Biomedical subjects

Mamoru Ishikawa

Publications and source records attributed to Mamoru Ishikawa.

9 recordsLinked to original sources

PubMed2006

Longevity-associated NADH dehydrogenase subunit-2 237 Leu/Met polymorphism influences the effects of alcohol consumption on serum uric acid levels in nonobese Japanese men.

NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is reportedly associated with longevity in the Japanese population. The ND2-237Met genotype may confer resistance to cardiovascular and cerebrovascular atherogenic diseases. Hyperuricemia is one of the risk factors for cardiovascular disease. To investigate whether ND2-237 Leu/Met polymorphism is associated with serum uric acid (SUA) levels, we conducted a cross-sectional study in 321 healthy Japanese male subjects. In nonobese (body mass index, BMI<25) male subjects, interaction between ND2-237 Leu/Met genotypes and drinking frequency on SUA levels was observed (P=0.031). The SUA levels were significantly higher in daily drinkers with ND2-237Leu than in non-daily drinkers with ND2-237Leu (P=0.018). In nonobese men, after adjustment for covariates, daily drinkers with ND2-237Leu had a significantly higher odds ratio (OR) for hyperuricemia (SUA> or =6.5 mg/dl: vs. daily drinkers with ND2-237Met, OR=3.26, 95% confidence interval (CI) 1.14-9.29; vs. non-daily drinkers with ND2-237Leu, OR=3.22, 95% CI 1.39-7.45; SUA> or =7.0 mg/dl: vs. non-daily drinkers with ND2-237Met, OR=3.53, 95% CI 1.00-12.4). However, in obese (BMI> or =25) men, no significant interaction between ND2-237 Leu/Met polymorphism and habitual drinking on SUA levels or on the risk for hyperuricemia was observed. These results suggest that ND2-237 Leu/Met polymorphism modulates the effects of daily alcohol consumption on SUA levels in nonobese Japanese men.

Alcohol Drinking↗

PubMed2005

Longevity-associated mitochondrial DNA 5178 C/A polymorphism is associated with fasting plasma glucose levels and glucose tolerance in Japanese men.

Mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism is reportedly associated with longevity in the Japanese population, and the Mt5178A genotype may resist the onset of type 2 diabetes. To investigate whether Mt5178 C/A polymorphism is associated with glucose tolerance, we conducted a cross-sectional study using the 75-g oral glucose tolerance test (OGTT) in which non-diabetic Japanese male subjects were classified into three subgroups by body mass index (BMI): BMI<22 (n=91); 22< or =BMI<25 (n=138); and BMI> or =25 (n=67). The frequency of Mt5178A was significantly lower among 'BMI<22' subjects exhibiting impaired fasting glucose and impaired glucose tolerance than among those with normal glucose tolerance. In the 'BMI<22' group, fasting plasma glucose (FPG) levels and plasma glucose levels at 60 and 120 min after glucose load (OGTT-1h and OGTT-2h, respectively) were significantly lower in the Mt5178A genotype than in the Mt5178C genotype. After adjusting for age, BMI, habitual smoking, habitual drinking and family history of diabetes, FPG levels and OGTT-2h levels were still significantly lower in the Mt5178A genotype than in the Mt5178C genotype. However, after adjusting for covariates, in both the '22< or =BMI<25' and 'BMI> or =25' groups, FPG levels were significantly higher in the Mt5178A genotype than in the Mt5178C genotype. Differences in the effect of alcohol consumption on FPG levels and glucose tolerance between the Mt5178 C/A genotypes were observed. The present results suggest that Mt5178 C/A polymorphism may be associated with FPG levels and glucose tolerance in middle-aged Japanese men.

Blood Glucose↗

PubMed2005

Longevity-associated NADH dehydrogenase subunit-2 polymorphism and serum electrolyte levels in middle-aged obese Japanese men.

