Increases in renal replacement therapy in Australia and New Zealand: understanding trends in diabetic nephropathy

Vision loss and diabetic retinopathy prevalence and risk among a cohort of Indigenous and non-Indigenous Australians with type 2 diabetes receiving renal haemodialysis treatment: The retinopathy in people currently on renal dialysis (RiPCORD) study

AIMS

Diabetic nephropathy, vision loss and diabetic retinopathy (DR) are frequent comorbidities among individuals with type 2 diabetes (T2D). The Retinopathy in People Currently On Renal Dialysis (RiPCORD) study sought to examine the epidemiology and risk of vision impairment (VI) and DR among a cohort of Indigenous and non-Indigenous Australians with T2D currently receiving haemodialysis for end-stage renal failure (ESRF).

METHODS

A total of 106 Indigenous and 109 non-Indigenous Australians were recruited in RiPCORD across five haemodialysis centres in urban and remote settings. Clinical assessments, questionnaires and medical record data determined the rates of ocular complications and risk factor profiles.

RESULTS

Prevalence rates include unilateral VI, 23.5 %; bilateral VI, 11.7 %; unilateral blindness, 14.2 %; and bilateral blindness, 3.7 %, with no significant differences between sub-cohorts (p=0.30). DR prevalence rates were 78.0 % among non-Indigenous Australians and 93.1 % among Indigenous Australians (p=<0.001). Non-Indigenous ethnicity (OR: 0.28) and pre-dialysis diastolic blood pressure (OR: 0.84 per 10-mmHg) were protective, while peripheral vascular disease (OR: 2.79) increased DR risk.

CONCLUSIONS

Ocular complications among individuals with T2D and ESRF are disproportionately high, especially for Indigenous Australians, and beyond what can be accounted for by risk factor variation. Findings suggest a need to improve screening and preventative efforts within this high-risk population group.

Temporal Trends in Distal Symmetric Polyneuropathy in Type 2 Diabetes: The Fremantle Diabetes Study

CONTEXT

Macrovascular outcomes in type 2 diabetes have improved over recent decades. There are scant equivalent distal symmetric polyneuropathy (DSPN) data.

OBJECTIVE

This work aimed to characterize temporal changes in DSPN prevalence and incidence rates (IRs) in community-based Australians.

METHODS

An observational study was conducted among an urban population. Participants included individuals with type 2 diabetes from the Fremantle Diabetes Study phases I (FDS1; n = 1296 recruited 1993-1996) and II (FDS2; n = 1509 recruited 2008-2011). Main outcome measures included Michigan Neuropathy Screening Instrument (MNSI) clinical grading.

RESULTS

DSPN prevalence by 8-point MNSI was 30.8% (FDS1) and 58.9% (FDS2; P < .001), and by 6-point (excluding foot appearance) and 2-point (biothesiometry alone) MNSI was 37.5% and 35.7% (P = .336), and 33.8% and 38.7% (P = .011), respectively. Given between-phase changes in appearance assessment, 8-point MNSI data were not analyzed further. In multivariable analysis, FDS2 vs FDS1 participation was associated with 6-point (odds ratio (95% CI) 0.68 (0.56-0.83); P < .001) but not 2-point (0.90 (0.74-1.11); P = .326) MNSI DSPN prevalence. Four-year DSPN IRs (95% CI) for 6-point MNSI were 13.6 (12.0-15.4) and 17.6 (15.9-19.4)/100 person-years in FDS1 and FDS2, respectively (IR ratio [IRR] 1.31 [1.12-1.55]; P < .001), and for 2-point MNSI were 13.9 (12.3-15.8) and 7.4 (16.3-8.6/100 person-years; IRR 0.53 [0.43-0.64]; P < .001). FDS2 vs FDS1 independently predicted incident DSPN for 6-point (hazard ratio [95% CI] 1.25 [1.06-1.48]; P = .009) and 2-point (0.42 [0.33-0.55]; P < .001) MNSI.

CONCLUSION

DSPN prevalence was lower or equivalent in FDS2 vs FDS1, and its incidence was greater or lower, in multivariable models depending on the MNSI features used.

The impact of the cytoplasmic ubiquitin ligase TNFAIP3 gene variation on transcription factor NF-κB activation in acute kidney injury

Nuclear factor κB (NF-κB) activation is a deleterious molecular mechanism that drives acute kidney injury (AKI) and manifests in transplanted kidneys as delayed graft function. The TNFAIP3 gene encodes A20, a cytoplasmic ubiquitin ligase and a master negative regulator of the NF- κB signaling pathway. Common population-specific TNFAIP3 coding variants that reduce A20's enzyme function and increase NF- κB activation have been linked to heightened protective immunity and autoimmune disease, but have not been investigated in AKI. Here, we functionally identified a series of unique human TNFAIP3 coding variants linked to the autoimmune genome-wide association studies single nucleotide polymorphisms of F127C; namely F127C;R22Q, F127C;G281E, F127C;W448C and F127C;N449K that reduce A20's anti-inflammatory function in an NF- κB reporter assay. To investigate the impact of TNFAIP3 hypomorphic coding variants in AKI we tested a mouse Tnfaip3 hypomorph in a model of ischemia reperfusion injury (IRI). The mouse Tnfaip3 coding variant I325N increases NF- κB activation without overt inflammatory disease, providing an immune boost as I325N mice exhibit enhanced innate immunity to a bacterial challenge. Surprisingly, despite exhibiting increased intra-kidney NF- κB activation with inflammation in IRI, the kidney of I325N mice was protected. The I325N variant influenced the outcome of IRI by changing the dynamic expression of multiple cytoprotective mechanisms, particularly by increasing NF- κB-dependent anti-apoptotic factors BCL-2, BCL-XL, c-FLIP and A20, altering the active redox state of the kidney with a reduction of superoxide levels and the enzyme super oxide dismutase-1, and enhancing cellular protective mechanisms including increased Foxp3⁺ T cells. Thus, TNFAIP3 gene variants represent a kidney and population-specific molecular factor that can dictate the course of IRI.

Trends in the incidence of renal replacement therapy by type of primary kidney disease in Japan, 2006-2020

AIM

Age-standardized incidence of end stage kidney disease requiring renal replacement therapy (RRT) has stabilized in men and declined in women in Japan since 1996. However, recent trends by primary kidney disease are unknown. The present study aimed to examine recent trends in incidence rates of RRT by primary kidney disease in Japan.

METHODS

Numbers of incident RRT patients aged ≥20 years by sex and primary kidney disease from 2006 to 2020 were extracted from the Japanese Society of Dialysis Therapy registry. Using the census population as the denominator, annual incidence rates of RRT were calculated and standardized to the WHO World Standard Population (2000-2025). Average annual percentage change (AAPC) and corresponding 95% confidence intervals (CIs) were calculated for trends using Joinpoint regression analysis.

RESULTS

From 2006 to 2020, the crude number of incident RRT patients due to nephrosclerosis increased by 132% for men and 62% for women. Age-standardized incidence rates of RRT due to nephrosclerosis increased significantly, by 3.3% (95% CI: 2.9-3.7) and 1.4% (95% CI: 0.8-1.9) per year for men and women, respectively. The AAPC of chronic glomerulonephritis (-4.4% [95% CI: -5.3 to -3.8] for men and -5.1% [95% CI: -5.5 to -4.6] for women) and diabetic nephropathy (-0.6% [95% CI: -0.9 to -0.3] for men and -2.8% [95% CI: -3.1 to -2.6] for women) significantly decreased from 2006 to 2020.

CONCLUSION

Incident RRT due to chronic glomerulonephritis and diabetic nephropathy decreased, while the number and incident rates of RRT due to nephrosclerosis increased, from 2006 to 2020 in Japan.

Ethnic differences in 25-year risk of incident chronic kidney disease among people with type 2 diabetes in New Zealand

INTRODUCTION

Insights into ethnic differences in the natural history of chronic kidney disease (CKD) among people with type 2 diabetes mellitus (T2DM) might inform clinical strategies to address disparities in hospitalization and mortality. Risks of CKD II-V stages over a 25-year period between New Zealand Europeans (NZEs), Māori and Pasifika, and with T2DM in Auckland, New Zealand (NZ) were compared.

