US Renal Data System 2018 Annual Data Report: Epidemiology of Kidney Disease in the United States

Performance of Creatinine Clearance and Estimated GFR in Assessing Kidney Function in Living Donor Candidates

BACKGROUND

Glomerular filtration rate (GFR) assessment is a key aspect in the evaluation of living kidney donor candidates; however, data on performance of commonly used methods are limited.

METHODS

We examined 769 living kidney donor candidates with 24-hour urine collections assessed as accurate by comparing measured creatinine excretion rate (CER) to CER estimated using a 4-variable equation previously developed and validated using robust methodology.

RESULTS

Of all collections, 42.6% would have been deemed inaccurate, mostly under-collections, using the conventional weight- and gender-based CER estimation. Creatinine clearance (CrCl) overestimated I-iothalamate GFR (iGFR), estimated GFR (eGFR), underestimated iGFR, and their average [Avg (CrCl and eGFR)] essentially eliminated the GFR bias (median bias = +2.2, -5.4, and -1.0 mL/min/1.73 m, respectively; P < 0.001). This held true for all subgroups except blacks, where all 3 measures overestimated iGFR. Avg (CrCl and eGFR) also offered modestly improved accuracy compared with CrCl alone, as measured by the proportion of values falling within 10% (50.7% versus 45.3%; P = 0.009) and 30% of iGFR (94.5% versus 89.3%; P < 0.001).

CONCLUSIONS

When measured GFR is unavailable, the Avg (CrCl and eGFR) provides a better estimate of kidney function in kidney donor candidates than either measure alone, although in blacks the estimates are neither better nor worse.

Effect of ultrafiltration profiling on outcomes among maintenance hemodialysis patients: a pilot randomized crossover trial

BACKGROUND

More rapid fluid removal during hemodialysis is associated with adverse cardiovascular outcomes and longer dialysis recovery times. The effect of ultrafiltration (UF) profiling, independent of concomitant sodium profiling, on markers of intradialytic hemodynamics and other outcomes has been inadequately studied.

METHODS

Four-phase, blinded crossover trial. Participants (UF rates > 10 mL/h/kg) were assigned in random order to receive hemodialysis with UF profiling (constantly declining UF rate, intervention) vs. hemodialysis with conventional UF (control). Each 3-week 9-treatment period was followed by a 1-week 3-treatment washout period. Participants crossed into each study arm twice (2 phases/arm); 18 treatments per treatment type. The primary outcomes were intradialytic hypotension, pre- to post-dialysis troponin T change, and change from baseline in left ventricular global longitudinal strain. Other outcomes included intradialytic symptoms and blood volume measured-plasma refill (post-dialysis volume status measure), among others. Each participant served as their own control.

RESULTS

On average, the 34 randomized patients (mean age 56 years, 24% female, mean dialysis vintage 6.3 years) had UF rates > 10 mL/h/kg in 56% of treatments during the screening period. All but 2 patients completed the 15-week study (prolonged hospitalization, kidney transplant). There was no significant difference in intradialytic hypotension, troponin T change, or left ventricular strain between hemodialysis with UF profiling and conventional UF. With UF profiling, participants had significantly lower odds of light-headedness and plasma refill compared to hemodialysis with conventional UF.

CONCLUSIONS

Ultrafiltration (UF) profiling did not reduce the odds of treatment-related cardiac stress but did reduce the odds of light-headedness and post-dialysis hypervolemia.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT03301740 (registered October 4, 2017).

Spontaneous Dislodgement of Tunneled Dialysis Catheters after De Novo versus Over-The-Wire-Exchange Placement

PURPOSE

To evaluate dislodgement of tunneled dialysis catheters (TDCs) in de novo (DN) placement with ultrasound versus over-the-wire exchange (OTWE).

MATERIALS AND METHODS

Data were collected retrospectively on all TDC placements at this institution from 2001 to 2019 and were excluded if no removal date was recorded or if dwell time was more than 365 days. Information on TDC brand, placement, insertion/removal, and removal reason were collected. Multiple logistic regression evaluated factors associated with TDC dislodgement. DN placement and OTWE were compared for rate of dislodgement (generalized estimating equations method) and TDC dwell time (survival analysis).

RESULTS

In total, 5328 TDCs were included with 66% (3522) placed DN and 32% (1727) via OTWE. Mean dwell time was 65 ± 72 days, and dislodgement occurred in 4% (224). TDC dislodgement rates in the DN and OTWE groups were 0.48 and 0.93 per 1000 catheter days, respectively. Brand (Ash Split vs. VectorFlow), placement technique (OTWE vs. DN), laterality (left vs. right), and site (left vs. right internal jugular vein) were significant predictors of dislodgement. OTWE placement exhibited 1.7 times the odds of dislodgement (95% confidence interval, 1.2-2.6; P = .004) compared to DN and had significantly higher probability of dislodgement across time (hazard ratio = 2.0; P < .001) compared to DN. Dislodgement rates for OTWE vs. DN were 8% vs. 3% (3 months), 13% vs. 6% (6 months), and 38% vs. 17% (1 year).

CONCLUSIONS

TDC spontaneous dislodgement rates were significantly and consistently higher after OTWE compared to DN placement. These data support more careful attention to catheter fixation after OTWE placement.

Epidemiology of dialysis-treated end-stage renal disease patients in Kazakhstan: data from nationwide large-scale registry 2014-2018

BACKGROUND

The epidemiology of dialysis patients has been little studied in developing countries and economies in transition. We examined the prevalence, incidence and mortality rate of dialysis patients in Kazakhstan, via aggregation and utilization of large-scale administrative healthcare data.

METHODS

The registry data of 8898 patients receiving dialysis therapy between 2014 and 2018 years were extracted from the Unified National Electronic Health System (UNEHS) and linked with the national population registry of Kazakhstan. We provide descriptive statistics of demographic, comorbidity and dialysis-related characteristics.

RESULTS

Among all patients undergoing maintenance dialysis for end-stage renal disease (ESRD), there were 3941 (44%) females and 4957 (56%) males. 98.7% of patients received hemodialysis and 1.3% peritoneal dialysis. The majority of the patients (63%) were ethnic Kazakhs, 18% were Russians and 19% were of other ethnicities. The prevalence and incidence rate in 2014 were 135.2 and 68.9 per million population (PMP), respectively, which were different in 2018 [350.2 and 94.9 PMP, respectively]. Overall mortality rate among dialysis patients reduced from 1667/1000 patient-years [95%Confidence Interval (CI): 1473-1886] (PY) in 2014 to 710/1000PY [95%CI: 658-767] in 2018. We observed 13% lower crude survival probability in females compared to males and in older patients compared to younger ones. Russian ethnicity had 58% higher risk of death, while other ethnicities had 34% higher risk of death compared to in those of Kazakh ethnicity.

CONCLUSION

We describe for the first time in Kazakhstan an increase in the prevalence and incidence of ESRD on dialysis, while mortality rate decreased over time, during 2014-2018. We observed statistically significant lower survival probability in female dialysis patients compared to males, in older patients compared to younger ones, and in patients of Russian ethnicity compared to Kazakh.

Increased Mortality Risk in People with Type 2 Diabetes Mellitus in Lithuania

This retrospective cohort study aimed to analyze overall and cause-specific mortality risk in people with type 2 diabetes mellitus (T2DM) in Lithuania. Information on the diagnosis of T2DM and glucose-lowering medication was obtained from the National Health Insurance Fund database, causes of death-from death certificates. Sex, age, and calendar period-standardized mortality ratios (SMRs) were calculated. In addition, 89,512 patients were followed-up between 2010 and 2017, contributing to the observation period of 592,321 person-years. Overall mortality risk was increased for both sexes (overall SMR = 1.35, 95% confidence interval (CI) 1.34-1.37). Greatest mortality risk was in the age group of 40-49 years at diabetes diagnosis (SMR = 1.68, 95% CI 1.60-1.76) and among those who had died before the age of 50 (SMR = 22.04, 95% CI 18.82-25.81). Patients treated with insulin only had the highest SMR (2.43, 95% CI 2.32-2.55). Mortality risk increased with increasing diabetes duration and was higher in women in all these groups. The highest cause-specific SMRs were infection-related causes (SMR = 1.44), particularly septicemia (SMR = 1.78), diseases of the circulatory system (SMR = 1.42), especially ischemic heart (SMR = 1.46) and cerebrovascular diseases (SMR = 1.38), as well as diseases of the digestive system (SMR = 1.35). Cancer mortality risk was elevated for women (SMR = 1.13), but not for men (SMR = 0.93). In conclusion, people with T2DM had an excess mortality risk, which was higher in women compared to men, younger people, in those who were diagnosed with T2DM at a younger age, had longer diabetes duration, and who required treatment with insulin.

Risk of Glaucoma in Patients Receiving Hemodialysis and Peritoneal Dialysis: A Nationwide Population-Based Cohort Study

This paper investigated the incidence and risk of newly diagnosed glaucoma after the initiation of maintenance dialysis in Taiwan. A case-control study was conducted using the National Health Insurance Research Database (NHIRD) in Taiwan. There were 3949 patients with dialysis in the study group and 78,980 non-dialysis subjects matched by age and sex in the comparison group. The incidence of newly diagnosed glaucoma after the initiation of maintenance dialysis was analyzed based on the diagnostic code for glaucoma. Patients with dialysis had a higher risk of glaucoma (adjusted hazard ratio (aHR): 1.270; 95% confidence interval (CI): 1.035-1.560) than patients without dialysis. The incidence rate of glaucoma was 8.18 per 10,000 person months in the dialysis group, which was higher than that in the non-dialysis group (5.01 per 10,000 person months). Patients with dialysis exhibited a significantly higher risk of angle-closure glaucoma (ACG) (aHR: 1.550; 95% CI: 1.074-2.239). In contrast, there was no significant risk of developing open-angle glaucoma or normal-tension glaucoma in dialysis patients. Our data suggest that dialysis patients are more susceptible to ACG. Regular ophthalmic examinations may be useful in patients with dialysis to identify high-risk individuals with glaucoma, and preventive measures can be applied to avoid permanent vision loss as soon as intraocular pressure (IOP) elevation is identified.

Oxidative stress accelerates the carotid atherosclerosis process in patients with chronic kidney disease

INTRODUCTION

The atherosclerosis process is highly accelerated in patients with chronic kidney disease (CKD). Oxidative stress is considered as one of the pro-atherogenic factors involved in accelerating the atherosclerosis process of the carotid artery. The aim of the present study was to determine the relationship between oxidative stress markers and the progression of carotid atherosclerosis in CKD patients.

MATERIAL AND METHODS

The study was conducted on 162 patients with CKD and 40 controls, and the disease stage was scored between 2 and 5D. Blood samples were taken and advanced oxidative protein product, myeloperoxidases, malondialdehyde, nitric oxide, glutathione, and oxidised low-density lipoprotein were measured. Furthermore, we studied the correlations between these biomarkers and clinical and para-clinical cardiovascular complications.

RESULTS

The average age of patients was 56.5 years. The oxidative stress markers average ± SD levels in CKD groups compared to the control were as follows: advanced oxidation protein product (61.89 ±1.4 vs. 26.65 ±1.05 µmol/l), myeloperoxidase (59.89 ±1.98 vs. 38.45 ±1.98 UI/ml), malondialdehyde (6.1 ±0.12 vs. 3.26 ±0.03 µmol/l), nitric oxide (65.82 ±1.06 vs. 52.19 ±2.1 µmol/l), glutathione (52.21 ±1.3 vs. 89.4 ±2.6 IU/ml), and oxLDL (15.57 ±1.07 vs. 1.72 ±0.82 µmol/l). While the glutathione level decreased significantly in advanced CKD stage (p < 0.05), the concentrations of all the other biomarkers increased significantly in accordance with CKD score (p < 0.05).

CONCLUSIONS

Cardiovascular diseases, mainly atherosclerosis, can be diagnosed indirectly by measuring oxidative stress markers. Furthermore, theses markers can be used to predict the progression of CKD, for better management of the disease.

Physical performance and chronic kidney disease development in elderly adults: results from a nationwide cohort study

Sarcopenia, which is characterized by muscle mass and physical performance, is closely associated with morbidities and mortality, especially among the elderly. However, the effect of physical performance on chronic kidney disease (CKD) development is not yet fully elucidated. A total of 30,871 adults aged 66 years with preserved renal function who underwent health screening examinations were evaluated. Physical performance was assessed using a 3-m timed up and go (TUG) test and the one-leg stand (OLS) test. The primary outcome was the development of CKD, defined as at least two consecutive measurements of estimated glomerular filtration rate < 60 mL/min/1.73 m². The rates of mortality and incident CKD development were significantly elevated with increases in TUG test scores but not in OLS scores. In the Cox hazards model, the highest TUG test score tertile was associated with an increased risk for CKD development (hazard ratio, 1.23; 95% confidence interval, 1.10-1.38) compared with the lowest tertile. No significant relationship was observed between OLS score and incident CKD risk. Poor physical performance, assessed using the TUG test, was related to an increased risk of CKD development.

Medication Reconciliation: The Foundation of Medication Safety for Patients Requiring Dialysis

Medication-related problems are a leading cause of morbidity and mortality. Patients requiring dialysis are at heightened risk for adverse drug reactions because of the prevalence of polypharmacy, multiple chronic conditions, and altered (but not well understood) medication pharmacokinetics and pharmacodynamics inherent to kidney failure. To minimize preventable medication-related problems, health care providers need to prioritize medication safety for this population. The cornerstone of medication safety is medication reconciliation. We present a case highlighting adverse outcomes when medication reconciliation is insufficient at care transitions. We review available literature on the prevalence of medication discrepancies worldwide. We also explain effective medication reconciliation and the practical considerations for implementation of effective medication reconciliation in dialysis units. In light of the addition of medication reconciliation requirements to the Centers for Medicare & Medicaid Services End-Stage Renal Disease Quality Incentive Program, this review also provides guidance to dialysis unit leadership for improving current medication reconciliation practices. Prioritization of medication reconciliation has the potential to positively affect rates of medication-related problems, as well as medication adherence, health care costs, and quality of life.

The PrEscription of intraDialytic exercise to improve quAlity of Life in patients with chronic kidney disease trial: study design and baseline data for a multicentre randomized controlled trial

Background

Exercise interventions designed to improve physical function and reduce sedentary behaviour in haemodialysis (HD) patients might improve exercise capacity, reduce fatigue and lead to improved quality of life (QOL). The PrEscription of intraDialytic exercise to improve quAlity of Life study aimed to evaluate the effectiveness of a 6-month intradialytic exercise programme on QOL and physical function, compared with usual care for patients on HD in the UK.

Methods

We conducted a prospective, pragmatic multicentre randomized controlled trial in 335 HD patients and randomly (1:1) assigned them to either (i) intradialytic exercise training plus usual care maintenance HD or (ii) usual care maintenance HD. The primary outcome of the study was the change in Kidney Disease Quality of Life Short Form (KDQOL-SF 1.3) Physical Component Score between baseline and 6 months. Additional secondary outcomes included changes in peak aerobic capacity, physical fitness, habitual physical activity levels and falls (International Physical Activity Questionnaire, Duke’s Activity Status Index and Tinetti Falls Efficacy Scale), QOL and symptom burden assessments (EQ5D), arterial stiffness (pulse wave velocity), anthropometric measures, resting blood pressure, clinical chemistry, safety and harms associated with the intervention, hospitalizations and cost-effectiveness. A nested qualitative study investigated the experience and acceptability of the intervention for both participants and members of the renal health care team.

Results

At baseline assessment, 62.4% of the randomized cohort were male, the median age was 59.3 years and 50.4% were white. Prior cerebrovascular events and myocardial infarction were present in 8 and 12% of the cohort, respectively, 77.9% of patients had hypertension and 39.4% had diabetes. Baseline clinical characteristics and laboratory data for the randomized cohort were generally concordant with data from the UK Renal Registry.

Conclusion

The results from this study will address a significant knowledge gap in the prescription of exercise interventions for patients receiving maintenance HD therapy and inform the development of intradialytic exercise programmes both nationally and internationally.

Trial Registration

ISRCTN N83508514; registered on 17 December 2014.

Cost Analysis of Dialysis Access Maintenance Interventions across Physician Specialties in U.S. Medicare Beneficiaries

Background Dialysis maintenance interventions account for billions of dollars in U.S. Medicare spending and are performed by multiple medical specialties. Whether Medicare costs differ by physician specialty is, to the knowledge of the authors, not known. Purpose To assess patency-adjusted costs of endovascular dialysis access maintenance by physician specialty. Materials and Methods In this retrospective longitudinal cohort study, patients who were beneficiaries of Medicare undergoing their first arteriovenous access placement in 2009 were identified by using billing codes in the 5% Limited Data Set. By tracking their utilization data through 2014, postintervention primary patency and aggregate payments associated with maintenance interventions were calculated. Unadjusted payments per year of access patency gain were compared across physician specialty. A general linear mixed-effects model adjusted for covariates was used, as follows: patient characteristics, access type (fistula vs graft), clinical severity, type of intervention (angioplasty, stent, thrombolysis), clinical location (hospital outpatient vs office-based laboratory), and resource utilization (operating room use, anesthesia use). Results First arteriovenous access was performed in 1479 beneficiaries (mean age, 63 years ± 15 [standard deviation]; 820 men) in 2009. Through 2014, 8166 maintenance interventions were performed in this cohort. Unadjusted mean Medicare payments for each incremental year of patency were as follows: $71 000 for radiologists, $89 000 for nephrologists, and $174 000 for surgeons. Billing for operating room (41.8% [792 of 1895], surgery; 10.2% [277 of 2709], nephrology; and 31.1% [1108 of 3562], radiology) and anesthesia (19.9% [377 of 1895], surgery; 2.6% [70 of 2709], nephrology; 4.7% [170 of 3562], radiology) varied by specialty and accounted for 407% and 132% higher payments, respectively. After adjusting for clinical severity and location, type of intervention, and resource utilization, nephrologists and surgeons had 59% (95% confidence interval: 44%, 73%; P < .001) and 57% (95% confidence interval: 43%, 72%; P < .001) higher payments, respectively, for the same patency gain compared with radiologists. Operating room use and anesthesia services were major drivers of higher cost, with 407% (95% confidence interval: 374%, 443%; P < .001) and 132% (95% confidence interval: 116%, 150%; P < .001) higher costs, respectively. Conclusion Patency-adjusted payments for hemodialysis access maintenance differed by physician specialty, driven partly by discrepant rates of billing for operating room and anesthesia use. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by White in this issue.

