Cerebrovascular diseases in a fixed population of Hiroshima and Nagasaki, with special reference to relationship between type and risk factors

Spontaneous Intracerebral Hemorrhage in the Young: An Institutional Registry Analysis

Background

Spontaneous intracerebral hemorrhage (SICH) accounts for about 10-15% of all strokes. Generally, it is a disease of the elderly; worldwide, the incidence of SICH in the young is showing an increasing trend, especially in India and the Asian continent. An attempt is also made to analyze the presence of factors, which may predict the risk of SICH among young hypertensives.

Methods

A six-year retrospective review of patients aged below 50 years who presented with SICH was included in the study. Patients with bleeds secondary to an identifiable cause such as tumor, trauma, vascular malformations, and coagulopathy-induced bleeds were excluded from the study. The outcome was measured at 90 days using the modified ranking scale, and predictors of outcome (good outcome modified ranking score (mRS): 0-3; poor outcome mRS: 4-6) were analyzed.

Results

SICH in the young accounted for 28.4% of all intracerebral hemorrhage (ICH) patients admitted during the study period (344/1210). The mean age of our male-dominant (78.5%) cohort was 42.9 ± 6.24 years, and the median Glasgow coma score (GCS) on presentation was 11 (IQR: 8-14). A prior history of hypertension (HTN) was obtained in 51.2% (176), and left ventricular hypertrophy (LVH) was documented in 237 (68.9%) patients. The basal ganglia was the most common location of the bleed (62.2%). At 90 days, 200 patients (58.1%) had good outcome and 144 (41.9%) had poor outcome with an overall mortality of 75 (21.8%). Independent predictors of poor outcome were poor GCS, larger volume, and high serum creatinine values.

Conclusion

The incidence of SICH among the young accounts for nearly 30% of admitted ICH. Poor outcome and mortality are high with HTN being the single most important modifiable risk factor in the cohort.

Japanese-Style Diet and Cardiovascular Disease Mortality: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

This systematic review and meta-analysis elucidate the effects of the Japanese-style diet and characteristic Japanese foods on the mortality risk of cardiovascular disease (CVD), cerebrovascular disease (stroke), and heart disease (HD). This review article followed the PRISMA guidelines. A systematic search in PubMed, The Cochrane Library, JDreamIII, and ICHUSHI Web identified prospective cohort studies on Japanese people published till July 2020. The meta-analysis used a random-effects model, and heterogeneity and publication bias were evaluated with I² statistic and Egger’s test, respectively. Based on inclusion criteria, we extracted 58 articles, including 9 on the Japanese-style diet (n = 469,190) and 49 (n = 2,668,238) on characteristic Japanese foods. With higher adherence to the Japanese-style diet, the pooled risk ratios (RRs) for CVD, stroke, heart disease/ischemic heart disease combined (HD/IHD) mortality were 0.83 (95% CI, 0.77–0.89, I² = 58%, Egger’s test: p = 0.625, n = 9 studies), 0.80 (95% CI, 0.69–0.93, I² = 66%, Egger’s test: p = 0.602, n = 6 studies), and 0.81 (95% CI, 0.75–0.88, I² = 0%, Egger’s test: p = 0.544, n = 6 studies), respectively. Increased consumption of vegetables, fruits, fish, green tea, and milk and dairy products decreased the RR for CVD, stroke, or HD mortality. Increased salt consumption elevated the RR for CVD and stroke mortality. Increased consumption of dietary fiber and plant-derived protein decreased the RR for CVD, stroke, and HD/IHD mortality. The Japanese-style diet and characteristic Japanese foods may reduce CVD mortality. Most studies conducted diet surveys between 1980 and the 1990s. This meta-analysis used articles that evaluated the same cohort study by a different method. A new large-scale cohort study matching the current Japanese dietary habits is needed to confirm these findings.

Nontraumatic intracerebral haemorrhage in young adults

Nontraumatic intracerebral haemorrhage (ICH) is a common subtype of stroke with a poor prognosis, high mortality and long-term morbidity. The incidence of ICH increases with age. ICH has not been widely investigated in young adults (herein defined as aged ∼18-50 years) despite an annual incidence of ∼5 per 100,000 individuals. Furthermore, ICH characteristics differ between young and elderly patients. Risk factors for ICH are surprisingly common in young adults, in whom ICH is often caused by structural lesions or hypertension, and only rarely by anticoagulation therapy and cerebral amyloid angiopathy (which are common predisposing factors in elderly patients). High short-term mortality (17% at 3 months) and long-term mortality (>25% at 10 years) persist even in contemporary series from high-income countries, and long-term disability is very common. Thus, an aggressive approach to identifying treatable underlying conditions and preventing ICH recurrence is indicated in young patients, although treatment strategies have generally not been investigated specifically in this age group. This narrative Review summarizes existing knowledge on the epidemiology, risk factors, causes, diagnosis, treatment and outcomes of ICH in young adults. We provide comparisons with the population of elderly patients with ICH and discuss challenges for future research.

