US Renal Data System 2015 Annual Data Report: Epidemiology of Kidney Disease in the United States

Blood urea nitrogen and risk of insulin use among people with diabetes

Laboratory evidence suggests that urea suppresses insulin secretion and sensitivity. Emerging epidemiologic evidence suggests that higher levels of urea are associated with increased risk of incident diabetes mellitus. However, whether elevated levels of blood urea nitrogen are associated with increased risk of insulin use among people with diabetes is unknown. We used the Department of Veterans Affairs databases to assemble a cohort of 197,994 incident users of non-insulin hypoglycaemic agents with an estimated glomerular filtration rate > 60 mL/min per 1.73 m² and followed them for a median of 4.93 years. Spline analyses suggested that the relationship between blood urea nitrogen and the risk of insulin use was neutral below blood urea nitrogen level of 25 mg/dL and increased exponentially with blood urea nitrogen levels above 25 mg/dL. In survival models, compared to those with blood urea nitrogen ⩽ 25 mg/dL, those with blood urea nitrogen > 25 mg/dL had an increased risk of insulin use (hazard ratio = 1.40; confidence interval = 1.30-1.50). The risk of insulin use was increased in models which accounted for haemoglobin A1c at time zero (hazard ratio = 1.39; confidence interval = 1.28-1.50) and as a time-varying variable (hazard ratio = 1.38; confidence interval = 1.28-1.50). Two-step residual estimation analyses showed that, independent of the impact of estimated glomerular filtration rate, every 10-mg/dL increase in blood urea nitrogen concentration was associated with increased risk of insulin use (hazard ratio = 1.16; confidence interval = 1.12-1.20). Our results suggest that, among people with diabetes, higher levels of blood urea nitrogen are associated with an increased risk of insulin use.

The role of kidney transplantation and phosphate binder use in vitamin K status

BACKGROUND

Cardiovascular disease is the leading cause of death in end-stage renal disease and is strongly associated with vascular calcification. Both kidney transplantation and phosphate binders may lower the risk of vascular calcification. Vascular calcification is actively inhibited by vitamin-K-dependent matrix γ-carboxyglutamic acid protein (MGP). Whether kidney transplantation or phosphate binders affect vitamin K status is unknown. Therefore, we studied the influence of kidney transplantation and phosphate binder use on vitamin K status.

METHODS

We measured plasma desphospho-uncarboxylated MGP (dp-ucMGP), a marker reflecting low vitamin K status, in a cross-sectional study of patients on hemodialysis (n = 82), peritoneal dialysis (n = 31) or who recently received a kidney transplantation (n = 36). By medication inventory, we assessed phosphate binder use. With linear regression, we assessed the influence of kidney transplantation and phosphate binder use on natural-log-transformed dp-ucMGP, adjusting for potential confounders.

RESULTS

Mean age of patients was 52±13 years; 102 (68%) were male. Dp-ucMGP levels were significantly lower in kidney transplant recipients (median 689 pmol/L) compared to patients on dialysis (median 1537 pmol/L, p<0.001). Eighty-nine patients on dialysis used phosphate binders. Using any phosphate binder was not associated with dp-ucMGP levels (median 1637 pmol/L, p = 0.09) compared to no phosphate binders (median 1142 pmol/L). Twenty-six patients used sevelamer monotherapy, which was associated with higher dp-ucMGP levels (median 1740 pmol/L, p = 0.04) after adjusting for age, sex and vitamin K antagonist use.

CONCLUSIONS

Recent kidney transplantation is associated with lower dp-ucMGP levels suggesting improved vitamin K status after transplantation. Sevelamer monotherapy is associated with higher dp-ucMGP levels suggesting worsening of vitamin K status. Both findings warrant more attention to vitamin K status in patients on dialysis, as vitamin K is necessary for protection against vascular calcification.

Low agreement between modified-Schwartz and CKD-EPI eGFR in young adults: a retrospective longitudinal cohort study

Background

While there is a great deal of research updating methods for estimating renal function, many of these methods are being developed in either adults with CKD or younger children. Currently, there is limited understanding of the agreement between the modified new bedside Schwartz estimated glomerular filtration rate (eGFR) formula and the adult CKD-EPI formula in adolescents and young adults (AYAs) with chronic kidney disease (CKD) measured longitudinally.

Methods

Longitudinal cohort study of 242 patients (10–30 years) with CKD, followed retrospectively in a single tertiary centre as they transitioned from the paediatric- to adult-focused settings. The study population came from a longitudinal cohort of AYAs undergoing healthcare transition at the STARx Program at the University of North Carolina, in the South-Eastern USA, from 2006 to 2015. We calculated and compared the eGFR using the new bedside Schwartz formula and the CKD-EPI eGFR. Measurements were repeated for each age in years. Agreement was tested using Bland & Altman analysis. Subgroup analysis was performed using the following age groups 10–15, 15–20, 20–25 and 25–30 years, glomerular and non-glomerular causes of CKD and height z-score.

Results

Using repeated measures, concordance between the new Schwartz and CKD-EPI eGFR was low at 0.74 (95% C.I. 0.67, 0.79) at the lowest age range of 10–15, 0.78 (95% C.I. 0.71, 0.84) at age 15–20, 0.80 (0.70, 0.87) at ages 20–25, and 0.82 (95% C.I. 0.70, 0.90) at age 25–30. Discordance was worse in males and largest in the 10–15 year-old age group, and in patients with stunted growth.

Conclusions

The Schwartz and CKD-EPI equations exhibit poor agreement in patients before and during the transition period with CKD-EPI consistently yielding higher eGFRs, especially in males. Further studies are required to determine the appropriate age for switching to the CKD-EPI equation after age 18.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0995-1) contains supplementary material, which is available to authorized users.

Association of early loss of primary functional patency of arteriovenous access with mortality in incident hemodialysis patients: A nationwide population-based observational study

The long-term survival and life quality of hemodialysis (HD) patients depend on adequacy of dialysis via a well-functioning vascular access. Loss of primary functional patency (PFP) of an arteriovenous access (AVA) eventually happens in HD patients. The association between time to loss of PFP of AVAs and mortality in HD patients remains unclear. The retrospective nationwide population-based cohort study compared the hazards of mortality with time to loss of PFP. We enrolled 1618 adult incident HD patients who received HD via AVAs for at least 90 days between January 1, 2001 and December 31, 2013. They were divided into early (≤1 year) and late (>1 year) loss of PFP according to intervention-free intervals (time from first successful cannulation to percutaneous transluminal angioplasty [PTA]). Patients with early loss of PFP were older; had more clinic visits annually and higher Charlson comorbidity index scores; were associated with higher proportions of diabetes mellitus, coronary artery disease, heart failure, stroke, chronic obstructive pulmonary disease, cancer, and use of arteriovenous graft, diuretic, antidiabetic drugs, and aspirin (all P < .05). Kaplan-Meier analysis revealed the cumulative incidence of mortality was significantly higher in patients with early loss of PFP (log-rank test; P < .01). After adjustment, early loss of PFP was independently associated with a higher risk of mortality (adjusted hazard ratio, 1.21; 95% confidence interval, 1.01-1.45; P = .045). Regarding the impact of time to PTA on mortality, patients with intervention-free intervals of ≤3, 3 to 6, and 6 to 12 months had similar trends of lower survival. Early loss of PFP is an independent risk factor for mortality in chronic HD patients. A comprehensive strategy for maintaining PFP and reducing dysfunctional AVAs may be required.

County-level air quality and the prevalence of diagnosed chronic kidney disease in the US Medicare population

BACKGROUND

Considerable geographic variation exists in the prevalence of chronic kidney disease across the United States. While some of this variability can be explained by differences in patient-level risk factors, substantial variability still exists. We hypothesize this may be due to understudied environmental exposures such as air pollution.

METHODS

Using data on 1.1 million persons from the 2010 5% Medicare sample and Environmental Protection Agency air-quality measures, we examined the association between county-level particulate matter ≤2.5 μm (PM2.5) and the prevalence of diagnosed CKD, based on claims. Modified Poisson regression was used to estimate associations (prevalence ratios [PR]) between county PM2.5 concentration and individual-level diagnosis of CKD, adjusting for age, sex, race/ethnicity, hypertension, diabetes, and urban/rural status.

RESULTS

Prevalence of diagnosed CKD ranged from 0% to 60% by county (median = 16%). As a continuous variable, PM2.5 concentration shows adjusted PR of diagnosed CKD = 1.03 (95% CI: 1.02-1.05; p<0.001) for an increase of 4 μg/m3 in PM2.5. Investigation by quartiles shows an elevated prevalence of diagnosed CKD for mean PM2.5 levels ≥14 μg/m3 (highest quartile: PR = 1.05, 95% CI: 1.03-1.07), which is consistent with current ambient air quality standard of 12 μg/m3, but much lower than the level typically considered healthy for sensitive groups (~40 μg/m3).

