Testes de capacidades físicas podem predizer a capacidade funcional em pacientes com doença renal crônica em tratamento hemodialítico: um estudo transversal aninhado a uma coorte

Abstract

Chronic Kidney Disease (CKD) is a progressive condition that affects multiple body systems and is often associated with reduced functional capacity in affected individuals. The Six-Minute Walk Test (6MWT) is widely used in clinical practice to assess this capacity. However, the 6MWT presents limitations regarding its applicability, such as the need for large spaces, prolonged execution time, and challenges related to the physical tolerance of patients. Therefore, this study aimed to verify the association and correlation between physical capacity tests and the 6MWT (functional capacity). The physical capacity tests included: the 30-Second Chair Stand Test (30CST), the Timed Up and Go (TUG), handgrip strength (HGS), and the Berg Balance Scale (BBS), in patients with CKD undergoing hemodialysis treatment. This is a cross-sectional observational study based on database analysis from a cohort of 155 patients treated at the São Francisco de Paula University Hospital, located in Pelotas, Rio Grande do Sul, Brazil. Data were analyzed using descriptive statistics and Spearman correlation; for the association analysis, simple and multiple linear regression were performed to assess how much the physical capacity tests explain performance on the functional capacity test (6MWT). The results demonstrated significant correlations between the 6MWT and the alternative tests, with a strong positive correlation observed with the BBS and a strong negative correlation with the TUG, indicating that a shorter TUG execution time is associated with better 6MWT performance. The 30CST and HGS showed moderate correlations with the 6MWT. Additionally, all tests were good predictors when analyzed individually (p < 0.0001), explaining between 37% and 51% of the variance in the 6MWT. A predictive equation considering the combined effect of the physical capacity tests on the 6MWT was generated: [6MWT prediction = 110.17 + 5.94 (30CST) – 7.58 (TUG) + 3.67 (HGS) + 4.04 (BBS)], which explained 71% of the 6MWT variance. In conclusion, the alternative functional tests analyzed showed good correlation with the 6MWT and can be considered feasible, easy-to-apply, and low-cost tools for assessing the functional capacity of individuals with CKD, especially in clinical settings with structural and operational limitations.