Global Dialysis Perspective: Japan

The medical cost and outcome of desensitization protocol in kidney transplantation recipients with high immunological risks

BACKGROUND

Kidney transplantation is a well-established alternative in renal replacement therapy. Compared with hemodialysis, low-immunological-risk kidney transplantation can reduce the medical treatment costs associated with end-stage renal disease. However, there are few reports on whether high-immunological-risk kidney transplantation reduces the financial burden on governments. We investigated the medical costs of high-immunological-risk kidney transplantation in comparison with the cost of hemodialysis in Japan.

METHODS

We compared the medical costs of high-immunological-risk kidney transplantation with those of hemodialysis. 15 patients who underwent crossmatch-positive and/or donor-specific antibody-positive kidney transplantations between 2020 and 2021 were enrolled in this study. The patients received intravenous immunoglobulin, plasmapheresis, and rituximab as desensitizing therapy.

RESULTS

Acute antibody-mediated rejection was detected in nine (60%) recipients, while there were no indications of graft function deterioration during the follow-up. For each patient, the transplant hospitalization cost was 38 428 ± 8789 USD. However, the cumulative costs were 59 758 ± 10 006 USD and 79 781 ± 16 366 USD, at 12 and 24 months, respectively. Compared with hemodialysis (34 286 USD per year), high-immunological-risk kidney transplantation tends to be expensive in the first year, but the cost is likely to be lower than that of hemodialysis after 3 years.

CONCLUSIONS

Although kidney transplantation is initially expensive compared with hemodialysis, the medical cost becomes advantageous after 3 years even in kidney transplant recipients with high immunological risk.

Dapagliflozin Utilization in Chronic Kidney Disease and Its Real-World Effectiveness Among Patients with Lower Levels of Albuminuria in the USA and Japan

INTRODUCTION

Sodium-glucose cotransporter 2 inhibitors such as dapagliflozin have been proven effective for slowing chronic kidney disease (CKD) progression in large outcomes trials that mainly included patients with higher levels of albuminuria. Understanding the real-world utilization and effectiveness of these drugs among patients with CKD with lower levels of albuminuria can inform clinical decision-making in this population.

METHODS

Claims data from the USA and Japan were used to describe patients with CKD and urinary albumin-to-creatinine ratio (UACR) < 200 mg/g who were eligible for dapagliflozin 10 mg treatment (initiators and untreated) following its approval for CKD. A quantile regression analysis was performed to evaluate the effect of dapagliflozin 10 mg initiation versus no initiation on estimated glomerular filtration rate (eGFR) slope in a propensity score-matched cohort, using a prevalent new-user design.

RESULTS

Dapagliflozin initiators (n = 20,407) mostly had stage 3-4 CKD (69-81% across databases). The most common comorbidities were type 2 diabetes, hypertension and cardiovascular disease. At baseline, a renin-angiotensin system inhibitor was prescribed in 53-81% of patients. Eligible but untreated patients were older and had a higher eGFR and lower comorbidity burden than initiators. Following dapagliflozin initiation, the differences in median eGFR slope between initiators and matched non-initiators were 1.07 mL/min/1.73 m2/year (95% confidence interval [CI] 0.40-1.74) in all patients with UACR < 200 mg/g and 1.28 mL/min/1.73 m2/year (95% CI - 1.56 to 4.12) in patients with UACR < 200 mg/g without type 2 diabetes.

CONCLUSIONS

Dapagliflozin 10 mg was prescribed to a broad range of patients with CKD. In patients with UACR < 200 mg/g, dapagliflozin initiation was associated with a clinically meaningful attenuation of eGFR slope compared with non-initiation. These findings supplement available clinical efficacy evidence and suggest that dapagliflozin effectiveness may extend to patients with CKD and UACR < 200 mg/g. Graphical Abstract and Video Abstract available for this article. (Video Abstract 245964 kb).

Long-term outcomes of lung transplantation requiring renal replacement therapy: A single-center experience

BACKGROUND

Life-long immunosuppressive therapy after lung transplantation (LT) may lead to end-stage renal disease (ESRD), requiring renal replacement therapy (RRT). We aimed to investigate the characteristics and long-term outcomes of patients undergoing LT and requiring RRT.

