Biomedical subjects

Hiroyasu Iso

Publications and source records attributed to Hiroyasu Iso.

15 recordsLinked to original sources

PubMed2003

Fat and protein intakes and risk of intraparenchymal hemorrhage among middle-aged Japanese.

The authors examined the relation between low intakes of saturated fat and animal protein and risk of intraparenchymal hemorrhage in a 14-year prospective study (ending in 1997) of 4,775 Japanese aged 40-69 years who undertook a single 24-hour dietary recall. Compared with the highest quartile of energy-adjusted saturated fat intake (median, 17 g/day), multivariate relative risks, after adjustment for age, sex, community, total energy intake, and known cardiovascular risk factors, were 0.77 (95% confidence interval (CI): 0.42, 1.42) for the second quartile (12 g/day), 0.66 (95% CI: 0.34, 1.25) for the third quartile (8 g/day), and 0.30 (95% CI: 0.12, 0.71) for the lowest quartile (5 g/day); p for trend = 0.005. An inverse relation was observed among both hypertensives and nonhypertensives; the respective relative risks with a one standard deviation increase in saturated fat intake (15.4 g/day) were 0.72 (95% CI: 0.52, 1.00) and 0.36 (95% CI: 0.14, 0.95). Intake of animal protein tended to correlate inversely with risk; the relative risk with a one standard deviation increase in animal protein intake (17.6 g/day) was 0.79 (95% CI: 0.61, 1.02); p = 0.07. Results are similar to those recently reported for US women and together help to explain the high rate of this stroke subtype in Asian countries, where intakes of these nutrients are low.

Adult↗

PubMed2003

Smoking raises the risk of total and ischemic strokes in hypertensive men.

To examine the relation between cigarette smoking and risk of stroke and coronary heart disease among Japanese, we conducted a 14-year prospective study of 3,626 men aged 40-69, initially free from history of stroke and coronary heart disease. We identified 257 strokes (75 hemorrhagic and 173 ischemic strokes) and 100 coronary heart disease events. When we adjusted for age and other cardiovascular risk factors, a significant excess risk among current smokers of > 20 cigarettes/day vs. never-smokers was found for total stroke (relative risk (RR) = 1.6 (95% confidence interval (CI), 1.1-2.4)). The excess risk of total stroke was particularly evident among hypertensives (RR = 2.3 (1.2-4.4)). The multivariate RR of ischemic stroke was 1.6 (1.0-2.5) for total subjects, and 2.2 (1.0-5.0) among hypertensives. Significant excess risks among current smokers of > 20 cigarettes/day vs. never-smokers were also found for coronary heart disease (RR = 4.6 (1.6-12.9)) and total cardiovascular disease (1.9 (1.3-2.7)). The estimated proportion of the events attributable to current smoking was 30 (95% CI, 11-44)% for total stroke and 34 (5-54)% for coronary heart disease. In conclusion, current smoking of > 20 cigarettes per day increased the risk of both total stroke and ischemic stroke among Japanese middle-aged men, and particularly among middle-aged hypertensive men.

Adult↗

PubMed2003

Ankle-arm blood pressure index and cardiovascular risk factors in elderly Japanese men.

Low ankle-arm systolic blood pressure index (AAI) correlates with various cardiovascular risk factors and with risk of subsequent coronary heart disease and stroke in Western countries. However, few epidemiological data are available among Japanese, in whom the reported prevalence of peripheral artery disease is low. We examined the relationship between AAI and cardiovascular risk factors among 1,219 men aged 60 to 79 years in two Japanese communities in 1999 and 2000. The prevalence of AAI<0.90 was 5% in both communities. Hypertension, major ECG abnormality, current smoking, and history of stroke were associated with two- to four-fold higher prevalence of AAI<0.90. One-standard deviation increments of body mass index and high density lipoprotein-cholesterol levels were associated with 60% and 40% lower prevalence of AAI<0.90, respectively. Although the prevalence of low AAI in Japanese elderly men is lower than that reported in the Unites States and European studies, similar correlations of low AAI with cardiovascular risk factors were observed among different ethnic groups. Low AAI is suggested to be a predictor for stroke among Japanese men, which should be confirmed by a prospective study.

Age Distribution↗

PubMed2003

Validity of the self-administered food frequency questionnaire used in the 5-year follow-up survey for the JPHC Study to assess folate, vitamin B6 and B12 intake: comparison with dietary records and blood level.

