1 In children, chronic kidney disease (CKD) is associated with significant cardiovascular
morbidity and mortality, hospitalizations, and common specific problems, such as impaired growth and biopsychosocial changes that have an impact on quality of life (QoL).2 Data from the Brazilian Society of Nephrology in 2012 showed that 0.3% of children with CKD aged 1 to 12 years and 4.2% between 13 and 18 years undergo dialysis.1 In recent years, the number of patients on dialysis has doubled, with an increase of 8% per year, increasing from 18,000 patients in 2001 to 91,314 in 2011, resulting in significant RG7420 purchase healthcare costs.3 Studies have shown that children and adolescents with CKD may have alterations in QoL, muscle strength, lung function, and functional capacity.4 and 5 The assessment of health-related QoL is an important criterion
when evaluating the effectiveness of treatments and interventions in healthcare, making it important to understand the existing association between the disease and QoL.6 Goldstein et al.,7 in 2008, developed Bosutinib the PedsQLTM questionnaire to specifically assess QoL in children and adolescents with CKD. This questionnaire assesses seven domains (general fatigue, kidney disease, treatment, interaction with family and friends, worry, physical appearance, and communication), and is applied to patients with CKD and their parents or guardians. Studies on QoL using the PedsQLTM have verified the impact of CKD on QoL of children and adolescents.7 and 8
The PedsQLTM version 3.0 was translated and culturally adapted into Brazilian Portuguese in 2011,9 but there are no published studies on its validation in Brazil. The reduction in functional capacity and performance of physical and recreational activities can be influenced by physical deconditioning, muscle disuse atrophy, weakness, fatigue, lower-limb edema, and back pain, among others, hindering the performance of daily living activities by these C59 children.10 and 11 Other factors may impair the muscular system of CKD patients, such as decreased protein-calorie intake and protein imbalance. The respiratory muscles may show decreased strength and endurance properties due to uremic myopathy.12, 13 and 14 Respiratory muscle strength measurement aids in the early identification of muscle weakness, as well as identification of the severity, functional consequences, and evolution of pulmonary and neuromuscular disorders.15 and 16 A study has demonstrated that children and adolescents with CKD have significantly lower muscular strength values, when compared to healthy subjects.4 Walking tests are submaximal tests used in the assessment of functional capacity of children with physical exertion limitations. They are easy to perform, reproducible, low-cost, and show good correlation with the maximum oxygen consumption obtained at maximal exercise tests.