Differences in progression of CKD and mortality amongst Caucasian, Oriental Asian and South Asian CKD patients

Identification of interactions between genetic risk scores and dietary patterns for personalized prevention of kidney dysfunction in a population-based cohort

BACKGROUND & AIM

Chronic kidney disease (CKD) is a heterogeneous disorder that affects the kidney structure and function. This study investigated the effect of the interaction between genetic factors and dietary pattern on kidney dysfunction in Korean adults.

METHODS

Baseline data were obtained from the Ansan and Ansung Study of the Korean Genome and Epidemiology Study involving 8230 participants aged 40-69 years. Kidney dysfunction was defined as an estimated glomerular filtration rate < 90 mL/minute/1.73 m2. Genomic DNAs genotyped on the Affymetrix® Genome-Wide Human SNP array 5.0 were isolated from peripheral blood. A genome-wide association study using a generalized linear model was performed on 1,590,162 single-nucleotide polymorphisms (SNPs). To select significant SNPs, the threshold criterion was set at P-value < 5 × 10-8. Linkage disequilibrium clumping was performed based on the R2 value, and 94 SNPs had a significant effect. Participants were divided into two groups based on their generic risk score (GRS): the low-GR group had GRS > 0, while the high-GR group had GRS ≤ 0.

RESULTS

Three distinct dietary patterns were extracted, namely, the "prudent pattern," "flour-based and animal food pattern," and "white rice pattern," to analyze the effect of dietary pattern on kidney function. In the "flour-based and animal food pattern," higher pattern scores were associated with a higher prevalence of kidney dysfunction in both the low and high GR groups (P for trend < 0.0001 in the low-, high-GR groups of model 1; 0.0050 and 0.0065 in the low-, high-GR groups of model 2, respectively).

CONCLUSIONS

The results highlight a significant association between the 'flour-based and animal food pattern' and higher kidney dysfunction prevalence in individuals with both low and high GR. These findings suggest that personalized nutritional interventions based on GR profiles may become the basis for presenting GR-based individual dietary patterns for kidney dysfunction.

Cost-effectiveness of add-on empagliflozin versus standard of care in management of CKD in Malaysia, Thailand and Vietnam - findings from a modelling study assessing an EMPA-KIDNEY eligible population, using CKD progression model

BACKGROUND AND OBJECTIVES

Nearly one in ten individuals in South-East Asia are estimated to be affected by chronic kidney disease (CKD). The burden of end-stage kidney disease is significant and can be heavy on the healthcare system. The recent EMPA-KIDNEY trial demonstrated a significant reduction in the risk of kidney disease progression or cardiovascular death in patients with CKD with a broad range of kidney function using add-on empagliflozin versus standard of care (SoC) alone. The objective of this study was to estimate the economic benefit of empagliflozin for patients with CKD in Malaysia, Thailand and Vietnam.

METHODS

An individual patient level simulation model with an annual cycle that estimates the progression of kidney function and associated risk-factors was employed. Local costs and mortality rates were estimated from a wide range of published literature. A healthcare perspective was used over a 50-year time horizon.

RESULTS

The use of add-on empagliflozin versus SoC alone was found to be cost-saving in Malaysia and Thailand and cost-effective (ICER: 77,838,407 Vietnam Dong/QALY vs. a willingness to pay threshold of 96,890,026/QALY) in Vietnam. The bulk of the costs avoided over a lifetime is derived from the prevention or delay of dialysis initiation or kidney transplant - the cost offsets were nearly twice the additional treatment cost. The results were similar in patients with and without diabetes and across broad range of albuminuria.

CONCLUSIONS

The use of add-on empagliflozin in a broad population of patients with CKD is expected to be cost-saving in Malaysia and Thailand and cost-effective in Vietnam and will help alleviate the increasing burden of CKD in the region.

Disentangling Dual Threats: Premature Coronary Artery Disease and Early-Onset Type 2 Diabetes Mellitus in South Asians

South Asian individuals (SAs) face heightened risks of premature coronary artery disease (CAD) and early-onset type 2 diabetes mellitus (T2DM), with grave health, societal, and economic implications due to the region's dense population. Both conditions, influenced by cardiometabolic risk factors such as insulin resistance, hypertension, and central adiposity, manifest earlier and with unique thresholds in SAs. Epidemiological, demographic, nutritional, environmental, sociocultural, and economic transitions in SA have exacerbated the twin epidemic. The coupling of premature CAD and T2DM arises from increased obesity due to limited adipose storage, early-life undernutrition, distinct fat thresholds, reduced muscle mass, and a predisposition for hepatic fat accumulation from certain dietary choices cumulatively precipitating a decline in insulin sensitivity. As T2DM ensues, the β-cell adaptive responses are suboptimal, precipitating a transition from compensatory hyperinsulinemia to β-cell decompensation, underscoring a reduced functional β-cell reserve in SAs. This review delves into the interplay of these mechanisms and highlights a prediabetes endotype tied to elevated vascular risk. Deciphering these mechanistic interconnections promises to refine stratification paradigms, surpassing extant risk-prediction strategies.

Using the kidney failure risk equation to predict end-stage kidney disease in CKD patients of South Asian ethnicity: an external validation study

BACKGROUND

The kidney failure risk equation (KFRE) predicts the 2- and 5-year risk of needing kidney replacement therapy (KRT) using four risk factors - age, sex, urine albumin-to-creatinine ratio (ACR) and creatinine-based estimated glomerular filtration rate (eGFR). Although the KFRE has been recalibrated in a UK cohort, this did not consider minority ethnic groups. Further validation of the KFRE in different ethnicities is a research priority. The KFRE also does not consider the competing risk of death, which may lead to overestimation of KRT risk. This study externally validates the KFRE for patients of South Asian ethnicity and compares methods for accounting for ethnicity and the competing event of death.

METHODS

Data were gathered from an established UK cohort containing 35,539 individuals diagnosed with chronic kidney disease. The KFRE was externally validated and updated in several ways taking into account ethnicity, using recognised methods for time-to-event data, including the competing risk of death. A clinical impact assessment compared the updated models through consideration of referrals made to secondary care.

RESULTS

The external validation showed the risk of KRT differed by ethnicity. Model validation performance improved when incorporating ethnicity and its interactions with ACR and eGFR as additional risk factors. Furthermore, accounting for the competing risk of death improved prediction. Using criteria of 5 years ≥ 5% predicted KRT risk, the competing risks model resulted in an extra 3 unnecessary referrals (0.59% increase) but identified an extra 1 KRT case (1.92% decrease) compared to the previous best model. Hybrid criteria of predicted risk using the competing risks model and ACR ≥ 70 mg/mmol should be used in referrals to secondary care.

CONCLUSIONS

The accuracy of KFRE prediction improves when updated to consider South Asian ethnicity and to account for the competing risk of death. This may reduce unnecessary referrals whilst identifying risks of KRT and could further individualise the KFRE and improve its clinical utility. Further research should consider other ethnicities.

Cardiorenal Outcomes with Finerenone in Asian Patients with Chronic Kidney Disease and Type 2 Diabetes: A FIDELIO-DKD post hoc Analysis

INTRODUCTION

In FIDELIO-DKD, finerenone significantly improved cardiorenal outcomes in patients with chronic kidney disease and type 2 diabetes (T2D). This post hoc analysis explores finerenone in patients from the Asian region.

METHODS

In FIDELIO-DKD, 5,674 patients with T2D and urine albumin-to-creatinine ratio (UACR) ≥30-<300 mg/g and estimated glomerular filtration rate (eGFR) ≥25-<60 mL/min/1.73 m2 or UACR ≥300-≤5,000 mg/g and eGFR ≥25-<75 mL/min/1.73 m2, treated with optimized renin-angiotensin system blockade, were randomized 1:1 to finerenone or placebo. Efficacy outcomes included a primary kidney composite (time to kidney failure, sustained decrease of ≥40% in eGFR from baseline, and death from renal causes) and secondary cardiovascular (CV) (time to CV death, non-fatal myocardial infarction, non-fatal stroke, or hospitalization for heart failure) and kidney (time to kidney failure, sustained decrease of ≥57% in eGFR from baseline, and death from renal causes) composites.

RESULTS

Of 1,327 patients in the Asian subgroup, 665 received finerenone. Finerenone reduced the ≥40% and ≥57% eGFR kidney and CV composite outcomes versus placebo in the Asian subgroup (hazard ratio [HR]: 0.70; 95% confidence interval [CI]: 0.56-0.87, HR: 0.73; 95% CI: 0.55-0.97, and HR: 0.85; 95% CI: 0.59-1.21, respectively), with no apparent differences versus patients from the rest of the world (HR: 0.88; 95% CI: 0.77-1.02; p interaction 0.09, HR: 0.78; 95% CI: 0.64-0.95; p interaction 0.71, and HR: 0.86; 95% CI: 0.74-1.00; p interaction 0.95, respectively). The safety profile of finerenone was similar across subgroups.

CONCLUSION

Finerenone produces similar cardiorenal benefits in Asian and non-Asian patients.

Kidney Function and Long-Term Risk of End-Stage Kidney Disease and Mortality in a Multiethnic Population

Introduction

Contemporary differences between South Asian and White ethnicities in the incidence of end-stage kidney disease (ESKD) and mortality are poorly described.

Methods

Data for all South Asian patients who had an estimated glomerular filtration rate (eGFR) measure after January 1, 2006, and 1 million randomly selected participants of other ethnicities were extracted from the Clinical Practice Research Datalink (CPRD). All participants were followed-up with from index date until ESKD, all-cause mortality, or end of study. All-cause mortality rate and ESKD incidence rate by age were described among Whites and South Asians, and adjusted hazard ratios (HRs) of these 2 outcomes by baseline eGFR estimated using Cox proportional hazard model.

