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

Consequences of low estimated glomerular filtration rate either before or early after kidney donation

In the general population, decreases in glomerular filtration rate (GFR) are associated with subsequent development of chronic kidney disease (CKD), cardiovascular disease (CVD), and death. It is unknown if low estimated GFR (eGFR) before or early after kidney donation was also associated with these risks. One thousand six hundred ninety-nine living donors who had both predonation and early (4-10 weeks) postdonation eGFR were included. We studied the relationships between eGFR, age at donation, and the time to sustained eGFR<45 (CKD stage 3b) and <30 mL/min/1.73m2 (CKD stage 4), hypertension, diabetes mellitus (DM), CVD, and death. Median follow-up was 12 (interquartile range, 6-21) years. Twenty-year event rates were 5.8% eGFR<45 mL/min/1.73m2; 1.2% eGFR<30 mL/min/1.73m2; 29.0% hypertension; 7.8% DM; 8.0% CVD; and 5.2% death. The median time to eGFR<45 mL/min/1.73m2 (N = 79) was 17 years, and eGFR<30 mL/min/1.73m2 (N = 22) was 25 years. Both low predonation and early postdonation eGFR were associated with eGFR<45 mL/min/1.73m2 (P < .0001) and eGFR<30 mL/min/1.73m2 (P < .006); however, the primary driver of risk for all ages was low postdonation (rather than predonation) eGFR. Predonation and postdonation eGFR were not associated with hypertension, DM, CVD, or death. Low predonation and early postdonation eGFR are risk factors for developing eGFR<45 mL/min/1.73m2 (CKD stage 3b) and <30 mL/min/1.73m2 (CKD stage 4), but not CVD, hypertension, DM, or death.

Has the time come for age-adapted glomerular filtration rate criteria to define chronic kidney disease: how soon is now?

PURPOSE OF REVIEW

The conventional definition of chronic kidney disease (CKD) primarily relies on the identification of albuminuria or a decline in estimated glomerular filtration rate (eGFR). For many years, a straightforward eGFR threshold of <60 ml/min/1.73 m 2 has been widely adopted as the standard for defining CKD. Nonetheless, this criterion fails to consider the natural aging process of the kidney, and this oversight may affect the accurate diagnosis of kidney disease particularly at the extremes of age.

RECENT FINDINGS

The fixed eGFR threshold of <60 ml/min/1.73 m 2 for defining CKD misses crucial opportunities for risk prevention. Studies have revealed that the eGFR threshold at which the risks for adverse long-term health outcomes such as mortality, cardiovascular events, and kidney failure begin to rise varies substantially by age. Specifically, this threshold is lower for the elderly and higher for young adults. Consequently, this results in the over-diagnosis of kidney disease in the elderly and the under-diagnosis of kidney disease in young adults.

SUMMARY

To address these limitations of the current CKD definition, we discuss a number of proposed age-adapted eGFR criteria and weigh their pros and cons against the current, simple, and universally accepted approach.

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.

Validation of the kidney failure risk equation in a Portuguese cohort

INTRODUCTION

In chronic kidney disease (CKD) patients, the risk of kidney replacement therapy (KRT) is highly variable. In 2011, Tangri et al. developed the kidney failure risk equations (KFRE) to predict the 2 and 5-year probability of requiring kidney replacement therapy (KRT). The KFRE is an easily calculated 4-variable equation which has been extensively validated in multiple cohorts. The aim of this study was to validate this risk score in a Portuguese cohort.

METHODS

We conducted a retrospective analysis of CKD patients stage 3-5 referred for nephrology consult at Centro Hospitalar Universitário Lisboa Norte during the first 6 months of 2018. Age, gender, estimated glomerular filtration rate (eGFR) and albuminuria were assessed. The 4-variable kidney failure risk equation (KFRE) calibrated to a non-North American population was calculated. Requirement of KRT was assessed in a 2-year follow-up. We assessed the Cox logistic regression method of the KFRE to predict KRT requirement and the discriminatory ability was determined using the receiver operating characteristic (ROC) curve. A cut-off value was defined as that with the highest validity.

RESULTS

360 patients were included and 54.4% were male. Mean age was 74.9±12.2 years, serum creatinine was 1.97±0.84mg/dL, eGFR was 33.4±12.13ml/min/1.73m2 and albuminuria was 571.1±848.3mg/g. Mean calculated risk score was 6.2±11.2%. Twenty-three patients required KRT (6.4%) in the two-year follow-up. The hazard ratio was 1.1 [95% CI (1.06-1.12), p<0.001] for the 2-year risk of KRT. The KFRE predicted progression to KRT requirement with an auROC of 0.903, [95% CI (0.86-0.95), p<0.001], with a sensitivity 91.3% and specificity of 71.8%. The optimal KFRE cut-off was >4.5% for 2-year nephrologist referral, with an hazard ratio of HR 26.7 [95% CI (6.15-116.3), p<0.001] for 2-year risk of KRT requirement.

DISCUSSION

We have independently externally validated the 2-year KFRE and shown that it has excellent discrimination. The KFRE should be incorporated in clinical care of patients with CKD to improve patient-clinician dialogue and provide guidance on timing of referral for nephrology evaluation and planning for dialysis access.

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.

Vaccination and mortality from COVID-19: a comparative study between hemodialysis, peritoneal dialysis, and non-dialysis adult population in Panama

PURPOSE

Dialysis patients have a different response than the non-dialysis population to infection with COVID-19. This study evaluates the prevalence of infection and lethality in patients receiving hemodialysis or peritoneal dialysis in Panama, compared to non-dialysis adult population, and reports of adverse events of vaccination.

METHODS

This is a prospective, multi-center cohort study of spatients aged 18 years or older and receiving in-center hemodialysis or ambulatory peritoneal dialysis in 13 centers in Panama from March 2021 to 2022. For comparison with general population, the study used an extended period of two years.

RESULTS

A total of 1531 patients receiving dialysis treatment accepted to participate. PD patients represented an 18% of study patients. Lethality was higher in peritoneal dialysis patients with COVID-19 infection than in hemodialysis in the study group (p 0.02). Total deaths in dialysis patients for 2020 were 156 patients, before vaccination; 79 in 2021; and 25 for the first trimester of 2022. Lethality for the period of 2020-2022 was 9.3% for dialysis patients and 0.2% for non-dialysis population. There was no difference in symptoms in first dose, but with second dose, hemodialysis patients reported fewer symptoms than peritoneal dialysis patients (p < 0.0001).

CONCLUSION

Ninety one percent of people in the country received BNT162b2 Pfizer BionTech vaccine. Lethality decreased from 30 to 5% once vaccination was available. There were no severe adverse effects and symptoms reported were less frequent than in general population, probably due to low reactogenicity in dialysis patients, or better tolerance to pain.

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.

