Uraemic symptoms, nutritional status and renal function in pre-dialysis end-stage renal failure patients

Background. Deciding on the right moment to initiate dialysis and finding t he best method to establish this critical stage of chronic renal failure ar e both controversial issues. This study attempted to address this subject b y correlating a uraemic score with the most common clinical methods for ass essing renal function in pre-dialysis chronic renal failure (end-stage rena l disease, ESRD) patients. Methods. The study group consisted of 201 nonselected ESRD patients. A urae mic score, composed of the uraemic symptoms, the subjective global assessme nt of nutritional status, serum albumin concentration, and protein cataboli c rate normalized for ideal body weight, was taken as a clinical marker of uraemic toxicity. Correlations that best fit this uraemic score with creati nine clearance (Ccr), the arithmetic mean of Ccr, urea clearance (Ccr-Cu) a nd Kt/V urea were then investigated. Results. Thirty-six per cent of patients had malnutrition. By multiple logi stic regression analysis, the presence of comorbidity, Ccr-Cu and haematocr it were the best determinants of malnutrition. The correlation that best fi t Ccr or Ccr-Cu with the uraemic score was a cubic curve (r = 0.38, P < 0.0 001, and r = 0.42, P < 0.0001, respectively), in which an ascending inflect ion was observed when Ccr and Ccr-Cu fell below 12-13 and 10 ml/min, respec tively. However, the relationship between Kt/V urea and the uraemic score w as less predictable, especially in male patients. Conclusion. Ccr or Ccr-Cu are reliable methods for establishing the degree of severity of chronic renal failure below which the development of symptom s and malnutrition are highly prevalent. In contrast, Kt/V urea may be a le ss sensitive and specific method for assessing the severity of uraemia in E SRD patients.