Epidemiological and clinicopathological study on cerebrovascular disease in Japan

Association between corneal hysteresis and glaucoma in a Japanese population: the Hisayama Study

AIMS

To investigate the association between corneal hysteresis and the presence of glaucoma and its subtypes in a general Japanese population.

METHODS

We analysed the data of 2338 Japanese community-dwellers aged ≥40 years (1059 men, 1279 women) who underwent an eye examination in 2018 as part of the population-based, cross-sectional Hisayama Study. Participants were divided into quartile levels of corneal hysteresis, which had been measured with an ocular response analyzer. Glaucoma was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria. We conducted a logistic regression analysis to determine the ORs and their 95% CIs for the presence of outcomes according to the corneal hysteresis quartiles.

RESULTS

Glaucoma was diagnosed in 154 participants: primary open-angle glaucoma (POAG), n=115; primary angle-closure glaucoma, n=17; exfoliation glaucoma, n=21 and secondary glaucoma without exfoliation glaucoma, n=1. After adjustment for confounders, the OR for prevalent glaucoma was significantly increased in the participants in the first corneal-hysteresis quartile compared with those in the fourth quartile (OR: 1.80; 95% CI: 1.03 to 3.17). Regarding glaucoma subtypes, the first-quartile participants had significantly greater likelihoods of the presence of POAG (OR: 1.63; 95% CI: 1.02 to 2.61) and exfoliation glaucoma (OR: 6.49; 95% CI: 1.44 to 29.30) compared with those in the third and fourth quartiles after adjustment for potential confounders.

CONCLUSIONS

These results demonstrated a significant inverse association between corneal hysteresis and the likelihood of glaucoma, suggesting that the measurement of corneal hysteresis would provide useful information for elucidating the aetiology of glaucoma.

Association between Vascular Calcification and Intraplaque Hemorrhage in Coronary Atherosclerosis from Autopsy: The Hisayama Study

AIMS

Vascular calcification is observed in advanced atherosclerotic lesions. Vascular calcification is considered to increase the risk of intraplaque hemorrhage and subsequent plaque destabilization; however, there is limited pathohistoological evidence of the association between vascular calcification and intraplaque hemorrhage. The aim of this study was to investigate the association between vascular calcification and intraplaque hemorrhage in the coronary arteries.

METHODS

We examined 374 coronary arteries obtained from the autopsy samples of 126 deceased individuals. The vascular calcification levels of each artery were categorized into no calcification and quintiles of calcification area size among the arteries with calcification. Macrophage infiltration and neovascularization were also evaluated. The association of the calcification area, macrophage area, or number of vessels with the presence of intraplaque hemorrhage in the coronary arteries was estimated using a logistic regression analysis.

RESULTS

Calcification lesions were observed in 149 coronary arteries. Arteries in the fourth quintile of calcification area size had a significantly greater likelihood of intraplaque hemorrhage than the arteries without calcification, after adjusting for confounders: odds ratio 13.13 (95% confidence interval: 2.97-58.16). After evaluating the influence of macrophage infiltration, the highest odds ratio of intraplaque hemorrhage was associated with the combination of large macrophage area and moderately sized calicification areas. The odds ratio of intraplaque hemorrhage additively increased with the combination of calcification and the number of vessels.

CONCLUSIONS

The present findings suggest that vascular calcification is significantly associated with intraplaque hemorrhage. The association between vascular calcification and intraplaque hemorrhage may decrease above a certain size of the calcification area.

Long-Term Trends in The 5-Year Risk of Recurrent Stroke over A Half Century in A Japanese Community: The Hisayama Study

AIM

Secular trends in the risk of recurrent stroke have been reported in several epidemiological studies worldwide, but this issue has not been investigated in general Japanese populations. We examined the trends in the 5-year risk of recurrent stroke over a half century using community-based prospective data in Japan.

METHODS

We established 4 cohort studies in 1961, 1974, 1988, and 2002. To examine the risk of recurrent stroke, participants who developed stroke during a 10-year follow-up period in each cohort were followed-up for 5 years from the date of first onset. A total of 154 (first sub-cohort: 1961-1971), 144 (second sub-cohort: 1974-1984), 172 (third sub-cohort: 1988-1998), and 146 (fourth sub-cohort: 2002-2012) participants from each cohort were enrolled in the present study. The 5-year cumulative risk of recurrent stroke was compared among the sub-cohorts using the Kaplan-Meier method and the age- and sex-adjusted Cox proportional hazards model.

RESULTS

The risks of recurrent stroke after any stroke and ischemic stroke decreased significantly from the first to the third sub-cohort, but they did not clearly change from the third to the fourth sub-cohort. The risk of recurrent stroke after hemorrhagic stroke decreased mainly from the first to the second sub-cohort and there was no apparent decrease from the second to the fourth sub-cohort. These trends were substantially unchanged after adjusting for age and sex.

CONCLUSIONS

In the Japanese community, the risk of recurrent stroke decreased mainly from the 1960s to 1990s, but there was no apparent decrease in recent years.

Prevalence of Glaucoma and Its Systemic Risk Factors in a General Japanese Population: The Hisayama Study

Purpose

To estimate the prevalence of glaucoma and its risk factors in a Japanese community.

Methods

This study included 3405 Japanese community dwellers who were ≥40 years of age and enrolled in the Hisayama Study. This population-based, cross-sectional study was conducted from 2017 to 2018. A glaucoma screening test was performed using stereo fundus images and swept-source optical coherence tomography. Glaucoma was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria.

Results

The prevalence of glaucoma was 7.6% (95% confidence interval [CI], 6.7–8.6) overall. The prevalence of primary open-angle glaucoma (POAG) was 5.8% (95% CI, 5.0–6.6); that of primary angle-closure glaucoma (PACG) was 0.7% (95% CI, 0.5–1.1); and that of exfoliation glaucoma was 1.1% (95% CI, 0.7–1.4). In addition to aging, lower estimated glomerular filtration rate (eGFR) (odds ratio [OR] = 1.15; 95% CI, 1.02–1.33), higher intraocular pressure (OR = 1.06; 95% CI, 1.01–1.12), longer axial length (OR = 1.44; 95% CI, 1.31–1.59), and thinner central corneal thickness (CCT) (OR = 1.09; 95% CI, 1.04–1.15) were significant risk factors for POAG. Diabetes (OR = 2.81; 95% CI, 1.19–6.62) was a significant risk factor for PACG, and diabetes (OR = 2.15; 95% CI, 1.03–4.47) and thinner CCT (OR = 1.14; 95% CI, 1.02–1.28) were significant risk factors for exfoliation glaucoma.

Conclusions

The prevalence of glaucoma was approximately 8%, probably due to the increase in the Japanese aging population. Not only ocular factors but also lower eGFR for POAG and diabetes for PACG and exfoliation glaucoma were risk factors in a general Japanese population.

Translational Relevance

Systemic factors such as eGFR and diabetes must also be considered when implementing preventive measures against glaucoma.

Cohort Profile: The Ganka-Ekigaku Network (GEN), a Network of Japanese Ophthalmological Epidemiology Studies

PURPOSE

Japan has been known as a super-aged society, and ageing is a well-known risk factor for blinding eye diseases. However, epidemiological studies in ophthalmology are still scarce in Japan, and the sizes of the cohorts are relatively small. "Ganka-Ekigaku Network" (GEN, an acronym for the epidemiological network in ophthalmology in Japanese) is established to develop a capacity to boost each epidemiological study and enrich a potential inter-study collaboration to identify risk factors of visual impairment in aged society.

METHODS

We reviewed cohort studies in Japan with the inclusion criteria as: (1) at least n = 1000 at baseline, (2) multiple modalities of ophthalmic data, and (3) diagnosis reviewed by ophthalmologist(s), and (4) ophthalmologists are involved in the investigators group. As of January 2020, GEN includes 4 individual Japanese epidemiological studies namely, Hisayama study, Yamagata Study (Funagata), Tsuruoka Metabolomics Cohort study, and the Nagahama Prospective Genome Cohort for Comprehensive Human Bioscience.

RESULTS

GEN includes approximately 25,000 Japanese participants. The baseline surveys started from 1998 to 2012, and since then the data has been prospectively collected approximately every 5 years. A variety of ophthalmic measurements and other factors have been collected in each study in GEN: ophthalmic measurements (fundus photography, optical coherence tomography, etc.), systemic conditions (laboratory data, etc.), and others (DNA, etc.).

