Nicotinamide Riboside Improves Muscle Function and Restores Muscle Mass: Preclinical Findings

Synopsis

NAD+ is an essential cofactor for breaking down metabolic fuels in all cells. However, NAD+ availability can become limited in certain tissues during genotoxic stress and natural aging. The exact point at which NAD+ shortage causes functional problems in tissues is not well understood. This study focused on mouse skeletal muscle by specifically deleting NAMPT, a key enzyme in the NAD+ salvage pathway. These knockout mice showed an 85% drop in muscle NAD+ levels, leading to muscle fiber degeneration and gradual loss of muscle strength and endurance. Treatment with the NAD+ precursor nicotinamide riboside quickly improved muscle function and restored muscle mass, even though it only modestly increased muscle NAD+ levels. Furthermore, mice with lifelong NAMPT overexpression maintained muscle NAD+ levels and exercise ability as they aged. These findings highlight the crucial role of maintaining NAD+ within muscle cells to preserve muscle mass and function.

Journal

Cell Metabolism