CKD: A Call for an Age-Adapted Definition

Examining the impact of renal dysfunction and diabetes on post-myocardial infarction mortality: insights from a comprehensive retrospective cohort study across different age groups

Aim. Chronic kidney disease (CKD) and diabetes mellitus (DM) contribute significantly to cardiovascular disease (CVD) and mortality, with prevalence increasing. The evolving demographic of myocardial infarction (MI) patients, influenced by sedentary lifestyles and advanced medical care, lacks understanding regarding the interplay of CKD, DM, age, and post-MI mortality. This study aims to address this gap by evaluating the long-term impact of CKD and DM on post-MI mortality across age groups. Methods. A retrospective cohort study utilized data from the Estonian Myocardial Infarction Registry (EMIR), Estonian Population Register (EPR), and six major hospitals in Estonia, covering AMI hospitalizations from 2012 to 2019. Statistical analyses included Cox proportional hazards regression models and Kaplan-Meier's curves. Results. Analysis of 17,085 MI patients revealed age-dependent associations between renal function and mortality. In patients <65 years, even minor decreases in renal function increased both short-term (HR 2.79, 95% CI 1.71-4.55) and long-term (HR 1.24, 95% CI 1.05-1.47) mortality. Mortality significantly increased in patients >80 years only below an estimated glomerular filtration rate (eGFR) of 44 ml/min/1.73 m2. Newly diagnosed DM patients exhibited higher mortality rates (average HR 1.53, 95% CI 1.45-1.62), while pre-DM did not significantly differ from non-DM patients across all age groups. The DM-renal failure interaction did not significantly influence mortality. Conclusions. An age-dependent association between eGFR and post-MI outcomes emphasizes the need for personalized therapeutic approaches considering age-specific eGFR thresholds and comorbidities to optimize patient management.

Chronic kidney disease in older adults: challenges and opportunities for the primary care provider

Kidney disease and its comorbidities disproportionately affect older persons. Kidney disease modifying therapy is underutilized in older adults, as guidelines lack consensus on approaching diagnosis and treatment in older adults. This review aims to highlight the challenges presented by, and opportunities for, identifying and treating CKD in older adults.

Cystatin C and Kidney Function Recovery in Patients Requiring Continuous KRT for Acute Kidney Injury

Background:

Plasma cystatin C is a reliable marker to estimate kidney function; however, it is unknown whether this remains true in patients receiving continuous kidney replacement therapy (CKRT). Herein, we tested the hypothesis that lower concentrations of plasma cystatin C during the first three days of CKRT would predict kidney function recovery.

Methods:

We performed a retrospective observational study of 72 patients from a 126-patient, single-center CKRT study. We studied two a priori defined cohorts of patients without advanced CKD who had acute kidney injury requiring CKRT (AKI-CKRT): 1) with early kidney function recovery defined as liberation from KRT within seven days of CKRT initiation versus 2) with delayed kidney function recovery defined as receipt of KRT for >21 days or death while on KRT. Subsequent analysis included patients with advanced CKD and intermediate kidney function recovery (liberation between 8 and 21 days). Cystatin C was then measured on stored plasma, urine, and dialysis effluent collected prior to CKRT initiation and on days 1, 2, and 3 of CKRT.

Results:

Plasma cystatin C was significantly lower in patients with early kidney function recovery in comparison to patients with delayed kidney function recovery on days 1 (1.79 vs. 2.39mg/L), 2 (1.91 vs. 2.38mg/L) and 3 (2.04 vs. 2.67mg/L) of CKRT. Sieving coefficient and CKRT clearance of cystatin C were similar for patients with early and delayed kidney function recovery. The lowest plasma cystatin C concentration on days 1-3 of CKRT predicted early kidney function recovery with an area under the receiver operating curve of 0.77 (P = 0.002), positive likelihood ratio of 5.60 for plasma cystatin C <1.30mg/L, and negative likelihood ratio of 0.17 for plasma cystatin C ≥1.88mg/L.

Conclusion:

Lower plasma cystatin C concentrations during the first three days of CKRT are associated with early kidney function recovery.

What every clinician needs to know about chronic kidney disease: Detection, classification and epidemiology

Chronic kidney disease (CKD) is a major healthcare challenge, affecting >800 million people worldwide. Implications for population health result from the strong associations of CKD with increased rates of cardiovascular disease, heart failure, progressive CKD leading to kidney failure, acute kidney injury (AKI), and mortality. In addition to a single disease perspective, CKD commonly coexists alongside other long-term conditions, in particular type 2 diabetes and cardiovascular disease. CKD is therefore an important component of multimorbidity that influences individual management and impacts prognosis. CKD is defined by abnormalities of kidney structure or function of any cause with implications for health that are present for longer than 3 months. The diagnosis is usually made on the basis of an abnormal glomerular filtration rate (GFR < 60 mL/min/1.73 m2) and/or the presence of proteinuria (urine albumin to creatinine ratio > 30 mg/g or >3 mg/mmol). GFR is usually estimated from serum creatinine concentration using a variety of validated equations. However, serum creatinine is closely related to muscle mass and may therefore not be an accurate marker of GFR in people with high or low muscle mass (sarcopaenia). Cystatin C is an alternative endogenous marker of GFR that is increasingly being used but also has limitations. An estimate of GFR based on both creatinine and cystatin C is the most accurate. Diagnosis should be followed by classification and risk stratification to guide the development of a risk-based, personalized care plan. Improved detection and widespread implementation of optimal CKD management has the potential to bring major benefits to population health.

Estimating the prevalence of chronic kidney disease in the older population using health screening data in Japan

BACKGROUND

In aging societies, the prevalence of chronic kidney disease (CKD) is expected to increase but may be underestimated because many asymptomatic patients remain undiagnosed. This study aimed to estimate the CKD prevalence among the general older population in Japan.

METHODS

This cross-sectional study used health screening data from the Japan Health Insurance Association collected between April 2014 and March 2023. Data from older people aged 65-90 years who underwent renal function screening for estimated glomerular filtration rate (eGFR) and urine protein tests were analyzed. CKD was defined as eGFR < 60 mL/min/1.73 m2 or proteinuria ≥ 1 + . Inverse probability weighting was used to account for the selection bias. The variables used for weighting were age, sex, insurance status, and the number of previous screenings.

RESULTS

Among 2.98 million older individuals, 588,809 (19.7%) had undergone screening (median [IQR] age, 69.9 [67.9-76.2] years, 337,862 women [57.4%]). Regarding the weighted CKD prevalence, 25.3% of the individuals aged 65-90 years had CKD; 11.8% of those aged 65-75 years and 34.6% of those aged 75 years and over showed an increase in prevalence with age. Among the patients with CKD, over half exhibited mild renal dysfunction without proteinuria. Hypertension and diabetes were common comorbidities in older patients with CKD.

CONCLUSIONS

This cross-sectional study revealed that the weighted prevalence of CKD in the older population aged 65-90 years was high (one in four individuals), indicating that it increases with age. Further studies are required to examine the clinical significance of these findings.

The renal histopathology of nonproteinuric kidney impairment: a three center experience

Proteinuria is a biomarker of kidney injury that typically results from glomerular and/or tubulointerstitial disease. Whereas kidney impairment with normal urinary protein excretion is usually less focused and understudied. We conducted a retrospective review of the renal histopathology of the patients with variable degrees of unexplained renal insufficiency but with normal range proteinuria between 2014 and 2024 of  three university teaching hospitals in Shenzhen city of Southern  China. Patients with kidney dysfunction of undetermined or uncertain etiology and with normal urinary protein excretion (defined by a 24hr urinary protein excretion < 150 mg or spot urinary protein to creatinine ratio [PCR] < 150 mg/g) were enrolled and analyzed. In a total of 2405 patients, 53 (2.2%) fulfilled the inclusion criteria  (male/female 40/13, age 47.3 ± 14.3 years) with a mean eGFR of 46.6 ± 16.8 ml/min per 1.73 m2. Glomerular disease (GD) was the most frequent pathological finding identified in 23 (43.4%) patients, while 19 (35.8%) cases  showed tubulointerstitial disease (TID) and 11 (20.8%) patients exhibited small vascular disease (SVD). Patients in the TID had the lowest mean eGFR and the highest numerical 24hr urinary protein excretion among the three groups. The incidence of acute kidney injury was significantly higher in TID than in other two groups. The patients in the SVD group had the highest fraction of underlying hypertension. Kidney dysfunction with normal range proteinuria may be related with, in descending order of probablity,  glomerular, tubulointerstitial and small vascular diseases. Renal biopsies were proved useful in informing therapeutic choice, long-term management and in predicting prognosis in this setting.