CONCLUSION

GEN is an open platform for observational ophthalmic epidemiological studies to share standardized methodologies. While each study in GEN pursues specific and original research questions, standardization of the methods will enable us to conduct reliable meta-analysis/pooled data analyses.

Glucose Tolerance Levels and Circumpapillary Retinal Nerve Fiber Layer Thickness in a General Japanese Population: The Hisayama Study

PURPOSE

To investigate the relationship between glucose tolerance levels and the circumpapillary retinal nerve fiber layer thickness (cpRNFLT) in a general Japanese population.

DESIGN

Population-based, cross-sectional study.

METHODS

In 2012 and 2013, a total of 2809 Japanese community dwellers aged 40-79 years in the Hisayama Study underwent eye examinations including cpRNFLT measurement with spectral domain optical coherence tomography. Of these, 1324 subjects (578 men and 746 women) were enrolled. Glucose tolerance levels were determined by a 75-g oral glucose tolerance test. We conducted an analysis of covariance to estimate the mean values of cpRNFLT according to the subjects' glucose intolerance status.

RESULTS

The subjects with prediabetes or with diabetes mellitus had significantly lower age- and sex-adjusted mean cpRNFLT values than those with normal glucose tolerance (P = .04 and P = .0004, respectively). The age- and sex-adjusted mean values of cpRNFLT decreased significantly with elevating fasting plasma glucose and 2-hour postload glucose levels (all P for trend < .05). These associations were substantially unchanged after adjustment for potential confounding factors. The coexistence of poorer glucose tolerance and higher intraocular pressure levels was additively associated with thinner cpRNFLT.

CONCLUSIONS

Our analyses revealed that poorer glucose tolerance was significantly associated with the reduction of cpRNFLT in a Japanese general population, suggesting that the loss of neural tissue in the eye begins at the prediabetic stage, and that hyperglycemia may play a role in the reduction of cpRNFLT.

Long-term regular exercise and intraocular pressure: the Hisayama Study

PURPOSE

To investigate the association between long-term regular exercise (exercise frequency and exercise time) and 5-year changes in intraocular pressure in a general Japanese population.

METHODS

This population-based, cohort study was conducted in 2007. A total of 3119 Japanese community dwellers aged ≥ 40 years underwent eye examinations including intraocular pressure measurement with a noncontact tonometer. Of these, 1871 subjects (801 men and 1070 women) who underwent intraocular pressure measurement in 2012 participated. We assessed the associations of exercise frequency and exercise time with intraocular pressure using a linear regression model, adjusted for age and possible risk factors that can affect intraocular pressure.

RESULTS

The mean 5-year intraocular pressure change ± standard deviation was - 0.84 ± 1.9 mmHg. After adjustment for age, sex, systolic blood pressure, diabetes, total cholesterol, high-density lipoprotein cholesterol, body mass index, waist circumference, smoking habit, alcohol intake, work intensity levels, and intraocular pressure at baseline, we observed that increased exercise frequency (times/week) and increased exercise time (min/week) were both significantly associated with reduced intraocular pressure (p < 0.05 each). In the subgroup analyses based on the presence/absence of possible confounding risk factors, there was no evidence of heterogeneity among all subgroups (p for heterogeneity > 0.2).

CONCLUSIONS

Increased exercise frequency levels and increased exercise time are both independently associated with reduced intraocular pressure levels after adjustment for confounding factors.

Prevalence and Risk Factors for Polypoidal Choroidal Vasculopathy in a General Japanese Population: The Hisayama Study

PURPOSE

To estimate the prevalence and risk factors for polypoidal choroidal vasculopathy (PCV) in a general Japanese population.

METHODS

This population-based, cross-sectional study was conducted in 2007 with subjects from the Hisayama Study. Of the 3,648 residents in Hisayama, Japan, 2,663 who were ≥ 50 years old were enrolled in this study. The characteristics of PCV were determined by fundus examination or based on indocyanine green and fluorescein angiographic findings. We evaluated the contributions of the risk factors for PCV.

RESULTS

Among the 207 participants with age-related macular degeneration (AMD), 174 (6.5%) had early AMD, and 33 (1.2%) had late AMD, including 10 participants with PCV (0.4%). Male and smoking habit were significant risk factors for the development of PCV.

CONCLUSIONS

The prevalence of PCV is higher among Japanese subjects than Caucasians in Western countries. Male gender and smoking habit were significant risk factors for PCV in a general Japanese population.

Secular trends in the incidence, risk factors, and prognosis of transient ischemic attack in Japan: The Hisayama Study

BACKGROUND AND AIMS

We aimed to investigate secular trends in the incidence, risk factors, and prognosis of transient ischemic attack (TIA) in a general Japanese population.

METHODS

Two cohorts consisting of stroke-free Japanese individuals aged ≥40 years in 1961 (n = 1621) and 1988 (n = 2646) were followed up for 24 years. The associations of potential risk factors with the development of TIA were estimated by a Cox proportional hazards model. The influence of TIA on the risk of total stroke over the subsequent 10 years was compared between the sub-cohorts of subjects with TIA and age- and sex-matched control subjects from each cohort.

RESULTS

During follow-up, 28 subjects in the 1961 cohort and 34 in the 1988 cohort experienced TIA. The age-standardized incidence of TIA was significantly lower in the 1988 cohort than the 1961 cohort (0.66 vs. 1.01 per 1000 person-years, p = 0.02). While elevated systolic blood pressure was significantly associated with the risk of TIA in both cohorts, glucose intolerance and higher serum cholesterol levels were associated with TIA risk only in the 1988 cohort. The subjects experiencing TIA had approximately 7-8-fold higher risks for the 10-year incidence of total and ischemic strokes compared with the corresponding control subjects without TIA both in the 1961 and 1988 sub-cohorts, and the relative risks were not significantly different between sub-cohorts.

CONCLUSIONS

Our results suggest that the incidence of TIA decreased during the past half century, probably due to the spread of antihypertensive treatments in the general Japanese population.

Cerebral Infarction in Hypertensive and Nonhypertensive Subjects in a Community of Japan: The Hisayama Study

To compare the clinical features associated with stroke in hypertensive pa tients with those in nonhypertensives, we analyzed the records and the autopsy findings of cases of cerebral infarction in the Hisayama prospective study from 1961 through 1973.

Of the total 128 cases of cerebral infarction, 79 (61.7%) occurred in patients admitted as hypertensives. In addition, of the 17 normotensive subjects at entry, (29.4%) had blood pressure levels that shifted into the hypertension range while 13 of 18 (72.2%) with borderline hypertension at entry had blood pressure levels that changed into the hypertensive range before stroke.

In reviewing clinical symptoms and autopsy findings we frequently found that small, deep cerebral infarction, most often located in basal ganglia, in hy pertensive old persons. On the other hand, arrhythmia on ECG and focal in farcts on sytemic organs of the body were more often found in nonhypertensive patients with cerebral infarction than in hypertensives. This suggested that em bolism of cardiac origin may at least contribute to the development. of cerebral infarction in nonhypertensive subjects.

Insulin Resistance Is a Risk Factor for Increased Intraocular Pressure: The Hisayama Study

PURPOSE

To investigate association of the homeostasis model assessment of insulin resistance (HOMA-IR), a surrogate index of insulin resistance, with IOP in a general Japanese population.

METHODS

In 2007, a total of 3119 Japanese community-dwellers, aged 40 years or older, underwent eye examinations, including IOP measurement with a noncontact tonometer. Of these, 2254 residents participated in this study. Fasting serum glucose and plasma insulin were measured to determine the HOMA-IR. The association of HOMA-IR with IOP was assessed using a linear regression model, adjusted for age and possible risk factors that can elevate IOP.

RESULTS

The mean IOP ± SD was 13.7 ± 2.7 mm Hg in the right eye and 13.6 ± 2.7 mm Hg in the left eye. After adjusting for age, sex, systolic blood pressure, diabetes, total cholesterol, high-density lipoprotein cholesterol, body mass index, waist circumference, smoking habits, alcohol intake, and regular exercise, increased HOMA-IR levels were significantly associated with increasing IOP (P < 0.05). In the subgroup analyses based on the presence or absence of possible confounding risk factors, there was no evidence of heterogeneity between all subgroups (P for heterogeneity > 0.08).

CONCLUSIONS

The HOMA-IR is independently associated with elevated IOP levels after adjustment for confounding factors.

Hematocrit and the risk of cardiovascular disease in a Japanese community: The Hisayama Study

OBJECTIVES

The association between hematocrit levels and the risk of cardiovascular disease (CVD) has been reported inconsistently. We aimed to investigate the association of hematocrit levels with the development of stroke and coronary heart disease (CHD) in a general Japanese population.

