Polymorphism of Nrf2, an antioxidative gene, is associated with blood pressure and cardiovascular mortality in hemodialysis patients.

OBJECTIVE: Nrf2 is a transcription factor that regulates the expression of antioxidant genes. This study aimed to investigate the association of Nrf2 gene single nucleotide polymorphisms (SNPs), rs35652124 (-653A/G) and rs6721961 (-617C/A), with laboratory data and mortality in hemodialysis (HD) patients. METHODS: Blood samples were obtained from 216 HD patients (119 males and 97 females; 60 diabetics and 156 non-diabetics) with mean age of 60.3±13.3 (SD) years, and mean HD duration of 9.10±8.28 years. Genotyping was performed using polymerase chain reaction with confronting two-pair primers (PCR-CTPP) assay. RESULTS: As for rs35652124, diastolic blood pressure (BP) was significantly high in total AA carriers. ß2-microglobulin was significantly low in male AA carriers. Systolic BP, diastolic BP and albumin were significantly high in female AA carriers. As for 6721961, systolic BP and diastolic BP were significantly high in female AA carriers. Cox proportional hazard analysis adjusted for age, HD duration, diabetes and Kt/V demonstrated that rs35652124 AA carriers showed higher cardiovascular mortality than (GG+GA) carriers. CONCLUSION: Nrf2 SNPs were associated with BP in Japanese HD patients. More notably, rs35652124 was associated with cardiovascular mortality in these patients.

Polymorphisms of Nrf2, an antioxidative gene, are associated with blood pressure in Japanese.

Nuclear factor-erythroid 2 (NF-E2)-related factor 2 (Nrf2) is a transcription factor that regulates the expression of antioxidant genes by activating Nrf2-antioxidant response element (ARE) pathway. This study aimed to investigate association of Nrf2 gene single nucleotide polymorphisms (SNPs), rs35652124 (A --> G) and rs6721961 (C --> A), with various laboratory data in 464 health evaluation examinees. The genotyping of these SNPs was performed using polymerase chain reaction with confronting two-pair primers (PCR-CTPP) assay. The genotype frequencies of rs35652124 SNP were 21.1% for AA, 44.0% for AG, and 34.9% for GG. The frequency of A allele was 0.431. In male subjects, cholinesterase was significantly high, and HDL cholesterol was significantly low in (AG+GG) carriers. In female subjects, diastolic blood pressure (BP) was significantly low in (AG+GG) carriers. The genotype frequencies of rs6721961 SNP were 55.2% for CC, 34.7% for CA, and 10.1% for AA. The frequency of A allele was 0.275. In male subjects, systolic BP, diastolic BP and cholinesterase were significantly low, and iron was significantly high in (CA+AA) carriers. In female subjects, cholinesterase was significantly high in (CA+AA) carriers, and diastolic BP was significantly high in AA carriers. In conclusion, Nrf2 polymorphisms are associated with BP in Japanese.

Association between Helicobacter pylori infection detected by the (13) C-urea breath test and low serum ferritin levels among Japanese adults.

BACKGROUND: Helicobacter pylori infection is a major risk factor for chronic gastritis, digestive ulcers, and gastric cancer. Previous studies have shown associations between H. pylori infection and decreased iron storage. Therefore, this study aimed to examine the associations between H. pylori infection and serum iron and ferritin levels in Japan. MATERIALS AND METHODS: Overall, 268 Japanese individuals who visited a clinic located in an urban area for H. pylori infection tests and subsequent eradication were enrolled. H. pylori infection was diagnosed by a (13) C-urea breath test, with positive results defined as values ≥2.5‰. RESULTS: The overall infection rate was 65.3% (175/268). The geometric mean serum iron levels in uninfected and infected subjects were 115.7 µg/dL and 108.9 µg/dL, respectively, in men, and 83.9 and 91.8 µg/dL, respectively, in women. The geometric mean serum ferritin levels were 128.9 and 81.0 ng/mL, respectively, in men, and 25.5 and 27.0 ng/mL, respectively, in women. Regression analysis adjusted for age showed that lower geometric mean serum ferritin levels were significantly associated with H. pylori infection in men (131.8 vs 79.4 ng/mL p = .009) and in women (33.9 vs 23.4 ng/mL p = .041). The difference was greater in subjects ≥50 years old, although the interaction was not statistically significant. Helicobacter pylori infection was not significantly associated with serum iron levels. CONCLUSION: This study showed that H. pylori infection was significantly associated with altered serum ferritin levels in Japanese individuals, particularly in those aged ≥50 years.

Significant association between serum interleukin-6 and Helicobacter pylori antibody levels among H. pylori-positive Japanese adults.

