Haemoglobin variability and all-cause mortality in haemodialysis patients: A systematic review and meta-analysis

Effects of Individualized Anemia Therapy on Hemoglobin Stability: A Randomized Controlled Pilot Trial in Patients on Hemodialysis

Key Points

Background

Anemia is common among patients on hemodialysis. Maintaining stable hemoglobin levels within predefined target levels can be challenging, particularly in patients with frequent hemoglobin fluctuations both above and below the desired targets. We conducted a multicenter, randomized controlled trial comparing our anemia therapy assistance software against a standard population-based anemia treatment protocol. We hypothesized that personalized dosing of erythropoiesis-stimulating agents (ESAs) improves hemoglobin target attainment.

Methods

Ninety-six patients undergoing hemodialysis and receiving methoxy polyethylene glycol-epoetin beta were randomized 1:1 to the intervention group (personalized ESA dose recommendations computed by the software) or the standard-of-care group for 26 weeks. The therapy assistance software combined a physiology-based mathematical model and a model predictive controller designed to stabilize hemoglobin levels within a tight target range (10–11 g/dl). The primary outcome measure was the percentage of hemoglobin measurements within the target. Secondary outcome measures included measures of hemoglobin variability and ESA utilization.

Results

The intervention group showed an improved median percentage of hemoglobin measurements within target at 47% (interquartile range, 39–58), with a 10% point median difference between the two groups (95% confidence interval, 3 to 16; P = 0.008). The odds ratio of being within the hemoglobin target in the standard-of-care group compared with the group receiving the personalized ESA recommendations was 0.68 (95% confidence interval, 0.51 to 0.92). The variability of hemoglobin levels decreased in the intervention group, with the percentage of patients experiencing fluctuating hemoglobin levels being 45% versus 82% in the standard-of-care group. ESA usage was reduced by approximately 25% in the intervention group.

Conclusions

Our results demonstrated an improved hemoglobin target attainment and variability by using personalized ESA recommendations using the physiology-based anemia therapy assistance software.

Clinical Trial registration number:

NCT04360902.

Safety of Roxadustat Versus Erythropoiesis-Stimulating Agents in Patients with Anemia of Non-dialysis-Dependent or Incident-to-Dialysis Chronic Kidney Disease: Pooled Analysis of Four Phase 3 Studies

INTRODUCTION

This study was conducted to elucidate the safety of roxadustat, an oral medication, in patients with non-dialysis-dependent (NDD) or incident dialysis dialysis-dependent (ID-DD) chronic kidney disease (CKD).

METHODS

Safety results from four phase 3, randomized, open-label studies comparing roxadustat to an erythropoiesis-stimulating agent (ESA) in men and women with NDD or ID-DD CKD with anemia were pooled and evaluated. Endpoints were time to major adverse cardiovascular event (MACE; myocardial infarction, stroke, and all-cause mortality) and MACE+ (MACE plus congestive heart failure or unstable angina requiring hospitalization), all-cause mortality, and treatment-emergent adverse events (TEAEs). MACE and MACE+ were evaluated for non-inferiority at 1.8- and 1.3-margins using hazard ratios (HRs) and 95% confidence intervals (CIs). TEAEs were descriptively summarized.

RESULTS

In total, 2142 patients were evaluated (1083 roxadustat; 1059 ESA). Roxadustat was comparable to ESA for risk of MACE (HR 0.79, 95% CI 0.61-1.02), MACE+ (HR 0.78, 95% CI 0.62-0.98), and all-cause mortality (HR 0.78, 95% CI 0.57-1.05). TEAEs were comparable between roxadustat and ESA groups, including any TEAE [incidence rate per 100 (IR/100) patient-exposure years 56.1 vs. 53.5], TEAEs leading to study drug discontinuation (IR/100 patient-exposure years 6.7 vs. 5.1), and TEAEs leading to death (IR/100 patient-exposure years 6.9 vs. 7.4).