METHODS

This study was a single-center, retrospective cohort study. The patients were divided into the RRT (n = 15) and non-RRT (n = 170) groups. We summarized the clinical features of patients in the RRT group and compared patient characteristics, overall survival, and chronic lung allograft dysfunction (CLAD)-free survival between the two groups.

RESULTS

The cumulative incidences of ESRD requiring RRT after LT at 5, 10, and 15 years were 0.8 %, 7.6 %, and 25.2 %, respectively. In the RRT group, all 15 patients underwent hemodialysis but not peritoneal dialysis, and two patients underwent living-donor kidney transplantation. The median follow-up period was longer in the RRT group than in the non-RRT group (P < 0.001). The CLAD-free survival and overall survival did not differ between the two groups. The 5-year survival rate even after the initiation of hemodialysis was 53.3 %, and the leading cause of death in the RRT group was infection.

CONCLUSIONS

Favorable long-term outcomes can be achieved by RRT for ESRD after LT.

Global variability of vascular and peritoneal access for chronic dialysis

AIM

Vascular and peritoneal access are essential elements for sustainability of chronic dialysis programs. Data on availability, patterns of use, funding models, and workforce for vascular and peritoneal accesses for dialysis at a global scale is limited.

METHODS

An electronic survey of national leaders of nephrology societies, consumer representative organizations, and policymakers was conducted from July to September 2018. Questions focused on types of accesses used to initiate dialysis, funding for services, and availability of providers for access creation.

RESULTS

Data from 167 countries were available. In 31 countries (25% of surveyed countries), >75% of patients initiated haemodialysis (HD) with a temporary catheter. Seven countries (5% of surveyed countries) had >75% of patients initiating HD with arteriovenous fistulas or grafts. Seven countries (5% of surveyed countries) had >75% of their patients starting HD with tunnelled dialysis catheters. 57% of low-income countries (LICs) had >75% of their patients initiating HD with a temporary catheter compared to 5% of high-income countries (HICs). Shortages of surgeons to create vascular access were reported in 91% of LIC compared to 46% in HIC. Approximately 95% of participating countries in the LIC category reported shortages of surgeons for peritoneal dialysis (PD) access compared to 26% in HIC. Public funding was available for central venous catheters, fistula/graft creation, and PD catheter surgery in 57%, 54% and 54% of countries, respectively.

CONCLUSION

There is a substantial variation in the availability, funding, workforce, and utilization of vascular and peritoneal access for dialysis across countries regions, with major gaps in low-income countries.

International Variability in the Epidemiology, Management, and Outcomes of CKD and ESKD: A Systematic Review

Key Points

There is dramatic global variability in the prevalence of ESKD. Higher per capita health care spending in each country is associated with increased delivery of care for ESKD.

Background

Approaches to treating ESKD may vary internationally on the basis of the availability of care and other factors. We performed a systematic review to understand the international variability in ESKD epidemiology, management, and outcomes.

Methods

We systematically searched PubMed for population-based studies of CKD and ESKD epidemiology and management. Population-level data from 23 predesignated nations were eligible for inclusion if they pertained to people receiving dialysis or kidney transplant for ESKD. When available, government websites were used to identify and extract data from relevant kidney registries. Measures gathered included those related to the prevalence and mortality of ESKD; the availability of nephrologists; per capita health care expenditures; and use of erythropoietin-stimulating agents.

Results

We obtained data from the United States; seven nations in Eastern Europe; four each in Western Europe, Latin America, and Africa; and three in Asia. The documented prevalence of ESKD per million population varied from a high of 3600 (Malaysia) to a low of 67 (Senegal). The annual mortality associated with ESKD varied from 31% (Ethiopia and Senegal) to 10% (the United Kingdom). Nephrologist availability per million population varied from 40 (Japan) to <1 (South Africa) and was associated with per capita health care expenditures.

