Masahiko Kiyama

Carotid Intima-Media Thickness and Plaque Characteristics as a Risk Factor for Stroke in Japanese Elderly Men

Background and Purpose— Few cohort studies have examined the association of carotid intima-media thickness (IMT) and plaque characteristics with the risk of stroke in apparently healthy persons. We examined the relationship of carotid IMT and the surface, morphology, and calcification of carotid plaques with the incidence of stroke among Japanese men. Methods— Carotid IMT and plaque were evaluated bilaterally with ultrasonography in 1289 men aged 60 to 74 years without a previous stroke or coronary heart disease. In this cohort, the subsequent incidence of stroke was investigated. Results— During the 4.5-year follow-up, 34 strokes occurred. The multivariate-adjusted relative risk (95% CI) for the highest versus lowest quartiles of maximum IMT of the common carotid artery (CCA; ≥1.07 versus ≤0.77 mm) was 3.0 (1.1 to 8.3) for stroke. The combination of CCA and internal carotid artery (ICA) wall thickness was a better predictor of the risk of stroke than was CCA wall thickness alone. Men with a plaque, defined as a focal wall thickness of ≥1.5 mm, in the ICA had a 3-fold higher risk of stroke than those without a plaque, and the plaque surface irregularity further increased the stroke risk. A significant excess risk of stroke was confined to men with an uncalcified plaque. Conclusions— Increased IMT of the CCA and an uncalcified plaque in the ICA, as assessed by ultrasonography, are risk factors for stroke in elderly Japanese men.

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.

Metabolic Syndrome and the Risk of Ischemic Heart Disease and Stroke Among Japanese Men and Women

Background and Purpose— Limited evidence was available on the metabolic syndrome and risk of cardiovascular disease in Asia. The purpose of this study is to examine the association of the metabolic syndrome and risk of ischemic cardiovascular disease in Japanese men and women. Methods— We conducted an 18-year prospective study of 9087 Japanese people aged 40 to 69 years (3595 men and 5492 women), initially free of ischemic heart disease or stroke. During follow-up, there were 116 (74 men and 42 women) cases of ischemic heart disease and 256 (144 men and 112 women) ischemic strokes. Metabolic syndrome was defined by the modified criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATPIII), with the presence of ≥3 of the following factors: (1) serum triglycerides ≥1.69 mmol/L (150 mg/dL); (2) HDL-cholesterol <1.03 mmol/L (40 mg/dL) for men and <1.29 mmol/L (50 mg/dL) for women; (3) glucose ≥6.11 mmol/L (110 mg/dL) fasting or ≥7.77 mmol/L (140 mg/dL) nonfasting, or on treatment; (4) blood pressure ≥130/85 mm Hg or medication use, and (5) body mass index ≥25.0 kg/m2. Results— For both sexes, high blood pressure, high triglycerides and low HDL cholesterol were associated with increased risks of ischemic heart disease or stroke after adjustment for cardiovascular risk factors. A dose-response relationship was found between the number of metabolic risk factors and incidence of these cardiovascular end points. The multivariable hazard ratio (95% CI) associated with metabolic syndrome was 2.4 (1.4 to 4.0) in men and 2.3 (1.2 to 4.3) in women for ischemic heart disease, and 2.0 (1.3 to 3.1) and 1.5 (1.0 to 2.3), respectively, for ischemic stroke. The contribution of metabolic syndrome to the risks was independent of serum total cholesterol levels but stronger among smokers. Conclusions— The metabolic syndrome is a major determinant of ischemic cardiovascular disease among middle-aged Japanese men and women, in particular among smokers.

The joint impact on being overweight of self reported behaviours of eating quickly and eating until full: cross sectional survey.

Objective To examine whether eating until full or eating quickly or combinations of these eating behaviours are associated with being overweight. Design and participants Cross sectional survey. Setting Two communities in Japan. Participants 3287 adults (1122 men, 2165 women) aged 30-69 who participated in surveys on cardiovascular risk from 2003 to 2006. Main outcome measures Body mass index (overweight ≥25.0) and the dietary habits of eating until full (lifestyle questionnaire) and speed of eating (validated brief self administered questionnaire). Results 571 (50.9%) men and 1265 (58.4%) women self reported eating until full, and 523 (45.6%) men and 785 (36.3%) women self reported eating quickly. For both sexes the highest age adjusted mean values for height, weight, body mass index, and total energy intake were in the eating until full and eating quickly group compared with the not eating until full and not eating quickly group. The multivariable adjusted odds ratio of being overweight for eating until full was 2.00 (95% confidence interval 1.53 to 2.62) for men and 1.92 (1.53 to 2.40) for women and for eating quickly was 1.84 (1.42 to 2.38) for men and 2.09 (1.69 to 2.59) for women. The multivariable odds ratio of being overweight with both eating behaviours compared with neither was 3.13 (2.20 to 4.45) for men and 3.21 (2.41 to 4.29) for women. Conclusion Eating until full and eating quickly are associated with being overweight in Japanese men and women, and these eating behaviours combined may have a substantial impact on being overweight.

