Fatores associados ao baixo índice de massa muscular no envelhecimento e sua relação com incapacidade funcional em uma coorte de idosos na cidade de São Paulo

• Ano de defesa: 2017
• Autor(a) principal: Naveira, Miguel Angelo Moscoso [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Muscle mass; Aging; Functional disability; Cross-sectional study; Longitudinal study; Survival analysis; Massa muscular; Envelhecimento; Incapacidade funcional; Estudo transversal; Estudo longitudinal; Análise de sobrevida; Saúde Coletiva
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=5190718; http://repositorio.unifesp.br/handle/11600/41888

Introduction: The growth of the elderly population is a worldwide phenomenon and is associated with profound changes in body composition. The purpose of this study was to describe the magnitude of the problem, to evaluate the associated factors and the relation with functional capacity in the study population. Objectives: To identify the main factors associated with the presence of low muscle mass index in non-obese individuals aged 65 and over, participating in the EPIDOSO Project, to estimate their frequency and to evaluate the relationship between low skeletal muscle mass index and functional capacity and / or death in the study population. Methodology: The reference population in this study was represented by the population of non-obese individuals aged 65 years or older living in the Vila Clementino neighborhood, in the city of São Paulo. Secondary data from the EPIDOSO Project were used in cross-sectional surveys conducted at the Center for the Study of Aging at the Paulista School of Medicine / Federal University of São Paulo (UNIFESP). Two studies were performed. Study 1: Transversal design with data of 563 non-obese elderly individuals belonging to the 1st moment of the EPIDOSO Project in the period 1991-1992. The values of skeletal muscle mass index obtained through anthropometric data and predictive equation were considered. The following variables were investigated: gender, age, ethnicity, marital status, schooling, physical activity level, medical history, cognitive deficit, falls in the last 12 months and functional capacity. For the analysis, multiple logistic regression was used with a hierarchical model with p <0,05 and 95% CI. Study 2: Longitudinal design consisting of a sample of 335 elderly individuals aged 65 years or over, non-obese and absence of functional disability at the beginning of the cohort. The variables gender, age, ethnicity, medical history and functional capacity were investigated. The values of muscle mass index (MMI) were obtained through anthropometric data and a predictive equation. The functional capacity was measured by means of a multidimensional questionnaire structured and validated for the Brazilian population. The deaths occurred in the period were investigated with relatives through household surveys, in registries and registries of the State System of Data Analysis Foundation. Estimates of event-free survival were calculated using Kaplan-Meier Curves, using the Log-Rank test to establish comparisons. A multiple Cox proportional hazards model was used to identify the independent effect of predictors of disability or death at p <0.05 and 95% CI. The statistical program SPSS 20.0 was used for all analyzes. Results: Study 1: 39,4% were male and 60,6% female. The mean age was 74,32 years (SD=6,17 years). The frequency of non-obese elderly with low muscle mass index was approximately 14.6%, being 15.8% in men and 13.8% in women. Significant associations with low muscle mass index were found in the final model only with the age range of 75 to 79 years (ORaj =4,88; 95%CI[2,22; 10,71]), 80 to 84 years (ORaj=8,25; 95%CI[3,45; 19,72]) and 85 years or more (ORaj=7,94; 95%CI[3,12; 10,23]). Study 2: The mean time found for the onset of functional disability and / or death was 7,1 years (95%CI [6,8; 7,5]). In the crude analysis, there were statistically significant differences in the time to occurrence of functional disability or death, by age group (p <0.001), arterial hypertension (p=0,046), diabetes mellitus (p=0,007) and marginal statistical difference muscle mass index (p=0,105). The factors associated with a greater risk of occurrence of functional disability were 75 to 79 years (HR=3,31;95% CI[1,88; 5,85]), 80 to 84 years old (HR=4,30;95%CI[2,22; 8,31]), 85 years or older (HR=8,22;95%CI[3,87;17,47]), both with p<0.001 and presence of diabetes mellitus (HR=1,85;95%CI[1,09; 3,12]) with p=0,022. Conclusion: In the first study, advanced age mainly above 75 years was an important factor in the regulation of the variable muscle mass index. In the second study, advancing age and presence of diabetes mellitus increased the risk of the elderly presenting functional disability.