Current status of renal replacement therapy in Japan: results of the annual survey of the Japanese Society for Dialysis Therapy

Improving Outcome of Capd: Twenty-Five Years’ Experience in a Single Korean Center

Background

Continuous ambulatory peritoneal dialysis (CAPD) is an established treatment for end-stage renal disease (ESRD). We investigated the outcome of CAPD over a period of 25 years at our institution.

Methods

CAPD has been performed in 2301 patients in 25 years. After excluding patients with less than 3 months of follow-up and missing data, we evaluated 1656 patients who started peritoneal dialysis between November 1981 and December 2005. Data for sex, age, primary disease, co-morbidities, follow-up duration, cause of death, and cause of technique failure were collected. We also examined data for urea kinetic modeling (UKM), beginning in 1990, and peritonitis episodes, including causative organisms, starting in 1992.

Results

Compared to incident patients from 1981 – 1992, mean age and incidence of ESRD caused by diabetic nephropathy increased in patients from 1993 to 2005. Technique survival after 5 and 10 years was 71.9% and 48.1% respectively. Technique survival was significantly higher in patients who started CAPD after 1992 than in those who started before 1992. Peritonitis was the main reason for technique failure. Overall peritonitis rate was 0.38 episodes per patient-year, with a significant downward trend to 0.29 per patient-year over 10 years, corresponding to a decrease in gram-positive peritonitis. Patient survival after 5 and 10 years was 69.8% and 51.8% respectively. Patient survival improved significantly during 1992 – 2005 compared to 1981 – 1992 after adjustment for age, gender, diabetes, and cardiovascular comorbidities [hazard ratio (HR) 0.68, p < 0.01]. Subgroup analysis based on UKM revealed that dialysis adequacy did not affect patient survival. However, diabetes (HR 2.78, p < 0.001), older age (per 1 year: HR 1.06; p < 0.001), serum albumin level (per 1 g/dL: increase, HR 0.52; p < 0.05), and cardiovascular comorbidities (HR 2.32, p < 0.01) were identified as significant risk factors.

Conclusion

Technique survival has improved due partly to a decrease in peritonitis, which was attributed to a decrease in gram-positive peritonitis. Patient survival has also improved considering increases in aged patients and ESRD caused by diabetes. The mortality rate of CAPD is still high in older, diabetic, malnourished, and cardiovascular diseased patients. A more careful management of higher risk groups will be needed to improve the outcome of CAPD patients in the future.

Elevated non-high-density lipoprotein cholesterol (non-HDL-C) predicts atherosclerotic cardiovascular events in hemodialysis patients

BACKGROUND AND OBJECTIVES

Dialysis patients show "reverse causality" between serum cholesterol and mortality. No previous studies clearly separated the risk of incident cardiovascular disease (CVD) and the risk of death or fatality after such events. We tested a hypothesis that dyslipidemia increases the risk of incident atherosclerotic CVD and that protein energy wasting (PEW) increases the risk of fatality after CVD events in hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was an observational cohort study in 45,390 hemodialysis patients without previous history of myocardial infarction (MI), cerebral infarction (CI), or cerebral bleeding (CB) at the end of 2003, extracted from a nationwide dialysis registry in Japan. Outcome measures were new onsets of MI, CI, CB, and death in 1 year.

RESULTS

The incidence rates of MI, CI, and CB were 1.43, 2.53, and 1.01 per 100 person-years, and death rates after these events were 0.23, 0.21, and 0.29 per 100 person-years, respectively. By multivariate logistic regression analysis, incident MI was positively associated with non-HDL cholesterol (non-HDL-C) and inversely with HDL cholesterol (HDL-C). Incident CI was positively associated with non-HDL-C, whereas CB was not significantly associated with these lipid parameters. Among the patients who had new MI, CI, and/or CB, death risk was not associated with HDL-C or non-HDL-C, but with higher age, lower body mass index, and higher C-reactive protein levels.

