RESUMO
Elederly seems to be caracterized for a declinaion in physical performance, and its associated with frailty, and the appearance of diseases, expressed in geriatric syndromes, functional discapacity, or higly prevalent sickness. Immobility worsenes thee processes. Exercise, however, may prevent, or delay those processes and may a useful resource in most of sckness. This article is a brief review of effects of excercise in normal aging and pathologic phenomenons.
Assuntos
Humanos , Masculino , Feminino , Idoso , Idoso de 80 Anos ou mais , Técnicas de Exercício e de Movimento , Exercício Físico/fisiologia , Terapia por ExercícioRESUMO
La población envejece en forma acelerada, y la comprensión de los cambios fisiológicos asociados al envejecimiento es una herramienta importante para enfrentar las demandas biomédicas y sociales de ese grupo etario. El objetivo de la presente revisión es definir los principales cambios morfológicos y funcionales en los sistemas cardiovascular, renal, nervioso central, muscular y metabolismo de la glucosa asociados a la edad. La evidencia de estudios clínicos y experimentales muestra que el envejecimiento de los vasos sanguíneos y el corazón se asocia a la pérdida de células musculares y menor distensibilidad. La fracción de eyección se mantiene constante. El riñón muestra disminución moderada de la velocidad de filtración glomerular, esclerosis vascular y glomerular, menor capacidad de concentración/dilución y de hidroxilación de la vitamina D. El cerebro disminuye su volumen, pero no por una pérdida generalizada de neuronas ni de arborización dendrítica. Hay menor capacidad de atención, memoria de trabajo y trastornosmotores. La masa muscular disminuye y aumenta su infiltración grasa, asociado a disminución progresiva de la fuerza. El aumento de grasa corporal, especialmente visceral, participaría en una mayor resistencia insulínica que asociada a la disminución de la masa de células beta facilitaría el desarrollo de diabetes. La evidencia disponible muestra importantes cambios morfológicos y funcionales asociados a la edad. El conocimiento de la población en edad media de la vida no debiera generalizarse a los adultos mayores. El reconocimiento de cambios debidos al envejecimiento normal es difícil por la gran variabilidad entre sujetos y la alta prevalencia de comorbilidad.
The population worldwide is aging rapidly and the understanding of physiological changes associated with aging is a key tool for answering the biomedical and social needs of elderly people. The aim of the present review is to describe the main morphological and functional changes of the cardiovascular system, central nervous system, kidney, skeletal muscle and glucose metabolism associated with normal aging. Clinical and experimental studies show that cardiovascular aging is associated with a reduction of muscular cells and wall distensibility. The cardiac ejection fraction does not change. With aging, the kidney develops vascular and glomerular sclerosis, with moderate reduction in glomerular filtration rate, lower concentration/dilution ability and a reduction of vitamin D synthesis. Aging associates with reduced brain volume, but without a generalized loss of neurons or dendritic arborization. Elderly people presents reduced attention span, lower work memory and motor impairment. There is a decrease in skeletal muscle mass, with increased in adipose infiltration associated with progressive force loss. The proportion of body fat, particularly the visceral fat, could play a role in the development of insulin resistance, which associated with a decrease in pancreatic beta cells may lead to the development of diabetes mellitus. The available evidence shows important morphological and physiological changes associated with aging. The knowledge of morphological characteristics and function a capabilities of middle age adults may not be extrapolated to elderly people. The identification of changes due to normal aging is hampered by the high variability among individuals and the high prevalence of co-morbidities.
Assuntos
Humanos , Idoso , Doença de Alzheimer , Doenças Cardiovasculares , Envelhecimento/fisiologia , Transtornos do Metabolismo de Glucose , Insuficiência Renal , Sarcopenia , Diabetes Mellitus , HipertensãoRESUMO
Ageing is a complex biological process that has been explained through different theories. Each one of these theories has produced a great body of knowledge and now days it seems possible find means of intervention the ageing process and develop therapeutical strategies from them. In this paper these theories are revised and some intervention means are mentioned.