Burden and Cost of Caring for US Veterans With CKD: Initial Findings From the VA Renal Information System (VA-REINS)

Kidney disease is a common, complex, costly, and life-limiting condition. Most kidney disease registries or information systems have been limited to single institutions or regions. A national US Department of Veterans Affairs (VA) Renal Information System (VA-REINS) was recently developed. We describe its creation and present key initial findings related to chronic kidney disease (CKD) without kidney replacement therapy (KRT). Data from the VA's Corporate Data Warehouse were processed and linked with national Medicare data for patients with CKD receiving KRT. Operational definitions for VA user, CKD, acute kidney injury, and kidney failure were developed. Among 7 million VA users in fiscal year 2014, CKD was identified using either a strict or liberal operational definition in 1.1 million (16.4%) and 2.5 million (36.3%) veterans, respectively. Most were identified using an estimated glomerular filtration rate laboratory phenotype, some through proteinuria assessment, and very few through International Classification of Diseases, Ninth Revision coding. The VA spent ∼$18 billion for the care of patients with CKD without KRT, most of which was for CKD stage 3, with higher per-patient costs by CKD stage. VA-REINS can be leveraged for disease surveillance, population health management, and improving the quality and value of care, thereby enhancing VA's capacity as a patient-centered learning health system for US veterans.

The Adverse Effect of COVID Pandemic on the Care of Patients With Kidney Diseases in India

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic has affected the care of patients with noncommunicable diseases, including those suffering from kidney-related ailments. Many parts of the world, including India, adopted lockdown to curb community transmission of disease. The lockdown affected transportation, access to health care facilities, and availability of medicines and consumables as well as outpatient and inpatient services. We aimed to analyze the effect of lockdown imposed due to the COVID-19 pandemic on the care of patients with kidney diseases in India.

METHODS

We surveyed 19 major hospitals (8 in the public and 11 in the private sector) to determine the effect of lockdown on the care of patients with kidney disease, including those on dialysis after the first 3 weeks of lockdown.

RESULTS

The total number of dialysis patients in these centers came down from 2517 to 2404. Approximately 710 (28.2%) patients missed 1 or more dialysis sessions, 69 (2.74%) required emergency dialysis sessions, 104 (4.13%) stopped reporting for dialysis, and 9 (0.36%) were confirmed to have died. Outpatient attendance in the surveyed hospital came down by 92.3%, and inpatient service reduced by 61%. Tele-consultation was started but was accessed by only a small number of patients.

CONCLUSION

Lack of preparedness before lockdown resulted in an interruption in health care services and posed an immediate adverse effect on the outcome of dialysis patients and patients with kidney disease in India. The long-term impact on the health of patients with less severe forms of kidney disease remains unknown.

Renal Replacement Knowledge and Preferences for African Americans With Chronic Kidney Disease

BACKGROUND

Renal replacement therapies (RRT) other than in-centre haemodialyses are underutilised by African Americans with end-stage renal disease (ESRD) even though they are associated with reduced costs, morbidity and mortality as well as improved quality of life for patients.

OBJECTIVES

To understand African American patients' knowledge of RRT options and how patient, provider and system-factors contribute to knowledge and preferences. Participants' interviews were conducted at the University of Chicago Medical Center with African American patients with chronic kidney disease (CKD). The final analysis included 28 interviews; 22 patients had CKD not yet on dialysis or having received a transplant, while 6 had reached ESRD and were receiving treatment for kidney failure. Approach Transcripts were uploaded into NVivo8 for coding. Thematic analysis was used for data interpretation.

RESULTS

Four themes were identified: (1) limited knowledge of home modalities and deceased donor options, (2) CKD patients gave little thought to choosing RRT options, (3) CKD patients relied on doctors for treatment decisions, and (4) while patients reported knowledge of living kidney donation transplants (LKDT), it did not translate to receiving an LKDT.

CONCLUSION

African Americans face significant knowledge and access barriers when deciding on their RRT treatment. Even patients with advanced CKD were still in the early stages of RRT selection. Understanding the knowledge gaps and barriers patients face will inform our subsequent intervention to educate and motivate patients to increase CKD self-care and improve communication between patients, their families and their providers about different RRT treatments.

Associations of serum sclerostin and Dickkopf-related protein-1 proteins with future cardiovascular events and mortality in haemodialysis patients: a prospective cohort study

Background

Sclerostin and Dickkopf-related protein-1 (Dkk-1) proteins are inhibitors of the canonical Wnt/β-catenin bone pathway. Sclerostin but not Dkk-1 is associated with increased arterial stiffness. This study examined the prognostic significance of sclerostin and Dkk-1 levels for cardiovascular outcomes and mortality in haemodialysis (HD) patients.

Methods

Serum sclerostin and Dkk-1 levels were measured with enzyme-linked immunosorbent assay in 80 HD patients that were followed-up for a median of 45 months. Factors that could interfere with the association of sclerostin and Dkk-1 with outcomes [including carotid–femoral pulse wave velocity (PWV), parathyroid hormone (PTH), calcium–phosphate product and others] were assessed at baseline. The primary endpoint was a combination of all-cause death, non-fatal myocardial infarction, non-fatal stroke, coronary revascularization, hospitalization for decompensated heart failure and new-onset atrial fibrillation. Secondary endpoints included cardiovascular and all-cause mortality.

Results

Cumulative freedom from the primary endpoint was significantly lower for higher tertiles of sclerostin (77.8, 69.2 and 40.7%; Tertiles 1–3, respectively; log-rank P = 0.004). The risk for the primary outcome gradually increased for higher sclerostin tertiles [Tertile 3: hazard ratio (HR) = 3.847, 95% confidence interval (CI) 1.502–9.851]. No significant association was evident between sclerostin and all-cause mortality, whereas higher sclerostin levels presented a trend towards higher risk for cardiovascular mortality. Dkk-1 levels exhibited no association with the risk of the primary or secondary endpoints. In stepwise Cox regression modelled analysis, sclerostin levels were associated with the primary outcome, independently of PTH, calcium–phosphate product, serum albumin, C-reactive protein and PWV levels (HR = 2.921, 95% CI 1.401–6.090; P = 0.004).

Conclusions

High sclerostin levels are associated with lower cumulative freedom and higher risk for a composite endpoint of cardiovascular events and mortality. Dkk-1 exhibited no association with the future risk of adverse outcomes.

Factors affecting the relationship between ionized and corrected calcium levels in peritoneal dialysis patients: a retrospective cross-sectional study

BACKGROUND

Chronic kidney disease-mineral and bone disorder (CKD-MBD) management in patients with end-stage renal disease is important owing to the risk of cardiovascular diseases. In clinical practice, we manage patients not by monitoring the levels of biologically active ionized calcium (iCa) but by monitoring total serum calcium or corrected calcium (cCa). We previously reported that iCa/cCa ratio was different between patients with hemodialysis and those with peritoneal dialysis (PD). In PD patients, several factors are expected to affect iCa/cCa ratio. Therefore, modifying the strategy to achieve better CKD-MBD management might be necessary; however, no reports have studied this to date. Therefore, we investigated the factors influencing iCa/cCa ratio in PD patients.

METHODS

This retrospective cross-sectional study examined background and laboratory data, including iCa, collected at routine outpatient visits. The patients were divided into the first, second, and third tertile of iCa/cCa ratio groups to compare patient background and laboratory data. Multiple regression analysis was used to investigate the factors influencing iCa/cCa ratio. We used multiple imputation to deal with missing covariate data.

RESULTS

In total, 169 PD patients were enrolled. In PD patients with lower iCa/cCa ratio, PD duration was longer and pH was higher. Urine volume and weekly renal Kt/V were lower in the patients with lower iCa/cCa ratio than in those with higher iCa/cCa ratio. iCa/cCa ratio and weekly renal Kt/V were directly correlated (r = 0.41, p < 0.01), and weekly renal Kt/V and pH were independent factors affecting iCa/cCa ratio (t = 2.86, p < 0.01 and t = - 5.42, p < 0.01, respectively).