CONCLUSION

There was no evidence of increased risk of cardiovascular events or mortality with roxadustat compared with ESA in patients with anemia who have NDD or ID-DD CKD. Although TEAEs occurred commonly in both the roxadustat and ESA groups, patients infrequently discontinued the study drug because of an adverse event.

CLINICAL TRIAL REGISTRATION NUMBERS

DOLOMITES, 1517-CL-0610 [NCT02021318]; HIMALAYAS, FGCL-4592-063 [NCT02052310]; SIERRAS, FGCL-4592-064 [NCT02273726]; and ROCKIES, D5740C00002 [NCT02174731].

The association of soluble Klotho levels with anemia and hemoglobin variability in hemodialysis patients

INTRODUCTION

The anti-aging protein Klotho levels are decreased, and Klotho deficiency is associated with cardiovascular diseases in patients with chronic kidney disease. There are recent studies about the relation between soluble Klotho levels and anemia. We aimed to investigate the correlation of anemia and hemoglobin variability with soluble Klotho levels in hemodialysis patients.

METHODS

Ninety-one hemodialysis patients were included in this study. The mean hemoglobin value, hemoglobin variability, and coefficient of variation of hemoglobin for each patient were calculated. According to mean hemoglobin levels, two groups were defined as under 11 and ≥11 g/dl. Soluble Klotho levels of each patient were studied.

RESULTS

Mean hemoglobin levels, hemoglobin variability, and coefficient of variation of hemoglobin were not significantly correlated with soluble Klotho levels. According to mean hemoglobin levels under 11 and ≥ 11 g/dl, there was no statistically significant correlation between anemia and soluble Klotho levels.

CONCLUSION

Soluble Klotho levels were not associated with anemia and hemoglobin variability in hemodialysis patients. Further studies are needed to reveal the complicated relation between anemia and soluble Klotho levels.

Anemia biomarkers and mortality in hemodialysis patients with or without diabetes: A 10-year follow-up study

BACKGROUND

Many studies have assessed the association between anemia and mortality in hemodialysis but few compared patients with and without diabetes. Our study aims to investigate the impact of hemoglobin and iron parameters on mortality in hemodialysis patients with or without diabetes.

METHODS

This is a two-center retrospective study that included all adult patients who started hemodialysis between February 2012 and February 2020, followed until January 2021. Averages of hemoglobin, ferritin and transferrin saturation of entire follow-up were recorded. Kaplan Meier survival, log rank test and cox regression analyses were performed to assess the association between anemia biomarkers and mortality.

RESULTS

A total of 214 patients were included. Mean age was 67.98 ±12.41 years, mean hemoglobin was 10.92 ±0.75 g/dL, mean ferritin was 504.43 ± 221.42 ng/mL and mean transferrin saturation was 26.23 ±7.77%. Log rank test showed an association between hemoglobin ≥11 g/dL and better survival in patients without diabetes (P = 0.028). Based on cox regression analysis, hemoglobin was associated with all-cause mortality in all patients (HR = 0.66; CI:0.49,0.89; P = 0.007). When comparing patients with and without diabetes, this association remained significant only in patients without diabetes (HR = 0.53; CI:0.37,0.77; P<0.001). Based on different multivariate models, hemoglobin, ferritin and age were independent factors associated with mortality in patients without diabetes.

CONCLUSIONS

This study showed that hemoglobin ≥11 g/dL is associated with better survival in hemodialysis patients without diabetes but not in those with diabetes. These differences need to be further explored in other countries and settings. An individualization of the hemoglobin target level might be necessary to improve patients' outcomes.