METHODS

A total of 2585 community-dwelling Japanese individuals aged 40 years or older in 1988 were followed up for 19 years. These subjects were divided into four groups according to the sex-specific quartiles of hematocrit at baseline.

RESULTS

During the follow-up, 301 subjects developed stroke (210 ischemic and 91 hemorrhagic) and 187 developed CHD. The risk of ischemic stroke was higher in both the lowest (Q1: men, ≤44.7%; women, ≤39.3%) and the highest (Q4: men, ≥49.7%; women, ≥43.8%) quartiles than in the third quartile (Q3: men, 47.1%-49.6%; women, 41.7%-43.7%) used as a reference (multivariable-adjusted hazard ratios [95% confidence intervals]: Q1, 1.55 [0.99-2.43]; Q2, 1.44 [0.93-2.23]; Q3, 1.00; and Q4, 1.62 [1.06-2.50]; P = 0.86 for trend). In contrast, hematocrit levels and the risk of hemorrhagic stroke showed a linear inverse association (Q1, 1.91 [1.03-3.54]; Q2, 1.26 [0.68-2.34]; Q3, 1.00; and Q4, 0.81 [0.41-1.61]; P = 0.009 for trend). The risk of CHD increased significantly in Q4 (Q1, 1.13 [0.71-1.80]; Q2, 1.08 [0.69-1.71]; Q3, 1.00; and Q4, 1.60 [1.04-2.46]; P = 0.13 for trend).

CONCLUSIONS

Our findings suggest that both elevated and decreased hematocrit levels are associated with an increased risk of CVD, but the influence of hematocrit is different among subtypes of CVD.

Dietary patterns and clinical outcomes in hemodialysis patients in Japan: a cohort study

Background & Objectives

Little is known about actual dietary patterns and their associations with clinical outcomes in hemodialysis patients. We identified dietary patterns in hemodialysis patients in Japan and examined associations between dietary patterns and clinical outcomes.

Design, setting, participants, measurements

We used data from 3,080 general-population participants in the Hisayama study (year 2007), and data from 1,355 hemodialysis patients in the Japan Dialysis Outcomes and Practice Patterns Study (JDOPPS: years 2005–2007). Food intake was measured using a brief self-administered diet-history questionnaire (BDHQ). To identify food groups with the Hisayama population data, we used principal components analysis with Promax rotation. We adjusted the resulting food groups for total daily energy intake, and then we used those adjusted food-group scores to identify dietary patterns in the JDOPPS patients by cluster analysis (Ward’s method). We then used Cox regression to examine the association between dietary patterns and a composite of adverse clinical outcomes: hospitalization due to cardiovascular disease or death due to any cause.

Results

We identified three food groups: meat, fish, and vegetables. Using those groups we then identified three dietary patterns: well-balanced, unbalanced, and other. After adjusting for potential confounders, we found an association between an unbalanced diet and important clinical events (hazard ratio 1.90, 95% C.I. 1.19–3.04).

Conclusions

Hemodialysis patients whose diet was unbalanced were more likely to have adverse clinical outcomes. Thus hemodialysis patients might benefit not only from portion control, but also from a diet that is well-balanced diet with regard to the food groups identified here as meat, fish, and vegetables.

Temporal trends in sudden unexpected death in a general population: the Hisayama study

BACKGROUND

Studies addressing the temporal trends in the prevalence of sudden unexpected death (SUD) and its underlying causes in the general population are limited.

METHODS

Among a total of 1934 residents aged ≥20 years of the town of Hisayama, Japan, who died of endogenous causes of death and underwent autopsy examination (autopsy rate 78.5%) from 1962 to 2009, 204 were determined to be cases of SUD within 24 hours.

RESULTS

The trend in the age- and sex-adjusted prevalence of SUD among all autopsy subjects was stable over four 12-year periods (13.1% in 1962-1973, 13.4% in 1974-1985, 15.0% in 1986-1997, and 14.6% in 1998-2009; P for trend = .80). Regarding causes of death, the prevalence of SUD from stroke significantly declined with time (8.0%, 5.0%, 2.3%, and 2.1%, respectively; P for trend < .001), whereas significant increments were observed in the prevalence of SUD from heart disease (4.0%, 6.2%, 8.6%, and 9.7%; P for trend = .02) and from aortic aneurysm and dissection (0.2%, 1.2%, 2.9%, and 2.8%; P for trend = .01). In particular, the prevalence of ischemic heart disease increased 3-fold from 2.1% in 1962-1973 to 6.6% in 1998-2009 (P = .04). Reflecting the increment of ischemic heart disease, SUD within 1 hour increased significantly from 2.5% to 7.6% during this period (P = .01).

CONCLUSIONS

The trend in the prevalence of SUD was stable across a half century in a general Japanese population. Despite the decrement in the prevalence of SUD from stroke, that from heart disease, especially ischemic heart disease, increased significantly with time.

Chronic kidney disease is associated with neovascularization and intraplaque hemorrhage in coronary atherosclerosis in elders: results from the Hisayama Study

There is little information regarding whether patients with chronic kidney disease (CKD) have a high incidence of vulnerable plaques in their coronary arteries. To gain additional evidence on this, we conducted a population-based study by randomly selecting 126 subjects from 844 consecutive autopsies of elderly residents of Hisayama, Japan. We then determined the relationships of CKD with neovascularization and intraplaque hemorrhage in coronary atherosclerosis with the subjects classified into four categories based on their estimated glomerular filtration rate (eGFR). Areas of oxidized low-density lipoprotein (oxLDL) and vascular endothelial growth factor (VEGF) expression, assessed by immunohistochemistry in a total of 375 coronary arteries, increased significantly with decreasing eGFR. A lower eGFR was also associated with increased numbers of newly formed blood vessels. These relationships remained substantially unchanged after adjustment for confounding factors. The multivariate-adjusted odds ratio of the presence of intraplaque hemorrhages was 6.2 (95% confidence interval, 1.1-35.0) in patients with an eGFR <30 ml/min/1.73 m(2) compared with those with an eGFR of ≥ 60 ml/min/1.73 m(2). Thus, elderly patients with CKD have intimal neoangiogenesis and an increased risk of intraplaque hemorrhage in coronary arteries, possibly favored by local accumulation of oxLDL and VEGF.

Altered expression of diabetes-related genes in Alzheimer's disease brains: the Hisayama study

Diabetes mellitus (DM) is considered to be a risk factor for dementia including Alzheimer's disease (AD). However, the molecular mechanism underlying this risk is not well understood. We examined gene expression profiles in postmortem human brains donated for the Hisayama study. Three-way analysis of variance of microarray data from frontal cortex, temporal cortex, and hippocampus was performed with the presence/absence of AD and vascular dementia, and sex, as factors. Comparative analyses of expression changes in the brains of AD patients and a mouse model of AD were also performed. Relevant changes in gene expression identified by microarray analysis were validated by quantitative real-time reverse-transcription polymerase chain reaction and western blotting. The hippocampi of AD brains showed the most significant alteration in gene expression profile. Genes involved in noninsulin-dependent DM and obesity were significantly altered in both AD brains and the AD mouse model, as were genes related to psychiatric disorders and AD. The alterations in the expression profiles of DM-related genes in AD brains were independent of peripheral DM-related abnormalities. These results indicate that altered expression of genes related to DM in AD brains is a result of AD pathology, which may thereby be exacerbated by peripheral insulin resistance or DM.

Insulin resistance and the development of cardiovascular disease in a Japanese community: the Hisayama study

AIMS

Although several surrogate measures of insulin resistance have been proposed, their associations with cardiovascular disease (CVD) have not been evaluated sufficiently.

METHODS

A total of 2,356 community-dwelling Japanese individuals aged 40 to 79 years who underwent a 75 g oral glucose tolerance test were followed up for 14 years. The status of insulin resistance was estimated by using the Matsuda index or homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

During follow-up, 260 subjects developed CVD. The age- and sex-adjusted hazard ratios of CVD significantly decreased with an increasing Matsuda index and rose with increasing HOMA-IR levels (both p for trend <0.05). After adjustment for age, sex, serum total cholesterol, electrocardiogram abnormalities, proteinuria, smoking habits, alcohol intake, and regular exercise, the risk of CVD was significantly lower in the third to fifth quintiles of the Matsuda index and higher in the fifth quintile of HOMA-IR values compared with the first quintile of the corresponding index (Matsuda index Q3: hazard ratio (HR)= 0.59 [95% confidence interval 0.40-0.87]; Q4: HR= 0.66 [0.45-0.97]; and Q5: HR= 0.67 [0.47-0.97]; HOMA-IR Q5: HR= 1.55 [1.05-2.29]); however, these associations were attenuated after further adjustment for the metabolic syndrome status. In regard to CVD subtypes, the risks for stroke and coronary heart disease significantly decreased with an increasing Matsuda index, while elevated HOMA-IR levels were a significant risk factor for stroke, but not for coronary heart disease.