RESEARCH DESIGN AND METHODS

As a primary care audit program in Auckland, the Diabetes Care Support Service was linked with national registration databases. People with existing CKD II-V were ruled out. To balance potential confounders, we applied a tapered matching method . 'Quasi-trial'-matched cohorts were set up separately between Māori and NZE and between Pasifika and NZE. Ethnic population differences in risk of any and each stage of CKD over 1994-2018 were examined by weighted Cox regression model.

RESULTS

The HRs for developing any CKD, CKD stages II-V for Māori (n=2215) versus NZE (n=2028) were 1.18 (95% CI 0.99 to 1.41), 1.10 (95% CI 0.91 to 1.32), 1.70 (95% CI 1.19 to 2.43), 3.93 (95% CI 2.16 to 7.14), and 3.74 (95% CI 1.74 to 8.05), respectively. Compared with NZE (n=2474), the HRs for developing any CKD, CKD stages II-V for Pasifika (n=3101) were 1.31 (95% CI 1.09 to 1.57), 1.26 (95% CI 1.05 to 1.52), 1.71 (95% CI 1.14 to 2.57), 3.75 (95% CI 1.40 to 10.05), and 4.96 (95% CI 1.56 to 15.75), respectively.

CONCLUSIONS

Among people with T2DM in NZ, significant ethnic differences exist in the risk of progressing to each stage of CKD (stage V in particular). Mechanism studies underlying these differences, as well as the need for identification of biomarkers to predict the early onset renal lesion, are warranted.

Developing and validating a prognostic prediction model for patients with chronic kidney disease stages 3-5 based on disease conditions and intervention methods: a retrospective cohort study in China

OBJECTIVES

To develop and validate a nomogram model to predict chronic kidney disease (CKD) stages 3-5 prognosis.

DESIGN

A retrospective cohort study. We used univariate and multivariate Cox regression analysis to select the relevant predictors. To select the best model, we evaluated the prediction models' accuracy by concordance index (C-index), calibration curve, net reclassification index (NRI) and integrated discrimination improvement (IDI). We evaluated the clinical utility by decision curve analysis.

SETTING

Chronic Disease Management (CDM) Clinic in the Nephrology Department at the Guangdong Provincial Hospital of Chinese Medicine.

PARTICIPANTS

Patients with CKD stages 3-5 in the derivation and validation cohorts were 459 and 326, respectively.

PRIMARY OUTCOME MEASURE

Renal replacement therapy (haemodialysis, peritoneal dialysis, renal transplantation) or death.

RESULTS

We built four models. Age, estimated glomerular filtration rate and urine protein constituted the most basic model A. Haemoglobin, serum uric acid, cardiovascular disease, primary disease, CDM adherence and predictors in model A constituted model B. Oral medications and predictors in model A constituted model C. All the predictors constituted model D. Model B performed well in both discrimination and calibration (C-index: derivation cohort: 0.881, validation cohort: 0.886). Compared with model A, model B showed significant improvement in the net reclassification and integrated discrimination (model A vs model B: NRI: 1 year: 0.339 (-0.011 to 0.672) and 2 years: 0.314 (0.079 to 0.574); IDI: 1 year: 0.066 (0.010 to 0.127), p<0.001 and 2 years: 0.063 (0.008 to 0.106), p<0.001). There was no significant improvement between NRI and IDI among models B, C and D. Therefore, we selected model B as the optimal model.

CONCLUSIONS

We constructed a prediction model to predict the prognosis of patients with CKD stages 3-5 in the first and second year. Applying this model to clinical practice may guide clinical decision-making. Also, this model needs to be externally validated in the future.

TRIAL REGISTRATION NUMBER

ChiCTR1900024633 (http://www.chictr.org.cn).

Temporal Trends in Renal Replacement Therapy in Community-Based People with or without Type 2 Diabetes: The Fremantle Diabetes Study

Background: Although rates of cardiovascular disease complicating type 2 diabetes are declining, equivalent data for renal replacement therapy (RRT) are conflicting. The aim of this study was to characterize temporal changes in RRT incidence rates (IRs) in Australians with or without type 2 diabetes. Methods: Participants with type 2 diabetes from the Fremantle Diabetes Study Phases I (FDS1; n = 1291 recruited 1993–1996) and II (FDS2; n = 1509 recruited 2008–2011) were age-, sex- and postcode-matched 1:4 to people without diabetes and followed for first hospitalization for/with RRT. Five-year IRs, IR ratios (IRRs) for those with versus without diabetes in FDS1 and FDS2, and IR differences (IRDs), were calculated. Results: The 13,995 participants had a mean age of 64.8 years and 50.4% were males. For the type 2 diabetes cohorts, the 5-year RRT IR was nearly threefold higher in FDS2 versus FDS1 (IRR (95% CI): 2.85 (1.01–9.87)). Sixteen more participants with type 2 diabetes/10,000 person-years received RRT in FDS2 than FDS1 compared with an IRD of 2/10,000 person-years in those without diabetes. Type 2 diabetes increased RRT risk at least 5-fold. This increased risk was greater in Aboriginal participants who were relatively young when RRT was initiated and more prone to rapid progression to RRT. Multivariable analysis using the combined FDS type 2 diabetes cohorts confirmed albuminuria as a strong independent RRT risk factor. Conclusions: The incidence of RRT is increasing substantially in Australians with type 2 diabetes, especially in Aboriginals who progress to RRT more rapidly at a younger age than non-Aboriginals.

Transplant Prognosis in Kidney Transplant Recipients with Diabetes under Mycophenolic Acid-Focused Therapeutic Drug Monitoring

Mycophenolate mofetil is a key immunosuppressant that is metabolized into mycophenolic acid (MPA). The prognostic impact of MPA-focused therapeutic drug monitoring on allograft prognosis has not been determined in kidney transplant recipients with diabetes. In this study, we assessed the pharmacokinetics of MPA and allograft prognosis in recipients with diabetes. This study retrospectively analyzed 64 adult kidney transplant recipients. MPA blood concentration data (e.g., the time to the maximum concentration (Tmax), and the area under the concentration–time curve from 0 to 12 h (AUC_0–12)) were collected at 3 weeks and 3 months after kidney transplantation. Of the 64 recipients, 15 had pre-existing diabetes. At 3 months after kidney transplantation, the Tmax of MPA was significantly longer in recipients with diabetes (mean (standard deviation): 2.8 (2.1) h) than in recipients without diabetes (1.9 (1.1) h, p = 0.02). However, the allograft estimated glomerular filtration rate and acute rejection rate, including borderline change, did not differ according to the diabetes status in patients with adjusted AUC_0–12 of MPA within the target range. In conclusion, a longer Tmax of MPA was observed in recipients with diabetes; however, acceptable allograft prognosis was observed in kidney transplant recipients with diabetes and a sufficient AUC_0–12 of MPA.

Projecting the Incidence of Type 2 Diabetes-Related End-Stage Kidney Disease Until 2040: A Comparison Between the Effects of Diabetes Prevention and the Effects of Diabetes Treatment

OBJECTIVE

This study sought to examine the effects of two diabetes prevention approaches and of widespread use of sodium-glucose cotransporter 2 inhibitors (SGLT2is) among people with diabetes on the future incidence of diabetes-related end-stage kidney disease (ESKD-D).

RESEARCH DESIGN AND METHODS

We developed a life table model to project the incidence of ESKD-D for type 2 diabetes in Australia until 2040. We projected incident ESKD-D under three separate scenarios: a large-scale lifestyle modification program for diabetes prevention; a population-wide sugar-sweetened beverage tax for diabetes prevention; and widespread use of SGLT2is among people with diabetes.

RESULTS

Assuming current trends, we projected that the annual incidence of ESKD-D will increase from 3.7 per 100,000 of the general population in 2014 to 5.7 by 2040. Incorporating the diabetes prevention approaches, we projected that the annual incidence of ESKD-D will be between 5.2 and 5.5 per 100,000 by 2040. When we modeled scenarios in which 50% and 70% of eligible people with diabetes were prescribed an SGLT2i, the annual incidence of ESKD-D by 2040 was projected to be 4.7 and 4.3 per 100,000, respectively. SGLT2is were projected to reduce the total number of incident ESKD-D cases between 2020 and 2040 by 12-21% compared with current trends, whereas diabetes prevention reduced cases by 1-3%.

CONCLUSIONS

It is likely that the number of people developing ESKD-D will increase over the coming decades, although widespread SGLT2i use will be effective at limiting this increase. Diabetes prevention will be crucial to prevent an ever-increasing burden of diabetes complications.