Impact of Statins on Risk of Stroke: A Meta-Analysis

Background:

Evidence from randomized, controlled trials suggests that reduction of low-density lipoprotein cholesterol with hydroxymethylglutaryl coenzyme A reductase inhibitor (statin) therapy in patients at high risk for cardiovascular disease reduces the incidence of ischemic stroke; however, data from large epidemiologic observational studies suggest an inverse relationship between risk of hemorrhagic stroke and cholesterol levels.

Objective:

To perform a meta-analysis of randomized controlled trials to assess the effect of statin therapy on all cerebrovascular events (CVEs), ischemic stroke, and hemorrhagic stroke.

Methods:

A systematic literature search of MEDLINE, EMBASE, Cumulative Index to Nursing&Allied Health Literature, and Web of Science citations from June 1975 through September 2006 was performed to identify randomized controlled trials of statin therapy. Trials were included if they met the following criteria: (1) controlled clinical trials of statin therapy versus placebo, (2) well-described protocol, and (3) data reported on incidence of all CVEs, ischemic stroke, or hemorrhagic stroke. All data were independently extracted by 3 investigators.

Results:

Weighted averages are reported as relative risk with 95% confidence intervals. A total of 26 trials (N = 100,560) reported incidence on all CVEs. Six trials (n = 37,292) reported incidence of ischemic stroke and 9 trials (n = 57,895) were included in the hemorrhagic stroke analysis. Statin therapy significantly reduced the risk of all CVEs (RR 0.83; 95% CI 0.76 to 0.91) and the risk of ischemic stroke (RR 0.79; 95% CI 0.63 to 0.99). Statin therapy did not significantly reduce risk of hemorrhagic stroke (RR 1, 11; 95% CI 0.77 to 1.60).

Conclusions:

Statin therapy significantly reduces risk of developing all CVEs and ischemic stroke; however, it is associated with a nonsignificant increase in risk of hemorrhagic stroke.

The Epidemiology of Stroke in the East Asian Region: A Literature-Based Review

Stroke is a leading cause of morbidity and mortality in the developed world. Our objective was to review comparable studies of stroke incidence, prevalence, and subtypes in the East Asian region. English language epidemiologic studies of stroke published from 1984 through 2004 were identified for the East Asian region (China, Hong Kong, Taiwan, Japan, North and South Korea and the ASEAN countries). The Sudlow–Warlow criteria were modified to identify comparable studies. Stroke epidemiology is relatively well characterized in China, Taiwan, and Japan; however, little information is available for other countries. Four studies of stroke incidence, from China, Taiwan, and Japan, were identified, which reported a total of 4995 first-ever stroke events. There was an over twofold difference in the age-adjusted incidence of stroke between the Chinese Seven Cities and Okinawa study (483 vs 201 per 100 000). The 1-month case fatality rate ranged from 12·7% to 17·3%. Only one population-based study on stroke prevalence, from Taiwan, was identified: Studies show the relatively high proportion of hemorrhagic stroke (30%). Stroke epidemiology is relatively well characterized in China, Japan, and Taiwan but not in other countries in the region. More recent data are needed to monitor stroke prevention efforts and guide planning of health care resources in the region.

A Comparative Analysis of Risk Factors and Stroke Risk for Asian and Non-Asian Men: The Asia Pacific Cohort Studies Collaboration

Background

The risk of stroke is high in men among both Asian and non-Asian populations, despite differences in risk factor profiles; whether risk factors act similarly in these populations is unknown.

Aim

To study the associations between five major risk factors and stroke risk, comparing Asian with non-Asian men.

Methods

We obtained data from the Asia Pacific Cohort Studies Collaboration, a pooled analysis of individual participant data from 44 studies involving 386 411 men with 9·4 years follow-up. Using cohorts from Asia and Australia/New Zealand Cox models were fitted to estimate risk factor associations for ischemic and haemorrhagic stroke.

