In the present study, tyrosine serum levels were significantly positively correlated with the serum levels of NT-proBNP, IL-6, and 2-HB (r = 0.24, P = 0.007), the markers of HF severity, inflammation, and oxidative stress, respectively, which are known to be associated with increased muscle proteolysis and protein turnover46,47. This evidence concerns the gene NPPB and hydrops fetalis.