To validate a self-administered food frequency questionnaire (FFQ) for the estimation of dietary intake of folate, vitamins B6 and B12, we compared measures of these vitamins by the FFQ and plasma concentrations among 87 male volunteers aged 40-89 years in the Japan Public Health Center-based prospective study (JPHC Study). No men used folate, vitamins B6 or B12 as supplements. There was a moderate association between energy-adjusted dietary intake and plasma concentration for folate and vitamin B6. The Spearman correlation coefficient was 0.26 and 0.23, respectively, in the total samples. These correlation coefficients were slightly higher when men in the Ishikawa PHC area were excluded from the analysis; the correlation coefficient was 0.29 for folate and 0.26 for vitamin B6. No significant correlation was found between dietary vitamin B12 intake and serum B12 concentration; the correlation coefficient was 0.06 in the total sample and 0.15 when the Ishikawa men were excluded from the analysis. In conclusion, we found that the FFQ used for the 5-year follow-up survey of JPHC Study could reasonably rank individuals by dietary intake of folate and vitamin B6, but not vitamin B12, among Japanese community-dwelling population samples.

Diet Records↗

PubMed2003

The relationship between smoking habits and serum levels of 8-OHdG, oxidized LDL antibodies, Mn-SOD and carotenoids in rural Japanese residents.

This study investigated the relationship between smoking habits and serum levels of 8-OHdG, oxidized LDL antibodies (oLAB), Mn-SOD, and carotenoids. Subjects were 79 males (mean age +/- standard deviation; 62.1 +/- 10.0 years) and 79 females (60.3 +/- 10.3 y) who attended a health examination screening in the town of Hokkaido, Japan. Serum 8-OHdG, Mn-SOD, and oLAB levels were measured by ELISA and serum carotenoids levels were measured by HPLC. Smoking habits were assessed by public health nurses using a questionnaire. Serum 8-OHdG levels were significantly higher in males than in females. On the other hand, serum levels of beta-carotene, alpha-carotene, beta-cryptoxanthin, and zeaxanthin and lutein were significantly lower in males than in females. Serum beta-carotene, beta-cryptoxanthin, and zeaxanthin and lutein were significantly lower in males who were current smokers, compared to non-smokers. Serum 8-OHdG levels were also significantly higher in current smokers. Furthermore, in males, serum oLAB and beta-carotene levels were significantly and negatively correlated with the number of cigarettes smoked per day. Serum Mn-SOD levels were unrelated to smoking habits in males. In conclusion, this preliminary study suggests that cigarette smoking increases serum 8-OHdG levels and reduces serum levels of oLAB and carotenoids, such as beta-carotene, beta-cryptoxanthin, and zeaxanthin and lutein in healthy male subjects. Serum levels of 8-OHdG, oLAB, and carotenoids may be useful biomarkers of oxidative conditions affected by smoking.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2003

[A follow-up study on mental and physical function function among stroke patients: comparisons between admission and discharge status in a rehabilitation-specialized hospital].

PURPOSE: To assess results of a 5 year-follow-up, in terms of disability, depression, quality of life, and social network in cases of stroke patients. This report deal with results at admission and discharge (in average, from 2.5 to 6 months of the onset) in a rehabilitation-specialzed hospital. OBJECT AND METHOD: The subjects were 87 stroke patients hospitalized in the Ibaraki Prefectural University Hospital. They were 64 men and 23 women, and their age were between 42 and 79 with an average of 59 years. Systematic evaluation for mental and physical functions was conducted at admission and discharge, and it is intended that the evaluation will be repeated 1, 2, 3 and 5 years from the stroke onset. RESULTS: There were substantial improvements in motor functions, general intelligence, and the status of dementia during the hospitalization. Activities of daily living and degrees of job execution and satisfactory were also improved. The prevalence of depression remained 40%, and the acceptance of limb paralysis or reduced quality of life did not change. Social network scores declined. DISCUSSION: Lack of improvement of depressive status and quality of life, and deterioration social network may increase the rist of major difficulties after discharge of stoke patients. Prevention programs at hospital may be necessary to cope with these potential problems.

Activities of Daily Living↗

PubMed2002

Perceived mental stress and mortality from cardiovascular disease among Japanese men and women: the Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study).