Mitochondrial DNA 5178 cytosine/adenine polymorphism, which is also called NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with Japanese longevity. This polymorphism is widely associated with blood pressure, serum lipid levels, hematological parameters, intraocular pressure, and serum protein fraction levels. However, there have been no reports on the association between ND2-237 Leu/Met polymorphism and serum electrolyte levels. To investigate this relationship, we performed an association study in 321 healthy middle-aged Japanese men. Crude data showed that serum sodium levels and serum chloride levels were significantly lower in men with ND2-237 Met than in those with ND2-237 Leu (P = 0.021 and 0.003, respectively). Cigarette consumption and body mass index were significantly and positively associated with serum chloride levels (P = 0.002 and 0.008, respectively) and hemoglobin levels were significantly and negatively associated with them (P = 0.007) in ND2-237 Leu genotypic men. In men with ND2-237 Met, only hemoglobin levels were significantly and negatively associated with serum chloride levels (P = 0.025). After adjusting for covariates, only in male obese (body mass index> or =25) subjects, serum sodium and chloride levels remained significantly lower, and serum calcium levels appeared to be significantly higher in ND2-237 Met than in ND2-237 Leu (P = 0.013, <0.001, and 0.046, respectively). Longevity-associated NADH dehydrogenase subunit-2 polymorphism may influence serum electrolyte levels in middle-aged obese Japanese men.

Amino Acid Substitution↗

PubMed2004

Longevity-associated mitochondrial DNA 5178 A/C polymorphism is associated with intraocular pressure in Japanese men.

BACKGROUND: Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism has been reported to be associated with longevity in Japanese individuals, with experimental findings concluding that mt5178 A is an anti-atherogenic genotype. The aim of this study was to determine whether mt5178 A/C polymorphism influences intraocular pressure (IOP), and its relationship with the development of arteriosclerosis. METHODS: Four hundred and forty-nine male volunteers who had visited a general hospital for medical check-up between August 1999 and August 2000 were enrolled. Of these, 386 Japanese men who had not undergone any medical treatment for hypertension, ocular hypertension or glaucoma were selected as subjects of this study. After these subjects were genotyped, a cross-sectional study regarding the relationship between genotype and IOP was conducted. RESULTS: Mean IOP was significantly higher in men with mt5178 C (13.3 mmHg) than in those with mt5178 A (12.7 mmHg) (P = 0.037). This significant difference in mean IOP between the two genotypes remained evident after adjusting for age, body mass index, blood pressure, habitual smoking and habitual drinking. Interactions between mt5178 A/C polymorphism and habitual smoking or daily alcohol consumption with regard to IOP were observed. According to multiple regression analysis, habitual smoking was significantly associated with IOP in men with mt5178 A (P for trend = 0.020), while daily alcohol consumption was significantly associated with IOP in those with mt5178 C (P for trend = 0.021). CONCLUSION: Longevity-associated mitochondrial DNA 5178 A/C polymorphism may be associated with IOP in Japanese men.

Blood Pressure↗

PubMed2003

Longevity-associated mitochondrial DNA 5178 A/C polymorphism influences effects of cigarette smoking on serum protein fraction levels in Japanese men.

Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism is reportedly associated with longevity and susceptibility to age-related diseases in Japanese individuals. We previously reported an association between mt5178 A/C polymorphism and serum protein fraction levels in healthy Japanese women. An association between habitual smoking and serum protein fraction levels has also been reported previously. The aim of this study was to examine whether mt5178 A/C polymorphism influenced the effects of habitual smoking on serum protein fraction levels in 321 healthy Japanese men. In mt5178C genotype men, alpha-1 and alpha-2 globulin levels were higher in smokers than in nonsmokers (P<0.001, and P=0.002, respectively). The influence of smoking on these globulin levels depended on cigarette consumption. However, in mt5178A genotype men, no significant difference was observed in alpha-1 or alpha-2 globulin levels between smokers and nonsmokers. These results suggest that longevity-associated mt5178 A/C polymorphism may influence the effects of cigarette smoking on serum protein fraction levels in healthy Japanese men.

Aging↗

PubMed2003

Longevity-associated mitochondrial DNA 5178 A/C polymorphism modulates effects of daily drinking and cigarette consumption on serum triglyceride levels in middle-aged Japanese men.

Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism is one of the longevity-associated mitochondrial DNA polymorphisms. The frequency of the mt5178A genotype is significantly higher in Japanese centenarians than in the general population. We previously reported that serum high-density lipoprotein cholesterol levels were significantly higher in men with mt5178A than in those with mt5178C. However, this significant difference disappeared after adjusting for drinking frequency. To investigate the interaction between mt5178 A/C polymorphism and habitual drinking on serum lipid levels, we performed an association study in 321 healthy middle-aged Japanese men. Interaction between mt5178 A/C polymorphism and daily drinking on serum triglyceride (TG) levels was observed (P=0.019). Moreover, interaction between mt5178 A/C polymorphism and cigarette consumption on serum TG levels was also observed (P=0.022). Multiple regression analysis showed that, in men with mt5178A, daily drinking decreased TG levels (P=0.025), and cigarette consumption increased TG levels (P<0.001), while in men with mt5178C, the effects of daily drinking and cigarette consumption on TG levels were unclear. No interaction was observed on other lipid levels. Longevity-associated mitochondrial DNA 5178 A/C polymorphism thus influences the effects of daily drinking and cigarette consumption on TG levels in middle-aged Japanese men.