Alcohol Intake and the Risk of Cardiovascular Disease in Middle-Aged Japanese Men

BACKGROUND AND PURPOSE Understanding the effects of alcohol intake on stroke and other cardiovascular diseases is an important issue for public health. METHODS A 10.5-year prospective study of the relationship between alcohol intake and cardiovascular disease incidence was conducted in 2890 men, aged 40 to 69 years and free of a history of stroke and coronary heart disease, in three rural communities of Japan. RESULTS One hundred seventy-eight strokes (40 intracerebral hemorrhages, 18 subarachnoid hemorrhages, 104 nonhemorrhagic strokes, and 16 unclassified strokes), 34 coronary heart disease events, and 19 sudden unclassified deaths occurred. Drinkers of > or = 70 g/d ethanol had an approximately 2.5 times higher age-adjusted risk of all stroke than never-drinkers; the excess risk was more evident for hemorrhagic stroke than nonhemorrhagic stroke. When hypertension category, serum total cholesterol level, cigarette smoking, and diabetes mellitus were taken into account, these excess risks were reduced but remained significant for all stroke (2.0; 95% confidence interval, 1.3 to 3.1) and hemorrhagic stroke (3.4; 95% confidence interval, 1.2 to 9.2). A J-shaped relationship was suggested between alcohol intake and risk of nonhemorrhagic stroke; drinkers of < 42 g/d ethanol had a slightly lower risk and heavy drinkers had a higher risk than never-drinkers. Current drinkers had a slightly lower risk of coronary heart disease than never-drinkers, although the risk difference was not statistically significant. The age-adjusted risk of sudden death was 10 times higher in heavy drinkers than never-drinkers, and the excess risk did not change when the covariates were controlled for. Total cardiovascular disease showed a similar pattern as did all stroke. CONCLUSIONS Heavy drinking appeared to increase the risk of hemorrhagic stroke, in part due to hypertension, and to increase the risk of sudden death, which was probably due to drinking per se. Light or moderate alcohol consumption seemed to protect against nonhemorrhagic stroke and coronary heart disease.

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

Effects of Habitual Alcohol Intake on Ambulatory Blood Pressure, Heart Rate, and Its Variability Among Japanese Men

We sought to examine effects of habitual alcohol intake on ambulatory blood pressure (BP), heart rate (HR), and HR variability among Japanese men. Subjects were 539 men aged 35 to 65 years from rural and urban communities. Ambulatory BP and HR were monitored with an automated, portable, noninvasive multibiomedical recorder. Power spectral analysis of the RR intervals on the ECG was performed every 5 minutes. Compared with nondrinkers, moderate drinkers (alcohol intake 23 to 45 g/d) and heavy drinkers (alcohol intake ≥46 g/d) showed higher age- and field-adjusted mean values of systolic and diastolic BPs during the morning and while awake, but there were no differences in BPs over 24-hour periods and while asleep among the alcohol intake categories. Alcohol intake was positively associated with mean values of sleep-morning differences and daytime variability in BPs, HRs while awake and asleep, and low frequency:high frequency ratio while asleep. The results were virtually unchanged after adjustment for body mass index, smoking, and diabetes mellitus. Compared with the nondrinkers, age- and field-adjusted odds ratios of the morning BP surge (excess elevation of BP in the morning: morning systolic BP minus sleep systolic BP ≥37 mm Hg) for light (alcohol intake 0 to 22 g/d), moderate, and heavy drinkers were 0.96 (95% CI: 0.34 to 2.78), 1.68 (95% CI: 0.64 to 4.38), and 2.73 (95% CI: 1.12 to 6.67), respectively. Habitual alcohol intake was associated with increased BP in the morning, HR while awake and asleep, and sympathetic activity while asleep, which may explain some of the mechanisms of the relationship between heavy alcohol intake and risk of cardiovascular diseases.

