Objective: We examined the protein anabolic effects of Pro-Stat 64, a high nitrogen-containing, enzyme-hydrolyzed, tryptophan-fortified, collagen protein supplement administrated during hemodialysis, at two different dosing regimens.
Design: This was a randomized, controlled, prospective study with 3 different groups: control, single dose of supplementation, and double dose of supplementation.
Setting: This study was performed at a clinical research center.
Patients: Six prevalent chronic hemodialysis (HD) patients were enrolled: 5 males, 1 female, 4 African Americans, and 2 Caucasians. Their mean age was 45 +/- 11 years (S.D.). Two patients were diabetic.
Methods: Protein turnover studies were performed using amino-acid (AA) balance and primed constant infusion of L-(1-(13)C) leucine.
Main outcome measure: Whole-body protein balance was determined according to substrate kinetics.
Results: There were no statistically significant difference at any time point between protocols for blood chemistries and hormonal markers, except for minor variations in plasma glucose. All plasma AA groups displayed decreases during a control study, in which no supplementation was given. Compared with the control group, plasma nonessential AA and total AA concentrations were statistically significantly higher during HD after both single and double doses of supplementation. The forearm arteriovenous AA balance was statistically significantly better for essential, nonessential, and total AA uptake after both single-dose and double-dose supplementation compared with the control group, except for nonessential AA, which was significantly better only after a double dose. Whole-body protein breakdown and net protein balance were statistically significantly better during HD with a double-dose administration in a dose-dependent manner, compared with the control and single-dose groups.
Conclusions: Oral AA supplementation alone improves whole-body and skeletal muscle protein anabolism in a dose-dependent manner in chronic HD patients. These data should be taken into account during clinical decision-making or when designing clinical trials of nutritional supplementation.