Karen Kato

Vitamin D receptor gene polymorphisms are associated with increased risk and progression of renal cell carcinoma in a Japanese population.

Aim:  Biological and epidemiologic data suggest that 1 alpha, 25 dihydroxyvitamin D3 (1,25(OH)2D3) levels may influence development of renal cell carcinoma. The vitamin D receptor (VDR) is a crucial mediator for the cellular effects of 1,25(OH)2D3 and additionally interacts with other cell signaling pathways that influence cancer progression. VDR gene polymorphisms may play an important role in risk of incidence for various malignant tumors. This study investigated whether VDR gene polymorphisms were associated with increased risk and prognosis of renal cell carcinoma (RCC) in a Japanese population.

Serum selenium levels are inversely associated with death risk among hemodialysis patients

BACKGROUND Previous studies have indicated that serum selenium levels are decreased in hemodialysis patients. Selenium deficiency may contribute to an increased risk for death among hemodialysis patients. METHODS A population-based prospective cohort study in adult hemodialysis patients was conducted. A total of 1041 patients were enrolled. Patients were divided into quartile groups according to serum selenium levels. Mortality rates between the groups were compared by the log-rank test. Associations between serum selenium levels and cause-specific mortality risks in hemodialysis patients were examined by Coxs regression model. RESULTS A total of 382 patients died during the 5-year follow-up period (median follow-up period, 4.9 years). Crude mortality rates in quartile groups according to serum selenium levels were 134.5, 99.9, 85.9 and 55.2 (per 1000 patient-years), respectively. The lowest quartile group had significantly higher mortality rates from all-cause and infectious disease-related death than the rates in the other three groups (P < 0.001, by log-rank test). Mortality rates from cardiovascular and malignant disease-related death were similar between the groups. A strong inverse relationship between selenium levels and infectious disease-related death was observed even after multivariate adjustment (trend P = 0.024). CONCLUSIONS Serum selenium levels were inversely associated with death risk, especially death risk due to infectious disease, among hemodialysis patients. Decreased serum selenium level may contribute to immunity dysfunction and may increase the risk of death from infectious disease in hemodialysis patients.

Standardized Prevalence Ratios for Chronic Hepatitis C Virus Infection Among Adult Japanese Hemodialysis Patients

Background Many studies have estimated the prevalence of anti-hepatitis C virus (HCV) antibody among hemodialysis (HD) patients; however, the prevalence of HCV core antigen—which indicates the presence of chronic HCV infection—is not known. Methods Standardized prevalence ratios (SPRs) for anti-HCV antibody and HCV core antigen among HD patients (n = 1214) were calculated on the basis of data from the general population (n = 22 472) living in the same area. Results The prevalences of anti-HCV antibody and HCV core antigen were 12.5% and 7.8%, respectively, in male hemodialysis patients, and 8.5% and 4.1% in female hemodialysis patients. The SPRs (95% confidence interval) for anti-HCV antibody and HCV core antigen were 8.39 (6.72–10.1) and 12.9 (9.66–16.1), respectively, in males, and 5.42 (3.67–7.17) and 8.77 (4.72–12.8) in females. Conclusions The prevalences of chronic HCV infection among male and female HD patients were 13-fold and 9-fold, respectively, those of the population-based controls. Further studies should therefore be conducted to determine the extent of chronic HCV infection among HD patients in other populations and to determine whether chronic HCV infection contributes to increased mortality in HD patients.

Seropositivity for Anti-HCV Core Antigen is Independently Associated With Increased All-Cause, Cardiovascular, and Liver Disease-Related Mortality in Hemodialysis Patients

Background It is not known whether chronic or past hepatitis C virus (HCV) infection contributes to the high mortality rate in hemodialysis patients. Methods This prospective study of 1077 adult hemodialysis patients without hepatitis B virus infection used Poisson regression analysis to estimate crude and sex- and age-adjusted rates (per 1000 patient-years) of all-cause, cardiovascular, infectious disease-related and liver disease-related mortality in patients negative for HCV antibody (group A), patients positive for HCV antibody and negative for anti-HCV core antigen (group B), and patients positive for anti-HCV core antigen (group C). The relative risks (RRs) for each cause of death in group B vs group C as compared with those in group A were also estimated by Poisson regression analysis after multivariate adjustment. Results A total of 407 patients died during the 5-year observation period. The sex- and age-adjusted mortality rate was 71.9 in group A, 80.4 in group B, and 156 in group C. The RRs (95% CI) for death in group B vs group C were 1.23 (0.72 to 2.12) vs 1.60 (1.13 to 2.28) for all-cause death, 0.75 (0.28 to 2.02) vs 1.64 (0.98 to 2.73) for cardiovascular death, 1.64 (0.65 to 4.15) vs 1.58 (0.81 to 3.07) for infectious disease-related death, and 15.3 (1.26 to 186) vs 28.8 (3.75 to 221) for liver disease-related death, respectively. Conclusions Anti-HCV core antigen seropositivity independently contributes to elevated risks of all-cause and cause-specific death. Chronic HCV infection, but not past HCV infection, is a risk for death among hemodialysis patients.

