Abstract: Described are cell surface and circulating markers for aging related disorders (specific isoforms of NADH oxidase (arNOX)). Recombinant age-related NADH oxidase isoforms and their coding sequences and methods for detecting arNOX isoform presence and quantitation in tissues and in blood, sera, urine, saliva, perspiration and in other body fluids, are provided. Recombinant arNOX proteins are useful in preparing antigens for use in the generation of monoclonal and polyclonal antibodies as well as immunogenic compositions for diagnosis and treatment of aging disorders. DNA probes based on the DNA sequence information provide may be used to identify individuals at risk for aging disorders and for development of therapeutic interventions or anti-aging cosmetic or other formulations of benefit in slowing the aging process in mammals.