CONCLUSION

A positive association was observed between county-level PM2.5 concentration and diagnosed CKD. The reliance on CKD diagnostic codes likely identified associations with the most severe CKD cases. These results can be strengthened by exploring laboratory-based diagnosis of CKD, individual measures of exposure to multiple pollutants, and more control of confounding.

The Incidence and Pathophysiology of the Obesity Paradox: Should Peritoneal Dialysis and Kidney Transplant Be Offered to Patients with Obesity and End-Stage Renal Disease?

PURPOSE OF REVIEW

To educate nephrologists and primary-care physicians about the incidence, pathophysiology, and survival benefits of the obesity paradox in end-stage renal disease (ESRD). This review also discusses the future of kidney transplant and peritoneal dialysis in obese dialysis patients.

RECENT FINDINGS

Obesity paradox in ESRD was first reported three decades ago, and since then, there have been several epidemiological studies that confirmed the phenomenon. Regardless of the anthropometric indices used to define obesity in ESRD patients, these markers serve to predict the dialysis patient's survival. The pathophysiology of obesity paradox tends to be multifactorial. Recent cohort studies demonstrated a survival benefit in all race and ethnic groups, but Hispanics and blacks experienced increased survival rates when compared to non-Hispanic whites. Obese dialysis patients should be offered peritoneal dialysis, especially if they are new to dialysis and have an adequate renal residual function. Several studies have shown that the benefit of receiving kidney transplant in obese patients exceeds the risks. The robotic-assisted kidney transplant (RAKT) procedure is the latest innovation that could offer hope for obese dialysis patients who have been denied or are waiting for kidney transplant. The obesity paradox phenomenon in ESRD is a unique illustration of survival benefit in a population that has a high overall annual mortality. Peritoneal dialysis should be encouraged for obese patients who have preserved residual renal function. Kidney transplant centers should encourage RAKT utilization in obese dialysis patients instead of denying them a kidney transplant.

Recurrent Peritoneal Pseudocyst: A Rare Complication of Peritoneal Dialysis

An alarming 468,000 people are dependent on dialysis for their end-stage renal disease (ESRD) management in the United States alone. Peritoneal dialysis is a preferred type of dialysis over hemodialysis, considering its initial survival advantage, patient satisfaction, and cost-effectiveness. One of the rare complications of peritoneal dialysis is abdominal and peritoneal pseudocyst formation. Literature regarding the accurate medical management of such peritoneal pseudocysts is scarce. Adding to this, management of recurrent loculated, non-malignant peritoneal pseudocyst poses to be challenging especially when pseudocysts recur after the offending peritoneal dialysis catheter is removed.

We report one such case of a patient with a history of ESRD managed on long-term peritoneal dialysis. He presented to the hospital with recurrent abdominal pain which was treated multiple times for spontaneous bacterial peritonitis. Due to recurrence, his peritoneal dialysis was discontinued and hemodialysis was initiated. While on hemodialysis and two years after peritoneal dialysis catheter removal, he presented with sudden onset abdominal distension. Imaging showed loculated peritoneal pseudocyst with multiple loculations. Standard recommendation of surgical removal of cyst could not be performed in this patient due to his coexisting medical co-morbidities. Interventional radiology (IR) guided cyst drainage was attempted but was limited due to multiple locutions. However, IR drainage proved to provide temporary relief and after repeated IR guided drainage, a temporary drainage tube was placed. This subsided the recurrence of fluid-filled pseudocysts and the patient improved.

This case emphasizes the importance of follow up of patients who have been or currently are on peritoneal dialysis for early recognition of late-onset complications. Our case also shows the routine challenges faced by the clinician when rare complications arise and standard treatment options cannot be applied.

Pediatric Vascular Surgical Practice Patterns

BACKGROUND

Vascular surgeons infrequently care for pediatric patients. As such, variability in operative management and available hospital resources at free-standing children's hospitals (CHs) may exist. The study aims were (1) to determine vascular surgeon comfort level with pediatric vascular surgery and (2) to determine variations in pediatric vascular surgery practice patterns.

METHODS

A survey composed of clinical vignettes emailed to all members of Vascular and Endovascular Surgery Society was designed to assess operative management of pediatric vascular conditions and hospital resources. Comparisons of surgeon satisfaction between free-standing CHs and a CH within an adult general hospital were made using Wilcoxon rank-sum tests. Comparison of surgeon comfort between hospital types was made using a McNemar's test. P-values less than or equal to 0.05 indicated statistical significance.

RESULTS

Response rate was 18% (93/525) with 96% (89/93) indicating completion of a 2 year vascular fellowship. Surgeon satisfaction with operative equipment (P = 0.002), support staff (P < 0.001), and vascular laboratory availability (P = 0.01) was significantly lower at CHs. Eighty-seven percent of surgeons operated on fewer than 2 children over the preceding 3 months. For the different clinical vignettes, there was a wide variation in practice patterns with a range of 50-89% of the surgeons performing fewer than 5 cases over the preceding 10 years. There was a significant decrease in surgeon's comfort level with elective pediatric vascular operations compared to the operative management of pediatric vascular trauma (P = 0.0025).

CONCLUSIONS

Most vascular surgeons do not feel comfortable in the operative management of pediatric vascular disease, and optimal resource availability within pediatric CHs may be lacking. Centralized care of this patient population may be warranted.

Investigating the Association between Chronic Kidney Disease and Ischaemic Stroke from a Health Examination Database

Stroke has become one of the leading causes of death, with ischaemic stroke as the most common type of stroke occurrence compared to haemorrhagic stroke. Chronic kidney disease(CKD), another important cause of death, shares several traditional cardiovascular riskfactors with ischaemic stroke. Therefore, it is important to examine the existence of shared risk factors in the association between CKD and ischaemic stroke. This study used a health examination database from a medical centre in Taiwan. A generalized linear regression analysis was used to determine the association between CKD and ischaemic stroke. The Maentel-Haenszel test was performed to analyse the effect of possible confounding factors on the association between CKD and ischaemic stroke. A prevalence rate study showed that more subjects with CKD suffered from ischaemic stroke than subjects without CKD. Diabetes, hypertension, hypertriglyceridemia, and hypercholesterolemia were associated with increased risks of ischaemic stroke in CKD subjects. There was an inverse association of the odds ratio of ischaemic stroke between CKD and non-CKD patients, which implied that younger subjects with CKD should be made aware of ischaemic stroke prevention.

Obesity Paradox in Advanced Kidney Disease: From Bedside to the Bench

While obesity is associated with a variety of complications including diabetes, hypertension, cardiovascular disease and premature death, observational studies have also found that obesity and increasing body mass index (BMI) can be linked with improved survival in certain patient populations, including those with conditions marked by protein-energy wasting and dysmetabolism that ultimately lead to cachexia. The latter observations have been reported in various clinical settings including end-stage renal disease (ESRD) and have been described as the "obesity paradox" or "reverse epidemiology", engendering controversy. While some have attributed the obesity paradox to residual confounding in an effort to "debunk" these observations, recent experimental discoveries provide biologically plausible mechanisms in which higher BMI can be linked to longevity in certain groups of patients. In addition, sophisticated epidemiologic methods that extensively adjusted for confounding have found that the obesity paradox remains robust in ESRD. Furthermore, novel hypotheses suggest that weight loss and cachexia can be linked to adverse outcomes including cardiomyopathy, arrhythmias, sudden death and poor outcomes. Therefore, the survival benefit observed in obese ESRD patients can at least partly be derived from mechanisms that protect against inefficient energy utilization, cachexia and protein-energy wasting. Given that in ESRD patients, treatment of traditional risk factors has failed to alter outcomes, detailed translational studies of the obesity paradox may help identify innovative pathways that can be targeted to improve survival. We have reviewed recent clinical evidence detailing the association of BMI with outcomes in patients with chronic kidney disease, including ESRD, and discuss potential mechanisms underlying the obesity paradox with potential for clinical applicability.

Plasma biomarkers improve prediction of diabetic kidney disease in adults with type 1 diabetes over a 12-year follow-up: CACTI study

Background

The objective of the study was to determine whether plasma biomarkers of kidney injury improve the prediction of diabetic kidney disease (DKD) in adults with type 1 diabetes (T1D) over a period of 12 years.

Methods

Participants (n = 527, 53% females) in the Coronary Artery Calcification in T1D (CACTI) Study were examined during 2002-04, at a mean (± standard deviation) age of 39.6 ± 9.0 years with 24.8 years as the median duration of diabetes. Urine albumin-to-creatinine (ACR) and estimated glomerular filtration rate (eGFR) by CKD-EPI (chronic kidney disease epidemiology collaboration) creatinine were measured at the baseline and after mean follow-up of 12.1 ± 1.5 years. Albuminuria was defined as ACR ≥30 mg/g and impaired GFR as eGFR <60 mL/min/1.73 m2. Kidney injury biomarkers (Meso Scale Diagnostics) were measured on stored baseline plasma samples. A principal component analysis (PCA) identified two components: (i) kidney injury molecule-1, calbindin, osteoactivin, trefoil factor 3 and vascular endothelial growth factor; and (ii) β-2 microglobulin, cystatin C, neutrophil gelatinase-associated lipocalin and osteopontin that were used in the multivariable regression analyses.

