An Overview of Regular Dialysis Treatment in Japan (as of 31 December 2002)+

Calculation of expected remaining lifetime of dialysis patients in Japan

Background

The expected remaining lifetime of dialysis patients in Japan was only reported in 2003 and has not been reported thereafter. From 2003 to the present, several new therapeutic agents have been introduced. These events may have improved outcomes for dialysis patients. Thus, expected remaining lifetime of dialysis patients in Japan was newly calculated in 2015.

Methods

The Japanese Society for Dialysis Therapy Renal Data Registry database was used for analyses. From this database, the following three indexes were compiled: the number of surviving dialysis patients (198,125 males and 111,962 females) at the end of 2014 and the number of surviving (179,649 males and 101,758 females) and dead (18,044 males and 111,417 females) patients at the end of 2015. Based on these values, expected remaining lifetime at 1-year increment was calculated using the life table method.

Results

Excerpts of the calculated expected remaining lifetimes of patients aged 60 years were as follows: 11.9 years for males and 14.1 years for females. These expected remaining lifetimes were 1.1 to 1.2 times as compared with those in 2003. Meanwhile, expected remaining lifetime of diabetic patients was 10.8 years for males and 12.5 years for females and that of nondiabetic patients was 13.0 years for males and 15.0 years for females.

Conclusion

Expected remaining lifetime of dialysis patients in Japan in 2015 was 10–20% longer than that in 2003. These results suggest that advances in dialysis technologies during this 12-year period improved the survival rate of dialysis patients.

Mortality trends among Japanese dialysis patients, 1988-2013: a joinpoint regression analysis

BACKGROUND

Evaluation of mortality trends in dialysis patients is important for improving their prognoses. The present study aimed to examine temporal trends in deaths (all-cause, cardiovascular, noncardiovascular and the five leading causes) among Japanese dialysis patients.

METHODS

Mortality data were extracted from the Japanese Society of Dialysis Therapy registry. Age-standardized mortality rates were calculated by direct standardization against the 2013 dialysis population. The average annual percentage of change (APC) and the corresponding 95% confidence interval (CI) were computed for trends using joinpoint regression analysis.

RESULTS

A total of 469 324 deaths occurred, of which 25.9% were from cardiac failure, 17.5% from infectious disease, 10.2% from cerebrovascular disorders, 8.6% from malignant tumors and 5.6% from cardiac infarction. The joinpoint trend for all-cause mortality decreased significantly, by -3.7% (95% CI -4.2 to -3.2) per year from 1988 through 2000, then decreased more gradually, by -1.4% (95% CI -1.7 to -1.2) per year during 2000-13. The improved mortality rates were mainly due to decreased deaths from cardiovascular disease, with mortality rates due to noncardiovascular disease outnumbering those of cardiovascular disease in the last decade. Among the top five causes of death, cardiac failure has shown a marked decrease in mortality rate. However, the rates due to infectious disease have remained stable during the study period [APC 0.1 (95% CI -0.2-0.3)].

CONCLUSIONS

Significant progress has been made, particularly with regard to the decrease in age-standardized mortality rates. The risk of cardiovascular death has decreased, while the risk of death from infection has remained unchanged for 25 years.

Risk Evaluation and Midterm Outcome of Cardiac Surgery in Patients on Dialysis

The medical charts of 54 patients on maintenance dialysis who underwent cardiovascular surgery (37 elective and 17 urgent/emergency) from 1994 to 2004 were retrospectively analyzed. Thirty patients had coronary artery bypass grafting (17 elective and 13 urgent/emergency), 18 had valve replacement (16 elective and 2 urgent/emergency), and 6 underwent aortic surgery (4 elective and 2 urgent/emergency). The overall early mortality rate was 11.1%, comprising 2 patients (5.4%) who had elective operations and 4 (23.5%) who had urgent or emergency operations ( p = 0.049). The overall 5-year survival rate was 48.4%. The 5-year survival rate was 67.2% for elective surgery and 10.5% for urgent/emergency surgery ( p = 0.0001). The midterm clinical results after elective cardiovascular surgery were acceptable, whereas the results after urgent/emergency surgery were poor. For elective surgery, sufficient and detailed preoperative examinations might have contributed to the better operative outcome. Early diagnosis and consultation to avoid urgent/emergency operations in dialysis patients is recommended.

Ischemic Heart Disease in Patients with End-Stage Kidney Disease

BACKGROUND

It was recently reported that the severity of coronary and carotid atherosclerosis in patients with end-stage kidney disease (ESKD) has improved over the last two decades. However, the frequency of coronary artery events observed at the initiation of dialysis remains high.

SUMMARY

Recently, 5 different clinical types of acute myocardial infarction (MI) were introduced in the third universal definition of MI. Type 2 MI, known as secondary MI, is a more heterogeneous entity, where a condition other than coronary artery narrowing contributes to an acute imbalance in oxygen supply and demand. In patients with chronic kidney disease, it has been demonstrated that type 2 MI is more common than type 1 MI, which is associated with coronary occlusive disease. It is suspected that patients with ESKD also often have type 2 MI. Factors associated with incremental increases in oxygen demand may cause myocardial ischemia in ESKD.

