title: Importance of the monthly biochemical evaluation to identify patients on hemodialysis with malnutrition.
abstract: BACKGROUND
  Malnutrition is a frequent complication in patients on hemodialysis and early diagnosis is important to reduce the morbidity and mortality of treatment.
  
  
  OBJECTIVE
  To investigate the usefulness of biochemical tests performed monthly in order to identify hemodialysis patients with malnutrition.
  
  
  METHODS
  The nutritional status of 252 patients was evaluated by objective and subjective global assessment, and the patients classified as malnourished and not malnourished. Then, during 4 consecutive months, serum creatinine, phosphorus, urea pre-and post-dialysis and Kt/V were recorded for calculation of averages. After analysis of these variables by the ROC curve we calculated the sensitivity and specificity of these parameters to identify patients with malnutrition.
  
  
  RESULTS
  In ROC curve, the area under the curve for urea was 0.683, 0.71 for phosphorus, 0.724 for Kt/V and 0.765 for creatinine. For values of urea ≤ 90 mg/dL, phosphorus ≤ 4.2 mg/dL, Kt/V ≥ 1.6 and creatinine ≤ 6.5 mg/dL, the specificity ranged between 80% and 88% and sensitivity between 26% and 51%. The negative predictive value ranged between 90% and 92% and positive predictive value between 23% and 32%. The association of two or more of these índices did not change significantly these values.
  
  
  CONCLUSIONS
  Our results suggest that serum urea ≤ 90 mg/dL, creatinine ≤ 6.5 mg/dL, phosphorus ≤ 4.2 mg/dL, and Kt/V ≥ 1.6 can be used for screening patients with malnutrition. However, using these cutoffs the parameters tend to overestimate the number of patients with malnutrition.
authors.affiliation: Instituto de Nefrologia de Taubaté, São Paulo. mmcastro@inefro.com.br
authors.forename: Manuel Carlos Martins
authors.initials: MC
authors.lastname: de Castro
authors.forename: Flávia Chiaradia Andrade
authors.initials: FC
authors.lastname: de Oliveira
authors.forename: Ana Castello Branco
authors.initials: AC
authors.lastname: da Silveira
authors.forename: Kátia de Barros Correia
authors.initials: Kde B
authors.lastname: Gonzaga
authors.forename: Magdaleni
authors.initials: M
authors.lastname: Xagoraris
authors.forename: Jerônimo Ruiz
authors.initials: JR
authors.lastname: Centeno
authors.forename: José Adilson Camargo
authors.initials: JA
authors.lastname: de Souza
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D044342:Malnutrition / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D008875:Middle Aged; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects