Body composition in patients treated with peritoneal dialysis

Background: Malnutrition is a common complication inuremia and during maintenance dialysis. Several factors contribute to itsdevelopment. Different modes of dialysis treatment may differ in theireffects on nutritional status. Methods: In order toanalyse the nutritional consequences of peritoneal dialysis (PD), bodycomposition analyses were performed in PD patients between February 1993and March 1996. Body cell mass (BCM) was estimated from measurements oftotal body potassium (TBK) in a whole-body counter. Total body water (TBW)was determined by measurement of tritiated water. Body fat (BF) wascalculated from body weight (BW), TBK and TBW. Observed values were relatedto predicted (o/p) derived from local population studies.Results: Sixty patients were repeatedly investigatedduring the study period. Of these, 34 were investigated during the firstyear of PD. At the start of dialysis, TBK o/p was 0.94 and BF o/p 0.76. Nochange in body composition was seen during the observation period in thegroup as a whole. However, within the group individual changes in BW werestrongly correlated with individual changes in BF (r=0.66, P=0.0001).Twenty-six patients were examined during the second and third year of PD.In this group, BW o/p remained constant over time. However, there was asmall but significant decline of TBK o/p and a concomitant increase of BFo/p (P<0.05). No correlation was observed between changes in TBK andchanges in serum albumin. Conclusions: The results ofthis study indicate, that there may be a risk for further reduction of bodycell mass during long-term PD treatment, while body energy stores aremaintained or even increased.