TitleEfficacy Of Intra-dialytic Cycling On Physical Performance And Cardiovascular Disease In Hemodialysis Patients
Publication TypeJournal Article
Year of Publication2009
AuthorsWu, PT, Tomayko, EJ, Chung, HR, Cachia, AJ, Cortez, FT, Fahs, CA, Rossow, LM, Fernhall, B, Vallurupalli, S, Wilund, KR
JournalMedicine & Science in Sports & Exercise
Date PublishedJan-01-2009

Chronic kidney disease patients receiving hemodialysis therapy suffer from a variety of metabolic disturbances that increase morbidity and mortality. Muscle wasting greatly reduces physical function and reduces physical activity levels. Furthermore, two-thirds of dialysis patients die within five years of initiation of long-term dialysis treatment, mostly of cardiovascular disease (CVD). It is well established that exercise training improves CVD risk in normal populations, but little is known regarding its effect on CVD risk factors in hemodialysis patients.

PURPOSE: To evaluate the efficacy of intra-dialytic cycling on physical function and CVD risk in hemodialysis patients.

METHODS: Seventeen hemodialysis patients were randomized assigned to either an exercise training group (EX; n=8) or control group (CON; n=9) for 4 months. The exercise training protocol involved cycling 3 days per week during dialysis treatment for 45 min per session at a moderate intensity. Before and after the intervention, physical function was measured by a shuttle walk test, and arterial function and structure (intima media thickness, IMT) was measured by applanation tonometry and ultrasound. In addition, echocardiography was used to assess atrial and ventricular dimensions, myocardial performance index, and the thickness of the epicardial fat layer, a novel CVD risk factor that has been positively correlated with the local production of pro-inflammatory cytokines in the artery wall.

RESULTS: Performance on the shuttle walk test increased by 17% in EX (p<0.05), but did not change in CON (-9%, p=0.87). Aortic pulse wave velocity, a measure of central artery stiffness, was reduced in EX (12.2±2.3 vs. 9.2±2.1 m/s, p<0.05), but did not change significantly in CON. There was no change in either carotid IMT or myocardial performance index. Lastly, the thickness of the epicardial fat layer was reduced significantly in EX (6.5±2.7 vs. 5.8±2.9 mm, p<0.05), but did not change in CON (6.93±1.89 vs. 7.03±0.84 mm, p=0.94).

CONCLUSION: These results support previous studies showing that intradialytic cycling improves physical function, but also identifies novel mechanisms by which endurance exercise training improves CVD risk in hemodialysis patients.

Short TitleMedicine & Science in Sports & Exercise