COMPARISON OF 5 BODY-COMPOSITION METHODS IN PERITONEAL-DIALYSIS PATIENTS

Body-composition assessment is an important method of evaluating nutri tional status in peritoneal dialysis patients. Because body-compositio n measurement estimates have not been fully validated in this populati on, we assessed five body-composition methods in 30 well-dialyzed peri toneal dialysis patients. The techniques studied included bioelectrica l impedance analysis, dual-energy X-ray absorptiometry, total-body pot assium counting, and anthropometry by two techniques. The dialysis pat ients were matched for age, race, sex, height, weight, and body mass i ndex with 29 healthy control subjects in our laboratory database. By 5 x 2 x 2 analysis of variance, significant differences were found betw een results by modality (P < 0.0001) as well as by sex, with women hav ing an increased percentage of fat (P < 0.0001). However, there was no significant intermethod difference by condition (peritoneal dialysis or control). That is, although significantly different percentage fat values were found between the body-composition techniques, this variab ility was independent of whether the measurement was made on control o r peritoneal dialysis patients. Despite the differences between modali ties, all techniques were found to correlate significantly with each o ther (P < 0.01 or better for men and P < 0.001 or better for women). O ur experience shows that these routine techniques for measuring body c omposition can be readily applied to stable peritoneal dialysis patien ts.