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Biomedical subjects

Shunroku Baba

Publications and source records attributed to Shunroku Baba.

14 recordsLinked to original sources
PubMed2006

Cigarette smoking and risk of coronary heart disease incidence among middle-aged Japanese men and women: the JPHC Study Cohort I.

BACKGROUND: Few data have been available on the sex-specific magnitude of the smoking effect on the risk of coronary heart disease (CHD) in Asia. DESIGN AND METHODS: A population-based prospective cohort study of 19 782 men and 21 500 women aged 40-59 years between 1990-1992 and 2001 was conducted to examine the relationship between smoking status and the risk of CHD. RESULTS: A total of 260 incidences of CHD were confirmed among men, including 174 myocardial infarctions (MI). The numbers among women were 66 and 43, respectively. The multivariate relative risk [95% confidence interval (CI)] for current smokers versus never-smokers in men after adjustment for cardiovascular risk factors, several life style factors and public health centre was 2.85 (1.98, 4.12) for total CHD and 3.64 (2.27, 5.83) for MI. These respective risks in women were 3.07 (1.48, 6.40) and 2.90 (1.18, 7.18). Among men, a dose-dependent relationship was observed between the number of cigarettes and the risk of MI. The population-attributable risk per cent (95% CI) of CHD was 46% (34, 55) in men and 9% (0, 18) in women. Smoking cessation, however, led to a rapid decline in the CHD risk within 2 years. CONCLUSION: Smoking raises the risk of CHD significantly in both sexes of middle-aged Japanese, with large public health significance especially in men. Smoking cessation would have an immediate effect on risk reduction.

Adult↗
PubMed2004

Cigarette smoking and risk of stroke and its subtypes among middle-aged Japanese men and women: the JPHC Study Cohort I.

BACKGROUND AND PURPOSE: We examined sex-specific relationships of smoking with risk of total stroke and stroke subtypes in Asian populations because of the limited data available. METHODS: A total of 19,782 men and 21,500 women aged 40 to 59 years who were free of prior diagnosis of stroke, coronary heart disease, or cancer and reported their smoking status were followed in the Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Disease (JPHC Study) from 1990 to 1992 to the end of 2001. RESULTS: During a 461,761 person-year follow-up, 702 total strokes were documented among men, of which 619 were confirmed by imaging studies, including 219 intraparenchymal hemorrhages, 73 subarachnoid hemorrhages, and 327 ischemic strokes. The respective numbers of cases among women were 447, 411, 129, 106, and 176. Multivariate relative risks (95% CIs) for current smokers compared with never-smokers after adjustment for cardiovascular risk factors and public health center were 1.27 (1.05 to 1.54) for total stroke, 0.72 (0.49 to 1.07) for intraparenchymal hemorrhage, 3.60 (1.62 to 8.01) for subarachnoid hemorrhage, and 1.66 (1.25 to 2.20) for ischemic stroke. The respective multivariate relative risks among women were 1.98 (1.42 to 2.77), 1.53 (0.86 to 4.25), 2.70 (1.45 to 5.02), and 1.57 (0.86 to 2.87). There was a dose-response relation between the number of cigarettes smoked and risks of ischemic stroke for men. A similar positive association was observed between smoking and risks of lacunar infarction and large-artery occlusive infarction, but not embolic infarction. CONCLUSIONS: Smoking raises risks of total stroke and subarachnoid hemorrhage for both men and women and risk of ischemic stroke, either lacunar or large-artery occlusive infarction, for men.

Adult↗
PubMed2004

Alcohol consumption and risk of stroke among middle-aged men: the JPHC Study Cohort I.

BACKGROUND AND PURPOSE: The impact of light-to-moderate alcohol consumption on risk of stroke has not been well examined in a single study, although the effect is hypothesized to differ among stroke subtypes from meta-analyses. METHODS: A total of 19 544 men aged 40 to 59 years living in communities were followed-up from 1990 to 1992 to the end of 2001 in the Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Disease (JPHC Study). RESULTS: After 214 504 person-years of follow-up, 694 incident strokes were documented, of which 611 were confirmed by imaging studies or autopsy, including 219 intraparenchymal hemorrhages, 73 subarachnoid hemorrhages, and 319 ischemic strokes. Alcohol consumption was positively associated with age-adjusted risk of total stroke with a 68% excess risk among drinkers of > or =450 g ethanol per week compared with occasional drinkers. This excess risk was confined primarily to hemorrhagic stroke, which remained statistically significant even after controlling for hypertension and other cardiovascular risk factors (RR: 2.15; 95% CI: 1.22 to 3.79). There was a lower risk of ischemic stroke, more specifically lacunar infarction, a higher risk of hemorrhagic stroke, and no excess risk of total stroke among drinkers of 1 to 149 g ethanol per week compared with occasional drinkers; the respective multivariate RR (95% CI) was 0.59 (0.37 to 0.93), 0.43 (0.22 to 0.87), 1.73 (0.98 to 3.07), and 0.98 (0.71 to 1.36). CONCLUSIONS: We found differential effects of light-to-moderate alcohol consumption on risks of hemorrhagic and ischemic strokes among middle-aged men. Light-to-moderate alcohol consumption, ie, < or =2 drinks per day, does not raise the risk of total stroke.

