In children with chronic kidney diseaseskeletal muscle mass index: fatigue, sleepimpairment, quality of life and functionalrelationship with performance

Introduction: Sarcopenia is a age-related condition characterized by progressive loss of muscle mass and strength. Chronic kidney disease (CKD) can cause sarcopenia as a secondary condition. Objective: The aim of this study is to evaluate the skeletal muscle mass index in children diagnosed with CKD and to determine its relationship with functional performance, balance, quality of life, fatigue and sleep disorders. Materials and Methods: In our study, 83 patients (49M/34F) diagnosed with CKD and followed up in the Pediatric Nephrology Department, and 71 healthy controls (40M/31F) were prospectively evaluated. Comparisons of the data of the patient and control groups were carried out in two age ranges (5-12 years) and (13-17 years). Additionally, a comparison was made between three different groups: pre-dialysis patients, patients undergoing dialysis treatment, and patients who had undergone kidney transplantation. Hand and quadriceps muscle strength of all participants were measured using a dynamometer. Six-minute walk test, timed up-and-go test, fiverepetition sit-to-stand test, and gait speed were used to assess functional performance. Quality of life, fatigue and sleep disorder were evaluated with the Pediatric Quality of Life Inventory 4.0, the Child Fatigue Scale parent form and the Children's Sleep Habits Questionnaire, respectively. Balance was assessed with Pediatric Balance Scale. Body muscle and fat mass measurements, which were calculated using bioelectrical impedance analysis, were recorded. Appendicular muscle mass index (ASMI) was calculated by dividing the appendicular muscle mass by the square of the height. Results: When patient and control groups were compared in terms of ASMI, hand and quadriceps muscle strength, and functional measurements, significant differences were found between the two groups (p<0.001). There were also significant differences between the groups regarding fatigue, balance, total score of sleep, and quality of life parameters (p<0.001). In the comparison of Tanita measurements, significant differences were detected in all values except fat mass (p<0.005). When the four groups as patient subgroups (pre-dialysis, dialysis, and transplant) and the control group were compared, the lowest values in all parameters were observed in the dialysis group. A significant positive correlation was found between fat-free mass and ASMI vi with muscle strength, functional performance, and balance (p<0.001) in the patient group. Conclusions: Balance level, muscle strength and functional performance were significantly decreased in children with CKD compared to healthy children. There was a correlation between muscle mass index and these measurements. It was also found that these children were more tired, had more disturbed sleep and lower quality of life. When the patient groups were compared within themselves, all parameters were found to be lower in the dialysis group. In order to prevent the decrease in muscle mass and strength in these children, it is important to start exercise and a good nutrition program early in the disease. In addition, treatments that will contribute to sleep quality, fatigue and emotional state can ensure that their participation in life continues in a healthy way. Keywords: chronic kidney disease, appendicular muscle mass index, balance, fatigue, quality of life