CONCLUSIONS

iCa levels were lower in PD patients with lower residual renal function (RRF) even though their cCa levels were equal to those with maintained RRF, warranting caution in the assessment and management of CKD-MBD in PD patients.

Hemodialysis Use and Practice Patterns: An International Survey Study

RATIONALE & OBJECTIVE

Hemodialysis (HD) is the most common form of kidney replacement therapy. This study aimed to examine the use, availability, accessibility, affordability, and quality of HD care worldwide.

STUDY DESIGN

A cross-sectional survey.

SETTING & PARTICIPANTS

Stakeholders (clinicians, policy makers, and consumer representatives) in 182 countries were convened by the International Society of Nephrology from July to September 2018.

OUTCOMES

Use, availability, accessibility, affordability, and quality of HD care.

ANALYTICAL APPROACH

Descriptive statistics.

RESULTS

Overall, representatives from 160 (88%) countries participated. Median country-specific use of maintenance HD was 298.4 (IQR, 80.5-599.4) per million population (pmp). Global median HD use among incident patients with kidney failure was 98.0 (IQR, 81.5-140.8) pmp and median number of HD centers was 4.5 (IQR, 1.2-9.9) pmp. Adequate HD services (3-4 hours 3 times weekly) were generally available in 27% of low-income countries. Home HD was generally available in 36% of high-income countries. 32% of countries performed monitoring of patient-reported outcomes; 61%, monitoring of small-solute clearance; 60%, monitoring of bone mineral markers; 51%, monitoring of technique survival; and 60%, monitoring of patient survival. At initiation of maintenance dialysis, only 5% of countries used an arteriovenous access in almost all patients. Vascular access education was suboptimal, funding for vascular access procedures was not uniform, and copayments were greater in countries with lower levels of income. Patients in 23% of the low-income countries had to pay >75% of HD costs compared with patients in only 4% of high-income countries.

LIMITATIONS

A cross-sectional survey with possibility of response bias, social desirability bias, and limited data collection preventing in-depth analysis.

CONCLUSIONS

In summary, findings reveal substantial variations in global HD use, availability, accessibility, quality, and affordability worldwide, with the lowest use evident in low- and lower-middle-income countries.

Associations of Serum Calciprotein Particle Size and Transformation Time With Arterial Calcification, Arterial Stiffness, and Mortality in Incident Hemodialysis Patients

RATIONALE & OBJECTIVE

Characteristics of the transformation of primary to secondary calciprotein particles (CPPs) in serum, including the size of secondary CPP (CPP2) aggregates and the time of transformation (T₅₀), may be markers for arterial calcification in patients undergoing hemodialysis (HD). We examined the associations of CPP2 aggregate size and T₅₀ with arterial calcification in incident HD patients.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Incident HD patients (n=402with available CPP2 measures and n=388with available T₅₀ measures) from the Predictors of Arrhythmic and Cardiovascular Risk in End-Stage Renal Disease (PACE) Study PREDICTORS: Serum CPP2 size and T₅₀ at baseline.

OUTCOMES

Primary outcomes were baseline coronary artery and thoracic aorta calcifications. Exploratory outcomes included baseline arterial stiffness, measured by pulse wave velocity (PWV) and ankle brachial index, and longitudinally, repeat measures of PWV and all-cause mortality.

ANALYTICAL APPROACH

Tobit regression, multiple linear regression, Poisson regression, linear mixed-effects regression, and Cox proportional hazards regression.

RESULTS

Mean age was 55±13 years, 41% were women, 71% were Black, and 57% had diabetes mellitus. Baseline CPP2 size and T₅₀ were correlated with baseline fetuin A level (r=-0.59 for CPP2 and 0.44 for T₅₀; P<0.001 for both), but neither was associated with baseline measures of arterial calcification or arterial stiffness. Baseline CPP2 size and T₅₀ were not associated with repeat measures of PWV. During a median follow-up of 3.5 (IQR, 1.7-6.2) years, larger CPP2 was associated with higher risk for mortality (HR, 1.17 [95% CI, 1.05-1.31] per 100nm larger CPP2 size) after adjusting for demographics and comorbid conditions, but there was no association between baseline T₅₀ and risk for mortality.

LIMITATIONS

Possible imprecision in assays, small sample size, limited generalizability to incident HD populations with different racial composition, and residual confounding.

CONCLUSIONS

In incident HD patients, neither CPP2 size nor T₅₀ was associated with prevalent arterial calcification and stiffness. Larger CPP2 was associated with risk for mortality, but this finding needs to be confirmed in future studies.

Use of a Supportive Kidney Care Video Decision Aid in Older Patients: A Randomized Controlled Trial

BACKGROUND

There are few studies of patient-facing decision aids that include supportive kidney care as an option. We tested the efficacy of a video decision aid on knowledge of supportive kidney care among older patients with advanced CKD.

METHODS

Participants (age ≥ 65 years with advanced CKD) were randomized to receive verbal or video education. Primary outcome was knowledge of supportive kidney care (score range 0-3). Secondary outcomes included preference for supportive kidney care, and satisfaction and acceptability of the video.

RESULTS

Among all participants (n = 100), knowledge of supportive kidney care increased significantly after receiving education (p < 0.01); however, there was no difference between study arms (p = 0.68). There was no difference in preference for supportive kidney care between study arms (p = 0.49). In adjusted analyses, total health literacy score (aOR 1.08 [95% CI: 1.003-1.165]) and nephrologists' answer of "No" to the Surprise Question (aOR 4.87 [95% CI: 1.22-19.43]) were associated with preference for supportive kidney care. Most felt comfortable watching the video (96%), felt the content was helpful (96%), and would recommend the video to others (96%).

CONCLUSIONS

Among older patients with advanced CKD, we did not detect a significant difference between an educational verbal script and a video decision aid in improving knowledge of supportive kidney care or preferences. However, patients who received video education reported high satisfaction and acceptability ratings. Future research will determine the effectiveness of a supportive kidney care video decision aid on real-world patient outcomes.

TRIAL REGISTRATION

NCT02698722 (ClinicalTrials.gov).

Peritoneal Dialysis Use and Practice Patterns: An International Survey Study

RATIONALE & OBJECTIVE

Approximately 11% of people with kidney failure worldwide are treated with peritoneal dialysis (PD). This study examined PD use and practice patterns across the globe.

STUDY DESIGN

A cross-sectional survey.

SETTING & PARTICIPANTS

Stakeholders including clinicians, policy makers, and patient representatives in 182 countries convened by the International Society of Nephrology between July and September 2018.

OUTCOMES

PD use, availability, accessibility, affordability, delivery, and reporting of quality outcome measures.

ANALYTICAL APPROACH

Descriptive statistics.

RESULTS

Responses were received from 88% (n=160) of countries and there were 313 participants (257 nephrologists [82%], 22 non-nephrologist physicians [7%], 6 other health professionals [2%], 17 administrators/policy makers/civil servants [5%], and 11 others [4%]). 85% (n=156) of countries responded to questions about PD. Median PD use was 38.1 per million population. PD was not available in 30 of the 156 (19%) countries responding to PD-related questions, particularly in countries in Africa (20/41) and low-income countries (15/22). In 69% of countries, PD was the initial dialysis modality for≤10% of patients with newly diagnosed kidney failure. Patients receiving PD were expected to pay 1% to 25% of treatment costs, and higher (>75%) copayments (out-of-pocket expenses incurred by patients) were more common in South Asia and low-income countries. Average exchange volumes were adequate (defined as 3-4 exchanges per day or the equivalent for automated PD) in 72% of countries. PD quality outcome monitoring and reporting were variable. Most countries did not measure patient-reported PD outcomes.

LIMITATIONS

Low responses from policy makers; limited ability to provide more in-depth explanations underpinning outcomes from each country due to lack of granular data; lack of objective data.

CONCLUSIONS

Large inter- and intraregional disparities exist in PD availability, accessibility, affordability, delivery, and reporting of quality outcome measures around the world, with the greatest gaps observed in Africa and South Asia.

Efficacy and utility of robotic single-access bilateral nephrectomy (r-SABN) in end-stage renal disease patients

PURPOSE

Bilateral native nephrectomies are needed in ESRD patients with select indications in a pre-transplant setting. Yet, the perioperative morbidity is significant in this population. Herein we evaluate the efficacy and utility of r-SABN.

METHOD

A total of 12 patients were consented at a single center. Of 12 patients, 3 patients did not meet study criteria and were excluded. Preoperative, perioperative, and postoperative data were prospectively collected from 9 patients from electronic health records and administered postoperative surveys. Patients were assessed at 30-180 days postoperatively for follow-up.