Population-based reference values for kidney function and kidney function decline in 25- to 95-year-old Germans without and with diabetes

Understanding normal aging of kidney function is pivotal to help distinguish individuals at particular risk for chronic kidney disease. Glomerular filtration rate (GFR) is typically estimated via serum creatinine (eGFRcrea) or cystatin C (eGFRcys). Since population-based age-group-specific reference values for eGFR and eGFR-decline are scarce, we aimed to provide such reference values from population-based data of a wide age range. In four German population-based cohorts (KORA-3, KORA-4, AugUR, DIACORE), participants underwent medical exams, interview, and blood draw up to five times within up to 25 years. We analyzed eGFRcrea and eGFRcys cross-sectionally and longitudinally (12,000 individuals, age 25-95 years). Cross-sectionally, we found age-group-specific eGFRcrea to decrease approximately linearly across the full age range, for eGFRcys up to the age of 60 years. Within age-groups, there was little difference by sex or diabetes status. Longitudinally, linear mixed models estimated an annual eGFRcrea decline of -0.80 [95% confidence interval -0.82, -0.77], -0.79 [-0.83, -0.76], and -1.20 mL/min/1.73m2 [-1.33, -1.08] for the general population, "healthy" individuals, or individuals with diabetes, respectively. Reference values for eGFR using cross-sectional data were shown as percentile curves for "healthy" individuals and for individuals with diabetes. Reference values for eGFR-decline using longitudinal data were presented as 95% prediction intervals for "healthy" individuals and for individuals with diabetes, obesity, and/or albuminuria. Thus, our results can help clinicians to judge eGFR values in individuals seen in clinical practice according to their age and to understand the expected range of annual eGFR-decline based on their risk profile.

Global health inequalities of chronic kidney disease: a meta-analysis

BACKGROUND

Chronic kidney disease (CKD) is a significant contributor to global morbidity and mortality. This study investigated disparities in age, sex and socio-economic status in CKD and updated global prevalence estimates through systematic review and meta-analysis.

METHODS

Five databases were searched from 2014 to 2022, with 14 871 articles screened, 119 papers included and data analysed on 29 159 948 participants. Random effects meta-analyses were conducted to determine overall prevalence, prevalence of stages 3-5 and prevalence in males and females. Influences of age, sex and socio-economic status were assessed in subgroup analyses and risk of bias assessment and meta-regressions were conducted to explore heterogeneity.

RESULTS

The overall prevalence of CKD was 13.0% [95% confidence interval (CI) 11.3-14.8] and 6.6% (95% CI 5.6-7.8) for stages 3-5. The prevalence was higher in studies of older populations (19.3% for stages 1-5, 15.0% for stages 3-5) and meta-regression demonstrated an association of age, body mass index, diabetes and hypertension with prevalence of stages 3-5. The prevalence of CKD stages 1-5 was similar in males and females (13.1% versus 13.2%), but the prevalence of stages 3-5 was higher in females (6.4% versus 7.5%). Overall prevalence was 11.4%, 15.0% and 10.8% in low-, middle- and high-income countries, respectively; for stages 3-5, prevalence was 4.0%, 6.7% and 6.8%, respectively. Included studies were at moderate-high risk of bias in the majority of cases (92%) and heterogeneity was high.

CONCLUSION

This study provides a comprehensive assessment of CKD prevalence, highlighting important disparities related to age, sex and socio-economic status. Future research should focus on targeted screening and treatment approaches, improving access to care and more effective data monitoring, particularly in low- and middle-income countries.

A Risk Prediction Model for New-Onset Chronic Kidney Disease in the Elderly

INTRODUCTION

Worsening renal function poses a significant health risk to elderly individuals. This study aimed to construct a simple risk prediction model for new-onset chronic kidney disease (CKD) among elderly populations.

METHODS

In this retrospective cohort study, 5,416 elderly residents (aged ≥65 years) who underwent physical examinations as part of the National Basic Public Health Service project at least twice between January 2017 and July 2021 were included. The endpoint was new-onset CKD, defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 during the follow-up period. Predictors of new-onset CKD were selected using multivariable Cox regression and a stepwise approach. A risk prediction model based on the selected predictors was constructed and evaluated using the concordance index (C-index) and area under curve (AUC). External validation was conducted to verify the model's performance.

RESULTS

During the median follow-up period of 2.3 years, the incident of new-onset CKD was 20.1% (n = 1,088). Age, female gender, diabetes, elevated triglyceride levels, and baseline eGFR were selected as predictors. The model demonstrated good predictive performance across the cohort, with a C-index of 0.802. The AUCs for 2-year, 3-year, and 4-year predictions were 0.831, 0.829, and 0.839, respectively. External validation confirmed the model's efficacy, with a 2-year AUC of 0.735.

CONCLUSION

This study developed a simple yet effective risk prediction model for new-onset CKD among elderly populations. The model facilitates prompt identification of elderly individuals at risk of renal function decline in primary care, enabling timely interventions.

The impact of population ageing on the burden of chronic kidney disease

The burden of chronic kidney disease (CKD) and its risk factors are projected to rise in parallel with the rapidly ageing global population. By 2050, the prevalence of CKD category G3-G5 may exceed 10% in some regions, resulting in substantial health and economic burdens that will disproportionately affect lower-income countries. The extent to which the CKD epidemic can be mitigated depends largely on the uptake of prevention efforts to address modifiable risk factors, the implementation of cost-effective screening programmes for early detection of CKD in high-risk individuals and widespread access and affordability of new-generation kidney-protective drugs to prevent the development and delay the progression of CKD. Older patients require a multidisciplinary integrated approach to manage their multimorbidity, polypharmacy, high rates of adverse outcomes, mental health, fatigue and other age-related symptoms. In those who progress to kidney failure, comprehensive conservative management should be offered as a viable option during the shared decision-making process to collaboratively determine a treatment approach that respects the values and wishes of the patient. Interventions that maintain or improve quality of life, including pain management and palliative care services when appropriate, should also be made available.

Treatment of chronic kidney disease in older populations

As the world population ages, an expected increase in the prevalence of chronic kidney disease (CKD) among older individuals will pose a considerable challenge for health care systems in terms of resource allocation for disease management. Treatment strategies for older patients with CKD should ideally align with those applied to the general population, focusing on minimizing cardiovascular events and reducing the risk of progression to kidney failure. Emerging therapies, such as SGLT-2 inhibitors and GLP-1 receptor agonists, hold promise for the effective management of CKD in older individuals. In addition, non-pharmacological interventions such as nutritional and exercise therapies have a crucial role. These interventions enhance the effects of pharmacotherapy and, importantly, contribute to the maintenance of cognitive function and overall quality of life. Various factors beyond age and cognitive function must be taken into account when considering kidney replacement therapy for patients with kidney failure. Importantly, all treatment options, including dialysis, transplantation and conservative management approaches, should be tailored to the individual through patient-centred decision-making. The dynamic integration of digital technologies into medical practice has the potential to transform the management of CKD in the aging population.

Use of kidney trajectory charts as an adjunct to chronic kidney disease guidelines- a qualitative study of general practitioners

OBJECTIVES

Chronic kidney disease (CKD) affects up to 11% of the population. General practice is at the forefront of the identification of patients with declining kidney function, and appropriate monitoring and management of patients with CKD. An individualized and patient-centred approach is currently recommended in guidelines, but would be enhanced by more detailed guidance on how this should be applied to different age groups, such as use of a kidney trajectory chart. We explored the opinion of general practitioners (GPs) about the potential utility of kidney trajectory charts.

METHODS

Qualitative study interviewing 27 Australian GPs about their management of chronic kidney disease. GPs were presented with charts that plotted percentiles of kidney function (eGFR) with age and discussed how they would use the charts manage to patients with declining kidney function. GPs' opinion was sought as to how useful these charts might be in clinical practice.

RESULTS

Most GPs were positive about the use of kidney trajectory charts to assist them with recognition and management of declining kidney function in general practice: e.g, comments included a "valuable tool", "a bit of an eye opener"," will help me explain to the patients", "I'll stick it on my wall.". GPs responded that the charts could help monitor patients, trigger early recognition of a younger patient at risk, and assist with older patients to determine when treatment may not be warranted. GPs also thought that charts could also be useful to motivate patients and help them monitor their own condition.

CONCLUSIONS

Use of percentile charts in conjunction with the current CKD guidelines help support a patient-centred model of care. Kidney trajectory charts can help patients to understand their risk of further kidney damage or decline. Research on the use of these charts in clinical practice should be undertaken to further develop their use.

