Shunroku Baba

Prevalence of Asymptomatic Carotid Atherosclerotic Lesions Detected by High-Resolution Ultrasonography and Its Relation to Cardiovascular Risk Factors in the General Population of a Japanese City The Suita Study

BACKGROUND AND PURPOSE Because extracranial carotid atherosclerotic lesions have been considered rare, no reports have been published on the prevalence and distribution of these lesions in a general Japanese population. However, recent changes in lifestyle are thought to have caused an increase in these lesions. The aim of this study was to use high-resolution ultrasonography to examine the prevalence of asymptomatic extracranial carotid artery lesions and its relation to cardiovascular risk factors in an urban Japanese population. METHODS The subjects were 814 men and 880 women aged 50 to 79 years randomly sampled from the residents of Suita, a city located in the second largest urban area of Japan. Asymptomatic carotid lesions were detected and evaluated by a single physician with high-resolution B-mode ultrasonography. RESULTS We found significant sex differences in the prevalence of atherosclerotic lesions in the extracranial carotid artery; 4.4% of all the subjects, 7.9% of the men, and 1.3% of the women had atherosclerosis accompanied by stenosis of >50%. A strong association between these lesions and the results of a 75-g oral glucose tolerance test was found in both sexes. Multiple regression analysis of carotid atherosclerosis showed significant relationships with age, systolic blood pressure, fasting blood glucose, pack-years of smoking, total serum cholesterol, and HDL cholesterol in men (P<.05) and significant relationships with age, systolic blood pressure, pack-years of smoking, and total serum cholesterol in women (P<.05). CONCLUSIONS Our data showed that cardiovascular risk factors were strongly related to carotid atherosclerosis and that the proportion of severe carotid atherosclerosis with >50% stenosis was not low and was almost equal to that reported in developed western countries.

Deletion Allele of Angiotensin-Converting Enzyme Gene Increases Risk of Essential Hypertension in Japanese Men The Suita Study

BACKGROUND The Framingham Study recently revealed that the homozygous deletion polymorphism of the angiotensin-converting enzyme gene (ACE DD) is associated with increased risk for essential hypertension in a male-specific manner. However, this association has not been confirmed in races other than whites. METHODS AND RESULTS Using a large number of Japanese subjects (n=5014) that were randomly selected from the general population (the Suita Study), we examined the association between ACE DD and hypertension. The frequency of DD (17.1%) in hypertensive men was significantly higher (P<0.0015) than that (11.8%) in other mildly hypertensive or normotensive men, and the estimated odds prevalence for hypertension (DD vs II) was 1.75 (95% CI 1.21 to 2.53). In contrast, no significant association was confirmed in women (OR 1.17, 95% CI 0.79 to 1.72). CONCLUSIONS Despite the lower frequency of the DD genotype in Japanese than in whites, the ACE gene polymorphism was associated with increased risk for hypertension, suggesting that this polymorphism is a mild but certain genetic risk factor for essential hypertension in men.

Alcohol Consumption and Risk of Stroke Among Middle-Aged Men: The JPHC Study Cohort I

Background and Purpose— The impact of light-to-moderate alcohol consumption on risk of stroke has not been well examined in a single study, although the effect is hypothesized to differ among stroke subtypes from meta-analyses. Methods— A total of 19 544 men aged 40 to 59 years living in communities were followed-up from 1990 to 1992 to the end of 2001 in the Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Disease (JPHC Study). Results— After 214 504 person-years of follow-up, 694 incident strokes were documented, of which 611 were confirmed by imaging studies or autopsy, including 219 intraparenchymal hemorrhages, 73 subarachnoid hemorrhages, and 319 ischemic strokes. Alcohol consumption was positively associated with age-adjusted risk of total stroke with a 68% excess risk among drinkers of ≥450 g ethanol per week compared with occasional drinkers. This excess risk was confined primarily to hemorrhagic stroke, which remained statistically significant even after controlling for hypertension and other cardiovascular risk factors (RR: 2.15; 95% CI: 1.22 to 3.79). There was a lower risk of ischemic stroke, more specifically lacunar infarction, a higher risk of hemorrhagic stroke, and no excess risk of total stroke among drinkers of 1 to 149 g ethanol per week compared with occasional drinkers; the respective multivariate RR (95% CI) was 0.59 (0.37 to 0.93), 0.43 (0.22 to 0.87), 1.73 (0.98 to 3.07), and 0.98 (0.71 to 1.36). Conclusions— We found differential effects of light-to-moderate alcohol consumption on risks of hemorrhagic and ischemic strokes among middle-aged men. Light-to-moderate alcohol consumption, ie, ≤2 drinks per day, does not raise the risk of total stroke.

