Effects of Isometric and Isotonic Exercise on Arteriovenous Access Flow in Hemodialysis Patients

Background: This study aimed to evaluate the effects of isometric and isotonic upper limb exercises on volume flow (VF) changes in native arteriovenous fistulas (AVFs) and synthetic arteriovenous grafts (AVGs) in maintenance hemodialysis patients.Material and Method: A retrospective review was conducted at a single AV access center between January and November 2024.Thirty patients (15 AVF, 15 AVG) underwent Doppler ultrasound assessment of VF before and after performing upper limb exercise.Patients were eligible if they could hold a 1 kg weight for 15 seconds.Exercise type (isometric or isotonic) was assigned based on physical capacity.The primary outcome was change in VF between access types; secondary outcomes included differences by exercise modality.Result: Post-exercise VF increased significantly in both groups (mean increase: 386.9408.7 mL/min; p=0.001), with a greater increase in AVG (438.0231.8mL/min) than AVF (252.5150.4mL/min; p=0.015).No significant difference was observed between exercise types (p=0.998).VF correlated inversely with body mass index (p=0.01).Conclusion: Upper limb exercise acutely increases AV access flow, particularly in patients with AVG.These findings support the use of targeted exercise strategies to improve short-term hemodynamics in dialysis patients.