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

Do MDR1 and SLCO1B1 polymorphisms influence the therapeutic response to atorvastatin? A study on a cohort of Egyptian patients with hypercholesterolemia

BACKGROUND

Statins are among the most prescribed drugs worldwide to reduce the risk of cardiovascular events. Interindividual variability in drug response is a major clinical problem and is of concern during drug development. Statins, such as atorvastatin, are taken orally and access to their site of action in the liver is greatly facilitated by both intestinal and hepatic transporters.

OBJECTIVE

To examine the impact of polymorphisms of the multidrug resistance 1(MDR1) and solute carrier organic anion transporter 1B1 (SLCO1B1) genes on the therapeutic response to atorvastatin as well as the presence of gender-gene interaction.

METHODS

Serum lipid levels were determined at baseline and 4 weeks following 40 mg/day atorvastatin treatment in 50 Egyptian hypercholesterolemic patients (27 males and 23 females). Identification of MDR1 C3435T and SLCO1B1 A388G gene polymorphisms was performed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

Treatment with atorvastatin resulted in a mean reduction of total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and triglyceride (TG) of 8.7 %, 9.2 %, and 4.1 %, respectively, and a mean increase of high density lipoprotein cholesterol (HDL-C) of 1 %. Baseline and post-treatment HDL-C levels were statistically significantly higher in the MDR 1 TT homozygotes when compared with the CC wild type. The percentage change in TC, LDL-C, TG, and HDL-C did not show any statistically significant difference when compared among the different MDR 1 C3435T or SLCO1B1 A388G genotypes. The SLCO1B1 GG homozygotes showed a decrease in TG, whereas there was an increase in TG following atorvastatin treatment in AA and AG carriers in females; however, males did not show any statistically significant difference. There was no statistically significant association between either the coronary artery disease (CAD) risk factors (family history of CAD, hypertension, diabetes mellitus, smoking) or concomitant medications with the percentage change in different lipid parameters.

CONCLUSION

MDR1 C3435T was associated with baseline and post-treatment HDL-C variation. SLCO1B1 A388G showed gender-related effects on TG change following atorvastatin treatment. None of the comorbidities or the concomitant medications influenced the percentage change of lipid parameters following atorvastatin treatment. The results of this study may lead to an improved understanding of the genetic determinants of lipid response to atorvastatin treatment.

Difference in effects of cigarette smoking or alcohol consumption on serum non-high-density lipoprotein cholesterol levels is related to mitochondrial DNA 5178 C/A polymorphism in middle-aged Japanese men: a cross-sectional study

BACKGROUND

Mitochondrial DNA 5178 cytosine/adenosine (Mt5178 C/A) polymorphism is associated with longevity in the Japanese. The purpose of this study is to investigate whether Mt5178 C/A polymorphism modifies the effects of habitual smoking or habitual drinking on serum non-high-density lipoprotein (non-HDL) cholesterol levels in middle-aged Japanese men.

METHODS

A total of 394 male subjects (age 53.9 ± 7.9 years; mean ± SD) were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, a cross-sectional study assessing the joint effects of Mt5178 C/A polymorphism and cigarette smoking or alcohol drinking on serum non-HDL cholesterol levels was conducted. High levels of serum non-HDL cholesterol were defined as serum non-HDL cholesterol levels ≥160 mg/dl or ≥190 mg/dl.

RESULTS

For men with Mt5178A, cigarette smoking may increase serum non-HDL cholesterol levels (P for trend < 0.001), as well as the risk of high levels of non-HDL cholesterol (serum non-HDL cholesterol levels ≥160 mg/dl, P for trend < 0.001; serum non-HDL cholesterol levels ≥190 mg/dl, P for trend = 0.004). On the other hand, for men with Mt5178C, after adjusting for age and body mass index, alcohol consumption may decrease serum non-HDL cholesterol levels (P for trend = 0.043) and the risk of high levels of non-HDL cholesterol (serum non-HDL cholesterol level ≥160 mg/dl, P for trend = 0.005).

