Chronic kidney disease (CKD) is characterized by abnormalities in the structure or function of the kidneys that persist for more than three months, with specific implications for health. Hemodialysis is a widely used and well-established treatment to prolong the survival of patients with CKD. However, these patients often experience a reduction in physical capacity, limitations in activities of daily living (ADL), and a deterioration in quality of life.

The aim of this study was to assess the physical fitness of children and adolescents with chronic kidney disease undergoing hemodialysis.

This cross-sectional study included patients aged between 6 and 16 years, of both sexes, who had been undergoing hemodialysis for at least three months. Medical records were reviewed, and physical fitness tests were conducted, including hand grip strength (HGS), the sit-to-stand test in 1 minute (STS1M), and the walking speed test (WST), along with upper and lower limb perimetry. The data were analyzed using Jamovi 2.3.28 software and presented using descriptive statistics (absolute and relative values, mean, standard deviation) and associations between results, with significance defined as p = 0.05.

A total of 20 patients with chronic kidney disease undergoing hemodialysis were evaluated, with 55% being female. The mean age was 9.35 ± 2.89 years, and the average treatment duration was 14.3 ± 12.1 months. Upper limb perimetry (ULP) measurements showed a mean of 15.6 ± 2.66 cm for the right limb and 15.3 ± 2.31 cm for the left limb. Lower limb perimetry (LLP) measurements showed a mean of 27.3 ± 3.95 cm for the right limb and 26.9 ± 4.07 cm for the left limb. Dominant hand strength (DHS) had a mean of 11.9 ± 7.14 kgf, while non-dominant hand strength (NDHS) had a mean of 9.85 ± 6.69 kgf. The STS1M test showed a mean of 22.4±5.45 repetitions, and the WST showed a mean of 0.958 ± 0.306 m/s. Correlations were observed between right upper limb perimetry and dominant hand strength (r = 0.668; p = 0.001), and between left upper limb perimetry and non-dominant hand strength (r = 0.722; p < 0.001). Correlations between lower limb perimetry and STS1M (r = 0.397; p = 0.083) and between left lower limb perimetry and STS1M (r = 0.411; p = 0.072) were not statistically significant. However, a significant correlation was observed between the walking speed test and the sit-to-stand test (r = 0.711; p < 0.001).

The results suggest that perimetry and hand grip strength values are below the expected range for children and adolescents in the age group studied, as described in the literature. Significant findings were observed in the correlations between left upper limb perimetry and non-dominant hand strength (p < 0.001) and between the walking speed test and the sit-to-stand test (p < 0.001).

The decline in physical fitness in children with CKD has significant physical, emotional, and social implications. Growth difficulties, influenced by factors such as malnutrition, hormonal imbalances, and bone disorders, result in reduced capacity to perform ADLs, participate in play, and engage in sports, thereby negatively impacting quality of life. This decline contributes to worsening cardiovascular conditions and, consequently, a poorer prognosis for disease progression.