Variability in the incidence of renal replacement therapy over time in Western industrialized countries: A retrospective registry analysis

Introduction

A growing number of patients started renal replacement therapy (RRT) in Western industrialized countries between 1980 an early 2000s. Thereafter reports from national and international registries suggest a trend towards stabilization and sometimes a decrease in the incidence rate.

Aim

To investigate the differences in overall and age-specific incidence rates between industrialized countries from 1998 until 2013. Secondly, to investigate changes in incidence rates over time and their association with specific age categories.

Method

We extracted the unadjusted overall incidence of RRT and age-specific incidence rates from renal registry reports in Europe, the United States, Canada, Australia and New Zealand. Time trends in the incidence rate by country and age categories were analyzed by Joinpoint regression analysis.

Results

The incidence rate in 2013 ranged from 89 per million population (pmp) in Finland to 363 pmp in the US. Incidence rates in the lower age categories (20–64 year) were similar between countries and remained stable over time. Higher incidence countries were characterized by higher numbers of patients in both the 65–74 and ≥75 year categories starting RRT.

Joinpoint analysis confirmed that most countries had significant reductions in the incidence rate at the end of the study period. These reductions were explained by lower numbers of older patients starting RRT and were observed also in countries with lower overall incidence rates.

Conclusion

This study confirmed different incidence rates of RRT between industrialized countries worldwide. Countries with the highest overall incidence rates also had the highest incidence rates in the oldest age categories. Since the early 2000’s the number of older patients starting RRT is either stabilizing or even decreasing in most countries. This reduction is universal and is also observed in countries with previously low incidence rates.

Elevated Platelet Galectin-3 and Rho-Associated Protein Kinase Activity Are Associated with Hemodialysis Arteriovenous Shunt Dysfunction among Subjects with Diabetes Mellitus

Introduction

Hyperglycemia is a major factor in influencing the patency rate of arteriovenous shunts, potentially associated with the RhoA/Rho-associated protein kinase (ROCK) pathway. Besides, galectin-3 mediates thrombotic mechanisms in venous thrombosis and peripheral artery disease. We hypothesized that high ROCK activity and galectin-3 levels are associated with arteriovenous shunt dysfunction.

Methods

We prospectively enrolled 38 patients diagnosed with arteriovenous shunt dysfunction. 29 patients received a complete follow-up and each provided two blood samples, which were collected at the first visit for occluded status of arteriovenous shunts and 1 month later for patent status. A Western blot assay for a myosin phosphatase target subunit (MYPT) was performed to examine Rho-kinase activity. A Western blot assay for platelet galectin-3 and enzyme-linked immunosorbent assay (ELISA) for circulating galectin-3 were completed.

Results

Higher platelet MYPT ratios and galectin-3 levels were identified at occluded arteriovenous shunts (MYPT ratio: 0.5 [0.3-1.4] vs. 0.4 [0.3-0.6], p = 0.01; galectin-3: 1.2 [0.4-1.6] vs. 0.7 [0.1-1.2], p = 0.0004). The plasma galectin-3 binding protein ELISA was also higher at occluded arteriovenous shunts (8.4 [6.0-9.7] μg/mL vs. 7.1 [4.5-9.1] μg/mL, p = 0.009). Biomarker ratios (occluded/patent status) trended high in patients with poorly controlled diabetes (MYPT ratio: 1.7 [1.0-3.0] vs. 1.1 [0.7-1.3], p = 0.06; galectin-3: 1.6 [1.3-3.4] vs. 1.1 [0.8-1.9], p = 0.05).

Conclusion

High platelet ROCK activity and galectin-3 levels are associated with increased risk in arteriovenous shunt dysfunction, especially in patients with poorly controlled diabetes.

International comparison of trends in patients commencing renal replacement therapy by primary renal disease

AIM

To examine international time trends in the incidence of renal replacement therapy (RRT) for end-stage renal disease (ESRD) by primary renal disease (PRD).

METHODS

Renal registries reporting on patients starting RRT per million population for ESRD by PRD from 2005 to 2014, were identified by internet search and literature review. The average annual percentage change (AAPC) with a 95% confidence interval (CI) of the time trends was computed using Joinpoint regression.

RESULTS

There was a significant decrease in the incidence of RRT for ESRD due to diabetes mellitus (DM) in Europe (AAPC = -0.9; 95%CI -1.3; -0.5) and to hypertension/renal vascular disease (HT/RVD) in Australia (AAPC = -1.8; 95%CI -3.3; -0.3), Canada (AAPC = -2.9; 95%CI -4.4; -1.5) and Europe (AAPC = -1.1; 95%CI -2.1; -0.0). A decrease or stabilization was observed for glomerulonephritis in all regions and for autosomal dominant polycystic kidney disease (ADPKD) in all regions except for Malaysia and the Republic of Korea. An increase of 5.2-16.3% was observed for DM, HT/RVD and ADPKD in Malaysia and the Republic of Korea.

CONCLUSION

Large international differences exist in the trends in incidence of RRT by primary renal disease. Mapping of these international trends is the first step in defining the causes and successful preventative measures of CKD.

Changing ethnic and clinical trends and factors associated with successful home haemodialysis at Auckland District Health Board

BACKGROUND

The health and diversity of the population in New Zealand (NZ) is changing under the influence of many socio-economic factors. This may have shifted the landscape of home haemodialysis (HHD).

AIMS

To examine the demographic and clinical changes, determinants of HHD training and technique outcome and mortality between 2008 and 2015 at Auckland District Health Board, NZ.

METHODS

We compared three incident cohorts of HHD patients between 2008 and 2015. Relevant factors, including demographic and clinical characteristics, training failure, technique failure and mortality were recorded. Factors associated with training and technique failure were examined by multivariate logistic regression.

RESULTS

Of 152 patients, 133 completed training, 13 (10%) experienced technique failure and 15 (11%) died. Significant changes in ethnicity (increased: Māori 1.7-fold, Asian 1.7-fold and Pasifika 1.4-fold; decreased: NZ European 2.7-fold, P = 0.001), and major comorbidities, ≥2 major comorbidities (1.8-fold increase, P = 0.03), diabetes (2.1-fold increase, P = 0.013) and heart failure (P = 0.04) were seen. HHD as first renal replacement therapy modality increased 15-fold (P = 0.0001) and training time increased by 4.5 weeks (P = 0.004). Death and technique failure were unchanged over time. Shorter training time, employment and lower C-reactive protein were associated with 'Successful HHD'. 'Unsuccessful HHD' patient characteristics differed by ethnicity.

CONCLUSIONS

The HHD population has become more representative of the NZ population, but significantly more comorbid over time. Patient training time has increased, but mortality and technique failure remain stable. 'Successful HHD' is predicted by social and clinical factors, and 'unsuccessful HHD' may have different mechanisms in different patient groups.

Fisetin supplementation prevents high fat diet-induced diabetic nephropathy by repressing insulin resistance and RIP3-regulated inflammation

Obesity-related renal disease is related to caloric excess promoting deleterious cellular responses.

Trends in Incidence of ESKD in People With Type 1 and Type 2 Diabetes in Australia, 2002-2013

RATIONALE & OBJECTIVE

The number of people with diabetes and end-stage kidney disease (ESKD) is increasing worldwide, but it is unknown whether this indicates an increasing risk for ESKD in people with diabetes. We examined temporal trends in the incidence of ESKD within the Australian population with diabetes from 2002 to 2013.

STUDY DESIGN

Follow-up study using a national health care services registry.

SETTING & PARTICIPANTS

Registrants with type 1 or type 2 diabetes in Australia's National Diabetes Services Scheme (NDSS).

PREDICTORS

Age, sex, indigenous status, diabetes type, and calendar year.

OUTCOME

Incidence of ESKD (dialysis or kidney transplantation) or death ascertained using the Australian and New Zealand Dialysis and Transplant Registry and the Australian national death index.

ANALYTICAL APPROACH

NDSS registrants were followed up from 2002 or date of registration until onset of ESKD, death, or December 31, 2013. The incidence of ESKD in type 1 diabetes was calculated only in those younger than 55 years.

RESULTS

Among 1,375,877 registrants between 2002 and 2013, a total of 9,977 experienced incident ESKD, representing an overall incidence of ESKD in people with diabetes of 10.0 (95% CI, 9.8-10.2) per 10,000 person-years. Among those with type 1 diabetes, the age-standardized annual incidence was stable during the study period. Among those with type 2 diabetes, the incidence increased in nonindigenous people (annual percentage change, 2.2%; 95% CI, 0.4%-4.1%) with the greatest increases in those younger than 50 and those older than 80 years. No significant change over time was observed in indigenous people, although the adjusted incident rate ratio for indigenous versus nonindigenous was 4.03 (95% CI, 3.68-4.41).