KEY MESSAGES

Significant epicardial coronary narrowing might not be a necessary precursor of myocardial ischemia in ESKD. To prevent ischemic heart disease and improve prognosis in patients with ESKD, we need to pay attention not only to coronary stenotic lesions, but also to the factors associated with the induction of an imbalance in myocardial oxygen supply and demand.

Contribution of dysregulated serum magnesium to mortality in hemodialysis patients with secondary hyperparathyroidism: a 3-year cohort study

BACKGROUND

The extent of contribution of disturbed magnesium balance to mortality remains unclear among hemodialysis patients.

METHODS

This was a cohort study involving 3276 patients on maintenance hemodialysis at 86 facilities in Japan from 2008 to 2010 who had secondary hyperparathyroidism (SHPT). Baseline serum magnesium (sMg) values were categorized into quintiles (≤2.3, >2.3-2.5, >2.5-2.7, >2.7-3.0 and >3.0 mg/dL), and the middle quintile was set as the reference. Outcome was all-cause death. Independent contribution to all-cause death was assessed via Cox regression to generate population-attributable fractions (PAFs).

RESULTS

A total of 2165 patients from 68 facilities were analyzed. The lowest quintile of sMg was positively associated with lower serum potassium and albumin levels, higher C-reactive protein (CRP) levels and prevalence of atrial fibrillation and cerebrovascular disease than the other quintiles. The highest sMg quintile was positively associated with higher potassium levels, and negatively associated with lower serum albumin levels and higher intact parathyroid hormone and CRP levels and prevalence of cerebrovascular disease than the other quintiles. During a median follow-up of 3 years, the lowest and the second lowest quintiles of sMg were associated with all-cause death [adjusted hazard ratio (HR) 1.737, 95% confidence interval (95% CI) 1.200-2.512 and HR 1.675, 95% CI 1.254-2.238, respectively). Point estimates of adjusted HRs of the highest and the second highest sMg quintiles were higher than those of the middle quintile for all-cause death. Adjusted PAFs of lower sMg and of higher and lower sMg for all-cause death were 24.0% (95% CI 13.0-35.0%) and 30.7% (95% CI 14.5-46.8%), respectively.

CONCLUSION

In hemodialysis patients with SHPT, dysregulated sMg is an important contributor to all-cause death. Further studies are warranted to examine whether or not correction of sMg improves survival.

Inverse association between docosahexaenoic acid and mortality in patients on hemodialysis during over 10 years

We have previously conducted a cohort study to investigate n-3 polyunsaturated fatty acids (PUFAs) in red blood cells (RBCs) and risk of all-cause mortality in hemodialysis (HD) patients over 5 years and found that n-3 PUFAs, especially docosahexaenoic acid (DHA), might be an independent predictor of all-cause mortality. In the present study, we extended the study for another 5 years to determine whether DHA levels in RBCs still predict the mortality of HD patients during a 10-year study period. The study cohort consisted of 176 patients (64.1 ± 12.0 [mean ± standard deviation] years of age, 96 men and 80 women) under HD treatment. The fatty acid composition of patients' RBCs was analyzed by gas chromatography. During the study period of 10 years, 97 deaths occurred. After adjustment for 10 confounding factors, the hazard ratio of all-cause mortality of the HD patients in the highest DHA tertile (>8.1%) was 0.52 (95% confidence interval 0.30-0.91) compared with those in the lowest DHA tertile (<7.2%). However, other n-3 PUFAs such as eicosapentaenoic acid and docosapentaenoic acid (n-3) did not reveal any significant correlations. The level of DHA in RBCs could be an independent predictor of all-cause mortality in HD patients even during a long period of follow-up.

Burden and management of chronic kidney disease in Japan: systematic review of the literature

Background

Chronic kidney disease (CKD) is a common disorder with increasing prevalence worldwide. This systematic literature review aims to provide insights specific to Japan regarding the burden and treatment of CKD.

Methods

We reviewed English and Japanese language publications from the last 10 years, reporting economic, clinical, humanistic, and epidemiologic outcomes, as well as treatment patterns and guidelines on CKD in Japan.

Results

This review identified 85 relevant articles. The prevalence of CKD was found to have increased in Japan, attributable to multiple factors, including better survival on dialysis therapy and a growing elderly population. Risk factors for disease progression differed depending on CKD stage, with proteinuria, smoking, hypertension, and low levels of high-density lipoprotein commonly associated with progression in patients with stage 1 and 2 disease. Serum albumin levels and hemoglobin were the most sensitive variables to progression in patients with stage 3 and 5 disease, respectively. Economic data were limited. Increased costs were associated with disease progression, and with peritoneal dialysis as compared with either hemodialysis or combination therapy (hemodialysis + peritoneal dialysis) treatment options. Pharmacological treatments were found potentially to improve quality of life and result in cost savings. We found no reports of treatment patterns in patients with early-stage CKD; however, calcium channel blockers were the most commonly prescribed antihypertensive agents in hemodialysis patients. Treatment guidelines focused on anemia management related to dialysis and recommendations for peritoneal dialysis treatment and preventative measures. Few studies focused on humanistic burden in Japanese patients; Japanese patients reported greater disease burden but better physical functioning compared with US and European patients.

