Japanese Men In Japan Research Articles

Language Choice in Intermarriages Indonesian and Japanese: Indonesian Wife's Life Story Study on Language Inheritance in Japan

This study aims to determine the language choice of intermarriage families of Indonesian women and Japanese men in Japan, the factors that determine the language choice, and the implications of language choice. The informants of this study are 8 Indonesian wives who married Japanese men living in Japan. The analysis results show that the primary language used at home is that Japanese wives have a dominant role in determining the language choice in the family. The informants’ mother tongue was deficient and used only in certain situations, namely when angry and joking. This causes children to have difficulty communicating with Indonesian families. Several factors determining the language choice in intermarriage families include residence, wife and husband's language skills, enthusiasm and effort to convey the Indonesian wife's mother tongue to children, Japanese family support, knowledge of language education for children, attitude towards language, psychological situation, and child development. Indonesian wives need knowledge of bilingual education so that children can communicate in Indonesian and Japanese. Therefore, in intermarriages, primary marriages of Indonesian wives and Japanese husbands in Japan, where the environment, facilities, and opportunities to learn Indonesian are limited, it is necessary to plan and discuss with partners how to use the language at home, language education for children, and extra effort if Indonesian wives want the children to have bilingual abilities or to be able to communicate in both the Indonesian and Japanese.

Cross-Sectional Comparison of Coronary Artery Calcium Scores Between Caucasian Men in the United States and Japanese Men in Japan: The Multi-Ethnic Study of Atherosclerosis and the Shiga Epidemiological Study of Subclinical Atherosclerosis

The incidence of coronary heart disease in the United States has declined, and prevalences of several coronary disease risk factors have become comparable to those in Japan. Therefore, the burden of coronary atherosclerosis may be closer among younger persons in the 2 countries. We aimed to compare prevalences of coronary atherosclerosis, measured with coronary artery calcium scores, between men in the 2 countries by age group (45-54, 55-64, or 65-74 years). We used community-based samples of Caucasian men in the United States (2000-2002; n = 1,067) and Japanese men in Japan (2006-2008; n = 832) aged 45-74 years, stratifying them into groups with 0, 1, 2, or ≥3 of the following risk factors: current smoking, overweight, diabetes, dyslipidemia, and hypertension. We calculated adjusted odds ratios of US Caucasian men's having Agatston scores of ≥10, ≥100, and ≥400 with reference to Japanese men. Overall, the odds of Caucasian men having each Agatston cutoff point were greater. The ethnic difference, however, became smaller in younger age groups. For example, adjusted odds ratios for Caucasian men's having an Agatston score of ≥100 were 2.05, 2.43, and 3.86 among those aged 45-54, 55-64, and 65-74 years, respectively. Caucasian men in the United States had a higher burden of coronary atherosclerosis than Japanese men, but the ethnic difference was smaller in younger age groups.

Abstract P039: Brachial-ankle Pulse Wave Velocity is Independently Associated with Presence of Coronary Calcification among 1131 Healthy Middle-aged Men. The ERA JUMP Study

Objective: In an international population-based cross-sectional study among men aged 40-49 years, we examined the association between brachial-ankle pulse wave velocity (baPWV): a biomarker of combined arterial stiffness of central and peripheral arteries, and the presence of coronary artery calcification (CAC). Methods: Out of 1,335 men without clinical cardiovascular disease recruited during 2002-06, a total of 204 participants taking anti-hypertensive medications, or having missing data were excluded. Remaining participants were 281 Whites and 83 Blacks in Pittsburgh, 235 Japanese Americans in Honolulu, 280 Koreans in Ansan, South Korea, and 292 Japanese in Kusatsu, Japan. baPWV was measured using automated waveform analyzer (VP2000, Omron, Japan). Intra-class correlations of baPWV within and between technicians were 0.97 and 0.91 respectively. CAC was determined using electron-beam computed tomography (Imatron C-150) at all centers; all images were read at University of Pittsburgh by trained staff. Using logistic regression, presence of CAC (≥ 10 Agatston Units) was evaluated with increasing baPWV as a predictor variable (per 100 cm/s; per 1 SD change). Results: Prevalence of CAC among individual racial groups was Whites (25%), Blacks (16%), Japanese Americans (28%), Japanese (10%), and Koreans (10%). Overall, increased baPWV was significantly associated with presence of CAC in unadjusted model (Odds ratio=1.31, 95% CI 1.20, 1.44) as well as multivariable adjusted model (Odds ratio=1.19, 95% CI 1.06, 1.35). There was no effect-modification by race in the models. Similar odds ratios for presence of CAC with increasing baPWV were seen for individual races, but were statistically non-significant among Japanese American men and Japanese men in Japan, possibly due to inadequate power. Conclusion: Increasing baPWV is associated with presence of CAC, independent of other cardiovascular disease risk factors.

