Low-normal hemoglobin levels and anemia are associated with increased risk of end-stage renal disease in general populations: A prospective cohort study

Mean Corpuscular Volume Is Not a Reliable Predictor of Iron Deficiency in Patients With Chronic Kidney Disease: A Post-Hoc Analysis of the BRIGHTEN Trial

Introduction Timely diagnosis of iron deficiency is crucial for managing anemia in patients with non-dialysis-dependent chronic kidney disease (ND-CKD). However, iron status results are not always immediately available. We aimed to examine the performance of mean corpuscular volume (MCV) in diagnosing iron deficiency as a primary objective and of iron status in predicting the onset of iron deficiency as a secondary objective. Methods This retrospective cohort study included adult patients with ND-CKD from the BRIGHTEN (oBservational clinical Research In chronic kidney disease patients with renal anemia: renal proGnosis in patients with Hyporesponsive anemia To Erythropoiesis-stimulating agents, darbepoetiN alfa) trial (enrolled from June 2014 to September 2016) in Japan who were started on darbepoetin-alpha for renal anemia and patients who were not started on iron supplementation during weeks 0-24. Diagnostic performance analysis assessed the MCV at week 24 and changes in MCV from week 12 to 24 for diagnosing iron deficiency (ferritin < 100 ng/mL) at week 24, using receiver operating characteristic curves, area under the curve (AUC), sensitivity, and specificity. For the patients without iron deficiency at week 12, ferritin levels at week 12 were assessed by predictive performance analysis to predict new-onset iron deficiency at week 24. Results A total of 796 participants were included in the diagnostic performance analysis (mean age, 70.0 years; mean estimated glomerular filtration rate, 19.2 mL/min/1.73 m²), and 338 were included in the predictive performance analysis. Diagnostic performance analysis revealed an AUC for MCV of 0.55 (95% confidence interval (CI), 0.51-0.59); for MCV changes, it was 0.52 (95% CI, 0.48-0.57). Prognostic performance analysis revealed that ferritin at week 12 demonstrated an AUC of 0.77 (95% CI, 0.67-0.86), with a sensitivity of 83% and a specificity of 66% at a cutoff of 131.5 ng/mL. Conclusion Neither MCV nor the changes in MCV could reliably diagnose iron deficiency in patients with ND-CKD. Ferritin level < 130 ng/mL could predict new-onset iron deficiency within 12 weeks.

Jian-Pi-Yi-Shen formula ameliorates renal fibrosis-induced anemia in rats with chronic kidney disease

ETHNOPHARMACOLOGICAL RELEVANCE

Jian-Pi-Yi-Shen (JPYS) formula is an effective herbal therapy against renal injury, and JPYS has been clinically applied to ameliorate chronic kidney disease (CKD) and CKD-associated anemia. Increasing evidence supports the link between renal fibrosis and anemia in CKD. JPYS possessed anti-fibrosis effects in experimental CKD. Nevertheless, research on the mechanisms of JPYS in ameliorating renal anemia (RA) through suppressing renal fibrosis remains to be clarified.

AIM OF THE STUDY

Our study here was carried out to investigate the mechanisms of JPYS in protecting against RA.

MATERIALS AND METHODS

An adenine-induced anemia model in rats with CKD at three different time points was established, and bio-samples taken from each group were analyzed. Biochemical analysis was employed to detect kidney function and hematological parameters. Masson staining was used to evaluate renal fibrosis of rats. Western blot and immunohistochemistry were utilized to evaluate the expressions of fibrotic markers, erythropoietin (EPO) and hypoxia inducible factor-2α (HIF-2α) in the kidneys of rats. Subsequently, transcriptomic analysis was conducted to disclose the possible mechanisms of JPYS in treating RA. Finally, the expression levels of key targets were analyzed and validated by using Western blot and enzyme-linked immunosorbent assay (ELISA).

RESULTS

JPYS treatment improved kidney function, suppressed renal fibrosis and enhanced hematological parameters in CKD rats. Moreover, JPYS treatment restored the increased expression levels of fibrotic markers and the declined EPO with time dependence. In parallel, data indicated JPYS treatment stimulated the translocation of HIF-2α into nucleus in the renal interstitium and thus promoted the expression of EPO. Transcriptomic profiling disclosed that activations of both nuclear factor kappa B (NF-κB) and transforming growth factor-β (TGF-β)/Smad pathways were closely associated with RA. Ultimately, experimental validation results presented that the increased expressions of target proteins from the above-mentioned two pathways in the kidneys were decreased significantly after JPYS treatment.

