Intradialytic cycling in children and young adults on chronic hemodialysis.

BACKGROUND: Intradialytic exercise has been poorly investigated in pediatric patients on chronic hemodialysis (HD). The aim of this study was to assess the acceptability, safety and efficacy of intradialytic exercise in children and young adults on HD. METHODS: The intradialytic exercise program consisted of 30-min sessions of intra-HD exercise using a cycloergometer two to three times a week for 3 months. Study endpoints were the 6-min walking test (6MWT) distances, lung function, number of stands in the chair test, lower extremity strength (LES), anthropometry, dietary intake, dialysis adequacy, incidence of symptomatic sessions, biochemistry and left ventricular mass index. RESULTS: Ten pediatric patients with a median age of 15.3 (range 9.1-24.2) years were enrolled. Two of these underwent kidney transplantation; the remaining eight completed the study and adapted well to the exercise program. At the end of the 3-month study period, all patients had significantly improved results for the 6MWT (+4.9 %; p < 0.05), chair test (+19 %; p < 0.05) and LES (+29.3 %; p < 0.05). Pre-HD albumin, creatinine and total protein levels and post-HD creatinine levels had also significantly improved. The incidence of symptomatic sessions did not increase during the study period. No adverse events occurred. CONCLUSIONS: Based on our results, we conclude that a 30-min exercise program of intradialytic cycling is feasible for the majority of pediatric patients on chronic HD and will be well accepted. Such an exercise program can lead to a significant improvement in the exercise capacity of this patient population.

Correlates of exercise capacity in pediatric patients on chronic hemodialysis.

OBJECTIVE: Pediatric patients on chronic hemodialysis (HD) are at high risk of inactivity and poor physical fitness. The aim of this study was to assess the main correlates of exercise capacity in a cohort of children and young adults on chronic HD. METHODS: Twelve patients on chronic HD (median age 15.6 years; range 9.1-24.2) underwent a 6-minute walking test (WT), spirometry, a 1-minute chair stand test, and the measurement of lower extremity strength. Demographic data, anthropometry (dry weight, height, body mass index, and skinfold thickness, all expressed as standard deviation scores [SDS]), biochemistry (serum albumin, hemoglobin, creatinine, C-reactive protein, bicarbonate), bioimpedance analysis, HD adequacy indices (spKt/V and eKt/V), left ventricular mass index, and medications were also recorded. RESULTS: There was a significant correlation among the distance covered during the WT (median 552 m, range 186-670), forced vital capacity (87.8% of predicted, range 49.7-136), forced expiratory volume in 1 second (86.7%, range 54.7-126.7), and peak expiratory flow (75.5%, 49.7-105.1). All of these indices positively correlated with the weight SDS (r 0.69-0.85), pre-HD serum creatinine (0.57-0.77), and serum albumin (0.60-0.77) and negatively correlated with weekly erythropoietin dose per kilogram of body weight (from -0.64 to -0.83), with P values ranging from <.05 to <.0005. Lower extremity strength (median 11.5 kg, range 3-15) positively correlated with the number of stands at the chair stand test (median 33, range 18-47; r 0.73, P < .05) and serum albumin (r 0.83, P < .01). Distance at the WT, forced vital capacity, lower extremity strength, and the number of stands at the chair stand test all negatively correlated with C-reactive protein levels (r from -0.81 to -0.67, P < .05). CONCLUSION: Our findings show that protein-energy wasting and chronic inflammation are strongly correlated with the exercise capacity of children and young adults on chronic HD.