CONCLUSIONS

These gene-environment interactions on serum non-HDL cholesterol levels may contribute to the establishment of individualized prevention of the risk of high levels of serum non-HDL cholesterol.

Combined effect of mitochondrial DNA 5178 C/A polymorphism and alcohol consumption on estimated glomerular filtration rate in male Japanese health check-up examinees: a cross-sectional study

Background

Prevention of chronic kidney disease (CKD) is a major public health issue. Although several studies have been performed on the association between alcohol consumption and CKD or renal function, it remains controversial. Numerous genetic polymorphisms have been reported to be associated with CKD and kidney function. Mitochondrial DNA cytosine/adenine (Mt5178 C/A) polymorphism is associated with longevity in Japanese. This polymorphism modifies the effects of alcohol consumption on blood pressure, risk of hypertension, serum triglyceride levels, risk of hyper-LDL cholesterolemia and serum uric acid levels. The objective of this study was to investigate whether Mt5178 C/A polymorphism modifies the effects of alcohol consumption on renal function in male Japanese health check-up examinees.

Methods

A total of 394 male subjects aged 29–76 years were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, a cross-sectional study assessing the combined effects of Mt5178 C/A polymorphism and habitual drinking on the risk of mildly decreased estimated glomerular filtration rate (eGFR) (<90 ml/min/1.73 m²) was conducted.

Results

For Mt5178A genotypic men, habitual drinking may increase eGFR (P for trend = 0.003) or reduce the risk of mildly decreased eGFR (P for trend = 0.003). Daily drinkers had a significantly higher eGFR than non-drinkers (P = 0.005). The crude odds ratio for decreased eGFR was significantly lower in daily drinkers than in non-drinkers (odds ratio = 0.092, 95% confidence interval: 0.012-0.727, P = 0.024). On the other hand, for Mt5178C genotypic men, habitual drinking does not appear to affect eGFR.

Conclusion

The present results suggest a joint effect of Mt5178 C/A polymorphism and alcohol consumption on eGFR and the risk of mildly decreased eGFR in male Japanese subjects.

Mitochondrial DNA 5178 C/A polymorphism influences the effects of habitual smoking on the risk of dyslipidemia in middle-aged Japanese men

Background

Several genetic polymorphisms have been reported to modify the effects of smoking on serum lipid levels. The objective of this study was to investigate whether longevity-associated mitochondrial DNA 5178 (Mt5178) C/A polymorphism modifies the effects of habitual smoking on the risk of dyslipidemia in middle-aged Japanese subjects.

Methods

A total of 394 male subjects (age, 53.9 ± 7.9 years; mean ± SD) were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, a cross-sectional study assessing the joint effect of Mt5178 C/A polymorphism and cigarette smoking on the risk of hypo-high-density lipoprotein (HDL) cholesterolemia, hyper-low-density lipoprotein (LDL) cholesterolemia or hypertriglyceridemia was conducted.

Results

For subjects with Mt5178C, the risk of hypo-HDL cholesterolemia increased with the number of cigarettes smoked daily (P for trend = 0.001). On the other hand, the association between Mt5178A genotype and the risk of hypo-HDL cholesterolemia did not appear to depend on the number of cigarettes smoked daily. For those with Mt5178A, the risk of hyper-LDL cholesterolemia or hypertriglyceridemia increased with cigarettes smoked daily (P for trend = 0.017 and P for trend = 0.002, respectively). However, the association between Mt5178C genotype and the risk of hyper-LDL cholesterolemia or hypertriglyceridemia did not depend on the number of cigarettes smoked daily.

Conclusions

The present results suggest that Mt5178 C/A polymorphism modulates the effects of habitual smoking on the risk of dyslipidemia in middle-aged Japanese men.