Conclusion

A dearth of evidence regarding the earlier stages of kidney disease presents an incomplete picture of CKD disease burden in Japan. Further research is needed to gain additional insight into CKD in Japan.

Overview of regular dialysis treatment in Japan (as of 31 December 2009)

A nationwide statistical survey of 4196 dialysis facilities was conducted at the end of 2009, and 4133 facilities (98.5%) responded. The number of patients undergoing dialysis at the end of 2009 was determined to be 290 661, an increase of 7240 patients (2.6%) compared with that of 2008. The number of dialysis patients per million at the end of 2009 was 2279.5. The crude death rate of dialysis patients from the end of 2008 to the end of 2009 was 9.6%. The mean age of the new patients introduced into dialysis was 67.3 years old and the mean age of the entire dialysis patient population was 65.8 years old. Primary diseases such as diabetic nephropathy and chronic glomerulonephritis for new dialysis patients, showed a percentage of 44.5% and 21.9%, respectively. Based on the facilities surveyed, 84.2% of the facilities that responded to the questionnaire satisfied the microbiological quality standard for dialysis fluids for the Japanese Society for Dialysis Therapy (JSDT), with an endotoxin concentration of less than 0.05 EU/mL in the dialysis fluid. Similarly, 98.2% of the facilities surveyed satisfied another standard of the society of a bacterial count of less than 100 cfu/mL in the dialysis fluid. The facility survey indicated that the number of patients who were treated by blood purification by both peritoneal dialysis and extracorporeal circulation, such as hemodialysis, was 1720. Among the total number of patients, 24.8% were satisfied with the management target recommended in the treatment guidelines for secondary hyperparathyroidism. These standards are set by the JSDT, based on the three parameters, i.e. serum calcium concentration, serum phosphorus concentration, and serum intact parathyroid hormone concentration. According to the questionnaire, 9.8% of the patients were considered to have a complication of dementia.

Height constitutes an important predictor of mortality in end-stage renal disease

Aim. Height is an important determinant of augmentation index (AI) that anticipates cardiovascular prognosis. There is a scanty of the data whether short height predicts survival in patients with end-stage renal diseases, a high risk population. Methods. Fifty two hypertensive patients with type 2 diabetic nephropathy receiving hemodialysis and 52 patients with nondiabetic nephropathy were enrolled. In addition to AI estimated with radial artery tonometry, classical cardiovascular risk factors were considered. Patients were followed for 2 years to assess cardiovascular prognosis. Results. Cox hazards regression revealed that both smoking and shortness in height independently contributed to total mortality and indicated that smoking as well as the presence of left ventricular hypertrophy predicted cardiovascular mortality. Our findings implicated that high AI, the presence of diabetes, and low high-density lipoprotein cholesterol were significant contributors to cardiovascular events. Conclusions. Our findings provide new evidence that shortness in height independently contributes to total mortality in hemodialysis patients.

Zigzagged augmentation index in diabetes

Although the patients with diabetic nephropathy suffered high cardiovascular risk, augmentation index (AI) in diabetic nephropathy has been poorly characterized. Cross-sectional studies were performed on 26 diabetic and 27 nondiabetic nephropathic patients. Home blood pressure was examined. In addition, blood pressure, pulse rate, and AI were measured in both supine and sitting positions. Patient backgrounds such as age, sex, sitting blood pressure, and pulse rate were similar between two groups. Circadian variations of home blood pressure were preserved in nondiabetic patients, but disappeared in diabetes. Changing from supine to sitting position induced greater decrements of systolic blood pressure (DeltaSBP -9 +/- 8 mmHg) and AI (DeltaAI -7 +/- 10) in the diabetic group than in nondiabetic patients (DeltaSBP -4 +/- 12 mmHg, DeltaAI -2 +/- 9). Multivariate regression analysis revealed that AI in a sitting position correlated positively to SBP and inversely to pulse rate. Of interest, AI in supine position related positively to age, the presence of diabetes and SBP, and inversely to pulse rate. The present data indicate autonomic dysfunction in patients with diabetic nephropathy. Furthermore, our findings provide the evidence that autonomic dysfunction elicits an inadequate physiological arterial contraction in response to postural change, thereby reducing AI that results in the fall of SBP. Finally, the present results suggest that AI in supine, but not sitting position, is suited for detecting cardiovascular risk in diabetes.

Percutaneous ethanol injection therapy for advanced renal hyperparathyroidism in Japan: 2004 survey by the Japanese Society for Parathyroid Intervention

Background. Marked hyperplasia of the parathyroid gland (PTG) is a characteristic feature of severe hyperparathyroidism in patients under chronic haemodialysis treatment. Percutaneous ethanol injection therapy (PEIT) is now becoming popular in Japan as a treatment option for secondary hyperparathyroidism (SHPT) and its cost is covered by the National Health Insurance (NHI) System. The Japanese Society for Parathyroid Intervention surveyed its membership in 2004 to revise the guidelines for the use of PEIT.

