Biomedical subjects

K Kayaba

Publications and source records attributed to K Kayaba.

At least 19 recordsLinked to original sources

PubMed1996

A common mutation in methylenetetrahydrofolate reductase gene among the Japanese population.

Hyperhomocysteinemia has been reported as an independent risk factor for atherosclerotic cerebrovascular and coronary heart diseases. 5, 10-Methylenetetrahydrofolate reductase (MTHFR) is one of the enzymes responsible for hyperhomocysteinemia. The C to T transition of the MTHFR gene at nucleotide position 677 results in decreasing the enzymatic activity and increasing the plasma homocysteine level. We studied the distribution of the MTHFR gene mutation among the Japanese population. The subjects were 129 Japanese males (aged 40-59 years). The allele frequency of the mutation was 0.38. The frequencies of the three genotypes were as follows: +/+, 11%; +/-, 54%; -/-, 35% (+ and-indicate the presence and absence of the mutation, respectively). We also studied the frequency of the MTHFR gene mutation in the middle-aged Japanese males with hypertension to investigate the possibility that this mutation is related to essential hypertension. The normotensive and hypertensive subjects were identical in the distribution of the mutated allele and the frequencies of the three genotypes. Furthermore, the prevalence of hypertension in each genotype group was same, although the mean diastolic pressure of the group with homozygous mutation was significantly higher than that of other groups (p < 0.05). Therefore, we concluded that there was no significant relationship between the MTHFR gene mutation and hypertensive subjects studied in this study.

Adult↗

PubMed1996

Characteristics of the insulin resistance syndrome in a Japanese population. The Jichi Medical School Cohort Study.

We investigated the relationships between hyperinsulinemia (a major indicator of the insulin resistance syndrome), blood pressure, dyslipidemia, and coagulation factors in 2606 community-dwelling Japanese individuals as part of the Jichi Medical School Cohort Study. An age-related decrease of the fasting insulin level was found in men but not in women. Body mass index, systolic and diastolic blood pressure, triglyceride and fasting glucose levels, and factor VII activity all increased in both sexes as the insulin level became higher, while the HDL cholesterol level decreased. In addition, total cholesterol and LDL cholesterol levels increased as the insulin level became higher and lipoprotein(a) levels decreased in the men. Fibrinogen levels were not related to the insulin level in either sex. Multiple logistic regression analysis revealed that fasting insulin levels were positively correlated with body mass index and fasting glucose and factor VII activity levels, whereas they were negatively correlated with HDL cholesterol in both sexes. In addition, fasting insulin levels were positively correlated with LDL cholesterol levels in men and with triglyceride levels in women. Our results indicate that hyperinsulinemia is associated with high factor VII activity in a general Japanese population as well as with high blood pressure and dyslipidemia. The accumulation of these cardiovascular risk factors in hyperinsulinemic subjects appears to contribute to cardiovascular events in the Japanese as well as in westerners.

Adult↗

PubMed1995

Correlation between lipoprotein(a) and aortic valve sclerosis assessed by echocardiography (the JMS Cardiac Echo and Cohort Study).

An elevated serum level of lipoprotein(a) (Lp[a]) may be an independent risk factor for atherosclerotic disease, but the relation of Lp(a) to aortic valve (AV) sclerosis has not been determined. We measured serum concentrations of Lp(a) and investigated their relation to the presence of echocardiographic AV sclerosis in residents of a rural village in Japan. We measured serum Lp(a) levels in 347 men and 437 women aged 35 to 90 years (mean +/- SD: 62 +/- 11 years) who participated in mass screening examinations in Wara village, Gifu, Japan. AV sclerosis was assessed by long- and short-axis 2-dimensional echocardiographic views and continuous-wave Doppler echocardiography. AV sclerosis was graded as follows: 0 = normal AV; 1 = increased echo density; 2 = thickening or calcific deposits > or = 3 mm; and 3 = same as 2 with mildly restricted motion (pressure gradient < 16 mm Hg). Lp(a) levels ranged from < 1 mg/dl to 153 mg/dl. The 25th, 50th, and 75th percentile values were 7, 16, and 28 mg/dl, respectively. Lp(a) levels were significantly higher in women than in men (p < 0.01), and did not increase significantly with age. The prevalence of AV sclerosis (grades 2 and 3) increased significantly with age (p < 0.001). AV sclerosis was present in 65 (36.1%) of 180 subjects with Lp(a) levels > or = 30 mg/dl and in 77 (12.7%) of 604 subjects with Lp(a) levels < 30 mg/dl (p < 0.001). There were no significant differences in the prevalence of AV sclerosis in terms of sex, blood pressure, or levels of total cholesterol, high-density lipoprotein cholesterol, triglycerides, or blood sugar. We conclude that increased serum levels of Lp(a), as well as aging, are closely related to AV sclerosis.

