Relationship of plasma cholesterol level to doses of branch-chain amino acids in sepsis.

Abstract

Plasma cholesterol levels, plasma lactate, and total body RQ were measured in septic patients undergoing total parenteral nutrition (TPN) with glucose, fat, and two different branch-chain amino acid admixtures (49% BCAA and 16% BCAA). Mean plasma cholesterol for all measurements (2.61 +/- 0.94 [SD] mmol/L) was lower than normal; however, it was higher with 49% BCAA than with 16% BCAA (2.94 +/- 0.95 vs. 2.27 +/- 0.81 mmol/L, p less than .001) for comparable loads of glucose, fat, and total amino acids. Plasma lactate and RQ were lower with 49% BCAA than with 16% BCAA (p less than .001 for both). Cholesterol was directly related to the absolute dose of BCAA (p less than .001), was unrelated to the dose of non-BCAA, and was inversely related to lactate (p less than .001). These results suggest that BCAA ketoacids contribute to cholesterol synthesis in sepsis, as well as being an oxidative source. The data also suggest that the reduction in alanine in BCAA-enriched amino-acid TPN assists in the lowering of plasma lactate secondary to abnormal septic glucose metabolism.