RESULTS

Mean operative time was 204.3 ± 59.7 min (142.0-314.0) and estimated blood loss during operation was 94.4 ± 87.3 ml (25.0-300.0). The mean length of hospital stay was 2 ± 0.7 days (1-3) for all patients. Total post-operative opioid usage was normalized to morphine dose equivalents (MDE) and calculated to be 56.1 ± 30.4 mg (30.8-101.8). Patients experienced a fourfold and tenfold respective increase in weekly structural and incidental physical activity from 30 to 180 days postoperatively. There were no procedure related intraoperative or postoperative complications reported in the cohort.

CONCLUSION

Overall, r-SABN afforded the patients low morbidity. Longitudinal studies are in progress to further assess the efficacy and outcome of this procedure. In a single-center study, we demonstrate r-SABN is viable and provides a novel tool for treatment of ESRD patients requiring this procedure.

Hierarchical Clustering Analysis for Predicting 1-Year Mortality After Starting Hemodialysis

Introduction

For patients with end-stage renal disease (ESRD), due to the heterogeneity of the population, appropriate risk assessment approaches and strategies for further follow-up remain scarce. We aimed to conduct a pilot study for better risk stratification, applying machine learning–based classification to patients with ESRD who newly started maintenance hemodialysis.

Methods

We prospectively studied 101 patients with ESRD, who were new to maintenance hemodialysis therapy, between August 2016 and March 2018. Baseline values of variables such as blood and urine tests were obtained before the initiation of hemodialysis. Agglomerative hierarchical clustering was conducted with the collected continuous data. The resulting clusters were followed up for the primary outcome of 1-year mortality, as analyzed by the Kaplan-Meier survival curve with log-rank test and the Cox proportional hazard model.

Results

The participants were divided into 3 clusters (cluster 1, n = 62; cluster 2, n = 15; cluster 3, n = 24) by hierarchical clustering, using 46 clinical variables. Patients in cluster 3 showed lower systolic blood pressures, and lower serum creatinine and urinary liver-type fatty acid-binding protein levels, before the initiation of hemodialysis. Consequently, cluster 3 was associated with the highest 1-year mortality in the study cohort (P < 0.001), and the difference was significant after adjustment for age and sex (hazard ratio: 10.2; 95% confidence interval: 2.94–46.8, cluster 1 as reference).

Conclusion

In this proof-of-concept study, hierarchical clustering discovered a subgroup with a higher 1-year mortality at the initiation of hemodialysis. Applying machine learning–derived classification to patients with ESRD may contribute to better risk stratification.

SGLT-2 inhibitors and nephroprotection: current evidence and future perspectives

Chronic kidney disease (CKD) is a major public health issue and an independent risk factor for cardiovascular and all-cause mortality. Diabetic kidney disease develops in 30-50% of diabetic patients and it is the leading cause of end-stage renal disease in the Western world. Strict blood pressure control and renin-angiotensin system (RAS) blocker use are the cornerstones of CKD treatment; however, their application in everyday clinical practice is not always ideal and in many patients CKD progression still occurs. Accumulated evidence in the past few years clearly suggests that sodium-glucose co-transporter-2 (SGLT-2) inhibitors present potent nephroprotective properties. In clinical trials in patients with type 2 diabetes mellitus, these agents were shown to reduce albuminuria and proteinuria by 30-50% and the incidence of composite hard renal outcomes by 40-50%. Furthermore, their mechanism of action appears rather solid, as they interfere with the major mechanism of proteinuric CKD progression, i.e., glomerular hypertension and hyperfiltration. The present review summarizes the current evidence from human trials on the effects of SGLT-2 inhibitors on nephroprotection and discusses their position in everyday clinical practice.

Thematic Analysis of Hospice Mentions in the Health Records of Veterans with Advanced Kidney Disease

BACKGROUND

Patients with advanced kidney disease are less likely than many patients with other types of serious illness to enroll in hospice. Little is known about real-world clinical decision-making related to hospice for members of this population.

METHODS

We used a text search tool to conduct a thematic analysis of documentation pertaining to hospice in the electronic medical record system of the Department of Veterans Affairs, for a national sample of 1000 patients with advanced kidney disease between 2004 and 2014 who were followed until October 8, 2019.

RESULTS

Three dominant themes emerged from our qualitative analysis of the electronic medical records of 340 cohort members with notes containing hospice mentions: (1) hospice and usual care as antithetical care models: clinicians appeared to perceive a sharp demarcation between services that could be provided under hospice versus usual care and were often uncertain about hospice eligibility criteria. This could shape decision-making about hospice and dialysis and made it hard to individualize care; (2) hospice as a last resort: patients often were referred to hospice late in the course of illness and did not so much choose hospice as accept these services after all treatment options had been exhausted; and (3) care complexity: patients' complex care needs at the time of hospice referral could complicate transitions to hospice, stretch the limits of home hospice, and promote continued reliance on the acute care system.

CONCLUSIONS

Our findings underscore the need to improve transitions to hospice for patients with advanced kidney disease as they approach the end of life.

Association of Longitudinal Trajectories of Systolic BP with Risk of Incident CKD: Results from the Korean Genome and Epidemiology Study

BACKGROUND

Although hypertension is a well known risk factor for CKD, few studies have evaluated the association between temporal trends of systolic BP and kidney function decline in persons without hypertension.

METHODS

We studied whether changes in systolic BP over time could influence incident CKD development in 4643 individuals without CKD and hypertension participating in the Korean Genome and Epidemiology Study, a prospective community-based cohort study. Using group-based trajectory modeling, we categorized three distinct systolic BP trajectories: decreasing, stable, and increasing. The primary outcome was incident CKD development, defined as two consecutive eGFR measurements <60 ml/min per 1.73 m².

RESULTS

Among participants with an increasing systolic BP trajectory, systolic BP increased from 105 to 124 mm Hg. During 31,936 person-years of follow-up (median 7.7 years), 339 participants developed incident CKD. CKD incidence rates were 8.9, 9.6, and 17.8 cases per 1000 person-years in participants with decreasing, stable, and increasing systolic BP trajectories, respectively. In multivariable cause-specific Cox analysis, after adjustment of baseline eGFR, systolic BP, and other confounders, increasing systolic BP trajectory associated with a 1.57-fold higher risk of incident CKD (95% confidence interval, 1.20 to 2.06) compared with a stable trajectory. There was a significant effect modification of baseline systolic BP on the association between systolic BP trajectories and CKD risk (P value for interaction =0.02), and this association was particularly evident in participants with baseline systolic BP <120 mm Hg. In addition, increasing systolic BP trajectory versus a stable trajectory was associated with higher risk of new development of albuminuria.

CONCLUSIONS

Increasing systolic BP over time without reaching the hypertension threshold is associated with a significantly increased risk of incident CKD in healthy adults.

Cardiopulmonary Resuscitation Preferences of People Receiving Dialysis

IMPORTANCE

Whether the cardiopulmonary resuscitation (CPR) preferences of patients receiving dialysis align with their values and other aspects of end-of-life care is not known.

OBJECTIVE

To describe the CPR preferences of patients receiving dialysis and how these preferences are associated with their responses to questions about other aspects of end-of-life care.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional survey study of a consecutive sample of patients receiving dialysis at 31 nonprofit dialysis facilities in 2 US metropolitan areas (Seattle, Washington, and Nashville, Tennessee) between April 22, 2015, and October 2, 2018. Analyses for this article were conducted between December 2018 and April 2020.

EXPOSURES

Participants were asked to respond to the question "If you had to decide right now, would you want CPR if your heart were to stop beating?" Those who indicated they would probably or definitely want CPR were categorized as preferring CPR.

MAIN OUTCOMES AND MEASURES

This study examined the association between preference for CPR and other treatment preferences, engagement in advance care planning, values, desired place of death, expectations about prognosis, symptoms, and palliative care needs.

RESULTS

Of the 1434 individuals invited to complete the survey, 1009 agreed to participate, and 876 were included in the analytic cohort (61.1%). The final cohort had a mean (SD) age of 62.6 (14.0) years; 492 (56.2%) were men, and 528 (60.3%) were White individuals. Among 738 of 876 participants (84.2%) who indicated that they would definitely or probably want CPR (CPR group), 555 (75.2%) wanted mechanical ventilation vs 13 of 138 (9.4%) of those who did not want CPR (do not resuscitate [DNR] group) (P < .001). A total of 249 of 738 participants (33.7%) in the CPR group vs 84 of 138 (60.9%) in the DNR group had documented treatment preferences (P < .001). In terms of values about future care, 171 participants (23.2%) in the CPR group vs 5 of 138 (3.6%) in the DNR group valued life prolongation (P < .001); 320 in the CPR group (43.4%) vs 109 of 138 in the DNR group (79.0%) valued comfort (P < .001); and 247 participants (33.5%) in the CPR group vs 24 of 138 (17.4%) in the DNR group were unsure about their wishes for future care (P < .001). In the CPR group, 207 (28.0%) had thought about stopping dialysis vs 62 of 138 (44.9%) in the DNR group (P < .001), and 181 (24.5%) vs 58 of 138 (42.0%) had discussed stopping dialysis (P = .001). No statistically significant associations were observed between CPR preference and documentation of a surrogate decision maker, thoughts or discussion of hospice, preferred place of death, expectations about prognosis, reported symptoms, or palliative care needs.

