Aggregation of multiple risk factors for stroke in siblings of patients with brain infarction and transient ischemic attacks

Common Familial Effects on Ischemic Stroke and Myocardial Infarction: A Prospective Population-Based Cohort Study

BACKGROUND

Recent genome-wide association studies suggest some overlap of genetic determinants of ischemic stroke (IS) and myocardial infarction (MI). This study aimed to assess shared familial risk between IS and MI in a large, population-wide cohort study.

METHODS

Study participants free of IS and MI and their affected siblings were extracted from the Swedish Hospital Discharge and Cause of Death Registers between 1987 and 2007, forming an exposed sib-pair. They were matched by birth year of both siblings and calendar period to up to five unexposed sib-pairs. Stratified Cox regression analyses were used to assess familial risk of MI and IS in those exposed to having a sibling with IS (n = 31,659) and MI (n = 62,766), respectively, compared to unexposed (n = 143,728 and 265,974).

RESULTS

The overall risk of MI when exposed to having a sibling with IS was statistically significantly increased (RR, 1.44; 95% CI, 1.34-1.55, p < 0.001) to a similar extent as risk of IS when exposed to having a sibling with MI (RR, 1.41; 95% CI, 1.32-1.50, p < 0.001). The familial risks were similar in full siblings for both groups (RR for MI, 1.46; 95% CI, 1.35-1.58, p < 0.001; and RR for IS, 1.40; 95% CI, 1.30-1.40, p < 0.001) and half siblings (RR for MI, 1.29; 95% CI, 1.05-1.59, p < 0.001; and RR for IS, 1.38; 95% CI, 1.16-1.65, p < 0.001).

CONCLUSION

This large, population-wide study indicates that there is considerable overlap of familial risk between IS and MI.

The vascular endothelium and human diseases

Alterations of endothelial cells and the vasculature play a central role in the pathogenesis of a broad spectrum of the most dreadful of human diseases, as endothelial cells have the key function of participating in the maintenance of patent and functional capillaries. The endothelium is directly involved in peripheral vascular disease, stroke, heart disease, diabetes, insulin resistance, chronic kidney failure, tumor growth, metastasis, venous thrombosis, and severe viral infectious diseases. Dysfunction of the vascular endothelium is thus a hallmark of human diseases. In this review the main endothelial abnormalities found in various human diseases such as cancer, diabetes mellitus, atherosclerosis, and viral infections are addressed.

Family history of hypertension is not an independent genetic factor predisposing to ischemic stroke subtypes

OBJECTIVES

The effect of family history of hypertension (FHx(HT)), as a genetic factor predisposing to some ischemic stroke subtypes and independently of hypertension as risk factor, has never been studied.

METHODS

A positive FHx(HT) was searched in 472 patients (312 men, 160 women; mean [S.D.] age, 67.9 [11.4] years) consecutively admitted for a first-ever ischemic stroke (348) or transient ischemic attack (TIA) (124) due to small vessel disease (SVD, 180), large vessel disease (156), or cardioembolism (136). In this population and in three age bands, the genetically transmitted vascular risk factors, age, gender and the ischemic stroke subtypes were compared between those with and without a positive FHx(HT).

RESULTS

None of the risk factors was associated with a positive FHx(HT), except for hypertension in the whole population (68.9% vs. 48.7%; p=0.001) and in the <65 year-old patients (72.5% vs. 39.5%; p<0.001). Regarding the stroke subtypes, a positive FHx(HT) was only associated with SVD in the subgroup of <65 year-old patients (odd ratios (OR), 2.07; 95% confidence interval (CI), 1.01 to 4.25; p=0.045). However, this finding disappeared in a logistic regression analysis, which only retained hypertension as independently associated with SVD.

CONCLUSIONS

FHx(HT) is not an independent genetic factor predisposing to some aetiological stroke subtypes.

Hypertension, stroke, and endothelium

Endothelial dysfunction, the complex, multifaceted, pathologic product of various vasculotoxic agents or injuries, is an intermediate attractant phenotype of cardiovascular diseases that usually has a long and unpredictable natural history. Furthermore, endothelial dysfunction may not only represent a vascular disease marker, but actually may play an important pathogenetic role that leads to the progression of the disease and the unfavorable outcomes. Among these vascular diseases, cerebrovascular accidents, particularly stroke, clearly represent a paradigmatic example of the potential role of dysfunctional endothelium. Elevated blood pressure has long been recognized as one of the most important risk factors for stroke; other factors, however, seem to play an important role. Indeed, epidemiologic evidence suggests that, in spite of an improved control of blood pressure, the secular trends of stroke in well-controlled populations are increasing. In this brief review, we analyze current evidence suggesting that endothelial dysfunction can play a role in the pathogenesis of ischemic stroke.

