Life at the extreme limit: phenotypic characteristics of supercentenarians in Okinawa.

BACKGROUND: As elite representatives of the rapidly increasing "oldest-old" population, centenarians have become an important model population for understanding human aging. However, as we are beginning to understand more about this important phenotype, another demographic group of even more elite survivors is emerging-so-called "supercentenarians" or those who survive 110-plus years. Little is known about these exceptional survivors.

METHODS: We assessed the Okinawa Centenarian Study (OCS) database for all information on supercentenarians. The database includes dates of birth and year of death for all residents of Okinawa 99 years old or older and a yearly geriatric assessment of all centenarians who consented, enabling prospective study of age-related traits. Of 20 potential supercentenarians identified, 15 had agreed to participate in the OCS interview, physical examination, and blood draw. Of these 15, 12 (3 men and 9 women) met our age validation criteria and were accepted as supercentenarians. Phenotypic variables studied include medical and social history, activities of daily living (ADLs), and clinical phenotypes (physiology, hematology, biochemistry, and immunology).

RESULTS: Age at death ranged from 110 to 112 years. The majority of supercentenarians had minimal clinically apparent disease until late in life, with cataracts (42%) and fractures (33%) being common and coronary heart disease (8%), stroke (8%), cancer (0%), and diabetes (0%) rare or not evident on clinical examination. Functionally, most supercentenarians were independent in ADLs at age 100 years, and few were institutionalized before the age of 105 years. Most had normal clinical parameters at age 100 years, but by age 105 exhibited multiple clinical markers of frailty coincident with a rapid ADL decline.

CONCLUSION: Supercentenarians displayed an exceptionally healthy aging phenotype where clinically apparent major chronic diseases and disabilities were markedly delayed, often beyond age 100. They had little clinical history of cardiovascular disease and reported no history of cancer or diabetes. This phenotype is consistent with a more elite phenotype than has been observed in prior studies of centenarians. The genetic and environmental antecedents of this exceptionally healthy aging phenotype deserve further study.