CONCLUSIONS AND RELEVANCE

The CPR preferences of patients receiving dialysis were associated with some, but not all, other aspects of end-of-life care. How participants responded to questions about these other aspects of end-of-life care were not always aligned with their CPR preference. More work is needed to integrate discussions about code status with bigger picture conversations about patients' values, goals, and preferences for end-of-life care.

National Trends in the Association of Race and Ethnicity With Predialysis Nephrology Care in the United States From 2005 to 2015

Importance

Predialysis nephrology care is associated with better survival among patients with end-stage kidney disease.

Objective

To examine national trends in racial/ethnic disparities in receipt of predialysis nephrology care at least 1 year before dialysis initiation in the United States from 2005 to 2015.

Design, Setting, and Participants

This national registry study assessed US registry data of 1 000 390 adults in the US Renal Data System who initiated maintenance dialysis treatment from January 1, 2005, to December 31, 2015, in multiple cross-sectional analyses. Multivariable logistic regression models were used to examine national trends in racial/ethnic disparities in receipt of predialysis nephrology care with adjustments for potential confounders. Data were analyzed April 17, 2020.

Exposure

Race/ethnicity of the patients.

Main Outcomes and Measures

Receipt of at least 12 months of predialysis nephrology care as determined by clinician-based documentation on the End Stage Renal Disease Medical Evidence Report Form CMS 2728.

Results

Among 1 000 390 adults (57.2% male; 54.6% White, 27.8% Black, 14.0% Hispanic, and 3.6% Asian; mean [SD] age, 62.4 [15.6] years) who initiated maintenance dialysis in the United States from 2005 to 2015, 310 743 (31.1%) received at least 12 months of predialysis nephrology care. In 2005 to 2007, compared with White adults, the adjusted odds ratio for receipt of at least 12 months of predialysis nephrology care was 0.82 (95% CI, 0.80-0.84) among Black adults, 0.67 (95% CI, 0.65-0.69) among Hispanic adults, and 0.84 (95% CI, 0.80-0.89) among Asian adults; in 2014 to 2015, the adjusted odds ratio was 0.76 (95% CI, 0.74-0.78) among Black adults, 0.61 (95% CI, 0.60-0.63) among Hispanic adults, and 0.90 (95% CI: 0.86-0.95) among Asian adults.

Conclusions and Relevance

In this cross-sectional study of more than 1 million US adults with end-stage kidney disease, racial and ethnic disparities in predialysis nephrology care did not substantially improve from 2005 to 2015. Study findings suggest that national strategies to address racial/ethnic disparities in predialysis nephrology care are needed.

Kidney retransplantation after anti-programmed cell death-1 (PD-1)-related allograft rejection

In this report, we describe the first kidney retransplantation performed after anti-programmed cell death-1 (PD-1)-related allograft rejection. In 2014, we administered pembrolizumab (anti-PD-1) for ~9 months to a 57-year-old kidney transplant recipient with metastatic cutaneous squamous cell carcinoma (CSCC). The patient experienced both a complete antitumor response and T cell-mediated allograft rejection requiring reinitiation of hemodialysis. Four-and-a-half years after initiating pembrolizumab, the patient remained without evidence of CSCC relapse and received a kidney transplant from a living-unrelated donor. Ten-and-a-half months after kidney retransplantation, the allograft is functioning well and the patient's CSCC remains in remission. This case illustrates the potential for PD-1 blockade to bring about durable immune-mediated tumor control in chronically immunosuppressed patients, and begins to address the feasibility of kidney retransplantation in patients who have previously received immune checkpoint inhibitor therapy for cancer. Results from this and future cases may help elucidate mechanisms of antitumor immunity and allograft tolerance, and inform updates to transplant decision models. Our report also underscores the need for clinical trials testing novel immunotherapy combinations in solid organ transplant recipients designed to uncouple antitumor and anti-allograft immunity.

Adiposity, Sex, and Cardiovascular Disease Risk in Children With CKD: A Longitudinal Study of Youth Enrolled in the Chronic Kidney Disease in Children (CKiD) Study

RATIONALE & OBJECTIVE

Traditional and nontraditional cardiovascular disease risk factors are highly prevalent in children with chronic kidney disease (CKD). We examined the longitudinal association of adiposity with cardiac damage among children with CKD and explored whether this association was modified by sex.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Children with mild-to-moderate CKD enrolled in the Chronic Kidney Disease in Children (CKiD) Study at 49 pediatric nephrology centers across North America.

EXPOSURE

Age- and sex-specific body mass index (BMI) z score.

OUTCOME

Age- and sex-specific left ventricular mass index (LVMI) z score and left ventricular hypertrophy (LVH).

ANALYTICAL APPROACH

Longitudinal analyses using mixed-effects models to estimate sex-specific associations of BMI z scores with LVMI z score and with LVH, accounting for repeated measurements over time.

RESULTS

Among 725 children with 2,829 person-years of follow-up, median age was 11.0 years and median estimated glomerular filtration rate was 52.6mL/min/1.73m2. Nearly one-third of both boys and girls were overweight or obese, median LVMI z score was 0.18 (IQR: -0.67, 1.08), and 11% had LVH. Greater BMI z scores were independently associated with greater LVMI z scores and greater odds of LVH. For each 1-unit higher BMI z score, LVMI z score was 0.24 (95% CI, 0.17-0.31) higher in boys and 0.38 (95% CI, 0.29-0.47) higher in girls (Pinteraction = 0.01). For each 1-unit higher BMI z score, the odds of LVH was 1.5-fold (95% CI, 1.1-2.1) higher in boys and 3.1-fold (95% CI, 1.8-4.4) higher in girls (Pinteraction = 0.005).

LIMITATIONS

Not all children had repeated measurements. LVH is a surrogate and not a hard cardiac outcome. The observational design limits causal inference.

CONCLUSIONS

In children, adiposity is independently associated with the markers of cardiac damage, LVMI z score and LVH. This association is stronger among girls than boys. Pediatric overweight and obesity may therefore have a substantial impact on cardiovascular risk among children with CKD.

Nanoparticles exhibit greater accumulation in kidney glomeruli during experimental glomerular kidney disease

Loss and dysfunction of glomerular podocytes result in increased macromolecule permeability through the glomerular filtration barrier and nephrotic syndrome. Current therapies can induce and maintain disease remission, but cause serious and chronic complications. Nanoparticle drug carriers could mitigate these side effects by delivering drugs to the kidneys more efficiently than free drug through tailoring of carrier properties. An important extrinsic factor of nanoparticle biodistribution is local pathophysiology, which may drive greater nanoparticle deposition in certain tissues. Here, we hypothesized that a "leakier" filtration barrier during glomerular kidney disease would increase nanoparticle distribution into the kidneys. We examined the effect of nanoparticle size and disease state on kidney accumulation in male BALB/c mice. The effect of size was tested using a panel of fluorescent polystyrene nanoparticles of size 20-200 nm, due to the relevance of this size range for drug delivery applications.Experimental focal segmental glomerulosclerosis was induced using an anti-podocyte antibody that causes abrupt podocyte depletion. Nanoparticles were modified with carboxymethyl-terminated poly(ethylene glycol) for stability and biocompatibility. After intravenous injection, fluorescence from nanoparticles of size 20 and 100 nm, but not 200 nm, was observed in kidney glomeruli and peritubular capillaries. During conditions of experimental focal segmental glomerulosclerosis, the number of fluorescent nanoparticle punctae in kidney glomeruli increased by 1.9-fold for 20 and 100 nm nanoparticles compared to normal conditions. These findings underscore the importance of understanding and leveraging kidney pathophysiology in engineering new, targeted drug carriers that accumulate more in diseased glomeruli to treat glomerular kidney disease.

CKD Awareness Among US Adults by Future Risk of Kidney Failure

RATIONALE & OBJECTIVE

Persons with chronic kidney disease (CKD) are often unaware of their disease status. Efforts to improve CKD awareness may be most effective if focused on persons at highest risk for progression to kidney failure.

STUDY DESIGN

Serial cross-sectional surveys.

SETTING & PARTICIPANTS

Nonpregnant adults (aged≥20 years) with CKD glomerular filtration rate categories 3-4 (G3-G4) who participated in the National Health and Nutrition Examination Survey from 1999 to 2016 (n = 3,713).

PREDICTOR

5-year kidney failure risk, estimated using the Kidney Failure Risk Equation. Predicted risk was categorized as minimal (<2%), low (2%-<5%), intermediate (5%-<15%), or high (≥15%).

OUTCOME

CKD awareness, defined by answering "yes" to the question "Have you ever been told by a doctor or other health professional that you had weak or failing kidneys?"

