Biomedical subjects

Isao Kato

Publications and source records attributed to Isao Kato.

26 records · Page 2Linked to original sources

PubMed2003

Dietary factors and development of impaired glucose tolerance and diabetes in a general Japanese population: the hisayama study.

BACKGROUND: There have been few prospective studies on diet and glucose abnormalities as determined by oral glucose tolerance test. METHODS: To investigate the impact of dietary factors on the development of glucose intolerance including diabetes and impaired glucose tolerance, we performed a follow-up survey of 1,075 subjects aged 40-74 years of normal glucose tolerance from 1988 through 1993/1994 by repeated 75 g oral glucose tolerance test and dietary survey. Information on habitual food consumption was obtained using a semiquantitative food frequency method. RESULTS: Of the total subjects studied, 119 (11.1%) developed impaired glucose tolerance and 24 (2.2%) developed diabetes during the follow-up. At baseline, the age-adjusted amount of alcohol intake was significantly higher in males who developed glucose intolerance than in those who did not (26.7 g vs. 15.7 g, p < 0.05), while the polyunsaturated/saturated fatty acids (P/S) ratio was significantly higher in females with future glucose intolerance (1.42 vs. 1.31, p < 0.05). Among the female subjects who developed glucose intolerance, the intake of animal fat less decreased during the follow-up period compared with normal subjects, resulting in a significant decrease in the P/S ratio (-0.09 vs. 0.05, p < 0.05). In a multiple logistic regression analysis, alcohol intake at baseline for males and decreased P/S ratio during the follow-up for females remained a significant risk factor for glucose intolerance independent of other dietary and non-dietary factors as well. CONCLUSIONS: These results suggest that a high intake of alcohol and a decreased P/S ratio contribute to the risk of glucose intolerance in contemporary Japanese.

Adult↗

PubMed2003

Age- and sex-specific prevalence of diabetes and impaired glucose regulation in 11 Asian cohorts.

OBJECTIVE: To report the age- and sex-specific prevalence of diabetes and impaired glucose regulation (IGR) according to revised World Health Organization criteria for diabetes in Asian populations. RESEARCH DESIGN AND METHODS: We performed 11 studies of 4 countries, comprising 24,335 subjects (10,851 men and 13,484 women) aged 30-89 years who attended the 2-h oral glucose tolerance test and met the inclusion criteria for data analysis. RESULTS: The prevalence of diabetes increased with age and reached the peak at 70-89 years of age in Chinese and Japanese subjects but peaked at 60-69 years of age followed by a decline at the 70 years of age in Indian subjects. At 30-79 years of age, the 10-year age-specific prevalence of diabetes was higher in Indian than in Chinese and Japanese subjects. Indian subjects also had a higher prevalence of IGR in the younger age-groups (30-49 years) compared with that for Chinese and Japanese subjects. Impaired glucose tolerance was more prevalent than impaired fasting glycemia in all Asian populations studied for all age-groups. CONCLUSIONS: Indians had the highest prevalence of diabetes among Asian countries. The age at which the peak prevalence of diabetes was reached was approximately 10 years younger in Indian compared with Chinese and Japanese subjects. Diabetes and IGR will be underestimated in Asians based on the fasting glucose testing alone.

Adult↗

PubMed2002

Effect of glucose, maltose, soluble starch, and CO2 on the growth of the hyperthermophilic archaeon Pyrococcus furiosus.

The hyperthermophilic archaeon Pyrococcus furiosus was cultivated in batch and continuous fermentations on different carbon substrates. The cultivation of P furiosus on soluble starch as the only carbon source resulted in cell densities three times higher than in cultivations on maltose, 1.06 x 10(10) cells/ml compared to 3.4 x 10(9) cells/ml. The yield coefficient, Y(x/y) = 0.12 g/g, and the growth rate, mu = 0.33 h(-1), were almost equal on soluble starch and on maltose, but on glucose no growth could be detected. An inhibitory effect of glucose, when added to other carbon substrates, also could not be found. Isobutyric and isovaleric acid were detected as novel metabolites produced by P. furiosus. Inhibitory effects of these acids, as well as of the well-known products acetic acid, propionic acid, and alanine, could be precluded. Concentrations of 10% CO2 in the gas supply respective to the exhaust gas enhanced the growth of P furiosus significantly. The maximum cell number was two orders of magnitude higher than was observed with pure nitrogen. Further increase of the CO2 concentration up to 100% had no significant effect on the growth of P. furiosus.

