The Mugello study, a survey of nonagenarians living in Tuscany: design, methods and participants' general characteristics.

BACKGROUND: Previous studies on nonagenarians have widely investigated functional and cognitive decline, falls, predictors of mortality, inflammation and aging genetics. However, some intriguing domains, such as body composition, daily energy expenditure, sleep quality and physical activity, as well as endothelial progenitor cells and "omics" fields, such as proteomics or metabolomics, have been poorly explored. In this preliminary paper we report design, methods and characteristics of participants in the Mugello Study, a survey of nonagenarians aimed at filling these gaps. METHODS: 475 non selected nonagenarians, 130 men and 345 women, mean age 92.6 years ± SD 2.6, received a visit by a trained physician at their residence. Along with the assessment of social, functional and cognitive status, reported in this paper, participants also underwent instrumental examinations, including body impedance assessment and continuous direct calorimetry, and were administered a series of validated questionnaires. Further, 385 participants accepted to undergo blood withdrawal. RESULTS: In 52 cases the visit was conducted in nursing homes. Among the 423 home-living participants, 91 lived alone and 77 were not looked after by any caregiver. Altogether, 154 participants over 475 were free from disabilities and 266 showed Mini Mental State Examination raw scores ≥ 21. Men showed less disability and cognitive impairment (p<0.001, for both). CONCLUSIONS: As a whole, our findings are comparable to those reported in other surveys. Future studies, by using the Mugello Study database and biologic bank, that will be available to all researchers, will shed some more light on the aging process in nonagenarians.