Results

A total of 40,888 South Asians and 236,634 Whites were followed for a median of 5.3 and 9.4 years for ESKD incidence and mortality outcomes, respectively. All-cause mortality rates were higher among Whites than South Asians; South Asian women aged between 70 and 85 years had a slightly higher ESKD incidence rate compared to their White counterparts. Compared to Whites with a baseline eGFR of 90 ml/min per 1.73 m2, adjusted HRs for all-cause mortality were significantly lower among South Asians than Whites; however, adjusted HRs for ESKD incidence by baseline eGFR were similar in both ethnicities. Calculating South Asian eGFRs using an ethnicity-specific equation had no impact on the results.

Conclusions

South Asians experience lower mortality than Whites but not substantially higher rates of ESKD. Further research is warranted to better understand the reasons for these ethnic differences and possible impacts on chronic kidney disease (CKD) service delivery and patient outcomes.

Ethnic differences in kidney function in childhood: the Born in Bradford Cohort Renal Study

Background: Endstage kidney failure rates are higher in South Asians than in White Europeans. Low birth weight is associated with adult chronic kidney disease and is more common in South Asians. Foetal kidney size was smaller in South Asians in the Born in Bradford (BiB) birth cohort. As part of BiB follow up, we aimed to investigate if there were ethnic differences in kidney function and blood pressure in early childhood and whether this was different by foetal kidney size. Methods: Serum creatinine, cystatin C, urea, and urinary albumin to creatinine ratio (ACR), protein to creatinine ratio (PCR) and retinol binding protein (RBP) were analysed in blood and urine samples from those who participated in the BiB follow-up at 7-11 years. Ethnicity was categorised by parental self-report as White European and South Asian. Estimated glomerular filtration rate (eGFR) was calculated using Schwartz, and cystatin C Zappitelli and Filler equations. Linear regression was used to examine the association between ethnicity and eGFR, PCR and blood pressure. Results: 1591 children provided blood (n=1403) or urine (n=625) samples. Mean eGFR was 92 ml/min/1.73m 2 (standard deviation (SD) 9) using Schwartz (n=1156) and 94 (SD 11) using Zappitelli (n=1257). CKD prevalence was rare (1 with eGFR <60 ml/min/1.73m 2, 14 (2.4%) had raised ACR (>2.5 mg/mmol in boys/3.5 mg/mmol in girls). Diastolic blood pressure was higher in South Asian children (difference 2.04 mmHg, 95% CI 0.99 to 3.10) but was not significant in adjusted analysis. There was no evidence of association in adjusted models between ethnicity and any eGFR or urinary measure at this age. Conclusions: There was no evidence of significant ethnic differences in kidney function at pre-pubertal age despite differences in kidney volume at birth. Longitudinal follow-up is required to track ethnic patterns in kidney function and blood pressure as children develop through puberty.

Risk Amplifiers for Vascular Disease and CKD in South Asians: When Intrinsic β-Cell Dysfunction Meets a High-Carbohydrate Diet

South Asians, comprising almost one fourth of the world population, are at higher risk of type 2 diabetes mellitus, hypertension, cardiovascular disease, and CKD compared with other ethnic groups. This has major public health implications in South Asia and in other parts of the world to where South Asians have immigrated. The interplay of various modifiable and nonmodifiable risk factors confers this risk. Traditional models of cardiometabolic disease progression and CKD evaluation may not be applicable in this population with a unique genetic predisposition and phenotype. A wider understanding of dietary and lifestyle influences, genetic and metabolic risk factors, and the pitfalls of conventional equations estimating kidney function in this population are required in providing care for kidney diseases. Targeted screening of this population for metabolic and vascular risk factors and individualized management plan for disease management may be necessary. Addressing unhealthy dietary patterns, promoting physical activity, and medication management that adheres to cultural factors are crucial steps to mitigate the risk of cardiovascular disease and CKD in this population. In South Asian countries, a large rural and urban community-based multipronged approach using polypills and community health workers to decrease the incidence of these diseases may be cost-effective.

Novel Genetic Variants Associated with Chronic Kidney Disease Progression

SIGNIFICANCE STATEMENT

eGFR slope has been used as a surrogate outcome for progression of CKD. However, genetic markers associated with eGFR slope among patients with CKD were unknown. We aimed to identify genetic susceptibility loci associated with eGFR slope. A two-phase genome-wide association study identified single nucleotide polymorphisms (SNPs) in TPPP and FAT1-LINC02374 , and 22 of them were used to derive polygenic risk scores that mark the decline of eGFR by disrupting binding of nearby transcription factors. This work is the first to identify the impact of TPPP and FAT1-LINC02374 on CKD progression, providing predictive markers for the decline of eGFR in patients with CKD.

BACKGROUND

The incidence of CKD is associated with genetic factors. However, genetic markers associated with the progression of CKD have not been fully elucidated.

METHODS

We conducted a genome-wide association study among 1738 patients with CKD, mainly from the KoreaN cohort study for Outcomes in patients With CKD. The outcome was eGFR slope. We performed a replication study for discovered single nucleotide polymorphisms (SNPs) with P <10 -6 in 2498 patients with CKD from the Chronic Renal Insufficiency Cohort study. Several expression quantitative trait loci (eQTL) studies, pathway enrichment analyses, exploration of epigenetic architecture, and predicting disruption of transcription factor (TF) binding sites explored potential biological implications of the loci. We developed and evaluated the effect of polygenic risk scores (PRS) on incident CKD outcomes.

RESULTS

SNPs in two novel loci, TPPP and FAT1-LINC02374 , were replicated (rs59402340 in TPPP , Pdiscovery =7.11×10 -7 , PCRIC =8.13×10 -4 , Pmeta =7.23×10 -8 ; rs28629773 in FAT1-LINC02374 , Pdiscovery =6.08×10 -7 , PCRIC =4.33×10 -2 , Pmeta =1.87×10 -7 ). The eQTL studies revealed that the replicated SNPs regulated the expression level of nearby genes associated with kidney function. Furthermore, these SNPs were near gene enhancer regions and predicted to disrupt the binding of TFs. PRS based on the independently significant top 22 SNPs were significantly associated with CKD outcomes.

CONCLUSIONS

This study demonstrates that SNP markers in the TPPP and FAT1-LINC02374 loci could be predictive markers for the decline of eGFR in patients with CKD.

Identifying Genetic Variants and Metabolites Associated with Rapid Estimated Glomerular Filtration Rate Decline in Korea Based on Genome-Metabolomic Integrative Analysis

Identifying the predisposing factors to chronic or end-stage kidney disease is essential to preventing or slowing kidney function decline. Therefore, here, we investigated the genetic variants related to a rapid decline in the estimated glomerular filtration rate (eGFR) (i.e., a loss of >5 mL/min/1.73 m2 per year) and verified the relationships between variant-related diseases and metabolic pathway signaling in patients with chronic kidney disease. We conducted a genome-wide association study that included participants with diabetes, hypertension, and rapid eGFR decline from two Korean data sources (N = 115 and 69 for the discovery and the validation cohorts, respectively). We identified a novel susceptibility locus: 4q32.3 (rs10009742 in the MARCHF1 gene, beta = −3.540, P = 4.11 × 10−8). Fine-mapping revealed 19 credible, causal single-nucleotide polymorphisms, including rs10009742. The pimelylcarnitine and octadecenoyl carnitine serum concentrations were associated with rs10009742 (beta = 0.030, P = 7.10 × 10−5, false discovery rate (FDR) = 0.01; beta = 0.167, P = 8.11 × 10−4, FDR = 0.08). Our results suggest that MARCHF1 is associated with a rapid eGFR decline in patients with hypertension and diabetes. Furthermore, MARCHF1 affects the pimelylcarnitine metabolite concentration, which may mediate chronic kidney disease progression by inducing oxidative stress in the endoplasmic reticulum.

South Asian ethnicity: What can we do to make this risk enhancer a risk equivalent?

South Asians account for around 25% of the global population and are the fastest-growing ethnicity in the US. This population has an increasing burden of atherosclerotic cardiovascular disease (ASCVD) which is also seen in the diaspora. Current risk prediction equations underestimate this risk and consider the South Asian ethnicity as a risk-enhancer among those with borderline-intermediate risk. In this review, we discuss why the South Asian population is at a higher risk of ASCVD and strategies to mitigate this increased risk.

Estimated glomerular filtration rate in Korean patients exposed to long-term lithium maintenance therapy

Background

Lithium-induced nephrotoxicity has long been debated. However, it has been rarely explored in Asian populations. The aim of the present study was to assess the effect of lithium maintenance therapy on estimated glomerular filtration rate (eGFR) in Korean patients diagnosed with a psychiatric illness.

Methods

This was a single-centered, retrospective study that included patients treated with lithium or comparator drug (valproate) in Samsung Seoul Medical Center between November 1994 and July 2020. Patients diagnosed with ICD codes F20-33 who had  ≥ 6 months of exposure to lithium or valproate were included. Patients had to have  ≥ 1 baseline and  ≥ 2 post-baseline eGFR data with post-baseline data having an interval of at least 30 days. Chronic kidney disease (CKD) was defined as CKD stage 3 (eGFR  < 60 mL/min/1.73²). To be considered as CKD, the threshold had to be met at two consecutive post-baseline measurements. Those treated with both lithium and valproate, diagnosed with CKD stages 3–5, diagnosed with a renal disease, or received kidney transplantation were excluded.