Comparison of Kidney Graft Function and Survival in an Emulated Trial With Living Donors and Brain-Dead Donors

Living donation (LD) transplantation is the preferred treatment for kidney failure as compared to donation after brain death (DBD), but age may play a role. We compared the 1-year estimated glomerular filtration rate (eGFR) after kidney transplantation for recipients of LD and DBD stratified by recipient and donor age between 2015 and 2018 in a matched cohort. The strength of the association between donation type and 1-year eGFR differed by recipient age (P interaction < 0.0001). For LD recipients aged 40-54 years versus same-aged DBD recipients, the adjusted odds ratio (aOR) for eGFR ≥60 mL/min/1.73 m2 was 1.48 (95% CI: 1.16-1.90). For DBD recipients aged ≥ 60 years, the aOR was 0.18 (95% CI: 0.12-0.29) versus DBD recipients aged 40-54 years but was 0.91 (95% CI: 0.67-1.24) versus LD recipients aged ≥60 years. In the matched cohort, 4-year graft and patient survival differed by donor age and type. As compared with DBD grafts, LD grafts increased the proportion of recipients with 1-year eGFR ≥60 mL/min/1.73 m2. Recipients aged ≥60 years benefited most from LD transplantation, even if the donor was aged ≥60 years. For younger recipients, large age differences between donor and recipient could also be addressed with a paired exchange program.

Longitudinal Trajectories of Estimated Glomerular Filtration Rate in a European Population of Living Kidney Donors

A living donor (LD) kidney transplant is the best treatment for kidney failure, but LDs safety is paramount. We sought to evaluate our LDs cohort's longitudinal changes in estimated glomerular filtration rate (eGFR). We retrospectively studied 320 LDs submitted to nephrectomy between 1998 and 2020. The primary outcome was the eGFR change until 15 years (y) post-donation. Subgroup analysis considered distinct donor characteristics and kidney function reduction rate (%KFRR) post-donation [-(eGFR6 months(M)-eGFRpre-donation)/eGFRpre-donation*100]. Donors had a mean age of 47.3 ± 10.5 years, 71% female. Overall, LDs presented an average eGFR change 6 M onward of +0.35 mL/min/1.73 m2/year. The period with the highest increase was 6 M-2 Y, with a mean eGFR change of +0.85L/min/1.73 m2/year. Recovery plateaued at 10 years. Normal weight donors presented significantly better recovery of eGFR +0.59 mL/min/1.73 m2/year, compared to obese donors -0.18L/min/1.73 m2/year (p = 0.020). Noteworthy, these results only hold for the first 5 years. The subgroup with a lower KFRR (<26.2%) had a significantly higher decrease in eGFR overall of -0.21 mL/min/1.73 m2/year compared to the groups with higher KFRR (p < 0.001). These differences only hold for 6 M-2 Y. Moreover, an eGFR<50 mL/min/1.73 m2 was a rare event, with ≤5% prevalence in the 2-15 Y span, correlating with eGFR pre-donation. Our data show that eGFR recovery is significant and may last until 10 years post-donation. However, some subgroups presented more ominous kidney function trajectories.

General practitioners' assessment and management of chronic kidney disease in older patients- a mixed methods study

BACKGROUND

Chronic kidney disease (CKD) is commonly managed in general practice, with established guidelines for diagnosis and management. CKD is more prevalent in the older population, and is associated with lifestyle diseases as well as social deprivation. Older patients also commonly experience multimorbidity. Current CKD guidelines do not take age into account, with the same diagnostic and management recommendations for patients regardless of their age. We sought to investigate general practitioners' (GPs') approach to older patients with CKD, and whether their assessment and management differed from guideline recommendations. We explored the reasons for variation from guideline recommendations.

METHODS

This was a mixed methods study of Australian GPs. An online anonymous survey about the use of CKD guidelines, and assessment and management of CKD was sent to 9500 GPs. Four hundred and sixty-nine (5%) of GPs responded, and the survey was completed by 399 GPs. Subsequently, 27 GPs were interviewed in detail about their diagnostic and management approach to older patients with declining kidney function.

RESULTS

In the survey, 48% of GPs who responded found the CKD guidelines useful for diagnosis and management. Four themes arose from our interviews: age-related decline in kidney function; whole person care; patient-centred care; and process of care that highlighted the importance of continuity of care. GPs recognised that older patients have an inherently high risk of lower kidney function. The GPs reported management of that higher risk focused on managing the whole person (not just a single disease focus) and being patient-centred. Patient-centred care expressed the importance of quality of life, shared decision making and being symptom focused. There was also a recognition that there is a difference between a sudden decline in kidney function and a stable but low kidney function and GPs would manage these situations differently.

CONCLUSIONS

GPs apply guidelines in the management of CKD in older patients using a patient-centred and whole person approach to care. Older patients have a high prevalence of multimorbidity, which GPs carefully considered when applying existing CKD-specific guidelines. Future iterations of CKD Guidelines need to give due consideration to multimorbidity in older patients that can adversely impact on kidney function in addition to the expected age-related functional decline.

Screening and Diagnosis of Chronic Kidney Disease in Adults Living With Diabetes: A Retrospective Cohort Study Using the Canadian Primary Care Sentinel Surveillance Network

OBJECTIVES

In Canada, regional evaluations of screening practices for chronic kidney disease (CKD) among people with diabetes highlight areas for improvement; however, national estimates are notably absent. Estimates of CKD incidence often discount the expected decline in estimated glomerular filtration rate (eGFR) associated with age; age-adaptive thresholds may help account for this. We describe the frequency of screening and diagnosis of CKD among adults with diabetes from a nationally representative primary care cohort.

METHODS

In this retrospective cohort study, we used electronic medical record data from the Canadian Primary Care Sentinel Surveillance Network. We followed adult patients (≥18 years of age) with diabetes without CKD at baseline for 5 years starting in 2014. We determined the frequency of urine albumin-to-creatinine ratio (uACr) and/or eGFR testing over time. We identified incident CKD diagnoses based on eGFR measurements using fixed-threshold and age-adaptive definitions and quantified the incidence proportion and rate.

RESULTS

We analyzed records from 37,604 patients with diabetes. Only 13% of patients had yearly eGFR and uACr testing for CKD, although roughly 60% had non-yearly use of both tests in 5 years. eGFR testing was performed more frequently than uACr testing (94.1% vs 76.6% having testing over follow-up). We found increased incidence proportions (14.6% vs 6.0%) and rates (33.1 vs 13.4 diagnoses per 1,000 person years) of CKD using the fixed-threshold compared with age-adaptive definition.

CONCLUSIONS

Our study presents the first national understanding of screening practices for CKD among people with diabetes in Canada. Specifically, increased use of uACr testing should be encouraged for early detection of changes in kidney function.

Single-Cell Advances in Investigating and Understanding Chronic Kidney Disease and Diabetic Kidney Disease

Chronic kidney disease (CKD) and its subset diabetic kidney disease are progressive conditions that affect >850 million people worldwide. Diabetes, hypertension, and glomerulonephritis are the most common causes of CKD, which is associated with significant patient morbidity and an increased risk of cardiovascular events, such as heart failure, ultimately leading to premature death. Despite newly approved drugs, increasing evidence shows that patients respond to treatment differently given the complexity of disease heterogeneity and complicated pathophysiology. This review article presents an integrative approach to understanding and addressing CKD through the lens of precision medicine and therapeutics. Leveraging advancements in single-cell omics technologies and artificial intelligence, we can explore the intricate cellular mechanisms underlying CKD and diabetic kidney disease pathogenesis. By dissecting the cellular heterogeneity and identifying rare cell populations using single-cell approaches, it will be possible to uncover novel therapeutic targets and biomarkers for personalized treatment strategies. Finally, we discuss the potential of artificial intelligence-driven analyses in predicting disease progression and treatment response, thereby paving the way for tailored interventions.

Individualized Risk of CKD Progression among US Adults

Key Points

Background

CKD is currently defined using GFR or albuminuria. This is on the basis of the relative risk of mortality and kidney outcomes compared with a healthy population and does not consider an individual's absolute risk of CKD progression.

Methods

Using National Health and Nutrition Examination Survey data from 1999 to 2020, we characterized the individual-level absolute 3-year risk of ≥40% decline in eGFR (ml/min per 1.73 m2) or kidney failure (3-year risk) among US adults. We categorized the 3-year risk and considered ≥5% as high risk.

Results

Among 199.81 million US adults, 8.42 million (4%) had a 3-year risk ≥5%, including 1.04 million adults without CKD (eGFR ≥60 and albuminuria <30 mg/g). These high-risk adults without CKD as currently defined had risk factors including hypertension (98%), heart failure (72%), and diabetes (44%). A total of 15.51 million adults had CKD with preserved eGFR (eGFR ≥60 and albuminuria ≥30 mg/g)—3.73 million had a 3-year risk ≥5%, 41% of whom did not have diabetes and thus would not be screened for albuminuria using current screening recommendations. The 3-year risk of CKD progression was low (risk <5%) in 94% of the 5.66 million US adults with CKD stage G3a-A1 (eGFR 45 to <60 and albuminuria <30 mg/g).