Adult↗
PubMed2004

A promoter variant of the heme oxygenase-1 gene may reduce the incidence of ischemic heart disease in Japanese.

Heme oxygenase-1 (HO-1) has been suggested to have antiatherogenic properties. This study was designed to examine the relationship between the HO-1 gene (HMOX1) and ischemic heart disease. The study population consisted of 1972 control subjects and 597 subjects with ischemic heart disease (myocardial infarction (MI) n = 393, HMOX1 n = 204). The control subjects were consecutively selected from the Suita study, an epidemiological cohort representing the general population in Japan. Patients with ischemic heart disease were recruited from the outpatient clinic of the National Cardiovascular Center (NCVC). We sequenced HMOX1 and found a T(-413)A polymorphism in the promoter region. Multiple logistic analyses indicated that the T(-413)A (T(-413)A (TA + TT/AA) polymorphism, sex, smoking habit, DM and BMI affected the occurrence of ischemic heart disease. The odds ratios of the TA + TT allele for MI and AP were 1.42 (P = 0.0468, 95% confidence interval: 0.01-0.35) and 1.86 (P = 0.0096, 95% confidence interval: 0.08-0.55), respectively. Luciferase reporter assay indicated that the A allele promoter had significantly higher activity than the T allele promoter. The AA genotype of HMOX1 reduced the incidence of ischemic heart disease, possibly due to the high expression level of HMOX1.

Base Sequence↗
PubMed2004

Potential of free-form TFPI and PAI-1 to be useful markers of early atherosclerosis in a Japanese general population (the Suita Study): association with the intimal-medial thickness of carotid arteries.

This study assessed markers of vascular endothelial cell dysfunction associated with early atherosclerosis in carotid arteries. We measured the plasma levels of free-form tissue factor pathway inhibitor (free TFPI), plasminogen activator inhibitor-1 (PAI-1), and von Willebrand factor (vWF) in 522 adults without cardiovascular disease enrolled in the Suita Study. For each sex, we analyzed the association of the degree of intimal-medial thickness (IMT) with hemostatic markers using logistic regression analysis considering potential confounding risk factors, including age, body mass index, lifestyle (current smoking and drinking), illness (diabetes mellitus and hyperlipidemia), systolic blood pressure, and antihypertensive drug use. The age-adjusted levels of free TFPI and PAI-1 were positively and independently associated with the degree of IMT for men. Even after adjustment for all confounding factors, the level of PAI-1 was positively associated with the degree of IMT. These results indicate that measurement of the levels of free TFPI and PAI-1 is a potentially useful tool for the detection of early atherosclerosis in men.

Adult↗
PubMed2003

Association of methylenetetrahydrofolate reductase gene polymorphism with carotid atherosclerosis depending on smoking status in a Japanese general population.

BACKGROUND AND PURPOSE: The association of the methylenetetrahydrofolate reductase gene (MTHFR) with carotid atherosclerosis remains inconsistent. This may be due to small sample size and inappropriate analysis. We investigated the association of C677T/MTHFR with blood pressure and carotid atherosclerosis in a Japanese general population. METHODS: Subjects (30 to 89 years of age; 1693 women, 1554 men) who gave informed consent were randomly selected from a general population in Suita, Japan. MTHFR genotypes were determined by TaqMan polymerase chain reaction. Carotid atherosclerosis was evaluated by high-resolution ultrasonography with atherosclerotic indexes of intimal-medial thickness (IMT), maximum IMT in the common carotid artery (CCA), plaque score, and stenosis (>50%). RESULTS: Age-adjusted diastolic blood pressure was significantly higher in women with the TT genotype than in those with the CC genotype. In a recessive model (CC+CT versus TT), all adjusted odds ratios for hypertension and >50% stenosis in women were 1.42 and 3.42 (95% confidence intervals, 1.01 to 1.99 and 1.23 to 9.53), respectively. In women, maximum IMT in CCA for smokers with the TT genotype was significantly higher than for smokers with the CC genotype and nonsmokers with the TT genotype (P<0.05). CONCLUSIONS: Our study suggests that the MTHFR TT genotype is a risk factor for hypertension and carotid stenosis in women. Significant interactions between C677T/MTHFR and smoking on maximum IMT in CCA were observed in women but not in men. Smoking cessation for subjects with the TT genotype is important in the prevention of cerebrovascular disease.