CONCLUSION

Our findings suggest that JPYS may improve RA by alleviating renal fibrosis, and the mechanisms of which involve in inhibiting the NF-κB and TGF-β/Smad pathways.

Is serum hemoglobin level an independent prognostic factor for IgA nephropathy?: a systematic review and meta-analysis of observational cohort studies

BACKGROUND

Decreased serum hemoglobin (Hb) level is associated with Immunoglobulin A nephropathy (IgAN) progression. However, whether serum Hb level is an independent prognostic factor of IgAN remains controversial. Herein, we aimed to investigate the prognostic value of serum Hb level in IgAN.

METHODS

The Cochrane Library, Embase, PubMed and Open Grey databases were systematically searched and reviewed. Kidney disease progression of IgAN was defined as a doubling of serum creatinine (SCr), a 30% reduction in estimated glomerular filtration rate (eGFR), end-stage renal disease (ESRD), or death. We evaluated the hazard ratio (HR) between serum Hb level and the incidence of kidney disease progression in IgAN before and after adjusting for relevant covariates.

RESULTS

We included nine studies with 10006 patients in the meta-analysis. As a continuous variable, we found that serum Hb was an independent prognostic factor of IgAN [unadjusted HR = 0.89, 95% confidence interval (CI) = 0.84-0.95, I² = 98%; adjusted HR = 0.85, 95% CI = 0.79-0.91, I² = 0%]. The sensitivity analysis confirmed the stability of these results. Consistently, as a dichotomous variable defined as the below/above cutoff for anemia, we observed a positive correlation between serum Hb and kidney disease progression in IgAN (unadjusted HR = 2.12, 95% CI = 1.44-3.12, I² = 79%; adjusted HR = 1.65, 95% CI = 1.20-2.27, I² = 0%).

CONCLUSION

Serum Hb level was independently correlated with the incidence of kidney disease progression in IgAN.

Anemia and Hypoxia Impact on Chronic Kidney Disease Onset and Progression: Review and Updates

Chronic kidney disease (CKD) is caused by hypoxia in the renal tissue, leading to inflammation and increased migration of pathogenic cells. Studies showed that leukocytes directly sense hypoxia and respond by initiating gene transcription, encoding the 2-integrin adhesion molecules. Moreover, other mechanisms participate in hypoxia, including anemia. CKD-associated anemia is common, which induces and worsens hypoxia, contributing to CKD progression. Anemia correction can slow CKD progression, but it should be cautiously approached. In this comprehensive review, the underlying pathophysiology mechanisms and the impact of renal tissue hypoxia and anemia in CKD onset and progression will be reviewed and discussed in detail. Searching for the latest updates in PubMed Central, Medline, PubMed database, Google Scholar, and Google search engines were conducted for original studies, including cross-sectional studies, cohort studies, clinical trials, and review articles using different keywords, phrases, and texts such as "CKD progression, anemia in CKD, CKD, anemia effect on CKD progression, anemia effect on CKD progression, and hypoxia and CKD progression". Kidney tissue hypoxia and anemia have an impact on CKD onset and progression. Hypoxia causes nephron cell death, enhancing fibrosis by increasing interstitium protein deposition, inflammatory cell activation, and apoptosis. Severe anemia correction improves life quality and may delay CKD progression. Detection and avoidance of the risk factors of hypoxia prevent recurrent acute kidney injury (AKI) and reduce the CKD rate. A better understanding of kidney hypoxia would prevent AKI and CKD and lead to new therapeutic strategies.

Anemia Prevalence, Type, and Associated Risks in a Cohort of 5.0 Million Insured Patients in the United States by Level of Kidney Function

RATIONALE & OBJECTIVE

Anemia is common in chronic kidney disease (CKD); although anemia is associated with adverse outcomes, the available treatments are not ideal. We characterized the burden, risk factors for, and risks associated with anemia by estimated glomerular filtration rate (eGFR) and hemoglobin level.

STUDY DESIGN

Cross-sectional and prospective cohort study.

SETTING & PARTICIPANTS

Outpatient data from 5,004,957 individuals across 57 health care centers in the United States from 2016 to 2019, extracted from the Optum Labs Data Warehouse.

EXPOSURE

Severity of anemia, presence of low iron test results, eGFR.

OUTCOME

Incident kidney failure with replacement therapy, cardiovascular disease, coronary heart disease, stroke, heart failure, death.