Abstract P317: Serum Soy Isoflavones Are Inversely Associated With Coronary Artery Calcification In A Population-based Sample Of 299 Men In Japan

Objectives: Epidemiological studies in Asia where consumption of soy isoflavones (ISF) are regular and high implicated that isoflavones are protective against coronary heart disease (CHD), especially in post-menopausal women. There is a lack of data on the association of isoflavones with atherosclerosis, especially in men. We aim to determine a cross sectional association of serum ISF with coronary artery calcification (CAC) in men in Japan. Methods: A population-based sample of 299 men aged 40-49 years in Japan was examined for CAC and other risk factors in 2002-06. Electron-beam CT was used to evaluate CAC. Stored serum samples were analyzed for ISF (genistein and daidzein). We defined serum ISFs as the sum of genistein and daidzein. Presence of CAC was defined as coronary calcium score ≥ 10. Because the distribution of serum ISF is skewed, we evaluated quartile of serum ISF and analyzed the association of ISF with the presence of CAC using a general linear model. Findings: The median value (interquartile range) of ISF was 517 (195, 1,147) nM/l. Serum ISF had a significant inverse association with CAC in crude analysis. After adjusting for age, LDL-C, smoking, and BMI, each of which had a significant univariate association with CAC, the inverse association of ISF with CAC remained, with littel change in point estimates. After further adjusting for other risk factors as well as serum levels of long-chain n-3 polyunsaturated fatty acids, the inverse association remained. Conclusions: Serum levels of ISF in Japanese men in Japan had an inverse association of CAC, suggesting that ISF at the levels Japanese in Japan regularly consume have anti-atherogenic properties in men.

Long chain n-3 polyunsaturated fatty acids and incidence rate of coronary artery calcification in Japanese men in Japan and white men in the USA: population based prospective cohort study

ObjectiveTo determine whether serum concentrations of long chain n-3 polyunsaturated fatty acids (LCn3PUFAs) contribute to the difference in the incidence rate of coronary artery calcification (CAC) between Japanese men in...

Abstract P446: Comparison of Markers Related to Insulin Resistance between US Caucasian Men and Japanese Men in Japan

Introduction: Although Asians including Japanese are more susceptible to developing type 2 diabetes (T2DM) compared to Caucasians, no previous studies have compared levels of insulin resistance between Japanese and Caucasians with the gold standard method, i.e., euglycemic glucose clamp. We have previously reported that levels of atherosclerosis are significantly lower in middle-aged men in Japan than US Caucasian after adjusting for risk factors including body-mass index (BMI). We hypothesized that Japanese men in Japan are less insulin resistant than Caucasian men and compared markers related to insulin resistance in these two groups. Methods: Population-based samples of 623 randomly selected men aged 40-49 years (313 Japanese men from Kusatsu, Shiga Japan and 310 Caucasian men from Allegheny County, PA) without clinical CVD were examined. We excluded 31 men with T2DM. Using ANCOVA, adjusting for BMI, we evaluated the following markers related to insulin resistance in the two populations: HOMA-IR, non-esterified fatty acids (NEFA), adiponectin, HDL-C, triglycerides, CRP, plasminogen-activator inhibitor 1 (PAI-1), systolic blood pressure (BP), and other risk factors (Table). Results: After adjusting for BMI, HOMA-IR, the most widely used marker of insulin resistance, was not statistically different between the two groups (Table). Among 19 variables compared, the results of NEFA, CRP, fibrinogen and HLD-P supported the hypothesis that Japanese are less insulin resistant. In contrast the results of adiponectin, PAI-1, triglycerides, total LDL-P, small LDL-P and systolic BP suggest that Japanese are more insulin resistant. Results of HOMA-β% and disposition index suggest that Japanese secrete less insulin than Caucasians. Conclusion: It is inconclusive whether Japanese are less insulin resistant than Caucasians based on comparisons of markers related to insulin resistance. Our data also suggest that Japanese as compared to Caucasians may secrete less insulin at the same levels of insulin resistance.