BACKGROUND: Perceived mental stress has been associated with risk of coronary heart disease (CHD) in white men, but no prospective data are available for other ethnic groups. METHODS AND RESULTS: From 1988 to 1990, a total of 73 424 Japanese (30 180 men and 43 244 women), aged 40 to 79 years, without a history of stroke, CHD, or cancer completed a lifestyle questionnaire including perception of mental stress under the Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study). Systematic surveillance was completed until the end of 1997, with a 580 378 person-year follow-up, and the underlying causes of death were determined according to the International Classification of Diseases, 10th revision. For women, there were 316 with total stroke, 113 with CHD, and 643 with total cardiovascular disease (CVD); for men, there were 341, 168, and 778, respectively. Women who reported high stress had a 2-fold higher age-adjusted risk of mortality from total stroke and CHD and 1.5-fold higher risk of total CVD compared with those who reported low stress. Further adjustment for known cardiovascular risk factors and selected psychological variables did not alter the associations materially. The multivariate relative risk for women who perceived high stress versus low stress was 2.24 (95% CI 1.52 to 3.31, P<0.001) for total stroke, 2.28 (95% CI 1.17 to 4.43, P=0.02) for CHD, and 1.64 (95% CI 1.25 to 2.16, P<0.001) for total CVD. For men, these relations were generally weaker but suggestive of myocardial infarction. CONCLUSIONS: Perceived mental stress was associated with increased mortality from stroke for women and with CHD for men and women.

Adult↗

PubMed2002

Trends in the incidence of coronary heart disease and stroke and the prevalence of cardiovascular risk factors among Japanese men from 1963 to 1994.

PURPOSE: To determine trends in the incidence of cardiovascular disease in Japan, we examined observational data on coronary heart disease, stroke, and cardiovascular risk factors among urban Japanese working men. SUBJECTS AND METHODS: The surveyed population included all male employees aged 40 to 59 years who worked for eight industrial companies in Osaka, the second largest metropolitan city in Japan. Surveillance for cardiovascular disease and risk factors was conducted from 1963 to 1994. RESULTS: The age-adjusted incidence of coronary heart disease increased from 0.4 per 1000 person-years during 1963 to 1970, to 1.5 per 1000 person-years during 1979 to 1986, and then plateaued until 1987 to 1994 (P for trend = 0.002), whereas the incidence of stroke declined from 1.2 per 1,000 person-years during 1971 to 1978, to 0.6 per 1,000 person-years in 1987 to 1994 (P for trend = 0.02). The age-adjusted mean (+/- SD) total cholesterol level, which was 4.87 +/- 2.88 mmol/L during 1963 to 1966, increased to 5.11 +/- 0.62 mmol/L during 1982 to 1983 (P <0.001), and 5.09 +/- 0.75 mmol/L during 1990 to 1991. Both mean systolic and diastolic blood pressures increased by 1 mm Hg between the periods of 1966 to 1967 and 1982 to 1983, and declined below the 1966 to 1967 levels during 1990 to 1991. The prevalence of smoking declined from 72% during 1975 to 1976, to 58% during 1990 to 1991 (P for trend <0.001). CONCLUSION: Although these findings were limited to urban middle-aged men, the increase in serum cholesterol is likely to attenuate the reduction in future rates of coronary heart disease in Japan that would have been expected to result from the declining prevalence of smoking.

Adult↗

PubMed2002

One-year community-based education program for hypercholesterolemia in middle-aged Japanese: a long-term outcome at 8-year follow-up.

To examine a long-term effect of community-based education program for hypercholesterolemia and an effect modification by apolipoprotein E polymorphism, we conducted a 1-year randomized clinical trial with 8 year-follow-up. One hundred four persons aged 40-64 years who had serum total cholesterol levels between 6.21 and 7.73 mmol/l (240 and 299 mg/dl) in 1988-89 cardiovascular risk surveys were enrolled in the trial. The intervention group (n=51, 82% for women) attended eight education classes in 1 year, while the control group (n=53, 85% for women) attended only two classes. Both groups were invited to the subsequent annual surveys. The mean serum cholesterol was 0.24-0.26 mmol/l less in the intervention than in the control group at both 6 month and 1 year (P=0.03, each) while the proportion of subjects using hypolipidemic agents was 0 and 6% in both groups, respectively. During 8-year follow-up, the probability of using hypolipidemic agents and/or total cholesterol > or =7.76 mmol/l was 51% in the education group and 69% in the control group; the risk ratio in the intervention vs control groups was 0.62 (95% CI: 0.36-1.06). When stratified by the apolipoprotein E polymorphism examined for 78% of the subjects, the risk ratio was 0.61 (0.31-1.18) among subjects without e4 allele (n=59) and 0.55 (0.14-2.14) among those with e4 allele (n=22). The intervention group had reduced intake of egg, fish egg, butter, mayonnaise and fatty meat compared to the control group at 6-month, 1- and 8-year follow-up. In conclusion, our community-based program was effective in reducing serum total cholesterol levels non-pharmacologically during the first year, and also reduced the likelihood of progressive worsening of hypercholesterolemia during the subsequent 8 years, regardless of the apolipoprotein E polymorphism.

