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

Age-associated decline in nicotinamide adenine dinucleotide (NAD) tissue levels has emerged as potential driving mechanism in the establishment of energy metabolism perturbations in the context of chronic diseases, notably heart failure.The aim of this study was to measure the blood NAD levels in a healthy blood donor population and in a population of elderly patients hospitalized for decompensated heart failure.Whole blood sample was collected from 151 healthy voluntary blood donors, aged 19 to 68 years, and from 19 patients aged 75 to 101 years and hospitalized for decompensated heart failure in a geriatric ward. Metabolites were extracted by the hot buffered ethanol procedure and NAD was quantified in triplicate for each sample.The mean concentration of NAD in blood of healthy donors was 23.4 (SD 4.05) μmol/L. There was no significant correlation between NAD levels and donors' age nor sex in the healthy population when studied as a whole. However, the linear regression curves of NAD concentration plotted against age differed between males and females (p = 0.0283) with a trend in males to decline with age that was not observed in females. The mean concentration of NAD in whole blood samples of the geriatric population was 20.7 (SD 3.6) μmol/L (p = 0.007 versus the healthy blood donor population). There were no differences between males and females (p = 0.7) nor between patients with ejection fraction inferior or superior to 50% (p = 0.86) in the geriatric population.This study highlighted a diminution of NAD blood levels for elderly patients hospitalized for decompensated heart failure in comparison to a healthy population, suggesting that new therapeutics to restore NAD stock and energy metabolism would be a major progress in the management of this type of geriatric patients.