Results

We identified significant, positive associations between all five risk factors and risk of ischemic stroke. The associations between body mass index, smoking, and diabetes with ischemic stroke were comparable for men from Asia and Australia/New Zealand. The association between systolic blood pressure and ischemic stroke was stronger for Asian than Australia/New Zealand cohorts, whereas the reverse was true for total cholesterol. For haemorrhagic stroke, only systolic blood pressure and smoking were associated with increased risk, although the relationship with systolic blood pressure was significantly stronger for men from Asia than Australia/New Zealand ( Pinteraction = 0·03), whereas the reverse was true for smoking ( Pinteraction = 0·001). There was an inverse trend of total cholesterol with haemorrhagic stroke, significant only for Asian men.

Conclusions

Men from the Asia-Pacific region share common risk factors for stroke. Strategies aimed at lowering population levels of systolic blood pressure, total cholesterol, body mass index, smoking, and diabetes are likely to be beneficial in reducing stroke risk, particularly for ischemic stroke, across the region.

Nontraumatic cerebral hemorrhage in the young: a study of 107 cases

BACKGROUND

Reports on intracerebral hemorrhage (ICH) in the young are rare, and information on the cause and prognosis of ICH in this age-group is sparse.

METHODS

All cases of ICH admitted to three major hospitals in Saudi Arabia over a 15-year period were retrospectively reviewed. Patients aged between 6 months and 45 years at stroke onset were studied. Pooling of our data with those published from other centers was used for final analysis.

RESULTS

One hundred seven cases (69 male, 38 female), including 12 children younger than 10, were analyzed. The causes of hemorrhage were as follows: arteriovenous malformations (AVMs), 23%; systemic hypertension, 20%; blood dyscrasias, 16%; berry aneurysms, 8%; other causes, 7%. No cause was found in 26%. Sixty-two percent of the ICHs were lobar and 3% multiple. Early death rate was high (27%). Twelve percent of the patients were lost to follow-up, and only 26% returned to a state of complete autonomy.

CONCLUSION

The pooling of the causative data from our cases and the 253 others reported in the literature showed that even before 45 years of age systemic hypertension is the leading cause of ICH. It accounts for approximately 30% of the cases, with AVMs (20%) being next. The pooled overall early mortality rate is approximately 20%, and only one third of the patients return to independent living.

Risk factors for primary intracerebral hemorrhage in patients in Izumo City, Japan

The annual incidence rate of primary intracerebral hemorrhage (ICH) in Izumo City, Japan, appears to be the highest rate among those reported. Despite improvement of management and surgical therapy, the overall morbidity and mortality after ICH are still high. The author investigated the risk factors for ICH in patients in Izumo. A case-control study of 242 patients (137 men and 105 women with ages ranging from 34 to 97 years) with primary ICH was conducted in Izumo between 1991 and 1998. Hypertension, diabetes mellitus, heart disease, liver disease, alcohol consumption, cigarette smoking, and serum levels of total cholesterol, aspartate aminotransferase, and alanine aminotransferase were assessed as possible risk factors for ICH by using conditional logistic regression. The prevalence of hypertension among ICH patients was 77% and the odds ratio (OR) for hypertension was 17.07 (95% CI: 8.30-35.09), which are much higher than figures reported from Western countries. The OR for hypertension was higher in individuals < or = 69 years of age than in those > or = 70 years of age and lower for lobar hemorrhage than for hemorrhages at other sites. High serum total cholesterol (> or = 220 mg/dl) was the second most important risk factor for ICH (OR: 2.52; 95% CI: 1.23-5.14), and low total cholesterol (< 160 mg/dl) decreased the risk of ICH (OR: 0.47; 95% CI: 0.27-0.82). In contrast, heart disease decreased the risk of ICH, and there was no observed association between alcohol consumption, cigarette smoking, or diabetes mellitus and ICH. This study conducted in Izumo suggests that hypertension is the most important risk factor for ICH and contrary to most previous studies indicates that serum total cholesterol concentration is also positively associated with the risk of ICH. In contrast, heart disease may decrease the risk of ICH.

Risk assessment chart for death from cardiovascular disease based on a 19-year follow-up study of a Japanese representative population

BACKGROUND

Based on the NIPPON DATA80, risk charts for the probability of death from coronary heart disease (CHD), stroke, and all cardiovascular disease (CVD) were constructed by sex and 10-year age groups.

