Adverse Effects of Sporadic Dialysis on Body Composition

The aim of this study is to analyze the body composition of patients receiving emergent dialysis and compare their body cell mass (BCM) and fat-free mass (FFM) with those of normal subjects. The care of patients receiving sporadic, emergent dialysis treatment is a growing public health concern and the magnitude of muscle wasting that occurs in this population is not known.

We used a cross-sectional design with matching to determine differences in total body potassium--an indicator of both BCM and FFM--between emergent dialysis patients and healthy normal subjects. We studied 22 subjects using a 40K counter that measures BCM and FFM and compared them to controls after matching with sex, height and weight.

In the matched comparison, BCM and FFM were significantly lower in subjects with end-stage renal disease (ESRD). Unadjusted BCM was 4.7 kg lower and FFM was 8.8 kg lower for those with ESRD compared to those without ESRD (p < 0.001, p < 0.001, respectively). Comparison with unmatched controls who underwent 40K analysis also revealed significantly lower BCM (4.1 kg) and FFM (7.7 kg) in the ESRD subjects (p = 0.004). After adjusting for age, height, weight and gender, BCM and FFM were lower by 4.2 and 7.8 kg, respectively (p < 0.001). Repeated observations were available for a subset of ESRD subjects, and the rate of FFM loss over time was significant, with the ESRD subjects demonstrating 2.2 kg per year decline (p = 0.01).

We conclude that among other consequences, muscle wasting indicated by decline in BCM and FFM is a significant concern in the growing emergent dialysis population.