[1] NIA, Epidemiol Demog & Biometry Program, Bethesda, MD 20892 USA
[2] Wake Forest Univ, Bowman Gray Sch Med, ACT Coordinating Ctr, Winston Salem, NC USA
[3] Stanford Univ, Sch Med, Stanford, CA 94305 USA
[4] Univ Texas, SW Med Ctr, Cooper Inst Aerob Res, Dallas, TX USA
[5] St Louis Univ, Sch Med, St Louis, MO USA
[6] Johns Hopkins Univ, Sch Med, Dept Geriatr, Baltimore, MD USA
[7] NIA, Gerontol Res Ctr, Baltimore, MD 21224 USA