Amino Acid Imbalance Is an Independent Factor for Mortality in Patients With Liver Cirrhosis

BACKGROUND: Amino acid imbalance, characterised by decreased branched-chain amino acids (BCAAs) and increased tyrosine levels, is a common metabolic disturbance associated with various complications in patients with cirrhosis. However, the independent prognostic value of these changes remains unclear. AIMS: This study aimed to elucidate the prognostic impact of amino acid imbalance by analysing BCAA and tyrosine levels in patients with cirrhosis. METHODS: This multicenter retrospective study reviewed patients hospitalised for cirrhosis in Gifu, Japan. Amino acid imbalance was evaluated using serum BCAA and tyrosine levels and the BCAA-to-tyrosine ratio (BTR). Prognosis was assessed using a Cox proportional hazards regression model. Multivariable analyses were conducted using a model that included BTR, which was then replaced with both BCAA and tyrosine levels. RESULTS: Amongst 541 patients (median age, 66 years; 50.3% female), 129 (23.8%) died during a median follow-up of 3.5 years. The median BTR, serum BCAA and tyrosine levels were 4.36, 378 and 90 μmol/L, respectively. Multivariable analysis identified BTR (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.72-0.94; p = 0.004) as a significant prognostic factor after adjustment for established factors. In the subsequent model, both BCAA (HR, 1.00; 95% CI, 1.00-1.00; p = 0.019) and tyrosine levels (HR, 1.01; 95% CI, 1.00-1.01; p = 0.002) independently predicted mortality. CONCLUSIONS: Amino acid imbalance is an independent factor for poor prognosis in patients with cirrhosis. Notably, decreased BCAA and increased tyrosine levels were identified as independent prognostic factors.