Amino acid losses during hemodialysis with polyacrylonitrile membranes: effect of intradialytic amino acid supplementation on plasma amino acid concentrations and nutritional variables in nondiabetic patients
Jf. Navarro et al., Amino acid losses during hemodialysis with polyacrylonitrile membranes: effect of intradialytic amino acid supplementation on plasma amino acid concentrations and nutritional variables in nondiabetic patients, AM J CLIN N, 71(3), 2000, pp. 765-773
Background: Malnutrition is highly prevalent in hemodialysis patients. Amin
o acid (AA) losses during the dialysis procedure may! be a contributing fac
tor.
Objectives: The objectives of this study were I) to prospectively evaluate
AA losses and their effect on plasma AA concentrations during dialysis with
polyacrylonitrile at baseline and after administration of AAs by intradial
ysis and 2) to investigate the effects of intradialytic AA supplementation
on nutritional status.
Design: Seventeen stable patients without diabetes who were receiving hemod
ialysis were studied. In the first phase, AA losses were evaluated over 2 w
k in 10 patients randomly assigned to receive AA supplementation. AA losses
were analyzed during the first week without supplementation and during the
second week with AA administration. In the second phase, the patients' nut
ritional status was investigated after 3 mo of AA supplementation and was c
ompared with those in 7 patients not receiving AAs.
Results: Mean ((x) over bar +/- SD) AA losses during a 4-h dialysis session
were 12 +/- 2 g; there was a significant decrease in plasma AA concentrati
ons (386 +/- 298 mu mol/L for essential and 902 +/- 735 mu mol/L for noness
ential AAs). After administration of AAs, the losses increased to 28 +/- 4
g. However, this procedure produced a positive net balance of AAs (10.6 +/-
5.6 g for total AAs), preventing a reduction in plasma concentrations. Aft
er 3 mo of AA administration, there was a significant increase in protein c
atabolic rate and serum albumin and transferrin. This improvement occurred
without any change in the dialysis dose, ruling out the possibility that an
increase in dialysis efficiency played a role.
Conclusions: Intradialysis adequately provides AA supplements. prevents red
uctions in plasma AA concentrations, and favorably affects the nutritional
status of patients receiving hemodialysis.