High‐Branched Chain Amino Acid Solutions: Relationship of Composition to Efficacy

Abstract

A prospective clinical trial was undertaken to determine the nitrogen-sparing efficacy of three amino acid solutions with different concentrations of branched-chain amino acids (BCAA) in 25 postoperative patients. The patients were a homogenous male population with stage I bladder cancer who underwent radical cystectomy. Administration rates of the intravenous solutions were designed to provide 30 kcal/kg/day and 1.5 g protein per kg per day during the 7-day study period. A control group (n = 4) received 5% dextrose in water (150 g/day). Nitrogen balance was determined daily and the whole body protein turnover was measured using a primed-constant infusion of 15N glycine on postoperative days 3 and 4. The group receiving the 45% BCAA enriched (low leucine) amino acid solution exhibited a significant decrease in cumulative (7 day) nitrogen balance (7.6 +/- 2.6 g) compared to the groups receiving either the standard 25% BCAA (19.9 +/- 2.1 g) or the 45% BCAA enriched (high leucine) (21.6 +/- 7.0 g) amino acid solution. The group receiving the 45% BCAA enriched (low leucine) amino acid solution exhibited a higher rate of mean whole body protein catabolism compared to the other groups. For patients undergoing major elective operations, the amount of leucine necessary for optimal daily nitrogen balance was 0.13 g/kg/day. These results demonstrate that the ratio of individual BCAA and the amount of leucine were more critical to nitrogen-sparing efficacy than the percentage total BCAA infused.

Effect of branched‐chain amino acids on the composition and cytolytic activity of liver‐associated lymphocytes in rats

“…It is of interest to note that valine, but not leucine or isoleucine, has been significantly associated with the increase in LAL number, although leucine is reported to be more effective in protein synthesis than valine and isoleucine. 2,28 This finding might be supported by a previous report using rats, 29 which suggested that valine plays a more important role in lymphopoiesis than other BCAA. Collectively, our present data suggest that valine may increase the number of LAL by stimulating the lymphopoiesis in the liver, which is known to be a haematopoietic organ in the embryo.…”

Intravenous Branched Chain Amino Acid Trial in Marrow Transplant Recipients

“…No significant differences were observed in the median day posttransplant of 2:500/mm3 granulocytes (day 18 for both BCAA groups), the median day when oral protein intake was 2:10g (day 24 for the 45% BCAA group and day 26 for the 23% BCAA group), or in weekly prealbumin. Baseline prealbumin levels were 33.5 (13,40) mg/dl in the 45% and 32.5 (6,40) mg/dl in the 23% BCAA group. The lowest levels in both groups were at the end of the study week 2: 13.0 (8,40) mg/dl in the 45% and 15.2 (7,40) mg/dl in the 23% BCAA group.…”

“…Furthermore, marrow transplant recipients require extended periods of total parenteral nutrition (TPN) and represent a more homogeneous population relative to other populations in which BCAA have been studied; most studies have examined response to BCAA for 7 days or less in heterogeneous groups of postoperative patients. [1][2][3][4][5][6][7] We conducted a prospective, randomized, doubleblinded study to compare the effects of a high-leucine, 45% BCAA us a standard 23% BCAA intravenous solution on nitrogen balance, urinary 3-methylhistidine (3-MH)-to-creatinine excretion ratio, upper arm anthropometry, serum prealbumin, and peripheral marrow engraftment in adult patients with leukemia treated by chemoradiotherapy and marrow transplantation during the first month posttransplant.…”

Total Parenteral Nutrition in the Critically Ill Patient

“…We reached 100% agreement on the inclusion of articles for this systematic review. Reasons for excluding relevant randomized studies included studies not generalizable to critically ill patients 40 ; studies that evaluated different kinds of TPN [41][42][43] ; studies that evaluated amino acids only [44][45][46][47] ; pseudorandomized studies (not true randomization) [48][49][50][51][52] ; studies duplicated in other publications 34,53,54 ; studies not reporting clinically important outcomes [55][56][57] ; studies available in abstract form only 58 ; and a study that also randomized patients to anabolic steroids. 59…”