Commentary: Shaper and Jones, 'Serum-cholesterol, diet and coronary heart-disease in Africans and Asians in Uganda': 50-year-old findings only need interpretational fine tuning to come up to speed!

Commentary: Shaper and Jones, 'Serum-cholesterol, diet and coronary heart-disease in Africans and Asians in Uganda': 50-year-old findings only need interpretational fine tuning to come up to speed!

The unexpected emotional similarities and behavioral differences of Japanese men experiencing parenthood in Japan and the USA

The purpose of this study was to understand the impact of childbirth and the experience of fatherhood on Japanese men in Japan and a foreign country. Descriptive phenomenology was used to study a total of 14 Japanese men who attended childbirth and experienced parenting in the United States and Japan. The Colaizzi method of data analysis was used to analyze responses to open-ended questions. Responses to these questions showed several similarities between the two groups of men. First, men in both countries felt closer to with their spouses having gone through the experience of childbirth together. Second, both groups nevertheless recognized a strong bond between mother and the baby, leading them to feel at times isolated. Third, both groups were concerned about their wives’ emotional swings during pregnancy and child rearing. Finally, both groups were more focused on their wives and babies than themselves. There were also several interesting differences. Japanese men who were living in Hawaii were more involved in taking care of their children and in helping with household chores than those living in Japan. This was due to living in a more family-oriented society, as well as a result of limited support from their extended families back in Japan. A result of spending more time with their wives and babies was that Japanese men in the United States understood more fully the stress of childcare. On the other hand, due to Japan’s work-oriented society, men in Japan relied more on support from their extended families, leaving them less time with their wives and children. This study clearly shows that social support systems alter gender roles and behavior, leading to significant differences in the experience of parenthood in Japan and a foreign country.

Associations of D-dimer and von Willebrand factor with atherosclerosis in Japanese and white men.

D-dimer and von Willebrand factor (vWF) are associated with atherosclerosis. We recently reported that in a post-World War II birth cohort, Japanese men in Japan had lower levels of atherosclerosis than white men in the United States (U.S.). We examined whether the differences in D-dimer and vWF levels are associated with differences in atherosclerosis between the two populations. Population-based samples of 99 Japanese and 100 white American men aged 40-49 years were examined for coronary artery calcification (CAC), carotid intima-media thickness (IMT), D-dimer, vWF, and other factors using a standardized protocol. When compared to white American men,Japanese had similar levels of D-dimer (0.22 +/- 0.28 vs. 0.19 +/- 0.24 microg/L, respectively, P = 0.39) but significantly higher levels of vWF (124.1 +/- 36.6 vs. 91.3 +/- 48.8%, respectively, P < 0.01). Japanese as compared to white American men had significantly lower prevalence of CAC (13.1 vs. 28.0%, P < 0.01, respectively) and significantly lower IMT (0.61 +/- 0.07 vs. 0.66 +/- 0.08 mm, P < 0.01, respectively). Japanese men had a significant positive association of D-dimer with the prevalence of CAC and a negative association of vWF with IMT, whereas white American men did not have any significant associations. In men aged 40-49 years, Japanese as compared to white Americans had similar levels of D-dimer and higher levels of vWF although Japanese had a significantly lower prevalence of CAC and IMT. These haemostatic factors are unlikely to explain the difference in atherosclerosis in these populations.