ANALYTICAL APPROACH

The prevalences of anemia, low iron test results, vitamin B12 deficiency, and erythropoiesis-stimulating agent (ESA) use, stratified by sex and eGFR, were characterized. Polychotomous logistic regression was used to estimate the adjusted odds ratios of different hemoglobin levels across eGFR. Cox proportional hazards regression was used to calculate adjusted hazard ratios for adverse outcomes across hemoglobin level.

RESULTS

The mean age was 54 years, and 42% were male. Lower eGFR was very strongly associated with increased prevalence of anemia, even after adjustment. Although iron studies were checked infrequently in patients with anemia, low iron test results were highly prevalent in those tested: 60.4% and 81.3% of men and women, respectively. ESA use was uncommon, with a prevalence of use of<4%. Lower hemoglobin was independently associated with increased risk of incident kidney failure with replacement therapy, cardiovascular disease, coronary heart disease, stroke, heart failure, and death.

LIMITATIONS

Reliance on ICD codes for medical diagnoses, death information obtained from claims data, observational study.

CONCLUSIONS

Severe anemia was common and strongly associated with lower eGFR and multiple adverse outcomes. Low-iron test results were highly prevalent in those tested despite iron studies being checked infrequently. ESA use in nondialysis CKD patients was uncommon.

Development and validation of a risk nomogram model for predicting pulmonary hypertension in patients with stage 3-5 chronic kidney disease

OBJECTIVES

The occurrence of pulmonary arterial hypertension (PAH) can greatly affect the prognosis of patients with chronic kidney disease (CKD). We aimed to construct a nomogram to predict the probability of PAH development in patients with stage 3-5 CKD to guide early intervention and to improve prognosis.

METHODS

From August 2018 to December 2021, we collected the data of 1258 patients with stage 3-5 CKD hospitalized at the Affiliated Hospital of Xuzhou Medical University as a training set and 389 patients hospitalized at Zhongda Hospital as a validation set. These patients were divided into PAH and N-PAH groups with pulmonary arterial systolic pressure ≥ 35 mmHg as the cutoff. The results of univariate and multivariate logistic regression analyses were used to establish the nomogram. Then, areas under the receiver operating characteristic curve (AUC-ROCs), a calibration plot, and decision curve analysis (DCA) were used to validate the nomogram.

RESULTS

The nomogram included nine variables: age, diabetes mellitus, hemoglobin, platelet count, serum creatinine, left ventricular end-diastolic diameter, left atrial diameter, main pulmonary artery diameter and left ventricular ejection fraction. The AUC-ROCs of the training set and validation set were 0.801 (95% confidence interval (CI) 0.771-0.830) and 0.760 (95% CI 0.699-0.818), respectively, which showed good discriminative ability of the nomogram. The calibration diagram showed good agreement between the predicted and observed results. DCA also demonstrated that the nomogram could be clinically useful.

CONCLUSION

The evaluation of the nomogram model for predicting PAH in patients with CKD based on risk factors showed its ideal efficacy. Thus, the nomogram can be used to screen for patients at high risk for PAH and has guiding value for the subsequent formulation of prevention strategies and clinical treatment.

Research on the relationship between serum indoxyl sulfate concentration and iron dynamics index in patients with end-stage kidney disease: a cross-sectional study

Background

Chronic kidney disease (CKD) is frequently associated with renal anemia. Erythropoiesis-stimulating agent-hyporesponsive anemia is often caused by iron deficiency in patients with CKD. We hypothesized that high accumulation of indoxyl sulfate, a uremic toxin, accelerates iron deficiency in patients with CKD. The aim of this study was to clarify whether the accumulation of indoxyl sulfate is a cause of iron deficiency in patients with CKD. Therefore, we investigated the association between serum indoxyl sulfate concentration and iron dynamics in patients with end-stage kidney disease (ESKD).

Methods

We performed a cross-sectional study on 37 non-dialyzed patients with ESKD, who were hospitalized to undergo maintenance hemodialysis treatment at Shirasagi Hospital. Serum indoxyl sulfate concentration, iron dynamics parameters and other laboratory data were measured immediately before the initiation of hemodialysis treatment. Clinical characteristics were obtained from electronic medical records.