Results

Component 2 of the PCA was associated with increase in log modulus ACR [β ± standard error (SE): 0.16 ± 0.07, P = 0.02] and eGFR (β ± SE: -2.56 ± 0.97, P = 0.009) over a period of 12 years after adjusting for traditional risk factors (age, sex, HbA1c, low-density lipoprotein cholesterol and systolic blood pressure and baseline eGFR/baseline ACR). Only Component 2 of the PCA was associated with incident-impaired GFR (odds ratio 2.08, 95% confidence interval 1.18-3.67, P = 0.01), adjusting for traditional risk factors. The addition of Component 2 to traditional risk factors significantly improved C-statistics and net-reclassification improvement for incident-impaired GFR (ΔAUC: 0.02 ± 0.01, P = 0.049, and 29% non-events correctly reclassified, P < 0.0001).

Conclusions

Plasma kidney injury biomarkers can help predict development of DKD in T1D.

Role of bicarbonate supplementation on urine uric acid crystals and diabetic tubulopathy in adults with type 1 diabetes

Uricosuria and crystallization are increasingly recognized risk factors for diabetic tubulopathy. This pilot clinical trial aimed to determine the acute effect of urinary alkalinization using oral sodium bicarbonate (NaHCO₃ ) on UA crystals in adults with type 1 diabetes (T1D). Adults with T1D, ages 18 to 65 years (n = 45, 60% female, HbA1c, 7.5 ± 1.2%, 20.2 ± 9.3 years duration) without chronic kidney disease (eGFR ≥60 mL/min/1.73 m² and albumin-to-creatinine ratio < 30 mg/g) received 2 doses of 1950 mg oral NaHCO₃ over 24 hours. Fasting urine and serum were collected pre- and post-intervention. UA crystals were identified under polarized microscopy. Urine measurements included: osmolality, pH, UA, creatinine and kidney injury molecule-1 (KIM-1). NaHCO₃ therapy increased mean ± SD urine pH from 6.1 ± 0.7 to 6.5 ± 0.7 (P < .0001). Prior to therapy, 31.0% of participants had UA crystals vs 6.7% post therapy (P = .005). Change in urine pH inversely correlated with change in urine KIM-1 (r:-0.51, P = .0003). In addition, change in urine UA over 24 hours correlated with change in urine KIM-1 (r:0.37, P = .01). In conclusion, oral NaHCO₃ normalized urine pH and decreased UA crystals, and may hold promise as an inexpensive and safe tubulo-protective intervention in individuals with T1D.

Incremental dialysis for preserving residual kidney function-Does one size fit all when initiating dialysis?

While many patients have substantial residual kidney function (RKF) when initiating hemodialysis (HD), most patients with end stage renal disease in the United States are initiated on 3-times per week conventional HD regimen, with little regard to RKF or patient preference. RKF is associated with many benefits including survival, volume control, solute clearance, and reduced inflammation. Several strategies have been recommended to preserve RKF after HD initiation, including an incremental approach to HD initiation. Incremental HD prescriptions are personalized to achieve adequate volume control and solute clearance with consideration to a patient's endogenous renal function. This allows the initial use of less frequent and/or shorter HD treatment sessions. Regular measurement of RKF is important because HD frequency needs to be increased as RKF inevitably declines. We narratively review the results of 12 observational cohort studies of twice-weekly compared to thrice-weekly HD. Incremental HD is associated with several benefits including preservation of RKF as well as extending the event-free life of arteriovenous fistulas and grafts. Patient survival and quality of life, however, has been variably associated with incremental HD. Serious risks must also be considered, including increased hospitalization and mortality perhaps related to fluid and electrolyte shifts after a long interdialytic interval. On the basis of the above literature review, and our clinical experience, we suggest patient characteristics which may predict favorable outcomes with an incremental approach to HD. These include substantial RKF, adequate volume control, lack of significant anemia/electrolyte imbalance, satisfactory health-related quality of life, low comorbid disease burden, and good nutritional status without evidence of hypercatabolism. Clinicians should engage patients in on-going conversations to prepare for incremental HD initiation and to ensure a smooth transition to thrice-weekly HD when needed.

What insights do patients and caregivers have on acute kidney injury and posthospitalisation care? A single-centre qualitative study from Toronto, Canada

OBJECTIVES

Hospitalisation with acute kidney injury (AKI) is associated with short-term and long-term adverse events, but patient and caregiver experiences with AKI are not well described. We sought to better understand patient and caregiver perspectives after a hospitalisation with AKI to inform discharge strategies that may improve outcomes for this high-risk population.

DESIGN

Qualitative study with semistructured interviews.

SETTING

Tertiary care hospital in Toronto, Ontario, Canada.

PARTICIPANTS

Adult patients (n=15) who survived a hospitalisation with Kidney Disease Improving Global Outcomes stage 2 or 3 AKI from May to December 2016. We also interviewed five patient caregivers. We required patients to have no previous evidence of severe chronic kidney disease (ie, prior receipt of dialysis, previous kidney transplantation or pre-existing estimated glomerular filtration rate (eGFR) under 30 mL/min/1.73 m2).

RESULTS

We identified three over-arching themes: (1) prioritisation of conditions other than AKI, reflected by the importance placed on other comorbidities and the omission of AKI as part of the ongoing medical history; (2) variability in comprehension of the significance of AKI, represented by minimal knowledge of the causes and symptoms associated with AKI, along with misinformation on the kidneys' ability to self-repair; and (3) anxiety from discharge planning and competing health demands, illustrated by complicated discharge plans involving multiple specialist appointments.

CONCLUSIONS

Patients and caregivers view AKI as a short-term and reversible condition, giving it little thought during the postdischarge period. As a result, reliance on patients and caregivers to report an episode of AKI to their outpatient physicians is unlikely to be successful. Patient-centred tools and decision aids are needed to bridge the gap between a hospitalisation with AKI and the safe transition to the outpatient setting.

Long-term outcomes of kidney transplant recipients with end-stage kidney disease attributed to presumed/advanced glomerulonephritis or unknown cause

People with biopsy-proven glomerulonephritis (GN) as their cause of end-stage kidney disease (ESKD) who undergo kidney transplantation incur significant risk of recurrent GN-related graft failure, but the risk in recipients with ESKD where GN was suspected but not biopsy proven (presumed/advanced GN) and when the cause of ESKD is unknown remains uncertain. Using the Australia and New Zealand Dialysis and Transplant registry, we examined the associations between primary kidney transplant recipients whose ESKD was attributed to: 1) commonly-recurring GN (i.e. IgA nephropathy, membranoproliferative GN, focal segmental glomerulosclerosis and membranous GN), 2) presumed/advanced GN, and 3) cause of ESKD unknown (uESKD) and GN-related graft failure using adjusted competing risk models. Of 5258 recipients followed for a median of 8 years, 3539 (67.3%) had commonly-recurring GN, 1195 (22.7%) presumed/advanced GN, and 524 (10.0%) uESKD. Compared to recipients with commonly-recurring GN, recipients with presumed/advanced GN or uESKD experienced a low incidence of GN-related graft failure (<1%) and a lower hazard of GN-related graft failure (adjusted sub-distribution hazard ratio [HR] 0.28 [95%CI 0.15-0.54,p < 0.001] and 0.20 [95%CI 0.06-0.64,p = 0.007], respectively). People with ESKD attributed to either presumed/advanced GN or unknown cause face a very low risk of graft failure secondary to GN recurrence after transplantation.

Modification of Erythrocyte Membrane Fatty Acid Contents After Kidney Transplantation: A Prospective Study

BACKGROUND

Modifications of erythrocyte membrane fatty acid (FA) contents may affect cellular function or transmembrane receptors. One cross-sectional study has shown that kidney transplant (KTP) recipients have lower erythrocyte membrane oleic acid content than dialysis patients do. Therefore, we prospectively tested whether erythrocyte membrane contents of FA including oleic acid change after KTP.

METHODS

We recruited 23 KTP recipients (September 2011 through May 2014). Blood samples were obtained immediately before KTP and 6 months after. Erythrocyte membrane FA contents were measured by gas chromatography.

RESULTS

Mean age of the enrolled KTP recipients was 45.3 ± 10.9 years, and men represented 66.7% of the cases. ABO-incompatible KTPs constituted 14.3% and cadaver donors 42.9% of the cases. Steroids, mycophenolate mofetil, and tacrolimus were used as immunosuppressive treatment. There was no significant difference in dietary consumption between time points before and 6 months after KTP. Total cholesterol and low-density lipoprotein cholesterol levels were significantly higher at 6 months after KTP as compared with baseline. Erythrocyte membrane contents of polyunsaturated FA, ω-3 FA, ω-6 FA, and the ω-3 index were significantly higher, but erythrocyte membrane contents of total saturated FAs, total monounsaturated FAs, including oleic acid, total trans-FA, palmitoleic acid, and the ω-6-to-ω-3 ratio were significantly lower at 6 months after KTP.