Associations of D-dimer and von Willebrand factor with atherosclerosis in Japanese and white men

Objective — D-dimer and von Willebrand factor (vWF) are associated with atherosclerosis. We recently reported that in a post-World War II birth cohort, Japanese men in Japan had lower levels of atherosclerosis than white men in the United States (US).We examined whether the differences in D-dimer and vWF levels are associated with differences in atherosclerosis between the two populations.Methods and results — Population-based samples of 99 Japanese and 100 white American men aged 40-49 years were examined for coronary artery calcification (CAC), carotid intima-media thickness (IMT), D-dimer, vWF, and other factors using a standardized protocol.When compared to white American men, Japanese had similar levels of D-dimer (0.22 ± 0.28 vs. 0.19 ± 0.24 mg/L, respectively, P= 0.39) but significantly higher levels of vWF (124.1 ± 36.6 vs. 91.3 ± 48.8%, respectively, P < 0.01). Japanese as compared to white American men had significantly lower prevalence of CAC (13.1 vs. 28.0%, P < 0.01, respectively) and significantly lower IMT (0.61 ± 0.07 vs. 0.66 ± 0.08 mm, P < 0.01, respectively). Japanese men had a significant positive association of D-dimer with the prevalence of CAC and a negative association of vWF with IMT, whereas white American men did not have any significant associations.Conclusions — In men aged 40-49 years, Japanese as compared to white Americans had similar levels of D-dimer and higher levels of vWF although Japanese had a significantly lower prevalence of CAC and IMT. These haemostatic factors are unlikely to explain the difference in atherosclerosis in these populations.

Risk Factor Effects and Total Mortality in Older Japanese Men in Japan and Hawaii

We sought to identify factors related to total mortality in older Japanese men in Japan and Hawaii. Baseline data were collected from 1980 to 1982 in 1379 men in Hawaii and 954 men in Japan. Ages ranged from 61 to 81 years, with mortality follow-up during a 19-year period. Compared with Japan, men in Hawaii had a 2-fold excess of diabetes and a 4-fold excess of prevalent coronary heart disease (P < .001). Total cholesterol and body mass index were also greater in Hawaiian men (P < .001). In contrast, men in Japan had greater systolic blood pressure and were nearly 3 times more likely to smoke cigarettes (P < .001). Although each cohort had elements of a poor risk factor profile, there was a 1.4-fold excess in the risk of death in Japan (49.4 vs. 36.2/1,000 person-years, P < .001). Although mortality was similar after risk factor adjustment, only blood pressure and cigarette smoking accounted for the higher risk of death in Japan. Cigarette smoking and hypertension explain much of the excess mortality in Japan versus Hawaii. In this comparison of genetically similar cohorts, evidence further suggests that Japanese in Japan are equally susceptible to develop the same adverse risk factor conditions that exist in Hawaii.

Coronary Artery Calcification in Japanese Men in Japan and Hawaii

Explanations for the low prevalence of atherosclerosis in Japan versus the United States are often confounded with genetic variation. To help remove such confounding, the authors compared coronary artery calcification (CAC), a marker of subclinical atherosclerosis, between Japanese men in Japan and Japanese men in Hawaii. Findings were based on risk factors and CAC measured from 2001 to 2005 in 311 men in Japan and 300 men in Hawaii. Men were aged 40-50 years and without cardiovascular disease. After age adjustment, there was a threefold excess in the odds of prevalent CAC scores of > or = 10 in Hawaii versus Japan (relative odds = 3.2, 95% confidence interval: 2.1, 4.9). Whereas men in Hawaii had a generally poorer risk factor profile, men in Japan were four times more likely to smoke cigarettes (49.5% vs. 12.7%, p < 0.001). In spite of marked risk factor differences between the samples, none of the risk factors explained the low amounts of CAC in Japan. After risk factor adjustment, the relative odds of CAC scores of > or = 10 in Hawaii versus Japan was 4.0 (95% confidence interval: 2.2, 7.4). Further studies are needed to identify factors that protect against atherosclerosis in Japanese men in Japan.