CONCLUSIONS

In this hemodialysis cohort, dyslipidemia was associated with increased risk of incident atherosclerotic CVD, and protein energy wasting/inflammation with increased risk of death after CVD events.

Prevalence and determinants of hypertension in chronic hemodialysis patients in Japan

Hypertension is common in chronic hemodialysis (HD) patients. However, its prevalence and determinants have not been studied in a large HD population. We analyzed the database of the Japanese Society for Dialysis Therapy (JSDT) registry, which conducts an annual survey of chronic dialysis patients throughout Japan. We compiled those who were on HD three-times per week and aged 20 years and over at the end of 2000 (JSDT standard analysis file 001). Hypertension was defined as predialysis systolic blood pressure (SBP) > or =140 mm Hg or predialysis diastolic blood pressure (DBP) > or =90 mm Hg. Adjusted odds ratios (95% confidence interval) for the determinants of hypertension were calculated by the multivariate logistic regression analysis. A total of 65 393 people (men, 60.2%; mean age +/- SD, 60.9 +/- 12.8 years; and mean duration of HD +/- SD, 95.3 +/- 74.0 months) were studied. Mean +/- SD levels of SBP and DBP were 154.9 +/- 23.8 mm Hg and 80.5 +/- 13.7 mm Hg before the HD session. Hypertension was noted in 77.5% of patients. Prescription of antihypertensive drugs and erythropoietin was made to 60.7% and 82.0% of patients, respectively. Both SBP and DBP were higher in those who were prescribed antihypertensive drugs (mean, 160.4/81.9 mm Hg), than those without drugs (mean, 146.9/78.5 mm Hg) (in both cases P < 0.0001). Hypertension was positively associated with men (adjusted odds ratio (OR), 1.258; 95% confidence interval (CI), 1.188-1.333; P < 0.0001), age (OR, 1.004; CI, 1.001-1.006; P < 0.01), duration of HD (OR, 0.769; CI, 0.728-0.812; P < 0.0001), serum albumin (OR, 1.369; CI, 1.286-1.458; P < 0.0001), and change in body weight by dialysis session (DeltaBW) (OR, 1.176; CI, 1.159-1.194; P < 0.0001), and was negatively associated with Kt/V (OR, 0.600; CI, 0.543-0.664; P < 0.0001), and hematocrit (OR, 0.964; CI, 0.959-0.970; P < 0.0001). The distribution of DeltaBW was normal in shape and in about 22% of patients the range was from 4.0% to 4.9%. There was a significant positive relationship between the prevalence of hypertension and DeltaBW (R(2) = 0.8549). The higher the DeltaBW, the more the prescription rate of antihypertensive drugs increased (R(2) = 0.9102). Results showed that the prevalence of hypertension was significantly associated with volume excess and serum levels of albumin, calcium, and phosphorous in chronic HD patients. Despite the high prescription rate of antihypertensive drugs, control of blood pressure remains unsatisfactory.

Increasing gender difference in the incidence of chronic dialysis therapy in Japan

The incidence of chronic kidney disease and its progression to end-stage renal disease (ESRD) differs between genders, so it can be surmised that the incidence of ESRD is different between men and women. We analyzed the annual incidence of ESRD by gender for a 20 year period, from 1983 to 2002, using Japanese Society for Dialysis Therapy (JSDT) registration data. The annual incidence of ESRD was calculated as the number of incident dialysis patients divided by the census population of the previous year in each gender, and expressed per million of each population (male and female). In men, the incidence of ESRD increased from 99.9 in 1983 to 330.2 in 2002, whereas it was 66.6 in 1983 and 184.9 in 2002 in women. The difference of incidence of ESRD from men to women increased from 33.3 in 1983 to 145.3 in 2002. The mean age at the start of dialysis was 51.5 years (men) and 52.5 years (women) in 1983, it increased to 63.8 years (men) and 66.1 years (women) in 2002. The difference in mean age increased from 0.9 years in 1983 to 2.3 years in 2002. There was no clear relationship between the available dialysis station per 100,000 population and the men to women ratio in the prevalent dialysis patients among the 47 prefectures. The acceptance of dialysis therapy might not be strong enough to explain the increasing difference in ESRD incidence between men and women in Japan. Differences in the socioeconomic conditions and lifestyles between men and women, which might be related to the gender difference in incidence in ESRD, should be studied further.