Results

A total of 766 patients were included (242 treated with lithium and 524 with valproate). Two (0.8%) in the lithium group and 8 (1.5%) in the valproate group developed CKD stage 3. None developed CKD stages 4–5. Median yearly eGFR change was − 1.3 mL/min/1.73² (IQR: − 6.8, 1.7) for the lithium group and − 1.1 mL/min/1.73² (IQR: − 4.5, 1.5) for the valproate group, showing no significant difference between the two groups (p  = 0.389). The rate of decline was more rapid for those with CKD in both groups. eGFR values of lithium and valproate groups did not show significant differences during a follow-up duration of 15 years or more. A significant negative correlation between baseline eGFR and yearly eGFR change was identified in a linear regression analysis.

Conclusions

In Korean patients, treatment with lithium did not increase the risk of developing CKD compared to treatment with valproate. Prevalence of CKD was lower than those previously reported in western populations. Low baseline eGFR showed significant correlation with changes in renal function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40345-022-00249-5.

Comorbidities and outcomes in South Asian individuals with chronic kidney disease: an observational primary care cohort

BACKGROUND

South Asian (SA) individuals are more likely to develop end-stage renal disease (ESRD), but how chronic kidney disease (CKD) differs in relation to demographics, comorbidities and outcomes has not been studied. We aimed to study differences in SA individuals with CKD compared with White individuals.

METHODS

This was an observational CKD cohort comparing SA with White individuals. Inclusion criteria were ≥18 years of age and two or more Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFRs <60 mL/min/1.73 m2 >3 months apart. Individuals with ESRD at baseline were excluded. Baseline characteristics, including eGFR formulae [CKD-EPI and CKD-EPI-Pakistan (CKD-EPI-PK)], were compared. Analysis using competing risk regression for cardiovascular (CV) and ESRD events and Cox proportional hazard model for mortality was performed.

RESULTS

From an adult population of 277 248 individuals, 17 248 individuals had CKD, of whom 1990 (11.5%) were of SA ethnicity. Age-adjusted prevalence of CKD was similar between ethnicities. SA individuals were more likely to be male, younger and socioeconomically deprived, and to have diabetes mellitus, CV disease and advanced CKD. Mean CKD-EPI-PK eGFR was 6.5 mL/min/1.73 m2 lower (41.1 versus 47.6, 95% confidence interval for difference 6.47-6.56) than for CKD-EPI. During 5 years of follow-up, 5109 (29.6%) individuals died, 2072 (12.0%) had a CV and 156 (0.90%) an ESRD event. Risk for SA individuals was higher for ESRD, similar to CV events and lower for mortality. Each 1 mL/min/1.73 m2 decrease in CKD-EPI-PK was associated with a 13.1% increased ESRD risk (adjusted subdistribution hazard ratio 0.869, 95% confidence interval 0.841-0.898).

CONCLUSIONS

SA individuals with CKD were younger and had more advanced disease than White individuals. Risk of ESRD was higher and CKD-EPI-PK was associated with ESRD risk in SA individuals. Specific CKD interventions, including the use of CKD-EPI-PK, should be considered in SA populations.

Association between Body Mass Index and Chronic Kidney Disease in Asian Populations: A Participant-level Meta-Analysis

Obesity and chronic kidney disease (CKD) are major public health problems worldwide. However, the association between body mass index (BMI) and CKD is inconclusive in Asians. In this meta-analysis, eight population-based studies, from China, India, Russia (Asian), Singapore and South Korea, provided individual-level data (n=50037). CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m². BMI was analyzed both as a continuous variable and in three categories: <25kg/m², normal; 25-29.9kg/m², overweight; and ≥30kg/m², obese. The association between BMI and CKD was evaluated in each study using multivariable logistic regression models and individual estimates were pooled using random-effect meta-analysis to obtain the pooled odds ratio (OR) and 95% confidence interval (CI). Associations were also evaluated in subgroups of age, gender, smoking, diabetes, and hypertension status. Of 50037 adults, 4258 (8.5%) had CKD. 13328 (26.6%) individuals were overweight while 4440 (8.9%) were obese. The prevalence of any CKD ranged from 3.5% to 29.1% across studies. In pooled analysis, both overweight and obesity were associated with increased odds of CKD, with pooled OR (95% CI) of 1.15 (1.03-1.29) and 1.23 (1.06-1.42), respectively. In subgroup analyses, significant associations between BMI and CKD were observed in adult males, non-smokers, and those with diabetes and arterial hypertension (all p<0.05). When evaluated as a continuous variable, BMI was not significantly associated with CKD. If confirmed in longitudinal studies, these results may have clinical implications in risk stratification and preventive measures, given that obesity and CKD are two major chronic diseases with substantial public health burden worldwide.

Prediction models and nomograms for 10-year risk of end-stage renal disease in Chinese type 2 diabetes mellitus patients in primary care

AIMS

To develop and validate 10-year risk prediction models, nomograms and charts for end-stage renal disease (ESRD) in Chinese patients with type 2 diabetes mellitus (T2DM) in primary care, in order to guide individualized treatment.

MATERIALS AND METHODS

This was a 10-year population-based observational cohort study. A total of 141 516 Chinese T2DM patients without history of cardiovascular disease or ESRD who were managed in public primary care clinics in 2008 were included and followed up until December 2017. Two-thirds of these patients were randomly selected to develop sex-specific ESRD risk prediction models using Cox regressions. The validity and accuracy of the models were tested on the remaining third of patients using Harrell's C-index. We selected variables based on their clinical and statistical importance to construct the nomograms and charts.

RESULTS

The median follow-up period was 9.75 years. The cumulative incidence of ESRD was 6.0% (men: 6.1%, women: 5.9%). Age, diabetes duration, systolic blood pressure (SBP), SBP variability, diastolic blood pressure, triglycerides, glycated haemoglobin (HbA1c), HbA1c variability, urine albumin to creatinine ratio (UACR), and estimated glomerular filtration rate (eGFR) were significant predictors for both sexes. Smoking and total cholesterol to HDL cholesterol ratio were additional significant predictors for men and women, respectively. The models showed Harrell's C-statistics of 0.889/0.889 (women/men). Age, eGFR, UACR, SBP and HbA1c were selected for both sexes to develop nomograms and charts.

CONCLUSIONS

Using routinely available variables, the 10-year ESRD risk of Chinese T2DM patients in primary care can be predicted with approximately 90% accuracy. We have developed different tools to facilitate routine ESRD risk prediction in primary care, so that individualized care can be provided to prevent or delay ESRD in T2DM patients.

Effects of CYP3A5 Polymorphism on Rapid Progression of Chronic Kidney Disease: A Prospective, Multicentre Study

Personalised medicine is potentially useful to delay the progression of chronic kidney disease (CKD). The aim of this study was to determine the effects of CYP3A5 polymorphism in rapid CKD progression. This multicentre, observational, prospective cohort study was performed among adult CKD patients (≥18 years) with estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2, who had ≥4 outpatient, non-emergency eGFR values during the three-year study period. The blood samples collected were analysed for CYP3A5*3 polymorphism. Rapid CKD progression was defined as eGFR decline of >5 mL/min/1.73 m2/year. Multiple logistic regression was then performed to identify the factors associated with rapid CKD progression. A total of 124 subjects consented to participate. The distribution of the genotypes adhered to the Hardy-Weinberg equilibrium (X2 = 0.237, p = 0.626). After adjusting for potential confounding factors via multiple logistic regression, the factors associated with rapid CKD progression were CYP3A5*3/*3 polymorphism (adjusted Odds Ratio [aOR] 4.190, 95% confidence interval [CI]: 1.268, 13.852), adjustments to antihypertensives, young age, dyslipidaemia, smoking and use of traditional/complementary medicine. CKD patients should be monitored closely for possible factors associated with rapid CKD progression to optimise clinical outcomes. The CYP3A5*3/*3 genotype could potentially be screened among CKD patients to offer more individualised management among these patients.

Cognitive impairment in patients with moderate to severe chronic kidney disease: the Salford kidney cohort study

Background

Cognitive impairment in chronic kidney disease (CKD) is common and underrecognized [1, 2]. Determining risk factors for cognitive impairment and whether speed of CKD progression is an important consideration may help identify cognitive impairment by nephrologists. Vascular disease is thought to underpin cognitive impairment in CKD and by segregating CKD patients with proven vascular disease, we may also be able to discover other important associations with cognitive impairment in CKD patients.

Method

A total of 250 patients in a UK prospective cohort of CKD patients underwent two cognitive assessments: Montreal Cognitive Assessment test and Trail Making Test. Cognitive impairment was defined using validated population cut-offs (cognitive impairment) and relative cognitive impairment. Relative cognitive impairment was defined by <1 standard deviation below the mean Z-score on any completed test. Two multivariable logistical regression models identified variables associated with cognitive impairment and realtive cognitive impairment.

Results

About 44 and 24.8% of patients suffered cognitive impairment and relative cognitive impairment, respectively. Depression, previous stroke and older age were significantly associated with cognitive impairment. Older age was significantly associated with relative cognitive impairment (P ≤ 0.05) and higher proteinuria and the use of psychodynamic medications were also significantly associated with relative cognitive impairment (P = 0.05). Delta estimated glomerular filtration rate (eGFR) in patients with cognitive impairment and relative cognitive impairment compared with those having normal cognition was similar (−0.77 versus −1.35 mL/min/1.73 m²/year, P = 0.34 for cognitive impairment and −1.12 versus −1.02 mL/min/1.73 m²/year, P = 0.89 for relative cognitive impairment).

