[1] Univ Colorado Boulder, Dept Integrat Physiol, Integrat Physiol Aging Lab, Boulder, CO 80309 USA
[2] Univ Colorado Anschutz Med Campus, Div Geriatr Med, Aurora, CO USA
[3] Educ & Clin Ctr, Vet Affairs Eastern Colorado Geriatr Res, Denver, CO USA
[4] Univ Colorado Anschutz Med Campus, Div Renal Dis & Hypertens, Aurora, CO USA