METHODS AND RESULTS

The 9,638 participants were followed-up for 19 years from 1980, excluding 28 individuals without the necessary baseline data and 257 participants with past history of stroke or CHD. Final analysis was performed on 9,353 participants (4,098 men, mean age 50.3 years; 5,255 women, mean age 50.8) using a Cox proportional hazards model. Death probabilities over a 10-year period from CHD, stroke, and all CVD were calculated and displayed as color coding on each chart by combining 10-year age, systolic blood pressure, smoking, and serum total cholesterol and glucose levels. Six different colors corresponding to probabilities of death were displayed on each chart.

CONCLUSIONS

The original charts based on the findings from NIPPON DATA80 are suitable for assessing CHD, stroke, and all CVD death risk in the general Japanese population. These charts should be used as a health-education tool for lifestyle modification targeting individuals with CVD risk factors.

What factors are associated with high plasma B-type natriuretic peptide levels in a general Japanese population?

There are few community-based epidemiologic studies that have dealt with risk factors for heart failure in non-Western populations. It has been reported that the measurement of plasma B-type natriuretic peptide (BNP) is useful for detecting patients with asymptomatic heart failure. To clarify the determinants of high plasma BNP level, the association of BNP with cardiovascular risk factors in community dwelling residents was examined. The plasma BNP levels were measured in 686 residents aged 35-69 years who received annual health check-up. The relationship of BNP to blood pressure, blood haemoglobin, serum cholesterol (total and high-density lipoprotein cholesterol), plasma glucose, electrocardiographic (ECG) findings, urinary salt excretion, and lifestyle factors (smoking and alcohol consumption) were cross-sectionally analysed. The plasma BNP geometric mean was 13.7 pg/ml. Both linear and logistic regression analyses indicated that the plasma BNP levels were positively associated with age, urinary salt excretion, higher blood pressure, high R-wave voltage in the 12-lead ECG (Minnesota Code 3-1 or 3-3), and female gender. Plasma BNP levels were inversely associated with blood haemoglobin levels. Gender-specific analysis showed similar results. However, plasma BNP did not correlate with other cardiovascular risk factors such as serum lipids.

Reduction in serum total cholesterol and risks of coronary events and cerebral infarction in Japanese men: the Kyushu Lipid Intervention Study

Lowering serum total cholesterol is shown to decrease the risk of coronary heart disease (CHD) in Western countries,but evidence is limited regarding cerebral infarction (CI). The present study used the Kyushu Lipid Intervention Study to examine the risks of CHD events and CI in relation to reduction in serum total cholesterol. Subjects were 4,615 men aged 45-74 years with serum total cholesterol of 220 mg/dl (5.68 mmol/L) or greater who had no history of CHD events or stroke. CHD events and CI numbered 125 and 92, respectively, in a 5-year follow-up. After adjustment for potential confounding factors, the relative risks of CHD events and CI for 15% or greater reduction in total cholesterol, compared with less than 5% reduction, were 0.78 (95% confidence limit [CL]0.46-1.32) and 0.39 (95% CL 0.22-0.69), respectively. As compared with on-treatment cholesterol levels of 240 mg/dl (6.20 mmol/L)or higher, the risk of CHD events was approximately 50% lower across 3 categories below 240 mg/dl (6.20 mmol/L), and that of CI was 70%lower at 2 categories below 220 mg/dl (5.68 mmol/L). Lowering serum total cholesterol below 220 mg/dl (5.68 mmol/L) seems desirable with regard to the prevention of CI.

Women do benefit from lipid lowering: latest clinical trial data

Cardiovascular disease is the leading cause of morbidity and mortality among women in industrialized nations. Optimizing cardiovascular risk reduction is therefore of paramount importance, particularly among postmenopausal women, in whom the incidence of cardiovascular disease is highest. Accumulated data from a series of landmark trials unequivocally demonstrate the efficacy of statin therapy in the primary and secondary prevention of cardiovascular outcomes in both men and women. Moreover, the recently released Heart Protection Study provides substantive evidence that lowering low-density lipoprotein cholesterol below levels currently defined as optimal by National Cholesterol Educational Program guidelines is strongly associated with further cardiovascular risk reduction, and that this benefit accrues in all subgroups of patients, including women and the elderly. Despite the ability of hormone replacement therapy to improve serum lipid profiles, randomized trials of hormone therapy have demonstrated no benefit in reducing coronary outcomes among postmenopausal women. In contrast, data from over 8,000 women enrolled in the statin trials demonstrate that lipid lowering with statins is as effective at reducing cardiovascular outcomes in women as it is in men and suggest that statins should be considered standard of care for the prevention of adverse cardiovascular events in women at risk for coronary heart disease.

