Dietary and other risk factors for stroke in Hawaiian Japanese men

As part of an on-going longitudinal study, 7895 men of Japanese ancestry living on the island of Oahu, aged 45-68 and free of evidence of prior stroke at entry examination, have been followed by re-examinations and surveillance. During ten years of follow-up 154 men developed thromboembolic stroke, 65 developed intracranial hemorrhage, and 19 developed stroke of unknown type. There were 79 deaths attributed to stroke. The independent risk factors for thrombo-embolic stroke were elevated blood pressure, glucose intolerance, age, electrocardiographic evidence of left ventricular hypertrophy or strain, cigarette smoking and proteinuria. Attributes associated with increased risk of intracranial hemorrhage were age, elevated blood pressure, cigarette smoking, serum uric acid and, inversely, serum cholesterol level. Electrocardiographic evidence of left ventricular hypertrophy or strain significantly increased the risk of cerebral hemorrhage, but was not associated with subarachnoid hemorrhage. In univariate analysis, there was an inverse relation between dietary fat intake and thrombo-embolic and total stroke incidence. An inverse relation was also shown between protein intake and total stroke incidence. These dietary relations became statistically not significant in multivariate analysis. No relation was found between salt intake and the incidence of stroke.

The effect of partial gastrectomy on lipoproteins and other characteristics

Among 6860 50-77 year old men of Japanese ancestry examined in Honolulu 291 were known to have had a gastrectomy for benign gastric (189) or duodenal (102) ulcer, and 132 had documented peptic ulcer disease treated medically. Total serum cholesterol averaged 12 mg% lower in the surgical group than in the general population (p less than 0.01) while the medically treated men had intermediate values. Fasting lipoprotein determinations done in a sub-sample showed that the lower total cholesterol in the surgical group was due to depressed LDL, while HDL was higher in the operated men than in either the general population or the medically treated patients (p less than 0.01). The surgical patients were heavier users of cigarettes, beer and coffee and averaged about 10 lb. lighter than either the medically treated patients or the rest of the population. However, in multivariate analysis these differences did not not account for the differences in lipoproteins. A small decrement in blood pressure in the surgical patients as compared to the rest of the population became non-significant when weight and others factors were taken into account.

Ten-year incidence of coronary heart disease in the Honolulu Heart Program. Relationship to nutrient intake

Nutrient intake was determined in over 8000 men of Japanese ancestry residing on the island of Oahu. Nutrient determination took place at the initial examination during the years 1965-1968. This report relates nutrient intake to the risk of developing coronary heart disease in the 10 years subsequent to the initial examination. Men who developed coronary heart disease had a lower average intake of calories, carbohydrates, starch, and vegetable protein than men who remained free of coronary heart disease. Men who developed coronary heart disease also had a higher mean intake of percentage of calories from protein, fat, saturated fatty acids, and polyunsaturated fatty acids than men who remained free of coronary heart disease. These men also had a significantly lower mean percentage of calories from carbohydrates and a higher mean ingestion of cholesterol per 1000 calories than men who remained free of coronary heart disease. In multivariate analyses including age, systolic blood pressure, serum cholesterol, cigarettes smoked per day, and physical activity index, carbohydrates, vegetable protein, percentage of calories from saturated fatty acids, and percentage of calories from polyunsaturated fatty acids are no longer significantly related to incidence.

Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii and California: incidence of stroke in Japan and Hawaii

As part of the Ni-Hon-San Study, stroke incidence was compared in the Japan and Hawaii cohorts. Stroke cases were classified in two types, intracranial hemorrhage (ICH) and thrombo-embolic stroke (T-E). For each type the incidence in Japan was about three times as great as in Hawaii. The ratio ICH/T-E was 1/2.2 and 1/1.6 in Japan and Hawaii, respectively. Blood pressure was the most important risk factor, followed by age for total stroke in both Japan and Hawaii. Proteinuria was also a risk factor in Hawaii. Conversely, an index of animal food intake was inversely related to total stroke, significantly in Hawaii, and at a suggestive level for total and hemorrhagic stroke in Japan. Since the levels of blood pressure do not differ between Japan and Hawaii, one possible explanation for the large difference in stroke incidence between the two cohorts may be the fact that animal protein and saturated fat intake, which is inversely associated with stroke incidence, is much greater in Hawaii than in Japan. This explanation would support epidemiologic and experimental studies in Japan which suggest that dietary animal protein and fat exert an inhibitory effect on the incidence of stroke.