Results

The estimated glomerular filtration rate (eGFR) of 37 patients with ESKD was 5.08 (3.78–7.97) mL/min/1.73 m2 (median [range]). Serum ferritin and transferrin saturation (TSAT) were 90 (10–419) ng/mL and 20 (8–59)% (median [range]), respectively. Serum indoxyl sulfate concentration was 62 (11–182) μM (median [range]). Serum indoxyl sulfate concentration was inversely correlated with serum ferritin level (ρ = − 0.422, p = 0.011), but not with TSAT, age, gender, eGFR and c-reactive protein (CRP) in 37 patients. In eight patients taking iron-containing agents, serum indoxyl sulfate concentration was strongly correlated with serum ferritin level (ρ = − 0.796, p = 0.037); however, in 29 patients not taking an iron-containing agent, this correlation was not observed (ρ = − 0.336, p = 0.076). In the multivariate analysis including age, gender, eGFR and CRP, the correlation between serum indoxyl sulfate concentration tended to be, but not significantly correlated with serum ferritin level in 37 patients (regression coefficient = − 54.343, p = 0.137).

Conclusion

Our study suggests that serum accumulation of indoxyl sulfate is one of causes not to increase serum ferritin level in patients with ESKD taking an iron-containing agent. Further clinical study is needed to reveal the appreciable relationship between serum ferritin and serum indoxyl sulfate.

Association between hemoglobin and chronic kidney disease progression: a secondary analysis of a prospective cohort study in Japanese patients

OBJECTIVE

Anemia has been reported as a risk factor for chronic kidney disease (CKD) progression. However, there are still few studies examining the relationship between specific hemoglobin (Hb) levels and renal prognosis and renal function decline simultaneously. Meanwhile, the possible non-linear relationship between Hb and CKD progression also deserves further exploration. On that account, our primary goal is to explore the link of Hb on renal prognosis and renal function decline in patients with CKD.

METHODS

This study was a secondary analysis of a prospective cohort study, which consecutively and non-selectively collected 962 participants from the research of CKD-ROUTE in Japan from November 2010 to December 2011. We used the Cox proportional-hazards and linear regression models to evaluate the independent association between baseline Hb and renal prognosis (renal composite endpoint, initiation of dialysis during follow-up or 50% decline in eGFR from baseline) and renal function decline(annual eGFR decline), respectively. A multivariate Cox proportional hazards regression analysis with cubic spline functions model and smooth curve fitting (penalized spline method) were conducted to address Hb and CKD prognosis's non-linearity. At the same time, a generalized additive model (GAM) and smooth curve fitting (penalized spline method) was conducted to explore the exact shape of the curve between Hb and renal function decline. Additionally, we did a series of sensitivity analyses to ensure the robustness of the results. Moreover, we conducted subgroup analyses.

RESULTS

The mean age of the included patients was 67.35 ± 13.56 years old, and 69.65% were male. The mean baseline Hb and estimated glomerular filtration rate (eGFR) was 12.06 ± 2.21 g/dL and 33.04 ± 18.01 ml/min per 1.73 m². The annual decline in eGFR was 2.09 mL/min/1.73 m²/year. During a median follow-up time of 33.5 months, 252(26.2%) people experienced renal composite endpoint. After adjusting covariates, the results showed that Hb was negatively associated with renal composite endpoint (HR = 0.836, 95%CI: 0.770, 0.907) and renal function decline (β = -0.436, 95%CI: -0.778, -0.093). There was also a non-linear relationship between Hb and renal composite endpoint, and the inflection point of Hb was 8.6 g/dL. The effect sizes(HR) on the left and right sides of the inflection point were 1.257 (0.841, 1.878) and 0.789 (0.715, 0.870), respectively. And the sensitive analysis demonstrated the robustness of the results. Subgroup analysis showed that Hb was more strongly associated with the renal composite endpoint in non-hypertensive, SBP < 140 mmHg, urine protein-to-creatinine ratio (UPCR) < 0.5 g/gCr, and diuretic use patients. In contrast, the weaker association was probed in hypertensive and non-diuretic use patients and the patients with SBP ≥ 140 mmHg, and UPCR ≥ 0.5 g/gCr.

CONCLUSION

This study demonstrates a negative and non-linear relationship between Hb and renal prognosis and renal function decline in Japanese CKD patients. Hb is strongly related to renal prognosis when Hb is above 8.6 g/dL.

High hemoglobin fluctuation was a protective factor for cardiovascular-related death in peritoneal dialysis (PD) patients: A retrospective analysis of 232 patients with PD

Objectives

This study aimed to investigate the effect of hemoglobin (Hb) fluctuation after dialysis on the prognosis of cardiovascular‐related and all‐cause deaths in peritoneal dialysis (PD).

