Mitsunori Doi

Trends for coronary heart disease and stroke and their risk factors in Japan.

Disease surveillance and population surveys of risk characteristics in a northeast rural community of Japan (1965 census population, 7,030) are combined in an attempt to relate morbidity and risk factor trends for coronary heart disease and stroke during the last 2 decades. Between 1964 and 1983, the incidence of coronary heart disease (i.e., combined myocardial infarction, angina pectoris, and sudden death) did not change significantly among men and women ages 40-69, and was lower than that for stroke. The incidence of all stroke declined about 60% for both men and women, ages 40-69, with a significant decrease in cerebral hemorrhage for both sexes and in cerebral infarction for men. Between 1963-1966 and 1980-1983, significant upward shifts occurred in the means and distributions of serum total cholesterol and serum total protein in every age and sex group, primarily during the 1st decade. Age-adjusted mean cholesterol levels rose 22 mg/dl to the 1980-1983 mean of 179 mg/dl in men ages 40-69. In women ages 40-69, the mean rose 29 mg/dl to 192 mg/dl. Among nutrients, animal fat intake doubled in men ages 40-59 from 4.5% of daily calories in 1969 to 9.6% in 1980-1983. Animal protein intake also increased, from 5.8% to 7.1%. Most of this increase occurred between 1969 and 1972-1975 and may be attributable to an increased intake of meat, eggs and dairy products. From 1963-1966 to 1980-1983, mean relative weight index rose significantly for all age-sex groups except men ages 50-69. Mean systolic and diastolic blood pressure levels declined for every age-sex group, with a 15-mm Hg age-adjusted decrease in systolic, 4-mm Hg decrease in diastolic pressure among men ages 40-69, and a 11-mm Hg systolic and 4-mm Hg diastolic decrease for women. Two cohorts of men and women ages 40-69 at baseline were followed for disease incidence: an early cohort (2,257 persons) followed from 1963-1966 to 1973 and a later cohort (2,711 persons) followed from 1972-1975 to 1983. In these cohorts, significant risk prediction for cerebral hemorrhage and infarction was obtained with blood pressure level and end organ effects in the electrocardiogram and fundus photographs. Serum cholesterol was inversely associated with cerebral hemorrhage in the early cohort but not in the later.(ABSTRACT TRUNCATED AT 400 WORDS)

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).

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.

Left ventricular mass and subsequent blood pressure changes among middle-aged men in rural and urban Japanese populations.

BACKGROUND It has been suggested that echocardiographically determined left ventricular mass (LVM) is useful in the prediction of hypertension. To examine the relation between LVM and subsequent blood pressure (BP) change, a 6- to 8-year follow-up was conducted in adult Japanese men. METHODS AND RESULTS LVM was determined by M-mode echocardiography using the American Society of Echocardiography formula among 354 normotensive men aged 30 to 59 years from a rural community (n = 193) and from urban companies (n = 161) in Japan between 1979 and 1983. BP was remeasured 6 to 8 years after baseline in 148 rural men (77%) and 127 urban men (79%). For men whose BP was remeasured, the mean +/- SD LVM index (LVM/body surface area [g/m2]) at baseline was 117 +/- 22 in rural men and 99 +/- 15 in urban men (the difference, P < .001). For both populations, LVM index was positively associated with age and physical activity but not with body mass index. Associations of LVM index with usual alcohol intake and initial BPs were generally weak. According to linear regression analyses after controlling for these covariates at baseline, a 20-g/m2 greater LVM index at baseline was associated with a 5 mm Hg increase in systolic and a 4 mm Hg increase in diastolic BP during the subsequent 6 to 8 years for urban men. A 1-mm greater average ventricular wall thickness was associated with a similar BP increase. For rural men, positive associations of LVM index with BP increase existed but were weak. The weaker association between LVM index and BP increase in rural compared with urban men was probably the result of effects of higher physical activity, leading to a larger left ventricular internal dimension. The increase in systolic and diastolic BPs over the 6 to 8 years of observation was significantly related to baseline LVM index in rural and urban men with a smaller internal dimension (rural men, < or = 49 mm; urban men, < or = 47 mm) but not in those with larger dimensions. CONCLUSIONS An increased LVM index predicts subsequent BP increase in middle-aged normotensive men in the presence of a normal or small internal dimension.

Secular trends in atherosclerosis of coronary arteries and basal cerebral arteries in Japan. The Akita pathology study.

The atherosclerotic lesions of the coronary arteries and basal cerebral arteries in the circle of Willis were examined in the bodies of decreased men ages 30 and over who had been admitted to a local hospital in northeast Japan during 1966 to 1974 (243 men) and 1975 to 1984 (602 men). The autopsy rates during the two periods were 86% and 89%, respectively. The extent of atherosclerosis was determined blindly by one pathologist using a grading method of cross-sectional stenosis scoring for coronary arteries and Bakers method for basal cerebral arteries. The age-adjusted mean scores for atherosclerosis in the coronary arteries and basal cerebral arteries were 30% and 42% lower, respectively, in the 1975 to 1984 period than in the 1966 to 1974 period (p less than 0.001). There was also a fall in age-adjusted blood pressure levels at admission: 10 mm Hg for systolic and 4 mm Hg for diastolic blood pressure (p less than 0.001). The opposite trend was seen in mean serum cholesterol: a rise from 171 mg/dl to 177 mg/dl (p = 0.018). Linear regression analysis indicated that blood pressure was positively associated with both atherosclerosis scores, controlling for age and serum cholesterol in both time periods (p less than 0.001). The association of serum cholesterol with the atherosclerosis scores was positive in both periods and statistically significant in 1975 to 1984. Similar findings were obtained when the analyses were conducted for cardiovascular disease (myocardial infarction and stroke) and for noncardiovascular disease, separately.(ABSTRACT TRUNCATED AT 250 WORDS)

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.