CONCLUSIONS

Erythrocyte membrane FA contents significantly changed toward a more favorable cardiovascular profile after KTP. These changes in erythrocyte membrane FA contents may be related to improved renal function because of the absence of significant dietary changes.

Acute Kidney Injury before Dialysis Initiation Predicts Adverse Outcomes in Hemodialysis Patients

BACKGROUND

Acute kidney injury (AKI) is associated with increased morbidity and mortality. Mortality in end-stage renal disease (ESRD) patients is highest during the first year of dialysis. The impact of pre-ESRD AKI events on long-term outcomes in incident ESRD patients remains unknown.

METHODS

We evaluated a retrospective cohort of 47,341 incident hemodialysis patients from the United States Renal Data System with linked Medicare data for at least 2 years prior to hemodialysis initiation. We examined the impact of pre-ESRD AKI events in the 2-year pre-ESRD period on the type of vascular access used at hemodialysis initiation (central venous catheter (CVC) versus arteriovenous access), and 1-year all-cause mortality after initiating hemodialysis.

RESULTS

The mean age was 72 ± 11 years. Of the study cohort, 18% initiated hemodialysis with arteriovenous access, and 54% of patients had at least one pre-ESRD AKI event. One-year, all-cause mortality was 32%. Compared to 75% for patients without a pre-ESRD AKI event, 89% of patients with a pre-ESRD AKI event initiated hemodialysis with CVC than arteriovenous access (p < 0.001). A pre-ESRD AKI event was associated with lower adjusted odds of starting hemodialysis with an arteriovenous access (OR 0.47; 95% CI 0.44-0.50, p < 0.001), and higher adjusted odds of 1-year mortality (OR 1.36; 95% CI 1.30-1.42, p < 0.001).

CONCLUSION

An AKI event prior to initiating hemodialysis independently increases the risk of CVC use and predicts 1-year mortality. Improving processes of care after AKI events may improve dialysis outcomes in patients who progress to ESRD.

Adherence to Hemodialysis and Associated Factors among End Stage Renal Disease Patients at Selected Nephrology Units in Rwanda: A Descriptive Cross-Sectional Study

Introduction

Worldwide, End Stage Renal Disease (ESRD) has become a public health concern increasing the number of patients maintained on hemodialysis prior to renal transplantation. Nonadherence to hemodialysis continues to impact on the care of ESRD patients, causing high increase in morbidity and mortality.

Purpose of the Study

The purpose of this study was to determine the level of adherence to hemodialysis and the associated factors among End Stage Renal Disease (ESRD) patients in selected nephrology units in Rwanda.

Methods

This was a descriptive cross-sectional design involving 41 participants. Participants were recruited using a purposive sampling technique. Demographic and adherence to hemodialysis data were collected with the use of structured interview schedules. Descriptive statistics were used to describe the demographic variables and the level of adherence to hemodialysis. Inferential statistics of chi-square was used to establish factors associated with adherence to hemodialysis.

Results

Twenty-one (51%) of ESRD participants adhered highly (scores < 80%) to HD. Seventeen (42%) adhered moderately (70–79%) to HD while three (7%) had low level of adherence to HD (below 70%). The factors associated with adherence to hemodialysis were age (mean = 27; 95% CI 26.76–29, 17; p = 038) and religion (95% CI 26.29–60.12, p = 003). Frequencies of education of health care workers about the importance of not missing dialysis (95% CI 26.71–42.56, p = .000), perceived relative importance of hemodialysis (95% CI 20.44–27.76, p = .020), and experiencing difficulties during the procedure (95% CI 20.80–28.36, p = .004) were significantly associated with adherence to hemodialysis. Conclusion. Adherence to hemodialysis is still a public health concern in Rwanda. Health care providers and particularly nurses should continue to advocate for adherence to HD for better health outcomes. Further research is needed to identify the barriers to HD in Rwanda.

Cytosine methylation predicts renal function decline in American Indians

Diabetic nephropathy accounts for most of the excess mortality in individuals with diabetes, but the molecular mechanisms by which nephropathy develops are largely unknown. Here we tested cytosine methylation levels at 397,063 genomic CpG sites for association with decline in the estimated glomerular filtration rate (eGFR) over a six year period in 181 diabetic Pima Indians. Methylation levels at 77 sites showed significant association with eGFR decline after correction for multiple comparisons. A model including methylation level at two probes (cg25799291 and cg22253401) improved prediction of eGFR decline in addition to baseline eGFR and the albumin to creatinine ratio with the percent of variance explained significantly improving from 23.1% to 42.2%. Cg22253401 was also significantly associated with eGFR decline in a case-control study derived from the Chronic Renal Insufficiency Cohort. Probes at which methylation significantly associated with eGFR decline were localized to gene regulatory regions and enriched for genes with metabolic functions and apoptosis. Three of the 77 probes that were associated with eGFR decline in blood samples showed directionally consistent and significant association with fibrosis in microdissected human kidney tissue, after correction for multiple comparisons. Thus, cytosine methylation levels may provide biomarkers of disease progression in diabetic nephropathy and epigenetic variations contribute to the development of diabetic kidney disease.

Exit site and tunnel infections in children on chronic peritoneal dialysis: findings from the Standardizing Care to Improve Outcomes in Pediatric End Stage Renal Disease (SCOPE) Collaborative

BACKGROUND

The Standardizing Care to Improve Outcomes in Pediatric End Stage Renal Disease (SCOPE) Collaborative is a quality improvement initiative to reduce dialysis-associated infections. The frequency of peritoneal dialysis (PD) catheter exit site infection (ESI) and variables influencing its development and end result are unclear. We sought to determine ESI rates, to elucidate the epidemiology, risk factors, and outcomes for ESI, and to assess for association between provider compliance with care bundles and ESI risk.

METHODS

We reviewed demographic, dialysis and ESI data, and care bundle adherence and outcomes for SCOPE enrollees from October 2011 to September 2014. ESI involved only the exit site, only the subcutaneous catheter tunnel, or both.

RESULTS

A total of 857 catheter insertions occurred in 734 children over 10,110 cumulative months of PD provided to these children. During this period 207 ESIs arose in 124 children or 0.25 ESIs per dialysis year. Median time to ESI was 392 days, with 69% of ESIs involving exit site only, 23% involving the tunnel only, and 8% involving both sites. Peritonitis developed in 6%. ESI incidence was associated with age (p = 0.003), being the lowest in children aged < 2 years and highest in those aged 6-12 years, and with no documented review of site care or an exit site score  of > 0 at prior month's visit (p < 0.001). Gender, race, end stage renal disease etiology, exit site orientation, catheter cuff number or mobilization, and presence of G-tube, stoma, or vesicostomy were unassociated with ESI incidence. Of the ESIs reported, 71% resolved with treatment, 24% required hospitalization, and 9% required catheter removal, generally secondary to tunnel infection.

CONCLUSIONS

Exit site infections occur at an annualized rate of 0.25, typically well into the dialysis course. Younger patient age and documented review of site care are associated with lower ESI rates. Although most ESIs resolve, hospitalization is frequent, and tunnel involvement/catheter loss complicate outcomes.

Moving on: transitioning young people with chronic kidney disease to adult care

Advances in the care of children mean that adolescents with chronic kidney disease (CKD) are surviving to adulthood and requiring transition to adult care. The transition phase is well-recognised to be associated with considerable excess morbidity and graft loss, but these outcomes may be avoidable through a structured transition programme. This review will discuss the (1) challenges encountered by patients with CKD, caregivers and clinicians during transition; (2) predictors and outcomes of transition; (3) current guidelines on transition from paediatric to adult renal services; (4) interventions and research directions that may help to improve the care and outcomes for young people with CKD in transition. In spite of the substantial improvement in health gains required for this disadvantaged population, there is to date only limited evidence on the effects of current transition programmes.

Vitamin D treatment attenuates cardiac FGF23/FGFR4 signaling and hypertrophy in uremic rats

Background

Vitamin D deficiency and excess of circulating fibroblast growth factor 23 (FGF23) contribute to cardiovascular mortality in patients with chronic kidney disease (CKD). FGF23 activates FGF receptor 4 and (FGFR4) calcineurin/nuclear factor of activated T cells (NFAT) signaling in cardiac myocytes, thereby causing left ventricular hypertrophy (LVH). Here, we determined if 1,25-dihydroxyvitamin D (calcitriol) inhibits FGF23-induced cardiac signaling and LVH.

Methods

5/6 nephrectomized (5/6 Nx) rats were treated with different doses of calcitriol for 4 or 10 weeks and cardiac expression of FGF23/FGFR4 and activation of calcineurin/NFAT as well as LVH were analyzed. FGFR4 activation and hypertrophic cell growth were studied in cultured cardiac myocytes that were co-treated with FGF23 and calcitriol.