Reduced frequency of high cholesterol levels among patients with intracerebral haemorrhage

To determine whether a relationship exists between high cholesterol levels and intracerebral haemorrhage (ICH) a case-control study was undertaken on 331 consecutive cases of first-episode primary ICH, verified by computed tomography, and 331 age- and sex-matched community controls. Using conditional logistic regression the adjusted odds ratio (OR) of ICH among individuals reporting a high cholesterol level was 0.45 [95% confidence interval (CI), 0.28-0.73]. A similar finding was observed when the analysis was limited to those using cholesterol-lowering drugs (OR 0.25; 95% CI, 0.08-0.80). These data provide support for an inverse relationship between high cholesterol levels and ICH. When considered together with previous findings, in which low cholesterol levels have been associated with an increased risk of haemorrhagic stroke, these data provide evidence that this inverse relationship may extend into a higher range of cholesterol values.

Hypertensive cerebral small vessel disease and stroke

Lacunar infarcts and "hypertensive" primary intracerebral hemorrhages, collectively often referred to as hypertensive small vessel strokes, constitute about one third of all strokes. However, despite their public health importance, their etiopathogenesis remains ill-understood. Like all strokes, they are a heterogeneous entity, but the autopsy pathology evidence suggests that the majority are caused by a limited number of cerebral small vessel lesions. Small vessel atherosclerosis is causally implicated in a proportion of lacunar infarcts, although modern concepts of atherosclerotic plaque biology and natural history have yet to be applied to small cerebral vessels. A lesion characterized in its acute form by fibrinoid necrosis appears to be important in causing both lacunar infarcts and primary intracerebral bleeds. Advances in molecular genetics may prove instrumental in understanding the cause of this lesion and therefore in designing its targeted prevention.

How well tolerated are lipid-lowering drugs?

It has been clearly established that lipid-lowering treatments [such as 3-hydroxyl-3-methylglutamyl coenzyme A reductase inhibitors ('statins') or fibrates] can reduce cardiovascular events, and with one of the statins even total mortality, in high-risk populations. Intervention studies have not included the very old, but it is generally assumed that this patient group would benefit from these treatments to an extent similar to younger patients. Worries about the associations seen in observational studies between low cholesterol levels and cancer, cerebral haemorrhage or mood and behaviour change have been largely overcome by findings from the latest large drug intervention trials, which do not show any increase in these conditions with statin or fibrate treatments. The common adverse effects associated with these drugs are relatively mild and often transient in nature. Potentially more serious adverse effects, which are more clearly related to drug treatment and are probably dose-dependent, include elevations in hepatic transaminase levels and myopathy; however, these effects are uncommon and generally resolve rapidly when treatment is stopped. The risk of myopathy with fibrate treatment is increased in patients with renal impairment, and the risk of myopathy with statin treatment increases with co-administration of drugs that inhibit statin metabolism or transport. Other adverse effects are related to specific drugs, for example, clofibrate is associated with an increased risk of gallstones. Studies in elderly patients have not shown an increased risk of adverse effects with lipid-lowering drugs compared with younger patients, but in clinical practice there may be some increased risk, particularly with regards to drug interactions. Therefore, lipid-lowering drugs should be administered with extra caution to elderly patients.

Intracerebral hemorrhage: update

The present review focuses on evolving concepts in the pathogenesis and management of deep and lobar intracerebral hemorrhage subtypes, with particular focus on the relationship between lobar intracerebral hemorrhage, apolipoprotein E subtypes and cerebral amyloid angiopathy; deep intracerebral hemorrhage and the potential interaction between hypertension and low cholesterol; and new concepts in medical and surgical therapy for acute intracerebral hemorrhage.

Intracerebral hemorrhage

Intracerebral hemorrhage (ICH) represents a significant fraction of all strokes and causes a disproportionate amount of stroke related morbidity and mortality, especially in young blacks. While diagnosis of this disorder has greatly improved in the CT era, morbidity and mortality remain essentially unchanged. Not one currently utilized therapeutic modality has been clearly associated with a beneficial effect on long term outcome in small prospective randomized treatment trials for ICH. In spite of the lack of scientific data regarding therapy, patients often require aggressive medical and surgical intervention because of the life-threatening presentation of many patients. Recent clinical and experimental ICH research has identified a number of potentially effective new therapeutic strategies, and time to treatment is likely to be very important as it is for ischemic stroke. Large prospective, randomized, placebo controlled trials to examine the judicious application of current therapeutic modalities, and to investigate the potential benefit of proposed new treatment modalities, are long overdue.