Alcohol Drinking↗

PubMed2002

Association of the longevity-associated mitochondrial DNA 5178 A/C polymorphism with serum protein fraction levels in healthy Japanese women.

Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism was reported to be associated with longevity and susceptibility to adult-onset diseases in Japanese. To examine whether mt5178 A/C genotypes are associated with serum protein fraction profiles, we genotyped 461 healthy Japanese individuals, and studied the relationship of mt5178 A/C genotypes to both proportion and levels of serum protein fraction. The mt5178 A/C was genotyped using polymerase chain reaction-restriction fragment length polymorphism method. The alpha-1, alpha-2, and beta globulin proportions in females carrying mt5178A were significantly higher than those in females carrying mt5178C (P=0.002, 0.006, and 0.008, respectively). Moreover, the alpha-1, alpha-2, and beta globulin levels in females carrying mt5178A were significantly higher than those in females carrying mt5178C (P=0.001, 0.002, 0.018, respectively). This difference in globulin fraction level between the two genotypes was more evident in premenopausal females than in postmenopausal females. However, no such difference was found in males. These results provide the first evidence that the mt5178 A/C polymorphism may influence the serum protein fraction levels of the healthy Japanese women.

Adult↗

PubMedDate not supplied

Interaction between longevity-associated mitochondrial DNA 5178 C/A polymorphism and cigarette smoking on hematological parameters in Japanese men.

Mitochondrial DNA 5178 C/A (mt5178 C/A), namely NADH dehydrogenase subunit 2 237 Leu/Met, polymorphism is as reported in literature associated with longevity and susceptibility to ischemic heart disease or cerebrovascular disorders in the Japanese population. Previous reports suggested that mt5178A genotype exerts antiatherogenic effects. The aim of this study was to investigate whether mt5178 C/A polymorphism is associated with hematological parameters, such as thrombogenic risk factors for myocardial infarction and stroke, in 321 healthy Japanese men. No significant differences were observed between mt5178 C/A genotypes, but in subjects with body mass index (BMI) of < or = 23, this polymorphism influenced the effects of habitual smoking on hematological parameters. Red blood cell (RBC) counts were significantly lower and mean corpuscular hemoglobin (MCH) levels were significantly higher in smokers with mt5178A than nonsmokers with mt5178A. Platelet counts were significantly higher in smokers with mt5178C than nonsmokers with mt5178C. Cigarette consumption was strongly associated with RBC counts, mean corpuscular volume levels, and MCH levels for men with mt5178A, and was associated with platelet counts for those with mt5178C. Moreover, BMI was significantly positively associated with RBC counts and platelet counts only in men with mt5178A, age was significantly negatively associated with RBC counts only in men with mt5178C. These data suggest that mt5178 C/A polymorphism may influence the effects of cigarette smoking on hematological parameters in healthy BMI < or = 23 Japanese men.

Age Factors↗

PubMedDate not supplied

Association of life-style with intraocular pressure in middle-aged and older Japanese residents.

PURPOSE: To evaluate the associations of several life-style-related factors with intraocular pressure (IOP). METHODS: Of a total of 649 men and women who had been examined in an annual health check-up being conducted by a general hospital in Ibaraki prefecture, Japan, 569 individuals (age range, 29-79 years) who had not undergone any medical treatment for hypertension, ocular hypertension, or glaucoma, were selected as the subjects of this study. The associations of several life-style-related factors with the IOP were evaluated by multiple regression analyses and analyses of covariance. RESULTS: Body mass index (BMI), alcohol consumption score, and cigarette consumption were found to have a significantly positive association with the IOP in men (P for trend =.002, <.001, and <.001, respectively). In women also, the BMI was positively related to the IOP (P for trend =.071). In respect to the effects of coffee consumption, it was shown that in men the mean IOP adjusted for age, the BMI, alcohol intake score, cigarette consumption, and blood pressure were significantly lower in habitual coffee drinkers than in coffee abstainers (P =.016). CONCLUSION: The results of this study suggest that the IOP level may be substantially affected by daily life-style among Japanese.

Adult↗