RESUMO
OBJECTIVES: To analyse disability trends over the 1980s-1990s in gender and race groups of early retirement ages in USA. METHODS: Disability trends for white and black males and females aged 65-69 and 70+ are analysed using the 1982-1999 NLTCS. Disability is analysed at three levels (instrumental activities of daily living (IADL), activities of daily living (ADL), and institutionalisation). RESULTS: 1) A larger increase in proportions of non-disabled blacks aged 65-69 compared with whites and males compared with females. 2) Differences in disability trends among gender and race groups. 3) A faster absolute decline in non-institutionalised disabled aged 65-69. 4) A larger absolute decline and a smaller relative decline in proportions of disabled aged 70+ compared with 65-69. 5) A significant decrease in the proportion of ADL disabled blacks and an increase of ADL disabled white females in the age group 70+. CONCLUSIONS: Americans aged 65-69 years manifest a significant improvement in health over the 1980s-1990s but the dynamics differs in gender and race groups. Possible reasons for these differences are discussed.
Assuntos
População Negra/estatística & dados numéricos , Pessoas com Deficiência/estatística & dados numéricos , Aposentadoria/tendências , População Branca/estatística & dados numéricos , Atividades Cotidianas/classificação , Fatores Etários , Idoso , Estudos Transversais , Avaliação da Deficiência , Feminino , Previsões , Inquéritos Epidemiológicos , Humanos , Assistência de Longa Duração/estatística & dados numéricos , Assistência de Longa Duração/tendências , Masculino , Fatores Sexuais , Estados UnidosRESUMO
We propose a "protein and energy" free radical model of aging that predicts patterns of survival and fertility curves for Mediterranean fruit flies. Mathematical and simulation models of individual physiological processes were constructed in terms of stochastic differential equations. The free radical theory of aging was used as a basis for construction of the model and was extended to describe the dynamics of the protein and energy balance in the functioning organism, including the concept of a maximum capacity for energy production. We fit the model to observed patterns of survival and fertility in flies given the basic diet schemes used in respective experiments. Age patterns of fertility and survival were predicted under various diet scenarios using the model, revealing that the predictions of the model are in good agreement with experimental data.
Assuntos
Envelhecimento/fisiologia , Ceratitis capitata/fisiologia , Metabolismo Energético , Radicais Livres/metabolismo , Proteínas/metabolismo , Reprodução/fisiologia , Sobrevida , Animais , Dieta , Feminino , Fertilidade/fisiologia , Expectativa de Vida , Modelos Teóricos , Processos EstocásticosRESUMO
We consider a scheme of aging with two possible mechanisms of senescence processes: aging with apoptosis and necrosis for differentiated cells and a multistage process of malignant transformation. Our model describes the multistage phenomena of aging and carcinogenesis by a set of stochastic equations using multivariate and diffusion processes. This model fits experimental data on the acceleration of aging processes from postnatal exposure to 5-bromodeoxyuridine (BrdU), and the induction of genome instability. The methods of stochastic modeling and computer simulation of the processes of aging and carcinogenesis have been used for the verification of the biological suggestions.
