OEF distal to the occluded carotid and 73 had normal OEFs. Thirty-nine of the 81 patients with prior ipsilateral ischemic symptoms had high OEFs (42%), whereas only 5 of the 31 asymptomatic patients had high OEFs (16%, P<.001). All of the other baseline risk factors were similar between the two groups of patients.

CONCLUSIONS

Investigations of the relationship between hemodynamic factors and stroke risk must take into account the lower frequency of hemodynamic abnormalities in asymptomatic patients.

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.

Epidemiology of risk factors for cardiovascular disease in diabetes and impaired glucose tolerance

Diabetes mellitus is a strong risk factor for all manifestations of atherosclerotic vascular disease, coronary heart disease (CHD), cerebrovascular disease and peripheral vascular disease. Diabetes can be classified into two main subtypes, insulin-dependent diabetes mellitus and non-insulin-dependent diabetes mellitus (NIDDM). This review focuses only on NIDDM. Also, in impaired glucose tolerance (IGT), a precursor stage of diabetes, the risk of macrovascular disease is substantially increased. NIDDM and IGT are known to be associated with several adverse cardiovascular risk factors, including hypertension, obesity, central obesity, hyperinsulinemia and serum lipid and lipoprotein abnormalities, characterized mainly by elevated serum total triglycerides and low high-density lipoprotein cholesterol. Practically no information is available on the role of different cardiovascular risk factors to predict macrovascular complications in subjects with IGT. The role of different cardiovascular risk factors with respect to the risk of CHD, stroke and peripheral vascular disease will be discussed.

Risk factors and antiplatelet therapy in TIA and stroke patients

Antiplatelet treatment is well established in the secondary prevention of ischemic cerebrovascular events. The reasons for the occurrence of stroke, even though the patient receives drug treatment, have remained unclear. We performed a subgroup analysis of the European Stroke Prevention Study (ESPS 1) to investigate the efficacy of treatment in patients with different cardiovascular risk factors. The ESPS 1 recruited 1306 patients with TIA, RIND or stroke in one single center of Kuopio in Finland. The patients were treated with aspirin 990 mg/day+dipyridamole 225 mg/day or placebo for 2 years or until an endpoint. The endpoints were stroke or death from any cause. The risk factors for endpoints were analyzed by Cox univariate regression analyses. The effect of a single risk factor on the efficacy of antiplatelet therapy was analyzed by Cox proportional hazards model in subgroups according to the significant risk factors found in the univariate analysis. The efficacy of treatment was statistically significant in all subgroups except diabetics and current smokers for the stroke endpoint. When the combined endpoint of stroke or death was used, the treatment failed also to show statistical significance in patients with coronary heart disease. This lack of efficacy might be due to the small sample size. The efficacy of treatment was significantly better in TIA patients than in stroke patients when analyzed with stroke as an end point. This study provides strong evidence that the effectiveness of antiplatelet treatment in ischemic stroke and TIA patients is independent of most cardiovascular risk factors. Furthermore, all patients with TIA and ischemic stroke should receive secondary prevention regardless of whether or not there are risk factors.

Smoking habits and risk of fatal stroke: 18 years follow up of the Oslo Study

STUDY OBJECTIVE

To examine the risk of fatal stroke in relation to smoking habits in men screened for the Oslo study.

DESIGN

The Oslo study is a prospective, cohort study of the epidemiology and preventive aspects of cardiovascular diseases in middle aged men. Screening started in May 1972 and results after 18 years of follow up are reported.

PARTICIPANTS

There were 16209 men aged 40-49 years, of whom 16173 had no stroke history. Eighty five men died from stroke, of whom 48 were daily cigarettes smokers, 7 were pipe and cigar smokers, 15 smoked cigarettes and pipe or cigars daily, 11 were previous cigarette smokers, and 4 had never smoked cigarettes.

