Renal anemia and hydration status in non-dialysis chronic kidney disease: Is there a link?

Abstract

Rationale Anemia, a common feature in chronic kidney disease (CKD), has multiple contributors to its pathogenesis. Besides the well recognized erythropoietin and iron deficiencies, hydration status might be involved. Objective To assess the prevalence and correlations of anemia, iron deficiency and overhydration in patients with stage 2 to 5 CKD. Methods and Results This cross-sectional study enrolled 125 erythropoietin and iron therapy naïve non-dialysis CKD patients, without a identifiable cause of anemia. Parameters of hematological, iron, inflammatory and nutritional status were measured. The overhydration parameter (OH) assessed by bioimpedance spectroscopy was used to characterize hydration status. The prevalence of decreased hemoglobin (Hb) <110g/L increased along CKD stages from 0% to 40% (p=0.008). Fluid overload (OH >1L) and lower serum albumin (<40g/L) were more common in stage 5 versus stage 3 CKD (53% vs. 10%, p<0.001, and 27% vs. 3%, p=0.02, respectively), suggesting a potential dilutional reduction in serum proteins. Conversely, decreased iron stores (ferritin <100mcg/L) and iron availability (transferrin saturation, TSAT<0.20) were similarly prevalent irrespective of kidney function decline. Hemoglobin was positively correlated with estimated glomerular filtration rate (eGFR), serum albumin, and transferrin saturation, but inversely with OH. However, in a model of multiple linear regression which explained 32% of hemoglobin variation, only eGFR and overhydration remained the independent predictors of anemia. Discussion As fluid overload is a common denominator for hemoglobin and TSAT levels, and is closely related to the declining kidney function, it should be considered in the management of renal anemia, at least in advanced CKD.

The diagnostic efficacy of diffusion tensor imaging generated by gadolinium-based magnetic resonance imaging for patients with chronic kidney disease

“…Chronic kidney disease (CKD) is a public health problem worldwide, which is a gradual impairment of renal function. [1] Patients with CKD are at an increased risk of cardiovascular disease and other chronic conditions with their daily lives. [2] Clinically, CKD is characterized by a low estimated glomerular filtration rate (eGFR, <60 mL/min/1.73 m 2 ), which may progress at varying rates depending on blood pressure management, history of decreased GFR, level of proteinuria.…”