Associations of serum total cholesterol, different types of stroke, and stenosis distribution of cerebral arteries. The Akita Pathology Study.

Background and Purpose The relation between serum total cholesterol levels and stroke is controversial. The Akita Pathology Study provides data on the association of serum total cholesterol, different types of stroke, and distribution of stenosis in cerebral arteries. Methods The data are based on 750 autopsied men aged 30 years and older who were admitted to a local hospital in northeast Japan between 1966 and 1984. The overall autopsy rate was 88%. The grade of stenosis in the cerebral arteries was determined blindly by one pathologist using Bakers method for basal cerebral arteries (atherosclerosis scores) and using microscopic examination of a single basal ganglion slide for the intracerebral penetrating arteries (arteriolosclerosis scores). Results The age-adjusted mean value of serum total cholesterol concentration was 164 mg/dL for cerebral hemorrhage, 177 mg/dL for infarction in penetrating artery regions, and 200 mg/dL for infarction in cortical artery regions. Mean serum cholesterol was lower in deaths caused by cerebral hemorrhage than in those caused by myocardial infarction and other cardiovascular disease. Mean atherosclerosis score of basal cerebral arteries was low for cerebral hemorrhage, intermediate for penetrating artery infarction, and high for cortical artery infarction. Stenosis of both basal and penetrating arteries was minimum or absent in cases of cerebral hemorrhage. Only the basal arteries were stenotic in cases of cortical artery infarction, whereas both basal and penetrating arteries were stenosed in cases of penetrating artery infarction. There were positive associations of serum cholesterol with stenosis of basal and penetrating arteries. Among cases of cerebral hemorrhage, serum total cholesterol levels were even lower in men with no significant stenosis in either basal or penetrating arteries than in men with stenosis in either type of artery. Conclusions The association of serum cholesterol with pathogenesis varies among stroke types. Elevated serum cholesterol levels were associated with the presence of cortical artery infarction, while low serum cholesterol levels were associated with cerebral hemorrhage.

Role of systolic blood pressure in determining prognosis of hemodialyzed patients

The role of blood pressure in determining the prognosis of hemodialyzed patients was examined in 195 patients who were introduced to hemodialysis. The relationship between blood pressure and survival or death was analyzed. In 46 patients who died within 3 years after the introduction of hemodialysis (nonsurvivors), the age was higher (61 +/- 2 years v 50 +/- 1 years), the occurrence of diabetic nephropathy was higher, and the systolic pressure was higher in both the introduction (178 +/- 4 mm Hg v 167 +/- 2 mm Hg) and maintenance (165 +/- 4 mm Hg v 147 +/- 2 mm Hg) phases than in 132 patients who survived more than 3 years (survivors). On the other hand, there were no significant differences in diastolic pressure during either phase between the two groups of patients. When diabetic nephropathy was excluded, only systolic pressure during the maintenance phase was higher in the nonsurvivors than in the survivors. Therefore, based on systolic pressure during the maintenance phase, patients were divided into two groups, the HT group (> or = 160 mm Hg) and the NT group (< 160 mm Hg), and cumulative survival rates were compared. Whether all patients, only those patients with diabetic nephropathy, or only those patients without diabetic nephropathy were examined, the survival rate was higher in the NT group than in the HT group.(ABSTRACT TRUNCATED AT 250 WORDS)

Cigarette Smoking and Risk of Stroke and its Subtypes Among Middle-Aged Japanese Men and Women: The JPHC Study Cohort I

