NPPB and left ventricular hypertrophy: Echocardiographic analysis showed that, despite lack of an obvious difference in left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) among HFD-fed WT and FNDC5−/− mice, FNDC5 deficiency significantly augmented left ventricular hypertrophy evidenced by increased IVSd and LVPWd and cardiac hypertrophy markers (Nppa, Nppb, Myh7) mRNA expression as well as LVW/BW (Table 1, Fig. 1c, d) after HFD treatment.