Methods

According to the Hb fluctuation, patients were divided into low fluctuation group, moderate fluctuation group, and high fluctuation group, and then, the effects of Hb fluctuation after dialysis on the prognosis of cardiovascular‐related and all‐cause death in PD were analyzed by regression analysis.

Results

A total of 232 patients were selected in this study. Compared with the low Hb fluctuation group, the moderate and high fluctuation groups had lower body mass index (BMI), estimated glomerular filtration rate (eGFR), and baseline Hb, and the moderate fluctuation group had less erythropoietin (EPO) and dialysis dose. Compared with survivors, patients with cardiovascular‐related and all‐cause deaths had lower mean Hb and Hb fluctuation (all p < 0.05). Cox regression analysis showed that before and after adjusting for confounding factors, Hb fluctuation was still independently correlated with cardiovascular prognosis, and higher Hb fluctuation was still a protective factor for cardiovascular‐related death in the Hb‐substandard group, but there was no significant correlation between Hb fluctuation and all‐cause death. Multivariate linear regression analysis revealed that Hb fluctuation was positively correlated with Kt/V and EPO dosage, but negatively correlated with the baseline Hb.

Conclusion

High Hb fluctuation was a protective factor for cardiovascular‐related death in PD with substandard Hb. Compared with Hb fluctuation, correction of anemia timely and making Hb reaches the standard level had a greater impact on reducing cardiovascular‐related death in PD.

Effect of traditional Chinese medicine Bailing capsule on renal anemia in maintenance hemodialysis patients: A protocol for systematic review and meta-analysis

BACKGROUND

Renal anemia (RA) is one of the most common complications in patients with end-stage renal disease, and it is also one of the reasons for the decline of quality of life and functional status in patients with end-stage renal disease. Traditional treatment methods often fail to achieve satisfactory therapeutic effects, so it is very necessary to find effective adjuvant treatment methods. Bailing capsule (BLC), a traditional Chinese medicine, which has been widely used in the treatment of RA in maintenance hemodialysis patients, but a systematic review of the efficacy and safety of this drug is currently lacking. Therefore, this study used meta-analysis to evaluate the efficacy and safety of BLC in the treatment of RA, in order to provide guidance for finding effective auxiliary methods for the treatment of RA in maintenance hemodialysis patients (MHP).

METHODS

Using the computer to retrieve PubMed, EMbase, Cochrane Library, CNKI, VIP Database, WANFANG Database, SinoMed from 1990 to 2021 and collecting the clinical randomized controlled trial and retrospective cohort study of BLC in the treatment of RA in MHP. Two researchers independently read and screened the literature, followed by evaluating the retrospective cohort studies that met the selection criteria using the Newcastle-Ottawa Scale (NOS) scale. The randomized controlled trial used the Cochrane manual standards to assess the risk of bias, and the RevMan 5.3 software was used to conduct a meta-analysis of the result data.

RESULTS

This study will use the method of meta-analysis to evaluate the clinical efficacy and incidence of adverse reactions of BLC in the treatment of RA in MHP through the primary and secondary outcome indicators.

CONCLUSION

The results of this study will help clinicians find safe and effective adjuvant therapy in the treatment of RA in MHP.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/732KP (https://osf.io/732kp).

Controversies in optimal anemia management: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Conference

In chronic kidney disease, anemia and disordered iron homeostasis are prevalent and associated with significant adverse consequences. In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) issued an anemia guideline for managing the diagnosis, evaluation, and treatment of anemia in chronic kidney disease. Since then, new data have accrued from basic research, epidemiological studies, and randomized trials that warrant a re-examination of previous recommendations. Therefore, in 2019, KDIGO decided to convene 2 Controversies Conferences to review the latest evidence, explore new and ongoing controversies, assess change implications for the current KDIGO anemia guideline, and propose a research agenda. The first conference, described here, focused mainly on iron-related issues, including the contribution of disordered iron homeostasis to the anemia of chronic kidney disease, diagnostic challenges, available and emerging iron therapies, treatment targets, and patient outcomes. The second conference will discuss issues more specifically related to erythropoiesis-stimulating agents, including epoetins, and hypoxia-inducible factor-prolyl hydroxylase inhibitors. Here we provide a concise overview of the consensus points and controversies resulting from the first conference and prioritize key questions that need to be answered by future research.