Conclusions

The delivery of kidney care related to ESKD varies widely among countries. Higher per capita health care spending is associated with increased delivery of kidney care. However, in part because documentation of kidney disease varies widely, it is difficult to determine how outcomes related to ESKD may vary across nations.

Birth cohort effects in incident renal replacement therapy in Japan, 1982-2021

BACKGROUND

This study aimed to investigate the long-term trends of incident end-stage kidney disease (ESKD) requiring renal replacement therapy (RRT) in Japan using age-period-cohort analysis and evaluated birth cohort effects for incident ESKD requiring RRT.

METHODS

The number of incident RRT patients aged between 20 and 84 years by sex from 1982 to 2021 was extracted from the Japanese Society of Dialysis Therapy registry data. Annual incidence rates of RRT were calculated using census population as denominators, and changes in the incidence rates were evaluated using an age-period-cohort model. The age and survey year period categories generated 20 birth cohorts with 5-year intervals (from 1902-1907 to 1997-2001).

RESULTS

The incidence rates of RRT in both sexes initially rose in the birth cohorts born in the early 1900s, and then decelerated and peaked during 1940-1960s in men and 1930-1940s in women, following a steady decline in both sexes. Compared with the reference 1947-1951 birth cohort, the highest cohort rate ratio was 1.14 (95% CI, 1.04-1.25) in the 1967-1971 birth cohort in men and 1.04 (95% CI, 0.98-1.10) in the 1937-1941 birth cohort in women.

CONCLUSIONS

Significant cohort effects were identified in both sexes, but the peak of RRT was different for each sex. Our findings suggest that men born between 1940 and 1960s and women born between 1930 and 40 s may be important target populations to consider when decreasing incidence rates of RRT among the general Japanese population.

The Etiology of Kidney Failure in Indonesia: A Multicenter Study in Tertiary-Care Centers in Jakarta

BACKGROUND

Despite a large number of patients requiring dialysis, the etiology of kidney failure is poorly documented in Indonesia. With the aim to reduce the disease burden, it is essential to obtain more insight in the etiology of chronic kidney disease (CKD).

OBJECTIVES

In the present study, we attempted to investigate the primary renal disease of kidney failure patients from five tertiary-care centers in Jakarta.

METHODS

This is a multicenter, cross-sectional study of kidney failure patients receiving kidney replacement therapy (KRT), from December 2021 to July 2022. We recruited patients aged ≥18 years, had been receiving dialysis for at least three months or a kidney transplantation.

FINDINGS

This study included 1,152 patients treated with hemodialysis (68.1%), peritoneal dialysis (7.5%), and kidney transplantation (24.4%). At the start of KRT, the median (interquartile-range [IQR]) age was 48 [37-58] years with low eGFR (median [IQR]: 5.9 [4.0-8.34] ml/minute/1.73 m2). Hypertension was the main comorbidity (74.2%), followed by diabetes mellitus (30.1%). The major primary kidney disease was diabetic kidney disease (27.2%), followed by glomerulonephritis (13.0%), hypertension (11.5%), and urolithiasis (10.3%). Lupus nephritis was the common underlying etiology of secondary glomerulonephritis (91%). A high rate of unknown cause (31.1%) was also observed.

CONCLUSIONS

Our results suggest that diabetic kidney disease is the leading cause of kidney failure in Jakarta, followed by glomerulonephritis. This study highlights the need for a better approach on primary prevention of diabetes mellitus as well as to better recognize glomerulonephritis at earlier stage might have a significant impact on reduction of the rate of kidney failure in Indonesia.

A Case of Drug-Resistant Myoclonus Improved by Only Slight Adjustment to the Hemodialysis Setting

Myoclonus, a rare complication in patients with end-stage renal disease, is typically ameliorated through hemodialysis. The present case concerns an 84-year-old male with chronic renal failure undergoing hemodialysis, presenting involuntary movements in his limbs, which gradually worsened from the initiation of hemodialysis without constant elevation of serum blood urea nitrogen and electrolytes levels. Surface electromyography revealed characteristic findings consistent with myoclonus. He was diagnosed with subcortical-nonsegmental myoclonus related to hemodialysis, and the myoclonus was significantly alleviated after slightly increasing the post-dialysis target weight even though drug treatment was ineffective. This case suggests that drug-resistant myoclonus in patients with renal failure may be improved by adjusting hemodialysis settings, even in cases of atypical dialysis disequilibrium syndrome.