MAIN RESULTS

Results of proportional hazards regression analysis adjusted for age, diastolic blood pressure, and glucose concentration showed the following rate ratios (RR) (95% confidence interval) of smoking groups compared with those who had never smoked or had previously smoked: combined cigarette and cigar or pipe smokers, RR = 6.1 (3.0, 12.5); cigarettes only, RR = 4.1 (2.3,7.4); and pipe and/or cigars only RR = 2.2 (0.9,5.5). The overall, age adjusted risk of smoking cigarettes daily was 3.5 and was found to increase with increasing cigarette consumption. Regardless of their smoking group, stroke cases had increased diastolic (DBP) and systolic blood pressure (SBP) when compared with men who had not had a stroke. The absolute differences in DBP and SBP between stroke cases and others for never and previous cigarette smokers versus daily smokers were twice as large: DBP, 12.1 mmHg versus 6.5 mmHg respectively and SBP, 16.0 mmHg versus 7.1 mmHg respectively. A high BMI increased the risk of fatal stroke of never and previous cigarette smokers. Men being treated for hypertension at the time of screening had three times the crude risk of fatal stroke of men who were not taking hypertensive treatment.

CONCLUSIONS

Daily cigarette smoking increased the risk of fatal stroke three and a half times. Combined cigarette and pipe or cigar smoking had a higher risk than smoking cigarettes only. An increased risk was found in relation to increased daily cigarette consumption.

Low total serum cholesterol and intracerebral hemorrhagic stroke: is the association confined to elderly men? The Kaiser Permanente Medical Care Program

BACKGROUND AND PURPOSE

Epidemiological studies indicate a higher incidence of intracerebral (but not subarachnoid) hemorrhagic stroke among persons with low total serum cholesterol levels. This report further examines the prospective relationship of total serum cholesterol with subsequent intracerebral hemorrhage in a large, well-defined population.

METHODS

The cohort included 61756 enrollees in a health plan from the San Francisco-Oakland metropolitan area (46% men, 63% white), aged 40 to 89 years and free of cardiovascular disease at baseline. Sixteen-year incidence of combined nonfatal and fatal intracerebral hemorrhagic stroke (International Classification of Diseases [ICD], 8th revision, code 431, or ICD, 9th revision, codes 431 and 432) was investigated in relation to serum cholesterol measured in multiphasic health checkups made in 1977 through 1985. Intracerebral hemorrhagic events were ascertained using hospital discharge records and as underlying cause of death by the California Mortality Linkage Information System.

RESULTS

From 1978 through 1993 (average of 10.7 years), there were 386 events (201 in men, 29% fatal; 185 in women, 42% fatal). By multivariate proportional hazards life-table regression analysis, serum cholesterol level below the sex-specific 10th percentile (< 4.62 mmol/L [178 mg/dL] in men), compared with higher cholesterol level, was associated with a significantly increased risk of intracerebral hemorrhage in men aged 65 years or older (relative risk, 2.7; 95% confidence interval, 1.4 to 5.0). An excess risk was also observed among elderly women at the lowest cholesterol range, but a chance finding could not be ruled out. No relationship was seen among men or women aged 40 to 64, and no statistical interaction of low serum cholesterol with hypertension was found in either sex.

CONCLUSIONS

In these data, the association between low serum cholesterol level and intracerebral hemorrhage was confined to elderly men.

Risk factors for cerebral hemorrhage in the era of well-controlled hypertension. Melbourne Risk Factor Study (MERFS) Group

BACKGROUND AND PURPOSE

Given that hypertension is now relatively well controlled and use of antiplatelet agents has increased, our primary aims were to investigate the risk of intracerebral hemorrhage (ICH) associated with hypertension and use of antiplatelet agents.

METHODS

In this city-wide case-control study, 370 consecutive cases of primary ICH, verified by CT or autopsy, were identified from one of 13 Melbourne hospitals. Ten subjects (or their next of kin) could not be located and 29 refused to participate, resulting in 331 eventual cases. Patients were aged between 18 and 80 years and had no prior stroke. Population-based control subjects were individually age- (+/- 5 years), sex-, and geographically matched to subject cases. A questionnaire administered to participants (or next of kin) elicited information about prior exposure to various potential risk factors.

RESULTS

Hypertension approximately doubled the risk of ICH (odds ratio, 2.55; 95% confidence interval, 1.72 to 3.79). The use of aspirinlike drugs, in doses used for secondary prevention of ischemic stroke or cardiac disease, was not associated with an increased risk of ICH (odds ratio, 0.66; 95% confidence interval, 0.20 to 2.21). Factors associated with a reduced risk of ICH were a history of cardiovascular disease, arthritis, or high cholesterol level; being moderately overweight or using hormone replacement therapy; and drinking coffee.