CONCLUSION

Our findings suggest that insulin resistance significantly increases the risk of incident CVD through metabolic syndrome in Japanese.

High serum bilirubin levels and diabetic retinopathy: the Hisayama Study

PURPOSE

To assess the association between serum total bilirubin levels and diabetic retinopathy prevalence in participants of the Hisayama Study who had diabetes and impaired glucose metabolism.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

Of 3119 participants of the Hisayama Study Eye Examinations in 2007, Japan, 1672 aged ≥40 years with either diabetes or impaired glucose metabolism (defined by a 75-g oral glucose tolerance test) were enrolled in the present study.

METHODS

Diabetic retinopathy was assessed via ophthalmic examination after pupil dilatation. The presence and the severity of diabetic retinopathy were determined by grading of color fundus photographs using the modified Airlie House classification system. Association of diabetic retinopathy with serum bilirubin quartiles was assessed using logistic regression model adjusting for age and known risk factors for diabetic retinopathy.

MAIN OUTCOME MEASURES

Prevalent diabetic retinopathy.

RESULTS

Diabetic retinopathy was present in 70 of 1672 (4.2%) participants. The prevalence of diabetic retinopathy in persons with the highest bilirubin quartile (≥0.9 mg/dL) was 2.7%, compared with the prevalence of 3.4%, 5.1%, and 5.1% in those with the first (<0.6 mg/dL), second (0.6-0.69 mg/dL), and third quartiles (0.7-0.89 mg/dL). After adjusting for factors known to be associated with diabetic retinopathy, the prevalence was significantly lower among persons with the highest bilirubin quartile compared with those with the lowest quartile (odds ratio [OR], 0.25; 95% confidence interval [CI], 0.09-0.72) or compared with those in the 3 lower quartiles (OR, 0.25; 95% CI, 0.11-0.58).

CONCLUSIONS

Elevated serum bilirubin levels may be protective against diabetic retinopathy among persons with either diabetes or impaired glucose metabolism, independent of known risk factors for diabetic retinopathy.

QT interval prolongation and the risks of stroke and coronary heart disease in a general Japanese population: the Hisayama study

Uncertainty remains regarding the value of heart-rate-corrected QT interval (QTc) prolongation on electrocardiogram for predicting cardiovascular disease (CVD), particularly among Asian populations. The objective of the present analysis was to analyze the association of QTc prolongation with the development of CVD in a general Japanese population. During the follow-up period, 303 CVD events were observed. Among men, the age-adjusted incidence rates of CVD rose with prolonged QTc levels: 10.9, 12.1, 14.1 and 37.8 per 1000 person-years for subgroups defined by QTc levels of <400, 400-419, 420-439 and > or =440 ms, respectively (P=0.0007 for trend). The risk of CVD in the highest group was 3.09-fold (95% confidence interval, 1.82-5.25) higher than that in the lowest group even after controlling for other confounding factors: age, hypertension, heart rate, electrocardiogram abnormalities, diabetes, impaired glucose tolerance, impaired fasting glycemia, body mass index, total and high-density lipoprotein cholesterols, alcohol intake, smoking habit and regular exercise. Similar associations were observed for the outcomes of stroke and coronary heart disease. Among women, in contrast, no clear associations were found between QTc levels and the risk of CVD events. In conclusion, prolonged QTc levels were associated with the development of CVD among general Japanese men. Measurement of QTc intervals is likely to provide additional information for the detection of individuals at high risk of future CVD events.

Trends in the prevalence of chronic kidney disease and its risk factors in a general Japanese population: the Hisayama Study

BACKGROUND

Chronic kidney disease (CKD) is increasingly recognized as a leading public health issue. However, there are limited data assessing secular trends in the prevalence of CKD in general Asian communities.

METHODS

We performed three repeated cross-sectional surveys of residents aged >or=40 years in 1974 [2118 subjects (participation rate, 81.2%)], 1988 [2741 subjects (80.9%)] and 2002 [3297 subjects (77.6%)] in a Japanese community. We compared the prevalence of CKD [one or both of proteinuria and estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2)] and potential risk factors among the three surveys.

RESULTS

The prevalence of CKD increased significantly with time in men (13.8% [95% confidence interval (95% CI), 11.4-16.2%] in 1974, 15.9% [95% CI, 13.6-18.2%] in 1988 and 22.1% [95% CI, 19.6-24.6%] in 2002; P for trend < 0.001), but not in women (14.3% [95% CI, 12.2-16.4%], 12.6% [95% CI, 10.9-14.3%] and 15.3% [95% CI, 13.4-17.2%]; P for trend = 0.97). The frequencies of individuals with CKD Stages 3-5 (eGFR < 60 mL/min/1.73 m(2)) increased over the three decades in both sexes. Despite the widespread use of antihypertensive agents, the proportions of individuals with CKD who reached blood pressure of <130/80 mmHg were only 27.0% in men and 47.5% in women. The frequency of metabolic disorders including diabetes, hypercholesterolaemia and obesity increased over the three decades in both sexes.

CONCLUSIONS

The prevalence of CKD increased significantly in men, but not in women over the last three decades in a general Japanese population. Our findings support the requirement for a comprehensive treatment for hypertension and metabolic disorders to reduce the burden of CKD.

Impact of blood pressure levels on different types of stroke: the Hisayama study

OBJECTIVE

Clinical uncertainty remains whether the blood pressure classification and risk stratifications recommended by the Japanese Society of Hypertension Guidelines for the Management of Hypertension (JSH 2009) are useful in predicting the risks of stroke and its subtypes in the general Japanese population.

METHODS

A total of 1621 stroke-free residents of a Japanese community aged at least 40 years were followed up for 32 years. Outcomes were total and cause-specific stroke (lacunar infarction, atherothrombotic infarction, cardioembolic infarction, cerebral haemorrhage and subarachnoid haemorrhage). Incidence was calculated by the pooling of repeated observations method.

RESULTS

The age-adjusted incidence of total stroke rose progressively with higher blood pressure levels in both sexes (both P for trend <0.0001). A similar pattern was observed for lacunar infarction in both sexes and for cerebral haemorrhage in men: the differences were significant between optimal blood pressure and grades 1-3 hypertension (all P < 0.05). The age-adjusted incidence of atherothrombotic infarction in either sex and that of cardioembolic infarction and subarachnoid haemorrhage in women significantly increased in grade 3 hypertension (all P < 0.05). These associations remained substantially unchanged even after adjustment for other risk factors. In regard to risk stratification, the age-adjusted incidence of stroke significantly increased with the level of risk in both sexes.

CONCLUSION

Our findings suggest that the blood pressure classification and risk stratifications recommended by the JSH 2009 guidelines are useful in predicting the risk of stroke in a general Japanese population, but the magnitude and patterns of the impact of blood pressure categories are different among stroke subtypes.

The effect of metabolic syndrome defined by various criteria on the development of ischemic stroke subtypes in a general Japanese population

OBJECTIVE

We evaluated the impact of metabolic syndrome (MetS) defined by various criteria on the occurrence of ischemic stroke subtypes in a general Japanese population.

METHODS

A total of 2452 residents of a Japanese community, Hisayama, aged 40 years or older, were followed up for 14 years. To define MetS, we used the original Japanese criteria, the modified Japanese criteria, the International Diabetes Federation (IDF) criteria, the original National Cholesterol Education Program's Adult Treatment Panel III (NCEP) criteria, and the modified NCEP criteria. We substituted a waist circumference of > or = 90 cm in men and > or = 80 cm in women for the values of > or = 85 cm and > or = 90 cm, respectively, in the modified Japanese criteria and for > 102 cm and > 88cm, respectively, in the modified NCEP criteria.

RESULTS

Only MetS defined by the modified Japanese criteria showed a significant association with the development of lacunar infarction, and its hazard ratios (HRs) for the development of atherothrombotic and cardioembolic infarction were significant and greater than those of MetS defined by the other criteria: adjusted HRs for lacunar, atherothrombotic and cardioembolic infarction were 1.94 (95% confidence interval (CI), 1.13-3.32; P=0.02), 2.55 (95% CI, 1.25-5.18; P=0.01) and 3.94 (95% CI, 1.89-8.22, P<0.001), respectively, after adjustment for confounding factors.