Cultural and biological inheritance of plasma lipids

A path analytic model for the analysis of nuclear family data is described and used to analyze the results of two major studies of cholesterol (CH) and triglyceride (TG), the Honolulu Heart Study (HHS) of Japanese-Americans and the Cincinnati Lipid Research Clinic (LRC) study of Caucasians. The studies were first analyzed separately to assess evidence for genetic and cultural transmission, marital resemblance, and maternal environmental effects for the two plasma lipids, and then simultaneously to identify the nature and sources of any between-study-heterogeneity. There were significant sources of heterogeneity between the two studies for CH (only marital environmental resemblance and non-transmitted sibling environmental resemblance) and for TG (only non-transmitted sibling environmental resemblance). The two studies were homogeneous with respect to the magnitude of genetic and cultural effects; for CH genetic heritability was estimated as h2 = .594 +/- .041 while cultural heritability was estimated as c2 = .035 +/- .008, and for TG the two heritabilities were estimated as h2 = .259 +/- .034 and c2 = .108 +/- .014. An additional bivariate analysis of the association between the two lipids revealed that all phenotypic resemblance could be explained in terms of an association of non-transmitted residual environments with little evidence for a genetic association. The relevance of these results for an understanding of the genetic epidemiology of plasma lipids is discussed.

Family resemblance for fasting blood glucose in a population of Japanese Americans

The pattern of inheritance of fasting blood glucose was examined in a Japanese cohort of 500 nuclear families living in Hawaii. A principal component of glucose was defined to improve the ranking of diabetics and individuals receiving treatment (medication and/or diet) for hyperglycemia, thereby allowing as well as possible for inability to determine untreated levels in patients. Results from path and segregation analysis show that family resemblance for glucose is low in this population. The additive variation can be explained by a cultural model of inheritance without introducing intergenerational differences, a maternal-paternal effect, or even genetic parameters. Heritability is approximately 0.125. Complex segregation analysis provides no convincing evidence for a major gene, with preliminary support based upon leptokurtic outliers in five families disappearing on further analysis by partial truncation. A claim by other workers of a major recessive gene for hyperglycemia may be due to their failure to allow for treatment, skewness, and multifactorial heritability. In future, the search for major loci acting on liability to hyperglycemia should use multiple determinations of fasting glucose or be addressed to more primary and repeatable variables than fasting blood glucose.

The relation of coronary disease, stroke, and mortality to weight in youth and in middle age

During ten years of follow-up 701 deaths occurred among 8006 45-68-year-old Honolulu Japanese men who were originally examined in 1965-68. Mortality was highest in both the leanest and fattest men and lowest in the fourth quintile of body mass index (BMI). The excess deaths in the top quintile were due primarily to coronary heart disease which was directly and positively related to BMI. In the bottom two quintiles excess mortality was due to cancer and "other" causes and was confined to men who had lost weight between age 25 and examination. This finding suggests that excess mortality in thin middle-aged men is due to occult antecedent disease rather than leanness per se. When BMI at age 25 was considered, men in the bottom quintile had the lowest mortality in middle age. It is concluded that upward revision of tables of desirable weight for young men would be unwarranted. A modest increase in the upper limit in middle-aged men may be justifiable, but the evidence is incomplete.