BACKGROUND: Interleukin-6 (IL-6) is a multifunctional cytokine produced by many types of cells. Inflammation plays a key role in the pathogenesis of atherosclerosis that is an underlying cause of coronary heart disease (CHD). Since the 1990s, some studies have shown an association between H. pylori infection and CHD, which may be mediated by inflammation. Therefore, this study aimed to evaluate the association between serum anti-H. pylori IgG levels and serum IL-6 levels in H. pylori-infected adults. METHODS: We enrolled 158 subjects who visited a clinic located in an urban area to be tested for H. pylori infection, using the (13)C-urea breath test, and who were found to be infected and subsequently received eradication. RESULTS: The geometric mean serum IL-6 level was 1.78 pg/mL for men, 1.57 pg/mL for women, and 1.64 pg/mL overall. Logarithms of serum IL-6 levels were positively correlated with logarithms of serum H. pylori IgG levels (r = 0.24, P = 0.002). In multiple linear regression analysis adjusting for sex and age, the serum IL-6 level was still significantly associated with the IgG level in all subjects (ß = 0.18, P = 0.012). CONCLUSION: Higher H. pylori IgG levels were significantly associated with higher serum IL-6 levels among H. pylori-infected individuals.

SIRTUIN 1 gene polymorphisms are associated with cholesterol metabolism and coronary artery calcification in Japanese hemodialysis patients.

OBJECTIVES: Sirtuin 1 (SIRT1), a longevity gene, protects cells against oxidative and genotoxic stress. This study aimed to investigate the association of SIRT 1 gene single-nucleotide polymorphisms, namely, rs7895833, rs7069102, and rs2273773 with lipid profiles and coronary artery calcification score in 219 Japanese hemodialysis (HD) patients. METHODS: Genotyping of these polymorphisms was performed using polymerase chain reaction with confronting two-pair primers assay. RESULTS: The A allele frequency of rs7895833 and G allele frequency of rs7069102 were significantly lower in HD patients (0.228 and 0.131, respectively) than those in 803 control subjects (general population) (0.289 and 0.181, respectively) (P = .010 and P = .012, respectively). However, the allele frequency of rs2273773 was not significantly different from that in the control subjects. Multivariate analysis adjusted for age and duration on HD demonstrated that the serum levels of total and low-density lipoprotein cholesterol were significantly high in G allele carriers of rs7069102 compared with CC genotype in male HD patients. Coronary artery calcification score was significantly high in C allele carriers of rs2273773 in all and male HD patients. CONCLUSIONS: SIRT 1 polymorphisms, rs7069102 and rs2273773, are associated with abnormal cholesterol metabolism and coronary artery calcification, respectively, in Japanese HD patients, especially in males.

Preventive medical services not covered by public health insurance at Daiko Medical Center in Japan, 2004-2011.

Preventive medical services not covered by public health insurance started in the Daiko Medical Center of Nagoya University in June, 2004. Those services included: (1) Helicobacter pylori (H. pylori) diagnosis and eradication treatments, for which CYP2C19 genotyping was introduced in November 2005; (2) smoking cessation support with genotype tests of CYP1A1 Ile462Val, GSTM1 present/null, GSTT1 present/null, and NQO1 Pro187Ser; (3) advice on alcohol consumption with genotype tests of ADH Arg47His and ALDH2 Glu487Lys; (4) advice on folate-associated diseases with a genotype test of MTHFR C677T; (5) advice on a tumor marker CA19-9 with genotype tests of Lewis and Secretor genes; and (6) raloxifene prescription aimed to prevent breast cancer for high-risk postmenopausal women. A total of 683 patients visited the Center until it closed in March 2011. Those given diagnoses and eradication treatments for H. pylori numbered 567, followed by 44 for smoking cessation support, 35 for advice on folate-associated diseases, 26 for advice on alcohol consumption, 8 for CA19-9, and 3 for raloxifene prescription. Around 2004, public interest in H. pylori was relatively high, but thereafter patient numbers dropped markedly. The Center closed in March 2011 due to the reduction in patient visits. Our unique trial showed that continuing to provide uninsured preventive services at a clinic was difficult in Japan without the affiliation of hospitals/clinics providing medical services covered by public health insurance.

No association between AICDA 7888 C/T polymorphism, Helicobacter pylori seropositivity, and the risk of atrophic gastritis and gastric cancer in Japanese.

