Adverse Effects of Sporadic Dialysis on Body Composition

Objective: 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. Design and Methods: 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. Results: 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). Conclusion: 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.