Neuropeptide-Y and atrial natriuretic peptide as prognostic markers in patients on hemodialysis

We conducted a study of the influence of the vasoactive peptides atrial natriuretic peptide (ANP) and neuropeptide Y (NPY) on survival of patients on hemodialysis and their association and relative importance with cardiac and clinical variables. Thirty-three hemodialysis patients were characterized by age, sex, diagnosis, blood pressure, serum (S)-albumin, serum (S)-urea, hemoglobin, dialysis dose, weight gain, duration of dialysis, cardiac hypertrophy, volume, failure, and ischemia and plasma levels of ANP and NPY. The outcomes were analyzed for early deaths (< 1 year) and for all deaths. The association of the variables to early deaths and all deaths, respectively, was studied in Cox proportional hazard analyses. The variables were also studied in three hierarchical steps: clinical variables only, clinical and cardiac variables, and all variables. For all deaths, the independent variables were plasma NPY (pmol/L) (hazard ratio [HR] = 1.035, p = 0.004), heart volume (ml/m2) (HR = 1.009, p = 0.001), and S-albumin (g/L) (HR = 0.750, p = 0.034). For early deaths, the independent variables were predialysis ANP (pmol/L) (HR = 1.008, p = 0.034) and NPY (pmol/L) (HR = 1.031, p = 0.026). In the hierarchical study, excluding the vasoactive peptides, heart volume, heart failure and S-albumin were independently associated with all deaths, and mean arterial blood pressure was associated with early death. When also excluding the cardiac parameters, S-albumin was associated with all deaths and mean arterial blood pressure with early death. In conclusion, plasma levels of the vasoactive peptides ANP and NPY are the most important group in a hierarchy of variables that predict imminent death in hemodialysis patients, and NPY is associated with late death. ANP and NPY apparently sum up the detrimental influence of many factors in hemodialysis patients.

Hypertension as cause of end-stage renal disease: lessons from international registries

The incidence of hypertension as cause of ESRD has doubled in the ERA-EDTA Registry in the past two decades, going from 7 to 13%. It is very possible that this is not a real increase in the incidence of hypertension as cause of ESRD, but rather a consequence of greater acceptance of older patients, a phenomenon that has simultaneously occurred. There are geographic differences in the incidence of hypertension as cause of ESRD, from 6% in Japan to 28.5% in the U.S., and 13% in Europe. With the present data, it is impossible to know if these differences are real. The diagnostic criteria used are not uniform and a consensus would be necessary to establish uniform diagnostic criteria for nephrosclerosis or ischemic nephropathy. The percentage of patients starting renal replacement therapy (RRT) with unknown primary renal disease is very different in the U.S. and Europe. This could be a critical factor in explaining these differences. Survival of patients at 5 and 10 years with renal vascular disease did not improve from 1977 to 1989. The same occurs with survival of patients with standard primary renal disease, although this is better than that of patients with renal vascular disease. To interpret this lack of improvement in survival of patients over a decade, we must take into account that at the same time there has been a significant increase in the age of patients starting RRT. Therefore, when the population of patients of under 55 is analyzed, there is evidence that those starting treatment in the 80's have much better survival than those starting in the 70's. However, survival of patients with renal vascular disease continues to be poorer than that of patients with standard primary renal disease. This lower survival of patients with renal vascular disease seems to be related to higher cardiac mortality, which is in alignment with the diagnosis of hypertension as cause of renal failure.