Background and Purpose— We examined sex-specific relationships of smoking with risk of total stroke and stroke subtypes in Asian populations because of the limited data available. Methods— A total of 19 782 men and 21 500 women aged 40 to 59 years who were free of prior diagnosis of stroke, coronary heart disease, or cancer and reported their smoking status were followed in the Japan Public Health Center–based Prospective Study on Cancer and Cardiovascular Disease (JPHC Study) from 1990 to 1992 to the end of 2001. Results— During a 461 761 person-year follow-up, 702 total strokes were documented among men, of which 619 were confirmed by imaging studies, including 219 intraparenchymal hemorrhages, 73 subarachnoid hemorrhages, and 327 ischemic strokes. The respective numbers of cases among women were 447, 411, 129, 106, and 176. Multivariate relative risks (95% CIs) for current smokers compared with never-smokers after adjustment for cardiovascular risk factors and public health center were 1.27 (1.05 to 1.54) for total stroke, 0.72 (0.49 to 1.07) for intraparenchymal hemorrhage, 3.60 (1.62 to 8.01) for subarachnoid hemorrhage, and 1.66 (1.25 to 2.20) for ischemic stroke. The respective multivariate relative risks among women were 1.98 (1.42 to 2.77), 1.53 (0.86 to 4.25), 2.70 (1.45 to 5.02), and 1.57 (0.86 to 2.87). There was a dose-response relation between the number of cigarettes smoked and risks of ischemic stroke for men. A similar positive association was observed between smoking and risks of lacunar infarction and large-artery occlusive infarction, but not embolic infarction. Conclusions— Smoking raises risks of total stroke and subarachnoid hemorrhage for both men and women and risk of ischemic stroke, either lacunar or large-artery occlusive infarction, for men.

Strong and significant relationships between aggregation of major coronary risk factors and the acceleration of carotid atherosclerosis in the general population of a Japanese city: the Suita Study.

BACKGROUND Carotid arterial intimal-medial thickness (IMT) measured by high-resolution B-mode ultrasonography has come to be used as a noninvasive surrogate end point to measure progression of atherosclerosis. However, there are no detailed data on the relationship between aggregation of coronary risk factors and carotid atherogenesis. METHODS Cross-sectional assessment of the relationship between carotid atherosclerosis detected by high-resolution ultrasonography and integration of major coronary risk factors by age and sex. Subjects aged 30 to 86 years were randomly selected from Suita, located in Osaka, the second largest urban area of Japan, including 1896 men and 2102 women. Carotid atherosclerosis was evaluated by using our atherosclerotic indexes of IMT, plaque number, plaque score, and percentage of stenosis of the carotid artery assessed using ultrasonography by sex and age group classified by number of major coronary risk factors (ie, hypertension [diastolic blood pressure > or =90 mm Hg and/or systolic blood pressure > or 140 mm Hg or receiving medication], smoking [current smoker], and hypercholesterolemia [serum total cholesterol level > or =5.68 mmol/L [220 mg/dL] or receiving medication]). RESULTS The mean carotid atherosclerotic index value, especially the mean IMT value, of the subjects with 1 major coronary risk factor was on average 0.028 mm (3.2%) higher for men and 0.025 mm (2.9%) higher for women than that of the subjects without major coronary risk factors; for subjects with 2 risk factors, 0.054 mm (6.3%) higher for men and 0.053 mm (6.2%) higher for women; and for high-risk subjects with 3 major risk factors, 0.135 mm (15.8%) higher for men and 0.137 mm (15.4%) higher for women. The percentage of the subjects with severe stenosis of at least 50% increased stepwise with increases in the number of coronary risk factors and showed a significant difference (P<.05) between men and women, ie, 2.4% vs 0. 6% (P =.01) among the subjects with no risk factors; 6.7% vs 1.5% (P<.001), subjects with 1 risk factor; 10.7% vs 2.7% (P<.001), subjects with 2 risk factors; and 18.6% vs 5.0% (P =.01), high-risk subjects. CONCLUSIONS Aggregation of established major coronary risk factors strongly influenced carotid atherogenesis in both sexes. There were significant differences between sexes in the acceleration or progression of carotid atherosclerosis.