Conclusion

Risk factors for cognitive impairment in CKD include previous stroke, depression or anxiety, higher proteinuria and prescription of psychodynamic medications. Patients with a faster eGFR decline do not represent a group of patients at increased risk of cognitive impairment.

Ethnic minority disparities in progression and mortality of pre-dialysis chronic kidney disease: a systematic scoping review

Background

There are a growing number of studies on ethnic differences in progression and mortality for pre-dialysis chronic kidney disease (CKD), but this literature has yet to be synthesised, particularly for studies on mortality.

Methods

This scoping review synthesized existing literature on ethnic differences in progression and mortality for adults with pre-dialysis CKD, explored factors contributing to these differences, and identified gaps in the literature. A comprehensive search strategy using search terms for ethnicity and CKD was taken to identify potentially relevant studies. Nine databases were searched from 1992 to June 2017, with an updated search in February 2020.

Results

8059 articles were identified and screened. Fifty-five studies (2 systematic review, 7 non-systematic reviews, and 46 individual studies) were included in this review. Most were US studies and compared African-American/Afro-Caribbean and Caucasian populations, and fewer studies assessed outcomes for Hispanics and Asians. Most studies reported higher risk of CKD progression in Afro-Caribbean/African-Americans, Hispanics, and Asians, lower risk of mortality for Asians, and mixed findings on risk of mortality for Afro-Caribbean/African-Americans and Hispanics, compared to Caucasians. Biological factors such as hypertension, diabetes, and cardiovascular disease contributed to increased risk of progression for ethnic minorities but did not increase risk of mortality in these groups.

Conclusions

Higher rates of renal replacement therapy among ethnic minorities may be partly due to increased risk of progression and reduced mortality in these groups. The review identifies gaps in the literature and highlights a need for a more structured approach by researchers that would allow higher confidence in single studies and better harmonization of data across studies to advance our understanding of CKD progression and mortality.

Infection in Advanced Chronic Kidney Disease and Subsequent Adverse Outcomes after Dialysis Initiation: A Nationwide Cohort Study

It remains unclear whether infection events before entering end stage renal disease (ESRD) have a long-term negative impact on patients with advanced chronic kidney disease (CKD) who survive to permanent dialysis. We enrolled 62,872 patients with advanced CKD who transitioned to maintenance dialysis between January 1, 2004 and December 31, 2013. We used multivariable Cox as well as Fine and Gray models to determine the association of pre-dialysis infection exposure with all-cause mortality after starting dialysis. Compared with no infection during advanced CKD, the presence of infection exposure during that period was independently associated with a higher risk of all-cause mortality in the first year of dialysis (hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.27–1.42) and also during the entire follow-up period (HR 1.19, 95% CI 1.16–1.22). The increased risks of all-cause mortality increased incrementally with higher annual number of infections during advanced CKD. Similar results were found for all other adverse outcomes, e.g. post-ESRD infection-related hospitalization and major cardiac and cerebrovascular events. In conclusion, infection events during advanced CKD was associated with increased risks of adverse outcomes after dialysis has been started. Timely interventions in such a vulnerable group may help attenuate these risks.

RAPID-ADPKD (Retrospective epidemiological study of Asia-Pacific patients with rapId Disease progression of Autosomal Dominant Polycystic Kidney Disease): study protocol for a multinational, retrospective cohort study

INTRODUCTION

Patients with autosomal dominant polycystic kidney disease (ADPKD) reach end-stage renal disease in their fifth decade on average. For effective treatment and early intervention, identifying subgroups with rapid disease progression is important in ADPKD. However, there are no epidemiological data on the clinical manifestations and disease progression of patients with ADPKD from the Asia-Pacific region.

METHODS AND ANALYSIS

The RAPID-ADPKD (Retrospective epidemiological study of Asia-Pacific patients with rapId Disease progression of Autosomal Dominant Polycystic Kidney Disease) study is a multinational, retrospective, observational cohort study of patients with ADPKD in the Asia-Pacific region (Australia, China, Hong Kong, South Korea, Taipei and Turkey). This study was designed to identify the clinical characteristics of patients with ADPKD with rapid disease progression. Adult patients with ADPKD diagnosed according to the unified ultrasound criteria and with an estimated glomerular filtration rate (eGFR) ≥45 mL/min/1.73 m² at baseline will be included. The cohort will include patients with ≥2 records of eGFR and at least 24 months of follow-up data. Demographic information, clinical characteristics, comorbidities, medications, eGFR, radiological findings that allow calculation of height-adjusted total kidney volume, ADPKD-related complications and the Predicting Renal Outcomes in autosomal dominant Polycystic Kidney Disease (PRO-PKD) score will be collected. Rapid progression will be defined based on the European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) guideline. All other patients without any of these criteria will be classified to be of slow progression. Clinical characteristics will be compared between patients with rapid progression and those with slow progression. The incidence of complications and the effects of race and water intake on renal progression will also be analysed. The planned sample size of the cohort is 1000 patients, and data from 600 patients have been collected as of 30 May 2019.

ETHICS AND DISSEMINATION

This study was approved or is in the process of approval by the institutional review boards at each participating centre. The results will be presented in conferences and published in a journal, presenting data on the clinical characteristics, risk factors for disease progression and patterns of complications of ADPKD in Asian populations.

Validation of the kidney failure risk equation for end-stage kidney disease in Southeast Asia

BACKGROUND

Patients with chronic kidney disease (CKD) are at high risk of end-stage kidney disease (ESKD). The Kidney Failure Risk Equation (KFRE), which predicts ESKD risk among patients with CKD, has not been validated in primary care clinics in Southeast Asia (SEA). Therefore, we aimed to (1) evaluate the performance of existing KFRE equations, (2) recalibrate KFRE for better predictive precision, and (3) identify optimally feasible KFRE thresholds for nephrologist referral and dialysis planning in SEA.

METHODS

All patients with CKD visiting nine primary care clinics from 2010 to 2013 in Singapore were included and applied 4-variable KFRE equations incorporating age, sex, estimated glomerular filtration rate (eGFR), and albumin-to-creatinine ratio (ACR). ESKD onset within two and five years were acquired via linkage to the Singapore Renal Registry. A weighted Brier score (the squared difference between observed vs predicted ESKD risks), bias (the median difference between observed vs predicted ESKD risks) and precision (the interquartile range of the bias) were used to select the best-calibrated KFRE equation.

RESULTS

The recalibrated KFRE (named Recalibrated Pooled KFRE SEA) performed better than existing and other recalibrated KFRE equations in terms of having a smaller Brier score (square root: 2.8% vs. 4.0-9.3% at 5 years; 2.0% vs. 6.1-9.1% at 2 years), less bias (2.5% vs. 3.3-5.2% at 5 years; 1.8% vs. 3.2-3.6% at 2 years), and improved precision (0.5% vs. 1.7-5.2% at 5 years; 0.5% vs. 3.8-4.2% at 2 years). Area under ROC curve for the Recalibrated Pooled KFRE SEA equations were 0.94 (95% confidence interval [CI]: 0.93 to 0.95) at 5 years and 0.96 (95% CI: 0.95 to 0.97) at 2 years. The optimally feasible KFRE thresholds were > 10-16% for 5-year nephrologist referral and > 45% for 2-year dialysis planning. Using the Recalibrated Pooled KFRE SEA, an estimated 82 and 89% ESKD events were included among 10% of subjects at highest estimated risk of ESKD at 5-year and 2-year, respectively.

CONCLUSIONS

The Recalibrated Pooled KFRE SEA performs better than existing KFREs and warrants implementation in primary care settings in SEA.

Impact of Kidney Function on Cardiovascular Risk and Mortality: A Comparison of South Asian and European Cohorts

BACKGROUND

Evidence is limited on ethnic differences in associations between kidney function markers and mortality or cardiovascular disease (CVD).

METHODS

Baseline cross-sectional analysis and longitudinal follow-up study of a UK population-based cohort of 1,116 Europeans and 1,104 South Asians of predominantly Indian descent, age 52 ± 7 years at baseline (1988-1991). Kidney function was estimated using Cystatin C and creatinine-based chronic kidney disease (CKD) Epidemiology Collaboration estimated glomerular filtration rate (eGFR) equations, and urinary albumin-creatinine ratio (ACR). Mortality was captured at 27 years, and incident CVD at 22 years, from death certification, medical records and participant report. Longitudinal associations between eGFR/ACR and mortality/incident CVD were examined using Cox models.

RESULTS

eGFRcys was lower and ACR higher in South Asians than Europeans. eGFRcys and -eGFRcreat were more strongly associated with outcomes in Europeans than South Asians. Conversely, associations between ACR and outcomes were greater in South Asians than Europeans, for example, for CVD mortality: HRs (95% CI) adjusted for CVD risk factors and ACR/eGFRcys as appropriate, p for ethnicity interaction: eGFRcys: Europeans: 0.76 (0.62-0.92), South Asians: 0.92 (0.78-1.07), p = 0.05, eGFRcreat: Europeans 0.81 (0.67-0.99), South Asians 1.18 (0.97-1.41), p = 0.002, ACR: -Europeans: 1.24 (1.08-1.42), South Asians: 1.39 (1.25-1.57), p= 0.23. Addition of all CKD measures to a standard CVD risk factor model modestly improved prediction capability in -Europeans; in South Asians only ACR contributed to improvement.

CONCLUSIONS

Strong associations between ACR and outcomes in South Asians of predominantly Indian origin, and null associations for eGFRcys and eGFRcreat, suggest that ACR may have greater utility in CVD risk prediction in South Asians. Further work is needed to validate these -findings.