Prefecture-specific prevalence of overweight/obesity is associated with regional variation in the incidence of treated ESKD in Japan

BACKGROUND

Overweight/obesity is a significant risk factor for chronic kidney disease and end-stage kidney disease (ESKD) in the general population. This study evaluated the impact of sex- and prefecture-specific prevalence of overweight/obesity on standardized incidence rates (SIRs) of treated ESKD in Japan.

METHODS

We conducted an ecological study of all prefectures in Japan (n = 47) using data from the Japanese Society of Dialysis Therapy, national census, the NDB Open Data, and the Statistics of Physicians, Dentists and Pharmacists. We calculated the prevalence of overweight/obesity and proteinuria, standardized mortality ratio, and ratio of nephrology specialists for each prefecture, and explored associations of these variables with sex- and prefecture-specific SIRs of treated ESKD using bivariate association analysis, multiple regression analysis, and structural equation modeling (SEM).

RESULTS

Prefecture-specific SIRs ranged from 0.72 to 1.24 for men and 0.69-1.41 for women. Prefecture-specific SIRs were significantly correlated with both the prevalence of overweight/obesity and prevalence of proteinuria. The prevalence of overweight/obesity showed direct, positive, and significant associations with prefecture-specific SIRs in men (standardized estimate (β) = 0.43, p < 0.001) and women (β = 0.40, p < 0.001). The prevalence of proteinuria showed a significant association with prefecture-specific SIRs only in women (β = 0.33, p = 0.01). The SEM models explained 26% of the variance in SIR for men and 28% for women.

CONCLUSIONS

Our findings provide evidence that the prefecture-specific prevalence of overweight/obesity in Japan can explain regional variation in prefecture-specific SIRs of treated ESKD in both sexes.

The associations between renal disease severity and exposure to organophosphate flame retardants in patients with chronic kidney disease

Organophosphate flame retardants (OPFRs) are emerging and widespread environmental pollutants with potential health hazards, including nephrotoxicity. However, the exposure patterns and nephrotoxic potential of OPFRs are yet to be investigated in patients with chronic kidney disease (CKD). We conducted a cross-sectional study involving 166 patients with CKD stratified by estimated glomerular filtration rate (eGFR) and severity of proteinuria. The urinary concentrations of 10 OPFR compounds were measured to evaluate the exposure patterns. Clinical and urinary OPFR profiles were compared among subgroups to identify whether the OPFR compounds were independently correlated with eGFR and proteinuria. Additionally, lifestyle factors were compared among subgroups stratified by median concentrations of urinary OPFR compounds associated with renal disease severity. This study revealed universal exposure to OPFRs in the CKD population, with an overall urinary detection rate of 98.80 %. Furthermore, after adjusting for covariates, the urinary concentration of bis(2-chloroethyl) phosphate (BCEP) was identified as an independent predictor of lower eGFR (low vs high eGFR, odds ratio (OR) (95 % confidence interval (CI)), 1.761 (1.032-3.005) per log μg/g creatinine, p = 0.038), and the urinary concentration of bis(2-butoxyethyl) phosphate (BBOEP) was independently correlated with overt proteinuria in CKD patients (with vs without overt proteinuria, OR (95 % CI), 1.813 (1.065-3.086) per log μg/g creatinine, p = 0.028). Moreover, frequent seafood consumption was negatively correlated with urinary BCEP concentration (high vs low BCEP, OR (95 % CI), 0.455 (0.228-0.908), p = 0.025), and age was inversely associated with urinary BBOEP concentration (high vs low BBOEP, OR (95 % CI), 0.968 (0.937-0.999) per year, p = 0.048). In conclusion, our investigation highlights the extensive exposure to OPFRs and the independent association between renal disease severity and urinary BCEP/BBOEP concentrations in the CKD population, indicating the nephrotoxic potential of these pollutants.

