Reproducibility of exercise tolerance in patients with end-stage renal disease

Abstract

Objective: To determine the interday reproducibility of peak and submaximal exercise tolerance of patients with end-stage renal disease (ESRD). Design: Repeated measures. Setting: Day-patient rehabilitation center. Participants: Twelve consecutively presenting, self-selected patients with ESRD. Interventions: All patients performed peak exercise tolerance assessments on a cycle ergometer up to the point of volitional fatigue, with a 1-week interval between the 2 tests. Main Outcome Measures: Cardiopulmonary, hemodynamic, and physical performance parameters were assessed at peak exercise and at the lactate threshold. Standard error of measurement, percentage coefficient of variation (CV%), intraclass correlation coefficient (ICC), and limits of agreement (LOA) were calculated to determine the reproducibility of all variables. Results: CV% (range, 5%–7%) and ICCs (range, .94 –.98) for oxygen uptake and heart rate at peak exercise and lactate threshold indicated highly acceptable levels of group mean reproducibility. LOA analysis revealed satisfactory levels of reproducibility for individual patients. Conclusion: Taken together, these reproducibility data may be applied to clinical work, requiring the quantification of changes in the exercise tolerance of patients with ESRD after short-term interventions (eg, exercise training, therapeutic use of recombinant erythropoietin). Key Words: Exercise tolerance; Kidney failure, chronic; Rehabilitation; Reproducibility of results.