Adult↗
PubMed2003

Lack of association between angiotensin II type 1 receptor gene polymorphism and hypertension in Japanese.

Angiotensin II type 1 (AT1) receptor mediates the vasoconstriction and growth-promoting effect of angiotensin II in humans. It has been reported that a polymorphism of the AT1 receptor gene (an A/C transversion at position 1166; A1166C) may be associated with essential hypertension (HT). However, several conflicting results have also been reported. Therefore, we conducted an association study between A1166C variants of the AT1 receptor gene and hypertension in the Japanese population. We genotyped this variant in 3,918 subjects (1,492 hypertensive subjects and 2,426 normotensive subjects) recruited from the Suita study. In subjects not receiving antihypertensive medication, the influence of the genotype on blood pressure values adjusted for clinical covariates was analyzed. The genotype distribution did not differ between hypertensive and normotensive subjects in either men (frequency of the C allele: 8.1% vs. 7.8%, p=0.74) or women (8.1% vs. 7.7%, p=0.60). There were no significant differences in systolic blood pressure, diastolic blood pressure, or pulse pressure among the three genotypes in either men or women who had not received hypertensive medication. Our data suggest that the A1166C polymorphism of AT1 receptor is unlikely to influence blood pressure status in the Japanese population.

Aged↗
PubMed2002

Association between SAH, an acyl-CoA synthetase gene, and hypertriglyceridemia, obesity, and hypertension.

BACKGROUND: The SA gene (SAH) has been isolated by differential screening from a genetically hypertensive rat strain as a candidate gene that may contribute to hypertension. Recently, the SA protein has been reported to be highly homologous to bovine xenobiotic-metabolizing medium-chain fatty acid:CoA ligase. METHODS AND RESULTS: To clarify the pathophysiological significance of SAH, we searched for polymorphisms of human SAH and performed association studies using a large cohort (4000 subjects) representing the general population in Japan. We found 2 polymorphisms in the promoter region and single-nucleotide polymorphisms in introns 5, 7, and 12 and exon 8. One of the variants, an A/G polymorphism in intron 12, just 7 bp upstream from exon 13, strongly affected plasma triglyceride, plasma cholesterol, body mass index (BMI), waist-to-hip ratio (W/H), and blood pressure status. The effect of this genotype on blood pressure seems to be conveyed through its effects on BMI and W/H. Transient expression of the SA protein in mammalian cells confirmed that it is expressed in mitochondria and has medium-chain fatty acid:CoA ligase activity. The A/G polymorphism was found to be associated with the expression level of SA mRNA in peripheral mononuclear cells in vivo. CONCLUSIONS: The G allele of SAH was found to be associated with multiple risk factors, including hypertriglyceridemia, hypercholesterolemia, obesity, and hypertension. This observation should open a new area for future research in multiple-risk-factor syndromes.

Alleles↗
PubMed2002

Epsilon 4 allele of apolipoprotein E gene associates with lower blood pressure in young Japanese subjects: the Suita Study.

OBJECTIVES: The apolipoprotein epsilon 4 allele (APOE/epsilon 4) increases plasma cholesterol level and the risk for the late onset type of Alzheimer's disease. However, the correlation between hypertension and APOE/epsilon 4 has not yet been clarified. To examine the APOE/epsilon 4 effect in the general population of Japan, we performed a large genetic epidemiological survey (the Suita Study). DESIGN AND METHODS: The Suita Study was a cohort study based on a random sample of 14,200 Japanese residents of Suita city. Subjects who gave informed consent for genetic analysis were recruited in the current study ( = 3997). APOE polymorphism was clearly determined by the TaqMan polymerase chain reaction method. RESULTS: Subjects with APOE/epsilon 4 were significantly ( P < 0.03) more frequent (19.7%) in normotensives than in hypertensives (16.9%), the estimated odds ratio for hypertension (with APOE/epsilon 4 versus without APOE/epsilon 4) being 0.83 [95% confidence interval (CI), 0.70-0.98]. The significance of the association (OR = 0.64; 95% CI, 0.48-0.86) was increased in young subjects ( < or = 60 years old) but disappeared in old subjects. APOE/epsilon 4 also significantly contributed to a 2.9% increase of total cholesterol, 11.8% increase of triglyceride and 3.2% of decrease of high-density lipoprotein-cholesterol. CONCLUSIONS: We concluded that APOE/epsilon 4 was associated with an increase of plasma lipid levels and with a decrease of systolic blood pressure. The final conclusion on whether APOE/epsilon 4 contributes to the risk for cardiovascular disease will be clarified by analysis of the cumulative incidence, which will be obtained in the future Suita Study.