Glucose intolerance and nine-year mortality in Japanese men in Hawaii

The relationship between glucose intolerance and nine-year mortality was examined in a cohort of approximately 8,000 men of Japanese ancestry living in Hawaii who were 45 to 68 years of age at baseline examination. Age-adjusted mortality for death from all causes, cardiovascular disease, coronary heart disease and causes other than cardiovascular disease and cancer were significantly higher in men with glucose intolerance, defined by either medication for diabetes or 1-hour post-load serum glucose levels above the 90th percentile cut-point (225 mg/dl) at baseline examination, than in normoglycemic men. Although many cardiovascular risk factors were found to be associated with glucose intolerance, both post-load serum glucose level and medication for diabetes remained significant as risk factors for overall, cardiovascular and coronary death in multivariate logistic analysis in which confounding effects of age, blood pressure, serum cholesterol, body mass index and other important risk factors were taken into account.

Serum cholesterol and colon cancer incidence in Hawaiian Japanese men

A prospective study of cancer and coronary heart disease (CHD) in 8,006 Hawaiian Japanese men, aged 45-68 years, showed that serum cholesterol levels below 180 mg/dl predicted low rates of CHD and high rates of colon cancer. Men with colon cancer had lower mean serum cholesterol levels than did other members of the cohort, including those with cancer at other sites. The lowest serum cholesterol levels were obtained from men who died as a result of colon cancer. The lack of such an association with other cancers and the persistence of this inverse association in colon cancer patients diagnosed 5-9.9 years after examination suggest that the low serum cholesterol was not due to preexisting disease. Right colon tumors showed the strongest inverse association with serum cholesterol. The differences between CHD and colon cancer in respect to serum cholesterol indicate that different subsets of the westernized Japanese population are affected.

Comparison of methods for diagnosing angina pectoris: the Honolulu heart study

Data from the Honolulu Heart Study suggest that the examining physician's clinical diagnosis, based on questioning the subject about chest pain, was more sensitive than the Rose questionnaire in detecting angina pectoris in a population of Japanese men. The 2 methods appear equally specific for coronary heart disease.

Alcohol and cardiovascular disease: the Hawaiian experience

Data from the Honolulu Heart Program indicate that there is an inverse relation between alcohol intake (up to 60 oz of ethanol/month) and the risk of coronary heart disease incidence and mortality. Alcohol intake is positively related to levels of systolic and diastolic blood pressure and to hypertension as defined by the criteria of the World Health Organization. Alcohol intake is not related to the incidence of cerebral infarction, but is positively related to the incidence of hemorrhage. Alcohol intake is also related to mortality from cirrhosis of the liver and from various types of cancer.

Serum cholesterol and mortality in a Japanese-American population: the Honolulu Heart program

The authors have examined the relation of baseline serum cholesterol level to subsequent 9-year mortality in a cohort of Japanese-American men. The baseline serum cholesterol level was positively related to coronary heart disease mortality. It was inversely related to total cancer mortality and to mortality from cancers of the esophagus, colon, liver and lung and to malignancies of the lymphatic and hematopoietic system. When mortality in the first two years after examination was removed from consideration in an attempt to allow for existing clinical or subclinical disease, the inverse relation to cancer persisted but was statistically significant only for colon cancer and lung cancer among the common sites as well as for malignancies of the lymphatic and hematopoietic system. When known prevalence cases of cancer were eliminated from the computation, the inverse relation between cholesterol level and cancer mortality persisted significantly only for colon among the common cancer sites. The relation of baseline serum cholesterol level to total mortality in this cohort was quadratic; that is, there was an excess of deaths associated with serum cholesterol level at the high end of the distribution (mainly due to coronary heart disease) and at the low end (mainly due to cancer).

Diet and its relation to coronary heart disease and death in three populations

Baseline 24-hour dietary recalls from 16,349 men ages 45-64 years who had no evidence of coronary heart disease (CHD) were obtained in three prospective studies: the Framingham Study (859 men), the Honolulu Heart Study (7272 men) and the Puerto Rico Heart Health Program (8218 men). These men were followed for up to 6 years for the first appearance of CHD or death. Men who had a greater caloric intake or a greater caloric intake per kilogram of body weight were less likely to develop CHD manifest as myocardial infarction (MI) or CHD death, even though men of greater weight were more likely to develop CHD. This may reflect the benefit of greater physical activity. Men who consumed more alcohol were less likely to develop CHD, but more likely to die of causes other than CHD, particularly in the Honolulu study. In the Honolulu and Puerto Rico studies, but not in the Framingham study, men who consumed more starch were less likely to develop MI or CHD death. There was an inverse relation between starch intake and serum cholesterol, but it was too weak to explain fully the inverse starch-CHD association. There was also no evidence that the inverse relation between starch intake and incidence of CHD in the Honolulu and Puerto Rico studies was an indirect result of differences in fat intake. While the findings suggest additional areas for research, none of them would lead to an alteration of currently recommended preventive diets that emphasize lowering fat intake, because in isocaloric diets the logical way to balance a decreased fat intake is to increase the consumption of foods containing starch.

