A Comprehensive Exercise (COMEX) Intervention to Optimize Exercise Participation for Improving Patient- Centered Outcomes and Physical Functioning in Patients Receiving Hemodialysis: Development and Pilot Testing

Rationale & Objective: To address the need for intradialytic exercise program that is easily delivered in clinical setting, engaging and scalable, we developed a novel COMprehensive EXercise (COMEX) program based on input from patients receiving hemodialysis (HD), dialysis staff members and nephrologists. The objective of this study was to determine the feasibility, safety, and acceptance of COMEX during HD. Study Design: Single-arm prospective pilot feasibility study. Setting & Participants: Seventeen patients receiving in-center HD. Intervention: Three-month participation in the COMEX program, which included video-based dialysis chair exercises (aerobic and resistance) integrated with educational and motivational components. Outcomes: Data on recruitment, adherence, safety and acceptability were collected. Additional assessments were performed to evaluate changes physical functioning, patient-reported symptoms, and objectively measured sleep and physical activity. We also examined the feasibility of obtaining skeletal muscle biopsies and blood samples to explore molecular mechanisms of muscle atrophy and assess platelet mitochondrial function and adaptation to exercise during HD. Results: Thirteen of the 17 (76%) participants completed the 3-month intervention. The mean participant age was 63.6 +/- 15.1 years. In total, 46% of participants were males, and 55% were White. The mean body mass index was 38.7 +/- 11.6 kg/m2. There were no reported adverse effects, and the adherence rate to exercise sessions was high with 88% of the sessions completed. Patient satisfaction was high, as 100% of the patients would recommend the program to other dialysis patients. It was feasible to collect data on physical functioning, patient-reported symptoms, and objective sleep and physical activity and to obtain muscle biopsies and blood samples. Limitations: Small sample size, lack of an onsite exercise professional, and technological issues with telemedicine behavioral motivation. Conclusions: The COMEX intradialytic exercise intervention is safe and acceptable to patients, and outcome measures were feasible to obtain. Future studies should consider including exercise pro- fessionals to facilitate progression through a personalized exercise protocol.