Bioelectrical impedance analysis of nutritional status in uremic patients on regular hemodialysis

The body composition of uremic patients on regular hemodialysis (HD) therapy was studied using the bioelectrical impedance analysis (BIA) technique. The accuracy of BIA in estimating fluid loss during HD was also studied. Thirty-five uremic patients (28 men and 7 women), regularly treated by hemodialysis (HD), were enrolled. The uremic patients had lower serum albumin levels and a marginally lower arm muscle circumference (AMC; p = 0.06) than 107 age- and sex-matched normal control subjects (86 men and 21 women). Before HD, the uremic patients presented with a similar percentage of body fat (BF), fat-free mass (FFM) and total body water (TBW) as normal controls, but they possessed a lower percentage of TBW and FFM, and a higher percentage of BF after HD. When BIA was applied to estimate the fluid loss during HD, overestimation usually occurred. A good correlation between the body fluid loss estimated by the BIA method (BIAL) and that estimated by the body weighing method (BWL) was noted. An equation of BWL = 0.452 BIAL + 0.844 (n = 35, R = 0.85, SEE = 0.58, p less than 0.0001) was derived following linear regression analysis. The weight of BF estimated by BIA before and after HD demonstrated a good correlation (n = 35, R = 0.98, p less than 0.0001). In conclusion, uremic patients on regular HD therapy seem to have decreased serum albumin levels and decreased AMC in anthropometry. After HD, they possess a lower percentage of FFM and TBW than normal controls. The results suggest that accelerated protein catabolism is a common problem in uremic patients on regular HD therapy.(ABSTRACT TRUNCATED AT 250 WORDS)