Potential Confounding by Intermediate Phenotypes in Studies of the Genetics of Ischaemic Stroke

BACKGROUND

Family history (FHx) of stroke is perceived to be an important risk factor for ischaemic stroke. However, there are several intermediate phenotypes that are often involved in the aetiology of ischaemic stroke and that have a substantial genetic component themselves. We studied FHx of ischaemic heart disease (IHD), hypertension (HTN) and diabetes mellitus (DM) as risk factors for ischaemic stroke.

METHODS

We performed a systematic review of case-control and cohort studies reporting on FHx(IHD), FHx(HTN) or FHx(DM) as risk factors for stroke using bibliographic databases, and by hand searching reference lists and journals. Odds ratios of FHx as a risk factor for stroke were calculated within individual studies. We included unpublished data from two Oxfordshire population-based studies to assess effects on subtypes of ischaemic stroke.

RESULTS

We identified 54 studies that investigated the odds of stroke conferred by a positive FHx, 24 of which reported data on FHx of one or more intermediate phenotypes in addition to FHx of stroke. Most studies reported an increased frequency of FHx(IHD) and FHx(HTN) in stroke patients versus controls. The association was significant in 6 out of 14 studies for FHx(IHD) and 4 out of 11 studies for FHx(HTN). In contrast, FHx(DM) was not associated with stroke. FHx(IHD) was particularly associated with large vessel strokes (OR 1.72, CI 1.3-2.2, p = 0.00004).

CONCLUSIONS

FHx(IHD) and FHx(HTN) are both risk factors for stroke. It is likely that the apparent heritability of stroke is partly accounted for by heritability of HTN and large vessel atherosclerosis. Analyses of heritability of stroke and candidate gene studies should be adjusted accordingly.

Angiotensin converting enzyme gene polymorphism and traditional Sasang classification in Koreans with cerebral infarction

Sasang constitutional medicine is a major branch of Korean traditional oriental medicine. Constitutions of Sasang medicine refer to Taeyangin, Taeumin, Soyangin, and Soumin. The differences of disease severity to be shown in the constitution may be due to genetic factors. Therefore, we examined interrelationship among cerebral infarction, CI, angiotensin converting enzyme (ACE) gene polymorphism, and Sasang constitutional classification. We investigated the association between ACE genotype and CI by case-control study in a Korean population. We also classified CI patients and control group into groups according to Sasang constitutional medicine. 208 CI patients and 643 controls without CI were examined. ACE genotype was determined by 7.5 % polyacrylamide gel separation after DNA amplification. The ACE/DD genotype was not associated with CI. The frequency of Taeumin of Sasang constitutional medicine in patients with CI was significantly higher than that in controls (chi2=41.202, p<0.001). However, the Taeumin constitution did not enhance the relative risk for CI in the subjects with ACE/DD genotype. Although we did not find any association between ACE gene polymorphism and CI in Koreans, there were significant differences in allele frequencies between Koreans and Europeans, but not Japanese and Chinese populations. Furthermore, we first attempted to evaluate the efficacy of Sasang constitutional medicine, and to find an association with CI.

Altered regulation of endothelin A receptor subtype in the cerebral arterioles in response to a Japanese-style diet, in stroke-prone hypertensive rats

OBJECTIVE

To investigate the expression of endothelin (ET)-1 and its receptors in the cerebral arterioles of stroke-prone (spSHR) and control spontaneously hypertensive rats (SHRs) and the changes in endothelin receptor subtypes A and B density elicited by a stroke-permissive diet, before the development of stroke.

METHODS

Six-week-old SHRs (n=11) and spSHRs (n=11) were assigned to either a regular or a "Japanese"-style diet, in addition to 1% NaCl in the drinking water, for 4 weeks. Cryosections (10 microm thick) of rat brain were assessed for endothelin receptor distribution and density by autoradiography with [125I]ET-1 (10(-10) mol/l) in the presence of cold ET-1 (10(-6) mol/l) or the peptide antagonists BQ-123 (10(-6) mol/l) or BQ-788 (10(-6) mol/l). Reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry were used to detect specific mRNAs and localize immunoreactive ET-1 and ET(A) and ET(B).