CONCLUSION

Our findings suggest that MetS defined by the Japanese criteria with the modification of a waist circumference of > or = 90 cm in men and > or = 80 cm in women is a better predictor of each ischemic stroke subtype in the Japanese population.

Secular Trends in the Incidence of and Risk Factors for Ischemic Stroke and Its Subtypes in Japanese Population

Background— The study of long-term trends in the incidence of and risk factors for ischemic stroke subtypes could offer insights into primary and secondary prevention.

Methods and Results— We established 3 cohorts of residents ≥40 years of age in 1961, 1974, and 1988 in the Japanese community of Hisayama. Morphological examinations by autopsy or brain imaging were performed on most of the ischemic stroke cases developed in these cohorts. When 13-year follow-up data were compared, the age-adjusted incidence of ischemic stroke and lacunar infarction declined significantly from the first to the third cohort for both sexes, whereas the incidences of atherothrombotic and cardioembolic infarction did not change during this period. Hypertension was a powerful risk factor for the development of ischemic stroke, and improvement of hypertension control would have largely influenced this declining trend: The age- and sex-adjusted hazard ratio of hypertension decreased from 3.25 (95% CI 2.17 to 4.86) in the first cohort to 1.83 (1.29 to 2.58) in the third cohort. A rapid increase in the prevalence of metabolic disorders may have offset the impact of improvements in hypertension control and resulted in a slowdown of the decline in the incidence of ischemic stroke in the cohorts in the present study; however, hypertension still makes a large contribution to the development of ischemic stroke.

Conclusions— These findings suggest that in the Japanese population, the incidence of ischemic stroke has declined significantly over the past 40 years, probably owing to better management of hypertension. There is a need for greater primary prevention efforts in the treatment of hypertension and metabolic disorders.

Clinicopathological outline of dementia with Lewy bodies applying the revised criteria: the Hisayama study

To explore the validity of the criteria for dementia with Lewy bodies (DLB) revised in 2005, we examined community based consecutive autopsy cases. 10.3% of the non-demented subjects and 31.2% of the demented subjects showed the Lewy body pathology. Applying the revised pathological criteria to the 205 demented subjects, the types of LB pathology of 11 cases (5.4%) were brainstem-predominant, 24 cases (11.7%) were limbic type and 24 cases (11.7%) were diffuse neocortical type, although there were many subjects not to fit the criteria exactly. The prevalence of Lewy bodies (LBs) was almost same regardless of gender; however, the extent of the LB pathology among females was more severe than that in males. The likelihood of DLB being modified by concomitant Alzheimer's pathology was as follows: 27 cases (13.2%) showed low likelihood, 16 cases (7.8%) showed intermediate likelihood and 16 cases (7.8%) showed high likelihood. Since the numbers of clinical features of DLB were significantly higher in the pathological intermediate and high likelihood DLB groups than in the low likelihood DLB group or no LB group, both the intermediate and high likelihood groups of DLB should be considered as pathological DLB.

Altered expression of COX-2 in subdivisions of the hippocampus during aging and in Alzheimer's disease: the Hisayama Study

BACKGROUND

It has been reported that nonsteroidal anti-inflammatory drugs may delay the onset of Alzheimer's disease (AD). Since nonsteroidal anti-inflammatory drugs inhibit cyclooxygenase (COX), COX-2, an inducible form of COX, may be involved in the pathology of AD in association with the arachidonic acid cascade. In addition, it has been suggested that alterations in the balance of polyunsaturated fatty acids are associated with brain dysfunctions such as neurodegerative pathologies of the aging brain.

METHOD

To explore COX-2 expression in the hippocampus, we analyzed 45 consecutive autopsy subjects without dementia and 25 AD patients derived from the town of Hisayama, Japan.

RESULTS

The neuronal expression of COX-2 in the CA3 subdivision of the hippocampus, subiculum, entorhinal cortex and transentorhinal cortex were consistently observed in both nondemented and AD brains, and COX-2 immunoreactivity correlated with age in nondemented brains. In AD patients, neurons of CA1 exhibited increased COX-2 immunoreactivity which correlated with the severity of AD pathology. This correlation was not apparent in nondemented subjects.

CONCLUSION

These results suggest that COX-2 expression may be differentially regulated among subdivisions of the hippocampus and that elevated COX-2 expression in the CA1 of AD brains may be associated with AD pathology and thus cognitive dysfunction.

Prehypertension increases the risk for renal arteriosclerosis in autopsies: the Hisayama Study

Information regarding the association between prehypertension BP level and renal arteriosclerosis is limited. In 652 consecutive population-based autopsy samples without hypertension treatment before death, the relationship between the severity of renal arteriosclerosis and BP levels classified according to the criteria of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure was examined. The age- and gender-adjusted frequencies of renal arteriosclerosis linearly increased with elevating BP levels; both hypertensive and prehypertensive subjects had significantly higher frequencies of renal arteriosclerosis than subjects with normal BP (normal 11.9%; prehypertension 28.5%; stage 1 hypertension 32.9%; stage 2 hypertension 58.2%; all P < 0.01 versus normal). In a logistic regression model, prehypertension was significantly associated with renal arteriosclerosis after adjustment for other cardiovascular risk factors (prehypertension multivariate-adjusted odds ratio [mOR] 5.99 [95% confidence interval (CI) 2.20 to 15.97]; stage 1 hypertension mOR 6.99 [95% CI 2.61 to 18.72]; stage 2 hypertension mOR 22.21 [95% CI 8.35 to 59.08]). This significant association was observed for all renal arterial sizes. The similar association was also observed for arteriolar hyalinosis. When the subjects were divided into those with and those without target organ damage, the impact of prehypertension on renal arteriosclerosis was similar for both groups (subjects without target organ damage mOR 5.04 [95% CI 1.36 to 18.62]; subjects with target organ damage mOR 6.42 [95% CI 1.29 to 32.04]). These findings suggest that both hypertension and prehypertension are associated significantly with the severity of renal arteriosclerosis, regardless of the presence or absence of target organ damage.

Impact of metabolic syndrome on the development of cardiovascular disease in a general Japanese population: the Hisayama study

BACKGROUND AND PURPOSE

The metabolic syndrome (MetS) is associated with an increased risk of cardiovascular disease (CVD) events in general populations. However, well-designed prospective studies in Asian populations are very limited.

METHODS

We prospectively evaluated a total of 2452 community-dwelling Japanese individuals aged 40 years or older from 1988 to 2002 and examined the effects of MetS defined by the modified National Cholesterol Education Program Adult Treatment Panel III criteria on incident CVD.

RESULTS

The prevalence of the MetS was 21% in men and 30% in women at baseline. During the follow up, 307 CVD events occurred. Compared with those without MetS, the age-adjusted incidence of CVD (per 1000 person-years) was significantly higher in subjects with the MetS in both men (21.8 versus 11.6, P<0.01) and women (12.9 versus 6.5, P<0.01). The risk of CVD events was significantly higher even after adjusting for the following confounding factors: age, proteinuria, electrocardiographic abnormalities, serum total cholesterol, smoking habits, alcohol intake, and regular exercise (hazard ratio, 1.86; 95% CI, 1.32 to 2.62 in men and hazard ratio, 1.70; 95% CI, 1.22 to 2.36 in women). The risk of incident CVD was found to increase with the number of components of MetS and became significantly predictive when the number of components reached 3. Similar associations were also observed when CVD was divided into coronary heart disease and stroke.

CONCLUSIONS

Our findings suggest that MetS is a significant risk factor for the development of CVD in the Japanese middle-aged population.

Angiotensin I-converting enzyme gene polymorphism modifies the smoking-cancer association: the Hisayama Study

We examined the long-term contribution of smoking and angiotensin I-converting enzyme (ACE) gene I/D polymorphism to total cancer deaths in a prospective study of a general Japanese population. A total of 937 subjects aged 40 years or older were selected from an original cohort of 1621 subjects and were followed up for 32 years. During the follow-up period, 176 subjects died of cancer. Cancer mortality increased significantly with increasing current smoking levels. Although no clear relationship was observed between ACE genotypes and fatal cancer, the interaction term between current smoking and ACE genotype DD was found to be significant. In stratified analysis by ACE genotype after controlling for age, sex, alcohol intake, body mass index, glucose intolerance, serum total cholesterol and systolic blood pressure, the risk of fatal cancer in currently smoking subjects with genotype DD was twofold greater than that in subjects with genotypes II and ID. Among current smokers, subjects with genotype DD also showed a significantly greater risk of death due to cancer compared with those with genotypes II and ID combined (hazard ratio 1.77; 95% confidence interval 1.04-3.00; P=0.03). In conclusion, our findings suggest that ACE genotype DD enhances the association between smoking and cancer death in the general population.