Conclusions

Assessment of the individual's absolute risk of CKD progression allowed further risk stratification of patients with CKD and identified individuals without CKD, as currently defined, who were at high risk of CKD progression.

Podcast

This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/JASN/2024_06_18_ASN0000000000000377.mp3

Care of Adults with Advanced Chronic Kidney Disease

Chronic kidney disease (CKD) impacts over 10% of the global population. Adults with CKD face significant morbidity and mortality. As kidney disease progresses, the risk of adverse outcomes increases. Here, we present an overview of strategies to care for adults with advanced CKD (stage 4-5 CKD, not receiving kidney replacement therapy). We aim to guide clinicians through several aspects of CKD care, ranging from recommended laboratory assessments to interdisciplinary support for patients as they plan for kidney replacement therapy (dialysis, transplantation, or conservative management). We incorporate considerations of health equity and person-centered care, empowering clinicians to deliver high-quality care to people with CKD.

Biomarkers of chronic kidney disease in older individuals: navigating complexity in diagnosis

Chronic kidney disease (CKD) in older individuals is a matter of growing concern in the field of public health across the globe. Indeed, prevalence of kidney function impairment increases with advancing age and is often exacerbated by age-induced modifications of kidney function, presence of chronic diseases such as diabetes, hypertension, and cardiovascular disorders, and increased burden related to frailty, cognitive impairment and sarcopenia. Accurate assessment of CKD in older individuals is crucial for timely intervention and management and relies heavily on biomarkers for disease diagnosis and monitoring. However, the interpretation of these biomarkers in older patients may be complex due to interplays between CKD, aging, chronic diseases and geriatric syndromes. Biomarkers such as serum creatinine, estimated glomerular filtration rate (eGFR), and albuminuria can be significantly altered by systemic inflammation, metabolic changes, and medication use commonly seen in this population. To overcome the limitations of traditional biomarkers, several innovative proteins have been investigated as potential, in this review we aimed at consolidating the existing data concerning the geriatric aspects of CKD, describing the challenges and considerations in using traditional and innovative biomarkers to assess CKD in older patients, highlighting the need for integration of the clinical context to improve biomarkers' accuracy.

Longitudinal Analysis of Renal Function Changes in Elderly Populations: Health Status Evaluation and Risk Factor Assessment

Background

This study aims to investigate GFR decline in elderly subjects with varying physical conditions and analyze key risk factors impacting renal function changes.

Methods

We obtained data from patients between 2017 and 2019, and matched healthy elderly subjects based on gender and age. Data collected for all subjects included annual measurements of fast blood glucose (GLU), glycated hemoglobin (HbA1c), low-density lipoprotein cholesterol (LDL-c), blood albumin (ALB), blood uric acid (UA), urine protein (UP), and systolic blood pressure (SBP). Additionally, information on coexisting diseases was gathered. The Full Age Spectrum (FAS) equation was used to calculate eGFR.

Results

A total of 162 patients with complete 3-year renal dynamic imaging were included, including 84 patients in the kidney disease group (K group) and 78 patients in the non-kidney disease group (NK group). Ninety individuals were selected as the healthy group (H group). The annual decline rate in the K group was the fastest, which exceeded 5mL/min/1.73m2 (P < 0.05). Group (K group: β=-40.31, P<0.001; NK group: β=-26.96, P<0.001), ALB (β=-0.38, P=0.038) and HbA1c (β=1.36, P=0.029) had a significant negative impact on the eGFR changes. For participants who had negative proteinuria: K group had the most significant annual eGFR decline.

Conclusion

The presence of kidney disease, along with proteinuria nor not, can lead to a marked acceleration in kidney function decline in elderly. We categorize elderly individuals with an annual eGFR decline of more than 5 mL/min/1.73m2 as the "kidney accelerated aging" population.

Chronic Kidney Disease Stage and Cardiovascular and Mortality Events Among Older Adults: The SPRINT Trial

Rationale & Objective

The risk implications of the Kidney Disease: Improving Global Outcomes (KDIGO) chronic kidney disease classification in older adults are controversial. We evaluated the risk of adverse outcomes in this population across categories of estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (UACR).

Study Design

Prospective cohort.

Settings & Participants

In total, 2,509 participants aged ≥75 years in the Systolic Blood Pressure Intervention Trial (SPRINT).

Exposure

KDIGO eGFR and UACR categories. We combined KDIGO categories G1 and G2, G3b and G4, as well as A2 and A3.

Outcomes

Primary SPRINT outcome (composite of myocardial infarction, other acute coronary syndromes, stroke, heart failure, or death from cardiovascular causes), and all-cause death.

Analytical Approach

Multivariable Cox proportional hazard models.

Results

Mean age was 79.8 years, and 37.4% were female. The mean eGFR was 64.0 mL/min/1.73 m2, and the median UACR was 13.1 mg/g. In multivariable Cox proportional hazard analysis, compared with participants with eGFR ≥ 60 mL/min/1.73 m2 and UACR < 30 mg/g, there was no statistically significant difference in the risk of the primary outcome among participants with eGFR 45-59 or 15-44 mL/min/1.73 m2 and UACR < 30 mg/g. However, those with eGFR 45-59 or 15-44 mL/min/1.73 m2 and UACR ≥ 30 mg/g had higher risk of the primary outcome (HR [95% CI], 1.97 [1.27-3.04] and 3.32 [2.23-4.93], respectively). The risk for all-cause death was higher for each category of abnormal eGFR and UACR, with the highest risk observed among those with eGFR 15-44 mL/min/1.73 m2 and UACR ≥ 30 mg/g (3.34 [2.05-5.44]).

Limitations

Individuals with diabetes and urine protein >1 g/day were excluded from SPRINT.

Conclusion

Among older adults SPRINT participants, low eGFR without albuminuria was associated with higher mortality but not with increased risk of cardiovascular events. Additional studies are needed to evaluate an adapted chronic kidney disease stage-based risk stratification for older adults.

Assessing the Benefits and Harms of Pharmacotherapy in Older Adults with Frailty: Insights from Pharmacoepidemiologic Studies of Routine Health Care Data

The objective of this review is to summarize and appraise the research methodology, emerging findings, and future directions in pharmacoepidemiologic studies assessing the benefits and harms of pharmacotherapies in older adults with different levels of frailty. Older adults living with frailty are at elevated risk for poor health outcomes and adverse effects from pharmacotherapy. However, current evidence is limited due to the under-enrollment of frail older adults and the lack of validated frailty assessments in clinical trials. Recent advancements in measuring frailty in administrative claims and electronic health records (database-derived frailty scores) have enabled researchers to identify patients with frailty and to evaluate the heterogeneity of treatment effects by patients' frailty levels using routine health care data. When selecting a database-derived frailty score, researchers must consider the type of data (e.g., different coding systems), the length of the predictor assessment period, the extent of validation against clinically validated frailty measures, and the possibility of surveillance bias arising from unequal access to care. We reviewed 13 pharmacoepidemiologic studies published on PubMed from 2013 to 2023 that evaluated the benefits and harms of cardiovascular medications, diabetes medications, anti-neoplastic agents, antipsychotic medications, and vaccines by frailty levels. These studies suggest that, while greater frailty is positively associated with adverse treatment outcomes, older adults with frailty can still benefit from pharmacotherapy. Therefore, we recommend routine frailty subgroup analyses in pharmacoepidemiologic studies. Despite data and design limitations, the findings from such studies may be informative to tailor pharmacotherapy for older adults across the frailty spectrum.

Kidney trajectory charts improve GP management of patients with reduced kidney function: a randomised controlled vignette study

BACKGROUND

The stages of chronic kidney disease (CKD) and estimated glomerular filtration rate (eGFR) reference ranges are currently determined without considering age.

AIM

To determine whether a chart that graphs age with eGFR helps GPs make better decisions about managing patients with declining eGFR.

DESIGN & SETTING

A randomised controlled vignette study among Australian GPs using a percentile chart plotting the trajectory of eGFR by age.

METHOD

Three hundred and seventy-three GPs received two case studies of patients with declining renal function. They were randomised to receive the cases with the chart or without the chart, and asked a series of questions about how they would manage the cases.

RESULTS

In an older female patient with stable but reduced kidney function, use of the chart was associated with GPs in the study recommending a longer follow-up period, and longer time until repeat pathology testing. In a younger male First Nations patient with normal but decreasing kidney function, use of the chart was associated with GPs in the study recommending a shorter follow-up period, shorter time to repeat pathology testing, increased management of blood pressure and lifestyle, and avoidance of nephrotoxic medications. This represents more appropriate care in both cases.