Impact of chronic kidney disease on mortality: A nationwide cohort study

Background

Mortality is higher in patients with chronic kidney disease (CKD) than in the general population, but little information is available on CKD-related mortality that is representative of the Korean population. Our objective was to investigate mortality risk in Korean patients with CKD.

Methods

We identified patients with incident CKD who had not undergone dialysis or kidney transplantation between January 1, 2003 and December 31, 2007 in Korea using the database of the Korean National Health Insurance Service-National Sample Cohort, and stratified the population into the following three groups: group 1 (n = 1,473), controls; group 2 (n = 2,212), patients with diabetes or hypertension, but without CKD; and group 3 (n = 2,212), patients with CKD. We then monitored them for all-cause mortality until December 2013.

Results

A total of 1,473 patients were included in this analysis. During the follow-up period, 941 patients in group 3 died (134 deaths/1,000 person-years) compared with 550 deaths in the group 2 (34 deaths/1,000 person-years) and 459 deaths in group 1 (30 deaths/1,000 person-years). The rate ratio for mortality rate was 4.5, and the hazard ratio for mortality was 4.88 (95% confidence interval [CI], 4.36-5.47, P < 0.001) in patients in group 3 compared with age- and sex-matched controls (group 1). The rate ratio for mortality rate was 4.0, and the hazard ratio for mortality was 4.36 (95% CI, 3.92-4.85, P < 0.001) in patients in group 3 compared with patients in group 2.

Conclusion

In this nationally representative sample cohort, excess mortality was observed in Korean patients with incident CKD.

Validation of Self-Reported Race in a Canadian Provincial Renal Administrative Database

Background:

Administrative data are commonly used to study clinical outcomes in renal disease. Race is an important determinant of renal health delivery and outcomes in Canada but is not validated in most administrative data, and the correlation with census-based definitions of race is unknown.

Objectives:

Validation of self-reported race (SRR) in a Canadian provincial renal administrative database (Patient Records and Outcome Management Information System [PROMIS]) and comparison with the Canadian census categories of race.

Design:

Prospective patient survey study to validate SRR in PROMIS.

Setting:

British Columbia, Canada.

Patients:

Adult patients registered in PROMIS.

Measurements:

Survey SRR was used as gold standard to validate SRR in PROMIS. Self-reported race in PROMIS was compared with census race categories.

Methods:

This is a cross-sectional telephone survey of a random sample of all adults in PROMIS conducted between February 2016 and November 2016. Responders selected a race category from PROMIS and from the Canadian census. Sensitivity (Sn) and specificity (Sp) were calculated with 95% confidence intervals (CIs).

Results:

A total of 21 039 patients met inclusion criteria, 1677 were selected for the survey and 637 participated (38% response rate). There were no differences between the PROMIS, sampled, and responder populations. PROMIS SRR had an accuracy of 95.3% (95% CI: 94.2%-97.0%) when validated against the survey SRR with Sn and Sp ≥90% in all race groups except in Aboriginals (Sn 87.5%). The positive and negative predictive values were ≥95%, except in very low and high–prevalence groups, respectively. The Canadian census had an accuracy of 95.7% (95% CI: 94.4%-97.6%) when validated against PROMIS SRR with Sn and Sp ≥90%. The results did not differ in subgroups based on age, sex, birth outside Canada, or renal group (glomerulonephritis, chronic kidney disease, hemodialysis, peritoneal dialysis, transplant recipients, or live donors).

Limitations:

Analysis of minority groups and lower prevalence groups is limited by sample size. Results may not be generalizable to other administrative databases.

Conclusions:

We have shown high accuracy of PROMIS SRR that validates its use in the secondary analysis of administrative data for research. There is high correlation between PROMIS and census race categories which allows linkage with other data sources that use census-based definitions of race.

How do patients from South Asian backgrounds experience life on haemodialysis in the UK? A multicentre qualitative study

OBJECTIVES

End-stage kidney disease disproportionately affects people of South Asian origin. This study aimed to uncover the lived experiences of this group of patients on centre-based haemodialysis (HD), the most prevalent dialysis modality.

DESIGN

The study utilised a qualitative focus group methodology. Seven focus groups were conducted across four NHS Trusts in the UK including three in Gujarati and two each in Punjabi and Urdu. This provided an inclusive opportunity for South Asian patients to contribute in their language of origin. A total of 24 patients participated. Focus groups were facilitated by bilingual project workers and data were forward translated and analysed using thematic analysis.

RESULTS

Four themes were identified. This included (1) 'treatment imposition', which comprised of the restrictive nature of HD, the effects of treatment and the feeling of being trapped in an endless process. (2) The 'patient-clinician relationship' centred around the impact of a perceived lack of staff time, and inadequacies in the quality of interactions. (3) 'Coping strategies' highlighted the role of cognitive reappraisal, living in the moment and family support networks in facilitating adjustment. (4) 'Pursuit of transplantation' included equating this form of treatment with restoring normality, alongside cultural factors limiting hopefulness for receiving an organ.

CONCLUSIONS

In general, the experiences of South Asian patients receiving HD were not unique to this ethnic group. We did find distinct issues in relation to interactions with healthcare professionals, views on access to transplantation and the importance of family support networks. The study provides useful insights which may help enhance culturally tailored renal care.

Empagliflozin and kidney outcomes in Asian patients with type 2 diabetes and established cardiovascular disease: Results from the EMPA-REG OUTCOME® trial

AIMS/INTRODUCTION

In the EMPA-REG OUTCOME® trial, empagliflozin added to standard of care improved clinically relevant kidney outcomes by 39%, slowed progression of chronic kidney disease, and reduced albuminuria in patients with type 2 diabetes and established cardiovascular disease. This exploratory analysis investigated the effects of empagliflozin on the kidneys in Asian patients.

MATERIALS AND METHODS

Participants in the EMPA-REG OUTCOME® trial were randomized (1:1:1) to empagliflozin 10 mg, 25 mg or a placebo. In patients of Asian race, we analyzed incident or worsening nephropathy (progression to macroalbuminuria, doubling of serum creatinine, initiation of renal-replacement therapy or renal death) and its components, estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio changes, and renal safety.

RESULTS

Of 7,020 treated patients, 1,517 (26.1%) were Asian. In this subgroup, consistent with the overall trial population, empagliflozin reduced the risk of incident or worsening nephropathy (hazard ratio 0.64, 95% confidence interval 0.49-0.83), progression to macroalbuminuria (hazard ratio 0.64, 95% confidence interval 0.49-0.85) and the composite of doubling of serum creatinine, initiation of renal-replacement therapy or renal death (hazard ratio 0.48, 95% confidence interval 0.25-0.92). Furthermore, empagliflozin-treated participants showed slower eGFR decline versus placebo, and showed rapid urine albumin-to-creatinine ratio reduction at week 12, maintained through week 164, with effects most pronounced in those with baseline microalbuminuria or macroalbuminuria. The kidney safety profile of empagliflozin in the Asian subgroup was similar to the overall trial population.

CONCLUSIONS

In Asian patients from the EMPA-REG OUTCOME® trial, empagliflozin improved kidney outcomes, slowed eGFR decline and lowered albuminuria versus placebo, consistent with the overall trial population findings.

Short-Term Outcomes in Newly Diagnosed Atrial Fibrillation and Chronic Kidney Disease: How Important Is Ethnicity?

See Article by Goto et al.

Clinical Characteristics of Patients with Type 2 Diabetes Mellitus Receiving a Primary Total Knee or Hip Arthroplasty

AIM

The purpose of this study is to explore clinical characteristics of patients with T2DM receiving a primary knee (TKA) or hip (THA) arthroplasty to patients without T2DM receiving a TKA or THA and patients with T2DM with no history of osteoarthritis (OA).

METHODS

The study included a retrospective database review of 500 consecutive primary TKA or THA identified with ICD-9 codes and 100 consecutive T2DM patients. Patients who received a TKA or THA were screened for inclusion and exclusion and divided into with or without T2DM groups. A comparison group of patients with T2DM only without arthroplasty was screened to exclude patients with a history of OA or arthroplasty. All groups were compared based on demographic and relevant comorbidity differences. OA characteristics, including OA and previous arthroplasty of the involved and contralateral joints, were compared between patients with and without T2DM receiving a TKA or THA. Finally, patients with T2DM with and without TKA or THA were compared for T2DM differences.

RESULTS

Study results found that among those receiving a primary arthroplasty, patients with T2DM were more likely to be obese and older and reported cardiovascular, urinary, dyslipidemia, and peripheral neuropathy than those with T2DM. Among the T2DM individuals, those receiving an arthroplasty surgery were older and obese and more likely to report peripheral neuropathy; however, those with T2DM with no OA were more likely to report atherosclerosis and cardiovascular disease. Within the arthroplasty subgroup of individuals with T2DM, those requiring antidiabetic medication were 4.5 times more likely to have contralateral OA or arthroplasty.

CONCLUSIONS

The results of this study suggest that patients with T2DM requiring a primary arthroplasty are a unique subgroup that requires careful considerations as they are often older, have obesity, and specific comorbidities predisposing to worse postoperative outcomes than their non-T2DM arthroplasty counterparts. Therefore, clinical practice and future studies must consider strategies that would limit OA and arthroplasty management delays while accounting for comorbidities and patient characteristics.

Impaired mental health status in patients with chronic kidney disease is associated with estimated glomerular filtration rate decline

AIM

Deteriorated health-related quality of life (HRQOL) is associated with increased risk for death in both chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients; however, the impact of HRQOL on CKD progression is not well investigated.