Methods. The project was approved by the Executive Committee of the Society, and the primary questionnaire was addressed to 3268 centres (departments) affiliated with the Japanese Society for Dialysis Therapy. A follow-up questionnaire was sent to all the centres that responded.

Results. Although the number of centres to which the questionnaire was sent in 2004 was 3268, compared with 2653 in 1998, the number of responses decreased from 1425 (53.7%) in 1998 to 962 (29.4%) in 2004. To the question of whether the centre performed PEIT, 114 (11.9%) answered ‘Yes’ and 848 (88.1%) answered ‘No’ in 2004. It was an increase from 1998 when only 83 (5.8%) of 1425 centres answered ‘Yes’. In the 1998 survey, 612 patients underwent PEIT at 74 centres, and in 2004, 2098 patients underwent PEIT at 111 centres.

Conclusions. PEIT may become the frequently performed treatment for SHPT patients who become resistant to medical therapy. However, the same problems as in 1998 remain unsolved; that is, recurrent nerve paralysis, difficulty of post-PEIT PTx and lack of evidence showing the long-term effectiveness of PEIT.

Arterial wave reflection is elevated in evening hemodialysis patients

AIM

Cardiovascular disease constitutes a major cause of death in patients with chronic kidney diseases and is related to enhanced arterial stiffness. It has been reported that daytime hemodialysis patients show better prognosis than evening hemodialysis patients.

METHODS

Aortic augmentation index (AI) and radial AI were measured in 20 non-diabetic hemodialysis patients, using SphygmoCor (PWV Medical) and HEM-9010AI (Omron Healthcare) as markers of arterial stiffness. Cardiovascular prognosis was followed for two years.

RESULTS

Mean age, blood pressure, pulse rate, and aortic and radial AI were 52 +/- 4 y/o, 142 +/- 6/74 +/- 4 mmHg, 78 +/- 4 bpm, 21 +/- 2, and 71 +/- 4%, respectively, in 10 daytime hemodialysis patients, and they averaged 52 +/- 3 y/o, 146 +/- 6/76 +/- 4 mmHg, 74 +/- 3 bpm, 26 +/- 2, and 73 +/- 3% in 10 evening hemodialysis patients, respectively. Thus, aortic AI was higher in evening hemodialysis patients (p < 0.05). In all, one patient was hospitalized due to cardiovascular complications in daytime hemodialysis patients, as well as three patients from those dialyzed in the evening.

CONCLUSION

Although a larger scale study is required to draw a definite conclusion, our findings suggest that a better prognosis in daytime hemodialysis non-diabetic patients is related to the lower AI.

Assessment of lower limb ischemia with measurement of skin perfusion pressure in patients on hemodialysis

Measurement of skin perfusion pressure (SPP) using laser Doppler has become available for the assessment of peripheral arterial disease. We studied whether measurements of SPP can be used to identify hemodialyzed patients with peripheral arterial disease by comparing it with measurements of the ankle brachial pressure index (ABI). The ABI at rest and the SPP in the foot were measured in 59 Japanese hemodialyzed patients (118 limbs). Twenty-one patients had diabetes mellitus. Five had intermittent claudication; however, 20 patients were accompanied by other exertional leg symptoms. The SPP could not be measured in three limbs because of involuntary movement due to previous stroke or restless leg syndrome. The SPP was correlated with the ABI. Depending upon these results of the ABI, the 114 limbs from which both the ABI and the SPP could measured were divided into three groups: (A) ABI > or = 1.3, (B) 0.9 < or = ABI < 1.3, and (C) ABI < 0.9. The average SPP of group C was significantly decreased among the three groups. All subjects of the three groups were divided into an extra two groups according to the presence of diabetes (non-diabetes groups, -I; diabetes groups, -II). The average SPP of group B-II was significantly decreased compared with those of group B-I. The SPP measurement is a noninvasive, useful screening method for limb ischemia that can be applied to exercise tolerance limited patients. The SPP measurements are expected to be useful for the evaluation of limb ischemia in hemodialyzed patients at risk.

Vascular compliance is secured under angiotensin inhibition in non-diabetic chronic kidney diseases

Cardiovascular diseases constitute major cause of death in chronic kidney diseases (CKDs). We examined the effects of angiotensin inhibition either with angiotensin-converting enzyme inhibitor or with angiotensin receptor blocker on patient prognosis and heart-ankle pulse wave velocity (haPWV) in CKDs. Randomized controlled study was performed on 102 patients with non-diabetic CKDs. Patients were divided into two groups with or without angiotensin inhibition, and followed until death, creatinine clearance was halved or starting renal replacement therapy, whichever occurred first. For 4 years, haPWV was assessed repeatedly in the surviving patients. While both groups showed well blood pressure control throughout 4 years (129+/-1 to 131+/-2/71+/-1 to 73+/-2 mm Hg), renal prognosis was better in angiotensin inhibition group (P<0.05). In addition, angiotensin inhibition reduced cardiovascular and renal death (P<0.05). Age, sex, heart rate, systolic blood pressure and proteinuria were correlated to haPWV (R(2)=0.76, P<0.0001). Although haPWV was similar between two groups at the start of the study (1098+/-31 vs 1094+/-37 cm/s), it was higher in patients without angiotensin inhibition than that with angiotensin inhibition 4 years later (1034+/-38 cm/s (n=28) vs 1242+/-37 cm/s (n=23), P<0.01). The present results provided the evidence that angiotensin inhibition arrested a time-dependent elevation of haPWV in non-diabetic CKDs, conferring organ protection. Furthermore, our data indicated that angiotensin inhibition improved patient prognosis in non-diabetic chronic kidney diseases with mild-to-moderate renal dysfunction.