CONCLUSION

Having access to a chart of percentile eGFR by age was associated with more appropriate management review periods of patients with reduced kidney function, either by greater compliance with current guidelines or greater awareness of a clinically relevant kidney problem.

Diagnostic standard: assessing glomerular filtration rate

Creatinine-based estimated glomerular filtration rate (eGFR) is imprecise at individual level, due to non-GFR-related serum creatinine determinants, including atypical muscle mass. Cystatin C has the advantage of being independent of muscle mass, a feature that led to the development of race- and sex-free equations. Yet, cystatin C-based equations do not perform better than creatinine-based equations for estimating GFR unless both variables are included together. The new race-free Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation had slight opposite biases between Black and non-Black subjects in the USA, but has poorer performance than that the previous version in European populations. The European Kidney Function Consortium (EKFC) equation developed in 2021 can be used in both children and adults, is more accurate in young and old adults, and is applicable to non-white European populations, by rescaling the Q factor, i.e. population median creatinine, in a potentially universal way. A sex- and race-free cystatin C-based EKFC, with the same mathematical design, has also be defined. New developments in the field of GFR estimation would be standardization of cystatin C assays, development of creatinine-based eGFR equations that incorporate muscle mass data, implementation of new endogenous biomarkers and the use of artificial intelligence. Standardization of different GFR measurement methods would also be a future challenge, as well as new technologies for measuring GFR. Future research is also needed into discrepancies between cystatin C and creatinine, which is associated with high risk of adverse events: we need to standardize the definition of discrepancy and understand its determinants.

Novel indications for referral and care for simultaneous liver kidney transplant recipients

PURPOSE OF REVIEW

Kidney dysfunction is challenging in liver transplant candidates to determine whether it is reversible or not. This review focuses on the pertinent data on how to best approach liver transplant candidates with kidney dysfunction in the current era after implementing the simultaneous liver kidney (SLK) allocation policy and safety net.

RECENT FINDINGS

The implementation of the SLK policy inverted the steady rise in SLK transplants and improved the utilization of high-quality kidneys. Access to kidney transplantation following liver transplant alone (LTA) increased with favorable outcomes. Estimating GFR in liver transplant candidates remains challenging, and innovative methods are needed. SLK provided superior patient and graft survival compared to LTA only for patients with advanced CKD and dialysis at least 3 months. SLK can provide immunological protection against kidney rejection in highly sensitized candidates. Post-SLK transplant care is complex, with an increased risk of complications and hospitalization.

SUMMARY

The SLK policy improved kidney access and utilization. Transplant centers are encouraged, under the safety net, to reserve SLK for liver transplant candidates with advanced CKD or dialysis at least 3 months while allowing lower thresholds for highly sensitized patients. Herein, we propose a practical approach to liver transplant candidates with kidney dysfunction.

Age- and gender-adjusted estimated glomerular filtration rate definition reveals hyperfiltration as a risk factor for renal function deterioration in type 2 diabetes

AIM

To assess the role of hyperfiltration for diabetic kidney disease (DKD) progression.

MATERIALS AND METHODS

A retrospective observational cohort study enrolled type 2 diabetes (T2D) patients with an initial estimated glomerular filtration rate (eGFR) of 60 mL/min/1.73m2 or higher. Patients were categorized into two groups: hyperfiltration (eGFR exceeding the age- and gender-specific 95th percentile values from a prior national cohort study) and normofiltration. Rapid DKD progression was defined as an eGFR decline of more than 5 mL/min/1.73m2/year. We used a linear mixed effect model and Cox regression with time-varying covariate model to compare eGFR changes and identify factors associated with rapid DKD progression.

RESULTS

Of the enrolled 7563 T2D patients, 7.2% had hyperfiltration. The hyperfiltration group exhibited a higher rate of eGFR decline compared with the normofiltration group (-2.0 ± 0.9 vs. -1.1 ± 0.9 mL/min/1.73m2/year; P < .001). During an average follow-up period of 4.65 ± 3.86 years, 24.7% of patients with hyperfiltration experienced rapid DKD progression, compared with 15.7% of patients with normofiltration (P < .001). Cox regression analyses identified that initial hyperfiltration was a significant determinant of rapid DKD progression, with a hazard ratio of 1.66 (95% confidence interval: 1.41-1.95; P < .001). When combined with albuminuria, the risk of progression was further compounded (hazard ratio 1.76-3.11, all P < .001).

CONCLUSIONS

In addition to using the current Kidney Disease: Improving Global Outcomes CGA classification system, considering glomerular hyperfiltration status can improve the accuracy of predicting DKD progression.

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.

Pathophysiological Link and Treatment Implication of Heart Failure and Preserved Ejection Fraction in Patients with Chronic Kidney Disease

Heart failure with preserved ejection fraction (HFpEF) results from a complex interplay of age, genetic, cardiac remodeling, and concomitant comorbidities including hypertension, obesity, diabetes, and chronic kidney disease (CKD). Renal failure is an important comorbidity of HFpEF, as well as a major pathophysiological mechanism for those patients at risk of developing HFpEF. Heart failure (HF) and CKD are intertwined conditions sharing common disease pathways; the so-called "kidney tamponade", explained by an increase in intracapsular pressure caused by fluid retention, is only the latest model to explain renal injury in HF. Recognizing the different phenotypes of HFpEF remains a real challenge; the pathophysiological mechanisms of renal dysfunction may differ across the HF spectrum, as well as the prognostic role. A better understanding of the role of cardiorenal interactions in patients with HF in terms of symptom status, disease progression, and prognosis remains essential in HF management. Historically, patients with HF and CKD have been scarcely represented in clinical trial populations. Current concerns affect the practical approach to HF treatment, and, in this context, physicians are frequently hesitant to prescribe and titrate both new and old treatments. Therefore, the extensive application of HF drugs in diverse HF subtypes with numerous comorbidities and different renal dysfunction etiologies remains a controversial matter of discussion. Numerous recently introduced drugs, such as sodium-glucose-linked transporter 2 inhibitors (SGLT2i), constitute a new therapeutic option for patients with HF and CKD. Because of their protective vascular and hormonal actions, the use of these agents may be safely extended to patients with renal dysfunction in the long term. The present review delves into the phenotype of patients with HFpEF and CKD from a pathophysiological perspective, proposing a treatment approach that suggests a practical stepwise algorithm for the proper application of life-saving therapies in clinical practice.

The association between circadian syndrome and chronic kidney disease in an aging population: a 4-year follow-up study

Introduction

Circadian syndrome (CircS) is proposed as a novel risk cluster based on reduced sleep duration, abdominal obesity, depression, hypertension, dyslipidemia and hyperglycemia. However, the association between CircS and chronic kidney disease (CKD) remains unclear. To investigate the cross-sectional and longitudinal association between CircS and CKD, this study was performed.

Methods

A national prospective cohort (China Health and Retirement Longitudinal Study, CHARLS) was used in this study. To define CKD, the estimated glomerular filtration rate (eGFR) was calculated based on the 2012 CKD-EPI creatinine-cystatin C equation. Participants with eGFR <60 mL.min-1/1.73/m2 were diagnosed with CKD. Multivariate binary logistic regression was used to assess the cross-sectional association between CircS and CKD. Subgroup and interactive analyses were performed to determine the interactive effects of covariates. In the sensitivity analysis, the obese population was excluded and another method for calculating the eGFR was used to verify the robustness of previous findings. In addition, participants without CKD at baseline were followed up for four years to investigate the longitudinal relationship between CircS and CKD.

Results

A total of 6355 participants were included in this study. In the full model, CircS was positively associated with CKD (OR = 1.28, 95% CI = 1.04-1.59, P < 0.05). As per one increase of CircS components, there was a 1.11-fold (95% CI = 1.04-1.18, P < 0.05) risk of prevalent CKD in the full model. A significant interactive effect of hyperuricemia in the CircS-CKD association (P for interaction < 0.01) was observed. Sensitivity analyses excluding the obese population and using the 2009 CKD-EPI creatinine equation to diagnose CKD supported the positive correlation between CircS and CKD. In the 2011-2015 follow-up cohort, the CircS group had a 2.18-fold risk of incident CKD (95% CI = 1.33-3.58, P < 0.01) in the full model. The OR was 1.29 (95% CI = 1.10-1.51, P < 0.001) with per one increase of CircS components.

Conclusion

CircS is a risk factor for CKD and may serve as a predictor of CKD for early identification and intervention.

Are there lost opportunities in chronic kidney disease? A region-wide cohort study

OBJECTIVES

Identify the windows of opportunity for the diagnosis of chronic kidney disease (CKD) and the prevention of its adverse outcomes and quantify the potential population gains of such prevention.

DESIGN AND SETTING

Observational, population-wide study of residents in the Stockholm and Skåne regions of Sweden between 1 January 2015 and 31 December 2020.