Adult↗
PubMed2002

Aldehyde dehydrogenase 2 gene is a risk factor for myocardial infarction in Japanese men.

In epidemiological studies, moderate alcohol consumption has been consistently associated with a reduced risk of myocardial infarction (MI). About half of Japanese show an extremely high sensitivity to alcohol (ethanol), which is due to a missense mutation from glutamic acid (Glu) to lysine (Lys) at codon 487 in an isoenzyme of aldehyde dehydrogenase (ALDH2) with a low Km. We obtained a preliminary result that subjects homozygous for the Lys 487 allele had higher risk for myocardial infarction. The purpose of the present study was to assess this hypothesis by employing a larger cohort of subjects with MI. The experimental group consisted of 342 male subjects with demonstrated MI who were selected randomly from our outpatient clinic. As controls, we employed 1,820 male subjects with no cardiovascular complications who were selected from the Suita Study. All subjects provided their written informed consent to participate in the genetic analyses. Subjects with MI were older and had higher body mass index, higher prevalence of diabetes mellitus, higher prevalence of smoking habit, higher prevalence of the Lys/Lys genotype (homozygous for Lys 487 allele), and lower high density lipoprotein (HDL) cholesterol level (HDL-C). The ALDH2 genotype affected the level of alcohol consumption, and HDL-C. Multiple logistic analyses indicated that the odds ratio of the Lys/Lys genotype to the Lys/Glu+Glu/Glu genotype was 1.56 (p=0.0359). Inclusion of HDL-C as one of the independent variables downplayed the importance of the ALDH2 genotype. This may indicate that the ALDH2 genotype affects MI via its effects on HDL-C. In conclusion, the ALDH2 Lys/Lys genotype is a risk factor for myocardial infarction in Japanese men due to its influence on HDL cholesterol level.

Alcohol Drinking↗
PubMed2002

A single-nucleotide polymorphism in C-type natriuretic peptide gene may be associated with hypertension.

We conducted an association study between genetic variants of C-type natriuretic peptide gene (CNP) and hypertension in a Japanese population. We found four genetic variants, two in the promoter region, one missense mutation, and one in the 3'-untranslated region (3'-UTR), and genotyped all four variants in 2,006 subjects recruited from the Suita study. One of the variants, G2628A in 3'-UTR, was found to be associated with blood pressure. Multiple logistic analyses indicated that the genotype of the G2628A polymorphism (GG=1, GA+AA=2) (p=0.0034), sex (p=0.0288), alcohol consumption (p=0.0002), age (p<0.0001), and body mass index (p<0.0001) were predictors of hypertension. The odds ratio of the GA+AA genotype over the GG genotype for hypertension was 1.40 (p=0.0034, 95% confidence interval (CI) 1.12-1.75). Multiple logistic analyses in a younger subpopulation aged below 65 years indicated that the odds ratio of the GA+AA genotype over the GG genotype for hypertension was 1.58 (p=0.0024, 95%CI 1.18-2.12). Thus, the CNP G2628A polymorphism made an even greater contribution to hypertension in the younger subpopulation.

Age Distribution↗
PubMed2002

Association of a sodium channel alpha subunit promoter variant with blood pressure.

The SCNNIA gene, which is located on human chromosome 12p13.3, encodes the alpha subunit of the amiloride-sensitive epithelial sodium channel, and mutations in SCNNIA can result in pseudohypoaldosteronism type I. It was postulated that genetic variations in SCNN1A could lead to an increased risk of hypertension. Sequence variations in SCNN1A were identified, and the association between these polymorphisms and BP was examined in a large cohort (n = 3898) representing the general population in Japan. Four polymorphisms in the promoter region, three polymorphisms in the exonic region, and one polymorphism in the first intron were identified. Because association studies with one-half of the study population indicated that the A(2139)G polymorphism, among others, significantly affected BP, this polymorphism was studied in the entire study population. Multiple logistic analyses indicated that the odds ratio for hypertension with the GA+GG genotype was 1.31 (P = 0.0154) in the total population and 1.77 (P = 0.0035) among subjects <60 yr of age. A significantly higher frequency of proteinuria was also observed among subjects with the GA+GG genotype. A transient transfection assay using MDCK cells indicated that the promoter activity of the G(2139) allele was higher than that of the A(2139) allele. Therefore, possession of the SCNN1A G(2139) allele significantly increased the risk of hypertension. A lower level of SCNN1A subunit expression among subjects with the AA genotype might lead to lower levels of sodium reabsorption in the kidney and might provide protection against the development of hypertension.

Alleles↗
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↗