Adult↗

PubMed2002

Effects of serum B vitamins on elevated plasma homocysteine levels associated with the mutation of methylenetetrahydrofolate reductase gene in Japanese.

High plasma homocysteine, a risk factor for atherosclerosis, is frequently caused by a common mutation in the gene for the enzyme, 5,10-methylenetetrahydrofolate reductase (MTHFR), C677T (alanine to valine substitution) or low intake of B vitamins that affect the remethylation or transsulfuration pathways in homocysteine metabolism. However, the interaction of the C677T mutation and B vitamins other than folate has not been well elucidated. We conducted a cross-sectional survey of 324 men and 641 women who participated in a 1996 health examination under a hypothesis that high nutritional status of folate, vitamin B12 and vitamin B6 expressed as high serum levels, may compensate for the hyperhomocysteinemia associated with homozygosity for the C677T mutation, but not for having the mutation per se. Age-adjusted plasma homocysteine levels were higher for both men and women with the homozygous genotype for the mutation than those who were heterozygous or had no mutation. Elevated homocysteine levels in homozygous genotype was attenuated among persons with higher serum levels of vitamin B12 and folate, but not vitamin B6, and among persons with the combination of lower folate and higher vitamin B12 and of higher folate and higher vitamin B12, split by the median. These findings suggest that elevated homocysteine levels among Japanese with the homozygous genotype for the MTHFR gene mutation can be modified efficiently by dietary supplement of vitamin B12 as well as folate.

Adult↗

PubMed2002

Determinants of platelet aggregation in 50-70-year-old men from three Japanese communities.

To investigate the association of lifestyle and constitutional variables with platelet aggregation, we examined the platelet aggregation, serum fatty acid composition, alcohol intake, smoking, and dietary intake of seafood and soybean estimated by a 1-week dietary record in 448 males aged 50-70 in three rural Japanese communities: Ikawa, Akita prefecture (northeast coast), Noichi, Kochi prefecture (southwest coast), and Kyowa, Ibaraki prefecture (central inland). Platelet aggregatory threshold index (PATI) was used to determine the minimum concentration of adenosine 5'-diphosphate (ADP) that caused a non-reversible aggregation of platelets. Intake of seafood and n3-polyunsaturated fatty acid and ingestion of ethanol were higher in the northeast coastal community than in the other two communities. Mean platelet and white blood cell counts were lower in northeast coastal community than in the other two communities. The geometric mean PATI was higher (i.e. platelet aggregation was lower) in the northeast coastal community than the other two communities. Within the entire sample, platelet aggregation correlated inversely with serum level of n3-polyunsaturated fatty acids and gamma-glutamyl transpeptidase, an index of alcohol consumption, and positively with platelet and white blood cell counts. Platelet aggregation tended to correlate positively with serum arachidonic acid. There was no correlation between smoking and platelet aggregation. Our results suggest that seafood intake and moderate alcohol consumption reduce platelet aggregation.

Aged↗

PubMed2002

The relation of anger expression with blood pressure levels and hypertension in rural and urban Japanese communities.

OBJECTIVE: To examine the relation of anger expression with blood pressure and hypertension among Japanese. DESIGN: A cross-sectional study. METHODS: Subjects were 4374 men and women aged 30-74 years from rural and urban communities. Anger expression was estimated using the anger-out and anger-in scores of the Spielberger Anger Expression Scale. Multiple linear regression analyses were performed to estimate the associations of anger expression scores with blood pressure. Proportions of hypertensives among the tertiles of anger expression scores and the relative odds of hypertension for low versus high tertiles of anger expression scales were calculated using logistic regression models. RESULTS: The anger-out score was inversely associated with systolic and diastolic blood pressure levels for men; a four-point (one standard deviation) lower anger-out score was associated with 1.6 mmHg [95% confidence interval (CI), 0.6-2.6] greater systolic blood pressure and 0.6 mmHg (95% CI, -0.03 to 1.2) greater diastolic pressure after adjustment for age, body mass index, alcohol intake, smoking category, and parental history of hypertension. The adjusted relative odds of hypertension for low versus high tertiles of anger-out was 1.60 (95% CI, 1.19-2.15). These inverse associations were more evident among men with low coping behavior than among those with high coping behavior. For women, the anger-out score was not associated with blood pressure. There was no relation between the anger-in score and either blood pressure or hypertension in either men or women. CONCLUSIONS: This study suggests that Japanese men who do not express their anger, especially when they have low coping behavior, may have an increased risk of high blood pressure.

Adult↗

PubMed2002

Linoleic acid, other fatty acids, and the risk of stroke.

