Atsushi Terao

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.

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.

Influences of daily physical labor on left ventricular dimensions in normotensive subjects

日常的な肉体労働の程度が異なると考えられる秋田, 大阪の4集団 (秋田農業従事者, 秋田事務職, 大阪現業職, 大阪事務職) に属する30～59歳男子正常血圧者471名を対象に, 超音波心臓検査を導入した循環器検診を実施し, 高血圧以外の要因として, 日常的な肉体労働が左室形態に及ぼす影響を検討した.左室形態を集団間で比較すると, 拡張末期左室内径, 心室中隔厚, 左室後壁厚の平均値は, 30～44歳, 45～59歳の両年齢群において, 秋田農業従事者が4集団の中で最も大であり, 大阪の2集団の間では, 現業職が事務職に比べて大であった. すなわち, 左室形態の値は肉体労働の程度が強いと考えられる集団ほど大きい傾向を認めた. また, 秋田農業従事者では, 30～44歳に比べ45～59歳の方が, 心室中隔厚, 左室後壁厚が有意に厚かった. これは長期間にわたる厳しい肉体労働の影響と考えられる.これらの地域間, 職種間の左室形態の差が, 高血圧の遺伝素因の差によってもたらされた可能性がある. そこで, 遺伝素因の影響を検討するために, 検診時の問診により両親の高血圧の有無を調べ, 両親の高血圧の有無による左室形態の差を比較した. その結果, 30～44歳の大阪事務職, 45～59歳の秋田農業従事者の左室後壁厚は, 高血圧の親を有する群は有しない群に比べ厚いことを認めたが, その他の集団, 年齢群では明らかな差を認めなかった. さらに, 秋田住民では, 両親の検診記録をもとに両親の高血圧の有無を調査し, 左室形態を比較した. 農業従事者, 事務職のいずれにおいても, 両親の高血圧の有無により拡張末期左室内径, 心室中隔厚, 左室後壁厚に有意の差を認めなかった.すなわち, 日常的な肉体労働は正常血圧者の左室形態に影響を与えること, そしてその影響は高血圧の遺伝素因によるものより大きいことを明らかにした.