Low-Dose Oral Iron Replacement Therapy Is Effective for Many Japanese Hemodialysis Patients: A Retrospective Observational Study

Western guidelines recommend the use of intravenous iron supplementation for hemodialysis patients. However, in Japanese patients with well-controlled inflammation, iron replacement may be achieved with oral iron supplementation. This study involved 108 courses in 77 outpatient hemodialysis patients who received low-dose oral iron replacement therapy. Data from baseline to week 28 of treatment were analyzed to identify factors associated with effectiveness. Changes over time in erythrocyte- and iron-related parameters and erythropoiesis-stimulating agent (ESA) dose were investigated in the effective group. A total of 84 courses (77.8%) satisfied the effectiveness criteria. Compared with the effective and ineffective groups, only C-reactive protein (CRP) was significantly different (p < 0.01). ROC curve analysis with efficacy as the endpoint showed a CRP cut point value of ≤0.1 mg/dL (area under the curve, 0.69; 95% confidence interval, 0.57−0.81). The relationship between serum ferritin and hemoglobin fluctuation by reducing the ESA dose showed a positive correlation (p < 0.001). In the ESA maintenance group, the serum ferritin gradually increased and then remained constant at about 60 ng/mL. Our data suggest that patients with CRP ≤ 0.1 mg/dL may benefit from low doses of oral iron supplementation. Approximately 60 ng/mL serum ferritin may be sufficient during stable hematopoiesis.

Is Hemoglobin Concentration a Linear Predictor of Mortality in Older Adults From Chinese Longevity Regions?

Introduction: The association patterns of hemoglobin (HB) concentrations with mortality among the longevity older adults are unclear. We aimed to evaluate the relationship among older adults form Chinese longevity regions. Methods: We included 1,785 older adults aged ≥65 years (mean age, 86.7 years; 1,002 women, 783 men) from the community-based Chinese Longitudinal Healthy Longevity Survey. We estimated the hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality using multivariable Cox proportional hazards models and Cox models with restricted cubic spline. Results: In total, 999 deaths occurred during a median follow-up of 5.4 years from 2011 to 2017. Restricted cubic spline analysis found no non-linear association between HB concentrations and all-cause mortality after a full adjustment for covariates among the older adults form longevity regions (p > 0.05 for non-linearity). The risk for all-cause mortality was significantly higher in the groups with HB concentration of <11.0 g/dL (HR: 1.37, 95% CI: 1.10-1.70) and 11.0-12.0 g/dL (HR: 1.25, 95% CI: 1.01-1.54); the risk of all-cause mortality was significantly lower in the groups with HB concentration ≥14.0 g/dL (HR: 0.76, 95% CI: 0.60-0.97) compared with the reference group (13.0-13.9 g/dL). Conclusions: Among older adults form Chinese longevity regions, HB concentrations were found to be inversely and linearly associated with all-cause mortality. Further prospective intervention trials are needed to confirm whether higher HB concentrations had a lower risk of mortality in these older adults.

Effects of the route of erythropoietin administration on hemoglobin variability and cardiovascular events in hemodialysis patients

Introduction

Despite of the routine use of erythropoietin in hemodialysis patients to correct anemia, its administration route's effects on hemoglobin variability and cardiovascular events remain elusive. Herein, we determined different erythropoietin administration routes' effects on hemoglobin variability in hemodialysis patients and the associated factors of hemoglobin variability and cardiovascular events.

Methods

This is a post hoc analysis of a prospective, controlled, randomized, unblinded study with 78 Korean hemodialysis patients receiving intravenous (n = 40) or subcutaneous (n = 38) erythropoietin therapy. We evaluated hemoglobin variability by calculating the frequency of hemoglobin measurements outside the target range during all visits. The high-frequency group was defined by those with hemoglobin variability over the median value (25%) while the low-frequency group was defined by those with hemoglobin variability of <25%.

Results

In this analysis, 37 patients (51.1%) were males, and the mean age was 50.6 ± 12.5 years. The frequency of the value being outside the target hemoglobin range was higher in the subcutaneous group compared to the intravenous group (p = 0.03). The low-frequency group required significantly lower erythropoietin doses compared to the high-frequency group. In the adjusted Cox analysis, the parameter high group was a significant independent risk factor for cardiovascular events (p = 0.03).

Conclusion

The risk out of the target hemoglobin range increased with subcutaneous administration compared with intravenous erythropoietin administration in hemodialysis patients. An increased frequency of the value being outside the target hemoglobin range was also associated with an increased risk of cardiovascular events.