BACKGROUND: The aberrant expression of activation-induced cytidine deaminase (AICDA) was reportedly induced in gastric epithelial cells infected with cytotoxin-associated gene A (cagA)-positive Helicobacter pylori, resulting in the accumulation of alterations in the TP53 tumor suppressor gene in gastric cells. We investigated the association of the AICDA 7888 C/T polymorphism with H. pylori infection and the risk of gastric cancer and atrophic gastritis in Japanese subjects. METHODS: The study subjects were 583 histologically diagnosed gastric cancer patients (cases) and 1637 age- and sex-frequency-matched control outpatients, who visited Aichi Cancer Center Hospital from the years 2001 to 2005. In the controls, serum anti-H. pylori IgG antibody and pepsinogens were measured to evaluate H. pylori infection and atrophic gastritis, respectively. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by a logistic model. RESULTS: H. pylori seropositivity in the controls was not significantly associated with the AICDA 7888 C/T genotypes. Among the H. pylori seropositive control subjects, the age and sex-adjusted ORs of atrophic gastritis were not statistically significant: 0.84 (95% CI, 0.62-1.13) for C/T, 0.82 (95% CI, 0.56-1.21) for T/T, and 0.83 (95% CI, 0.63-1.11) for C/T+T/T, relative to the C/C genotype. The age- and sex-adjusted ORs of gastric cancer relative to atrophic gastritis were also not statistically significant, at 1.17 (95% CI 0.89-1.54), 1.21 (95% CI, 0.85-1.71), and 1.18 (95% CI, 0.91-1.53), respectively. The OR of gastric cancer cases compared with the whole cohort of control subjects was also not significant. CONCLUSION: The hypothetical association of the AICDA 7888 C/T polymorphism with the risk of gastric cancer or gastric atrophy was not shown in this study.

KLOTHO gene polymorphisms G-395A and C1818T are associated with low-density lipoprotein cholesterol and uric acid in Japanese hemodialysis patients.

BACKGROUND/AIMS: This study aimed to investigate the association of the KLOTHO gene single nucleotide polymorphisms (SNPs), G-395A and C1818T, with various laboratory data in 219 Japanese hemodialysis (HD) patients. METHODS: The genotyping of G-395A in the promoter region and C1818T in exon 4 was performed using polymerase chain reaction with confronting two-pair primers (PCR-CTPP) assay. RESULTS: In HD patients, the allele frequencies of G-395A were 0.847 for the G allele and 0.153 for the A allele and those of the C1818T were 0.829 for the C allele and 0.171 for the T allele. There were no significant differences in allele frequencies of G-395A and those of the C1818T between HD patients and healthy subjects. Multivariate analysis adjusted for age and duration on HD demonstrated that uric acid was significantly high in A allele carriers of G-395A compared with GG genotype in all and female patients. Low-density lipoprotein cholesterol was significantly low in T allele carriers of C1818T compared with CC genotype in all and male patients. CONCLUSION: KLOTHO gene SNPs G-395A and C1818T are associated with low-density lipoprotein cholesterol and uric acid in HD patients.

Toll-like receptor 4 +3725 G/C polymorphism, Helicobacter pylori seropositivity, and the risk of gastric atrophy and gastric cancer in Japanese.

BACKGROUND: Toll-like receptor 4 (TLR4) Asp299Gly and Thr399Ile polymorphisms were reported to be a risk factor of gastric carcinoma or its precursors in Caucasian and Indian population, but these polymorphisms are absent in Japanese. We investigated the associations of TLR4+3725 G/C polymorphism, another functional polymorphism of TLR4, with risk of gastric cancer and gastric atrophy in Japanese. MATERIALS AND METHODS: Study subjects were 583 histologically diagnosed gastric cancer patients and age- and sex-matched 1592 control outpatients, who visited Aichi Cancer Center Hospital from 2001 to 2005. Serum anti-H. pylori IgG antibody and pepsinogens were measured to evaluate H. pylori infection and gastric atrophy, respectively. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by a logistic model. RESULTS: Among the seropositive subjects, the age- and sex-adjusted OR of gastric atrophy was 1.17 (95%CI: 0.91-1.50) for G/C, 1.20 (95%CI: 0.76-1.89) for C/C, and 1.18 (95%CI: 0.93-1.49) for G/C+C/C relative to G/G genotype. The age- and sex-adjusted OR of severe gastric atrophy among H. pylori seropositive subjects was 1.43 (95%CI: 0.99-2.06) for G/C, 1.47 (95%CI: 0.76-2.88) for C/C, and 1.43 (95%CI: 1.01-2.04) for G/C+C/C. The OR of gastric cancer compared with gastric atrophy controls was not statistically significant. CONCLUSION: Our study found that TLR4+3725 G/C polymorphism was a risk factor of severe gastric atrophy in H. pylori seropositive Japanese. Our results underscored the significance of the variations in host innate immunity due to TLR4 polymorphism as genetic predispositions to gastric precancerous lesions in Eastern Asian populations with the same backgrounds.

Inverse correlation between serum interleukin-6 and iron levels among Japanese adults: a cross-sectional study.