Oral iron supplementation in patients with chronic kidney disease: Can it be harmful to the gut microbiota?

Patients with chronic kidney disease (CKD) have several pathophysiological alterations, including anemia, one of the first changes in CKD patients. More recently, researchers have observed that the intestinal microbiota alterations are also another complication in these patients. The most common treatment for anemia is oral (mainly ferrous sulfate) or intravenous iron supplementation. Despite being a necessary treatment, recent studies have reported that supplementation with oral iron may increase its availability in the intestine, leading to disturbance in the gut microbiota and also to oxidative stress in the enterocytes, which may change the permeability and the microbiota profile. Although it is a therapy routinely used in patients with CKD, supplementation with oral iron on the gut microbiota has been rarely studied in these patients. Thus, this review will discuss the relationship between iron and the gut microbiota and the possible effects of oral iron supplementation on gut microbiota in patients with CKD.

Nomogram prediction model for renal anaemia in IgA nephropathy patients

In this study, we focused on the influencing factors of renal anaemia in patients with IgA nephropathy and constructed a nomogram model. We divided 462 patients with IgA nephropathy diagnosed by renal biopsy into anaemic and non-anaemic groups. Then, the influencing factors of renal anaemia in patients with IgA nephropathy were analysed by least absolute shrinkage and selection operator (LASSO) regression and multivariable logistic regression, and a nomogram model for predicting renal anaemia was established. Eventually, nine variables were obtained, which are easy to apply clinically. The areas under the receiver operating characteristic (ROC) curve and precision-recall (PR) curve reached 0.835 and 0.676, respectively, and the C-index reached 0.848. The calibration plot showed that the model had good discrimination, accuracy, and diagnostic efficacy. In addition, the C-index of the model following internal validation reached 0.823. Decision curve analysis suggested that the model had a certain degree of clinical significance. This new nomogram model of renal anaemia combines the basic information, laboratory findings, and renal biopsy results of patients with IgA nephropathy, providing important guidance for predicting and clinically intervening in renal anaemia.

Prevalence of Anemia and Its Associated Factors Among Chronic Kidney Disease Patients Attending Selected Public Hospitals of Addis Ababa, Ethiopia: Institutional-Based Cross-Sectional Study

BACKGROUND

Anemia is a global public health problem with high mortality and morbidity. It is becoming more prevalent in Ethiopia. Therefore, this study aimed to estimate the prevalence of anemia and its associated factors among chronic kidney disease patients at selected public hospitals of Addis Ababa, Ethiopia.

METHODS

An institutional-based cross-sectional study was conducted on selected public hospitals in Addis Ababa for studies on anemia in CKD patients. Data was entered into EPI Info version 4.4.1 and exported to SPSS version 24 for analysis. Both bivariate and multivariate logistic regression analyses were used to identify independently associated factors of anemia in CKD patients. Multivariate analysis was used to control the possible effect of confounders.

RESULTS

A total of 387 participants were included to estimate the prevalence of anemia among chronic kidney disease patients. The prevalence of anemia was 53.5% (95% CI). Being females were 2 times more likely to develop anemia as compared to their counterparts (AOR=2.04, 95%:1.18, 2.46) and hemodialysis history had two times higher odds for anemia (AOR=2.754, 95% CI: 1.218-6.229, P=0.015) compared to patients without hemodialysis history.

CONCLUSION

The overall prevalence of anemia across all stages of CKD is 53.5%. From the stage of CKD, stage 5 CKD has a higher (90.9%) anemia prevalence compared to others, and females showed a higher frequency of anemia when compared with males. Therefore, situation-based interventions and country context-specific preventive strategies should be developed to reduce the prevalence of anemia in this patient group.

Development of a Biomarker Panel to Distinguish Risk of Progressive Chronic Kidney Disease

Chronic kidney disease (CKD) patients typically progress to kidney failure, but the rate of progression differs per patient or may not occur at all. Current CKD screening methods are sub-optimal at predicting progressive kidney function decline. This investigation develops a model for predicting progressive CKD based on a panel of biomarkers representing the pathophysiological processes of CKD, kidney function, and common CKD comorbidities. Two patient cohorts are utilised: The CKD Queensland Registry (n = 418), termed the Biomarker Discovery cohort; and the CKD Biobank (n = 62), termed the Predictive Model cohort. Progression status is assigned with a composite outcome of a ≥30% decline in eGFR from baseline, initiation of dialysis, or kidney transplantation. Baseline biomarker measurements are compared between progressive and non-progressive patients via logistic regression. In the Biomarker Discovery cohort, 13 biomarkers differed significantly between progressive and non-progressive patients, while 10 differed in the Predictive Model cohort. From this, a predictive model, based on a biomarker panel of serum creatinine, osteopontin, tryptase, urea, and eGFR, was calculated via linear discriminant analysis. This model has an accuracy of 84.3% when predicting future progressive CKD at baseline, greater than eGFR (66.1%), sCr (67.7%), albuminuria (53.2%), or albumin-creatinine ratio (53.2%).