PARTICIPANTS

All patients who did not yet have a diagnosis of CKD in healthcare but had CKD according to laboratory measurements of CKD biomarkers available in electronic health records.

OUTCOME MEASURES

We assessed the proportions of the patient population that received a subsequent diagnosis of CKD in healthcare, that used guideline-directed pharmacological therapy (statins, renin-angiotensin aldosterone system inhibitors (RAASi) and/or sodium-glucose cotransporter-2 inhibitors (SGLT2i)) and that experienced adverse outcomes (all-cause mortality, cardiovascular mortality or major adverse cardiovascular events (MACE)). The potential to prevent adverse outcomes in CKD was assessed using simulations of guideline-directed pharmacological therapy in untreated subsets of the study population.

RESULTS

We identified 99 382 patients with undiagnosed CKD during the study period. Only 33% of those received a subsequent diagnosis of CKD in healthcare after 5 years. The proportion that used statins or RAASi was of similar size to the proportion that didn't, regardless of how advanced their CKD was. The use of SGLT2i was negligible. In simulations of optimal treatment, 22% of the 21 870 deaths, 27% of the 14 310 cardiovascular deaths and 39% of the 22 224 MACE could have been avoided if every patient who did not use an indicated medication for their laboratory-confirmed CKD was treated with guideline-directed pharmacological therapy for CKD.

CONCLUSIONS

While we noted underdiagnosis and undertreatment of CKD in this large contemporary population, we also identified a substantial realisable potential to improve CKD outcomes and reduce its burden by treating patients early with guideline-directed pharmacological therapy.

[Screening for Chronic Kidney Disease in the Community Pharmacy. CRIERFAC Study: Description of the Methodology]

Abstract

Chronic kidney disease (CKD) is the existence of abnormalities in renal structure or function with an impact on health. This is usually considered when estimated glomerular filtration (eGF) falls under 60 mL/min/1.73m2. Its clinical course leads to renal replacement therapy (dialysis or transplant) when eGF falls under 15 mL/min/1.73m2. Screening in at risk populations has been proven to be cost-effective. The aim of this work is to perform CKD screening in the community pharmacy. In this publication we report and justify the methodology in detail.

Methodology

Pharmacists from the community pharmacies taking part selected patients who complied with inclusion and not exclusion criteria. Creatinine was measured by means of a finger prick and eGF calculated with the formula CKD-EPI. If this is lower than a set value, which depends on age, referral to the general practitioner takes place.

Results

A total of 141 out of 200 pharmacies took part in the study. In all 2116 patients were recruited and 116 patients were lost. The final sample size was 2000 patients.

Discussion

The protocol was successfully implemented by community pharmacists and was extremely well received by community pharmacy users. The age adjustment for eGF thresholds provides a novel additional filter. The aim is not to overburden primary care centres with potential referrals of false positives. Confirmation of the diagnosis is subject to voluntary communication by the patient to the pharmacist.

Estimated glomerular filtration rate in observational and interventional studies in chronic kidney disease

Estimated glomerular filtration rate is considered the principal measure of kidney function and, together with albuminuria, is a relevant prognostic factor for the development of end-stage kidney disease. Due to the strong association between estimated glomerular filtration rate and clinical events, such as commencement of dialysis, cardiovascular outcomes and all-cause death, estimated glomerular filtration rate is crucial for clinical decision-making in terms of scheduling follow-up and pharmacological interventions, and planning renal replacement therapies in advanced chronic kidney disease. In this review we discuss the available methods for measuring glomerular filtration rate and for estimating it through mathematical equations developed over the last few decades. We summarize the prognostic association of different percentages of estimated glomerular filtration rate decline and the main clinical outcomes, and how treatments modify estimated glomerular filtration rate decline and the risk of future endpoints. We also examine the role of pre-clinical trial slope and that of estimated glomerular filtration rate as a useful biomarker when evaluating patients for inclusion into both observational and interventional studies.

Association between dietary diversity and chronic kidney disease in community-dwelling older adults

OBJECTIVE

The present study examined whether dietary diversity is associated with chronic kidney disease (CKD) in community-dwelling older Japanese adults.

METHODS

Participants comprised 8,195 older adults (mean age was 74.0 ± 5.6 years; 42.7% were men) in this cross-sectional study. In this study, CKD was defined as estimated Glomerular Filtration Rate (eGFR) < 45 mL/min/1.73 m2. Diet variety was assessed using the Food Frequency Score (FFS) (maximum, 30 points). The FFS assessed the one-week consumption frequency of ten foods (meat, fish/shellfish, eggs, milk, soybean products, green & yellow vegetables, potatoes, fruits, seafood, and fats & oil). Participants with an FFS of 16 or fewer points were defined as having low dietary diversity.

RESULTS

The prevalence of CKD was 376 (4.6%), and the low dietary diversity group had higher prevalence (5.6%) compared with the high and low dietary diversity group (4.3%). Multiple logistic regression analysis revealed low dietary diversity was associated with CKD in older adults (OR 1.30, 95%CI 1.01-1.68). Stratified analysis showed that low dietary diversity was independently associated with CKD (OR 1.43, 95% CI 1.07-1.91) in older adults with hypertension, but not in adults without hypertension (OR 0.94, 95% CI 0.54-1.64).

CONCLUSIONS AND IMPLICATIONS

This cross-sectional study revealed that low dietary diversity was associated with CKD among older adults. Furthermore, low dietary diversity was associated with CKD among older adults with hypertension.

Comparative Analysis of Seven Equations for Estimated Glomerular Filtration Rate and Their Impact on Chronic Kidney Disease Categorization in Korean Patients at Local Clinics and Hospitals

(1) Background: Accurate estimation of the glomerular filtration rate (eGFR) is essential for the early detection of chronic kidney disease (CKD), targeted interventions, and ongoing monitoring. Although various equations for calculating eGFR exist, comparative studies on eGFR levels and the impact of these equations on CKD prevalence are limited in the Korean population. (2) Methods: We compared eGFR levels calculated using seven equations and investigated the prevalence of CKD through a retrospective analysis of the data from Korean adult patients who visited local clinics and hospitals and underwent simultaneous serum creatinine (Cr) and cystatin C (Cys-C) measurements. The equations analyzed were: 2006 MDRD, 2009 CKD-EPI Cr, 2012 CKD-EPI Cys-C, 2012 CKD-EPI Cr & Cys-C, 2021 CKD-EPI Cr, 2021 CKD-EPI Cr & Cys-C, and 2021 EKFC. (3) Results: This study included 6688 Korean patients (3736 men and 2952 women; median age: 61.4; IQR: 47.2-73.4). Among the equations, the median eGFR levels were the highest when using the 2021 CKD-EPI Cr & Cys-C equation (85.1 mL/min/1.73 m2) and the lowest when using the 2006 MDRD equation (73.4 mL/min/1.73 m2). The highest prevalence of decreased eGFR < 60 mL/min/1.73 m2 (equivalent to or worse than G3a CKD) was noted with the 2012 CKD-EPI Cys-C equation (32.4%), while the lowest was with the 2021 CKD-EPI Cr equation (22.9%), resulting in a maximum prevalence difference of 9.5%. (4) Conclusions: The prevalence of CKD varies based on the eGFR equation used and the patient's age. Equations that include Cys-C may identify a larger number of patients with decreased kidney function.

Association of Low Glomerular Filtration Rate With Adverse Outcomes at Older Age in a Large Population With Routinely Measured Cystatin C

BACKGROUND

The commonly accepted threshold of glomerular filtration rate (GFR) to define chronic kidney disease (CKD) is less than 60 mL/min/1.73 m2. This threshold is based partly on associations between estimated GFR (eGFR) and the frequency of adverse outcomes. The association is weaker in older adults, which has created disagreement about the appropriateness of the threshold for these persons. In addition, the studies measuring these associations included relatively few outcomes and estimated GFR on the basis of creatinine level (eGFRcr), which may be less accurate in older adults.

OBJECTIVE

To evaluate associations in older adults between eGFRcr versus eGFR based on creatinine and cystatin C levels (eGFRcr-cys) and 8 outcomes.

DESIGN

Population-based cohort study.

SETTING

Stockholm, Sweden, 2010 to 2019.

PARTICIPANTS

82 154 participants aged 65 years or older with outpatient creatinine and cystatin C testing.

MEASUREMENTS

Hazard ratios for all-cause mortality, cardiovascular mortality, and kidney failure with replacement therapy (KFRT); incidence rate ratios for recurrent hospitalizations, infection, myocardial infarction or stroke, heart failure, and acute kidney injury.