BACKGROUND: Interleukin-6 (IL-6) is a multifunctional cytokine that is produced by many different cell types, and plays an important role in the regulation of inflammation, immune responses, the acute-phase response, and hematopoiesis. Previous laboratory and clinical studies have shown that IL-6 causes a significant decrease in serum iron levels. Therefore, we conducted an epidemiological study to examine the association between serum IL-6 and iron levels. METHODS: In total, 280 Japanese individuals aged 20-78 years were enrolled when they visited a clinic located in an urban area for Helicobacter pylori (H. pylori) infection tests and subsequent eradication; 65.3% were infected with H. pylori. Subjects with gastric cancer, idiopathic thrombocytopenia, or IL-6 > 10 pg/mL were excluded from the study. Serum iron and IL-6 levels were measured using the 2-nitroso-5-(N-propyl-3-sulfopropylamino) phenol method and chemiluminescence enzyme immunoassay, respectively. RESULTS: Geometric mean iron and IL-6 levels were 111.5 µg/dL and 1.77 pg/mL, respectively, for men, and 89.4 µg/dL and 1.55 pg/mL, respectively, for women. The logarithm of serum iron levels was negatively correlated with the logarithm of IL-6 levels in men (r = -0.19, p = 0.047), but not in women (r = -0.035, p = 0.65). Regression analysis, adjusted for sex, age, and H. pylori infection status, showed that the logarithm of serum iron levels was significantly associated with a decreased logarithm of IL-6 levels (ß = -0.053, p = 0.041). The odds ratio for low serum iron levels adjusted for sex, age, and H. pylori infection status was 7.88 (95% CI 1.29-48.06) in those with an IL-6 level > 4 pg/mL. CONCLUSION: Lower serum iron levels are significantly associated with higher serum IL-6 levels among Japanese adults.

A new PCR method: one primer amplification of PCR-CTPP products.

Polymerase chain reaction with confronting two-pair primers (PCR-CTPP) is a convenient method for genotyping single nucleotide polymorphisms, saving time, and costs. It uses four primers for PCR; F1 and R1 for one allele, and F2 and R2 for the other allele, by which three different sizes of DNA are amplified; between F1 and R1, between F2 and R2, and between F1 and R2. To date, we have applied PCR-CTPP successfully for genotyping more than 60 polymorphisms. However, it is not rare that PCR does not produce balanced amplification of allele specific bands. Accordingly, the method was modified by attaching a common sequence at the 5' end of two-pair primers and adding another primer with the common sequence in PCR, in total five different primers in a tube for PCR. The modification allowed one primer amplification for the products of initial PCR with confronting two-pair primers, named as one primer amplification of PCR-CTPP products (OPA-CTPP). This article demonstrates an example for an A/G polymorphism of paraoxonase 1 (PON1) Gln192Arg (rs662). PCR-CTPP failed clear genotyping for the polymorphism, while OPA-CTPP successfully produced PCR products corresponding to the allele. The present example indicated that the OPA-CTPP would be useful in the case that PCR-CTPP failed to produce balanced PCR products specific to each allele.

Significant association of RUNX3 T/A polymorphism at intron 3 (rs760805) with the risk of gastric atrophy in Helicobacter pylori seropositive Japanese.

BACKGROUND: This study aimed to examine the associations of a RUNX3 T/A polymorphism at exon 1 (Asn18Ile) (rs6672420) and another RUNX3 intronic T/A polymorphism (rs760805) with the risk of gastric cancer together with the risk of H. pylori seropositivity and gastric atrophy in Japanese people. METHODS: Study subjects were 583 histologically diagnosed gastric cancer patients and age- and sex-frequency-matched 1,742 control outpatients (among whom 1,637 subjects were eligible for the analyses), who visited Aichi Cancer Center Hospital from 2001 to 2005. Serum pepsinogens were measured to evaluate gastric atrophy. RESULTS: There was no significant association between the RUNX3 polymorphisms and the seropositivity. Among H. pylori seropositive subjects, we found a significant association between RUNX3 rs760805 polymorphism and the risk of gastric atrophy with the age- and sex-adjusted OR of 1.51 (95% CI 1.11-2.05, P = 0.008) in T/A, 1.59 (95% CI 1.08-2.33, P = 0.019) in A/A, and 1.53 (95% CI 1.14-2.05, P = 0.004) in T/A + A/A, compared with T/T genotype. We found no statistically significant associations between RUNX3 rs6672420 polymorphism and risk of gastric atrophy, nor between these two RUNX3 polymorphisms and the risk of gastric cancer relative to the subjects with gastric atrophy. CONCLUSIONS: Our study results revealed that the RUNX3 intronic T/A polymorphism (rs760805) might modulate the risk of gastric atrophy among H. pylori seropositive subjects, and the RUNX3 T/A polymorphism at exon 1 (rs6672420) had little influence on the risks of H. pylori infection, gastric atrophy or gastric cancer in Japanese people. Further investigation is required to verify our findings.