Results

In 5/6Nx rats with LVH, we detected elevated FGF23 expression in bone and myocardium, increased cardiac expression of FGFR4 and elevated cardiac activation of calcineurin/NFAT signaling. Cardiac expression levels of FGF23 and FGFR4 significantly correlated with the presence of LVH in uremic rats. Treatment with calcitriol reduced LVH as well as cardiac FGFR4 expression and calcineurin/NFAT activation. Bone and cardiac FGF23 expression were further stimulated by calcitriol in a dose-dependent manner, but levels of intact cardiac FGF23 protein were suppressed by high-dose calcitriol. In cultured cardiac myocytes, co-treatment with calcitriol blocked FGF23-induced activation of FGFR4 and hypertrophic cell growth.

Conclusions

Our data suggest that in CKD, cardioprotective effects of calcitriol stem from its inhibitory actions on the cardiac FGF23/FGFR4 system, and based on their counterbalancing effects on cardiac myocytes, high FGF23 and low calcitriol synergistically contribute to cardiac hypertrophy.

Dialysis versus Medical Management at Different Ages and Levels of Kidney Function in Veterans with Advanced CKD

Background Appropriate patient selection and optimal timing of dialysis initiation among older adults with advanced CKD are uncertain. We determined the association between dialysis versus medical management and survival at different ages and levels of kidney function.Methods We assembled a nationally representative 20% sample of United States veterans with eGFR<30 ml/min per 1.73 m² between 2005 and 2010 (n=73,349), with follow-up through 2012. We used an extended Cox model to determine associations among the time-varying exposures, age (<65, 65-74, 75-84, and ≥85 years), eGFR (<6, 6-<9, 9-<12, 12-<15, and 15-<29 ml/min per 1.73 m²), and provision of dialysis, and survival.Result Over the mean±SEM follow-up of 3.4±2.2 years, 15% of patients started dialysis and 52% died. The eGFR at which dialysis, compared with medical management, associated with lower mortality varied by age (P<0.001). For patients aged <65, 65-74, 75-84, and ≥85 years, dialysis associated with lower mortality for those with eGFR not exceeding 6-<9, <6, 9-<12, and 9-<12 ml/min per 1.73 m², respectively. Dialysis initiation at eGFR<6 ml/min per 1.73 m² associated with a higher median life expectancy of 26, 25, and 19 months for patients aged 65, 75, and 85 years, respectively. When dialysis was initiated at eGFR 9-<12 ml/min per 1.73 m², the estimated difference in median life expectancy was <1 year for these patients.Conclusions Provision of dialysis at higher levels of kidney function may extend survival for some older patients.

Tradeoffs in Vascular Access Selection in Elderly Patients Initiating Hemodialysis With a Catheter

RATIONALE & OBJECTIVE

National vascular access guidelines recommend placement of arteriovenous fistulas (AVFs) over grafts (AVGs) in hemodialysis patients, but have not been comprehensively assessed in the elderly. We evaluated clinically relevant vascular access outcomes in elderly patients receiving an AVF or AVG after hemodialysis therapy initiation.

STUDY DESIGN

Retrospective cohort study using national administrative data.

SETTINGS & PARTCIPANTS

Claims data from the US Renal Data System of 9,458 US patients 67 years and older who initiated hemodialysis therapy from July 1, 2010, to June 30, 2011, with a catheter and received an AVF (n=7,433) or AVG (n=2,025) within the ensuing 6 months.

PREDICTOR

Arteriovenous access subtype, AVF or AVG.

OUTCOMES

Successful use of vascular access, interventions to make vascular access functional, duration of catheter dependence before successful use of vascular access, frequency of interventions, and abandonment after successful use of vascular access.

ANALYTICAL APPROACH

Multivariable logistic regression analysis was used to compare the need for intervention before successful use of AVFs and AVGs, and negative bionomial regression was used to calculate the frequency of intervention after successful use of vascular access.

RESULTS

Unsuccessful use of vascular access within 6 months of creation was higher for AVFs versus AVGs (51% vs 45%; adjusted HR, 1.86; 95% CI, 1.73-1.99). Interventions to make vascular access functional were greater in AVFs versus AVGs (42% vs 23%; OR, 2.66; 95% CI, 2.26-3.12). AVFs had a lower 1-year abandonment rate after successful use compared with AVGs (OR, 0.71; 95% CI, 0.62-0.83) and required one-fourth fewer interventions after successful use (relative risk, 0.75; 95% CI, 0.69-0.81). Patients receiving an AVF had substantially longer catheter dependence before successful use than those receiving an AVG (median time, 3 vs 1 month; P<0.001).

LIMITATIONS

Residual confounding due to vascular access choice, restriction to an elderly population, and 1-year follow-up period.

CONCLUSIONS

In elderly hemodialysis patients initiating hemodialysis therapy with a catheter, the optimal vascular access selection depends on tradeoffs between shorter catheter dependence and less frequent interventions to make the vascular access (AVG) functional versus longer access patency and fewer interventions after successful use of the vascular access (AVF).

Awareness of Racial Disparities in Kidney Transplantation among Health Care Providers in Dialysis Facilities

BACKGROUND AND OBJECTIVES

Despite the important role that health care providers at dialysis facilities have in reducing racial disparities in access to kidney transplantation in the United States, little is known about provider awareness of these disparities. We aimed to evaluate health care providers' awareness of racial disparities in kidney transplant waitlisting and identify factors associated with awareness.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a cross-sectional analysis of a survey of providers from low-waitlisting dialysis facilities (n=655) across all 18 ESRD networks administered in 2016 in the United States merged with 2014 US Renal Data System and 2014 US Census data. Awareness of national racial disparity in waitlisting was defined as responding "yes" to the question: "Nationally, do you think that African Americans currently have lower waitlisting rates than white patients on average?" The secondary outcome was providers' perceptions of racial difference in waitlisting at their own facilities.

RESULTS

Among 655 providers surveyed, 19% were aware of the national racial disparity in waitlisting: 50% (57 of 113) of medical directors, 11% (35 of 327) of nurse managers, and 16% (35 of 215) of other providers. In analyses adjusted for provider and facility characteristics, nurse managers (versus medical directors; odds ratio, 7.33; 95% confidence interval, 3.35 to 16.0) and white providers (versus black providers; odds ratio, 2.64; 95% confidence interval, 1.39 to 5.02) were more likely to be unaware of a national racial disparity in waitlisting. Facilities in the South (versus the Northeast; odds ratio, 3.05; 95% confidence interval, 1.04 to 8.94) and facilities with a low percentage of blacks (versus a high percentage of blacks; odds ratio, 1.86; 95% confidence interval, 1.02 to 3.39) were more likely to be unaware. One quarter of facilities had >5% racial difference in waitlisting within their own facilities, but only 5% were aware of the disparity.

CONCLUSIONS

Among a limited sample of dialysis facilities with low waitlisting, provider awareness of racial disparities in kidney transplant waitlisting was low, particularly among staff who may have more routine contact with patients.

Co-Administration of Melatonin Effectively Enhances the Therapeutic Effects of Pioglitazone on Mesenchymal Stem Cells Undergoing Indoxyl Sulfate-Induced Senescence through Modulation of Cellular Prion Protein Expression

Background: Mesenchymal stem cells (MSCs) are a promising source for regenerative medicine. However, their therapeutic potential in patients with chronic kidney disease (CKD) is restricted by the presence of uremic toxins. To address this limitation, we explored the protective effect of melatonin and pioglitazone on MSCs undergoing senescence induced by the uremic toxin, indoxyl sulfate (IS). Methods: MSC senescence was induced by IS, and the therapeutic effects of melatonin and pioglitazone were identified. The expression of cellular prion protein (PrP^C) was suppressed by transfection of MSCs with prion protein gene (PRNP) siRNA. Subsequently, these cells were used to study the protective effects of melatonin and pioglitazone against IS-induced senescence; Results: The IS-induced senescence of MSCs was significantly reduced by co-treatment with melatonin and pioglitazone compared to treatment with melatonin or pioglitazone alone. In the presence of IS, the reduced MSC proliferation was rescued by co-treatment with melatonin and pioglitazone. Melatonin and pioglitazone enhanced the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) in MSCs, which resulted in the augmentation of PrP^C level. The inhibitory effect of the co-treatment with melatonin and pioglitazone on IS-induced senescence in MSCs was blocked by the knockdown of PRNP. In addition, the restorative effect of the co-treatment on the reduced MSC proliferation induced by IS was also blocked by the knockdown of PRNP. These findings indicate that co-treatment with melatonin and pioglitazone protected MSCs from uremic toxin-induced senescence through the regulation of the PPAR-γ-PrP^C axis. Conclusions: Our study suggests that co-treatment of MSCs with melatonin and pioglitazone may represent a novel strategy for the development of MSC-based therapies for patients with CKD.

