The importance of the nutritional state of our dialysis patients has been stressed for many years. Although the calculation of the protein catabolic rate has become common practice in many dialysis units, there are several problems with this measurement. In addition, the serum albumin level is subject to multiple influences making its interpretation in individual patients difficult. This paper examines a different approach to nutritional assessment – that of using longer term measures of nutrition. Several techniques for measuring body composition are explored and their use in end-stage renal disease (ESRD) examined. Total body nitrogen measurement is a gold standard technique which has been validated in renal patients, unfortunately it is not widely available. Of the alternatives, dual energy X-ray absorptiometry scanning for assessment of fat-free mass appears to be the best technique with the narrowest limits of agreement compared to gold standard techniques. Whilst bioelectrical impedance is reasonable for body water assessment, it is not reliable in ESRD patients for lean-body mass estimation.
- Fat-free mass