RESULTS

The associations between eGFRcr-cys and outcomes were monotonic, but most associations for eGFRcr were U-shaped. In addition, eGFRcr-cys was more strongly associated with outcomes than eGFRcr. For example, the adjusted hazard ratios for 60 versus 80 mL/min/1.73 m2 for all-cause mortality were 1.2 (95% CI, 1.1 to 1.3) for eGFRcr-cys and 1.0 (CI, 0.9 to 1.0) for eGFRcr, and for KFRT they were 2.6 (CI, 1.2 to 5.8) and 1.4 (CI, 0.7 to 2.8), respectively. Similar findings were observed in subgroups, including those with a urinary albumin-creatinine ratio below 30 mg/g.

LIMITATION

No GFR measurements.

CONCLUSION

Compared with low eGFRcr in older patients, low eGFRcr-cys was more strongly associated with adverse outcomes and the associations were more uniform.

PRIMARY FUNDING SOURCE

Swedish Research Council, National Institutes of Health, and Dutch Kidney Foundation.

Comparison of chronic kidney disease progression and associated complications between geriatric and non-geriatric groups

There is no consensus on the physiologic decline in estimated glomerular filtration rate (GFR) due to geriatric conditions related with the aging or chronic kidney disease (CKD) itself. In this study, we aimed to compare the CKD progression and associated complications in a large sample of geriatric and non-geriatric patients. The data of in 506 patients at age between 30 to 90 years and diagnosed with CKD at stage 2 and above (15 mL/min/1.73 m2 ≤ eGFR < 90 mL/min/1.73 m2) were collected retrospectively and compared among geriatric (>65 years old) and non-geriatric individuals. The rate of hypertension was higher in geriatrics compared to non-geriatrics (96.6% vs 91.9%, P = .04). Among laboratory findings, only PTH level was significantly lower and HCO3 concentration was higher in geriatrics compared to non-geriatrics (P = .02, P < .001, respectively). There was no significant difference in last measured eGFR (P = .99) while that measured 4 years ago was lower in geriatrics compared to that of non-geriatrics (P < .001). eGFR change was smaller in geriatrics compared to non-geriatrics (P < .001), and rate of progressive renal disease among non-geriatric group (39%) was found to be significantly higher than in the geriatrics (17.2%) (P < .001). The prevalence of hyperkalemia was lower in geriatrics at stage 3a (P = .02); prevalence of hyperparathyroidism was lower in those at stage 3b (P = .02) and lastly the acidosis was observed significantly lower in geriatric patients at stage 3a, 3b, and 4 compared to the non-geriatrics at corresponding stages (P < .001, P = .03, and P = .04, respectively). The eGFR change was significantly smaller in geriatrics at stage 3b and 4 (P < .001 and P = .04, respectively) while the rate of progressed renal disease was lower in geriatrics at stage 3a and 3b (21.1% vs 9.9%, P = .03 and 41.2% vs 11.1%, P < .001, respectively). eGFR change in 4-year period and the rates of progressive renal disease are higher in the non-geriatrics and also the prevalence of secondary complications of CKD, such as hyperparathyroidism, acidosis, and hyperkalemia, are higher in non-geriatrics. This may reflect that decline of GFR in geriatric individuals is at least partially related to physiological aging rather than kidney disease. Therefore, devising age related CKD definitions might be appropriate.

Kidney function assessment in the geriatric population

PURPOSE OF REVIEW

Kidney function declines with normal aging. But it also declines with the progression of some diseases. This review calls for a more nuanced interpretation of kidney function in the geriatric population, who may have frailty and comorbidities.

RECENT FINDINGS

GFR declines with healthy aging kidneys. Aging kidney changes include decreased cortical volume, senescent global glomerulosclerosis, and reduced nephron numbers. Yet normal aging is not associated with increased glomerular volume or single-nephron GFR. The prevalence of GFR less than 60 ml/min/1.73 m 2 in the geriatric population is high. However, the decline in GFR with normal aging may not reflect true CKD without albuminuria. Although the risk of ESKD and mortality increases in all age groups when eGFR less than 45 ml/min/m 2 , there is no significant increased relative risk of ESKD and mortality in the geriatric population when eGFR 45-59 ml/min/m 2 in the absence of albuminuria. Innovative approaches are needed to better estimate GFR and define CKD in the geriatric population.

SUMMARY

The expected GFR decline in the geriatric population is consistent with normal aging kidney changes. To avoid CKD overdiagnosis and unnecessary referrals to nephrology for possible CKD, age-adapted definitions of CKD in the absence of albuminuria are needed.

General practitioners' representation of early-stage CKD is a barrier to adequate management and patient empowerment: a phenomenological study

BACKGROUND

In high-income countries, chronic kidney disease (CKD) affects over 10% of the population. Identifying these patients early is a priority, especially as new treatments are available to reduce the risk of cardiovascular and renal morbidity. We aimed at understanding the management and care pathway of patients with early-to-moderate CKD defined as an estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m2 (CKD-EPI), by analyzing the experience of general practitioners in a region in France.

METHODS

This qualitative semiopragmatic phenomenological study analyzed in-depth interviews held with a purposive sample (age, gender, training, type of practice, rural/urban context) of 24 general practitioners, with triangulation of research until data saturation.

RESULTS

From diagnostic, etiological and prognostic viewpoints, the general practitioners enrolled in our study perceived CKD as a complex, poorly-defined clinical entity in asymptomatic and multimorbid patients. They distinguished it from a rare condition they considered as 'mainly renal'. The fact that they did not perceive early-stage CKD as a disease was a hindrance to patient care, which should protect the kidneys with a preventive approach. Indeed, general practitioners perceived CKD patient management as a pathway requiring a personalized, integrative model, common to all chronic diseases, without necessarily involving a nephrologist, at least in the early stages.

CONCLUSIONS

This study shows how the general practitioners' representations influence their attitudes and interventions. Clarifying the concept of early-stage CKD by taking factors like age and etiology into account would facilitate personalized management of this heterogeneous, often multimorbid, population. Finally, organizational models to support patient empowerment in an integrative care pathway must be established and validated.

Rivaroxaban vs Vitamin K Antagonist in Patients With Atrial Fibrillation and Advanced Chronic Kidney Disease

Background

Treatment with vitamin K antagonists (VKAs) has been linked to worsening of kidney function in patients with atrial fibrillation (AF).

Objectives

XARENO (Factor XA-inhibition in RENal patients with non-valvular atrial fibrillation Observational registry; NCT02663076) is a prospective observational study comparing adverse kidney outcomes in patients with AF and advanced chronic kidney disease receiving rivaroxaban or VKA.

Methods

Patients with AF and an estimated glomerular filtration rate (eGFR) of 15 to 49 mL/min/1.73 m2 were included. Blinded adjudicated outcome analysis evaluated adverse kidney outcomes (a composite of eGFR decline to <15 mL/min/1.73 m2, need for chronic kidney replacement therapy, or development of acute kidney injury). A composite net clinical benefit outcome (stroke or systemic embolism, major bleeding, myocardial infarction, acute coronary syndrome, or cardiovascular death) was also analyzed. HRs with 95% CIs were calculated using propensity score overlap weighting Cox regression.

Results

There were 1,455 patients (764 rivaroxaban; 691 VKA; mean age 78 years; 44% females). The mean eGFR was 37.1 ± 9.0 in those receiving rivaroxaban and 36.4 ± 10.1 mL/min/1.73 m2 in those receiving VKA. After a median follow-up of 2.1 years, rivaroxaban was associated with less adverse kidney outcomes (HR: 0.62; 95% CI: 0.43-0.88) and all-cause death (HR: 0.76, 95% CI: 0.59-0.98). No significant differences were observed in net clinical benefit.

Conclusions

In patients with AF and advanced chronic kidney disease, those receiving rivaroxaban had less adverse kidney events and lower all-cause mortality compared to those receiving VKA, supporting the use of rivaroxaban in this high-risk group of patients.

Glomerular Filtration Rate Estimation in Adults: Myths and Promises

BACKGROUND

In daily practice, glomerular filtration rate (GFR) is estimated with equations including renal biomarkers. Among these biomarkers, serum creatinine remains the most used. However, there are many limitations with serum creatinine, which we will discuss in the current review. We will also discuss how creatinine-based equations have been developed and what we can expect from them in terms of performance to estimate GFR.

SUMMARY

Different creatinine-based equations have been proposed. We will show the advantages of the recent European Kidney Function Consortium equation. This equation can be used in children and adults. This equation can also be used with some flexibility in different populations.

KEY MESSAGES

GFR is estimated by creatinine-based equations, but the most important for nephrologists is probably to know the limitations of these equations.