METHODS

We aimed to evaluate the association between HRQOL and CKD progression in Japanese patients with CKD. One hundred and three outpatients who visited the department of nephrology at our hospital (mean estimated glomerular filtration rate (eGFR); 32.1 ± 11.2 mL/min per 1.73 m² ) between April 2007 and March 2012 were enrolled in this study. The primary outcome was 30% decline of eGFR or ESRD. We assessed HRQOL of all participants at baseline, including the physical component summary (PCS), the mental component summary (MCS) and the role/social component summary (RCS), using SF-36. Based on the baseline score of PCS, MCS and RCS, we divided all subjects into two groups by median.

RESULTS

We studied 66 men (64.1%) and 37 women aged 61.7 ± 10.0 years old. During approximately 2.5 years of follow-up period, 59 patients (57.3%) reached 30% eGFR decline or ESRD. Cox regression analyses demonstrated that lower MCS score was significantly associated with CKD progression (hazard ratio (HR) = 1.83, 95% CI = 1.04-3.21, P = 0.035), but that lower PCS score and RCS score were not (HR = 0.70, 95% CI = 0.39-1.25, P = 0.223; HR = 0.95, 95% CI = 0.54-1.67, P = 0.854, respectively).

CONCLUSION

We found that impaired mental health was associated with CKD progression. The evaluation of the mental health should be performed in the patients with CKD.

Atherosclerotic Cardiovascular Disease in South Asians in the United States: Epidemiology, Risk Factors, and Treatments: A Scientific Statement From the American Heart Association

South Asians (from Bangladesh, Bhutan, India, the Maldives, Nepal, Pakistan, and Sri Lanka) make up one quarter of the world's population and are one of the fastest-growing ethnic groups in the United States. Although native South Asians share genetic and cultural risk factors with South Asians abroad, South Asians in the United States can differ in socioeconomic status, education, healthcare behaviors, attitudes, and health insurance, which can affect their risk and the treatment and outcomes of atherosclerotic cardiovascular disease (ASCVD). South Asians have higher proportional mortality rates from ASCVD compared with other Asian groups and non-Hispanic whites, in contrast to the finding that Asian Americans (Asian Indian, Chinese, Filipino, Japanese, Korean, and Vietnamese) aggregated as a group are at lower risk of ASCVD, largely because of the lower risk observed in East Asian populations. Literature relevant to South Asian populations regarding demographics and risk factors, health behaviors, and interventions, including physical activity, diet, medications, and community strategies, is summarized. The evidence to date is that the biology of ASCVD is complex but is no different in South Asians than in any other racial/ethnic group. A majority of the risk in South Asians can be explained by the increased prevalence of known risk factors, especially those related to insulin resistance, and no unique risk factors in this population have been found. This scientific statement focuses on how ASCVD risk factors affect the South Asian population in order to make recommendations for clinical strategies to reduce disease and for directions for future research to reduce ASCVD in this population.

Ethnic differences in the progression of chronic kidney disease and risk of death in a UK diabetic population: an observational cohort study

OBJECTIVE

To determine ethnic differences in the progression of chronic kidney disease (CKD) and risk of end-stage renal failure (ESRF) and death in adults with type 2 diabetes mellitus (T2DM), and to identify predictors of rapid renal decline.

DESIGN

Observational community-based cohort study undertaken from 2006 to 2016 with nested case-control study.

SETTING

135 inner London primary care practices contributing to the east London Database.

PARTICIPANTS

General practice-registered adults aged 25-85 years with established T2DM and CKD at baseline.

OUTCOMES

The annual rate of renal decline was compared between white, south Asian and black groups, and stratified by proteinuria and raised blood pressure (BP) at baseline. Predictors of rapid renal decline were identified in a nested case-control study. Cox proportional hazards regression was used to determine ethnic differences in the risk of ESRF and death.

RESULTS

Age-sex adjusted annual decline was greatest in the Bangladeshi population. There was stepwise increase in the rate of decline when stratifying the cohort by baseline proteinuria and BP control, with south Asian groups being most sensitive to the combined effect of proteinuria and raised BP after accounting for key confounders.The odds of rapid renal decline were increased for individuals of Bangladeshi, African and Caribbean ethnicity, those with hypertension, proteinuria, cardiovascular disease and with increasing duration of diabetes. Rapid progression was more frequent in younger age groups. Risk of developing ESRF was highest in the black group compared with the white group (HR 1.88, 95% CI 1.11 to 3.19). Risk of death from any cause was 29% lower in the south Asian group compared with the white group (HR 0.71, 95% CI 0.56 to 0.91).

CONCLUSIONS

Proteinuria and hypertension trigger accelerated estimated glomerular filtration rate decline differentially by ethnicity. Active monitoring of younger adults, who have greater odds of rapid progression and the most to gain from interventions, is essential.

Analytic Considerations for Repeated Measures of eGFR in Cohort Studies of CKD

Repeated measures of various biomarkers provide opportunities for us to enhance understanding of many important clinical aspects of CKD, including patterns of disease progression, rates of kidney function decline under different risk factors, and the degree of heterogeneity in disease manifestations across patients. However, because of unique features, such as correlations across visits and time dependency, these data must be appropriately handled using longitudinal data analysis methods. We provide a general overview of the characteristics of data collected in cohort studies and compare appropriate statistical methods for the analysis of longitudinal exposures and outcomes. We use examples from the Chronic Renal Insufficiency Cohort Study to illustrate these methods. More specifically, we model longitudinal kidney outcomes over annual clinical visits and assess the association with both baseline and longitudinal risk factors.

Progression of chronic kidney disease: an illness-death model approach

BACKGROUND

Chronic kidney disease (CKD) is a major contributor to mortality in the general population. Understanding the factors that drive this process will help delay progression of CKD. The study aimed to estimate the risks of kidney failure and death prior to and after the development of kidney failure among patients with pre-existing CKD, and to identify potential prognostic factors.

METHOD

Data were obtained from patients with CKD from Ubon Ratchathani province, Thailand from 1997 to 2011. The probability of each transition (i.e., CKD➔death (T1), CKD➔kidney failure (T2), and kidney failure➔death (T3)) was estimated using a competing risk model. A parametric survival model with restricted cubic spline function was applied to assess prognostic factors. Illness-death models were constructed for the 3 transitions. Among 32,106 patients with CKD, 5576 (17.4%), 4768 (14.9%), and 3056 (9.5%) respectively moved through T1, T2, and T3.

RESULTS

Diabetics had 22.6%, 13.5%, and 60.7% higher risks of T1, T2, and T3 than non-diabetics respectively (p < 0.001). Hypertension increased risks of T2 and T3 by 8.7% (p = 0.01) and 27.2% (p < 0.001), whereas cardiovascular disease increased risk of T1 and T3 by 76% and 42.7%, respectively (p = 0.01). Increasing HDL by 10 units respectively decreased risk of T1 and T2 by 0.5% (p = 0.002) and 1.4% (p < 0.001). In addition, renin-angiotensin blockade decreased risk of T2 by 35% (p < 0.001).

CONCLUSIONS

Diabetes and cardiovascular disease are associated with increasing mortality among CKD patients both before and after the development of kidney failure while hypertension is associated with increasing mortality mainly following kidney failure. Diabetes and hypertension are associated with an elevated risk of kidney failure while elevated HDL levels and renin-angiotensin blockade appear protective.

Health-Related Quality of Life Impacts Mortality but Not Progression to End-Stage Renal Disease in Pre-Dialysis Chronic Kidney Disease: A Prospective Observational Study

Background

Chronic kidney disease (CKD) is associated with reduced health-related quality of life (HRQL). However, the relationship between pre-dialysis CKD, HRQL and clinical outcomes, including mortality and progression to end-stage renal disease (ESRD) is unclear.

Methods

All 745 participants recruited into the Renal Impairment In Secondary Care study to end March 2014 were included. Demographic, clinical and laboratory data were collected at baseline including an assessment of HRQL using the Euroqol EQ-5D-3L. Health states were converted into an EQ-5D_index score using a set of weighted preferences specific to the UK population. Multivariable Cox proportional hazards regression and competing risk analyses were undertaken to evaluate the association of HRQL with progression to ESRD or all-cause mortality. Regression analyses were then performed to identify variables associated with the significant HRQL components.

Results

Median eGFR was 25.8 ml/min/1.73 m² (IQR 19.6–33.7ml/min) and median ACR was 33 mg/mmol (IQR 6.6–130.3 mg/mmol). Five hundred and fifty five participants (75.7%) reported problems with one or more EQ-5D domains. When adjusted for age, gender, comorbidity, eGFR and ACR, both reported problems with self-care [hazard ratio 2.542, 95% confidence interval 1.222–5.286, p = 0.013] and reduced EQ-5D_index score [hazard ratio 0.283, 95% confidence interval 0.099–0.810, p = 0.019] were significantly associated with an increase in all-cause mortality. Similar findings were observed for competing risk analyses. Reduced HRQL was not a risk factor for progression to ESRD in multivariable analyses.

Conclusions

Impaired HRQL is common in the pre-dialysis CKD population. Reduced HRQL, as demonstrated by problems with self-care or a lower EQ-5D_index score, is associated with a higher risk for death but not ESRD. Multiple factors influence these aspects of HRQL but renal function, as measured by eGFR and ACR, are not among them.

Association of Skin Autofluorescence Levels With Kidney Function Decline in Patients With Peripheral Artery Disease

Objective—

Skin autofluorescence (SAF), a measure of advanced glycation end product accumulation, is associated with kidney function. We investigated the association of SAF with rate of kidney function decline in a cohort of patients with peripheral artery disease.