CONCLUSIONS

Hypertension was the most important risk factor for ICH but not as high as previously reported, nor was it higher than that reported for ischemic stroke. There was no evidence for any association between the use of aspirinlike drugs and ICH.

Smoke-derived nitric oxide and vascular prostacyclin are unable to counteract the platelet effect of increased thromboxane formation in healthy female smokers

The incidence of cigarette smoking tends to be higher in women, justifying directed studies on smoke-related mechanisms of cardiovascular disorder in females. Platelet activity plays an important etiological role in several settings of cardiovascular disease. Cigarette smoking facilitates platelet formation of proaggregatory thromboxane A2. However, cigarette smoke contains nitric oxide (NO), which has antiplatelet activity. Furthermore, the formation of anti-aggregatory prostacyclin (PGI2) may be higher in smokers than in non-smokers. Hence, the concerted action of NO and PGI2 on platelet activity in smoking females is important to elucidate. The metabolites of TxA2, NO, and PGI2, as well as cyclic guanosine 3':5'-monophosphate (cGMP; second messenger for NO in the platelets) and cyclic adenosine 3':5'-monophosphate (cAMP; second messenger for PGI2 in the platelets), were analysed in 23 healthy female smokers (daily consumption 11-20 cigarettes per day) and in 26 matched non-smokers. The urinary excretion of 2,3-dinor TxB2 (metabolite of TxA2) was considerably higher in smokers than in non-smokers (177 vs. 72 pg/mg creatinine, respectively; P<0.001). Plasma and urinary levels of nitrate (metabolite of inhaled NO) did not differ between the groups. Plasma and urinary cGMP were slightly increased (252 vs. 193 nmol/L; P<0.05 and 0.63 vs. 0.51 micromol/24 h; P<0.05, respectively) in smokers compared to non-smokers, while platelet cGMP was lower in smokers than in non-smokers (81 vs. 10.3 pmol/10(6) platelets, respectively; P<0.05). The urinary excretion of 2,3-dinor-6-keto-PGF1a (metabolite of PGI2) did not differ between the groups. Platelet or urinary cAMP did not differ between the groups either, while plasma cAMP was lower in smokers than in non-smokers (19.2 vs. 26.2 nmol/l, respectively; P<0.001). In healthy female smokers NO is not absorbed from the inhaled smoke, and endothelial PGI2 formation is not enhanced to counterbalance the increased platelet formation of proaggregatory TxA2.

Stroke in the People’s Republic of China

Background and Purpose Stroke is a major cause of death in the People’s Republic of China (PRC), and the geographic distribution of stroke death varies substantially. We conducted an ecological analysis to investigate the relationship of prevalence of hypertension and other risk factors with stroke incidence and mortality in the PRC.

Methods The relationship between prevalence of risk factors and stroke incidence and mortality in the PRC was assessed in 29 provinces by examining risk factor data from PRC national surveys and incidence and mortality from the 1986 PRC National Stroke Study.

Results A highly statistically significant correlation between prevalence of hypertension and stroke incidence ( r =.838, P <.001) and mortality ( r =.841, P <.001) was observed. Prevalence of hypertension explained over 70% of the geographic variability in stroke incidence (partial R 2 =.703) and mortality (partial R 2 =.707) in the PRC. There was a north-south gradient, with a higher prevalence of hypertension and stroke incidence and mortality in the north compared with the south of the country. In multiple Poisson regression analysis, a 10% increase in the prevalence of hypertension was associated with a 2.80-fold higher incidence and 2.68-fold higher mortality from stroke, whereas a 10% increase in the prevalence of alcohol consumption was associated with a 29% higher incidence and a 16% higher mortality from stroke. A 10% increase in the prevalence of cigarette smoking was associated with a 19% higher mortality from stroke.

Conclusions In the PRC, the prevalence of hypertension is strongly associated with the risk of stroke, and the geographic variation in stroke incidence and mortality is due mainly to differences in the prevalence of hypertension.

Cigarette smoking and clinically significant drug interactions

OBJECTIVE

To review clinically significant drug interactions associated with cigarette smoking.

DATA SOURCES

Data from scientific literature were identified by using a MEDLINE search. Data were extracted, evaluated, and summarized for this review.

STUDY SELECTION

Findings and experiences were selected from clinical, epidemiologic, and pharmacokinetic studies; review articles; case studies; abstracts; letters to the editor, and proceedings.