Case-Fatality and Temporal Trends in Patients with Psoriasis and End-Stage Renal Disease

Background and Objectives: During the last decades, growing evidence corroborates that chronic inflammatory disease impairs the body beyond the cutaneous barrier. Linkage between psoriasis and kidney disease, and in particular between psoriasis and end-stage renal disease (ESRD), have not yet been elucidated. We sought to analyze the impact of concomitant psoriasis on the in-hospital outcomes of patients hospitalized with ESRD. Patients and Methods: We analyzed data on characteristics, comorbidities, and in-hospital outcomes of all hospitalized patients with ESRD stratified for concomitant psoriasis in the German nationwide in-patient sample between 2010 and 2020. Results: Overall, 360,980 hospitalizations of patients treated for ESRD in German hospitals were identified from 2010 to 2020 and among these 1063 patients (0.3%) additionally suffered from psoriasis. While the annual number of all ESRD patients increased within this time, the number of patients with ESRD and the additional psoriasis diagnosis decreased slightly. Patients with ESRD and psoriasis were five years younger (66 [IQR, 56−75] vs. 71 [59−79] years, p < 0.001), were more often obese (17.5% vs. 8.2%, p < 0.001) and more frequently had cancer (4.9% vs. 3.3%, p < 0.001), diabetes mellitus (42.7% vs. 38.5%, p = 0.005) and coronary artery disease (31.1% vs. 28.0%, p = 0.026). Multivariate regression models demonstrated that psoriasis was not associated with in-hospital case-fatality in patients with ESRD (OR 1.02 (95%CI 0.78−1.33), p = 0.915). Conclusions: ESRD patients with the concomitant psoriasis diagnosis were hospitalized on average 5 years earlier than patients without psoriasis. A higher prevalence of severe life-shortening comorbidities including coronary artery disease and cancer was detected in ESRD patients with psoriasis despite their younger age. Our findings support the understanding of psoriasis as an autoimmune skin disease crossing the boundary between dermatology and internal medicine.

Aspirin to target arterial events in chronic kidney disease (ATTACK): study protocol for a multicentre, prospective, randomised, open-label, blinded endpoint, parallel group trial of low-dose aspirin vs. standard care for the primary prevention of cardiovascular disease in people with chronic kidney disease

Background

Chronic kidney disease (CKD) is a very common long-term condition and powerful risk factor for cardiovascular disease (CVD).

Low-dose aspirin is of proven benefit in the secondary prevention of myocardial infarction (MI) and stroke in people with pre-existing CVD. However, in people without CVD, the rates of MI and stroke are much lower, and the benefits of aspirin in the primary prevention of CVD are largely balanced by an increased risk of bleeding.

People with CKD are at greatly increased risk of CVD and so the absolute benefits of aspirin are likely to be greater than in lower-risk groups, even if the relative benefits are the same. Post hoc evidence suggests the relative benefits may be greater in the CKD population but the risk of bleeding may also be higher. A definitive study of aspirin for primary prevention in this high-risk group, recommended by the National Institute for Health and Care Excellence (NICE) in 2014, has never been conducted. The question has global significance given the rising burden of CKD worldwide and the low cost of aspirin.

Methods

ATTACK is a pragmatic multicentre, prospective, randomised, open-label, blinded endpoint adjudication superiority trial of aspirin 75 mg daily vs. standard care for the primary prevention of CVD in 25,210 people aged 18 years and over with CKD recruited from UK Primary Care.

Participants aged 18 years and over with CKD (GFR category G1-G4) will be identified in Primary Care and followed up using routinely collected data and annual questionnaires for an average of 5 years. The primary outcome is the time to first major vascular event (composite of non-fatal MI, non-fatal stroke and cardiovascular death [excluding confirmed intracranial haemorrhage and other fatal cardiovascular haemorrhage]). Deaths from other causes (including fatal bleeding) will be treated as competing events. The study will continue until 1827 major vascular events have occurred. The principal safety outcome is major intracranial and extracranial bleeding; this is hypothesised to be increased in those randomised to take aspirin. The key consideration is then whether and to what extent the benefits of aspirin from the expected reduction in CVD events exceed the risks of major bleeding.

Discussion

This will be the first definitive trial of aspirin for primary CVD prevention in CKD patients. The research will be of great interest to clinicians, guideline groups and policy-makers, in the UK and globally, particularly given the high and rising prevalence of CKD that is driven by population ageing and epidemics of obesity and diabetes. The low cost of aspirin means that a positive result would be of relevance to low- and middle-income countries and the impact in the developed world less diluted by any inequalities in health care access.

Trial registration

ISRCTN: ISRCTN40920200. EudraCT: 2018-000644-26. ClinicalTrials.gov: NCT03796156

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06132-z.

Chronic kidney disease biomarkers and mortality among older adults: A comparison study of survey samples in China and the United States

OBJECTIVES

Among older adults in China and the US, we aimed to compare the biomarkers of chronic-kidney-diseases (CKD), factors associated with CKD, and the correlation between CKD and mortality.

SETTING

China and the US.

STUDY DESIGN

Cross-sectional and prospective cohorts.

PARTICIPANTS

We included 2019 participants aged 65 and above from the Chinese Longitudinal Healthy Longevity Study (CLHLS) in 2012, and 2177 from US National Health and Nutrition Examination Survey (NHANES) in 2011-2014.

OUTCOMES

Urinary albumin, urinary creatinine, albumin creatinine ratio (ACR), serum creatinine, blood urea nitrogen, plasma albumin, uric acid, and estimated glomerular filtration rate (eGFR). CKD (ACR ≥ 30 mg/g or eGFR< 60 ml/min/1.73m2) and mortality.

ANALYTICAL APPROACH

Logistic regression and Cox proportional hazard models. Covariates included age, sex, race, education, income, marital status, health condition, smoking and drinking status, physical activity and body mass index.

RESULTS

Chinese participants had lower levels of urinary albumin, ACR, and uric acid than the US (mean: 25.0 vs 76.4 mg/L, 41.7 vs 85.0 mg/g, 292.9 vs 341.3 μmol/L). In the fully-adjusted model, CKD was associated with the risk of mortality only in the US group (hazard ratio [HR], 95% CI: 2.179, 1.561-3.041 in NHANES, 1.091, 0.940-1.266 in CLHLS). Compared to eGFR≥90, eGFR ranged 30-44 ml/min/1.73m2 was only associated with mortality in the US population (HR, 95% CI: 2.249, 1.141-4.430), but not in the Chinese population (HR, 95% CI: 1.408, 0.884-2.241).

CONCLUSIONS

The elderly participants in the US sample had worse CKD-related biomarker levels than in China sample, and the association between CKD and mortality was also stronger among the US older adults. This may be due to the biological differences, or co-morbid conditions.

Development of the simulation-based German albuminuria screening model (S-GASM) for estimating the cost-effectiveness of albuminuria screening in Germany

Background

Chronic kidney disease is often asymptomatic in its early stages but constitutes a severe burden for patients and causes major healthcare systems costs worldwide. While models for assessing the cost-effectiveness of screening were proposed in the past, they often presented only a limited view. This study aimed to develop a simulation-based German Albuminuria Screening Model (S-GASM) and present some initial applications.

Methods

The model consists of an individual-based simulation of disease progression, considering age, gender, body mass index, systolic blood pressure, diabetes, albuminuria, glomerular filtration rate, and quality of life, furthermore, costs of testing, therapy, and renal replacement therapy with parameters based on published evidence. Selected screening scenarios were compared in a cost-effectiveness analysis.

Results

Compared to no testing, a simulation of 10 million individuals with a current age distribution of the adult German population and a follow-up until death or the age of 90 shows that a testing of all individuals with diabetes every two years leads to a reduction of the lifetime prevalence of renal replacement therapy from 2.5% to 2.3%. The undiscounted costs of this intervention would be 1164.10 € / QALY (quality-adjusted life year). Considering saved costs for renal replacement therapy, the overall undiscounted costs would be—12581.95 € / QALY. Testing all individuals with diabetes or hypertension and screening the general population reduced the lifetime prevalence even further (to 2.2% and 1.8%, respectively). Both scenarios were cost-saving (undiscounted, - 7127.10 €/QALY and—5439.23 €/QALY).

