Certain groups of patients with nondialysis-dependent chronic kidney disease (CKD) require additional management to control their hemoglobin levels (Hb), according to investigators.
In the national Swedish Renal Registry, 5000 patients with CKD stages 3 to 5 initiated anemia treatment during 2012 to 2016 and logged 25,431 consecutive healthcare visits. Hb levels were within the recommended 10 to 12 g/dL target range in 50% of patient visits, less than 10 g/dL in 9% of visits, and exceeded 12 g/dL in 39% of visits (23% between 12 and 13 g/dL).
Compared with patients who had glomerulonephritis, those with polycystic kidney disease, diabetic nephropathy, or nephrosclerosis had 49%, 29%, and 52% increased odds of having Hb levels less than 10 g/dL, respectively, Yang Xu, MD, and colleagues from Karolinska Institutet in Solna, Sweden, reported in Clinical Kidney Journal. Similarly, patients with recent bleeding, transfusion, C-reactive protein of 5 mg/dL or greater, higher phosphate levels (top tertile), and lower calcium levels (bottom tertile) had significant 20%, 26%, 16%, 33%, and 36% increased odds of Hb below target range, respectively, they reported.
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Conversely, the odds of having an Hb level above 12 g/dL were a significant 13% greater among patients aged 65 to 75 years compared with those younger than 65 years, and 85% and 34% greater among patients with CKD stage 3b and stage 4, respectively, compared with those who had CKD stage 5, according to Dr Xu’s team. Patients with CKD stage 5 were more likely to maintain Hb levels within normal range than those with CKD stage 3b and stage 4, “a difference that we speculate may be explained by the more frequent nephrologist consultation and better care at later CKD stages including better Hb monitoring and management,” the authors stated.
Patients with a functioning kidney transplant had significant 83% increased odds of having Hb levels above 12 g/dL, which the investigators said may reflect more aggressive management of post-transplant anemia.
Compared with women, men had significant 23% and 22% increased odds of a having Hb levels less than 10 and more than 12 g/dL, respectively.
In addition, each 1 g/dL increase in albumin was significantly associated with 5% increased odds for having above-target Hb. Iron medication and erythropoiesis stimulating agent (ESA) doses of 3600-6400 IU/wk and more than 6400 IU/wk (vs no ESA) significantly increased the odds of above target Hb by 6%, 18%, and 35%, respectively, according to the investigators.
Of the 1361 patients initiating dialysis, 220 died and 453 experienced a major adverse cardiovascular event (MACE) within 1 year. A greater time spent with a predialysis Hb higher than 12 g/dL was associated with a significant 24% lower risk of MACE, defined as non-fatal myocardial infarction, stroke, heart failure, or death attributed to cardiovascular disease. The investigators noted that this finding was based on achieved rather than targeted Hb and likely reflects patients who respond well to ESA treatment. Further, a lower predialysis erythropoietin resistance index (ERI) of less than 0.52 IU/kg/week/g/dL significantly correlated with 39% improved survival compared with higher ERI.
According to Dr Xu’s team, “our results credibly illustrate the multiple conditions that may affect Hb control, and identify many of the factors that lead to ESA hypo-responsiveness. As a clinical application, knowledge of patient phenotypes with difficulties in attaining Hb targets may allow the implementation of corrective measures, through more stringent monitoring of Hb, intensified or alternative therapeutic strategies.”
Disclosure: This clinical trial was supported by AstraZeneca. Please see the original reference for a full list of authors’ disclosures.
Reference
Xu Y, Evans M, Barany P, James G, Sjölander A, Carrero JJ. Factors affecting pre-end-stage kidney disease haemoglobin control and outcomes following dialysis initiation: a nationwide study. Published online February 5, 2021. Clin Kidney J. 2021:1-9. doi:10.1093/ckj/sfaa213