Mitochondrial dysfunction and mitochondrial DNA mutations in atherosclerotic complications in diabetes

Mitochondrial DNA (mtDNA) is particularly prone to oxidation due to the lack of histones and a deficient mismatch repair system. This explains an increased mutation rate of mtDNA that results in heteroplasmy, e.g., the coexistence of the mutant and wild-type mtDNA molecules within the same mitochondrion. In diabetes mellitus, glycotoxicity, advanced oxidative stress, collagen cross-linking, and accumulation of lipid peroxides in foam macrophage cells and arterial wall cells may significantly decrease the mutation threshold required for mitochondrial dysfunction, which in turn further contributes to the oxidative damage of the diabetic vascular wall, endothelial dysfunction, and atherosclerosis.

Influence of mitochondrial DNA 5178 C/A polymorphism on serum cholesterol changes: a short-term follow-up in middle-aged Japanese men

OBJECTIVE

The mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism is reportedly associated with longevity in the Japanese population, and the Mt5178A genotype may exert anti-atherogenic effects. The aim of this study was to determine whether there were longitudinal differences in serum lipid levels between carriers of the Mt5178C genotype and those of the Mt5178A genotype and to assess the impact of these genotypes on serum cholesterol levels.

METHODS

The serum levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), and low-density lipoprotein cholesterol (LDLC) were measured and the Mt5178 C/A genotypes determined in 110 Japanese men aged 41-66 (mean 52.3) years who had received medical checkups twice in the period 1999-2005. The longitudinal changes of TC, HDLC, and LDLC were calculated according to genotype.

RESULTS

The serum levels of TC at baseline and follow-up were significantly different, whereas those of HDLC and LDLC were not. The changes in HDLC differed significantly between the two Mt5178 C/A genotype groups, with the changes in HDLC level being significantly greater in the Mt5178A genotype group than in the Mt5178C group (p = 0.015).

CONCLUSIONS

The Mt5178 C/A genotype may modify longitudinal changes in serum TC and HDLC levels in middle-aged Japanese men.

Joint effect of longevity-associated mitochondrial DNA 5178 C/A polymorphism and alcohol consumption on risk of hyper-LDL cholesterolemia in middle-aged Japanese men

BACKGROUND

Combined effects between mitochondrial DNA 5178 (Mt5178) C/A polymorphism and alcohol consumption on the risk of hypertension or hyperuricemia have been reported. The objective of this study was to investigate whether Mt5178 C/A polymorphism modulates the effects of alcohol consumption on the risk of dyslipidemia.

METHODS

A total of 394 male subjects were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, a cross-sectional study assessing the combined effect of Mt5178 polymorphism and alcohol consumption on the risk of dyslipidemia was conducted.

RESULTS

For men with Mt5178C, alcohol consumption was significantly and negatively associated with the risk of hyper-low-density lipoprotein (LDL) cholesterolemia (serum LDL cholesterol ≥ 140 mg/dl) (P for trend = 0.015). After adjustment for age, body mass index (BMI), habitual smoking, coffee consumption and use of antihypertensive medicine, the odds ratio (OR) for hyper-LDL cholesterolemia was significantly lower in daily drinkers with Mt5178C than non-drinkers with Mt5178C (OR = 0.360, 95% confidence intervals: 0.153-0.847). A significant and negative association between alcohol consumption and serum LDL cholesterol levels was also observed in Mt5178C genotypic men (P for trend < 0.01). On the other hand, the association between Mt5178A genotype and risk of hyper-LDL cholesterolemia does not appear to depend on alcohol consumption.

CONCLUSIONS

For Mt5178C genotypic men, alcohol consumption may reduce the risk of hyper-LDL cholesterolemia.