Carbon Dioxide↗

PubMed2002

Alcohol reduces insulin-hypertension relationship in a general population: the Hisayama study.

Insulin resistance may be a factor in the etiology of hypertension, and habitual alcohol intake may modify this relationship. We prospectively examined this hypothesis in 1,133 nonhypertensive, nondiabetic Japanese subjects, aged 40-79 years. Alcohol drinkers were more frequent among men than women at baseline (57.7 vs. 8.2%). The age-adjusted incidence of hypertension significantly increased with the elevating baseline insulin levels in women (P =.003 for trend), but not in men. The age- and sex-adjusted insulin levels and insulin resistance index decreased with elevating alcohol intake, while fasting glucose levels remained unchanged, suggesting that alcohol improves insulin sensitivity. Among nondrinkers, the age-adjusted incidence of hypertension significantly increased with elevating insulin tertiles in both sexes (P =.048 and.002 for trend in men and women, respectively), but not among drinkers. Our findings suggest a close association between insulin resistance and the incidence of hypertension in Japanese. However, alcohol modified and reduced this relationship.

Adult↗

PubMed2002

Alcohol intake and future incidence of hypertension in a general Japanese population: the Hisayama study.

BACKGROUND: The question remains as to whether light to moderate alcohol intake is associated with an increased risk of hypertension. METHODS: In 1978, a total of 1101 residents (433 men and 668 women) in a subrural community, Hisayama, in Japan, aged 40 years or more, with normal blood pressure, who were free from cardiovascular disease, were enrolled in a 10-year follow-up study. Inquiries regarding regular drinking were made in an interview based on a self-administered questionnaire. RESULTS: During the follow-up, 101 men and 166 women developed hypertension (blood pressure > or =140/90 mm Hg or use of antihypertensive drugs). The age-adjusted incidence of hypertension among current male drinkers increased significantly even with a light intake of alcohol (<23 g of ethanol per day). In women, the incidence was also significantly higher in drinkers than in nondrinkers. In multivariate analysis, alcohol intake, in addition to age and body mass index, remained a significant independent risk factor for hypertension in men, but not in women. In men, all three categories of current drinking were found to be significant risk factors for the development of hypertension after adjustment for age and body mass index [relative risk (RR), 2.00; 95% confidence interval (CI), 1.07-3.76 for light drinking compared with nondrinking; RR, 2.60; 95% CI, 1.50-4.49 for moderate drinking (23-45 g per day); and RR, 2.24; 95% CI, 1.26-3.99 for heavy drinking (> or =46 g/day)]. CONCLUSIONS: Our results suggest that alcohol intake, even light drinking, is a predictor of future hypertension among Japanese men.

Adult↗

PubMed2002

Codenitrification and denitrification are dual metabolic pathways through which dinitrogen evolves from nitrate in Streptomyces antibioticus.

We screened actinomycete strains for dinitrogen (N(2))-producing activity and discovered that Streptomyces antibioticus B-546 evolves N(2) and some nitrous oxide (N(2)O) from nitrate (NO(3)(-)). Most of the N(2) that evolved from the heavy isotope ([(15)N]NO(3)(-)) was (15)N(14)N, indicating that this nitrogen species consists of two atoms, one arising from NO(3)(-) and the other from different sources. This phenomenon is similar to codenitrification in fungi. The strain also evolved less, but significant, amounts of (15)N(15)N from [(15)N]NO(3)(-) in addition to (15)N(15)NO with concomitant cell growth. Prior to the production of N(2) and N(2)O, NO(3)(-) was rapidly reduced to nitrite (NO(2)(-)) accompanied by distinct cell growth, showing that the actinomycete strain is a facultative anaerobe that depends on denitrification and nitrate respiration for anoxic growth. The cell-free activities of denitrifying enzymes could be reconstituted, supporting the notion that the (15)N(15)N and (15)N(15)NO species are produced by denitrification from NO(3)(-) via NO(2)(-). We therefore demonstrated a unique system in an actinomycete that produces gaseous nitrogen (N(2) and N(2)O) through both denitrification and codenitrification. The predominance of codenitrification over denitrification along with oxygen tolerance is the key feature of nitrate metabolism in this actinomycete.