Conclusions

The S-GASM can be used for the comparison of various albuminuria testing strategies. The exemplary analysis demonstrates cost savings through albuminuria testing for individuals with diabetes, diabetes or hypertension, and for population-wide screening.

Risk Factors for Progression of CKD with and without Diabetes

OBJECTIVE

We aim to identify independent risk factors to predict CKD progression to end stage renal disease (ESRD) in patients with or without diabetes.

METHODS

In this retrospective study, we enrolled CKD stage 3-4 patients between January 2013 and December 2018 and followed them until December 2020 or the initiation of dialysis. We used Kaplan-Meier to plot the survival curve. Univariate and multivariable Cox proportional hazards model was used to explore risk factors affecting the progression of CKD. The final model was used to construct nomogram for predicting CKD progression. Calibration plots and concordance index (C-index) were used to evaluate the accuracy and discrimination of the risk model.

RESULTS

We enrolled 309 CKD patients, including 80 cases in G3a, 98 cases in G3b, and 131 cases in G4. Among them, 141 patients had diabetes and 168 did not. The mean age of patients at enrolled was 57.86 ± 15.10 years, and 67% were male. The median follow-up time was 25.6 months. There were 81 patients (26.2%) that started dialysis in the total CKD cohort, 52 cases (36.9%) in the CKD with diabetes group, and 29 cases (17.3%) in the CKD without diabetes group. Hypoalbuminemia (HR =2.655, P < 0.001), proteinuria (HR =2.592, P = 0.042), increased LDL (HR =2.494, P < 0.001), diabetes (HR =2.759, P < 0.001), hypertension (HR =3.471, P = 0.037), and CKD stage (HR =2.001, P = 0.046) were risk factors for CKD progression to ESRD in the overall population. For those without diabetes, only hypoalbuminemia (HR =2.938, P = 0.030) was a risk factor for CKD progression to ESRD. For those with diabetes, both hypoalbuminemia (HR =2.758, P = 0.002), the increased level of LDL (HR =3.982, P < 0.001), and CKD stage (HR =3.781, P = 0.001) were risk factors for CKD progression to ESRD. The C-index of the final nomograms was 0.760 (P < 0.001).

CONCLUSIONS

The results from our risk factor model suggest that CKD disease progression can be predicted and early strategic intervention is necessary for CKD patients to avoid renal function deterioration.

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.

Cardiovascular complications after COVID-19 in chronic kidney disease, dialysis and kidney transplant patients

The coronavirus disease 2019 (COVID-19) is associated with increased mortality in patients with chronic kidney disease (CKD), dialysis patients and kidney transplant recipients (KTR). Cardiovascular complications, such as sudden arrhythmias, thromboembolic events, coronary events, cardiomyopathies and heart failure, may present in about 10–20% of patients with COVID-19. Patients with CKD, dialysis patients and KTR are all at increased cardiovascular risk and present with more cardiovascular complications after COVID-19 compared to the general population. During the pandemic, health care giving has rapidly changed by reducing elective outpatient reviews, which may refrain these high-risk patients from the appropriate management of their medical conditions, further increasing cardiovascular risk. Importantly, acute kidney injury (AKI) is another common complication of severe COVID-19 and associates with increased mortality. A large proportion of the AKI patients need renal replacement treatment, while 30% of them may not present renal function recovery and remain dialysis-dependent after discharge, thereby having potentially increased future cardiovascular risk. This review summarizes current knowledge regarding the cardiovascular events and mortality in patients with CKD or undergoing hemodialysis and in KTR.

Chronic kidney disease measures for cardiovascular risk prediction

Chronic kidney disease (CKD) affects 15-20% of adults globally and causes various complications, one of the most important being cardiovascular disease (CVD). CKD has been associated with many CVD subtypes, especially severe ones like heart failure, independent of potential confounders such as diabetes and hypertension. There is no consensus in major clinical guidelines as to how to incorporate the two key measures of CKD (glomerular filtration rate and albuminuria) for CVD risk prediction. This is a critical missed opportunity to appropriately refine predicted risk and personalize prevention therapies according to CKD status, particularly since these measures are often already evaluated in clinical care. In this review, we provide an overview of CKD definition and staging, the subtypes of CVD most associated with CKD, major pathophysiological mechanisms, and the current state of CKD as a predictor of CVD in major clinical guidelines. We will introduce the novel concept of a "CKD Add-on", which allows the incorporation of CKD measures in existing risk prediction models, and the implications of taking into account CKD in the management of CVD risk.

Healthy lifestyle reduces incidence of trace/positive proteinuria and rapid kidney function decline after 2 years: from the Japan Ningen Dock study

BACKGROUND

Lifestyle modification is recommended for subjects with trace proteinuria during health checkups. However, whether overall healthy lifestyle reduces the incidence of trace/positive proteinuria or rapid decline in estimated glomerular filtration rate (eGFR) is not clarified.

METHODS

A total of 451 534 people (277 494 men and 174 040 women) ages 20-79 years with negative proteinuria were included. The number of three healthy lifestyle factors (LFs) was assessed: noncurrent smoking, healthy eating habits (late dinner, snacking and skipping breakfast <3 times/week) and body mass index <25. The incidence of trace (±) and positive (≥1+) proteinuria by the dipstick method and eGFR decline ≥20% over 2 years were compared with the number of healthy LFs.

RESULTS

The incidence of trace/positive proteinuria and rapid eGFR decline decreased with an increasing number of healthy LFs as follows: odds ratios (ORs) for trace proteinuria, 0.91 [95% confidence interval (CI) 0.86-0.96], 0.82 (0.78-0.87) and 0.72 (0.68-0.77); ORs for positive proteinuria, 0.76 (95% CI 0.67-0.86), 0.56 (0.50-0.63) and 0.46 (0.40-0.53); and ORs for an eGFR decline ≥20%, 0.93 (95% CI 0.82-1.05), 0.90 (0.79-1.02) and 0.81 (0.70-0.93) for those with one, two and three healthy LFs compared with those with none of the three healthy LFs, respectively. Overall, subjects with a healthy lifestyle showed 28, 54 and 19% reduced risk of developing trace proteinuria, positive proteinuria and eGFR decline ≥20%, respectively, compared with those with an unhealthy lifestyle after 2 years. This association was similarly observed even among subjects without hypertension (HT) or diabetes mellitus (DM).

CONCLUSIONS

Subjects with an overall healthy lifestyle showed a lower incidence of trace/positive proteinuria by dipstick test and rapid eGFR decline over 2 years in a nationwide general population. Thus lifestyle modification should be recommended for subjects with trace proteinuria during health checkups, even for subjects without HT or DM.

Presentation and outcome of chronic kidney disease in Italian and immigrant citizens: results from the Emilia-Romagna PIRP project

INTRODUCTION

In recent decades, high income countries (HIC) have been exposed to huge human migratory flows. Consistent with this influx, there has been a dramatic increase in the number of chronic kidney disease (CKD) patients in the immigrant population. In Italy, comparisons between Italian and immigrant CKD patients are still lacking, thus we aimed to describe the baseline clinical characteristics and the main outcomes of CKD patients who immigrated to Italy and reside in the Emilia Romagna region.

