1. Geriatric Unit & Gerontology-Geriatrics Research Laboratory, Department of Medical Sciences, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.
2. Unit of Biostatistics, Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.
3. Department of Clinical Pharmacology and Epidemiology, Consorzio Mario Negri Sud, S.Maria Imbaro (CH), Italy.
4. Division of Nutrition and Aging, Istituto Superiore di Sanità, Rome, Italy and Division of Geriatrics and Nutritional Science, Washington University in St. Louis, Missouri.