Short-Term Efficacy and Safety of Intradialytic Exercise: Benefit for Highly Comorbid Population?

Background: In Mexico, Chronic Kidney Disease (CKD) is the the fifth leading cause of death with an increasing trend. Patients undergoing maintenance hemodialysis typically have low physical activity, worsening their health outcomes. Intradialytic exercise, specifically cycling, has shown documented effects on cardiovascular health and physical function. Methods: This study recruited adult patients receiving maintenance hemodialysis two or three times weekly at a tertiary care hospital in Monterrey, Mexico. The intervention involved 60 minutes of cycling during each hemodialysis session over 8 weeks. The primary outcome was the change in distance covered in the 6-minute walk test before and after the intervention, assessing efficacy. The frequency of adverse events was measured for safety. Results: Fifty-nine patients were evaluated; 27 were excluded for not meeting inclusion criteria. Of the 32 who started the intervention, two withdrew consent and one died, leaving 29 for final analysis. The cohort was 50% male and female, with a mean age of 52.6 years (±14.77). Common comorbidities included hypertension (96.3%), diabetes (53.8%), and heart failure (46%). The mean Charlson Comorbidity Index was 4.73 (±1.95). Only 42.3% of patients received hemodialysis three times weekly, with the rest twice weekly; the median time on hemodialysis was 13 months (IQR 8.5 - 31.25). A central venous catheter was the most frequent vascular access (88.5%). Mean hemoglobin was 9.59 g/dL (±2.02), urea nitrogen 88.92 mg/dL (±47.02), serum sodium 135.7 mEq/L (±2.96), and serum potassium 5.5 mEq/L (±1.06). Adherence to planned sessions was 89.06%, with an average of 3607.96 rotations per session. A significant improvement in the 6-minute walk test distance was observed (280.25 vs 366.14 meters, p = 0.029). Adverse events occurred in 12.28% of sessions, most frequently leg pain (8.77%), followed by intradialytic hypotension (2.63%) and hospitalizations (0.8%). No anginal events were reported. Conclusion: Our study indicates that intradialytic exercise is effective and associated with a low proportion of adverse events, even without an ideal patient population.