Risk Factors for Anemia in Patients with Chronic Renal Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Anemia in patients with chronic kidney disease presents significant impacts on patients, the health-care system and financial resources. There is a significant variation in the primary studies on risk factors of anemia in this patient population across the globe. Therefore, this study aimed to identify the risk factors of anemia among chronic kidney disease patients at the global level.

METHODS

PubMed, Scopus, African Journals Online, Web of Science and Google Scholar were searched and complemented by manual searches. A Funnel plot and Egger's regression test were used to determine publication bias. DerSimonian and Laird random-effects modes were applied to estimate pooled effect sizes, odds ratios, and 95% confidence interval across studies. Analysis was performed using STATA™ Version 14 software.

RESULT

A total of 28 studies with 24,008 study participants were included in this study. Female sex (AOR= 1.36; 95% CI 1.11, 1.67), stage 5 CKD (AOR = 13.66; 95% CI: 5.19, 35.92), body mass index ≥ 30 kg/m2 (AOR = 0.51; 95% CI: 0.29, 0.91), comorbidities (AOR = 2.90; 95% CI: 1.68, 5.0), proteinuria 3+(AOR = 3.57; 95% CI: 1.03, 12.93), hypocalcemia (AOR=3.61, 95%CI: 1.56-8.36), and iron therapy (AOR: 0.59; 95% CI:0.31, 0.98) were significantly associated with anemia of chronic kidney disease.

CONCLUSION

Female sex, stage 5 CKD, body mass index ≥ 30 kg/m2, comorbidity, and hypocalcemia were found to be significantly associated with anemia of chronic kidney disease. Therefore, situation-based interventions and country context-specific preventive strategies should be developed to reduce the risk factors of anemia in patients with chronic renal failure.

The Association of Low Hemoglobin Levels with IgA Nephropathy Progression: A Two-Center Cohort Study of 1,828 Cases

AIM

To investigate the relationship between hemoglobin levels and the progression of IgA nephropathy (IgAN).

METHODS

In a two-center cohort of 1,828 cases with biopsy-proven IgAN, we examined the association of hemoglobin levels with the primary outcome of a composite of all-cause mortality or kidney failure defined as a 40% decline in eGFR, or ESKD (defined as eGFR <15 mL/min/1.73 m2 or need for kidney replacement therapy including hemodialysis, peritoneal dialysis, or kidney transplantation), or the outcome of kidney failure, assessed using Cox and logistic regression models, respectively, with adjustment for confounders.

RESULTS

At baseline, mean age, eGFR, and hemoglobin levels were 33.75 ± 11.03 years, 99.70 ± 30.40 mL/min/1.73 m2, and 123.47 ± 18.36 g/L, respectively. During a median of approximately 7-year follow-up, 183 cases reached the composite outcome. After adjustment for demographic and IgAN-specific covariates and treatments, a lower quartile of hemoglobin was nonlinearly associated with an increased risk of the primary outcome or kidney failure in the Cox proportional hazards models (primary outcome: HR for quartile 3 vs. 4, 1.37; 95% CI, 0.83-2.25; HR for quartile 2 vs. 4, 1.18; 95% CI, 0.68-2.07; HR for quartile 1 vs. 4, 1.91; 95% CI, 1.15-3.17; kidney failure: HR for quartile 3 vs. 4, 1.39; 95% CI, 0.84-2.31; HR for quartile 2 vs. 4, 1.20; 95% CI, 0.68-2.11; HR for quartile 1 vs. 4, 1.83; 95% CI, 1.09-3.07) in the fully adjusted model. Then, hemoglobin levels were transformed to a binary variable for fitting the model according to the criteria for anemia of 110 g/L in the women and 120 g/L in men in China. The participants in the anemia group had an increased risk of developing outcomes compared with the nonanemia group in both genders (primary outcome: male: HR, 1.64; 95% CI, 1.01-2.68; female: HR, 1.68; 95% CI, 1.02-2.76; kidney failure: male: HR, 1.60; 95% CI, 0.97-2.64; female: HR, 1.58; 95% CI, 0.95-2.61) in the fully adjusted model.