Vegetable oils high in phytosterols make erythrocytes less deformable and shorten the life span of stroke-prone spontaneously hypertensive rats

Previous studies have shown that canola oil (CA), compared with soybean oil (SO), shortens the life span of stroke-prone spontaneously hypertensive (SHRSP) rats, a widely used model for hemorrhagic stroke. SHRSP rats are highly sensitive to dietary cholesterol manipulations because a deficiency of membrane cholesterol makes their cell membranes weak and fragile. Phytosterols, abundant in CA but not in SO, can inhibit the absorption of cholesterol and also replace a part of cholesterol in cell membranes. This study was performed to determine whether the high concentration of phytosterols in CA might account for its life-shortening effect on SHRSP rats. Male, 35-d-old SHRSP rats (n = 28/group) were fed semipurified diets containing CA, SO, CA fortified with phytosterols (canola oil + phytosterols, CA + P), SO fortified with phytosterols (soybean oil + phytosterols, SO + P), corn oil (CO), olive oil (OO) or a fat blend that mimicked the fat composition of a representative Canadian diet (Canadian fat mimic, CFM; 10 g/100 g diet). These fats provided 97, 36, 207, 201, 114, 27 and 27 mg phytosterols/100 g diet, respectively. Ten rats from each group were killed after 30-32 d for blood and tissue analyses. The remaining rats (18/group) were used for determination of life span. The life span of SHRSP rats fed the high phytosterol oils (CA, CA + P, SO + P and CO) was significantly (P<0.05) shorter than that of CFM- and SO-fed rats. At 30-32 d, the groups fed the high phytosterol oils had greater levels of phytosterols and significantly (P<0.05) higher ratios of phytosterols/cholesterol in plasma, RBC, liver and kidney, and a significantly (P<0.05) lower RBC membrane deformabilty index than the groups fed oils low in phytosterols (SO, OO and CFM). The mean survival times were correlated with RBC deformability index (r(2) = 0.91, P = 0.0033) and cholesterol concentration (r(2) = 0.94, P = 0.0016), and inversely correlated with RBC phytosterol concentration (r(2) = 0.58, P = 0.0798) and phytosterols/cholesterol (r(2) = 0.65, P = 0.0579), except in the OO group. This study suggests that the high concentration of phytosterols in CA and the addition of phytosterols to other fats make the cell membrane more rigid, which might be a factor contributing to the shortened life span of SHRSP rats.

Prevalence and risks of dementia in the Japanese population: RERF's adult health study Hiroshima subjects. Radiation Effects Research Foundation

OBJECTIVES

To study the prevalence rate of dementia and its subtypes in Japan and to investigate the relationship of risk factors, such as demographic features and disease history, to the prevalence of Alzheimer's disease or vascular dementia.

DESIGN

A prevalence study within a longitudinal cohort study.

SETTING

The original Adult Health Study (AHS) cohort consisted of atomic-bomb survivors and their controls selected from residents in Hiroshima and Nagasaki using the 1950 national census supplementary schedules and the Atomic Bomb Survivors Survey. Since 1958, the AHS subjects have been followed through biennial medical examinations.

PARTICIPANTS

Subjects were 637 men and 1585 women aged 60 years or older in the AHS cohort. Forty-eight subjects resided in hospitals and institutions.

MEASUREMENTS

In addition to the biennial medical examinations ongoing since 1958, a screening test for cognitive impairment (CASI) was conducted by trained nurses between September 1992 and September 1996. The prevalence of dementia and its subtypes was assessed in 343 subjects suspected to have dementia and in 272 subjects with high CASI scores who were selected randomly.

RESULTS

The prevalence of dementia based on DSM III/R criteria, using neurological examination, the IQCODE, and CDR > or = 1, was 7.2%. The prevalence of Alzheimer's disease was 2.0% in men and 3.8% in women, and the prevalence of vascular dementia was 2.0% in men and 1.8% in women. The relationship of risk factors to Alzheimer's disease or vascular dementia was investigated by the multivariate logistic linear regression analysis. Odds ratios of Alzheimer's disease for age (in 10-year increments), attained education (in 3-year increments), history of head trauma, and history of cancer are 6.3, 0.6, 7.4, and 0.3, respectively. Odds ratios of vascular dementia for age, history of stroke, and history of hypertension are 2.0, 35.7, and 4.0, respectively. Neither type of dementia showed any significant effect of sex or radiation exposure.

