Table 1.

Effects of BCKAs and ketoanalogues of essential amino acids (KAEAAs) in subjects with liver disease.

Study Design	Results	Reference
Patients with cirrhosis and PSE; AA + KAEAA, infusion (1–5 days) or orally (3–12 days).	↑ BCAA, methionine and phenylalanine, ↓ glutamine. No effect on ammonia levels. Improvement in mental status and psychological testing.	[55]
Patients with cirrhosis and PSE; BCAA, ornithine, or calcium salts of BCKA orally for 7–10 days; double-blind crossover comparison.	Combination of ornithine and BCKA improved EEG and clinical signs of PSE more than BCAA or components given separately.	[9]
Patients with cirrhosis and healthy controls; KIC infusion (300 µmol/min for 150 min).	↑ leucine and ammonia; ↓ urea, valine, isoleucine, methionine, phenylalanine, and GLN.	[56]
Patients with cirrhosis and PSE; lactulose and protein restriction; BCKA (15 g/day) or placebo for 4 weeks in a crossover regimen.	No effect on ammonia and BCAA levels, EEG, number connection test, and clinical state.	[57] *
Rats, acute liver injury (CCl4); BCKA (sodium or ornithine salts); infusion (60 min) or intragastric administration.	Higher BCAA levels after BCKA in CCl4-treated animals than in controls after infusion. Only slight increases in BCAAs after gavage of BCKAs.	[47]

AA + KAEAA, mixture of amino acids and ketoanalogues of essential amino acids; PSE, portal systemic encephalopathy. * The possible cause of the unobserved rise in the BCAAs after BCKA administration is that the collection of blood samples was performed in a post-absorptive state, in which most of the changes induced by BCAA supplementation disappear [58].