Blood NAD levels are reduced in very old patients hospitalized for heart failure

•NAD coenzyme is a key player in energy metabolism and signaling that isdepleted in many tissues with aging•Blood NAD levels measured in a healthy population of 151 voluntary donors aged 19 to 68 years was 23.4 (SD 4.05) μmol/L•Correlation between blood NAD levels and age differed between males and females with a trend toward reduction in males only•Blood NAD levels were lower in elderly patients hospitalized for heart failure with a mean at 20.7 (SD 3.6) μmol/L (p=0.007)•Our study suggests that administration of NAD precursors to this type of patients should be tested for clinical benefits