Knowledge of Chronic Kidney Disease among the General Population: A Questionnaire Survey in Hokkaido Prefecture, Japan

Public education programs about chronic kidney disease (CKD) are important activities worldwide. The present study investigated the knowledge of CKD in the general population of 58 out of 179 cities or towns in Hokkaido between 1 April and 30 September 2019. A total of 15,012 respondents who underwent specific health checkups at these centers answered the questionnaire. In response to a questionnaire item asking about the respondent's familiarity with the term "CKD", only 6% of the respondents answered "know it well" and 13% answered "heard of it". In contrast, in response to a questionnaire item asking about the respondent's familiarity with "chronic kidney disease", 31% answered "know it well" and 33% answered "heard of it". The leading avenue by which the respondents learned about CKD was television, followed by newspapers, magazines, and a family doctor or nurse. The leading component that the respondents considered essential for the diagnosis of CKD was proteinuria. These results indicated that the knowledge of CKD in Hokkaido prefecture is still inadequate. Many people did not appear to realize that the term "CKD" represents "chronic kidney disease". Further continuous public education efforts are required to enlighten people about CKD.

Economics of drug-coated balloons for arteriovenous fistula stenosis in Japan and Korea based on the IN.PACT AV access trial

AIM

The recent IN.PACT AV Access study found drug-coated balloon therapy to be associated with reduced reinterventions compared to percutaneous transluminal angioplasty using standard balloons in the management of arteriovenous fistula stenosis. The economic implications of drug-coated balloon use in Asia, including Japan and Korea, remain unknown.

METHODS

A decision-analytic model was developed to calculate strategy-specific costs for Korea and Japan through 5-year follow-up. The analysis assumed maintained therapy benefit beyond current trial follow-up of 1 year in the base case, with several alternative scenarios explored in sensitivity analysis. Costs were derived from claims and reimbursement data, and projections were evaluated at 3 and 5 years post-index procedure.

RESULTS

Model-projected access circuit reintervention events for drug-coated versus standard balloons were 1.70 versus 2.76 (-1.06) and 2.53 versus 4.10 (-1.57) at 3 and 5 years in the base case. Corresponding 3- and 5-year costs were ₩6 211 103 versus ₩7 605 553 (-₩1 394 451) and ₩7 766 051 versus ₩10 124 954 (-₩2 358 904) in Korea, and ¥1 469 824 versus ¥1 504 161 (-¥34 337) and ¥1 956 931 versus ¥2 106 632 (-¥149 701) in Japan. In scenario analyses, drug-coated balloons remained cost saving at 3- and 5-year follow-up in Korea, but required up to 5 years to reach cost-savings in Japan. Drug-coated balloon use in reinterventions increased projected savings, as did younger treatment age.

CONCLUSION

Treatment of arteriovenous fistulas with the IN.PACT AV drug-coated balloon, based on preliminary data, may lead to meaningful reductions in reintervention costs that would render it cost-saving at timeframes of around 1 year in Korea and between 3 and 5 years in Japan.

Perioperative Management and Surgical Outcomes of Colorectal Cancer Patients Undergoing Peritoneal Dialysis for End-Stage Kidney Disease

Introduction: Despite the fact that the number of peritoneal dialysis (PD) patients is increasing, there is little evidence on the surgical outcomes of PD patients who have colorectal cancer surgery, and there is no consensus on the safety and practicality of continuing PD.

Methods: We retrospectively evaluated the short- and long-term results, as well as the feasibility of continuing PD, in eight patients with PD who had colorectal cancer surgery at our institution between January 2010 and January 2021.

Results: The scheduled open-fashioned resection was performed in one patient, whereas the other seven surgeries were all conducted laparoscopically, with no intraoperative conversion to laparotomy necessary. Except for one patient with a history of recurring PD-related peritonitis, the PD catheter was kept in seven of the eight cases. Five of the seven patients continuing PD underwent temporary postoperative hemodialysis. At a median of 24.5 months of postoperative monitoring, no infectious complications were observed, six cases continued PD, and no recurrence of colorectal cancer was observed in all cases.