DATA EXTRACTION

Data from human studies published in English were evaluated. Only interactions deemed clinically significant are included in this review. Conclusions derived from review articles on the subject of smoking and drug interactions also were used.

DATA SYNTHESIS

Cigarette smoking can affect drug therapy via pharmacokinetic and pharmacodynamic mechanisms. Pharmacokinetic drug interactions are presented for theophylline, tacrine, insulin, flecainide, propoxyphene, propranolol, diazepam, and chlordiazepoxide. Pharmacodynamic interactions are described for antihypertensive and antianginal agents, antilipidemics, oral contraceptives, and histamine2-receptor antagonists.

CONCLUSIONS

Cigarette smoking can reduce the efficacy of certain drugs or make drug therapy more unpredictable. Pharmacokinetic interactions may cause smokers to require a larger dosage of certain drugs through an increase in plasma clearance, a decrease in absorption, an induction of cytochrome P450 enzymes, or a combination of these factors. Pharmacodynamic interactions may increase the risk of adverse events in smokers with cardiovascular or peptic ulcer disease, and in women who smoke and use oral contraceptives. Healthcare professionals should pay special attention to patients with these profiles and should try to prevent cigarette smoking or encourage patients to discontinue this addictive habit.

The association of combined alpha and beta fibrinogen genotype on plasma fibrinogen levels in smokers and non-smokers

OBJECTIVE

To determine in healthy men: (1) whether an extended genotype of the fibrinogen gene cluster using the G/A-455 and the BclI polymorphism of the beta fibrinogen gene and TaqI of the alpha fibrinogen gene explains a significantly larger proportion of variance in plasma fibrinogen levels in either smokers or non-smokers than a single polymorphism (G/A-455); (2) whether there is any evidence for genotype-smoking interaction in the determination of fibrinogen levels.

DESIGN

A cross sectional study of healthy, white men recruited at the screening for entry into the Thrombosis Prevention Trial.

SETTING

The subjects were drawn from four general practices in the United Kingdom.

RESULTS

The frequency of the rare alleles in the sample was 0.19 for the G/A-455 polymorphism (A-455), 0.15 for BclI (B+), and 0.27 for TaqI (T+) alleles. BMI and age made significant contributions to the variance in plasma fibrinogen levels only in non-smokers of 5.4% and 2.3% respectively and, in the group as a whole, smoking accounted for 6.6% of the variance. In the non-smokers, of the individual polymorphisms only the G/A-455 showed a significant association with plasma fibrinogen levels (p = 0.03). The mean fibrinogen in non-smokers homozygous for the G-455 allele was 2.54 g/l v 2.85 g/l in those homozygous for the A-455 allele, with the polymorphism explaining 3.6% of the variance in plasma fibrinogen levels in this group. On investigation of the association of fibrinogen levels with combined genotypes, the most significant effect was seen with the combination of the G/A-455 and TaqI polymorphisms, with those with no "fibrinogen raising alleles" having a mean fibrinogen of 2.57 g/l v 3.10 g/l for those with four "fibrinogen raising alleles" (p = 0.0036), and this combination explained 8.9% of the variance in plasma fibrinogen levels (p < 0.005). Although the contribution to variance was greater with the G/A-455/TaqI combination than the G/A-455 polymorphism alone (8.9% v 3.6%), this did not reach significance (p = 0.09). By contrast, in the smoking group, the only significant contribution to the difference in plasma fibrinogen levels was the G/A-455 genotype alone which, after adjustment for BMI and age, contributed 3.8% to the variance (p < 0.05). No interaction was shown between smoking and genotype.

CONCLUSION

These data suggest that in non-smokers an extended genotype using the G/A-455 beta fibrinogen gene polymorphism and the TaqI alpha fibrinogen gene polymorphism explains a larger proportion of the variance in plasma fibrinogen levels than any one polymorphism alone, but that smoking has an overriding effect so that other variables such as age and BMI make little additional contribution.