Key role of insulin resistance in vascular injury among hemodialysis patients

Insulin resistance prevails not only among diabetic patients but also among hypertensive and obese patients. The relationship between insulin resistance and cardiovascular diseases was investigated in hemodialysis (HD) patients. Eighty-one maintenance HD patients were enrolled. The homeostasis model assessment of insulin resistance (HOMA-IR) method was used to assess insulin resistance. The relationship of HOMA-IR with cardiovascular and all-cause events was assessed. Compared with nondiabetic patients (n = 55), diabetic patients (n = 26) showed higher HOMA-IR (2.5 +/- 0.3 vs 1.4 +/- 0.2, P < .05), lower ankle-brachial pressure index (ABI, 0.85 +/- 0.09 vs 1.12 +/- 0.02, P < .01), and shorter HD duration (3 +/- 1 vs 9 +/- 1 years, P < .01), although their body mass index was similar (22.3 +/- 0.5 vs 21.5 +/- 0.4 kg/m(2)). Nondiabetic patients taking angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (n = 36) had lower HOMA-IR (1.2 +/- 0.2 vs 1.8 +/- 0.4, P < .05) and higher ABI (1.18 +/- 0.02 vs 1.02 +/- 0.05, P < .01) than those without (n = 17). Cardiovascular events were less common in HD patients with normal HOMA-IR (P < .05) or ABI (P < .01). Our data indicate that 69% of diabetic and 27% of nondiabetic patients have HOMA-IR greater than 1.6, implying reduced insulin sensitivity in HD patients. The present results provide evidence that angiotensin inhibition improves insulin resistance, possibly preventing vascular injury in HD patients. Finally, our findings suggest that insulin resistance is prognostic of cardiovascular events in HD patients.

Changes in the Demographics and Prevalence of Chronic Kidney Disease in Okinawa, Japan (1993 to 2003)

To compare the risk factor demographics and the prevalence of chronic kidney disease (CKD), we analyzed two databases from the 1993 (N=143,948) and 2003 (N=154,019) mass screenings in Okinawa, Japan (Okinawa General Health Maintenance Association registry). We estimated the glomerular filtration rate (GFR) using serum creatinine (SCr) levels. SCr was measured by the modified Jaffe method in 1993 and by enzyme assay in 2003; the relation between the two methods was: SCr (Jaffe) = 0.194 + 1.079 x SCr (enzyme). CKD prevalence was compared using the estimated GFR calculated by the abbreviated Modification of Diet in Renal Disease (MDRD) equation. SCr was measured in 66.2% (1993) and 69.8% (2003) of the total screenees. Proteinuria was present in 3.4% (1993) and 4.3% (2003) of the total screened population, respectively. The prevalence of CKD (GFR<60 ml/min/1.73 m(2)) was similar between the two databases, being 15.7% in 1993 and 15.1% in 2003. However, the demographics of the CKD risk factors changed during the study period. The mean level of systolic blood pressure decreased, whereas the prevalence of obesity and the mean levels of serum cholesterol and fasting plasma glucose increased. In 2003, the estimated prevalence of metabolic syndrome in the general population of Japan calculated using the modified National Cholesterol Education Program (NCEP) criteria was 19.1%. The prevalence of CKD was significantly associated with that of metabolic syndrome: the age- and sex-adjusted odds ratio was 1.332 (95% confidence interval [CI], 1.277-1.389; p<0.0001). In conclusion, the demographics of the participants of the general screenings in Okinawa, Japan differed between the 1993 and 2003 screenings, but the prevalence of CKD seemed to be similar, or at least did not increase substantially, between the two databases.

Prospective randomized study evaluating the efficacy of the spherical adsorptive carbon AST-120 in chronic kidney disease patients with moderate decrease in renal function

AIMS

We studied whether adding the spherical adsorptive carbon AST-120 to conventional treatments is effective in inhibiting progression of chronic kidney disease (CKD) at the stage of moderate decrease in renal function.

METHODS

43 CKD patients with moderately impaired renal function indicated by glomerular filtration rate (GFR) of 20-70 ml/min as measured by non-radiolabeled iothalamate clearance method were enrolled in the study. 26 patients showing a decrease of GFR by 5 ml/min during a 1-year observation period were randomized to receive ongoing treatments only (control group, 12 cases) or with AST-120 co-administered with ongoing treatment (AST-120 group, 14 cases). The intervention period was 1 year and the change in GFR was the primary evaluation variable.

RESULTS

The mean changes of GFR per month (DeltaGFR) in the intervention period were not significantly different between both groups. However, when comparing the DeltaGFR in the observation and intervention periods for each group, the rate of decline in GFR was significantly retarded (p < 0.001) in the AST-120 group while no significant difference was observed in the control group.