METHODS

This is a retrospective cohort study based on CKD patients from the Prevenzione Insufficienza Renale Progressiva (PIRP) project, which included 963 (3.1%) immigrants among the 30,702 patients seen by nephrologists between April 1st, 2004 and June 30th, 2020. We sub-divided the immigrants into seven groups based on their area of origin, and compared their baseline characteristics, CKD progression and time to end-stage kidney disease (ESKD) to those of Italian CKD patients.

RESULTS

At presentation, Italian subjects were on average older (73.1 years) and had less preserved kidney function (eGFR 34.3 ml/min), while South and East Asians had the highest proportion of diabetes and obesity (approximately 45% and 30%, respectively). At 4-year follow-up, about 20% of patients from South Asia, Eastern Europe and Arab Countries were diagnosed with ESKD, compared to only 11% of Italians and Latin Americans.

CONCLUSIONS

We found important differences between Italian and immigrant CKD patients, as well as among immigrant subgroups. First clinical encounters with nephrologists revealed that immigrants had varied patterns of clinical presentation and of nephropathy. During follow-up, immigrants showed faster kidney function decline which led to a higher risk of disease evolution and progression towards ESKD.

Reclassification of chronic kidney disease patients for end-stage renal disease risk by proteinuria indexed to estimated glomerular filtration rate: multicentre prospective study in nephrology clinics

BACKGROUND

In non-dialysis chronic kidney disease (CKD), absolute proteinuria (Uprot) depends on the extent of kidney damage and residual glomerular filtration rate (GFR). We therefore evaluated, as compared with Uprot, the strength of association of proteinuria indexed to estimated GFR (eGFR) with end-stage renal disease (ESRD) risk.

METHODS

In a multi-cohort prospective study in 3957 CKD patients of Stages G3-G5 referred to nephrology clinics, we tested two multivariable Cox models for ESRD risk, with either Uprot (g/24 h) or filtration-adjusted proteinuria (F-Uprot) calculated as Uprot/eGFR ×100.

RESULTS

Mean ± SD age was 67 ± 14 years, males 60%, diabetics 29%, cardiovascular disease (CVD) 34%, eGFR 32 ± 13 mL/min/1.73 m2, median (interquartile range) Uprot 0.41 (0.12-1.29) g/24 h and F-Uprot 1.41 (0.36-4.93) g/24 h per 100 mL/min/1.73 m2 eGFR. Over a median follow-up of 44 months, 862 patients reached ESRD. At competing risk analysis, ESRD risk progressively increased when F-Uprot was 1.0-4.9 and ≥5.0 versus <1.0 g/24 h per 100 mL/min/1.73 m2 eGFR in Stages G3a-G4 (P < 0.001) and Stage G5 (P = 0.002). Multivariable Cox analysis showed that Uprot predicts ESRD in Stages G3a-G4 while in G5 the effect was not significant; conversely, F-Uprot significantly predicted ESRD at all stages. The F-Uprot model allowed a significantly better prediction versus the Uprot model according to Akaike information criterion. Net reclassification improvement was 12.2% (95% confidence interval 4.2-21.1), with higher reclassification in elderly, diabetes and CVD, as well as in diabetic nephropathy and glomerulonephritis, and in CKD Stages G4 and G5.

CONCLUSIONS

In patients referred to nephrology clinics, F-Uprot predicts ESRD at all stages of overt CKD and improves, as compared with Uprot, reclassification of patients for renal risk, especially in more advanced and complicated disease.

Physicians' Recognition and Management of Kidney Disease: A Randomized Vignette Study Evaluating the Impact of the KDIGO 2012 CKD Classification System

Rationale & Objective

The Kidney Disease Outcome Quality Initiative (KDOQI) and Kidney Disease: Improving Global Outcomes (KDIGO) chronic kidney disease (CKD) classification systems published in 2002 and 2012, respectively, are recommended worldwide and based on strong epidemiologic data. However, their impact on CKD recognition and management is not well evaluated in clinical practice, and we therefore investigated whether they help physicians recognize and appropriately care for patients with CKD.

Study Design

Randomized vignette experiment with fractional factorial design based on 6 kidney-related scenarios and 3 laboratory presentation methods reflecting the CKD guidelines. Participants evaluated 1 of 3 subsets of the 18 vignettes (ie, 6 vignettes each with 4 answer alternatives).

Setting & Participants

249 interns, general practitioners, and residents/fellows attending postgraduate meetings and courses in Norway and the United States.

Intervention

Kidney-related results (serum creatinine level and urinary albumin excretion) were presented as the “minimal data” (high/low levels), KDOQI-2002 (estimated glomerular filtration rate [eGFR] reported automatically), or KDIGO-2012 (eGFR + albuminuria categorization + risk for complications) laboratory report.

Outcome

CKD management choice by physicians.

Results

When kidney laboratory data were presented as the KDOQI-2002 report (automatic eGFR calculation), there was a significantly higher odds for correct patient management decisions compared with the minimal data report (OR, 1.57; P < 0.001). Additional significant improvement was obtained with the KDIGO-2012 report (OR, 2.28 for correct answer vs minimal data report [P < 0.001]; OR, 1.45 compared to KDOQI-2002 report [P = 0.005]). The KDIGO classification system improved physician management in 4 of the 6 clinical scenarios covering a wide range of kidney-related topics. Interaction analysis showed that general practitioners and those with 1 to 3 years of internal medicine experience had the greatest improvements with the new presentation techniques.

Limitations

Physicians’ management was evaluated by theoretical scenarios rather than direct patient care.

Conclusions

Automatic GFR estimation, albuminuria categorization, and notification of the associated risk for complications improve most physicians` recognition and management of a wide range of CKD clinical scenarios.

Non-diabetic end-stage renal disease in Saudis associated with polymorphism of MYH9 gene but not UMOD gene

The prevalence of risk factors of chronic kidney disease in Saudi Arabia has augmented an already serious public health problem, therefore, determination of genetic variants associated with the risk of the disease presents potential screening tools that help reducing the incidence rates and promote effective disease management.The aim of the present study is to determine the association of UMOD and MYH9 genetic variants with the risk of non-diabetic end-stage renal disease (ESRD) in the Saudi population.Two single nucleotide polymorphisms (SNP), rs12917707 in gene UMOD and rs4821480 in gene MYH9 were genotyped in 154 non-diabetic ESRD Saudi patients and 123 age-matched healthy controls using Primers and Polymerase chain reaction conditions (PCR), Sanger sequencing, and TaqMan Pre-designed SNP Genotyping Assay. The association of these genetic variants with the risk of the disease and other renal function determinants was assessed using statistical tools such as logistic regression and One-way Analysis of Variance tests.The genotypic frequency of the two SNPs showed no deviation from Hardy-Weinberg equilibrium, the minor allele frequency of UMOD SNP was 0.13 and MYH9 SNP was 0.08. rs4821480 in MYH9 was significantly associated with the risk of non-diabetic ESRD (OR = 3.86; 95%CI: 1.38-10.82, P value .010), while, rs12917707 showed lack of significant association with the disease, P value .380. and neither of the 2 SNPs showed any association with the renal function determinants, serum albumin, and alkaline phosphatase enzyme.

Effects of lower versus higher phosphate diets on fibroblast growth factor-23 levels in patients with chronic kidney disease: a systematic review and meta-analysis

Background

Elevated fibroblast growth factor-23 (FGF23) levels increase the risk of cardiovascular diseases in patients with chronic kidney disease (CKD). We aimed to compare the effects of different dietary interventions, lower versus higher phosphate levels, on FGF23 in patients with CKD.