Less Subclinical Atherosclerosis in Japanese Men in Japan than in White Men in the United States in the Post-World War II Birth Cohort

Coronary heart disease incidence and mortality remain very low in Japan despite major dietary changes and increases in risk factors that should have resulted in a substantial increase in coronary heart disease rates (Japanese paradox). Primary genetic effects are unlikely, given the substantial increase in coronary heart disease in Japanese migrating to the United States. For men aged 40-49 years, levels of total cholesterol and blood pressure have been similar in Japan and the United States throughout their lifetimes. The authors tested the hypothesis that levels of subclinical atherosclerosis, coronary artery calcification, and intima-media thickness of the carotid artery in men aged 40-49 years are similar in Japan and the United States. They conducted a population-based study of 493 randomly selected men: 250 in Kusatsu City, Shiga, Japan, and 243 White men in Allegheny County, Pennsylvania, in 2002-2005. Compared with the Whites, the Japanese had a less favorable profile regarding many risk factors. The prevalence ratio for the presence of a coronary calcium score of > or =10 for the Japanese compared with the Whites was 0.52 (95% confidence interval: 0.35, 0.76). Mean intima-media thickness was significantly lower in the Japanese (0.616 mm (standard error, 0.005) vs. 0.672 (standard error, 0.005) mm, p < 0.01). Both associations remained significant after adjusting for risk factors. The findings warrant further investigations.

Proteomic analysis of cancer tissues: Shedding light on carcinogenesis and possible biomarkers

Lung, gastric, colorectal, pancreatic, and esophageal cancers, as well as hepatocellular carcinoma (HCC), were the six most common and highly fatal cancers for Japanese men in Japan in 2003, while for women uterine cervical cancer could also be added to this list. To identify diagnostic or therapeutic biomarkers for these cancers, investigators are nowadays performing proteomic analyses of cancer tissues and cells, and revealing a large number of molecules which are diagnostic, prognostic and informative of carcinogenesis. From reports of proteomic analyses of cancerous tissues and noncancerous tissues sampled from HCC, and pancreatic, esophageal, gastric, colorectal, lung and uterine cervical cancers, we classified the proteins into digestive enzymes, growth factors, cell adhesion molecules, calcium-binding proteins, proteases, protease inhibitors, transporter proteins, structural molecules, apoptosis inhibitor, molecular chaperone, as well as proteins related to cell growth, cell differentiation, cell transformation, tumor invasion, carcinogen metabolism, and others. The aim of this study was to understand carcinogenesis of major cancers from a proteomics perspective using samples from cancer patients, and to elucidate their tumor biomarkers.

Relation of long chain n-3 polyunsaturated fatty acid intake to serum high density lipoprotein cholesterol among Japanese men in Japan and Japanese–American men in Hawaii: the INTERLIPID study

Epidemiologic evidence shows an inverse relationship between fish consumption and coronary heart disease (CHD) mortality. Associations between dietary intake of long chain n-3 polyunsaturated fatty acids (PUFA) and serum high density lipoprotein (HDL) cholesterol concentration are unknown. In this study, the association between n-3 PUFA (eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA)) intake and serum HDL cholesterol among Japanese men and women in Japan and Hawaii was examined. The study population consisted of Japanese ancestries from five research centers of the International Study of Macronutrients and Blood Pressure (INTERMAP) study, in Japan and Hawaii (672 men and 676 women), surveyed between 1996 and 1998. Four 24-h dietary recalls and one set of serum lipid measurements were performed. For men, n-3 PUFA intake and HDL cholesterol were higher in Japan than in Hawaii (n-3 PUFA: 1.32 g/day versus 0.47 g/day, p < 0.001). For women, n-3 PUFA intake was higher in Japan than in Hawaii ( p < 0.001) but HDL cholesterol was not significantly different ( p = 0.752). After adjustment for age, body mass index, physical activity, number of cigarettes per day, alcohol intake, and hormone replacement therapy (for women), n-3 PUFA intake was positively associated with serum HDL cholesterol in men (4.6 mg/dl higher HDL cholesterol with 1%kcal higher n-3 PUFA intake, p = 0.011). This association was not observed in women. This positive association of dietary n-3 PUFA with serum HDL cholesterol may partially explain the low mortality from CHD among Japanese men.