CONCLUSION

These results suggest that co-administration of AST-120 with conventional treatments retards decline in renal function in CKD patients with moderate decrease in renal function.

Surveillance of infection control procedures in dialysis units in Japan: a preliminary study

As there is a high risk of indirect and direct transmission of infectious agents in chronic hemodialysis, infection control procedures should be established in dialysis units. This paper presents the findings of a questionnaire designed to survey the current status of infection control procedures in hemodialysis settings. Two hundred and forty-three hemodialysis units in Japan were surveyed. Nearly 90% of hemodialysis units reported compliance with each procedure recommended by the Center for Disease Control and Prevention in the United States, including use of disposable gloves, handling of non-disposable or non-single-use items, and routine serological testing of blood-borne viruses. However, more than 50% of units reported that they did not comply with recommendations concerning some procedures, such as places for preparing medications and their delivery, clean areas in the units, vaccination for hepatitis B, and additional measures for hepatitis B surface antigen (HBs-Ag) positive patients. Especially, the concept of universal precautions seemed to be misunderstood in units with a high prevalence of anti-hepatitis C antibody-positive (anti-HCV Ab-positive) patients. In conclusion, further intensive education and training will be necessary to establish infection control procedures.

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.

Relationship between serum albumin level before initiating haemodialysis and angiographic severity of coronary atherosclerosis in end-stage renal disease patients

BACKGROUND

In patients with chronic kidney disease (CKD), although strong associations have been observed between malnutrition and atherosclerosis, the relationship between serum albumin concentration and angiographic changes of coronary artery disease (CAD) remains poorly explored. The goal of the present study was, in patients with CKD, to clarify the relationship between the angiographic severity of CAD and serum albumin concentration reflecting either inflammation or nutrition or both.

METHODS

In this study, 100 end-stage renal disease (ESRD) patients were enrolled, who commenced long-term dialysis therapy at our hospital and underwent coronary angiography within 3 months of the first haemodialysis (HD) session. Mean age was 63+/-11 years, 20% of the subjects were female and 62% had diabetes. Severity of CAD was evaluated in terms of (i) number of vessels exhibiting CAD (>or=75% stenosis) and (ii) Gensini score (GS). Clinical characteristics and laboratory findings were recorded at initiation of long-term HD therapy. We then evaluated a possible association with the presence and degree of CAD.

RESULTS

Sixty-four patients exhibited signs of CAD. Forty-one among them (64%) had multivessel disease. On univariate logistic regression analysis, age, diabetes and hypoalbuminaemia were significantly associated with multivessel CAD. Univariate linear regression analysis demonstrated a positive correlation of age and diabetes with GS, and an inverse correlation of BMI and serum albumin level with GS. Stepwise regression analysis showed age and serum albumin level to be independently associated with multivessel CAD and GS. The ROC curves demonstrated best cut-off levels of age and albumin for predicting multivessel CAD to be 70 years and 3.15 g/dl, respectively.

CONCLUSION

Hypoalbuminaemia at the initiation of dialysis is an important predictor of advanced CAD, particularly in male and in diabetic patients. It may reflect mainly a state of inflammation. However, malnutrition as a confounding factor cannot be entirely excluded.

Genetic susceptibility to type 2 diabetic nephropathy in human and animal models

Diabetic nephropathy is the most common cause of end-stage renal disease (ESRD) in Japan, Western Europe, and the United States. Mega studies such as Diabetes Control and Complication Trial (DCCT), Epidemiology of Diabetes Interventions and Complications (EDIC), and the United Kingdom Prospective Diabetes Study (UKPDS) clarified that poor glycemic and blood pressure control are undoubtedly involved in the development of nephropathy. However, these factors are not sufficient to predict which diabetic patients will develop renal disease, because not all patients with poor glycemic and blood pressure control develop renal disease. Since ethnic variations and familial clustering of diabetic nephropathy have been observed, genetic factors might contribute to susceptibility to this disease. Several methods such as (genome wide) association studies, sib-pair analysis, and quantitative trait loci (QTLs) analysis are available to examine polygenic diseases. However, no mutations that could explain the majority of nephropathy cases have been identified so far. The development of most diabetic nephropathy might be explained by the polygenic effect (i.e. many minor gene-gene interactions might be very important in the development of nephropathy). Identification of candidate genes of nephropathy enables targeting of therapy in patients at risk and development of novel therapeutic agents.

Losartan reduces the costs of diabetic end-stage renal disease: an Asian perspective

OBJECTIVE

To evaluate losartan and conventional antihypertensive therapy (CT) compared with CT alone on the cost associated with end-stage renal disease (ESRD) in Hong Kong, Japan, Korea, Malaysia, Singapore and Taiwan.