Methods

We conducted electronic literature searches of Medline, PubMed, Embase and the Cochrane Library for publications up to 29 October 2016 for randomized clinical trials that compared lower versus higher phosphate dietary interventions in adults with CKD. The primary outcome was the difference in change-from-baseline FGF23 levels between intervention groups. Considering the difference in measurement units between intact FGF23 and C-terminal FGF23 assays, the treatment effect was analysed as the standardized mean difference (SMD) with the 95% confidence interval (CI).

Results

We identified five trials enrolling a total of 94 normophosphataemic patients with Stage 3B CKD. The study duration ranged from 1 to 12 weeks. Compared with higher phosphate diets, lower phosphate diets tended to reduce FGF23 levels (SMD -0.74, 95% CI -1.54 to 0.07, P = 0.07). Subgroup analyses showed a trend (P for interaction = 0.09) towards a better FGF23-lowering effect by lower phosphate diets in studies using the intact FGF23 assay (SMD -1.14, 95% CI -2.24 to -0.04) than those using the C-terminal FGF23 assay (SMD -0.05, 95% CI -0.67 to 0.57).

Conclusions

Short-term dietary phosphate restriction tends to reduce FGF23 levels in patients with moderately decreased kidney function, and the FGF23-lowering effects tend to be more prominent when measured with the intact FGF23 assay.

CKD: A Call for an Age-Adapted Definition

Current criteria for the diagnosis of CKD in adults include persistent signs of kidney damage, such as increased urine albumin-to-creatinine ratio or a GFR below the threshold of 60 ml/min per 1.73 m2 This threshold has important caveats because it does not separate kidney disease from kidney aging, and therefore does not hold for all ages. In an extensive review of the literature, we found that GFR declines with healthy aging without any overt signs of compensation (such as elevated single-nephron GFR) or kidney damage. Older living kidney donors, who are carefully selected based on good health, have a lower predonation GFR compared with younger donors. Furthermore, the results from the large meta-analyses conducted by the CKD Prognosis Consortium and from numerous other studies indicate that the GFR threshold above which the risk of mortality is increased is not consistent across all ages. Among younger persons, mortality is increased at GFR <75 ml/min per 1.73 m2, whereas in elderly people it is increased at levels <45 ml/min per 1.73 m2 Therefore, we suggest that amending the CKD definition to include age-specific thresholds for GFR. The implications of an updated definition are far reaching. Having fewer healthy elderly individuals diagnosed with CKD could help reduce inappropriate care and its associated adverse effects. Global prevalence estimates for CKD would be substantially reduced. Also, using an age-specific threshold for younger persons might lead to earlier identification of CKD onset for such individuals, at a point when progressive kidney damage may still be preventable.

Primary care physicians' perceptions of barriers and facilitators to management of chronic kidney disease: A mixed methods study

BACKGROUND

Given the high prevalence of chronic kidney disease (CKD), primary care physicians (PCPs) frequently manage early stage CKD. Nonetheless, there are challenges in providing optimal CKD care in the primary care setting. This study sought to understand PCPs' perceptions of barriers and facilitators to the optimal management of CKD.

STUDY DESIGN

Mixed methods study.

SETTINGS AND PARTICIPANTS

Community-based PCPs in four US cities: Baltimore, MD; St. Louis, MO; Raleigh, NC and San Francisco, CA.

METHODOLOGY

We used a self-administered questionnaire and conducted 4 focus groups of PCPs (n = 8 PCPs/focus group) in each city to identify key barriers and facilitators to management of patients with CKD in primary care.

ANALYTIC APPROACH

We conducted descriptive analyses of the survey data. Major themes were identified from audio-recorded interviews that were transcribed and coded by the research team.

RESULTS

Of 32 participating PCPs, 31 (97%) had been in practice for >10 years, and 29 (91%) practiced in a non-academic setting. PCPs identified multiple barriers to managing CKD in primary care including at the level of the patient (e.g., low awareness of CKD, poor adherence to treatment recommendations), the provider (e.g., staying current with CKD guidelines), and the health care system (e.g., inflexible electronic medical record, limited time and resources). PCPs desired electronic prompts and lab decision support, concise guidelines, and healthcare financing reform to improve CKD care.

CONCLUSIONS

PCPs face substantial but modifiable barriers in providing care to patients with CKD. Interventions that address these barriers and promote facilitative tools may improve PCPs' effectiveness and capacity to care for patients with CKD.

The future for diagnostic tests of acute kidney injury in critical care: evidence synthesis, care pathway analysis and research prioritisation

BACKGROUND

Acute kidney injury (AKI) is highly prevalent in hospital inpatient populations, leading to significant mortality and morbidity, reduced quality of life and high short- and long-term health-care costs for the NHS. New diagnostic tests may offer an earlier diagnosis or improved care, but evidence of benefit to patients and of value to the NHS is required before national adoption.

OBJECTIVES

To evaluate the potential for AKI in vitro diagnostic tests to enhance the NHS care of patients admitted to the intensive care unit (ICU) and identify an efficient supporting research strategy.

DATA SOURCES

We searched ClinicalTrials.gov, The Cochrane Library databases, Embase, Health Management Information Consortium, International Clinical Trials Registry Platform, MEDLINE, metaRegister of Current Controlled Trials, PubMed and Web of Science databases from their inception dates until September 2014 (review 1), November 2015 (review 2) and July 2015 (economic model). Details of databases used for each review and coverage dates are listed in the main report.

REVIEW METHODS

The AKI-Diagnostics project included horizon scanning, systematic reviewing, meta-analysis of sensitivity and specificity, appraisal of analytical validity, care pathway analysis, model-based lifetime economic evaluation from a UK NHS perspective and value of information (VOI) analysis.

RESULTS

The horizon-scanning search identified 152 potential tests and biomarkers. Three tests, Nephrocheck^® (Astute Medical, Inc., San Diego, CA, USA), NGAL and cystatin C, were subjected to detailed review. The meta-analysis was limited by variable reporting standards, study quality and heterogeneity, but sensitivity was between 0.54 and 0.92 and specificity was between 0.49 and 0.95 depending on the test. A bespoke critical appraisal framework demonstrated that analytical validity was also poorly reported in many instances. In the economic model the incremental cost-effectiveness ratios ranged from £11,476 to £19,324 per quality-adjusted life-year (QALY), with a probability of cost-effectiveness between 48% and 54% when tests were compared with current standard care.

LIMITATIONS

The major limitation in the evidence on tests was the heterogeneity between studies in the definitions of AKI and the timing of testing.

CONCLUSIONS

Diagnostic tests for AKI in the ICU offer the potential to improve patient care and add value to the NHS, but cost-effectiveness remains highly uncertain. Further research should focus on the mechanisms by which a new test might change current care processes in the ICU and the subsequent cost and QALY implications. The VOI analysis suggested that further observational research to better define the prevalence of AKI developing in the ICU would be worthwhile. A formal randomised controlled trial of biomarker use linked to a standardised AKI care pathway is necessary to provide definitive evidence on whether or not adoption of tests by the NHS would be of value.

STUDY REGISTRATION

The systematic review within this study is registered as PROSPERO CRD42014013919.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Genetic risk score raises the risk of incidence of chronic kidney disease in Korean general population-based cohort

BACKGROUND

Chronic kidney disease (CKD) is a common disease, affecting about 10% of the general population. The genetic component about CKD incidence in Asian population is not well known. The aim of the study is to find the genetic loci associated with incident CKD and to figure out the effect of genetic variation on the development of CKD.