Coronary-prone behavior among Japanese men.

The Japanese Coronary-prone Behavior Scale (JCBS) is a questionnaire developed by the Eastern Collaborative Group Study (ECGS), a multi-center study of coronary-prone behavior among Japanese men in Japan. From the JCBS, a subscale was extracted consisting of 9 items that were independently associated with the presence of coronary artery disease (CAD) in patients undergoing coronary angiography (CAG). The subscale, named Scale C, represents job-centered lifestyle, social dominance, and suppressed overt type A behavior. To further validate the association of Scale C with CAD among Japanese men, the present study examined if such an association would be observed in a newly sampled population. The JCBS was carried out by 311 men undergoing CAG. The association between Scale C score and the presence of CAD was evaluated with logistic regression analysis that included established coronary risk factors. The Scale C score was significantly higher in subjects with CAD than in those without and stepwise multivariate logistic regression showed that the Scale C score was associated with the presence of CAD independent of age, low-density lipoprotein cholesterol, diabetes mellitus, and obesity. These results indicate that the Scale C score is independently associated with the presence of CAD even among a newly sampled population of Japanese men undergoing CAG. Scale C may reflect an important feature of coronary-prone behavior among Japanese men.

Biological and lifestyle factors, and lipid and lipoprotein levels among Japanese Americans in Seattle and Japanese men in Japan.

It has been previously shown that Japanese Americans in Seattle have significantly higher cholesterol levels than native Japanese. The present study examines the association of biological and lifestyle factors with plasma lipid and lipoprotein levels among Japanese Americans (JA) and native Japanese (NJ) to determine if these associations are consistent between these high and low cholesterol populations. Study samples consisted of 710 JA male and 728 JA female volunteers living in the Seattle area and a random sample of 3833 NJ male urban workers who participated in parallel cardiovascular disease screening and lifestyle surveys for 1989-1994. Multiple regression analysis was conducted to examine the association of lifestyle and biological factors with lipid and lipoprotein levels. Alcohol consumption was positively and linearly associated with high density lipoprotein cholesterol (HDL-C) levels and negatively associated with both low density lipoprotein cholesterol (LDL-C) levels and the ratio of total cholesterol (TC)/HDL-C (P < 0.05 to P < 0.001) among JA males and JA females and NJ males. Current smoking habit was observed to be negatively associated with HDL-C levels and positively with TC/HDL-C ratio and log TG levels (logarithmic transformation of triglyceride values) (P < 0.05 to P < 0.001) among all three groups. Body mass index (BMI) was negatively associated with HDL-C levels and positively associated with log TG and TC/HDL-C ratio among all three groups (P < 0.05 to P < 0.001). Moderate alcohol consumption was negatively associated with log TG levels among JA males and females (P < 0.05), whereas heavy alcohol consumption was positively associated with log TG levels in NJ males (P < 0.001). Smoking was positively associated with TC and LDL-C levels (P < 0.05) among JA males, whereas a negative association (P < 0.05) was observed in NJ males. Overall, the fitted models were consistent between JA males and females and NJ males with the exception of smoking on TC and LDL-C. The results suggest that moderate alcohol consumption favourably influences lipid profiles in both high and low cholesterol populations. The results also indicate that light alcohol consumption is associated with decreased triglyceride levels, whereas heavy alcohol consumption is associated with increased triglyceride levels.

