Changes in urine volume and serum albumin in incident hemodialysis patients

CUPRAC-Reactive Advanced Glycation End Products as Prognostic Markers of Human Acute Myocardial Infarction

Cardiovascular disorders, especially acute coronary syndromes, are among the leading causes of mortality worldwide, and advanced glycation end products (AGEs) are associated with cardiovascular disease and serve as biomarkers for diagnosis and prediction. In this study, we investigated the utility of AGEs as prognostic biomarkers for acute myocardial infarction (AMI). We measured AGEs in serum samples of AMI patients (N = 27) using the cupric ion reducing antioxidant capacity (CUPRAC) method on days 0, 2, 14, 30, and 90 after AMI, and the correlation of serum AGE concentration and post-AMI duration was determined using Spearman's correlation analysis. Compared to total serum protein, the level of CUPRAC reactive AGEs was increased from 0.9 to 2.1 times between 0-90 days after AMI incident. Furthermore, the glycation pattern and Spearman's correlation analysis revealed four dominant patterns of AGE concentration changes in AMI patients: stable AGE levels (straight line with no peak), continuous increase, single peak pattern, and multimodal pattern (two or more peaks). In conclusion, CUPRAC-reactive AGEs can be developed as a potential prognostic biomarker for AMI through long-term clinical studies.

A faster decline of residual kidney function and erythropoietin stimulating agent hyporesponsiveness in incident hemodialysis patients

INTRODUCTION

Erythropoietin stimulating agents (ESA) hyporesposiveness has been associated with increased mortality in hemodialysis (HD) patients. However, the impact of decline of residual kidney function (RKF) on ESA hyporesposiveness has not been adequately elucidated among patients receiving HD.

METHODS

The associations of RKF decline with erythropoietin resistance index (ERI; average weekly ESA dose [units])/post-dialysis body weight [kg]/hemoglobin [g/dL]) were retrospectively examined across four strata of annual change in RKF (residual renal urea clearance [KRU] < -3.0, -3.0 to <-1.5, -1.5 to <0, ≥0 mL/min/1.73 m² per year; urinary volume < -600, -600 to<-300, -300 to <0, ≥0 mL/day per year) using logistic regression models adjusted for clinical characteristics and laboratory variables in 5239 incident HD patients in a large US dialysis organization between 1 January 2007 and 31 December 2011.

FINDINGS

The median values of the annual change in KRU and urinary volume were -1.2 (interquartile range [IQR]: -2.8 to 0.1) mL/min/1.73 m² per year and -250 (IQR: -600 to 100) mL/day per year. A faster KRU decline in the first year of HD was associated with higher odds for ESA hyporesponsiveness: KRU decline of <-3.0, -3.0 to <-1.5, and -1.5 to <0/min/1.73 m² per year were associated with adjusted odds ratios (OR) of 2.07 (95% confidence interval [CI]: 1.66-2.58), 1.54 (95%CI: 1.28-1.85), and 1.26 (95%CI: 1.07-1.49), respectively (reference: ≥0 mL/min/1.73 m² per year). These associations were consistent across strata of baseline KRU, age, sex, race, diabetes, congestive heart failure, hemoglobin, and serum albumin. Sensitivity analyses using urinary volume as another index of RKF showed consistent associations.

DISCUSSION

A faster RKF decline during the first year of dialysis was associated with ESA hyporesponsiveness and low hemoglobin levels among incident HD patients.

Cardiac MRI measurements of pericardial adipose tissue volumes in patients on in-centre nocturnal hemodialysis

BACKGROUND

Conversion from conventional hemodialysis (CHD) to in-centre nocturnal hemodialysis (INHD) is associated with left ventricular (LV) mass regression, but the underlying mechanisms are not fully understood. Using cardiac MRI (CMR), we examined the effects of INHD on epicardial adipose tissue (EAT) and paracardial adipose tissue (PAT), and the relationships between EAT, PAT and LV remodeling, biomarkers of nutrition, myocardial injury, fibrosis and volume.

METHODS

We conducted a prospective multicenter cohort study of 37 patients transitioned from CHD to INHD and 30 patients on CHD (control). Biochemical markers and CMR were performed at baseline and 52 weeks. CMR images were analyzed by independent readers, blinded to order and treatment group.

RESULTS

Among 64 participants with complete CMR studies at baseline (mean age 54; 43% women), there were no significant differences in EAT index (60.6 ± 4.3 mL/m² vs 64.2 ± 5.1 mL/m², p = 0.99) or PAT index (60.0 ± 5.4 mL/m² vs 53.2 ± 5.9 mL/m², p = 0.42) between INHD and CHD groups. Over 52 weeks, EAT index and PAT index did not change significantly in INHD and CHD groups (p = 0.21 and 0.14, respectively), and the changes in EAT index and PAT index did not differ significantly between INHD and CHD groups (p = 0.30 and 0.16, respectively). Overall, changes in EAT index inversely correlated with changes in LV end-systolic volume index (LVESVI) but not LV end-diastolic volume index (LVEDVI), LV mass index (LVMI), and LV ejection fraction (LVEF). Changes in PAT index inversely correlated with changes in LVESVI, LVMI and positively correlated with changes in LVEF. There were no correlations between changes in EAT index or PAT index with changes in albumin, LDL, triglycerides, troponin-I, FGF-23, or NT-proBNP levels over 52 weeks (all p > 0.30).

