Effect of a ketoacid-aminoacid-supplemented very low protein diet on the progression of advanced renal disease: a reanalysis of the MDRD feasibility study.
BACKGROUND
We reanalyzed the data of the Modification of Diet in Renal Disease (MDRD) feasibility study to ascertain the effects of ketoacid- and aminoacid-supplemented very low protein diets.


METHODS
Sixty-six patients with advanced renal disease (Study B, baseline glomerular filtration rate (GFR) 7.5-24 ml/min/1.73 m2) were randomly assigned to a low protein diet (L, 0.575 g/kg/d), or a very low protein diet (0.28 g/kg/d) supplemented either with a ketoacid-aminoacid mixture (diet K) or with a mixture of essential aminoacids (diet J). Thirty patients with moderate renal disease (Study A, baseline GFR 25-80 ml/min/1.73 m2) were randomly assigned to a usual protein diet (M, 1.2 g/kg/d), diet L, or diet K. Mean follow-up was 14 months.


RESULTS
In Study B, GFR decline differed among the three diets (p = 0.028). Pairwise comparisons showed that the mean +/- SE GFR decline in ml/min/mo in diet K [-0.250+/-0.072] was slower than in diet J [-0.533+/-0.074] (p = 0.008) despite similar achieved protein intakes. The mean GFR decline in diet L [-0.394+/-0.068] was intermediate between, and did not differ significantly from the rates of decline in the other two groups. In Study A, consistent with a hemodynamic effect, the mean GFR decline varied directly with the reduction in protein intake in diets M, L and K (p = 0.028) during the first four months of follow-up, but thereafter did not differ among the diet groups (p = 0.76).


CONCLUSIONS
The study suggests that supplementation of a very low protein diet with the ketoacid-aminoacid mixture used in this feasibility study slowed the progression of advanced renal disease more than supplementation with an amino acid mixture.
Teschan
P E
PE
Vanderbilt University, USA.
Beck
G J
GJ
Dwyer
J T
JT
Greene
T
T
Klahr
S
S
Levy
A S
AS
Mitch
W E
WE
Snetselaar
L G
LG
Steinman
T I
TI
Walser
M
M
D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000008:administration & dosage*; D018753:Diet, Protein-Restricted; D004044:Dietary Proteins / Q000008:administration & dosage; D018450:Disease Progression; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D005527:Food, Fortified; D005919:Glomerular Filtration Rate; D006801:Humans; D007651:Keto Acids / Q000008:administration & dosage*; D007674:Kidney Diseases / Q000178:diet therapy* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015596:Nutrition Assessment; D013997:Time Factors
D000596:Amino Acids; D004044:Dietary Proteins; D007651:Keto Acids