Second nation-wide study of atherosclerosis in infants, children and young adults in Japan

Abstract This paper reports the results of a nation-wide cooperative study of atherosclerosis in young, first generation Japanese with ages ranging from 1 month to 39 years, who were autopsied between 1978 and 1982 in hospitals distributed over the entire archipelago of Japan. Atherosclerotic lesions in 2320 aortas, 1620 coronary arteries and 344 cerebral arteries were classified into fatty streaks, fibrous plaques and complicated lesions and were then quantificated with the point-counting method. Atherosclerosis of aortas, coronary arteries and cerebral arteries, determined by surface involvement (SI) of atherosclerotic lesions and atherosclerotic index (AI), increased with age; the severest were seen in aortas, and then, with decreasing severity, in the coronary and cerebral arteries. Fatty streaks preceded the other lesions and accounted for the largest portion of the lesions in aortas and coronary arteries. Fibrous plaques and complicated lesions developed in the later decades of life. The patients with collagen diseases had a greater severity of aortic atherosclerosis in the 2nd and 3rd decades of life, than those without such disorders. Correlation of antemortem clinical data with SI and Al of each artery were analyzed, using simple correlation analysis and multiple regression analysis. Age, serum cholesterol and blood pressure were significantly and positively correlated with SI and AI of aortas and coronary arteries. Serum cholesterol was more strongly correlated with the extent of fatty streaks than was mean blood pressure and vice versa with that of fibrous plaques. Atherosclerosis of cerebral arteries, however, showed a significant correlation only with the factor of mean blood pressure. Therefore the susceptibility to risk factors varies with the artery in cases of early lesions of atherosclerosis in young Japanese.

Human prostacyclin synthase gene and hypertension : the Suita Study

BACKGROUND Prostacyclin (prostaglandin I(2)) is a strong vasodilator that inhibits the growth of vascular smooth muscle cells and is also the most potent endogenous inhibitor of platelet aggregation. Therefore, it has been considered to play an important roles in cardiovascular disease. On the basis of the hypothesis that variations of the prostacyclin synthase gene may also play an important role in human cardiovascular disease, we performed a screening for variations in the human prostacyclin synthase gene. METHODS AND RESULTS We have detected a repeat polymorphism in the promoter region of the human prostacyclin synthase gene. The number of 9-bp (CCGCCAGCC) repeats in the promoter region, which encodes a tandem repeat of Sp1 transcriptional binding sites, varied between 3 and 7 in Japanese subjects. Luciferase reporter analysis indicated that the alleles of 3 and 4 repeats (R3 and R4, respectively) had less promoter activity in cultured human umbilical vein endothelial cells. We then investigated the possible association of this repeat polymorphism with blood pressure in a large population-based sample (the Suita Study), which consisted of 4971 Japanese participants. Multivariate models indicated that participants with the R3R3, R3R4, or R4R4 genotype (SS genotype, n=80) had significantly higher systolic pressure (P=0.0133) and pulse pressure (P=0.0005). The odds ratio of hypertension (140/90 mm Hg) for the SS genotype was 1.942 (95% confidence interval 3.20 to 1.19, P=0.0084). CONCLUSIONS Repeat polymorphism of the human prostacyclin synthase gene seems to be a risk factor for higher pulse pressure and is consequently a risk factor for systolic hypertension in the Japanese population.

Association analyses between genetic polymorphisms of endothelial nitric oxide synthase gene and hypertension in Japanese: The Suita Study.

Objectives Endothelium-derived nitric oxide plays a key role in the regulation of vascular tone. Recently, endothelial nitric oxide synthase (eNOS) gene polymorphisms were reported to be associated with hypertension or coronary spasm. We investigated the association between the eNOS gene polymorphisms and hypertension in a large population-based sample of 4055 Japanese. Design and methods We investigated two polymorphisms of the eNOS gene, Glu298Asp polymorphism of exon 7 and T(−786)C polymorphism of the promoter region. The genotype distribution in hypertensive subjects was compared to that in the other subjects. The influence of the genotype on blood pressure values was analyzed in the subjects not taking hypertensive medication. The promoter activities of the eNOS gene with the (−786)T or (−786)C allele were measured by a luciferase reporter gene assay. Results There was significant linkage disequilibrium between the two polymorphisms (P < 0.0001). The genotype distribution of the Glu298Asp or T(−786)C polymorphism did not differ between the hypertensive and the other subjects. No significant differences in the blood pressure of subjects not taking hypertensive medication were observed among the three genotypes of Glu298Asp or T(−786)C polymorphisms. No significant differences in the promoter activity were observed between bovine endothelial cells transfected with the (−786)T and (−786)C alleles. Conclusions Our data suggested that these polymorphisms of the eNOS gene are unlikely to be major factors in the susceptibility to hypertension in the Japanese population studied.