Aerobiosis↗

PubMed2002

Plasma homocyst(e)ine concentrations and the risk of subtypes of cerebral infarction. The Hisayama study.

Moderately elevated plasma total homocyst(e)ine (tHcy) levels have been linked with cardiovascular disease. However, the findings of previous studies regarding the relationship between tHcy levels and subtypes of cerebral infarction (CI) have been conflicting. The aim of the present study was to examine this issue in a community-based case-control study performed in Hisayama Town in Japan. Fasting tHcy levels were compared among 75 CI cases, of which 43 were lacunar (LI), 24 atherothrombotic (ATI) and 8 cardioembolic infarctions (CEI), and 248 age- and sex-matched healthy controls. The mean tHcy concentrations were higher in CI than in controls (13.0 vs. 11.8 micromol/l; p = 0.018). LI and CEI also had significantly higher tHcy levels than did the corresponding controls (12.3 vs. 11.3 micromol/l for LI; p = 0.037 and 16.3 vs. 12.7 micromol/l for CEI; p = 0.036). The same tendency was also observed for ATI, but the difference was only marginally significant probably due to the small number of the cases (13.4 vs. 11.9 micromol/l; p = 0.087). After adjustment for age, sex, hypertension, serum creatinine, total protein, folate and vitamin B(12) levels, the risk of LI was not significant in the second tertile of the tHcy distribution, but significantly increased in the third compared with the first tertile (adjusted odds ratio, AOR, 3.4; 95% confidence limits, CL, 1.3-8.9; p = 0.015), while the risk of ATI was significant even in the second tertile (AOR, 5.0; 95% CL, 1.0-23.7; p = 0.042) and higher in the third tertile (AOR, 7.5; 95% CL, 1.5-38.3; p = 0.015). However, the odds ratios for CEI could not be estimated, as there was no case of CEI in the first tertile. These findings suggest that elevated tHcy is an independent risk factor for all subtypes of CI, but that its impact is higher in ATI and probably in CEI than in LI.

Aged↗

PubMed2002

Detection of angiotensin-converting enzyme gene insertion/deletion polymorphism from paraffin-embedded tissues: the Hisayama study.

Previous studies have suggested that archival materials from formalin-fixed paraffin-embedded blocks are unsuitable for most molecular techniques because the extracted DNA can be severely degraded. Therefore, the present study was designed to investigate the accuracy of genotyping for the insertion (I)/deletion (D) polymorphism of the angiotensin-converting enzyme (ACE) gene from paraffin-embedded tissues of autopsy cases from Hisayama Town, Japan. The genotype was determined using the double polymerase chain reaction method and to test the accuracy of the method, the polymorphism was investigated using paraffin-embedded tissues from 18 cases whose ACE genotypes (6 cases for each genotype) were known in advance from analysis of fresh-frozen tissue samples. Genotyping using paraffin-embedded tissues was then determined for 968 autopsy subjects. The genotype could be determined in 16 of the 18 test samples (88.9%) and there was no discrepancy with the results obtained from the fresh-frozen tissues. Of the 968 autopsy cases, the frequency of the DD, ID, and II genotypes was 12.4%, 47.3%, and 40.3%, respectively, a distribution that did not deviate from the Hardy-Weinberg equilibrium (chi(22df )= 0.67, p=0.72). These findings suggest the accuracy of the present method of ACE genotyping from paraffin-embedded tissues.

Autopsy↗