Masamitsu Konishi

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.

High-density lipoprotein cholesterol and premature coronary heart disease in urban Japanese men.

BACKGROUND The objective of this study was to examine the relation of high-density lipoprotein cholesterol (HDL-C) to coronary heart disease in Japanese men whose serum total cholesterol is low by Western standards. METHODS AND RESULTS A prospective, observational study based on 7.7 years of follow-up for incidence of coronary heart disease and stroke was conducted. The subjects were 6408 middle-aged male workers aged 40 to 59 years at baseline in urban companies in Osaka, Japan, whose mean serum total cholesterol was 5.10 mmol/L. Mean HDL-C adjusted for age, total cholesterol, systolic blood pressure, alcohol intake, cigarette smoking, and body mass index was 1.27 to 1.28 mmol/L for men who developed coronary heart disease (n = 46) or definite myocardial infarction (n = 21) compared with 1.46 mmol/L for those free of cardiovascular disease (n = 6256; difference, P < .01). There was no significant difference in mean HDL-C between stroke cases (n = 33) and those free of cardiovascular disease. The incidence rates of coronary heart disease and definite myocardial infarction, adjusted for the other risk factors, were three to four times higher in the lowest HDL-C quartile (< 1.24 mmol/L) than the highest quartile (> or = 1.66 mmol/L), and there was a significant dose response for definite myocardial infarction. Serum total cholesterol was positively and significantly associated with coronary heart disease incidence. Furthermore, the inverse association for HDL-C was apparent among men with total cholesterol < 5.69 mmol/L (mean total cholesterol, 4.76 mmol/L) and men with total cholesterol > or = 5.69 mmol/L (mean total cholesterol, 6.26 mmol/L). CONCLUSIONS Coronary heart disease incidence is inversely related to HDL-C in urban Japanese middle-aged men, whose mean total cholesterol (5.10 mmol/L) is relatively low.

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.

Multivariate analysis of risk factors for stroke eight-year follow-up study of farming villages in Akita, Japan

Akita Prefecture has an especially high mortality rate from stroke, and its age-adjusted death rate from stroke is the highest in Japan. We have carried out an epidemiological survey of cardio- and cerebrovascular diseases (CVD) in farming villages in this prefecture since 1963, with a response rate of 84%. During our 8-year follow-up, 94 new stroke cases were observed among 1,814 subjects. Multiple logistic function analysis was carried out on nonstroke and stroke cases from subjects aged 40 to 69 years at time of initial examination, in order to clarify the risk factors for stroke. The analysis used eight variables: age, sex, systolic blood pressure, obesity index, urinary sugar, urinary protein, serum total cholesterol, and total protein. The results showed that hypertension was the most important risk factor for stroke. However, regarding cholesterol, multivariate analysis showed that among men and women aged 40 to 69 years at entry, subjects with low serum total cholesterol levels were more prone to cerebral hemorrhage, but that serum cholesterol level had no weight as a risk factor for cerebral infarction. These results correspond well with the observed fact that stroke incidence or death rate in Japan is higher in populations with high prevalence of hypertension and low concentration of cholesterol, and also with the fact that death rate from hemorrhage declines with the increment of serum total cholesterol and the westernization of diet.

Trends in the Incidence of Coronary Heart Disease and Stroke and Their Risk Factors in Japan, 1964 to 2003 : The Akita-Osaka Study

A continuous decline in mortality and morbidity from coronary heart disease (CHD) has been documented in the U.S. ([1–4][1]). This decline is accompanied by a reduction in serum total cholesterol levels, which has been attributed to improvements in medical care and community-based prevention

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.

Alcohol intake and hypertension among urban and rural Japanese populations

A significant positive relationship was found between alcohol intake and blood pressure for men 40-69 years old living in urban Osaka (492 men) and in rural Akita (395 men), Japan, surveyed from 1975 to 1977. Both mean blood pressure and the prevalence of hypertension were related to alcohol intake in a graded fashion. Stepwise multiple regression also showed that both systolic and diastolic pressure were associated with alcohol intake independent of ponderosity index, serum cholesterol, triglycerides, hemoglobin, uric acid, smoking, and age. This cross-sectional study indicates a continuous--and not a threshold--relationship between alcohol and blood pressure, with the effect of even moderate consumption, e.g. 28-55 g per day (equivalent to about 2-4 U.S. drinks per day).

The impact of the metabolic syndrome and its components on the incidence of ischemic heart disease and stroke: the Japan public health center-based study.

In this study, we aimed to examine the impact of the metabolic syndrome and its components on the risk of cardiovascular disease among a relatively less-obese population. A total of 8249 men and 15 064 women, aged 40–69 years, with no history of ischemic heart disease, stroke and/or cancer completed a risk-factor survey between 1993 and 1995. The metabolic syndrome was defined based on modified criteria of the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) and the International Diabetes Federation (IDF). Systematic cardiovascular surveillance was carried out throughout 2003, and 693 events of ischemic heart disease and stroke were identified. We observed significant associations of the metabolic syndrome with the risk of ischemic heart disease and ischemic stroke, but not with hemorrhagic stroke. The multivariable hazard ratio (95% confidence interval) of ischemic heart disease among men for the metabolic syndrome based on the AHA/NHLBI criteria was 2.25 (1.44–3.51) and that of ischemic stroke was 1.88 (1.40–2.52). The respective hazard ratios for the metabolic syndrome based on the IDF criteria were 1.61 (0.99–2.64) for ischemic heart disease and 1.94 (1.41–2.68) for ischemic stroke. The population-attributable fraction (PAF) of the metabolic syndrome based on the AHA/NHLBI criteria was higher than that based on the IDF criteria: 19 vs. 12% (P for difference=0.003) for ischemic cardiovascular disease among men, because non-overweight men with ⩾2 risk factors were also at high risk (20% of the PAF). Our data suggest that the metabolic syndrome based on the AHA/NHLBI criteria predicts ischemic cardiovascular disease better than the syndrome based on the IDF criteria, because of the exclusion of non-overweight high-risk individuals from the reference group.

Dietary intake and serum total cholesterol level: their relationship to different lifestyles in several Japanese populations.

Serum total cholesterol level and dietary intake were surveyed 1975–1977 in six Japanese population groups with different lifestyles, including groups in both rural (Akita and Kochi) and urban (Osaka) areas. Clerical workers in Osaka, who had the most westernized lifestyle of all the study groups, had the highest mean serum total cholesterol level (202 mg/dl for men ages 40-49 and 50-59 years), while farmers in Akita had the lowest mean serum total cholesterol level (163 mg/dl for men 40-49 years old, 159 mg/dl for men 50-59 years old, 165 mg/dl for men 60-69 years old). Nutrient intake data for men ages 40-59 years showed 23% of calories from fat for clerical workers in Osaka, the highest among the study groups, whereas farmers in Akita showed a low level of 14%. The ratio of dietary polyunsaturated to saturated fatty acids was over 1.1 for all groups. Cholesterol intake was 339-487 mg/day. Total carbohydrate as a percentage of calories was 53-65%; 75-80% of carbohydrate energy was ingested from cereals. Sugar accounted for less than 3.5% of total calories.In the cross-group correlation analysis between dietary lipid intake and serum total cholesterol, a significant strong positive correlation was found between the dietary lipid factor (44 of Keys et al. and the mean serum total cholesterol level. A weak but significant correlation was observed between the dietary lipid factor and serum total cholesterol for individual inhabitants of Osaka.