Serum arylesterase activity was inversely correlated with log-transformed NT-proBNP levels (non-diabetes: r = −0.257, P = 0.004; diabetes: r = −0.353, P = 0.003; Fig. 2a) and NYHA functional class (non-diabetes: r = −0.301, P < 0.001; diabetes: r = −0.474, P < 0.001; Fig. 2b) both in non-diabetic and diabetic subgroups, whereas a positive correlation between arylesterase activity and log-transformed LVEF was only present in diabetic patients (r = 0.303, P = 0.007; Fig. 2c). This evidence concerns the gene NPPB and diabetes mellitus.