CONCLUSIONS

A low level of hemoglobin was nonlinearly associated with IgAN progression. The anemic IgAN patients presented a higher risk of developing poor outcomes compared with the nonanemic patients.

Chronic Kidney Disease Increases the Risk of Hip Fracture: A Prospective Cohort Study in Korean Adults

This study was conducted to examine the association between renal function and hip fracture. We followed up 352,624 Korean adults, who participated in health examinations during 2009-2010 until 2013. Kidney function was assessed by creatinine-based estimated glomerular filtration rate (eGFR) and albuminuria using urine reagent strip results. The incidence of hip fracture was examined by hospital discharge records. Hazard ratios (HRs) for hip fracture were calculated using Cox proportional hazard models after adjusting for multiple confounders. During a mean follow-up of 4.0 years, 1177 participants suffered a hip fracture. Lower eGFR and more severe albuminuria were associated with a higher risk of hip fracture. The HRs for hip fracture were 1.89 (95% confidence interval [CI] 1.47-2.43) and 3.75 (95% CI 2.30-6.11) among participants with eGFRs of 30 to 44 and 15 to 29 mL/min/1.73m² relative to those with an eGFR ≥60 mL/min/1.73m² , respectively. The HRs were 1.30 (95% CI 1.02-1.65) for moderate albuminuria and 1.58 (95% CI 1.07-2.35) for severe albuminuria (p for trend = 0.002). Participants with albuminuria had a higher risk of hip fracture than those without albuminuria, even when they belonged to the same eGFR category (HR = 1.75 versus 3.30 for an eGFR of 30 to 44 mL/min/1.73m² ; HR = 2.72 versus 7.84 for an eGFR of 15 to 29 mL/min/1.73m² ). The effects of each 10 mL/min/1.73m² decrease in eGFR were stronger with advancing albuminuria severity (p_interaction = 0.016). In conclusion, both low eGFR and albuminuria were risk factors for incident hip fracture in Korean adults. Moreover, these factors exerted a synergistic effect on the risk of hip fracture. © 2020 American Society for Bone and Mineral Research.

[Specificity of anemic syndrome in geriatric patients with chronic kidney disease.]

Anemic syndrome is detected in 10-25% of geriatric patients, and with increasing age, there is a tendency to increase the incidence of the disease. Among the diseases that lead to the development of anemia, kidney pathology plays an important role. Progressive deterioration of kidney function in old age is associated with an increased risk of fractures, sarcopenia, and the development of cognitive impairment. Also, nephrogenic anemia aggravates the prognosis in patients with cardiovascular diseases, which is associated with an increase in myocardial ischemia, an increase in tissue hypoxia, a progression of left ventricular hypertrophy, and a decrease in left ventricular systolic function.

Low-Normal Thyroid Function Predicts Incident Anemia in the General Population With Euthyroid Status

CONTEXT

Thyroid hormones (THs) have direct and indirect effects on hematopoiesis. However, few studies have directly evaluated the effect of THs on incident anemia among euthyroid subjects. This cohort study aimed to explore whether THs under physiological conditions can affect the development of anemia in the general population.

DESIGN

A total of 12,310 participants were enrolled in the cohort study (∼5-year follow-up period; mean, 3.1 years). A chemiluminescence immunoassay was used to measure free T3 (FT3), free T4 (FT4), and TSH, and anemia was defined according to the World Health Organization recommendation. THs, TSH, and Hb were assessed yearly during follow-up. Multivariable Cox proportional hazards regression models were used to assess the association between THs, TSH, and incident anemia.

RESULTS

The fully adjusted hazards ratios (95% CI) of anemia per 1-unit change in FT3, FT4, and TSH concentrations were 0.70 (0.56, 0.87), 0.93 (0.88, 0.98), and 1.19 (0.94, 1.50) (P < 0.01, P < 0.01, and P = 0.14, respectively). Moreover, a significant and positive association between FT3, FT4, and annual changes in Hb (standard regression coefficients of 0.056 and 0.028, respectively; both P < 0.01) was observed. Similar associations were observed when the participants who had thyroid dysfunction upon follow-up were excluded.

CONCLUSIONS

The current study demonstrated that THs significantly predict future anemia and annual changes in Hb, even in the euthyroid population.