890.5 - The Effect of Aerobic Exercise Training on Sympathetic Nervous Activity and Vascular Compliance in Patients with Chronic Kidney Disease

Jin Hee Jeong (Emory University, Emory University), Justin Sprick (Emory University, Emory University), Dana DaCosta (Emory University, Emory University), Kevin Mammino (Department of Veterans Affairs Health Care System, Department of Veterans Affairs Health Care System), Joe Nocera (Emory University, Emory University, Emory University, Emory University), Jeanie Park (Department of Veterans Affairs Health Care System, Department of Veterans Affairs Health Care System, Department of Veterans Affairs Health Care System, Department of Veterans Affairs Health Care System)

Intro: Chronic kidney disease (CKD) is characterized by sympathetic nervous system (SNS) overactivity, which increases risk of cardiovascular (CV) disease and mortality. SNS overactivity can elevate CV risk by impairing vascular compliance and promoting inflammation. Aerobic exercise training exerts CV protective effects and has shown to reduce resting SNS level in populations at heightened CV risk. We tested the hypothesis that aerobic exercise training would reduce resting SNS activity and vascular inflammation and improve arterial compliance in patients with CKD.

Method: In this randomized controlled trial, sedentary individuals with CKD stages III-IV underwent 12 weeks of aerobic cycling exercise (EX, spinning at 85% of maximal heart rate reserve, n=22) or stretching (ST, n=20, active control intervention). Both interventions were performed 45 minutes/session 3 days/week and matched for duration. Resting muscle sympathetic nervous activity (MSNA) was measured via microneurography, augmentation index (Aix75) was measured by brachial tonometry and vascular cell adhesion protein1 (VCAM) and tumor necrosis factor-α (TNF-α) were measured from venous blood samples. All measurements were performed at baseline and following the 12-week intervention.

Results: There was a significant group by time interaction in MSNA (p=0.030) with no change in the EX group (32.8 ± 11.9 to 28.1 ± 12.9 bursts/min; p=0.215, n=15), but an increase in the ST group (30.2 ± 11.3 to 37.2 ± 12.9 bursts/min; p=0.042, n=10) after 12 weeks. The similar trend was observed in Aix75 (p=0.031) with no change in EX group (24.9 ± 7.9 to 24.3 ± 9.7; p=0.683, n=22), but an increase in ST group (22.6 ± 7.4 to 26.7 ± 10.5; p=0.012, n=20). We observed no significant change in VCAM and TNF-α after 12 weeks in either group. The magnitude of change in MSNA was inversely associated with baseline MSNA in EX group (r=-0.51, p=0.051). In the combined groups, MSNA was positively associated with Aix75 (r=0.38, p=0.06), VCAM (r=0.49, p=0.03) and TNFa (r=0.32, p=0.18) at baseline.

Conclusion: Our data demonstrates that 12 weeks of cycling exercise has beneficial effects on resting SNS activity and arterial compliance in CKD patients. Specifically, an increase in MSNA and Aix75 observed in the control group over 12 weeks was blunted following exercise training. This sympathoinhibitory effect of exercise training was independent of inflammation and showed greater magnitude in CKD patients with higher resting MSNA.

This work was supported by National Institutes of Health Grants R01HL135183 and R61AT010457 (J.P).