RESULTS

In both strains, immunoreactive ET-1 was detected in the endothelium of cerebral arterioles, and RT-PCR and autoradiography demonstrated the coexistence of both receptor subtypes in brain homogenates and the cerebral arteriole walls, respectively. With the regular diet, the ET(A) receptor density was lower in SHRs than in spSHRs (P = 0.007), whereas the ET(B) receptor density was similar (P = NS). The Japanese-style diet increased the density of ET(A) receptors (P = 0.006) in SHRs, but decreased it (P = 0.019) in spSHRs. No effect was seen on ET(B) receptor density.

CONCLUSIONS

ET(A) and ET(B) receptor subtypes are expressed in the wall of cerebral arterioles of SHRs and spSHRs. The latter strain showed a marked increase in ET(A) receptor density under a regular diet, in addition to an altered regulation in response to a stroke-permissive diet.

Family history of stroke in stroke types and subtypes

Many studies have provided data showing that family history of stroke (FHS) is associated with an increased risk of stroke. The association of the FHS with the various stroke subtypes has not been adequately studied. The purpose of this study was to assess the association of the FHS with the two major stroke types (cerebral haematomas and ischaemic strokes) and the four stroke subtypes (cardioembolic, large artery disease, small artery disease, and undetermined) in a Greek population. The FHS was obtained from 421 consecutive acute stroke patients and from 239 matched control subjects. Positive FHS was observed in 49% of all stroke patients compared with 28% of the control subjects [adjusted OR=2.06 (95% confidence intervals (CI) 1.42-3.00)]. Haematomas, ischaemic strokes, and from the ischaemic strokes, both large and small artery disease strokes were strongly associated with positive FHS compared with the control subjects [adjusted OR=2.06 (95% CI 9-3.04), 2.07 (95% CI 1.09-3.91), 2.05 (95% CI 1.24-3.38), and 2.76 (95% CI 1.55-4.91), respectively]. There was no difference between maternal and paternal heritable contribution.In conclusion, FHS was found in this study to be an independent risk factor for all strokes combined, for each stroke type, and for the large and small-artery disease stroke subtypes, but not for the cardioembolic and undetermined stroke subtypes.

Endothelial dysfunction and stroke

Endothelial dysfunction, intended as the complex multifaced pathological product of different vasculotoxic agents or injuries, is viewed today as an attractant intermediate phenotype of cardiovascular diseases with usually long and unpredictable natural history. Furthermore, endothelial dysfunction may not only represent a vascular disease marker, but may actually play an important pathogenetic role, leading to progression of the disease and unfavourable outcomes. Among these vascular diseases, cerebrovascular accidents, namely stroke, clearly represent a paradigmatic example of the potential role of dysfunctional endothelium. In fact, in the world's growing elderly population few diseases are more dreaded than stroke. With an increasing incidence and mortality of 30%, stroke carries the threat of death or long-term disability and suffering. Endothelium produces nitric oxide (NO) under basal conditions and in response to a variety of vasoactive stimuli in large cerebral arteries and in the cerebral microcirculation. In addition to exerting a tonic dilator effect on the cerebral circulation, basal release of NO may protect cerebral endothelium by inhibiting aggregation of platelets and leukocytes. In this paper, we analyse current evidence suggesting that endothelial dysfunction can play a role in the pathogenesis of ischaemic stroke.

Altered gene expression in cerebral capillaries of stroke-prone spontaneously hypertensive rats

Stroke-prone spontaneously hypertensive rats (SHRSP) are a well-characterized, genetic model for stroke. We showed earlier that the structure and function of the tight junctions in SHRSP blood-brain barrier endothelial cells is disturbed prior to stroke. To investigate the molecular events leading to endothelial dysfunction in SHRSP cerebral capillaries, we carried out suppression subtractive hybridization (SSH) in combination with a cDNA filter screening step. We identified two cDNA fragments that were upregulated in SHRSP, compared to stroke-resistant spontaneously hypertensive rats (SHR), and found open reading frames of 133 and 138 amino acids, respectively. These peptides did not match any known proteins in public databases. A third upregulated SHRSP cDNA fragment was identified as the rat sulfonylurea receptor 2B (SUR2B). We also isolated and cloned the cDNA of the rat homologue for the mouse G-protein signaling 5 (RGS5) regulator. This regulator was downregulated in SHRSP. We used in situ hybridization to show that rat RGS5 is expressed in the brain capillary endothelium and in the choroid plexus. Our findings may lead to the identification of new stroke-related genes.