ANALYTICAL APPROACH

Prevalence of CKD awareness was estimated within each risk group using complex sample survey methods. Associations between Kidney Failure Risk Equation risk and CKD awareness were assessed using multivariable logistic regression. CKD awareness was compared with awareness of hypertension and diabetes during the same period.

RESULTS

In 2011 to 2016, unadjusted CKD awareness was 9.6%, 22.6%, 44.7%, and 49.0% in the minimal-, low-, intermediate-, and high-risk groups, respectively. In adjusted analyses, these proportions did not change over time. Awareness of CKD, including among the highest risk group, remains consistently below that of hypertension and diabetes and awareness of these conditions increased over time.

LIMITATIONS

Imperfect sensitivity of the "weak or failing kidneys" question for ascertaining CKD awareness.

CONCLUSIONS

Among adults with CKD G3-G4 who have 5-year estimated risks for kidney failure of 5%-<15% and≥15%, approximately half were unaware of their kidney disease, a gap that has persisted nearly 2 decades.

Outcomes Among Patients With Left Ventricular Assist Devices Receiving Maintenance Outpatient Hemodialysis: A Case Series

RATIONALE & OBJECTIVE

The incidence of left ventricular assist device (LVAD) implantation as destination therapy for heart failure is increasing and kidney failure requiring maintenance hemodialysis is a common complication. Because little is known about the safety or efficacy of outpatient hemodialysis among patients with LVADs, this study sought to describe their clinical course.

STUDY DESIGN

Case series of patients with an LVAD undergoing maintenance outpatient hemodialysis whose clinical data were obtained from an electronic medical record.

SETTING & PARTICIPANTS

Adults who received an LVAD, survived to hospital discharge, and were subsequently treated with maintenance hemodialysis by a not-for-profit dialysis provider between 2011 and 2019.

RESULTS

11 patients were included. 6 had a known history of chronic kidney disease. Patients underwent outpatient hemodialysis for a mean duration of 165.2 (range, 31-542) days, during which they were treated with 544 total dialysis sessions. 6 of these sessions were stopped early due to dialysis-related adverse events (1.1%). More than 80% of follow-up time was spent out of the hospital; however, 55% of patients were rehospitalized within 1 month of starting outpatient hemodialysis. The most common reason for hospitalization was infection (32%), followed by hypervolemia (14%), and cerebrovascular accident or transient ischemic attack (11%). 4 patients recovered kidney function, 1 underwent combined heart and kidney transplantation, 2 continued treatment, 2 died, and 2 were lost to follow-up.

LIMITATIONS

Retrospective design, small number of cases, and lack of complete follow-up data.

CONCLUSIONS

Approximately half the patients with complete follow-up either recovered kidney function or underwent combined heart and kidney transplantation. This case series demonstrates that outpatient hemodialysis centers, in partnership with LVAD treatment teams, can successfully provide hemodialysis to patients on LVAD support.

A comparative study of ambulatory central hemodynamics and arterial stiffness parameters in peritoneal dialysis and hemodialysis patients

BACKGROUND

Ambulatory pulse-wave velocity (PWV), augmentation pressure, and augmentation index (AIx) are associated with increased cardiovascular events and death in hemodialysis. The intermittent nature of hemodialysis generates a distinct ambulatory pattern, with a progressive increase of augmentation pressure and AIx during the interdialytic interval. No study so far has compared the ambulatory course of central hemodynamics and PWV between peritoneal dialysis and hemodialysis patients.

METHODS

Thirty-eight patients under peritoneal dialysis and 76 patients under hemodialysis matched in a 1 : 2 ratio for age, sex and dialysis vintage underwent 48-h ambulatory blood pressure (BP) monitoring with the oscillometric Mobil-O-Graph device. Parameters of central hemodynamics [central SBP, DBP and pulse pressure (PP)], wave reflection [AIx, heart rate-adjusted AIx; AIx(75) and augmentation pressure] and PWV were estimated from the 48-h recordings.

RESULTS

Over the total 48-h period, no significant differences were observed between peritoneal dialysis and hemodialysis patients in mean levels of central SBP, DBP, PP, augmentation pressure, AIx, AIx(75) and PWV. However, patients under peritoneal dialysis and hemodialysis displayed different trajectories in all the above parameters over the course of the recording: in peritoneal dialysis patients no differences were noted in central SBP (125.0 ± 19.2 vs. 126.0 ± 17.8 mmHg, P = 0.25), DBP, PP, augmentation pressure (13.0 ± 6.8 vs. 13.7 ± 7. mmHg, P = 0.15), AIx(75) (25.9 ± 6.9 vs. 26.3 ± 7.8%, P = 0.54) and PWV (9.5 ± 2.1 vs. 9.6 ± 2.1 m/s, P = 0.27) from the first to the second 24-h period of the recording. In contrast, hemodialysis patients showed significant increases in all these parameters from the first to second 24 h (SBP: 119.5 ± 14.4 vs. 124.6 ± 15.0 mmHg, P < 0.001; augmentation pressure: 10.9 ± 5.3 vs. 13.1 ± 6.3 mmHg, P < 0.001; AIx(75): 24.7 ± 7.6 vs. 27.4 ± 7.9%, P < 0.001; PWV: 9.1 ± 1.8 vs. 9.3 ± 1.8 m/s, P < 0.001). Peritoneal dialysis patients had numerically higher levels than hemodialysis patients in all the above parameters during all periods studied and especially during the first 24-h.

CONCLUSION

Central BP, wave reflection indices and PWV during a 48-h recording are steady in peritoneal dialysis but gradually increase in hemodialysis patients. During all studied periods, peritoneal dialysis patients have numerically higher levels of all studied parameters, a fact that could relate to higher cardiovascular risk.

American Indian chronic Renal insufficiency cohort study (AI-CRIC study)

BACKGROUND

Chronic kidney disease (CKD) is an increasing epidemic globally that is associated with adverse health outcomes including end stage kidney disease (ESKD), cardiovascular disease (CVD), and death. American Indians (AIs) have a higher prevalence of CKD than most other racial/ethnic groups, due in part to a high prevalence of type 2 diabetes. Other genetic and environmental factors not yet identified may also contribute to the disproportionate burden of CKD in AIs.

METHOD

We will establish 3 clinical centers to recruit AIs from the Southwest United States (US) to expand the Chronic Renal Insufficiency Cohort (CRIC) study. We will follow the current CRIC protocol for kidney and cardiovascular measures and outcomes, which include ambulatory monitoring of kidney function and the use of mobile health technologies for CVD sub-phenotyping, and compare the outcomes in AIs with those in other racial/ethnic groups in CRIC.

DISCUSSION

AI-CRIC will identify the role of various risk factors for rapid loss of kidney function among AIs of the Southwest US. In addition, to better understand the natural history of CKD and CVD in this high-risk population, we will identify unique risk factors for CKD and CVD progression in AIs. We will also compare event rates and risk factors for kidney and cardiovascular events in AIs with the other populations represented in CRIC.

Dietary zinc intake and incident chronic kidney disease

BACKGROUND & AIMS

Previous studies have shown that dietary zinc intake is closely related to cardiovascular complications and metabolic derangements. However, the effect of dietary zinc intake on renal function is not fully elucidated.

METHODS

Data from the Korean Genome and Epidemiology Study were used. Dietary zinc intake was assessed by a Food Frequency Questionnaire and dietary zinc density was calculated as absolute zinc intake amount per daily energy intake (mg/1000 kcal day). The participants were categorized into quartiles according to dietary zinc density. The primary end point was incident chronic kidney disease (CKD), defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m².

RESULTS

A total of 7735 participants with normal renal function was included in the final analysis. The mean age was 52.0 ± 8.8 years, 47.5% were male, and mean eGFR was 92.1 ± 16.1 ml/min/1.73 m². The mean daily zinc intake and zinc intake density were 8.6 ± 3.4 mg and 4.4 ± 0.9 mg/1000 kcal, respectively. During a median follow up of 11.5 (1.7-12.5) years and 70,617 person-years of observation, CKD developed in 1409 (18.2%) participants. Multivariable cox hazard analysis revealed that risk for CKD development was significantly higher in the quartile with a mean zinc intake density of 3.6 ± 0.2 mg/1000 kcal compared with the quartile with a mean zinc intake density of 5.6 ± 1.0 mg/1000 kcal (Hazard ratio; 1.36; 95% Confidence Interval 1.18-1.58; P < 0.001). This relationship remained significant even after adjustments for confounding factors.

CONCLUSION

Low dietary zinc intake may increase the risk of CKD development in individuals with normal renal function.