Chronic Kidney Disease in the Older Adult Patient with Diabetes

Diabetes mellitus (DM) and chronic kidney disease (CKD) are common in middle aged and older adult individuals. DM may accelerate the aging process, and the age-related declines in the estimated glomerular filtration rate (eGFR) can pose a challenge to diagnosing diabetic kidney disease (DKD) using standard diagnostic criteria especially with the absence of severe albuminuria among older adults. In the presence of CKD and DM, older adult patients may need multidisciplinary care due to susceptibility to various health issues, e.g., cognitive decline, auditory or visual impairment, various comorbidities, complex medical regimens, and increased sensitivity to medication adverse effects. As a result, it can be challenging to apply recent therapeutic advancements for the general population to older adults. We review the evidence that the benefits from these newer therapies apply equally to older and younger patients with CKD and diabetes type 2 and propose a comprehensive management. This framework will address nonpharmacological measures and pharmacological management with renin angiotensin system inhibitors (RASi), sodium glucose co-transporter 2 inhibitors (SGLT2i), non-steroidal mineralocorticoids receptor antagonists (MRAs), and glucagon like peptide 1 receptor agonists (GLP1-RAs).

The burden of end-stage renal disease in Khartoum, Sudan: cost of illness study

BACKGROUND AND PURPOSE

The incidence of end-stage renal disease (ESRD) in Sudan is increasing, affecting the economic status of patients, caregivers and society. This study aimed to measure ESRD's costs, including direct and morbidity indirect expenditures, and to investigate any associated factors and financial consequences.

MATERIALS AND METHODS

This cross-sectional study used a standardized questionnaire to collect data from 150 ESRD patients who had been receiving dialysis for at least one year before the time of data collection at 13 specialized renal centres in Khartoum state. Data about sociodemographic, clinical, and economic factors were gathered, and their relationship to the cost of ESRD was examined using both bivariate (Man Whitney test, Kruskal Wallis test and Spearman correlation) and multivariate analytical procedures (multivariate linear regression).

RESULTS

This study reported a median direct per capita ESRD cost of 38 600 SDG ($1 723.2 PPP) annually with an interquartile range of 69 319.3 SDG ($3 094.6 PPP). The median morbidity indirect cost was estimated to be 0.0 ± 3 352 SDG ($ 0.0 ± 149.6 PPP) per annum. In 28.8% of cases, the patients were their family's primary income earner and over 85% were covered by medical insurance. Our study found that none of the study variables were significantly associated with the total cost of ESRD.

CONCLUSION AND LIMITATIONS

Our findings point out considerable direct out-of-pocket expenses and productivity losses for patients and their households. However, these results should be carefully applied for comparison between the different countries due to differences in the cost of medical interventions and insurance coverage. Further longitudinal studies and studies on health finance and insurance policies are recommended.

Estimating glomerular filtration rate with new equations: can one size ever fit all?

Glomerular filtration rate (GFR) is thought to be the best overall indicator of kidney health. On an individual patient basis, a working knowledge of GFR is important to understand the future risk for chronic kidney disease (CKD) progression, enhanced risk for cardiovascular disease and death, and for optimal medical management including the dosing of certain drugs. Although GFR can be directly measured using exogenous compounds that are eliminated by the kidney, these methods are not scalable for repeated and routine use in clinical care. Thus, in most circumstances GFR is estimated, termed estimated GFR (eGFR), using serum biomarkers that are eliminated by the kidney. Of these, serum creatinine, and to a lesser extent cystatin C, are most widely employed. However, the resulting number is simply a population average for an individual of that age and sex with a given serum creatinine and/or cystatin C, while the range of potential GFR values is actually quite large. Thus, it is important to consider characteristics of a given patient that might make this estimate better or worse in a particular case. In some circumstances, cystatin C or creatinine might be the better choice. Ultimately it is difficult, if not impossible, to have an eGFR equation that performs equally well in all populations. Thus, in certain cases it might be appropriate to directly measure GFR for high consequence medical decision-making, such as approval for kidney donation or prior to certain chemotherapeutic regimens. In all cases, the eGFR thresholds of CKD stage should not be viewed as absolute numbers. Thus, clinical care should not be determined solely by CKD stage as determined by eGFR alone, but rather by the combination of an individual patient's likely kidney function together with their current clinical situation.

Living Donors' Age Modifies the Impact of Pre-Donation Estimated Glomerular Filtration Rate on Graft Survival

BACKGROUND

The global scarcity of organs for kidney transplants (KTs) has led to the increased acceptance of living donors (LDs) with minor abnormalities to increase the donor pool.. We sought to evaluate the effects of some of these LDs' clinical characteristics (older age, borderline renal function, hypertension, dyslipidemia, smoking, and obesity) on graft outcomes.

METHODS

We studied 352 recipients of LDKTs (1998-2020). Firstly, considering the recipients and KT variables, we identified relevant predictors of overall and censored graft failure (GF). Then, adjusting for these predictors, we explored LD variables as predictors of overall and censored GF in a multivariable Cox model.

RESULTS

The recipients from LD with higher eGFR (≥90 mL/min/1.73 m2) had significantly better overall and censored graft survival GS) at 15 y after KT (respectively, 67 and 75% vs. 46 and 46%, p < 0.001). Importantly, none of the remaining LD factors which were evaluated (hypertension, dyslipidemia, smoking, proteinuria, and obesity) were independent predictors of GF. In recipients from LDs < 50 y, having an eGFR < 90 was an independent predictor of overall GF [adjusted HR (95%CI) of 2.578 (1.120-5.795)] and censored GF [adjusted HR (95%CI) of 3.216 (1.300-7.959)], compared to recipients from LDs with eGFR ≥ 90. Contrarily, when donors were older, no difference in the risk of GF was observed between eGFR categories.

CONCLUSION

In our cohort, lower pre-donation eGFR had an impact on GS only in younger LDs. An age-adjusted eGFR cutoff may be pursued for improved donor admissibility.

Diagnostic challenges of diabetic kidney disease

Diabetic kidney disease (DKD) is one of the most common microvascular complications of both type 1 and type 2 diabetes and the most common cause of the end-stage renal disease (ESRD). It has been evidenced that targeted interventions at an early stage of DKD can efficiently prevent or delay the progression of kidney failure and improve patient outcomes. Therefore, regular screening for DKD has become one of the fundamental principles of diabetes care. Long-established biomarkers such as serum-creatinine-based estimates of glomerular filtration rate and albuminuria are currently the cornerstone of diagnosis and risk stratification in routine clinical practice. However, their immanent biological limitations and analytical variations may influence the clinical interpretation of the results. Recently proposed new predictive equations without the variable of race, together with the evidence on better accuracy of combined serum creatinine and cystatin C equations, and both race- and sex-free cystatin C-based equation, have enabled an improvement in the detection of DKD, but also require the harmonization of the recommended laboratory tests, wider availability of cystatin C testing and specific approach in various populations. Considering the complex pathophysiology of DKD, particularly in type 2 diabetes, a panel of biomarkers is needed to classify patients in terms of the rate of disease progression and/or response to specific interventions. With a personalized approach to diagnosis and treatment, in the future, it will be possible to respond to DKD better and enable improved outcomes for numerous patients worldwide.

Glomerular hyperfiltration is an independent predictor of postoperative outcomes: A NSQIP multi-specialty surgical cohort analysis

AIM

While high estimated glomerular filtration rate (eGFR) has been associated with increased overall mortality, its effect on postoperative outcomes is relatively understudied. We sought to investigate the association between high eGFR and 30-day postoperative outcomes using a multi-specialty surgical cohort.

METHODS

Using the National Surgical Quality Improvement Program database, we selected adult for whom eGFR could be calculated using the 2021 Chronic Kidney Disease Epidemiology Collaboration equation. Based on sex-specific distributions of eGFR stratified by age quintiles, we classified patients into low (<5th percentile), normal (5-95th percentile) and high eGFR (>95th percentile). The primary outcome was a composite of any 30-day major adverse outcomes, including: death, reoperation, cardiac arrest, myocardial infarction and stroke. Secondary outcomes included 30-day infectious complications, venous thromboembolism (VTE), bleeding requiring transfusion, prolonged length of stay and unplanned readmission. After matching for demographic differences, comorbidity burden and operative characteristics, logistic regression models were used to evaluate the association between extremes of eGFR and the outcomes of interest.

RESULTS

Of 1 668 447 patients, 84 115 (5.07%) had a high eGFR. High eGFR was not associated with major adverse outcomes (odds ratio [OR] 1.00 [95% confidence interval (CI): 0.97, 1.03]); however, it was associated with reoperation (OR 1.04 [95% CI: 1.00,1.08]), infectious complications (OR 1.14 [95% CI: 1.11, 1.16]), VTE (OR 1.15 [95% CI: 1.09, 1.22]) and prolonged length of stay (OR 1.19 [95% CI: 1.16, 1.21]).

CONCLUSION

Our findings support an association between high eGFR and adverse 30-day postoperative outcomes.