Abnormalities of endothelial function in the pathogenesis of stroke: the importance of endothelin

Endothelial cells play a key role in the local regulation of the vascular smooth muscle tone by producing and releasing relaxing and contracting factors. Endothelin (ET)-1, one of the most potent endogenous vasoconstrictor substances known, is produced by endothelial cells. In the cerebral vasculature ET-1 is thought to be involved in several pathological conditions, including vasospasm following subarachnoid hemorrhage and stroke. This review contains evidence suggesting that endothelial dysfunction may contribute to the development of ischemic stroke and discusses the current knowledge concerning the role of ET-1 in the pathogenesis of stroke in animal models and in humans.

Differential brain atrial natriuretic peptide expression co-segregates with occurrence of early stroke in the stroke-prone phenotype of the spontaneously hypertensive rat

OBJECTIVE

To determine how the downregulation of atrial natriuretic peptide (ANP) gene expression, previously demonstrated to occur only in the brain of the stroke-prone spontaneously hypertensive rat (SHRsp), in contrast to the stroke-resistant SHR (SHRsr), co-segregates with stroke occurrence in SHRsp/SHRsr F2 descendants in order to study the 'protective' role towards stroke previously demonstrated in SHRsp for the quantitative trait locus STR2 that also carries the ANP gene.

DESIGN AND METHODS

Eight male SHRsp, eight male SHRsr and 16 male SHRsp/SHRsr F2-intercross animals (progeny of brother/sister mated F1 hybrids from an original cross between F0 SHRsp and SHRsr) were selected for this study. All rats were exposed to a stroke-permissive Japanese-style diet starting at the age of 6 weeks. Half of the F2 animals had early strokes; the remainder had late strokes. Blood pressure was measured before sacrifice. Analysis of brain ANP expression using an RNase protection assay was performed in all animals.

RESULTS

Downregulation of brain ANP in the stroke-prone phenotype was found to co-segregate with the occurrence of early strokes in the F2 rats independently of blood pressure levels.

CONCLUSIONS

The observed lower expression of ANP in the brains of stroke-prone rats appears to be the result of an inhibitory effect by another gene or genes. It seems unlikely that this specific trait represents a primary protective mechanism.

Evidence for a common defect associated with pressure in the aorta of two hypertensive rat strains

1. Thoracic aortas of normotensive (Wistar-Kyoto (WKY) and Lyon normotensive (LN)) and hypertensive (spontaneously hypertensive rats (SHR) and Lyon hypertensive (LH)) rats from two groups (Japanese (WKY rats and SHR) and Lyon (LN and LH rats)) were compared using organ chambers. Changes in endothelium and smooth muscle reactivity to noradrenaline (NA), carbamylcholine and N omega-nitro-L-arginine (L-NNA) were analysed to distinguish between changes in reactivity that are associated with the presence of hypertension and those that are dependent on group (Japanese vs Lyon). 2. Aortas of hypertensive rats had lower pD2 values for NA than aortas from normotensive rats. These differences were associated with hypertension (P < 0.005 and P < 0.01) and group (P < 0.005 and P < 0.005) in presence or absence of endothelium, respectively, whereas no difference was seen in the maximal developed tension in response to NA. 3. Aortas also differed by a reduced ability to relax in response to carbamylcholine in hypertensive rats; this effect is hypertension (P < 0.05) and group (P < 0.005) dependent, without any change in carbamylcholine pD2 values. 4. Changes in maximum developed tension in the presence of L-NNA were found to be endothelium dependent and pressure and group independent. Furthermore, the change in tension induced by L-NNA appears significantly more pronounced in SHR than in LH rats (P < 0.05). 5. These results indicate that the common defect associated with hypertension appears to be linked to the endothelium through alpha-adrenoceptors and muscarinic receptors in both the Japanese and Lyon groups. However, SHR differs markedly from LH rats by having a higher developed tension in response to NA, this increased tension being counterbalanced by the release of nitric oxide, as observed in the presence of L-NNA.