Adult↗

PubMed1995

Lipoprotein(a) levels in the Japanese population: influence of age and sex, and relation to atherosclerotic risk factors. The Jichi Medical School Cohort Study.

The authors studied the distribution of lipoprotein(a) (Lp(a)) levels with stratification for age and sex, as well as the relation between Lp(a) and atherosclerotic risk factors in a large Japanese population between 1992 and 1993. The subjects were 1,235 males and 1,762 females over 30 years old. Lp(a) was measured by an enzyme-linked immunosorbent assay. Lp(a) levels were higher in females than in males. The increase in Lp(a) with age was statistically significant, and the proportion of subjects with Lp(a) levels > 30 mg/dl also increased with age. In the obese subjects (body mass index (BMI) (kg/m2) > 26), Lp(a) levels were lower than in the non-obese subjects (BMI < or = 26) (p < 0.01 in males; p < 0.05 in females). Male alcohol drinkers had lower Lp(a) levels than nondrinkers (p < 0.05). Age, low density lipoprotein subtracting Lp(a) cholesterol [Lp(a) x 0.3], and fibrinogen level were all positively correlated with Lp(a) in both sexes. Alcohol consumption (g/day) and triglycerides were inversely correlated with Lp(a) in males, while total cholesterol subtracting Lp(a) cholesterol [Lp(a) x 0.3], high density lipoprotein, and factor VII were positively correlated in females. Multiple logistic regression analysis showed that triglycerides in males and BMI and fibrinogen in females were significant independent variables. The authors conclude that Lp(a) level is affected by various factors, such as alcohol drinking, BMI, sex, and age, and is not only correlated with lipid levels but also with hemostatic factors such as fibrinogen and factor VII.

Adult↗

PubMed1995

[Perceived quality of life and social factors in elderly hypertensive patients].

We conducted a cross-sectional study of elderly outpatients with hypertension to examine the relationship between quality of life (QOL) scores and social background factors. The subjects consisted of 516 outpatients (267 females), age of 60 or over, at nine clinics of major hospitals which participated in the National Cardiovascular Center Research Project. The perceived QOL was evaluated by the QOL scale originally based on Japanese patients with cardiovascular diseases. The scale consisted of the following 5 subscales; difficulty due to disease, psychological stability, independence, satisfaction in daily living and vitality. The background factors included family structure, socioeconomic factors and work status, and physical activity of daily living (ADL). After adjusting for age, sex, administered drugs and complicating conditions such as ischemic heart disease and/or apoplexy, a significant odds ratio of a low score of difficulty due to disease, psychological stability, satisfaction in daily living and vitality was found in the impaired physical ADL group with low socioeconomic class, and a significant odds ratio of low score of independence were found in the impaired physical ADL group who had lost jobs due to illness and had no children.

Aged↗

PubMed1995

Genetic determinants of plasma factor VII activity in the Japanese.

We investigated the frequency of the factor VII Gln353 (FVII Gln353) allele in Japan, where coronary artery disease is much less common and factor VII coagulant activity (FVIIc) is lower than in Western countries. Japanese males (n = 144) aged 40-59 years living in 2 different districts were studied, and the FVIIc and activated factor VII (FVIIa) levels were measured with human (FVIIa Hum) and bovine soluble tissue factor (FVIIa Bov). The frequency of the FVII Gln353 allele in the 2 districts was 0.026 and 0.052 (combined: 0.034), which was about one third of that in a European population. Thus, the lower FVIIc level in Japanese is not due to the effect of FVII Gln353 allele. Ten individuals with the Gln353 allele showed a 39% decrease of FVIIa Hum levels and a 29% decrease of the FVIIa Bov level compared with 134 individuals homozygous for the FVII Arg353 allele. These decreases of FVIIa were greater than the decrease of FVIIc (17%), suggesting that FVII Gln353 may be difficult to activate in vivo. The marked decrease of FVIIa levels in individuals with the FVII Gln353 allele suggests that they are genetically protected against cardiovascular disease irrespective of ethnic background, by virtue of their decreased FVIIa level.

