International Journal of Nephrology and Renovascular Disease (Jan 2021)
Slipping Through the Pores: Hypoalbuminemia and Albumin Loss During Hemodialysis
Abstract
Kamyar Kalantar-Zadeh,1– 3 Linda H Ficociello,4 Jennifer Bazzanella,5 Claudy Mullon,4 Michael S Anger4 1Division of Nephrology, Hypertension and Kidney Transplantation, University of California, Irvine, School of Medicine, Orange, CA, USA; 2Department of Epidemiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA; 3Los Angeles Biomedical Research Institute at Harbor–UCLA, Torrance, CA, USA; 4Fresenius Medical Care Renal Therapies Group, Waltham, MA, USA; 5Fresenius Kidney Care, Madison, WI, USACorrespondence: Kamyar Kalantar-ZadehDivision of Nephrology, Hypertension and Kidney Transplantation, University of California, Irvine Medical Center, 101 the City Drive South, Orange, CA 92868-3217, USATel +1-714-456-5142Fax +1-714-456-6034Email [email protected]: Hypoalbuminemia results when compensatory mechanisms are unable to keep pace with derangements in catabolism/loss and/or decreased synthesis of albumin. Across many disease states, including chronic kidney disease (CKD), hypoalbuminemia is a well-established, independent risk factor for adverse outcomes, including mortality. In the setting of CKD, reduced serum albumin concentrations are often a manifestation of protein-energy wasting, a state of metabolic and nutritional alterations resulting in reduced protein and energy stores. The progression of CKD to kidney failure and the initiation of maintenance hemodialysis (HD) further predisposes an already at-risk population toward hypoalbuminemia such that approximately 60% of HD patients have albumin concentrations < 4.0 g/dl. Albumin loss into the dialysate through the dialyzer appears to be a potentially modifiable cause of hypoalbuminemia in some patients. A group of newer dialyzers for maintenance HD—sometimes termed protein-leaking or medium cut-off membranes—aim to improve clearance of middle molecules (vs high flux dialyzers) but are associated with increased albumin losses. In this article, we will examine the impact of dialyzer selection on albumin losses during conventional HD, including the clinical relevance of such losses on serum albumin levels. Data on the clinical relevance of albumin losses during dialysis and current gaps in the evidence base are also discussed.Keywords: dialysis membrane, dialyzer, nutrition, hemodialysis, protein-energy wasting