Residual Function Effectively Controls Plasma Concentrations of Secreted Solutes in Patients on Twice Weekly Hemodialysis

Background Most patients on hemodialysis are treated thrice weekly even if they have residual kidney function, in part because uncertainty remains as to how residual function should be valued and incorporated into the dialysis prescription. Recent guidelines, however, have increased the weight assigned to residual function and thus reduced the treatment time required when it is present. Increasing the weight assigned to residual function may be justified by knowledge that the native kidney performs functions not replicated by dialysis, including solute removal by secretion. This study tested whether plasma concentrations of secreted solutes are as well controlled in patients with residual function on twice weekly hemodialysis as in anuric patients on thrice weekly hemodialysis.Methods We measured the plasma concentration and residual clearance, dialytic clearance, and removal rates for urea and the secreted solutes hippurate, phenylacetylglutamine, indoxyl sulfate, and p-cresol sulfate in nine patients on twice weekly hemodialysis and nine patients on thrice weekly hemodialysis.Results Compared with anuric patients on thrice weekly dialysis with the same standard Kt/V_urea, patients on twice weekly hemodialysis had lower hippurate and phenylacetylglutamine concentrations and similar indoxyl sulfate and p-cresol sulfate concentrations. Mathematical modeling revealed that residual secretory function accounted for the observed pattern of solute concentrations.Conclusions Plasma concentrations of secreted solutes can be well controlled by twice weekly hemodialysis in patients with residual kidney function. This result supports further study of residual kidney function value and the inclusion of this function in dialysis adequacy measures.

Thyroid Status and Death Risk in US Veterans With Chronic Kidney Disease

OBJECTIVE

Given that patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) have a disproportionately higher prevalence of hypothyroidism compared with their non-CKD counterparts, we sought to determine the association between thyroid status, defined by serum thyrotropin (TSH) levels, and mortality among a national cohort of patients with NDD-CKD.

PATIENTS AND METHODS

Among 227,422 US veterans with stage 3 NDD-CKD with 1 or more TSH measurements during the period October 1, 2004, to September 30, 2012, we first examined the association of thyroid status, defined by TSH categories of less than 0.5, 0.5 to 5.0 (euthyroidism), and more than 5.0 mIU/L, with all-cause mortality. We then evaluated 6 granular TSH categories: less than 0.1, 0.1 to less than 0.5, 0.5 to less than 3.0, 3.0 to 5.0, more than 5.0 to 10.0, and more than 10.0 mIU/L. We concurrently examined thyroid status, thyroid-modulating therapy, and mortality in sensitivity analyses.

RESULTS

In expanded case-mix adjusted Cox analyses, compared with euthyroidism, baseline and time-dependent TSH levels of more than 5.0 mIU/L were associated with higher mortality (adjusted hazard ratios [aHRs] [95% CI], 1.19 [1.15-1.24] and 1.23 [1.19-1.28], respectively), as were baseline and time-dependent TSH levels of less than 0.5 mIU/L (aHRs [95% CI], 1.18 [1.15-1.22] and 1.41 [1.37-1.45], respectively). Granular examination of thyroid status showed that incrementally higher TSH levels of 3.0 mIU/L or more were associated with increasingly higher mortality in baseline and time-dependent analyses, and TSH categories of less than 0.5 mIU/L were associated with higher mortality (reference, 0.5-<3.0 mIU/L) in baseline analyses. In time-dependent analyses, untreated and undertreated hypothyroidism and untreated hyperthyroidism were associated with higher mortality (reference, spontaneous euthyroidism), whereas hypothyroidism treated-to-target showed lower mortality.

CONCLUSION

Among US veterans with NDD-CKD, high-normal TSH (≥3.0 mIU/L) and lower TSH (<0.5 mIU/L) levels were associated with higher death risk. Interventional studies identifying the target TSH range associated with the greatest survival in patients with NDD-CKD are warranted.

Abrupt Decline in Kidney Function Precipitating Initiation of Chronic Renal Replacement Therapy

INTRODUCTION

Abrupt declines in kidney function often occur in patients with advanced chronic kidney disease and may exacerbate the need to initiate dialysis treatment. It is unclear how frequently such events occur in patients transitioning to chronic dialysis therapy, and what outcomes they are associated with.

METHODS

We examined a national cohort of 23,349 US veterans with incident end-stage renal disease (ESRD) and with available pre-ESRD estimated glomerular filtration rate (eGFR) to identify abrupt declines in kidney function, defined as an unexpected >50% decrease in eGFR at the time of chronic dialysis transition. Associations with all-cause mortality and with renal recovery were examined in Cox proportional hazard and competing risk regression models.

RESULTS

A total of 4804 (21%) patients experienced an abrupt decline in kidney function at dialysis transition. Renal recovery occurred in 586 (12.2%) and 297 (1.6%) patients with and without an abrupt decline, respectively (adjusted subhazard ratio: 4.42; 95% confidence interval [CI]: 3.72-5.27; P < 0.001). In the first 6 months after dialysis transition 1178 patients (24.5%) with abrupt decline died (annualized mortality rate 574/1000 patient-years), compared with 2354 deaths (12.7%) in patients without abrupt decline (274 deaths/1000 patient-years). An abrupt decline was associated with 45% higher mortality after multivariable adjustments (hazard ratio: 1.45; 95% CI: 1.33-1.57).

CONCLUSION

Abrupt declines in kidney function are common in patients transitioning to chronic dialysis, and are associated with higher mortality. Patients with abrupt declines also experience a higher rate of renal recovery; hence, careful attention to residual kidney function is warranted in these patients.

The Ebb and Flow of Echocardiographic Cardiac Function Parameters in Relationship to Hemodialysis Treatment in Patients with ESRD

Cardiovascular disease is the leading cause of mortality in patients receiving hemodialysis. Cardiovascular events in these patients demonstrate a day-of-week pattern; i.e., they occur more commonly during the last day of the long interdialytic interval and the first session of the week. The hemodialysis process causes acute decreases in cardiac chamber size and pulmonary circulation loading and acute diastolic dysfunction, possibly through myocardial stunning and other non-myocardial-related mechanisms; systolic function, in contrast, is largely unchanged. During interdialytic intervals volume overload, acid-base, and electrolyte shifts, as well as arterial and myocardial wall changes, result in dilatation of right cardiac chambers and pulmonary circulation overload. Recent studies suggest that these alterations are more extended during the long interdialytic interval or the first dialysis session of the week and are associated with excess volume overload or removal, respectively, thus adding a mechanism for the day-of-week pattern of mortality in patients receiving hemodialysis. This review summarizes the existing data from echocardiographic studies of cardiac morphology and function during the hemodialysis session, as well as during the interdialytic intervals.

Long-Term Extensions of Randomized Vaccination Trials of ACC-001 and QS-21 in Mild to Moderate Alzheimer's Disease

OBJECTIVES

Long-term safety and tolerability of ACC-001 (vanutide cridificar), an antiamyloid- beta therapeutic vaccine, was evaluated in subjects with mild to moderate Alzheimer's disease.

DESIGN

Phase 2a extension studies of randomized parent trials were conducted in the United States, European Union, and Japan.

METHODS

Four immunizations of ACC-001 were administered at the same 3 dose levels (3, 10, and 30 μg) to subjects randomized in the parent studies; ACC-001 was administered with QS-21 adjuvant. Safety, tolerability, and immunogenicity were assessed during active treatment and 6-month follow-up.

RESULTS

ACC-001 + QS-21 was well tolerated in the United States (N=110) and European Union (N=50), and Japan (N=53) extension studies; safety profile was similar to that observed in the parent studies, and no new safety signals were identified. Overall, injection site reactions were the most common adverse event in these studies. Anti-amyloid antibody titers were elicited in all groups, with the highest titers observed in subjects who received ACC-001 + QS-21 in both the parent and extension studies.

CONCLUSIONS

Long-term exposure to ACC-001 + QS-21 was well tolerated in subjects with Alzheimer's disease, suggesting that side effects do not pose a principal limitation for anti-amyloid active immunotherapy. The highest anti-amyloid-beta IgG titers are elicited during long-term therapy with ACC-001 + QS-21 compared with other regimens.

Efficacy and Safety of Different Bisphosphonates for Bone Loss Prevention in Kidney Transplant Recipients: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Mineral and bone disorder is one of the severe complications in kidney transplant recipients (KTRs). Previous studies showed that bisphosphonates had favorable effects on bone mineral density (BMD). We sought to compare different bisphosphonate regimens and rank their strategies.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) up to April 01, 2017, for randomized controlled trials (RCTs) comparing bisphosphonate treatments in adult KTRs. The primary outcome was BMD change. We executed the tool recommended by the Cochrane Collaboration to evaluate the risk of bias. We performed pairwise meta-analyses using random effects models and network meta-analysis (NMA) using Bayesian models and assessed the quality of evidence.