Adult↗

PubMed1995

Effect of the angiotensinogen gene Met235-->Thr variant on blood pressure and other cardiovascular risk factors in two Japanese populations.

OBJECTIVE: To investigate the gene frequency of the T235 allele and its relationship with hypertension in two Japanese populations. METHODS: T235 was investigated by restriction fragment length polymorphism using the polymerase chain reaction technique in 213 Japanese males aged 40-59 years, who were randomly selected from participants in the Jichi Medical School Cohort Study (Awaji-Hokudan population, n = 157; Niigata-Yamato population, n = 56). RESULTS: The gene frequency of the T235 allele in the two populations was very similar (Awaji-Hokudan 0.65, Niigata-Yamato 0.62; mean 0.64). The T235 frequency was 0.60 in normotensive males, approximately 1.2- to 1.7-fold that in Caucasians. Hypertension, in particular that associated with a positive family history of hypertension, was more common in individuals homozygous for the T235 allele. The levels of total cholesterol, blood glucose and fibrinogen showed a weak and non-significant relationship with the angiotensinogen genotype. CONCLUSION: The T235 angiotensinogen allele was more common in Japanese than in Caucasians, and was a predisposing factor for hypertension.

Adult↗

PubMed1994

Close relation between lipoprotein (a) levels and atherothrombotic disease in Japanese subjects > 75 years of age.

Levels of lipoprotein (a) (Lp[a]) and various hemostatic factors were studied in 132 Japanese aged > 75 years (mean 83). The group consisted of 50 healthy persons, 36 hypertensive subjects, 31 patients with chronic cerebral infarction, and 15 with coronary artery disease. Lp(a) levels were slightly lower in the healthy "old old" subjects than in the 184 healthy younger adults (mean +/- SD: 10.7 +/- 7.9 vs 12.1 +/- 10.1 mg/dl). There were no gender-related differences in the Lp(a) levels of healthy adults and healthy old old subjects. Lp(a) levels were higher in the hypertensive old old subjects (14.6 +/- 15.4 mg/dl) and the old old patients with cerebral infarction (21.3 +/- 16.2 mg/dl) and coronary artery disease (26.5 +/- 20.4 mg/dl). The prevalence of subjects with high Lp(a) levels (> 30 mg/dl) was the greatest among old old patients with coronary artery disease (27%). Lp(a) levels in the 132 old old subjects showed positive correlations with sialic acid, fibrinogen, factor VII activity, and D-dimer levels. These results indicate a close association between Lp(a) levels and atherothrombotic disease as well as the characteristics of Lp(a) as an acute phase reactant in old old Japanese. Subjects with higher Lp(a) levels may develop cardiovascular disease later in life, whereas the remaining healthy old old subjects have lower Lp(a) levels.

Aged↗

PubMed1994

[Development of a perceived social support scale: for a Japanese population].

Social support is increasingly attracting interest in as a factor in epidemiological research of disease risks. However, at present, few methods for measuring social support that can be credited as having reliability and validity exist in Japan. Therefore a perceived social support scale was developed in relation to a population study of a town in Fukuoka prefecture. A method for measuring functional support from several external sources was designed consisting of a self-administered test provided with only two available response options--yes & no. Pretests were conducted twice in order to evaluate content validity and adjust the number of determinants and resulted in spouse, family members, and friends being selected to be primary sources of support. A factor analysis was applied to select 10 conditions with high internal consistency for each of the sources. Responses were scored 0 or 1, for 'no' or 'yes,' respectively. Subsequently each set of 10 variables was summed into an index ranking social support conditions for each of the three sources. The three highest ranking indicators from each of the respective sources were then integrated into a single comprehensive total social support score of the individuals. The inquiry method was applied on 277 adults, aged from 40 to 69 years, in the town. Intercorrelation between the indicators of support derived from the three sources was low and coefficients of reliability ranged from 0.892 to 0.978. The score of each set of the 10 variables were incorporated into a principal components analysis in order to determine factorial validity. All of the first factor loadings of the items measuring support from both spouse and family were greater than 0.7 and high eigenvalues were obtained. Therefore the methods applied to spouse and family were considered adequate to measure a given construct. The items measuring support from friends were divided into two factors, emotional support and tangible support.