CONCLUSION

This study is the first study of Japanese dementia rates carried out with a protocol similar enough to that of a US study to allow meaningful comparisons. The prevalence rates demonstrated are more similar to US rates than were found in many previous reports in Japan.

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).

Stroke: Incidence and pattern in Benghazi, Libya

Over a period of three years (January 1991 to December 1993), a total of 921 cases of stroke occurred in Benghazi, Libya. This provides a crude annual incidence rate for stroke of 48 per 100,000 population and a rate of 52 and 42 per 100,000 population for males and females respectively. The age-adjusted incidence rates were 162 and 133 per 100,000 population for males and females respectively for >/=45 years of age. Cerebral infarction was the most common type of stroke, accounting for 77%. Hypertension, smoking, diabetes mellitus and cardiac lesions were common risk factors among the male patients while hypertension, diabetes and cardiac lesions were common risk factors in females. Furthermore, females were found to have a high incidence of hypertension and diabetes when compared to males. However, 25% of males and 15% of females had no significant underlying risk factors. Fifty-four cases of stroke occurred during the study period in the age group of 15 to 45 years and constituted "stroke in the young", giving an annual incidence rate of 14 per 100,000 and rates of 15 and 13 per 100,000 population for males and females respectively in this age group. Hypertension, diabetes and heart disease were important risk factors for stroke in the young. However, nearly 45% of males and 20% of females had no significant risk factors.

ACAT inhibitors as antiatherosclerotic agents: compounds and mechanisms

Atherosclerosis is a major death cause in western industrialized countries. A diagnosing system, medical prevention, and treatment of atherosclerosis is not sufficient so far. A direct acting antiatherosclerotic agent is eagerly waited. ACAT inhibitor approach could provide such an agent. In the formation of atherosclerosis, cholesteryl esters, which are the lipids which accumulate in atheromatous plaques by an aid of macrophages and smooth muscle cells, forming foam cells, may play an important role. ACAT enzyme is responsible for the acylation of cholesterol to cholesteryl esters, a transformation which can be essential in not only cholesteryl esters accumulation at arterial walls but also the absorption of cholesterol in the intestine and the excretion of cholesterol in the liver. From these points, ACAT inhibitors might work against atherosclerosis in three different ways: first, cholesteryl ester accumulation inhibition at arterial walls could be a direct antiatherosclerotic effect; second, cholesterol absorption inhibition at the intestine; and third, cholesterol excretion acceleration at the liver, while the later two effects would result in a reduction of blood cholesterol level--a major risk factor of atherosclerosis. Taking account of this discussion, the ACAT inhibitors would be potent antiatherosclerotic agents. Medicinal research has been contributing full strength to produce an ultimate compound. These efforts should provide a drug which will be useful to patients.

Stroke trends in Japan

In Japan, stroke now ranks third among all causes of death following cancer and heart disease. Stroke was the leading cause of death for 3 decades after 1951. Stroke mortality tended to increase until about 1970, but it decreased and yielded first place to cancer in 1981. Heart disease deaths outnumbered stroke deaths beginning in 1985. There have not been any nationwide studies of stroke incidence in Japan, but results of studies in model areas such as Akita/Osaka, Nagano, Hiroshima/Nagasaki, and Hisayama show remarkable decreases in the incidence of cerebral infarction and cerebral hemorrhage. However, the decrease in cerebral infarction is less, especially at advanced ages where the frequency of disability is still high, and a major problem. There have not been any nationwide studies of survival rates after stroke either. In the Hiroshima/Nagasaki Study, the cumulative survival rates of cerebral hemorrhage and cerebral infarction improved from 1958 to 1969 to the period from 1970 to 1984. The decreasing incidence and mortality rates of stroke and the improving survival rate may be explained by the trends toward less severe strokes and improved medical service; however, the most influential factors are considered to be adoption of a less traditional life-style and improved blood pressure management throughout Japan.

Subarachnoid hemorrhage, cerebral hemorrhage, and serum cholesterol concentration in men and women

The role of serum cholesterol in predicting the risk of stroke is unclear and may depend on the subtype of the disease. In 1964 to 1965, 54,385 Swedish men and women participated in a health survey with serum cholesterol and diastolic blood pressure determinations. The Swedish mortality register was used to identify causes of death in this cohort during 20.5 years of follow-up (1964 to 1985). A person-year-based Poisson model was used for multivariate analysis. Relative risk increased with decreasing serum cholesterol level for subarachnoid hemorrhage in men and for cerebral hemorrhage in women but not for subarachnoid hemorrhage in women. For cerebral hemorrhage in men, the risk function was U-shaped. Adjustment for diastolic blood pressure did not significantly change the relation between the risk for any of the different stroke types and the cholesterol level. A low cholesterol level predicts death from intracranial bleeding, but the data suggest that there is differing risk pattern for men and women.