RESULTS

A total of 21 RCTs (1332 participants) comparing 6 bisphosphonate regimens were included. All bisphosphonates showed a significantly increased percentage change in BMD at the lumbar spine compared to calcium except clodronate. Pamidronate with calcium and Vitamin D analogs showed improved BMD in comparison to clodronate with calcium (mean difference [MD], 9.84; 95% credibility interval [CrI], 1.06-19.70). The combination of calcium and Vitamin D analogs had a significantly lower influence than adding either pamidronate or alendronate (MD, 6.34; 95% CrI, 2.59-11.01 and MD, 6.16; 95% CrI, 0.54-13.24, respectively). In terms of percentage BMD change at the femoral neck, both pamidronate and ibandronate combined with calcium demonstrated a remarkable gain compared with calcium (MD, 7.02; 95% CrI, 0.30-13.29 and MD, 7.30; 95% CrI, 0.32-14.22, respectively). The combination of ibandronate with calcium displayed a significant increase in absolute BMD compared to any other treatments and was ranked best.

CONCLUSIONS

Our NMA suggested that new-generation bisphosphonates such as ibandronate were more favorable in KTRs to improve BMD. However, the conclusion should be treated with caution due to indirect comparisons.

Peritoneal dialysis as initial dialysis modality: a viable option for late-presenting end-stage renal disease

Late-presenting end-stage renal disease is a significant problem worldwide. Up to 70% of patients start dialysis in an unplanned manner without a definitive dialysis access in place. Haemodialysis via a central venous catheter is the default modality for the majority of such patients, and peritoneal dialysis is usually not considered as a feasible option. However, in the recent years, some reports on urgent-start peritoneal dialysis in the late-presenting end-stage renal disease have been published. The collective experience shows that PD can be a safe, efficient and cost-effective alternative to haemodialysis in late-presenting end-stage renal disease with comparable outcomes to the conventional peritoneal dialysis and urgent-start haemodialysis. More importantly, as compared to urgent-start haemodialysis via a central venous catheter, urgent-start peritoneal dialysis has significantly fewer incidences of catheter-related bloodstream infections, dialysis-related complications and need for dialysis catheter re-insertions during the initial phase of the therapy. This article examines the rationale and feasibility for starting peritoneal dialysis urgently in late-presenting end-stage renal disease patients and reviews the literature to compare the urgent-start peritoneal dialysis with conventional peritoneal dialysis and urgent-start haemodialysis.

Heart Rate Variability and Its Relation to Chronic Kidney Disease: Results From the PREVEND Study

OBJECTIVE

In the general population, reduced heart rate variability (HRV) has been associated with cardiovascular disease. However, its relation to chronic kidney disease (CKD) is debated. We therefore investigated the relation between low HRV and renal outcomes.

METHODS

In the population-based Prevention of REnal and Vascular ENdstage Disease study, renal outcomes (CKD, estimated glomerular filtration rate [eGFR], urinary albumin) were measured at baseline and three consecutive examinations. HRV measures (among which SDNN [standard deviation of normal-to-normal RR intervals]) were calculated from time series of beat-to-beat pulse wave recordings at baseline. The lowest (risk) quartile was compared with the upper three quartiles combined, in multivariable survival and linear mixed-effects analyses.

RESULTS

In 4605 participants (49% males, age range = 33-80, 0.6% blacks), we observed 341 new participants of CKD during a median follow-up duration of 7.4 years. Low SDNN was associated with higher incidence of CKD (crude HR = 1.66, 95% CI = 1.30 to 2.12, p < .001), but this association was no longer significant after adjustment for age, sex, and cardiovascular risk factors (adjusted HR = 1.13, 95% CI = 0.86 to 1.48, p = .40, similar for other HRV measures). No associations between SDNN and eGFR trajectories were found in the total sample. However, in a subgroup of participants with baseline CKD (n = 939), we found a significant association of low SDNN (but not other HRV measures) with lower baseline eGFR, even after multivariable adjustment (adjusted βlevel difference = -3.73 ml/min/1.73 m, 95% CI = -6.70 to -0.75, p = .014), but not with steeper eGFR decline.

CONCLUSIONS

These results suggest that reduced HRV may be a complication of CKD rather than a causal factor.

Activation of podocyte Notch mediates early Wt1 glomerulopathy

The Wilms' tumor suppressor gene, WT1, encodes a zinc finger protein that regulates podocyte development and is highly expressed in mature podocytes. Mutations in the WT1 gene are associated with the development of renal failure due to the formation of scar tissue within glomeruli, the mechanisms of which are poorly understood. Here, we used a tamoxifen-based CRE-LoxP system to induce deletion of Wt1 in adult mice to investigate the mechanisms underlying evolution of glomerulosclerosis. Podocyte apoptosis was evident as early as the fourth day post-induction and increased during disease progression, supporting a role for Wt1 in mature podocyte survival. Podocyte Notch activation was evident at disease onset with upregulation of Notch1 and its transcriptional targets, including Nrarp. There was repression of podocyte FoxC2 and upregulation of Hey2 supporting a role for a Wt1/FoxC2/Notch transcriptional network in mature podocyte injury. The expression of cleaved Notch1 and HES1 proteins in podocytes of mutant mice was confirmed in early disease. Furthermore, induction of podocyte HES1 expression was associated with upregulation of genes implicated in epithelial mesenchymal transition, thereby suggesting that HES1 mediates podocyte EMT. Lastly, early pharmacological inhibition of Notch signaling ameliorated glomerular scarring and albuminuria. Thus, loss of Wt1 in mature podocytes modulates podocyte Notch activation, which could mediate early events in WT1-related glomerulosclerosis.

The PD-1/PD-L1 Inhibitory Pathway is Altered in Primary Glomerulonephritides

The pathogenesis of primary proliferative and non-proliferative glomerulonephritides (PGN and NPGN) is still not fully understood, however, current evidence suggests that most cases of PGN and NPGN are the results of immunologic response to different etiologic agents that activates various biological processes leading to glomerular inflammation and injury. Programmed cell death protein 1 (PD-1) is the major inhibitory receptor regulating T cell exhaustion. The aim of this study was to evaluate the frequencies of PD-1-positive and PD-ligand 1 (PD-L1)-positive T and B lymphocytes in patients with NPGN and PGN in relation to clinical parameters for the first time. The study included peripheral blood (PB) samples from 20 newly diagnosed PGN and NPGN patients. The control group comprised of 20 healthy age- and sex-matched subjects. The viable PB lymphocytes underwent labelling with fluorochrome-conjugated monoclonal antibodies anti-PD-1 and anti-PD-L1, and were analyzed using a flow cytometer. The frequencies of CD4+/PD1+ T lymphocytes, CD8+/PD1+ T lymphocytes, and CD19+/PD-1+ B lymphocytes in the PGN group exceeded values obtained both in the NPGN group, and the control group. Alteration of PD-1/PD-L1 pathway may be involved in poorer prognosis, as patients with PGN are characterized by higher frequencies of PD-1-positive and PD-L1-positive T and B lymphocytes than patients with NPGN. Our results suggest that deregulation of PD-1/PD-L1 axis may contribute to the PGN and NPGN pathogenesis. High percentages of lymphocytes with PD-1 and PD-L1 expression may be related to the continuous T-cell activation and development of glomerular inflammation and injury.

Nitrolipids in kidney physiology and disease

The kidneys are vital organs responsible for maintaining body fluid homeostasis within proper physiologic ranges. Kidney disease is an epidemic clinical problem causing significant morbidity and mortality, and current treatments are limited to renin-angiotensin system blockade or renal replacement therapy for the majority of affected individuals. There is a critical, unmet need for novel pharmacological agents to improve the outcome of patients with kidney disease. Nitro-oleic acid (NO2-OA) is an endogenously generated electrophilic compound with the capacity to modify thiols in proteins, altering their function. The most important targets appear to be the Keap1/Nrf2 and NF-κB pathways, which have widespread effects on antioxidant, detoxifying, and inflammatory responses in cells and tissues. Through these and potentially additional protective actions, NO2-OA may be capable of preserving or enhancing kidney function in acute and chronic kidney diseases.

Glomerular Endothelial Cell Stress and Cross-Talk With Podocytes in Early [corrected] Diabetic Kidney Disease

Diabetic kidney disease (DKD) is one of the major causes of morbidity and mortality in diabetic patients and also the leading single cause of end-stage renal disease in the United States. A large proportion of diabetic patients develop DKD and others don't, even with comparable blood glucose levels, indicating a significant genetic component of disease susceptibility. The glomerulus is the primary site of diabetic injury in the kidney, glomerular hypertrophy and podocyte depletion are glomerular hallmarks of progressive DKD, and the degree of podocyte loss correlates with severity of the disease. We know that chronic hyperglycemia contributes to both microvascular and macrovascular complications, as well as podocyte injury. We are beginning to understand the role of glomerular endothelial injury, as well as the involvement of reactive oxygen species and mitochondrial stress, which play a direct role in DKD and in other diabetic complications. There is, however, a gap in our knowledge that links genetic susceptibility to early molecular mechanisms and proteinuria in DKD. Emerging research that explores glomerular cell's specific responses to diabetes and cell cross-talk will provide mechanistic clues that underlie DKD and provide novel avenues for therapeutic intervention.

