Can a reduction in extracellular fluid volume result in increased serum albumin in peritoneal dialysis patients?

Abstract

Serum albumin predicts survival in end-stage renal failure. The literature has emphasized the dependence of albumin on inflammation. We previously proposed an independent relationship with overhydration. To date, there is no proven therapy that increases serum albumin in dialysis patients. We investigated whether decreasing dry weight increases serum albumin in peritoneal dialysis patients. Twenty-one subjects (15 continuous ambulatory peritoneal dialysis patients and 6 continuous cycled peritoneal dialysis patients) were assessed at 0 and 4 weeks. Body weight, blood pressure, 4-site skin-fold thickness, subjective global assessment score, and use of antihypertensive medication were recorded. Fluid samples were collected for estimation of serum albumin, C-reactive protein, and 24-hour dialysate and urine volume. The extracellular fluid volume was estimated by multiple-frequency bioelectric impedance. Between the 0- and 4-week assessments, dialysis prescription was altered to increase the daily ultrafiltrate volume (1.00 ± 0.71 L to 1.29 ± 0.75 L; P = 0.04). Significant decreases were seen in body weight (70.7 ± 12.1 kg to 69.9 ± 12.2 kg; P = 0.0002), extracellular fluid volume (16.2 ± 3.3 L to 15.5 ± 3.2 L; P = 0.0006), systolic blood pressure (147.7 ± 26.3 mm Hg to 124.2 ± 20.9 mm Hg; P < 0.0001), diastolic blood pressure (84.2 ± 14.5 mm Hg to 76.6 ± 11.7 mm Hg; P = 0.01), and number of antihypertensive drugs (1.9 ± 1.0 to 1.6 ± 1.1; P = 0.02). Serum albumin increased (34.6 ± 4.1 g/L to 35.9 ± 3.6 g/L; P = 0.01). C-reactive protein did not change. Decreasing dry weight in peritoneal dialysis by an increase in ultrafiltration volume results in a decreased extracellular fluid volume, which is reflected by an improvement in blood pressure control. This improvement in blood pressure was associated with an increase in serum albumin. This finding strengthens the argument that overhydration is a cause of hypoalbuminemia in peritoneal dialysis and offers a therapeutic option in management of this patient group. © 2002 by the National Kidney Foundation, Inc.