Fatores associados à capacidade funcional em pacientes com doença renal crônica

Abstract

Introduction: Patients with chronic kidney disease (CKD) present functional capacity reduction with a consequent decrease in exercise tolerance, reduction of physical activity level and health-related quality of life, which accelerate disease progression and result in high mortality rates in this population. Few studies have evaluated the factors associated with functional capacity in patients with CKD in the pre-dialysis phase. Objective: To evaluate factors associated with functional capacity in patients with CKD in stages 3A to 5. Methods: The sample was composed of patients from the Urinary System Unit of the University Hospital of the Federal University of Juiz de Fora, diagnosed with CKD stages 3A, 3B, 4 and 5 non-dialytic. All patients underwent the 6-minute walk test (6MWT), sit and stand test and application of SF-36. Laboratory data were collected from electronic medical records. For statistical analysis, the Shapiro-Wilk, Pearson and Spearman tests, Student’s t-test and Mann-Whitney, chi square test, a stepwise multiple linear regression and a binary multiple logistic model was constructed to evaluate the impact of variables on decrease in functional capacity using the group with functional capacity <80% of predicted as reference were used. A p-value <0.05 was considered statistically significant. Results: A total of 135 CKD patients were evaluated, the majority of the patients were on stage 3B (39.3%). The patients walked an average of 403.3 ± 79.3 meters on the 6MWT (75% of predicted distance), and did the sit-to stand test on 32.3 ± 9.2 seconds. Patients with functional capacity ≥80% exhibited higher absolute and predicted 6MWT distance, muscle strength, physical functioning of health-related quality of life. Factors associated with functional capacity were gender, age, family income, muscle strength, physical component summary of questionnaire SF-36 and CKD stage. The CKD progression leads to decreased functional capacity after adjusting for confounding variables. Older age and lower family income were independently associated with decreased functional capacity. Moreover, male gender and physical component summary had a protective effect on functional capacity. Conclusion: Factors associated with functional capacity of pre-dialysis CKD patients are gender, age, family income, lower limb muscle strength, physical component summary of questionnaire SF-36 and CKD stages.