BACKGROUND AND PURPOSE: The role of serum fatty acids as a risk factor for stroke and stroke subtypes is largely unknown. METHODS: A prospective nested case-control study of Japanese 40 to 85 years of age was conducted through the use of frozen serum samples from 7450 participants in cardiovascular risk surveys collected from 1984 to 1989 for 1 community and 1989 to 1992 for the other 2 communities. By the end of 1998, we identified 197 incident strokes whose subtypes were confirmed by imaging studies. Three controls per case were selected by matching for sex, age, community, year of serum storage, and fasting status. RESULTS: Compared with controls, total (n=197), hemorrhagic (n=75), and ischemic (n=122) strokes had similar proportions of n3 polyunsaturated fatty acids, lower proportions of linoleic and arachidonic acids, and higher proportions of saturated and monosaturated acids, determined by gas chromatography. The multivariate odds ratios associated with a 1-SD increase in linoleic acid (5%) after adjustment for hypertension, diabetes, serum total cholesterol, and other cardiovascular risk factors were 0.72 [95% confidence interval (CI), 0.59 to 0.89] for total stroke, 0.66 (95% CI, 0.49 to 0.88) for ischemic stroke, 0.63 (95% CI, 0.46 to 0.88) for lacunar infarction, and 0.81 (95% CI, 0.59 to 1.12) for hemorrhagic stroke. The respective odds ratios for saturated fatty acids (4%) were 1.13 (95% CI, 1.05 to 1.65), 1.35 (95% CI, 1.01 to 1.79), 1.44 (95% CI, 1.03 to 2.01), and 1.21 (95% CI, 0.82 to 1.80). Further adjustment for other fatty acids attenuated these relations, but the relation between linoleic acid and risk of ischemic stroke remained statistically significant. CONCLUSIONS: A higher intake of linoleic acid may protect against ischemic stroke, possibly through potential mechanisms of decreased blood pressure, reduced platelet aggregation, and enhanced deformability of erythrocyte cells.

Adult↗

PubMed2002

Association of low job control with a decrease in memory (CD4+ CD45RO+) T lymphocytes in Japanese middle-aged male workers in an electric power plant.

To clarify the relationship between perceived job stress and lymphocyte subpopulations, a cross-sectional study was conducted in 231 male electric power plant workers (aged 40 to 60, mean 46 years). Job stress, i.e., job control, job demands, and social support at work, was assessed by means of the Japanese version of the Job Content Questionnaire. Blood samples were taken from all the workers, and numbers of CD4+ T lymphocyte subpopulations, total CD4+ T, T (CD3+) lymphocytes, CD16CD56+ natural killer (NK) cells, total lymphocytes, and white blood cells were determined. After controlling for age, number of cigarettes smoked per day, alcohol drinking, frequency of regular exercise, job demands, and social support at work by the partial correlation coefficients, numbers of memory (CD4+ CD45RO+) T, total CD4+ T, and total T (CD3+) lymphocytes were positively correlated with job control (p<0.05). Neither job demands nor social support at work showed significant correlations with lymphocyte subpopulations. It is suggested that lower job control is associated with a decrease in the number of CD4+ CD45RO+ T lymphocytes in male middle-aged workers.

Adult↗

PubMed1994

Can Blood Pressure in the Elderly be Reduced? Findings From a Long-term Population Survey in Japan.

To examine whether blood pressure (BP), a major risk factor of cardiovascular disease, can be controlled in the elderly as well as in middle-aged persons, we analyzed the data of observational studies on trends for BP and cardiovascular disease incidence in a northeast rural community of Japan. This community was the subject of an ongoing hypertension control program that was initiated in 1963. A significant decline in BP levels was noted in each sex-age group between 1963 and 1966 and 1987 and 1991. The decline was greater in older persons compared with younger individuals. The BP decline was attributable to an increase in antihypertensive medication use, beginning in the 1970s. We compared BP levels of untreated offspring and parents when both were 40 to 49 years old. Blood pressure levels were significantly lower in the offspring than in parents. This result and the large downward shift of BP distribution in the second decade of follow-up suggested that the improvements in diets and other environmental factors contributed to the BP decline. Between 1964 and 1968 and 1989 and 1992, stroke incidence declined 70% to 79% for all sex and age groups (40-69 and greater than 70 years). The number of totally dependent stroke patients decreased in both the middle-aged and the elderly between 1976 and 1991. The decline in stroke mortality tended to be larger in the surveyed community than in adjacent communities. These results indicated that hypertension control is effective in preventing stroke in the elderly as well as in the middle-aged.

Journal Article↗