Effect of hydroxyapatite impregnation on skeletal bonding of porous coated implants

Skeletal fixation of permanent implants by new methods such as fixation by mechanical interlocking of bone with porous prosthetic coatings or chemical bonding with bioactive materials shows growing potential. This paper reports on the resulting skeletal fixation of a combined porous and bioactive material. Metal plugs with a porous metal fiber coating impregnated with hydroxyapatite were implanted for 2, 4, and 12 weeks and were compared to the parent porous, nonbioactive, metal fiber material. Statistical analysis of the interfacial failure shear stress, as obtained by mechanical testing, shows there is a marked influence of hydroxyapatite impregnation on the rate of bone ingrowth and the strength of the interfacial bond the few weeks following surgery. Microscopical examination reveals that the apparent stimulation of bone ingrowth into the surface pores of the implant is the reason for the increased rate of bond formation. The results are of particular clinical interest: with an increased rate of bone ingrowth, weight bearing might be allowed much earlier, thus reducing the recuperation period.

Alcohol and mortality: the Honolulu Heart Study

It has been shown previously that coronary heart disease was less likely to develop in Japanese men in Honolulu who drank alcoholic beverages than in those who abstained, and that the more they drank (up to about 60 ml/day of ethanol) the lower the risk. In this report on the same men, it is shown that the same sort of relation holds for mortality from coronary heart disease but that the reverse is true for death from cancer and from stroke. Men who drank were more likely to die from these causes than those who abstained, and the more they drank the greater the risk of death. Men who drank relatively large amounts were more likely to die from cirrhosis of the liver than other men. The resultant curve for total mortality is u-shaped, the lowest risk being for men who consumed from 1 to 10 ml/day of ethanol. Even at that low level of consumption, however, the risk of death from cancer or stroke was greater than it was for nondrinkers. In short, for this population of Japanese men, alcohol consumption appears to have some benefits and some hazards with regard to mortality, and the benefit or hazard depends on which cause of death is being considered.

Determinants of blood pressure in Japanese-American Families

Blood pressure gave evidence for genetic heritability (0.24 for systolic 0.19 for diastolic) and for cultural heritability (0.16 for systolic, 0.09 for diastolic in children) in a sample of Japanese-American families. A small but significant fraction of cultural inheritance was due to maternal effects, possibly mediated through dietary habits. There was no convincing evidence for major loci causing hypertension in this population, and the polymorphism proposed by Platt was excluded as a principal cause of hypertension.

Factors related to stroke incidence in Hawaii Japanese men. The Honolulu Heart Study

As part of an ongoing longitudinal study of coronary heart disease and stroke among Japanese men in Hawaii, 8,006 men of Japanese ancestry living on the island of Oahu and aged 45-68 at entry examination have been followed by reexamination and surveillance. One hundred and eleven were found to have evidence of prior stroke at the time of the initial examination. During a six-year follow up period of the remaining 7,895 men, 94 developed definite thromboembolic stroke, 33 definite intracranial hemorrhage, and 6 developed stroke of unknown type. The principal risk factors for thromboembolic stroke were: elevated blood pressure, glucose intolerance, age, and electrocardiography evidence of left ventricular hypertrophy or strain. Attributes associated with increased risk of intracranial hemorrhage were elevated blood pressure, electrocardiographic evidence of left ventricular hypertrophy or strain, and alcohol intake. Serum cholesterol level was negatively associated with risk of intracranial hemorrhage.