Lymphoma survivors have an increased long-term risk of chronic kidney disease

With improving lymphoma survival, late effects of therapy have emerged. Here, we describe pattern of long-term chronic kidney disease (CKD) in lymphoma survivors. Demographics, comorbidities, lymphoma histology, treatment, and outcome were recorded. Glomerular filtration rate (GFR) was recorded at diagnosis, 1, 2, 5, and 10 years. Rate of GFR decline with time and CKD-free survival were recorded. In 397 patients, median age was 55.3 (18-88), 54% were male, 60% were African Americans, 42% had hypertension (HTN), 15% had DM, 13% had hyperuricemia, 86% received chemotherapy, and 14% had baseline CKD. Total 125 (31%) patients developed CKD in 10 years after lymphoma diagnosis. Probability of CKD development increased significantly with time (23% at 1 year to 41% at 10 years). Rate of GFR decline was 4.6 mL/min/per year. Age, HTN, hyperuricemia, and DM (in young patients) predicted risk of CKD. Thus, lymphoma survivors are at substantial long-term risk of CKD development.

Feasibility of Tablet-Based Patient-Reported Symptom Data Collection Among Hemodialysis Patients

Introduction

Individuals receiving in-center hemodialysis have high symptom burdens but often do not report their symptoms to care teams. Evidence from other diseases suggest that use of symptom electronic patient-reported outcome measures (ePROMs) may improve outcomes. We assessed the usability of a symptom ePROM system and then implemented a quality improvement (QI) project with the objective of improving symptom communication at a US hemodialysis clinic. During the project, we assessed the feasibility of ePROM implementation and conducted a substudy exploring the effect of ePROM use on patient-centered care.

Methods

After conducting usability testing, we used mixed methods, guided by the Quality Implementation Framework, to implement a 16-week symptom ePROM QI project. We performed pre-, intra-, and postproject stakeholder interviews to identify implementation barriers and facilitators. We collected ePROM system-generated data on symptoms, e-mail alerts, and response rates, among other factors, to inform our feasibility assessment. We compared pre- and postproject outcomes.

Results

There were 62 patient participants (34% black, 16% Spanish-speaking) and 19 care team participants (4 physicians, 15 clinic personnel) at QI project start, and 32 research participants. In total, the symptom ePROM was administered 496 times (completion rate = 84%). The implementation approach and ePROM system were modified to address stakeholder-identified concerns throughout. ePROM implementation was feasible as demonstrated by the program’s acceptability, demand, implementation success, practicality, integration in care, and observed trend toward improved outcomes.

Conclusions

Symptom ePROM administration during hemodialysis is feasible. Trials investigating the effectiveness of symptom ePROMs and optimal administration strategies are needed.

Arteriovenous Fistula Placement, Maturation, and Patency Loss in Older Patients Initiating Hemodialysis

RATIONALE & OBJECTIVE

The current clinical guidelines for vascular access do not have specific recommendations for older hemodialysis patients. Our study aimed to determine the association of age with arteriovenous fistula (AVF) placement, maturation, and primary and secondary patency loss among older hemodialysis recipients.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A US national cohort of incident hemodialysis patients 67 years or older (N = 43,851) assembled from the US Renal Data System.

EXPOSURE

Age at dialysis initiation.

OUTCOMES

AVF placement, maturation, primary patency loss, and abandonment.

ANALYTICAL APPROACH

Cause-specific and subdistribution proportional hazards models were used to examine the association of age and AVF outcomes, with kidney transplantation, peritoneal dialysis, and death treated as competing events. Age cutoff was identified by restricted cubic splines. We compared crude and inverse probability-weighted cumulative incidence functions using Gray's test.

RESULTS

As compared with those aged 67-<77 years, patients 77 years or older had significantly lower probabilities of AVF placement (adjusted cause-specific HR [cHR], 0.96 [95% CI, 0.92-0.99]; adjusted subdistribution HR [sHR], 0.92 [95% CI, 0.89-0.95]; Gray's test P < 0.001) and maturation (adjusted cHR, 0.95 [95% CI, 0.91-0.99]; adjusted sHR, 0.93 [95% CI, 0.90-0.97]; P < 0.001). However, age was not associated with AVF primary (adjusted cHR, 1.05 [95% CI, 1.00-1.11]; adjusted sHR, 1.04 [95% CI, 0.99-1.09]; P = 0.09) or secondary (adjusted cHR, 1.06 [95% CI, 0.94-1.20]; adjusted sHR, 1.05 [95% CI, 0.93-1.18]; P = 0.4) patency loss.

LIMITATIONS

Reliance on administrative claims to ascertain AVF outcomes.

CONCLUSIONS

The likelihood of AVF maturation is an important consideration for vascular access planning. Age alone should not be the basis for excluding older dialysis patients from AVF creation because maintenance of fistula patency was not reduced with older age despite a modest reduction in fistula maturation.

An update review of intradialytic hypotension: concept, risk factors, clinical implications and management

Intradialytic hypotension (IDH) is a frequent and serious complication of chronic haemodialysis, linked to adverse long-term outcomes including increased cardiovascular and all-cause mortality. IDH is the end result of the interaction between ultrafiltration rate (UFR), cardiac output and arteriolar tone. Thus excessive ultrafiltration may decrease the cardiac output, especially when compensatory mechanisms (heart rate, myocardial contractility, vascular tone and splanchnic flow shifts) fail to be optimally recruited. The repeated disruption of end-organ perfusion in IDH may lead to various adverse clinical outcomes affecting the heart, central nervous system, kidney and gastrointestinal system. Potential interventions to decrease the incidence or severity of IDH include optimization of the dialysis prescription (cool dialysate, UFR, sodium profiling and high-flux haemofiltration), interventions during the dialysis session (midodrine, mannitol, food intake, intradialytic exercise and intermittent pneumatic compression of the lower limbs) and interventions in the interdialysis period (lower interdialytic weight gain and blood pressure–lowering drugs). However, the evidence base for many of these interventions is thin and optimal prevention and management of IDH awaits further clinical investigation. Developing a consensus definition of IDH will facilitate clinical research. We review the most recent findings on risk factors, pathophysiology and management of IDH and, based on this, we call for a new consensus definition of IDH based on clinical outcomes and define a roadmap for IDH research.

Use of QT Prolonging Medications by Hemodialysis Patients and Individuals Without End-Stage Kidney Disease

Background The rate of sudden cardiac death in the hemodialysis population exceeds that of the general population by >20-fold. Hemodialysis patients may be particularly susceptible to sudden cardiac death provoked by drug-induced QT prolongation because of their substantial cardiovascular disease burden, exposure to electrolyte shifts during dialysis, and extensive polypharmacy. However, population-specific data regarding the frequency and patterns of QT prolonging medication use are limited. Methods and Results We conducted a descriptive drug utilization study using 3 administrative databases, the United States Renal Data System, MarketScan, and Medicare claims. We characterized the extent and patterns of QT prolonging medication use by adult hemodialysis patients and individuals without end-stage kidney disease annually from 2012 to 2016. We also identified instances of high-risk QT prolonging medication use among hemodialysis patients. In total, 338 515 hemodialysis patients and 40.7 million individuals without end-stage kidney disease were studied. Annual utilization rates of QT prolonging medications with known torsades de pointes risk in hemodialysis patients were ~1.4 to ~2.5 times higher than utilization rates in individuals without end-stage kidney disease. Hemodialysis patients with demographic and clinical risk factors for drug-induced QT prolongation were exposed to medications with known torsades de pointes risk more often than patients without risk factors. Conclusions Hemodialysis patients use QT prolonging medications with known torsades de pointes risk more extensively than individuals without end-stage kidney disease. Given the widespread use and instances of high-risk prescribing, future studies evaluating the cardiac safety of these drugs in the hemodialysis population are needed.

Transplantation of a single kidney from pediatric donors less than 10 kg to children with poor access to transplantation: a two-year outcome analysis

Background

Access to kidney transplantation by uremic children is very limited due to the lack of donors in many countries. We sought to explore small pediatric kidney donors as a strategy to provide transplant opportunities for uremic children.

Methods

A total of 56 cases of single pediatric kidney transplantation and 26 cases of en bloc kidney transplantation from pediatric donors with body weight (BW) less than 10 kg were performed in two transplant centers in China and the transplant outcomes were retrospectively analyzed.

Results

The 1-year and 2-year death-censored graft survival in the en bloc kidney transplantation (KTx) group was inferior to that in the single KTx group. Subgroup analysis of the single KTx group found that the 1-year and 2-year death-censored graft survival in the group where the donor BW was between 5 and 10 kg was 97.7 and 90.0%, respectively. However, graft survival was significantly decreased when donor BW was ≤5 kg (p < 0.01), mainly because of the higher rate of thrombosis (p = 0.035). In the single KTx group, the graft length was increased from 6.7 cm at day 7 to 10.5 cm at 36 months posttransplant. The estimated glomerular filtration rate increased up to 24 months posttransplant. Delayed graft function and urethral complications were more common in the group with BW was ≤5 kg.

Conclusions

Our study suggests that single kidney transplantation from donors weighing over 5 kg to pediatric recipients is a feasible option for children with poor access to transplantation.