Malhotra D, Tzamaloukas AH, Murata GH, Fox L, Goldman RS,
Serum albumin in continuous peritoneal dialysis: Its
predictors and relationship to urea clearance
(Jul) 50:243-249 1996
This excellent study has two components. Step wise logistic regression is
used to identify the
predictors of serum albumin, in 92 CAPD patients. The findings are then
successfully validated in a
further 102 patients. Predictors are found to be, in order of significance,
transport status on PET, older age, presence of diabetes and a high daily
dialysate drain volume.
It is notable that neither Kt/V, creatinine clearance or protein catabolic
rate were predictive and,
although uncorrected PCR was higher in those with a higher serum albumin, it
did not come out as
positive in the multiple regression analysis. These findings support very
similar results obtained
by our group and published in 1993 [JASN 3:1501]
In the second part
of the study, the
authors ask whether prospective increases in peritoneal dialytic dose can
increase serum albumin.
Thirty-seven patients are studied, an average of eight months after an
increase in mean weekly Kt/V
from 1.4 to 2.1. The normalised PCR had increased from 0.74 to 0.96 but the
serum albumin was
unchanged. Within the 37 patients, however, there was a subgroup of 15 in
whom the albumin did
increase. This subgroup were notable in that they were younger than the group
as a whole and that
they also had a greater increase in their serum urea after the increase in
Kt/V. They also showed a
somewhat higher nPCR both before and after the intervention.
The implication of this study is that serum albumin
in PD patients is a
complex index and its main determinants are not dialytic dose nor PCR.
Rather, factors that are not
easily modified such as peritoneal transport status, age, and co-morbidity
are more influential.
Prospective increases in dialytic dose should be still be considered in the
malnutrition in PD patients but a response in the serum albumin should not be
reliably be expected.
(Peter G. Blake, M.D., Victoria Hospital, London, Ontario)