LIMITATIONS

Lack of covariates such as comorbid conditions, medication use, measures of quality of care, and baseline kidney function.

CONCLUSIONS

The age-standardized annual incidence of ESKD increased in Australia from 2002 to 2013 for nonindigenous people with type 2 diabetes but was stable for people with type 1 diabetes. Efforts to prevent the development of ESKD, especially among indigenous Australians and those with early-onset type 2 diabetes, are warranted.

Inequity in dialysis related practices and outcomes in Aotearoa/New Zealand: a Kaupapa Māori analysis

BACKGROUND

In Aotearoa/New Zealand, Māori, as the indigenous people, experience chronic kidney disease at three times the rate of non-Māori, non-Pacific New Zealanders. Māori commence dialysis treatment for end-stage kidney disease at three times the rate of New Zealand European adults. To examine for evidence of inequity in dialysis-related incidence, treatment practices, and survival according to indigeneity in Aotearoa/New Zealand, utilising a Kaupapa Māori approach.

METHODS

We conducted a retrospective cohort study involving adults who commenced treatment for end-stage kidney disease in Aotearoa/New Zealand between 2002 and 2011. We extracted data from the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA) linked to the New Zealand National Health Index (NHI). Propensity score methods were used to assemble a cohort of 1039 Māori patients matched 1:1 on clinical and socio-demographic characteristics with a cohort of 1026 non-Māori patients. We compared incidence of end-stage kidney disease and treatment practices. Differences in the risks of all-cause mortality during treatment between propensity-matched cohorts were estimated using Cox proportional hazards and generalised linear models.

RESULTS

Non-Māori patients were older, more frequently lived in urban areas (83% versus 67% [standardised difference 0.38]) and bore less socioeconomic deprivation (36% living in highest decile areas versus 14% [0.53]). Fewer non-Māori patients had diabetes (35% versus 69%, [- 0.72]) as a cause of kidney failure. Non-Māori patients were more frequently treated with peritoneal dialysis (34% versus 29% [0.11]), received a pre-emptive kidney transplant (4% vs 1% [0.19]), and were referred to specialist care < 3 months before treatment (25% vs 19% [0.15]) than Māori patients. Fewer non-Māori started dialysis with a non-tunnelled dialysis vascular catheter (43% versus 47% [- 0.08]). The indigenous-age standardised incidence rate ratio for non-Māori commencing renal replacement therapy in 2011 was 0.50 (95% CI, 0.40-0.61) compared with Māori. Propensity score matching generated cohorts with similar characteristics, although non-Māori less frequently started dialysis with a non-tunnelled venous catheter (30% versus 47% [- 0.35]) or lived remotely (3% versus 14% [- 0.50]). In matched cohorts, non-Māori experienced lower all-cause mortality at 5 yr. after commencement of treatment (risk ratio 0.78, 95% CI 0.72-0.84). New Zealand European patients experienced lower mortality than Māori patients in indigenous age-standardised analyses (age-standardised mortality rate ratio 0.58, 95% CI 0.51-0.67).

CONCLUSIONS

Non-Māori patients are treated with temporary dialysis vascular access less often than Māori, and experience longer life expectancy with dialysis, even when socioeconomic, demographic, and geographical factors are equivalent. Based on these disparities, health services should monitor and address inequitable treatment practices and outcomes in end-stage kidney disease care.

Social disparities in the prevalence of diabetes in Australia and in the development of end stage renal disease due to diabetes for Aboriginal and Torres Strait Islanders in Australia and Maori and Pacific Islanders in New Zealand

BACKGROUND

Disparities in health status occur between people with differing socioeconomic status and disadvantaged groups usually have the highest risk exposure and the worst health outcome. We sought to examine the social disparities in the population prevalence of diabetes and in the development of treated end stage renal disease due to type 1 diabetes which has not previously been studied in Australia and New Zealand in isolation from type 2 diabetes.

METHODS

This observational study examined the population prevalence of diabetes in a sample of the Australian population (7,434,492) using data from the National Diabetes Services Scheme and of treated end stage renal disease due to diabetes using data from the Australian and New Zealand Dialysis and Transplant Registry. The data were then correlated with the Australian Bureau of Statistics Socioeconomic Indexes for Areas for an examination of socioeconomic disparities.

RESULTS

There is a social gradient in the prevalence of diabetes in Australia with disease incidence decreasing incrementally with increasing affluence (Spearman's rho = .765 p < 0.001). There is a higher risk of developing end stage renal disease due to type 1 diabetes for males with low socioeconomic status (RR 1.20; CI 1.002-1.459) in comparison to females with low socioeconomic status. In Australia and New Zealand Aboriginal and Torres Strait Islanders, Maori and Pacific Islanders appear to have a low risk of end stage renal disease due to type 1 diabetes but continue to carry a vastly disproportionate burden of end stage renal disease due to type 2 diabetes (RR 6.57 CI 6.04-7.14 & 6.48 CI 6.02-6.97 respectively p < 0.001) in comparison to other Australian and New Zealanders.

CONCLUSION

Whilst low socioeconomic status is associated with a higher prevalence of diabetes the inverse social gradient seen in this study has not previously been reported. The social disparity seen in relation to treated end stage renal disease due to type 2 diabetes for Aboriginal and Torres Strait Islanders, Maori and Pacific Islanders has changed very little in the past 20 years. Addressing the increasing incidence of diabetes in Australia requires consideration of the underlying social determinants of health.

Paeoniflorin prevents TLR2/4-mediated inflammation in type 2 diabetic nephropathy

Paeoniflorin is an effective Chinese traditional medicine with anti-inflammatory and immune-regulatory effects. The aim of this study was to investigate the underlying renoprotective mechanism of Paeoniflorin. In vivo, db/db mice were intraperitoneally injected with Paeoniflorin at a dose of 15, 30, or 60 mg/kg respectively. The immunostaining of TLR2, TLR4, CD68, NF-kB p65 and the mRNA level of inflammatory factors, together with the protein expression of TLR2/4 signaling were evaluated. Our data demonstrated that Paeoniflorin could decrease the urinary albumin excretion rate and inhibit macrophage infiltration and activation through blockage of the TLR2/4 signaling pathway compared with the db/db group in vivo. In vitro, RAW264.7 cells were categorized into control, bovin serum albumin (BSA)-stimulated, advanced glycation end products (AGEs)-stimulated, Paeoniflorin intervention and oxidized phospholipid (OxPAPC)-inhibited groups. The cell viability, the optimal stimulated time and concentration were measured as well as the TLR2/4 signaling activation determined by RT-PCR, Western blot and ELISA. Our data demonstrated that Paeoniflorin reduced the AGEs-induced TLR2/4 activation and inflammatory responses, which was consistent with the TLR2/4 inhibitor group. These findings indicate that Paeoniflorin prevents macrophage activation via inhibition of TLR2/4 signaling expression in type 2 diabetic nephropathy.

HbA1c variability in type 2 diabetes is associated with the occurrence of new-onset albuminuria within three years

AIMS

To evaluate the association between HbA1c coefficient of variation (HbA1c-CV) and 3-year new-onset albuminuria risk.

METHODS

A retrospective cohort study involving 716 normoalbuminuric type 2 diabetes patients was conducted between 2010 and 2014. HbA1c-CV was used to categorize patients into low, moderate or high variability groups. Multivariate logistic models were constructed and validated. Integrated discrimination (IDI) and net reclassification (NRI) improvement indices were used to quantify the added predictive value of HbA1c-CV.

RESULTS

The mean age of our cohort was 56.1±12.9years with a baseline HbA1c of 8.3±1.3%. Over 3-years of follow-up, 35.2% (n=252) developed albuminuria. An incremental risk of albuminuria was observed with moderate (6.68-13.43%) and high (above 13.44%) HbA1c-CV categories demonstrating adjusted odds ratios of 1.63 (1.12-2.38) and 3.80 (2.10-6.97) for 3-year new-onset albuminuria, respectively. Including HbA1c-CV for 3-year new-onset albuminuria prediction improved model discrimination (IDI: 0.023, NRI: 0.293, p<0.05). The final model had a C-statistic of 0.760±0.018 on validation.