Combined effect of longevity-associated mitochondrial DNA 5178 C/A polymorphism and coffee consumption on the risk of hyper-LDL cholesterolemia in middle-aged Japanese men

The objective of this study was to investigate whether the mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism modifies the effects of coffee consumption on serum lipid levels and the risk of dyslipidemia in middle-aged Japanese men. A total of 397 male subjects (age, 53.9±7.8 years; mean±s.d.) were selected from among individuals visiting the hospital for regular medical check-ups. After adjustment for age, body mass index, habitual alcohol consumption, habitual smoking and use of antihypertensive medication, among subjects who consumed <1 cup of coffee per day, the odds ratio (OR) for hyper-low-density lipoprotein (LDL) cholesterolemia (serum LDL cholesterol > or =140 mg per 100 ml) was significantly lower in those with Mt5178A than in those with Mt5178C (OR=0.378, 95% confidence interval: 0.153-0.919). After adjustment, the association between the Mt5178A genotype and hyper-LDL cholesterolemia depended on coffee consumption (P for trend=0.018). Coffee consumption was positively associated with serum LDL cholesterol levels only in subjects with Mt5178A. However, in subjects with Mt5178C, serum LDL cholesterol level or risk of hyper-LDL cholesterolemia did not seem to depend on coffee consumption. These results suggest that for men with Mt5178A, coffee consumption negates the genetic benefit of lower risk for hyper-LDL cholesterolemia.

NADH dehydrogenase subunit-2 237 Leu/Met polymorphism modulates the effects of coffee consumption on the risk of hypertension in middle-aged Japanese men

Background

Habitual coffee consumption has been reported to lower blood pressure in the Japanese population. The NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with longevity and modifies the effects of alcohol consumption on blood pressure in the Japanese population. The objective of this study was to determine whether this polymorphism also modifies the effects of coffee consumption on blood pressure or the risk of hypertension in middle-aged Japanese men.

Methods

A total of 398 men (mean age ± standard deviation, 53.8 ± 7.8 years) were selected from among individuals visiting the hospital for regular medical check-ups. Hypertension was defined as a systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or antihypertensive drug treatment. Polymerase chain reaction-restriction fragment length polymorphism using the restriction enzyme AluI was performed to determine ND2-237 Leu/Met genotype.

Results

In subjects with ND2-237Leu, coffee consumption was significantly and negatively associated with diastolic blood pressure (P = 0.007). The odds ratio (OR) for hypertension was significantly lower in subjects with ND2-237Leu who consumed 2 or 3 cups of coffee per day than in those who consumed less than 1 cup of coffee per day (OR, 0.517; 95% confidence interval [CI], 0.276 to 0.968; P = 0.039). After adjustment, the OR remained significant (OR = 0.399; 95% CI, 0.184 to 0.869; P = 0.020). Moreover, after adjustment, the OR was significantly lower in subjects with ND2-237Leu who consumed more than 4 cups of coffee per day than in those who consumed less than 1 cup of coffee per day (OR, 0.246; 95% CI, 0.062 to 0.975; P = 0.046). However, the association between ND2-237Met genotype and hypertension did not depend on coffee consumption.

Conclusions

The present results suggest that the ND2-237 Leu/Met polymorphism modulates the effects of coffee consumption on hypertension risk in middle-aged Japanese men.

NADH dehydrogenase subunit-2 237 Leu/Met polymorphism modifies the effects of alcohol consumption on risk for hypertension in middle-aged Japanese men

NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with longevity in the Japanese population, and the ND2-237Met genotype may exert antiatherogenic effects. To investigate whether ND2-237 Leu/Met polymorphism is associated with risk of hypertension, we conducted a cross-sectional study of 398 Japanese male subjects. The frequency of hypertension was significantly higher in ND2-237Leu genotypic men than in ND2-237Met genotypic men. On analysis of covariance, the interaction between ND2-237 Leu/Met polymorphism and habitual drinking was significantly associated with both systolic blood pressure and diastolic blood pressure. Multiple logistic regression analysis revealed that the ND2-237Met genotype, particularly in younger subjects (age <60 years), had a lower odds ratio for hypertension than the ND2-237Leu genotype. Moreover, the association of ND2-237 Leu/Met polymorphism with hypertension may depend on the frequency of alcohol consumption. The odds ratio for hypertension was significantly higher in daily drinkers with ND2-237Leu when compared with non- or ex-drinkers with ND2-237Leu. However, the association between the ND2-237Met genotype and hypertension may not depend on the frequency of alcohol consumption. The present results suggest that ND2-237 Leu/Met polymorphism is associated with hypertension and that modification of hypertension risk is dependent on alcohol consumption in middle-aged Japanese men.