Genetics of stroke--a review

Evidence from twin and family shows that genetic factors contribute to the risk of stroke and that their role may be at least as important in stroke as in coronary heart disease. Additional support for the significance of genetic factors comes from other findings such as epidemiological data showing phenotypic heterogeneity of stroke, genetic influence on many of the risk factors for stroke, and racial and geographic differences in morbidity and mortality in stroke victims. Yet, apart from the reported associations of a small number of cases with Mendelian cerebrovascular diseases, only a few studies have directly investigated gene markers or molecular genetics of stroke. This review presents the existing evidence on the genetic background of stroke and discusses results from the genetic studies of stroke published to date.

Polymorphism of the angiotensin-converting enzyme (ACE) gene in patients with thrombotic brain infarction

The relationship between cerebrovascular disease and an insertion/deletion (I/D) polymorphism in intron 16 of the angiotensin-converting enzyme (ACE) gene is still being debated. We examined its role as a risk factor in patients with thrombotic brain infarction. The association between ACE polymorphism and ischemic stroke was examined in 181 patients with thrombotic brain infarction and 271 controls without strokes. The I/D polymorphism was examined using the polymerase chain reaction. Distributions of the ACE genotypes and alleles did not differ between the infarcted patients and the controls. Both distributions in patients with onset at age 60 years or younger were significantly higher than those in younger controls (genotype: chi 2 = 7.6, P = 0.02; allele: chi 2 = 5.6, P = 0.02). There were no significant differences in the distributions of ACE genotypes and alleles between the patients with lacunar infarcts and with cortical infarcts in all ages. There were also significant differences in the distribution of ACE genotypes and alleles between the younger and the elderly subgroup of patients with brain infarction (genotype: chi 2 = 12.9, P = 0.002; allele: chi 2 = 11.1, P = 0.0009). Furthermore, there was a significant decline in the frequency of the ACE D allele with increasing age in all patients with thrombotic brain infarction. These observations demonstrated a significant association between the ACE gene polymorphism and thrombotic brain infarction in patients age 60 years or younger in a Japanese population. Furthermore, there may be an association between the ACE D allele and mortality after cerebral infarction.

Chromosomal mapping of quantitative trait loci contributing to stroke in a rat model of complex human disease

Stroke is a complex disorder with a poorly understood multifactorial and polygenic aetiology. We used the stroke-prone spontaneously hypertensive rat (SHRSP) as a model organism, mated it with the stroke-resistant spontaneously hypertensive rat (SHR) and performed a genome-wide screen in the resultant F2 cohort where latency until stroke, but not hypertension (a major confounder) segregated. We identified three major quantitative trait loci, STR1-3, with lod scores of 7.4, 4.7 and 3.0, respectively, that account for 28% of the overall phenotypic variance. STR2 colocalizes with the genes encoding atrial and brain natriuretic factor, peptides with important vasoactive properties. Our results demonstrate the existence of primary, blood pressure-independent genetic factors predisposing to a complex form of stroke.

Association and cosegregation of stroke with impaired endothelium-dependent vasorelaxation in stroke prone, spontaneously hypertensive rats

While hypertension is a major risk factor for stroke, it is not its sole determinant. Despite similar blood pressures, spontaneously hypertensive rats (SHR) do not share the predisposition to cerebrovascular disease typical of stroke-prone spontaneously hypertensive rats (SHRSP). We investigated vascular function in male SHR and SHRSP as well as in SHRSP/SHR-F2 hybrid animals. Animals were maintained on the appropriate dietary regimen necessary for the manifestation of stroke. Among the hybrid animals, a group of stroke-prone and a group of stroke-resistant rats were selected. Blood pressure was similar in all groups. Endothelium-independent vascular reactivity tested on isolated rings of thoracic aorta and basilar artery after death showed similar contractile and dilatory responses to serotonin and nitroglycerin, respectively, in all groups. In contrast, endothelium-dependent relaxation, in response to acetylcholine or substance P, was markedly reduced in SHRSP compared with SHR. Similarly, reduced vasodilatory responses were present in aortae of F2 rats that had suffered a stroke when compared with SHR or F2 rats resistant to stroke. The observed association and cosegregation of stroke with significant and specific impairment of endothelium-dependent vasorelaxation among SHRSP and stroke-prone F2 hybrids, respectively, suggest a potential causal role of altered endothelium-dependent vascular relaxation in the pathogenesis of stroke.