CONCLUSION

HbA1c-CV improves 3-year prediction of new-onset albuminuria. Together with mean HbA1c, baseline urine albumin-to-creatinine ratio and presence of hypertension, accurate 3-year new-onset albuminuria prediction may be possible.

Self-management in patients with diabetes and chronic kidney disease is associated with incremental benefit in HRQOL

AIMS

There is insufficient and inconsistent data regarding the association between diabetes self-management, the process of facilitating the knowledge, skill, and ability necessary for diabetes self-care, and health-related quality of life (HRQOL) in people with diabetes and moderate to severe chronic kidney disease (CKD).

METHODS

In a cross sectional study, participation in diabetes self-management assessed by the Summary of Diabetes Self-Care Activities (SDSCA) questionnaire and HRQOL was examined in 308 patients with diabetes and CKD (stages 3 to 5) recruited from outpatient diabetes and renal clinics of 4 public tertiary hospitals. Associations were examined by Pearson correlation coefficients and hierarchical multiple regression after controlling for potential confounders. An examination of trend across the levels of patient participation in self-management was assessed using a non-parametric test for trend.

RESULTS

The median age and interquartile range (IQR) of patients were 68 and 14.8years, respectively with 59% of the population being over 65years old and 69.5% male. The median durations of diabetes and CKD were 18years (IQR-17) and 5years (IQR-8) respectively. General diet, exercise and medication taking were positively associated with at least one HRQOL subscale (all p<0.05) but diabetes specific diet, blood sugar testing and foot checking were not. As levels of participation in self-management activities increased there was a graded increase in mean HRQOL scores across all subscales (p for trend <0.05).

CONCLUSIONS

In people with diabetes and moderate to severe CKD, participation in diabetes self-management activities, particularly those focused on general diet, exercise and medication taking, was associated with higher HRQOL.

TGP attenuates endoplasmic reticulum stress and regulates the expression of thioredoxin-interacting protein in the kidneys of diabetic rats

Recent evidence suggests that the endoplasmic reticulum stress (ERS)-thioredoxin-interacting protein (TXNIP)-inflammation chain contributes to diabetic renal injury. The aim of the current study was to investigate whether total glucosides of peony (TGP) could inhibit ERS and attenuate up-regulation of TXNIP in the kidneys of rats with streptozotocin-induced diabetes. TGP was orally administered daily at a dose of 50, 100, or 200 mg/kg for 8 weeks. The expression of glucose-regulated protein 78 (GRP78), phospho-protein kinase RNA-like ER kinase (p-PERK), phosphor- eukaryotic translation initiation factor 2α (p-eIF2α), C/EBP-homologous protein (CHOP), and TXNIP was assessed. Results indicated that TGP significantly decreased diabetes-induced albuminuria and it acted by down-regulating activation of the ERS-TXNIP-inflammation chain in the kidneys of diabetic rats. These findings indicate that renoprotection from TGP in diabetic rats possibly contributed to inhibition of ERS and decreased expression of TXNIP. These findings also offer a new perspective from which to study the molecular mechanisms of diabetic nephropathy and prevent its progression.

Gender differences in the dialysis treatment of Indigenous and non-Indigenous Australians

OBJECTIVE

Access to dialysis treatment and the types of treatments employed in Australia differs by Indigenous status. We examined whether dialysis treatment utilisation in Indigenous and non-Indigenous Australians also differs by gender.

METHODS

Using registry data we evaluated 21,832 incident patients (aged ≥18 years) commencing dialysis, 2001-2013. Incidence rates were calculated and multivariate regression modelling used to examine differences in dialysis treatment (modality, location and vascular access creation) by race and gender.

RESULTS

Dialysis incidence was consistently higher in Indigenous women compared to all other groups. Compared to Indigenous women, both non-Indigenous women and men were more likely to receive peritoneal dialysis as their initial treatment (non-Indigenous women RR=1.91, 95%CI 1.55-2.35; non-Indigenous men RR=1.73, 1.40-2.14) and were more likely to commence initial treatment at home (non-Indigenous women RR=2.07, 1.66-2.59; non-Indigenous men RR=1.95, 1.56-2.45). All groups were significantly more likely than Indigenous women to receive their final treatment at home.

CONCLUSIONS

Contemporary dialysis treatment in Australia continues to benefit the dominant non-Indigenous population over the Indigenous population, with non-Indigenous men being particularly advantaged. Implications for Public Health: Treatment guidelines that incorporate a recognition of gender-based preferences and dialysis treatment options specific to Indigenous Australians may assist in addressing this disparity.

Diabetic kidney disease in Australia: current burden and future projections

Diabetes mellitus is now the most common cause of new cases of end-stage kidney disease treated with kidney replacement therapy in Australia. In addition to the approximately 5000 Australians receiving maintenance dialysis or living with a kidney transplant as a consequence of diabetes, many die from untreated end-stage kidney disease due to diabetes (DM-ESKD) each year. For every Australian receiving renal replacement therapy due to diabetes, at least 50 others have earlier stages of diabetic kidney disease (DKD). Based on projected increases in type 2 diabetes prevalence, the size of this underlying population with DKD will potentially exceed half a million by 2025. In addition to the risk of developing DM-ESKD, this population is at increased risk of premature cardiovascular morbidity and all-cause mortality. Higher rates of hospitalization, use of specialist services and prescription drugs mean that those with DKD also incur significantly greater health care costs compared with those with diabetes or chronic kidney disease alone. However, in contrast to the increasing prevalence of diabetes and early stages of DKD, recent trends in the incidence of DM-ESKD suggest that better management in the earlier stages of DKD has been successful in slowing rates of disease progression. Simultaneous improvements in use of renin-angiotensin inhibitors and improved glycaemic and blood pressure control are likely to be largely responsible for this trend. Primary prevention, maximizing early detection of DKD and optimal management of diabetes and kidney disease hold great potential to attenuate the future health burden attributable to DKD in Australia.

Epigenetic Mechanisms in Diabetic Kidney Disease

Progressive kidney disease is a common companion to both type 1 and type 2 diabetes. However, the majority of people with diabetes do not develop diabetic kidney disease. This may in part be explained by good control of glucose, blood pressure, obesity and other risk factors for kidney disease. It may also be partly due to their genetic makeup or ethnicity. However, the vast majority of the variability in incident nephropathy remains unaccounted for by conventional risk factors or genetics. Epigenetics has recently emerged as an increasingly powerful paradigm to understand and potentially explain complex non-Mendelian conditions-including diabetic kidney disease. Persistent epigenetic changes can be acquired during development or as adaptations to environmental exposure, including metabolic fluctuations associated with diabetes. These epigenetic modifications-including DNA methylation, histone modifications, non-coding RNAs and other changes in chromatin structure and function-individually and co-operatively act to register, store, retain and recall past experiences in a way to shape the transcription of specific genes and, therefore, cellular functions. This review will explore the emerging evidence for the role of epigenetic modifications in programming the legacy of hyperglycaemia for kidney disease in diabetes.

C-Terminal Fragment of Agrin (CAF): A Novel Marker for Progression of Kidney Disease in Type 2 Diabetics

Background

Diabetes is the leading cause of CKD in the developed world. C-terminal fragment of agrin (CAF) is a novel kidney function and injury biomarker. We investigated whether serum CAF predicts progression of kidney disease in type 2 diabetics.

Methods

Serum CAF levels were measured in 71 elderly patients with diabetic nephropathy using a newly developed commercial ELISA kit (Neurotune®). Estimated glomerular filtration rate (eGFR) and proteinuria in spot urine were assessed at baseline and after 12 months follow up. The presence of end stage renal disease (ESRD) was evaluated after 24 months follow-up. Correlation and logistic regression analyses were carried out to explore the associations of serum CAF levels with GFR, proteinuria, GFR loss and incident ESRD. Renal handling of CAF was tested in neurotrypsin-deficient mice injected with recombinant CAF.

Results

We found a strong association of serum CAF levels with eGFR and a direct association with proteinuria both at baseline (r = 0.698, p<0.001 and r = 0. 287, p = 0.02) as well as after 12 months follow-up (r = 0.677, p<0.001 and r = 0.449, p<0.001), respectively. Furthermore, in multivariate analysis, serum CAF levels predicted eGFR decline at 12 months follow-up after adjusting for known risk factors (eGFR, baseline proteinuria) [OR (95%CI) = 4.2 (1.2–14.5), p = 0.024]. In mice, injected CAF was detected in endocytic vesicles of the proximal tubule.