Approach and Results—

We performed a post hoc analysis of an observational longitudinal cohort study. We included 471 patients with peripheral artery disease, and SAF was measured at baseline. Primary end point was rate of estimated glomerular filtration rate (eGFR) decline. Secondary end points were incidence of eGFR <60 and <45 mL/min/1.73 m 2 and rapid eGFR decline, defined as a decrease in eGFR of >5 mL/min/1.73 m 2 /y. During a median follow-up of 3 years, the mean change in eGFR per year was −1.8±4.4 mL/min/1.73 m 2 /y. No significant difference in rate of eGFR decline was observed per 1 arbitrary unit increase in SAF (−0.1 mL/min/1.73 m 2 /y; 95% confidence interval, −0.7 to 0.5; P =0.8). Analyses of the secondary end points showed that there was an association of SAF with incidence of eGFR <60 and <45 mL/min/1.73 m 2 (hazard ratio, 1.54; 95% confidence interval, 1.13–2.10; P =0.006 and hazard ratio, 1.76; 95% confidence interval, 1.20–2.59; P =0.004, respectively), but after adjustment for age and sex, significance was lost. There was no association of SAF with rapid eGFR decline.

Conclusions—

In conclusion, in this cohort of patients with peripheral artery disease, elevated SAF was associated with lower baseline eGFR. Although SAF has previously been established as a predictor for cardiovascular disease and mortality, it did not predict the rate of kidney function decline during follow-up in this study.

Risk factors for CKD progression in Japanese patients: findings from the Chronic Kidney Disease Japan Cohort (CKD-JAC) study

BACKGROUND

Chronic kidney disease (CKD) eventually progresses to end-stage renal disease (ESRD). However, risk factors associated with CKD progression have not been well characterized in Japanese patients with CKD who are less affected with coronary disease than Westerners.

METHODS

A large-scale, multicenter, prospective, cohort study was conducted in patients with CKD and under nephrology care, who met the eligibility criteria [Japanese; age 20-75 years; and estimated glomerular filtration rate (eGFR): 10-59 mL/min/1.73 m²]. The primary endpoint was a composite of time to a 50 % decline in eGFR from baseline or time to the initiation of renal replacement therapy (RRT). The secondary endpoints were the rate of decline in eGFR from baseline, time to a 50 % decline in eGFR from baseline, time to the initiation of RRT, and time to doubling of serum creatinine (Cre) concentration.

RESULTS

2966 patients (female, 38.9 %; age, 60. 3 ± 11.6 years) were enrolled. The incidence of the primary endpoint increased significantly (P < 0.0001) in concert with CKD stage at baseline. The multivariate Cox proportional hazards models revealed that elevated systolic blood pressure (SBP) [hazard ratio (HR) 1.203, 95 % confidence interval (CI) 1.099-1.318)] and increased albumin-to-creatinine ratio (UACR ≥ 1000 mg/g Cre; HR: 4.523; 95 % CI 3.098-6.604) at baseline were significantly associated (P < 0.0001, respectively) with the primary endpoint.

CONCLUSIONS

Elevated SBP and increased UACR were risk factors that were significantly associated with CKD progression to ESRD in Japanese patients under nephrology care. UMIN clinical trial registry number: UMIN000020038.

Smaller kidney size at birth in South Asians: findings from the Born in Bradford birth cohort study

BACKGROUND

Rates of advanced chronic kidney disease and renal replacement therapy are higher in South Asian than in white British populations. Low birth weight is also more frequent in South Asian populations and has been associated with increased risks of kidney disease, perhaps due to a reduced nephron endowment.

METHODS

Using ultrasound scans at 34 weeks of gestation, we measured fetal kidney dimensions (transverse and anteroposterior diameters, length and circumference) and derived volume in a random sample of 872 white British and 715 South Asian participants in the Born in Bradford cohort study. Kidney measurements were compared between ethnic groups.

RESULTS

Birth weight for gestational age at 40 weeks was 200 g less in South Asian babies compared with white British babies. The mean kidney volume for gestational age was 16% lower in South Asian than in white British babies [8.79 versus 10.45 cm(3), difference 1.66 cm(3) (95% confidence interval 1.40-1.93, P < 0.001)]. The difference was robust after adjustment for maternal age, socio-economic factors, marital status, body mass index, smoking and alcohol use in pregnancy, parity, baby's gender and birth weight for gestational age [adjusted difference 1.38 cm(3) (0.97-1.84), P < 0.001]. There were smaller reductions in other fetal measures.

CONCLUSION

South Asian babies have smaller kidneys compared with white British babies, even after adjusting for potential confounders including birth weight. This finding may contribute to increased risks of adult kidney disease in South Asian populations.

Impact of weaning from acute dialytic therapy on outcomes of chronic kidney disease following urgent-start dialysis

Discontinuation of acute, unplanned dialysis is always an important therapeutic goal in dialysis-requiring patients with existing chronic kidney disease. Only a limited proportion of patients could be weaned off dialysis and remained dialysis-free. Here we performed a multicenter, observational study to investigate factors associated with successful weaning from acute dialysis, and to explore the potential impact of weaning itself on outcomes of patients with chronic kidney disease following urgent-start dialysis. We recruited 440 chronic kidney disease patients with a baseline estimated glomerular filtration rate <45 ml/min per 1/73 m2, and used propensity score-adjusted Cox regression analysis to measure the effect of weaning from acute dialysis on death during the index hospitalization and death or readmission after discharge. Over 2 years, 64 of 421 (15.2%) patients who survived >1 month died, and 36 (8.6%) were removed from dialysis, with 26 (6.2%) remaining alive and dialysis-free. Logistic regression analysis found that age ≧ 65 years, ischemic acute tubular necrosis, nephrotoxic exposure, urinary obstruction, and higher predialysis estimated glomerular filtration rate and serum hemoglobin were predictors of weaning off dialysis. After adjustment for propensity scores for dialysis weaning, Cox proportional hazards models showed successful weaning from dialysis (adjusted hazard ratio 0.06; 95% confidence interval 0.01 to 0.35), along with a history of hypertension and serum albumin, were independent protectors for early death. Conversely, a history of stroke, peripheral arterial disease and cancer predicted the occurrence of early mortality. In conclusion, this prospective cohort study shows that compared to patients with chronic kidney disease who became end-stage renal disease after acute dialysis, patients who could be weaned off acute dialytic therapy were associated with reduced risk of premature death over a 2-year observation period.

The effect of delayed graft function on graft and patient survival in kidney transplantation: an approach using competing events analysis

OBJECTIVE

In kidney transplantation, the impact of delayed graft function (DGF) on long-term graft and patient survival is controversial. We examined the impact of DGF on graft and recipient survival by accounting for the possibility that death with graft function may act as a competing risk for allograft failure.

STUDY DESIGN AND SETTING

We used data from 1281 adult primary deceased-donor kidney recipients whose allografts functioned at least 1 year.

RESULTS

The probability of graft loss occurrence is overestimated using the complement of Kaplan-Meier estimates (1-KM). Both the cause-specific Cox proportional hazard regression model (standard Cox) and the subdistribution hazard regression model proposed by Fine and Gray showed that DGF was associated with shorter time to graft failure (csHR = 2.0, P = 0.002; sHR = 1.57, P = 0.009), independent of acute rejection (AR) and after adjusting for traditional factors associated with graft failure. Regarding patient survival, DGF was a predictor of patient death using the cause-specific Cox model (csHR = 1.57, P = 0.029) but not using the subdistribution model.

CONCLUSIONS

The probability of graft loss from competing end points should not be reported with the 1-KM. Application of a regression model for subdistribution hazard showed that, independent of AR, DGF has a detrimental effect on long-term graft survival, but not on patient survival.

The impact of social disadvantage in moderate-to-severe chronic kidney disease: an equity-focused systematic review*

It is unclear whether a social gradient in health outcomes exists for people with moderate-to-severe chronic kidney disease (CKD). We critically review the literature for evidence of social gradients in health and investigate the ‘suitability’ of statistical analyses in the primary studies. In this equity-focused systematic review among adults with moderate-to-severe CKD, factors of disadvantage included gender, race/ethnicity, religion, education, socio-economic status or social capital, occupation and place of residence. Outcomes included access to healthcare, kidney disease progression, cardiovascular events, all-cause mortality and suitability of analyses. Twenty-four studies in the pre-dialysis population and 34 in the dialysis population representing 8.9 million people from 10 countries were included. In methodologically suitable studies among pre-dialysis patients, a significant social gradient was observed in access to healthcare for those with no health insurance and no home ownership. Low income and no home ownership were associated with higher cardiovascular event rates and higher mortality [HR 1.94, 95% confidence interval (CI) 1.27–2.98; HR 1.28, 95% CI 1.04–1.58], respectively. In methodologically suitable studies among dialysis patients, females, ethnic minorities, those with low education, no health insurance, low occupational level or no home ownership were significantly less likely to access cardiovascular healthcare than their more advantaged dialysis counterparts. Low education level and geographic remoteness were associated with higher cardiovascular event rates and higher mortality (HR 1.54, 95% CI 1.01–2.35; HR 1.21, 95% CI 1.08–1.37), respectively. Socially disadvantaged pre-dialysis and dialysis patients experience poorer access to specialist cardiovascular health services, and higher rates of cardiovascular events and mortality than their more advantaged counterparts.

Renal replacement therapy in Brunei Darussalam: comparing standards with international renal registries

BACKGROUND AND AIM

Brunei Darussalam is a small South East Asian country with a high prevalence and incidence of end stage kidney disease (ESRD). This study aims to compare key performance indicators recorded in the Brunei Dialysis and Transplant Registry and department records against international practice. Registries from the USA (USRDS), UK (UK Renal Registry), Australasia (ANZDATA), Europe (ERA-EDTA Registry) and Malaysia (MDTR) were used for comparisons.

