NPPA and heart failure: As shown in Fig. 9a, myl7 expression (an index of muscle mass and hypertrophy) in the heart was over 20% greater in KDs (p < 0.0001, n = 3), while nppa expression (activated in response to ventricular stress during hypertrophy and heart failure [95, 96]) was reduced by approximately 40% (p = 0.0012, n = 3).