Family history and socioeconomic factors as predictors of myocardial infarction, unstable angina and stroke in an Italian population. PROGETTO 3A Investigators

A comprehensive case-control study was conducted in an Italian region in order to compare the influence of family history of cardiovascular events, socioeconomic factors, social networks, and their joint associations with major risk factors, on the risk, of myocardial infarction (MI), unstable angina (UA) and ischemic stroke (IS). A total of 513 patients with MI, 178 with UA, 237 with IS, and 928 hospitalised controls were recruited. The odds ratio (OR) of MI for two or more relatives with a positive history of MI was 3.6 (95% CI: 1.8-7.3). Family history of MI was predictive for UA (OR = 5.8; 95% CI: 1.2-28.7), but not for IS. A family history of stroke was more associated with the risk of MI than of IS. After adjustment for known risk factors, the OR of MI for more educated people was 2.1 (1.3-3.6) compared with less-educated people. Large family size seemed to be protective for MI. The effect of major risk factors on MI ranged from additive (diabetes) to multiplicative jointly with high education and family history of MI. A family history of stroke increased IS risk threefold jointly with smoking and hyperlipidemia, and eightfold with diabetes. Besides a family history of MI and IS, in this community a higher educational status seems to better identify groups at increased risk of MI. The joint associations have important preventive implications since by identifying high-risk individuals (for MI and IS) a more careful assessment and control of risk factors amenable to intervention may be performed.

Risk factors for transient ischemic attacks in middle-age. A population-based case-control study

A case-control study was based on "unselected" transient ischemic attacks (TIAs) in a middle-aged Italian population. The identified cases included 52 prevalent and 25 incident TIAs. There was an incidence rate ratio (female/male) of 1.8 for definite cases. Comparison with the whole population for medical history of hypertension, diabetes and heart attack showed age/sex-adjusted odds ratios of 4.3, 2.1, 7.9 for incident cases. The results were similar when a more detailed investigation of risk factors was performed with all the cases and a random sample of the controls. Moreover, female sex had an odds ratio for incident cases of 3.3 (95% confidence interval 1.0-11.3) after adjustment for age and presence of all the main risk factors. The presence of at least one cardiopathy showed an odds ratio of 8.3 for incident cases (95% confidence interval 2.4-28.4).

Transient ischemic attacks: an update

This is a review of extant concepts of transient ischemic attacks (TIAs), their definitions, prognostic significance, pathogenesis, physiology, and management. The natural history of TIAs depends upon the risk factors of the population group studied, so that therapeutic trials should be controlled and randomized and not dependent upon published natural history data. A strong association between TIAs and coronary artery disease has now been established. It may be difficult to establish the cause or pathogenesis of TIAs in any given patient in view of the relatively poor correlation between the patient's symptoms and location of arterial plaques. Recent studies have suggested mechanisms aside from impaired perfusion or embolization from carotid plaques or vertebral basilar disease. There are no proven indications for carotid endarterectomy, a procedure which has been excessively used in the United States, but presently ongoing prospective, randomized, controlled multi-center studies will likely resolve this important issue. Neither is there scientific validation for the use of long-term anticoagulants, but data support the efficacy of ASA in reducing the incidence of stroke and myocardial infarction in patients with TIAs.

Characteristics of stroke victims associated with early cardiovascular mortality in their children

We assessed the relationship between characteristics of stroke victims and the risk of early death from coronary or cerebrovascular disease (CCVD) among their children. For each of 55 stroke patients selected from a registry which enrolled patients between 1969 and 1973, an index of their progeny's survival was calculated using the age in 1987 of 197 surviving children, and the age at and cause of death for 55 deceased children. Increased risk of CCVD death within families was significantly related to parental age at the time of first stroke, and with the parental history of diabetes mellitus. No significant relationship was found between the children's risk of CCVD death and the stroke patient/parent's sex, race, history of hypertension or cardiac disease, stroke diagnosis (infarction vs hemorrhage), or severity upon admission. These results suggest that family histories of cerebrovascular disease may impart differential risks, depending upon a family history of diabetes, and perhaps, the ages at which ancestral strokes first occurred.