Relação entre indicadores de obesidade, desempenho muscular e capacidade funcional de idosas comunitárias

Abstract

As life expectancy increases, chronic-degenerative diseases and their complications become more frequent. Obesity, characterized by excessive accumulation of body fat, has been considered the main nutritional disorder in developed and developing countries, such as Brazil. The aging process itself is accompanied by changes in body composition, since they can culminate in significant muscle reduction with the increase of body fat, making the elderly more susceptible to loss of muscle strength with consequent functional limitations. Thus, the present study, with an observational cross-sectional exploratory design, approved by the Research Ethics Committee of the Federal University of Minas Gerais (CAAE 39702014.2.0000.5149), aimed to investigate the relationship between indicators of obesity, muscle performance and functional capacity of community elderly in Belo Horizonte-MG. The study included women aged 65 years and over, without distinction of race and/or social class, who did not practice regular physical activity for three months or more. Exclusion criteria were: cognitive deficit (Mini Mental State Examination); neurological and/or rheumatological diseases and sequelae; acute musculoskeletal pain that prevented the performance of the tests; dependent gait; joint or hip arthroplasty; history of cancer in the last five years; use of corticosteroids and/or immunosuppressants. Thus, 104 elderly women were eligible to participate in the sample. A structured multidimensional questionnaire was used to record the socio-clinical-demographic characteristics of the participants. Obesity indicators were identified through anthropometric measures body mass index (BMI) and waist circumference (WC). The muscular performance was measured by means of the concentric muscle strength test of the knee extensors, at angular velocities of 60º and 180º, by the isokinetic dynamometer Byodex System 4 Pro. Functional capacity was assessed using the Short Physical Performance Battery (SPPB) test. The normality of the data was verified through the Shapiro-Wilk test and visual analysis of scatter plots. The associations between the variables of interest were initially explored by Pearson correlation, and later performed multiple linear regression. In all tests it was considered a 5% alpha. The results showed that the anthropometric measurements of obesity (BMI and WC) and age influenced the results of muscle strength of knee extensors (R2> 0.10, p <0.002), as well as functional capacity (R2 = 0.15, p = 0.0001). In this sense, it can be observed that better functional capacity was associated with lower values of BMI, WC and age. On the other hand, in relation to muscular strength, the results showed that those that presented higher values of muscle performance parameters were associated with higher BMI and WC. On the other hand, those with higher age presented worse parameters of the muscular performance. These results point to the importance of considering the deleterious effects of obesity on the functional capacity of the elderly, but suggest new investigations regarding the impact of obesity on muscle performance.