Serum levels of prostate-specific antigen among Japanese-American and native Japanese men.

Fourfold to sixfold higher prostate cancer rates in Japanese-American men in the United States compared with Japanese men in Japan have been cited to support a role for environmental risk factors in the etiology of the disease. To examine the hypothesis that part or all of the elevated prostate cancer rates in Japanese-American men may reflect more intensive prostate cancer screening in the United States than in Japan, we compared prostate-specific antigen (PSA) levels in community-based samples of serum from men without prostate cancer. Japanese-American men aged 40-85 years and native Japanese men aged 40-89 years with no history of prostate cancer provided sera, respectively, in the United States from March 1990 through March 1992 (n = 237) or in Japan from January 1992 through December 1993 (n = 3522). Age-specific PSA levels were used to estimate the prevalences of undetected prostate cancer in the two populations. Age-specific mean PSA levels were significantly lower in Japanese-Americans than in native Japanese (two-sided P<.001). The prevalence of an elevated PSA level increased with age in both populations and exceeded 5% among men aged 60 years or more. Combined with data on prevalence of detected prostate cancer in the two populations, our data suggest that some 10.0% of Japanese-Americans aged 75 years have prostate cancer, with 31% of that fraction remaining undiagnosed. The corresponding estimates in Japan are a total cancer prevalence of 5.4%, of which 81% has not been detected clinically. The total cancer prevalence ratio 10.0/5.4 = 1.9 (95% confidence interval = 1.5-2.3) in Japanese-American men compared with Japanese men in Japan suggests an increased risk for Japanese-American men, but of less magnitude than the fourfold to sixfold increase indicated by the incidence data.

Is Hypertension Related Intra- and Extracerebral Artery Disease Responsible for the Difference in Stroke Incidence among Japanese Men in Japan and Hawaii?

The accumulated data from a collaborative study of stroke among Japanese men in Japan and Hawaii since 1965, was used to examine the question of why the risk of stroke is much higher in Japan, in spite of lower coronary heart disease. Earlier studies have shown that these differences are not due to misclassification of disease, that the higher risk of stroke in Japan is true for both thromboembolic and hemorrhagic disease, and that the higher risk could not be accounted for by atherosclerosis in large vessels of the Circle of Willis, as such pathology was more common in Hawaii than in Japan. A more likely explanation is that the difference in stroke is due to lesions in the small intracerebral arteries. The present study compares the prevalence of different measures of small artery pathology and lacunar infarcts found in histologic sections of basal ganglia from 232 Japanese men in Japan and 175 men of Japanese ancestry in Hawaii. Most of the lesions were more common at every age in Japan than in Hawaii. Such lesions were also much more common among men who died of stroke than of other causes, in both study populations. Among a large number of risk factors measured at the baseline exam in Hawaii, only high- blood pressure and reported diet of Asian food were significantly associated with one or more of the measures of small artery lesions. The inferences from the accumulated data are that small artery pathology plays a more important role in the high risk of stroke in Japan than does atherosclerosis in the larger arteries. These studies support the idea that hypertension is an important causal factor, but also indicate that some other factors must be involved. (Hypertens Res 1994; 17 Suppl. I: S37-S42)

Body fat and obesity in Japanese Americans

In 1965 a prospective study of greater than 12,000 Japanese men 45-69 y old and living in Japan, Hawaii, and California was initiated. Among the factors measured were height, weight, skinfold thicknesses, and 24-h dietary recall. The mean body mass index (BMI) was substantially lower for Japanese men in Japan than for Japanese men in California or Hawaii for each 5-y age group. Mean BMIs in Hawaii and California were similar. Values for subscapular skinfold thickness were also lower in Japan than in Hawaii or California in all age groups. Although total caloric intake was not greatly different between Japan and Hawaii, the percent caloric intake as fat was two times greater in Hawaii. Thus, these largely first- and second-generation immigrants exhibit increases in body weight that could be expected to significantly affect cardiovascular risk factor levels and endpoints.