Secular trends in the incidence, mortality, and survival rate of gastric cancer in a general Japanese population: the Hisayama study

To examine secular trends in the incidence and mortality of gastric cancer in a Japanese community, Hisayama, we established three study-cohorts of Hisayama residents aged > or =40 years in 1961 (1637 subjects), 1974 (2054), and 1988 (2602). Each cohort was followed up for ten years. The age-standardized mortality from gastric cancer significantly decreased from 2.4 per 1000 person-years in the first cohort to 0.8 in the third cohort for men, and from 1.0 to 0.2, respectively, for women (p < 0.01 for trend in both sexes). The five-year survival rate after gastric cancer significantly improved from the first (32.6%) to the third cohort (73.0%, p < 0.01) for men and from 43.2% to 72.3% (p < 0.05), respectively, for women. The age-standardized incidence of cancer in men was not different among the cohorts (4.3 per 1000 person-years in the first, 5.0 in the second, and 4.9 in the third cohort), while it decreased significantly in women (2.0, 1.8, and 1.2, respectively, p < 0.01 for trend). In conclusion, our findings suggest that in a Japanese population, the mortality from gastric cancer declined during the past 40 years, due mainly to the improvement of survival in both sexes and a decrease in the incidence for women.

Impact of fasting plasma glucose levels on gastric cancer incidence in a general Japanese population: the Hisayama study

OBJECTIVE

Several studies have shown associations between diabetes and various types of cancer other than gastric cancer. The aim of this cohort study was to evaluate the impact of fasting plasma glucose (FPG) levels on gastric cancer occurrence.

RESEARCH DESIGN AND METHODS

A total of 2,466 Japanese subjects aged > or =40 years were stratified into three groups according to FPG tertiles (<5.3 mmol/l, low FPG; 5.3-5.8 mmol/l, modest FPG; >5.8 mmol/l, high FPG) and followed up prospectively for 9 years.

RESULTS

During the follow-up, 66 subjects experienced gastric cancer. In men, the age-adjusted incidences were significantly higher in the modest-FPG (7.0 per 1,000 person-years, P < 0.05) and high-FPG (7.2, P < 0.05) groups than in the low-FPG group (2.2). In women, the high-FPG group also had a significantly higher age-adjusted incidence of gastric cancer compared with the low-FPG group (2.5 vs. 0.8, P < 0.05). The multivariate analysis with Cox's proportional hazards model revealed that the risks of gastric cancer in the modest-FPG (relative risk [RR] 2.3 [95% CI 1.1-5.0]) and high-FPG (3.1 [1.5-6.4]) groups were significantly higher than that in the low-FPG group, even after adjusting for other comprehensive risk factors, including Helicobacter pylori status, smoking, and dietary factors. However, this FPG-cancer association was observed only among H. pylori-seropositive subjects.

CONCLUSIONS

Our findings suggest that a modest increase in FPG is a risk factor for gastric cancer and that hyperglycemia is a possible cofactor increasing the risk posed by Helicobacter pylori infection.

Ten year recurrence after first ever stroke in a Japanese community: the Hisayama study

BACKGROUND

Very few population based cohort studies have focused on the long term recurrence of stroke.

OBJECTIVE

To examine 10 year cumulative recurrence rates for stroke in a Japanese cohort according to pathological type and clinical subtype of brain infarction.

METHODS

During a 32 year follow up of 1621 subjects >/=40 years of age, 410 developed first ever stroke. These were followed up prospectively for 10 years after stroke onset.

RESULTS

During follow up, 108 (26%) experienced recurrent stroke. The cumulative recurrence rates were 35.3% at five years and 51.3% at 10 years. The 10 year recurrence rates of subarachnoid haemorrhage (SAH), brain haemorrhage, and brain infarction were 70.0%, 55.6%, and 49.7%, respectively; the difference between SAH and brain infarction was significant (p = 0.004). Most recurrent episodes after SAH or brain haemorrhage happened within a year after the index stroke, whereas recurrence of brain infarction increased consistently throughout the observation period. Cardioembolic stroke had a higher recurrence rate (75.2%) than lacunar infarction (46.8%) (p = 0.049). The 10 year risk of stroke recurrence increased with age after lacunar or atherothrombotic brain infarction, but not after the other types or subtypes. After atherothrombotic brain infarction, cardioembolic stroke, or SAH, the type and subtype of most recurrent strokes were the same as for the index stroke, but recurrence after lacunar infarction or brain haemorrhage showed divergent patterns.

CONCLUSIONS

Japanese people have higher recurrence rates of stroke than other populations. Recurrence rate after a first brain infarct increases consistently through the next 10 years.

Incidence and prognosis of gastric cancer in a population-based cohort survey: the Hisayama study

BACKGROUND

No population-based cohort studies have been undertaken to evaluate the incidence and prognosis of gastric cancer. The purpose of this investigation was to clarify the incidence and fatal prognosis of gastric cancer and to determine the factors that contribute to the prognosis in a general Japanese population in Hisayama using a prospective study design.

METHODS

From 1988 to 1998 a total of 2605 subjects aged 40 years or older with no history of gastrectomy or gastric cancer were followed-up prospectively after a health examination. The diagnosis of gastric cancer was based on clinical records or autopsy findings.

RESULTS

During the follow-up period, 76 subjects developed gastric cancer. The age-adjusted incidence of gastric cancer for men (4.9 per 1000 person-years) was 4-fold higher than that for women (1.2, P < 0.05). In men, the incidence of gastric cancer increased with advancing age, but this trend was not observed in women. The age- and sex-adjusted 5-year survival rate was significantly higher in cancers of the middle third of the stomach than in those of the upper third of the stomach. The survival rate was higher in cancers of well-differentiated adenocarcinoma than in those of the other histological types. There were no cases of cancer-related death among the early gastric cancers during the follow-up period.

CONCLUSIONS

Our data suggest that men are at higher risk of gastric cancer than women in the general Japanese population. Clinical stage, histological type, and site of cancer in the stomach contribute to a fatal prognosis.

Trends in the incidence, mortality, and survival rate of cardiovascular disease in a Japanese community: the Hisayama study

BACKGROUND AND PURPOSE

The slowdown of a steeply declining trend in cardiovascular mortality has been reported in Japan, but precise reasons for this trend are uncertain.

METHODS

We established 3 study cohorts of Hisayama residents aged > or =40 years without a history of stroke or myocardial infarction in 1961 (1618 subjects, first cohort), 1974 (2038 subjects, second cohort), and 1988 (2637 subjects, third cohort). We followed up with each cohort for 12 years, comparing the incidence, mortality, and survival rate of cardiovascular disease.

RESULTS

The age-adjusted incidence of cerebral infarction significantly declined by 37% for men and by 32% for women from the first to the second cohort. It continued to decline by 29% for men, but the decline decelerated for women in the third cohort. The incidence of cerebral hemorrhage steeply declined by 61% from the first to the second cohort in men only, while it was sustained for both sexes in the third cohort. Stroke mortality continuously declined as a result of these incidence changes and significant improvement of survival. In contrast, the incidence and mortality rate of coronary heart disease were unchanged except for the increasing incidence in the elderly. The prevalence of severe hypertension and current smoking significantly decreased, while that of glucose intolerance, hypercholesterolemia, and obesity greatly increased among the cohorts.

CONCLUSIONS

Our data suggest that the decline in stroke incidence is slowing down and that the incidence of coronary heart disease has been increasing in the elderly in recent years. Insufficient control of hypertension and the increase in metabolic disorders may contribute to these trends.

Ten-year prognosis of stroke and risk factors for death in a Japanese community: the Hisayama study

BACKGROUND AND PURPOSE

There have been very few population-based cohort studies of long-term prognosis and risk factors for death after stroke. We examined the 10-year prognosis, causes, and risk factors of death after stroke in a Japanese cohort.

METHODS

During a 26-year follow-up of a cohort of 1621 subjects > or =40 years of age, 333 subjects developed first-ever stroke and were prospectively followed up for 10 years after onset. During these 10-year follow-up periods, 268 of the 333 stroke patients died. Of those, 239 (89.2%) underwent autopsy.