Conclusion

Serum CAF levels reflect renal function and are highly associated with eGFR and proteinuria at several time points. Serum CAF was able to predict subsequent loss of renal function irrespective of baseline proteinuria in diabetic nephropathy. CAF is likely removed from circulation by glomerular filtration and subsequent endocytosis in the proximal tubule. These findings may open new possibilities for clinical trial design, since serum CAF levels may be used as a selection tool to monitor kidney function in high-risk patients with diabetic nephropathy.

Valproate attenuates diabetic nephropathy through inhibition of endoplasmic reticulum stress‑induced apoptosis

Previous studies have suggested that endoplasmic reticulum stress (ERS) is one of the mechanisms responsible for the pathogenesis of diabetic nephropathy (DN). Histone acetylation modification can regulate the transcription of genes and is involved in the regulation of ERS. Valproate (VPA), a nonselective histone deacetylase inhibitor, has been reported to have a protective role in kidney tissue injury, however, whether VPA can prevent DN remains to be elucidated. In the present study, it was found that VPA increases the expression of glucose-regulated protein (GRP78) and reduces the protein expression of C/EBP-homologous protein (CHOP), growth arrest and DNA-damage-inducible gene 153 and caspase-12 in a rat model of DN. VPA can reduce renal cell apoptosis and alleviate proteinuria and alterations in serum creatinine. VPA also upregulates the acetylation level of histone H4 in the promoter of GRP78 and downregulates the acetylation level of histone H4 in the promoter of CHOP. Collectively, the data indicate that VPA can relieve ERS and reduce renal cell apoptosis, and thus attenuate renal injury in a rat model of DN by regulating the acetylation level of histone H4 in ERS-associated protein promoters.

The changing trends and outcomes in renal replacement therapy: data from the ERA-EDTA Registry

BACKGROUND

This study examines the time trends in incidence, prevalence, patient and kidney allograft survival and causes of death (COD) in patients receiving renal replacement therapy (RRT) in Europe.

METHODS

Eighteen national or regional renal registries providing data to the European Renal Association-European Dialysis and Transplant Association Registry between 1998 and 2011 were included. Incidence and prevalence time trends between 2001 and 2011 were studied with Joinpoint and Poisson regression. Patient and kidney allograft survival and COD between 1998 and 2011 were analysed using Kaplan-Meier and competing risk methods and Cox regression.

RESULTS

From 2001 to 2008, the adjusted incidence of RRT rose by 1.1% (95% CI: 0.6, 1.7) annually to 131 per million population (pmp). During 2008-2011, the adjusted incidence fell by 2.2% (95% CI: -4.2, -0.2) annually to 125 pmp. This decline occurred predominantly in patients aged 45-64 years, 65-74 years and in the primary renal diseases diabetes mellitus type 1 and 2, renovascular disease and glomerulonephritis. Between 2001 and 2011, the overall adjusted prevalence increased from 724 to 1032 pmp (+3.3% annually, 95% CI: 2.8, 3.8). The adjusted 5-year patient survival on RRT improved between 1998-2002 and 2003-2007 [adjusted hazard ratio (HRa) 0.85, 95% CI: 0.84, 0.86]. Comparing these time periods, the risk of cardiovascular deaths fell by 25% (HRa 0.75, 95% CI: 0.74, 0.77). However the risk of malignant death rose by 9% (HRa 1.09, 95% CI: 1.03, 1.16) in patients ≥65 years.

CONCLUSION

This European study shows a declining RRT incidence, particularly in patients aged 45-64 years, 65-74 years and secondary to diabetic nephropathy. Encouragingly, the adjusted RRT patient survival continues to improve. The risk of cardiovascular death has decreased, though the risk of death from malignancy has increased in the older population.

Non-Proteinuric Diabetic Nephropathy

Diabetic nephropathy patients traditionally show significant macroalbuminuria prior to the development of renal impairment. However, this clinical paradigm has recently been questioned. Epidemiological surveys confirm that chronic kidney disease (CKD) diagnosed by a low glomerular filtration rate (GFR) is more common in diabetic patients than in the non-diabetic population but a low number of patients had levels of proteinuria above that which traditionally defines overt diabetic nephropathy (>500 mg/g). The large number of patients with low levels of proteinuria suggests that the traditional clinical paradigm of overt diabetic nephropathy is changing since it does not seem to be the underlying renal lesion in most of diabetic subjects with CKD.

Depression and diabetes: treatment and health-care delivery

Despite research efforts in the past 20 years, scientific evidence about screening and treatment for depression in diabetes remains incomplete and is mostly focused on North American and European health-care systems. Validated instruments to detect depression in diabetes, although widely available, only become effective and thus recommended if subsequent treatment pathways are accessible, which is often not the case. Because of the well known adverse effects of the interaction between depression and diabetes, treatment goals should focus on the remission or improvement of depression as well as improvement in glycaemic control as a marker for subsequent diabetes outcome. Scientific evidence evaluating treatment for depression in type 1 and type 2 diabetes shows that depression can be treated with moderate success by various psychological and pharmacological interventions, which are often implemented through collaborative care and stepped-care approaches. The evidence for improved glycaemic control in the treatment of depression by use of selective serotonin reuptake inhibitors or psychological approaches is conflicting; only some analyses show small to moderate improvements in glycaemic control. More research is needed to evaluate treatment of different depression subtypes in people with diabetes, the cost-effectiveness of treatments, the use of health-care resources, the need to account for cultural differences and different health-care systems, and new treatment and prevention approaches.

The Concept and the Epidemiology of Diabetic Nephropathy Have Changed in Recent Years

Diabetes Mellitus (DM) is a growing worldwide epidemic. It was estimated that more than 366 million people would be affected. DM has spread its presence over the world due to lifestyle changes, increasing obesity and ethnicities, among others. Diabetic nephropathy (DN) is one of the most important DM complications. A changing concept has been introduced from the classical DN to diabetic chronic kidney disease (DCKD), taking into account that histological kidney lesions may vary from the nodular or diffuse glomerulosclerosis to tubulointerstitial and/or vascular lesions. Recent data showed how primary and secondary prevention were the key to reduce cardiovascular episodes and improve life expectancy in diabetic patients. A stabilization in the rate of end stage kidney disease has been observed in some countries, probably due to the increased awareness by primary care physicians about the prognostic importance of chronic kidney disease (CKD), better control of blood pressure and glycaemia and the implementation of protocols and clinical practice recommendations about the detection, prevention and treatment of CKD in a coordinated and multidisciplinary management of the DM patient. Early detection of DM and DCKD is crucial to reduce morbidity, mortality and the social and economic impact of DM burden in this population.

Long-term effectiveness of a community-based model of care in Māori and Pacific patients with type 2 diabetes and chronic kidney disease: a 4-year follow up of the DElay Future End Stage Nephropathy due to Diabetes (DEFEND) study

BACKGROUND/AIM

The Delay Future End Stage Nephropathy due to Diabetes study was a randomised controlled trial of Māori and Pacific patients with advanced diabetic nephropathy, comparing a community-based model of care with usual care. The intervention group achieved lower blood pressure (BP), proteinuria and less end-organ damage. After the intervention ended, all patients reverted to usual care, and were followed to review the sustainability of the intervention.

METHODS

A retrospective observation of 65 patients (aged 47-75 years) with type 2 diabetes, hypertension, chronic kidney disease 3/4 and proteinuria (>0.5 g/day) previously randomised to intervention/community care or usual care for 11-21 months. Follow up thereafter was until death, end-stage renal disease (ESRD) (estimated glomerular filtration rate (eGFR) ≤ 10 mL/min/1.73 m(2) )/dialysis or 1 February 2014. Primary end-points were death and ESRD/dialysis. Secondary outcomes were annualised glomerular filtration rate decline, non-fatal vascular events and hospitalisations.

RESULTS

Median (interquartile ranges (IQR)) post-trial follow up was 49 (21-81) months and similar in both groups. The median (IQR) eGFR decline was -3.1 (-5.5, -2.3) and -5.5 (-7.1, -3.0) mL/min/year in the intervention and usual care groups respectively (P = 0.11). Similar number of deaths, renal and vascular events were observed in both groups. At the end of follow up, the number of prescribed antihypertensive medications was similar (3.4 ± 1.0 vs 3.3 ± 1.4; P = 0.78). There were fewer median (IQR) hospital days (8 (3, 18) vs 15.5 (6, 49) days, P = 0.03) in the intervention group.