Trends for Blood Pressure and Its Contribution to Stroke Incidence in the Middle-Aged Japanese Population The Circulatory Risk in Communities Study (CIRCS)

BACKGROUND AND PURPOSE Hypertension is a major risk factor for stroke. However, a substantial decrease in blood pressure levels in Japanese during the past 3 decades may have reduced contributions of hypertension to risk of stroke. The population attributable fraction, the percentage of outcomes attributable to exposure, of blood pressure for the incidence of stroke was investigated during 3 survey periods between 1963 and 1994 by means of a population-based cohort study. METHODS We explored 3 cohort data of residents aged 40 to 69 years in 4 Japanese communities in 1963 to 1971 (n=5439), 1975 to 1984 (n=9945), and 1985 to 1994 (n=11 788) baseline surveys. Mean follow-up period for each cohort was 10 years. RESULTS Higher blood pressure levels were associated with higher risk of stroke. Positive associations were also observed even within nonhypertension levels. From the first to the third cohorts, the blood pressure category with a majority of stroke incidence shifted from severe or moderate hypertension to mild hypertension. The population attributable fraction of the severe hypertension category in the first, second, and third cohorts were 20%, 14%, and 9%, respectively, and those of the moderate hypertension category were 19%, 24%, and 11%, respectively, whereas those of the mild hypertension category were 17%, 26%, and 23%, respectively. The results were similar when participants on antihypertensive medication were excluded. CONCLUSIONS The higher risk of stroke incidence with higher blood pressure levels even in nonhypertension categories and the shift of stroke burden from severe/moderate hypertension to mild hypertension support the early management of hypertension and primary prevention of high blood pressures for the prevention of stroke.

Proportions of Stroke Subtypes Among Men and Women ≥40 Years of Age in an Urban Japanese City in 1992, 1997, and 2002

Background and Purpose— Higher proportions of hemorrhagic stroke and lacunar infarction were reported in rural Japan compared with those in Western countries. We examined the relative proportions of stroke subtypes in an urban Japanese city where westernized lifestyles are more common than in rural areas. Methods— Stroke registration was performed in 1992, 1997, and 2002 for residents ≥40 years of age who were admitted with acute strokes to all of the 10 hospitals with ≥90 beds in Yao City, Osaka, Japan. Strokes were classified as intraparenchymal hemorrhage, subarachnoid hemorrhage, or ischemic strokes (embolic infarction, large-artery occlusive infarction, lacunar infarction, and unclassified thrombotic infarction) by criteria using computed tomography or MRI. Results— A total of 650 first-ever strokes were registered. The age-adjusted proportion of each stroke subtype was not significantly different among the 3 study periods in both men and women. Throughout the 3 periods, intraparenchymal hemorrhage, subarachnoid hemorrhage, and ischemic stroke accounted for 26%, 7%, and 65% in men, respectively. In women, the respective proportions were 29%, 21%, and 44%. The proportion of each subtype for total ischemic strokes was as follows: 51% to 61% lacunar infarction, 25% to 26% large-artery occlusive infarction, and 11% to 17% embolic infarction. Conclusions— Our study showed that hemorrhagic stroke represented a large proportion of all strokes, especially among women, and lacunar infarction was the most common subtype of ischemic stroke among both men and women in Yao City, which differed from findings in Western countries.

Serum total cholesterol and mortality in a Japanese population

Although the relation between serum total cholesterol and coronary heart disease is well established, the relation with mortality from non-coronary disease is controversial. Inverse relations of serum cholesterol with hemorrhagic stroke and cancer have stimulated the examination of cholesterol-non-coronary mortality associations. The population surveyed is 12,187 men and women aged 40-69 years living in Yao City, a suburb of Osaka, who undertook baseline examinations between 1975 and 1984 and had no history of stroke and coronary heart disease at baseline. The subjects were followed on average 8.9 years until the end of 1988 using systematic mortality surveillance. During the follow-up, there were 343 deaths, comprising 170 cancer deaths (International Classification of Death 9th edition: ICD-9, 140-239), 21 coronary heart disease deaths (ICD-9, 410-414), 67 other cardiovascular deaths (ICD-9, 390-458 excluding 410-414), and 85 non-cardiovascular, non-cancer deaths. There was a significant inverse association of serum cholesterol with total and cancer mortality for men, and no significant association for women. The cholesterol-disease association, although not significant, was positive for coronary heart disease and other cardiovascular disease deaths, and inverse for non-cardiovascular, non-cancer deaths in both sexes. The inverse association of serum cholesterol with total and cancer mortality for men remained significant after controlling for age, job classification, hypertension category, usual alcohol intake, cigarette smoking, and relative weight index.(ABSTRACT TRUNCATED AT 250 WORDS)