RESULTS

The risk of death was greatest in the first year after first-stroke onset in both sexes (men, 40.3%; women, 43.7%). Thereafter, the survival curves decreased gradually, and risk of death reached 80.7% for men and 80.2% for women by the end of the 10-year follow-up. The 30-day case fatality rate was substantially greater in patients with cerebral hemorrhage (63.3%) or subarachnoid hemorrhage (58.6%) than in patients with cerebral infarction (9.0%). The risk of dying after the first stroke was twice the risk for stroke-free subjects. The most common cause of death was the index stroke in the first year. Thereafter, the impact of the first stroke gradually decreased, while that of recurrent stroke increased. Multivariate analysis revealed that age, lower body mass index, and hemorrhagic stroke were significant risk factors for death after stroke.

CONCLUSIONS

Our findings suggest that the risk of death after first-ever stroke is high, in part because of the larger proportion of hemorrhagic stroke in Japanese relative to stroke victims in Western countries.

Detection of angiotensin-converting enzyme gene insertion/deletion polymorphism from paraffin-embedded tissues: the Hisayama study

Previous studies have suggested that archival materials from formalin-fixed paraffin-embedded blocks are unsuitable for most molecular techniques because the extracted DNA can be severely degraded. Therefore, the present study was designed to investigate the accuracy of genotyping for the insertion (I)/deletion (D) polymorphism of the angiotensin-converting enzyme (ACE) gene from paraffin-embedded tissues of autopsy cases from Hisayama Town, Japan. The genotype was determined using the double polymerase chain reaction method and to test the accuracy of the method, the polymorphism was investigated using paraffin-embedded tissues from 18 cases whose ACE genotypes (6 cases for each genotype) were known in advance from analysis of fresh-frozen tissue samples. Genotyping using paraffin-embedded tissues was then determined for 968 autopsy subjects. The genotype could be determined in 16 of the 18 test samples (88.9%) and there was no discrepancy with the results obtained from the fresh-frozen tissues. Of the 968 autopsy cases, the frequency of the DD, ID, and II genotypes was 12.4%, 47.3%, and 40.3%, respectively, a distribution that did not deviate from the Hardy-Weinberg equilibrium (chi(22df )= 0.67, p=0.72). These findings suggest the accuracy of the present method of ACE genotyping from paraffin-embedded tissues.

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.

Prevalence of intracranial saccular aneurysms in a Japanese community based on a consecutive autopsy series during a 30-year observation period. The Hisayama study

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage is a life-threatening disease that occurs mostly because of the rupture of intracranial saccular aneurysms. However, little is known about the prevalence of ruptured and unruptured aneurysms in the general population. The aim of the present study was to examine the prevalence of intracranial aneurysms on the basis of a consecutive autopsy series over a 30-year observation period in a general Japanese population in Hisayama.

METHODS

We evaluated 1230 consecutive autopsy cases with craniotomy among the total deaths of Hisayama residents during 1962 through 1991 (overall autopsy rate, 80.1%).

RESULTS

A total of 73 intracranial saccular aneurysms were found in 57 cases (4.6%). The prevalence of aneurysms for women was 2.4 times higher than that for men (7.1% versus 2.9%). Among men, the prevalence of aneurysms remained unchanged across the range of age groups. In contrast, there were 2 peaks in the prevalence of aneurysms for women falling in the 40- to 49-year (14.3%) and 60- to 69-year age groups (14.5%). The most common site of the aneurysms was the middle cerebral artery (31.5%), followed by the anterior communicating artery (30.1%), anterior cerebral artery (15.1%), vertebrobasilar artery (12.3%), and internal carotid artery (11.0%). Among these 73 aneurysms, 29 (39.7%) were ruptured. Ruptured aneurysms were common in subjects <80 years of age, whereas unruptured aneurysms were prevalent in those >/=80 years of age. The frequency of ruptured aneurysms was highest in the vertebrobasilar system (66.7%) and lowest in the middle cerebral artery (13.0%).

CONCLUSIONS

Our data suggest that intracranial aneurysms are more frequent in women in the general Japanese population. Aneurysms are more prevalent in the middle cerebral artery, but the risk of rupture is highest in the vertebrobasilar system.

The impact of alcohol and hypertension on stroke incidence in a general Japanese population. The Hisayama Study

BACKGROUND AND PURPOSE

The relationship between alcohol intake and stroke has been inconsistent in previous studies. We examined the separate and combined effects of drinking habits and hypertension on stroke incidence in a prospective survey of a general Japanese population.

METHODS

A total of 1621 stroke-free Hisayama residents aged 40 years or older were classified by their alcohol intake into nondrinkers, light drinkers (< 34 g of ethanol per day), and heavy drinkers (> or = 34 g of ethanol per day) and followed up prospectively for 26 years from 1961.

RESULTS

During the follow-up period, cerebral infarction developed in 244 subjects and cerebral hemorrhage in 60. For men, the incidence of cerebral hemorrhage increased significantly with rising alcohol consumption. In contrast, the incidence of cerebral infarction was slightly lower in light drinkers than in nondrinkers, while it increased significantly in heavy drinkers compared with light drinkers. Female drinkers had a lower incidence of cerebral infarction but a slightly higher incidence of cerebral hemorrhage than nondrinkers, as did male light drinkers. Among the hypertensive subjects, the age- and sex-adjusted relative risk of cerebral hemorrhage was significantly elevated in heavy drinkers versus abstainers (3.13; 95% confidence interval [CI], 1.08 to 9.10), but the increase was not significant for light drinkers. In contrast, the relative risk did not significantly increase for normotensive light and heavy drinkers. Compared with hypertensive light drinkers, the relative risk of cerebral infarction significantly increased in hypertensive heavy drinkers (1.96; 95% CI, 1.08 to 3.57) but remained unchanged in normotensive heavy drinkers. Significant associations between alcohol intake and stroke were substantially the same even after controlling for other risk factors in multivariate analysis.

CONCLUSIONS

Among hypertensive individuals, heavy alcohol consumption leads to a significant increase in the risk of cerebral hemorrhage, suggesting a synergistic effect of alcohol and hypertension, while light alcohol consumption significantly reduces the risk of cerebral infarction.

Silent cerebral infarction in a community-based autopsy series in Japan. The Hisayama Study

BACKGROUND AND PURPOSE

The purpose of this study was to assess the prevalence and characteristics of silent cerebral infarction in a population-based consecutive autopsy series of residents of Hisayama, Kyushu, Japan.

METHODS

Autopsy records, cerebral pathological findings, and clinical charts of 966 Hisayama residents recorded during the 26 years from 1961 to 1987 were examined (autopsy rate, 82.4%). The subjects were divided into three groups: those with both clinically apparent strokes and pathologically verified cerebral infarcts (stroke group), those having pathological evidence of cerebral infarction in the brain but without clinical stroke episodes (silent infarction group), and those with neither infarction nor stroke episode (noninfarction group). Risk factors and brain pathology in the three groups were compared.

RESULTS

Silent cerebral infarction was found in 12.9% of the 966 subjects who had undergone autopsy, and its frequency increased with age. The subjects with silent infarcts were older, had higher systolic or diastolic blood pressure, and had atrial fibrillation more frequently than subjects in the noninfarction group. There were no significant differences in the locations of infarcts between the stroke and silent infarction groups, although infarcts tended to be located in the deeper area of the brain in the latter. The number and size of infarcts were smaller in the silent infarction group than in the stroke group.

CONCLUSIONS

Diastolic blood pressure and atrial fibrillation appear to be strong predictors of silent cerebral infarction in the Japanese general population. Stroke becomes clinically apparent as infarct volume increases.

Prevalence of type 2 (non-insulin-dependent) diabetes mellitus and impaired glucose tolerance in the Japanese general population: the Hisayama Study

We determined the population-based prevalence of diabetes mellitus in members of the Japanese community, Hisayama aged 40-79 years old by a 75-g oral glucose tolerance test. The basic population used to calculate diabetic prevalence was 1,077 men (72.8% of the whole population in the same age range) and 1,413 women (80.8%) including ten diabetic patients on insulin therapy. In addition, we compared the prevalence of history of diabetes which was acquired by interview or questionnaire, between participants and non-participants in the 75-g oral glucose tolerance test, but they were not statistically different. The age-adjusted prevalence of diabetes to world population was 12.7% for men and 8.4% for women, and that of impaired glucose tolerance was 19.6% for men and 18.4% for women. These figures were much higher than those previously reported from several Japanese communities. The results obtained from the present study could reveal true prevalence of diabetes among the Japanese population. In addition, the reasons for the increasing prevalence of diabetes among the recent Japanese population are also discussed.

