Determinants of functional status in healthy Italian nonagenarians and centenarians: A comprehensive functional assessment by the instruments of geriatric practice

OBJECTIVE: To evaluate the physical ability and psychocognitive status of a population more than 90 years of age with regard to sociodemographic, behavioral, and biomedical variables known to affect functional status in old age. DESIGN: A survey design was used. SETTING: Emilia Romagna, Northern Italy. PARTICIPANTS: Eighty-four healthy community-dwelling subjects aged 90 to 106 years. MEASUREMENTS: Sociodemographic variables, health behavior, anthropometric indices, and serum DHEAS levels were recorded. Functional assessment was performed by instruments currently used in geriatric practice: the Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), and Activities of Daily Living (ADL) scale. A stepwise multiple regression analysis was performed. RESULTS: GDS scores correlated directly with MMSE scores and inversely with ADL severity scores. Poor education, institutionalization, sensory impairment, muscular mass loss, and lower DHEAS levels were the variables with the highest correlation to functional impairment. Smoking, alcohol consumption, and marital status were relatively unimportant. An inverse association was found between DHEAS levels and dependency scores of single ADLs (continence, mobility). CONCLUSION: Impaired cognitive and physical ability with no increase in depression prevalence was found in a sample of subjects more than 90 years of age free of major age-related disease. Muscular mass and DHEAS levels seem to play a role in maintaining physical independence. In turn, physical independence, as well as social and cultural factors, strongly affect the compliance of long-lived subjects with psychocognitive tests currently used in the clinical evaluation of younger old people, suggesting that these instruments are not reliable for screening for cognitive impairment and depression in the oldest old subjects. The avoidance of age-related diseases is not the only criteria for assessing quality of life in old age: physical mobil-ity, mental alertness, and self-satisfaction are recognized widely as crucial components of both health and quality of life. A number of screening tests for cognitive and physical impairment are currently regarded as indispensable complements to the standard clinical evaluation of older people.1 About 10 years ago, Rowe and Kahn2 proposed the term “successful aging” to describe the concept that decline in functioning may be not an inherent part of aging itself. Beside genetic predisposition, a multitude of variables, including life-style, cultural background, and psychosocial factors, must be taken in account.3 Malnutrition is another important risk factor for mortality and morbidity in older people,4 and the age-related changes in body composition, primarily the loss of muscular mass, influence functional outcome by severely affecting mobility and independence.5,6 Aging is also associated with a general impairment in endocrine function, and virtually all hormonal systems are assumed to play a role in maintaining physical integrity.7 Healthy persons more than 90 years old represent an interesting population for gerontologists because these subjects have reached the extreme limits of human life escaping the major age-related diseases. Studies have recently been published on their immunological parameters,8 thyroid function9 and body composition.10 We reported a direct relationship between circulating levels of the adrenal androgen dehydroepiandrosterone sulfate (DHEAS) and physical independence in a sample of healthy Italians more than 90 years of age.11 Because a full functional assessment of long-lived people has not yet been reported, we evaluated the physical, mental, and emotional status of 84 clinically healthy individuals aged 90 to 106 years by means of assessment instruments currently used in geriatric practice. A number of medical and sociodemographic variables, including serum DHEAS levels, were