Impacts of Nicotinamide Riboside on Functional Capacity and Muscle Physiology in Older Veterans

Frailty is increasingly seen within the aging population and is driven largely by musculoskeletal declines. Nearly 9 million Veterans are now 65 years of age or older with impairments in functional capacity, reduction in quality of life, and an increase in the use of health care services and associated costs. An estimated 45-50% of those over the age of 85 are frail, which could represent well over 1 million Veterans. Aging, which significantly contributes to frailty, is highly correlated with reduced levels of nicotinamide adenine dinucleotide (NAD+), an essential mediator in mitochondrial function. Restoration of cellular NAD+ levels is gaining support as a therapeutic strategy to maintain and even enhance functional capacity during aging. Nicotinamide riboside (NR) - an NAD+ precursor - enhances physical activity and mitochondrial health in mice. Furthermore, NR was recently shown to be safe in human clinical trials for boosting NAD+, yet the benefits for human physical performance and muscle physiology are unknown. Therefore, the goal of this project is to establish a double-blind randomized control trial to assess the impacts of NR on functional capacity, muscle function and structure, and mRNA signaling in healthy older adults. Towards this goal, this study will investigate healthy older individuals between the ages of 65 and 85 who will receive NR or a placebo for a period of 3 months. Participants will be tested for frailty, gait speed, and muscle strength at each time point. Additionally, muscle biopsies and serum will be collected to assess changes in muscle fiber histology, mitochondrial biomass and activity, and mRNA profiles. This project will provide greater insight into NR supplementation as a therapeutic strategy to stave off frailty and maintain resilience during aging.