Longevity-associated mitochondrial DNA 5178 C/A polymorphism and its interaction with cigarette consumption are associated with pulmonary function in middle-aged Japanese men

Pulmonary function is a crucial factor associated with longevity. Mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism is reported to be associated with longevity in the Japanese population. We have previously reported that Mt5178 C/A polymorphism is widely associated with physiological and biochemical status. The objective of this study was to investigate whether Mt5178 C/A polymorphism is associated with pulmonary function. The subjects were 463 Japanese men (mean age +/- SD 54.0 +/- 7.6 years). Genotyping of Mt5178 C/A was performed by polymerase chain reaction-restriction fragment length polymorphism. A cross-sectional study of the relationship between genotype and spirometric data, namely forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)), was conducted. Among younger subjects (age <55 years), FVC and FEV(1) were significantly higher for men with Mt5178A than for those with Mt5178C. Interaction between Mt5178 C/A polymorphism and smoking habits in FEV(1)/FVC ratio was observed. Cigarette consumption (pack-years of smoking) was significantly and negatively associated with FEV(1)/FVC ratio for men with Mt5178C. Among older subjects (age >or=55 years), FEV(1)/FVC ratio was significantly lower for current smokers with Mt5178C than for never smokers with Mt5178C or for never smokers with Mt5178A. Mt5178 C/A polymorphism and its interaction with cigarette consumption may be associated with pulmonary function in Japanese men.

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.

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.

Genetic epidemiological studies of longevity-associated mitochondrial DNA 5178 C/A polymorphism

Mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism is associated with longevity in the Japanese population, and the Mt5178A genotype may confer antiatherogenic advantages. Individuals with the Mt5178A genotype may be more resistant to adult-onset diseases, such as myocardial infarction, cerebrovascular diseases and type 2 diabetes, than those with the Mt5178C genotype. Moreover, Mt5178 C/A polymorphism has been reported to be associated with blood pressure, serum lipid levels, hematological parameters, intraocular pressure, serum protein fraction levels and serum electrolyte levels in healthy Japanese individuals. Differences in the influence of habitual drinking or habitual smoking on health status between the Mt5178C genotype and the Mt5178A genotype have been reported. The individual modification of drinking habits or smoking habits based on the genotyping of Mt5178 C/A may promote improved health and lead to the establishment of personalized prevention strategies for adult-onset diseases.

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.

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.

Phylogeographic analysis of mitochondrial DNA haplogroup F2 in China reveals T12338C in the initiation codon of the ND5 gene not to be pathogenic

In this report, we studied on a homoplasmic T12338C change in mitochondrial DNA (mtDNA), which substituted methionine in the translational initiation codon of the NADH dehydrogenase subunit 5 gene ( ND5) with threonine. This nucleotide change was originally identified in two mtDNAs belonging to haplogroup F2 by our previous complete sequencing of 48 mtDNAs. Since then, a total of 76 F2 mtDNAs have been identified by the variations occurring in the hypervariable segments and coding regions among more than 3,000 individuals across China. As the T12338C change was detected in 32 samples representing various sub-clades of the F2 haplogroup while not in 14 non-F2 controls, we believe that the T12338C change is specific to the F2 haplogroup. As F2 and its sub-clades were widely distributed in normal individuals of various Chinese populations, we conclude that T12338C is not pathogenic. In addition, based on the average distribution frequency, haplotype diversity and nucleotide diversity of haplogroup F2 in the populations across China, the T12338C nucleotide substitution seems to have been occurred in north China about 42,000 years ago. Our results provided a good paradigm for distinguishing a polymorphic change from a pathogenic mutation based on mtDNA phylogeny.

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.