Serum cholesterol levels and six-year mortality from stroke in 350,977 men screened for the multiple risk factor intervention trial

We examined the relation between the serum total cholesterol level and the risk of death from stroke during six years of follow-up in 350,977 men, 35 to 57 years of age, who had no history of heart attack and were not currently being treated for diabetes mellitus. The diagnosis of stroke and the type of stroke were obtained from death certificates. Using proportional-hazards regression to control for age, cigarette smoking, diastolic blood pressure, and race or ethnic group, we found that the six-year risk of death from intracranial hemorrhage (International Classification of Diseases, ninth edition [ICD-9], categories 431 and 432) was three times higher in men with serum cholesterol levels under 4.14 mmol per liter (160 mg per deciliter) than in those with higher cholesterol levels (P = 0.05 by omnibus test across five cholesterol levels). On the other hand, a positive association was observed between the serum cholesterol level and death from nonhemorrhagic stroke (P = 0.007). The inverse association of the serum cholesterol level with the risk of death from intracranial hemorrhage was confined to men with diastolic blood pressure greater than or equal to 90 mm Hg, in whom death from intracranial hemorrhage is relatively common. We conclude that there is an inverse relation between the serum cholesterol level and the risk of death from hemorrhagic stroke in middle-aged American men, but that its public health impact is overwhelmed by the positive association of higher serum cholesterol levels with death from nonhemorrhagic stroke and total cardiovascular disease (ICD-9 categories 390 through 459).

Clinical profiles of cerebrovascular disorders in a population-based patient sample

Clinical features of different types of stroke were investigated in a sample of 409 patients representative of all cases admitted for acute stroke, except subarachnoidal hemorrhages, within a well defined population. A specific cerebrovascular diagnosis was obtained by detailed clinical investigation, including CT scan. In people greater than 50 years old, men/women risk for stroke was estimated to be 1.40:1. The risk was higher in men up to the age of 80; above this age similar risk for the two genders was observed. Eleven per cent had intracerebral hemorrhage, 13% TIA, 51% non-embolic and 25% embolic brain infarction. In all diagnostic categories there were similar proportions of patients who had a history of hypertension and previous stroke, neither did hemoglobin and hematocrit levels differ between the different stroke disorders. TIA preceded intracerebral hemorrhage in 11% and brain infarction in 15-20%. As opposed to patients with ischemic lesions, subjects with intracerebral hemorrhage had higher systolic blood pressure levels and more severe symptoms on admission to hospital. Ischemic stroke was associated with male predominance, different ischemic manifestations of heart diseases and diabetes.

Incidence and pattern of cerebrovascular diseases in Benghazi, Libya

During a 12 month study period, a total of 329 incident cases of stroke occurred in Benghazi, Libya. This provided an unadjusted annual incidence rate for stroke of 63 per 100,000 population; the corresponding rates for the male and female were 69 and 58 per 100,000 respectively. The sex dependent difference in the incidence was not statistically significant. Cerebral infarction was the commonest type of stroke accounting for 80.9%. The incidence rates increased with age in all categories of stroke. Hypertension and ischaemic heart disease were common risk factors among the male patients, while diabetes and hypercholesterolaemia were more frequent in the female patients.

Relationship between longitudinal changes in blood pressure and stroke incidence

The relationship of changes in blood pressure with time to stroke incidence was examined on members of the Adult Health Study sample who have participated in biennial clinical examinations at the Radiation Effects Research Foundation since their inception in 1958. The regression coefficient of blood pressure regressed on time (the increase in blood pressure per cycle) was used as an index of the change in blood pressure with time. Cox's regression analysis, a technique which is suitable for follow-up studies was used. The data suggest that a single blood pressure measurement is not sufficient for predicting risk; the accumulated value or average over a period of time should be considered for this purpose. In addition to the actual blood pressure, the increase in blood pressure with time is a risk factor, particularly for cerebral hemorrhage. Cerebral hemorrhage was more strongly related to diastolic than to systolic blood pressure, while cerebral infarction appeared to be more strongly related to systolic than to diastolic blood pressure.