Conclusions: Routine curative-intent colorectal cancer surgery with the preservation of the PD catheter is possible and safe in individuals receiving PD. This patient population's short- and long-term oncological results are comparable to general surgical outcomes of those without chronic kidney disease. PD can be maintained for a long period of time following major colorectal cancer surgery.

Cost-Effectiveness Analysis of Initiating Type 2 Diabetes Therapy with a Sodium-Glucose Cotransporter 2 Inhibitor Versus Conventional Therapy in Japan

INTRODUCTION

Many patients with type 2 diabetes mellitus (T2DM) suffer from complications that impose substantial burdens on prognosis and medical costs. Accumulating evidence has demonstrated the clinical benefit of sodium-glucose cotransporter 2 inhibitors (SGLT2i) on cardiovascular and renal complications. However, the health economic impact of SGLT2i remains unclear. The aim of this study was to evaluate the cost-effectiveness of initiating antidiabetic therapy with an SGLT2i using Japanese real-world data.

METHODS

We constructed a natural history model incorporating heart failure (HF), myocardial infarction, stroke, chronic kidney disease, and end-stage renal disease (ESRD) as complications. The target population comprised patients with T2DM who newly initiated their first oral glucose-lowering drugs. By using a population-based microsimulation, we estimated the 10-year medical costs in Japanese yen (JPY) and outcomes (hospitalization for/development of complications and quality-adjusted life years [QALY]) for patients who initiated antidiabetic therapy with an SGLT2i or conventional therapy. Sensitivity analyses included a probabilistic sensitivity analysis (PSA) with 1,000,000 iterations.

RESULTS

In the base-case analysis, the total medical cost per person was JPY 1,638,806 versus JPY 1,825,033 and the QALYs were 8.732 versus 8.513 for the SGLT2i strategy versus the conventional strategy, respectively. Thus, initiating treatment with an SGLT2i was dominant, more effective (QALY gain), and lower cost. When treating 10,000 patients, the SGLT2i strategy would reduce all-cause deaths by 410 (552 vs 962), HF events by 201 (897 vs 1098), and ESRD events by 16 (16 vs 32) versus the conventional strategy. The PSA revealed that the probability of dominance for initiating SGLT2i therapy was 90.5%, demonstrating the robustness of the results.

CONCLUSION

Our results suggest that initiating T2DM treatment with SGLT2i, aimed at managing cardiovascular and renal complications from the early stages of diabetes, can improve the clinical outcome and reduce cost burden of T2DM.

A Survey on the Current Status of Ophthalmological Consultations in Patients With Diabetes Undergoing Maintenance Hemodialysis and the Effectiveness of Education on Consultation Behavior –Experience of a Single Hemodialysis Clinic in Japan

Introduction

It is extremely important for patients with diabetes undergoing maintenance hemodialysis (MHD) to receive regular ophthalmologic examinations. However, even in the field of MHD in Japan, where there are many hemodialysis patients and the survival rate is said to be one of the highest in the world, we often see patients with diabetes who do not receive regular ophthalmologic examinations. In this study, we surveyed the status of ophthalmology consultations and the use of diabetic eye notebook (DEN) among hemodialysis patients with diabetes at hemodialysis clinics to confirm the current situation, with the aim of confirming the effectiveness of education on consultation behavior by medical care staff.

Materials and Methods

This study included 38 diabetic hemodialysis patients attending one MHD clinic in Japan for one year from March 2018 to March 2019. In the first fact-finding survey in March 2018, hemodialysis care unit nurses (HCUNs) in the hemodialysis unit asked the diabetic hemodialysis patients whether they had consulted an ophthalmologist and used the DEN. Based on the results, the HCUNs recommended that hemodialysis patients with complications of diabetes be educated about the usefulness of regular ophthalmologic examinations, even during MHD, and that they use the DEN. This was followed by a second fact-finding survey in March 2019 to reconfirm ophthalmology consultations and DEN use.