Transient ischemic attacks (TIA): current issues in diagnosis and management

Transient ischemic attacks (TIAs) affect more than 500,000 Americans each year. Stroke risk approximates 4% to 8% within 1 month and increases to 12% to 13% at one year. This has led to stroke being one of the leading causes of death and disability. TIAs are focal neurologic events that are temporary in nature and warn of potential stroke. Most TIAs resolve within 24 hours. Hypertension, smoking, heart disease, and diabetes are the major risk factors for stroke. A comprehensive history of symptoms can help identify carotid vs. vertebrobasilar disease. Timely evaluation of TIAs should be performed according to recent guidelines set forth by the American Heart Association. Aspirin continues to be the gold standard for stroke prevention, conferring a 48% risk reduction in stroke or death. The use of ticlopidine has been recommended as a second-line agent in patients with aspirin intolerance. Surgical intervention (carotid endarterectomy) is indicated in symptomatic patients with high grade stenosis of 70% or greater. For patients with less significant stenosis, inconclusive data exists regarding the benefit of medical vs. surgical treatment. Patient education should address identification of symptoms, the need for prompt medical attention, and risk factor modification. A collaborative plan between clinician and client will facilitate early intervention ultimately leading to preservation of function and prevention of the catastrophic sequelae of stroke.

Impact of alcohol consumption and cigarette smoking on stroke among the elderly in Taiwan

BACKGROUND AND PURPOSE

We investigated the influence of alcohol consumption and cigarette smoking on all types of stroke and cerebral infarction, in particular among a representative sample of elderly residents in Taiwan.

METHODS

This study was a component of a nationwide survey of health and living status of residents aged 65 years or older in Taiwan in which subjects received detailed physical, neurological, and laboratory examinations. Inquiries were made about medical history, and information on the amount and duration of drinking and smoking was obtained. Diagnoses of stroke were made according to the results of brain computed tomography at the onset of disease or were based on criteria established by the World Health Organization.

RESULTS

Of the 2600 subjects, there were 155 elderly persons with stroke (prevalence, 6%). Excessive drinking of more than 367.6 g/wk of alcohol was associated with a high prevalence of cerebral infarction. Consumption of < or = 367.5 g/wk of alcohol did not have an influence on stroke prevalence. The relationship between duration of alcohol drinking and stroke was equivocal. More than 30 pack-years of cigarette smoking was a significant risk factor for all types of stroke and cerebral infarction in particular. Using multiple logistic regression to control for possible confounders, it was found that smoking was an independent risk factors for all stroke and was of borderline significance for cerebral infarction. Although excessive drinking was a significant risk factor for cerebral infarction in univariate analysis, this effect was lost after adjustment for other confounders.

CONCLUSIONS

Cigarette smoking was a more important risk factor for stroke and cerebral infarction than excessive drinking of alcohol.

Body mass index and thromboembolic stroke in nonsmoking men in older middle age. The Honolulu Heart Program

BACKGROUND AND PURPOSE

While evidence suggests that obesity has an independent relation to coronary artery disease, similar findings for stroke have not been established. The purpose of this study was to examine the relation between body mass index and the risk of thromboembolic stroke independently of other risk factors.

METHODS

Since 1965, the Honolulu Heart Program has followed a cohort of men in a prospective study of cardiovascular disease. This article examines the relationship between the baseline measurement of body mass index and the risk of thromboembolic stroke in 1163 nonsmoking men in older middle age (55 to 68 years). Men who had an elevated risk of stroke due to hypertension, diabetes, and other risk factors were excluded from the analysis.

RESULTS

After 22 years of follow-up, the rate of stroke increased significantly with increasing levels of body mass (P < .01). In the bottom tertile of the body mass index, the rate of thromboembolic stroke was 28.7 per 1000 (11/383). In the middle tertile, the rate was increased by 40% to 40.7 per 1000 (16/393), and in the top tertile, the rate of thromboembolic stroke was 55.4 per 1000 (21/387), a twofold excess compared with the bottom tertile. After adjustment for age and the residual effects of confounding risk factors, including systolic blood pressure and serum glucose, the estimated relative risk of stroke for the average body mass index in the top tertile (26.6 kg/m2) compared with that in the bottom tertile (20.3 kg/m2) was 2.1 (95% confidence interval, 1.1 to 4.1). These findings were not affected by coronary events that occurred in the course of follow-up, nor did they appear to be influenced by deaths from other causes.

CONCLUSIONS

We conclude that elevated body mass is associated with an increased risk of thromboembolic stroke in nonsmoking men in older middle age who are free of commonly observed conditions related to cardiovascular disease.