Prevalence and etiology of dementia in a Japanese community

BACKGROUND AND PURPOSE

We sought to determine the type-specific prevalence of dementia and its risk factors in elderly persons from the Japanese community of Hisayama.

METHODS

We studied the prevalence of dementia in 887 Hisayama residents (353 men and 534 women) aged 65 years or older (screening rate, 94.6%) using various items of clinical information, neurological examination, and dementia scales. We also studied brain morphology in 50 of 59 determined to have dementia by computed tomography or autopsy during the subsequent 54-month period. Factors relevant to dementia were compared between 27 patients with vascular dementia and 789 control subjects without dementia in a retrospective fashion.

RESULTS

The prevalence rate of dementia among Hisayama residents aged 65 or older was estimated at 6.7%, with a females to males ratio of 1:2. Among 50 cases of dementia in which brain morphology was examined, the frequency of vascular dementia was 56%; this rate was 2.2 times higher than that for senile dementia of the Alzheimer type. Aging, hypertension, electrocardiographic abnormalities, and high hematocrit were significantly (p less than 0.05) and independently associated with the occurrence of vascular dementia.

CONCLUSIONS

Prevalence of dementia among the Hisayama residents was relatively identical to that previously reported, but vascular dementia was more predominant. Risk factors for vascular dementia were similar to those for lacunar infarcts. Control of hypertension may be a key to reducing dementia among the Japanese population.

Cerebrovascular disease in Saudi Arabia

We studied the pattern and outcome of strokes in 200 Saudi patients. Cerebral infarction constituted 87% of strokes, subarachnoid hemorrhage 4.5%, cerebral hemorrhage 6.5%, and venous infarction 2%. The vessel most commonly involved was part or all of the middle cerebral artery, constituting 52% (90) of the 174 arterial infarcts. Lacunar infarcts were seen in 21% (37) of the patients with arterial infarcts. Among all 200 patients, 8% died and 8% had secondary generalized seizures. Hypertension occurred in 41% of the 174 patients with arterial infarcts and 62% of the 13 with cerebral hemorrhages. The highest incidence of hypertension as a risk factor was among those with lacunar infarcts (81%), ganglionic cerebral hemorrhages (80%), and infarcts of deep branches of the middle cerebral artery (57%). Embolic infarcts due to rheumatic heart disease constituted 11% of all arterial infarcts. We conclude that our pattern of strokes is similar to that of the west rather than that of the Japanese, but with less frequent arteriovenous malformations and aneurysms.

Seasonal variation in stroke incidence in Hisayama, Japan

We investigated seasonal variation in the incidence of cerebral stroke among the general population aged greater than or equal to 40 years in November of 1961 in Hisayama, Japan. During the 24-year follow-up period, 311 cases of cerebrovascular diseases occurred. The date or month of onset was determined in 308 cases, of which 51 were classified as intracerebral hemorrhage, 223 as cerebral infarction, and 27 as subarachnoid hemorrhage. We observed a significant seasonality in the incidence of all stroke (p less than 0.01), of intracerebral hemorrhage (p less than 0.05), and of cerebral infarction (p less than 0.01), whereas subarachnoid hemorrhage had no significant seasonal pattern. Subjects less than 64 years of age showed a significant seasonal variation in the incidence of both intracerebral hemorrhage (p less than 0.05) and cerebral infarction (p less than 0.01). A significant seasonal pattern for the incidence of intracerebral hemorrhage was also noted among persons with hypertension (p less than 0.05) or a high serum cholesterol level (p less than 0.05), whereas such a pattern for cerebral infarction was documented among normotensive persons (p less than 0.05) and those with a low serum cholesterol level (p less than 0.01). In addition, the incidences of intracerebral hemorrhage and cerebral infarction were negatively correlated with mean ambient temperature (p less than 0.01 and p less than 0.05, respectively), and all stroke and intracerebral hemorrhage in men were significantly related to intradiurnal temperature change (p less than 0.05 and p less than 0.01, respectively). The significance of the seasonal occurrence of stroke is discussed in relation to relevant risk factors.

Incidence and prognosis of subarachnoid hemorrhage in a Japanese rural community

Twenty-six first episodes of subarachnoid hemorrhage occurred among 1,621 Hisayama residents aged greater than or equal to 40 years during the 22-year follow-up of a prospective study. Subarachnoid hemorrhage was confirmed by both clinical and autopsy findings. The average annual incidence (96.1/100,000 population) was 3-13 times higher than any previously reported and steeply increased with age in both sexes, being 2.3 times higher for women than for men after adjusting for age. Nine patients (35%) died less than or equal to 8 hours after the onset of subarachnoid hemorrhage. None was correctly diagnosed on the death certificates, and four of the nine (44%) were misdiagnosed as intracerebral hemorrhage. We found the survival rate of patients suffering subarachnoid hemorrhage to be much lower than previously reported because we detected a large number of sudden deaths due to subarachnoid hemorrhage through the high rate of autopsy in our cohort (81.4%).

Accuracy of diagnosis on death certificates for underlying causes of death in a long-term autopsy-based population study in Hisayama, Japan; with special reference to cardiovascular diseases

Major categorical diagnosis by International Classification of Diseases and type-specific diagnosis for cardiovascular diseases in death certificates were compared to the diagnosis made at autopsy in 864 consecutive autopsy cases aged 20 or over, among the Japanese residents in Hisayama town. Cerebral stroke was correctly diagnosed in 84%, malignant neoplasms in 78% and cardiac disease in 66%. Cerebral stroke and cardiac disease tended to be overdiagnosed, while malignant neoplasms were underdiagnosed. The validation of certified diagnosis was less reliable in the aged population, and in type-specific diagnosis of cardiovascular diseases. Cerebral hemorrhage with false negative or false positive diagnoses was usually classified into type unspecified stroke or different categories of cerebral stroke, while those misdiagnosed as cases of cerebral infarction frequently had no significant lesions in the autopsied brain. Finally, the relationship between the validation of diagnosis on the death certificates and the secular trend in cardiovascular disease in the Japanese vital statistics was discussed.

Autopsy study of incidence and distribution of cerebral amyloid angiopathy in Hisayama, Japan

The incidence of cerebral amyloid angiopathy in a general population was evaluated in brains of 400 consecutive autopsies of residents of Hisayama, Japan (November 1971-October 1983). Six samples taken from frontal lobe, parietal lobe, temporal lobe, occipital lobe, hippocampus, and basal ganglia of the same side of each brain were stained with both hematoxylin and eosin and Congo red. The specimens were surveyed microscopically with polarized light for deposition of amyloid in the vascular wall. In 26 cases with brain hemorrhage, the region surrounding the hemorrhagic sites was further examined to study the probable causal relation between cerebral amyloid angiopathy and brain hemorrhage. Cerebral amyloid angiopathy was found in 40 of 218 men (18.3%) and 51 of 182 women (28.0%). The incidence increased with age in both sexes. The frontal lobe was most frequently affected (66 cases), followed by parietal lobe (65), occipital lobe (49), temporal lobe (44), and hippocampus (32); the putamen was never affected. The incidence of cerebral amyloid angiopathy did not correlate with blood pressure or with the severity of cerebral atherosclerosis. Among the 26 cases in which there was brain hemorrhage, only one cerebellar hemorrhage, in an 85-year-old man, was attributed to cerebral amyloid angiopathy. This case showed four microaneurysms in vessels, with cerebral amyloid angiopathy surrounding the hemorrhagic site. Thirty similar lesions were observed in eight cases without brain hemorrhage. Cerebral amyloid angiopathy may play an etiologic role in the development of brain hemorrhage through formation of angionecrosis and microaneurysm.

Intracerebral hemorrhage in a Japanese community, Hisayama: incidence, changing pattern during long-term follow-up, and related factors

The incidence of intracerebral hemorrhage over 13 years is compared between two Hisayama cohorts. Among men aged 40 years or older, the annual incidence declined significantly from 3.1/1,000 in the early cohort (1961-1970) to 1.2/1,000 in the recent cohort (1974-1983). Massive ganglionic hemorrhage decreased, while small or medium-sized intracerebral hemorrhage increased in the recent cohort on pathologic or computed tomographic examination. These trends could be due to the reduced prevalence of hypertension in the Hisayama population. The association of serum total cholesterol with intracerebral hemorrhage is discussed based on the results during a 22-year follow-up period.