METHODS

Reduction of end-points in non-insulin-dependent diabetes mellitus with the angiotensin II antagonist losartan (RENAAL) was a multinational, double-blind, randomized, placebo-controlled trial to evaluate the renal protective effects of losartan on a background of CT in patients with type 2 diabetes and nephropathy. The primary composite end-point was a doubling of serum creatinine, ESRD or death. Data on the duration of ESRD for the Asian subgroup of patients enrolled in RENAAL were used to estimate the economic benefits of slowing the progression of nephropathy. The cost associated with ESRD was estimated by combining the number of days each patient experienced ESRD with the average daily cost of dialysis from the third-party payer perspective in Hong Kong, Japan, Korea, Malaysia, Singapore and Taiwan. Total cost, converted to US dollars, was the sum of ESRD and losartan costs.

RESULTS

Losartan plus CT reduced the number of days with ESRD by 37.9 per patient over 3.5 years compared with CT alone. This reduction in ESRD days resulted in a decrease in the cost associated with ESRD, which ranges from $910 to $4346 per patient over 3.5 years across the six countries or regions. After accounting for the cost of losartan, the reduction in ESRD days resulted in net savings in each of the six countries or regions, ranging from $55 to $515 per patient.

CONCLUSION

Treatment with losartan in patients with type 2 diabetic nephropathy not only reduced the incidence of ESRD among Asian patients, but resulted in direct medical cost savings in countries or regions representing Asia.

Inhibition of mTOR signaling with rapamycin attenuates renal hypertrophy in the early diabetic mice

Early diabetic nephropathy is characterized by renal hypertrophy that is mainly due to proximal tubular hypertrophy. Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase, and its signaling has been reported to regulate protein synthesis and cellular growth, specifically, hypertrophy. Therefore, we examined the effect of mTOR signaling on diabetic renal hypertrophy by using the specific inhibitor for mTOR, rapamycin. Ten days after streptozotocin-induced diabetes, mice showed kidney hypertrophy with increases in the phosphorylation of p70S6kinase and the expression of cyclin kinase inhibitors, p21(Cip1) and p27(Kip1), in the kidneys. The intraperitoneal injection of rapamycin (2 mg/kg/day) markedly attenuated the enhanced phosphorylation of p70S6kinase, the increment of cyclin-dependent kinase inhibitors, and renal enlargement without any changes of clinical parameters, including blood glucose, blood pressure, and food intake. Overexpression of a constitutive active form of p70S6kinase resulted in increased cell size of cultured mouse proximal tubule cells; thus, activation of p70S6kinase causes hypertrophy of proximal tubular cells. Our findings suggest that activation of mTOR signaling causes renal hypertrophy at the early stage of diabetes.

An Overview of Regular Dialysis Treatment in Japan as of 31 December 2003

A statistical survey of 3750 nationwide dialysis facilities was carried out by the Japanese Society for Dialysis Therapy (JSDT) at the end of 2003, with answers to the questionnaires received from 3717 facilities (99.12%). The population of dialysis patients in Japan at the end of 2003 was 237,710, and the number of dialysis patients per million people was 1862.7. The crude death rate during a 1-year period from the end of 2002 to the end of 2003 was 9.3%. The mean age of patients newly introduced to dialysis was 65.4 years, and the mean age of the entire dialysis population was 62.3 years. The primary diseases in the patients newly introduced to dialysis in 2003 included diabetic nephropathy (41.0% of patients) and chronic glomerulonephritis (29.1% of patients). The mean serum neutral fat concentration for all the dialysis patients was 113.9 +/- 71.7 mg/dL (+/- SD). The mean serum low density lipoprotein (LDL)-cholesterol concentration was 90.8 +/- 30.9 mg/dL. Dialysate calcium concentrations ranging from 3.0 mEq/L to less than 3.5 mEq/L were used for majority of the dialysis patients (55.4%). Among anticoagulants given to the dialysis patients, heparins were the most commonly used in 79.3% of the dialysis patients. The relationship between blood pressure during dialysis and life expectancy for 1 year was analyzed for 43,465 patients who had undergone dialysis three times per week at the end of 2001. Results showed a significantly high mortality risk for patients who had systolic blood pressure of less than 100 mm Hg at the start of dialysis, systolic blood pressure of less than 100 mm Hg at the end of dialysis, and the greatest decrease (lowest) in systolic blood pressure of less than 120 mm Hg during dialysis. Patients who received vasopressor therapy during dialysis had a higher mortality risk than those who received no vasopressor therapy.

Role of platelet factor 4-heparin complex antibody (HIT antibody) in the pathogenesis of thrombotic episodes in patients on hemodialysis

Heparin-induced thrombocytopenia (HIT) is a severe complication in patients on hemodialysis (HD). It has been reported that platelet factor-4 (PF-4)-heparin complex antibody (HIT antibody) plays an important role in the pathogenesis of this serious complication. In the present study, we investigated the role of HIT antibody in the pathogenesis of thrombotic complications including shunt failure, cerebrovascular disease (CVD) and atherosclerosis in patients on dialysis. Plasma concentration of HIT antibody in patients on HD was 0.143+/-0.008 (n=105). This was significantly higher in patients on continuous ambulatory peritoneal dialysis (CAPD: 0.087+/-0.006, p=0.0008, n=22) and in non-dialysis patients (0.113+/-0.011, p=0.0011, n=12). There was a significant negative correlation between HIT antibody and the duration of dialysis. However, no significant correlation was found between HIT antibody and other factors including age, dose of heparin, platelet count and hemoglobin. There was a significant correlation between the number of failed arteriovenous fistula and HIT antibody levels. In addition, in patients with a history of CVD, plasma concentrations of HIT antibody were significantly higher compared with patients without CVD (CVD(+): 0.200+/-0.029 vs. (-): 0.127+/-0.005, p<0.0001). It is possible that genetic factors may also play a role in the expression of HIT antibody. From these data, it appears possible that HIT antibody plays an important role in the pathogenesis of thrombosis in patients on HD. Further studies are needed to clarify the role of HIT antibody in the pathogenesis of thrombotic episodes in these patients.