Vascular access for home haemodialysis

Introduction:

Home haemodialysis has been advocated due to improved quality of life. However, there are very little data on the optimum vascular access for it.

Method:

A retrospective cohort study was carried on all patients who initiated home haemodialysis between 2011 and 2016 at a large university hospital. Access-related hospital admissions and interventions were used as primary outcome measures.

Results:

Our cohort consisted of 74 patients. On initiation of home haemodialysis, 62 individuals were using an arteriovenous fistula as vascular access, while the remaining were on a tunnelled dialysis catheter. Of the 12 patients who started on a tunnelled dialysis catheter, 5 were subsequently converted to either an arteriovenous fistula ( n = 4) or an arteriovenous graft ( n = 1). During the period of home haemodialysis use, four arteriovenous fistula failed or thrombosed with patients continuing on home haemodialysis using an arteriovenous graft ( n = 3) or a tunnelled dialysis catheter ( n = 1). To maintain uninterrupted home haemodialysis, interventional rates were 0.32 per arteriovenous fistula/arteriovenous graft access-year and 0.4 per tunnelled dialysis catheter access-year. Hospital admission rates for patients on home haemodialysis were 0.33 per patient-year.

Conclusion:

Our study has shown that home haemodialysis can be safely and independently performed at home within a closely managed home haemodialysis programme. The authors also advocate the use of arteriovenous fistulas for this cohort of patients due to both low complication and intervention rates.

Renal Hyperfiltration in Adolescents with Type 2 Diabetes: Physiology, Sex Differences, and Implications for Diabetic Kidney Disease

PURPOSE OF REVIEW

Compared to adult-onset type 2 diabetes (T2D), youth with T2D have a more aggressive phenotype with greater insulin resistance (IR), more rapid β cell decline, and higher prevalence of diabetic kidney disease (DKD).

RECENT FINDINGS

Hyperfiltration is common in youth with T2D and predicts progressive DKD. Hyperfiltration is a consequence of early changes in intrarenal hemodynamic function, including increased renal plasma flow (RPF) and glomerular pressure. Girls with T2D are disproportionally affected by DKD, with a 3-fold greater risk of developing hyperfiltration over 5 years compared to boys. Despite the high prevalence and gravity of DKD in youth-onset T2D, widely effective therapeutic options are lacking. In this review, we focus on pathophysiology underlying early DKD in T2D and sex differences and summarize promising novel medical therapies and bariatric surgery.

Placement issues of hemodialysis catheters with pre-existing central lines and catheters

OBJECTIVE

It has been a widely accepted practice that a previous placed pacemaker, automatic implantable cardioverter defibrillators, or central line can be a contraindication to placing a hemodialysis catheter in the ipsilateral jugular vein. Fear of dislodging pacing wires, tunneling close to the battery site or causing venous obstruction has been a concern for surgeons and interventionalists alike. We suggest that this phobia may be unfounded.

METHODS

A retrospective review was conducted of patients in whom hemodialysis catheters were placed over a period of 10 years. For each hemodialysis catheter that was placed, perioperative chest X-ray performed was used to evaluate for pre-existing pacemakers and central lines. The position and laterality of placement of the hemodialysis catheter along with presence of arteriovenous fistula with functional capacity for access were noted.

RESULTS

A total of 600 hemodialysis catheters were placed in patients over the period of 10 years. The mean age of the patients was 73.6 ± 12 years with a median age of 76 years. We found 20 pacemakers or automatic implantable cardioverter defibrillators and 19 central lines on the same side of the neck as the hemodialysis catheter that was placed in the ipsilateral jugular vein. No patient exhibited malfunction or dislodgment of the central line, the pacemaker, or automatic implantable cardioverter defibrillator or evidence of upper extremity venous obstruction based upon signs symptoms or duplex exams.

CONCLUSION

Based on our experience, we suggest that placement of hemodialysis catheter in the internal jugular vein ipsilateral to the pre-existing catheter/leads is safe and spares the contralateral limb for arteriovenous fistula creation.

Long-term clinical parameters after switching to nocturnal haemodialysis: a Dutch propensity-score-matched cohort study comparing patients on nocturnal haemodialysis with patients on three-times-a-week haemodialysis/haemodiafiltration

OBJECTIVES

Nocturnal haemodialysis (NHD), characterised by 8-hour sessions ≥3 times a week, is known to improve clinical parameters in the short term compared with conventional-schedule haemodialysis (HD), generally 3×3.5-4 hours a week. We studied long-term effects of NHD and used patients on conventional HD/haemodiafiltration (HDF) as controls.

DESIGN

Four-year prospective follow-up of patients who switched to NHD; we compared patients with patients on HD/HDF using propensity score matching.

SETTING

28 Dutch dialysis centres.

PARTICIPANTS

We included 159 patients starting with NHD any time since 2004, aged 56.7±12.9 years, with median dialysis vintage 2.3 (0.9-5.1) years. We propensity-score matched 100 patients on NHD to 100 on HD/HDF.

PRIMARY AND SECONDARY OUTCOME MEASURES

Control of hypertension (predialysis blood pressure, number of antihypertensives), phosphate (phosphate, number of phosphate binders), nutritional status and inflammation (albumin, C reactive protein and postdialysis weight) and anaemia (erythropoiesis-stimulating agent (ESA) resistance).

RESULTS

Switching to NHD was associated with a non-significant reduction of antihypertensives compared with HD/HDF (OR <2 types 2.17, 95% CI 0.86 to 5.50, P=0.11); and a prolonged lower need for phosphate binders (OR <2 types 1.83, 95% CI 1.10 to 3.03, P=0.02). NHD was not associated with significant changes in blood pressure or phosphate. NHD was associated with significantly higher albumin over time compared with HD/HDF (0.70 g/L/year, 95% CI 0.10 to 1.30, P=0.02). ESA resistance decreased significantly in NHD compared with HD/HDF, resulting in a 33% lower ESA dose in the long term.

CONCLUSIONS

After switching to NHD, the lower need for antihypertensives, phosphate binders and ESA persists for at least 4 years. These sustained improvements in NHD contrast significantly with the course of these parameters during continued treatment with conventional-schedule HD and HDF. NHD provides an optimal form of dialysis, also suitable for patients expected to have a long waiting time for transplantation or those convicted to indefinite dialysis.

Solid Organ Transplantation for HIV-Infected Individuals

Purpose of Review

The prevalence of end-stage organ disease is increasing among HIV-infected (HIV+) individuals. Individuals with well-controlled HIV on antiretroviral therapy (ART), without active opportunistic infections or cancer, and with specified minimum CD4 cell counts are appropriate transplant candidates. Infectious disease clinicians can improve access to transplantation for these patients and optimize management pre- and post-transplant.

Recent Findings

Clinical trials and registry-based studies demonstrate excellent outcomes for select HIV+ kidney and liver transplant recipients with similar patient and graft survival as HIV-uninfected patients. Elevated allograft rejection rates have been observed in HIV+ individuals; this may be related to a dysregulated immune system or drug interactions. Lymphocyte-depleting immunosuppression has been associated with lower rejection rates without increased infections using national registry data. Hepatitis C virus (HCV) coinfection has been associated with worse outcomes, however improvements are expected with direct-acting antivirals.

Summary

Solid organ transplantation should be considered for HIV+ individuals with end-stage organ disease. Infectious disease clinicians can optimize ART to avoid pharmacoenhancers, which interact with immunosuppression. The timing of HCV treatment (pre- or post-transplant) should be discussed with the transplant team. Finally, organs from HIV+ donors can now be considered for HIV+ transplant candidates, within research protocols.

Research Priorities for Palliative Care for Older Adults with Advanced Chronic Kidney Disease

Older adults with advanced chronic kidney disease (CKD) often have multiple comorbid conditions, a high symptom burden, and limited life expectancy. There is mounting concern that the intensive patterns of care that many of these patients receive at the end of life are discordant with their values and preferences. The nephrology community has recognized that there are significant unmet palliative care needs in this population. In this article, we identify three broad areas of knowledge deficit where more evidence is needed to support the "best care possible" for this population: (1) what matters most to older adults with advanced CKD and their caregivers near the end of life; (2) how the nephrology community can best support older adults with advanced CKD to navigate complex treatment decisions throughout their illness; and (3) how the healthcare system should be reconfigured to promote patient- and family-centered care for older adults with advanced CKD. Research priorities include identifying opportunities for improving the end-of-life experience of older adults with CKD and their caregivers; developing and testing communication interventions before and during dialysis to ensure that treatment decisions reflect patients' preferences; and assessing the effectiveness of palliative care in improving quality of life for patients and caregivers, satisfaction with care, and aligning treatment decisions with patient goals and preferences.