CONCLUSIONS

Short-term intensive BP control followed by usual care did not translate into reduction in long-term mortality or ESRD rates, but was associated with reduced hospitalisations.

Incidence of renal replacement therapy for diabetic nephropathy in the Netherlands: Dutch diabetes estimates (DUDE)-3

OBJECTIVES

Describe the incidence, prevalence and survival of patients needing renal replacement therapy (RRT) for end-stage renal disease (ESRD) due to diabetes mellitus (DM)-related glomerulosclerosis or nephropathy (diabetic nephropathy, DN) in the Netherlands.

DESIGN

Using the national registry for RRT (RENINE-registry), data of all Dutch individuals initiating RRT for ESRD and having DN as primary diagnosis in the period 2000-2012 were obtained.

SETTING

Observational study in the Netherlands.

PATIENTS

Patients with ESRD needing RRT for DN.

OUTCOME MEASUREMENTS

Age and gender adjusted incidence and prevalence of RRT for DN in the period 2000-2012. In addition, trends in time and patient's survival were examined.

RESULTS

The prevalence of DM in the general population increased from approximately 466 000 in 2000 to 815 000 in 2011. The number of individuals who started RRT with DN as primary diagnosis was 17.4 per million population (pmp) in 2000 and 19.1 pmp in 2012, with an annual percentage change (APC) of 0.8% (95% CI -0.4 to 2.0). For RRT due to type 1 DN, the incidence decreased from 7.3 to 3.5 pmp (APC -4.8%, 95% CI -6.5 to -3.1) while it increased for type 2 DN from 10.1 to 15.6 pmp (APC 3.1%, 95% CI 1.3 to 4.8). After 2009, the prevalence of RRT for DN remained stable (APC 1.0%, 95% CI -0.4 to 2.5). Compared to the period 2000-2004, patients initiating RRT and dialysis in 2005-2009 had better survival, HRs 0.8 (95% CI 0.7 to 0.8) and 0.8 (95% CI 0.7 to 0.9), respectively, while survival after kidney transplantation remained stable, HR 0.8, 95% CI 0.5 to 1.1).

CONCLUSIONS

Over the last decade, the incidence of RRT for DN was stable, with a decrease in RRT due to type 1 DN and an increase due to type 2 DN, while survival increased.

Trends in the epidemiology and care of diabetes mellitus-related end-stage renal disease in France, 2007-2011

AIMS/HYPOTHESIS

The aim was to study geographic variations and recent trends in the incidence of end-stage renal disease (ESRD) by diabetes status and type, and in patient condition and modalities of care at initiation of renal replacement therapy.

METHODS

Data from the French population-based dialysis and transplantation registry of all ESRD patients were used to study geographic variations in 5,857 patients without diabetes mellitus, 227 with type 1 diabetes mellitus, and 3,410 with type 2. Trends in incidence and patient care from 2007 to 2011 were estimated.

RESULTS

Age- and sex-adjusted incidence rates were higher in the overseas territories than in continental France for ESRD unrelated to diabetes and related to type 2 diabetes, but quite similar for type 1 diabetes-related ESRD. ESRD incidence decreased significantly over time for patients with type 1 diabetes (-10% annually) and not significantly for non-diabetic patients (0.2%), but increased significantly for patients with type 2 diabetes (+7% annually until 2009 and seemingly stabilised thereafter). In type 2 diabetes, the net change in the absolute number was +21%, of which +3% can be attributed to population ageing, +2% to population growth and +16% to the residual effect of the disease. Patients with type 2 diabetes more often started dialysis as an emergency (32%) than those with type 1 (20%) or no diabetes.

CONCLUSIONS/INTERPRETATION

The major impact of diabetes on ESRD incidence is due to type 2 diabetes mellitus. Our data demonstrate the need to reinforce strategies for optimal management of patients with diabetes to improve prevention, or delay the onset, of diabetic nephropathy, ESRD and cardiovascular comorbidities, and to reduce the rate of emergency dialysis.

Psychosocial factors in people with chronic kidney disease prior to renal replacement therapy

Increasing evidence implicates psychosocial factors including depression, anxiety, perceived social support and health-related quality of life in the pathophysiology of various chronic diseases. Research examining the psychosocial aspects of kidney disease has focussed predominantly on depressive disorders in dialysis patients where they are independently associated with increased risk of mortality and poor health-related quality of life. In contrast, studies examining the influence of psychosocial factors in people with chronic kidney disease (CKD) prior to the initiation of renal replacement therapy are sparse. Limited data indicate that clinical depression and depressive symptoms are common and may independently predict progression to dialysis, hospitalization and death. In contrast, the influence of anxiety disorders, lower perceived social support and impaired health-related quality of life on the clinical course of CKD have received little attention. Large-scale prospective cohort studies are needed to clarify the burden and prognostic impact of these factors in this vulnerable population. Given the escalating burden of CKD worldwide examining the role of these potentially modifiable risk factors is crucial. Identifying and implementing targeted interventions in order to prevent or delay the progression of CKD and improve quality of life will be a major challenge.

Survival advantage of peritoneal dialysis relative to hemodialysis in the early period of incident dialysis patients: a nationwide prospective propensity-matched study in Korea

BACKGROUND

The impact of dialysis modality on survival is still somewhat controversial. Given possible differences in patients' characteristics and the cause and rate of death in different countries, the issue needs to be evaluated in Korean cohorts.

METHODS

A nationwide prospective observational cohort study (NCT00931970) was performed to compare survival between peritoneal dialysis (PD) and hemodialysis (HD). A total of 1,060 end-stage renal disease patients in Korea who began dialysis between September 1, 2008 and June 30, 2011 were followed through December 31, 2011.

RESULTS

The patients (PD, 30.6%; HD, 69.4%) were followed up for 16.3 ± 7.9 months. PD patients were significantly younger, less likely to be diabetic, with lower body mass index, and larger urinary volume than HD patients. Infection was the most common cause of death. Multivariate Cox regression with the entire cohort revealed that PD tended to be associated with a lower risk of death compared to HD [hazard ratio (HR) 0.63, 95% confidence interval (CI) 0.36-1.08]. In propensity score matched pairs (n=278 in each modality), cumulative survival probabilities for PD and HD patients were 96.9% and 94.1% at 12 months (P=0.152) and 94.3% and 87.6% at 24 months (P=0.022), respectively. Patients on PD had a 51% lower risk of death compared to those on HD (HR 0.49, 95% CI 0.25-0.97).

CONCLUSIONS

PD exhibits superior survival to HD in the early period of dialysis, even after adjusting for differences in the patients' characteristics between the two modalities. Notably, the most common cause of death was infection in this Korean cohort.

Pregnancy outcomes according to dialysis commencing before or after conception in women with ESRD

BACKGROUND AND OBJECTIVES

Pregnancy in ESRD is rare and poses substantial risk for mother and baby. This study describes a large series of pregnancies in women undergoing long-term dialysis treatment and reviews maternal and fetal outcomes. Specifically, women who had conceived before and after starting long-term dialysis are compared.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENT

All pregnancies reported to the Australian and New Zealand Dialysis and Transplantation Registry from 2001 to 2011 (n=77), following the introduction of specific parenthood data collection, were analyzed.

RESULTS

Between 2001 and 2011, there were 77 pregnancies among 73 women. Of these, 53 pregnancies were in women who conceived after long-term dialysis was established and 24 pregnancies occurred before dialysis began. The overall live birth rate (after exclusion of elective terminations) was 73%. In pregnancies reaching 20 weeks gestation, the live birth rate was 82%. Women who conceived before dialysis commenced had significantly higher live birth rates (91% versus 63%; P=0.03), but infants had similar birthweight and gestational age. This difference in live birth rate was primarily due to higher rates of early pregnancy loss before 20 weeks in women who conceived after dialysis was established. In pregnancies that reached 20 weeks or more, the live birth rate was higher in women with conception before dialysis commenced (91% versus 76%; P=0.28). Overall, the median gestational age was 33.8 weeks (interquartile range, 30.6-37.6 weeks) and median birthweight was 1750 g (interquartile range, 1130-2417 g). More than 40% of pregnancies reached >34 weeks' gestation; prematurity at <28 weeks was 11.4% and 28-day neonatal survival rate was 98%.