Adult↗

PubMed1992

[Health problems treated by primary care physician].

For the purpose of clarifying functions expected of primary care physicians (PC physicians) in Japan, a study of the types and frequencies of health problems seen in primary care clinics located in three areas, together with consultation/referral rates of the patients to other institutes. The study was conducted using ICHPPC-2 (Japan version) which had been compiled by WONCA as a classification of diseases. In order to obtain much more generalized characteristics of the primary care, clinics located in the city, suburban district and remote places in the mountains were studied. The results were as follows: 1) The health problems treated by the clinics in each of the three areas were respectively: 162 types/7,207 items/4 months: 303 types/17,519 items/2 years: and 280 types/61,916 items/2 years. 2) The consultation/referral rates were under 2%. 3) PC physicians treated over 98% of the health problems encountered. This was found by the investigation, which had been intended to disclose a range of so-called COMMON DISEASES treated by PC physicians themselves, based on a relation between the referral rates and the types of health problems. The above findings suggested that the COMMON DISEASES should include at least 95% of the health problems which had been treated by the PC physicians. This corresponded to approximately 100 types of diseases.

Humans↗

PubMed1990

The relevance of psychosocial factors in acute ischemic heart disease. A case-control study of a Japanese population.

We investigated, by case-control study, the relevance of psychosocial factors on the prevalence of acute ischemic heart disease (IHD) in middle aged Japanese men. We questioned 109 acute IHD patients and 80 individuals in an age-adjusted sampled control group. Multiple logistic regression analysis showed the following statistically significant factors: hypertension (odds ratio 4.01, p less than 0.001), Type A behavior pattern (2.25, p less than 0.05) and high job demand (2.23, p less than 0.02). No direct influence of family function or social support to the prevalence of acute IHD was apparent. These results suggest that, among men in Japan, Type A behavior pattern and high job demand represent psychosocial risk factors of IHD. Due to the case-control protocol, causal relationships cannot be decided. The limitation of the study design is discussed within that context.

Coronary Disease↗

PubMed1989

[Tuberculosis and cancer: primary lung cancer cases after treatment with anti-tuberculous drugs].

Out of 939 primary lung cancer cases (histologically confirmed), 54 cases had received treatment with anti-tuberculous drugs before diagnosis of lung cancer was made. Fifty-one percent of the cases were detected by the mass survey and 55.6% of them were adenocarcinoma. The duration of treatment for tuberculosis was less than 3 months in 63.0% and more than 13 months in 5.6% of the cases. Surgery for lung cancer was performed in 25 cases (46.3%). The ratio of surgical intervention for patients previously treated with anti-tuberculous drugs was not different from that for patients who had received no anti-tuberculous drugs.

Adenocarcinoma↗

PubMed1985

Cardiovascular and blood gas responses to ketanserin in canine pulmonary edema induced by oleic acid.

This study was performed to determine the cardiovascular and respiratory effects of ketanserin, a specific 5-HT2 antagonist, following oleic acid lung injury in anesthetized dogs. Following intravenous administration of oleic acid (0.1 ml/kg) to a control group (N = 7), systemic blood pressure decreased significantly. This lowered level of systemic blood pressure was maintained throughout the experiment. Cardiac output gradually decreased following oleic acid administration, while total peripheral resistance, pulmonary vascular resistance, and pulmonary arterial pressure were increased significantly. In a group treated with intravenous ketanserin (0.16 mg/kg, N = 7) 60 min after the injection of oleic acid, no decrease in cardiac output was seen. The increased total peripheral resistance, pulmonary vascular resistance, and pulmonary arterial pressure following injection of oleic acid also were returned toward preoleic acid levels. However systemic blood pressure showed no significant improvement after treatment with ketanserin nor did ketanserin protect against progressive hypoxemia following pulmonary injury with oleic acid. A progressive increase in hemoglobin concentration was seen after oleic acid in the control group. This recovered toward the preoleic acid level following treatment with ketanserin. The postmortem lung wet-dry weight ratio was significantly lower in the treated group compared with the control group. In conclusion, these data suggest that serotonin may have a role in including cardiopulmonary hemodynamic disturbances and in producing increases in extravascular lung water when pulmonary edema is induced by oleic acid injection in anesthetized dogs.

Animals↗

PubMed1985