Results

Regarding the presence of ophthalmology consultations, 22 of 38 (58%) patients had regular ophthalmology consultations in March 2018, and 27 of 38 (71%) patients had consultations in the following year after receiving information from an HCUN. Only 1 of 22 patients (5%) who consulted the ophthalmologist in March 2018 used a DEN, but 19 of 27 patients (70%) used it the following year.

Conclusion

In the future, the development and utilization of a new DEN that includes more detailed patient information, and the spread of self-care guidance to patients by multidisciplinary health care professionals, will increase the consultation rate of MHD patients in Japan and reduce the incidence and progression of ocular diseases in MHD patients.

Welfare receipt and the risk of vitamin D deficiency in Japanese patients on maintenance hemodialysis: a cross-sectional, retrospective study

BACKGROUND

Vitamin D deficiency is often observed in patients undergoing maintenance hemodialysis and is associated with significantly increased risk of overall mortality. Despite reports of poor nutrition/intake, vitamin D status among patients on maintenance hemodialysis receiving welfare remains unknown. This study investigated the vitamin D status in welfare recipients undergoing maintenance hemodialysis.

METHODS

This cross-sectional study investigated vitamin D status among 106 outpatients undergoing maintenance hemodialysis at two medical facilities in Japan. Patients were divided into welfare and non-welfare groups based on their status as of September 2018. Patients were divided into two categories: serum vitamin D deficiency, defined as serum 25(OH)D concentrations < 12 ng/mL, or non-deficiency. Vitamin D deficiency was used as a dependent variable, while welfare receipt was used as the main predictor variable.

RESULTS

Mean [± standard deviation] patient age, median [interquartile range] body mass index, and hemodialysis duration were 66.9 [± 10.8] years, 21.5 [19.6, 24.3] kg/m2, and 7.9 [2.9, 12.3] years, respectively. Among 106 patients, 45 were women (42.5%) and 16 (15.1%) were receiving welfare. The welfare group had a higher diabetes prevalence (P = 0.003) and significantly lower median serum 25-hydroxyvitamin D concentrations (11.5 [8.7, 14.0] vs. 14.8 [11.2, 19.9] ng/mL, P = 0.005). Multiple logistic regression analysis revealed that welfare receipt was a significant risk factor for vitamin D deficiency (odds ratio [95% confidence interval], 4.41 [1.08, 18.07]).

CONCLUSIONS

Welfare recipients undergoing maintenance hemodialysis are at significantly increased risks of vitamin D deficiency compared with patients not receiving welfare.

Sustainability in dialysis therapy: Japanese local and global challenge

Human-induced climate change is considered the greatest health threat of the 21st century. The health effects of climate change are becoming increasingly apparent, and there is substantial evidence indicating increased risk of kidney injury due to heat illness and other climate change-related meteorological abnormalities. On the other hand, healthcare itself is responsible for environmental burdens and has been estimated to generate between 3 and 10% of total national CO2 equivalent emissions. Dialysis has been estimated as one of the major contributors to healthcare’s carbon footprint. Especially in Australia and the UK, nations that have high awareness regarding environmental research, “Green Nephrology” has emerged as a new discipline. From both of these countries, a series of papers have been produced outlining the carbon footprint of hemodialysis, the results of surveys of specialists’ awareness of environmental issues, and proposals for how to save resources in dialysis therapy. Following on from this, several national and international nephrology societies have committed themselves to a range of initiatives aiming at “greening” the kidney sector. In Japan, where water and electricity supplies currently are stable, we occasionally are reminded of the potential for shortages of water and energy and of waste disposal problems. These issues particularly come to the fore in times of disasters, when hemodialysis patients need to be evacuated to distant dialysis facilities. Irrespective of the current state of resource availability, however, continuous efforts and the establishment of resource-saving procedures as a part of Japanese culture are highly desirable and would contribute to environmentally friendly healthcare. Japan needs to build awareness of these issues before the country faces a catastrophic situation of resource shortages. This review is intended as a call to action regarding environmental sustainability in kidney healthcare in Japan and the world.