Qualification of arterial stiffness as a risk factor to the progression of chronic kidney diseases

BACKGROUND

Reflection pressure may influence the clinical course of chronic kidney diseases (CKDs). The relationship between the augmentation index (AI) and progression of non-diabetic CKDs was characterized.

METHODS

Ninety-nine patients were enrolled into the study. Pulse wave form analysis was performed to determine AI that assesses arterial stiffness.

RESULTS

In a cross-sectional study, a multiple regression analysis found that AI correlated positively to age and weight, and negatively to height and heart rate (R(2) = 0.50). Furthermore, echocardiography was performed in 51 patients who gave their consent. In male patients under angiotensin inhibition, left ventricular mass index increased as AI was elevated (r = 0.33, slope = 0.85 +/- 0.30 g/m(2)/%, p < 0.05, n = 23). A prospective study was performed in 41 patients who consented to having their creatinine clearance measured repeatedly. In the patients with angiotensin inhibition a higher basal AI resulted in a greater annual decrease in creatinine clearance (r = -0.52, slope = -0.43 +/- 0.14 ml/min/year/%, p < 0.01, n = 27).

CONCLUSION

The present data indicate that AI as well as angiotensin contribute to the development of left ventricular hypertrophy. Furthermore, our results suggest that in addition to angiotensin, AI is a risk factor of progression of non-diabetic CKDs.

The Japanese Artificial Organs Scene: Current Status

Artificial organs and regenerative medicine are the subjects of very active research and development (R&D) in Japan and various artificial organs are widely used in patients. Results of the R&D are presented at the annual conference of the Japanese Society for Artificial Organs (JSAO). Progress in the fields of artificial organs and regenerative medicine are reviewed annually in the Japanese Journal of Artificial Organs. The official English-language journal of JSAO, Journal of Artificial Organs, also publishes many original articles by Japanese researchers. Although the annual conference and the publications of JSAO provide the world with update information on artificial organs and regenerative medicine in Japan, the information is not always understood appropriately in the rest of the world, mainly due to language problems. This article therefore introduces the current status of artificial organs and regenerative medicine in Japan. Artificial hearts and metabolic support systems are reviewed here and other interesting areas such as regenerative medicine can be found elsewhere.

Problems in adapting the K/DOQI guidelines for Japanese patients with end stage renal failure

The National Kidney Foundation published The K/DOQI Clinical Practice Guidelines for Bone Metabolism and Disease in Chronic Kidney Disease. We should also consider differences in clinical features of management for renal osteodystrophy between Japan and the USA. The first problem is related to a difference in the method of Ca correction. The second problem is related to a difference in the timing of measurement. In the USA the timing of measurement varies with each institution. Briefly, it is performed at midweek (2 days after the last dialysis) in some of institutions, while at the beginning of next week (3 days after the last dialysis) in some others. In addition, differences in the dose and type of the calcium-containing phosphorus adsorbent and active vitamin D used should also be taken into consideration.

Different Routes Bridging Calcium in Japanese Hemodialysis Patients

There is growing evidence that not only serum calcium concentration but also excess calcium load is associated with vascular calcification and mortality in hemodialysis patients. Calcium load in hemodialysis patients cumulatively comes from three different routes: oral intake of calcium including calcium-based phosphate binders, traffic of calcium from/to dialysate, and calcemic action of vitamin D. The K/DOQI guidelines recommend sevelamer hydrochloride instead of calcium-containing phosphate binders to control serum phosphate concentration. However, in Japan, both kinds of phosphate binders are used concomitantly, mainly because Japanese patients are prone to a higher incidence of sevelamer-associated adverse events such as gastrointestinal symptoms. Regarding the calcium concentration of dialysate (D-Ca) in Japan, 3.0 mEq/L is more popular than 2.5 mEq/L. Calcium loaded through 3.0 mEq/L dialysate may lead to metastatic calcification rather than to bone formation because serum phosphate concentration rebounds several hours after the end of each hemodialysis session when plasma pH is still high. In contrast, use of 2.5 mEq/L dialysate may result in an unfavorable increase of intact parathyroid hormone particularly when the amount of oral calcium intake is reduced. Although a higher dose of vitamin D is required to counteract the stimulation of parathyroid glands, hypercalcemia is less likely with 2.5 mEq/L dialysate. As the new K/DOQI guidelines are released, it is time to discuss the appropriate D-Ca as well as doses and kinds of phosphate binders and vitamin D for the comprehensive management of Japanese hemodialysis patients.