METHODS

We conducted a genome-wide association (GWA) study regarding the development of CKD based on two population-based cohorts of Korean Genome Epidemiology Study. 3617 Koreans from two different cohorts, aged 40-49 years without CKD at initial visit, were included in our analysis. We used 2510 individuals in Ansan as the discovery set and another 1107 individuals from Ansung as the replication set. At baseline, members of both cohorts provided information on creatinine, and DNA samples were collected for genotyping. Single nucleotide polymorphisms that surpassed a significance threshold of P < 5 × 10^-3 were selected.

RESULTS

A total of 281 among 3617 developed CKD during the follow-up period. Incident CKD group was older (P < 0.001), included more female (P < 0.001), and had more hypertension and diabetes (P < 0.001). We identified 12 SNPs that are associated with incident CKD in the GWA study and made genetic risk score using these SNPs. In multiple Cox regression analysis, genetic risk score was still a significant associated factor (HR 1.311, CI 1.201, 1.431, P < 0.001).

CONCLUSIONS

We identified several loci highly associated with incident CKD. The findings suggest the need for further investigations on the genetic propensity for incident CKD.

Trace proteinuria by dipstick screening is associated with metabolic syndrome, hypertension, and diabetes

BACKGROUND

The purpose of this study is to determine the association of dipstick-determined trace proteinuria with metabolic syndrome (MetS) and its components in each age, gender, and eGFR category among a large general population.

METHODS

A total of 270,190 people (102,223 men and 167,967 women) aged 40-74 years were included. Subjects were categorized as having negative, trace, and positive proteinuria by the dipstick method.

RESULTS

The prevalence of MetS increased with increasing levels of proteinuria in any estimated glomerular filtration rate (eGFR) category (odds ratios for MetS relative to negative proteinuria: 1.22, 1.23, and 1.25 for trace proteinuria, and 2.19, 1.81, and 1.80 for positive proteinuria among subjects with eGFR of ≥ 90, 60-89, and 45-59 ml/min/1.73 m², respectively). These associations were statistically significant in each age and sex category. Among MetS components, the prevalence of hypertension and diabetes increased with increasing levels of proteinuria (odds ratios for hypertension: 1.23 and 1.87, and odds ratios for diabetes: 1.28 and 2.18 for trace and positive proteinuria, respectively), which were similarly observed in any eGFR category. There were little or no differences in the prevalence of abdominal obesity and dyslipidemia (reduced HDL-cholesterol and/or elevated triglycerides) between the levels of proteinuria.

CONCLUSION

Subjects with dipstick-determined trace proteinuria showed intermediate risk of having MetS, hypertension, and diabetes between negative and positive proteinuria in any eGFR category in a large general population. Thus, MetS components should be checked for subjects with trace proteinuria even in those with normal eGFR for the early prevention of cardiovascular diseases.

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.

Mortality risk of chronic kidney disease: A comparison between the adult populations in urban China and the United States

BACKGROUND

Chronic kidney disease (CKD) is a risk factor for all-cause mortality in the United States, but the evidence from China is limited. We investigate whether prognosis of CKD (mortality) differs between the two countries. In particular, we sought to compare the strength of association between CKD stage and all-cause mortality, by country.

METHODS

Mortality-linked data from China National Survey of Chronic Kidney Disease (urban population, n = 25,269) and US NHANES (2005-2010, n = 15,209) for adults >20 years old were analyzed. The Chinese cohort was followed until Dec 31, 2013, while the NHANES cohort until Dec 31, 2011. CKD was defined by eGFR <60ml/min/1.73m2 or albuminuria (defined as ACR ≥30mg/g). Weighted Cox models were used to evaluate the association between the two CKD indicators and mortality. Both stratified and combined models (with country interactions) were explored.

RESULTS

The Chinese sample had a lower proportion of eGFR<60 ml/min/1.73m2 (3.7% vs. 6.9%) and albuminuria (7.6% vs. 9.0%), compared to the US. Higher rates of mortality were observed with higher stages of CKD in both countries. HRs for mortality in the more advanced CKD categories reached 2.18 (1.14-4.15) in China and 1.66 (1.18-2.32) in the US in the absence of albuminuria, and 2.30 (1.13-4.68) and 3.04 (2.33-3.96) in the presence of albuminuria. No significant interactions were detected between country and these categories.

CONCLUSION

The association between albuminuria and reduced eGFR and all-cause mortality was similar in both countries, with albuminuria being associated with the larger effect size compared to lower eGFR.

Do attributes of persons with chronic kidney disease differ in low-income and middle-income countries compared with high-income countries? Evidence from population-based data in six countries

Kidney biopsies to elucidate the cause of chronic kidney disease (CKD) are performed in a minority of persons with CKD living in high-income countries, since associated conditions—that is, diabetes mellitus, vascular disease or obesity with pre-diabetes, prehypertension or dyslipidaemia—can inform management targeted at slowing CKD progression in a majority. However, attributes of CKD may differ substantially among persons living in low-income and middle-income countries (LMICs). We used data from population or community-based studies from five LMICs (China, urban India, Moldova, Nepal and Nigeria) to determine what proportion of persons with CKD living in diverse regions fit one of the three major clinical profiles, with data from the US National Health Nutrition and Examination Survey as reference. In the USA, urban India and Moldova, 79.0%–83.9%; in China and Nepal, 62.4%–66.7% and in Nigeria, 51.6% persons with CKD fit one of three established risk profiles. Diabetes was most common in urban India and vascular disease in Moldova (50.7% and 33.2% of persons with CKD in urban India and Moldova, respectively). In Nigeria, 17.8% of persons with CKD without established risk factors had albuminuria ≥300 mg/g, the highest proportion in any country. While the majority of persons with CKD in LMICs fit into one of three established risk profiles, the proportion of persons who have CKD without established risk factors is higher than in the USA. These findings can inform tailored CKD detection and management systems and highlight the importance of studying potential causes and outcomes of CKD without established risk factors in LMICs.

Risk scores to predict decreased glomerular filtration rate at 10 years in an Asian general population

BACKGROUND

Asians have among the highest prevalence of chronic kidney disease (CKD) or end-stage renal disease in the world. A risk score capable of identifying high risk individuals at the primary care level could allow targeted therapy to prevent future development of CKD. Risk scores for new CKD have been developed in US general populations, but the impact of various risks factors for development of CKD may differ in Asian subjects. In this study, we aimed to develop risk models and simplified risk scores to predict the development of decreased glomerular filtration rate (GFR) at 10 years in an Asian general population using readily obtainable clinical and laboratory parameters.

METHODS

Employees of EGAT (The Electric Generating Authority of Thailand) were studied prospectively. Multivariable logistic regression models were used to assess risk factors and used to derive risk models and risk scores for developing decreased GFR at 10 years: Model 1 (Clinical only), Model 2 (Clinical + Limited laboratory tests), and Model 3 (Clinical + Full laboratory tests). The performance of the risk models or risk scores to predict incident cases with decreased GFR were evaluated by tests of calibration and discrimination.

RESULTS

Of 3186 subjects with preserved GFR (eGFR ≥60) at baseline, 271 (8.5%) developed decreased GFR (eGFR < 60) at 10 years. Model 1 (Age, sex, systolic blood pressure, history of diabetes, and waist circumference) had good performance (χ2 = 9.02; AUC = 0.72). Model 2 (Age, Sex, systolic blood pressure, diabetes, glomerular filtration rate) had better discrimination (χ2 = 10.87, AUC = 0.79) than Model 1. Model 3 (Model 2+ Uric acid, Hemoglobin) did not provide significant improvement over Model 2. Based on these findings, simplified categorical risk scores were developed for Models 1 and 2.