Phase angle values, a good indicator of nutritional status, are associated with median value of hemoglobin rather than hemoglobin variability in hemodialysis patients

Background

Our aim was to elucidate whether Hb variability affects nutritional status in HD patients.

Methods

This study included chronic HD patients (n = 76) with available monthly Hb levels up to 24 months prior to the body composition monitoring (BCM) measurement. The parameters obtained in the BCM included body mass index (BMI), lean tissue index (LTI), fat tissue index (FTI), body cell mass index (BCMI), overhydration/extracellular water ratio (OH), and phase angle (PhA). The coefficient of variation (Hb-CV), standard deviation (Hb-SD), and range of Hb (Hb-RAN) were used as indexes of Hb variability. In addition, minimum (Hb-Min), maximum (Hb-Max), average (Hb-Avg), and median (Hb-Med) Hb levels (g/dL) were analyzed.

Results

There were no significant differences in clinical, biochemical, and nutritional indexes based on the Hb-CV level. Compared to patients with an Hb-Med ≤ 10.77, those with an Hb-Med >10.77 had higher albumin levels, total iron-binding capacity (TIBC), and PhA and lower average weekly prescribed darbepoetin. Age, female sex, OH, and darbepoetin dosage were negatively correlated with PhA. Serum albumin, phosphorus, TIBC, Hb-Med, and Hb-Avg were positively correlated with PhA. In multiple linear regression analysis, PhA was positively associated with Hb-Med and serum albumin level, whereas PhA was negatively associated with age and female sex. The area under the curve (AUC) of Hb-Med was 0.665 (p = 0.040) in predicting PhA >5.00°

Conclusions

PhA was not affected by indexes of Hb variability, whereas PhA was associated with Hb-Med in chronic HD patients.

Artificial intelligence supported anemia control system (AISACS) to prevent anemia in maintenance hemodialysis patients

Anemia, for which erythropoiesis-stimulating agents (ESAs) and iron supplements (ISs) are used as preventive measures, presents important difficulties for hemodialysis patients. Nevertheless, the number of physicians able to manage such medications appropriately is not keeping pace with the rapid increase of hemodialysis patients. Moreover, the high cost of ESAs imposes heavy burdens on medical insurance systems. An artificial-intelligence-supported anemia control system (AISACS) trained using administration direction data from experienced physicians has been developed by the authors. For the system, appropriate data selection and rectification techniques play important roles. Decision making related to ESAs poses a multi-class classification problem for which a two-step classification technique is introduced. Several validations have demonstrated that AISACS exhibits high performance with correct classification rates of 72%-87% and clinically appropriate classification rates of 92%-98%.

Association between long-term hemoglobin variability and mortality in Korean adults: a nationwide population-based cohort study

Hemoglobin variability is known to be associated with mortality in patients with chronic renal failure and cardiovascular disease. However, the effect of hemoglobin variability on mortality in the general population has not yet been studied. We aimed to investigate the association between hemoglobin variability and mortality using Korean cohort from National Health Insurance Service-Health Screening 2002–2015 database. This study was conducted on 182,757 adults who underwent more than 4 health screenings from 2002 to 2009. Hemoglobin variability was assessed by 3 indices of coefficient of variation (CV), standard deviation (SD), and variability independent of the mean (VIM). Cox proportional hazard regression analysis was performed for each index of quartile groups (Q1–Q4). The hazard ratio and 95% confidence interval^l for all-cause mortality comparing Q2, Q3 and Q4 with Q1 of hemoglobin variability CV in the multivariable adjusted model were 1.07 [0.96–1.20], 1.18 [1.06–1.31] and 1.43 [1.29–1.58] respectively. As the 5% CV, SD, and VIM increased, the hazard ratio for mortality increased by 1.08 [1.06–1.10] in the multivariable adjusted model. Hemoglobin variability is not only important predictor in patients with chronic renal failure and cardiovascular disease but could also be considered as a useful predictor of mortality in the general population.