CONCLUSIONS

Women with kidney disease who start long-term dialysis after conception have superior live birth rates compared with those already established on dialysis at the time of conception, although these pregnancies remain high risk.

Estimated GFR reporting influences recommendations for dialysis initiation

Automated reporting of estimated GFR (eGFR) with serum creatinine measurement is now common. We surveyed nephrologists in four countries to determine whether eGFR reporting influences nephrologists' recommendations for dialysis initiation. Respondents were randomly allocated to receive a survey of four clinical vignettes that included either serum creatinine concentration only or serum creatinine and the corresponding eGFR. For each scenario, the respondent was asked to rank his or her likelihood of recommending dialysis initiation on a modified 8-point Likert scale, ranging from 1 ("definitely not") to 8 ("definitely would"). Analysis of the 822 eligible responses received showed that the predicted likelihood of recommending dialysis increased by 0.55 points when eGFR was reported (95% confidence interval, 0.33 to 0.76), and this effect was larger for eGFRs >5 ml/min per 1.73 m(2) (P<0.001). Subgroup analyses suggested that physicians who had been in practice ≥13 years were more affected by eGFR reporting (P=0.03). These results indicate that eGFR reporting modestly increases the likelihood that dialysis is recommended, and physicians should be aware of this effect when assessing patients with severe CKD.

Association between TNF-α -308G/A polymorphism and diabetic nephropathy risk: a meta-analysis

Background

Several candidate genes on the short arm of chromosome 6 including the HLA locus, TNF, LTA and AGER could be associated with late diabetic complications. The aim of our study was therefore to explore whether polymorphisms (TNF -308 G→A, LTA T60N C→A and AGER -374 T→A) in these genes alone or together (as haplotypes) increased the risk for diabetic complications.

Methodology/Principal Findings

The studied polymorphisms were genotyped in 742 type 1 and 2957 type 2 diabetic patients as well as in 206 non-diabetic control subjects. The Haploview program was used to analyze putative linkage disequilibrium between studied polymorphisms. The TNF, LTA and AGER polymorphisms were associated with the HLA-DQB1 risk genotypes. The AGER -374 A allele was more common in type 1 diabetic patients with than without diabetic nephropathy (31.2 vs. 28.4%, p = 0.007). In a logistic regression analysis, the LTA but not the AGER polymorphism was associated with diabetic nephropathy (OR 2.55[1.11–5.86], p = 0.03). The AGER -374 A allele was associated with increased risk of sight threatening retinopathy in type 2 diabetic patients (1.65[1.11–2.45], p = 0.01) and also with increased risk for macrovascular disease in type 1 diabetic patients (OR 2.05[1.19–3.54], p = 0.01), but with decreased risk for macrovascular disease in type 2 diabetic patients (OR 0.66[0.49–0.90], p = 0.009). The TNF A allele was associated with increased risk for macrovascular complications in type 2 (OR 1.53 [1.04–2.25], p = 0.03, but not in type 1 diabetic patients.

Conclusions/Significance

The association between diabetic complications and LTA, TNF and AGER polymorphisms is complex, with partly different alleles conferring susceptibility in type 1 and type 2 diabetic patients. We can not exclude the possibility that the genes are part of a large haplotype block that also includes HLA-DQB1 risk genotypes.

Association between TNF-α -308G/A polymorphism and diabetic nephropathy risk: a meta-analysis

PURPOSE

TNF-α -308G/A polymorphism has been implicated in the susceptibility of diabetic nephropathy, but studies have reported inconclusive results. The present study investigated the relationship between -308G/A polymorphism in the TNF-α gene and diabetic nephropathy risk by meta-analysis.

METHODS

Data from PubMed, Embase, Ovid, Cochrane Library, China National Knowledge Infrastructure, Wanfang, VIP and China Biology Medicine disc databases were evaluated and analyzed. Statistical analysis was performed using RevMan 4.2 and Stata 10.0 software.

RESULTS

A total of 1,277 diabetic nephropathy cases and 1,740 controls in eight case-controlled studies were identified for data analysis. The results suggested that A allele carriers (GA + AA) may not have an altered risk of diabetic nephropathy when compared with homozygote GG carriers with boarder-line statistical significance (OR = 0.84, 95 % CI = 0.71-1.00, p = 0.05 for GA + AA vs. GG). However, in Asian subgroup analysis, the A allele variant was associated with a decreased diabetic nephropathy risk (OR = 0.69, 95 % CI = 0.51-0.94, p = 0.02 for GA + AA vs.

GG) CONCLUSIONS

Meta-analysis suggests that the A allele of TNF-α -308G/A polymorphism might be protective against diabetic nephropathy with ethnic selectivity. Future studies are needed to validate these findings.

Epidemiology of diabetic kidney disease

The increasing prevalence of diabetes has led to DKD becoming the leading cause of ESRD in many regions. The economic cost of DKD will grow to prohibitive amounts unless strategies to prevent its onset or progression are urgently implemented. In type 1 and type 2 diabetes, the presence of microalbuminuria and macroalbuminuria confers increased risk of developing ESRD and of death. Comparison of recent studies with earlier historical studies shows that the incidence of ESRD and death has decreased in DKD. Increased risk of albuminuria has been identified in certain non-European ethnic groups. However, the initial concept of progression of DKD as an albuminuric phenotype involving development of microalbuminuria, macroalbuminuria, and then ESRD has had to be modified. Albumin excretion frequently regresses, and GFR can decline without abnormality in albumin excretion. There is emerging evidence that changes in renal function occurring early in the course of diabetes predict future outcomes. The major challenges are to prevent DKD onset, to detect it early, and to improve DKD outcomes globally.

Body mass index and postoperative complications in kidney transplant recipients

BACKGROUND

There is a growing number of overweight and obese patients receiving kidney transplants, despite elevated body mass index (BMI) being associated with postoperative complications. Understanding associations between BMI and complications would allow more objectivity when recommending patients for transplantation or otherwise.

METHODS

We analysed a retrospective cohort of 508 adult patients who received primary kidney grafts at a single centre in South Australia, 2002-2009, using hospital records and Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) data. Complications within 1 year of transplantation were classified into: surgical, wound, urological, delayed graft function, early nephrectomy and admission to intensive care unit (ICU).

RESULTS

Overall, 62% of transplant recipients had a BMI above 25 kg/m(2) at transplant. Higher BMI was associated with an increased risk of wound complications (P < 0.001), early nephrectomy (P = 0.002) and delayed graft function (P = 0.03), but not associated with surgical or urological complications, or ICU admission. These associations were stronger for Indigenous Australians than other patients, especially for surgical complications. There was no BMI value above which risks of complications increase substantially.

CONCLUSION

  Delayed graft function is an important determinant of patient outcomes. Wound complications can be serious, and are more common in patients with higher BMI. This may justify the use of elevated BMI as a contraindication for transplantation, although no obvious cut-off value exists. Investigations into other measures of body fat composition and distribution are warranted.

Meta-analysis of the relationship between ACE I/D gene polymorphism and end-stage renal disease in patients with diabetic nephropathy

AIMS

  Diabetic nephropathy (DN) is the major cause for end-stage renal disease (ESRD) and the pathogenesis for DN developing into ESRD is not clear at present. Results from published studies on the relationship between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and ESRD risk in DN patients are still conflicting. This meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and ESRD risk in DN patients.

METHODS

  Association studies were identified from the databases of PubMed, Embase and Cochrane Library on 1 October 2011, and eligible investigations were identified and synthesized using the meta-analysis method. Results were expressed using odds ratios (OR) for dichotomous data and 95% confidence intervals (CI) were also calculated.

RESULTS

  Twelve studies reporting the relation between ACE I/D gene polymorphism and ESRD risk in DN patients were identified. In overall populations, there was a notable association between D allele or DD genotype and ESRD susceptibility (D: OR = 1.32, 95% CI: 1.11-1.56, P = 0.002; DD: OR = 1.67, 95% CI: 1.25-2.21, P = 0.0004). In the sub-group analysis according to ethnicity, D allele or DD genotype was associated with ESRD risk in Asians. In Caucasians, the association of DD genotype with ESRD risk was observed, but the D allele was not. Furthermore, ACE I/D gene polymorphism was associated with ESRD risk in patients with DN due to diabetes mellitus type 2, but the association was not found for patients with DN due to diabetes mellitus type-1.

CONCLUSIONS

  Our results indicate that D allele or DD homozygous is associated with the ESRD susceptibility in DN patients. However, more investigations are required to further this association.