CONCLUSIONS

Clinical or combined clinical and laboratory risk models or risk scores using tests readily available in a resource-limited setting had good accuracy and discrimination power to estimate the 10-year probability of developing decreased GFR in a Thai general population. The benefits of the risk scores in identifying high risk individuals in the Thai or other Asian communities for special intervention requires further studies.

Dual kidney transplant techniques: A systematic review

BACKGROUND

Dual kidney transplantation (DKT) was developed to improve outcomes from transplantation of extended criteria donors (ECD). This study examined which surgical techniques have been reported for DKT and whether any technique had superior patient and graft survival.

METHOD

Electronic databases were searched for published studies mapping to MESH terms: "kidney or renal" AND "transplan*" AND "dual or double." Single case reports, studies of patients less than 18 years old, studies which did not describe the surgical technique, and studies that did not report patient or graft survival were excluded.

RESULTS

Fifteen reports of 434 DKT recipients were identified. Three techniques were described: bilateral placement; unilateral placement with separate anastomoses; and unilateral placement with patch anastomoses. Patient survival across all three techniques was over 95% at 1 year, and graft survival was also similar at over 90%. Rates of delayed graft function were between 20% and 30% across all techniques.

CONCLUSION

The three techniques have equivalent delayed graft function as well as patient and graft survival rates. This is an encouraging result as it means that the surgeon can choose to use the technique which is most appropriate for their own skills and for the patient.

Race and contrast-induced nephropathy in patients undergoing coronary angiography and cardiac catheterization

Contrast-induced nephropathy (CIN) is an acute worsening of renal function after receiving intravascular contrast during a procedure. Some of the predisposing factors include underlying diabetes, chronic kidney disease, congestive heart failure, periprocedural hypotension, anemia, contrast volume, and osmolality of contrast; however, it remains unclear if risk varies for CIN with race and ethnicity. There is evidence in the literature showing the link between race/ethnicity and the discrepancies in the utilization of preventive care services and the resources related to cardiovascular and renal health. While these disparities continue to exist and affect some of the predictors of CIN, this review will explore the extent to which race and ethnicity directly affect CIN.

Chronic kidney disease and cardiovascular risk in six regions of the world (ISN-KDDC): a cross-sectional study

BACKGROUND

Chronic kidney disease is an important cause of global mortality and morbidity. Data for epidemiological features of chronic kidney disease and its risk factors are limited for low-income and middle-income countries. The International Society of Nephrology's Kidney Disease Data Center (ISN-KDDC) aimed to assess the prevalence and awareness of chronic kidney disease and its risk factors, and to investigate the risk of cardiovascular disease, in countries of low and middle income.

METHODS

We did a cross-sectional study in 12 countries from six world regions: Bangladesh, Bolivia, Bosnia and Herzegovina, China, Egypt, Georgia, India, Iran, Moldova, Mongolia, Nepal, and Nigeria. We analysed data from screening programmes in these countries, matching eight general and four high-risk population cohorts collected in the ISN-KDDC database. High-risk cohorts were individuals at risk of or with a diagnosis of either chronic kidney disease, hypertension, diabetes, or cardiovascular disease. Participants completed a self-report questionnaire, had their blood pressure measured, and blood and urine samples taken. We defined chronic kidney disease according to modified KDIGO (Kidney Disease: Improving Global Outcomes) criteria; risk of cardiovascular disease development was estimated with the Framingham risk score.

FINDINGS

75,058 individuals were included in the study. The prevalence of chronic kidney disease was 14·3% (95% CI 14·0-14·5) in general populations and 36·1% (34·7-37·6) in high-risk populations. Overall awareness of chronic kidney disease was low, with 409 (6%) of 6631 individuals in general populations and 150 (10%) of 1524 participants from high-risk populations aware they had chronic kidney disease. Moreover, in the general population, 5600 (44%) of 12,751 individuals with hypertension did not know they had the disorder, and 973 (31%) of 3130 people with diabetes were unaware they had that disease. The number of participants at high risk of cardiovascular disease, according to the Framingham risk score, was underestimated compared with KDIGO guidelines. For example, all individuals with chronic kidney disease should be considered at high risk of cardiovascular disease, but the Framingham risk score detects only 23% in the general population, and only 38% in high-risk cohorts.

INTERPRETATION

Prevalence of chronic kidney disease was high in general and high-risk populations from countries of low and middle income. Moreover, awareness of chronic kidney disease and other non-communicable diseases was low, and a substantial number of individuals who knew they were ill did not receive treatment. Prospective programmes with repeat testing are needed to confirm the diagnosis of chronic kidney disease and its risk factors. Furthermore, in general, health-care workforces in countries of low and middle income need strengthening.

FUNDING

International Society of Nephrology.

Risk of end-stage renal disease in Japanese patients with chronic kidney disease increases proportionately to decline in estimated glomerular filtration rate

Predominantly based on North American and European studies, 30% to 40% declines in estimated glomerular filtration rate (eGFR) over a few years are strongly associated with the risk of end-stage renal disease (ESRD) and have been proposed as surrogate endpoints of ESRD for clinical research. However, this association has not been systematically quantified in Asian populations. To do this we studied adult Japanese patients with baseline eGFR 10-59 ml/min/1.73m². Changes in eGFR from baseline measured by centrally assessed serum creatinine were linked to subsequent ESRD in 2410 patients after one year and in 2079 patients after year 2. After year 1, 1.4% experienced a 53% decrease in eGFR (equivalent to doubling of serum creatinine), whereas 4.3% and 9.7% had eGFR decrease of 40% or 30% or more, respectively. The corresponding numbers after 2 years were 4.2%, 10.9%, and 19.3%, respectively. After year 1 baseline period, 498 patients developed ESRD over a median follow-up of 2.9 years (365 ESRD cases over a median follow-up of 2 years after year 2). In year 1, after accounting for potential confounders, a strong linear association was found between eGFR declines and subsequent ESRD, with adjusted hazard ratios of 20.7 (95% confidence interval 14.3-30.1) for a 53% decrease, 9.6 (7.4-12.5) for a 40% decrease, and 5.3 (4.1-6.9) for a 30% decrease compared to no change. Corresponding hazard ratios for year two analysis were 17.3 (11.8-25.3), 6.5 (4.7-9.1), and 3.1 (2.2-4.4), respectively. The associations were consistent across demographics and kidney diseases. Thus, 30% to 40% declines in eGFR are strongly associated with the risk of ESRD in Japanese patients with reduced eGFR, broadening global implications as a surrogate endpoint in clinical research.

Diabetic nephropathy: where are we on the journey from pathophysiology to treatment?

Diabetic nephropathy affects 30-40% of people with diabetes, and is the leading cause of end-stage kidney disease. The current treatment paradigm relies on early detection, glycaemic control and tight blood pressure management with preferential use of renin-angiotensin system blockade. This strategy has transformed outcomes in diabetic kidney disease over the last 20 years. Over the last two decades we have also witnessed significant advances in the understanding of the pathophysiology of diabetic nephropathy; however, despite this new knowledge, we have yet to develop new treatments of proven efficacy. Whilst a continued emphasis on preclinical and clinical research is clearly needed, clinicians treating people with diabetes should not forget that, in the short term, the greatest gains are likely to be realised by more consistent deployment of existing therapies.