CONCLUSIONS

INHD was not associated with any changes in EAT index and PAT index over 12 months. Changes in EAT index were not significantly associated with changes in markers of LV remodeling, nutrition, myocardial injury, fibrosis, volume status. In contrast, changes in PAT index, which paradoxically is expected to exert less paracrine effect on the myocardium, were correlated with changes in LVESVI, LVMI and LVEF. Larger and longer-term studies may clarify the role of PAT in cardiac remodeling with intensified hemodialysis. CLINICALTRIALS.

GOV IDENTIFIER

NCT00718848.

Association of Pre-End-Stage Renal Disease Serum Albumin With Post-End-Stage Renal Disease Outcomes Among Patients Transitioning to Dialysis

OBJECTIVE

Serum albumin is a marker of malnutrition and inflammation and has been demonstrated as a strong predictor of mortality in chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients. Yet, whether serum albumin levels in late-stage CKD are associated with adverse outcomes after the transition to ESRD is unknown. We hypothesize that lower levels and a decline in serum albumin in late-stage CKD are associated with higher risk of mortality and hospitalization rates 1 year after transition to ESRD.

DESIGN AND METHODS

This retrospective cohort study included 29,124 US veterans with advanced CKD transitioning to ESRD between 2007 and 2015. We evaluated the association of pre-ESRD (91 days before transition) serum albumin with 12-month post-ESRD all-cause, cardiovascular, and infection-related mortalities and hospitalization rates as well as the association of 1-year pre-ESRD albumin slope and 12-month post-ESRD mortality using hierarchical multivariable adjustments.

RESULTS

There was a negative linear association between serum albumin and all-cause mortality, such that risk doubled (hazard ratio [HR]: 2.07, 95% confidence interval [CI]: 1.87, 2.28) for patients with the lowest serum albumin <2.8 g/dL (ref: ≥4.0 g/dL) after full adjustment. A consistent relationship was observed between serum albumin and cardiovascular and infection-related mortality, and hospitalization outcomes. An increase in serum albumin of >0.25 g/dL/year was associated with reduced mortality risk (HR: 0.76, 95% CI: 0.63, 0.91) compared with a slight decline in albumin (ref: >-0.25 to 0 g/dL/year), whereas a decline more than 0.5 g/dL/year was associated with a 55% higher risk in mortality (HR: 1.55, 95% CI: 1.43, 1.68) in fully adjusted models.

CONCLUSIONS

Lower pre-ESRD serum albumin was associated with higher post-ESRD all-cause, cardiovascular, and infection-related mortalities and hospitalization rates. Declining serum albumin levels in the pre-ESRD period were also associated with worse 12-month post-ESRD mortality.

Individualized Hemodialysis Treatment: A Perspective on Residual Kidney Function and Precision Medicine in Nephrology

Background: Residual kidney function (RKF) is often expected to inevitably and rapidly decline among hemodialysis patients and, hence, has been inadvertently ignored in clinical practice. The importance of RKF has been revisited in some recent studies. Given that patients with end-stage renal disease now tend to initiate maintenance hemodialysis therapy with higher RKF levels, there seem to be important opportunities for incremental hemo­dialysis by individualizing the dose and frequency according to their RKF levels. This approach is realigned with precision medicine and patient-centeredness. Summary: In this article, we first review the available methods to estimate RKF among hemodialysis patients. We then discuss the importance of maintaining and monitoring RKF levels based on a variety of clinical aspects, including volume overload, blood pressure control, mineral and bone metabolism, nutrition, and patient survival. We also review several potential measures to protect RKF: the use of high-flux and biocompatible membranes, the use of ultrapure dialysate, the incorporation of hemodiafiltration, incremental hemodialysis, and a low-protein diet, as well as general care such as avoiding nephrotoxic events, maintaining appropriate blood pressure, and better control of mineral and bone disorder parameters. Key Message: Individualized hemodialysis regimens may maintain RKF, lead to a better quality of life without compromising long-term survival, and ensure precision medicine and patient-centeredness in nephrology practice.

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.

Nutritional status after conversion from conventional to in-centre nocturnal hemodialysis

INTRODUCTION

Recipients of conventional hemodialysis (CHD; 3-4 h/session, 3 times/week) experience volume expansion and nutritional impairment which may contribute to high mortality. Prolongation of sessions with in-centre nocturnal hemodialysis (INHD; 7-8 h/session, 3 times/week) may improve clinical outcomes by enhancement of ultrafiltration and uremic toxin removal.

MATERIALS AND METHODS

In this prospective cohort study, 56 adult patients who were receiving maintenance CHD for at least 90 days were assigned to CHD (patients who remained in CHD) and INHD (patients who switched to INHD) groups. Both groups were followed for 1 year divided into four 13-week quarters; post-dialysis weight and interdialytic weight gain (IDWG) were captured in each quarter. Repeated measures analysis of variance was used to calculate group main effect, time main effect or time-group interaction effect.

RESULTS

Conversion to INHD was associated with a mean (95% confidence interval) change in IDWG of 0.5 (0.08, 1.2) kg as compared to -0.3 (-0.9, 0.1) kg in the CHD group (p < 0.01). In the INHD group, post-dialysis weight (% of baseline pre-dialysis weight) decreased after conversion, reaching a nadir during the first 3 months (0.7%) and subsequently it gradually increased and returned to its baseline at the end of follow-up. A similar temporal trend was seen for serum creatinine but not serum N-terminal pro-brain natriuretic peptide (NT-proBNP) which is a marker of extracellular volume. The changes in serum albumin, prealbumin and hs-CRP were not different between the two groups.

CONCLUSIONS

Conversion to INHD was associated with greater IDWG and relatively stable body mass. We speculate that this gain in weight reflects an increase in lean body mass following the change in dialysis modality, which can be concluded from the parallel increase in serum creatinine and the lack of increase in NT-proBNP.