1. Department of Internal Medicine and Biomedical Sciences (M.M., G.P.C., A.A., E.G., G.V.), Section of Geriatrics, University Hospital of Parma, 43100 Parma, Italy
2. Geriatric Unit (F.L.), Geriatric Rehabilitation Department, University Hospital of Parma, 43100 Parma, Italy
3. Geriatric Rehabilitation (S.Ban.), Azienda Sanitaria di Firenze, 50122 Florence, Italy
4. Longitudinal Studies Section (E.J.M., C.R., S.M.L., S.Bas., L.F.), Clinical Research Branch, National Institute on Aging Intramural Research Program, National Institutes of Health (NIH), Baltimore, Maryland 20892
5. Laboratory of Epidemiology, Demography, and Biometry (J.M.G.), National Institute on Aging, NIH, Bethesda, Maryland 20892
6. Department of Medicine (S.Bas.), Division of Endocrinology, Johns Hopkins University School of Medicine, Bayview Medical Center, Baltimore, Maryland 21224