METHODS AND RESULTS

Haemodialysis (83%) and renal transplantation (6%) were the most and least favoured modality of renal replacement therapy in Brunei. Diabetes mellitus as a cause of ESRD (57%) was high in Brunei but on par with other South East Asian countries. Dialysis death rates (11%) and living-related transplant survival rates (5 year graft and patient survival 91% and 96% respectively) were favourable compared with other registries. Anaemia and mineral bone disease management were similar to Malaysia but slightly inferior to the others, but generally in keeping with KDOQI and KDIGO targets. Haemodialysis adequacy (48% achieving urea reduction ratio of >65%) was relatively poorer due to poor dialysis flow rates and low fistula usage (71%). Peritoneal dialysis peritonitis (24.5 patient-month/episode) and adequacy (78% achieving kt/v of 1.7) were in keeping with ISPD targets and international registries' results.

CONCLUSION

Brunei has achieved reasonable and commendable standards in many areas pertaining to the renal services. This report has identified several key areas for developments but this is to be expected for a service making its first foray into international benchmarked practice.

Incidence of end stage renal disease among type 1 diabetes: a nationwide cohort study in Taiwan

The aim of our study was to estimate the risk of end-stage renal disease (ESRD) in type 1 diabetes mellitus (T1DM) in Taiwanese people; in addition, our goal was to determine how the age, year, and sex at registration of T1DM affects the risk. Population-based cohort study. A nationwide cohort study of 7203 Taiwanese patients with T1DM registered in 1999 to 2010 was followed up until ESRD, death, or the end of follow-up on December 31, 2010. Annual age-, sex-, and calendar year-specific incidence rates of ESRD of the general population were used to calculate the standardized incidence ratio (SIR) of ESRD in relation to T1DM. The SIR of ESRD for male and female patients with T1DM was significantly increased at 25.85 (95% CI 23.40-28.29) and 28.08 (95% 25.45-30.71), respectively; the peak was at age 15 to 29 years for both genders. The cumulative incidence of ESRD was similar in male and female patients but was significantly higher in patients≥ 30 years old than in patients<30 years old (10.25% vs. 3.57%, P<0.001). Patients aged <15 years had a significantly lower risk of ESRD as compared to those aged 15 to 29 years; patients aged 30 to 44 (adjusted HR, 1.491) and 45 to 60 years (adjusted HR, 2.111) showed significantly increased hazards. Our data also demonstrated a lower risk of ESRD in patients who were registered in later years than in earlier years. The risk of ESRD is substantially increased in T1DM in the ethnic Chinese population. The continuously declining risk of ESRD in T1DM may advocate the use of a multidisciplinary chronic kidney disease care system in Taiwan.

Analysis of risk factors associated with renal function trajectory over time: a comparison of different statistical approaches

BACKGROUND

The most commonly used methods to investigate risk factors associated with renal function trajectory over time include linear regression on individual glomerular filtration rate (GFR) slopes, linear mixed models and generalized estimating equations (GEEs). The objective of this study was to explain the principles of these three methods and to discuss their advantages and limitations in particular when renal function trajectories are not completely observable due to dropout.

METHODS

We generated data from a hypothetical cohort of 200 patients with chronic kidney disease at inclusion and seven subsequent annual measurements of GFR. The data were generated such that both baseline level and slope of GFR over time were associated with baseline albuminuria status. In a second version of the dataset, we assumed that patients systematically dropped out after a GFR measurement of <15 mL/min/1.73 m(2). Each dataset was analysed with the three methods.

RESULTS

The estimated effects of baseline albuminuria status on GFR slope were similar among the three methods when no patient dropped out. When 32.7% dropped out, standard GEE provided biased estimates of the mean GFR slope in normo-, micro- and macroalbuminuric patients. Linear regression on individual slopes and linear mixed models provided slope estimates of the same magnitude, likely because most patients had at least three GFR measurements. However, the linear mixed model was the only method to provide effect estimates on both slope and baseline level of GFR unaffected by dropout.

CONCLUSION

This study illustrates that the linear mixed model is the preferred method to investigate risk factors associated with renal function trajectories in studies, where patients may dropout during the study period because of initiation of renal replacement therapy.

Estimating time to ESRD using kidney failure risk equations: results from the African American Study of Kidney Disease and Hypertension (AASK)

BACKGROUND

Planning for renal replacement therapy, such as referral for arteriovenous fistula placement and transplantation, often is guided by level of estimated glomerular filtration rate (eGFR). The use of risk equations might enable more accurate estimation of time to end-stage renal disease (ESRD), thus improving patient care.

STUDY DESIGN

Prospective observational study.

SETTING & PARTICIPANTS

1,094 participants in the African American Study of Kidney Disease and Hypertension (AASK) cohort.

PREDICTOR

Age, sex, urine protein-creatinine ratio ≥ 1g/g, APOL1 high-risk status, and 3-year antecedent eGFR decline.

OUTCOME

Cumulative incidence of ESRD from 5 different starting points: eGFR of 30 and 15mL/min/1.73m(2) and 1-year ESRD risk of 5%, 10%, and 20%, estimated by a published 4-variable kidney failure risk equation.

RESULTS

566 participants developed eGFR of 30mL/min/1.73m(2), 244 developed eGFR of 15mL/min/1.73m(2), and 437, 336, and 259 developed 1-year ESRD risks of 5%, 10%, and 20%, respectively. The 1-year cumulative incidence of ESRD was 4.3% from eGFR of 30mL/min/1.73m(2), 49.0% from eGFR of 15mL/min/1.73m(2), 6.7% from 5% ESRD risk, 15.0% from 10% ESRD risk, and 29% from 20% ESRD risk. From eGFR of 30mL/min/1.73m(2), there were several risk factors that predicted ESRD risk. From eGFR of 15mL/min/1.73m(2), only level of proteinuria did; median time to ESRD was 9 and 19 months in those with higher and lower proteinuria, respectively. Median times were less variable from corresponding ESRD risk thresholds. For example, median times to ESRD from 20% ESRD risk were 22 and 25 months among those with higher and lower proteinuria, respectively.

LIMITATIONS

Relatively homogeneous population of African Americans with hypertensive kidney disease.

CONCLUSIONS

Results of the present study suggest the potential benefit of incorporating kidney failure risk equations into clinical care, with selection of a specific threshold guided by its intended use.

Relative risks of chronic kidney disease for mortality and end-stage renal disease across races are similar

Some suggest race-specific cutpoints for kidney measures to define and stage chronic kidney disease (CKD), but evidence for race-specific clinical impact is limited. To address this issue, we compared hazard ratios of estimated glomerular filtration rates (eGFR) and albuminuria across races using meta-regression in 1.1 million adults (75% Asians, 21% Whites, and 4% Blacks) from 45 cohorts. Results came mainly from 25 general population cohorts comprising 0.9 million individuals. The associations of lower eGFR and higher albuminuria with mortality and end-stage renal disease (ESRD) were largely similar across races. For example, in Asians, Whites, and Blacks, the adjusted hazard ratios (95% confidence interval) for eGFR 45-59 versus 90-104 ml/min per 1.73 m(2) were 1.3 (1.2-1.3), 1.1 (1.0-1.2), and 1.3 (1.1-1.7) for all-cause mortality, 1.6 (1.5-1.7), 1.4 (1.2-1.7), and 1.4 (0.7-2.9) for cardiovascular mortality, and 27.6 (11.1-68.7), 11.2 (6.0-20.9), and 4.1 (2.2-7.5) for ESRD, respectively. The corresponding hazard ratios for urine albumin-to-creatinine ratio 30-299 mg/g or dipstick 1+ versus an albumin-to-creatinine ratio under 10 or dipstick negative were 1.6 (1.4-1.8), 1.7 (1.5-1.9), and 1.8 (1.7-2.1) for all-cause mortality, 1.7 (1.4-2.0), 1.8 (1.5-2.1), and 2.8 (2.2-3.6) for cardiovascular mortality, and 7.4 (2.0-27.6), 4.0 (2.8-5.9), and 5.6 (3.4-9.2) for ESRD, respectively. Thus, the relative mortality or ESRD risks of lower eGFR and higher albuminuria were largely similar among three major races, supporting similar clinical approach to CKD definition and staging, across races.

Effect of dialysis initiation timing on clinical outcomes: a propensity-matched analysis of a prospective cohort study in Korea

BACKGROUND

Controversy persists regarding the appropriate initiation timing of renal replacement therapy for patients with end-stage renal disease. We evaluated the effect of dialysis initiation timing on clinical outcomes. Initiation times were classified according to glomerular filtration rate (GFR).

METHODS

We enrolled a total of 1691 adult patients who started dialysis between August 2008 and March 2013 in a multi-center, prospective cohort study at the Clinical Research Center for End Stage Renal Disease in the Republic of Korea. The patients were classified into the early-start group or the late-start group according to the mean estimated GFR value, which was 7.37 ml/min/1.73 m2. The primary outcome was patient survival, and the secondary outcomes were hospitalization, cardiovascular events, vascular access complications, change of dialysis modality, and peritonitis. The two groups were compared before and after matching with propensity scores.

RESULTS

Before propensity score matching, the early-start group had a poor survival rate (P<0.001). Hospitalization, cardiovascular events, vascular access complications, changes in dialysis modality, and peritonitis were not different between the groups. A total of 854 patients (427 in each group) were selected by propensity score matching. After matching, neither patient survival nor any of the other outcomes differed between groups.

CONCLUSIONS

There was no clinical benefit after adjustment by propensity scores comparing early versus late initiation of dialysis.