Associação entre marcadores inflamatórios e o padrão locomotor durante a ultrapassagem de obstáculos em idosos / Association between inflammatory markers and locomotor pattern during obstacle avoidance in older adults

Resumo Objetivo investigar a associação dos biomarcadores inflamatórios na tarefa de ultrapassagem de obstáculos com diferentes níveis de complexidade manipulados pela característica do obstáculo (sólido e frágil) em idosos. Método 17 idosos (≥60 anos) foram avaliados em dois momentos: 1) Análise do padrão locomotor durante a ultrapassagem de obstáculo em duas condições (sólido e frágil). As variáveis estudadas, para membros de abordagem e suporte foram: velocidade, comprimento, largura e duração da passada, distância horizontal pé-obstáculo, distância horizontal obstáculo-pé, distância vertical pé-obstáculo e Máxima elevação do pé. 2) A análise dos biomarcadores interleucina 6 (IL-6) e proteína C Reativa (PCR) foi realizada por meio de coleta de sanguínea. A análise de regressão linear múltipla foi realizada para verificar associação entre o padrão locomotor e os biomarcadores inflamatórios (IL-6 e PCR) com nível de significância de p≤0,05. Resultados A análise de regressão mostrou que a Interleucina 6 apresentou associação com as seguintes variáveis: 1) largura da passada na condição obstáculo sólido, 2) máxima elevação do pé (membro de suporte) para ultrapassagem do obstáculo frágil, 3) distância horizontal pé-obstáculo (membro de abordagem) na condição de obstáculo sólido, 4) máxima elevação do pé (membro de abordagem) para ultrapassagem do obstáculo frágil, 5) máxima elevação do pé (membro de abordagem) para ultrapassagem do obstáculo sólido. A PCR apresentou associação com a variável Distância Horizontal Pé-Obstáculo (membro de abordagem) apenas para a condição de obstáculo frágil. Conclusão Os biomarcadores inflamatórios apresentam uma associação com o comportamento locomotor em idosos, independente da condição de fragilidade do obstáculo.

Abstract Objective to investigate the association of inflammatory biomarkers on the locomotor pattern during obstacle avoidance with different levels of complexity manipulated by the characteristic of the obstacle (solid and fragile) in older adults. Method 17 older adults (≥60 years old) were evaluated in two moments: 1) Analysis of the locomotor pattern during obstacle crossing in two conditions (solid and fragile). The variables studied for trailing and leading limbs were: speed, length, width and duration of the stride, horizontal foot-obstacle distance, horizontal obstacle-foot distance, vertical foot-obstacle distance and Maximum foot elevation. 2) Blood collection, for analysis of the inflammatory biomarkers Interleukin 6 (IL6) and C-Reactive Protein (CRP). Multiple linear regression analysis was performed to verify association between locomotor pattern and inflammatory biomarkers (IL6 and CRP) with a significance level of p≤0.05. Results The regression analysis showed that Interleukin 6 was associated with the following variables: 1) stride width in the solid obstacle condition, 2) maximum foot elevation (leading limb) to avoidance the fragile obstacle, 3) horizontal foot-obstacle distance (trailing limb) in solid obstacle condition, 4) maximum foot elevation (trailing limb) to avoidance the fragile obstacle, 5) maximum foot elevation (trailing limb) to avoidance the solid obstacle. C-Reactive Protein was associated with the horizontal foot-obstacle distance (trailing limb) only for the fragile obstacle condition. Conclusion Inflammatory biomarkers are associated with the locomotor pattern in older adults, regardless of the fragility of the obstacle.

Postural control performance of active and inactive older adults assessed through postural tasks with different levels of difficulty

Abstract Aim: To investigate postural control between active (AOA) and inactive (IOA) older adults and active young adults (YA) due to the difficulty level of the postural task. Methods: 25 active YA, 31 AOA, and 30 IOA were invited to perform postural tasks with eyes open and closed: bipedal stance on a rigid surface, bipedal stance on an unstable surface, semi-tandem stance on a rigid surface, and semi-tandem stance on an unstable surface. Results: IOA (0.74 cm) presented higher COP displacement amplitude in the mediolateral direction than AOA (0.64 cm) only in bipedal stance on an unstable surface with eyes closed condition (p ≤ 0.0001). In relation to frequency variables, IOA (0.37 Hz) presented a greater frequency band with 50% of the spectral power in the mediolateral direction than AOA (0.28 Hz) in all experimental conditions, except for semi-tandem stance on a rigid surface (p ≤ .0001). AOA (0.62 cm - 0.28 Hz) and IOA (0.67 cm - 0.37 Hz) presented an increase in time/frequency variables in both directions (anterior-posterior and mediolateral) than YA (0.52 cm - 0.17 Hz) (p ≤ 0.0001) that indicates a worse performance of postural control as the level of task difficulty increased, such as unstable base with eyes open and closed. Conclusion: Older adults tend to present greater COP sway and velocity when subjected to complex tasks compared with younger, which is more evident in older adults physically inactive. This could be considered an adaptive strategy by older adults to minimize the risk of losing balance and, consequently, falling.