Long-term trends in the prevalence of chronic kidney disease and the influence of cardiovascular risk factors in Norway

Surveillance of chronic kidney disease (CKD) prevalence over time and information on how changing risk factors influence this trend are needed to evaluate the effects of general practice and public health interventions. Because very few studies addressed this, we studied the total adult population of a demographically stable county representative of Norway using cross-sectional studies 10 years apart (Nord-Trøndelag Health Study (HUNT)2 and Nord-Trøndelag Health Study (HUNT)3, 65,237 and 50,586 participants, respectively). Thorough quality-control procedures and comparisons of methods over time excluded analytical drift, and multiple imputations of missing data combined with nonattendance weights contributed to unbiased estimates. CKD prevalence remained stable in Norway from 1995 through 1997 (11.3%) to 2006 through 2008 (11.1%). The association of survey period with CKD prevalence was modified by a strong decrease in blood pressure, more physical activity, and lower cholesterol levels. Without these improvements, a 2.8, 0.7, and 0.6 percentage points higher CKD prevalence could have been expected, respectively. In contrast, the prevalence of diabetes and obesity increased moderately, but the proportion of diabetic patients with CKD decreased significantly (from 33.4% to 28.6%). A CKD prevalence of 1 percentage point lower would have been expected without these changes. Thus, CKD prevalence remained stable in Norway for more than a decade in association with marked improvements in blood pressure, lipid levels, and physical activity and despite modest increases in diabetes and obesity.

Kidney Function and Cardiovascular Events in Postmenopausal Women: The Impact of Race and Ethnicity in the Women's Health Initiative

BACKGROUND

Kidney disease disproportionately affects minority populations, including African Americans and Hispanics; therefore, understanding the relationship of kidney function to cardiovascular (CV) outcomes within different racial/ethnic groups is of considerable interest. We investigated the relationship between kidney function and CV events and assessed effect modification by race/ethnicity in the Women's Health Initiative.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Baseline serum creatinine concentrations (assay traceable to isotope-dilution mass spectrometry standard) of 19,411 postmenopausal women aged 50 to 79 years who self-identified as either non-Hispanic white (n=8,921), African American (n=7,436), or Hispanic (n=3,054) were used to calculate estimated glomerular filtration rates (eGFRs).

PREDICTORS

Categories of eGFR (exposure); race/ethnicity (effect modifier).

OUTCOMES

The primary outcome was the composite of 3 physician-adjudicated CV events: myocardial infarction, stroke, or CV-related death.

MEASUREMENTS

We evaluated the multivariable-adjusted associations between categories of eGFR and CV events using proportional hazards regression and formally tested for effect modification by race/ethnicity.

RESULTS

During a mean follow-up of 7.6 years, 1,424 CV events (653 myocardial infarctions, 627 strokes, and 297 CV-related deaths) were observed. The association between eGFR and CV events was curvilinear; however, the association of eGFR with CV outcomes differed by race (P=0.006). In stratified analyses, we observed that the U-shaped association was present in non-Hispanic whites, whereas African American participants had a rather curvilinear relationship, with lower eGFR being associated with higher CV risk, and higher eGFR, with reduced CV risk. Analyses among Hispanic women were inconclusive owing to few Hispanic women having very low or high eGFRs and very few events occurring in these categories.

LIMITATIONS

Lack of urinary albumin measurements; residual confounding by unmeasured or imprecisely measured characteristics.

CONCLUSIONS

In postmenopausal women, the patterns of association between eGFR and CV risk differed between non-Hispanic whites and African American women.

Multinational Assessment of Accuracy of Equations for Predicting Risk of Kidney Failure: A Meta-analysis

IMPORTANCE

Identifying patients at risk of chronic kidney disease (CKD) progression may facilitate more optimal nephrology care. Kidney failure risk equations, including such factors as age, sex, estimated glomerular filtration rate, and calcium and phosphate concentrations, were previously developed and validated in 2 Canadian cohorts. Validation in other regions and in CKD populations not under the care of a nephrologist is needed.

OBJECTIVE

To evaluate the accuracy of the risk equations across different geographic regions and patient populations through individual participant data meta-analysis.

DATA SOURCES

Thirty-one cohorts, including 721,357 participants with CKD stages 3 to 5 in more than 30 countries spanning 4 continents, were studied. These cohorts collected data from 1982 through 2014.

STUDY SELECTION

Cohorts participating in the CKD Prognosis Consortium with data on end-stage renal disease.

DATA EXTRACTION AND SYNTHESIS

Data were obtained and statistical analyses were performed between July 2012 and June 2015. Using the risk factors from the original risk equations, cohort-specific hazard ratios were estimated and combined using random-effects meta-analysis to form new pooled kidney failure risk equations. Original and pooled kidney failure risk equation performance was compared, and the need for regional calibration factors was assessed.

MAIN OUTCOMES AND MEASURES

Kidney failure (treatment by dialysis or kidney transplant).

RESULTS

During a median follow-up of 4 years of 721,357 participants with CKD, 23,829 cases kidney failure were observed. The original risk equations achieved excellent discrimination (ability to differentiate those who developed kidney failure from those who did not) across all cohorts (overall C statistic, 0.90; 95% CI, 0.89-0.92 at 2 years; C statistic at 5 years, 0.88; 95% CI, 0.86-0.90); discrimination in subgroups by age, race, and diabetes status was similar. There was no improvement with the pooled equations. Calibration (the difference between observed and predicted risk) was adequate in North American cohorts, but the original risk equations overestimated risk in some non-North American cohorts. Addition of a calibration factor that lowered the baseline risk by 32.9% at 2 years and 16.5% at 5 years improved the calibration in 12 of 15 and 10 of 13 non-North American cohorts at 2 and 5 years, respectively (P = .04 and P = .02).

CONCLUSIONS AND RELEVANCE

Kidney failure risk equations developed in a Canadian population showed high discrimination and adequate calibration when validated in 31 multinational cohorts. However, in some regions the addition of a calibration factor may be necessary.

Subnormal Estimated Glomerular Filtration Rate Strongly Predict Incident Cardiovascular Events in Type 2 Diabetic Chinese Population With Normoalbuminuria

No study has evaluated whether subnormal estimated glomerular filtration rate (eGFR) (between 61 and 90 mL/min) and high normal albumin-creatinine ratio (ACR) (<30 mg/g) are associated with cardiovascular (CV) events and mortality in type 2 diabetic (T2DM) patients with normoalbuminuria.We observed a longitudinal cohort study of 1291 T2DM patients with normoalbuminuria who were receiving intensified multifactorial treatment from 2004 to 2008. Cox regression models were used to evaluate eGFR and ACR as the risk factors of major CV events (nonfatal myocardial infarction and stroke) and mortality.During the 4-year period, 56 patients died and 159 patients developed major CV events. We found eGFR, but not ACR, to be associated with major CV events. Compared to those with eGFR higher than 90 mL/min, patients with subnormal eGFR (HR: 3.133, 1.402-7.002, P = 0.005) were at greater risk of incident major CV events. Extremely low eGFR (<30 mL/min) was associated with mortality only in patients under 65 years old.Subnormal eGFR was a strong predictor of major CV events in diabetic patients with normoalbuminuria. Normoalbuminuric diabetic patients with subnormal eGFR may need intensive CV risk factor intervention to prevent and treat CV events.