Serum Selenium Levels in Hemodialysis Patients Are Significantly Lower than Those in Healthy Controls

Serum selenium levels have been thought to be decreased in hemodialysis patients; however, results of previous studies have been inconsistent. Population-based hemodialysis patients (n = 1,041) and randomly recruited healthy controls (n = 384) were enrolled. Serum selenium levels were determined by inductively coupled plasma mass spectrometry and compared in hemodialysis patients and controls using analysis of covariance after adjustment for confounding factors with p < 0.1 as the result of the multiple regression analysis. Age, serum albumin levels, hsCRP levels, LDLC levels, HDLC levels, regular drinking habit and hemodialysis treatment were significantly associated with serum selenium levels in multiple regression analysis. Multivariate-adjusted means (95% CIs) of serum selenium levels were 103 µg/l (101–105) in hemodialysis patients and 117 µg/l (114–121) in controls. Selenium levels in hemodialysis patients were decreased. Whether decreased serum selenium levels contribute to increased risks for morbidity and mortality in hemodialysis patients should be examined.

Associations of marital status with mortality from all causes and mortality from cardiovascular disease in Japanese haemodialysis patients

BACKGROUND Marital status is an important social factor associated with increased mortality from cardiovascular disease (CVD) and all causes. However, there has been no study on the association of marital status with mortality in haemodialysis patients. METHODS We analysed data from a 5-year prospective cohort study of 1064 Japanese haemodialysis patients aged 30 years or older. Marital status was classified into three groups: married, single and divorced/widowed. Coxs regression was used to estimate multivariate hazard ratios (HRs) [95% confidence intervals (CIs)] for all-cause mortality and CVD mortality according to marital status after adjusting for age, sex, duration of haemodialysis, cause of renal failure, body mass index, systolic blood pressure, total cholesterol, high density lipoprotein-cholesterol, albumin, high-sensitivity C-reactive protein, co-morbid conditions, smoking, alcohol consumption, education levels and job status. RESULTS Single patients had higher risks than married patients for mortality from all causes (HR = 1.51, 95% CI: 1.06-2.16) and mortality from CVD (HR = 1.68, 95% CI: 1.03-2.76), and divorced/widowed patients had a higher risk than married patients for mortality from CVD (HR = 1.73, 95% CI: 1.15-2.60). After stratification by age, single patients aged 30-59 years had significantly higher risks for all-cause mortality and CVD mortality. CONCLUSIONS The findings suggest that single status is a significant predictor for all-cause mortality and CVD mortality and that divorced/widowed status is a significant predictor for CVD mortality in haemodialysis patients.

Standardized Prevalence Ratios for Atrial Fibrillation in Adult Dialysis Patients in Japan.

Background While it is assumed that dialysis patients in Japan have a higher prevalence of atrial fibrillation (AF) than the general population, the magnitude of this difference is not known. Methods Standardized prevalence ratios (SPRs) for AF in dialysis patients (n = 1510) were calculated compared to data from the general population (n = 26 454) living in the same area. Results The prevalences of AF were 3.8% and 1.6% in dialysis patients and the general population, respectively. In male subjects, these respective values were 4.9% and 3.3%, and in female subjects they were 1.6% and 0.6%. The SPRs for AF were 2.53 (95% confidence interval [CI], 1.88–3.19) in all dialysis patients, 1.80 (95% CI, 1.30–2.29) in male dialysis patients, and 2.13 (95% CI, 0.66–3.61) in female dialysis patients. Conclusions The prevalence of AF in dialysis patients was twice that in the population-based controls. Since AF strongly contributes to a higher risk of cardiovascular mortality and morbidity in the general population, further longitudinal studies should be conducted regarding the risk of several outcomes attributable to AF among Japanese dialysis patients.BACKGROUND While it is assumed that dialysis patients in Japan have a higher prevalence of atrial fibrillation (AF) than the general population, the magnitude of this difference is not known. METHODS Standardized prevalence ratios (SPRs) for AF in dialysis patients (n = 1510) were calculated compared to data from the general population (n = 26 454) living in the same area. RESULTS The prevalences of AF were 3.8% and 1.6% in dialysis patients and the general population, respectively. In male subjects, these respective values were 4.9% and 3.3%, and in female subjects they were 1.6% and 0.6%. The SPRs for AF were 2.53 (95% confidence interval [CI], 1.88-3.19) in all dialysis patients, 1.80 (95% CI, 1.30-2.29) in male dialysis patients, and 2.13 (95% CI, 0.66-3.61) in female dialysis patients. CONCLUSIONS The prevalence of AF in dialysis patients was twice that in the population-based controls. Since AF strongly contributes to a higher risk of cardiovascular mortality and morbidity in the general population, further longitudinal studies should be conducted regarding the risk of several outcomes attributable to AF among Japanese dialysis patients.

The Blood Compatibilities of Blood Purification Membranes and Other Materials Developed in Japan

The biocompatibilities in blood purification therapy are defined as “a concept to stipulate safety of blood purification therapy by an index based on interaction in the body arising from blood purification therapy itself.” The biocompatibilities are associated with not only materials to be used but also many factors such as sterilization method and eluted substance. It is often evaluated based on impacts on cellular pathways and on humoral pathways. Since the biocompatibilities of blood purification therapy in particular hemodialysis are not just a prognostic factor for dialysis patients but a contributory factor for long-term complications, it should be considered with adequate attention. It is important that blood purification therapy should be performed by consistently evaluating not only risks associated with these biocompatibilities but also the other advantages obtained from treatments. In this paper, the biocompatibilities of membrane and adsorption material based on Japanese original which are used for blood purification therapy are described.